A catalyst capable of reducing the curing temperature of saturated polyester resins with carboxyl groups

Abstract

The invention relates to a catalyst capable of reducing the curing temperature of saturated polyester resin taking carboxyl as the end group. The catalyst comprises the following raw materials in parts by weight: 70-95 parts of low-viscosity polyester resin, 5-20 parts of phase transfer catalyst capable of catalyzing carboxyl, 1-10 parts of catalyst capable of promoting ring opening of an epoxy group and 5-20 parts of antioxidant. The catalyst provided by the invention reduces the curing temperature of polyester / epoxy or pure-polyester powder coating, shortens the curing time, and can promote reaction of the powder coating at relatively low temperature to realize an energy saving function without influencing the decorativeness and functionality of the powder coating; the color yellowing of the powder coating is avoided, and the catalyst can be applied to white or light-colored powder; and meanwhile, a preparation method of the catalyst is simple and convenient to operate, the state call for saving energy and reducing emission is answered, the production cost is lowered, and the economic benefits of an enterprise are increased.

Description

Technical field [0001] The invention belongs to the technical field of catalysts, and relates to a catalyst, in particular a catalyst capable of reducing the curing temperature of a saturated polyester resin with a carboxyl group at its end group and a preparation method thereof. Background technique [0002] Powder coating and coating technology is a new technology developed in the middle of the 20th century. The new technology has the characteristics of no need to discharge organic matter into the air, reduction of environmental pollution, simple technology, easy realization of industrial automation, and excellent coating performance. The coating industry of all countries attaches great importance to it. The powder coating itself is a new type, solvent-free, 100% solid powder coating. Although it is non-polluting, it needs to be melted and solidified at a baking temperature of 180 ℃ or higher to meet the requirements of use. Now the country and society Energy saving and emissi...

AI Technical Summary

Problems solved by technology

To solve the problem of low-temperature curing of powder coatings, it is necessary to start with a curing agent or a catalyst. After selecting a suitable curing agent, the catalyst needs to be considered. Now the conventional catalyst is also the most effective catalyst. The catalyst is imidazole, which promotes the ring opening of epoxy resin. It can cure epoxy powder coatings or epoxy / polyester powder coatings at the lowest temperature of 120°C, but the decorative function of the surface will basically disappear, so pure imidazole catalysts are not ideal catalysts for powder coatings to achieve low temperature curing. This requires the development of a low-temperature catalyst that can not only meet the decorative requirements but also achieve low-temperature curing and its performance remains unchanged.

[0003] At the same time, pure imidazole catalysts have the disadvantages of poor decorativeness of powder coatings, easy occurrence of true pore bubbles, pollution, and discoloration such as yellowing of color.

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