Patent GB-1104939-A (GB)
Title: Improvements in and relating to the treatment of pigments
Inventor: FELD RAOUL
IPC: C09C3/08
Filed: 1964-06-10
Abstract: Particles of a pigment to be used in a paint or lacquer (e.g TiO2, SiO2, blanc fixe, lithopone, BaCO3, ZrO2, ZnO, Al2O3, chrome yellow or phthalocyanine) are treated by contacting them with 0.01-5% by wt. (based on the wt. of the particles) of a dicarbonyl compound of formula R1COXCOR2 wherein R1, R2 may be the same o different and may be a substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy, aralkyl or aralkoxy group or R1, R2 may form a ring with the -COXCO- group, and wherein X is the -CH2-, -NH-, or -CHR3- group wherein R3 may be an alkyl, aralkyl or aryl group or, when R1, R2 do not form a ring with the -COXCO- group, R3 and R1 may complete a ring therewith, and drying the particles.  The dicarbonyl compound, which may be acetylacetone, benzoylacetone, dibenzoylmethane, ethylacetoacetate, diethylmalonate, phthalimide, succinimide, methylacetylacetone or 2-acetylcyclohexanone, may be dissolved in an alcohol, acetone or water, or if liquid, may be dispersed in another liquid.  The paint or lacquer may be made by incorporation of the pigment in, for examle, air-drying or stoving acrylic or alkyd media.  In the examples, the pigment was mixed with an oil paint medium consisting of a linseed oil pentaerythritol modified alkyd resin, soya lecithin oil and white spirit in wt. proportions 100:20:570 respectively.ALSO:Particles of a pigment to be used in a paint or lacquer (e.g TiO2, SiO2, blanc fixe, lithopone, BaCO3, ZrO2, ZnO, Al2O3, chrome yellow or phthalocyanine) are treated by contacting them with 0.01-5% by wt. (based on the wt. of the particles) of a dicarbonyl compound of formula R1COXCOR2, wherein R1, R2 may be the same or different, and may be a substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy, aralkyl or aralkoxy group or R1, R2 may form a ring with the -COXCO- group, and wherein X is the -CH2-, -NH-, or -CHR3- group, wherein R3 may be an alkyl, aralkyl or aryl group or when R1, R2 do not form a ring with the -COXCO- group, R3 and R1 may complete a ring therewith, and drying the treated particles.  The dicarbonyl compound, which may be e.g. acetylacetone, benzoylacetone, dibenzoyl methane, ethyl acetoacetate, diethyl malonate, phthalimide, succinimide, methyl-acetylacetone or 2-acetylcyclohexanone, may be dissolved in an alcohol, acetone or water, or if liquid may be dipersed in another liquid.  The pigment particles may be mixed with water before treatment to form a slurry, pulp or paste and may be dried thereafter by heating, e.g. at 120 DEG  C.  Such treatment gives improved gloss and/or hiding power in the paint or lacquer, which may be made by incorporation of the pigment in, for example, air-drying or stoving acrylic or alkyd media.ALSO:Particles of a pigment (e.g. TiO2, SiO2, blanc fixe, lithopone, BaCO3, ZrO2, ZnO, Al2O3, chrome yellow or phthalocyanine) are treated by contacting them with 0.01-5% (preferably 0.1-1.5%) by wt., based on the wt. of the particles) of a dicarbonyl compound of formula R1COXCOR2 in which R1, R2, which may be th same or different, each is a substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy, aralkyl or aralkoxy group or in which R1 and R2 form a ring system with the group-COXCO-, and in which X is the -CH2-, -NH-, or -CHR3-group, wherein R3 is an alkyl, aralkyl or aryl group or, when R1 and R2 do not form a ring system with the group -COXCO-,R3 and R1 together complete a ring system, and drying the treated particles.  The dicarbonyl compound may be, for example, acetylacetone, benzoyl-acetone, dibenzoyl methane, ethyl acetoacetate, diethyl malonate, phthalimide, succinimide, methyl acetylacetone or 2-acetyl cyclohexanone. The dicarbonyl compound may be dissolved in an alcohol, acetone or water or if a liquid may be dispersed in another liquid.  The pigment particles may be mixed with water before treatment to form a slurry, pulp or paste and may be dried after treatment by heating, e.g. at 120 DEG  C. The pigment may be used in a paint or lacquer.