POWDER FOR COATING AND COATED ARTICLE
To provide a powder for coating, whereby it is possible to form a coating film excellent in acid resistance. The powder comprises a fluororesin and particles of a composite oxide containing at least two metals selected from the group consisting of Cu, Mn, Co, Ni and Zn.
1 . A powder characterized by comprising a fluororesin and particles of a composite oxide containing at least two metals selected from the group consisting of Cu, Mn, Co, Ni and Zn.
2 . The powder according to claim 1 , wherein the powder comprises particles of the fluororesin and the particles of the composite oxide.
3 . The powder according to claim 1 , wherein the average particle size of a powder consisting of the particles of the composite oxide is from 0.01 μm to 50 μm.
4 . The powder according to claim 2 , wherein the average particle size of a powder consisting of the particles of the fluororesin is from 1 to 1,000 μm.
5 . The powder according to claim 1 , wherein the powder comprises particles containing said fluororesin and said composite oxide particles.
6 . The powder according to claim 5 , wherein the average particle size of a powder consisting of the particles containing said fluororesin and said composite oxide particles is from 1 to 1,000 μm.
7 . The powder according to claim 1 , wherein the fluororesin is a fluororesin consisting of a fluorinated copolymer having units derived from a monomer represented by CF 2 ═CFX (X is F or Cl).
8 . The powder according to claim 7 , wherein the fluorinated copolymer is
a copolymer having units derived from ethylene and units derived from tetrafluoroethylene,
a copolymer having units derived from tetrafluoroethylene and units derived from a perfluoroalkyl vinyl ether, and having no units derived from ethylene,
a copolymer having units derived from tetrafluoroethylene and units derived from hexafluoropropylene, and having no units derived from ethylene and no units derived from a perfluoroalkyl vinyl ether, or
a copolymer having units derived from ethylene and units derived from chlorotrifluoroethylene, and having no units derived from tetrafluoroethylene.
9 . The powder according to claim 1 , wherein said composite oxide is a composite oxide containing Cu and Mn, or a composite oxide containing Co, Ni and Zn.
10 . An article comprising a substrate and a coating film formed from the powder as defined in claim 1 .
11 . The article according to claim 10 , wherein the thickness of the coating film is from 5 to 10,000 μm.
12 . A method for producing a coated article, which comprises forming a primer layer on a substrate and then forming a top coating layer on the primer layer using the powder as defined in claim 1 , wherein the heat treatment temperature for forming the primer layer is from 80 to 200° C.
13 . The method for producing a coated article according to claim 12 , wherein said primer layer consists of a film of a fluororesin containing no composite oxide particles.