GB291477A - Process for the manufacture of articles from synthetic resins or shellac - Google Patents

Abstract

291,477. Dunlop Rubber Co., Ltd., and Davies, R. C. Dec. 3, 1926. Emulsions, making. - A liquid dispersion for use in electrodeposit.ion of a synthetic resin is prepared in the following way. 30 parts of a phenol-formaldehyde condensation product, which is brittle and at an intermediate stage, yet insoluble in dilute alkaline liquids, is dispersed colloidally in 100 parts of water containing ¢ per cent ammonia to which has been added 2 per cent gelatine and 2 per cent casein as protective colloids. To a second dispersion consisting of 100 parts aqueous ammonia (0.5 per cent), 3 parts casein, 1 part gelatine is added sufficient formaldehyde to neutralize the free ammonia. 3 parts of the first dispersion are added to 2 parts of the second, together with 1-2 per cent of a modifying agent such as castor oil, linseed oil, or shellac in the form of an emulsion in water or dilute ammonia. In another example, casein is dispersed in 1 per cent. ammonia solution to a concentration of 10 per cent. Sufficient formaldehyde is then added to neutralize 95 per cent of the ammonia. A modifier such as gelatine or a water emulsion of castor oil to the extent of 5 per cent of the casein may be added. Vulcanizing-agents, modifiers such as castor oil, softeners such as oleic acid, adulterants such as carbon black, binding agents such as shellac or dyes such as turkey red, may be added to the dispersion. Hexamethylenetetramine may be added as a catalyst. Insoluble resins mav be dispersed in a colloid mill. Vulcanized or unvulcanized latices of rubber, guttapercha, or balata may be added for deposition along with the synthetic resin.