阅读说明：本技术 聚合物材料及其制造方法、气体吸收材料、气体回收装置 (Polymer material, method for producing same, gas-absorbing material, and gas recovery device ) 是由 星野友 山下知惠 寺山友规 藤原智美 渡边猛 于 2020-05-21 设计创作，主要内容包括：本发明的聚合物材料为包括包含单官能单体和超过10摩尔％且为30摩尔％以下的多官能单体的单体混合物的聚合物的含胺聚合物材料,并且为低含水性的同时显示大的气体可逆吸收量。本发明的聚合物材料的有效率的制造方法包括：聚合物合成工序,通过使包含单官能单体、多官能单体、溶剂及引发剂的反应混合物中的单体聚合来合成聚合物；及胺含浸工序,使所述聚合物含浸含有胺的处理液,将反应混合物的总单体浓度设为0.7摩尔/L以上,将反应混合物中所包含的单体中多官能单体的比例设为超过10摩尔％且为30摩尔％以下。但是,在单官能单体具有氨基的情况下,可以不进行胺含浸工序。(The polymer material of the present invention is an amine-containing polymer material including a polymer of a monomer mixture containing a monofunctional monomer and a polyfunctional monomer in excess of 10 mol% and 30 mol% or less, and is low in water-containing property while showing a large reversible absorption amount of gas. An efficient manufacturing process for the polymer material of the present invention comprises: a polymer synthesis step of synthesizing a polymer by polymerizing monomers in a reaction mixture containing a monofunctional monomer, a polyfunctional monomer, a solvent, and an initiator; and an amine impregnation step for impregnating the polymer with a treatment liquid containing an amine, wherein the total monomer concentration of the reaction mixture is 0.7 mol/L or more, and the ratio of the polyfunctional monomer to the monomers contained in the reaction mixture is more than 10 mol% and 30 mol% or less. However, when the monofunctional monomer has an amino group, the amine impregnation step may not be performed.)

1. An amine-containing polymeric material comprising a polymer of a monomer mixture comprising a monofunctional monomer and more than 10 mole% and 30 mole% or less of a multifunctional monomer.

2. The polymeric material of claim 1,

the monofunctional monomer has an amino group.

3. The polymeric material of claim 1 or 2, wherein,

the multifunctional monomer is N, N' -alkylene bis (meth) acrylamide.

4. The polymeric material of claim 1 or 2, wherein,

the polyfunctional monomer has an amino group.

5. The polymeric material of claim 1 or 2, wherein,

the multifunctional monomer has a plurality of amino groups.

6. The polymeric material of any one of claims 1 to 5, comprising a surfactant.

7. The polymeric material of any one of claims 1 to 6,

the monomer mixture contains a monomer having a hydrophobic group.

8. The polymeric material according to any one of claims 1 to 7, which is a polymeric material for gas absorption.

9. The polymeric material of any one of claims 1 to 8,

the water content of 1 gram of the dried polymer is 3 grams or less when the polymer is immersed in water at 30 ℃ overnight.

10. A method of making a polymeric material, comprising:

a polymer synthesis step of synthesizing a polymer by polymerizing monomers in a reaction mixture containing a monofunctional monomer, a polyfunctional monomer, a solvent, and an initiator; and

an amine impregnation step of impregnating the polymer with a treatment liquid containing an amine,

the total monomer concentration of the reaction mixture is 0.7 mol/L or more,

the proportion of the polyfunctional monomer in the monomers contained in the reaction mixture exceeds 10 mol% and is 30 mol% or less,

when the monofunctional monomer has an amino group, the amine impregnation step may not be performed.

11. The method for producing a polymer material according to claim 10,

the monofunctional monomer has an amino group, and the amine impregnation step is performed.

12. The method for producing a polymer material according to claim 10,

the monofunctional monomer has an amino group, and the amine impregnation step is not performed.

13. The method for producing a polymer material according to any one of claims 10 to 12,

the reaction mixture comprises a surfactant.

14. The method for producing a polymer material according to any one of claims 10 to 13,

the polymer obtained in the polymer synthesis step is pulverized.

15. The method for producing a polymer material according to any one of claims 10 to 14,

filtering the polymer obtained in the polymer synthesis step.

16. The method for producing a polymer material according to any one of claims 10 to 15,

drying the polymer obtained in the polymer synthesis step.

17. The method for producing a polymer material according to any one of claims 10 to 16,

as the solvent, water and alcohol are used.

18. The method for producing a polymer material according to any one of claims 10 to 17,

a monomer having a hydrophobic group is contained in the reaction mixture.

19. The method for producing a polymer material according to claim 18,

the method for producing a polymer of the present invention includes a step of adding a monomer having a hydrophobic group to a mixture containing a monomer having an amino group, a polyfunctional monomer, and water after heating the mixture before the polymer synthesis step.

20. The method for producing a polymer material according to claim 19,

the monomer having a hydrophobic group is added as an alcohol solution.

21. The method for producing a polymer material according to any one of claims 18 to 20,

the total monomer concentration of the reaction mixture is 3 mol/L or less.

22. A polymer material produced by the production method according to any one of claims 10 to 21.

23. A gas absorbing material comprising the polymeric material of any one of claims 1 to 9 and claim 22.

24. The gas absorbing material of claim 23, further comprising a filler.

25. The gas absorbing material of claim 24,

the filler is powder.

26. The gas absorbing material according to claim 24 or 25, which is a fine particle having a particle diameter of primary particles of the filler of 1000nm or less.

27. The gas absorbing material of claim 26,

the water contact angle of the fine particles is 70 DEG or more.

28. The gas absorbing material according to any one of claims 24 to 27,

the filler is fumed silica.

29. The gas absorbing material according to any one of claims 24 to 27,

the filler is hydrophobic treated fumed silica.

30. A gas absorption cassette filled with the gas absorbing material according to any one of claims 23 to 29.

31. A gas supply device comprising the gas absorbing material of any one of claims 23 to 29.

32. A gas recovery device comprising the gas absorbing material of any one of claims 23 to 29.

Technical Field

The present invention relates to a polymer material and a method for producing the same.

Background

In recent years, global warming due to carbon dioxide discharged from facilities such as thermal power plants, iron works, and cement plants, and environmental pollution due to harmful gases such as hydrogen sulfide have become problems, and research and development for separating and recovering gases have been conducted in order to prevent such influences due to gases. Among these, the present invention is also considered to be a gas absorbing material and a gas separating material that utilize the gas reversible absorption ability of polymer particles synthesized by polymerizing a monomer having an amino group and a monomer having a hydrophobic group.

For example, patent documents 1 and 2 disclose that polymer particles are produced by adding 2,2 '-azobis (2-methylpropionamidine) dihydrochloride as an initiator to a monomer mixture (total monomer concentration of 0.312 mol/L) prepared by dissolving 55 mol% of N- (dimethylaminopropyl) methacrylamide, 43 mol% of N-tert-butylacrylamide and 2 mol% of N, N' -methylenebisacrylamide in water, followed by freeze-drying. It is also shown that the produced polymer particles can be formed into a film by a method such as spraying an aqueous dispersion thereof onto a porous body, and the obtained film absorbs carbon dioxide and is useful as a gas reversible absorbing material that diffuses carbon dioxide by heating.

Prior art documents

Patent document

Patent document 1: international publication No. 2016/024633

Patent document 2: international publication No. 2017/146231

Disclosure of Invention

Technical problem to be solved by the invention

The present inventors have conducted studies with an object of providing a method for efficiently producing a polymer material having reversible gas absorption properties and low water content while developing the polymer material.

Means for solving the technical problem

Specifically, the following solutions are provided.

[1] An amine-containing polymeric material comprising a polymer of a monomer mixture comprising a monofunctional monomer and more than 10 mole% and 30 mole% or less of a multifunctional monomer.

[2] The polymer material according to [1], wherein,

the monofunctional monomer has an amino group.

[3] The polymer material according to [1] or [2], wherein,

the multifunctional monomer is N, N' -alkylene bis (meth) acrylamide.

[4] The polymer material according to [1] or [2], wherein,

the polyfunctional monomer has an amino group.

[5] The polymer material according to [1] or [2], wherein,

the multifunctional monomer has a plurality of amino groups.

[6] The polymer material according to any one of [1] to [5], wherein,

the polymer is polymerized by using 2, 2' -azobis (2-methyl propionitrile) as an initiator.

[7] The polymer material according to any one of [1] to [6], wherein,

the polymer is a polymer polymerized in the presence of a surfactant.

[8] The polymer material according to any one of [1] to [7], which comprises a surfactant.

[9] The polymer material according to [7] or [8], wherein,

the surfactant is cetyl trimethyl ammonium bromide.

[10] The polymer material according to any one of [1] to [9], which is a pulverized product.

[11] The polymer material according to any one of [1] to [10], which is a filtrate.

[12] The polymer material according to any one of [1] to [11], which is a dried product.

[13] The polymer material according to any one of [1] to [12], wherein,

the polymer is polymerized by taking water and alcohol as solvents.

[14] The polymer material according to any one of [1] to [13], wherein,

the monomer mixture contains a monomer having a hydrophobic group.

[15] The polymer material according to any one of [1] to [14], which is a polymer material for gas absorption.

[16] The polymer material according to any one of [1] to [15], which is a carbon dioxide gas absorbing polymer material.

[17] The polymer material according to any one of [1] to [16], which is capable of reversibly absorbing carbon dioxide gas.

[18] The polymer material according to any one of [1] to [17], wherein,

the water content of 1 gram of the dried polymer is 3 grams or less when the polymer is immersed in water at 30 ℃ overnight.

[19] A method of making a polymeric material, comprising:

a polymer synthesis step of synthesizing a polymer by polymerizing monomers in a reaction mixture containing a monofunctional monomer, a polyfunctional monomer, a solvent, and an initiator; and

an amine impregnation step of impregnating the polymer with a treatment liquid containing an amine,

the total monomer concentration of the reaction mixture is 0.7 mol/L or more,

the proportion of the polyfunctional monomer in the monomers contained in the reaction mixture is 10 to 30 mol%,

when the monofunctional monomer has an amino group, the amine impregnation step may not be performed.

[20] The method for producing a polymer material according to [19], wherein,

the monofunctional monomer has an amino group, and the amine impregnation step is performed.

[21] The method for producing a polymer material according to [19], wherein,

the monofunctional monomer has an amino group, and the amine impregnation step is not performed.

[22] The method for producing a polymer material according to any one of [19] to [21], wherein,

the multifunctional monomer is N, N' -alkylene bis (meth) acrylamide.

[23] The method for producing a polymer material according to any one of [19] to [21], wherein,

the polyfunctional monomer has an amino group.

[24] The method for producing a polymer material according to any one of [19] to [21], wherein,

the multifunctional monomer has a plurality of amino groups.

[25] The method for producing a polymer material according to any one of [19] to [24], wherein,

the initiator is 2, 2' -azobis (2-methyl propionitrile).

[26] The method for producing a polymer material according to any one of [19] to [25], wherein,

the reaction mixture comprises a surfactant.

[27] The method for producing a polymer material according to [26], wherein,

the surfactant is cetyl trimethyl ammonium bromide.

[28] The method for producing a polymer material according to any one of [19] to [27], wherein,

the polymer obtained in the polymer synthesis step is pulverized.

[29] The method for producing a polymer material according to any one of [19] to [28], wherein,

filtering the polymer obtained in the polymer synthesis step.

[30] The method for producing a polymer material according to any one of [19] to [29], wherein,

drying the polymer obtained in the polymer synthesis step.

[31] The method for producing a polymer material according to any one of [19] to [30], wherein,

as the solvent, water and alcohol are used.

[32] The method for producing a polymer material according to any one of [19] to [31], wherein,

a monomer having a hydrophobic group is contained in the reaction mixture.

[33] The method for producing a polymer material according to [32], wherein,

the method for producing a polymer of the present invention includes a step of adding a monomer having a hydrophobic group to a mixture containing a monomer having an amino group, a polyfunctional monomer, and water after heating the mixture before the polymer synthesis step.

[34] The method for producing a polymer material according to [33], wherein,

the monomer having a hydrophobic group is added as an alcohol solution.

[35] The method for producing a polymer material according to any one of [32] to [34], wherein,

the total monomer concentration of the reaction mixture is 3 mol/L or less.

[36] The method for producing a polymer material according to any one of [19] to [35], which is a method for producing a polymer material for a gas-absorbing material.

[37] The method for producing a polymer material according to any one of [19] to [36], which is a method for producing a polymer material for absorbing carbon dioxide gas.

[38] The method for producing a polymer material according to any one of [19] to [36], which is a method for producing a polymer material capable of reversibly absorbing carbon dioxide gas.

[39] The method for producing a polymer material according to [38], wherein the polymer material has a water content of 3 g or less when 1g of a dried polymer is immersed in water at 30 ℃ overnight.

[40] A polymer material produced by the production method of any one of [19] to [39 ].

[41] A gas-absorbing material comprising the polymer material according to any one of [1] to [18] and [40 ].

[42] The gas absorbing material according to [41], further comprising a thermoplastic resin.

[43] The gas absorbing material according to [42], wherein,

the thermoplastic resin is polyethylene.

[44] The gas absorbing material according to any one of [41] to [43], further comprising a filler.

[45] The gas absorbing material according to [44], wherein,

the packing has a gas adsorption capacity.

[46] The gas absorbing material according to [44] or [45], wherein,

the filler is powder.

[47] The gas absorbing material according to any one of [44] to [46], which is a fine particle having a particle size of primary particles of the filler of 1000nm or less.

[48] The gas absorbing material according to any one of [44] to [47], wherein,

the water contact angle of the fine particles is 70 DEG or more.

[49] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is carbon black.

[50] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is hydrophobic treated carbon black.

[51] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is fumed silica.

[52] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is hydrophobic treated fumed silica.

[53] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is fluorinated resin powder.

[54] The gas absorbing material according to any one of [44] to [48], wherein,

the filler was Teflon (registered trademark) powder.

[55] The gas absorbing material according to any one of [44] to [48], wherein,

the filler is active carbon or zeolite.

[56] The gas-absorbing material according to [41] to [55], which is swollen by water.

[57] The gas absorbing material according to [41] to [56], which is added with water by water vapor.

[58] The gas absorbing material according to [57], wherein,

carbon dioxide gas and bicarbonate ions are added when water is added.

[59] A gas absorption cassette filled with the gas absorbing material as recited in any one of [41] to [58 ].

[60] A gas supply device comprising the gas absorbing material according to any one of [41] to [58 ].

[61] A gas recovery device comprising the gas absorbing material as recited in any one of [41] to [58 ].

[62] The gas recovery apparatus according to item [61], wherein,

desorbing the gas by increasing the temperature of the gas absorbing material after the gas is absorbed by the gas absorbing material.

[63] The gas recovery apparatus according to item [61], wherein,

desorbing the gas by decreasing the partial pressure of the gas after the gas is absorbed and stored by the gas absorbing material.

[64] The gas recovery apparatus according to item [61], wherein,

desorbing the gas by circulating water vapour after absorption of the gas by the gas absorbing material.

[65] The gas recovery apparatus according to item [61], wherein,

desorbing the gas by passing water having a high temperature therethrough after the gas is absorbed by the gas absorbing material.

