Patent GB-863704-A (GB)
IPC: C08G63/40
Abstract: 863,704. Aromatic polyesters. FARBWERKE HOECHST A.G. May 20, 1957 [May 18, 1956], No. 16010/57. Class 2(5). Aromatic polyesters, suitable for the production of fibres, foils, coatings and moulded articles are made by reacting (a) a free dihydric phenol in which the hydroxyl groups are separated from each other by at least 3 carbon atoms with (b) a dihalide of an aromatic dicarboxylic acid that contains no aliphatic double bonds and in which the carbonyl groups are separated from each other by at least 3 carbon atoms; the reaction being effected at a raised temperature (e.g. 65- 130‹C.) and in the absence of water or substance forming water. The reaction is preferably effected in the presence of an inert diluent (e.g. a hydrocarbon, a halogenated hydrocarbon or an ether) which preferably dissolves at least the starting materials and at least the latter part of the reaction is preferably effected in the presence of an acid-binding agent (e.g. a tertiary amine or an acyl-ethylene-imide). The temperature in the reaction vessel can be regulated automatically by using a mixture of diluents, the low boiling constituent of which is slowly distilled off and replaced by a corresponding amount of the higher boiling constituent. Reaction may be effected continuously, in which case the polyester is separated out in a subsidiary cycle and the acidbinding agent is added only to this subsidiary cycle. Specified dihalides are the fluorides, chlorides or bromides of terephthalic, isophthalic, 5-tert.-butyl-isophthalic, mono-chloroterephthalic, 2 : 5-dichloroterephthalic, diphenyl ether- 4 : 4<SP>1</SP>-dicarboxylic, diphenoxyethene-4 : 4<SP>1</SP>-dicarboxylic and diphenylmethane -4 : 4<SP>1</SP>- dicarboxylic acids. Specified dihydric phenols are hydroquinone, resorcinal, 4:4<SP>1</SP>-dihydroxydiphenyl-methane; methyl-bis-[4-hydroxyphenyl]- methane; dimethyl -bis- [4- hydroxyphenyl]- methane or the corresponding methylethyl, diethyl, methylpropyl, methylbutyl, methylisobutyl or methylhexyl derivatives; 1 : 2 -bis- [4- hydroxyphenyl] -ethane; 2 : 2 -bis- [4- hydroxyphenyl] -4- methylpentane; 2 : 2 -bis- [4- hydroxyphenyl] -butane; 1 : 10 -bis- [4 -hydroxyphenyl] -decane; 4 : 4<SP>1</SP> -dihydroxy -diphenoxyethane; 1 : 4 -bis- [4-hydroxyphenoxy] -butane; 1 : 1 -bis- [4 -hydroxyphenyl] -cyclohexane or methylcyclohexane; 1: 10 -bis- [4 -hydroxyphenyl] -decanedione (1 : 10); 4 : 4<SP>1</SP> -dihydroxydiphenyl; 4 : 4<SP>1</SP> -dihydroxy -diphenylether; 4 : 4<SP>1</SP>- dihydroxy -diphenylsulphone; and 2:6- or 2 : 7- dihydroxynaphthalene. Examples describe the production of polyesters by reacting terephthalyl or isophthalyl chloride with many of the above specified dihydric phenols. Some of the polyesters are soluble in benzene, toluene, xylene, tetrahydronaphthalene, α-methylnaphthalene, pyridine, methylene chloride, monochlorobenzene, o-dichlorobenzene, trichlorobenzenes, o-chlorophenol, dimethyl formamide, ethyl acetate, dioxane, p-cresol and a mixture of phenol and tetrachloroethane. Specification 724,759 and U.S.A. Specification 2,035,578 are referred to and the invention of Specification 781,185 is disclaimed.