Hoechst Celanese Corporation

Celanese Acetate Limited

M Ishaq Haider

James B Stamatoff

Michael L Jaffe

John A Flint

Edward C Chenevey

Joseph J DiBiase

Joseph D Menczel

John Edward Cornetta

Barbara J Long

James E Kuder

Subhash Makhija

Michael Bayer

Michael J Jaffe

Eui W Choe

Paul N Chen, Sr

Marie Borzo

John D Gibbon

Norman S Anderson

Vincent J Sullivan

Stuart M French

John L Wesley

Gerard Lees

Harry S Pulaski

Robert M Mininni

The present invention discloses and claims a novel process for the formation of high denier as-spun and heat-treated multilobal filaments of a thermotropic liquid crystalline polymer. Preferred embodiments include process for the formation of as-spun and heat treated octalobal monofilaments of a few wholly aromatic polyesters and polyesteramides. The process involves (a) heating of a thermotropic liquid crystalline polymer to above its melting transition temperature; (b) passing said molten polymer through an extrusion chamber equipped with an extrusion capillary having a multilobal cross-section to form a multilobal filament; and (c) winding the filament at a suitable draw-down. The filaments so formed are of at least 50 denier per filament (dpf) and feature essentially uniform molecular orientation across their cross-section. In a final optional step, the filaments are heat treated in stages to form filaments exhibiting excellent tensile properties. Both as-spun and heat-treated filaments feature remarkably good tensile properties comparable to those of round filaments. Most importantly, the multilobal filaments of this invention feature much superior adhesion properties than the conventional round filaments.

Process for making high denier multilobal filaments of thermotropic liquid crystalline polymers and compositions thereof

The present invention discloses and claims a novel process for the heat treatment of high denier filaments of a thermotropic liquid crystalline polymer. Preferred embodiments include process for the formation of heat treated filaments of a few wholly aromatic polyesters and polyesteramides. The process involves: (a) heating of a thermotropic liquid crystalline polymer to above its melting transition temperature; (b) passing said molten polymer through an extrusion chamber equipped with an extrusion capillary of an aspect ratio of greater than about 1 and less than about 15 to form a filament; (c) winding the filament on to a bobbin at a low tension and draw-down ratio of at least about 4; and (d) heat treating the filament directly on the bobbin at suitable temperature and pressure conditions for a sufficient period of time. The filaments so formed are of at least 50 denier per filament (dpf) and feature essentially uniform molecular orientation across the cross-section. The heat-treated filaments feature remarkably good tensile properties retaining at least 80 to 90 percent of the properties expected of conventional low denier (5 to 10 dpf) filaments.

Process for direct on-bobbin heat treating of high denier filaments of

The invention is directed to LCP monofilaments and yarn made therefrom which have improved adhesion properties, said monofilaments, and yarn made therefrom, comprising a liquid crystalline polymer filament having a finish selected from the group consisting of esters formed between (a) pentaerythritol and saturated polyols of up to 10 carbon atoms and 2 to 6 hydroxyl groups, and (b) a carboxylic acid of formula C.sub.x H.sub.2x=1 COOH, wherein x is from 2 to 20, and wherein 2 to 6 of the hydroxy functions are converted to ester functions. In a preferred embodiment of the invention the finish is an ester formed from the reaction of pentaerythritol and a carboxylic acid of formula C.sub.x H.sub.2x=1 COOH, wherein x is from 2 to 20, and preferably between 14 and 20. The most preferred esters are pentaerythritol tetrapelargonate and pentaerythritol tetraisostearate.

