Polyester fibers

Abstract

Polyester filaments of 0.5-2 denier per filament from ethylene terephthalate polymers modified both by polyethylene oxide and by tetraethyl silicate to give polymers of commercial spinning viscosities, and textile fibers and fabrics having greatly improved dye rates, good color stability to standard lightfastness and wash cycles and good pilling, when compared to unmodified polyester and polyester/cotton blend fabrics.

I claim: 
     
       1. Textile fibers of about 0.5 to 2 denier per filament, consisting essentially of poly(ethylene terephthalate) polymer of relative viscosity (LRV) in the range about 9 to 17, modified to provide a Relative Dye Rate (RDR) of at least 150 by containing about 1.5 to about 5% by weight of polyethylene oxide of molecular weight in the range about 200 to about 2000, and modified to provide spinning continuity by having been polymerized in the presence tetraethyl silicate in amount about 0.05 to 0.3 mole percent. 
     
     
       2. Textile fibers according to claim 1 that are of round cross-section and that are optically whitened with 0.1 to 0.4 weight percent titanium dioxide. 
     
     
       3. Textile fibers according to claim 1 or 2, characterized in that they have been crimped and then relaxed at a temperature in the range of about 110°-155° C. 
     
     
       4. Textile fibers according to claim 1 or 2, characterized in that they have been annealed at a temperature in the range of about 150°-230° C. and have been crimped and relaxed at a temperature in the range of about 60°-100° C. 
     
     
       5. Textile fibers according to claim 1 or 2 that are of deliberately mixed denier. 
     
     
       6. Textile fibers according to claim 1 or 2, that are staple fibers of cut length about 5 to 75 mm.