Patent GB-784512-A (GB)
Title: Process for the production of pigmented rolled masses for use in lacquers
IPC: C09C3/00
Filed: 1954-03-31
Abstract: Pigmented rolled masses for use in lacquers are made by intensively stirring an aqueous dispersion of a finely-divided pigment or filler with an aqueous dispersion of a finely-divided, hydrocarbon-soluble, synthetic resin or cellulose derivative film-former to cause the pigment or filler to deposit on the finely-divided filmformer, adding a gelatinizing agent to the dispersion of the pigment or filler and the film former, separating a major proportion of the water, and then working up the product into a rolled mass in the usual manner. Specified filmformers are collodion wool, polyvinyl butyraldehyde acetals, polyvinyl acetaldehyde acetals, polyvinyl acetate, polymethyl acrylate and copolymers of vinyl chloride.  Specified pigments are carbon black, Berlin blue, cadmium sulphide, lead chromate, iron oxide, organic pigments of the indanthrene dyestuff group, aluminium oxide, zinc oxide, silicon dioxide and titanium dioxide.  In examples: (1) a dispersion of carbon black in water is added to a dispersion of collodion wool in water and the mixture stirred intensively with addition of dibutyl phthalate and toluylene bisguanide.  The mixture is run into a centrifuge and water is centrifuged off.  The resultant cake is treated in a kneader until no further water issues and then formed into thin sheets in a rolling mill; (2) an aqueous paste of carbon black is added to a dispersion in water of a copolymer of vinyl chloride and vinyl isobutyl ether. The mixture is intensively stirred with addition of a solution, in methyl alcohol, of paraphenylenediamine and a polycondensation product of butyl carbamate and formaldehyde.  Water is separated out on a suction filter.  The coagulate is treated in a kneader and thereafter rolled to form a skin.  Specifications 291,539, 309,964, [both in Class 2 (ii)], and 759,919 are referred to.ALSO:Pigmented rolled masses for use in lacquers are made by intensively stirring an aqueous dispersion of a finely divided pigment or filler with an aqueous dispersion of a finely-divided, hydrocarbon-soluble, synthetic resin or cellulose derivative film former to cause the pigment or filler to deposit on the finely divided film-former, adding a gelatinizing agent to the dispersion of the pigment or filler and the film former, separating a major proportion of the water and then working up the product into a rolled mass in the usual manner.  Specified film formers are collodion wool, polyvinyl acetal and butyral, polyvinyl acetate, polymethyl acrylate and vinyl chloride copolymers.  Specified pigments are carbon black, Berlin blue, cadmium sulphide, lead chromate, iron oxide, organic pigments of the indanthrene dyestuff group, aluminium oxide, zinc oxide, silicon dioxide and titanium dioxide.  In examples: (1) a dispersion of carbon black in water is added to a dispersion of collodion wool in water and the mixture stirred intensively with addition of dibutyl phthalate and toluylene bisguanide.  The mixture is run into a centrifuge and water is centrifuged off.  The resultant cake is treated in a kneader until no further water issues and then formed into thin sheets in a rolling mill; (2) an aqueous paste of carbon black is added to an aqueous dispersion of a copolymer of vinyl chloride and vinyl-isobutyl ether.  The mixture is intensively stirred with the addition of a methyl alcohol solution of paraphenylene diamine and a polycondensation product of butyl carbamate and formaldehyde.  Water is separated out on a suction filter and the coagulate is kneaded and then rolled to form a skin which is comminuted to form chips soluble in esters, ketones and mixtures thereof with aromatic hydrocarbons.  Specifications 291,539, 309,964, [both in Class 2 (ii)], and 759,919, [Group III], are referred to.