阅读说明：本技术 一种大粒径水性聚氨酯分散体及其制备方法 (Large-particle-size aqueous polyurethane dispersion and preparation method thereof ) 是由 李有刚 杜泽川 谭鸿 柏兴华 冉忠祥 于 2021-01-20 设计创作，主要内容包括：本发明涉及一种大粒径水性聚氨酯分散体,其原料按质量份数计,包括大分子二元醇50～100份,羧酸型亲水性扩链剂0.5～1.5份,二异氰酸酯30～45份,小分子醇扩链剂2～4份,小分子胺扩链剂0.3～1.5份,催化剂0.05～0.1份,中和剂0.5～1.5份,丙酮25～100份,疏水性溶剂50～125份,乳化剂0.5～1.5份,去离子水150～200份。本发明制备方法可制得粒径较大的水性聚氨酯分散体,且分散性、机械稳定性、稀释稳定性好,不产生沉淀或分层。具有与普通水性聚氨酯分散体相当的稳定性,可拓展了水性聚氨酯分散体的应用领域。(The invention relates to a large-particle-size aqueous polyurethane dispersion which comprises, by mass, 50-100 parts of macromolecular diol, 0.5-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-45 parts of diisocyanate, 2-4 parts of small molecular alcohol chain extender, 0.3-1.5 parts of small molecular amine chain extender, 0.05-0.1 part of catalyst, 0.5-1.5 parts of neutralizing agent, 25-100 parts of acetone, 50-125 parts of hydrophobic solvent, 0.5-1.5 parts of emulsifier and 150-200 parts of deionized water. The preparation method can prepare the aqueous polyurethane dispersion with larger particle size, has good dispersibility, mechanical stability and dilution stability, and does not generate precipitation or delamination. Has the stability equivalent to that of the common aqueous polyurethane dispersion, and can expand the application field of the aqueous polyurethane dispersion.)

1. The large-particle-size aqueous polyurethane dispersion is characterized by comprising the following raw materials in parts by mass:

50-100 parts of macromolecular diol, 0.5-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-45 parts of diisocyanate, 2-4 parts of small molecular alcohol chain extender, 0.3-1.5 parts of small molecular amine chain extender, 0.05-0.1 part of catalyst, 0.5-1.5 parts of neutralizer, 25-100 parts of acetone, 50-125 parts of hydrophobic solvent, 0.5-1.5 parts of emulsifier and 150-200 parts of deionized water.

2. The large-particle-size aqueous polyurethane dispersion according to claim 1, wherein the large-particle-size aqueous polyurethane dispersion comprises the following raw materials in parts by mass:

60-90 parts of macromolecular diol, 1-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-35 parts of diisocyanate, 2.5-3.0 parts of micromolecular alcohol chain extender, 0.3-0.5 part of micromolecular amine chain extender, 0.1 part of catalyst, 0.8-1.2 parts of neutralizer, 30-75 parts of acetone, 75-120 parts of hydrophobic solvent, 1-1.5 parts of emulsifier and 150-200 parts of deionized water.

3. The large-particle-size aqueous polyurethane dispersion according to claim 1 or 2, wherein the macrodiol is one or more of polybutylene adipate diol, phthalic anhydride polyester diol, polycarbonate diol, and polyethylene glycol bifunctional methyl ether.

4. The large-particle-size aqueous polyurethane dispersion according to claim 1 or 2, wherein the carboxylic acid-type hydrophilic chain extender is one or a mixture of two of DMPA and DMBA.

5. The large-particle-size aqueous polyurethane dispersion according to claim 1 or 2, wherein the diisocyanate is one or more selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, and 4, 4-dicyclohexylmethane diisocyanate.

6. The large particle size aqueous polyurethane dispersion according to claim 1 or 2, wherein the small molecule alcohol chain extender is a mixture of one or more of 1, 4-butanediol, Ethylene Glycol (EG), neopentyl glycol (NPG), 1, 4-dimethylolcyclohexane; the catalyst is one or a mixture of two of dibutyltin dilaurate and stannous octoate;

7. the large-particle-size aqueous polyurethane dispersion according to claim 1 or 2, wherein the hydrophobic solvent is one or a mixture of two of dimethyl carbonate and diethyl carbonate; the neutralizer is one or a mixture of triethylamine, ammonia water and dimethylethanolamine; the micromolecular amine chain extender is one or a mixture of more of ethylenediamine, hexamethylenediamine, diethylenetriamine and triethylene tetramine; the emulsifier is one or more of sodium dodecyl sulfate, polyoxyethylene fatty acid ester and polysorbate.

