GB348266A - Improvements in or relating to the production of coatings - Google Patents

Abstract

Primers or fillers for coating wood, ceramic, brick, metal or other surfaces comprise more than 50 per cent of a cellulose derivative, or of a plasticizer for a cellulose derivative, or of both together. A coating containing the same cellulose derivative may be applied over the primer. Cellulose derivatives specified are the nitrate, the organic esters e.g., acetate, formate, propionate, butyrate, and the ethers, e.g. ethyl, methyl, and benzyl ethers. Plasticizers specified are camphor, triacetin, diethyl phthalate, dibutyl phthalate, diethyl tartrate, dibutyl tartrate, xylene monomethyl sulphonamide, and ethyl o-, m-, and ptoluene sulphonamides. A small quantity of a synthetic resin compatible with the cellulose derivative may be added. The ingredients may be made into a paste with benzene, toluene, petrol, mixtures of benzene with toluene or petrol, or other softener or diluent. Carbon black or other pigment may be added. In one example, a filler consisting of cellulose acetate, diethyl phthalate and benzene is rubbed on to a wood surface which has been wetted with triacetin. The coating applied over the primer may contain the same cellulose derivative; synthetic resins, e.g. A-stage phenol-formaldehyde resins acid-catalyzed, diphenylolpropane-formaldehyde resins, toluene sulphonamide-formaldehyde resins; a plasticizer as specified above; a low-boiling solvent, e.g. acetone, alcohol, benzene; medium or high boiling solvents or both, e.g. dioxane, ethylene glycol monomethyl ether, ethyl lactate, diacetone alcohol, benzyl alcohol; and pigments, e.g. burnt umber or Prussian blue. Examples of cellulose acetate coatings are given. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a filler consisting of ethyl m-toluene sulphonamide, diethyl phthalate, or dibutyl phthalate, 20 parts and xylene 50 parts (by weight), with or without 5 to 10 parts of carbon black or other pigment. This subject-matter does not appear in the Specification as accepted.