阅读说明：本技术 低分子量聚（亚芳基醚）及其制备方法 (Low molecular weight poly (arylene ether) and method of making same ) 是由 郝景峰 戴伍国 凌俊杰 于 2020-06-11 设计创作，主要内容包括：本发明提供了低分子量聚(亚芳基醚)及其制备方法,制备方法包括：(1)在氧化剂和催化剂的存在下,酚单体在聚(亚芳基醚)良溶剂中氧化聚合,得到在25℃氯仿溶液中的特性粘度为0.05～0.3dl/g的低分子量聚(亚芳基醚)的混合溶液；(2)水洗；(3)搅拌下及在惰性气氛下将水洗后的混合溶液加入到聚(亚芳基醚)不良溶剂中形成料浆,过滤得到湿物料；其中,水洗后的混合溶液中低分子量聚(亚芳基醚)的固含量控制为30～80wt％,聚(亚芳基醚)不良溶剂与水洗后的聚(亚芳基醚)混合溶液的重量比为3或以上；(4)干燥湿物料,得到低分子量聚(亚芳基醚)。本发明制备的低分子量聚(亚芳基醚)的醌含量低,分子量分布窄,玻璃化转变温度高。(The present invention provides low molecular weight poly (arylene ether) and a method of making the same, the method comprising: (1) oxidatively polymerizing a phenol monomer in a good poly (arylene ether) solvent in the presence of an oxidizing agent and a catalyst to obtain a mixed solution of a low molecular weight poly (arylene ether) having an intrinsic viscosity of 0.05 to 0.3dl/g in a chloroform solution at 25 ℃; (2) washing with water; (3) adding the mixed solution after water washing into a poor poly (arylene ether) solvent under stirring and inert atmosphere to form slurry, and filtering to obtain a wet material; wherein the solid content of the low molecular weight poly (arylene ether) in the water-washed mixed solution is controlled to 30 to 80 wt%, and the weight ratio of the poor poly (arylene ether) solvent to the water-washed poly (arylene ether) mixed solution is 3 or more; (4) the wet mass is dried to provide the low molecular weight poly (arylene ether). The low molecular weight poly (arylene ether) prepared by the present invention has low quinone content, narrow molecular weight distribution, and high glass transition temperature.)

1. A method of preparing a low molecular weight poly (arylene ether), wherein the method of preparing comprises the steps of:

(1) oxidatively polymerizing a phenol monomer in a good poly (arylene ether) solvent in the presence of an oxidizing agent and a catalyst to obtain a mixed solution of a low molecular weight poly (arylene ether) having an intrinsic viscosity of 0.05 to 0.3dl/g in a chloroform solution at 25 ℃;

(2) washing the mixed solution of low molecular weight poly (arylene ether) to obtain a washed mixed solution of low molecular weight poly (arylene ether);

(3) adding the water-washed mixed solution of low molecular weight poly (arylene ether) to a poor poly (arylene ether) solvent under stirring and in an inert atmosphere to form a low molecular weight poly (arylene ether) slurry, and filtering to obtain a wet low molecular weight poly (arylene ether) material; wherein the solid content of the low molecular weight poly (arylene ether) in the water-washed mixed solution of low molecular weight poly (arylene ether) is controlled to 30 to 80 wt%, and the weight ratio of the poor solvent for poly (arylene ether) to the water-washed mixed solution of poly (arylene ether) is 3 or more;

(4) the low molecular weight poly (arylene ether) wet mass is dried to provide the low molecular weight poly (arylene ether).

2. The production method according to claim 1, wherein the phenol monomer in the step (1) is a monohydric phenol, a polyhydric phenol, or a mixture thereof;

preferably, the monohydric phenol has the structure shown in formula (I):

wherein M is₁、M₂、M₃And M₄Each independently is a hydrogen atom, an alkyl group (e.g., C1-6 alkyl), a halogen, a haloalkane, or an alkoxy group;

more preferably, the monohydric phenol is 2, 6-dimethylphenol or 2,3, 6-trimethylphenol;

preferably, the polyphenol is polyphenol with the phenolic hydroxyl number of 2-7, and is preferably dihydric phenol;

more preferably, the dihydric phenol has the structure shown in formula (II):

wherein N is₁、N₂、N₃And N₄Each independently is a hydrogen atom or a saturated or unsaturated alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, an allyl group; w is an alkyl group of 1 to 4 in number of C atoms such as ethyl, isopropyl or methylene;

more preferably, the phenolic monomer is 2, 6-dimethylphenol or a mixture of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol; the ratio of the amounts of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol in the mixture of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol is preferably 1:0.00001 to 0.1, more preferably 1:0.0001 to 0.01, and still more preferably 1:0.0005 to 0.003.

3. The method of claim 1 or 2, wherein the low molecular weight poly (arylene ether) has an intrinsic viscosity of 0.07 to 0.15dl/g in chloroform at 25 ℃.

4. The production method according to any one of claims 1 to 3, wherein the oxidizing agent is oxygen;

preferably, the catalyst is a metal amine composite catalyst;

more preferably, the metal salt in the metal amine composite catalyst is one or more selected from cuprous chloride, cuprous bromide, cuprous sulfate, cuprous tetramine sulfate, cuprous acetate, cupric chloride, cupric bromide, cupric sulfate, cupric tetramine sulfate, and cupric acetate; further preferably, the ratio of the amount of the metal salt to the amount of the phenol monomer is 0.005-2: 100;

more preferably, the amine compound in the metal amine composite catalyst is a monoamine compound, for example, a primary amine, a tertiary amine, a secondary amine, etc.; a diamine compound; or mixtures thereof;

further preferably, the amine compound is one or more selected from the group consisting of N-propylamine, isopropylamine, N-butylamine, sec-butylamine, tert-butylamine, N-pentylamine, N-hexylamine, cyclohexylamine, di-N-propylamine, di-N-butylamine, di-tert-butylamine, N-butyl-N-pentylamine, di-N-hexylamine, triethylamine, tri-N-propylamine, tri-N-butylamine, dimethyl-N-pentylamine, N '-tetramethyl-1, 3-diaminopropane and N, N' -di-tert-butylethylenediamine;

more preferably, the ratio of the amount of the amine compound to the amount of the metal salt is 1 to 100:1, preferably 10 to 60: 1.

