Method of preparing polyethylene glycol modified polyester filaments

Abstract

Disclosed is a method of copolymerizing polyethylene glycol (PEG) into polyethylene terephthalate (PET) to achieve a polyethylene glycol-modified polyester composition that can be spun into filaments. The method includes the steps of copolymerizing polyethylene glycol into polyethylene terephthalate in the melt phase to form a copolyester composition, then polymerizing the copolyester composition in the solid phase until the copolyester is capable of achieving a melt viscosity that facilitates the spinning of filaments, and thereafter spinning filaments from the copolyester. A copolyester composition comprised of polyethylene glycol and polyethylene terephthalate is also disclosed. Fabrics made from fibers formed from the copolyester composition possess wetting, wicking, drying, flame-retardancy, static-dissipation, and soft hand properties that are superior to those of fabrics formed from conventional polyethylene terephthalate fibers of the same yarn and fabric construction.

Description

[0001] This application is a division of copending U.S. application Ser. No. 09 / 444,192, filed Nov. 19, 1999.[0002] The present invention relates to the production of polyethylene glycol modified polyester fibers. The present invention also relates to the manufacture of yarns and fabrics from these copolyester fibers.[0003] Polyester filament is strong, yet lightweight, and has excellent elastic memory characteristics. Polyester fabric resists wrinkles and creases, retains its shape in garments, resists abrasions, dries quickly, and requires minimal care. Because it is synthetic, however, polyester is often considered to have an unacceptable appearance for garment purposes when initially formed as a filament. Accordingly, polyester filaments require texturing to produce acceptable characteristics of appearance, hand, and comfort in yarns and fabrics. Even then, polyester is often viewed unfavorably in garments.[0004] In pursuit of improved polyesters, various chemical modifications ...

AI Technical Summary

Benefits of technology

[0009] Therefore, it is an object of this invention to provide polyethylene glycol modified polyester filaments that possess favorable characteristics similar to natural fibers, yet retain the advantages of polyester. It is a further object of the present invention to provide a method of copolymerizing polyethylene glycol (PEG) into polyethylene terephthalate (PET) to achieve a PEG-modified polyester composition that is readily spun into filaments, wherein the presence of branching agents is nonessential.

[0010] As is understood by those of ordinary skill in the art, modifying conventional polyesters with polyethylene glycol can improve certain polyester characteristics, yet can adversely affect others. For example, adding polyethylene glycol to polyethylene terephthalate improves wetting and wicking, but slows melt-phase polymerization kinetics. It also depresses melt viscosity and renders the processing of such PEG-modified polyesters somewhat impractical in commercial polyester spinning operations.

[0011] Accordingly, in one aspect, the invention is a method of copolymerizing polyethylene glycol into polyethylene terephthalate in a way that retains the favorable properties of polyethylene glycol while attaining a high intrinsic viscosity. This facilitates the commercial spinning of the PEG-modified polyester using conventional spinning equipment. As will be understood by those having ordinary skill in the art, copolymerizing polyethylene glycol into polyethylene terephthalate is conventionally achieved by reacting ethylene glycol and either terephthalic acid or dimethyl terephthalate in the presence of polyethylene glycol.

Problems solved by technology

As is understood by those of ordinary skill in the art, modifying conventional polyesters with polyethylene glycol can improve certain polyester characteristics, yet can adversely affect others.

For example, adding polyethylene glycol to polyethylene terephthalate improves wetting and wicking, but slows melt-phase polymerization kinetics.

It also depresses melt viscosity and renders the processing of such PEG-modified polyesters somewhat impractical in commercial polyester spinning operations.

Although polyesters having lower intrinsic viscosities can be spun by employing lower temperatures, this is often impractical using conventional spinning equipment.

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