Patent GB-963320-A (GB)
Title: Improvements in melt spun polyamide filaments
IPC: C08G63/672
Filed: 1962-10-19
Abstract: Antistatic oriented melt-spun synthetic fibres comprising a polyamide and uniformly mixed therewith as a separate phase, at least 2% by weight of the polyamide of a poly (alkylene ether) the molecule of which is capped by at least one ether end group, the poly (alkylene ether) being of average molecular weight at least 600 and being substantially non-reactive with and insoluble in the polyamide and stable under melt spinning conditions, and being uniformly distributed throughout the fibre structure in the form of elongated particles having a mean diameter between 0.05 and 2 microns and having their longest dimension parallel to the fibre axis may be produced by melt spinning under conditions of high shear a polyamide containing, uniformly dispersed therein, microscopic particles of the capped poly (alkylene ether).  The polyethers may be condensation products of ethylene oxide, propylene oxide or both.  The ether end groups terminating the polyether polymer chain have the formula -OR, where R is an alkyl, aryl, or aralkyl group, such as methyl, ethyl, i-octyl, decyl, lauryl, tridecylphenyl, naphthyl, nonylphenyl, or dodecylphenyl.  Residues of coupling compounds or chain-initiating agents, such as bis-phenol, may be present.  Generally the polyether part of the chain should constitute at least 50% by weight of the total and it is preferred that it contain at least 30 ethylene or propylene oxide units corresponding to a molecular weight (for the polyether portion of a polyethylene oxide) of at least about 1300. Higher molecular weights are even more effective, especially about 10,000 to 20,000.  Especially suitable end groups are nonylphenoxy radicals. Up to about 30% of the polyether may be added to the polyamide, 3 to 15% being preferable. The polyethers may be mixed with the monomeric constituents of the polyamides before polymerization or, preferably if the polyether tends to oxidize or degrade at polyamide melt spinning temperatures, the polyether may be mixed with a preformed polyamide. The polyether may usually be mixed with the polyamide by melting the components in a screw extruder, although mechanical mixers are more effective.  Excessive mixing must be avoided so that the polyether component does not become so highly dispersed that it can no longer conduct away static charges. In an example, a 50% aqueous solution of a polyethylene ether having a number average molecular weight of 650 and having a hydroxyl radical at one end of the molecule and a nonylphenyl radical at the other is mixed at 235 DEG C. and 250 p.s.i.g. in an autoclave with a 60% aqueous solution of hexamethylene diammonium adipate in such a proportion that the polyamide subsequently formed contains 7.5% by weight of the polyether.  After polymerization of the amide is completed the autoclave is discharged by extruding the polymer through a narrow slot as a ribbon at 275 DEG C. and at 100 p.s.i.g. of inert gas and the ribbon is quenched on a water cooled casting wheel and cut to flake which is then melt spun to form filaments.  In another example, 66 nylon polymer is melt blended with 2% of a nonylphenoxy capped polyethylene ether alcohol of number average molecular weight 1600.  Composite fibres comprising two different polymer components in side by side or in sheath core arrangement may be melt spun, one polymer component being a polyamide containing a capped poly (alkylene ether) according to the invention. Specifications 567,674, 639,893, 787,157, 805,033, 839,418, 902,905, 902,907 and 905,895 are referred to.