Process for producing photocurable material, photocurable material and article

1. A process for producing a photocurable material, which comprises the following steps (i) to (iii):

(i) a step of reacting a polymerizable component (A) comprised of at least one type of a compound (a) having a (meth)acryloyloxy group, and a compound (B) having a mercapto group and a carboxy group to obtain a surface modifier (C) which has the carboxy group derived from the compound (B) at a terminal,

(ii) a step of modifying the surface of inorganic fine particles (D) with the surface modifier (C) to obtain surface-modified inorganic fine particles (E),

(iii) a step of obtaining a photocurable material which contains the surface-modified inorganic fine particles (E), a polymerizable component (F) comprised of at least one type of a compound (f) having a (meth)acryloyloxy group, and a photopolymerization initiator (G).

2. The process for producing a photocurable material according to claim 1 , wherein in the step (i), the molar amount of the polymerizable component (A) is from 0.5 to 10 times of the molar amount of the compound (B).

3. The process for producing a photocurable material according to claim 1 , wherein in the step (ii), the mass of the inorganic fine particles (D) is from 0.2 to 10 times of the mass of the compound (B) used in the step (i).

4. The process for producing a photocurable material according to claim 1 , wherein in the total (100 mass %) of the polymerizable component (A), the compound (B), the inorganic fine particles (D), the polymerizable component (F) and the photopolymerization initiator (G), the total of the polymerizable component (A) and the polymerizable component (F) is from 10 to 98.8 mass %, the compound (B) is from 0.01 to 28 mass %, the inorganic fine particles (D) are from 0.1 to 75 mass % and the photopolymerization initiator (G) is from 0.1 to 9 mass %, as represented by the proportions of the starting materials charged.

5. The process for producing a photocurable material according to claim 1 , wherein the compound (B) has a pKa of at most 4.4.

6. The process for producing a photocurable material according to claim 1 , wherein the compound (B) satisfies the following conditions (1) to (3):

condition (1): having at least one mercapto group;

condition (2); having at least one carboxy group;

condition (3): having no primary amino group.

7. The process for producing a photocurable material according to claim 1 , wherein the compound (B) is a compound which is a C 2-20 aliphatic carboxylic acid, and has a mercapto group at least at any one of the α-, β- and γ-positions to the carboxy group, and no primary amino group.

8. The process for producing a photocurable material according to claim 1 , wherein the compound (B) has a molecular weight of at most 600.

9. The process for producing a photocurable material according to claim 1 , wherein the inorganic fine particles (D) are fine particles of a metal oxide.

10. The process for producing a photocurable material according to claim 9 , wherein the metal oxide is at least one member selected from the group consisting of titanium oxide, zirconium oxide, aluminum oxide, barium titanate, cerium oxide, tin oxide, zinc oxide, tantalum oxide, manganese oxide, nickel oxide, iron oxide, silicon oxide, niobium oxide, lanthanum oxide and gadolinium oxide.

11. The process for producing a photocurable material according to claim 1 , wherein the inorganic fine particles (D) have an average primary particle size of from 2 to 100 nm.

12. The process for producing a photocurable material according to claim 1 , wherein the polymerizable component (F) contains a compound having fluorine atoms and at least one (meth)acryloyloxy group.

13. The process for producing a photocurable material according to claim 1 , wherein the polymerizable component (F) contains a compound (f1) having at least two (meth)acryloyloxy groups (provided that the compound (f2) is excluded), the compound (f2) having fluorine atoms and at least one (meth)acryloyloxy group, and a compound (f3) having one (meth)acryloyloxy group (provided that the compound (f2) is excluded); and in the total (100 mass %) of the compound (f1), the compound (f2) and the compound (f3), the compound (f1) is from 15 to 70 mass %, the compound (f2) is from 5 to 45 mass % and the compound (f3) is from 10 to 65 mass %.

14. The process for producing a photocurable material according to claim 1 , wherein the polymerizable component (A) is comprised of at least one type of the compound (f) constituting the polymerizable component (F).

15. The process for producing a photocurable material according to claim 14 , wherein the polymerizable component (A) is a polymerizable component identical to the polymerizable component (F).