摘要:
A preparation process of polyhydroxycarboxylic acid comprising conducting dehydration polycondensation of hydroxycarboxylic acid or an oligomer of the same in a reaction mixture containing said hydroxycarboxylic acid or the oligomer of the same and an organic solvent substantially in the absence of water to give polyhydroxycarboxylic acid having an weight average molecular weight of 50,000 or more, successively mixing the reaction mixture containing said polyhydroxycarboxylic acid with at least one binder selected from the group consisting of (1) polyisocyanate compound, (2) polybasic acid anhydride, (3) cyclic imino ester, (4) cyclic imino ether, (5) aromatic hydroxycarboxylic acid, (6) polyamino compound, (7) polyhydric alcohol, (8) epoxy compound, (9) polyfunctional aziridine compound, (10) lactam, (11) lactone, and (12) diethylene glycol bischloroforate, and reacting to obtain polyhydroxycarboxylic acid having a weight average molecular weight of 100,000 or more the polyhydroxycarboxylic acid which is obtained by the process has a weight average molecular weight of 100,000 or more, has satisfactory mechanical strength in the form of molded articles and is useful as a degradable polymer for substituting medical materials and general purpose resins.
摘要:
A preparation process of polyhydroxycarboxylic acid having an inherent viscosity of 0.3 dl/g or more by dehydrating polycondensation of lactic acid containing hydroxycarboxylic acid in an organic solvent in the presence or absence of a catalyst, comprising using a hydroxycarboxylic acid raw material which comprises one or more impurities selected from the group consisting of methanol, ethanol, acetic acid, pyruvic acid, fumaric acid, methyl lactate, ethyl lactate and butyl lactate in a total amount of 0.3% by mole or less for the amount of said hydroxycarboxylic acid raw material.
摘要:
A process for preparing polyhydroxycarboxylic acid by conducting dehydration polycondensation of hydroxycarboxylic acids in the presence or absence of a catalyst and in the presence or absence of an organic solvent, comprising using a vertical high viscosity reactor during all or a portion of the dehydration polycondensation steps and conducting hot polycondensation while separating and removing low boiling components. The process can provide high molecular weight polyhydroxycarboxylic acid with ease and cheaply in industry.
摘要:
A purification process for polyhydroxycarboxylic acids which comprises dissolving polyhydroxycarboxylic acid in an water-immiscible phenol or an organic solvent containing said water-immiscible phenol, successively bringing the resulting solution into contact with water which contains an acidic material, separating the organic layer from an aqueous layer, and isolating polyhydroxycarboxylic acid from the organic layer. The process can efficiently remove a catalyst contained in the polyhydroxycarboxylic acid prepared in the presence of the catalyst, does not require polyhydroxycarboxylic acid to be in the form of a solid, and can treat polyhydroxycarboxylic acid in a higher concentration as compared with using chlorinated hydrocarbon as a solvent.
摘要:
A preparation process of polyhydroxycarboxylic acid having an inherent viscosity of 0.3 dl/g or more by dehydrating polycondensation of lactic acid containing hydroxycarboxylic acid in an organic solvent in the presence or absence of a catalyst, comprising using a hydroxycarboxylic acid raw material which comprises one or more impurities selected from the group consisting of methanol, ethanol, acetic acid, pyruvic acid, fumaric acid, methyl lactate, ethyl lactate and butyl lactate in a total amount of 0.3% by mole or less for the amount of said hydroxycarboxylic acid raw material.
摘要:
A polylactic acid-based resin composition composed of a high molecular ingredient (A) comprising polylactic acid (a1) and an aliphatic polyester (B), and a film, particularly an inflation film, prepared from the resin composition. The film comprising the polylactic acid-based resin composition of the invention is biodegradable and excellent in flexibility and resistance to blocking of film and bleeding-out of plasticizer, has no anisotropy in tear strength, and can be suitably used for an agricultural multi-film and garbage bag. When the film of the invention is used for food wrapping, the film prevents fungus growth and contamination of color or odor, and thus can be suitably used.
摘要:
A moldable polyimide resin composition which has melt-flowability and excellent processability in addition to essential heat-resistant of polyimide and comprises an aromatic bisimide compound and polyimide resin. A further aspect relates to a carbon fiber reinforced polyimide resin composition which has excellent mechanical strengths and comprises a carbon fiber coated with aromatic bisimide compound on the surface and the polyimide resin. A still further aspect relates to a novel bisimide compound which is very useful as the aromatic bisimide compound in the composition.
摘要:
A moldable polyimide resin composition which has melt-flowability and excellent processability in addition to essential heat-resistant of polyimide and comprises an aromatic bisimide compound and polyimide resin. A further aspect relates to a carbon fiber reinforced polyimide resin composition which has excellent mechanical strengths and comprises a carbon fiber coated with aromatic bisimide compound on the surface and the polyimide resin. A still further aspect relates to a novel bisimide compound which is very useful as the aromatic bisimide compound in the composition.
摘要:
The present invention solves the motion blur of moving images in hold-type display devices. An amount of a moving image is detected from image data included in frames and an image at the intermediate state between an image of the current frame and an image of the next frame is made as an interpolation image. Thus, the movement of the image can follow the movement of human eyes and the luminance of the interpolation image is changed, and thus, display can be made close to pseudo impulse type display. In this manner, hold-type display devices without motion blur and methods of driving the hold-type display devices can be provided.
摘要:
The invention provides an active matrix EL display device which can perform a clear multi-gray scale color display. In particular, the invention provides a large active matrix EL display device at low cost by a manufacturing method which can selectively form a pattern. Power supply lines in a pixel portion are arranged in matrix by the manufacturing method which can selectively form a pattern. Further, capacitance between wirings is reduced by providing a longer distance between adjacent wirings by the manufacturing method which can selectively form a pattern.