Mitsubishi Gas Chemical Company, Inc.

Victor Company of Japan, Limited

Nof Corporation

Toshikazu Umemura

Akitoshi Sugio

Tomotaka Furusawa

Katsumasa Tanaka

Mutsuhiko Takeda

Akira Amemiya

Tadashi Kunii

Kenji Maeda

Toshiaki Izumida

Isamu Masumoto

Junichi Miyawaki

Masanori Sakurai

Akiyoshi Shibata

Yoshiharu Ohtsuki

Yoshihiro Ono

Tetsuya Abe

Hideaki Takahashi

Masaharu Kimura

Tatsuo Iwai

Yutaka Kojima

Michio Ohba

Satoshi Kanayama

Toshiaki Takata

Masanori Furukawa

Makoto Mizutani

Toshiaki Asoh

Motoyuki Sugiura

Hiroyuki Urabe

Kazuyuki Akahori

Takeo Suzumori

Takeaki Megumi

Kiyokazu Kawaguchi

Makoto Matsumura

Tatsuhide Hosomi

Kou Tanabe

Toshikatsu Kawata

Yukihiro Iha

Shigeo Kondoh

Noriyasu Nakao

Kazuyoshi Taka

Shinzi Kiboshi

Shuji Tsukahara

Kazuyoshi Ichise

Yuki Ohtani

Yuji Mori

A method of producing polycarbonate resin pellets containing very less residual organic solvent and low molecular weight volatile matters and having a high transparency by melt-kneading a polycarbonate resin powder in an extruder equipped with a screw having a material seal mechanism, and vents, and devolatilizing the residual organic solvent and/or the low molecular weight volatile matters at the vent portion and then extruding the molten resin. The polycarbonate resin pellets are suitable for optical grade articles and automobile lenses.

Production method of polycarbonate resin pellets

A grafted aromatic polycarbonate resin is produced by melt-kneading a graft precursor comprising a mixture of 35 to 95% by weight of aromatic polycarbonate resin particles and 65 to 5% by weight of vinylic copolymer containing active oxygen, the vinylic copolymer being present in the aromatic polycarbonate resin particles, thereby subjecting to grafting reaction of the aromatic polycarbonate resin and the vinylic copolymer, where the grafting reaction can be sufficiently carried out and thus the grafted polycarbonate resin is useful for molding materials for optical disks, optical lenses, etc. a polymer blend-compatible agent, adhesives, paints, etc.

Graft precursor and process for producing grafted aromatic polycarbonate

A polycarbonate resin solution for forming a thermal-sublimating dye-receiving layer film, comprising a random copolycarbonate resin dissolved in an organic solvent, the resin having a structural unit represented by following formula (1) and a structural formula represented by following formula (2) or (3), the molar ratio of the structural unit represented by formula (1) to the structural unit represented by formula (2) or (3) being from 35/65 to 65/35, and having a number average molecular weight of from 5,000 to 50,000. ##STR1## wherein R.sup.1 to R.sup.12 each represents a hydrogen atom, a halogen atom, or an alkyl group having from 1 to 4 carbon atoms and in formula (1), A represents a straight chain, branched, or cyclic alkylidene group having from 1 to 10 carbon atoms, an aryl-substituted alkylidene group, an arylene group, or a sulfonyl group.

Method for preparing a thermal transfer image-receiving sheet involving

Disclosed is a process for producing a grafted polycarbonate resin for optical use, which comprises adding to an aqueous suspension of an aromatic polycarbonate resin having radical-polymerizable unsaturated terminal group on a molecule wherein the aromatic polycarbonate resin has an average particle diameter of 0.1 to 5 mm and an apparent density of 0.2 to 0.9 g/cm.sup.3, a vinyl monomer and a radical-polymerization initiator, heating the aqueous suspension at a lower temperature by 5.degree. C. to 20.degree. C. than the decomposition temperature for a half-life period of 10 hours of the radical-polymerization initiator, thereby impregnating the polycarbonate resin with the vinyl monomer and the radical-polymerization initiator, then elevating the temperature to the range of from a lower temperature by 50.degree. C. to a higher temperature by 30.degree. C. than the decomposition temperature for a half-life period of 10 hours of the radical-polymerization initiator, thereby conducting a graft-polymerization reaction to obtain 90% by weight or more of conversion of vinyl monomer.

Process for producing grafted polycarbonate resin

In a process for producing a halogenated polycarbonate molded article from a powder or pellets of a halogenated polycarbonate resin or composition thereof by means of injection molding using an injection molding machine, the improvement wherein the injection molding machine comprises a cylinder whose inner circumferential wall being made of a corrosion-resistant and abrasion-resistant alloy comprising alloy component (1), (2), or (3) given below, and a screw part made of a steel having a metal coating formed by hard chromium plating or hard nickel plating or made of SUS420, SUS440, Hastelloy C, or a steel comprising alloy component (4) given below:

Process for producing halogenated polycarbonate molded article

A method of coloring a polycarbonate extruded or molded product for optical members, which is colored by a liquid coloring process for obtaining a colored polycarbonate extruded or molded product for optical members by extrusion or injection molding. The process involves mixing a polycarbonate resin for optical members and a liquid coloring agent dispersion obtained by dispersing a coloring agent in a dispersing agent. The dispersing agent includes a specific saturated fatty acid ester or silicon oil. After mixing the polycarbonate resin and liquid coloring agent dispersion, the resulting mixture is melted and thereafter extruded or molded to form a product for optical members.

