GB1055444A - Resinous polyesters - Google Patents

Abstract

A resinous polyester comprises the heat reaction product of (a) a dicarboxylic acid component consisting wholly or mainly of ethylenically unsaturated dicarboxylic acid comprising at least a major proportion of fumaric acid and no, or at most 25 mol. per cent based on total acids, saturated dicarboxylic acid, (b) a glycol component, and (c) a diene component comprising a major molar proportion of dicyclopentadiene in an amount providing from 0.6 to 0.9 mol. of dicyclopentadiene per mol. of ethylenically unsaturated dicarboxylic acid. The glycol may be: ethylene glycol, propylene glycol, butylene glycol, 1:5-pentanediol, dimethylol propane, neopentyl glycol or a polyoxyalkylene glycol of M.W. up to 1200 and bisphenol based diols. Up to 20 mol. per cent of polyhydric alcohols, e.g. glycerine and pentaerythritol or polyepoxides may be present. Up to 50 mol. per cent of the diene component may be cyclopentadiene, 1:4-butadiene, tricyclopentadiene and tetracyclopentadiene. The polyester resin may be dissolved in an organic solvent, e.g. benzene, toluene, xylene, butanol diethylene glycol or methyl ethyl ketone. Up to 35% by weight of an amino plast resin may be incorporated into the polyester, e.g. reaction products of HCHO with urea and substituted molamines and benzoguanamine, which may be partially etherified with a C3-C8 alcohol. In Example (1) an epoxy resin of M.W. 1000 consisting of the diglycidyl ether of 221 bis-(p-hydroxyphenyl propane), diethylene glycol, azelaic acid and xylol were heated to 400 DEG F., cooled, dicyclopentadiene added and reheated to 400 DEG F. In Example (4) diethylene glycol, neopentyl glycol, fumaric acid and xylol were heated to 400 DEG F., cooled, dicyclopentadiene added and reheated. The polyester thus produced was mixed in Example (5) with a resinous chlorinated polyphenyl and xylol and applied as an enamel to tin cans. Reference has been directed by the Comptroller to Specification 937,980.ALSO:A coating composition comprising an organic solvent having dissolved therein an unsaturated polyester (derived from a reaction mixture containing fumaric acid, dicyclopentadiene and a glycol) and optionally a heat hardenable aminoplast resin is used to coat metal articles e.g. coils, cans or sheets. The metal may be aluminium. In example (3) an unsaturated polyester solution was mixed with finely divided silica, toluene, aluminium pigment and petrolatum solution and sprayed onto a metallic base to give a coating of 2.8 mils which was cured at 385 DEG F. In example (4) an unsaturated polyester was mixed with a resinous chlorinated polyphenyl and xylol and used as an enamel for the post solder side seam of tin cans. Reference has been directed by the Comptroller to Specification 937,980.