Chemical conversion agent and metal surface treatment method

• US 10,138,559 B2
• Filed: 04/03/2014
• Issued: 11/27/2018
• Est. Priority Date: 04/03/2013
• Status: Active Grant

• Current Assignee: Nippon Paint Surf Chemicals Co., Ltd. (Rainbow Light Limited)
• Original Assignee: Nippon Paint Surf Chemicals Co., Ltd. (Rainbow Light Limited)
• Inventors: Mizuno, Akihiro, Matsui, Norizumi
• Primary Examiner(s): Zheng, Lois L
• Application Number:
  US14/782,100
• Publication Number:
  US 20160040298A1
• Time in Patent Office: 1,699 Days
• Field of Search: 148247
• CPC Class Codes: C08K 2003/3045 Sulfates
• CPC Class Codes: C08K 3/28 Nitrogen-containing compounds
• CPC Class Codes: C08K 3/30 Sulfur-, selenium- or tellurium-containing compounds
• CPC Class Codes: C08K 5/04 Oxygen-containing compounds C08K5/0091 takes precedence
• CPC Class Codes: C08K 5/057 Metal alcoholates metal enolates C08K5/0091
• CPC Class Codes: C08K 5/098 Metal salts of carboxylic acids
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C09D 5/08 Anti-corrosive paints
• CPC Class Codes: C09D 5/084 Inorganic compounds
• CPC Class Codes: C23C 22/40 containing molybdates, tungstates or vanadates
• CPC Class Codes: C23C 22/44 containing also fluorides or complex fluorides
• CPC Class Codes: C23C 22/82 After-treatment

Abstract

Provided is a chemical conversion agent that, with respect to an aluminum metal material, etc., contributes to superior corrosion and moisture resistance, contributes to superior adhesion with a laminate film, and contributes to superior hydrofluoric acid and alkali resistance. The chemical conversion agent includes: one or more type of metal element (A) selected from a group comprising of zirconium, titanium, and hafnium; vanadium element (B); and a resin (C). The resin (C) includes a polyvinyl alcohol resin (C1). The ratio (Wa/Wb) of the weight-based total content (Wa) of the metal element (A) relative to the weight-based content (Wb) of vanadium element (B) is 0.1-15, and the ratio ((Wa+Wb)/Wc1) of the weight-based total content (Wa+Wb) of the metal element (A) and the vanadium element (B) relative to the weight-based total content (Wc1) of the polyvinyl alcohol resin (C1) is 0.25-15.

Claims

1. A chemical conversion agent comprising one, or two or more metal element(s) (A) selected from the group consisting of zirconium, titanium, and hafnium,

a vanadium element (B), and

a resin (C),

wherein the chemical coversion agent only includes, as the resin (C), a polyvinyl alcohol-based resin (C1) consisting of at least one of polyvinyl alcohol and a derivative thereof, and one, or two or more metal ion-crosslinkable polymer(s) (C2),

wherein a polymerization degree of the polyvinyl alcohol-based resin (C1) is 500 to 1,100,

wherein the metal ion-crosslinkable polymer (C2) is one, or two or more polymer(s) selected from the group consisting of polyacrylic acid, phosphoric acid polymer, phosphonic acid polymer, water-soluble or water-dispersible epoxy polymer, water-soluble or water-dispersible urethane-based polymer, and polyester,

wherein the value of a ratio (Wa/Wb) of the mass-based total content (Wa) of the metal element (A) to the mass-based content (Wb) of the vanadium element (B) is 0.1-15,

wherein the value of a ratio ((Wa+Wb)/Wc1) of the mass-based total content (Wa+Wb) of the metal element (A) and the vanadium element (B) to the mass-based total content (Wc1) of the polyvinyl alcohol-based resin (C1) is 0.25-15, and

wherein the value of a ratio (Wc2/(Wc1+Wc2)) of the mass-based total content (Wc2) of the metal ion-crosslinkable polymer (C2) to the mass-based total content (Wc1+Wc2) of the polyvinyl alcohol-based resin (C1) and the metal ion-crosslinkable polymer (C2) is 0.4 or less.

2. The chemical conversion agent according to claim 1, wherein the concentration of the metal element (A) in the chemical conversion agent is 50-100,000 ppm by mass,

wherein the concentration of the vanadium element (B) is 50-100,000 ppm by mass,

wherein the total concentration of the resin (C) is 50-100,000 ppm by mass, and

wherein a pH is 0.5-6.5.

3. The chemical conversion agent according to claim 1, wherein an average saponification degree of the polyvinyl alcohol-based resin (C1) is 80% or more.

4. The chemical conversion agent according to claim 1, which further includes a surfactant.

5. The chemical conversion agent according to claim 1, which is used for a surface treatment of an aluminum-based metal material.

6. A metal surface treatment method for treating a surface of a metal material, which comprises the steps of:

applying the chemical conversion agent according to claim 1 on the metal material, and drying the chemical conversion agent applied on the metal material.