GB699185A - Improvements in pigmented compositions and in their preparation - Google Patents

Abstract

A pigmented plastic composition is made by introducing solid particles of pigment and plastic into a liquid mixture of water and a water-miscible solvent for the resin, in such proportions as to cause the plastic to become pigment receptive but not to dissolve the plastic or cause it to gel or agglomerate, and in amount sufficient to give fluidity to the mixture of solids and liquids and to permit desirable grinding action, milling the mixture, preferably in a ball, pebble, or colloid mill, until the pigment is dispersed in the plastic, and then separating off the pigmented plastic particles. Plastics specified are ethyl cellulose, cellulose acetate, rosin modified maleic resins, dibasic acid-modified alkyd resins, glyceryl phthalate resin, phenol - aldehyde resins, urea - formaldehyde resins, melamine-formaldehyde resins, polyvinyl chloride, copolymers of vinyl chloride with vinyl acetate, polyvinylidene chloride, polystyrene, polymethyl methacrylate, and coumarone-indene resin. Suitable solvents for the plastics are methyl, ethyl, isopropyl, and diacetone alcohols, methyl and ethyl lactates, acetone, methyl ethyl ketone, and the glycol ethers known under the Trade Name "Carbitol" and the Registered Trade Mark "Cellosolve." The grinding medium may also contain buffering agents, wetting agents such as turkey red oil, and metallic soaps. Numerous pigments of the organic and inorganic type are specified. The pigmented plastics may be employed in coating compositions, spinning dopes, and mouldings.ALSO:A composition consisting essentially of a natural resin or other plastic material, such as paraffin wax, stearic acid, cetyl alcohol, or dicyclohexyl phthalate, and a pigment is made by introducing solid particles of pigment and resin or other material into a liquid grinding medium comprising water and a water-miscible solvent for the resin or other material, the ratio of water to water -miscible solvent being such as to produce a liquid mixture which causes the resin or other material to become pigment receptive, but which does not dissolve the resin or other material or cause it to gel or agglomerate, the liquid grinding medium being present in amount sufficient to give fluidity to the mixture of solids and liquids and to permit desirable grinding action, milling the mixture, preferably in a ball, pebble, or colloid mill until the pigment is dispersed in the resin or other material, and then separating off the pigmented particles. Natural resins specified are dammar resin, shellac, wood resin, and zinc resinate. Suitable solvents for the resins are methyl, ethyl, isopropyl and diacetone alcohols, methyl and ethyl lactates, acetone, methyl ethyl ketone, and the glycol ethers known under the trade name "Carbitol" and the Registered Trade Mark "Cellosolve." The grinding medium may also contain buffering agents, wetting agents such as Turkey red oil and metallic soaps. Pigments specified are Toluidine Maroon powder, Victoria Blue Toner, Benzidine Yellow Toner, and titanium dioxide. The pigmented resins may be used in the preparation of lacquers, inks, lipstick bases, and candles.ALSO:A composition consisting of chlorinated rubber and a pigment, such as standardized Toluidine Toner, is made by introducing solid particles of chlorinated rubber and pigment into a liquid medium comprising water and a water-miscible solvent for the chlorinated rubber, such as ethyl acetate, the ratio of water to water-miscible solvent being such as to produce a liquid mixture which causes the chlorinated rubber to become pigment receptive without causing it to dissolve or gel or agglomerate, the liquid grinding medium being present in amount sufficient to give fluidity to the mixture of solids and liquids and to permit desirable grinding action, milling the mixture, preferably in a pebble mill, until the pigment is dispersed in the chlorinated rubber, and then separating off the pigmented particles.