Abstract: 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.

Abstract: A process for the production of polymers in which an oligomeric precursor is formed first in a melt phase. A phase transition is then induced in the polymerizing reaction medium under the action of shear in such a way that the simultaneous action of the shear, and the ongoing polymerization through the phase transition produces a product that is in a powdered form.

Abstract: Ovenware for microwave ovens which contain a composition comprising a susceptor which has a Curie point temperature of about 100° C. to about 300° C. and a thermoplastic or thermoset polymer are improved and said composition is in contact with the food or drink to be heated or cooked, and/or composition has a thermal conductivity of about 0.7 W/m° 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. The relatively low Curie point of the susceptor prevent overheating of the ovenware and food being cooked. Also described are designs for various pieces of ovenware containing this composition.

Abstract: A polymer cutter with a rotary cutting head in which the cutting edges are on the circumferential periphery of the head is described. The knife blades on the rotary head have a knife angle (as defined) of about 40° to about 60°. The apparatus is especially useful for cutting hard and/or brittle thermoplastics and may be used for preparing polymer granules or pellets.

Abstract: 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.

Abstract: 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° 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.

Abstract: The melt viscosity of polyesters can be reduced by heating the polyester in a melt which is in contact with a hydrate that loses water at the temperature of the process. The process is typically carried out in a polymer melt mixer such as an extruder, and usually a reproducible decrease in the polymer melt viscosity is obtained. The resulting polyesters are useful for making films and moldings.

Abstract: 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.

Abstract: 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.

Abstract: A liquid crystal polymer composition comprising specified amounts of unsized glass filler and a liquid crystalline polymer having a melting point of about 280° 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.