Patent ID: 8642806

Claim:
A squarylium compound represented by the following Formula (1): wherein, in Formula (1), R 1 and R 2 each independently represent an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group of which the number of ring-forming atoms is from 5 to 14, or a heteroaryl group of which the number of ring-forming atoms is from 5 to 14; wherein the alkyl group, cycloalkyl group, aryl group, and heteroaryl group may independently be substituted by an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, a carbamoyl group, a halogen atom, an alkyloxycarbonyl group having 2 to 7 carbon atoms, an aryloxycarbonyl group having 7 to 11 carbon atoms, an alkylcarbonyloxy having 2 to 7 carbon atoms, an arylcarbonyloxy group having 7 to 11 carbon atoms, an alkylcarbamoyl group having 2 to 7 carbon atoms, or an arylcarbamoyl group having 7 to 11 carbon atoms; R 3 and R 4 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; X 1 and X 2 each independently represent an oxygen atom or —NR 5 —, in which R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Y 1 , Y 2 , Y 3 and Y 4 each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 4 to 6 carbon atoms, an aryl group of which the number of ring-forming atoms is from 5 to 14, a heteroaryl group of which the number of ring-forming atoms is from 5 to 14, an arylcarbonyloxy group of which the number of ring-forming atoms is from 5 to 14, or an alkylcarbonyloxy group having 2 to 7 carbon atoms; when a plurality of Y 1 's is present, the plurality of Y 1 's may be bonded to each other to form a ring structure; when a plurality of Y 2 's is present, the plurality of Y 2 's may be bonded to each other to form a ring structure; when a plurality of Y 3 's is present, the plurality of Y 3 's may be bonded to each other to form a ring structure; when a plurality of Y 4 's is present, the plurality of Y 4 's may be bonded to each other to form a ring structure; Y 1 and Y 2 may be bonded to each other to form a ring structure; Y 3 and Y 4 may be bonded to each other to form a ring structure; n 1 and n 4 each independently represent an integer of from 0 to 3; and n 2 and n 3 each independently represent an integer of from 0 to 2.