GB538592A - Improvement in method of speeding up the making of pigment pastes and product thereof - Google Patents

Abstract

538,592. Inks. NUODEX PRODUCTS CO., Inc. Nov. 6, 1939, Nos. 29461 and 29462. Convention dates, Dec. 22, 1938, and Oct. 5, 1939. Drawings to Specification. [Class 146 (iii)] [Also in Group III] In making inks the preparation of the pigment paste is speeded up by grinding the pigment and organic liquid vehicle in the presence of a grinding aid comprising a xylol-soluble natural or synthetic rubber and a wetting agent capable of forming a homogeneous solution with the rubber; the rubber is present in an amount not exceeding 2¢ per cent. by weight of the resulting composition. Examples I-XVII describe the preparation of grinding aids in which barium. aluminium, zinc, and calcium naphthenates, zinc resinate, lead oleate, glycol dinaphthenate, triethanolamine naphthenate, lecithin, linseed oil fatty acids and soya bean fatty acids are used as wetting agents in association with crepe rubber, para rubber, balata gum chlorinated rubber and isobutylene polymer; xylol, hydrogenated petroleum hydrocarbons, naphtha and toluol are used as solvents; the ingredients are mixed with heating, and an inert gas, e.g. nitrogen, may be injected. The resulting grinding aid should have a viscosity of at least 50 centipoises at 25‹C. Examples XVIII-XL describe the preparation of paints, enamels, pigment pastes and inks using the grinding aids; specified ingredients are leaded zinc, asbestine, titanium dioxide, white lead, chrome green, whiting, lithopone, burnt umber, iron oxide, carbon black, china clay, toluidine red, Prussian blue, alkali blue, chrome yellow, zinc oxide, blanc fixe, para red, barytes, perilla oil, linseed oil, resin varnish, gilsonite varnish, wood-fish stand oil, fish oil, soya oil, castor oil, phenol, oilmodified alkyd resin, litho oils, petroleum oil, ethylene glycol monobutyl ether, xylol, dibutyl phthalate, shellac solution and methyl violet toner solution. The use of the grinding aid results in a finer dispersion of the pigment and in an increased output from conventional grinding apparatus, e.g. three-roll mill.