Ene-thiol-type curable composition and cured product thereof

1. An ene-thiol based curable composition comprising:

(A) a thiol compound having two or more groups represented by a following general formula (1) in the molecule; and

(B) an ene oligomer having an alicyclic or aromatic ring structure and two or more ethylenically unsaturated groups in the molecule, with a number average molecular weight of 500 to 20,000 in terms of polystyrene:

wherein in the general formula (1), each of R 1 and R 2 independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms; a is an integer of 0 to 2; and b is 0 or 1,

wherein said thiol compound (A) is ester compounds of mercapto group-containing carboxylic acids represented by a following general formula (lb) and polyhydric alcohols,

wherein in the general formula (1b), R 1 , R 2 , a and b are the same as defined in the general formula (1),

wherein said ene oligomer (B) is any one or more of oligomers represented by the following general formulae (2) to (4):

wherein in the general formula (2), c is 1; R 3 is an alkylene group having 1 to 10 carbon atoms in the main chain which may have an alkyl group of 1 to 5 carbon atoms as a substituent and which may have an ether linkage inserted therewithin; X is a phenylene group or a cyclohexylene group which may have an alkyl group of 1 to 4 carbon atoms as a substituent; and n is an integer of 3 to 20,

wherein in the general formula (3), d is the same as c described above; R 4 is an alkyl group of 1 to 4 carbon atoms or a group represented by the following formula (3′); Y is the same as X described above; and m is an integer of 3 to 70,

wherein in the general formula (3′), d and Y are the same as described above in the general formula (3),

wherein in the general formula (4), e is the same as c described above; each of R 5 and R 6 independently represents an alkylene group having 1 to 10 carbon atoms in the main chain which may have an alkyl group of 1 to 5 carbon atoms as a substituent; Z is the same as X described above; p is an integer of 1 to 10; and q is an integer of 5 to 50.

2. The ene-thiol based curable composition according to claim 1 , wherein b is 0 in said thiol compound (A).

3. The ene-thiol based curable composition according to claim 1 ,

wherein said thiol compound (A) is a thiol compound (A1) having two or more groups represented by the general formula (1) in the molecule and having no hydroxyl group in the molecule.

4. The ene-thiol based curable composition according to claim 1 ,

wherein said thiol compound (A) comprises both of a thiol compound (A1) having two or more groups represented by said general formula (1) in the molecule and having no hydroxyl group in the molecule, and a thiol compound (A2) having two or more groups represented by said general formula (1) in the molecule and having a hydroxyl group in the molecule.

5. The ene-thiol based curable composition according to claim 4 , wherein said thiol compound (A2) accounts for from 0.1 to 30% by mass of said thiol compound (A).

6. The ene-thiol based curable composition according to claim 3 , wherein said thiol compound (A1) is pentaerythritol tetrakis(3-mercaptobutyrate).

7. The ene-thiol based curable composition according to claim 4 , wherein said thiol compound (A2) is pentaerythritol tris(3-mercaptobutyrate).

8. The ene-thiol based curable composition according to claim 1 ,

wherein said thiol compound (A) and said ene oligomer (B) are included in such a manner that the ethylenically unsaturated group in said ene oligomer (B) is contained at a ratio of 0.5 to 10 mol relative to 1 mol of a mercapto group in said thiol compound (A).

9. The ene-thiol based curable composition according to claim 1 , further comprising a photopolymerization initiator and/or a thermal polymerization initiator.

10. A cured product which is formed by curing the ene-thiol based curable composition according to claim 1 .