Method for improving pinholes and levelling property of hydroxyalkylamide/polyester powder paint

A hydroxyalkylamide, polyester powder technology, applied in polyurea/polyurethane coatings, powder coatings, polyester coatings, etc., to reduce the speed of curing, help thick coating, and improve the effect of leveling

Active Publication Date: 2011-10-12
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
View PDF2 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It is a good choice to use additives and benzoin to increase the degassing effect and reduce yellowing, but the accompanying yellowing problem adds new problems to the application of powder coatings. Therefore, it is necessary to develop some new substances that can be used with coatings. The resin has good compatibility, can increase the leveling of powder coatings, increase the threshold of air bubble removal, and reduce the appearance of pinholes, which has great market prospects and application value

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for improving pinholes and levelling property of hydroxyalkylamide/polyester powder paint

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Dissolve isophorone diisocyanate in a solvent and add it dropwise into trimethylolpropane to prepare highly branched polyurethane (HBPU-1). The molecular weight of the obtained HBPU-1 is 2000, and the degree of branching is 0.7; Precipitate HBPU-1 with water, suction filter and dry the precipitate to obtain HBPU-1 powder; mix HBPU-1 powder with hydroxyalkylamide / polyester powder coating, in the mixture, HBPU-1 powder and hydroxyalkylamide The weight ratio of the carboxylic acid polyester contained in the polyester powder coating is 0.01:1, and then the mixture is melted, extruded, and pressed into sheets by a twin-screw extruder, and the temperature in the first zone of the twin-screw extruder is 90°C, the temperature in the second zone is 100°C; the sheet is ground into a fine powder with a colloid mill, and the fine powder is sieved with a 160-mesh filter to obtain a modified hydroxyalkylamide / polyester powder coating.

[0019] The modified hydroxyalkylamide / polyester...

Embodiment 2

[0021] Dissolving isophorone diisocyanate and 1,4-butanediol in a solvent for prepolymerization to form NCO-terminated polyurethane prepolymer. Then, the prepolymer was added dropwise into trimethylolpropane to react to prepare highly branched polyurethane (HBPU-2). The molecular weight of the prepared HBPU-2 was 6000, and the degree of branching was 0.6. Precipitate HBPU-2 with water, suction filter and dry the precipitate to obtain HBPU-2 powder; mix HBPU-2 powder with hydroxyalkylamide / polyester powder coating, in the mixture, HBPU-2 powder and hydroxyalkylamide The weight ratio of the carboxylic acid polyester contained in the polyester powder coating is 0.02:1, and then the mixture is melted, extruded, and tableted by a twin-screw extruder to form a sheet. The temperature in the first zone of the twin-screw extruder is 90°C, the temperature in the second zone is 100°C; the sheet is ground into a fine powder with a colloid mill, and the fine powder is sieved with a 160-mes...

Embodiment 3

[0024] Dissolving 2,4-toluene diisocyanate and 1,2-propanediol in a solvent for prepolymerization into NCO-terminated polyurethane prepolymer. Then the prepolymer is added dropwise in trimethylolethane to continue the reaction, and finally the epoxy resin is added to react to obtain highly branched polyurethane (HBPU-3). The molecular weight of the HBPU-3 obtained is 12000, and 0.52. Precipitate HBPU-3 with water, filter and dry the precipitate to obtain HBPU-3 powder; mix HBPU-3 powder with hydroxyalkylamide / polyester powder coating, in the mixture, HBPU-3 powder and hydroxyalkylamide The weight ratio of the carboxylic acid polyester contained in the polyester powder coating is 0.05:1, and then the mixture is melted, extruded, and tableted by a twin-screw extruder to form a sheet. The temperature in the first zone of the twin-screw extruder is 95°C, the temperature in the second zone is 105°C; the sheet is ground into a fine powder with a colloid mill, and the fine powder is...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
flow lengthaaaaaaaaaa
flow lengthaaaaaaaaaa
flow lengthaaaaaaaaaa
Login to view more

Abstract

The invention relates to a method for improving the pinholes and levelling property of hydroxyalkylamide / polyester powder paint. After the existing hydroxyalkylamide / polyester powder paint is cured, pinholes are generated on the surface of the paint. The method comprises the following steps: firstly, adopting the highly branched polymer synthesis method and using isocyanate monomer and polyfunctional monomer to synthesize highly branched polyurethane solution; secondly, using water to precipitate the solution, performing suction filtering, drying to obtain highly branched polyurethane powder,mixing the highly branched polyurethane powder with hydroxyalkylamide / polyester powder paint according to a ratio, using a double-screw extruder to melt, extrude and tablet the mixture and obtain sheet, grinding the sheet to fine powder, and sieving to obtain the modified hydroxyalkylamide / polyester powder paint. By adopting the method, the problem that as the viscosity of the powder paint is increased too fast in the curing process, pinholes are generated, can be obviously improved, the curing speed can be reduced, the effect of high levelling can be realized and high thickness coating of the powder paint is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of powder coatings, and relates to a method for improving the pinhole and leveling properties of hydroxyalkylamide / polyester powder coatings. Background technique [0002] Powder coatings have developed rapidly in the coatings industry due to their energy saving and environmental protection. Especially powder coatings for outdoor use are becoming more and more widely used. At present, hydroxyalkylamide / polyester powder coating is the latest development in the field of weather-resistant powder coatings. As the most important substitute for TGIG (triglycidyl isocyanate) / polyester system coatings, it is a non-toxic, New powder coating with better performance. However, hydroxyalkylamide / polyester powder coatings also have certain defects. During the curing process, water molecules will overflow, and pinholes will be formed on the surface of the coating film, which will not only affect the appearance but also l...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C09D167/00C09D175/04C09D175/14C09D175/08C09D5/03C08G18/32C08G18/76C08G18/67C08G18/50
Inventor 乌学东刘丹袁仁能
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap