GB1046831A - Improvements relating to the preparation of polymeric linear esters of aromatic dicarboxylic acids - Google Patents

Abstract

Organic phosphorus compounds of formula <FORM:1046831/C2/1> and <FORM:1046831/C2/2> are made by reacting equimolecular proportions of triethyl phosphite and 2-chloroethanol or 2-bromoethanol respectively.ALSO:In the manufacture of linear polyesters by the catalytic polymerization of a bis-(o -hydroxyalkyl) or bis-(hydroxycycloakyl) ester of an aromatic dicarboxylic acid, polymerization is effected in the presence of at least 0.05% (based on the weight of the dimethyl ester of the aromatic dicarboxylic acid equivalent to the hydroxyesters) of an organic phosphorous compound of formula <FORM:1046831/C3/1> wherein at least one radical of the group R1, R2 and R3 is haloalkyl or hydroxyalkyl and any remaining radicals are alkyl, haloalkyl, hydroxyalkyl, alkoxy, haloalkoxy, hydroxyalkoxy, hydroxy - polyalkyleneoxy, aryl, alkenyl or aryloxy; <FORM:1046831/C3/2> wherein R3 is a divalent organic radical and at least one radical of each of the groups R1 and R2, R4 and R5 is an alkyl, haloalkyl, haloalkoxy hydroxyalkyl, aryl, alkenyl, haloalkenyl, hydroxyalkenyl or aryloxy radical and the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryloxy, aryl, alkenyl, haloalkenyl or hydroxyalkenyl; <FORM:1046831/C3/3> wherein R3 and R5 are divalent organic radicals and at least one radical of each of the groups R1, R2, R4; and R6, R7 is alkyl, haloalkyl, haloalkoxy, hydroxyalkyl, aryl, aryloxy or alkenyl, and the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryl, aryloxy or alkenyl; (d) Reaction products of alkyl phosphites of formula <FORM:1046831/C3/4> where R1, R2 and R3 and C1- 5 alkyl with compounds of formula <FORM:1046831/C3/5> where X is a halogen or hydrogen atom, said reaction products having the emperical formula <FORM:1046831/C3/6> where n is an integer greater than one and R4 is an alkylene group containing 1-5 carbon atoms; (e) reaction products of alkyl phosphonates of formula <FORM:1046831/C3/7> wherein R1, R2 and R3 are alkyl groups with a polymethylene glycol of 2-10 carbon atoms, said reaction products having the empirical formula <FORM:1046831/C3/8> where y is 2-10 and n is an integer greater than 1; (f) Compounds of formula <FORM:1046831/C3/9> wherein R is an alkyl or alkenyl radical; or (g) Compounds of formula <FORM:1046831/C3/100> wherein R1 and R2 are alkyl or alkenyl radicals Films made from such polyesters have an improved insulation resistance, have an improved colour and show fewer striations. Specified polyesters are those derived from acids of formula <FORM:1046831/C3/11> where R8 is an alkylene chain of 1-3 carbon atoms, an oxygen or sulphur atom or one of the radicals <FORM:1046831/C3/12> and ethylene glycol, propylene glycols, butylene glycols, decamethylene glycol, neopentyl glycol and 1,4 - di - (hydroxymethyl) - cyclohexane. Preferably, the polyesters are made by effecting an ester-interchange reaction between a dialkyl ester of the dicarboxylic acid and the glycol and polycondensing the product. The phosphorus compounds may be added at the start of the ester-interchange, at the start of the polycondensation reaction or during the polycondensation when the intrinsic viscosity of the polyester is at most 0.2. Examples describe the modification of (1)-(39) polyethylene terephthalate; (40) polyethylene naphtalene - 2,6 - dicarboxylate; (41) a copolyester of ethylene glycol, bibenzoic acid and 4,41-isopropylidene bibenzoic acid.