Quick-drying scratch-resistant varnish composition with high solid content as well as preparation method and application of quick-drying scratch-resistant varnish composition

Abstract

The invention discloses quick-drying scratch-resistant varnish composition with high solid content. The quick-drying scratch-resistant varnish composition comprises varnish and a curing agent in a volume ratio being 2:1, wherein the varnish comprises components in parts by weight as follows: 60-80 parts of acrylic resin, 3-20 parts of polyester resin, 0.4-1 part of a leveling agent, 0.02-0.5 parts of a catalyst, 1-2 parts of an ageing-resistant auxiliary and 10-20 parts of a first solvent; the curing agent comprises components in parts by weight as follows: 60-80 parts of isocyanate and 10-20 parts of a second solvent. The quick-drying scratch-resistant varnish composition with high solid content has quick-drying performance and scratch resistance, further has good paint film property, workability and high construction solid content and is particularly applicable to painting for automobile repairing, and the VOC (volatile organic compounds) can be reduced to 420 g / L or lower.

Description

technical field [0001] The invention relates to the technical field of coatings, in particular to a high-solid fast-drying scratch-resistant varnish composition, a preparation method and an application. Background technique [0002] In order to protect the environment, the development direction of automotive refinish paint is water-based paint and high-solid varnish. However, the traditional high-solid varnish needs to meet high construction solid content, the molecular weight of the resin is small, and the glass transition temperature is low. The (Tg) point is low, which causes the initial drying speed of the varnish to be slow, and it cannot be polished and assembled according to normal baking conditions or natural drying time, which reduces the production efficiency of automobile repair. [0003] It is difficult to balance the drying speed and construction solid content of traditional automotive refinish varnishes. Using high molecular weight and high Tg resins can increa...

AI Technical Summary

Problems solved by technology

[0002] In order to protect the environment, the development direction of automotive refinish paint is water-based paint and high-solid varnish. However, the traditional high-solid varnish needs to meet high construction solid content, the molecular weight of the resin is small, and the glass transition temperature is low. The (Tg) point is low, resulting in a slow initial drying speed of the varnish. It cannot be polished and assembled according to normal baking conditions or natural drying time, which reduces the production efficiency of car repair.

[0003] It is difficult to balance the drying speed and construction solid content of traditional automotive refinish varnishes. Using high molecular weight and high Tg resins can increase the drying speed, but often cannot achieve high construction solid content, and the drying speed of varnishes with high construction solid content cannot make people satisfy

By changing the main resin type of the paint from acrylic to a special functional resin, a fast drying speed and a good balance of construction solids can be achieved, but it will also bring new problems: a) too short usable time, usually In a sense, the varnish of automotive refinish paint needs at least 1 hour of usable time after it is prepared. After the usable time is exceeded, the paint will gel and cannot continue to be used. However, the usable time of this resin is only 10- 20 minutes, unable to adapt to the actual requirements of production; b) difficult to polish, in order to play a decorative and protective role, automotive repair varnishes need a certain cross-linking density, hardness and flexibility, high cross-linking density and flexibility are conducive to obtaining good Chemical resistance, scratch resistance and stone chip resistance, but the high crosslinking density and flexibility of this special functional resin will make it difficult to polish the varnish after construction and reduce production efficiency; the above shortcomings make this special function The resin cannot be used as the main resin of the paint, and meets the requirements of the refinish paint clear coat

To sum up, automotive refinish paint lacks a high-solid varnish with fast drying and good scratch resistance, especially a varnish with VOC<420g / L

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