[66] The gas recovery apparatus according to any one of [61] to [65], wherein,

when the gas is absorbed by the gas absorbing material, the temperature rise of the gas absorbing material due to the absorption reaction heat of the gas is suppressed by evaporation of moisture from the gas absorbing material.

[67] The gas recovery apparatus according to any one of [61] to [66], wherein,

the temperature of the gas absorbing material is lowered by circulating a dry gas while the gas is absorbed by the gas absorbing material.

[68] The gas recovery apparatus according to any one of [61] to [67], wherein,

the gas is an acid gas.

[69] The gas recovery apparatus according to any one of [61] to [67], wherein,

the gas is carbon dioxide gas.

[70] The gas recovery apparatus according to any one of [61] to [67], wherein,

the gas is water vapor.

Effects of the invention

According to the method for producing a polymer material of the present invention, a polymer material having a low water-containing property together with a reversible gas-absorbing property can be produced, and the produced polymer material can be effectively used as a reversible gas-absorbing material. A gas recovery device using the gas absorbing material of the present invention can efficiently recover acidic gases such as carbon dioxide, water vapor, and the like.

Drawings

Fig. 1 is a schematic view showing a gas recovery apparatus 1 according to an embodiment of the present invention.

Fig. 2 is a schematic view showing embodiment 2 of the gas recovery apparatus of the present invention.

Fig. 3 is a particle size distribution of a mixture (polymer material containing fine particles) of various polymer pulverized materials and RY 300.

FIG. 4 shows CO in the course of absorption of a polymer material containing fine particles (sample 18) comprising a pulverized polymer of 7 cm mesh and RY300 and a pulverized polymer of 7 cm mesh (sample 19)₂Absorption and CO diffusion₂Graph of the amount of diffusion.

FIG. 5 shows CO in the absorption process of a polymer material containing fine particles (sample 18) comprising a pulverized polymer of amino group-containing polymer having been pulverized with 7 cm mesh and RY300, and a pulverized material (sample 20) obtained by pulverizing a mixture of a pulverized polymer of 1.5 min mesh and RY300 with a bead mill₂Graph of the absorption capacity.

Detailed Description

The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment and a specific example, but the present invention is not limited to such an embodiment. In the present specification, the numerical range expressed by the term "to" means a range including numerical values before and after the term "to" as a lower limit value and an upper limit value. In the present specification, "(meth) acrylamide" means "acrylamide" and "methacrylamide", and "(meth) acrylate" means "acrylate" and "methyl acrylate".

< polymeric Material >

The polymer material can be, for example, an amine-containing polymer material including a polymer of a monomer mixture including a monofunctional monomer and more than 10 mol% and 30 mol% or less of a polyfunctional monomer.

The proportion of the polyfunctional monomer in the monomer mixture may be more than 10 mol% and 30 mol% or less, and may be 15 mol% or more and 30 mol% or less.

The polymer material can be appropriately crosslinked or polymerized without excessive swelling, and has low water-containing properties even after being immersed in water, and also has a large amount of amine and can increase the reversible absorption amount of acidic gases such as carbon dioxide gas and water vapor.

Also, even under high humidity conditions, a large amount of acid gas can be reversibly absorbed. Even when used in a high humidity environment, the resin composition does not swell due to excessive water content, and can be used for a long period of time at a high filling rate per unit volume.

Further, the water content is not excessive, and it is possible to eliminate the need for extra energy for adjusting the water temperature when the gas such as carbon dioxide is diffused by temperature adjustment such as heating.

The polymer material can be efficiently produced by the production method described below.

< method for producing Polymer Material >

The method of manufacturing the polymer material can include, for example: a polymer synthesis step of synthesizing a polymer by polymerizing monomers in a reaction mixture containing a monofunctional monomer, a polyfunctional monomer, a solvent, and an initiator; and an amine impregnation step of impregnating the polymer with a treatment liquid containing an amine, wherein the total monomer concentration of the reaction mixture is 0.7 mol/L or more, and the ratio of the polyfunctional monomer to the monomers contained in the reaction mixture is more than 10 mol% and 30 mol% or less.

However, when the monofunctional monomer has an amino group, the amine impregnation step may not be performed.

In the method for producing a polymer material, by setting the total monomer concentration and the ratio of the polyfunctional monomer in the reaction mixture within the above ranges, a polymer material having a low water-containing property and a large reversible gas absorption amount can be efficiently obtained.

Also, a sufficient amount of polymer can be synthesized with a relatively small amount of solvent, and the manufacturing apparatus can be prevented from becoming large-scale.

Further, the obtained polymer material has low swellability, and thus the volume filling rate can be sufficiently increased when the polymer material is produced as a gas absorbing material or a gas separating material.

Hereinafter, each step will be described in detail.

[1]Polymer Synthesis procedure

In this step, a polymer is synthesized by polymerizing monomers in a reaction mixture containing a monofunctional monomer, a polyfunctional monomer, a solvent, and an initiator.

The monomers, solvents, initiators, and optionally surfactants used in the polymer synthesis step, the conditions of the polymerization reaction, and the post-treatment of the polymer will be described below.

[ monofunctional monomer ]

The "monofunctional monomer" is, for example, a monomer having only 1 polymerizable group in the molecule. Examples of the polymerizable group include polymerizable groups having an ethylenically unsaturated group such as a vinyl group, an acryloyl group, a methacryloyl group, and a styryl group.

The reversible gas absorption capacity of the produced polymer is exhibited by, for example, a reaction between an amino group and a gas component, or a reaction between an amino group, a gas component, and water, but the monofunctional monomer used here may be, for example, a monofunctional monomer having an amino group, or a monofunctional monomer having no amino group.

Furthermore, a monofunctional monomer having no amino group and a monofunctional monomer having an amino group may be used in combination.

In the case where a monofunctional monomer having an amino group is used as the monofunctional monomer, the "amine impregnation step" described later may not be performed.

Examples of the monofunctional monomer having no amino group include acrylamide, methacrylamide, acrylic acid, acrylate, methacrylic acid, methacrylate, 2-acrylamido-2-methylpropanesulfonic acid salt, N-alkylacrylamide, N-alkylmethacrylamide, alkyl acrylate, alkyl methacrylate, N-dialkylacrylamide, N- (hydroxyalkyl) acrylamide, (hydroxyalkyl) acrylate, N-dialkylmethacrylamide, N- (hydroxyalkyl) methacrylamide, and (hydroxyalkyl) methacrylate, and other substituted (meth) acrylamides can also be used.

Specific examples of the monofunctional monomer having no amino group include N-methacrylamide, N-ethylacrylamide, N-propylacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, N-dimethylacrylamide, N-diethylacrylamide, N-dipropylacrylamide, N-dimethylmethacrylamide, N-diethylmethacrylamide, N-dipropylmethacrylamide, and N, N-dipropylmethacrylamide.

Here, the terminal propyl group may be an n-propyl group or an isopropyl group.

These monomers having no amino group may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

In the case where the monofunctional monomer has an amino group, the amino group may be any of a primary amino group, a secondary amino group, and a tertiary amino group.

"amino" can also not be taken to mean a constituent of the amide structure (-CO-NR)₂: r is a hydrogen atom or a substituent).

The amino group of the monofunctional monomer can also be designed with an acid dissociation constant (pKa) as the conjugate acid.

From the viewpoint of improving the carbon dioxide absorption efficiency of the produced polymer, the acid dissociation constant (pKa) of the amino group in the environment where carbon dioxide is absorbed can be equal to or larger than the acid dissociation constant (pKa) of carbonic acid.

The primary amino group and a part of the secondary amino group form a strong covalent bond with carbon dioxide, and carbon dioxide absorbed in a short time may not diffuse.

Therefore, when the monofunctional monomer has an amino group, the amino group may be a secondary amino group or a tertiary amino group, or a secondary amino group or a tertiary amino group having a hydroxyl group, an amide group, or an alkyl group in the vicinity thereof, or a dialkylamino group such as a dimethylamino group.

The amine may be a monofunctional monomer having a cyclic amine such as piperidine or piperazine or a derivative thereof.

When the acid dissociation constant of the amino group is too high, carbon dioxide may not be efficiently diffused at the time of diffusion.

Therefore, by copolymerizing a monomer having a hydrophobic side chain with a monomer having an amino group or introducing a certain amount of a polyfunctional monomer, it is also possible to provide an environment in which the surroundings of the amino group in the gel are mixed.

The amino group in the monofunctional monomer may be bonded to a portion constituting the main chain of the polymer or a portion constituting the side chain, but may be bonded to a portion constituting the side chain.

The number of amino groups of the monofunctional monomer is not particularly limited, and may be 1 or 2 or more.

When the monomer has 2 or more amino groups, the amino groups may be the same or different.

Examples of the monomer having an amino group include N- (aminoalkyl) acrylamide, N- (aminoalkyl) methacrylamide, aminoalkyl acrylate, aminoalkyl methacrylate, and the like.

In these monomers, the amino group may be substituted with a substituent such as an alkyl group.

Specific examples of the monomer having an amino group include N, N-dimethylaminopropyl methacrylamide, N-diethylaminopropyl methacrylamide, N-dimethylaminoethyl methacrylamide, N-diethylaminoethyl methacrylamide, N-dimethylaminopropyl methacrylate, N-diethylaminopropyl methacrylate, N-dimethylaminoethyl methacrylate, N-diethylaminoethyl methacrylate, N-dimethylaminopropyl acrylamide, N-diethylaminopropyl acrylamide, N-dimethylaminoethyl acrylamide, N-diethylaminoethyl acrylamide, 3-aminopropyl methacrylamide, N-diethylaminoethyl acrylamide, N-dimethylaminopropyl methacrylamide, N-diethylaminoethyl acrylamide, 3-aminopropyl methacrylamide, N-diethylaminoethyl acrylamide, N-ethyl acrylamide, N-diethylaminoethyl acrylamide, N-ethyl acrylamide, N-diethylaminoethyl acrylamide, N, 3-aminopropylacrylamide, N-dimethylaminopropyl acrylate, N-diethylaminopropyl acrylate, N-dimethylaminoethyl acrylate, N-diethylaminoethyl acrylate, 3-aminopropyl methacrylate, 3-aminopropyl acrylate and the like.

Alternatively, salts of these compounds and acidic substances, such as hydrochloride and bicarbonate, may be used. Alternatively, acrylamide may be synthesized by condensing commercially available oligoamines or polyamines having primary or secondary amines with acrylic acid, methacrylic acid, or derivatives thereof.

Furthermore, ethyleneimine, vinylamine, allylamine hydrochloride, and the like can also be used as the monomer having an amino group.

These monofunctional monomers having an amino group may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

[ polyfunctional monomer ]

The "polyfunctional monomer" is, for example, a monomer having 2 or more polymerizable groups in the molecule. As specific examples of the polymerizable group, reference can be made to the description in the column of [ monofunctional monomer ]. The number of the polymerizable groups of the polyfunctional monomer is not particularly limited, but may be 2 to 6, 2 to 5, 2 to 4, or 2. The plural polymerizable groups of the polyfunctional monomer may be the same or different. By containing a polyfunctional monomer in a predetermined ratio in the reaction mixture, a crosslinked structure is formed between polymer chains, and a hard polymer having suppressed water-containing property and swelling degree can be obtained.

By copolymerizing an appropriate amount of a polyfunctional monomer with a monomer having an amino group, a material that diffuses efficiently can be synthesized by introducing hydrophobicity and steric hindrance around the amino group to decrease the acid dissociation constant of the amino group under carbon dioxide diffusion conditions. At this time, if the amount of the polyfunctional monomer introduced is too large, the acid dissociation constant of the amino group under the carbon dioxide absorption conditions becomes too low, and therefore the carbon dioxide absorption amount decreases. Therefore, it is important to appropriately design the amount of the polyfunctional monomer to be introduced.

Examples of the polyfunctional monomer include polyfunctional (meth) acrylamide monomers, polyfunctional (meth) acrylate monomers, and crosslinking agents such as titanium crosslinking agents, and acrylamide monomers (acrylamide derivatives) having 2 polymerizable groups can be used. Examples of the acrylamide monomer having 2 polymerizable groups include N, N' -alkylenebis (meth) acrylamide. The number of carbon atoms of the alkylene group of the N, N' -alkylenebis (meth) acrylamide is not particularly limited, but may be 1 to 12, 1 to 4, or 1 to 2. Specific examples of the acrylamide derivative having 2 polymerizable groups include N, N' -methylenebisacrylamide (BIS). Instead of the alkylene group, a crosslinking agent having a linear or cyclic crosslinking chain having an amino group, such as oligoethyleneimine, N' -bis (2-aminoethyl) -1, 3-propanediamine, iminodipropylamine, methyliminodipropylamine, or 1,4- (bisaminopropyl) piperazine, can be used as the polyfunctional monomer. Likewise, instead of the alkylene group, a crosslinking agent in which an oligoethylene glycol constitutes a crosslinking chain can also be used as the polyfunctional monomer. Specific examples of the polyfunctional (meth) acrylate monomer include ethylene glycol dimethacrylate (EGDM a).

These polyfunctional monomers may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

[ monomer having a hydrophobic group ]

The reaction mixture may contain a monomer having a hydrophobic group.

The "hydrophobic group" may represent a functional group that is hardly soluble in water, such as an alkyl group or a phenyl group.

The monomer having a hydrophobic group may be, for example, a monofunctional monomer having a hydrophobic group but not having an amino group, or a polyfunctional monomer having a hydrophobic group.

A monofunctional monomer having both a hydrophobic group and an amino group can be classified as a "monofunctional monomer having an amino group", and a multifunctional monomer having a hydrophobic group can be classified as a "multifunctional monomer". Thus, a monofunctional monomer having a hydrophobic group but not having an amino group is referred to as "a monofunctional monomer having a hydrophobic group".

The hydrophobic group of the monomer may be, for example, C_XH_2XOr C_XH_2X+1(X isInteger), methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, isopentyl, hexyl, cyclohexyl, and the like can be used. The hydrophobic group may be a group in which a hydrogen atom of the hydrophobic group is substituted with a hydroxyl group, such as hydroxyethyl, hydroxypropyl, and hydroxybutyl.

The hydrophobic group in the monomer may be bonded to a portion constituting the main chain of the polymer or may be bonded to a portion constituting the side chain, but may be bonded to a portion constituting the side chain. The number of hydrophobic groups that the monomer has is not particularly limited, and may be 1, or 2 or more. In the case where a monomer has 2 or more hydrophobic groups, each hydrophobic group may be the same or different.

Specific examples of the monomer having a hydrophobic group include N-alkylacrylamide, N-alkylmethacrylamide, alkyl acrylate, alkyl methacrylate, N-dialkylacrylamide, N- (hydroxyalkyl) acrylamide, (hydroxyalkyl) acrylate, N-dialkylmethacrylamide, N- (hydroxyalkyl) methacrylamide, (hydroxyalkyl) methacrylate, N-phenyl methacrylamide, and phenyl N-methacrylate.

