GB303898A - Coated articles and method of making the same - Google Patents

Abstract

303,898. British Celanese, Ltd., (Assignees of Dreyfus, C.). Jan. 12, 198, [Convention date]. Processes.-Articles or sheets are coated by applying thereto layers or coatings of powders, consisting of mixtures of finely-divided organic derivatives of cellulose and one or more plasticizers with or without fillers, dyes, dyestuffs, pigments and effect materials, and subjecting to heat and pressure to form adherent coatings. The plasticizers may include camphor substitutes, high boiling solvents, softeners, gelatinizing agents or mixtures thereof. The powders may be prepared as described in Specification 282,723, [Class 70, Indiarubber &c.]. The following examples of the production of powders are given :-(1) 80 lbs. cellulose acetate of an average fineness of 6-8 mesh is put into a pebble mill with 800 lbs. 1¢ to 2 inch flint stones and ground for 6-8 hours, after which is added 24 lbs. triacetin and 4 lbs. diethyl phthalate and grinding continued for a further 8 hours; (2) 80 lbs. cellulose butyrate of 6-8 mesh is ground as in (1) and 10 lbs. triacetin, 10 lbs. diethyl phthalate and 6 lbs. tricresylphosphate added and grinding continued as in (1); (3) to 80 lbs. cellulose ethyl ether of 20 mesh ground as in (1) is added 20 lbs. of dibutyl phthlate and grinding continued as before. For a white composition, 75 lbs. zinc white is added to the above mixtures followed by further grinding for several hours. The powder is applied to the surface to be coated and the article &c. placed in a press and subjected to a temperature of 50-80‹ C. and a pressure of 300-500 lbs. per square inch. Surfaces with a high polish are obtained by using moulds or presses having surfaces of glass, nickel, &c. The invention is applicable to sheets, plates, slabs, wire, rods, or cores of any shape for producing automobile body parts, furniture, &c. The surface to be coated may be of wood, metal, pottery, glass, cardboard, leather, synthetic resins of phenol-aldehyde type, &c. Paper or fabrics such as cotton, wool, silk, hemp, flax and artificial silk may be coated. Glass substitutes are formed by applying the coating to a wire cloth or screen. Phonograph records are formed by applying the powder to a suitable core. Gum may be used to secure temporary adhesion of the powder to the surface. To secure the coatings to glass or metallic sheets, the latter are perforated, roughened, grooved, recessed or formed with threaded or undercut holes to anchor the coating. The cellulose derivatives include esters. such as the acetate, formate, propionate or butyrate and ethers such as methyl, ethyl and benzyl cellulose. The invention does not include powders produced by incorporating the ingredients under the action of heat, e.g. by melting, or powders containing volatile solvents. Specification 249,600, [Class 70, Indiarubber &c.], also is referred to.