5. The method of any of claims 1-4, wherein the good poly (arylene ether) solvent is one or more of benzene, toluene, xylene, chloroform, and tetrahydrofuran;

preferably, the mass ratio of the good solvent for the poly (arylene ether) to the phenolic monomer is 1 to 10:1, preferably 2 to 7: 1.

6. The production method according to any one of claims 1 to 5, wherein the oxidative polymerization in step (1) is carried out at a temperature of 15 to 80 ℃, preferably 20 to 45 ℃;

preferably, the mixed solution of low molecular weight poly (arylene ether) is water washed in step (2) with an aqueous solution comprising a copper ion chelating agent; more preferably, the copper ion chelating agent is one or more selected from EDTA, EDTA-2Na, EDTA-3Na, EDTA-4Na, sodium citrate and trisodium nitrilotriacetate; more preferably, the ratio of the copper ion chelating agent to the amount of metal ion in the metal salt is 1.1-3: 1;

preferably, the inert atmosphere in the step (3) is a nitrogen atmosphere, a helium atmosphere or an argon atmosphere;

preferably, the low molecular weight poly (arylene ether) has an intrinsic viscosity of 0.07 to 0.15dl/g in chloroform solution at 25 deg.C, and the solid content of the low molecular weight poly (arylene ether) in the water-washed mixed solution of the low molecular weight poly (arylene ether) in step (3) is controlled to 60 to 80 wt%.

7. The method of any of claims 1-6, wherein the poly (arylene ether) poor solvent is a C1-C5 alcohol or a mixture thereof, preferably one or more of methanol, ethanol, n-propanol, n-butanol, and n-pentanol, more preferably methanol;

preferably, the weight ratio of the poor poly (arylene ether) solvent to the water-washed mixed solution of low molecular weight poly (arylene ether) is 5-8: 1;

preferably, the mixed solution of the low molecular weight poly (arylene ether) after washing in step (3) is added to the poor poly (arylene ether) solvent at a constant rate for 10 to 30min, for example 20 to 30 min;

preferably, the forming of the low molecular weight poly (arylene ether) slurry in step (3) is performed at a temperature of 0 to 65 deg.C, preferably 30 to 55 deg.C, more preferably 35 to 45 deg.C.

8. The method of any of claims 1-7, wherein the low molecular weight poly (arylene ether) has an intrinsic viscosity of 0.05 to 0.3dl/g, preferably 0.07 to 0.15dl/g, in 25 ℃ chloroform solution; the water-washed mixed solution of low molecular weight poly (arylene ether) in step (3) has a solid content of 60 to 80 weight percent, the weight ratio of the poor solvent for poly (arylene ether) to the water-washed mixed solution of low molecular weight poly (arylene ether) in step (3) is 3 to 10:1, preferably 5 to 8:1, and the forming of the low molecular weight poly (arylene ether) slurry in step (3) is performed at a temperature of 35 to 45 ℃.

9. The production method according to any one of claims 1 to 8, wherein the stirring in step (3) is shear stirring at a rotation speed of 50 to 1000rpm, preferably 400 to 800 rpm;

preferably, the formation of the low molecular weight poly (arylene ether) slurry in step (3) is performed as follows:

(301) adding a poly (arylene ether) poor solvent to the precipitation kettle, and introducing nitrogen to vent air;

(302) adding the washed low molecular weight poly (arylene ether) mixed solution into a precipitation kettle filled with a poly (arylene ether) poor solvent at a constant speed within 20-30 min under the condition of spiral shearing stirring at the rotating speed of 400-800 rpm, and continuously stirring for 5-10 min to form low molecular weight poly (arylene ether) slurry;

(303) filtering the low molecular weight poly (arylene ether) slurry to obtain a low molecular weight poly (arylene ether) wet mass;

preferably, the drying in the step (4) is carried out under the condition of negative pressure and at the temperature of 30-120 ℃.

10. A low molecular weight poly (arylene ether) prepared by the method of any of claims 1 to 9.

Technical Field

The present invention is in the field of poly (arylene ether) resin technology, and specifically relates to low molecular weight poly (arylene ether) and methods of making the same.

Background

Poly (arylene ether) s are one of five general purpose engineering plastics and have found wide application in electronic appliances, automobiles, household appliances, office equipment, and industrial machinery. In recent years, with the rapid development of communication technology, the 5 th generation (5G) communication technology has been popularized and used in the global scope, the 5G communication is a high-frequency communication technology, the requirements on the electrical property, especially the dielectric property, of materials are high, the requirements on the dielectric loss factor of the basic materials, especially the copper-clad plate, of communication equipment are high, and the smaller the dielectric loss factor in a certain range, the more favorable the signal transmission is. In the application field of copper-clad plates, the electrical performance of the traditional epoxy resin-based copper-clad plate can not meet the requirements of the current communication technology.

Poly (arylene ether) resins have excellent electrical properties, relatively low dielectric loss factor, and relatively small and stable dielectric constants due to their high molecular chain symmetry and low polarity. Thus, the poly (arylene ether) resin is advantageous for use in 5G communications. However, large molecular weight poly (arylene ether) (number average molecular weight over 10000g/mol) is difficult to be directly applied to the field of copper clad laminate and the like because of the defects of large melt viscosity, large solution viscosity and the like, and the molecular weight needs to be reduced to obtain low molecular weight poly (arylene ether). Techniques for the preparation of low molecular weight poly (arylene ether) s include mainly redistribution methods and direct monomer synthesis methods.

