WATER-BASE INK FOR INK JET RECORDING

摘要

PROBLEM TO BE SOLVED: To obtain a water-base ink for ink jet recording, which does not cause nozzle plugging and can give a water-resistant print by suspending micelles which are made of a specified polyester and in each of which a dye is enclosed in water. SOLUTION: This water-base ink is prepared by suspending micelles which are made of a polyester (A) having a glass transition point of 25 deg.C or above and in each of which a dye (B) is enclosed in water. Component A is particularly desirably one prepared by cocondensing a diol component represented by the formula (wherein R is an alkylene; (x) and (y) are each 1 or greater; and x+y is 2-7 on the average) with polycarboxylic acids (anhydrides or lower alkyl esters). A desirable example of the compound of the formula is an adduct of bisphenol A with ethylene or propylene oxide. Component B is enclosed in component A by emulsification caused by phase inversion. To perform effective enclosure, component B is dissolved in a ketonic solvent to form a solution having a concentration of 100-600g/l. The particle diameter of the suspended particles is desirably 0.01-0.5μm. This ink has good color developing properties and does not cause nozzle plugging. It is suited also for use in writing utensils.