阅读说明：本技术 一种应用于高铁表面涂层的水性丙烯酸分散体及制备方法 (Water-based acrylic acid dispersion applied to high-speed rail surface coating and preparation method ) 是由 陈玉英 于 2020-07-06 设计创作，主要内容包括：本发明涉及涂料技术领域,尤其涉及一种应用于高铁表面涂层的水性丙烯酸分散体及制备方法。本发明按照质量份数包括8～15份含双键反应性多元醇溶剂、46份单体及链转移剂、35～40份去离子水、2～8份二甲基乙醇胺；单体按照质量份数包括10～12份甲基丙烯酸甲酯、8份丙烯酸羟乙酯、16～18份苯乙烯、10份链转移剂丙烯酸丁酯、10～12份双键反应性多元醇溶剂聚乙烯醇；其制备步骤为：将聚乙烯醇投入反应釜中；将单体与链转移剂用4个小时向反应釜内滴加,并在150℃下反应釜保温2小时；将反应釜降温到90℃,加入去离子水和二甲基乙醇胺中和高速搅拌1小时后降温到80℃以下即可包装。本发明解决了现有的水性丙烯酸分散体助剂过多,固含低,粘度高,VOC含量低,符合环保要求。(The invention relates to the technical field of coatings, in particular to a water-based acrylic acid dispersoid applied to a high-speed rail surface coating and a preparation method thereof. The double-bond reactive polyol cleaning agent comprises, by mass, 8-15 parts of double-bond reactive polyol solvent, 46 parts of monomer and chain transfer agent, 35-40 parts of deionized water and 2-8 parts of dimethylethanolamine; the monomer comprises, by mass, 10-12 parts of methyl methacrylate, 8 parts of hydroxyethyl acrylate, 16-18 parts of styrene, 10 parts of a chain transfer agent butyl acrylate and 10-12 parts of double-bond reactive polyol solvent polyvinyl alcohol; the preparation method comprises the following steps: putting polyvinyl alcohol into a reaction kettle; dropwise adding the monomer and the chain transfer agent into the reaction kettle for 4 hours, and keeping the temperature of the reaction kettle at 150 ℃ for 2 hours; cooling the reaction kettle to 90 ℃, adding deionized water and dimethylethanolamine for neutralization, stirring at a high speed for 1 hour, cooling to below 80 ℃, and packaging. The invention solves the problems of excessive auxiliary agents, low solid content, high viscosity and low VOC content of the existing aqueous acrylic acid dispersoid, and meets the requirement of environmental protection.)

1. The water-based acrylic acid dispersoid applied to the high-speed rail surface coating is characterized by comprising 8-15 parts by mass of double bond-containing reactive polyol solvent, 46 parts by mass of monomer and chain transfer agent, 35-40 parts by mass of deionized water and 2-8 parts by mass of dimethylethanolamine.

2. The aqueous acrylic dispersion applied to the surface coating of the high-speed rail as claimed in claim 1, wherein the monomers comprise, by mass, 10-12 parts of methyl methacrylate, 8 parts of hydroxyethyl acrylate and 16-18 parts of styrene.

3. The aqueous acrylic dispersion applied to the high-speed rail surface coating is characterized in that the chain transfer agent butyl acrylate is 10 parts by mass.

4. The aqueous acrylic acid dispersion applied to the high-speed rail surface coating is characterized in that the double-bond reactive polyol solvent is polyvinyl alcohol and accounts for 10-12 parts by weight.

5. The aqueous acrylic dispersion applied to the surface coating of the high-speed rail as claimed in claim 1, wherein the molecular weight of the polyvinyl alcohol is 500-1000.

6. The preparation method of the aqueous acrylic acid dispersion applied to the high-speed rail surface coating is characterized by comprising the following steps of:

step one, putting reactive polyol solvent containing double bonds in required mass percentage into a reaction kettle for reaction;

step two, closing the feeding hole, starting nitrogen to replace air in the kettle, starting to heat the kettle, and starting a stirring motor to stir when the temperature of materials in the kettle reaches 150 ℃;

weighing the components according to the design proportion of each monomer of the aqueous acrylic acid dispersoid and the chain transfer agent, dropwise adding the weighed methyl methacrylate, hydroxyethyl acrylate, styrene and butyl acrylate into the reaction kettle for 4 hours, and keeping the temperature of the reaction kettle at 150 ℃ for 2 hours to obtain an acrylate prepolymer;

after the reaction in the fourth step and the third step is finished, cooling the reaction kettle to 90 ℃, adding deionized water and dimethylethanolamine for neutralization, stirring at a high speed for 1 hour, cooling to below 80 ℃ after stirring is finished, and packaging.

7. The method for preparing the aqueous acrylic dispersion applied to the surface coating of the high-speed rail according to claim 6, wherein the packaged aqueous acrylic dispersion is stored in a shade.