The redistribution method is as follows: the preparation method comprises the steps of taking large molecular weight poly (arylene ether) (the number average molecular weight is more than 10000g/mol) as a raw material, adding a bisphenol or polyphenol redistribution monomer, dissolving in a good solvent of the poly (arylene ether) to form a solution, adding a free radical initiator, and initiating reaction at a certain temperature to form the low molecular weight poly (arylene ether). For example, chinese patent CN101389691A discloses a method for producing a low molecular weight poly (arylene ether) by performing a redistribution reaction using a poly (arylene ether) having a number average molecular weight of 10000g/mol or more, a polyphenolic compound, and a radical initiator to produce a low molecular weight poly (arylene ether) having a number average molecular weight of 4000g/mol or less. Also, large molecular weight poly (arylene ether) resins are synthesized by monomer synthesis and then a redistribution reaction is performed in the synthesized solution by the addition of a redistributed phenolic monomer to form small molecular weight poly (arylene ether) resins. For another example, chinese patent CN1140565C discloses a method for producing low molecular weight polyphenylene ether resins by redistribution by first synthesizing a large molecular weight poly (arylene ether) by oxidative coupling to form a poly (arylene ether) solution and then adding a functionalized phenolic monomer to the solution without the need to add an additional redistribution catalyst to produce a low molecular weight poly (arylene ether). In addition, chinese patent CN1188450C discloses a method for preparing low molecular weight poly (arylene ether) by redistribution. However, when a redistribution method is used to prepare a low molecular weight poly (arylene ether), it is difficult to control the chain scission length of the molecular chain during the reaction, and an oil-soluble free radical catalyst is introduced, which is difficult to remove during subsequent processing, and the processing is complicated. Thus, the use of redistribution methods to prepare low molecular weight poly (arylene ether) s is not commercially available.

The direct synthesis method is a method of synthesis in a solvent for poly (arylene ether) using a monomeric phenol under catalysis by a copper amine complex catalyst. For example, chinese patent CN1142965C discloses a method of preparing a low molecular weight poly (arylene ether) resin having an intrinsic viscosity of 0.08dl/g to 0.16dl/g by oxidatively coupling at least one monovalent phenol in a reaction solution using an oxygen-containing gas and a complex metal catalyst to prepare a low molecular weight poly (arylene ether) resin solution, washing with water to remove the catalyst, and devolatilizing the reaction solution to remove the organic solvent to obtain the low molecular weight poly (arylene ether) resin. For example, chinese patent CN100352848C discloses a method for the manufacture of bifunctional phenylene ether oligomers, wherein oligomeric poly (arylene ether) prepared by oxidative polymerization methods with the addition of biphenol and monophenol 2, 6-dimethylphenol monomers. For another example, chinese patent CN101305030B discloses the preparation of poly (arylene ether) with multiple functionality having intrinsic viscosity of 0.04-0.3 dl/g, the prepared poly (arylene ether) is washed with water to remove catalyst impurities, and then the solvent is removed by complete separation methods such as degassing extrusion, spray drying, trans-membrane evaporation, etc. to prepare low molecular weight poly (arylene ether) products. In addition, WO2017105682a1, CN101479319B and CN1125107C also disclose similar methods for preparing low molecular weight poly (arylene ether). However, for the preparation of low molecular weight poly (arylene ether) by the disclosed direct synthesis method, the low molecular weight poly (arylene ether) is mostly prepared by a complete elimination method, which has the characteristics of short preparation process, easy production and the like, but the complete elimination method retains impurities (such as red quinone) in the polymerization process and has the defects of wide molecular weight distribution, poor high-temperature decomposition resistance and the like.

Disclosure of Invention

Accordingly, it is an object of the present invention to address the deficiencies of the prior art by providing low molecular weight poly (arylene ether) s and methods of making the same that produce low molecular weight poly (arylene ether) s having low quinone content, narrow molecular weight distribution, and high glass transition temperature.

The purpose of the invention is realized by the following technical scheme.

In one aspect, the present invention provides a method of preparing a low molecular weight poly (arylene ether), wherein the method of preparing comprises the steps of:

(1) oxidatively polymerizing a phenol monomer in a good poly (arylene ether) solvent in the presence of an oxidizing agent and a catalyst to obtain a mixed solution of a low molecular weight poly (arylene ether) having an intrinsic viscosity of 0.05 to 0.3dl/g in a chloroform solution at 25 ℃;

(2) washing the mixed solution of low molecular weight poly (arylene ether) to obtain a washed mixed solution of low molecular weight poly (arylene ether);

(3) adding the water-washed mixed solution of low molecular weight poly (arylene ether) to a poor poly (arylene ether) solvent under stirring and in an inert atmosphere to form a low molecular weight poly (arylene ether) slurry, and filtering to obtain a wet low molecular weight poly (arylene ether) material; wherein the solid content of the low molecular weight poly (arylene ether) in the water-washed mixed solution of low molecular weight poly (arylene ether) is controlled to 30 to 80 wt%, and the weight ratio of the poor solvent for poly (arylene ether) to the water-washed mixed solution of poly (arylene ether) is 3 or more;

(4) the low molecular weight poly (arylene ether) wet mass is dried to provide the low molecular weight poly (arylene ether).

