CN-120484658-B - Preparation method of aqueous single-component plastic paint

CN120484658BCN 120484658 BCN120484658 BCN 120484658BCN-120484658-B

Abstract

The invention relates to the technical field of cured lacquer coatings, in particular to a preparation method of water-based single-component plastic paint. The aqueous single-component plastic paint prepared by the invention overcomes the problems of poor environmental protection and difficulty in balancing the comprehensive performance of a paint film. The preparation method comprises the steps of preparing aqueous single-component plastic paint by optimizing a preparation method and a raw material system, selecting alicyclic isocyanate, reacting step by step, combining ring-opening epoxy resin, quercetin and disulfide to form a compact coating, improving corrosion resistance and adhesive force, introducing fluorine-containing monomers to enhance waterproofness and low-temperature stability by utilizing a hydrolysis KH560 and polyurethane-polyurea composite system, constructing a three-dimensional network by free radical copolymerization, adding triethylamine to resist polymerization, optimizing feeding and post-curing steps, and realizing balance of hardness, drying speed and surface state after cooking. The aqueous single-component plastic paint is suitable for various plastic substrates such as automobile interior and exterior trim, 3C products and the like, and has remarkable advantages in the aspects of protection performance and construction adaptability.

Inventors

ZHOU YAN
ZHANG ZHAO
LI XIAOSONG

Assignees

益帆涂料(无锡)有限公司

Dates

Publication Date: 20260508
Application Date: 20250519

Claims (7)

1. A preparation method of a water-based single-component plastic paint is characterized by comprising the following steps: Completely and uniformly mixing the dried polyurethane prepolymer and the polyurea prepolymer to obtain a water-based single-component plastic paint precursor; adding the aqueous single-component plastic paint precursor into the dispersed mixed solution, emulsifying and dispersing, standing for defoaming to obtain the aqueous single-component plastic paint; the preparation raw materials of the mixed solution comprise deionized water, hydrolyzed KH560, 1, 4-butanediol, tripropylene glycol diacrylate, potassium persulfate and triethylamine; The polyurethane prepolymer is prepared from diisocyanate, quercetin, 2-hydroxyethyl disulfide and ring-opening epoxy resin; The polyurea prepolymer is obtained by reacting diisocyanate and diamine; The preparation method of the ring-opened epoxy resin comprises the steps of adding epoxy resin into a four-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating, then dropwise adding glycidyl methacrylate and boron trifluoride-amine complex, stirring, adding hydroquinone, heating, continuing to react to obtain modified epoxy resin, cooling the modified epoxy resin, adding N, N-dimethylformamide, and stirring to obtain the ring-opened epoxy resin.
2. The preparation method of the aqueous single-component plastic paint according to claim 1 is characterized in that the polyurethane prepolymer is 80-100 parts by mass, the polyurea prepolymer is 24-40 parts by mass, the hydrolyzed KH560 is 5.5-7.5 parts by mass, the 1, 4-butanediol is 4.0-5.5 parts by mass, the tripropylene glycol diacrylate is 7.2-8.0 parts by mass, and the deionized water is 420-500 parts by mass.
3. The preparation method of the aqueous single-component plastic paint according to claim 1, wherein the post-curing temperature is 65-75 ℃, the heat preservation time is 3-7h, and the dispersing speed is 1500-2500r/min.
4. The preparation method of the aqueous single-component plastic paint is characterized by comprising the steps of adding diisocyanate and N, N-dimethylformamide into a four-necked flask, heating, adding dibutyltin dilaurate, 1/2 mass of quercetin and 1/2 mass of 2-hydroxyethyl disulfide, reacting, adding the rest of quercetin and 2-hydroxyethyl disulfide, heating, cooling, adding ring-opening epoxy resin, reacting to obtain a polyurethane prepolymer precursor, and neutralizing after cooling to obtain the polyurethane prepolymer.
5. The method for preparing a water-based one-component plastic paint according to claim 4, wherein the diisocyanate used for preparing the polyurethane prepolymer is one of 4, 4-dicyclohexylmethane diisocyanate and isophorone diisocyanate, the amount of the diisocyanate used for preparing the polyurethane prepolymer is 68.9-84.0 parts, the total amount of the quercetin is 30.2-36.3 parts, and the total amount of the 2-hydroxyethyl disulfide is 15.4-18.5 parts.
6. The preparation method of the aqueous single-component plastic paint is characterized by comprising the steps of adding diisocyanate and N, N-dimethylformamide into a four-neck flask, heating, dripping diamine solution, heating after the dripping is finished, reacting to obtain the polyurea prepolymer, wherein the diamine solution is obtained by mixing and dissolving diamine and N, N-dimethylformamide.
7. The method for preparing a water-based one-component plastic paint as claimed in claim 6, wherein the diamine is one of isophorone diamine, diethyl toluene diamine, 4 '-diamino dicyclohexylmethane and 2,2' -bis (trifluoromethyl) diaminobiphenyl.

