Patent GB-956833-A (GB)
Title: Improvements in oriented melt span polyester filaments
IPC: C08L67/02
Filed: 1962-10-19
Abstract: Antistatic oriented melt-spun synthetic fibres comprise a polyester, and, uniformly admixed therein as a separate phase, at least 2% by weight, preferably 3-15%, of a high molecular weight poly(alkylene ether), said poly(alkylene ether) being substantially non-reactive with and insoluble in the polyester and stable under melt-spinning conditions, and distributed throughout the fibre structure in the form of elongated particles having their longest dimension parallel to the fibre axis. The fibres are made by blending the fibre-forming polyester and poly(alkylene ether) to form a uniform mixture, and melt-spinning the mixture so obtained. Blending is preferably effected at a temperature above the melting point of the polyester. The polyester component may be wholly or predominantly polyethylene terephthalate, but in general, synthetic linear condensation polyesters of bifunctional ester-forming compounds in which at least about 75% of the repeating structural units of the polymer chain include at least one divalent carbocyclic ring containing at least six carbon atoms present as an integral part of the polymer chain and having a minimum of four carbon atoms between the points of attachment of the ring in the polymer chain (para-relationship in the case of a single six-membered ring) maybe used, the polyesters being derived from any suitable combination of bifunctional ester-forming compounds.  Specified dicarboxylic acid ester-forming compounds are terephthalic, bromoterephthalic, 4-41-disulphonyl benzoic, 4,41-diphenic and 4-41-benzophenone dicarboxylic acids, 1,2-bis(4-carboxy phenyl) ethane, 1,2-bis(p-carboxyphenoxy) ethane, bis-4-carboxyphenyl ether and various naphthalene dicarboxylic acids, especially the 1,4-, 1,5-, 2,6-, and 2,7-isomers. Isophthalic and carbonic acids may also be used, especially in combination with a 1,4-dihydroxyaromatic compounds.  Specified dihydroxy compounds include the glycols, e.g. ethylene glycol and other glycols of formula HO(CH2)nOH, where n is 2 to 10; cis- and trans-p-hexahydroxylylene glycol; diethylene glycol; quinitol; neopentylene glycol; 1,4-bis-(hydroxyethyl) benzene; 1,4-bis(hydroyxethoxy) benzene, 2,2-bis(4-hydroxy-3, 5-dichlorophenyl) propane, 2,2-bis(4-hydroxyphenyl) propane, hydroquinone, and 2,5- and 2,6-dihydroxynaphthalene. Light stabilizers, ultraviolet absorbers, delusterants, pigments, dyes and anti-oxidants may be added to the blend. Desirably, the poly(alkylene ether) is capped by one or more ether end groups and has at most one hydroxyl end group, a singly or doubly capped polyethylene oxide in which the polyether portion of the chain has a molecular weight of at least 1300 being preferred. Especially suitable end groups for the polyethers are nonylphenoxy and methoxy radicals.  Mixing of the components may be carried out in a screw extruder or mechanical mixer, excessive mixing being avoided, since the polyether phase then becomes highly dispersed and formation of the two-phase striated structure is prevented. Composite filaments of the side-by-side or sheath-core type may be made using the polymer blend of the invention as one component. Specifications 787,157, 839,418 and 905,895 are referred to.