Patent GB-982575-A (GB)
Title: Copolyesters
Inventor: CALDWELL JOHN RICHARD
IPC: C08L67/00
Filed: 1961-02-21
Abstract: New segmented copolyesters melting at above 200 DEG  C. and having an average molecular weight of about 10,000 to about 100,000 contain two different types of segments each being composed of repeating units having one of the formulae (1), (2) and (3) <FORM:0982575/C3/1> <FORM:0982575/C3/2> <FORM:0982575/C3/3> wherein r, s and t are each such that the average molecular weight of the segment is 4000 to 10,000 and wherein in the first type of segment W or Z or at least one of X and Y each represents a radical having the formula <FORM:0982575/C3/4> wherein m is 1 to 4, n is 0 to 4, and each of x and y is 0 to 2, <FORM:0982575/C3/5> which is the 1,4-isomer or the corresponding 1,1-, 1,2- or 1,3-isomers, <FORM:0982575/C3/6> or <FORM:0982575/C3/7> or <FORM:0982575/C3/8> or <FORM:0982575/C3/9> which is the 2,5-isomer or the corresponding 2,2- or 2,6-isomers, or <FORM:0982575/C3/100> and when only one of X and Y is a radical of the formulae (4) to (10), the other is such that HO-OC-Y-CO-OH is a bifunctional dicarboxylic acid having 2 to 20 carbon atoms or HO-CH2-X-CH2-OH is a bifunctional glycol having 2 to 12 carbon atoms and, in the second type of segment, W, X, Y and Z each represent a radical having any of the formulae (4) to (10), or is such that HO-OC-W-CO-OH and HO-OC-Y-CO-OH are bifunctional dicarboxylic acids having 2 to 20 carbon atoms, or HO-CH2-X-CH2-OH is a bifunctional glycol having 2 to 12 carbon atoms or HO-CH2-Z-CO-OH is a bifunctional hydroxycarboxylic acid having 4 to 20 carbon atoms; the weight ratio of the first type of segment to the second type of segment being between 5:95 and 40:60.  The copolyesters may be made by heating the two homopolymers in the form of solid particles of average sizes 0.05 to 10-5 inch at 5 DEG  C. below the sticking temperatures of particles whilst stirring the particles at least 5% of the heating period and at least once every 30 minutes.  The mixture of homopolyesters may be made (a) by adding one homopolyester to a melt of the other polyester, cooling and then comminuting or (b) adding particles of one homopolyester to a solution of the other homopolyester to form moistened particles and then evaporating the solvent.  In examples copolyesters were made by heating together (1) 60 to 95% by weight of polyethylene terephthalate, poly - 1,4 - cyclohexylenedimethylene terephthalate, polyethylene 4,41 - ethylenedioxydibenzoate, polytetramethylene 4,41 - ethylenedioxydibenzoate, polytetramethylene 4,41 - diphenate or polytetramethylene 4,41-sulphonyl dibenzoate with (2) 40 to 5% by weight of poly(hydroxypivalate), poly(4 - hydroxymethylhexanoate), poly - 2,2 - dimethyl - 1,3 - propylene terephthalate, poly - 2,2 - dimethyl 1,3 - propylene 2,2 - dimethylmalonate, poly - 2 - methyl - 2 - ethyl - 1,3 - propylene norcamphane - 2,5 - dicarboxylate, poly - 1,1 - cyclohexylenedimethylene cyclohexane - 1,2 - dicarboxylate, poly - 1,4 - cyclohexylenedimethylene trans - cyclohexane - 1,4 - dicarboxylate, poly - 2,2 - dimethyl - 1,3 - propylene transcyclohexane - 1,4 - dicarboxylate, poly - 2,5 - norcamphanedimethylene 4,41 - diphenate, or a polyester of hydroxypival hydroxypivalate and tetramethyl succinic acid. Uses.-Fibres, films and moulded objects. Specification 818,157 is referred to.