阅读说明：本技术 基于蓖麻油的水性聚氨酯乳液及胶粘剂的制备方法 (Preparation method of aqueous polyurethane emulsion and adhesive based on castor oil ) 是由 张博 毛祖秋 姚卫琴 宋利青 石红翠 麻爱仙 贾金兰 吴建兵 郭晓勇 周艳明 吉 于 2021-07-01 设计创作，主要内容包括：本发明涉及一种基于蓖麻油的水性聚氨酯乳液及其胶粘剂的制备方法,该方法以蓖麻油作为主要原料,通过蓖麻油与含芳香环或脂肪环的四甲酸二酐的单酯化反应,合成蓖麻油基聚酯酸,并通过马来酸酐或邻苯二甲酸酐调节其羟基官能度,再以所合成的蓖麻油基聚酯酸为软段合成水性聚氨酯乳液；然后向所合成的水性聚氨酯乳液中加入以氮丙啶作为固化基团的增稠固化剂,得到用于PVC革/玻璃钢板粘结的水性聚氨酯胶粘剂。本发明制备的水性聚氨酯乳液固含量高、存储稳定性好,其胶粘剂的粘结性能良好。(The invention relates to a preparation method of aqueous polyurethane emulsion and adhesive based on castor oil, which takes castor oil as main raw material, synthesizes castor oil-based polyester acid through the mono-esterification reaction of the castor oil and tetracarboxylic dianhydride containing aromatic ring or aliphatic ring, adjusts the hydroxyl functionality through maleic anhydride or phthalic anhydride, and synthesizes aqueous polyurethane emulsion by taking the synthesized castor oil-based polyester acid as soft segment; and then adding a thickening curing agent which takes aziridine as a curing group into the synthesized waterborne polyurethane emulsion to obtain the waterborne polyurethane adhesive for bonding the PVC leather/glass steel plate. The aqueous polyurethane emulsion prepared by the invention has high solid content, good storage stability and good adhesive property.)

1. A preparation method of a castor oil-based aqueous polyurethane emulsion is characterized by comprising the following steps:

step one, preparing castor oil based polyester acid: dissolving 6-11 parts by weight of dried anhydride in 0-15 parts by weight of solvent, adding 100 parts by weight of castor oil, heating to 110-140 ℃, reacting for 2-5 hours under the protection of nitrogen, detecting that the acid value reaches 32-40mgKOH/g, dissolving 10-38 parts by weight of dried tetracarboxylic dianhydride in 20-50 parts by weight of solvent, adding the mixture, continuously reacting for 2-5 hours, detecting that the acid value reaches 74-100mgKOH/g, and cooling to generate castor oil based polyester acid containing carboxyl and hydroxyl functional groups;

step two, preparing the aqueous polyurethane emulsion: adding 19-48 parts by weight of diisocyanate and 0.01-0.04 part by weight of catalyst into the castor oil based polyester acid obtained in the step one, heating to 60-80 ℃ for reaction for 1-3 hours, adding 0-9 parts by weight of glycol chain extender, continuing to react for 1-3 hours to obtain isocyanate group-terminated prepolymer, cooling to 30-40 ℃, adding 50-90 parts by weight of acetone to adjust viscosity, adding 5-13.5 parts by weight of neutralizer, salting for 20-40 minutes, then adding 180-245 parts by weight of deionized water under high-speed stirring for emulsification and dispersion, then adding 3-12 parts by weight of diamine chain extender, 0-0.3 part by weight of molecular weight regulator and 6-20 parts by weight of deionized water for reaction for 2-3 hours, and finally removing residual acetone in vacuum to prepare the waterborne polyurethane emulsion.

2. The method for preparing the aqueous polyurethane emulsion based on castor oil according to claim 1, wherein the method comprises the following steps: in the first step, the acid anhydride is one or two of maleic anhydride and phthalic anhydride; the tetracarboxylic dianhydride is one or more of pyromellitic dianhydride, bisphenol A type diether dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, diphenyl sulfide tetracarboxylic dianhydride, triphenyl diether tetracarboxylic dianhydride and cyclobutane tetracarboxylic dianhydride.

3. The method for preparing the aqueous polyurethane emulsion based on castor oil according to claim 1 or 2, wherein: in the second step, the diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, 4-dicyclohexylmethane diisocyanate and toluene diisocyanate; the catalyst is one of dibutyltin dilaurate, stannous octoate and bismuth neodecanoate; the diol chain extender is one or more of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, diethylene glycol, 2-methyl-1, 3-propylene glycol, neopentyl glycol, 1, 5-pentanediol and 1, 6-hexanediol; the neutralizing agent is one of triethylamine, triethanolamine and N, N-dimethylethanolamine; the diamine chain extender is one or more of isophorone diamine, ethylene diamine, 1, 6-hexamethylene diamine, diethylenetriamine, ethylene diamine sodium ethanesulfonate and diaminobenzene sodium sulfonate; the molecular weight regulator is one of ethanolamine and diethanolamine.

