Polyester resin for powder coating for structural member of engineering machine and preparation method of polyester resin

Abstract

The invention discloses polyester resin for a powder coating for a structural member of an engineering machine. The polyester resin has the acid value of 29-45mgKOH/g, the hydroxyl value of smaller than 6mgKOH/g, the glass transition temperature of 55-65 DEG C, the melt viscosity of 3-6Pa.s and the 180-DEG C reactivity of 80-200S and is mainly prepared by cocondensing the following raw materials in percentage by weight: 30-45% of polyalcohol, 45-55% of aromatic polyacid, 0-2% of aliphatic polyacid, 0-2% of a branching agent, 5-15% of an acidolysis agent, 0.005-0.15% of an esterification catalyst, 0.04-0.3% of a curing accelerator and 0.1-1% of an antioxidant. The invention also discloses a preparation method of the polyester resin. The polyester resin disclosed by the invention is of a TGIC-cured type, has favorable weather resistance, corrosion resistance, mechanical property and low-temperature curing characteristics and can be used for solving the problems of frosting and curing incompleteness existing at present when being applied to the powder coating for the structural member of the engineering machine.

Description

technical field [0001] The invention relates to a polyester resin, in particular to a polyester resin for powder coating of structural parts of engineering machinery. Meanwhile, the invention also relates to a preparation method of the polyester resin. Background technique [0002] Construction machinery is an important foundation for my country's industrial construction and national defense construction infrastructure. Its products are rich in types, including excavators, cranes, forklifts, bulldozers, etc., and are widely used in various construction sites such as mines, construction sites, ports, airports, and warehouses. . The operating conditions of construction machinery are harsh, facing the wind and sun, dust pollution and rain erosion, etc., and the road conditions and environmental factors are poor, which requires the sprayed coating to have good mechanical properties and anti-corrosion properties. At present, most products of foreign construction machinery still ...

AI Technical Summary

Problems solved by technology

[0007] One of the objectives of the present invention is to provide a polyester resin for powder coatings of engineering machinery structural parts. The polyester resin can be prepared into powder coatings and applied to engineering machinery structural parts to solve the existing problems of blooming, insufficient curing degree, and mechanical properties. Poor, poor corrosion resistance and other disadvantages, but also has good weather resistance, especially suitable for powder coatings of polyester / TGIC curing system

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