Method for dyeing fibrous materials

A method according to claim 4 wherein the blend of aromatic polyamide and polybenzimidazole fibers is in a weight ratio of about 60:40 to about 80:20.

In a method for dyeing and/or flame retarding fibers which includes the step of contacting aromatic polyamide fibers, polybenzimidazole fibers, aromatic polyimides, copolymers of the monomers thereof, or blends thereof with a mixture of a carrier and a dye and/or flame retardant soluble or dispersed in the carrier, the improvement comprising the use, as the carrier, of a mixture comprising N-cyclohexyl-2-pyrrolidone and an alkyl or aryl benzoate in emulsified form in a weight ratio of N-cyclohexyl-2-pyrrolidone to alkyl or aryl benzoate of from about 2:3 to about 8:1.

In a method for dyeing fibers which includes the step of contacting poly(p-phenyleneterephthalamide) fibers with a mixture of a carrier and a dye soluble or dispersed in the carrier, the improvement comprising the use, as the carrier, of a mixture comprising N-cyclohexyl-2-pyrrolidone and an alkyl or aryl benzoate wherein the weight ratio of N-cyclohexyl-2-pyrrolidone to alkyl or aryl benzoate is from about 2:3 to about 8:1.

A fibrous material selected from the group consisting of fibers of aromatic polyamides, polybenzimidazoles, aromatic polyimides, copolymers of the monomers thereof, or blends thereof, which has been dyed with a mixture of an effective amount of a carrier and a dye soluble or dispersed in the carrier, the carrier comprising a mixture of N-cyclohexyl-2-pyrrolidone and an alkyl or aryl benzoate wherein the weight ratio of N-cyclohexyl-2-pyrrolidone to alkyl or aryl benzoate is from about 2:3 to about 8:1.

A fiber of aromatic polyamides polybenzimidazoles, aromatic polyimides, copolymers of the monomers thereof or blends thereof which has been dyed and/or flame retarded with a mixture of a carrier and a dye and/or flame retardant soluble or dispersed in the carrier, the carrier comprising a mixture of N-cyclohexyl-2-pyrrolidone and alkyl or aryl benzoate in emulsified form in a weight ratio of N-cyclohexyl-2-pyrrolidone to alkyl or aryl benzoate of from about 2:3 to about 8:1.

A fiber of poly(p-phenyleneterephthalamide) which has been dyed with a mixture of a carrier and a dye soluble or dispersed in the carrier, the carrier comprising a mixture of N-cyclohexyl-2-pyrrolidone and alkyl or aryl benzoate.