Abstract: An acrylic fiber having dispersed therein 2 to 10 weight percent of a colloidal silica having an average particle size of about 1 to 4 microns, with a mean particle size of 2-3, preferably about 2, microns. This acrylic fiber has excellent whiteness and moisture transport characteristics and fabrics made from it have an improved crispness of hand.

Abstract: The process of continuously polymerizing acrylonitrile and other non-acidic mono-olefinic monomers with small amounts of certain acidic mono-olefinic monomers copolymerizable with acrylonitrile wherein the acrylonitrile and other non-acidic mono-olefinic monomers are continuously charged to a reactor and the acidic monomer is fed to the reactor in increments and in cycles, with a tall amount in a given cycle of 0.5 to 5 weight percent of the acidic monomer, based on total monomer weight fed in the cycle, being fed to the reactor during each cycle. Each cycle is made up of two time periods, with at least 65 percent of the acidic monomer being fed during the first time period and up to 35 percent being fed during the second time period. Preferably, all of the acidic monomer is fed to the reactor in the first time period. The first time period of the cycle is 5 to 25 percent of the second time period and the sum of first and second time periods, or cycle time, is about 15 to 25 percent of the reactor dwell time.

Abstract: The method of preventing color-degrading interactions between certain optical brighteners and filaments made from a modacrylic polymer containing as a copolymer a halogenated ethylenically unsaturated monomer, the optical brightener preferably having the formula: ##STR1## where X and Y are basic groups selected from the group consisting of --NH.sub.2, --H(CH.sub.3).sub.2, and --N.sup.+ (CH.sub.3).sub.3 Z, where Z is selected from the group consisting of chloride, sulphate and bromide anions, n is 0 to 3, and R is an alkyl group containing 1 to 4 carbon atoms, wherein an aqueous liquid is applied to the filaments, the liquid containing 0.01 to 0.5 weight percent of a compound having the formula: ##STR2## wherein R is a member selected from the group consisting of an alkyl radical having 1 to 11 carbon atoms, a phenyl radical and an alkyl phenyl radical containing no more than eight carbon atoms.

Abstract: Method for making substantially void-free fibers having improved abrasion resistance wherein a spinning dope is formed by dissolving a dry acrylonitrile-containing polymer in a solvent/water mixture to form a spin dope which is wet spun at a temperature within the range of about 40.degree.C to about 75.degree.C. More specifically, the dope will contain from about 20 to about 28 weight percent of the polymer dissolved in a solvent containing about 1 to 8 weight percent water, based on the weight of the dope, with the solvent and water being mixed prior to contact with the polymer. The presence of water in the solvent brings about an improvement of the filamentary gel structure which results in fibers having enhanced durability and abrasion resistance.