8. The preparation method of the large-particle-size aqueous polyurethane dispersion according to any one of claims 1 to 7, which comprises the following specific steps:

(1) dehydrating macromolecular diol in vacuum at 100-120 ℃ for 1-2 h, adding a carboxylic acid type hydrophilic chain extender, uniformly mixing, adding diisocyanate at 80-90 ℃ for reacting for 2-3 h, adding a small molecular alcohol chain extender, a catalyst and acetone, and continuously reacting for 1-2 h to obtain a polyurethane prepolymer;

(2) adding acetone and a hydrophobic solvent into the polyurethane prepolymer, cooling and reducing the viscosity, and adding a neutralizer to react for 15-30 min after the temperature is reduced to 40-50 ℃ to obtain a polyurethane prepolymer solution;

(3) uniformly mixing the small molecular amine chain extender, the emulsifier and deionized water to form an aqueous solution, transferring the polyurethane prepolymer solution prepared in the step (2) to an emulsifier, adding the deionized water solution mixed with the small molecular amine chain extender and the emulsifier under the action of high-speed shearing, and emulsifying for 30-60 min to obtain a solvent-containing aqueous polyurethane dispersion;

(4) and (4) carrying out reduced pressure distillation on the aqueous polyurethane dispersion prepared in the step (3) to remove the solvent, and filtering with a 80-120-mesh filter screen to obtain the large-particle-size aqueous polyurethane dispersion.

9. The method for preparing the large-particle-size aqueous polyurethane dispersion according to claim 8, wherein the amount of acetone used in step (1) is 10 to 15 percent of the total amount of the macrodiol, the chain extender and the diisocyanate.

10. The method for preparing a large-particle-size aqueous polyurethane dispersion according to claim 8, wherein the mass of the mixed solvent of acetone and the hydrophobic solvent in the step (2) is 75 to 100% of the mass of the polyurethane prepolymer.

Technical Field

The invention belongs to the technical field of aqueous polyurethane dispersions, and particularly relates to a large-particle-size aqueous polyurethane dispersion and a preparation method thereof.

Background

The aqueous polyurethane dispersion is a polyurethane resin taking water as a dispersion medium, and is widely applied to various fields due to the unique performance of polyurethane and the characteristics of environmental protection and no toxicity. The aqueous polyurethane dispersion is generally prepared by an acetone method, the particle size of the aqueous polyurethane dispersion is small and is generally less than 200nm, and the aqueous polyurethane dispersion with large particle size prepared by the method has poor stability and cannot meet the field of application of the aqueous polyurethane dispersion with large particle size, such as a glass fiber film forming agent. Therefore, the preparation of the large-particle-size aqueous polyurethane dispersion with good stability can expand the application field of the aqueous polyurethane dispersion. And the particle size of the aqueous polyurethane dispersion affects the storage stability of the aqueous polyurethane emulsion. When the dispersion particle size of the aqueous polyurethane dispersion particles is too large, the stability of the dispersion is generally poor, and particle sedimentation is easy to occur; when the dispersion particle diameter of the aqueous polyurethane dispersion particle is too small, the emulsion viscosity is large, the electric double layer of the particle is thick, the charge effect is strong, and the aqueous polyurethane dispersion is easy to generate the creaming effect.

At present, methods for improving the particle size of the aqueous polyurethane dispersion generally adopt the modes of adjusting the proportion, the type, the emulsification process and the like of hydrophilic groups, but the aqueous polyurethane dispersion prepared by the methods can be kept stable under the condition of smaller particle size, and the effect is effective. Therefore, the development of the aqueous polyurethane dispersion with large particle size and good stability can greatly widen the application field of the aqueous polyurethane dispersion.

Disclosure of Invention

In view of the above, the present invention is directed to a large-particle-size aqueous polyurethane dispersion, and is directed to a specific method for preparing a large-particle-size aqueous polyurethane dispersion.

In order to achieve the purpose, the invention provides the following technical scheme:

1. the large-particle-size aqueous polyurethane dispersion comprises the following raw materials in parts by mass:

50-100 parts of macromolecular diol, 0.5-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-45 parts of diisocyanate, 2-4 parts of small molecular alcohol chain extender, 0.3-1.5 parts of small molecular amine chain extender, 0.05-0.1 part of catalyst, 0.5-1.5 parts of neutralizer, 25-100 parts of acetone, 50-125 parts of hydrophobic solvent, 0.5-1.5 parts of emulsifier and 150-200 parts of deionized water.

