摘要:
A polycarbonate having excellent color and stability and a production process therefor. In the production of a polycarbonate by melt polycondensing a dihydroxy compound and a carbonic acid diester in the presence of an ester exchange catalyst, the each content of an aldehyde group in the dihydroxy compound and the carbonic acid diester is reduced to 3×10−6 equivalent/mol or less.
摘要:
An aromatic polycarbonate composition which contains 0.05 to 65 ppm of bonded phosphorus atoms to polycarbonate chains and free phosphorus compounds consisting of a tervalent phosphorus compound and a pentavalent phosphorus compound in a specific ratio. It is excellent in transparency, color stability and residence stability at the time of molding and is suitably used in disk substrates.
摘要:
A method for producing a high-quality thermoplastic branched polycarbonate which is used in blow-molding, extrusion or vacuum molding from a linear aromatic polycarbonate efficiently. The thermoplastic branched polycarbonate is produced by melt-mixing and reacting a substantially linear aromatic polycarbonate with an acid anhydride having at least two cyclic acid anhydride groups in a molecule in the presence of a basic catalyst.
摘要:
A method of producing a polycarbonate or the like which is excellent in hydrolysis and heat stability such as a reduction in molecular weight at the time of molding and color retention and moldability such as releasability and transferability, rarely experiences residence deterioration such as coloring, crosslinking and gel formation and has an extremely small content of foreign matter by employing a special structure for an opening in the side surface of a horizontal cylindrical vacuum resin treating apparatus, supplying a molten polycarbonate into a unidirectional rotary intermeshing double-screw extruder under specific conditions, adding a specific agent under specific conditions and cleaning the inner surface of a production apparatus by a specific method.
摘要:
Aromatic polycarbonate having a reduced discoloration and improved heat stability, hue, etc. is provided by keeping a pressure in a raw material melting vessel and the linear velocity of a gas in a transporting piping in a specific range, keeping the concentration of a nitrogen-containing basic compound in a specific range, recycling a byproduct containing specific amounts of impurities, suppressing the amounts of a nitrogen-containing basic compound, metallic elements and a silicic acid derivative in the carbonic acid diester at specific values or less, prescribing the material quality of the reaction facilities, and/or forming an oxide layer at the inner wall surfaces of the reaction facilities.
摘要:
A polycarbonate which is stable against thermal decomposition at a temperature range for melt molding without adding a heat resistant stabilizer and suitable for the melt molding of a thin product, production method and molded products thereof. The polycarbonate is comprising mainly a recurring unit represented by the following formula (1), and has a percentage of the total of integrated intensities of all signals detected at four ranges, &dgr;=2.14 to 2.17 ppm, &dgr;=3.46 to 3.49 ppm, &dgr;=3.62 to 3.69 ppm and &dgr;=5.42 to 5.46 ppm to the integrated intensity of a signal derived from a methyl group detected at a range of &dgr;=1.50 to 2.00 ppm of 0.01 to 2.0% in its 1H-NMR spectrum in heavy chloroform and a viscosity average molecular weight of 10,000 to 100,000.
摘要:
In a process for producing a polyarylate through the polycondensation of an aromatic dihydroxy compound and an aromatic ester bond forming precursor, a salicylic acid ester compound having a specific structure is used as a terminal modifying agent. In a process for producing a polyarylate through the polycondensation of an aromatic dihydroxy compound and an ester bond forming aromatic dicarboxylic acid derivative, a polyarylate of high-molecular weight having excellent color tone and hue stability is obtained.
摘要:
The present invention provides a salicylic acid ester derivative having an impurity content lower than a specific level and expressed by the following formula (1) (in the formula, R1 is methyl group or ethyl group, R2, which may be substituted optionally, is an alkyl group having a carbon number of from 1 to 30, alkoxy group having a carbon number of from 1 to 30, aryl group having a carbon number of from 6 to 30, aryloxy group having a carbon number of from 6 to 30, aralkyl group having a carbon number of from 6 to 30 or aralkyloxy group having a carbon number of from 6 to 30). The salicylic acid ester derivative is effective as a terminal blocking agent or a polymerization. promoting agent for a polycarbonate, and gives a polycarbonate having good color tone and suitable for optical material use.
摘要:
A process for the production of a terminal-blocked aromatic polycarbonate by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding a specific carbonate or carboxylic ester after a polycarbonate formed has an intrinsic viscosity of at least 0.3 dl/g, to form a terminal-blocked polycarbonate having an intrinsic viscosity which is greater than, or smaller than, the intrinsic viscosity of the polycarbonate formed before the addition by 0.1 dl/g at the most; and a process for the production of a polycarbonate having an increased intrinsic viscosity by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding a specific diaryl carbonate or dicarboxylic diaryl ester after a polycarbonate formed has an intrinsic viscosity of at least 0.3 dl/g, to form a polycarbonate having an intrinsic viscosity greater than the intrinsic viscosity of the polycarbonate formed before the addition by more than 0.1 dl/g.
摘要:
The relative intensity of fluorescent light of a melt-polycondensed aromatic polycarbonate produced by the transesterification process (melt polymerization process) of an aromatic dihydroxy compound and a carbonic acid diester in the presence of a catalyst comprising a basic nitrogen compound and/or a basic phosphorus compound in combination with an alkali metal compound is suppressed to 4.0×10−3 or below at a wavelength of 465 nm based on a standard substance in a fluorescent light spectrum obtained by the excitation wavelength of 320 nm. An aromatic polycarbonate having good color stability, especially good stability to the deterioration of the chip color during storage of the chip in air at room temperature can be produced by the present invention.