Idemitsu Petrochemical Co., Ltd.

Idemitsu Kosan Company, Limited

Munehiro Chosa

Hiroshi Kawato

Tatsuya Tomioka

Masaya Okamoto

Yasuhiro Ishikawa

Takayoshi Tanaka

Yasunobu Yamazaki

Hiroshi Akamine

Haruo Yasui

A method for producing a transparent thermoplastic resin pellet comprising a step of kneading a transparent thermoplastic resin with a kneader under a condition under which a damage history calculated according to the following formula is 500 to 2,500:Damage history={Residence time ()}&#xd7;{Shear rate (&#x3b3;)}Residence time ()=()/Shear rate (&#x3b3;)=(&#x3c0;&#xd7;)/in the formulae, W represents a screw groove width (pitch) [cm]; H represents a screw groove depth [cm]; L represents a screw length [cm]; Q represents a resin supply amount [g/s]; D represents a screw diameter [cm]; and N represents a screw rotation number [rps].

Transparent thermoplastic resin pellet manufacturing method

The present invention provides an aromatic polycarbonate resin product for producing optical disc substrates of high reliability at high molding yield. The aromatic polycarbonate resin for optical disc substrates is produced by adding 0.015 to 0.05 parts by mass of a C&#x2013;Cfatty acid monoglyceride to 100 parts by mass of an aromatic polycarbonate resin, adding water having an electric conductivity, as measured at 25&#xb0; C., of 1 &#x3bc;S/cm or less to the resin, the water content of the resin being controlled to 0.05 to 0.3 mass %, melt-extruding the water-added resin, cooling, and cutting to form pellets, the resin having a viscosity average molecular weight (Mv) of 10,000 to 20,000.

Aromatic polycarbonate resins for optical disk substrates

The present invention relates to a polycarbonate resin that has a viscosity average molecular weight of from 10,000 to 17,000 and has characteristic features in an iron content, a free total phenol content, a content of a releasing agent, a fraction of hydroxyl end groups, aH-NMR spectrum or the like. The polycarbonate resin has less defects due to flash without increase of an addition amount of a releasing agent to an unnecessary level and therefore is suitable for a material of an optical disk substrate.

Polycarbonate resin for optical disk substrate and optical disk substrate

The present invention relates to a polycarbonate resin that has a viscosity average molecular weight of from 10,000 to 17,000 and has characteristic features in an iron content, a free total phenol content, a content of a releasing agent, a fraction of hydroxyl end groups, a H-NMR spectrum or the like. The polycarbonate resin has less defects due to flash without increase of an addition amount of a releasing agent to an unnecessary level and therefore is suitable for a material of an optical disk substrate.

A digital versatile disk (DVD) excellent in transferability on injection molding, and excellent in releasability from a mold and in strength is provided. The substrate of the digital versatile disk (DVD) comprises an aromatic polycarbonate resin composition containing a fatty acid monoglyceride having from 14 to 30 carbon atoms in an amount of from 0.015 to 0.05% by weight, wherein the aromatic polycarbonate resin contains an end group, 30% by mol or more of which is a p-cumylphenoxy group and/or a p-tert-octylphenoxy group, and has a viscosity average molecular weight (Mv) of from 10,000 to 17,000. The thickness of the substrate is generally 0.6 mm or less.

Substrate for digital versatile disk and process for producing the same

In forming a diamond film on a surface of substrate by means of plasma method, there is employed in a plasma reacting chamber a supporting member having a top surface for placing the substrate so disposed as to be smaller than a bottom surface of the substrate and having engagement means for engaging with the substrate. When the substrate (particularly substrate for a cutting tool) placed on the top surface of the supporting member is brought into contact with plasma obtainable by exciting raw material gases, a diamond film is coated on the face, land and flank of the substrate for the cutting tool with a uniform film thickness.

Suscepter device for the preparation of a diamond film-coated body

A microwave plasma chemical vapor deposition apparatus allows the position of a plasma to be two-dimensionally adjusted in a reaction tube. A second plunger 9 (plunger assembly 8) is disposed on an H plane of a microwave waveguide 2a connected to a microwave oscillator 1 adjacent to an end 2b of the microwave waveguide 2a in facing relationship to a reaction region 7. The plunger 9 is actuated to move the plasma also in a direction perpendicular to the direction of travel of a microwave in the microwave waveguide 2a for two-dimensionally adjusting the position of the plasma. Using the microwave plasma chemical vapor deposition apparatus, a diamond film having a uniform quality and a uniform thickness is formed as on a substrate.

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Tokyo, Japan

Munehiro Chosa