Spandex of a particular composition and process for making same

1 - 4 . (canceled)

5 . A process for making spandex comprising the steps of:

a) providing poly(tetramethylene ether) glycol;

b) providing 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene;

c) contacting the poly(tetramethylene ether) glycol and the 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene to form a capped glycol wherein the weight percent of isocyanate moiety is from about 2.2 to about 2.9 based upon the weight of the capped glycol;

d) providing a solvent;

e) mixing the solvent and the capped glycol to form a capped glycol solution;

f) contacting the capped glycol solution and a mixture of chain extenders comprising:

from about 35 mole percent ethylene diamine;

to about 55 mole percent ethylene diamine; and

from about 45 mole percent 1,2-propanediamine;

to about 65 mole percent 1,2-propanediamine

to form a polyurethaneurea solution; and

g) spinning the polyurethaneurea solution to form the spandex.

6 . The process of claim 5 wherein steps c) and f) are carried out as batch steps and the falling ball viscosity of the polyurethaneurea solution is about 1000 to 4000 poise.

7 . The process of claim 5 wherein the solvent is dimethylformamide and the poly(tetramethylene ether) glycol is substantially free of diols having molecular weight of less than 250 daltons.

8 . The process of claim 5 wherein the mixture of chain extenders comprises at least about 40 mole percent ethylene diamine, at most about 50 mole percent ethylene diamine, at least about 50 mole percent 1,2-propanediamine, and at most about 60 mole percent 1,2-propanediamine.

9 . The process of claim 5 wherein the mixture of chain extenders of step (f) further comprises at least one primary amine chain terminator.

10 . (canceled)