Description

Preparation method of aqueous single-component plastic paint Technical Field The invention relates to the technical field of cured lacquer coatings, in particular to a preparation method of water-based single-component plastic paint. Background The traditional plastic paint is mostly solvent-type paint, and has good adhesive force, hardness, tolerance and the like, but contains a large amount of Volatile Organic Compounds (VOCs), so that the environment and the human health are seriously affected. With the increasing strictness of environmental regulations and the improvement of environmental awareness of people, water-based plastic paint is developed and developed rapidly. Most of water-based plastic paint, especially water-based acrylic ester system plastic paint, in the current market is a two-component system, and a curing agent is required to be added before use, so that the construction complexity is increased, and the mixed paint liquid has the limitation of an activation period, so that waste is caused. The single-component water-based plastic paint is convenient to construct, but is difficult to compare favorably with solvent-based paint or double-component water-based paint in performance, particularly in corrosion resistance, stability and freeze thawing resistance, and particularly in fields of demanding automobile interior and exterior trim, 3C electronics, household appliances and the like, has extremely high comprehensive performance requirements on paint films, and needs to show excellent comprehensive performances such as adhesive force, hardness and the like on the base materials made of the materials. Some aqueous one-component acrylate systems used to prepare coatings may incorporate small amounts of organic solvents as film forming aids or leveling agents in order to improve performance, contrary to the currently proposed "zero VOC" or "ultra low VOC" environmental concepts. Therefore, the development of the water-based single-component acrylic ester plastic paint which does not contain an organic solvent and is pure water, has a good surface state after digestion before use, is excellent in corrosion resistance, adhesive force and freeze thawing resistance after solidification, and has important practical significance and market value. Therefore, a preparation method of the water-based single-component plastic paint is provided. Disclosure of Invention The invention aims to provide a preparation method of a water-based single-component plastic paint, which is characterized in that the corrosion resistance and adhesive force of the water-based single-component plastic paint are obviously improved by adopting alicyclic isocyanate and ring-opening epoxy resin in combination through optimizing the selection of isocyanate types and a step reaction method. The dynamic disulfide bond and the phenolic hydroxyl group cooperate to delay oxidative degradation, and the bubble defect is avoided by vacuum dehydration. Aiming at water resistance and low-temperature stability, a hydrophobic silanol layer is formed by hydrolysis of a silane coupling agent, and a polyurethane-polyurea composite system is combined, so that the hydrophobic freezing resistance is enhanced by utilizing the complementation of a rigid-flexible chain segment and a fluorine-containing monomer, and the compactness of the coating in freeze thawing cycle is ensured. The three-dimensional cross-linked network is constructed through free radical copolymerization, the surface state after cooking is regulated and controlled by combining a neutralizing agent, the drying efficiency is optimized through the steps of step chain extension and post-curing, the internal stress is relieved through dynamic bonds, and the unification of high hardness, quick drying property and long-acting stability is realized. The technology is suitable for plastic such as automobile interior and exterior trim, 3C electronics, household appliances and the like, and acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate (PC) and carbon fiber base materials, and has excellent comprehensive performance. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a preparation method of a water-based single-component plastic paint, which comprises the following steps: The preparation method comprises the steps of completely and uniformly mixing a dried polyurethane prepolymer and a polyurea prepolymer to obtain a water-based single-component plastic paint precursor, adding the water-based single-component plastic paint precursor into a dispersed mixed solution, emulsifying and dispersing, standing and defoaming to obtain the water-based single-component plastic paint, heating the water-based single-component plastic paint, preserving heat and performing post curing, wherein the VOCs content of the water-based single-component plastic paint is lower than 5g/L. The preparation raw materials