Patent GB-777220-A (GB)
Title: Improvements in the preparation of linear polyesters
IPC: C08G63/688
Filed: 1953-10-02
Abstract: A linear polyester is made by condensing a p : p1-sulphonyl dibenzoic ester of formula: <FORM:0777220/IV(a)/1> wherein R1 and R4 are o -hydroxyalkyl radicals containing 3-12 carbon atoms or alkyl radicals containing 1-6 carbon atoms, with 50 to 100 mol. per cent of an aliphatic ether glycol (or ester thereof) of formula: R5O-(R7-O)q-R7-OR6 wherein R7 is an alkylene radical containing 2-4 carbon atoms, q is 1-10 and R5 and R6 are hydrogen atoms or acyl radicals containing 2-4 carbon atoms, and 50-0 mol. per cent of a polymethylene glycol (or ester thereof) of formula: R5O-(CH2)p-OR6 where p is 2-12.  Part of the p : p1-sulphonyl dibenzoic ester may be replaced by isomers thereof or homologues thereof, e.g. (m.m1-dimethyl)-, (o-ethyl)- or (m-methyl-o-propyl)-p : p1-sulphonyl dibenzoic acid.  The first part of the condensation is effected in an inert atmosphere (e.g. nitrogen or hydrogen) generally at 150-220 DEG C. while the latter part is effected at 225-310 DEG  C. under vacuum (generally less than 5 mm. of Hg. pressure).  Condensation catalysts which may be used are those disclosed in Specifications 777,215 and 777,216 and also an alkali or alkaline earth metal, an alkoxide containing 1-8 carbon atoms of an alkali or alkaline earth metal, an oxide, carbonate or borate of an alkali or alkaline earth metal, magnesium activated by iodine vapours, methyl magnesium iodide, the reaction product of magnesium and propyl bromide, a compound of formula: M(HZr(OR)6), M1(HZr(OR)6)2, M2(Zr(OR)6), M1(Zr(OR)6), (RR1R11R111N)2(Ti(OR)6) (RR1R11R111N)H(Ti(OR)6) Ti(OR)4, PbR4 or RMgHal where M is an alkali metal, M1 is magnesium, calcium or strontium, R is an alkyl group containing 1-6 carbon atoms and R1, R11 and R111 each represent R on an aryl group of the benzene series containing 6-9 carbon atoms and Hal is a halogen atom, or is an organo-tin compound of formula: M2(Sn(OR)4), MH(Sn(OR)4), M1(Sn(OR)4), M1(HSn(OR)4 M2(Sn(OR)6), MH(Sn(OR)6), M1(Sn(OR)6, M1(HSn(OR)6) Sn(OR)2, Sn(OR)4 SnR12, SnR14, R1SnO <FORM:0777220/IV(a)/2> where M is an alkali metal, M1 is an alkaline earth metal, R is an alkyl radical containing 1-8 carbon atoms, R1 is an alkyl radical containing 1-8 carbon atoms or an aryl radical of the benzene series containing 6-9 carbon atoms and Ac is an acyl radical derived from an organic acid containing 2-18 carbon atoms. Condensation may be effected in the presence of a solvent e.g. diphenyl ether, diphenyl, mixed tolyl sulphones, chlorinated naphthalene, chlorinated diphenyl or dimethyl sulpholane.  The polyesters may be used in the manufacture of sheets, films (e.g. for use as a photographic film bases), fibres, threads, filaments, electrical insulation or extrusion or compression moulded articles. Some of the polyesters are soluble in dimethyl sulpholene, gamma-butynlactone, ethylene carbonate and a mixture of phenol and tetrachlorethane.  In examples a dialkyl ester of p:p1-sulphonyl dibenzoic acid is condensed with (1), (7) and (8) diethylene glycol, (2) bis(4-hydroxybutyl) ether, (3) diethylene glycol and pentamethylene glycol, (4) diethylene glycol and ethylene glycol, (6) triethylene glycol and ethylene glycol. Specification 777,218 also is referred to.