Polyplastics Co., Ltd.

Celanese Gmbh

Hoechst Celanese Corporation

Tsuneyoshi Okada

Toshio Kanoe

Kenji Hijikata

Katsuhiko Takahashi

Yukio Ikenaga

Toshikatsu Nitoh

Hiroshi Nakatsuji

Hirotaka Miyazaki

Takeshi Asano

Hiromitsu Sakai

Masato Togami

Yukimasa Yanase

An injection molding process includes using a mold provided with a resin reservoir having a retractable piston and protruding from a mold cavity in at least one of divided resin passages ranging from the point where the injected molten resin is divided into two streams to a weld formed by the union of the resin streams, feeding the molten resin into the mold while the piston is in a retracted or advanced state to form the weld, and either advancing the piston toward the mold cavity side to force the resin from the resin reservoir into the cavity or retracting the piston to withdraw the resin from the cavity side into the resin reservoir so as to cause the migration of the resin in the weld to thereby force the resin on one side of the weld into the resin on the other side, thus reinforcing the weld, and which is capable of remarkably improving the strength of the weld and its periphery of a molding which otherwise forms a weld having an extremely low strength.

Injection molding process using a resin reservoir containing a

An improved method for encapsulating an electronic component with a highly stable protective layer is provided. Such encapsulation is carried out by injection molding about the surface of the electronic component of an encapsulant composition comprising a molten melt-processable polyester which is capable of forming an anisotropic melt phase having uniformly blended therein about 0.1 to 30 percent by weight based upon the total weight of the composition of silicone oil and/or a silicone rubber. Quality encapsulation is made possible under conditions wherein damage to the electronic component is minimized, and the resulting product is well protected without damage under a wide variety of end use conditions including variations in temperature. The process is carried out in the substantial absence of deleterious mold shrinkage and the product exhibits an extremely low linear coefficient of thermal expansion which well protects the electronic component encased therein.

Improvements in the encapsulation of electronic components employing low

A resin composition is suitable for injection moulding and comprises 40 to 80 percent by weight of a thermotropic, liquid crystalline polyester being capable of forming the an anisotropic phase in the molten state and having a weight-average molecular weight of 2,000 to 200,000 and 20 to 60 percent by weight of a fibrous material having a tensile modulus of not less than 6,000 kg/mm2, a weight-average length of 0.15 to 0.60 mm and an aspect ratio of not less than 10.

Composition for injection molding

A resin composition of the invention, exhibiting the anisotropism when melted, comprises (1) a resin having rigid structure and exhibiting the anisotropism when melted and (2) a resin having a rigid structure portion and a soft structure portion, both resins having been uniformly mixed with each other.

Resin composition which exhibits anisotropism when melted

A resin composition is suitable for molding to a gear and comprises 30 to 98 percent by weight of a resin being capable of the anisotropic phase in the molten state and the melt processing and 2 to 70 percent by weight of fibers such as metal fibers, carbon fibers, glass fibers, inorganic fibers, synthetic fibers and mineral fibers.

Gear comprising fiber-reinforced anisotropic melt-forming polymer formed

An electroconductive resin composite is produced by polymerizing at least one monomer a polymer of which is electroconductive in a matrix of a resin which exhibits the anisotropy in the melt phase to form a composite of the obtained polymer and the resin. The resin composite is obtained in the form of film and a moulded article.

Process for producing electroconductive resin composite

A laminated film comprises a metallic film and a polymer layer which has been laminated on the metallic film, the polymer being anisotropic in the melt phase.

Metallic film with laminated layer of an anisotropic melt phase forming

A magnetic disk comprises a substrate of a resin composition comprising a polymer being capable of the anisotropic phase in the molten state and a magnetic layer formed on at least one surface of said substrate. The substrate is a laminate of a plurality, preferably two, of monoaxially oriented sheets, eventually being multiaxially oriented.

Magnetic disk

An optical disc comprises a substrate formed from a polymer being capable of the anisotropic melt phase and being melt-processable, a recording layer having pits and grooves, formed on the substrate, and a metal coating layer, formed on the recording layer.

Optical disc

A laminated sheet comprises a first layer of a melt-phase anisotropy exhibiting thermoplastic polymer, having a negative linear expansion coefficient in the direction of the polymer flow and a second layer having a positive linear expansion coefficient in the direction of the polymer flow, both layers having been laminated one on another in the alternative way, further each layer having a thickness such that the negative linear expansion coefficient of said first layer and the positive linear expansion coefficient of the second layer having been offset against each other.

Method of manufacturing a molded article having good dimensional

A polyacetal resin composition comprises a polyacetal and a potassium titanate fiber, being suitable for moulding a slidable part or article.

Polyacetal resin composition

A magnetic composite comprises a magnetic powder and a resin binder of a melt-processable polymer to form the anisotropic melt phase.

Magnetic composite

After crude polyacetal polymers mainly comprising bonded oxymethylene groups in the main chain thereof were once molten, they are heated at temperatures of 80.degree. C. or above in liquid mediums, in which said crude polyacetal polymers are insoluble, with keeping a heterogeneous system after they were once molten.

Method of producing polyacetal polymer showing improved heat resistance

In an article molded from a non-burning, non-dripping filled polyester composition having a high level of arc resistance and tracking resistance, decay in the arc resistance with time is substantially decreased or prevented by incorporating a minor but critical amount of polyethylene terephthalate. Typical compositions comprise (a) approximately 30 to 60 percent by weight, based on the composition, of a mixture of polyethylene terephthalate and polybutylene terephthalate wherein polyethylene terephthalate comprises approximately 3 to 20 percent by weight; (b) approximately 30 to 60 percent by weight of the composition of a mixture of fiber glass and talc wherein talc comprises approximately 15 to 35 percent by weight of the composition; and (c) an effective amount, up to 20 percent by weight of the composition of a flame retardant additive or a mixture thereof. Typical compositions possess superior electrical properties, comparable to those of thermosetting molding resins.

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Kawasaki, Japan

Tsuneyoshi Okada