Coating composition and method for forming multilayer coating film

Patent metadata

Field	Value
Publication number	US-12503621-B2
Application number	US-202017788836-A
Country	US
Kind code	B2
Filing date	Nov 19, 2020
Priority date	Dec 26, 2019
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

Provided is a coating composition from which a coating film having excellent decontamination properties, scratch resistance, and transparency can be formed. Specifically, provided is a coating composition containing a resin (A) having a hydroxyl group and an alkoxysilyl group, a curing agent (B), and an acrylic resin-coated silica particle (C) dispersion, wherein: the acrylic resin-coated silica particle (C) dispersion is a reaction product of silica particles with a polymerizable unsaturated group (c1) and a polymerizable unsaturated monomer mixture (c2); and the polymerizable unsaturated monomer mixture (c2) contains, as at least a part of components thereof, a polymerizable unsaturated monomer having a polysiloxane structure (c21) and an alkoxysilyl group-containing polymerizable unsaturated monomer (c22).

First claim

The invention claimed is:

1 . A coating composition comprising a resin with a hydroxyl group and an alkoxysilyl group (A), a curing agent (B) and a dispersion of acrylic resin- coated silica particles (C), wherein the dispersion of acrylic resin-coated silica particles (C) is a dispersion of acrylic resin-coated silica particles (C) that is the reaction product of silica particles with a polymerizable unsaturated group (c1) and a polymerizable unsaturated monomer mixture (c2), and the polymerizable unsaturated monomer mixture (c2) includes, as at least a portion of its components, a polymerizable unsaturated monomer having a polysiloxane structure (c21) represented by the following formula (I):

wherein R 1 represents a hydrogen atom or a methyl group, Z represents a structure including the following formula (II), and X represents a hydrogen atom or a (meth) acryloyl, alkyl, hydroxyl, amino, (alicyclic) epoxy, carboxyl, mercapto, vinyl, isocyanate or aryl group,

wherein m represents a number of 2 to 160, R 2 represent phenyl groups or alkyl groups of 1 to 6 carbon atoms, which may be the same or different, and R 3 represents an alkylene group of 1 to 6 carbon atoms, and an alkoxysilyl group-containing polymerizable unsaturated monomer (c22), wherein a proportion of the alkoxysilyl group-containing polymerizable unsaturated monomer (c22) in the polymerizable unsaturated monomer mixture (c2) is in a range of 15 mass % to 55 mass % with respect to a total amount of the polymerizable
unsaturated monomer mixture (c2), and
wherein the alkoxysilyl group-containing polymerizable unsaturated monomer (c22) is different in structure from the polymerizable unsaturated monomer having a polysiloxane structure (c21).

2 . The coating composition according to claim 1 , wherein the polymerizable unsaturated monomer mixture (c2) comprises a hydroxyl group-containing polymerizable unsaturated monomer.

3 . The coating composition according to claim 1 , wherein a number-average molecular weight of the polymerizable unsaturated monomer having a polysiloxane structure (c21) is in a range of 100 to 13,000.

4 . The coating composition according to claim 2 , wherein a hydroxyl value of the acrylic resin produced from the polymerizable unsaturated monomer mixture (c2) is in a range of 100 mgKOH/g to 200 mgKOH/g.

5 . The coating composition according to claim 1 , wherein a mass ratio of the silica particles with a polymerizable unsaturated group (c1) and the polymerizable unsaturated monomer mixture (c2) is in a range of (c1): (c2)=20/80 to 90/10.

6 . The coating composition according to claim 1 , wherein the dispersion of the acrylic resin-coated silica particles (C) comprises trimethyl orthoacetate.

7 . The coating composition according to claim 1 , wherein the curing agent (B) includes a polyisocyanate compound (B1).

8 . The coating composition according to claim 1 , wherein the resin with a hydroxyl group and an alkoxysilyl group (A) includes an acrylic resin having a hydroxyl group and an alkoxysilyl group (A1).

9 . The coating composition according to claim 1 , wherein the resin with a hydroxyl group and an alkoxysilyl group (A) does not have a polydimethylsiloxane structure.

10 . A multilayer coating film-forming method, whereby a multilayer coating film is formed by applying at least one colored base coating material and least one clear coating material in that order on an article to be coated, wherein the coating composition according to claim 1 , is applied as an uppermost clear coating material.

Assignees

• Kansai Paint Co Ltd

Inventors

• Mori Kenji
• Azuma Tatsuya
• Hidaka Takahiro

Classifications

• B05D2518/10

  Silicon-containing polymers · CPC title

• B05D2451/00

  Type of carrier, type of coating (Multilayers) · CPC title

• B05D7/53

  Base coat plus clear coat type · CPC title

• C09D7/62

  modified by treatment with other compounds · CPC title

• C09D7/63

  organic · CPC title