Abstract: A flame-retardant resin composition comprising (A)(1) a resin component containing an aromatic polycarbonate resin and a styrene-containing resin or (2) a resin component containing a polyphenylene ether resin and a polystyrene, and (B) a flame retardant that is a phosphoric ester of the following formula (I), wherein each of R1, R2, R3 and R4 is independently an aryl group having 6 to 12 carbon atoms, each of R5 and R6 is independently methyl or a hydrogen atom, each of R7 and R8 is methyl, m1 and m2 are 0 or integers of 1 or 2, each of a, b, c and d is independently 0 or 1, and n is 0 or an integer of 1 or 5.

Abstract: A polycarbonate resin molding material containing (A) 100 parts by weight of a polycarbonate resin and 0.001 to 1.0 part by weight of a mold release agent (B) which is composed of a fatty acid ester and a phosphorus-containing heat stabilizer and contains 0.0001 to 50 parts by weight, per 100 parts by weight of the fatty acid ester (b1), of the phosphorus-containing heat stabilizer (b2). The present invention provides a polycarbonate resin molding material excellent in mold releasability and heat resistance during molding, and a molded article therefrom. According to the present invention, particularly, there is provided a polycarbonate resin molding material excellent in mold releasability and thermal stability during molding and suitable for producing a optical disk by incorporating a small amount of a mold release agent and a heat stabilizer.

Abstract: A disc-shaped recording medium having transcription characteristics for fine signals simultaneously with resonance characteristics and stiffness which are characteristics contrary to the transcription characteristics. At least a recording layer and a light transmitting layer are sequentially formed on a substrate and light is illuminated from a light transmitting layer side to record and/or reproduce information signals. The substrate includes a core layer formed of a resin composition comprised of a mixture of two or more resin sorts. The resin composition has tan?, as an index indicating the internal loss, equal to not less than 0.015 as a system in its entirety. The resin composition constituting the core layer is a compounded resin of the incompatible system and is of an islands-sea structure.

Abstract: An optical disk substrate and a light guide plate which are formed from a resin composition comprising 0.1 to 20 parts by weight of compound represented by the following formula (I): based on 100 parts by weight of polycarbonate resin. There can be provided an optical disk substrate formed from the resin composition of the present invention, particularly an optical disk substrate which allows the shape of a stamper to be transferred thereon with high precision and hardly undergoes warpage caused by environmental changes as a high density recording medium, and a light guide plate which has little uneven brightness and hardly undergoes warpage.

Abstract: An optical recording medium which comprises a 0.3 to 2.0 mm-thick substrate made from a thermoplastic resin and having embossed pits or guide grooves, a reflection layer formed on the substrate and a 3 to 200 ?m-thick transparent protective layer formed on the reflection layer and which reproduces recorded information based on a change in the intensity of reflected light by applying a light beam from the transparent protective layer side, wherein the substrate is formed from a polycarbonate resin having a specific chemical structure and a thermoplastic resin having specific physical properties. According to the present invention, there is provided an optical recording medium for surface recording and reproduction having a simple structure. Particularly, there is provided an optical recording medium having high recording density.

Abstract: An optical polycarbonate resin molding material comprising pellets formed from a polycarbonate resin, wherein the pellets satisfy the following properties (1) and (2): (1) an average of surface areas (hereinafter referred to as “cross sectional areas”) in cutting cross sections of the pellets is 3.0 to 6.5 mm2, and a standard deviation thereof is not larger than 0.65 mm2, and (2) an average of ratios of long diameters to short diameters (hereinafter referred to as “long diameter/short diameter”) in the cutting cross sections of the pellets is 1.3 to 1.7, and a standard deviation thereof is 0.08 to 0.15, and an optical disc substrate formed from the material. According to the present invention, when the aromatic polycarbonate resin pellets which satisfy the properties (1) and (2) are used for molding, an optical disc substrate which hardly undergoes occurrence of silver streaks can be obtained, and operations at the time of molding can be facilitated.

Abstract: A surface-protected plastic composite material comprising a transparent plastic, a coating layer (I) as a first layer stacked on the transparent plastic and a thermally cured coating layer (II) as a second layer stacked on the first layer, the coating layer (I) being formed of a resin composition containing at least 50% by weight, based on the resin content thereof, of an acrylic resin which is an acrylic resin containing at least 50 mol % of recurring unit based on an alkyl methacrylate, the thermally cured coating layer (II) being made of an organosiloxane resin formed from the following components a, b and c, (A) colloidal silica (component a), (B) a hydrolysis condensate (component b) of a trialkoxysilane, (C) a hydrolysis condensate (component c) of a tetraalkoxysilane, the organosiloxane resin containing 5 to 45% by weight of the component a, 50 to 80% by weight of the component b and 2 to 30% by weight of the component c, and use of the composite material as a window glass.

