Quick-curing super-weather-resistant low-gloss polyester resin for powder coating with flexibility and high hardness and preparation method thereof

Abstract

The invention discloses a group of fast-curing super-weather-resistant low-gloss polyester resin with flexibility and high hardness for a powder coating and a preparation method thereof. According to the formula, hydrogenated bisphenol A is introduced into a high-acid-value polyester component polyol; a fat polyacid structure is matched in the polyacid component; the polyester with the low acid value is matched with the combination of polyhydric alcohol hydroxyl pivalate hydroxyl pivalate, 2,2,4-trimethyl-1,3-pentanediol and 3-methyl-1,5-pentanediol; the ester polyol hydroxyl pivalate hydroxyl pivalate is introduced into polyester synthesis polyol with a low acid value; and aliphatic ring structures are introduced into polyacid components of the high-acid-value polyester component and the low-acid-value polyester component; and long-chain fatty acid is introduced into the end-capping reagent with a low acid value. The curing speed of the powder coating prepared from the polyester resin is high; thus, the obtained coating film has high surface hardness, soft low gloss, excellent weather resistance, durability, protection performance and processability, and good flexibility.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a polyester resin for super-weather-resistant low-gloss powder coating and a preparation method thereof. Background technique [0002] As an environmentally friendly coating, powder coatings have been highly recognized by the market in the past 30 years of development. Among them, powder coatings with super weather resistance are increasingly favored. Super weather-resistant powder coatings can meet the harsh conditions of outdoor high ultraviolet rays, high humidity and other conditions, such as: curtain walls, roofs, balconies, etc. In addition, it is difficult to recoat powder coatings, that is, it is difficult to repair the coating film in the later stage, which also makes the weather resistance of powder coatings more and more demanding. [0003] At present, there are few researches on pure polyester high-weather-resistant powder coatings. In the market, silicone-modified ...

AI Technical Summary

Problems solved by technology

There are also high and low acid value two-component polyester resin compositions for super-weather-resistant dry-blended matting powder coatings on the market, including high-acid-value polyester resins for super-weather-resistant powder coatings and low-acid-value polyester resins for super-weather-resistant powder coatings. The matting system of polyesters with different acid values ​​can achieve glossiness in the range of 17-50°. Due to the limitation of using a large amount of isophthalic acid monomer in this system, the brittleness of the entire coating film is relatively large, and the coating film can pass through 50kg.cm positive impact, failed to pass the 50kg.cm recoil, will be subject to certain restrictions in practical applications

[0004] At present, the main problems of ultra-weather-resistant low-gloss powder coatings on the market are: it is difficult to achieve a coating film with excellent comprehensive properties. First, the brittleness of the coating film is relatively large, and the mechanical properties cannot be recoiled. Using conventional technology to achieve flexibility will sacrifice part Weather resistance and surface hardness; the second is that when two-components are used to achieve low light, in order to ensure the speed difference, it is difficult to achieve rapid curing. Once the curing speed increases, the gloss of the coating film will not be easy to control

The market needs a kind of polyester resin with fast curing speed for preparing powder coating, and the obtained coating film has characteristics such as soft low gloss (17-50%), super weather resistance, high surface hardness and good flexibility. The present invention solves the above problems

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