INK FOR USE IN WATER-FREE LITHOGRAPHY

摘要

PURPOSE: To obtain a printing ink with no concern about the relevant workplace environment pollution and offensive odor, and having both adequate printability and printing effect as an ink for water-free lithography. CONSTITUTION: This ink for use in water-free lithography contains 20-40wt.% of a rosin-modified phenolic resin with a weight-average molecular weight of 80000-200000 and 20-40% in the cloud point defined as the relationship described below and 25-50wt.% of a petroleum-based solvent <=1wt.% in aromatic hydrocarbon content, 75-95 deg.C in aniline point and 260-350 deg.C in boiling point. The definition of the cloud point is as follows: cloud point (%) = resin(2g)/[resin (2g) + solvent (Xg)]×100 (X is the minimum amount of n-tetradecane to cause the solution to be cloudy when cooled to 25 deg.C following preparation of the solution in such a way that n-tetradecane is added to 2g of the resin and heated to dissolve the resin in the n-tetradecane).