Curable resin composition, transparent laminate, and process for producing transparent laminate

1. A curable resin composition comprising:

unsaturated urethane oligomer (A): an unsaturated urethane oligomer having from 2 to 3 curable functional groups as mentioned below, on average per molecule, which is a reaction product of the following polyol component (A1), a polyisocyanate (A2) and the following unsaturated hydroxy compound (A3), or a reaction product of the following polyol component (A1) and an unsaturated isocyanate (A4) having the following curable functional group,

polyol component (A1): a polyol component comprising the following polyol (a1),

polyol (a1): a polyoxyalkylene polyol having a hydroxy value of from 15 to 30 mgKOH/g and an oxyethylene group content of from 8 to 50 mass % in the total oxyalkylene groups of 100 mass %, which is obtained by reacting a monoepoxide having at least three carbon atoms and ethylene oxide with an initiator having from 2 to 4 active hydrogen atoms on average,

unsaturated hydroxy compound (A3): a compound having the following curable functional group and a hydroxy group, and

curable functional group: a group represented by CH 2 ═C(R)C(O)O— wherein R is a hydrogen atom or a methyl group,

monomer (B): a compound represented by CH 2 ═C(R)C(O)O—R 2 , wherein R is a hydrogen atom or a methyl group, and R 2 is a C 3-8 hydroxyalkyl group having from 1 to 2 hydroxy groups and

monomer (C): a compound represented by CH 2 ═C(R)C(O)O—R 3 , wherein R is a hydrogen atom or a methyl group, and R 3 is a C 8-22 alkyl group.

2. The curable resin composition according to claim 1 , wherein the polyol (a1) is a polyoxyalkylene polyol having a hydroxy value of from 15 to 30 mgKOH/g and an oxyethylene group content of from 8 to 50 mass % in the total oxyalkylene groups of 100 mass %, which is obtained by reacting propylene oxide and ethylene oxide with an initiator having from 2 to 4 active hydrogen atoms on average.

3. The curable resin composition according to claim 1 , wherein a laminate produced by curing the curable resin composition interposed between a pair of transparent substrates is transparent.

4. The curable resin composition according to claim 3 , which further comprises a photopolymerization initiator (D).

5. A transparent laminate comprising a pair of transparent substrates and a layer of a cured resin interposed between the pair of transparent substrates, wherein the cured resin is a cured product of the curable resin composition as defined in claim 3 .

6. A process for producing a transparent laminate, comprising a first step of forming a sealed space having the curable resin composition as defined in claim 3 , internally accommodated between a pair of transparent substrates in a reduced pressure atmosphere, to produce a laminate precursor having the pair of transparent substrates and the above curable resin composition sealed between the pair of transparent substrates, and a second step of placing the above laminate precursor in an atmosphere having a pressure higher than the reduced pressure atmosphere, and curing the curable resin composition in the atmosphere.

7. The process according to claim 6 , wherein the above reduced pressure atmosphere is a pressure atmosphere of at most 100 Pa, and the atmosphere having a pressure higher than the reduced pressure atmosphere is an atmospheric pressure atmosphere.

8. The process according to claim 6 , wherein the curable resin composition is a photocurable resin composition, and the curable resin composition is cured by irradiating the laminate precursor with light in the second step.

9. The curable resin composition according to claim 1 , wherein a proportion of oligomer (A) is 20 to 75 mass % per 100 mass % of said curable resin composition.

10. The curable resin composition according to claim 1 , wherein a proportion of monomer (B) is 25 to 65 mass % per 100 mass % of said curable resin composition.

11. The curable resin composition according to claim 1 , wherein a proportion of monomer (B) is 35 to 50 mass % per 100 mass % of said curable resin composition.

12. The curable resin composition according to claim 1 , wherein a proportion of monomer (C) is 3 to 50 mass % per 100 mass % of said curable resin composition.

13. The curable resin composition according to claim 1 , wherein monomer (B) is at least one monomer selected from the group consisting of 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate and 6-hydroxyhexyl methacrylate.

14. The curable resin composition according to claim 1 , wherein monomer (C) is at least one monomer selected from the group consisting of n-dodecyl methacrylate, n-octadecyl methacrylate and n-behenyl methacrylate.

15. The curable resin composition according to claim 1 , wherein polyol component (A1) further comprise a polyol (a2): a polyoxyalkylene polyol having no oxyethylene groups.

16. The curable resin composition according to claim 1 , wherein polyol component (A1) further comprise a polyol (a2): a polyoxyelkylene polyol having at least 5 hydroxy groups, on average.

17. The curable resin composition according to claim 1 , wherein polyol component (A1) further comprise a polyol (a2): a polyoxyalkylene polyol having a hydroxyl value exceeding 30 mg KOH/g.

18. The curable resin composition according to claim 1 , wherein said polyisocyanate (A2) is not an aromatic polyisocyanate having isocyanate groups bonded to an aromatic ring.