Metallic tone powder coating composition

Claim 2

A powdery metallic powder-acrylic resin coating composition comprising a mixture of (a) solid powder particles of vinyl copolymer having a glass transition point of at least 20° C and wherein an acrylic ester and a methacrylic ester monomer together constituting at least 30% by weight of the total monomers of said copolymer, and (b) for each about 100 parts by weight of said copolymer particles about 0.1-50 parts by weight of solid particles of a polymer-encapsulated metal powder obtained by activating a metallic powder by treatment with (1) an organic or mineral acid followed by neutralization of the thus-treated powder with an alkali, or (2) an aqueous solution of phosphoric acid; and subjecting the activated metallic powder to an in situ polymerization in an aqueous medium of at least one vinyl monomer in the presence of a radical polymerization initiator, the amount of such vinyl monomer being such as to form about 0.2 - 20 parts by weight of said encapsulating polymer per 100 parts of said metallic powder.

Claim 3

A composition according to claim 1 wherein said metal powder is at least one of aluminum, brass, bronze, stainless steel, and copper powders.

Claim 4

A composition according to claim 1 wherein the vinyl monomer used for polymer-capsulation of said metal powder is selected from the group consisting of styrene, alphamethylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, hydroxyethyl acrylate, a phosphoric ester of hydroxyethyl acrylate, hydroxypropyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, cyclohexyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, oleyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, hydroxyethyl methacrylate, a phosphoric ester of hydroxyethyl methacrylate, hydroxypropyl methacrylate, cyclohexyl methacrylate, glycidyl methacrylate, beta-methylglycidyl methacrylate, diethylaminoethyl methacrylate or gamma-methacryloxypropyl(trimethoxy)silane and a combination thereof.

Claim 5

A composition according to claim 1 wherein said polymer capsulated metal powder composite material is obtained by capsulation of said metal powder with said polymer of said vinyl monomer, said capsulation being carried out by polymerizing said vinyl monomer in the presence of a radical polymerization initiator which is 2,2'-azo-bis(2-amidinopropane) hydrochloride, tert-butyl permaleate, succinic acid peroxide, a combination of hydrogen peroxide and l-ascorbic acid, cumene hydroperoxide or a combination of a persulfate and bisulfite ion.

Claim 6

A composition according to claim 1 wherein said acrylic ester used as a component of said copolymer is methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl acrylate, hydroxyporpyl acrylate or glycidyl acrylate.

Claim 7

A composition according to claim 1 wherein said methacrylic ester used as a component of said copolymer is methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, beta-methylglycidyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or tert-butylaminoethyl methacrylate.

Claim 8

The coating composition of claim 1 including about 2 - 15 parts by weight of said polymer encapsulated metallic particles per 100 parts of said copolymer particles.

Claim 9

The composition of claim 1 wherein said copolymer particles have an average diameter of about 20-100 micron.