Abstract Powder coating compositions are disclosed. In general, individual powder coating compositions of this invention are a mixture of the following materials. A copolymer of glycidyl methacrylate of glycidyl acrylate and an ethylenically unsaturated compound is formed in such proportions as to obtain a copolymer with a glass transition temperature in the range of 40*C to 90*C and a molecular weight (Mn) in the range of 2,500 to 8,500. The glycidyl compound is present in the copolymer from at least about 8 percent by weight to no more than about 25 percent by weight. Another material of the coating composition is a compound which contains tertiary nitrogen atoms in the amount of 0.5 to 10 parts by weight for 100 parts of the copolymer. A third material utilized in forming the powder coating mixture is a flow control agent which forms at least 0.05 percent by weight of the mixture. The flow control agent is a polymer having a molecular weight (Mn) of at least 1,000. The flow control agent also has a glass transition temperature at least 50*C below the glass transition temperature of the copolymer.
The powder coating composition of claim 1 wherein: said glycidyl compound is selected from the group consisting of glycidyl acrylates and glycidyl methacrylate.
Claim 2
Dependent Claim
45 words
The powder coating composition of claim 1 wherein: said cross linking agent containing tertiary nitrogen atoms is selected from the group consisting of: tertiary amines, tetra alkylammonium salts that decompose on heating to produce tertiary amines, pyrimidines, piperidines, pyridenis, quinolines, isoquinolines, benzoguanamine, sicyandiamide and imidazoles.
Claim 3
Dependent Claim
36 words
The powder coating composition of claim 1 wherein: said ethylenically unsaturated compound is selected from the group consisting of methyl methacrylate, butyl methacrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, styrene, alpha methyl styrene, acrylonitrile and methacrylonitrile.