4. The method for preparing the aqueous polyurethane emulsion based on castor oil according to claim 3, wherein the method comprises the following steps: the solvent is one of tetrahydrofuran, dimethyl sulfoxide, N-methyl pyrrolidone, N-dimethylformamide and N, N-dimethylacetamide.

5. An aqueous polyurethane emulsion obtained by the production method according to any one of claims 1 to 4.

6. The preparation method of the water-based polyurethane adhesive is characterized by comprising the following steps:

step one, preparation of a thickening curing agent: adding 100 parts by weight of dehydrated polyoxyethylene glycol, 3-7.5 parts by weight of polyoxypropylene glycol mixed oligomer dihydric alcohol, 24-84 parts by weight of isocyanate tripolymer and 0.005-0.015 part by weight of catalyst into a reactor, heating to 50-70 ℃ under stirring for reaction for 0.5-2 hours, adding 1-2.5 parts by weight of diethylene glycol for continuous reaction for 0.5-2 hours to obtain an intermediate, and then adding 1-4 parts by weight of long carbon chain alcohol and 6.5-22 parts by weight of 1-hydroxyethylaziridine for end capping reaction for 1-2 hours; finally, adding 10-38 parts by weight of solvent, and cooling to obtain the thickening curing agent;

and step two, mixing 5-8 parts by weight of thickening curing agent obtained in the step one with 100 parts by weight of the waterborne polyurethane emulsion to obtain the waterborne polyurethane adhesive.

7. The method for preparing the aqueous polyurethane adhesive according to claim 6, wherein: in the first step, the number average molecular weight of the polyoxyethylene glycol is 2000-; the number average molecular weight of the polyoxypropylene diol is 400-2000; the isocyanate tripolymer is one or more of isophorone diisocyanate tripolymer, hexamethylene diisocyanate tripolymer and toluene diisocyanate tripolymer; the catalyst is one of dibutyltin dilaurate, stannous octoate and bismuth neodecanoate; the long-carbon-chain alcohol is one of dodecanol, tetradecanol, hexadecanol and octadecanol.

8. The method for preparing an aqueous polyurethane adhesive according to claim 6 or 7, wherein: in the first step, the solvent is one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide and N, N-dimethylacetamide.

9. An aqueous polyurethane adhesive obtainable by the process of any one of claims 6 to 8.

Technical Field

The invention belongs to the technical field of waterborne polyurethane synthesis, and particularly relates to a preparation method of a castor oil-based waterborne polyurethane emulsion and an adhesive.

Background

The waterborne polyurethane takes water as a dispersion medium, is not easy to burn, has low VOCs, has better cohesiveness and film forming property, and is an environment-friendly material widely applied to the industries of coatings, printing ink, adhesives and the like. At present, the preparation method of the waterborne polyurethane generally comprises the steps of reacting polyether or polyester polyol, a hydrophilic chain extender, an alcohol chain extender and polyisocyanate to synthesize a prepolymer, and then carrying out preparation processes such as salinization, emulsification and dispersion on the prepolymer. The waterborne polyurethane prepared by the conventional method has the defects of low solid content, slow drying and curing, short storage time, poor wettability to a base material and the like, and the application range of the waterborne polyurethane is limited. In order to improve the performance deficiency of the waterborne polyurethane, methods such as introducing functional groups or molecular chain segments into the molecular structure of the polyurethane, blending or copolymerizing with other polymers, micro-nano modifying, adding an auxiliary agent and the like are generally adopted.

Castor oil is a renewable natural fatty acid triglyceride from a wide source, is the only vegetable oil containing hydroxyl groups with an average functionality of 2.7. Generally, castor oil is mainly used as a cross-linking agent or a chain extender, and is introduced into the molecular structure of the waterborne polyurethane through the reaction of hydroxyl groups in the molecules of the castor oil and isocyanate groups, so that the introduction of the castor oil not only can improve the cross-linking density of the waterborne polyurethane, but also introduces a long carbon chain structure with low polarity into the molecular structure of the polyurethane, thereby improving the physical and mechanical properties of the waterborne polyurethane and the wettability of the waterborne polyurethane to a substrate to a certain extent. The castor oil modified waterborne polyurethane is usually less in dosage and limited in improvement of the application performance of the polyurethane, and the viscosity of the polyurethane prepolymer can be rapidly improved along with the increase of the dosage of the castor oil, so that the castor oil modified waterborne polyurethane is not beneficial to emulsification and dispersion, and the castor oil modified waterborne polyurethane is larger in particle size and poorer in storage stability.

Disclosure of Invention

The invention aims to provide a preparation method of a castor oil-based waterborne polyurethane emulsion and an adhesive, so that the prepared waterborne polyurethane emulsion has high solid content, good storage stability and good adhesive property.

