Dyeable spandex
AssigneeInvista North America S.A.R.L.
InventorsNathan E. Houser, Gordon W. Selling, Beverly Jean Selle, Steven Peter Pardini, Robert Dewhurst, Elizabeth Todd Singewald
Life of this patent
Estimating the term…
Abstract
Commercial spandex can be prepared with greater efficiency, improved consistency and at lower costs from a high-solids content polyurethaneurea polymer solution. The polyurethaneurea is prepared using a combination of 4,4′-MDI and 2,4′-MDI, and an amount of chain extenders and chain terminators such that the polymer solution, prior to spinning, is highly soluble and has an appropriate pre-spun IV and primary amine content. Such spandex fibers, and the fabrics and garments comprising them, have good dyeability and colorfastness, as well as other desirable characteristics.
Claims9
A method of making a polyurethaneurea comprising the steps of:
- (a) contacting at least one polymeric glycol selected from the group consisting of polyether glycols and polyester glycols;
- with a diisocyanate mixture comprising at least about 78 mole percent 4,4′-MDI and at least about 5 mole percent 2,4′-MDI;
- wherein the molar ratio of the at least one glycol to the total moles of diisocyanate is between about 1:1.5 and about 1:2;
- (b) contacting the product of step (a) with a composition comprising:
- (1) a solvent selected from the group consisting of N,N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N,N-dimethylpyrrolidinone, and mixtures thereof;
- (2) at least one chain extender comprising ethylenediamine or a mixture of chain extenders comprising ethylenediamine and a secondary chain extender;
- wherein ethylenediamine is at least about 90 mole percent of the total moles of chain extenders;
- (3) a chain terminator selected from the group consisting of diethylamine, diisopropylamine, piperidine, dibutylamine, and mixtures thereof;
- to form a polymer, wherein the pre-spun IV of the polymer is between about 0.65 and about 1.0 dl/g and the primary amine content is between about 25 and about 70 meq/Kg.
A polyurethaneurea polymer formed by the reaction of:
- (a) at least one polymeric glycol selected from the group consisting of polyether glycols and polyester glycols;
- (b) a diisocyanate mixture comprising at least about 78 mole percent 4,4′-MDI and at least about 5 mole percent 2,4′-MDI;
- wherein the molar ratio of the at least one glycol to the total moles of diisocyanate is between about 1:1.5 and about 1:2;
- and
- (c) a composition comprising:
- (1) at least one chain extender comprising ethylenediamine or a mixture of chain extenders comprising ethylenediamine and a secondary chain extender;
- wherein ethylenediamine is at least about 90 mole percent of the total moles of chain extenders;
- and (2) a chain terminator selected from the group consisting of diethylamine, diisopropylamine, piperidine, dibutylamine, and mixtures thereof;
- wherein the resulting polyurethaneurea polymer has a pre-spun IV between about 0.65 and about 1.0 dl/g and a primary amine content between about 25 and about 70 meq/Kg.
Dependencies are inferred from the claim text.