Patent GB-376989-A (GB)
Title: Improvements relating to the preparation of pigmented bases of nitrocellulose, cellulose acetate and the like
IPC: C08J3/21
Filed: 1931-08-20
Abstract: For preparing a pigmented base containing nitrocellulose, cellulose acetate or the like, suitable for working up into lacquers and enamels, a relatively large quantity of pigment and a relatively small quantity of a fibrous cellulose derivative are subjected to prolonged kneading under non-aqueous conditions and in the presence of a solvent for the cellulose derivative while maintaining the viscosity of the mixture at such a value that at no time will the mixture flow freely or have a syrupy consistency. During the kneading, the pigment particles are broken down, and thus it becomes possible to use commercial grades of pigment. Conveniently, the cellulose derivative, nitrocellulose for example, is first kneaded with the addition of a diluent such as alcohol, xylene, toluene or benzene, and thereafter further kneaded after the addition of pigment until all the particles of the mass are wetted; a solvent such as ethyl acetate is then added, and the kneading continued for one hour or a few hours; the resulting plastic putty-like product is brought into use as a lacquer by the addition of solvents, diluents, plasticizers, &c. The constituents of the mixture may however be all mixed together at one time.  Kneading is conveniently conducted in a baker's dough machine.  The method is applicable to pigments of mineral and organic origin, such as titanium dioxidebarytes, chrome yellow, carbon black, boneblack, and madder.ALSO:For preparing a pigmented base containing nitrocellulose, cellulose acetate or the like, suitable for working up into lacquers and enamels, and for finishing, protective or decorative coatings, a relatively large quantity of pigment and a relatively small quantity of a fibrous cellulose derivative are subjected to prolonged kneading under non-aqueous conditions and in the presence of a solvent for the cellulose derivative while maintaining the viscosity of the mixture at such a value that at no time will the mixture flow freely or have a syrupy consistency. During the kneading, the pigment particles are broken down, and thus it is possible to use commercial grades of pigment. Conveniently, the cellulose derivative, nitrocellulose for example, is first kneaded with the addition of a diluent such as alcohol, xylene, toluene or benzene, and thereafter further kneaded after the addition of pigment until all the particles of the mass are wetted; a solvent such as ethyl acetate is then added, and the kneading continued for one hour or a few hours; the resulting plastic putty-like product may be sold as such, or it may be further mixed with solvents and diluents, such as ethyl acetate, alcohol and toluene.  The constituents of the mixture may however be mixed together all at one time.  Kneading is conveniently conducted in a baker's dough machine.  The method is applicable to pigments of mineral and organic origin, such as titanium dioxide-barytes, chrome yellow, carbon black, bone black, and madder.ALSO:For preparing a pigmented composition containing nitrocellulose, cellulose acetate and the like, a relatively large quantity of pigment and a relatively small quantity of a fibrous cellulose derivative are subjected to prolonged kneading under non-aqueous conditions and in the presence of a solvent for the cellulose derivative while maintaining the viscosity of the mixture at such a value that at no time will the mixture flow freely or have a syrupy consistency.  During the kneading, the pigment particles are broken down, and thus it is possible to use commercial grades of pigment.  Conveniently, the cellulose derivative, nitrocellulose for example, is first kneaded with the addition of a diluent such as alcohol, xylene, toluene, benzene, &c., and thereafter further kneaded after the addition of the pigment until all the particles of the mass are wetted; a solvent such as ethyl acetate is then added, and the kneading continued for one or a few hours; the resulting plastic putty-like product may be sold as such, or it may be further mixed with solvents and diluents, such as ethyl acetate, alcohol, and toluene.  The constituents of the mixture may, however, be mixed together all at one time.  Kneading is conveniently conducted in a baker's dough machine.  The method is applicable to pigments of mineral and organic origin, such as titanium dioxide-barytes, chrome yellow, carbon black, boneblack, and madder.