Hoechst Celanese Corporation

Honeywell International Inc.

Edward R Kafchinski

Tai-Shung Chung

Gunilla E Gillberg-LaForce

John A Flint

Robert Bruce Sandor

Herman Leslie Lanieve

Scott W Thompson

Etheridge Odell Oakley, Jr

William F Clear

Michele C Carter

Mohammed Ishaq Haider

Gordon W Calundann

Rachel S Kohn

Herman L LaNieve, Iii

Rohitkumar H Vora

Edward C Chenevey

Paul Foley

Frank J Onorato

Michael Haubs

James J Lowery

Frank Haimbach, Iv

Brenda A Bembry-Ross

Hubert Bader

William Timmons

Jeanne Gasman

A fiber having increased cut resistance is made from a fiber-forming polymer and a hard filler having a Mohs Hardness Value greater than about 3. The filler is included in an amount of about 0.05% to about 20% by weight. In preferred embodiments, the fiber-forming polymer is poly(ethylene terephthalate) or a liquid crystalline polyester comprising monomer units derived from 6-hydroxy-2-naphthoic acid and 4-hydroxybenzoic acid. Preferred fillers include tungsten and alumina.

Cut-resistant gloves

Cut-resistant sheath/core fiber

A fiber having increased cut resistance is made from a fiber-forming polymer and a hard filler having a Mohs Hardness Value greater than about 3. The filler is included in an amount of about 0.05% to about 20% by weight. In preferred embodiments, the fiber-forming polymer is poly(ethylene terephthalate) or a liquid crystalline polyester including monomer units derived from 6-hydroxy-2-naphthoic acid and 4-hydroxybenzoic acid. Preferred fillers include tungsten and alumina.

Composite yarn comprising filled cut-resistant fiber

Method of making a cut-resistant fiber and fabrics, and the fabric made

Filled cut-resistant fiber

Cut-resistant fiber containing a hard filler

A polypropylene or polyethylene film or fiber coated with a maleic-acid grafted polypropylene or polyethylene copolymer layer over which is coated a layer of selective polymer. The copolymer securely bonds the selective polymer to the film or fiber. These fibers and films can be used in fluid separation membranes.

Coated polypropylene or polyethylene useful for membranes

PVP-coated asymmetric hollow fibers made from SIXEFT.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These coated fibers have a separation factor that exceeds 6 for oxygen and nitrogen and a permeance of at least about 10 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ('NMP') and an organic acid such as propionic acid ('PA') is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to acid. The dope is wet-spun into hollow fibers; the fibers are coagulated in water. The fibers are then evenly coated with PVP, preferably by dipping the fibers in a dilute PVP solution.

High selectivity hollow fibers

Asymmetric fluoropolymer hollow fibers having a thin, dense, inner separation layer that is essentially defect-free. In the process of this invention, a fluoropolymer dope is spun into a hollow fiber using a hollow fiber die, a core solvent, preferably comprising water, and a coagulation bath, preferably comprising a water-acetone mixture. Due to solubility and surface tension differences, the outer layer of the fiber does not coagulate quickly enough to form a dense layer, and remains porous, but the core solvent causes the inner surface of the hollow fiber to coagulate into a thin, dense, defect-free layer.

Fabrication of a fluoropolymer hollow fiber having a defect-free

Asymmetric hollow fibers of SIXEF.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These uncoated fibers have a separation factor that exceeds 4 for oxygen and nitrogen and a permeance of at least about 50 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ('NMP') and an organic acid such as propionic acid ('PA') is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to the organic acid. The dope is wet-spun into hollow fibers using a core solvent such as PA or glycerine; the fibers are coagulated in water.

SIXEF.TM.-durene polyimide hollow fibers

A breathable water-resistant fabric in which a surface of a fabric material is coated with a microporous layer of ETFE, and a process for making same. An ETFE dope containing a blend of ETFE and a binder polymer is cast or extruded into a film which is subsequently bonded or laminated to the fabric material. The binder is extracted to produce a microporous ETFE layer.

Breathable water-resistant fabrics

A novel method for making a composite separation membrane, and the product of that method. This novel method includes applying one or more perfluoroethers to the surface of a microporous fiber or film made of a polymer such as PAN, and subsequently coating that fiber or film surface with a layer of selective material. This method provides a more permeable composite membrane than would be obtained by coating a fiber or film that had not been pre-wetted with perfluoroether.

Pan composite membranes

A process for coating a polypropylene or polyethylene surface with a maleic acid-grafted polypropylene or polyethylene copolymer. In this process, a dope containing the graft copolymer is applied to the polypropylene or polyethylene surface, e.g. by dip coating, at a temperature high enough to keep the copolymer solvated in the dope solvent. The surface is then dried to leave a porous graft polymer coating bonded to the polypropylene or polyethylene. The coated product has superior adhesion characteristics compared to uncoated polypropylene or polyethylene.

Process for surface-modifying polypropylene or polyethylene

Asymmetric hollow fibers having a microporous hollow fiber core comprising a polyolefin, e.g. polypropylene, and an asymmetric coating comprising a fluoropolymer, e.g. SIXEF.TM.-Durene. Optionally, the coating may also comprise glycerine which is applied prior to the fluoropolymer. The fibers are coated by wet-spinning, or alternately by dry jet-wet spinning, through a spinning jet in which a fluoropolymer-containing fluid is applied to the outer surface of the fibers as they pass through the jet. The fibers exit the jet into a water bath. If greater selectivity is needed, the fiber later may be coated with an additional layer of a highly selective material, e.g. polyvinyl alcohol, PVP, and the like.

Asymmetric fluoropolymer-coated polyolefin hollow fibers

Asymmetric hollow fibers comprising a fluoropolymer, and a process for making such fibers. The hollow fibers are useful for making fluid separation membranes, especially gas separation membranes. In one embodiment of the process of this invention, a polymer dope having a viscosity of about 3000 poise or greater is prepared by solvating the polymer in a solvent system containing about 40%-90% N-methyl-2-pyrrolidone and about 60%-10% propionic acid by weight. The dope is dry-jet wet-spun into hollow fibers using a water-NMP core solvent. The fibers are coagulated in methanol. The fibers are then coated with a highly permeable material.

Growing community of inventors

Winfield, NJ, United States of America

Edward R Kafchinski