To achieve the above object, according to one aspect of the present invention, there is provided a method for preparing an aqueous polyurethane emulsion based on castor oil, comprising:

step one, preparing castor oil based polyester acid: dissolving 6-11 parts by weight of dried anhydride in 0-15 parts by weight of solvent, adding 100 parts by weight of castor oil, heating to 110-140 ℃, reacting for 2-5 hours under the protection of nitrogen, detecting that the acid value reaches 32-40mgKOH/g, dissolving 10-38 parts by weight of dried tetracarboxylic dianhydride in 20-50 parts by weight of solvent, adding the mixture, continuously reacting for 2-5 hours, detecting that the acid value reaches 74-100mgKOH/g, and cooling to generate castor oil based polyester acid containing carboxyl and hydroxyl functional groups;

step two, preparing the aqueous polyurethane emulsion: adding 19-48 parts by weight of diisocyanate and 0.01-0.04 part by weight of catalyst into the castor oil based polyester acid obtained in the step one, heating to 60-80 ℃ for reaction for 1-3 hours, adding 0-9 parts by weight of glycol chain extender, continuing to react for 1-3 hours to obtain isocyanate group-terminated prepolymer, cooling to 30-40 ℃, adding 50-90 parts by weight of acetone to adjust viscosity, adding 5-13.5 parts by weight of neutralizer, salting for 20-40 minutes, then adding 180-245 parts by weight of deionized water under high-speed stirring for emulsification and dispersion, then adding 3-12 parts by weight of diamine chain extender, 0-0.3 part by weight of molecular weight regulator and 6-20 parts by weight of deionized water for reaction for 2-3 hours, and finally removing residual acetone in vacuum to prepare the waterborne polyurethane emulsion.

Preferably, in the first step, the acid anhydride is one or two of maleic anhydride and phthalic anhydride; the tetracarboxylic dianhydride is one or more of pyromellitic dianhydride, bisphenol A type diether dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, diphenyl sulfide tetracarboxylic dianhydride, triphenyl diether tetracarboxylic dianhydride and cyclobutane tetracarboxylic dianhydride.

Preferably, in the second step, the diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, 4-dicyclohexylmethane diisocyanate and toluene diisocyanate; the catalyst is one of dibutyltin dilaurate, stannous octoate and bismuth neodecanoate; the diol chain extender is one or more of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, diethylene glycol, 2-methyl-1, 3-propylene glycol, neopentyl glycol, 1, 5-pentanediol and 1, 6-hexanediol; the neutralizing agent is one of triethylamine, triethanolamine and N, N-dimethylethanolamine; the diamine chain extender is one or more of isophorone diamine, ethylene diamine, 1, 6-hexamethylene diamine, diethylenetriamine, ethylene diamine sodium ethanesulfonate and diaminobenzene sodium sulfonate; the molecular weight regulator is one of ethanolamine and diethanolamine.

Preferably, the solvent is one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide and N, N-dimethylacetamide.

According to another aspect of the present invention, provided is an aqueous polyurethane emulsion obtained by the above preparation method.

According to the invention, castor oil is used as a main raw material, castor oil-based polyester acid is synthesized through the mono-esterification reaction of castor oil and tetracarboxylic dianhydride containing aromatic rings or aliphatic rings, and the hydroxyl functionality of the castor oil-based polyester acid is adjusted through maleic anhydride or phthalic anhydride. The invention uses the synthesized castor oil based polyester acid as a soft segment to synthesize the waterborne polyurethane, and introduces an aromatic ring or aliphatic ring structure, a low-polarity long carbon chain structure and a hydrophilic group into the soft segment structure while properly crosslinking the polyurethane. The introduction of an aromatic ring or an aliphatic ring structure can improve the physical and mechanical properties of the polyurethane, and the introduction of a low-polarity long carbon chain structure can effectively improve the wettability of the polyurethane to a base material; due to the special distribution of hydrophilic groups, the water dispersibility of the polyurethane is better, the solid content is higher, and the storage stability is better.

According to another aspect of the present invention, there is provided a method of preparing an aqueous polyurethane adhesive, comprising:

step one, preparation of a thickening curing agent: adding 100 parts by weight of dehydrated polyoxyethylene glycol, 3-7.5 parts by weight of polyoxypropylene glycol mixed oligomer dihydric alcohol, 24-84 parts by weight of isocyanate tripolymer and 0.005-0.015 part by weight of catalyst into a reactor, heating to 50-70 ℃ under stirring for reaction for 0.5-2 hours, adding 1-2.5 parts by weight of diethylene glycol for continuous reaction for 0.5-2 hours to obtain an intermediate, and then adding 1-4 parts by weight of long carbon chain alcohol and 6.5-22 parts by weight of 1-hydroxyethylaziridine for end capping reaction for 1-2 hours; finally, adding 10-38 parts by weight of solvent, and cooling to obtain the thickening curing agent;

and step two, mixing 5-8 parts by weight of thickening curing agent obtained in the step one with 100 parts by weight of the waterborne polyurethane emulsion to obtain the waterborne polyurethane adhesive.

