Latent contractable elastomers, composite yarns therefrom and methods of formation and use

Claim 2

A latent contractable melt extruded segmented, inherently elastic thermoplastic polymer filament characterised by containing interspersed relatively hard segments and relatively soft segments, which contracts at least 15% in length when subjected to an elevated temperature, as compared to the length of the melt extruded filament prior to contraction,to yield an elastic filament.

Claim 3

A melt extruded polymer as claimed in claim 1 which is a polyesterpolyether or polyester p olyester segmented copolymer.

Claim 4

A melt extruded polymer as claimed in claim 1 which is a segmented thermoplastic copolyester consisting essentially of a multiplicity of recurring long-chain ester units and short-chain ester units joined head to tail through ester linkages, the long-chain ester units comprising from 40-70% by weight of the copolyester and being represented by the formula: and the short-chain ester units being represented by the formula: where L in the long-chain unit is a divalent radical remaining after removal of terminal hydroxyl groups from a poly-(oxyalkylene) glycol having at least one thermally stable hydantoin ring per molecule, each of the rings being attached to the chain through an amide or imide linkage and giving the radical, L, a carbon to nitrogen ratio in the range of from 3/1 to 350/, and a member average molecular weight in the range of from 200 to 8,000; R is a divalent radical remaining after the removal of carboxyl groups from a dicarboxylic acid having a molecular weight of less than 300; and E in the short-chain unit is a divalent radical remaining after the removal of hydroxyl groups from a low molecular weight diol having from 2 to 15 carbon atoms per molecule and a molecular weight of less than 250.

Claim 5

A melt extruded copolyester as claimed in claim 3 wherein substantially all of the dicarboxylic acid is terephthalic acid and wherein substantially all of the diol having a molecular weight of less than about 250 is 1,4-butane diol.

Claim 6

A melt extruded copolyester as claimed in claim 4 wherein -OLO- in the long chain ester unit.is a poly(oxyalkylene) glycol unit formed by the oxyalkylation of: where R' and R" are lower alkyl groups.

Claim 7

A melt extruded polymer as claimed in any one of the preceding claims in the form of a composite yarn wherein the melt extruded filament is intimately associated with inelastic fibers or filaments.

Claim 8

A melt extruded polymer as claimed inanv one of claims 1 to 5 which has been contracted at least 15% in length by exnosure to an elevated temperature of above 80°C to provide an elastic filament.

Claim 9

A contracted polymer as claimed in claim 7 in the form of a composite yarn wherein the melt extruded filament is intimately associated with inelastic fibers or filaments.

Claim 11

A process for combining a latent contractable melt extruded filament as claimed in any one of claims 1 to 5 with a relatively inelastic synthetic polymer filament, to produce a composite yarn which comprises continuously feeding at least one melt extruded filament at a first predetermined feed rate and at least one relatively inelastic filament at a second predetermined feed rate through a jetted high velocity fluid and impinging the jetted fluid on the filament axis at an angle of 90° + 45 G to separate the inelastic filaments and entangle the inelastic filaments around the melt extruded filament at spaced intervals; the rate of feed of the inelastic filaments being adjusted with respect to the rate of feed of the melt extruded filaments so that the rate of feed of the inelastic filaments is less than twice the rate of feed of the melt extruded filament and is a rate so that when the resultant composite yarn is exposed to an elevated contraction inducing temperature the melt extruded filament is contracted at least 15% to provide an elastic filament and when the resultant composite yarn is stretched the inelastic filaments become load-bearing at a nredetermined percent of elastic stretching below the break elongation of the elastic filament.

Claim 12

A method as claimed in claim 10 wherein the melt extruded filament and the inelastic filament are fed at about the same rate.

Claim 13

A process of forming a stretchable textile article which comprises forming a predetermined over-sized article with yarns comprising a latent contractable filament which contracts at least 15% as compared to its original length when exposed to an elevated contraction inducing temperature to provide an elastic filament and exposing the resultant textile article to an elevated temperature sufficient to contract the latent contractable filament at least 15% to form a stretchable article of a desired size.

Claim 14

A process of forming a stretchable textile article which comprises forming a predetermined over-sized article with yarns comprising a latent contractable filament which contracts at least 15% as compared to its original length when exposed to an elevated contraction inducing temperature to provide an elastic filament and exposing the resultant textile article to an elevated temperature sufficient to contract the latent contractable filament at least 15% to form a stretchable article of a desired size.

Claim 15

A process as claimed in claim 12 wherein the latent contractable filament is covered with a relatively inelastic companion filament or fiber.