When the low molecular weight poly (arylene ether) mixture prepared by the oxidative coupling method is treated by a complete disengagement method such as spray drying or devolatilization, the resulting low molecular weight poly (arylene ether) product has high content of quinone impurities, reddish color, broad molecular weight distribution, and poor high temperature decomposition resistance. The present inventors have discovered that a water-washed low molecular weight poly (arylene ether) mixed solution from which residual catalyst is removed can be effectively reduced in quinone content while having a narrow molecular weight distribution and a high glass transition temperature in low molecular weight poly (arylene ether) by controlling its concentration, the amount of poor solvent for the poly (arylene ether), and the particular precipitation conditions. Without wishing to be bound by theory, it is believed that the low molecular weight poly (arylene ether) produced by the method of the present invention has a reduced quinone content by removing at least a portion of the quinone by reduction to a phenol that is soluble in the good poly (arylene ether) solvent and/or the poor poly (arylene ether) solvent under the protection of an inert gas such as nitrogen during slurry formation.

According to the preparation method provided by the present invention, wherein a mixed solution of a low molecular weight poly (arylene ether) having an intrinsic viscosity of 0.05 to 0.3dl/g in a chloroform solution at 25 ℃ can be prepared using a raw material and an oxidative polymerization method (oxidative coupling method) known in the art.

According to the preparation method provided by the invention, in the step (1), the phenol monomer can be monohydric phenol, polyhydric phenol or a mixture thereof.

In the present invention, a monohydric phenol of the formula (I):

wherein M is₁、M₂、M₃And M₄Each independently is a hydrogen atom, an alkyl group (e.g., C1-6 alkyl), a halogen, a haloalkane, or an alkoxy group. Specifically, examples of the monohydric phenol include, but are not limited to: 2, 6-dimethylphenol and 2,3, 6-trimethylphenol.

In the invention, the polyphenol can be polyphenol with 2-7 phenolic hydroxyl groups, and is preferably dihydric phenol.

The dihydric phenols suitable for use in the present invention may be those represented by the formula (II):

wherein N is₁、N₂、N₃And N₄Each of which isIndependently hydrogen atom or C atom number such as methyl, ethyl, allyl saturated or unsaturated alkyl with 1-8; w is an alkyl group having 1 to 4 carbon atoms such as ethyl, isopropyl or methylene. In addition, those dihydric phenols in which the W group is deleted in the dihydric phenols represented by the formula (II) can also be used in the present invention. Specifically, examples of the dihydric phenol include, but are not limited to: tetramethyl bisphenol a, and tetramethyl biphenol.

In some preferred embodiments, the phenolic monomer is 2, 6-dimethylphenol or a mixture of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol. The invention has no special requirement on the proportion of the 2, 6-dimethylphenol to the 2,3, 6-trimethylphenol in the mixture of the 2, 6-dimethylphenol and the 2,3, 6-trimethylphenol. In some embodiments, the ratio of the amount of species of 2, 6-dimethylphenol to 2,3, 6-trimethylphenol may be 1:0.00001 to 0.1; in some embodiments from 1:0.0001 to 0.01; and in some embodiments 1:0.0005 to 0.003.

According to the preparation method provided by the present invention, low molecular weight poly (arylene ether) having different main chain structures can be obtained by selecting different kinds of phenol monomers and/or their ratios.

In some embodiments, the low molecular weight poly (arylene ether) has the structure shown in formula (IV):

wherein, K₁And K₂Each independently a C1-C8 hydrocarbyl group, preferably methyl; n is an integer of 5 to 100.

In other embodiments, the low molecular weight poly (arylene ether) has the structure shown in formula (V):

wherein n and m can be independently 0 or an integer more than 1, and the range of n + m is an integer of 5-100;X₁、X₂、X₃and X₄Each independently is a hydrogen atom, an alkyl group, a halogen, a haloalkane or an alkoxy group, X₁、X₂、X₃And X₄The same or different; y is₁And Y₂Each independently is a hydrogen atom, an alkyl group, a halogen, a haloalkane, a phenolic hydroxyl group or an alkoxy group, Y₁And Y₂The same or different.

In some preferred embodiments, X₁And X₂Each independently being hydrogen or methyl, X₃And X₄Each independently of the other being methyl, Y₁And Y₂Is methyl.

The preparation method provided by the invention is characterized in that the intrinsic viscosity of the low molecular weight poly (arylene ether) in a chloroform solution at 25 ℃ is 0.07-0.15 dl/g. In particular, the present inventors have discovered that by controlling the solids content and the poly (arylene ether) poor solvent ratio, the yield of low molecular weight poly (arylene ether) s having intrinsic viscosities in the range of 0.07 to 0.15dl/g can be increased to greater than 90% during the elution process.

According to the preparation method provided by the invention, the oxidant is oxygen. In general, oxygen can be produced by air purification, and generally contains components contained in air such as nitrogen. The oxygen gas may be oxygen gas produced by other methods such as electrolysis of water. In some embodiments, the concentration of oxygen is from 5% to 100% by volume; and in some embodiments, from 80% to 100% by volume.

According to the preparation method provided by the invention, the catalyst is a metal amine composite catalyst. The metal amine composite catalyst contains a complexing agent formed by complexing a metal salt and an amine compound. The metal ion of the metal salt includes chromium, manganese, cobalt, or copper ion, preferably copper ion. Examples of metal salts (copper salts) suitable for use in the present invention include, but are not limited to: cuprous chloride, cuprous bromide, cuprous sulfate tetraamine, cuprous acetate, cupric chloride, cupric bromide, cupric sulfate tetraamine, and cupric acetate. In some embodiments, the ratio of the amount of species of the metal salt to the phenolic monomer may be 0.005 to 2: 100.

