Aqueous paint composition and method of manufacturing painted article

Patent metadata

Field	Value
Publication number	US-9475957-B2
Application number	US-201314390060-A
Country	US
Kind code	B2
Filing date	Apr 4, 2013
Priority date	Apr 4, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

The first objective of the present invention is to provide an aqueous paint composition that can form a paint film with excellent smoothness, image clarity, adhesion and water resistance. This aqueous paint is characterized in comprising (A) an aqueous dispersion of an acrylic modified polyester resin, (B) a block polyisocyanate compound having a nonionic hydrophilic group, and (C) an aqueous dispersion of acrylic polymer fine particles.

First claim

What is claimed is:

1. An aqueous coating composition comprising:
an aqueous dispersion of an acryl-modified polyester resin (A);
a blocked polyisocyanate compound having a nonionic hydrophilic group (B); and
an aqueous dispersion of acrylic-based polymer fine particles; (C);
wherein the blocked polyisocyanate compound (B) has at least one blocked isocyanate group selected from the group consisting of:
blocked isocyanate groups of the following formula (I):

wherein R 1 , R 2 , R 4 and R 5 independently represent a C1-12 hydrocarbon group
and R 3 represents a C1-12 straight-chain or branched alkylene group;

blocked isocyanate groups of the following formula (II):

wherein R 2 , R 3 , R 4 and R 5 have the same definitions as above; and

blocked isocyanate groups of the following formula (III):

wherein R 2 , R 3 , R 4 and R 5 have the same definitions as above, and R 6
represents a C1-12 hydrocarbon group;

and any combination of said blocked isocyanate groups, and
wherein the polyester resin of the acryl-modified polyester resin is obtained by reacting an acid component which comprises an acid anhydride group-containing unsaturated monomer and an alicyclic polybasic acid, with an alcohol component.

2. The aqueous coating composition according to claim 1 , wherein the nonionic hydrophilic group of the blocked polyisocyanate compound (B) is a polyoxyalkylene group.

3. The aqueous coating composition according to claim 1 , wherein R 1 in formula (I) is an isopropyl group, and R 6 in formula (III) is an isopropyl group.

4. The aqueous coating composition according to claim 1 , wherein the blocked polyisocyanate compound (B) includes a blocked polyisocyanate compound obtained by reacting:
a blocked polyisocyanate compound (B 11 ) having a blocked isocyanate group represented by the following formula (IV):

wherein the R 1 groups are as defined above, and each R 1 group may be the same or different,

and a nonionic hydrophilic group, with a secondary alcohol (b 4 ) represented by the following formula (VI):

wherein R 2 , R 3 , R 4 and R 5 are as defined above.

5. The aqueous coating composition according to claim 1 , wherein the blocked polyisocyanate compound (B) includes a blocked polyisocyanate compound obtained by reacting:
a blocked polyisocyanate compound (B 12 ) having a blocked isocyanate group represented by the following formula (V):

wherein R 6 is as defined above, and R 7 represents a C1-12 hydrocarbon group,

and a nonionic hydrophilic group, with a secondary alcohol (b 4 ) represented by the following formula (VI):

wherein R 2 , R 3 , R 4 and R 5 are as defined above.

6. The aqueous coating composition according to claim 1 , comprising an aqueous dispersion of an acryl-modified polyester resin (A), a blocked polyisocyanate compound (B) and an aqueous dispersion of acrylic-based polymer fine particles (C) at 10 to 70 parts by mass, 1 to 30 parts by mass and 10 to 60 parts by mass, respectively, as solid content based on 100 parts by mass of the resin solid content in the aqueous coating composition.

7. The aqueous coating composition according to claim 1 , further comprising a melamine resin (D).

8. A method for producing a coated article, comprising:
a step of coating an article to be coated with an aqueous coating composition according to claim 1 as a base coat material to form an uncured base coating film on the article to be coated, followed by
a step of coating the article to be coated having the uncured base coating film with a clear coating material, and forming an uncured clear coating film thereover.

9. A method for producing a coated article, comprising:
a step of coating an article to be coated with an aqueous coating composition according to claim 1 as a top coat material, and forming a top coating film on the article to be coated.

10. The aqueous coating composition according to claim 1 , wherein the acryl-modified polyester resin is obtained by reacting at least one polymerizable unsaturated monomer comprising an aromatic ring-containing polymerizable unsaturated monomer with a polyester resin.

11. The aqueous coating composition according to claim 10 , wherein the acryl-modified polyester resin is obtained by radical polymerization of the polymerizable unsaturated monomer and the polyester resin.

Assignees

• Kansai Paint Co Ltd

Inventors

• Ishikura Minoru
• Nakayabu Takashi
• Yamada Yuki
• Hirai Katsunori

Classifications

• C08G18/283

  Compounds containing ether groups, e.g. oxyalkylated monohydroxy compounds · CPC title

• C08G18/8093

  Compounds containing active methylene groups · CPC title

• C09D171/02

  Polyalkylene oxides · CPC title

• C08G18/6254

  Polymers of alpha-beta ethylenically unsaturated carboxylic acids and of esters of these acids containing hydroxy groups · CPC title

• C09D133/08

  Homopolymers or copolymers of acrylic acid esters · CPC title