Photocurable resin composition and optical parts

1. A photocurable resin composition comprising:

(A) 10-99,999 wt % of a di or more functional urethane (meth)acrylate compound, said urethane (meth)acrylate compound being obtained by reacting a polyether polyol with a number average molecular weight of 500 or more which comprises an alkyleneoxy structure in the molecule, an organic polyisocyanate compound, and a (meth)acrylate compound containing a hydroxyl group,

(B) 0-70 wt % of a monofunctional (meth)acrylate compound,

(C) 0-10 wt % of a photoinitiator; and

(D) 0,001-10 wt % of a polyoxyalkylene alkyl ether phosphate represented by the following formula (2):

 wherein R 3 is an alkyl group having 1-20 carbon atoms or an alkyl-substituted phenyl group, r is an integer from 1 to 15, and A is a hydroxyl group or R 4 O(CH 2 CHBO) S —, wherein R 4 is an alkyl group having 1-20 carbon atoms or an alkyl-substituted phenyl group, s is an integer from 1 to 15, and B represents a hydrogen atom or methyl group.

2. The photocurable resin composition according to claim 1 , wherein compound (B) is a monofunctional (meth)acrylate compound represented by the following formula (1);

wherein R 1 represents a hydrogen atom or a methyl group, R 2 represents —(CH 2 CH 2 O) p —, —(CH(CH 3 )CH 2 O) q —, or —CH 2 CH(OH)CH 2 O— (wherein p and q represent integers from 0 to 10), and Y 1 to Y 3 individually represent a hydrogen atom, bromine atom, an alkyl group having 1-10 carbon atoms, phenyl group, or —C(CH 3 ) 2 C 6 H 5 .

3. The photocurable resin composition according to claim 1 , wherein the component (A) is a urethane (meth)acrylate produced by reacting a diol compound of the following formula (3), said polyether polyol said organic polyisocyanate compound, and said (meth)acrylate containing a hydroxyl group,

wherein R 5 individually represents a hydrogen atom or a methyl group, R 6 individually represents an oxygen atom or sulfur atom, R 7 is a group —CH 2 —, —C(CH 3 ) 2 —, —S—, —SO—, or —SO 2 —, X 1 to X 4 individually represent a hydrogen atom, methyl group, or bromine atom, and t and u individually represent an integer from 0 to 9.

4. The photocurable resin composition according to claim 1 , containing 30-70 wt % of component (A), 20-60 wt % of component (B), 0.5-7 wt % of component (C), and 0.01-5 wt % of component (D).

5. The photocurable resin composition according to claim 1 , wherein the cured product made from the photocurable resin composition has a refractive index of 1.53 or more at 25° C.

6. The photocurable resin composition according to claim 1 , wherein the cured product made from the photocurable resin composition has a Young's modulus of 0.5-30 kg/mm 2 .

7. A process for making optical parts comprising curing the photocurable resin composition as defined in claim 1 .

8. Optical parts comprising a cured product, obtained by curing of the photocurable resin composition as defined in claim 1 .