| abstract |
The present invention provides a filter for electronic display devices, comprising a squarylium compound represented by General Formula (I):n n[wherein R 1 and R 2 may be the same or different and each represents a hydrogen atom, an alkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aryl group optionally having substituent(s), or a heterocyclic group optionally having substituent(s); X represents a group represented by following Formula (A):n n(wherein R 3 and R 4 may be the same or different and represents a hydrogen atom, an alkyl group optionally having substituent(s), an alkoxy group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aryl group optionally having substituent(s), or a heterocyclic group optionally having substituent(s), wherein R 3 and R 4 may be combined together with the adjacent nitrogen atom thereto form a heterocyclic group optionally having substituent(s))]. |