Powder coating material, coated article, and method for producing coated article
View Patent ↗The invention provides a powder coating material capable of forming a film excellent in metallic hue, concealing property and weather resistance. The powder coating material comprises the following fluororesin (A), the following resin (B) and the following pigment (C) as constituents thereof, wherein the content of the pigment (C) is from 0.7 to 23 mass %; Fluororesin (A): a fluororesin having a fluorine content of at least 10 mass %; Resin (B): a resin having a SP value larger than that of the fluororesin (A), and the difference between the SP value thereof and the SP value of the fluororesin (A) is at least 0.4 (J/cm 3 ) 1/2 ; Pigment (C): a pigment which is a metallic pigment covered with a covering material, and the SP value of the covering material exceeds the SP value of the fluororesin (A) and less than the SP value of the resin (B).
1. A powder coating material comprising a fluororesin (A), a resin (B) and a pigment (C), wherein a content of the pigment (C) to a total amount of the powder coating material is from 0.7 to 23 mass %, wherein:
the fluororesin (A) has a fluorine content of at least 10 mass %;
the resin (B) is at least one selected from the group consisting of a polyester resin and an acrylic resin, and has a SP value larger than a SP value of the fluororesin (A), and a difference between the SP value of the resin (B) and the SP value of the fluororesin (A) is at least 2.0 (J/cm 3 ) 1/2 ; and
the pigment (C) is a metallic pigment covered with a covering material, the covering material is at least one selected from the group consisting of a phosphoric acid group-containing resin, an acrylic resin, a silicone resin, a polyethylene resin, an aliphatic compound, an aromatic compound, and a silane compound, and a SP value of the covering material is larger than the SP value of the fluororesin (A) by at least 0.2 (J/cm 3 ) 1/2 and smaller than the SP value of the resin (B) by at least 0.2 (J/cm 3 ) 1/2 .
2. The powder coating material according to claim 1 , wherein the powder coating material is made of a powder comprising: powder particles comprising the fluororesin (A) and the resin (B); and powder particles composed of the pigment (C).
3. The powder coating material according to claim 1 , wherein the powder coating material is made of a powder comprising: powder particles comprising the fluororesin (A); powder particles comprising the resin (B); and powder particles composed of the pigment (C).
4. The powder coating material according to claim 1 , wherein the fluororesin (A) is a polyvinylidene fluoride.
5. The powder coating material according to claim 1 , wherein the fluororesin (A) is a fluororesin having hydroxy groups or carboxy groups.
6. The powder coating material according to claim 5 , wherein the powder coating material comprises powder particles comprising: the fluororesin (A); and a curing agent.
7. The powder coating material according to claim 1 , wherein the resin (B) is a fluororesin having a fluorine content of less than 10 mass %, or a resin having no fluorine atom.
8. The powder coating material according to claim 1 , wherein the powder coating material comprises powder particles comprising: the resin (B); and a curing agent.
9. The powder coating material according to claim 1 , wherein the pigment (C) is composed of scaly aluminum particles covered with the covering material.
10. The powder coating material according to claim 1 , wherein the difference between the SP value of the resin (B) and the SP value of the fluororesin (A) is from 2.0 to 12 (J/cm 3 ) 1/2 .
11. The powder coating material according to claim 1 , wherein the SP value of the covering material is larger than the SP value of the fluororesin (A) by at least 0.4 (J/cm 3 ) 1/2 and smaller than the SP value of the resin (B) by at least 0.4 (J/cm 3 ) 1/2 .
12. The powder coating material according to claim 1 , wherein the SP value of the covering material is larger than the SP value of the fluororesin (A) by at least 0.6 (J/cm 3 ) 1/2 and smaller than the SP value of the resin (B) by at least 0.6 (J/cm 3 ) 1/2 .
13. A coated article comprising:
a substrate; and
a coating film provided on a surface of the substrate and formed from the powder coating material as defined in claim 1 .
14. A method for producing a coated article, the method comprising:
applying the powder coating material as defined in claim 1 to a substrate to form a film of a powder;
heating the film of the powder to form a film made of a melt of the powder; and
cooling the film made of the melt to form a coating film.