Preferably, in the first step of the preparation method of the aqueous polyurethane adhesive, the number average molecular weight of the polyoxyethylene glycol is 2000-6000; the number average molecular weight of the polyoxypropylene diol is 400-2000; the isocyanate tripolymer is one or more of isophorone diisocyanate tripolymer, hexamethylene diisocyanate tripolymer and toluene diisocyanate tripolymer; the catalyst is one of dibutyltin dilaurate, stannous octoate and bismuth neodecanoate; the long-carbon-chain alcohol is one of dodecanol, tetradecanol, hexadecanol and octadecanol.

Preferably, in the first step of the method for preparing the aqueous polyurethane adhesive, the solvent is one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide and N, N-dimethylacetamide.

According to another aspect of the present invention, provided is an aqueous polyurethane adhesive obtained by the above preparation method.

The thickening curing agent prepared by the invention has the functions of thickening and curing the waterborne polyurethane, and can effectively improve the adhesive property of the waterborne polyurethane adhesive. Wherein, the polyoxyethylene glycol is taken as a non-ionic hydrophilic chain segment, which endows the thickening curing agent with good water dispersibility; the introduction of the polyoxypropylene diol reduces the crystallinity of the thickening and curing agent; the isocyanate tripolymer contains isocyanurate ring, and the physical and mechanical properties of the polyurethane can be well improved by introducing the isocyanurate ring into a polyurethane molecular structure. The thickening curing agent prepared by the invention takes aziridine as a curing group, and has good storage stability compared with an isocyanate curing agent. The obtained waterborne polyurethane adhesive shell is used for bonding PVC leather/glass steel plates.

Drawings

FIG. 1 is an infrared spectrum of the aqueous polyurethane prepared in example 1 of the present invention.

Detailed Description

Example 1

Adding 7.38g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 130 ℃, reacting for 2.5 hours under the protection of nitrogen, and detecting that the acid value is 39.34 mgKOH/g; 10.76g of pyromellitic dianhydride which is dried is dissolved in 20g N-methyl pyrrolidone, the mixture is added into a reactor to continue to react for 2.5 hours, the acid value is detected to be 82.65mgKOH/g, and the temperature is reduced to generate castor oil based polyester acid with the hydroxyl value of 55.32mgKOH/g and the average hydroxyl functionality of 2.

Adding 47.16g of isophorone diisocyanate and 0.012g of bismuth neodecanoate, heating to 60 ℃ to react for 1.5 hours, adding 5.24g of 1, 4-butanediol and 3.64g of neopentyl glycol, and continuing to react for 2 hours, wherein the percentage content of isocyanate groups is detected to be 2.64%; cooling to 35 ℃, adding 75g of acetone for dilution, adding 7.91g of triethylamine for salinization for 30 minutes, then adding 220g of deionized water for emulsification and dispersion under high-speed stirring, then adding 9.34g of isophorone diamine, 0.31g of diethylenetriamine and 10g of deionized water for reaction for 2.5 hours, and removing acetone in vacuum to obtain the waterborne polyurethane emulsion with solid content of 48.3%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 6000), 4.76g of polyoxypropylene glycol (number average molecular weight 2000), 27.48g of hexamethylene diisocyanate trimer and 0.011g of dibutyltin dilaurate into a reactor, heating to 65 ℃ under stirring, reacting for 1.5 hours, adding 1.44g of diethylene glycol, continuing to react for 1.5 hours, and detecting that the percentage content of isocyanate groups is 3.08%; then, 1.90g of hexadecanol and 7.94g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1.5 hours. Finally, 16g N-methyl pyrrolidone is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 90.1 percent.

And adding 5g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 2

Adding 6.75g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 130 ℃, reacting for 2.5 hours under the protection of nitrogen, and detecting that the acid value is 36.2 mgKOH/g; 37.34g of bisphenol A type diether dianhydride which is dried is dissolved in 50g N-methyl pyrrolidone, and is added into a reactor to continue the reaction for 3 hours, the acid value is detected to be 82.68mgKOH/g, and the temperature is reduced, thus generating castor oil based polyester acid with the hydroxyl value of 30.45mgKOH/g and the average hydroxyl functionality of 2.18.

Adding 35.28g of isophorone diisocyanate and 0.028g of bismuth neodecanoate, heating to 65 ℃ for reaction for 1.5 hours, adding 4.09g of 1, 2-propylene glycol, and continuing to react for 2 hours, wherein the percentage content of isocyanate groups is detected to be 2.38%; cooling to 35 ℃, adding 50g of acetone for dilution, adding 5.36g of triethylamine for salinization for 30 minutes, then adding 235g of deionized water for emulsification and dispersion under high-speed stirring, adding 11.13g of isophorone diamine, 0.16g of ethanolamine and 20g of deionized water for reaction for 2.5 hours, and removing acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 49.8%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 2000), 5g of polyoxypropylene glycol (number average molecular weight 400), 83.25g of isophorone diisocyanate trimer and 0.011g of dibutyltin dilaurate into a reactor, heating to 65 ℃ under stirring, reacting for 1 hour, adding 1.33g of diethylene glycol, and continuing to react for 1 hour, wherein the percentage content of isocyanate groups is detected to be 4.98%; then, 3.37g of tetradecanol and 18.41g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1 hour. Finally, 18g N-methyl pyrrolidone is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 92.2 percent.

