GB740265A - Improvements relating to organo-silicon modified alkyd resins - Google Patents

Abstract

An organo-silicon modified alkyd resin, suitable for use in varnishes, is obtained by esterifying part of the hydroxyl content of a mixture of a fatty acid mono-ester of a polyhydric alcohol and a free polyhydric alcohol with one or more polycarboxylic acids or esterforming derivatives of such acids and condensing the other part of the hydroxyl content with one or more bi- or tri-functional organosilane monomers having halogen atoms or alkoxy or aryloxy groups attached to two or three valencies of the silicon atom. The monoester is present in an amount of at least 80 per cent by weight of the free polyhydric alcohol. The modified alkyds may be copolymerized with normal polysiloxane resins. Specified are: polyhydric alcohols-glycerol and pentaerythritol; polycarboxylic acids - phthalic, maleic, sebacic and suberic acids or anhyhydrides; organosilane monomers - diphenyldichloro-, diethyldichloro-, methylphenyldichloro-, diethyldiethoxy-, phenyltrichloro-, ethyltrichloro-, phenyltriethoxy-, methyltriethoxy- and ethyltriethoxy-silanes. In examples: (1) To a mixture of the monoglyceride of soya bean oil acids or linseed oil acids, glycerol and toluene was added phenyltrichlorosilane dissolved in toluene and the mixture heated to remove hydrochloric acid. After cooling, phthalic anhydride and toluene were added and heating was recommenced. (2)-(7) The following were reacted in a manner similar to example (1), some of the examples using xylene or white spirit instead of toluene: (2) the monoglyceride of soya bean oil acids, glycerol, phenyltrichlorosilane, phthalic anhydride and maleic anhydride; (3) the monoglyceride of soya bean oil acids, glycerol, phenyltriethoxy-silane and phthalic anhydride; (4) the mono-glyceride of soya bean oil acids, glycerol, phenyltrichlorosilane and phthalic anhydride; (5) the monoglyceride of soya bean oil acids, glycerol, ethyltrichlorosilane and phthalic anhydride; (6) the monoglyceride of linseed oil fatty acids, glycerol, ethyltrichlorosilane, phenyltrichlorosilane and phthalic anhydride; (7) the monoglyceride of linseed oil acids, glycerol, methyl phenyldichlorosilane and phthalic anhydride. (8) A mixture of the monoglyceride of soya bean oil acids, glycerol, toluene and phthalic anhydride was heated to 170-200 DEG C. After cooling, diethyldichlorosilane, ethyltrichlorosilane and toluene were slowly added and the mixture heated to reflux. (9) A mixture of the resin of example (1), methylphenylpolysiloxane resin and toluene was heated to reflux.