| 摘要 |
PROBLEM TO BE SOLVED: To obtain an aq. ink compsn. which is free of sagging, spreading, blurring, etc., and gives a feeling of smooth writing by incorporating at least a colorant, water, and a specified amt. of a specific anionic surfactant as a shear thinning agent into the same. SOLUTION: A metal salt of and/or an amine salt of a dialkyl- or dialkenylsulfosuccinic acid represented by the formula, as a shear thinning agent, in an amt. of 5-50 wt.%, pref. 5-20 wt.%, is incorporated. In the formula, R is a 7-18C alkyl or alkenyl; and X is an alkali metal or an amine. If necessary, a betaine, pref. a betaine of an ampholytic surface active type, (e.g. lauryldimethylaminoacetic acid betaine) is further incorporated. Pref., the compsn. has a viscosity measured with an E-type rotational viscometer at 100 rpm of 20-200 mPa.s (25 deg.C) and a shear viscosity index of 0.1-0.7. |
