Cationic electrodeposition coating composition

Patent metadata

Field	Value
Publication number	US-9822262-B2
Application number	US-201415030685-A
Country	US
Kind code	B2
Filing date	Jun 11, 2014
Priority date	Oct 25, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An object of the present invention is to find a cationic electrodeposition coating composition excellent in coating composition stability, finished appearance, and corrosion resistance, and to provide a coated article excellent in these coating film properties.
The present invention provides a cationic electrodeposition coating composition containing a polyester resin (A), an amino group-containing epoxy resin (B), and a blocked polyisocyanate curing agent (C), the polyester resin (A) being present in an amount of 3 to 40 mass %, the amino group-containing epoxy resin (B) being present in an amount of 20 to 60 mass %, and the blocked polyisocyanate curing agent (C) being present in an amount of 10 to 40 mass %, based on the total mass of the components (A), (B), and (C) on a solids basis, wherein the solubility parameter δA of the component (A) and the solubility parameter δB of the component (B) satisfy the relationship |δA−δB|<1.0.

First claim

The invention claimed is:

1. A cationic electrodeposition coating composition comprising
a polyester resin (A),
an amino group-containing epoxy resin (B), and
a blocked polyisocyanate curing agent (C),

the polyester resin (A) being present in an amount of 3 to 40 mass %, the amino group-containing epoxy resin (B) being present in an amount of 20 to 60 mass %, and the blocked polyisocyanate curing agent (C) being present in an amount of 10 to 40 mass %, based on the total mass of the components (A), (B), and (C) on a solids basis, wherein the solubility parameter δA of the component (A) and the solubility parameter δB of the component (B) satisfy the relationship |δA−δB|<1.0, wherein the polyester resin (A) has an acid value of 0.01 to 15 mg KOH/g, a hydroxy value of 50 to 300 mg KOH/g, and a number average molecular weight of 1,000 to 8,000.

2. The cationic electrodeposition coating composition according to claim 1 , wherein the polyester resin (A) has an oil length of less than 5 mass %.

3. A method for forming a cationic electrodeposition coating film, the method comprising the steps of
immersing a substrate in an electrodeposition bath comprising the cationic electrodeposition coating composition according to claim 1 ; and
applying an electric current using the substrate as a cathode.

4. A method for forming a cationic electrodeposition coating film, the method comprising the steps of
immersing a substrate in an electrodeposition bath comprising the cationic electrodeposition coating composition according to claim 2 ; and
applying an electric current using the substrate as a cathode.

Assignees

• Kansai Paint Co Ltd

Inventors

• Iijima Hideki
• Ito Kei

Classifications

• C08G59/4028

  Isocyanates; Thioisocyanates · CPC title

• C09D163/00

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• C09D167/00

  Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09D177/12; based on polyester-imides C09D179/08); Coating compositions based on derivatives of such polymers · CPC title

• C08G18/58

  Epoxy resins {(C08G18/42, C08G18/48 take precedence; reaction products of epoxy resins with at least equivalent amounts of compounds containing active hydrogen C08G18/6407, with at least equivalent amounts of amines C08G18/6415; polymeric products of isocyanates or isothiocyanates with epoxy compounds having no active hydrogen C08G18/003)} · CPC title

• C25D13/04

  with organic material · CPC title