Resin-coated metal powder, method for producing same and aqueous coating composition using same

Patent metadata

Field	Value
Publication number	US-12497518-B2
Application number	US-202017769629-A
Country	US
Kind code	B2
Filing date	Oct 14, 2020
Priority date	Oct 18, 2019
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A resin-coated metal powder according to the present invention is obtained by covering at least a part of the surface of a metal powder with a hydrolyzable resin that has an average composition of general formula (1) and a number average molecular weight of from 500 to 100,000; and this resin-coated metal powder exhibits sufficient dispersibility in an aqueous solution, while being stable for a relatively long period of time even in the coexistence of water in an aqueous coating material.

(In the formula, R 1 represents a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms, said group optionally having a specific substituent such as a hydroxyalkyl group; each of R 3 , R 4 and R 5 independently represents a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms; each of R 2 and R 6 independently represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms; and a and b represent numbers that satisfy 0≤a<1, 0<b≤1 and (a+b)=1.)

First claim

The invention claimed is:

1 . A resin-coated metal powder comprising:
a metal powder selected from the group consisting of a magnesium powder, an aluminum powder, a zinc powder, an iron powder, a nickel powder, a tin powder, and a lead powder; and a hydrolyzable resin, the metal powder having a surface at least partially coated with the hydrolyzable resin, the hydrolyzable resin being represented by the general formula (1) described below, and having a polystyrene-equivalent numerical average molecular weight of 500 to 100,000 by gel permeation chromatography:

wherein R 1 represents a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, the linear or branched monovalent hydrocarbon group in which a part or all of hydrogen atoms may be substituted with an alkoxyalkyl group, an alkoxysilyl group, a hydroxyalkyl group, a polyoxyalkylene group, or a terminal alkyl polyoxyalkylene group,
R 3 , R 4 , and R 5 each independently represent a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms,
R 2 and R 6 each independently represent a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, and
a and b represent numbers satisfying 0≤a<1, 0<b≤1, and a +b=1.

2 . The resin-coated metal powder of claim 1 , wherein R 3 , R 4 , and R 5 each independently represent a linear or branched monovalent hydrocarbon group having 1 to 4 carbon atoms.

3 . The resin-coated metal powder of claim 1 , wherein the metal powder is a zinc powder.

4 . The resin-coated metal powder of claim 1 , wherein the resin-coated metal powder has a mean particle size, measured with a laser diffraction/scattering method, of 1 to 20 μm.

5 . An aqueous coating composition comprising:
the resin-coated metal powder of claim 1 ; and an epoxy resin aqueous emulsion comprising said epoxy resin and water, wherein said aqueous coating composition is formed by mixing said resin-coated metal powder with said aqueous emulsion to form said aqueous coating composition.

6 . A method for producing a resin-coated metal powder, the method comprising:
mixing a metal powder; and a solution containing a hydrolyzable resin, the metal powder having a surface at least partially coated with the hydrolyzable resin, the hydrolyzable resin being represented by the general formula (1) described below, and having a polystyrene-equivalent numerical average molecular weight of 500 to 100,000 by gel permeation chromatography:

wherein R 1 represents a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, the linear or branched monovalent hydrocarbon group in which a part or all of hydrogen atoms may be substituted with an alkoxyalkyl group, an alkoxysilyl group, a hydroxyalkyl group, a polyoxyalkylene group, or a terminal alkyl polyoxyalkylene group,
R 3 , R 4 , and R 5 each independently represent a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms,
R 2 and R 6 each independently represent a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, and
a and b represent numbers satisfying 0≤a<1, 0<b≤1, and a +b=1; and
coating at least a part of said surface of the metal powder with the hydrolyzable resin.

7 . The method for producing the resin-coated metal powder of claim 6 , wherein said metal powder is selected from the group consisting of a magnesium powder, an aluminum powder, a zinc powder, an iron powder, a nickel powder, a tin powder, and a lead powder.

8 . A method for producing a resin-coated metal powder, the method comprising:
mixing a metal powder and a silane coupling agent previously to obtain the metal powder treated with the silane coupling agent, the silane coupling agent having a polymerizable group having the general formula (2) described below:

wherein R 7 represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, R 8 and R 9 represent a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, n represents an integer of 0 to 2, and R 10 represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms; and
subjecting the metal powder treated with the silane coupling agent, a polymerizable monomer having the general formula (3) described below:

wherein R 11 , R 12 , and R 13 each independently represent a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 14 represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms,
and a silane coupling agent having a polymerizable group having the general formula (2) described above and/or a polymerizable monomer having the general formula (4) described below:

wherein R 15 represents a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 16 represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms
to radical polymerization reaction to coat at least a part of a surface of the metal powder treated with the silane coupling agent with the hydrolyzable resin to produce said resin-coated metal powder, said resin coated metal powder having a surface at least partially coated with the hydrolyzable resin,
the hydrolyzable resin being represented by the general formula (1) described below, and having a polystyrene-equivalent numerical average molecular weight of 500 to 100,000 by gel permeation chromatography:

wherein R 1 represents a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, the linear or branched monovalent hydrocarbon group in which a part or all of hydrogen atoms may be substituted with an alkoxyalkyl group, an alkoxysilyl group, a hydroxyalkyl group, a polyoxyalkylene group, or a terminal alkyl polyoxyalkylene group,
R 3 , R 4 , and R 5 each independently represent a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms,
R 2 and R 6 each independently represent a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, and
a and b represent numbers satisfying 0≤a<1, 0<b≤1, and a +b=1.

9 . The method for producing the resin-coated metal powder of claim 8 , wherein said metal powder is selected from the group consisting of a magnesium powder, an aluminum powder, a zinc powder, an iron powder, a nickel powder, a tin powder, and a lead powder.

Assignees

• Shinetsu Chemical Co

Inventors

• Aoki Shotaro
• Kiyomori Ayumu

Classifications

• C09C1/625

  the particles consisting of zinc or a zinc alloy · CPC title

• C09D5/028

  Pigments; Filters · CPC title

• C09D163/00

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

• C09C3/12

  Treatment with organosilicon compounds {(C09C3/006 takes precedence)} · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title