These polymers having a hydrophobic group may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

[ combination of monomers ]

Examples of the combination of the monofunctional monomer and the polyfunctional monomer include a combination of a monofunctional monomer and a polyfunctional monomer having an amino group, a combination of a monofunctional monomer and a polyfunctional monomer each having neither an amino group nor a hydrophobic group, a combination of a monofunctional monomer and a polyfunctional monomer having a hydrophobic group, a combination of a monofunctional monomer having an amino group, a combination of a monofunctional monomer and a polyfunctional monomer having a hydrophobic group, a combination of a monofunctional monomer and a polyfunctional monomer having an amino group, a combination of a monofunctional monomer and a polyfunctional monomer each having an amino group and a hydrophobic group, and a combination of a monofunctional monomer and a polyfunctional monomer each having neither an amino group nor a hydrophobic group.

Examples of the combination of the monofunctional monomer having an amino group and the polyfunctional monomer include a combination of N- (aminoalkyl) (meth) acrylamide and an acrylamide derivative having 2 polymerizable groups or a (meth) acrylate having 2 polymerizable groups. Specific examples thereof include a combination of N, N-dimethylaminopropyl (meth) acrylamide (DMAPM) and N, N' -methylenebisacrylamide (BIS).

Examples of the combination of a monofunctional monomer having an amino group, a monofunctional monomer having a hydrophobic group, and a polyfunctional monomer include N- (aminoalkyl) (meth) acrylamide, N-alkyl (meth) acrylamide, an acrylamide derivative having 2 polymerizable groups, and a combination of (meth) acrylates having 2 polymerizable groups. Specific examples thereof include a combination of N, N-dimethylaminopropyl (meth) acrylamide (DMAPM), N-t-butylacrylamide (TBAm) and N, N' -methylenebisacrylamide (BIS).

Examples of the combination of a monofunctional monomer having no amino and hydrophobic groups and a polyfunctional monomer include a combination of N, N-dialkyl (meth) acrylamide and an acrylamide derivative having 2 polymerizable groups or a (meth) acrylate having 2 polymerizable groups, a combination of N-alkyl (meth) acrylamide and an acrylamide derivative having 2 polymerizable groups or a (meth) acrylate having 2 polymerizable groups. Specific examples thereof include a combination of N, N-dimethyl (meth) acrylamide (DMAm) and N, N '-methylenebisacrylamide (BIS), and a combination of N-isopropylacrylamide (NiPAm) and N, N' -methylenebisacrylamide (BIS).

[ solvent ]

The solvent functions as a reaction medium for the polymerization reaction. By including a solvent in the reaction mixture, a polymer having an appropriate space around the amino group in the polymer can be synthesized. Therefore, the gas reversible absorption capacity of the polymer obtained by polymerization with addition of an appropriate solvent tends to be high.

Examples of the solvent include polar solvents such as water, alcohols (methanol, ethanol, isopropanol, etc.), and dimethyl sulfoxide, and a mixed solvent obtained by combining 2 or more of these polar solvents may be used. Further, water or a mixed solvent of water and another polar solvent may be used, a mixed solvent of water and alcohol may be used, water and ethanol may be used, and a mixed solvent of water and methanol may be used. The mixing volume ratio of water to alcohol (water: alcohol) can be 1:0 to 1:1, or 1:0.2 to 1:0.8, or 1:0.3 to 1: 0.5. The solvent may contain a salt or a solvent-soluble polymer.

[ initiator ]

The initiator is a compound added to initiate polymerization of the monomer, and a compound that can be converted into a highly reactive intermediate by application of energy can be used. Examples thereof include thermal polymerization initiators which generate active species such as radicals and cations by heating, and photopolymerization initiators which generate active species such as radicals, cations and anions by light irradiation. Examples of the initiator for thermal radical polymerization include azo compounds such as 2,2 '-azobis (2-methylpropionitrile) (AIBN), 2' -azobisbutyronitrile, 2 '-azobis (2, 4-dimethylvaleronitrile) (V-65) and 2, 2' -azobis (4-methoxy-2, 4-dimethylvaleronitrile) (V-70), and peroxides such as benzoyl peroxide, t-butyl hydroperoxide, hydrogen peroxide, persulfate, t-butyl hydroperoxide and ferrous sulfate, and examples of the thermal cationic polymerization initiator include benzenesulfonate and alkylsulfonium salt. Examples of the initiator that generates radicals by ultraviolet irradiation or electron beam irradiation include benzoin derivatives, benzyl derivatives, acetophenone derivatives, benzophenone derivatives, and azo derivatives.

The initiator such as AIBN may be used after purification (recrystallization) or may be used without purification.

[ surfactant ]

If necessary, a surfactant or the like may be added to the reaction mixture. This enables synthesis of a uniform polymer.

As the additive, an amphiphilic polymer such as polyethylene oxide, polyvinylpyrrolidone, or polyvinyl alcohol, an oligomer thereof, or a surfactant such as cetyltrimethylammonium bromide or the like can be used.

[ polymerization reaction ]

In the production method, the polymer is produced by polymerizing the monomers in the reaction mixture containing the monofunctional monomer, the polyfunctional monomer, the solvent and the initiator as described above, but in this case, the total monomer concentration of the reaction mixture can be set to 0.7 mol/L or more, and the proportion of the polyfunctional monomer in the monomers contained in the reaction mixture can be set to more than 10 mol% and 30 mol% or less. Here, the "total monomer concentration" of the reaction mixture can mean, for example, the total number of moles of all monomers contained per 1L of the reaction mixture.

When the monomers are polymerized in the reaction mixture, a polymer having a polymer chain including a constitutional unit derived from a monofunctional monomer and a crosslinked structure derived from a polyfunctional monomer is synthesized. In this case, in the production method, the total monomer concentration of the reaction mixture can be set to 0.7 mol/L or more, and in the reaction mixture of a limited volume, polymer chains can efficiently form noncovalently bonded crosslinking points by interaction and entanglement with each other, and further, can be polymerized in a structure-stabilized state by crosslinking by covalent bonding with a crosslinking agent. As a result, the polymer does not excessively contain water and deform in a wet state. It is possible to synthesize a polymer having low swellability, that is, having a large reversible absorption amount of gas per unit volume, with high yield while maintaining the reversible absorption amount of gas per unit mass.

Further, the total monomer concentration can be set to 0.7 mol/L or more, and the ratio of the polyfunctional monomer in the monomer can be set to 10 mol% or more, and a crosslinked structure can be formed relatively closely between polymer chains. Thus, a polymer which is hard and has a lower water content and a lower swelling property can be obtained. Further, the upper limit of the total monomer concentration can be set to 4 mol/L and the upper limit of the proportion of the polyfunctional monomer can be set to 30 mol%, and a decrease in the reversible absorption amount of gas per unit mass due to an excessively high concentration of the polyfunctional monomer can be suppressed. From the above, a polymer material having a large reversible absorption amount of gas per unit volume can be produced with high productivity.

The total concentration of the monomers in the reaction mixture can be, for example, 1.0 to 2.8 mol/L or 1.5 to 3 mol/L.

The proportion of the polyfunctional monomer in the monomer may be, for example, more than 10 mol% and 30 mol% or less, and 15 mol% or more and 30 mol% or less.

When the reaction mixture contains a monofunctional monomer having an amino group, the proportion of the monofunctional monomer having an amino group in the monomer can be, for example, 1 to 95 mol%, or 5 to 90 mol%, or 30 to 85 mol%.

In the case where a monofunctional monomer having a hydrophobic group is contained in the reaction mixture, the proportion of the monofunctional monomer having a hydrophobic group in the monomer can be set to, for example, 1 to 50 mol%, or 5 to 45 mol%, or 10 to 43 mol%.

In the case where the reaction mixture contains a monofunctional monomer having an amino group and a monofunctional monomer having a hydrophobic group, the molar ratio of the monofunctional monomer having an amino group to the monofunctional monomer having a hydrophobic group can be set to, for example, 95:5 to 5:95 or 3:1 to 1: 2.

The step of mixing the components of the reaction mixture is not particularly limited, but in the case of using a monofunctional monomer having an amino group and a monofunctional monomer having a hydrophobic group in combination, after heating a mixture containing a monofunctional monomer having an amino group, a polyfunctional monomer, and water, a monofunctional monomer having a hydrophobic group may be added to the mixture, or a monofunctional monomer having a hydrophobic group may be added to the mixture as an alcohol solution. This makes it possible to uniformly mix the monomers while suppressing the amount of solvent to a small amount.

The reaction temperature of the reaction mixture can be, for example, 0 to 200 ℃, or 30 to 120 ℃, or 50 to 105 ℃.

The reaction time can be set to 0.1 to 5 hours or 0.2 to 3 hours, for example.

[ post-treatment of Polymer ]

In the production method of the present invention, a low-swelling polymer is generated as a precipitate in the reaction solution or the reaction solution as a whole is gelled. The polymer produced may be mechanically pulverized to prepare a slurry or powder, or the liquid component may be removed from the reaction solution and the remaining precipitate (polymer) may be mechanically pulverized to prepare a powder. Further, the obtained powder may be suspended in a dispersion medium to prepare a slurry.

The gel can be pulverized by various pulverizers. For example, it can be carried out by a jaw crusher, a gyratory crusher, an impact crusher, a pair of roll crushers, a roll crusher, a pulverizer, a semi-autogenous mill, an autogenous mill, a ball mill, a rod mill, a jet mill, an attritor, an extrusion/shear mill, a meat chopper, a Feiz micro-pulverizer.

The prepared slurry may be coated and dried to form a porous membrane containing polymer powder, or the slurry may be filtered to leave the polymer on the filter in the form of a membrane and dried to form a polymer membrane or a filler layer.

In the polymer particles used in the conventional gas absorbent, when the particles absorb moisture and swell, the particles swell and the gaps between the particles are closed. Therefore, it is difficult to remove moisture between particles, and it is difficult to perform filtration and drying. On the other hand, since the polymer powder of the present invention has low swellability, it can be easily molded into a film form or a shape of a packed layer by a method such as filtration and extraction. The polymer molded or filled into a film shape may be once stored and then redispersed in water to form a film or be refilled, or may be kneaded with a resin to be molded.

Examples of the method of applying the slurry include sandpaper method, spray coating method, casting method, bar coating method, roll coating method, wire bar coating method, and dip coating method.

The precipitate of the polymer formed in the reaction solution, and the powder, slurry and film prepared from the precipitate may be freeze-dried or spray-dried. Alternatively, the drying may be performed by hot air using a fluidized bed. The polymer of the present invention does not excessively supply water and maintains appropriate swellability even when redispersed in water after freeze-drying. When the polymer is swollen again after being dried once, an acid such as hydrochloric acid or carbon dioxide may be added. Alternatively, a resin having low volatility and high hydrophilicity, such as polyethylene glycol or glycerin, may be added during drying to accelerate re-swelling.

Further, the powder, slurry, membrane and freeze-dried products thereof prepared from the precipitates of the polymer can be washed as necessary and supplied to the following gas-absorbing materials.

[2]Amine impregnation step

In the production method of the present invention, the polymer material is obtained by impregnating the polymer obtained in the polymer synthesis step [1] with a treatment liquid containing an amine (hereinafter, referred to as "amine-containing treatment liquid"). However, when a monofunctional monomer containing an amino group is used in the polymer synthesis step [1], the amine impregnation step may not be performed.

When the amine-containing treatment liquid is impregnated into the polymer, the amine-containing treatment liquid penetrates and diffuses between polymer chains, and the polymer is in an amine-containing state. In this case, since the polymer obtained in the polymer synthesis step has a crosslinked structure formed relatively tightly between the polymer chains, the polymer is hard to swell even when impregnated with the amine-containing treatment liquid and remains in a hard state. The polymer material thus obtained exhibits excellent reversible gas absorption capability by suppressing swelling of the polymer and allowing gas to diffuse well during filling, and the amino group of the amine or the amino group derived from the monofunctional monomer to effectively function as a functional group that reversibly absorbs gas.

The amine-containing treatment liquid used in the amine impregnation step and the conditions of the amine impregnation treatment will be described below.

[ amine-containing treatment solution ]

The amine-containing treatment liquid used in the amine impregnation step may be any liquid material containing an amine, and may be, for example, an amine solution prepared by dissolving an amine in a solvent, or may be a liquid amine. Also, the amine-containing treatment liquid may contain an appropriate amount of water.

(amine)

The amine contained in the amine-containing treatment liquid may be either low molecular weight amine or high molecular weight amine.

The molecular weight of the amine can be, for example, 61 to 10000, or 75 to 1000, or 90 to 500.

With regard to the description and specific examples of the compounds useful as amines, reference can be made to the description and specific examples of the low-molecular amines in the description of the absorption accelerator and the diffusion accelerator described later.

(solvent)

When an amine solution is used as the amine-containing treatment liquid, for example, an amine as a dissolved substance can be dissolved in the solvent, and a solvent having high compatibility with a polymer and high solubility for carbon dioxide and bicarbonate ions can be used. Specifically, water, ethylene glycol, glycerin, and the like can be mentioned, and a mixed solvent obtained by combining 2 or more of these solvents may be used.

The concentration of the amine in the amine solution can be, for example, 0.1 to 12N, 1 to 10N, or 3 to 9N in terms of the amine concentration.

(other Components)

Components (other components) other than the amine and the solvent may be added to the amine-containing treatment liquid. As other components, antioxidants, oxidation inhibitors, and the like can be cited.

[ conditions for the amine impregnation treatment ]

The impregnation of the polymer with the amine-containing treatment liquid (amine impregnation treatment) can be performed, for example, by impregnating the polymer with the amine-containing treatment liquid.

The polymer to be treated may be a dried polymer or a polymer swollen with a liquid such as water. When the polymer swollen with the liquid is immersed in the amine-containing treatment liquid, at least a part of the liquid is replaced with the amine-containing treatment liquid, and a polymer material containing the amine-containing treatment liquid or a mixed liquid of the liquid and the amine-containing treatment liquid therein can be obtained.

The amount of the amine-containing treatment liquid used for the amine impregnation treatment can be set to, for example, 0.1 to 10 times, or 0.2 to 5 times, or 0.3 to 3 times the mass of the polymer to be treated.

The temperature of the amine-containing treatment liquid can be set to 5 to 100 ℃, 10 to 80 ℃, or 15 to 60 ℃, for example.

The treatment time of the amine impregnation treatment varies depending on the concentration and temperature of the amine-containing treatment liquid, but may be, for example, 0.1 to 100 hours, 1 to 24 hours, or 2 to 12 hours.

The amine impregnation treatment can be performed while shaking the amine-containing treatment liquid impregnated with the polymer.

< polymeric Material >

Next, the polymer material of the present invention will be described.

The polymer material of the present invention is characterized by being produced by the production method of the present invention.

For the description of the production method of the present invention, reference can be made to the above description in the section of < production method of polymer material >.

