GB1470655A - Ink formulation - Google Patents

Abstract

1470655 Intaglio plate printing ink BRADBURY WILKINSON & CO Ltd 17 May 1974 [5 June 1973] 26709/73 Heading C4A [Also in Division C3] An ink formulation suitable for intaglio plate printing of security papers and becoming permanently infusible after printing, comprising from 25 to 82% by weight, based on the ink formulation, of pigment and extender, and from 18 to 75% by weight, based on the ink formulation, of an oxidizable varnish containing a wax component, if necessary a wax viscosity modifier, and an oxidizable component which is an oil and/or a resin, the wax component, together with the wax viscosity modifier if present, forming a solid solution with the oxidizable component at ambient temperature and a homogeneous composition at the melting point of the varnish as well as at a temperature at least as high as the melting point of the ink formulation. The oxidizable component may be an alkyd resin, linseed oil or tung oil. Suitable alkyd resins are derived from soya oil and pentaerythritol or linseed oil and phthalic anhydride. The wax visicosity modifier may be a solid fusible resin compatible with the wax component, e.g. a hydrocarbon resin derived from petrochemicals. Driers may also be present, e.g. cobalt naphthenate and cobalt octoate. Suitable waxes are earnauba wax, paraffin wax, a polyvinyl ether of octa-decyl alcohol and hydrogenated castor oil.