US Patent 7736737 Fibers formed from immiscible polymer blends

The present invention relates to soft touch fibers and nonwoven fabrics made from such fibers. The fibers comprise an incompatible polymer system which leads to the soft touch quality. The fibers comprise a mixture of at least two thermoplastic polymers each having different viscosities and wherein the mixture has an interfacial tension from about 0.5 to about 20 mN/m, and wherein the mixture comprises a portion of the fiber surface. The fibers may include from 40-98 percent of a polyolefin continuous phase and from 2 to 60 weight percent of an amorphous thermoplast dispersed phase, such as polystyrene or polyamide.