阅读说明：本技术 一种水性天冬氨酸树脂的合成方法及其应用 (Synthetic method and application of water-based aspartic acid resin ) 是由 杨轩 易松 徐涛 龙绪俭 熊东路 肖增钧 李斌仁 陈林生 于 2020-06-05 设计创作，主要内容包括：本发明提供了一种水性天冬氨酸树脂的合成方法及其应用。该合成方法包括以下步骤：步骤一：将马来酸酯与聚乙二醇单甲醚按照摩尔比1:(0.2-1)的比例混合,在160-180℃的真空条件下,通过酯交换反应合成亲水性马来酸酯；步骤二：将所述亲水性马来酸酯与伯胺类物质按照摩尔比(2-2.06)：1的比例混合,在50-80℃条件下,继续反应得到水性天冬氨酸树脂。通过先对马来酸酯进行水性改造的方式,使后续合成的天冬氨酸树脂具有亲水性,易分散,进而使应用时所得天冬氨酸聚脲涂料为水性涂料,克服油性天冬氨酸聚脲树脂施工粘度高的缺点,能够用水直接稀释而不加入挥发性有机溶剂的情况下实现薄涂和喷涂,且涂膜性能好。(The invention provides a synthetic method and application of water-based aspartic acid resin. The synthesis method comprises the following steps: the method comprises the following steps: mixing maleic acid ester and polyethylene glycol monomethyl ether according to the molar ratio of 1 (0.2-1), and synthesizing hydrophilic maleic acid ester through ester exchange reaction under the vacuum condition of 160-180 ℃; step two: mixing the hydrophilic maleate and the primary amine substance according to a molar ratio (2-2.06): 1, and continuously reacting at 50-80 ℃ to obtain the waterborne aspartic resin. The subsequent synthesized aspartic acid resin has hydrophilicity and is easy to disperse by firstly carrying out water-based modification on the maleate, so that the aspartic acid polyurea coating obtained in application is a water-based coating, the defect of high construction viscosity of oily aspartic acid polyurea resin is overcome, the thin coating and the spraying can be realized under the condition of directly diluting with water without adding a volatile organic solvent, and the coating performance is good.)

1. A method for synthesizing aqueous aspartic acid resin is characterized by comprising the following steps:

the method comprises the following steps: mixing maleic acid ester and polyethylene glycol monomethyl ether according to the molar ratio of 1 (0.2-1), and synthesizing hydrophilic maleic acid ester through ester exchange reaction under the vacuum condition of 160-180 ℃;

step two: mixing the hydrophilic maleate and the primary amine substance according to a molar ratio (2-2.06): 1, and continuously reacting at 50-80 ℃ to obtain the waterborne aspartic resin.

2. The method for synthesizing the aqueous aspartic resin of claim 1, wherein in the first step, the reaction is carried out by adding organic tin-containing catalyst, and the weight of the organic tin-containing catalyst is 0.05-3% of the mass of the polyethylene glycol monomethyl ether.

3. The method for synthesizing the aqueous aspartic resin according to claim 2, wherein the organic tin-containing catalyst is dibutyltin dilaurate or dibutyltin oxide.

4. The method for synthesizing an aqueous aspartic resin according to claim 3, wherein in the second step, the primary amine is 4,4 ' -diaminodicyclohexylmethane or 3,3' -dimethyl-4, 4 ' -diaminodicyclohexylmethane.

5. The method of claim 4, wherein in step one, the maleate has the formulaThe structural formula of the polyethylene glycol monomethyl ether is H- (OCH)₂CH₂)n-OCH₃Wherein R is₁is-CH₃or-C₂H₅or-C₃H₇And n ranges from 1 to 1000.

6. The method for synthesizing the waterborne aspartic resin of any one of claims 2 to 5, wherein in the first step, before adding the organic tin-containing catalyst, the raw materials are subjected to water removal treatment: adding a water carrying agent into a mixed system of maleate and polyethylene glycol monomethyl ether, and then heating and refluxing while stirring; the water-carrying agent is cyclohexane or toluene.

7. The method for synthesizing an aqueous aspartic resin according to claim 6, wherein when the water-carrying agent is cyclohexane, the heating reflux treatment is: firstly, under the condition of 75-90 ℃, cyclohexane takes away water, and then under the condition of 100-120 ℃, cyclohexane is removed by reduced pressure distillation; when the water-carrying agent is toluene, the heating reflux treatment comprises the following steps: the water is taken out by the toluene under the conditions of 100-120 ℃, and then the toluene is removed by distillation under the conditions of 130-150 ℃.

8. The method for synthesizing an aqueous aspartic resin according to claim 7, wherein in the first step, after adding the organic catalyst containing tin, the ester exchange reaction is carried out under the condition that the vacuum degree is more than 0.095Mpa until no alcohol substances are precipitated; in the second step, the reaction is carried out for 48 to 240 hours under the condition of constant-temperature stirring.

9. The application of the waterborne aspartic resin is characterized in that the waterborne aspartic resin is applied to an aspartic polyurea coating, and the aspartic polyurea coating is formed by mixing and reacting the waterborne aspartic resin with an isocyanate curing agent; in the aspartic acid polyurea coating, the ratio of the amine value to the total molar weight of isocyanate groups is in a range of 1: (1-1.5).

10. The application of the waterborne aspartic resin of claim 9, wherein in use, water is added into the aspartic polyurea coating for dilution and auxiliary agents, the mixture is uniformly mixed and coated on the surface of wood, metal and ceramic, and the coating is dried; the mass of the added water is 0.4-1 time of that of the aspartic acid polyurea coating; the added auxiliary agent comprises one or more of wetting agent, cosolvent and defoaming agent.

Technical Field

The invention relates to the technical field of chemical synthesis, in particular to a synthetic method and application of water-based aspartic acid resin.

