Epoxy cured 70:30 polyester resin excellent in levelability and solvent resistance and preparation method thereof

Abstract

The invention relates to an epoxy cured 70:30 polyester resin excellent in levelability and solvent resistance, and a preparation method thereof, and belongs to the technical field of power paint chemistry. According to the preparation method, long chain flexible raw materials such as tetradecanedioic acid are adopted, so that polyester melting viscosity is reduced effectively, and coating film surface levelability is improved; high-functionality fluorine-containing end-capping reagent tetra(3, 4, 5, 6-tetrafluorophthalic acid) pentaerythritol ester is adopted for polyester end capping to reduce polyester resin carboxyl end group activity, reducing curing speed with E-12 epoxy resin, prolonging gelling time, ensuring enough leveling time, and achieving excellent cured coating film levelability; the end capping reagent is extremely high in functionality, so that cured coating film crosslinking density is large; end capping reagent self fluorine content is high, so that the cured coatingfilm possesses excellent resistance on routine organic solvents; the epoxy cured 70:30 polyester resin is applied in powder paint, so that coating layers excellent in levelability and solvent resistance are obtained. The raw materials are easily available, operation of the preparation process is simple and convenient, the preparation method is suitable for large scale production, and it is benefical for improvement of powder paint popularization and applications.

Description

technical field [0001] The invention relates to a polyester resin for powder coatings and a preparation method thereof, in particular to an epoxy-cured 70:30 polyester resin with excellent leveling properties and solvent resistance and a preparation method thereof, belonging to the technical field of powder coating chemical industry. Background technique [0002] Powder coating has the characteristics of economy, environmental protection and excellent performance, and has attracted more and more attention from people. Among them, hybrid powder coatings account for more than 80% of the total powder coatings. Considering energy saving and consumption reduction and coating substrate factors, hybrid powder coatings have become a new development direction of the powder coating industry and are widely used in household appliances, hardware Components, metal furniture and other fields. [0003] Hybrid powder coatings are also called polyester-epoxy hybrid powder coatings, which ca...

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Problems solved by technology

[0006] In view of the high activity of the carboxyl group in the 70:30 hybrid powder coating polyester in the prior art, the gelation time is short, the softening point of the polyester resin and the high-temperature melt viscosity are relatively large, resulting in insufficient leveling of the final coating film surface and The defect that the conventional coating film that forms is poor in solvent resistance, in order to improve the leveling and solvent resistance of 70:30 mixed type powder coating, the object of the present invention is to provide a kind of epoxy curing 70 with excellent leveling property and solvent resistance : 30 polyester resin and preparation method, this method uses tetradecanedioic acid, the use of 1,9-nonanediol long-chain flexible raw material can effectively reduce the melt viscosity of polyester, increase the leveling property of film surface, use Polyethylene glycol trimethoxysilyl propyl ether, glyceryl monocaprate and other components with low surface tension and viscosity are used as raw materials, which have excellent self-lubricating properties and can improve the compatibility of various materials in powder coatings during curing. , at the same time, it has the ability to migrate to the coating surface, and has the function of helping leveling and improving the fineness of the coating film surface

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