And adding 6g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 3

Dissolving dried 9.88g of phthalic anhydride in 15g N, N-dimethylformamide, adding the phthalic anhydride and 100g of castor oil into a reactor, heating to 130 ℃, reacting for 3 hours under the protection of nitrogen, and detecting that the acid value is 34.06 mgKOH/g; 23.12g of benzophenone tetracarboxylic dianhydride which is dried is dissolved in 35g N, N-dimethylformamide, and is added into a reactor to continue reacting for 3 hours, the acid value is detected to be 88.66mgKOH/g, and the temperature is reduced to generate castor oil based polyester acid with the hydroxyl value of 33.89mgKOH/g and the average hydroxyl functionality of 2.24.

Then 32.61g of 4, 4-dicyclohexyl methane diisocyanate and 0.026g of bismuth neodecanoate are added, the temperature is raised to 75 ℃ for reaction for 1.5 hours, 1.64g of 1, 3-propylene glycol is added for continuous reaction for 2 hours, and the percentage content of isocyanate group is detected to be 2.43%; cooling to 35 ℃, adding 50g of acetone for dilution, adding 6.37g of triethylamine for salinization for 30 minutes, then adding 223g of deionized water for emulsification and dispersion under high-speed stirring, then adding an aqueous dispersion consisting of 5.34g of isophorone diamine, 1.85g of ethylenediamine, 0.26g of diethanolamine and 15g of deionized water, reacting for 2.5 hours, and removing the acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 49.1%.

Adding 100g of dehydrated polyoxyethylene glycol (with the number average molecular weight of 4000), 5g of polyoxypropylene glycol (with the number average molecular weight of 1000), 37.80g of hexamethylene diisocyanate trimer and 0.011g of dibutyltin dilaurate into a reactor, heating to 65 ℃ under stirring, reacting for 1 hour, adding 1.43g of diethylene glycol, continuing to react for 1 hour, and detecting that the percentage content of isocyanate groups is 4.02%; then, 2.61g of stearyl alcohol and 11.31g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1 hour. Finally, 22g N, N-dimethylformamide is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 87.9 percent.

And adding 6g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 4

Dissolving 10.84g of phthalic anhydride subjected to drying treatment in 15g N, N-dimethylformamide, adding the phthalic anhydride and 100g of castor oil into a reactor, heating to 140 ℃, reacting for 2.5 hours under the protection of nitrogen, and detecting that the acid value is 37.04 mgKOH/g; 22.24g of diphenyl ether tetracarboxylic dianhydride which is dried is dissolved in 35g N, N-dimethylformamide, and is added into a reactor to continue reacting for 2.5 hours, the acid value is detected to be 91.33mgKOH/g, and the temperature is reduced, thus generating castor oil based polyester acid with the hydroxyl value of 31.15mgKOH/g and the average hydroxyl functionality of 2.06.

Adding 32.49g of isophorone diisocyanate and 0.026g of dibutyltin dilaurate, heating to 70 ℃ for reaction for 2 hours, adding 2.28g of diethylene glycol and 2.24g of 1, 5-pentanediol, and continuing to react for 2.5 hours, wherein the percentage content of isocyanate groups is detected to be 2.53%; cooling to 35 ℃, adding 50g of acetone for dilution, adding 5.47g of triethylamine for salinization for 30 minutes, then adding 242g of deionized water for emulsification and dispersion under high-speed stirring, then adding 6.92g of 1, 6-hexamethylene diamine, 0.47g of diethylenetriamine and 10g of deionized water for reaction for 2.5 hours, and removing the acetone in vacuum to prepare the waterborne polyurethane emulsion with the solid content of 47.6%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 6000), 5.56g of polyoxypropylene glycol (number average molecular weight 1000), 30.12g of hexamethylene diisocyanate trimer and 0.011g of dibutyltin dilaurate into a reactor, heating to 60 ℃ under stirring, reacting for 2 hours, adding 1.27g of diethylene glycol, and continuing to react for 2 hours, wherein the percentage content of isocyanate groups is detected to be 3.4%; then, 2.29g of hexadecanol and 8.93g of 1-hydroxyethylaziridine were added thereto and the reaction was continued for 2 hours. And finally, adding 17g N, N-dimethylformamide, and cooling to obtain the thickening curing agent with the solid content of 89.8%.

And adding 5g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 5

Adding 6.64g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 120 ℃, reacting for 3.5 hours under the protection of nitrogen, and detecting that the acid value is 35.64 mgKOH/g; 15.83g of biphenyl tetracarboxylic dianhydride which is dried is dissolved in 25g N, N-dimethylacetamide, and is added into a reactor for continuous reaction for 3.5 hours, the acid value is detected to be 80.35mgKOH/g, and the temperature is reduced, thus generating castor oil based polyester acid with the hydroxyl value of 52.74mgKOH/g and the average hydroxyl functionality of 2.14.