Examples of the polymer material of the present invention include: (A) a mode in which a polymer having a polymer chain including a constitutional unit derived from a monofunctional monomer and a crosslinked structure derived from a polyfunctional monomer and an amine derived from an amine-containing treatment liquid are contained; and (B) a mode in which the polymer having a polymer chain including a constitutional unit derived from a monofunctional monomer having an amino group and a crosslinked structure derived from a polyfunctional monomer is contained and the component derived from the amine-containing treatment liquid is not contained. (A) The monofunctional monomer according to embodiment (a) and the polyfunctional monomer according to embodiment (B) may or may not have an amino group. In the polymer material of the present invention, at least one of the constituent units of the polymer and the impregnated amine contains an amino group, and thus an acidic gas such as carbon dioxide or hydrogen sulfide can be selectively absorbed. Then, the absorbed acid gas is diffused by heating to lower the pKa, increase the hydrophobic interaction of the hydrophobic group, or the like. That is, the polymer material of the present invention has a gas reversible absorption capacity of selectively and reversibly absorbing an acid gas. Further, since the polymer material of the present invention is produced by the production method of the present invention, the water-containing property and the swelling property are low. Therefore, when the polymer is produced as a gas absorbing material or a gas separating material, the volume filling rate can be sufficiently increased, and when a gas containing moisture is made to flow through a gas recovery apparatus to which the product is applied, the polymer swells with water, but only a limited amount of water is absorbed, and the degree of swelling is limited. Therefore, the gas flow path can be sufficiently ensured, and the amount of heat required for the heating step for gas diffusion can be suppressed to be low. Further, even when liquid water is added to the absorbent material, the gaps between the water-containing polymers can be maintained, the flow path of water can be sufficiently ensured, and water can be easily discharged and gas can be introduced into the gaps by the subsequent gas flow. Thus, the polymer material of the present invention can be effectively used as a gas absorbing material for reversibly absorbing an acid gas such as carbon dioxide, and the gas absorbing material can be effectively used as a gas separating material for separating an acid gas from a mixed gas.

The average molecular weight of the polymer contained in the polymer material of the present invention, the amount of each group when the polymer has an amino group and a hydrophobic group, the physical property value of the polymer, and the content of amine when the polymer material contains amine will be described below.

[ average molecular weight, amino group and hydrophobic group amount of Polymer ]

When the polymer has an amino group, the amount of the amino group can be, for example, 1 to 23mmol/g, 1 to 18mmol/g, or 2 to 7 mmol/g. Alternatively, the proportion of the monomer having an amino group in all the monomers may be, for example, 5 to 100 mol%, or 30 to 100 mol%, or 50 to 90 mol%.

In the case where the polymer has a hydrophobic group, the amount of the hydrophobic group can be set to, for example, 1 mol% to 50 mol%, or 5 mol% to 45 mol%, or 10 mol% to 43 mol%.

The degree of crosslinking of the polymer can be, for example, 0 to 50 mol%, or 5 to 40 mol%, or 10 to 30 mol%.

In the case where the polymer material contains an amine, the content thereof can be set to, for example, 1 to 30mmol/g, or 2 to 20mmol/g, or 3 to 10mmol/g per unit dry weight of the polymer.

[ degree of swelling of Polymer ]

The swelling degree of the polymer contained in the polymer material of the present invention can be evaluated, for example, as the water content when the polymer material is immersed in water for a long period of time.

[ Water content of Polymer ]

The water content of the polymer contained in the polymer material of the present invention when swollen with an excessive amount of water can be set to, for example, 4 g/g or less, 3 g/g or less, or 2 g/g or less.

As used herein, "water content" of a polymer means that excess water will be added to the polymer using a hand-held mixer pair andthe weight of the polymer in a wet state after the polymer left standing overnight at room temperature was pulverized and then removed of water by filtration using a filter paper or a metal mesh was set to M₁M represents the weight of the polymer obtained by freeze-drying or natural drying of the polymer₀The value obtained by the following equation.

Water content ═ M₁-M₀)/M₀

[ reversible gas-absorbing Capacity of Polymer Material ]

In the polymer material, CO per unit of dry polymer weight₂The reversible absorption capacity can be set to, for example, 30mL/g or more, 45mL/g or more, or 60mL/g or more. Thus, for example, when applied to a gas recovery device that recovers carbon dioxide from an exhaust gas, carbon dioxide contained in the exhaust gas can be efficiently absorbed and recovered.

With respect to CO₂The reversible absorption amount can be determined by referring to (CO) in the examples₂Reversible absorption test).

[ means of Polymer Material ]

The form of the polymer material of the present invention is not particularly limited, and may be, for example, any of powder, slurry, film, block, and the like. As for the production method of the powder, slurry, and film, reference can be made to the description in the column of [ post-treatment of polymer ] in the production method of the polymer material.

< gas absorbing Material >

Next, the gas absorbing material of the present invention will be explained.

The gas absorbing material of the present invention comprises the polymer material of the present invention.

The gas absorbing material of the present invention contains the polymer material of the present invention, and thus has a gas reversible absorbing ability of diffusing an acidic gas such as carbon dioxide or hydrogen sulfide or water vapor in response to a change in temperature or gas partial pressure after absorbing the acidic gas or water vapor. For the description of the polymer material of the present invention, reference can be made to the above-mentioned description in the column of < polymer material >.

The gas absorbing material of the present invention may contain a component (other component) other than the polymer material of the present invention in addition to the polymer material of the present invention. Examples of other components that can be used in the gas absorbing material include moisture, pKa regulators, absorption accelerators, diffusion accelerators, moisture absorbents, antioxidants, thermoplastic resins, and fillers. The moisture can be contained in the gas absorbing material by intentionally adding water using water or water vapor, for example. When water is added, for example, carbon dioxide gas or bicarbonate ions can be added.

[ pKa regulator ]

The pKa adjuster can be added for the purpose of adjusting the pKa of the polymer after polymerization to a desired value by adding the pKa adjuster at the time of polymerization, for example. This makes it possible to control the type of gas absorbed by the polymer, the type of gas or liquid selectively permeating through the gas absorbing material, the flow flux, the selectivity of the gas to be absorbed with respect to another gas, and the like. As the pKa regulator, for example, a substance capable of protonating or deprotonating an amino group of the polymer can be used, and for example, an acid such as hydrochloric acid or a base such as sodium hydroxide can be used with the concentration appropriately adjusted according to the desired pKa. Further, the PKa of the amine can be controlled by adjusting the local environment such as the polymer density around the amine, the amine distance, and the polarity in the polymer according to the crosslinking ratio based on the polyfunctional monomer, and therefore the polyfunctional monomer can be used as the PKa adjuster as well. In addition, since the pKa of the amine can be controlled by adjusting the local environment such as the polymer density around the amine, the amine distance, and the polarity by adding a hydrophobic monomer, an alcohol, and a hydrophilic polymer at the time of polymerization, they can be used as a pKa regulator as well.

[ absorption enhancer, diffusion enhancer ]

The absorption accelerator is a compound having a function of accelerating absorption of an acid gas into the polymer of the present invention. The diffusion promoter is a compound having a function of promoting diffusion of an acid gas from a polymer. In the present invention, an absorption-diffusion promoter having both functions of an absorption promoter and a diffusion promoter may be used. These absorption accelerator, diffusion accelerator, and absorption diffusion accelerator may each have a function of a stabilizer for stabilizing the gas absorbing material. The total content of the absorption enhancer, the diffusion enhancer, and the absorption diffusion enhancer in the gas absorbent material of the present invention can be, for example, 0.05mL or more, or 0.1mL or more per 1g of the solid content. The content of the absorption accelerator in the gas absorbent can be, for example, 0.1 to 12N, 1 to 10N, or 3 to 9N in terms of amine concentration.

As the absorption accelerator, the diffusion accelerator, and the absorption diffusion accelerator, low-molecular amines can be used. The molecular weight of the low molecular amine may be, for example, 61 to 10000, 75 to 1000, or 90 to 500. The boiling point of the low-molecular amine may be, for example, 80 ℃ or higher, 120 ℃ or higher, or 150 ℃ or higher, from the viewpoint of long-term availability and practical use. An amine-containing compound that has a site that forms a salt with a counter ion like an ionic liquid for increasing the boiling point and is liquid can be used.

The low-molecular-weight amine may contain any one of a primary amino group, a secondary amino group, a tertiary amino group, an ammonium group, and an imidazolium group, may contain a plurality of amino groups, ammonium groups, and imidazolium groups, and may contain, for example, 1 to 3 groups. The secondary or tertiary amino group may be a cyclic amino group. Further, functional groups other than amino groups, ammonium groups, imidazolium groups, for example, hydroxyl groups may be contained in the low-molecular amine. The number of hydroxyl groups contained in the low molecular amine may be 0 to 2. Examples of the low-molecular amine include amines having an amino group and a hydroxyl group, amines having 3 amino groups, and the like, and examples thereof include amines having a secondary amino group and a hydroxyl group. In the high concentration region, the amount of diffusion of the acid gas can be dramatically increased, and the method is suitable for recycling, and therefore, for example, an amine having a secondary amino group and a hydroxyl group and having a boiling point of 150 ℃ or higher can be selected.

Specific examples of the low-molecular amine include compounds represented by the following formulae.

[ chemical formula 1]

Among these, DMAE, IPAE, Bis (2DMAE) ER, 1-2HE-PRLD, 1-2HE-PP, TM-1,4-DAB, TMHAD and PMDETA can be selected from the viewpoint of increasing the amount of diffusion of the acid gas, and IPAE, TM-1, 4-DAD and PMDETA can be selected from the viewpoint of relatively high boiling point and difficulty in evaporation, and IPAE, Bis (2DMAE) ER, 1-2HE-PP, TM-1,4-DAB, TMHAD and PMDETA can be selected from the viewpoint of increasing the amount of diffusion of the acid gas significantly by increasing the concentration thereof, and IPAE, TM-1,4-DAB, TMHAD and PMDETA can be selected from the viewpoint of easiness in availability.

[ moisture absorbent ]

As the moisture absorbent that can be used as an additive, for example, a moisture absorbent having a relative humidity of 90% or less at 25 ℃ when prepared as a saturated aqueous solution can be used. Examples of such a moisture absorbent include ions such as bromide ion, chloride ion, acetate ion, carbonate ion, bicarbonate ion, lithium ion, potassium ion, calcium ion, magnesium ion, and sodium ion. Examples of the moisture absorbent include salts such as lithium bromide, lithium chloride, calcium chloride, potassium acetate, magnesium chloride, potassium carbonate, and sodium carbonate. When the moisture absorbent is added, the amount of the moisture absorbent added can be set to, for example, 0.01 to 10 mass% relative to the total amount of the gas absorbent.

[ antioxidant ]

The antioxidant that can be used as an additive can be added to suppress or prevent oxidation. Examples of such antioxidants include vitamin C (ascorbic acid), vitamin E (tocopherol), BHT (dibutylhydroxytoluene), BHA (butylhydroxyanisole), sodium erythorbate, propyl gallate, sodium sulfite sulfur dioxide, hydroquinone, and derivatives thereof. When the antioxidant is added, the amount of the antioxidant added may be, for example, 0.01 to 10% by mass relative to the total amount of the gas absorbent.

[ thermoplastic resin ]

The gas absorbing material may contain a thermoplastic resin. Thus, the thermoplastic resin, the polymer of the present invention and other components added as necessary can be kneaded and molded into pellets or films.

As the thermoplastic resin, a known thermoplastic resin can be used. Examples thereof include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymers, liquid crystal polymers such as modified polyolefins, polyamides, thermoplastic polyimides, and aromatic polyesters, various thermoplastic elastomers such as polyesters such as polyphenylene ether, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether ether ketone, polyether imide, polyacetal resins, styrene, polyolefin, polyvinyl chloride, polyurethane, and polyethylene lactate, chlorinated polyethylene such as polyamide, polybutadiene, trans-polyisoprene, fluororubber, polyvinyl chloride, and polyvinylidene chloride, copolymers, mixtures, and polymer alloys mainly containing these, and polyolefin resins such as polyethylene can be selected. When the gas absorbent contains a thermoplastic resin, the content of the thermally active resin can be set to, for example, 10 to 40 mass% with respect to the total amount of the gas absorbent.

[ Filler ]

A filler may be contained in the gas absorbing material. This can form voids in the gas-absorbing material, promote diffusion of the gas into the gas-absorbing material, and increase the reversible absorption rate and the reversible absorption amount of the gas. Further, by using the filler having a gas adsorbing ability, gas adsorption by the adsorbent can be performed in addition to gas adsorption by the adsorbent. It is known that a gas adsorbent material exhibits a large reversible gas adsorption capacity at low humidity and a gas adsorbent material exhibits a large gas adsorption performance at high humidity, and therefore a material having a large reversible gas adsorption capacity under wide humidity conditions can be realized by using a gas adsorbent as a filler. As the filler having a gas adsorption ability, for example, various materials having a large pore area such as activated carbon and zeolite can be used. An adsorbent material having a particularly large carbon dioxide gas adsorption capacity can be selectively used. Further, when the polymer material constituting the gas absorbing material is gelled by containing water or when the polymer material is a pulverized product of a gelled polymer (pulverized polymer), the volume is decreased and the filling amount is increased by adding the filler, and the reversible gas absorbing ability can be improved. As the filler, fine particles having a primary particle diameter of 1000nm or less, which will be described later, can be preferably used. Further, when the gas absorbing material including the crushed polymer and the filler is crushed, the reversible gas absorbing capacity can be further improved. The pulverization of the gas absorbing material containing the polymer pulverized product and the filler can be performed by a planetary ball mill device using a bead mill or the like.

The filler may be selected to be a powdered filler to promote diffusion of the gas into the interior of the absorbent material. Further, fine particles having an average primary particle size of, for example, 1000nm or less can be used. The primary particle diameter referred to herein can be measured by transmission electron microscope observation. The fine particles having a primary particle diameter of 1000nm or less used in the present invention may include only fine particles having a primary particle diameter of 1000nm or less. The particle diameter may be 0.1 to 1000nm, or 0.3 to 500nm, or 0.5 to 300nm, or 1 to 200nm, or 1.5 to 100nm, or 2 to 50nm, or 2.5 to 25nm in terms of average primary particle diameter. As a result, the gas diffusion phase is more reliably formed in the molded body of the gas absorbing material, and the absorption rate and diffusion rate of the gas tend to be further increased. The microparticles may be microparticles with 1 particle agglomeration. The aggregate is preferably 100nm to 200. mu.m, more preferably 500nm to 100. mu.m, and most preferably 2.5 to 50 μm. In addition, fine particles having a water contact angle of, for example, 70 ° or more can be used as the filler. The water contact angle may be 80 ° or more, or 100 ° or more, or 110 ° or more, or 120 ° or more, or 130 ° or more, or 140 ° or more.

Fine particles having a primary particle diameter of 1000nm or less

Hereinafter, fine particles having a primary particle diameter of 1000nm or less, which can be used as a filler, will be specifically described.

The fine particles having a primary particle diameter of 1000nm or less may be composed of an inorganic material, an organic material, or a combination of an organic material and an inorganic material. The fine particles may be either hydrophobic fine particles or hydrophilic fine particles, but hydrophobic fine particles are preferable. Since the fine particles are hydrophobic fine particles, the pores formed by the fine particles are prevented from being blocked by moisture contained in the gas absorbing material, and the pores effectively function as a gas diffusion phase.

Here, the "water repellent fine particles" mean fine particles having a primary particle diameter of 1000nm or less and a water contact angle of 70 ° or more. The "water contact angle" of the fine particles means a contact angle with water measured on the surface of a fine particle deposition film formed of the fine particles. The water contact angle of the surface of the fine particle deposited film can be measured by static contact angle measurement with water.

