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: 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: 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: 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° C. or more, and are useful for molded articles and for films, particularly for uses where good high temperature resistance is needed.

Abstract: 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° C. or more, and are useful for molded articles and for films, particularly for uses where good high temperature resistance is needed.

Abstract: Liquid crystalline polymers (LCP) with relatively high melting points are prepared by a process which includes solid state polymerization of a (pre)polymer, which contains alkali metal cations, to raise the LCP molecular weight. The presence of the alkali metal cations in the (pre)polymer usually results in a final polymer with less color and/or a higher melting point. The LCPs are useful as molding resins and for films.

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: Static dissipative compositions containing thermoplastic polymers and having surface resistivities of about 104 to 1013 ohms/square can be readily and reproducibly made by mixing into the thermoplastic polymers specified amounts of carbon fiber and carbon black. The composition is useful for housings and other parts for shielding electronic equipment and components.

Abstract: 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.

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: 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: This invention relates to liquid crystalline polymers (LCPs) derived from (I) hydroquinone and/or 4,4'-biphenol and/or bis(4-hydroxylphenyl) ether, (II) terephthalic acid, (lII) 2,6-naphthalene dicarboxylic acid and/or 4,4'-bibenzoic acid, (IV) 4-hydroxybenzoic acid, (V) 6-hydroxy-2-naphthoic acid, and optionally (VI) an aliphatic diol in specified ratios. In addition to forming exceptionally tough films, the LCPs are useful as molding resins or for blending with other thermoplastic polymers.

Abstract: Novel thermotropic liquid crystalline polyesters derived from t-butylhydroquinone, terephthalic acid, 2,6-naphthalene dicarboxylic acid and 4-hydroxybenzoic acid are described. These polymers are useful as molding resins.

Abstract: An improved die, containing one or more orifices, for the extrusion of polymers is disclosed wherein the orifices are flared at the polymer discharge end, and the orifices have certain relative dimensions and configurations. The dies are useful for producing items such as films, shaped profiles, sheets, fibers, strands, etc. Also disclosed are a process for using the die, and an extrusion apparatus containing such a die.

Abstract: The heat resistance of polyester liquid crystalline polymers containing repeat units in selected ratios derived from hydroquinone, 4,4'-biphenol, terephthalic acid, 4-hydroxybenzoic acid, and one or both of 4,4'-bibenzoic acid and 2,6-naphthalene dicarboxylic acid is improved by the addition thereto of 15 to 3000 ppm of an alkali metal or 50 to 3000 ppm magnesium or calcium.

Abstract: This invention relates to thermotropic liquid crystalline polyester compositions containing recurring units derived from hydroquinone, 4,4'-dihydroxybiphenyl, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-bibenzoic acid, and 4-hydroxybenzoic acid which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 1.5%, and heat distortion temperatures greater than 200.degree. C.This invention further relates to the same compositions containing 20 to 40 weight percent of at least one glass reinforcing/filling agent and which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 1.8%, and heat distortion temperatures greater than 230.degree. C.The compositions are useful as films, fibers, and shaped or molded articles.

Abstract: This invention relates to thermotropic liquid crystalline polyester compositions containing recurring units derived from 2-methylhydroquinone, terephthalic acid, 2,6-napthalenecarboxylic acid, and hydroquinone, characterized as having a heat distortion temperature of greater than 200.degree. C. and improved elongation. The inclusion of a reinforcing/filling agent selected from the group consisting of glass reinforcing agents, glass fillers, carbon metasilicate, calcium carbonate, talc, titanium dioxide, and calcined aluminum silicate in said compositions, and also in those same compositions lacking recurring units of hydroquinone, results in an improvement in the elongation of said compositions. The inclusion of carbon fiber into these compositions results in no significant decrease in the elongation of said compositions. The compositions are useful as films, fibers, and shaped articles.

Abstract: This invention relates to thermotropic liquid crystalline polyester compositions containing recurring units derived from hydroquinone, 4-4'-dihydroxybiphenyl, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 4-hydroxybenzoic acid which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 1.5%, and heat distortion temperatures greater than 200.degree. C.This invention further relates to the same compositions containing 20 to 40 weight percent of at least one glass reinforcing/filling agent and which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 2.0%, and heat distortion temperatures greater than 230.degree. C.The compositions are useful as films, fibers, and shaped or molded articles.

Abstract: Mixtures of imidized acrylic polymers and polyamides are described which have good flexural modulus properties.

Abstract: Thermoplastic polyarylate-polyamide compositions optionally including an elastomeric modifier show improved notched Izod toughness with the further inclusion of a small quantity of polycarbodiimide.