Photocurable resin composition, fuel cell, and sealing method

1. A photocurable resin composition comprising the following (A) to (C) ingredients:

(A) ingredient: a polymer having a polyisobutylene backbone and represented by a general formula (1):

wherein R 1 represents a monovalent or polyvalent aromatic hydrocarbon group or a monovalent or polyvalent aliphatic hydrocarbon group, PIB represents a polyisobutylene backbone containing a —[CH 2 C(CH 3 ) 2 ]— unit, R 4 represents a divalent hydrocarbon group having 2 to 6 carbon atoms and optionally containing an oxygen atom, R 2 and R 3 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, R 5 represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group, and n is any integer of 1 to 6;

(B) ingredient: a photo-radical polymerization initiator; and

(C) ingredient: one or more compounds selected from the group consisting of silicone oligomers each having one or more alkoxy groups and one or more (meth)acryloyl groups, silicone oligomers each having one or more alkoxy groups and one or more amino groups, and silane compounds each having one or more isocyanate groups.

2. The photocurable resin composition according to claim 1 , further comprising a (meth)acrylate monomer as (D) ingredient.

3. The photocurable resin composition according to claim 2 , wherein the (D) ingredient is a (meth)acrylate monomer containing an alkyl group having 5 to 30 carbon atoms or an alicyclic group having 5 to 30 carbon atoms.

4. The photocurable resin composition according to claim 1 , wherein a content of the (C) ingredient is 0.1 to 30 parts by mass relative to 100 parts by mass of the (A) ingredient.

5. The photocurable resin composition according to claim 1 , wherein

the (C) ingredient is at least one of the silicone oligomers each having one or more alkoxy groups and one or more (meth)acryloyl groups and the silicone oligomers each having one or more alkoxy groups and one or more amino groups, and

a dynamic viscosity at 25° C. of the least one silicone oligomer is less than 45 mm 2 /s.

6. A photocurable sealing agent for a fuel cell, the sealing agent comprising the photocurable resin composition according to claim 1 .

7. The sealing agent according to claim 6 , wherein the photocurable sealing agent for a fuel cell is a photocurable sealing agent for a fuel cell to be applied to a periphery of any member selected from the group consisting of a separator, a frame, an electrolyte, a fuel electrode, an air electrode, and an electrolyte membrane electrode conjugant which are members constituting the fuel cell.

8. The sealing agent according to claim 6 , wherein the photocurable sealing agent for a fuel cell is a sealing agent between adjacent separators in a fuel cell, a sealing agent between a separator and a frame in the fuel cell, or a sealing agent between a frame and an electrolyte membrane or an electrolyte membrane electrode conjugant in the fuel cell.

9. The sealing agent according to claim 6 , wherein the fuel cell is a solid polymer fuel cell.

10. A cured product obtained by photocuring the photocurable resin composition according to claim 1 .

11. A fuel cell comprising any seal selected from the group consisting of a seal between adjacent separators in the fuel cell, a seal between a separator and a frame in the fuel cell, and a seal between a frame and an electrolyte membrane or an electrolyte membrane electrode conjugant in the fuel cell, wherein

any one of the seals contains the cured product according to claim 10 .

12. The fuel cell according to claim 11 , wherein the fuel cell is a solid polymer fuel cell.

13. A method for sealing at least part of between at least two flanges of seal target components including the at least two flanges, at least one of which is a light-transmissive flange that allows active energy rays to pass therethrough, the method comprising the steps of:

applying the photocurable resin composition according to claim 1 to a surface of at least one of the flanges;

sticking the one flange with the photocurable resin composition applied thereto onto the other flange with the photocurable resin composition interposed in between; and

sealing the at least part of between the at least two flanges by curing the photocurable resin composition by irradiation with active energy rays through the light-transmissive flange.

14. A method for sealing at least part of between at least two flanges of seal target components including the at least two flanges, the method comprising the steps of:

applying the photocurable resin composition according to claim 1 to at least one of the flanges;

irradiating the applied photocurable resin composition with active energy rays to cure the photocurable resin composition, thereby forming a gasket composed of a cured product of the photocurable resin composition; and

placing the other flange on the gasket, and sealing the at least part of between the at least two flanges in such a way that the other flange and the one flange with the photocurable resin composition applied thereto are pressure bonded together with the gasket interposed in between.

15. A method for sealing at least part of between at least two flanges of seal target components including the at least two flanges, the method comprising the steps of:

placing a gasket formation mold on at least one of the flanges;

injecting the photocurable resin composition according to claim 1 into at least part of a cavity formed between the gasket formation mold and the flange on which the mold is placed;

irradiating the photocurable resin composition with the active energy rays to cure the photocurable resin composition, thereby forming a gasket composed of a cured product of the photocurable resin composition;

detaching the mold from the one flange; and

placing the other flange on the gasket and sealing the at least part of between the at least two flanges by pressure bonding the one flange and the other flange together with the gasket interposed in between.