Technical Field

The invention relates to the technical field of coatings, in particular to a water-based acrylic acid dispersoid applied to a high-speed rail surface coating and a preparation method thereof.

Background

The water-based acrylic acid dispersion system is used as an environment-friendly water-based anticorrosive paint and is mainly used for corrosion prevention of steel structures. With the attention of people on environmental protection and construction safety, the discharge requirement of VOC in the conventional solvent-based coating is increasingly strict, and the prevention and comprehensive treatment of VOC are advanced to unprecedented heights. The development-friendly coating is a necessary choice for realizing transformation and upgrading of products and maintaining sustainable development in the coating industry of China, and the water-based coating is safe and environment-friendly and convenient to construct, and the water-based coating is an important way for developing the development-friendly coating. The water-based anticorrosive coating system has the advantages of meeting the environmental protection standard, low VOC and safety, and the water-based acrylic acid dispersoid is actively popularized and applied to the industrial anticorrosive coating industry, ships, offshore platform facilities and other anticorrosive projects at present.

The conventional acrylic acid aqueous dispersion needs 8-10% of cosolvent, so that the low emission of VOC cannot be completely realized, and the conventional acrylic acid aqueous dispersion has low solid content and high viscosity, and is difficult to break through high solid content and low viscosity, so that the invention provides the aqueous acrylic acid dispersion applied to the high-iron surface coating to solve the problems.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides the aqueous acrylic acid dispersion applied to the surface coating of the high-speed rail. The core content is that a stable high-solid polyacrylic acid dispersion is prepared by a reactive polyol solvent through a chain transfer polymerization method.

The synthesis principle of the invention is as follows:

the water-based acrylic acid dispersion comprises, by mass, 8-15 parts of double bond-containing reactive polyol solvent, 46 parts of monomer and chain transfer agent, 35-40 parts of deionized water and 2-8 parts of dimethylethanolamine.

Preferably, the monomer comprises, by mass, 10-12 parts of methyl methacrylate, 8 parts of hydroxyethyl acrylate and 16-18 parts of styrene;

preferably, the chain transfer agent butyl acrylate is 10 parts by mass;

preferably, the double-bond reactive polyol solvent is polyvinyl alcohol and is 10-12 parts by mass;

preferably, the molecular weight of the polyvinyl alcohol is 500-1000.

The invention also provides a preparation method of the aqueous acrylic acid dispersion applied to the surface coating of the high-speed rail, which comprises the following steps:

step one, putting reactive polyol solvent containing double bonds in required mass percentage into a reaction kettle for reaction;

step two, closing the feeding hole, starting nitrogen to replace air in the kettle, starting to heat the kettle, and starting a stirring motor to stir when the temperature of materials in the kettle reaches 150 ℃;

weighing the components according to the design proportion of each monomer of the aqueous acrylic acid dispersoid and the chain transfer agent, dropwise adding the weighed methyl methacrylate, hydroxyethyl acrylate, styrene and butyl acrylate into the reaction kettle for 4 hours, and keeping the temperature of the reaction kettle at 150 ℃ for 2 hours to obtain an acrylate prepolymer;

after the reaction in the fourth step and the third step is finished, cooling the reaction kettle to 90 ℃, adding deionized water and dimethylethanolamine for neutralization, stirring at a high speed for 1 hour, cooling to below 80 ℃ after stirring is finished, and packaging.

Preferably, the packaged aqueous acrylic dispersion is stored in the shade.

Compared with the prior art, the invention has the beneficial effects that: the invention solves the problems of excessive auxiliary agents, low solid content, high viscosity and low VOC content of the existing aqueous acrylic acid dispersoid, and meets the requirement of environmental protection;

the aqueous acrylic dispersion is formed by polymerizing a plurality of monomers, the most commonly used monomers are methyl methacrylate and styrene, the styrene is used as a hard monomer to improve the hardness of a paint film and can replace part of methyl methacrylate, so that the production cost is reduced; the most commonly used soft monomer is butyl acrylate, which can improve the flexibility of the paint film; the most commonly used hydroxyl functional monomer is hydroxyethyl acrylate, and the introduction of hydroxyl functional groups can provide sites for crosslinking reaction;

methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and N, N-dimethylethanolamine are used as main raw materials to synthesize the aqueous acrylic acid dispersoid. It was found that the stability of the dispersion is improved by adding the acrylic acid monomer in a two-step process, increasing the degree of neutralization of the system, and slowing the rate of addition of water. The prepared dispersoid and the water-based curing agent have better compatibility, so the cross-linking degree of a paint film is higher, and the water resistance is better;

the synthetic principle of the aqueous acrylic acid dispersoid is chain transfer polymerization reaction, the operation is simple, the aqueous acrylic acid dispersoid applied to the high-speed rail surface coating is prepared by utilizing a chemical grafting method, and the comprehensive performance of a paint film is excellent.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.