Background

The aspartic acid polyurea resin is an elastomer substance synthesized by taking an amino compound and isocyanate as raw materials. The construction is carried out by adopting special equipment, the solid content is 100 percent, and the paint has no solvent and no pollution. It has the advantages of fast curing, good chemical corrosion resistance, high strength, high impermeability, high wear resistance and flexibility, high and low temperature resistance, etc. Has wide application prospect in the projects of corrosion prevention, water prevention, wear resistance and the like. However, the reaction rate of the primary amine in the amino compound with the urea resin is too fast, and the gel time is too short, so that the aspartic acid polyurea resin has difficulty in forming a paint film and poor adhesion. At present, the reaction speed with isocyanate can be reduced by changing the amino compound into secondary amine, and the gel time can be adjusted within a few minutes to a few hours.

The water-based paint has the advantages of low VOC, non-inflammability, environmental protection and the like, so the development of the field of the water-based paint is relatively fast in recent years. The aspartic acid polyurea coating mainly comprises 2 components: aspartic acid resin and isocyanate curing agent. Currently, polyurea aspartate coatings are rendered aqueous primarily by the hydration of isocyanates. There are two main methods for isocyanate hydration: 1) an anionic group is grafted; 2) and (3) introducing a nonionic group. When introducing nonionic hydrophilic groups into the curing agent molecules, the commonly used nonionic hydrophilic groups mainly include two types: 1) polyethylene glycols polymerized with ethylene oxide, 2) polypropylene glycols polymerized with propylene oxide.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: a new water-based aspartic acid resin is prepared by another way, and then the water-based aspartic acid polyurea coating is prepared, so that the defect of high construction viscosity of the obtained coating can be overcome, and thin coating and spraying can be realized without adding a volatile organic solvent.

In order to solve the technical problems, the invention adopts the technical scheme that:

a synthetic method of aqueous aspartic acid resin comprises the following steps: the method comprises the following steps: mixing maleic acid ester and polyethylene glycol monomethyl ether according to the molar ratio of 1 (0.2-1), and synthesizing hydrophilic maleic acid ester through ester exchange reaction under the vacuum condition of 160-180 ℃; step two: mixing the hydrophilic maleate and the primary amine substance according to a molar ratio (2-2.06): 1, and continuously reacting at 50-80 ℃ to obtain the waterborne aspartic resin.

Further, in the first step, a tin-containing organic catalyst is added for reaction, wherein the weight of the tin-containing organic catalyst is 0.05-3% of the mass of the polyethylene glycol monomethyl ether.

Further, the organic tin-containing catalyst is dibutyltin dilaurate or dibutyltin oxide.

Further, in the second step, the primary amine species is 4,4 ' -diaminodicyclohexylmethane (HMDA) or 3,3' -dimethyl-4, 4 ' -diaminodicyclohexylmethane.

Further, in the first step, the structural formula of the maleic acid ester is shown asThe structural formula of the polyethylene glycol monomethyl ether is H- (OCH)₂CH₂)n-OCH，₃Wherein R is₁is-CH₃or-C₂H₅or-C₃H₇And n ranges from 1 to 1000.

Further, in the first step, before adding the tin-containing organic catalyst, the raw materials are subjected to water removal treatment: adding a water carrying agent into a mixed system of maleate and polyethylene glycol monomethyl ether, and then heating and refluxing while stirring; the water-carrying agent is cyclohexane or toluene.

Further, in the first step, when the water-carrying agent is cyclohexane, the heating reflux treatment is: firstly, under the condition of 75-90 ℃, cyclohexane takes away water, and then under the condition of 100-120 ℃, cyclohexane is removed by reduced pressure distillation; when the water-carrying agent is toluene, the heating reflux treatment comprises the following steps: the water is taken out by the toluene under the conditions of 100-120 ℃, and then the toluene is removed by distillation under the conditions of 130-150 ℃.

Further, in the first step, after adding a tin-containing organic catalyst, carrying out the ester exchange reaction under the condition that the vacuum degree is more than 0.095Mpa until no alcohol substances are separated out; in the second step, the reaction is carried out for 48 to 240 hours under the condition of constant-temperature stirring.

The application of the water-based aspartic acid resin is applied to an aspartic acid polyurea coating, and the aspartic acid polyurea coating is formed by mixing and reacting the water-based aspartic acid resin with an isocyanate curing agent.

Further, in the aspartic acid polyurea coating, the ratio of the amine value to the total molar amount of isocyanate groups is in the range of 1: (1-1.5).

Further, when in use, water is added into the aspartic acid polyurea coating for dilution and an auxiliary agent, the mixture is uniformly mixed and coated on the surfaces of wood, metal and ceramic, and the mixture is dried; the mass of the added water is 0.4-1 time of that of the aspartic acid polyurea coating; the added auxiliary agent comprises one or more of wetting agent, cosolvent and defoaming agent.

The invention has the beneficial effects that: through the mode of carrying out waterborne transformation to maleate earlier, make the aspartic acid resin of follow-up synthesis have hydrophilicity, easily disperse, and then make during the application gained aspartic acid polyurea coating be water-based coating, can directly dilute the use with water, and the coating performance is good, overcomes the high shortcoming of oily aspartic acid polyurea resin construction viscosity, can directly add water and dilute and can reduce viscosity under the condition of not adding volatile organic solvent, and then realize thin coating and spraying.

Detailed Description

The most key concept of the invention is as follows: the aquosity of the aspartic acid polyurea resin is realized by a method of inoculating a nonionic hydrophilic group into the aspartic acid resin.

In order to further discuss the feasibility of the inventive concept, the detailed description of the technical content, the constructional features, the objects and the effects achieved according to the invention is given in detail.