The water contact angle of the water repellent fine particles is preferably 80 ° or more, more preferably 100 ° or more, further preferably 110 ° or more, further preferably 120 ° or more, particularly preferably 130 ° or more, and most preferably 140 ° or more.

(hydrophobic fine particles)

The water-repellent fine particles having a primary particle diameter of 1000nm or less may be fine particles having water repellency as they are, or fine particles obtained by imparting water repellency to the surfaces of particles serving as a base (base particles). Examples of the fine particles having water repellency imparted to the surface of the base particles include coated fine particles having a water repellent coating formed on the surface of the base, and surface-modified fine particles obtained by surface modification of the base particles to impart water repellency.

First, carbon black is an example of fine particles having water repellency. Examples of the carbon black include acetylene black, furnace black, channel black, thermal black, lamp black, and ketjen black, and among them, acetylene black is preferable.

Examples of the other water repellent fine particles include fine particles containing CNovel (porous carbon, manufactured by Toyo tang co., ltd.), titanium oxide, mesoporous silicon oxide, and the like.

Further, as the fine particles themselves having water repellency, fine particles formed of a water repellent organic material can also be used. Examples of the water-repellent organic material that can be used for forming particles include a compound represented by the formula- (CA)¹A²-CA³A⁴) A fluororesin of constituent unit represented by (wherein A)¹～A⁴Represents a hydrogen atom, a fluorine atom, a chlorine atom or a perfluoroalkyl group A¹～A⁴At least 1 of which is a fluorine atom). Specific examples of the fluororesin include Polytetrafluoroethylene (PTFE), a copolymer of tetrafluoroethylene and another monomer, Polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene and another monomerCopolymers of (a), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polytetrafluoroethylene (HEP), and the like. Examples of the copolymer of tetrafluoroethylene and another monomer include perfluoroalkoxyalkane (PFA: copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether), perfluoroethylene-propylene copolymer (FEP: copolymer of tetrafluoroethylene and hexafluoropropylene), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluorodifuran copolymer (TFE/PDD), and the like. Further, as a copolymer of chlorotrifluoroethylene with another monomer, an ethylene-chlorotrifluoroethylene copolymer (ECTFE) can be mentioned.

These hydrophobic organic materials may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The coated fine particles and the base particles of the surface-modified fine particles may be inorganic particles or organic particles, but are preferably inorganic particles. Further, when fine particles having water repellency themselves are used as the base particles, and a water repellent coating or a surface modification for imparting water repellency is applied to the fine particles, the amount of gas absorption/diffusion can be increased together with the gas absorption rate and diffusion rate.

As the inorganic particles, known inorganic particles can be used, and examples thereof include particles containing carbon black such as acetylene black, furnace black, channel black, thermal black, lamp black, ketjen black, etc., inorganic compounds such as oxides, hydroxides, nitrides, halides, carbonates, sulfates, acetates, phosphates, etc., of metal elements or semimetal elements, natural mineral particles, etc. Examples of the inorganic compound of the metal element or the semimetal element include lithium fluoride, calcium carbonate, calcium phosphate, calcium sulfate, calcium fluoride, barium sulfate, titanium dioxide (titania), zirconium dioxide (zirconia), aluminum oxide (alumina), aluminum silicate (silicic acid alumina, kaolin, kaolinite), silicon oxide (silica, silica gel), and the like, and examples of the natural mineral include talc, clay, and the like. Among these, particles containing carbon black and silica are preferable.

As the organic particles, known organic particles can be used, and examples thereof include particles made of styrene-based, acrylic-based, melamine-based, benzoguanamine-based, or silicone-based polymers. In this case, a filler may be used in combination, and for example, activated carbon or zeolite can be preferably used as the filler.

As the water-repellent coating film formed on the base particles, in addition to the water-repellent organic materials exemplified above as water-repellent materials that can be used for the formation of fine particles, a coating film of an organopolysiloxane or an organohydrogenpolysiloxane can be used. Examples of the organopolysiloxane include a dialkylpolysiloxane and an alkylphenylpolysiloxane, and examples of the organohydrogenpolysiloxane include an alkylhydrogenpolysiloxane. The alkyl group in the dialkylpolysiloxane, alkylphenylpolysiloxane, and alkylhydrogenpolysiloxane may be linear, branched, or cyclic, but is preferably linear. The number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 10, and still more preferably 1 to 6. Here, the 2 alkyl groups bonded to the silicon atom may be the same as or different from each other. Specific examples of the organopolysiloxane include dimethylpolysiloxane and methylphenylpolysiloxane, and specific examples of the organohydrogenpolysiloxane include methylhydrogenpolysiloxane.

Examples of a method for modifying the surface of the base particle include a method in which a hydrophobic group such as an alkyl group or a fluorinated alkyl group is introduced into the surface of the base particle. The alkyl group or fluorinated alkyl group introduced into the base particle may be linear, branched, or cyclic, but is preferably linear. The alkyl group or fluorinated alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 1 to 10 carbon atoms. The fluorinated alkyl group may be a partially fluorinated alkyl group in which a part of hydrogen atoms of the alkyl group are substituted with fluorine atoms, or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

The surface modification for introducing these water-repellent groups into the base particles can be performed using a silane coupling agent, a silane compound such as silazane, or the like. Examples of the silane coupling agent include compounds represented by the following general formula (1).

General formula (1)

R¹ _nSiX_(4-n)

(in the general formula (1), X represents a hydrolyzable group which forms a silanol group by hydrolysis, R¹Represents a group containing a hydrophobic group. n is an integer of 1 to 3. )

In the silane coupling agent represented by the general formula (1), a silanol group or a silyl group formed by hydrolysis of X reacts with a functional group on the surface of the substrate particle, thereby introducing a water repellent group into the substrate particle.

In the general formula, examples of the "silanol group-forming hydrolyzable group" represented by X include alkoxy groups such as methoxy and ethoxy groups, and halogen groups.

As R¹Examples of the hydrophobic group in (1) include an alkyl group, a fluorinated alkyl group, and dimethylsiloxane. With regard to the description and preferred ranges of the alkyl group and the fluorinated alkyl group, reference can be made to the description and preferred ranges of the hydrophobic group that can be introduced to the surface of the substrate particle. The hydrophobic group may be bonded directly to Si or may be bonded via a linking group.

n is an integer of 1 to 3, preferably 1 or 2. When n is 2 or more, plural R¹May or may not be identical to each other. When n is 2 or less, a plurality of xs may be the same or different from each other.

Examples of the silane coupling agent represented by the general formula (1) include triethoxyalkylsilane, diethoxydialkylsilane, ethoxytrialkylsilane, trimethoxyalkylsilane, dimethoxydialkylsilane, methoxytrialkylsilane, and trichloroalkylsilane. Specific examples of the silane coupling agent include triethoxycaprylylsilane (triethoxy-n-octylsilane), octadecyltrichlorosilane, and the like.

The formation of the water repellent coating on the substrate particles and the surface modification treatment can be carried out by a conventional method.

Commercially available products of water repellent fine particles include Microdispers-200 (manufactured by Techno Chemical corporation on), AEROSIL RY200, AEROSIL RY300, AEROSIL R805 (both manufactured by Evonik corporation), Ketjen black (manufactured by Lion Specialty Chemicals Co., Ltd.).

The number of the water repellent fine particles may be 1 or 2 or more.

(Fine particles other than hydrophobic fine particles)

The fine particles having a primary particle diameter of 1000nm or less that can be used as the filler are not limited to water repellent fine particles, and fine particles other than water repellent fine particles, that is, fine particles having a water contact angle of less than 70 ° may be used. Further, a combination of hydrophobic fine particles and fine particles having a water contact angle of less than 70 ° may be used. In the fine particles having a water contact angle of less than 70 °, the water contact angle may be 50 ° or less, 30 ℃ or less, or 10 ° or less. The lower limit of the water contact angle of the fine particles is 0 °.

As the fine particles other than the water repellent fine particles, there can be mentioned particles of inorganic compounds containing metal elements and semimetal elements and organic particles described as examples of the fine particles with a coating film and the base particles of surface-modified fine particles in the above (water repellent fine particles), and it is preferable to use silica particles. The inorganic particles and the organic particles may have a coating film of an organic compound formed on the surface thereof, or may have an organic functional group introduced thereto.

As a commercially available product of fine particles other than the water repellent fine particles, aersil 200 (manufactured by Evonik corporation) can be mentioned.

(specific surface area of Fine particles)

The specific surface area of the fine particles is preferably 1 to 3000m²(iv)/g, more preferably 2.5 to 2750m²(iv)/g, more preferably 5 to 2500m²(ii) in terms of/g. As a result, the gas diffusion phase is more reliably formed in the molded body of the gas absorbing material, and the absorption rate and diffusion rate of the gas tend to be further increased.

The specific surface area of the fine particles can be measured by the BET method.

The ratio of the amount of the polymer material to the amount of the fine particles having a primary particle diameter of 1000nm or less

The mixing ratio of the polymer material to the solid content of the fine particles (polymer material: fine particles) is preferably 95:5 to 5:95, more preferably 90:10 to 30:70, and still more preferably 80:20 to 50: 50. Further, the content of the polymer material in the gas absorbing material is preferably larger than the content of the water repellent fine particles in terms of solid content. When the polymer material is gelled by containing water or is a pulverized product of a gelled polymer, if a filler is added to the gas absorbent, the volume decreases and the filling amount increases, thereby improving the reversible gas absorption performance. From the viewpoint of effectively obtaining such an effect, the volume ratio of the gelled polymer or its pulverized product to the fine particles (gelled polymer or its pulverized product: fine particles) is preferably 99.9:0.1 to 98:2, more preferably 99.75:0.25 to 98.5:1.5, and further preferably 99.5:0.5 to 99: 1.

By setting the amount ratio of the polymer material to the fine particles within the above range, the absorption rate and diffusion rate of the gas tend to be further increased.

However, the gas absorbing material of the present invention is not limited to containing fine particles having a primary particle diameter of 1000nm or less. That is, the gas absorbing material of the present invention may not contain fine particles having a primary particle diameter of 1000nm or less.

Other fillers

In the gas absorbent of the present invention, a known filler can be used in addition to the fine particles exemplified above. Examples thereof include activated carbon, zeolite, silica, fumed silica, hydrophobized fumed silica, hydrophobic silica, alumina, hydrophobized alumina, hydrophobic alumina, boehmite, diatomaceous earth, titanium oxide, iron oxide, zinc oxide, magnesium oxide, oxides such as metal ferrite, hydroxides such as aluminum hydroxide and magnesium hydroxide, carbonates such as calcium carbonate (light and heavy), magnesium carbonate, dolomite and dawsonite, sulfates such as calcium sulfate, barium sulfate, ammonium sulfate and calcium sulfite, or sulfates, talc, mica, clay, glass fibers, silicates such as calcium silicate, montmorillonite and bentonite, borates such as zinc borate, barium metaborate, aluminum borate, calcium borate and sodium borate, carbon black, hydrated carbon black, water-repellent carbon black, graphite and carbon fibers, carbon powders such as other iron powders, copper powders, and soaps, Aluminum powder, zinc white, molybdenum sulfide, boron fiber, potassium titanate, lead zirconate titanate, fluorinated resin powder, Teflon (registered trademark) powder, and the like, and a hydrophobic substance can be selected and used to suppress condensation or condensation of water vapor. Further, a filler containing carbon such as carbon black can be selectively used. In these fillers, the primary particle diameter may be 1000nm or less, or may exceed 1000 nm. The gas absorbing material of the present invention may contain particles which are made of the same material as particles exemplified as fine particles having a primary particle diameter of 1000nm or less and have a primary particle diameter of more than 1000 nm. When the filler is contained in the gas absorbent, the content of the filler can be set to, for example, 0.1 to 60 mass% with respect to the total amount of the gas absorbent.

[ dispersing Medium ]

The gas absorbing material may comprise a dispersion medium in which the polymeric material of the present invention and the additive are suspended. With respect to the preferable range and specific example of the dispersion medium, reference can be made to the description in the column of [ solvent ] in the production method of the polymer material.

The other components usable in the gas absorbing material described above may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

< use of gas-absorbing Material >

The gas absorbing material comprising the polymer material of the present invention can be used in various ways. Examples of the use of the gas absorbing material include: filling a gas absorbing material in a container such as a drum; forming the gas absorbing material into a sheet shape to form a laminate with a nonwoven fabric, a mesh, or the like, and a roll body; filling a gas absorption material into the interior of the filter; mixing the gas absorbing material with hard materials such as polyethylene and the like to form independent films, fibers and particles; a membrane supporting a gas absorbing material with a carrier; filling gas absorber powder into the honeycomb structure; and the like. When the gas absorbing material is formed in a sheet or film shape, the thickness is not particularly limited, but may be, for example, 1 to 10000 μm, 10 to 5000 μm, or 100 to 1000 μm.

Here, in the case where the gas absorbing material is supported by the carrier, a sheet, a fiber aggregate, or the like can be used as the carrier. Hereinafter, a sheet and a fiber aggregate which can be used as a support will be described.

[ sheet ]

As the thin plate, a sheet, or a foil having a flat plate shape and a thickness of, for example, 2mm or less and 5 μm or more can be used.

As the material of the sheet, a constant pressure specific heat of, for example, 2500 KJ/(m) can be used³K) The following materials may have a thermal conductivity of 10W/(mK) or more. The temperature of the thin plate having such thermal characteristics changes in response to the external temperature change, and the temperature change can be efficiently transmitted to the entire gas absorbing material.

Here, in the present specification, the "constant pressure specific heat" is a value measured by a calorimeter such as a water calorimeter and a differential scanning calorimeter. The "thermal conductivity" is a value measured by a laser flash method or a steady-state heat flow method.

As the thin plate, a metal thin plate (metal foil), a sheet made of a carbon material, a carbon sheet, a resin thin film (polymer thin film), or the like can be used. Examples of the sheet made of a carbon material include a graphite sheet, and examples of the resin film include polyethylene, polypropylene, PET, polyimide, and the like. From the viewpoint of high thermal conductivity, for example, an aluminum thin plate, an iron thin plate, or a graphite sheet can be used as the thin plate. Alternatively, for example, an aluminum thin plate, a graphite sheet, or a resin film can be used from the viewpoint of low specific heat. Examples of the metal thin plate include a stainless steel thin plate, an iron thin plate, an aluminum thin plate, and a nickel thin plate, and among them, an iron thin plate, an aluminum thin plate, and a nickel thin plate can be particularly selected from the viewpoint of relatively high thermal conductivity.

The sheet may be a plate body having a uniform internal structure, or may be a porous body or a honeycomb structure. In the case of a porous body or a honeycomb structure, since the pores can be filled with a gas-absorbing material, the heat of the thin plate can be easily transmitted to the gas-absorbing material, and the responsiveness of the gas-absorbing material to temperature changes can be improved. In particular, porous bodies of foamed metal, foamed nickel, and porous carbon have high thermal conductivity to the gas absorbing material, and by using them as a carrier, the responsiveness of the gas absorbing material to temperature changes can be greatly improved. The pore diameter of the porous body such as foamed metal can be set to 0.1 to 10mm or 0.4 to 4mm, for example. The specific surface area can be set to 100 to 10000m, for example²/m³Or 200 to 6000m²/m³. Further, when a support containing a porous resin or porous carbon is used as the porous support, the thermal efficiency of the absorber can be improved because the heat capacity is small. As the porous material used as the carrier, for example, a porous material having a porosity of 1 to 99%, or 10 to 99%, or 20 to 95% can be selected.

