US 7,968,639 B2 · Polyvinyl acetal powder and powder coating material using the same

Abstract

The present invention provides a polyvinyl acetal powder which is excellent in flowability during the coating process when it is applied to a powder coating material. This polyvinyl acetal powder enables to obtain a coating film having good impact resistance and uniformity of thickness (uniformity of coating film thickness). The present invention also provides a powder coating material using the polyvinyl acetal powder. Specifically, the present invention is a polyvinyl acetal powder having an average particle diameter of 10 to 150 μm, a maximum particle diameter of 250 μm or less, and a melt flow rate of 1 to 200 g/10 min. as measured in accordance with JIS K7210: 1999. The present invention also is a powder coating material containing this polyvinyl acetal powder.

Claims19

Dependent claims

A powder coating material comprising:

a polyvinyl acetal powder (A);
and
a pigment powder (B),
wherein the polyvinyl acetal powder (A) and the pigment powder (B) are dry-blended to form the powder coating material, and
the powder coating material satisfies the following conditions:
(1) the powder (A) has a melt flow rate of 1 to 200 g/10 min. as measured in accordance with JIS K7210:
1999;
(2) the powder (A) has an average particle diameter (AD) of 10 to 150 μm and a maximum particle diameter of 250 μm or less;
(3) the powder (B) has an average particle diameter (BD) of 2 to 150 μm and a maximum particle diameter of 250 μm or less;
(4) |AD−BD |<100;
and
(5) a ratio by weight of the pigment powder (B)/the polyvinyl acetal powder (A) is 0.5/100 to 50/100.

9 more elements

Dependencies are inferred from the claim text.

Polyvinyl acetal powder and powder coating material using the same

Life of this patent

Polyvinyl acetal powder and powder coating material using the same

Life of this patent

Abstract

Claims19