Sumitomo Chemical Company, Limited

Mituo Maeda

Kuniaki Asai

Hiroshi Nakamura

Tadayasu Kobayashi

Hideo Nomura

Tohru Nagashima

Satoshi Nagano

Manabu Hirakawa

Provided is a liquid crystal polyester resin composition, which comprises 5-20 parts by weight of glass fiber having a specific number average fiber diameter and fiber length after molding and 100 parts by weight of a specific liquid crystal polyester resin, and the flexural modulus thereof measured with using a test piece of 0.5 mm thickness is 25 GPa or more; and also provided a process for producing a molded article therefrom. The liquid crystal polyester resin composition is low in specific gravity, and is excellent in processability, mechanical properties, and heat resistance.

Liquid crystal polyester resin composition, process for producing the same, and molded article thereof

Provided is a process for producing a thermoplastic resin composition of low specific gravity containing hollow spheres by a melt processing extrusion method, wherein a melt-kneading extruder equipped with a screw is used and the extruder has an upper stream side supplying portion at the upper stream part of the extrusion direction, and a lower stream side supplying portion at the lower stream part from said upper stream side supplying portion, and the ratio (L/D) of the distance (L) between said upper stream side supplying portion and said lower stream side supplying portion to the diameter (D) of a screw is 4-30 (L and D are the same scale units); and under screw rotation, a thermoplastic resin having a specific gravity of 1.10 or more is supplied from the upper stream side supplying portion, and hollow spheres in an amount of 2-50 parts by weight based on 100 parts by weight of the thermoplastic resin are supplied from the lower stream side supplying portion.

Process for producing thermoplastic resin composition

A liquid crystal polyester resin mixture having a stabilized plastication time and accordingly possible to be molded in constant cycles and giving a molded article excellent in mechanical properties and thermal stability is provided. The liquid crystal polyester resin mixture comprises 100 parts by weight of a liquid crystal polyester resin composition which comprises 100 parts by weight of a liquid crystal polyester and from 0 to 150 parts by weight of a filler, and either from 0.001 to 5 parts by weight of a fatty acid amide having a formula; R &mdash;CO&mdash;NH (wherein R denotes a saturated or unsaturated hydrocarbon of 10 to 30 carbons) or from 0.001 to 2 parts by weight of a high molecular weight polyethylene with a molecular weight of 10,000 or higher.

Liquid crystal polyester resin mixture

Provided is a liquid crystal polyester resin composition comprising 100 parts by weight of a liquid crystal polyester resin, 2 to 50 parts by weight of hollow sphere having an average particle diameter of 5 to 500 &mgr;m and a volume hollowness of 60 to 80%, and 0 to 40 parts by weight of inorganic fiber, wherein said liquid crystal polyester resin composition has the specific range of fracture rate of the hollow sphere. The liquid crystal polyester resing composition gives a molded product having necessary mechanical physical properties, light-weighted and excellently low thermal conductivity, with good reproducibility.

Liquid crystal polyester resin composition and molded product thereof

Liquid crystal polyester resin composition and molded article

Provided is a liquid crystal polyester resin composition prepared by compounding glass fiber with a liquid crystal polyester resin, wherein said glass fiber has been surface-treated with a thermosetting resin and the ignition loss of the surface-treated glass fiber is from 0.05 to 0.4% by weight. The molded article obtained by using the composition of the present invention have excellent mechanical property and heat-resistance, particularly, solder heat-resistance, and are extremely useful as materials for which heat-resistance is required such as electric and electronic parts.

Liquid crystal polyester resin composition and molded article thereof

A thermoplastic resin composition in which 5 to 45 parts by weight of carbon fiber and 0.1 to 10 parts by weight of conductive carbon black are compounded per 100 parts by weight of resin components comprising an aromatic polycarbonate resin and an aromatic polysulfone resin. The thermoplastic resin composition is excellent in heat-resistance and mechanical strength, and heat-resistant IC trays therefrom are useful products which can endure drying of IC at high temperature and are excellent in handling properties.