Adding 33.68g of isophorone diisocyanate and 0.024g of dibutyltin dilaurate, heating to 70 ℃ to react for 1.5 hours, adding 4.48g of neopentyl glycol, and continuing to react for 2 hours, wherein the percentage content of isocyanate groups is detected to be 2.31%; cooling to 40 ℃, adding 90g of acetone for dilution, adding 13.08g of triethanolamine for salinization for 25 minutes, then adding 195g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 4.34g of isophorone diamine, 4.83g of ethylenediamine ethanesulfonic acid sodium salt, 0.12g of ethanolamine and 10g of deionized water, reacting for 2 hours, and removing the acetone in vacuum to obtain the aqueous polyurethane emulsion with the solid content of 51.7%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 4000), 3.33g of polyoxypropylene glycol (number average molecular weight 400), 40.48g of toluene diisocyanate trimer and 0.01g of dibutyltin dilaurate into a reactor, heating to 50 ℃ under stirring, reacting for 0.5 hour, adding 1.23g of diethylene glycol, and continuing to react for 1 hour, wherein the percentage content of isocyanate groups is detected to be 4.15%; then, 1.33g of dodecanol and 11.99g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1 hour. Finally, 18g N, N-dimethylacetamide is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 89.9 percent.

Adding 8g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 6

Adding 6.33g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 140 ℃, reacting for 2 hours under the protection of nitrogen, and detecting that the acid value is 34.08 mgKOH/g; 17.54g of dried diphenyl sulfide tetracarboxylic dianhydride is dissolved in 28g of dimethyl sulfoxide, added into a reactor and continuously reacted for 2 hours, the acid value is detected to be 77.98mgKOH/g, and the temperature is reduced, so that the castor oil based polyester acid with the hydroxyl value of 53.61mgKOH/g and the average hydroxyl functionality of 2.2 is generated.

Then adding 19.25g of toluene diisocyanate, 4.65g of hexamethylene diisocyanate and 0.036g of bismuth neodecanoate, heating to 75 ℃ to react for 1.5 hours, adding 2.42g of 2-methyl-1, 3-propylene glycol to continue to react for 2 hours, and detecting that the percentage content of isocyanate groups is 2.46%; cooling to 30 ℃, adding 80g of acetone for dilution, adding 7.37g of 7.37g N, salting N-dimethylethanolamine for 40 minutes, adding 182g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 1.57g of ethylenediamine, 5.37g of sodium diaminobenzenesulfonate, 0.22g of diethanolamine and 10g of deionized water, reacting for 3 hours, and removing the acetone in vacuum to obtain the aqueous polyurethane emulsion with the solid content of 50.3%.

Adding 100g of polyoxyethylene glycol (number average molecular weight 6000), 3.33g of polyoxypropylene glycol (number average molecular weight 1000), 24.03g of hexamethylene diisocyanate trimer and 0.015g of bismuth neodecanoate which are subjected to dehydration treatment into a reactor, heating to 70 ℃ under stirring, reacting for 1.5 hours, adding 1.01g of diethylene glycol, continuing to react for 1.5 hours, and detecting that the percentage content of isocyanate groups is 2.75%; then, 1.22g of hexadecanol and 6.96g of 1-hydroxyethylaziridine were added to continue the reaction for 1.5 hours. And finally, adding 12g of dimethyl sulfoxide, and cooling to obtain the thickening curing agent with the solid content of 92.0%.

Adding 7g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 7

Adding 6.85g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 130 ℃, reacting for 2.5 hours under the protection of nitrogen, and detecting that the acid value is 36.7 mgKOH/g; 21.65g of dried tribasic diether tetracarboxylic dianhydride is dissolved in 35g of tetrahydrofuran, added into a reactor and continuously reacted for 2.5 hours, the acid value is detected to be 77.52mgKOH/g, and the temperature is reduced, thus generating the castor oil based polyester acid with the hydroxyl value of 49.33mgKOH/g and the average hydroxyl functionality of 2.1.

Adding 39.77g of isophorone diisocyanate and 0.020g of bismuth neodecanoate, heating to 65 ℃ for reaction for 1.5 hours, adding 1.67g of ethylene glycol and 3.18g of 1, 6-hexanediol for continuous reaction for 1.5 hours, and detecting that the percentage content of isocyanate groups is 2.78%; cooling to 35 ℃, adding 65g of acetone for dilution, adding 7.92g of 7.92g N, carrying out salinization on N-dimethylethanolamine for 30 minutes, then adding 236g of deionized water for emulsification and dispersion under high-speed stirring, then adding an aqueous dispersion consisting of 11.63g of isophorone diamine, 0.17g of ethanolamine and 15g of deionized water, reacting for 2.5 hours, and removing the acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 47.2%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 4000), 7.14g of polyoxypropylene glycol (number average molecular weight 2000), 19.98g of toluene diisocyanate trimer, 25.5g of isophorone diisocyanate trimer and 0.005g of stannous octoate into a reactor, heating to 55 ℃ under stirring, reacting for 1 hour, adding 2.03g of diethylene glycol, and continuing to react for 1.5 hours, wherein the percentage content of isocyanate groups is detected to be 3.65%; then, 2.93g of hexadecanol and 10.77g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1.5 hours. And finally, adding 23g of tetrahydrofuran, and cooling to obtain the thickening curing agent with the solid content of 88%.

