Patent ID: 6894096
Filing Date: 2005-05-17
Classification: C09D

Abstract:
1. A method of producing resin varnish for printing ink, said resin varnish having a weight average molecular weight of 10,000 to 1,000,000, said method comprising the steps of: (a) condensing phenol and formaldehyde in an ink solvent to produce a solution of a phenol-formaldehyde initial condensate in said ink solvent; (b) reacting reactants comprising said solution of said phenol-formaldehyde initial condensate in said ink solvent and a rosin ester containing 30-60 wt % of a non-aromatic conjugate resin acid and 20-60 wt % of an aromatic resin acid, in a resinification reaction, at a temperature of 100-250° C., to produce a resin varnish; and (c) terminating said resinification reaction when said resin varnish has a weight average molecular weight of 10,000 to 1,000,000.