KR-20260062956-A - Powder particles, a powder paint composition containing powder particles and a fluororesin, and a method for manufacturing the same.

Abstract

The object of the present invention is to provide powder particles for improving the adhesion strength between a substrate and a fluororesin layer. The present invention is a powder particle obtained by pre-mixing a high-temperature melt polymer and a filler in water to obtain an aqueous dispersion, and then heating the aqueous dispersion.

Inventors

• 리우, 유칭

Assignees

• 더 케무어스 컴퍼니 에프씨, 엘엘씨
• 미쯔이 케무어스 플루오로프로덕츠 가부시끼가이샤

Dates

Publication Date

20260507

Application Date

20240830

Priority Date

20230831

Claims (14)

1. Powder particles obtained by pre-mixing a high-temperature molten polymer and a filler in water to obtain an aqueous dispersion, and then heating the aqueous dispersion.
2. In claim 1, the high-temperature melt polymer and the filler are fused, powder particles.
3. In claim 1, the high-temperature melt polymer is a powder particle selected from at least one of polyimide, polyamideimide, polyamide, polyester, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyetherimide, polyethersulfone, polyether ether ketone, and polyether ketone ketone.
4. In claim 1, the high-temperature melt polymer is a powder particle selected from at least one of polyphenylene sulfide, polyetherimide, polyether ether ketone, and polyether ketone ketone.
5. In claim 1, the filler is a powder particle, which is at least one of inorganic particles selected from silicon carbide, silicon oxide, aluminum oxide, zinc oxide, tin oxide, titanium oxide, barium sulfate, and carbon black.
6. Powder particles according to claim 1, comprising 30 to 300 parts by weight of the filler per 100 parts by weight of the high-temperature-melt polymer.
7. In claim 1, powder particles having a particle size of 150 μm or less.
8. A powder paint composition comprising powder particles according to any one of claims 1 to 7; and fluororesin powder.
9. In claim 8, the fluororesin powder is a powder paint composition containing a high-temperature molten fluororesin.
10. In claim 8, the fluororesin powder is a powder paint composition containing perfluororesin.
11. A powder paint composition according to claim 8, comprising 80 to 50 weight% of the powder particles and 20 to 50 weight% of the fluororesin powder based on the total amount of the powder paint composition.
12. As a method for manufacturing powder particles, (1) A step of mixing a high-temperature molten polymer and a filler in water to obtain an aqueous dispersion; (2) a step of heating the aqueous dispersion and removing water to obtain a solid; and (3) A method for manufacturing powder particles comprising the step of grinding the solid to obtain powder particles.
13. A method for manufacturing powder particles according to claim 12, further comprising, after step (2), a step of heating at a temperature above the glass transition point of the high-temperature molten polymer.
14. As a method for manufacturing a powder paint composition, (1) A step of mixing a high-temperature molten polymer and a filler in water to obtain an aqueous dispersion; (2) A step of heating the aqueous dispersion and removing water to obtain a solid; (3) A step of crushing the above solid to obtain powder particles; and (4) A method for preparing a powder paint composition, comprising the step of adding fluororesin powder to the powder particles and mixing to obtain a powder paint composition.

Description

Powder particles, a powder paint composition containing powder particles and a fluororesin, and a method for manufacturing the same. Cross-reference regarding related applications This application claims the benefit of priority to Japanese Patent Application No. 2023-141274 filed on August 31, 2023, the full text of which is incorporated herein by reference. Technology field The present invention relates to powder particles that improve adhesion between a substrate and a fluororesin layer; and a powder paint composition containing powder particles and a fluororesin that is useful as a primer. Furthermore, the present invention also relates to a method for manufacturing such powder particles and a powder paint composition. Fluoropolymers possess excellent chemical resistance, non-pressure-sensitive adhesion, heat resistance, and electrical insulation properties, and have been widely used as coating materials. Fluoropolymers have non-pressure-sensitive adhesion, which tends to cause adhesion defects when coated directly onto a substrate (particularly various metal substrates). Therefore, in many cases, a primer layer having good adhesion to the substrate is provided as an undercoat layer for the fluoropolymer. The applicant has proposed polymer particles that have excellent adhesion between a substrate and a layer and prevent peeling due to heat, moisture, etc., and a paint composition containing said polymer particles (Patent Document 1). Although such a paint composition has excellent effects, there are some problems, such as the use of organic solvents in the manufacture of polymer particles which can cause environmental burden, and the fact that the resulting paint composition is an aqueous dispersion, so the addition of a surfactant is required to ensure the dispersibility of the fluororesin. On the other hand, powder coating is known to have advantages such as being environmentally friendly because it does not use solvents, resource-efficient because the powder can be easily reused, and having excellent coating workability. Patent Document 2 discloses a powder primer composition containing fused fluororesin powder and polyethersulfone powder. However, a paint composition with excellent adhesion and corrosion resistance is still needed. 1. Powder particles The powder particles of the present invention are powder particles in which (A) a high-temperature melt polymer and (B) a filler are fused. The powder particles can be obtained by pre-mixing the high-temperature melt polymer and the filler in water to obtain an aqueous dispersion, and then heating the aqueous dispersion. A. High-temperature melt polymer The high-temperature melt polymer of the present invention is a polymer that melts upon heating and has a glass transition point and/or a melting point. Specific examples of high-temperature melt polymers include polyimide (PI), polyamideimide (PAI), polyamide, polyester, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyetherimide, polyethersulfone (PES), polyether ether ketone, polyether ketone ketone, etc. Among these high-temperature melt polymers, polyetherimide (PEI), polyphenylsulfone (PPS), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), etc. are preferred due to their heat resistance and high mechanical strength. Since the high-temperature melt polymer is used in combination with a filler, the high-temperature melt polymer used in the present invention generally does not contain a fluororesin having excellent non-pressure-sensitive adhesion. The shape of the high-temperature-melt polymer is not particularly limited, but may be, for example, powder, granules or granulated granules, pellets, etc. The average particle size of the high-temperature-melt polymer is preferably 0.1 to 300 μm, more preferably 1 to 100 μm, and even more preferably 5 to 70 μm. Commercially available hot-melt polymers may be used. Examples of commercially available hot-melt polymers include the ULTEM® series available from SABIC and PPS available from DIC Corporation. B. Filler Inorganic particles may be used as fillers for the present invention and may be selected according to the application of the coating film, taking into account their water resistance, chemical resistance, etc. The fillers of the present invention are preferably manufactured from materials that are insoluble in water. Specific examples of fillers include metal powder, metal oxides (aluminum oxide, zinc oxide, tin oxide, titanium oxide, etc.), glass beads, glass flakes, glass particles, ceramics, silicon carbide, silicon oxide, calcium fluoride, carbon black, graphite, mica, barium sulfate, etc. The fillers of the present invention have heat resistance of at least 200°C, preferably 300°C, and preferably do not promote the decomposition of the fluororesin. Among the fillers, silicon oxide, aluminum oxide, zinc oxide, tin oxide, and barium sulfate are preferred. The particle size of the filler is not particularly limited,