And adding 5g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 8

4.78g of phthalic anhydride which is dried is dissolved in 10g N, N-dimethylformamide, then the phthalic anhydride, 3.8g of maleic anhydride which is dried and 100g of castor oil are added into a reactor, the temperature is raised to 130 ℃, the reaction is carried out for 3 hours under the protection of nitrogen, and the acid value is detected to be 36.71 mgKOH/g; 7.82g of pyromellitic dianhydride and 7.03g of cyclobutane tetracarboxylic dianhydride which are dried are dissolved in 30g N N-dimethylformamide and added into a reactor to continue the reaction for 3 hours, the acid value is detected to be 97.50mgKOH/g, and the temperature is reduced to generate the castor oil based polyester acid with the hydroxyl value of 34.56mgKOH/g and the average hydroxyl functionality of 2.12.

Then adding 19.47g of toluene diisocyanate and 0.036g of stannous octoate, heating to 80 ℃ for reaction for 2 hours, adding 0.97g of 1, 4-butanediol for continuous reaction for 2 hours, and detecting that the percentage content of isocyanate groups is 2.88%; cooling to 40 ℃, adding 60g of acetone for dilution, adding 8g of triethanolamine for salinization for 25 minutes, then adding 212g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 3.72g of ethylenediamine, 0.26g of diethanolamine and 8g of deionized water, reacting for 2 hours, and removing the acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 47.7%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 4000), 3.57g of polyoxypropylene glycol (number average molecular weight 1000), 36.72g of hexamethylene diisocyanate trimer and 0.011g of dibutyltin dilaurate into a reactor, heating to 60 ℃ under stirring, reacting for 1.5 hours, adding 1.78g of diethylene glycol, continuing to react for 1.5 hours, and detecting that the percentage content of isocyanate groups is 3.78%; then, 3.46g of stearyl alcohol and 10.14g of 1-hydroxyethylaziridine were added thereto to continue the reaction for 1.5 hours. And finally adding 27g N, N-dimethylformamide, and cooling to obtain the thickening curing agent with the solid content of 85.2%.

And adding 5g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 9

Adding 6g of maleic anhydride and 100g of castor oil which are subjected to drying treatment into a reactor, heating to 140 ℃, reacting for 2 hours under the protection of nitrogen, and detecting that the acid value is 32.39 mgKOH/g; 10g of pyromellitic dianhydride after drying treatment is dissolved in 20g N, N-dimethylformamide, added into a reactor and continuously reacted for 2 hours, the acid value is detected to be 74.09mgKOH/g, and the temperature is reduced, so that the castor oil based polyester acid with the hydroxyl value of 66.35mgKOH/g and the average hydroxyl functionality of 2.23 is generated.

Then adding 19g of toluene diisocyanate and 0.01g of bismuth neodecanoate, heating to 60 ℃ for reaction for 3 hours, and detecting that the percentage content of isocyanate groups is 2.2%; cooling to 30 ℃, adding 50g of acetone for dilution, adding 5g N, N-dimethylethanolamine for salinization for 20 minutes, then adding 180g of deionized water for emulsification and dispersion under high-speed stirring, then adding an aqueous dispersion consisting of 1.7g of ethylenediamine, 1.3g of 1, 6-hexanediamine, 0.3g of diethanolamine and 6g of deionized water, reacting for 2 hours, and removing the acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 47.4%.

Adding 100g of dehydrated polyoxyethylene glycol (number average molecular weight 6000), 3g of polyoxypropylene glycol (number average molecular weight 400), 24g of hexamethylene diisocyanate trimer and 0.005g of dibutyltin dilaurate into a reactor, heating to 70 ℃ under stirring, reacting for 0.5 hour, adding 1g of diethylene glycol, and continuing to react for 0.5 hour, wherein the percentage content of isocyanate groups is detected to be 2.48%; then, 1g of stearyl alcohol and 6.5g of 1-hydroxyethylaziridine were added thereto and the reaction was continued for 1 hour. Finally, 10g N N-dimethylformamide is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 93.1 percent.

And adding 5g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Example 10

Dissolving 11g of phthalic anhydride subjected to drying treatment in 15g N, N-dimethylacetamide, adding the phthalic anhydride and 100g of castor oil into a reactor, heating to 110 ℃, reacting for 5 hours under the protection of nitrogen, and detecting that the acid value is 37.54 mgKOH/g; 38g of bisphenol A type tetracarboxylic dianhydride which is dried is dissolved in 50g N, N-dimethylacetamide, and is added into a reactor for continuous reaction for 5 hours, the acid value is detected to be 82.93mgKOH/g, and the temperature is reduced, thus generating castor oil based polyester acid with the hydroxyl value of 26.3mgKOH/g and the average hydroxyl functionality of 2.03.

Adding 48g of 4, 4-dicyclohexylmethane diisocyanate and 0.04g of bismuth neodecanoate, heating to 80 ℃ for reaction for 1 hour, adding 9g of 1, 6-hexanediol for continuous reaction for 1 hour, and detecting that the percentage content of isocyanate groups is 2.37%; cooling to 40 ℃, adding 90g of acetone for dilution, adding 13.5g of triethanolamine for salinization for 40 minutes, then adding 245g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 6g of isophorone diamine, 5.5g of ethylenediamine ethanesulfonic acid sodium salt, 0.5g of diethylenetriamine and 20g of deionized water, reacting for 3 hours, and removing the acetone in vacuum to obtain the waterborne polyurethane emulsion with the solid content of 49.5%.

Adding 100g of polyoxyethylene glycol (with the number average molecular weight of 4000), 7.5g of polyoxypropylene glycol (with the number average molecular weight of 1000), 84g of isophorone diisocyanate trimer and 0.015g of dibutyltin dilaurate into a reactor, heating to 50 ℃ under stirring, reacting for 2 hours, adding 2.5g of diethylene glycol, continuing to react for 2 hours, and detecting that the percentage content of isocyanate groups is 5.76%; then 4g of dodecanol and 22g of 1-hydroxyethylaziridine were added to continue the reaction for 2 hours. And finally, 38g N, N-dimethylacetamide is added, and the temperature is reduced to obtain the thickening curing agent with the solid content of 85.3 percent.

Adding 8g of the prepared thickening curing agent into 100g of the aqueous polyurethane emulsion, and uniformly mixing to obtain the aqueous polyurethane adhesive.

Comparative example 1

Adding 100g of dehydrated 1, 4-butanediol adipate glycol (the number average molecular weight is 2000), 40.52g of isophorone diisocyanate and 0.011g of dibutyltin dilaurate into a reactor in sequence, heating to 70 ℃ under stirring, reacting for 1 hour, adding a mixture consisting of 9.38g of 2, 2-dimethylolpropionic acid, 9.29g of castor oil and 15g N of N-dimethylformamide, and continuing to react for 2 hours to detect that the percentage content of isocyanate groups is 2.36%; cooling to 45 ℃, adding 50g of acetone for dilution, adding 6.72g of triethylamine for salinization for 30 minutes, then adding 235g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 4.58g of isophorone diamine, 4.75g of ethylenediamine ethanesulfonic acid sodium salt and 15g of deionized water, reacting for 2 hours, and removing acetone in vacuum to obtain the aqueous polyurethane emulsion with the solid content of 44.6%.

And (3) adding 0.4g of aqueous polyurethane associative thickener and 5g of polyisocyanate type aqueous polyurethane curing agent into 100g of the prepared aqueous polyurethane emulsion, and uniformly stirring and mixing to obtain the required adhesive.

Comparative example 2

Adding 100g of dehydrated polytetrahydrofuran ether glycol (number average molecular weight 2000), 31.76g of toluene diisocyanate and 0.011g of dibutyltin dilaurate into a reactor in sequence, heating to 66 ℃ under stirring, reacting for 1 hour, adding a mixture consisting of 9.38g of 2, 2-dimethylolpropionic acid, 9.29g of castor oil and 15g N, N-dimethylformamide, and continuing to react for 2 hours to detect that the percentage content of isocyanate groups is 2.49%; cooling to 45 ℃, adding 50g of acetone for dilution, adding 6.72g of triethylamine for salinization for 30 minutes, then adding 271g of deionized water for emulsification and dispersion under high-speed stirring, adding an aqueous dispersion consisting of 3.1g of ethylenediamine and 6g of deionized water, reacting for 2 hours, and removing the acetone in vacuum to obtain the aqueous polyurethane emulsion with the solid content of 40.3%.

And adding 5g of the thickening curing agent prepared in the example 1 into 100g of the prepared waterborne polyurethane emulsion, and uniformly stirring and mixing to obtain the required adhesive.

Performance testing

(1) Peel Strength test

The bonding materials are PVC leather and glass fiber reinforced plastic plates according to the test of GB/T2790-1995.

(2) Storage stability test

And (3) placing the aqueous polyurethane emulsion in a sealed container at room temperature, and observing and recording the storage time of the emulsion when layering or flocculation obviously occurs.

TABLE 1 Properties of aqueous polyurethane Adhesives

The storage time of the waterborne polyurethane adhesive prepared by the invention exceeds 240 days, the initial peel adhesion strength reaches more than 2.5kN/m, and the final adhesion strength reaches more than 3.0 kN/m.