PRINTING INK FOR METAL, PRINTING WITH SAID INK AND PROCESS COMPRISING COATING SURFACE OF PRINT OF SAID INK WITH OVERPRINT VARNISH

摘要

PURPOSE:To obtain the subject ink excelling in printability and giving a film not causing cissing on a wet coating film of an overprinting varnish by adding an organic solvent having aromatic rings to a printing ink and controlling a wetting index to be within a specified range. CONSTITUTION:The objective ink contains an organic solvent having aromatic rings and has a wetting index within a range of 32-36 dyn/cm. Examples of the organic solvents used include aromatic compounds of formulas I-V and hydrogenation products thereof. In the formulas, R1, R2 and R3 are aliphatic alkyl groups; (1), (m) and (n) are each 0-5; X and Y are each 0 or 1; R4 and R5 are bivalent aliphatic groups; (p) is 1 or 2; (p+q) >=2; and L, M and N are each 0-4. Because the surface tension of the organic solvent is about 32 dyn/cm or above and the wetting index of an ink containing this solvent is 32 dyn/cm or above, it can give a coating film which does not cause cissing on a water- base overprinting varnish.