Proton-conducting compound and proton-conducting polymer
View Patent ↗Provided is a proton-conducting compound which provides proton conductivity without humidification and is suitable for electrochemical device materials such as solid electrolytes for fuel cells and electrolytes for batteries. Provided also is a proton-conducting polymer. The proton-conducting compound is composed of a melamine compound salt obtained from a melamine compound represented by the following formula (1) and a Bronsted acid and the proton-conducting polymer is obtained by homopolymerizing or copolymerizing the melamine compound salt. In formula (1), R 1 , R 2 , R 3 , R 4 , and R 5 each is independently an alkyl group, an aryl group, an alkenyl group, a heterocyclic group, or a hydrogen atom; at least one of them is a group other than hydrogen; R 2 and R 3 or R 4 and R 5 may join together to form a heterocyclic structure; and the alkyl group, the aryl group, the alkenyl group, or the heterocyclic group may have a substituent. A melamine compound salt wherein R 1 is CH 2 ═CR 6 —CO—O(CH 2 ) n — polymerizes to yield a proton-conducting polymer. In this particular R 1 group, R 6 is hydrogen or an alkyl group and n is an integer equal to or larger than 1.
1. A proton-conducting compound composed of a melamine compound salt obtained from a melamine compound represented by the following formula (1) and a Bronsted acid:
wherein:
R 1 is CH 2 ═CR 6 —CO—O(CH 2 ) n —;
R 2 , R 3 , R 4 , and R 5 each is independently an alkyl group, an aryl group, a heterocyclic group, or hydrogen and at least one of them is an alkyl group, an aryl group, or a heterocyclic group; R 2 and R 3 or R 4 and R 5 may join together to form a heterocyclic structure;
R 6 is hydrogen or an alkyl group and n is an integer equal to or larger than 1; and
the alkyl group, the aryl group, and the heterocyclic group each may have a substituent selected from the group of alkyl groups of 1 to 6 carbon atoms, aryl groups of 6 to 12 carbon atoms, heterocyclic groups, an amino group, alkylamino groups of 1 to 6 carbon atoms, a nitro group, a carboxyl group, acyl groups of 1 to 6 carbon atoms, acyloxy groups of 1 to 6 carbon atoms, a cyano group, alkylsulfonyl groups of 1 to 6 carbon atoms, alkylsulfonyloxy groups of 1 to 6 carbon atoms, a sulfoxide group, a sulfonic acid group, alkoxycarbonyl groups of 1 to 6 carbon atoms, aryloxycarbonyl groups of 6 to 12 carbon atoms, aryloxy groups of 6 to 12 carbon atoms, and alkynyl groups of 2 to 6 carbon atoms;
and wherein the Bronsted acid is sulfuric acid, phosphoric acid, boric acid, a heteropolyacid, alkylsulfonic acid, a fluorine-containing alkylsulfonic acid, an alkylcarboxylic acid, or an imide acid, wherein the alkyl moiety contains 1 to 6 carbon atoms.
2. A proton-conducting compound as described in claim 1 wherein the said compound is composed of a melamine compound salt produced by the reaction of a melamine compound represented by formula (1) with a Bronsted acid in a ratio of 0.5 to 2 equivalents of Bronsted acid per 1 mole of melamine compound.
3. A proton-conducting solid electrolyte comprising the proton-conducting compound described in claim 1 .
4. A proton-conducting solid electrolyte as described in claim 3 wherein the proton-conducting compound is held in a polymeric gelling material.
5. A proton-conducting solid electrolyte membrane formed by molding the proton-conducting solid electrolyte described in claim 4 into membrane.
6. An electrolyte for electrochemical cells comprising the proton-conducting solid electrolyte described in claim 3 .
7. A fuel cell comprising the electrolyte for electrochemical cells described in claim 6 .
8. A fuel cell comprising the proton-conducting solid electrolyte membrane described in claim 5 .