Further, the large-particle-size aqueous polyurethane dispersion comprises the following raw materials in parts by mass:

60-90 parts of macromolecular diol, 1-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-35 parts of diisocyanate, 2.5-3.0 parts of micromolecular alcohol chain extender, 0.3-0.5 part of micromolecular amine chain extender, 0.1 part of catalyst, 0.8-1.2 parts of neutralizer, 30-75 parts of acetone, 75-120 parts of hydrophobic solvent, 1-1.5 parts of emulsifier and 150-200 parts of deionized water.

Further, the mass ratio of the total mass of the acetone to the hydrophobic solvent is 1: 1-4.

Furthermore, the macrodiol is one or a mixture of more of polybutylene adipate diol, phthalic anhydride polyester diol, polycarbonate diol and polyethylene glycol bifunctional methyl ether.

Further, the carboxylic acid type hydrophilic chain extender is one or a mixture of two of DMPA and DMBA.

Further, the diisocyanate is one or a mixture of hexamethylene diisocyanate, isophorone diisocyanate and 4, 4-dicyclohexylmethane diisocyanate.

Further, the chain extender of the small molecular alcohol is one or a mixture of more of 1, 4-butanediol, Ethylene Glycol (EG), neopentyl glycol (NPG) and 1, 4-dimethylolcyclohexane; the catalyst is one or a mixture of two of dibutyltin dilaurate and stannous octoate;

further, the hydrophobic solvent is one or a mixture of dimethyl carbonate and diethyl carbonate; the neutralizer is one or a mixture of triethylamine, ammonia water and dimethylethanolamine; the micromolecular amine chain extender is one or a mixture of more of ethylenediamine, hexamethylenediamine, diethylenetriamine and triethylene tetramine; the emulsifier is one or more of sodium dodecyl sulfate, polyoxyethylene fatty acid ester and polysorbate.

2. The preparation method of the large-particle-size aqueous polyurethane dispersion comprises the following specific steps of:

(1) dehydrating macromolecular diol in vacuum at 100-120 ℃ for 1-2 h, adding a carboxylic acid type hydrophilic chain extender, uniformly mixing, adding diisocyanate at 80-90 ℃ for reacting for 2-3 h, adding a small molecular alcohol chain extender, a catalyst and acetone, and continuously reacting for 1-2 h to obtain a polyurethane prepolymer;

(2) adding acetone and a hydrophobic solvent into the polyurethane prepolymer, cooling and reducing the viscosity, and adding a neutralizer to react for 15-30 min after the temperature is reduced to 40-50 ℃ to obtain a polyurethane prepolymer solution;

(3) uniformly mixing the small molecular amine chain extender, the emulsifier and deionized water to form an aqueous solution, transferring the polyurethane prepolymer solution prepared in the step (2) to an emulsifier, adding the deionized water solution mixed with the small molecular amine chain extender and the emulsifier under the action of high-speed shearing, and emulsifying for 30-60 min to obtain a solvent-containing aqueous polyurethane dispersion;

(4) and (4) carrying out reduced pressure distillation on the aqueous polyurethane dispersion prepared in the step (3) to remove the solvent, and filtering with a 80-120-mesh filter screen to obtain the large-particle-size aqueous polyurethane dispersion.

Further, the dosage of acetone in the step (1) is 10-15% of the total amount of the macromolecular diol, the chain extender and the diisocyanate.

Further, the mass of the mixed solvent of acetone and hydrophobic solvent in the step (2) is 100-120% of the mass of the polyurethane prepolymer.

The invention has the beneficial effects that: the invention is based on the preparation of the aqueous polyurethane dispersoid by an acetone method, creatively introduces a certain proportion of hydrophobic solvent by utilizing the principles of hydrophilic shell formation and hydrophobic nucleation in micelle self-assembly, and prepares the aqueous polyurethane dispersoid with larger particle size by properly proportioning the hydrophobic solvent, macromolecular diol, chain extender, diisocyanate and other components, and has good dispersibility, mechanical stability and dilution stability without generating precipitation or delamination. The particle size of the large-particle-size aqueous polyurethane dispersion prepared by the invention can reach 400 nm-500 nm, and the large-particle-size aqueous polyurethane dispersion has a larger particle size than that of a common aqueous polyurethane dispersion; and the stability is good, the stability is equivalent to that of the common aqueous polyurethane dispersion, and the application field of the aqueous polyurethane dispersion can be expanded.

Drawings

In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:

FIG. 1 is a large particle size aqueous polyurethane dispersion prepared in accordance with the present invention.

FIG. 2 is a photograph of a 3% dilute solution of the sample of example 1 after standing for 3 days.

FIG. 3 is a large particle size aqueous polyurethane dispersion prepared by a comparative example.

