DYE COMPOUNDS, METHOD OF MAKING THE COMPOUNDS AND INK COMPOSITION EMPLOYING THE COMPOUNDS

摘要

The present invention relates to a dye compound of formula 1. In formula, R and R′are substituents independently selected from the group consisting of soluble residues including an alkyl group of C_1-C_4, a substituted or un-substituted hydrocarbyl group of C_10-C_70 and a hydrogen atom. At least one among R and R′is not the hydrogen atom or the alkyl group of C_1-C_4. R″and R″′are independently selected from the group consisting of a hydrogen atom, alkyl group of C_1-C_6 or halogens. X is a squaric acid residual group. The dye compound absorbs wavelength in a range of about 700-1400 nm.