Patent ID: 7686993

Claim:
A method for producing a colored polymeric fiber via melt spinning, which method comprises melt spinning a blend of at least one unformulated heat stable black, blue or violet dye wherein the at least one unformulated blue or violet dye is selected from the group consisting of B) a blue anthraquinone dye according to formula II wherein M is Na, K, Li, NH 4 , NH 2 (C 2 H 4 OH), NH(C 2 H 4 OH) 2 or N(C 2 H 4 OH) 3 , C) a blue anthraquinone dye according to formula (III) wherein M is Na, K, Li, NH 4 , NH 2 (C 2 H 4 OH), NH(C 2 H 4 OH) 2 or N(C 2 H 4 OH) 3 , and D) a violet anthraquinone dye according to formula IV wherein R is H or a group of the formula —CH 2 —NH—CO—Y in which Y is C 1 -C 4 alkyl, C 2 -C 4 alkenyl or an single or double ring aryl group, each optionally substituted one or more times with a halogen group selected from chlorine, fluorine and mixtures thereof, and at least one R group is other than hydrogen, and a polymeric material in a melt spinning device, wherein at least one portion of the device operates at a temperature greater than 220° C.