Abstract: A polycarbonate resin molding material for optical use which is pellets formed from a polycarbonate resin and having a bulk density of 0.72 kg/l or more and an optical disk substrate formed therefrom. According to the present invention, use of the above pellets makes it possible to obtain an optical disk substrate which rarely experiences the production of a silver streak, reduce the molding cycle and smoothen the molding operation.

Abstract: A highly elaborately designed sheet-shaped laminated structure wherein: (1) the sheet-shaped laminated structure is a sheet-shaped laminated structure composed of at least two layers formed of a thermoplastic resin, (2) at least one outer layer forming a surface of said laminated structure is a layer (B) formed of a transparent resin, (3) at least one layer composing said laminated structure contains a dye, a pigment or a light-diffusing agent and has a monotonous thickness change at least in one direction of a sheet surface of the laminated structure, and (4) said laminated structure shows a continuous change in color tone along the sheet surface when visually observed toward an outer surface of the layer (B) formed of a transparent resin, and use thereof.

Abstract: A transmission screen sheet which is given a large number of lens-like forms on the surface like ridges and has a thickness of 0.1 to 2.0 mm, wherein (i) the sheet is formed from a thermoplastic resin whose inclination (W) obtained from the relationship between melt viscosity (Y) and load (X) satisfies the following expression (1) when the melt viscosity is in the range of 102 to 103 Pa·s, and (i) the lens-like forms change in height substantially non-stepwise from the center portion or a portion near the center portion to the end portions of the sheet in a direction perpendicular to the ridges: 2×10−2≦W≦6×10−2  (1) wherein W is represented by the following equation: W=−(log Y/X) wherein X is a load (MPa) and Y is the melt viscosity (Pa·s) of the resin.

Abstract: A plastic lens, an optical molded article, a film or a sheet formed of a copolycarbonate resin comprising a structural unit (I) of the following general formula (I), and a structural unit (II) of the following formula (II), the structural unit (I) having a molar amount percentage of 15 to 85% on the basis of the total amount of the structural units (I) and (II). According to the present invention, there are provided a plastic lens, an optical molded article, and the like, which are excellent in physical properties such as transparency, thermal stability and impact resistance and are excellent in optical properties such as a balance between a refractive index and an Abbe's number and a photoelasticity constant.

Abstract: An aromatic polycarbonate resin composition comprising: 100 parts by weight of a resin component consisting of (1) 50 to 100 wt % of an aromatic polycarbonate resin (component A) and (2) 0 to 50 wt % of at least one thermoplastic resin (component B) selected from the group consisting of a thermoplastic polyester resin (component B-1) and a styrene unit component-containing resin having a rubber component content of less than 40 wt % (component B-2); and (3) 1 to 100 parts by weight of wollastonite particles having such particle shape characteristics that the particles have a number average fiber length measured by a method specified in this text of 10 &mgr;m or less and a number average fiber diameter measured by a method specified in this text of 4 &mgr;m or less and include particles having a fiber length of 5 to 25 &mgr;m in a number proportion of less than 50% of the total and moldings thereof.

Abstract: A flame retardant aromatic polycarbonate resin composition comprising: (1) 100 parts by weight of resin components comprising 50 to 100 wt % of an aromatic polycarbonate resin (component A-1), 0 to 50 wt % of a styrene-based resin (component A-2) and 0 to 50 wt % of an aromatic polyester resin (component A-3); and (2) 0.1 to 10 parts by weight of a silicone compound (component B) which contains an Si—H group and an aromatic group in the molecule based on 100 parts by weight of the total of the resin components, wherein the silicone compound is at least one selected from silicone compounds which have (1) an Si—H group content (Si—H content) of 0.1 to 1.

Abstract: An optical disk substrate formed of an aromatic polycarbonate resin obtained by a reaction between an aromatic dihydroxy compound and a carbonate diester and in which the content of undissolved substances that emit light by irradiation with light having a wavelength of 380 nm and have a size of 30 &mgr;m or greater is 100 pieces or less per kg of said resin, and a molding material therefor. According to the present invention, there can be provided an optical disk substrate in which the number of white spots that occur in the passage of a long period of time is very small and the reliability of writing and reading of information is highly stable.

