Patent ID: 7871596

Claim:
A compound represented by the following general formula (I), or a salt thereof: wherein R 1 , R 2 and R 3 independently represent an alkyl group having 8 to 25 carbon atoms, or an alkenyl group having 8 to 25 carbon atoms; X represents —O—, or —N(Z)— (Z represents hydrogen atom, or an alkyl group having 1 to 3 carbon atoms); and L represents a divalent bridging group constituted by atoms selected from the group consisting of carbon atom, hydrogen atom, oxygen atom, nitrogen atom and sulfur atom, provided that, in L, the number of oxygen atom is 0 to 8, that of nitrogen atom is 0 to 7, and that of sulfur atom is 0 to 1, and the number of carbon atom, oxygen atom, nitrogen atom and sulfur atom constituting L is 1 to 40, and number of atoms constituting main chain of L is 1 to 32; Ch represents a functional group represented by the following general formula (II): wherein any one of the hydrogen atom H a , H b , H c , H d , H e , and H f is substituted with L.