The present invention concerns processes for reducing water in never-dried fiber comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole; and terephthaloyl dichloride, the process having the following steps in a continuous process, (a) a step of drying a never-dried fiber at less than 100 C until the moisture content of the fiber is less than 60 weight percent; and (b) a step of further drying the fiber above 150 C. while the moisture content of the fiber is no more than 40 weight percent; and the fiber being further heated to at least 350 C. in either an additional continuous or separate step.

A filament comprising a polymer blend and specific articles comprising the filament are disclosed. The polymer blend includes an aliphatic nylon and a semiaromatic nylon. The aliphatic nylon is the major component of the blend and semiaromatic nylon is the minor component of the blend. The aliphatic nylon can be Nylon 6, Nylon 66, Nylon 610, Nylon 612, Nylon 12, and mixtures thereof. The semiaromatic nylon can be 6I/6T, 6T/6I, and mixtures thereof. The nylon blend filament provides enhanced mechanical properties such as modulus, ultimate strength, and yield strength with improved processability and reduced diameter variability at a reduced cost.

The invention relates to a yarn comprising a copolyamide in an amount of at least 90 wt % with respect to the total weight of the yarn, which copolyamide comprises a) at least 95 wt % by weight with respect to the total weight of copolyamide, monomeric units derived from hexamethylene diamine and adipic acid and b1) cyclic monomeric units derived from a diamine X, and cyclic monomeric units derived from a diacid Y, and/or b2) cyclic monomeric units derived from an amino acid Z, in which the summed amount of monomeric units derived from X, Y and Z is between 0.1 to 4.5 wt % by weight with respect to the total weight of the copolyamide and wherein the yarn has a tensile strength of at least 80 cN/tex as measured according to ASTM D885-04. The invention also relates to a process for preparing the yarn.

A filament comprising a polymer blend and specific articles comprising the filament are disclosed. The polymer blend includes an aliphatic nylon and a semiaromatic nylon. The aliphatic nylon is the major component of the blend and semiaromatic nylon is the minor component of the blend. The aliphatic nylon can be Nylon 6, Nylon 66, Nylon 610, Nylon 612, Nylon 12, and mixtures thereof. The semiaromatic nylon can be 6I/6T, 6T/6I, and mixtures thereof. The nylon blend filament provides enhanced mechanical properties such as modulus, ultimate strength, and yield strength with improved processability and reduced diameter variability at a reduced cost.

The present invention concerns methods for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising 5-(6)-amino-2-(p-aminophenyl)benzimidazole, an aromatic para-diamine, and an aromatic para-diacid; the method comprising: a) spinning said copolymer from an inorganic acid solvent to produce the aramid yarn; b) washing said yarn with a basic aqueous solution for at least 5 seconds; and c) heating said yarn; wherein the yarn is heated in at least two process steps, characterized in that (i) in a first step the yarn is heated at a temperature of 200 to 360 C. at a tension of at least 0.2 cN/dtex, followed by (ii) a second step wherein the yarn is heated at a temperature of 370 to 500 C. at a tension of less than 1 cN/dtex. In some embodiments, the yarn has an effective polymer cation to sulfur content molar ratio of at least 0.3. In some embodiments, the yarn has a hydrolytic strength retention of the yarn is greater than 60%.

This invention relates to a sheet comprising fibers and fibrids wherein either comprises a mixture of at least a first polymer and a second polymer; the first polymer derived from the reaction of one or more amine monomers and a plurality of acid monomers, wherein the one or more amine monomers includes at least 60 mole percent 5(6)-amino-2-(p-aminophenyl)benzimidazole, based on the total amount of amine monomers; and
the plurality of acid monomers include those having a structure of
ClCOAr.sub.1COCl & ClCOAr.sub.2COCl wherein Ar.sub.1 is an aromatic group having para-oriented linkages and Ar.sub.2 is an aromatic group having meta-oriented linkages, and wherein the plurality of acid monomers has at least 50 mole percent of the monomer containing aromatic group Ar.sub.2; and the second polymer derived from the reaction of metaphenylene diamine and isophthaloyl chloride.

A fiber comprising poly(p-phenylene terephthalamide) having monomers such as N-(4-vinylphenyl)maleimide grafted onto the fiber surface.

The present invention provides for a process for reducing the content of one or more residuals in aramid fibers or filaments, comprising, in this order, the steps of introducing the aramid fiber or filaments into a extraction solution adjusted to a pH ranging from of 2 to 7, adjusting the extraction solution and the aramid fibers or filaments to a temperature of to from 80 C. to 140 C., removing the aramid fibers or filaments from the extraction solution, introducing the aramid fiber or filaments into a first rinsing solution adjusted to a pH ranging from of 2 to 7, optionally comprising a detergent, adjusting the first rinsing solution and the aramid fibers and filaments to a temperature of from 70 C. to 100 C., removing the aramid fibers or filaments from the first rinsing solution.

A problem of the invention is to provide a colored organic fiber that has a deep color and excellent flame retardancy, a cloth and garments each composed of the foregoing organic fiber, and a method for producing a cloth. To solve this problem, a colored organic fiber having a content of a carrier agent of 1.8% by mass or less relative to the fiber mass is provided. A cloth or garments are obtained, if desired.

The present invention concerns methods for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising 5-(6)-amino-2-(p-aminophenyl)benzimidazole, an aromatic para-diamine, and an aromatic para-diacid; the method comprising: a) spinning said copolymer from an inorganic acid solvent to produce the aramid yarn; b) washing said yarn with a basic aqueous solution for at least 5 seconds; and c) heating said yarn; wherein the yarn is heated in at least two process steps, characterized in that (i) in a first step the yarn is heated at a temperature of 200 to 360 C. at a tension of at least 0.2 cN/dtex, followed by (ii) a second step wherein the yarn is heated at a temperature of 370 to 500 C. at a tension of less than 1 cN/dtex. In some embodiments, the yarn has an effective polymer cation to sulfur content molar ratio of at least 0.3. In some embodiments, the yarn has a hydrolytic strength retention of the yarn is greater than 60%