Generally, the amine compound may be an amine compound, for example, a primary amine, a tertiary amine, a secondary amine, etc.; a diamine compound; or mixtures thereof. Examples of primary amines suitable for use in the present invention include, but are not limited to: n-propylamine, isopropylamine, n-butylamine, sec-butylamine, tert-butylamine, n-pentylamine, n-hexylamine, and cyclohexylamine. Examples of secondary amines suitable for use in the present invention include, but are not limited to: di-n-propylamine, di-n-butylamine, di-tert-butylamine, n-butyl-n-pentylamine, and di-n-hexylamine. Examples of tertiary amines suitable for use in the present invention include, but are not limited to: triethylamine, tri-n-propylamine, tri-n-butylamine, dimethyl-n-butylamine and dimethyl-n-pentylamine.

Diamine compounds suitable for use in the present invention have the structure shown in formula (III):

wherein R is₁、R₂、R₄And R₅Each independently is a hydrogen atom, a C1-6 straight chain alkyl group or a C3-6 branched chain alkyl group; r₃Is a saturated alkyl group having 2 or more carbon atoms. Specifically, examples of the diamine compound suitable for use in the present invention include, but are not limited to: n, N, N ', N ' -tetramethyl-1, 3-diaminopropane and N, N ' -di-tert-butylethylenediamine.

In some embodiments, the ratio of the amount of the amine compound to the amount of the metal salt is 1 to 100:1, preferably 10 to 60: 1.

In some embodiments, the catalyst is a copper amine catalyst comprising a complexing agent formed by complexing a copper metal salt and an amine compound.

In some embodiments, the cuprammonium catalyst comprises cuprous bromide, N-dimethylbutylamine, di-N-butylamine, and N, N' -tetramethyl-1, 3-diaminopropane in a ratio of materials of 1:20:10: 5.

The preparation method provided by the invention is characterized in that the good solvent of the poly (arylene ether) is an organic solvent capable of dissolving the poly (arylene ether), particularly a low molecular weight poly (arylene ether) with the number average molecular weight of less than 10000 g/mol. Examples of good poly (arylene ether) solvents suitable for use in the present invention include, but are not limited to: benzene, toluene, xylene, chloroform and tetrahydrofuran. In the present invention, the poly (arylene ether) good solvent may be one of the above-mentioned solvents, or may be a mixed solvent composed of these solvents. In a preferred embodiment, the good poly (arylene ether) solvent is toluene.

The preparation method provided by the invention is characterized in that the mass ratio of the good solvent of the poly (arylene ether) to the phenol monomer is 1-10: 1, preferably 2-7: 1.

According to the preparation method provided by the invention, the oxidative polymerization in the step (1) is carried out at the temperature of 15-80 ℃. In some embodiments, the oxidative polymerization in step (1) is carried out at a temperature of 25 to 45 ℃.

According to the preparation method provided by the present invention, in the step (2), the mixed solution of the low molecular weight poly (arylene ether) is water-washed with an aqueous solution containing a copper ion chelating agent.

Examples of copper ion chelating agents suitable for use in the present invention include, but are not limited to: EDTA, EDTA-2Na, EDTA-3Na, EDTA-4Na, sodium citrate and trisodium nitrilotriacetate.

In the present invention, the aqueous solution containing the copper ion-chelating agent is not particularly limited as long as it can effectively chelate the metal ion of the catalyst. In some embodiments, the ratio of the copper ion chelating agent to the amount of species of metal ions in the metal salt is 1.1-3: 1.

According to the preparation method provided by the invention, the water washing operation in the step (2) is as follows: adding an aqueous solution comprising a copper ion chelating agent to the mixed solution of low molecular weight poly (arylene ether), phase separating, and liquid-liquid separating.

In the present invention, liquid-liquid separation can be performed by centrifugal separation. Of course, any other oil-water separation method known in the art may be used for liquid-liquid separation.

According to the preparation method provided by the invention, the inert atmosphere in the step (3) is a nitrogen atmosphere, a helium atmosphere or an argon atmosphere.

The preparation method provided by the invention is characterized in that the solid content of the low molecular weight poly (arylene ether) in the mixed solution of the water-washed low molecular weight poly (arylene ether) in the step (3) is controlled to be 30-80 wt%. For low molecular weight poly (arylene ether) s having different intrinsic viscosities, the solids content ranges of the mixed solutions may vary. Generally, for low molecular weight poly (arylene ether) s having a lower intrinsic viscosity, the solids content of the mixed solution may be relatively high. For example, for a low molecular weight poly (arylene ether) having an intrinsic viscosity of 0.07 to 0.15dl/g in chloroform at 25 ℃, the combined solution of the water-washed low molecular weight poly (arylene ether) of step (3) may have a solids content of 60 to 80 weight percent.

The preparation method according to the present invention provides, wherein the solid content of the low molecular weight poly (arylene ether) in the water-washed mixed solution of the low molecular weight poly (arylene ether) may be increased by a method such as reduced pressure distillation, atmospheric distillation, flash evaporation, or wiped film evaporation in step (3). Of course, it is also possible to add a good poly (arylene ether) solvent to the water-washed mixed solution of low molecular weight poly (arylene ether) to reduce the concentration and thereby control the solid content within the target range.

The method of preparation provided herein, wherein the poly (arylene ether) poor solvent is a C1-C5 alcohol or a mixture thereof. Examples of poor solvents for poly (arylene ether) s suitable for use in the present invention include, but are not limited to: methanol, ethanol, n-propanol, n-butanol and n-pentanol. In some preferred embodiments, the poly (arylene ether) poor solvent is methanol.

According to the preparation method provided by the present invention, when the ratio of the poor solvent of the poly (arylene ether) is less than 3:1, the product yield after precipitation is low; on the contrary, high proportion results in high consumption and high post-treatment cost. In some embodiments, the weight ratio of the poly (arylene ether) poor solvent to the water-washed mixed solution of low molecular weight poly (arylene ether) is 3-10: 1; and in some embodiments from 5 to 8: 1.

