METHOD FOR PRODUCTION OF PLASTICIZED AND PIGMENTED NITROCELLULOSE OR COLLOXYLIN Russian patent published in 2001 - IPC

FIELD: paper-and-pulp industry. SUBSTANCE: in a method including preparing aqueous suspension of nitrocellulose or colloxylin, plasticizing them in presence of process additives, separating liquid phase of suspension from its solid phase, and granulating solid phase, novelty resides in that above-said suspension contains 2 to 12 wt % of nitrocellulose or colloxylin and that second 10-40% aqueous suspension of one or several dispersed pigments is prepared for mixing with the first suspension to obtain homogeneous mixture. After that, mixture of plasticizer with process additives (0.05 to 1.0% of the weight of plasticizer) is prepared and used to prepare emulsion, in which concentration of plasticizer ranges from 5 to 50% of the weight nitrocellulose or colloxylin. Emulsion is then added to combined suspension and resulting mixture is stirred for 1 to 10 h at 10 to 60 C to achieve homogeneity. Liquid phase of thus obtained suspension is separated from its solid phase by way of preliminarily transporting suspension across filtration surface followed by compression, while granulation of solid phase is performed by preliminarily extruding it through perforations in worm filter press followed by cutting. According to invention, separation of liquid phase of suspension and granulation are conducted at pressure 0.5 to 7 MPa and temperature 60 to 90 C to obtain granules with moisture content up to 4%. Pigment suspension, prior to be mixed with nitrocellulose or colloxylin suspension, is dispersed at mixing criterion =10000-600000 by being passed through hydrodynamic apparatus. Process additives are monobasic unsaturated acid salts such as oleic acid salts. Invention can be used in manufactures of paints, varnishes, films, and other commodities. EFFECT: increased assortment of technical possibilities for production of title products. 2 cl