VEHICLE FOR LITHOGRAPHIC INK

PURPOSE: To obtain a lithographic ink vehicle useful for preparing an ink which little differs in viscosity before and after emulsification in lithographic printing and hardly produces mist by incorporating a specific binder resin, a specific petroleum-derived solvent, and a (semi)drying oil into the vehicle. CONSTITUTION: A petroleum-resin-modified phenol resin having a wt.-average mol.-wt. of 30,000-200,000 is obtd. by reacting 30-150 pts.wt. 4-9C alkylphenol resin with 100 pts.wt. acid-modified hydrocarbon resin which is a reaction product of 100 pts.wt. component mainly comprising a 5-membered cyclic compd. of the formula (wherein H is hydrogen; R is 1-3C alkyl; and m and n are each 0, 1, or higher provided m+n is 6) or its Diels-Alder reaction product (e.g., dicyclopentadiene), 1-40 pts.wt. a-olefin (e.g., a 6-10C α-olefin mixture), and 1-20 pts.wt. unsatd. carboxylic acid (anhydride) (e.g., maleic anhydride). The obtd. modified phenol resin is used as a binder resin and is incorporated, together with a nonarom. petroleum-derived solvent and a (semi)drying oil, into a lithographic ink vehicle.