The preparation method provided by the invention is characterized in that the mixed solution of the low molecular weight poly (arylene ether) after water washing is uniformly added into the poor solvent of the poly (arylene ether) in the step (3) within 10-30 min, preferably within 20-30 min. The addition speed is too high, large block-shaped polymer precipitates which are difficult to stir are easy to appear, and impurities may be contained in the precipitates, so that the quality of products is influenced; on the contrary, the adding speed is too slow, and the production efficiency is low.

The preparation method provided by the invention is characterized in that the operation of forming the low molecular weight poly (arylene ether) slurry in the step (3) is carried out at the temperature of 0-65 ℃, preferably 30-55 ℃, and more preferably 35-45 ℃.

In some embodiments, the low molecular weight poly (arylene ether) preferably has an intrinsic viscosity of 0.05 to 0.3dl/g, preferably 0.07 to 0.15dl/g, in chloroform solution at 25 ℃; the water-washed mixed solution of low molecular weight poly (arylene ether) in step (3) has a solid content of 60 to 80 weight percent, the weight ratio of the poor solvent for poly (arylene ether) to the water-washed mixed solution of low molecular weight poly (arylene ether) in step (3) is 3 to 10:1, preferably 5 to 8:1, and the forming of the low molecular weight poly (arylene ether) slurry in step (3) is performed at a temperature of 35 to 45 ℃.

According to the preparation method provided by the invention, the stirring in the step (3) is shearing stirring, and the rotating speed is 50-1000 rpm, preferably 400-800 rpm. In addition, the form of stirring may be helical, blade-type or paddle-type.

The preparation method provided in accordance with the present invention, wherein the forming of the low molecular weight poly (arylene ether) slurry in step (3) is performed as follows:

(301) adding a poly (arylene ether) poor solvent to the precipitation kettle, and introducing nitrogen to vent air;

(302) adding the washed low molecular weight poly (arylene ether) mixed solution into a precipitation kettle filled with a poly (arylene ether) poor solvent at a constant speed within 20-30 min under the condition of spiral shearing stirring at the rotating speed of 400-800 rpm, and continuously stirring for 5-10 min to form low molecular weight poly (arylene ether) slurry;

(303) the low molecular weight poly (arylene ether) slurry is filtered to provide a low molecular weight poly (arylene ether) wet mass.

According to the production method provided by the present invention, the filtration is performed in a solid-liquid two-phase filter. Examples of solid-liquid two-phase filters suitable for use in the present invention include, but are not limited to: a suction filtration barrel, a washing and filtering integrated machine, a centrifugal filter and a rotary drum filter.

According to the preparation method provided by the invention, the drying in the step (4) is carried out under the condition of negative pressure and at the temperature of 30-120 ℃. In some embodiments, the drying may be performed by gradually increasing the temperature, for example, in a first stage, the temperature is increased to 40-50 ℃ for 1-5 hours; in the second stage, heating to 70-80 ℃, and keeping for 1-3 h; and in the third stage, heating to 100-120 ℃ until the volatile component is reduced to below 0.5 wt%. More specifically, the temperature rise rate may be 5 to 20 ℃/h.

According to the production process provided by the present invention, wherein the drying in step (4) may be performed in an industrial dryer or a dryer such as a vacuum dryer, a rake dryer and a drum dryer.

In another aspect, the present invention also provides a low molecular weight poly (arylene ether) prepared by the above method.

The invention has the following advantages:

(1) the low molecular weight poly (arylene ether) prepared by the preparation method of the invention has low quinone content, narrow molecular weight distribution and high glass transition temperature;

(2) by controlling parameters such as the intrinsic viscosity of the low molecular weight poly (arylene ether), the solids content, the proportion of poor solvent for the poly (arylene ether), and the temperature at which the low molecular weight poly (arylene ether) slurry is formed, the yield of low molecular weight poly (arylene ether) can be increased while having a low quinone content, narrow molecular weight distribution, and high glass transition temperature.

(3) The preparation method of the invention has short process, is easy to produce and popularize and apply.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The specific techniques or conditions are not indicated in the examples, and are performed according to the techniques or conditions described in the literature in the field or according to the product specifications. The reagents or instruments used are conventional products available from regular distributors, not indicated by the manufacturer.

Intrinsic viscosity

A sample of poly (arylene ether) was dissolved in chloroform to form a solution having a concentration of 0.5g/dl, measured in dl/g using an Ubbelohde viscometer at 25 ℃.

Molecular weight distribution

The molecular weight distribution of the low molecular weight poly (arylene ether) was analyzed using a gel permeation chromatograph sold under the trade name "showex GPC system 21" by Showa Denko k.k. Wherein the eluting agent is chloroform, the flow rate is 1.0ml/min, and the column temperature is 40 deg.C.

Glass transition temperature

The glass transition temperature was measured using a pyril differential scanning calorimeter. Wherein the atmosphere is nitrogen atmosphere, and the heating rate is 20 ℃/min.

Poly (arylene ether) yield

The poly (arylene ether) yield is expressed as the weight percent of the final product obtained versus the phenol monomer used.

Quinone content

The poly (arylene ether) and the reference sample were prepared as 0.3g/100ml solutions, respectively, using chloroform as a solvent using the difference in electron absorption spectra of the poly (arylene ether) and the quinone, allowed to stand at 25 ℃ for 2 hours, and then absorbance at 421nm was measured in a visible ultraviolet spectrophotometer using the reference sample as a reference to calculate the content.