In the present specification, "porosity of a sheet" means porosity measured from the surface volume and mass of the sheet and the density of a material.

The carrier may be a laminate obtained by laminating a plurality of these thin plates. In the laminate, the thin plates may be all the same, or a plurality of thin plates having different materials and thicknesses may be combined.

[ fiber aggregate ]

The fiber aggregate is a fiber aggregate in which many fibers are processed into a thin and wide plate shape. Examples of the fiber aggregate include cloth and paper, and among them, a porous fiber aggregate such as a filter is preferably used. The fabric may be any of woven fabric, felt, nonwoven fabric, and the like. Further, a sintered body obtained by sintering a metal fiber mat can also be used as the carrier. The fiber sintered body has a shape in which fibers are densely packed, and can obtain high thermal conductivity. For example, a sintered body obtained by sintering a felt containing stainless steel fibers and a sintered body obtained by sintering a felt containing nickel fibers can be used, and among these, a sintered body obtained by sintering a felt containing nickel fibers can be used alternatively.

As the fibers used in the fiber aggregate, a constant pressure specific heat of, for example, 2500 KJ/(m) can be used³K) The following materials, and materials having a thermal conductivity of 10W/(mK) or more. The temperature of the fiber aggregate having such thermal characteristics changes in response to an external temperature change, and the temperature change can be efficiently transmitted to the entire gel-like film.

The fibers used in the fiber aggregate may be inorganic fibers, organic fibers, or composite fibers obtained by combining inorganic fibers and organic fibers. Examples of the inorganic fiber include metal fibers such as stainless steel fiber, aluminum fiber, and nickel fiber, and carbon fiber, and nickel fiber can be selected from the viewpoint of obtaining high thermal conductivity. As the organic fiber, natural fibers such as cotton and hemp, artificial fibers, and synthetic fibers such as polyester can be used.

The diameter of the fiber is not particularly limited, but for example, a fiber having a diameter of 8 to 100 μm can be used. This makes it possible to obtain a gas-absorbing material film having excellent gas absorption performance and gas diffusion performance.

The carrier may be an integrated body obtained by stacking a plurality of these fiber aggregates. In the integrated body, the fiber aggregates may be all the same, or a plurality of fiber aggregates different in the kind of fiber, the fiber diameter, the fiber density, and the like may be combined. The support may be a laminate obtained by laminating a sheet and a fiber aggregate.

The shape of the carrier is not particularly limited, and can be appropriately selected depending on the application. Specific examples of the shape of the carrier include a plate shape, a cylindrical shape, and the like, and the planar shape of the plate and the sectional shape of the cylindrical shape may be any of a polygonal shape such as a square or a rectangle, a perfect circle, an ellipse, and the like.

The gas absorbent carried on the carrier can be formed by a method of applying slurry or powder of the gas absorbent to the surface of the carrier, or by bonding a film of the gas absorbent formed in advance to the surface of the carrier. A binder may be used to stably fix the slurry or powder of the gas absorbing material to the carrier.

< gas recovery device >

As described above, the gas absorbent of the present invention can reversibly absorb an acidic gas such as carbon dioxide or water vapor, and has a low swellability of the polymer component, so that the volume filling rate can be increased when the gas absorbent is produced as a product or the like. Therefore, for example, the present invention can be suitably used as a material for a gas absorber of a gas recovery device that selectively recovers carbon dioxide from an exhaust gas. Embodiments 1 and 2 of a gas recovery apparatus to which the gas absorbing material of the present invention is applied will be described below. Fig. 1 is a schematic view showing a gas recovery apparatus according to embodiment 1, and fig. 2 is a schematic view showing a gas recovery apparatus according to embodiment 2.

As shown in fig. 1, the gas recovery apparatus according to embodiment 1 includes a heat exchanger 21, a desulfurizer 22, a cylindrical gas absorber 23, and a 1 st pipe 24, a 2 nd pipe 25, and a 3 rd pipe 26 connected to these parts. The first pipe 24 has one end serving as a gas inlet for introducing exhaust gas (gas to be treated), and the other end connected to the desulfurizer 22. The 2 nd pipe 25 has one end connected to the desulfurizer 22 and the other end connected to one side surface of the gas absorber 23. The 3 rd pipe 26 has: a circulation path 26a connected to, for example, one side surface and the other side surface of the gas absorber 23; and a branch path 26b that branches from the circulation path 26a on one side surface side of the gas absorber 23, one end of the branch path 26b being a gas discharge port that discharges the recovered carbon dioxide gas. The connection portions of the 2 nd tube 25 and the 3 rd tube 26 on one side surface of the gas absorber 23 are provided on the side surfaces having a circular shape, for example, with the center portion interposed therebetween, at substantially the same diameter. The heat exchanger 21 is connected to a middle portion of the 1 st pipe 24 and a middle portion of the circulation path 26 a.

The gas absorber 23 is made of the gas absorbing material of the present invention, and has a temperature similar to the ambient temperature when the gas recovery device is closed.

The gas absorber 23 may be formed in a filter shape and disposed at a position passing through at least a part of the gas flow path in the gas recovery device.

Further, the gas absorber 23 may not be formed into a filter shape, but may be disposed at a position deviated from at least a part of the gas flow path in the gas recovery device.

In order to recover carbon dioxide from the exhaust gas using this gas recovery device, the operation of each part is opened, and the high-temperature exhaust gas collected by dust is introduced from one end of the 1 st pipe 24. The introduced exhaust gas is introduced into the desulfurizer 22 having a cooling capacity of about 30 ℃ through the 1 st pipe 24. Here, the desulfurizer and the cooler may be different devices. The temperature of the gas after passing through the desulfurizer 22 having cooling capability need not be 30 ℃ and may be about 40 ℃ or 50 ℃. When passing through the 1 st pipe 24, a part of the heat of the exhaust gas is transferred to the circulation path 26a of the 3 rd pipe 26 via the heat exchanger 21, and the temperature is adjusted so that the gas temperature or the dew point temperature of the gas in the circulation path 26a is heated to about 60 ℃. The heating of the gas in the circulation path 26a may be based on the heating of heated water. The temperature and dew point temperature of the gas in the circulation path 26a may be 60 ℃ or higher, or about 75 ℃ or 85 ℃. Also, the gas in the circulation path 26a can be depressurized. When the gas in the circulation path 26a is depressurized and the gas in the circulation path 26a is heated by heated water, the gas in the circulation path 26a may not flow and the flow rate of the gas may be very small. The exhaust gas introduced into the desulfurizer 22 is desulfurized by the desulfurizer 22 and then flows into the 2 nd pipe 25. The exhaust gas flowing into the 2 nd pipe 25 has a temperature or dew point of about 30 ℃, and is introduced into the gas absorber 23 at a temperature near this temperature. In the gas absorber 23, the temperature of the exhaust gas is about 30 ℃, whereby the absorber is cooled in the region where the exhaust gas contacts, the acidic gas such as carbon dioxide is efficiently absorbed by the gas absorbing material, and the gas other than carbon dioxide is discharged to the outside of the gas absorber 23. When the dew point temperature of the exhaust gas is lower than the temperature of the absorbent, the absorbent and the exhaust gas are efficiently cooled by the evaporation of the moisture from the absorbent, and the temperature can be appropriately adjusted. In addition, when the absorber is insufficiently cooled by the cooled exhaust gas, additional cooling using latent heat of evaporation of water due to introduction of a cooling gas, pressure reduction, or introduction of a dry gas can be performed. On the other hand, the region of the gas absorber 23 that has absorbed carbon dioxide moves to the vicinity of the connection portion of the 3 rd pipe 26 by the rotation of the gas absorber 23, and comes into contact with the gas introduced through the circulation path 26a of the 3 rd pipe 26. Since the gas introduced from the circulation path 26a is heated to about 75 ℃ by heat exchange with the exhaust gas, the gas absorbent 23 in the region where the gas contacts heats the gas absorbent and acidic gas such as carbon dioxide is diffused. At this time, when the dew point temperature of the gas in the circulation path 26a is higher than the temperature of the absorbing material, the absorbing material is heated more efficiently by the condensation heat of the water vapor, which is preferable. Further, even when the gas in the circulation path 26a is depressurized, the carbon dioxide can be effectively released by lowering the partial pressure of the carbon dioxide. A part of the diffused carbon dioxide flows into the branch path 26b of the 3 rd pipe 26, and is discharged to the outside from the gas discharge port of the branch path 26b and recovered. Another part of the diffused carbon dioxide flows into the circulation path 26a of the 3 rd pipe 26. The carbon dioxide flowing into the circulation path 26a is heated or humidified by the heat exchanger 21 in the middle of the circulation path 26a, and then is reintroduced into the gas absorber 23, and the heat thereof is used for heating the gas absorbing material.

As described above, in the carbon dioxide gas recovery device according to embodiment 1, the gas absorber is heated by the heat of the exhaust gas repeatedly, and the state of absorbing the acid gas is switched to the state of diffusion. In the present embodiment, since the heat of the exhaust gas is effectively used, the energy consumption in the carbon dioxide gas separation and recovery process can be significantly reduced. In embodiment 1, when the temperature of the exhaust gas and the gas absorber cannot be controlled to a temperature suitable for absorption and diffusion of carbon dioxide, the temperature control is improved by adding a heat exchange means or an additional heating means to the piping and the absorber.

Next, embodiment 2 of the gas recovery device will be described.

As shown in fig. 2, the gas recovery apparatus according to embodiment 2 includes a 1 st heat exchanger 31 and a 2 nd heat exchanger 32, a desulfurizer 33, a 1 st tank 34 and a 2 nd tank 35, and a 1 st pipe 36 and a 2 nd pipe 37 connected to these components. The 1 st pipe 36 has one end serving as a gas inlet for introducing exhaust gas (gas to be treated), and the other end connected to a desulfurizer 33 having cooling capability. Here, the desulfurizer and the cooler may be different devices. The 2 nd pipe 37 has a main path 37a having one end connected to the desulfurizer 33, and a 1 st path 37b and a 2 nd path 37c branching off from the other end of the main path 37 a. The 1 st path 37b has one end connected to the main path 37a and the other end connected to the 1 st tank 34. The 2 nd path 37c has one end connected to the main path 37a and the other end connected to the 2 nd tank 35. Valves, not shown, for opening and closing the respective paths 37b, 37c are provided near the respective other end portions of the 1 st path 37b and the 2 nd path 37 c. The 1 st heat exchanger 31 is connected to the 1 st intermediate portion of the 1 st tube 36 and the 1 st tank 34, respectively, and the 2 nd heat exchanger 32 is connected to the 2 nd intermediate portion of the 1 st tube 36 and the 2 nd tank 35, respectively.

In the gas recovery device according to embodiment 2, gas absorbing materials (gas absorbers) 38 and 39 are formed on the heat exchange surface of the 1 st heat exchanger 31 in the 1 st tank 34 and the heat exchange surface of the 2 nd heat exchanger 32 in the 2 nd tank 35, respectively, and when the gas recovery device is turned off, the gas absorbers 38 and 39 have a temperature (about 30 ℃) that is approximately equal to the ambient temperature.

In order to recover carbon dioxide gas from exhaust gas using this carbon dioxide gas recovery device, first, the valve of the 1 st path 37b of the 2 nd pipe 37 is opened, the valve of the 2 nd path 37c of the 2 nd pipe 37 is closed, the 1 st heat exchanger 31 is closed, and the 2 nd heat exchanger 32 is opened. In this state, the 1 st tank 34 functions as an absorption tower. That is, in this state, when the exhaust gas after high-temperature dust collection is introduced from one end of the 1 st pipe 36, the introduced exhaust gas is introduced into the desulfurizer 33 through the 1 st pipe 36. While passing through the 1 st pipe 36, a part of heat of the exhaust gas is transferred to the 2 nd tank 35 via the 2 nd heat exchanger 32, and the exhaust gas is cooled. The exhaust gas introduced into the desulfurizer 33 is desulfurized by the desulfurizer 33 having a cooling capability, is further cooled, and then flows into the main passage 37a of the 2 nd pipe 37. The temperature or dew point temperature of the exhaust gas flowing into the main path 37a is about 30 ℃, and the exhaust gas is introduced into the 1 st tank 34 through the main path 37a and the 1 st path 37b in the vicinity of the temperature. In the 1 st tank 34, when the temperature of the exhaust gas or the dew point temperature is about 30 ℃, the gas absorber 38 is efficiently cooled, and as a result, carbon dioxide is efficiently absorbed, and gases other than carbon dioxide are discharged to the outside through the gas outlet provided in the 1 st tank 34. The temperature or dew point temperature of the exhaust gas flowing into the main path 37a and cooling the absorber need not be 30 c, and may be about 40 c or 50 c.

After the gas absorber 38 has sufficiently absorbed carbon dioxide, the valve of the 1 st path 37b of the 2 nd pipe 37 is switched to the closed state, the valve of the 2 nd path 37c of the 2 nd pipe 37 is switched to the open state, the 1 st heat exchanger 31 is switched to the open state, and the 2 nd heat exchanger 32 is switched to the closed state. Thereby, the heat of the exhaust gas passing through the 1 st pipe 36 is transferred to the 1 st tank 34 and the gas absorber 38 via the 1 st heat exchanger 31. In the 1 st heat exchanger 31, water is preferably used as the heat medium, and the gas absorber 38 is heated by introducing the heated water or water vapor. The gas absorber 38 in the 1 st tank 34 is heated to about 75 ℃ by the heat from the 1 st heat exchanger 31, and diffuses carbon dioxide. The temperature of the heated gas absorber 38 may be about 60 ℃ or 85 ℃. Also, the gas absorber 38 may be depressurized upon heating. The diffused carbon dioxide is discharged from a gas outlet provided in the 1 st tank 34 and recovered. On the other hand, in the 2 nd tank 35, the exhaust gas of about 30 ℃ flowing into the 2 nd pipe 37 through the same path as described above is introduced through the 2 nd path 37c, and carbon dioxide is absorbed by the gas absorber 39 filled in the tank 35. When the dew point temperature of the exhaust gas is lower than the temperature of the absorbent, the absorbent and the exhaust gas are effectively cooled by the evaporation of moisture from the absorbent, which is preferable. In addition, when the absorber is insufficiently cooled by the cooled exhaust gas, additional cooling using latent heat of evaporation of water due to introduction of a cooling gas, decompression, or introduction of a dry gas is desired. That is, in this state, the 1 st tank 34 functions as a diffusion tower, and the 2 nd tank 35 functions as an absorption tower, and absorption and diffusion of carbon dioxide gas can be performed simultaneously.

After carbon dioxide is sufficiently diffused from the gas absorber 38 and absorbed by the gas absorber 39, as shown in fig. 2, the valve of the 1 st path 37b of the 2 nd pipe 37 is opened, the valve of the 2 nd path 37c of the 2 nd pipe 37 is closed, the 1 st heat exchanger 31 is closed, the 2 nd heat exchanger 32 is opened, and the 1 st tank 34 is switched to function as an absorption tower and the 2 nd tank 35 functions as a diffusion tower. In this way, the absorption and diffusion of carbon dioxide gas are performed simultaneously in the column opposite to the column before switching. Further, by repeating the switching operation as described above, the absorption and diffusion of the carbon dioxide gas in the exhaust gas can be continuously performed, and the carbon dioxide gas can be efficiently separated and recovered from a large amount of exhaust gas. The number of columns filled with the gas absorber may be 2 columns or more.

