Photocurable sheet-shaped sealing agent for fuel cell, cured product, fuel cell, and sealing method
One embodiment of the present invention aims to provide a photocurable sheet-shaped sealing agent having adherence to an electrolyte membrane and a hydrogen gas barrier. A photocurable sheet-shaped sealing agent for fuel cell, comprising a component (A): urethane (meth)acrylate, a component (B): a phenoxy resin, and a component (C): a photopolymerization initiator.
1 . A photocurable sheet-shaped sealing agent for a fuel cell, comprising a component (A): urethane (meth)acrylate, a component (B): a phenoxy resin, a component (C): a photopolymerization initiator, and a component (D): a (meth)acrylate monomer having 8 to 25 repeating ether bond structural units.
2 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein the component (A) has a polycarbonate backbone.
3 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein a glass transition temperature of the component (B) is 50 to 120° C.
4 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein a weight average molecular weight of the component (A) is 20,000 to 100,000.
5 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein the sealing agent comprises 4 to 70 parts by mass of the component (B) per 100 parts by mass of the component (A).
6 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein the component (C) has a photoinitiator compound that has an absorption wavelength at 365 nm or more and decomposes upon irradiation with ultraviolet light with a wavelength at 365 nm or more, thereby generating radicals involved in polymerization.
7 . The photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 , wherein the photocurable sheet-shaped sealing agent for the fuel cell is a sealing agent between adjacent separators in a fuel cell, or a sealing agent between a fuel cell frame and an electrolyte membrane or electrolyte membrane electrode assembly.
8 . A cured product obtained by curing the photocurable sheet-shaped sealing agent for the fuel cell according to claim 1 .
9 . The cured product according to claim 8 , wherein the cured product has a hydrogen gas permeability of 1.0×10 −14 mol·m/m 2 ·s·Pa or less.
10 . A fuel cell, comprising the cured product according to claim 8 .
11 . A photocurable sheet-shaped sealing agent for a fuel cell, obtained by applying, to a seal adherend, a coating solution comprising a component (A): urethane (meth)acrylate, a component (B): a phenoxy resin, a component (C): a photopolymerization initiator, a component (D): a (meth)acrylate monomer having 8 to 25 repeating ether bond structural units, and an organic solvent, and drying the organic solvent.