Polycarbonate modified acrylic resin and preparation method thereof

Abstract

The invention relates to a polycarbonate modified acrylic resin and a preparation method thereof. The polycarbonate modified acrylic resin comprises the following raw materials in percentage by weight: 5-30 percent of polycarbonate prepolymer, 5-15 percent of styrene monomer, 1-3 percent of acrylic acid monomer, 20-30 percent of hydroxyethyl acrylate monomer, 10-30 percent of butyl acrylate monomer, 10-20 percent of methyl methacrylate monomer and 4-10 percent of ethyl acrylate monomer, and is formed in a solvent by using an initiator through free radical polymerization, wherein the resin content is 60-80 percent by weight based on solid; the weight-average molecular weight is 10,000-20,000; the viscosity at the temperature of 25 DEG C is 2,000-6,000mPa.s; the resin chain of the resin comprises a constitutional unit of the polycarbonate prepolymer; and the sum of said raw materials is 100 percent. In a double-component polycarbonate automotive paint prepared by using the polycarbonatemodified acrylic resin, the appearance of a coating is improved, and the weather resistance of the coating is also improved.

Description

technical field [0001] The invention relates to a polycarbonate-modified acrylic resin and a preparation method thereof. The resin is particularly suitable as a hydroxyl component for preparing two-component polyurethane coatings for vehicle topcoats. Background technique [0002] Acrylic resin has become a kind of synthetic resin for coating with the most types and good comprehensive performance in the coating system because of its excellent light resistance and outdoor aging resistance, especially the hydroxyl acrylic polymer because of its light color, good gloss and color retention, It has been widely used in automotive coatings due to its advantages such as high hardness. With the development of society, while people pay attention to the high weather resistance, high corrosion resistance and high wear resistance of vehicle coating films, the requirements for the appearance quality of automobile coating films, that is, the decorative properties of coating films are also ...

AI Technical Summary

Problems solved by technology

In order to improve the appearance of the paint film, improving the properties of the film-forming resin is a key factor. One of the methods is to prepare acrylic resin with low viscosity and high solid content. The content of paint thinner prepared with this type of resin is relatively small, and the amount of solvent volatilized at the moment of spraying may be Doubling down, so the increase in viscosity is not large, and the wet film maintains a low viscosity after spraying, which provides good fluidity for the coating film in the flash leveling stage, thereby having a better leveling effect and greatly improving the The gloss and fullness of the coating film, but the synthesis of this type of resin often requires the addition of a large number of special monomers containing ester ring structures and tertiary carbonic acid groups, such as isobornyl methacrylate, glycidyl tertiary carbonic acid, etc. The high price of monomers leads to a great increase in production costs; the second method is to use the characteristics of good gloss retention of compounds containing benzene ring structures (such as styrene), and the introduction of benzene ring structures into the main chain of the resin can make the coating The sharpness of image has been significantly improved, but its weather resistance is obviously insufficient. Therefore, when the benzene ring structure exceeds a certain amount, the coating film is prone to yellowing, which affects the outdoor use effect. Therefore, the benzene ring structure (such as benzene Only when the content of ethylene) compounds is controlled within a certain range can the film’s clear image and outdoor weather resistance be taken into account, but this control is difficult to achieve

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