The main raw materials used in the following examples are as follows:

phenol monomer: 2, 6-dimethylphenol; tetramethyl bisphenol A;

good solvent for poly (arylene ether): toluene;

oxidizing agent: 99.99% oxygen;

copper ion chelating agent: EDTA-2 Na;

the copper ammonium composite catalyst comprises the following components: cuprous bromide, N, N-dimethylbutylamine, di-N-butylamine and N, N, N ', N' -tetramethyl-1, 3-diaminopropane in a mass ratio of 1:20:10: 5;

poly (arylene ether) poor solvent: methanol.

Example 1

(1) Preparing 10Kg of 2, 6-dimethylphenol monomer, 150Kg of toluene and 2Kg of cuprammonium composite catalyst into a solution, injecting the solution into a reaction kettle, starting stirring, introducing 99.99 percent of oxygen into the reaction kettle at the temperature of 20 +/-5 ℃, starting oxidative polymerization at the temperature of 40 +/-2 ℃, then adding 40Kg of 2, 6-dimethylphenol into the reaction kettle at constant speed within 60 minutes, continuing the reaction after the dropwise addition is finished, sampling and detecting on line until the intrinsic viscosity of a polymerization product reaches 0.12dl/g, and stopping the polymerization.

(2) Adding an aqueous solution of a copper ion chelating agent into the mixed solution of the low molecular weight poly (arylene ether), stirring and extracting for 15 minutes, standing for 20-30 minutes, and separating to remove the lower aqueous phase. Wherein the concentration of the aqueous solution of the copper ion chelating agent is 0.1mol/L, and the dosage is 35L.

(3) The washed low molecular weight poly (arylene ether) mixed solution was transferred to a debenzolization kettle, heated under negative pressure to debenzolize, and concentrated at 80 ℃ to 65 wt% solids.

(4) 450Kg of methanol is injected into a precipitation kettle, the temperature is raised to 45 ℃, nitrogen is introduced to exhaust air, the concentrated low molecular weight poly (arylene ether) mixed solution is added at a constant speed within 30 minutes by a pump under the shearing and stirring of a blade with the rotating speed of 500rpm, and then the stirring is continued for 10 minutes to form low molecular weight poly (arylene ether) slurry.

(5) The low molecular weight poly (arylene ether) slurry was suction filtered using a suction filtration drum to obtain a low molecular weight poly (arylene ether) wet mass.

(6) Transferring the low molecular weight poly (arylene ether) wet material into a drum dryer, drying in a manner of gradually increasing the temperature under the condition of negative pressure, and in the first stage, increasing the temperature to 45 ℃ and keeping the temperature for 1 h; in the second stage, the temperature is increased to 80 ℃ and kept for 2 hours; and in the third stage, the temperature is increased to 110 ℃ until the volatile content is reduced to be below 0.5 wt%, wherein the temperature increasing speed is 20 ℃/h. An off-white low molecular weight poly (arylene ether) product is obtained.

Comparative example 1

A concentrated poly (arylene ether) solution having a solids content of 65 weight percent was prepared according to the methods described in steps (1) - (3) of example 1, and was placed in a vacuum wiped film evaporator to remove toluene and cooled to provide a reddish brown low molecular weight poly (arylene ether) product.

Example 2

(1) Taking 10Kg of a mixture with a molar ratio of 1: 0.8 of mixed monomer of 2, 6-dimethylphenol monomer and tetramethyl bisphenol A, 150Kg of toluene and 2Kg of cuprammonium composite catalyst are prepared into solution, the solution is injected into a reaction kettle, stirring is started, 99.99 percent of oxygen is introduced into the reaction kettle within the temperature range of 20 +/-5 ℃, the oxidative polymerization reaction is started at the temperature of 40 +/-2 ℃, then 40Kg of 2, 6-dimethylphenol is added into the reaction kettle at constant speed within 60 minutes, the reaction is continued after the dropwise addition is finished, online sampling and detection are carried out until the intrinsic viscosity of a polymerization product reaches 0.09dl/g, and the polymerization is stopped.

(2) Adding an aqueous solution of a copper ion chelating agent into the mixed solution of the low molecular weight poly (arylene ether), stirring and extracting for 15 minutes, standing for 20-30 minutes, and separating to remove the lower aqueous phase. Wherein the concentration of the aqueous solution of the copper ion chelating agent is 0.1mol/L, and the dosage is 35L.

(3) The washed low molecular weight poly (arylene ether) mixed solution was transferred to a debenzolization kettle, heated under negative pressure to debenzolize, and concentrated at 80 ℃ to 70 wt% solids.

(4) 450Kg of methanol is injected into a precipitation kettle, the temperature is raised to 45 ℃, nitrogen is introduced to exhaust air, the concentrated low molecular weight poly (arylene ether) mixed solution is added at a constant speed within 30 minutes by a pump under the shearing and stirring of a blade with the rotating speed of 500rpm, and then the stirring is continued for 5 minutes to form low molecular weight poly (arylene ether) slurry.

(5) The low molecular weight poly (arylene ether) slurry was suction filtered using a suction filtration drum to obtain a low molecular weight poly (arylene ether) wet mass.

(6) Transferring the low molecular weight poly (arylene ether) wet material into a drum dryer, drying in a manner of gradually increasing the temperature under the condition of negative pressure, and in the first stage, increasing the temperature to 45 ℃ and keeping the temperature for 1 h; in the second stage, the temperature is increased to 80 ℃ and kept for 2 hours; and in the third stage, the temperature is increased to 110 ℃ until the volatile content is reduced to be below 0.5 wt%, wherein the temperature increasing speed is 10 ℃/h. An off-white low molecular weight poly (arylene ether) product is obtained.

Comparative example 2

A concentrated poly (arylene ether) solution having a 70 wt% solids content was prepared according to the procedure described in example 2 for preparation (1) - (3), and was placed in a vacuum wiped film evaporator to remove toluene and cooled to provide a reddish brown low molecular weight poly (arylene ether) product.

