Low shrinkage, dyeable MPD-I yarn
View Patent ↗The invention relates a heat-treated poly(metaphenylene isophthalamide) polymer fiber having a crystalline structure as represented by a carbonyl stretch peak at a wavelength of 1,650 cm−1 in a Raman spectra response which before coloration with a dye, shrinks linearly 0.4 percent or less when exposed to 285 degrees Centigrade for 30 minutes; and which after contact with an aqueous red dye solution for 1 hour at 120 degrees Centigrade, has an “L” value coloration of at least 40 units lower than the “L” value of the fiber before coloration.
1. A poly(metaphenylene isophthalamide) polymer fiber having a crystalline structure as represented by a carbonyl stretch peak at a wavelength of 1,650 cm −1 in a Raman spectra response;
said fiber, before coloration with a dye, shrinks linearly 0.4 percent or less when exposed to 285 degrees Centigrade for 30 minutes; and
said fiber, after contact with an aqueous red dye solution for 1 hour at 120 degrees Centigrade, has an “L” value coloration of at least 40 units lower than the “L” value of the fiber before coloration.
2. The polymer fiber of claim 1 , wherein the “L” value of the fiber after coloration is 45 or less.