E.i. Dupont De Nemours and Company

Ticona Gmbh

Marion G Waggoner

Michael Robert Samuels

Richard Alan Jackson

Joel David Citron

James L Webster

John Charles Gebhard, Jr

Dennis Jack Royer

Charles J Molnar

David Neil Marks

Julius Uradnisheck

Olaf Norbert Kirchner

Irene Greenwald Plotzker

Harold Kirkwood Inskip

Gregory R Alms

Roger Moons

David F Adcock

Julie Anderson Rakestraw

The properties of a liquid crystalline polymer (LCP) containing ester linkages and made in the presence of an excess of diol are improved by treating the LCP with a dicarboxylic acid at elevated temperature. The resulting LCPs are useful as molding resins and for films.

Manufacturing process for liquid crystalline polymer

Ovenware for microwave ovens which contain a composition comprising a susceptor and a thermoplastic or thermoset polymer are improved when the composition also has a thermal conductivity of about 0.7 W/m&#xb0; K. or more. Heat generated by absorption of microwave radiation by the susceptor is more readily conducted to the food being cooked when the thermal conductivity of the composition is high, particularly when the part containing the susceptor is relatively thick. Also described are designs for various pieces of ovenware containing this composition.

Ovenware for microwave oven

An improved process for the pelletization of polymers is disclosed, using a die in which the die holes incorporate a reverse taper along at least a portion of the length thereof. Conditions for operation of an under melt cutter incorporating this die are also disclosed.

Polymer pelletization process and apparatus

Aromatic polyesters are made in a continuous process in an extruder or extruder-like apparatus by reacting at elevated temperatures dicarboxylic acids, aliphatic esters of aromatic diols, and optionally aliphatic esters of aromatic hydroxyacids in an extruder while removing byproduct aliphatic carboxylic acid. The resulting aromatic polyesters, especially thermotropic liquid crystalline aromatic polyesters, are useful as molding resins for a variety of uses, for example electronic and electrical parts.

Manufacture of aromatic polyester

A liquid crystal polymer composition comprising specified amounts of unsized glass filler and a liquid crystalline polymer having a melting point of about 280&#xb0; C. or more has improved high temperature stability compared with similar compositions containing sized glass fillers. The compositions are particularly useful where the composition is exposed for long time periods to high temperatures, such as parts in electrical and electronic apparatus, and cookware.

Liquid crystalline polymer composition

Liquid crystalline polymers containing specified ratios of repeat units derived from hydroquinone, 2,6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid and optionally terephthalic acid have exceptionally high heat distortion temperatures, making especially useful for service at high temperatures. Compositions containing reinforcing agents, especially fibrous or platy reinforcing agents are particularly useful. These polymers and compositions are useful for electrical and electronic connectors, and as films for the electronics industry, and for other uses.

Underwater melt pelletizer dies which have a highly thermally conductive pathway from their heating source to the vicinity of the polymer exit end of their die holes and have a thermally insulating material at that end of their die holes have improved operability and can pelletize thermoplastics which are otherwise difficult or impossible to pelletize with such an apparatus.

Polymer underwater pelletizer apparatus and process incorporating same

Thermotropic liquid crystalline polymers are produced by the reaction of a polyester made from an aromatic dicarboxylic acid and a diol, one or more hydroxycarboxylic acids, a stoichiometric excess of an aromatic diol, and a carboxylic acid anhydride. Also disclosed are novel liquid crystalline polymers that may be produced by this process. These liquid crystalline polymers are useful as molding resins and shaped articles thereof are produced. In particular, the articles include films, sheets, containers and portions thereof comprising these LCPs.

Liquid crystalline polymers, processes for their manufacture, and articles thereof

Liquid crystalline polymer having repeat units derived from 4,4'-biphenol, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 4-hydroxybenzoic acid in a limited compositional range have melting points of 400&#xb0; C. or more, and are useful for molded articles and for films, particularly for uses where good high temperature resistance is needed.

A composition comprising a thermotropic liquid crystalline polymer (LCP) and small quantities of low molecular weight polyethylene (PE) is disclosed. The PP acts as an internal lubricant or mold release, but suprisingly does not significantly increase the flammability of the LCP.

A polymer cutter with a rotary cutting head in which the cutting edges are on the circumferential periphery of the head, and in which the cutting edges shear rather than slice the polymer is described. The knife blades on the rotary head have a cutting edge angle of greater than 70&deg;. The apparatus is especially useful for cutting thermoplastics and may be used for preparing polymer granules or pellets.

Polymer cutting apparatus and method

Liquid crystalline polyesters made from hydroquinone, terephthalic acid, 2,6-naphthalene dicarboxylic acid and 4-hydroxybenzoic acid, and having a selected composition range, have melting points of about 350.degree. C. or less, good physical properties, and are readily manufactured. The polymers are useful as molding resins.

Liquid crystalline polyester resin

Disclosed herein are thermotropic liquid crystalline poly(ester-amides) containing repeat units derived from alipatic diamines and other monomers, such as aromatic diols, aromatic dicarboxylic acids, aromatic hydroxycarboxylic acids, and optionally aliphatic diols. The polymers are particularly useful as films and in multilayer structures as barrier layers because of their relatively low permeability to various compounds.

Growing community of inventors

Hockessin, DE, United States of America

Marion G Waggoner