Abstract: A method of producing an optically molded product of a thermoplastic resin by injection compression molding, the method comprising the steps of: (1) expanding the volume of a cavity more than the volume of the optically molded product of interest; (2) injecting a molten thermoplastic resin into the cavity through an injection cylinder; (3) compressing the expanded cavity to a prescribed thickness of the molded product; (4) returning an excess of the thermoplastic resin produced by the compression into the injection cylinder; and (5) keeping the molten thermoplastic resin in the cavity until the molded product of interest is formed. The present invention makes it possible to produce an optically molded product (for example, a spectacle lens) free from a weld line and excellent in surface accuracy using a metal mold having a simple structure industrially advantageously.

Abstract: Coloring master pellets for an optical molded article which are formed from a coloring composition, comprising a transparent thermoplastic resin (component A) containing a colorant (component B), wherein the proportion of pellets having colorant concentrations which satisfy a range of 0.5X to 1.5X when the concentrations of the colorants in the pellets are indicated in terms of absorbance and the average concentration is expressed as X is at least 90%. The coloring master pellets of the present invention have extremely small variations in the concentrations of colorants contained in the pellets. These master pellets are suitably used for obtaining an optical molded article such as an optical disk which has extremely few occurrences of color non-uniformity and color streaks and excellent electric properties.

Abstract: According to the present invention, there are provided a polycarbonate resin composition which comprises (A) 40 to 92 wt % of an aromatic polycarbonate resin (component “a”), (B) 5 to 40 wt % of a styrene-based resin (component “b”), (C) 3 to 20 wt % of a phosphate-based flame retardant (component “c”), and (D) 0.1 to 30 parts by weight of a silicate filler (component “d”) based on 100 parts by weight of the total of the components “a”, “b” and “c”, and which has a chlorine compound content in terms of chlorine atoms of 100 ppm or less as well as a molded product thereof. The resin composition of the present invention can provide a molded product having excellent resistance to wet heat and flame retardancy.

Abstract: A method of producing an optically molded product of a thermoplastic resin by injection compression molding, the method comprising the steps of: (1) expanding the volume of a cavity more than the volume of the optically molded product of interest; (2) injecting a molten thermoplastic resin into the cavity through an injection cylinder; (3) compressing the expanded cavity to a prescribed thickness of the molded product; (4) returning an excess of the thermoplastic resin produced by the compression into the injection cylinder; and (5) keeping the molten thermoplastic resin in the cavity until the molded product of interest is formed. The present invention makes it possible to produce an optically molded product (for example, a spectacle lens) free from a weld line and excellent in surface accuracy using a metal mold having a simple structure industrially advantageously.

Abstract: The tank type container of the present invention comprises a long, horizontally placed, drum-shaped tank 3 and a parallelopiped container frame 5 surrounding the tank 3. The tank 3 is provided with a charging tube 20 at the top of the longitudinal front end, a discharging tube 21 at the bottom of the longitudinal back end, and, at the outside, an air-supplying apparatus for supplying compressed air into the tank to discharge polycarbonate resin pellets. The tank 3, the charging tube 20, the discharging tube 21 and the air-supplying apparatus are accommodated in a space surrounded by the container frame 5. The container frame 5 is provided with metal fitting members 6 for locking engagable with a locking mechanism possessed by the bed of a trailer. Therefore, the present tank type container is usable as a large-capacity container for land transportation and sea transportation, allowing for improved efficiency in transportation of polycarbonate resin pellets.

Abstract: A vibration-damping thermoplastic resin composition comprising (a) 50 to 90 wt % of an amorphous thermoplastic resin (component A) having a loss tangent (tan &dgr;) value of 0.01 to 0.04 and a deflection temperature under load of not lower than 120° C. and (b) 50 to 10 wt % of a methyl methacrylate resin (component B), wherein an article molded from the resin composition has the following physical properties (1) to (4), i.e., (1) a loss factor of 0.04 to 0.08, (2) a water absorption of not higher than 0.30 wt %, (3) a specific gravity of 1.05 to 1.3, and (4) a deflection temperature under load of 110 to 170° C.; and an article molded therefrom. According to the present invention, a thermoplastic resin composition and an article molded therefrom which are excellent in vibration dampability as well as dimensional accuracy, rigidity and heat resistance and are light in weight, is provided.