Highly branched alkyd resin with high solid content and low viscosity and preparation method of alkyd resin

Abstract

The invention discloses highly branched alkyd resin with high solid content and low viscosity. The alkyd resin is prepared from components in parts by weight as follows: 100-120 parts of fatty acid, 120-140 parts of polyacids, 140-160 parts of polyols, 15-20 parts of benzoic acid, 1-2 parts of an antioxidant and 30-40 parts of ethyl acetate. Highly branched polyester is obtained from polyols and polyacids through copolymerization and is then modified with fatty acid and benzoic acid, an end group of polyester is enabled to contain a long-chain alkyl group and a benzyl group, the long-chain alkyl group provides a flexibility function and reduces the viscosity of highly branched polyester, the prepared highly branched alkyd resin with high solid content and low viscosity has high branching degree, the solid content is 90%-95%, the viscosity is 10,000 mPa*s / 30 DEG C, the coating VOC (VOC is lower than or equal to 420 g / L) of paint is reduced greatly, a paint film is thicker after one-time spraying, the fullness is improved, and good dryness and hardness can be kept.

Description

technical field [0001] The invention belongs to the technical field of coating chemicals, and in particular relates to a highly branched, high-solid, low-viscosity alkyd resin and a preparation method thereof. Background technique [0002] Alkyd resins currently used in the manufacture of solvent-based two-component polyurethane coatings are generally synthesized from components such as fatty acids, phthalic anhydride, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, and xylene under certain process conditions. After the alkyd resin is prepared, various pigments and fillers, additives, solvents and other components are added to prepare various A components, and then the polyurethane curing agent B component and the diluent C component are combined to obtain a two-component Polyurethane coating. The problem of this kind of coating is that usually the solid content of alkyd resin is generally 70-85%, and the viscosity is 20000mPa.s / 30°C. :15-25S), low solid co...

AI Technical Summary

Problems solved by technology

The problem of this kind of coating is that usually the solid content of alkyd resin is generally 70-85%, and the viscosity is 20000mPa.s / 30°C. :15-25S), low solid content, high coating VOC (generally 480-580g / L), serious pollution, and at the same time, the paint film is thinner and the fullness is poor after one spraying

Although some alkyd resins have a solid content of 90-95% and a viscosity below 10,000mPa.s / 30°C, the coatings produced by them have extremely poor dryness and hardness, and can only be used as raw materials for color wiping, which cannot meet the requirements of polyurethane coatings. Performance requirements for dryness and hardness

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