Patent GB-1016396-A (GB)
Title: Improvements in or relating to polyester resins
IPC: C08G63/52
Filed: 1962-10-05
Abstract: Polyesters are made by reacting a high molecular weight polyester of terephthalic acid and a dihydric alcohol with (a) a dicarboxylic acid (other than terephthalic acid) or an anhydride, monoester, diester or oligomeric ester thereof and (except where reactant (a) is an ester which contains at least an equivalent amount of polyhydric alcohol units in relation to dicarboxylic acid units) (b) a polyhydric alcohol.  Preferably the terephthalic acid polyester is first heated with one of the reactants to effect solution thereof and the other reactant is then added and heating continued.  The reaction mixture may also include a monohydric alcohol, a monocarboxylic acid (e.g. a resinic acid, a fatty acid containing 12-22 carbon atoms, or benzoic acid) or a polycarboxylic acid containing more than two carboxyl groups (e.g. pyromellitic acid) or a hydroxycarboxylic acid (e.g. ricinoleic or hydryxoystearic acid).  The reaction may be effected in the presence of a solvent, e.g. an aliphatic, aromatic or terpenic hydrocarbon. Specified dicarboxylic acids are maleic, fumaric, itaconic, citraconic, mesaconic, tetrahydrophthalic, endomethylene tetrahydrophthalic, chlorendic, endomethylene hexahydrophthalic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, phthalic, imphthalic, hexahydro-, ortho-, iso- or tere-phthalic, tri- or tetra-chlorophthalic or tetrachlorosuccinic acids. Specified polyhydric alcohols are ethylene, 1:2- or 1:3-propylene-, diethylene- or triethylene-glycol; a butanediol, pentanedial or hexanediol; 2:2-dimethylpropane-1:3-diol, 2-ethyl - 2 - butyl - propane - 1:3 - diol, 1:4-butenediol, hydrogenated bis-phenol A, partially etherified or acetalized products of alcohol containing at least three hydroxy groups; dimethylol benzene, toluene or xylene; and addition products of ethylene oxide, propylene oxide or butylene oxide with the above dihydric alcohols or with dihydric phenols. In addition to the above dihydric alcohols small amounts of higher polyhydric alcohols may be used, e.g. glycerol, trimethylol ethane, trimethylol propane or hexanetriol.  The polyesters containing residues from unsaturated dicarboxylic acid may be copolymerized with unsaturated monomers, e.g. styrene and its substitution products, vinyl esters, allyl esters, vinyl pyrrolidone, divinyl benzene, esters of acrylic or methacrylic acid, or acrylonitrile. Copolymerization may be effected in the presence of the usual catalysts and accelerators. Examples describe the manufacture of polyesters by reacting polyethylene terephthalate with (1) maleic anhydride and 1:2-propanediol; (2) maleic anhydride, phthalic anhydride and 1:2-propanediol; (3) dibutyl maleate and 2:2 - dimethylpropane - 1:3 - diol; (4) 2:2-dimethylpropane - 1:3 - diol, fumaric acid and phthalic anhydride; (5) 2:2-dimethylpropane-1:3-diol, phthalic anhydride and maleic anhydride; (6) 1:3-butanediol, phthalic anhydride and maleic anhydride; (7) 2:2-dimethyl-propane-1:3-diol, chlorendic anhydride and maleic anhydride; (8) adipic acid, 2:2-dimethylpropane-1:3-diol and maleic anhydride; (9) and (10) maleic anhydride and 1:2-propane-diol; (11) and (12) 2:2-dimethylpropane-1:3-diol, maleic anhydride and either pentaerythritol diallyl ether or trimethylolpropane monallyl ether; (13) and (14) 2:2-dimethylpropane-1:3-diol, ricinoleic acid or hydroxystearic acid and maleic anhydride; (15) 2:2-dimethylpropane-1:3-diol, phthalic anhydride and maleic anhydride.  The polyesters of Example (1) are dissolved in a mixture of ethylene glycol monethyl ether and ethylene glycol monoethyl ether acetate to form a coating composition.  The polyesters of Examples (1), (2), (7), (8), (9), (10), (12) and (14) (possibly after stabilization with hydroquinone) were copolymerized with styrene using as a catalyst either benzoyl peroxide or a mixture of cyclohexanone peroxide and cobalt napthenate. In Examples (1) and (14) copolymerization was effected in the presence of glass fibres. The polyester of Example (15) could be used as a plasticizer for unsaturated polyesters.