GB733230A - Aqueous emulsions of oil modified alkyd resins - Google Patents

Abstract

An emulsion paint comprises a dispersion of a soap of an air-drying oil-modified alkyd resin in an aqueous phase containing a protective colloid (e.g. casein or glue), the acid number of the alkyd before soap formation being at least 15 and the amount of base used in soap formation being such as to reduce the acid number by 15-35 units. If the base is volatile, it may be added in excess to an alkyd of acid number 15-35, the excess base volatilizing from the paint film. The alkyd preferably has a viscosity at 25 DEG C. of 150-300 poises. A vinyl polymer produced by emulsion polymerization, e.g. polyvinyl acetate, polystyrene or a butadiene styrene copolymer may be added to the emulsified alkyd, preferably in an amount of 15-45 per cent by weight of the alkyd. Pigments or extenders may also be added, e.g. anatase or rutile titanium dioxide, lithophone, iron oxide, sienna, organophthalocyanine pigments, barytes, blance fixe or Paris white. In examples emulsion paints are made by mixing together (1) a glyceryl phthalate resin modified by a mixture of linseed and dehydrated castor oils (A.N. 23.8), excess ammonia solution, titanium dioxide, water and casein (solubilized with borax and preserved with NaF); (2) a linseed oil modified glyceryl isophthalate resin (A.N. 25) ammonia solution sufficient to neutralize the acidity of the resin, cobalt naphthenate in white spirit, water and casein (solubilized with NaOH and preserved with sodium pentachlorophenate; (3) a dehydrated castor oil modified glyceryl phthalate resin (A.N. 32), potassium hydroxide sufficient to reduce the A.N. to 15, mineral spirits, water, casein (solubilized with KOH and preserved with NaF), lithophone and blanc fixe; a glyceryl phthalate resin modified with a mixture of linseed and dehydrated castor oils (A.N. 23.8), triethanolamine sufficient to neutralize the acidity of the resin, lead naphthenate in white spirit, casein (solubilized with NaOH and preserved with NaF), water and titanium dioxide; (5) linseed fatty acid modified pentaerythritol phthalate resin (A.N. 24.7), excess ammonia solution, titanium dioxide, whiting, water, casein (solubilized with borax and preserved with NaF) and bentonite; (6) a glyceryl phthalate resin modified by a mixture of linseed and dehydrated castor oils (A.N. 23.8), triethanolamine sufficient to neutralize the acidity of the resin, lead naphthenate in white spirit, casein (solubilized with NaOH and stabilized with sodium pentachlorphenate), water and a plasticized polyvinyl acetate emulsion.