Example 3

(1) Preparing 10Kg of 2, 6-dimethylphenol monomer, 150Kg of toluene and 3Kg of cuprammonium composite catalyst into a solution, injecting the solution into a reaction kettle, starting stirring, introducing 99.99 percent of oxygen into the reaction kettle at the temperature of 20 +/-5 ℃, carrying out oxidative polymerization at the temperature of 40 +/-2 ℃, then adding 40Kg of 2, 6-dimethylphenol into the reaction kettle at a constant speed within 60 minutes, continuing the reaction after the dropwise addition is finished, carrying out online sampling detection until the intrinsic viscosity of a polymerization product reaches 0.28dl/g, and stopping the polymerization.

(2) Adding an aqueous solution of a copper ion chelating agent into the mixed solution of the low molecular weight poly (arylene ether), stirring and extracting for 15 minutes, standing for 20-30 minutes, and separating to remove the lower aqueous phase. Wherein the concentration of the aqueous solution of the copper ion chelating agent is 0.1mol/L, and the dosage is 52.5L.

(3) The washed low molecular weight poly (arylene ether) mixed solution was transferred to a debenzolization kettle, heated under negative pressure to debenzolize, and concentrated at 80 ℃ to a solids content of 40 wt%.

(4) 450Kg of methanol is injected into a precipitation kettle, the temperature is raised to 45 ℃, nitrogen is introduced to exhaust air, the concentrated low molecular weight poly (arylene ether) mixed solution is added at a constant speed within 30 minutes by a pump under the shearing and stirring of a blade with the rotating speed of 500rpm, and then the stirring is continued for 3 minutes to form low molecular weight poly (arylene ether) slurry.

(5) The low molecular weight poly (arylene ether) slurry was suction filtered using a suction filtration drum to obtain a low molecular weight poly (arylene ether) wet mass.

(6) Transferring the low molecular weight poly (arylene ether) wet material into a drum dryer, drying in a manner of gradually increasing the temperature under the condition of negative pressure, and in the first stage, increasing the temperature to 45 ℃ and keeping the temperature for 1 h; in the second stage, the temperature is increased to 80 ℃ and kept for 2 hours; and in the third stage, the temperature is increased to 110 ℃ until the volatile content is reduced to be below 0.5 wt%, wherein the temperature increasing speed is 10 ℃/h. The result was a light yellow low molecular weight poly (arylene ether) product.

Comparative example 3

A concentrated poly (arylene ether) solution having a solids content of 65 weight percent was prepared according to the methods described in steps (1) - (3) of example 3, and was placed in a vacuum wiped film evaporator to remove toluene and cooled to provide a reddish brown low molecular weight poly (arylene ether) product.

Example 4

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: the water-washed mixed solution of low molecular weight poly (arylene ether) was concentrated in step (3) to a poly (arylene ether) solids content of 60 weight percent.

And finally, an off-white low molecular weight poly (arylene ether) product is obtained.

Example 5

A low molecular weight poly (arylene ether) was prepared essentially as in example 2, except that: concentrating the water-washed mixed solution of low molecular weight poly (arylene ether) in step (3) to a poly (arylene ether) solids content of 80 weight percent; the amount of the methanol added in the step (4) is 400 Kg.

And finally, an off-white low molecular weight poly (arylene ether) product is obtained.

Example 6

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: step (4) is carried out at a temperature of 35 ℃.

And finally, an off-white low molecular weight poly (arylene ether) product is obtained.

Example 7

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: step (4) is carried out at a temperature of 25 ℃.

The final product was a tan colored low molecular weight poly (arylene ether) product.

Example 8

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: the water-washed mixed solution of low molecular weight poly (arylene ether) was concentrated in step (3) to a poly (arylene ether) solids content of 35 weight percent.

And finally, an off-white low molecular weight poly (arylene ether) product is obtained.

Example 9

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: step (4) employs ethanol as the poor solvent for the low molecular weight poly (arylene ether).

The final product was a tan colored low molecular weight poly (arylene ether) product.

Comparative example 4

A low molecular weight poly (arylene ether) was prepared essentially as in example 1, except that: the concentrated mixed solution of low molecular weight poly (arylene ether) was added in step (4) under an air atmosphere and then stirred for 3 min.

The final product was a tan colored low molecular weight poly (arylene ether) product.

Comparative example 5

A low molecular weight poly (arylene ether) was prepared essentially as in example 2, except that: adding 200Kg of methanol in the step (4), and then continuing stirring for 5 min.

And finally, an off-white low molecular weight poly (arylene ether) product is obtained.

The properties of the low molecular weight poly (arylene ether) prepared in examples 1-7 and comparative examples 1-5 are shown in Table 1.

TABLE 1 Low molecular weight Poly (arylene ether) Properties

As can be seen from Table 1, the low molecular weight poly (arylene ether) products prepared according to the present invention have relatively lower quinone content, relatively narrower molecular weight distribution, relatively higher glass transition temperature, and higher yield. In particular, as can be seen from a comparison of example 1 with comparative example 1, adding a water-washed mixed solution of a low molecular weight poly (arylene ether) to a poor poly (arylene ether) solvent with agitation and under an inert atmosphere to form a low molecular weight poly (arylene ether) slurry and removing the toluene, has a reduced quinone content as compared to removing the toluene in a vacuum wiped film evaporator; as can be seen from example 1 and comparative example 4, the low molecular weight poly (arylene ether) prepared by the method of the present invention has a reduced quinone content under the protection of nitrogen as an inert gas during slurry formation. As can be seen from the comparison among examples 1, 6 and 7, the temperature of the system has a great influence on the quinone content during the slurry forming process, and the quinone content is more favorably reduced at 35-45 ℃.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.