Cation exchange resin, and cation exchange membrane and fuel cell electrolyte membrane using same
The present invention provides a cation exchange resin, and a cation exchange membrane and an electrolyte membrane for a fuel cell using the same. The cation exchange resin comprises a divalent hydrophobic unit; and a divalent hydrophilic unit having divalent hydrophilic groups which are repeated via carbon-carbon bond. The divalent hydrophilic groups being composed of one aromatic ring, or being composed of a plurality of aromatic rings which are bonded to each other via a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or carbon-carbon bond, and at least one of the aromatic rings having a cation exchange group; wherein the hydrophobic unit and the hydrophilic unit are bonded to each other via carbon-carbon bond.
1. A cation exchange resin, comprising:
a divalent hydrophobic unit shown in any one of the following formulae (1a′), (1b′), (1c′) and (1d′); and
a divalent hydrophilic unit having divalent hydrophilic groups which are repeated via carbon-carbon bond, the divalent hydrophilic groups being composed of one aromatic ring, or being composed of a plurality of aromatic rings which are bonded to each other via a divalent hydrocarbon group, a divalent silicon-containing group, a divalent nitrogen-containing group, a divalent phosphorus-containing group, a divalent oxygen-containing group, a divalent sulfur-containing group, or carbon-carbon bond, at least one of the aromatic rings having a cation exchange group;
wherein the hydrophobic unit and the hydrophilic unit are bonded to each other via carbon-carbon bond;
wherein R′ is the same or different and represents a divalent aliphatic hydrocarbon groups having carbon atoms of 1 to 20 or direct bond, a is an integer of 1 to 10.
2. The cation exchange resin according to claim 1 , wherein the hydrophilic group is a bisphenol residue which is substituted with a substituent group having a cation exchange group, as shown in the following formula (2), or an o-, m- or p-phenylene group which is substituted with a substituent group having a cation exchange group, as shown in the following formula (2′)
(In the formula, R represents a hydrocarbon group, a silicon-containing group, a nitrogen-containing group, a phosphorus-containing group, an oxygen-containing group, a sulfur-containing group, an aromatic group, or direct bond, which is not substituted or which is substituted with a substituent group having a cation exchange group; each Alk is the same or different and represents an alkyl group; each Ion is the same or different and represents a substituent group having a cation exchange group; a′ and b′ are the same or different and represent an integer of 0 to 4; and s, t and u are the same or different and represent an integer of 0 to 4 and at least one of s, t and u is 1 or more)
(In the formula, Alk represents an alkyl group; Ion represents a substituent group having a cation exchange group; a′ represents an integer of 0 to 4; and s represents an integer of 1 to 4).
3. The cation exchange resin according to claim 1 , wherein the hydrophobic unit is a divalent fluorinated saturated hydrocarbon group or a divalent saturated hydrocarbon group.
4. A cation exchange membrane, comprising the cation exchange resin according to claim 3 .
5. An electrolyte membrane for a fuel cell, comprising the cation exchange resin according to claim 3 .
6. The cation exchange resin according to claim 2 , wherein the hydrophobic unit is a divalent fluorinated saturated hydrocarbon group or a divalent saturated hydrocarbon group.
7. A cation exchange membrane, comprising the cation exchange resin according to claim 6 .
8. An electrolyte membrane for a fuel cell, comprising the cation exchange resin according to claim 6 .