Recording devices, as well as writing instruments and writing and recording for pigment ink

摘要

PROBLEM TO BE SOLVED: To obtain a low-viscosity pigment ink for writing and recording scarcely adversely affecting the environment, excellent in pigment dispersibility and color developing properties and useful as an ink, etc., for marking pens by including a specific resin, a specified solvent and a specific organic pigment. SOLUTION: This pigment ink comprises (A) preferably 0.5-30 wt.% of an organic pigment such as an azo-based pigment, (B) a resin containing 1-80 wt.% of isobornyl (meth)acrylate unit and having =300 acid value and 2,000-50,000 number-average molecular weight and (C) a solvent containing =10 wt.% thereof having one alcoholic hydroxyl group in the molecule and having =150 deg.C boiling point such as ethyl alcohol or propyl alcohol. The core for writing utensils is preferably porous and recording equipment is preferably an ink jet printer.