White curable composition for printed circuit board, cured coating film using the same, and printed circuit board
An object of the present invention is to obtain a white curable composition that can yield a highly reflective cured coating film without requiring a complicated step and show good dispersion even without being subjected to an extended dispersion treatment. Provided is a white curable composition for a printed circuit board comprising: (A) a white pigment; (B) a (meth)acrylate compound having a hydroxyl group; (C) a photopolymerization initiator; and (D) a wetting dispersant. The above-described (A) white pigment is preferably titanium oxide. Further, it is also preferred that the above-described titanium oxide be a rutile-type titanium oxide and have a maximum particle size of 1 μm or smaller.
1. A white curable composition for a printed circuit board, comprising:
a white pigment;
a (meth)acrylate compound having a hydroxyl group;
a photopolymerization initiator;
a wetting dispersant; and
a thermosetting component which is one of an amino resin, a block isocyanate compound, a cyclocarbonate compound, a thermosetting resin having a cyclic (thio)ether group, a bismaleimide, and a carbodiimide resin.
2. The white curable composition for a printed circuit board according to claim 1 , wherein the white pigment is titanium oxide.
3. The white curable composition for a printed circuit board according to claim 2 , wherein the titanium oxide is a rutile-type titanium oxide.
4. A cured coating film, which is obtained by irradiating the white curable composition for a printed circuit board according to claim 3 with light.
5. A printed circuit board, comprising:
a pattern-cured coating film obtained by printing the white curable composition for a printed circuit board according to claim 3 on a substrate and then irradiating the thus printed white curable composition with light.
6. The white curable composition for a printed circuit board according to claim 3 , wherein the rutile-type titanium oxide is included in an amount of 9.8 to 24.5% of the white curable composition, and the thermosetting component is dimethylpyrazole-blocked trifunctional isocyanate.
7. The white curable composition for a printed circuit board according to claim 2 , wherein the titanium oxide has a maximum particle size of 1 μm or smaller.
8. A cured coating film, which is obtained by irradiating the white curable composition for a printed circuit board according to claim 7 with light.
9. A printed circuit board, comprising:
a pattern-cured coating film obtained by printing the white curable composition for a printed circuit board according to claim 7 on a substrate and then irradiating the thus printed white curable composition with light.
10. A cured coating film, which is obtained by irradiating the white curable composition for a printed circuit board according to claim 2 with light.
11. A printed circuit board, comprising:
a pattern-cured coating film obtained by printing the white curable composition for a printed circuit board according to claim 2 on a substrate and then irradiating the thus printed white curable composition with light.
12. The white curable composition for a printed circuit board according to claim 1 , wherein the wetting dispersant has an acid value.
13. The white curable composition for a printed circuit board according to claim 1 , further comprising:
a bifunctional (meth)acrylate compound.
14. The white curable composition for a printed circuit board according to claim 13 , wherein the bifunctional (meth)acrylate compound has a viscosity of 5 to 50 mPa·s at 25° C.
15. The white curable composition for a printed circuit board according to claim 1 , having a viscosity of 5 to 50 mPa·s at 50° C.
16. The white curable composition for a printed circuit board according to claim 1 , having a Y value of 70 or greater at a film thickness of 30 μm.
17. A cured coating film, which is obtained by irradiating the white curable composition for a printed circuit board according to claim 1 with light.
18. A printed circuit board, comprising:
a pattern-cured coating film obtained by printing the white curable composition for a printed circuit board according to claim 1 on a substrate and then irradiating the thus printed white curable composition with light.
19. A printed circuit board, comprising:
a pattern-cured coating film obtained by printing the white curable composition for a printed circuit board according to claim 1 on a substrate by an ink-jet printing method and then irradiating the thus printed white curable composition with light.
20. The white curable composition for a printed circuit board according to claim 1 , wherein the white pigment is included in an amount of 5 to 50 parts by mass in 100 parts by mass of the white curable composition.