Method of coloring polycarbonate extruded or molded products for optical

A process for producing a low-particle-content transparent thermoplastic resin solution, which comprises centrifuging a solution of a transparent thermoplastic resin containing free water to separate it into a resin solution phase, an aqueous phase and an intermediate layer, and separating the resin solution phase from the aqueous phase and the intermediate layer. By this process, the number of particles having a size of at least 0.5 .mu.m in the resin solution can be decreased to 10,000 or less, preferably substantially zero, per gram of the transparent thermoplastic resin.

Process for producing a low-particle-content transparent thermoplastic

A process for producing a polycarbonate molded article having a low dust level from a polycarbonate resin in the form of a powder or pellets by injection molding using an injection molding machine. The injection molding machine includes a cylinder whose inner circumferential wall is made of a corrosion- and abrasion-resistant alloy from alloy components (1), (2), or (3) given below and a screw part made of a steel having a metal coating formed of hard chromium plating or hard nickel plating or formed of titanium carbide or tungsten carbide, or is made of SUS420, SUS440, Hastelloy C, or a steel of alloy component (4) given below:

Process for producing low-dust-level polycarbonate molded article

A method for producing a purified polycarbonate resin is disclosed, comprising contacting a solid polycarbonate resin with a fluid comprising at least 70% by weight of carbon dioxide and having a temperature of 30.degree. to 120.degree. C. and a pressure of at least 10 kg/cm.sup.2. The method can effectively remove almost all the impurities contained in the polycarbonate resin within a very short period of time, thereby providing highly purified polycarbonate resin materials which are suitably used in the fields of information, electronic and medical industries.

Method for producing purified polycarbonate resin with fluid containing

A process for producing a low-particle polycarbonate resin molding material suitable for use as molding material for optical materials is disclosed, which comprises directly supplying a polycarbonate resin wet powder having a water content of from 0.5 to 10.0% by weight and an organic solvent content of from 0.01 to 5.0% by weight, said wet powder, when dried, having a weight average particle diameter of from 5 to 60 mesh, to a vented extruder and extruding the wet powder while venting to obtain pellets containing not more than 20 ppm of a residual halogenated hydrocarbon. The molding material has a greatly decreased solvent content while being freed from a particle content increase.

Process for producing polycarbonate resin molding material having low

A process for producing an oxymethylene copolymer by copolymerizing trioxane with at least one cyclic comonomer selected from the group consisting of cyclic ethers and cyclic formals, said process comprising

Process for producing oxymethylene copolyer

An acetal resin composition comprising an acetal resin and a low molecular weight polycarbonate compound having an intrinsic viscosity of 0.2 dl/g or less in methylene chloride at 25.degree. C. and, optionally, an organic or inorganic filler is disclosed. Said composition has improved surface gloss and weather resistance.

Acetal resin composition

In a process for producing a stabilized oxymethylene copolymer by heat-melting, at a temperature ranging between the melting point of the copolymer and a temperature 100.degree. C. higher than the melting point in a degassing apparatus in the presence of a heat stabilizer, a crude oxymethylene copolymer of trioxane with a cyclic acetal or cyclic ether, to decompose and eliminate the instable portions of the copolymer, the improvement which comprises using as the degassing apparatus in heat stabilizing the crude oxymethylene copolymer a combination of (A) an extruder and (B) a surface renewing-type mixer, and carrying out the operation by first feeding a crude oxymethylene copolymer to said extruder (A) to heat-melt and decompose 30-90% by weight of the instable portions of the crude copolymer, removing the decomposed gas via a vent provided in said extruder, and thereafter introducing the molten resin continuously to said surface renewing-type mixer (B) where substantially all of the remaining instable portions of the oxymethylene copolymer are heat-decomposed until the content of the instable portions falls below about 2 wt. %, thereby heat stabilizing the copolymer; said extruder (A) having a single or a plurality of shafts, said surface renewing-type mixer functioning to mix and knead the resin thereby constantly renewing the surface of the resin to volatize the volatiles contained therein.

Process for heat stabilizing oxymethylene copolymers

A process for producing a polyacetal homopolymer or copolymer which comprises continuously feeding a liquid starting mixture containing molten trioxane and a catalyst and optionally a comonomer through a feed opening of a reactor, said reactor being a continuously stirring-type mixer having two stirring shafts having a plurality of plate-like paddles fixed thereto the cross-section of each of said paddles taken perpendicularly of the axial direction of the stirring shaft having a shape of a convex lens, an ellipse or a quasipolygon inscribing a phantom circle at each vertex, one of said paddles facing another paddle fixed to the other stirring shaft and said one paddle being positioned such that it rotates while the edges thereof keep a slight clearance from the inner surface of the barrel and the other paddle; polymerizing the starting mixture while moving it toward the discharge opening by the rotation of the paddles, the improvement wherein the profiles of the paddles are changed, or the arrangement of the paddles is changed continuously or stepwise, so that the transportability of the reaction mixture becomes progressively smaller from the feed opening toward the discharge opening of the reactor.

Process for continuously polymerizing trioxane

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Osaka, Japan

Toshikazu Umemura