Pattern-forming method and composition
A composition includes two types of polymers each having a different weight average molecular weight. The two types of polymers are each a styrene polymer having a group which bonds to at least one end of a main chain and which includes at least one of a hydroxy group, a carboxy group, a sulfanyl group, an epoxy group, a cyano group, a vinyl group or a carbonyl group. A difference in weight average molecular weight between the two types of polymers is no less than 2,000 and no greater than 30,000.
1. A composition comprising a smaller molecular weight polymer and a larger molecular weight polymer, each having a different weight average molecular weight,
wherein the smaller molecular weight polymer and the larger molecular weight polymer are each a styrene polymer having a group which bonds to at least one end of a main chain of the smaller molecular weight polymer and the larger molecular weight polymer and which comprises at least one group selected from the group consisting of a hydroxy group, a carboxy group, a sulfanyl group, an epoxy group, a cyano group, a vinyl group and a carbonyl group,
a difference in weight average molecular weights between the smaller molecular weight polymer and the larger molecular weight polymer no less than 2,000.
2. The composition according to claim 1 , wherein a weight average molecular weight of the smaller molecular weight polymer is no greater than 25,000, and a weight average molecular weight of the larger molecular weight polymer is greater than 25,000.
3. The composition according to claim 1 , wherein a weight average molecular weight of the smaller molecular weight polymer is no less than 5,000 and no greater than 25,000, and a weight average molecular weight of the larger molecular weight polymer is greater than 25,000 and no greater than 50,000.
4. The composition according to claim 1 , wherein the styrene polymer is an unsubstituted styrene homopolymer.
5. The composition according to claim 1 , wherein a lower limit of a total content of the smaller molecular weight polymer and the larger molecular weight polymer in the composition with respect to a total solid content of the composition is 80% by mass.
6. The composition according to claim 1 , wherein a lower limit of a total content of the smaller molecular weight polymer and the larger molecular weight polymer in the composition with respect to a total solid content of the composition is 90% by mass.
7. The composition according to claim 1 , wherein a lower limit of a total content of the smaller molecular weight polymer and the larger molecular weight polymer in the composition with respect to a total solid content of the composition is 95% by mass.
8. The composition according to claim 1 , further comprising a solvent.
9. The composition according to claim 8 , wherein the solvent comprises a polyhydric alcohol partially etherified carboxylate solvent.
10. The composition according to claim 8 , wherein the solvent comprises propylene glycol monomethyl ether acetate.
11. The composition according to claim 1 , wherein the difference in weight average molecular weights between the smaller molecular weight polymer and the larger molecular weight polymer is no less than 5,000.
12. The composition according to claim 1 , wherein the difference in weight average molecular weights between the smaller molecular weight polymer and the larger molecular weight polymer is no less than 8,000.
13. The composition according to claim 1 , wherein the difference in weight average molecular weights between the smaller molecular weight polymer and the larger molecular weight polymer is no less than 15,000.
14. The composition according to claim 1 , wherein the difference in weight average molecular weights between the smaller molecular weight polymer and the larger molecular weight polymer is no greater than 30,000.