GB622235A - Alkyd copolymers - Google Patents

Abstract

Low pressure laminating compositions are prepared by copolymerizing, e.g. by heating, preferably in the presence of a catalyst, up to 150 DEG C., an unsaturated alkyd resin with an ester of carbamic acid or an N-alkyl derivative thereof and an alcohol having a double bond between the second and third carbon atoms from the hydroxyl group. The alkyd resins are those obtained by condensing a polyhydric alcohol, e.g. ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol, pentaerythritol, glycerine, trimethylene glycol, thiodiglycol, monoethylin, and 1,2-propylene glycol, with a polycarboxylic acid, e.g. maleic, acetylene dicarboxylic, fumaric, mesaconic, itaconic, aconitic, monochloromaleic, monochlorofumaric, citraconic, alpha-methyl itaconic and alpha-ethyl itaconic acids or their anhydrides, partly replaced by a non-ethylenic polycarboxylic acid, e.g. succinic, phthalic, benzoylphthalic, adipic, sebacic, suberic, and pimelic, up to 75 mol. per cent. Modifiers may be included, e.g. monohydric alcohols such as propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, allyl, methallyl, crotyl alcohols, monocarboxylic acids such as acetic, propionic, butyric, benzoic, acrylic, methacrylic acids and drying or semi-drying oils, e.g. tung, soya, castor and linseed. The carbamates have the general formula RR1NCO2R11, R and R1 being H or alkyl and R11 being the residue of the unsaturated alcohol, e.g. allyl, 3-chloro-allyl, methallyl, crotyl, a -ethyl allyl, b -ethyl allyl, 2-chloro-allyl, tiglyl or b -propyl-allyl alcohol. Catalysts for the copolymerization are benzoyl peroxide, hydrogen peroxide, ammonium persulphate, sodium perborate, barium peroxide, sodium peroxide, acetyl peroxide, lauroyl peroxide or stearyl peroxide. In the example, diethylene glycol and maleic anhydride were condensed to an alkyd resin which was mixed with allyl carbamate containing dissolved benzoyl peroxide. A multi-ply structure of glass cloth was impregnated with the mixture, was enveloped in "Cellophane" (Registered Trade Mark), pressed between glass sheets and heated to 80 DEG C. The mixture was also polymerized in a mould to form a clear sheet. The products are insoluble in common organic solvents and resistant to acids and alkalis. The mixture to be polymerized may include fillers, e.g. carbon black, textile flocs, e.g. cotton, rayon, silk, nylon, wool, or hemp, dyes, plasticizers, pigments and resins.