FIG. 4 is a photograph showing that the precipitate was separated clearly after the 3% diluted solution of the sample of comparative example 1 was allowed to stand for 3 days.

FIG. 5 is an electron micrograph of the large-particle-size aqueous polyurethane dispersion prepared in this example.

FIG. 6 is an electron micrograph of the large-particle-size aqueous polyurethane dispersion prepared in example 2.

FIG. 7 is an electron micrograph of a large-particle-size aqueous polyurethane dispersion prepared in comparative example 1.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The experimental procedures, in which specific conditions are not specified in the examples, are generally carried out under conventional conditions or under conditions recommended by the manufacturers.

The large-particle-size aqueous polyurethane dispersion comprises the following raw materials in parts by mass:

50-100 parts of macromolecular diol, 0.5-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-45 parts of diisocyanate, 2-4 parts of small molecular alcohol chain extender, 0.3-1.5 parts of small molecular amine chain extender, 0.05-0.1 part of catalyst, 0.5-1.5 parts of neutralizer, 25-100 parts of acetone, 50-125 parts of hydrophobic solvent, 0.5-1.5 parts of emulsifier and 150-200 parts of deionized water.

Preferably, the large-particle size aqueous polyurethane dispersion comprises the following raw materials in parts by mass:

60-90 parts of macromolecular diol, 1-1.5 parts of carboxylic acid type hydrophilic chain extender, 30-35 parts of diisocyanate, 2.5-3.0 parts of micromolecular alcohol chain extender, 0.3-0.5 part of micromolecular amine chain extender, 0.1 part of catalyst, 0.8-1.2 parts of neutralizer, 30-75 parts of acetone, 75-120 parts of hydrophobic solvent, 1-1.5 parts of emulsifier and 150-200 parts of deionized water.

The macrodiol is one or more of polybutylene adipate diol (PBA 2000 can be selected), phthalic anhydride polyester diol (STEPANPOLPN-110 can be selected), polycarbonate diol (AS-302 can be selected from Asahi chemical synthesis), and polyethylene glycol bifunctional methyl ether, and has a molecular weight of 900-3500, preferably 1000-2000; wherein, the phthalic anhydride polyester diol refers to 2-functional phthalic anhydride polyester polyol; the polyethylene glycol bifunctional methyl ether is Ymer N120 and polyhydric alcohols with the structures.

The carboxylic acid type hydrophilic chain extender is one or a mixture of two of DMPA (2, 2-dimethylolpropionic acid) and DMBA (2, 2-dimethylolbutyric acid), and is preferably DMPA.

The diisocyanate is one or more of hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI and 4, 4-dicyclohexylmethane diisocyanate HMDI;

the chain extender of the small molecular alcohol is one or a mixture of more of 1, 4-butanediol, Ethylene Glycol (EG), neopentyl glycol (NPG) and 1, 4-dimethylolcyclohexane;

the catalyst is one or a mixture of two of dibutyltin dilaurate and stannous octoate;

the hydrophobic solvent is one or a mixture of dimethyl carbonate and diethyl carbonate;

the neutralizer is one or a mixture of triethylamine, ammonia water and dimethylethanolamine;

the micromolecular amine chain extender is one or a mixture of more of ethylenediamine, hexamethylenediamine, diethylenetriamine and triethylene tetramine;

the emulsifier is one or more of sodium dodecyl sulfate, polyoxyethylene fatty acid ester and polysorbate; the polysorbate emulsifier is nonionic emulsifier, and can be selected from Tween 20, Tween 40, Tween 60 or Tween 80.

The invention obtains the polyurethane dispersoid with larger grain diameter than the conventional aqueous polyurethane dispersoid by the combined action of the hydrophilic chain extender and the external emulsifier, and regulates the regularity of the appearance of the large-grain-diameter aqueous polyurethane dispersoid particles by 2 solvents of acetone and hydrophobic solvents with different polarities so as to change the defective appearance into regular spherical appearance and further improve the stability of the large grain diameter.

A preparation method of a large-particle-size aqueous polyurethane dispersion comprises the following specific steps:

(1) dehydrating macromolecular diol at 120 ℃ in vacuum for 1-2 h, adding a carboxylic acid type hydrophilic chain extender, uniformly mixing, adding diisocyanate at 80-90 ℃ for reacting for 2-3 h, adding a small molecular alcohol chain extender and a catalyst for several drops, controlling the reaction viscosity by using a small amount of solvent acetone, and continuously reacting for 1-2 h to obtain a polyurethane prepolymer; the dosage of the acetone is about 10 to 15 percent of the total amount of the macromolecular dihydric alcohol, the chain extender and the diisocyanate, and can be adjusted according to the size of the viscosity.

