Patent GB-330897-A (GB)
Title: Improvements in the preparation of coatings
IPC: C09D101/18
Filed: 1929-03-16
Abstract: 330,897. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). March 16, 1929. Emulsions, making. - Paints, lacquers and other coatings, for leather, paper, metals, wood, brickwork, asbestos, webs, and the like, are prepared by mechanically dispersing water-insoluble cellulose derivatives such as nitrocellulose, acetyl cellulose, or water-insoluble cellulose ethers in water, as by grinding, with or without first gelatinizing, or by precipitating with water from solution, and adding to the water dispersion, or to the ingredients during dispersion, an aqueous emulsion of a solvent, softening or gelatinizing agents or the like, or mixture of such substances. Fillers, dyestuffs and the like may be dispersed with the cellulose derivative. The aqueous emulsion is obtained with the aid of protective colloids, such as gelatine, glue, methyl cellulose and other soluble, carbohydrate derivatives, polymerised vinyl alcohol, water-soluble urea-formaldehyde condensation products &c., or of emulsifying agents such as alkyl naphthalene sulphonic acid salts, soaps, resin soaps or mixtures of such substances. Organic or inorganic colouring materials, colophony, wax-freed gum-dammar, resins such as polymerised cyclohexanone, rubber latex or other substances may be incorporated in the emulsion. The quantity of emulsion added must be insufficient to produce gelatinization but sufficient to prevent lumpiness of the preparation. The cellulose derivatives may be rendered free from fibrous or coarse constituents by treatment, before grinding, on friction rollers. The products may be in paste or liquid form and may be applied by spraying, brushing or knifing, or may be employed in immersion baths or as printing media. After drying the coatings may be treated with solvents with or without moderate heating and pressing, or may be'otherwise treated, for example by lacquering. Examples of the invention are as follow-(1) 50 parts nitrocellulose 100 parts water and 20 parts Lithol Fast Scarlet RN paste are treated on friction rollers and subsequently ground in a mill; the product is mixed with an emulsion containing 30 parts butyl stearate 15 parts dibutyl phthalate, 5 parts methyl cellulose and 50-100 parts water, with or without 2-5 parts of a cyclohexanone polymerisation resin, to form a paint which, after dilution, is applied three times to chrome leather which may be already treated with a nitrocellulose lacquer. After drying, the leather is sprayed with a solvent such as ethyl acetate and passed through moderately hot calender rollers, or is sprayed with nitrocellulose lacquer. Paper such as wall-paper may be similarly treated. (2) 100 parts of a 40 per cent aqueous paste of benzyl cellulose, containing 5 per cent of methyl cellulose, and 10 parts of a dyestuff such as Lithol Fast Scarlet RN are intimately mixed with an emulsion containing 20 parts dibutyl phthalate, 0.75 parts methyl cellulose, 0.75 parts sodium butyl naphthalene sulphonate and 20 parts water. The product is brushed on to metal, wood, brickwork &c. and, after drying and smoothing, may be covered with a lacquer comprising nitrocellulose, esterified colophony, tricresyl phosphate, butyl acetate, butanol, the acetate of ethylene glycol monoethyl ether, benzene and ethyl alcohol. (3) 50 parts of a 25-30 per cent aqueous paste prepared by treating nitrocellulose, and water on friction rollers and subsequently grinding, are mixed with 15 parts chalk, 15 parts lithopone, 30 parts of slate meal, 15 parts talc or graphite and 25 parts of an emulsion containing 0.8 parts of each of sodium butyl naphthalene sulphonate and methyl cellulose, 40 parts of water and approximately 19.5 parts of each of butyl stearate, dibutyl phthalate and polymerised cyclohexanone resin. The product is a thick paste which after dilution may be applied as a priming composition and may be further treated as in previous examples or may be coated with the product of example (1). (4) 50 parts of nitrocellulose are wetted with from 50-100 parts of water and treated 5-10 times in a friction roller mill; the product is ground with 100 parts of 10 per cent aqueous methyl cellulose solution and mixed with 50 parts of an emulsion similar to that of example 3 and with 8 parts of Lithol Fast Scarlet R.N. powder. The product is a lacquer suitable for treating wood. (5) A dispersion containing nitrocellulose, ochre, lithopone, slate meal, talcum &c., and water is mixed with an aqueous emulsion of dibutyl phthalate or tricresyl phosphate in a 5 per cent methyl cellulose solution. (6) A dispersion as in (5) is mixed with an aqueous emulsion containing castor oil, tributyl phosphate and 5 per cent methyl cellulose solution. The product is suitable for painting fabrics. (7) 50 parts nitrocellulose and 100 parts water are passed several times through a roller mill with an emulsion of 15 parts castor oil, 55 parts 5 per cent methyl cellulose solution and 10 parts Lithol Fast Scarlet RN. The product is ground in a ball mill with an emulsion of 5 parts dibutyl phthalate, 15 parts castor oil, 4 parts methyl cellulose, 0.5 part sodium diisopropyl naphthalene sulphonate and 50 parts water and further diluted if necessary for use as in example (1). Specification 330,957, [Class 95. Paints &c.], is referred to.