Liquid crystalline polymer monofilaments having improved adhesion

The present invention discloses and claims a novel process for the formation of high denier as-spun and heat-treated filaments of a thermotropic liquid crystalline polymer. Preferred embodiments include process for the formation of as-spun and heat treated monofilaments of a few wholly aromatic polyesters and polyesteramides. The process involves (a) heating of a thermotropic liquid crystalline polymer to above its melting transition temperature; (b) passing said molten polymer through an extrusion chamber equipped with an extrusion capillary of an aspect ratio of greater than about 1 and less than about 15 to form a filament; and (c) winding the filament at a draw-down ratio of at least about 4. The filaments so formed are of at least 50 denier per filament (dpf) and feature essentially uniform molecular orientation across the cross-section. In a final optional step, the filaments are heat treated in stages to form filaments exhibiting excellent tensile properties. Both as-spun and heat-treated filaments feature remarkably good tensile properties retaining at least 80 to 90 percent of the properties expected of conventional low denier (5 to 10 dpf) filaments.

Process for making high denier filaments of thermotropic liquid

A thermally expandable wax composition and its use in polymer-based actuators is disclosed and claimed. The compositions are wax-based and include conductive filler as well as a viscosity modifier to stabilize the composition against segregation. Optionally included are thermoxidative stabilizers.

Thermally expandable, viscosity modified wax compositions and method of

This invention discloses a thermally expandable composition for use in actuators. The composition contains about 10-50 volume percent hollow glass spheres in a wax or a polymer. The spheres contain a conducting coating affixed thereon. During use in an actuator, the composition is heated to melt the wax or polymer, when the density of the spheres substantially match the density of the melt, thereby substantially eliminating phase separation. The high thermal conductivity of the composition increases the speed of heat transfer out of the composition during the cooling cycles.

Electronically and thermally conducting compositions for actuators

A process for making a transparent film comprising a liquid crystalline polymer, and a transparent film made thereby having high barrier properties. In this process, the LCP is dissolved in an appropriate solvent, then cast into a film at ambient or near-ambient temperatures. The film optionally may be dried at elevated temperatures and/or reduced pressures to remove the solvent. The film is then annealed at a temperature between the glass transition temperature (T.sub.g) and the melting point temperature (T.sub.m) of the polymer. The result is a highly transparent film having liquid crystalline morphology and high barrier properties.

high barrier transparent films

A process for enhancing the thermo-oxidation stability of a polybenzimidazole-containing article wherein the article contains from about 5 to about 100 weight percent of polybenzimidazole and from about 0 to about 95 weight percent of a thermoplastic polymer, by the steps of providing a phosphoric acid solution of about 2.0 to about 10.0 weight percent of acid; contacting the polybenzimidazole-containing article with the acid solution for sufficient time to produce an acid-treated article; drying the acid-treated article at a low temperature to remove excess acid; and heat treating the dried article at a temperature ranging from about 400.degree. to about 500.degree. C. in an inert atmosphere to form a phosphate barrier layer on the surface of the article, wherein the article retains at least about 50 percent of its weight after isothermal aging at about 600.degree. F. for a period of at least about 300 hours.

Thermo-oxidatively stabilized polybenzimidazole-containing articles

A method of making controlled sequence condensation copolymers from mer systems capable of forming at least two unique recurring units is disclosed and claimed. Sequenced polyesters containing the residue of hydroxyacids are specifically exemplified.

Condensation copolymers with sequenced mer structure

A moldable thermoset composition comprising about 5-60% liquid crystal polymer and about 95-40% of an epoxy-functional rubber by weight, a process for making and a process for using same. The composition is made by melt mixing the LCP and the epoxy-rubber to form a blend. This blend is then cooled and may be molded, extruded, or otherwise formed into a desired shape. The composition is then heat-treated to make it set.

Thermoset LCP blends

Preceramic fibers are produced by dissolving a solid organosilicon preceramic polymer in a solvent to form a spinning solution containing at least seventy percent polymer solids, dry spinning and extracting solvent in the presence of a non-oxidizing gas at a temperature and pressure sufficient to vaporize solvent from the fiber, and at least one curing agent being added to the non-oxidizing gas or spinning solution, or both, to induce on-line curing of the fiber or to aid in subsequent curing of the fiber or both. The preceramic fibers are thereafter pyrolyzed to ceramic form.

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Bernardsville, NJ, United States of America

M Ishaq Haider