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

Claim 2

A latent contractable melt extruded segmented, inherently elastic polyester-polyester or polyester-polyether thermoplastic polymer filament characterized 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 without deliberate drawing prior to contraction to yield an elastic filament.

Claim 3

The melt extruded filament of claim 1, said 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, said long-chain ester units comprising from 40-70% by weight of the copolyester and being represented by the formula: ##STR7## and said shot-chain ester units being represented by the formula: ##STR8## where L in said long-chain unit is a divalent radical remaining after removal of terminal hydroxyl groups from a poly(oxyalkylene) glycol having at lest one thermally stable hydantoin ring per molecule, each of said rings attached to said chain through amide or imide linkages and giving said radical, L, a carbon to nitrogen ratio between about 3/1 and about 350/1, and a number average molecular weight of between 200 and 8,000; R is a divalent radical remaining after removal of carboxyl groups from a dicarboxylic acid having a molecular weight of less than 300; and E in short-chain unit is a divalent radical remaining after removal of hydroxyl groups from a low molecular weight diol having 2 to 15 carbon atoms per molecule and a molecular weight less than about 250.

Claim 4

The melt extruded copolyester filament of claim 2, wherein substantially all of the dicarboxylic acid is terephthalic acid and wherein substantially all of the diol having a molecular weight less than about 250 is 1,4-butane diol.

Claim 5

The melt extruded copolyester filament of claim 2, wherein --OLO-- in said long chain ester unit is a poly(oxyalkylene) glycol unit formed by the oxyalkyation of: ##STR9## where R' and R" are methyl.

Claim 6

The melt extruded filament of claims 1, 2, 3, or 4 in the form of a composite yarn wherein the melt extruded filament is intimately associated with inelastic fibers or filaments.

Claim 7

The melt extruded filament of claims 1, 2, 3, or 4 which has been contracted at least 15% in length as compared to the length of the melt extruded filament without deliberate drawing by exposure to an elevated temperature above about 80° C to provide an elastic filament.

Claim 8

The contracted filament of claim 6 in the form of a composite yarn wherein the melt extruded filament is intimately associated with inelastic fibers or filaments.

Claim 9

The melt extruded filament of claim 6 which has been contracted at least 25% in length.

Claim 10

The melt extruded filament of claim 6 which has been contracted at least 40% in length.

Claim 11

The melt extruded filament of claim 1 which contracts at least about 40% in length when subjected to an elevated temperature as compared to the length of the melt extruded filament prior to contraction.

Claim 12

The melt extruded filament of claim 1 incorporating a stabilizer selected from the group consisting of heat stabilizers and ultraviolet radiation stabilizers.

Claim 14

A process which comprises core spinning relatively inelastic fibers about the melt extruded filaments as in claims 1, 2, 3 or 4.

Claim 15

A process as in claim 13, where the melt extruded filament is not appreciably stretched during the core-spinning process.