Thermoplastic resin composition and heat-resistant tray for IC

Provided is an aromatic polysulfone resin composition comprising 100 parts by weight of an aromatic polysulfone resin compounded with 5 to 240 parts by weight of glass fiber whose surface is treated with an urethane resin. The aromatic polysulfone resin composition is extremely useful as a material for heat-resistant usage including electronic and electric parts because of excellent heat resistance, excellent mechanical properties, high heat stability during mold-procession and low level of gas occluded in the resulting molded article.

Aromatic polysulfone resin composition

A melt extrusion processing method of a thermoplastic resin, wherein a thermoplastic resin having a flow temperature of 200.degree. C. or higher is subjected to extrusion processing using a melt kneading type extruder in which a vent port is provided at a downstream position by length L from the most upper stream portion of a melt kneading type extruder screw and L/D is from 4 to 18 (wherein D indicates the screw diameter and D and L are in the same scale unit), while continuously sucking from the said vent port at a reduced pressure of lower then 660 mmHg. The invention provides a method which causes little resin degradation in an extruder to give an extruded article containing small amounts of discolored and degraded materials even when the processing is conducted for a relatively long time.

Melt extrusion processing method of thermoplastic resin

A thermoplastic resin composition comprising an aromatic polycarbonate resin and an aromatic polysulfone resin and having the specific melt viscosity ratio between the two resins in the composition. This composition is excellent in heat resistance and gives a molded article of especially high temperature of deflection under load.

Thermoplastic resin composition and molded article

A liquid crystal polyester resin composition comprising (a) a liquid crystal polyester, (b) an aluminum powders, flakes and/or fibers, and if necessary (c) titanium oxide and/or talc, has high heat resistance and a small thermal storage even when exposed to high temperatures, and thus is useful for producing a lamp reflector hardly deformed by heat from a halogen lamp, etc.

Liquid crystal polyester resin composition and lamp reflector

There are provided a liquid crystal polyester resin composition comprising 100 parts by weight of a liquid crystal polyester, 45 to 80 parts by weight of graphite having an average particle size of 5 .mu.m or more and 0 to 140 parts by weight of talc having an average particle size of 5 .mu.m or more, the total amount of the graphite and the talc being 55 to 185 parts by weight. There are provided a molded article such as a carrier for electronic part, a heat-resistant tray for IC, or the like, which has high heat resistance in soldering, only slight anisotropy and warpage, a surface resistivity of 1.times.10.sup.4 to 1.times.10.sup.8 .OMEGA., and an initial voltage due to electrification and a half-life (a time required for the initial voltage due to electrification to be reduced to one-half) which are controlled to be further reduced; and a liquid crystal polyester resin composition excellent in moldability which gives said molded article.

A wholly aromatic polyester resin composition contains:

Wholly aromatic polyester resin composition and ovenware obtained by

An aromatic polysulfone resin composition improved in dispersibility of fluorocarbon polymer comprising 0.3 to 50 parts by weight of a low molecular weight fluorocarbon polymer fluorinated up to its molecular end, having a flow temperature of 350.degree. C. or lower as measured by the following method, and 100 parts by weight of an aromatic polysulfone resin: Flow temperature: A temperature at which melt viscosity reaches 48,000 poises when a molten sample is extruded from a nozzle (1 mm in inner diameter and 10 mm in length) of a capillary rheometer under a load of 100 kg/cm.sup.2 at a temperature elevation speed of 4.degree. C./minute.

Aromatic polysulfone resin compositions

An aromatic polysulfone resin composition comprising 100 parts by weight of an aromatic polysulfone resin, 3 to 15 parts by weight of an electro-conductive carbon black having a dibutyl phthalate absorption of 150 ml/100 g or more and 0.1 to 2.5 parts by weight of a fluorocarbon-type surface active agent. The aromatic polyslfone resin composition has surface resistivity in a range of 10.sup.7 to 10.sup.13 .OMEGA., remarkably lowered initial charged voltage and half-life period, and excellent thermal stability and dimensional accuracy, so that it is suitable for use as a material for electronic parts, office automation equipment parts and audiovisual equipment parts.

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Tsukuba, Japan

Mituo Maeda