As described above, in the gas recovery apparatus according to embodiment 2, the gas absorber is heated by the heat of the exhaust gas repeatedly, and the state of absorbing the acid gas is switched to the state of diffusion. Therefore, the utilization efficiency of energy can be significantly improved as compared with the case of using the conventional carbon dioxide gas separation and recovery process. In embodiment 2, when the temperature of the exhaust gas and the absorber cannot be controlled to a temperature suitable for absorption and diffusion of carbon dioxide, the temperature control is improved by adding a heat exchange means or an additional heating means to the piping and the absorber.

The gas recovery device can also be used for supplying gas. In the case of supplying gas, it is provided as a gas supply device.

The features of the present invention will be described in more detail below with reference to examples and comparative examples. The materials, the amounts used, the ratios, the contents of the treatment, the treatment steps, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the specific examples shown below. In the following description, the concentration in parentheses indicates the concentration of the objective component in the reaction mixture.

In this example, the gas reversible absorption test was performed in the following manner.

(CO₂Reversible absorption test)

A polymer sample was placed in a reactor, water was added thereto, and the reactor was closed and transferred into a 30 ℃ thermostatic bath. In the reactor, 10% CO humidified at 60 ℃ was introduced at a flow rate of 10mL/min₂Gas (CO)₂:N₂10:90) for 46 minutes to allow the polymer sample to absorb CO₂. Then, the temperature in the thermostatic bath was increased to 75 ℃ and kept for 25 minutes, and CO was diffused₂A gas. At this time, CO discharged from the reactor was measured₂Gas emission, CO as polymer₂Reversible absorption capacity. In examples 1 to 6 and comparative examples 1 to 8 below, 20g of a polymer sample was placed in a reactor having a capacity of 90mL, and 40mL of water was added to measure the amount of the polymer sample.

[1] Investigation of the Total monomer concentration of the reaction mixture

Comparative example 1 production of Polymer having a Total monomer concentration of 1.1 mol/L

N- (dimethylaminopropyl) methacrylamide (DMAPM: 5842.98mg (6215.94mL), 55 mol%), N' -methylenebisacrylamide (BIS: 962.02mg, 10 mol%), cetyltrimethylammonium bromide (CTAB: 36.445mg, 2mM) were dissolved in MilliQ water, and the total amount was made 50mL to prepare a mixture. After the mixture was heated to 70 ℃ while being stirred by a mechanical stirrer, a solution of N-t-butylacrylamide (TBAm: 2779.80mg, 35 mol%) dissolved in methanol (5mL) was added, and nitrogen bubbling was performed for 30 minutes. To the mixture was added an acetone solution (250. mu.L) containing 2, 2' -azobis (2-methylpropionitrile) (AIBN: 21.18mg, 2.58mM) to prepare a reaction mixture, and polymerization was carried out at 70 ℃ for 3 hours under a nitrogen atmosphere, whereby a precipitate of a polymer was obtained. This reaction solution was filtered, and the polymer extracted by the filtration was freeze-dried to obtain comparative sample 1.

Comparative example 2 production of Polymer having a Total monomer concentration of 0.57 mol/L

A lyophilized product of the polymer (comparative sample 2) was obtained in the same manner as in comparative example 1, except that the amounts of DMAPM, TBAm, and BIS were changed as shown in table 1.

Example 1 production of Polymer having Total monomer concentration of 1.7 mol/L

A polymer precipitate was obtained in the same manner as in comparative example 1, except that the amounts of DMAPM, TBAm, and BIS were changed as shown in table 1, and TBAm was dissolved in 8mL of methanol and added to the mixture. To the polymer precipitate, 100mL of MilliQ water was added and pulverized with a hand-held mixer to prepare a slurry. The slurry was filtered, and the polymer extracted by the filtration was freeze-dried to obtain sample 1.

Example 2 production of Polymer having Total monomer concentration of 2.4 mol/L

After dissolving a portion of the BIS by adding DMAPM (14045.63mg (14942.15mL), 55 mol%) to a flask containing BIS (4625.10mg, 20 mol%) and CTAB (36.445mg, 2mM), 30mL of MilliQ water was added. After the mixture was warmed to 70 ℃ while being stirred by a mechanical stirrer, a solution of TBAm (4773.00mg, 25 mol%) dissolved in methanol (12mL) was added, and nitrogen bubbling was performed for 30 minutes. To the mixture was added an acetone solution (250. mu.L) containing AIBN (21.18mg, 2.58mM) to prepare a reaction mixture, and polymerization was carried out at 70 ℃ for 3 hours under a nitrogen atmosphere, whereby a precipitate of a polymer was obtained. After the precipitate of the polymer was immersed in water overnight, the polymer was pulverized with a hand mixer to obtain a slurry. The slurry was filtered, and the polymer extracted by the filtration was freeze-dried to obtain sample 2.

Comparative example 3 production of Polymer having a Total monomer concentration of 0.31 mol/L

A polymer was synthesized in the same manner as in Synthesis example 1 of International publication No. 2016/024633.

Specifically, 1 liter of pure water was placed in a three-necked flask, and after heating to 70 ℃, 2mM CTAB was added, and further a methanol solution containing DMAPM (55 mol%), TBAm (43 mol%) and BIS (2 mol%) were added so that the total monomer concentration became 0.31 mol/L, and dissolution was performed. The mixture was kept at 70 ℃ and stirred with a mechanical stirrer, and nitrogen bubbling was performed for 1 hour. To the mixture was added 5mL of an aqueous solution containing 2, 2' -azobis (2-methylpropionamidine) dihydrochloride (700mg) to prepare a reaction mixture, and polymerization was performed at 70 ℃ for 3 hours under a nitrogen atmosphere, thereby obtaining polymer particles having a particle size of 800nm (comparative sample 3).

The amounts of the components of the reaction mixture used for the polymer synthesis are shown in table 1 for the samples produced in the examples and comparative examples. In addition, 2' -azobis (2-methylpropionamidine) dihydrochloride was used as an initiator in comparative sample 3 of the following table (reference to the x-symbol in the table).

The yield and CO of the measurement samples 1 and 2 and the comparative samples 1 to 3 were measured₂The results of reversible absorption are shown in Table 2. Here, the "yield" is a ratio (%) of an actual yield to a theoretical yield of the polymer calculated from the amounts of the respective monomers used in the reaction mixture.

[ Table 2]

As shown in Table 2, regarding CO₂The samples 1 and 2 are excellent in reversible absorption amount, and the sample 2 is most excellent. Also, samples 1 and 2 significantly improved the yield as compared with comparative sample 3. The yields of samples 1 and 2 and comparative samples 1 and 2 were equivalent. That is, in sample 2 in which the total monomer concentration was increased, yields equivalent to those of sample 1 and comparative samples 1 and 2 in which the total monomer concentration was decreased were obtained. This means that the production yield is improved without enlarging the production vessel, and that the production method of the present invention is industrially advantageous.

Further, it is shown that when water is added to each sample and the water content is examined, the water content decreases in the order of samples 2 and 1 and comparative samples 1, 2 and 3.

Further, in the case of sample 2, when the durability test in which the gas reversible absorption test was performed 50 times was performed, it was confirmed that the same CO as that of sample 1 was exhibited even in the 50 th time₂Reversible absorption amount, and sufficient durability.

Further, as a modification of sample 2, a polymer sample was produced by adding methanol to which TBAm was not added to the reaction mixture in place of a methanol solution of TBAm, setting the ratio of DMAPM to 80 mol%, and CO was performed₂CO in reversible absorption test, compared with sample 2₂The reversible absorption capacity increases. And, the CO₂Polymer prepared by adding water instead of methanol in reversible absorption amountThe compound sample (polymer sample produced using a 100% water solvent) has a large value.

As another modification of sample 2, when a polymer sample was prepared using dimethylaminopropylacrylamide (DMAPAAm) as a monofunctional monomer instead of DMAPM, the same result as that of sample 2 was obtained.

[2] Investigation of the concentration of polyfunctional monomer and the action of surfactant

Example 3 production of Polymer without surfactant (CTAB)

A lyophilized product of a polymer (sample 3) was obtained in the same manner as in example 1, except that CTAB was not added to the reaction mixture.

Comparative example 4 production of Polymer in which the proportion of polyfunctional Polymer (BIS) was 10 mol%

A lyophilized product of a polymer (comparative sample 4) was obtained in the same manner as in example 3, except that the ratio of TBAm in the monomer was changed to 35 mol% and the ratio of BIS was changed to 10 mol%.

Comparative example 5 production of a Polymer in which the proportion of the polyfunctional Polymer (EGDMA) was 10 mol%

A lyophilized product of a polymer was obtained in the same manner as in example 1 except that the ratio of TBAm in the monomer was changed to 35 mol% and Ethylene Glycol Dimethacrylate (EGDMA) was used instead of BIS, and the ratio thereof was set to 10 mol% (comparative sample 5).

The amounts of the components of the reaction mixture used for the polymer synthesis for the samples produced in example 3, comparative example 4, and comparative example 5 are shown in table 3. In comparative sample 5 in the following table, EGDMA was used as a polyfunctional monomer (reference symbol in the table).

When water was added to sample 1 produced in example 1 and to sample 3 and comparative samples 4 and 5 produced herein, both comparative samples 4 and 5 using 10 mol% of a polyfunctional monomer (BIS or EGDMA) had a high water content and swelled and softened, but samples 1 and 3 using 20 mol% of BIS had a relatively low water content and remained hard. This shows that the polyfunctional monomer needs to be used in a proportion of 15 mol% or more in order to obtain a polymer having a low degree of swelling. When sample 1 using a surfactant (CTAB) is compared with sample 3 not using CTAB, some transparent phases are observed only in the vicinity of the surface of sample 3. It follows that it is preferable to add a surfactant to the reaction mixture in order to obtain a homogeneous polymer.

Comparative examples 6 to 8 production of polymers wherein the proportion of the polyfunctional Polymer (BIS) was 0 to 10 mol%, and the total monomer concentration was 2.4 mol/L

Freeze-dried products of polymers (comparative samples 6 to 8) were obtained in the same manner as in example 2, except that the proportions of TBAm and BIS in the monomers were changed as shown in table 4.

Example 4 production of Polymer in which the proportion of polyfunctional Polymer (BIS) was 30 mol%, and the total monomer concentration was 2.4 mol/L

A freeze-dried polymer (sample 4) was obtained in the same manner as in example 2, except that the proportions of TBAm and BIS in the monomers were changed as shown in table 4.

The amounts of the components of the reaction mixture used for the polymer synthesis of the samples produced in comparative examples 6 to 8 and example 4 are shown in table 4 together with the amounts of the components of the reaction mixture used for the polymer synthesis of sample 2 produced in example 2.

When water was added to the sample 2 produced in example 2, the sample 4 produced therein, and the comparative samples 6 to 8, the comparative sample 6 in which the polyfunctional monomer (BIS) was not used, and the comparative samples 7 and 8 in which the proportion of BIS was 5 mol% or 10 mol% each had a high water content and swelled and softened, whereas the samples 2 and 4 in which the proportion of BIS was 20 mol% or 30 mol% did not swell and became softAnd still be rigid. And, with respect to yield and CO₂The reversible absorption amounts were the same for comparative samples 7 and 8 and samples 2 and 4(BIS concentration: 5 to 30 mol%), but when a polymer sample having a BIS concentration exceeding 30 mol% was tested, CO was found₂The reversible absorption amount tends to decrease. This shows that it is necessary to use a polyfunctional monomer at a ratio of 15 mol% or more in order to obtain a polymer having a small water content and a small degree of swelling, and that sufficient CO can be expressed₂The reversible absorption capacity requires that the polymer be synthesized with the polyfunctional monomer in a proportion of 30 mol% or less.

Here, as a modification of sample 2, a polymer sample was produced using 20 mol% of EGDMA in place of BIS for the polyfunctional monomer, and CO was carried out₂In the reversible absorption test, CO equivalent to that of sample 2 was obtained₂Reversible absorption capacity. Further, the polymer sample produced using 20 mol% of EGDMA had a significantly smaller water content/swelling volume (about 1/3 when EGDMA was 10 mol% and less than 1/2 when EGDMA was 5 mol%) than the comparative sample in which the ratio of EGDMA was 5 mol% or 10 mol%, and significantly larger CO was obtained₂The amount of reversible absorption (about 1.5 times for 10 mol% of EGDMA and more than 2 times for 5 mol% of EGDMA).

[3] Investigation of solvents

(examples 5 and 6) production of Polymer having a Total monomer concentration of 3.0 mol/L

A freeze-dried product of a polymer (samples 5 and 6) was obtained in the same manner as in example 2, except that the amount of MilliQ water added to the reaction mixture and the amount of dissolved methanol for TBAm (the amount of methanol added to the reaction mixture) were changed as shown in table 5.

The amounts of MilliQ water and methanol added to the reaction mixtures in examples 2, 5 and 6 and the CO measured for samples 2, 5 and 6 were measured₂The reversible absorption is shown in Table 5.

[ Table 5]

The water content of the polymer in each of examples 5 and 6 was 0.7g (H)₂O)/1g (water-containing polymer) or less, a good polymer material can be obtained with low water content. As shown in Table 5, in sample 5 in which the amount of the solvent was reduced, CO was compared with that in sample 2₂The reversible absorption capacity decreases. When the alcohol is removed from the solvent composition and only water is used, CO is present₂The reversible absorption capacity further decreases. From this result, it was found that when the amount of the solvent was extremely reduced, the concentration of a low-polarity monomer such as TBAm in the polymer was increased during polymerization, the local environment around the amine in the gel was extremely low-polarity, and the basicity of the amine was reduced, thereby CO was reduced₂The reversible absorption capacity decreases. It is known that even if the monomer is a liquid, a certain amount of a solvent such as water or alcohol needs to be added to the reaction mixture. Furthermore, sample 5 using methanol showed a larger CO than sample 6 not using methanol₂The reversible absorption amount is thus expressed by using an alcohol such as methanol in combination with a solvent.

Polymer samples were produced and tested in the same manner as in examples 2, 5 and 6 except that ethanol, isopropanol, butanol or tert-butanol was used instead of methanol, and the results equivalent to those obtained when the methanol was used were obtained.

[4] Production of Polymer having amine impregnation step

Example 7 production of Polymer having amine impregnation step Using DMAm (monofunctional monomer having No amino group) as monofunctional monomer

Dimethylacrylamide (DMAm: 80 mol%), BIS (20 mol%), and CTAB (2mM) were dissolved in MilliQ water, and the total amount was set to 50mL to prepare a mixture. The mixture was subjected to nitrogen bubbling for 30 minutes while being heated to 70 ℃. After methanol (12mL) subjected to nitrogen bubbling was added to the mixture, an acetone solution (250 μ L) containing AIBN (2.58mM) was added to prepare a reaction mixture, and polymerization was performed at 70 ℃ for 3 hours under a nitrogen atmosphere, thereby obtaining a precipitate of a polymer. The polymer precipitate was left to stand in water overnight, then pulverized with a hand mixer, and filtered, thereby obtaining a polymerThe polymer (aqueous polymer) is recovered. The water content of the recovered polymer was 0.6774g (H)₂O)/1g (aqueous polymer).

