Patent ID: 8378006

Claim:
An ink composition comprising: a dye having a molecular structure in which an auxochrome selected from an amino group(—NH 2 ), a secondary amino group (—NHR), a tertiary amino group (—NR 2 ), a hydroxyl group (—OH), a sulfone group (SO 3 ), a carboxyl group (—COOH), a mercapto group(—SH), an alkoxy group (—OR) or a halide (—X) is substituted at first to third carbon positions from a carbon which is substituted with a chromophore selected from an azo group (—N═N—), a carbonyl group (>C═O), a nitro group (—NO 2 ), a thiocarbonyl group (>C═S), a nitroso group (—N═O), an ethylene linkage (—C═C—) or a cyano group (—C═N—); and a reaction product of a decoloring accelerator and a stabilizer, wherein the decoloring accelerator is one or a mixture of two or more selected from tertiary amino alcohols consisting of polyoxyethylenelaurylamine, ethanolamine, triethanolamine and diethanolamine, and wherein the stabilizer is one or a mixture of two compounds selected from C10-C22 saturated fatty acid and C10-C22 unsaturated fatty acid.