(2) Adding a certain amount of acetone and a hydrophobic solvent into the polyurethane prepolymer, cooling and reducing the viscosity, and adding a neutralizer to react for 15-30 min after the temperature is reduced to 40-50 ℃ to obtain a polyurethane prepolymer solution; wherein the mass of the mixed solvent of the acetone and the hydrophobic solvent is 100 to 120 percent of the mass of the polyurethane prepolymer.

(3) Uniformly mixing the micromolecule amine chain extender, the emulsifier and deionized water to form an aqueous solution, transferring the polyurethane prepolymer solution prepared in the step (2) into an emulsifier, adding the deionized water solution mixed with the micromolecule amine chain extender and the emulsifier at a constant speed under the action of high-speed shearing, and emulsifying for 30-60 min to obtain the aqueous polyurethane dispersion containing the solvent, wherein the high-speed is 2000-3000 rpm, preferably 2000 rpm.

(4) And (4) carrying out reduced pressure distillation on the aqueous polyurethane dispersion prepared in the step (3) to remove the solvent, and filtering by using a 120-mesh filter screen to obtain the large-particle-size aqueous polyurethane dispersion.

FIG. 1 shows that the aqueous polyurethane dispersion with large particle size prepared by the invention has good emulsification effect, the particle size can reach 408nm, and FIG. 2 shows that the 3% diluted solution of the sample in example 1 is still standing for 3 days, and no layering and no precipitation exist. FIG. 5 is an electron microscope image of the large-particle-size aqueous polyurethane dispersion prepared in this example, which shows that the particle size is spherical and quite regular. The large-particle-size aqueous polyurethane dispersion prepared by the invention can be further used as a glass fiber film forming agent (one of glass fiber impregnating compound components), and the particle size is one of key indexes. The surface of the glass fiber is provided with hundreds of nanometers of grooves, when the small-particle-size aqueous polyurethane dispersion is used as a film forming agent and applied to the glass fiber impregnating compound, the problems of less glue retention, low effective utilization rate, high use cost, easy migration during drying and the like exist in the glass fiber drawing process, and when the particle size of the aqueous polyurethane dispersion is larger, the problems can be well overcome.

Examples 1 to 5

The addition amount of each component in examples 1 to 5 and comparative examples 1 to 3 is added in the following mass parts:

through a large number of component tests, the invention finds that the addition of the hydrophobic solvent has a remarkable influence on the appearance, the particle size and the stability of the dispersion. Furthermore, the content of the hydrophobic solvent in the whole formula is mutually and importantly influenced, the dosage of the hydrophobic solvent is properly reduced, and the stability of the large-particle-size aqueous polyurethane dispersion is better kept and no particle precipitation or delamination occurs when the mass ratio of the total mass of the acetone to the hydrophobic solvent is 1: 1-4. Furthermore, the particle size of each component can reach 400-600 nm under a proper proportion, and the mechanical stability and the dilution stability are excellent.

Example 2

The physical properties of examples 1 to 5 and comparative examples 1 to 3 were compared, and the results were as follows:

example 1

Example 2

Example 3

Example 4

Example 5

Comparative example 1

Comparative example 2

Comparative example 3

Solids content/%

40.0

39.7

40.1

40.7

41.2

39.8

40.5

40.5

Particle size/nm

408

488

466

575

453

394

563

322

Appearance of the product

Milky white color

Milky white color

Milky white color

Milky white color

Milky white color

Milky white color

Milky white color

Milky white color

Mechanical stability

No precipitation

No precipitation

No precipitation

No precipitation

No precipitation

More precipitate

Precipitation of

Partial precipitation

Stability in dilution

Not delaminating

Not delaminating

Not delaminating

Not delaminating

Not delaminating

Layering

Layering

Layering

FIG. 3 is a photograph showing that the aqueous polyurethane dispersion having a large particle size prepared in comparative example 1 starts to precipitate and separate after being left for 1 hour, and FIG. 4 is a photograph showing that the 3% dilute solution of the sample of comparative example 1 is left to stand for 3 days, and the precipitation and separation are remarkable. FIG. 6 is an electron micrograph of the large-particle-size aqueous polyurethane dispersion prepared in example 2, which shows that substantially all the particle sizes are spherical and quite regular. FIG. 7 is an electron microscope image of the large-particle-size aqueous polyurethane dispersion prepared in comparative example 1, and it is obvious that the particle size is irregular and the agglomeration and the dispersion are not uniform.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.