1g of the obtained polymer was weighed and impregnated with 2- (isopropylamino) ethanol (IPAE: 7490. mu.L) as an amine-containing treatment solution. The amine-containing treatment solution was gently stirred overnight with a shaker, and water contained in the polymer was replaced with 8N IPAE, followed by filtration, thereby obtaining a polymer material impregnated with IPAE (sample 7).

Example 8 production of Polymer Using NiPAm (monofunctional monomer having no amino group) as monofunctional monomer and having been subjected to a step of swelling the Polymer with an amine solution

A polymer material impregnated with 8N IPAE was obtained in the same manner as in example 7, except that N-isopropylacrylamide (NiPAm) was used instead of DMAm (sample 8).

Example 9 production of a polymer having a step of swelling the polymer with an amine solution using DMAPM (monofunctional monomer having amino group) and TBAm (monofunctional monomer having a hydrophobic group) as monofunctional monomers

After the polymer obtained in the same manner as in example 2 was allowed to stand in water overnight, it was pulverized with a hand mixer and filtered, thereby recovering an aqueous polymer. By the same procedure as in example 7, the water content of the polymer was replaced with 8N of IPAE, thereby obtaining a polymer material impregnated with 8N of IPAE (sample 9).

Example 10 production of Polymer having a step of swelling the Polymer with an amine solution Using DMAPM (monofunctional monomer having amino group) as monofunctional monomer

A polymer material impregnated with 8N IPAE was obtained in the same manner as in example 9 except that methanol to which TBAm was not added was added to the reaction mixture instead of the methanol solution of TBAm, and the ratio of DMAPM was set to 80 mol% (sample 10).

The amounts of the components of the reaction mixtures used for the polymer synthesis for the samples produced in examples 7 to 10 are shown in table 6.

[ Table 6]

CO of samples 7-10 swollen by amine solution₂Reversible uptake of CO from Polymer samples made in the same manner except for swelling with water₂The reversible absorption amount was greatly increased by about 3 times in samples 7 and 8, by about 5 times in sample 9, and by about 2 times in sample 10, as compared with the reversible absorption amount. Further, it was also shown that the gas reversible absorption capacity can be further improved by improving the rate of replacement of water with IPAE.

[5] Manufacture of sheet material

Example 11 production of sheet Using Polymer

The precipitate of the polymer synthesized in the same manner as in example 2 was extracted by filtration and pulverized, thereby obtaining a powder of the polymer. The polymer powder and polyethylene pellets were kneaded at a mass ratio of 1:2 to be biaxially extruded, and the strands were spread to a width of about 4mm using a roll, and cut into sheets of about 5mm 200 μm, 4mm in width and 5mm in length using a pelletizer. When the sheet was subjected to a gas reversible absorption test, 33mL/g of CO was obtained₂Reversible absorption capacity. It was thus confirmed that the produced polymer exhibited gas reversible absorption properties even when used as a sheet.

[6] Investigation of the concentration of polyfunctional monomers and Total monomer concentration

Comparative example 9 production of Polymer having a proportion of polyfunctional monomer (BIS) of 5 mol% and a Total monomer concentration of 2.3 mol/L

Dimethylaminopropylacrylamide (DMAPAAm: 95 mol%) and BIS (5 mol%) were dissolved in MilliQ water at 60 ℃ to prepare a total 30mL aqueous solution, and ethanol was further added so that the total monomer concentration of the reaction mixture reacted in the subsequent step became 2.3 mol/L, thereby preparing a mixture. After the mixture was heated to 70 ℃, nitrogen bubbling was performed for 30 to 60 minutes while stirring. To the mixture was added a solution prepared by dissolving AIBN in a mixed solvent of acetone and water (AIBN concentration in the reaction mixture: 2.58mM) to prepare a reaction mixture, and polymerization was carried out at 70 ℃ for 3 hours under a nitrogen stream, whereby a polymer material (comparative sample 9) was obtained.

Comparative example 10, example 11, and example 12 production of Polymer in which the proportion of polyfunctional monomer (BIS) was 10 to 30 mol%, and the total monomer concentration was 2.3 mol/L

Polymer materials (comparative sample 10, samples 11 and 12) were obtained in the same manner as in comparative example 8, except that the proportions of DMAPAAm and BIS were changed as shown in table 7.

Examples 13 to 16 production of Polymer having a proportion of polyfunctional monomer (BIS) of 20 mol% and a total monomer concentration of 0.54 to 2.3 mol/L

Polymer materials (samples 13 to 16) were obtained in the same manner as in comparative example 9, except that reaction mixtures were prepared so that the total monomer concentrations shown in table 7 were achieved, with the ratio of DMAPAAm to BIS being 80 mol% to 20 mol%.

The monomer composition and total monomer concentration of the reaction mixture used in the polymer synthesis, and the water content, swelling volume, and CO of the polymer material were measured for the samples produced in comparative example 9, comparative example 10, and examples 11 to 16₂The measurement results of the reversible absorption amount are shown in Table 7. In Table 7, "g (wet)" represents the weight of the polymer in a wet state, "mL (wet)" represents the capacity of the polymer in a wet state, and "g/dry" represents the unit (g or mL) of the weight of the polymer in a dry state.

In Table 7, when samples 9, 10 and samples 11, 12 in which the ratio of the polyfunctional monomer (BIS) was changed with the total monomer concentration of the reaction mixture set to 2.3 mol/L were compared, it was found that the ratio of BIS was set to more than 10 mol% and 30 mol% or less, and the ratio of BIS was changedIn comparison with samples 9 and 10, which were set to 10 mol% or less, the water content and the degree of swelling were suppressed to be low, and CO per unit volume was reduced₂The reversible absorption capacity is improved. Further, when samples 13 to 16 in which the total monomer concentration of the reaction mixture was changed by setting the ratio of the polyfunctional monomer to 20 mol% were compared, it was found that the larger the total monomer concentration of the reaction mixture was, the lower the water content and the degree of swelling were, and the CO per unit volume was₂The greater the reversible uptake. From this result, it was found that CO per unit volume can be achieved by setting the ratio of the polyfunctional monomer within a predetermined range and increasing the polymerization concentration (the total monomer concentration of the reaction mixture)₂Materials with a greater reversible uptake. With such materials, sufficient CO can be obtained even if used in a relatively small volume₂Since the amount of reversible absorption is small, the amount of heat used for temperature rise can be reduced.

[7] Investigation of the kind of initiator

Example 17 production of Polymer Using 2, 2' -azobis (2, 4-dimethylvaleronitrile) (V-65) as initiator

DMAPAAm (80 mol%), BIS (20 mol%) and MilliQ water were placed in a 5L separable flask (reactor 1) and immersed in a hot water bath at 50 ℃ with stirring. Ethanol was added to the mixture, and the liquid amount was adjusted so that the total monomer concentration of the reaction mixture to be reacted in the subsequent step became 3 mol/L and the total amount became 3000 mL. After stirring the mixture at 100rpm for 1 hour while bubbling nitrogen gas, the 1 st reactor was immersed in a hot water bath at 55 ℃. Then, after the temperature of the hot water bath was lowered to 45 ℃ to depressurize the inside of the 1 st reactor, V-65(2.58mM) was added to the mixture as an initiator and stirred at 240rpm for 2 minutes, thereby preparing a reaction mixture. The reaction mixture was transferred to a stainless steel reactor (2 nd reactor) using a pipe, and after the 2 nd reactor was immersed in a hot water bath at 55 ℃ and subjected to a reaction for 3 hours, it was taken out from the hot water bath to remove residual heat, thereby obtaining a polymer material (sample 17).

Sample 17 has a moisture content of 2.5g (wet)/g (dry), CO₂The reversible absorption capacity was 69.5mL/g (dry).

V-65 is an initiator which initiates the reaction at 47 ℃ and by using which the polymerization can be carried out at a relatively low temperature (here 55 ℃). Also, under the same conditions, even if the polymerization reaction is performed in the resin container (plastic bag), the polymer material can be synthesized in the same manner. Further, the polymerization reaction can be carried out while the monomer solution (mixture) is being poured onto the conveyor.

[8]CO of comminuted polymeric materials₂Study of reversible absorption

CO determination by crushing the polymeric materials synthesized in the above examples with a meat chopper or a Feiz Mill₂Reversible absorption showed equivalent CO regardless of the pulverization method₂Reversible absorption capacity.

[9] Investigation of Effect due to addition of Fine particles to Polymer Material

(examples 18 and 19) production of Polymer Material containing Fine particles

A polymer material was obtained in the same manner as in comparative example 9, except that the ratio of DMAPAAm to BIS was set to 85 mol% to 15 mol%. The moisture content of the polymeric material was 73.7 wt%.

The polymer material was pulverized by a meat chopper in the order of 1.5 mesh (pore size 4.8mm), 1.3 mesh (pore size 4.0mm), 1 mesh (pore size 3.2mm), 7 cm mesh (pore size 2.4mm) and 3 cm mesh (pore size 1.1mm), thereby obtaining various pulverized polymers having different degrees of pulverization. Water-repellent silica RY300 (AEROSIL RY300, manufactured by Evonik corporation; average primary particle diameter: 7 nm; water contact angle: 100 ℃ or more) was added to each of the pulverized polymer particles at the mixing ratio shown in Table 8, to produce fine particle-containing polymer materials.

After the polymer material containing fine particles was put into a 250mL plastic container and mixed with shaking, the surface was flattened to measure the height. The results are shown in Table 8. Further, the particle size distribution of the fine particle-containing polymer material in which the proportion of the hydrophobic silica RY300 was 0.50 vol% among the fine particle-containing polymer materials is shown in FIG. 3, and the resultant agglomerates were pulverized to 7 cm meshA polymer material (sample 18) containing fine particles obtained by adding hydrophobic silica RY300(0.50 vol%) to the pulverized compound and a pulverized polymer (sample 19) having a particle size of 7 cm, and CO in the absorption process measured by pressure swing absorption were used₂Absorption and CO diffusion₂The amount of diffusion is shown in fig. 4. In FIGS. 3 and 4, "3-cl" to "1.5-min" polymers respectively represent crushed polymers of 3-cl to 1.5-min, and "RY 300" represents hydrophobic silica RY 300.

CO based on pressure swing absorption₂The reversible absorption property was evaluated by the following procedure.

First, a sample (10L) to be measured contained in a reactor was placed in a constant temperature bath at a temperature of 40 ℃ and a relative humidity of more than 98% to be sufficiently humidified, and then the temperature was adjusted to 30 ℃. Then, the humidified CO is introduced into a reactor₂And N₂Mixed gas (CO) of₂Concentration: 10.03 vol%) was introduced into a sample to be measured at a flow rate of 1000 mL/min, and the flow rate was measured by a multi-gas analyzer (HORIBA, ltd: VA-3000) measurement of CO in gas discharged from a sample to be measured₂Concentration (a) (absorption process). Then, the gas introduced into the sample to be measured is replaced with the humidified N₂The gas was introduced into the sample to be measured at a flow rate of 1000 mL/min, and the CO content of the gas discharged from the sample to be measured was measured₂Concentration (B) (diffusion process). Introducing CO of the mixed gas₂Concentration and CO measured during absorption₂The cumulative value of the difference in concentration (A) is taken as CO₂The amount of CO absorbed and measured during diffusion₂The integrated value of the concentration (B) is taken as CO₂Diffusion amount of CO into a sample to be measured₂The reversible absorption properties were evaluated. In addition, the CO to be measured here₂The absorption is shown in the graph for CO₂The diffusion amount is differentiated, and the value may be shown on the negative side on the vertical axis with a "-" sign.

As shown in table 8, the volume (filling amount) of the polymer material was changed by changing the proportion of the water-repellent silica RY300, and the volume was minimized (the filling amount was maximized) when the water-repellent silica RY300 was set to 0.50 vol%. As shown in fig. 4, the polymer material containing fine particles with a large loading amount (sample 18) has CO per unit mass as compared with the crushed polymer (sample 19) containing no hydrophobic silica RY300₂Reversible absorption capacity and CO₂The absorption/diffusion speed is greatly improved.

It was found that the addition of fine particles can increase the filling amount of the polymer material to increase CO₂Reversible absorption capacity and CO₂Absorption/diffusion rate.

[10] Investigation of Effect due to pulverization of Polymer Material containing Fine particles

Example 20 production of pulverized Polymer Material containing Fine particles including pulverized product obtained by pulverizing Polymer Material containing Fine particles further finely

A polymer material containing fine particles was obtained by mixing a crushed polymer of 1.5 mesh size obtained in the crushed polymer obtained in example 18 with hydrophobic silica RY300 at a volume ratio of 99.5:0.5 (polymer crushed material/hydrophobic silica RY 300). This fine particle-containing polymer material was pulverized at 230rpm using beads made of zirconia having a diameter of 5mm by a planetary ball mill device (Fritsch Japan Co., Ltd.: P-5), whereby a pulverized product of the fine particle-containing polymer material (fine particle-containing polymer pulverized product, sample 20) was obtained. When the particle size distribution of the sample 20 was measured, it was confirmed that most of the pulverized material had a particle size of less than 100. mu.m. The moisture content of sample 20 was 72.45 wt%, and the moisture content of the polymer pulverized material contained in sample 19 was 73.17 wt%, which was slightly smaller than the moisture content (73.7 wt%) of the polymer material used in the material.

For samples 20 and 19, CO in the absorption process measured by the pressure swing absorption method was used₂The absorption is shown in FIG. 5. In this case, 10L of gas was addedThe body absorbing material is used as a sample to be measured, and CO is added₂And N₂Mixed gas of (2) and N₂The flow rate of the gas was measured at 3000 mL/min.

As is clear from FIG. 5, the crushed polymer material containing fine particles (sample 20) crushed by the bead mill has CO in comparison with the crushed polymer material containing fine particles (sample 18) not crushed by the bead mill₂The absorption rate was dramatically increased. It was thus found that by increasing the degree of pulverization of the polymer material containing fine particles, the CO can be further increased₂Reversible absorption properties.

The structures of the monomer, the surfactant and the initiator used in the present example are shown below.

[ chemical formula 2-1]

[ chemical formula 2-2]

Industrial applicability

According to the production method of the present invention, a polymer having a low water-containing property and a large reversible gas absorption amount can be efficiently produced. Therefore, when the polymer of the present invention is used, CO can be supplied at low cost₂A gas-absorbing material having high reversible absorption capacity and excellent handleability. Thus, the present invention has high industrial applicability.

Description of the symbols

21-heat exchanger, 22, 33-desulfurizer, 23-gas absorber, 24-1 st tube, 25-2 nd tube, 26-3 rd tube, 26 a-circulation path, 26 b-branch path, 31-1 st heat exchanger, 32-2 nd heat exchanger, 34-1 st tank, 35-2 nd tank, 36-1 st tube, 37-2 nd tube, 37 a-main path, 37 b-1 st path, 37 c-2 nd path, 38, 39-gas absorber.