摘要:
According to this invention, the prior art problem that relatively many steps and a long time are required for obtaining a high quality polycarbonate of a high molecular weight by a solid phase polymerization method has been solved by subjecting a polycarbonate oligomer to swollen solid phase polymerization under an atmosphere containing a swelling solvent gas or subjecting a polycarbonate oligomer to poor solvent solid phase polymerization under a stream of a poor solvent gas.
摘要:
Provided is a method for producing a granular polycarbonate prepolymer for solid-phase polymerization, comprising dissolving a polycarbonate prepolymer in a solvent under heat, then crystallizing it by cooling, and shaping it. The grains of the granular prepolymer hardly fuse together in polymerization, and the granular prepolymer is suitable for high-speed solid-phase polymerization to give polycarbonate.
摘要:
There are disclosed a process for producing a polycarbonate through transesterification which comprises using, as a polymerization catalyst, (1) a combination of a nitrogen-containing organic basic compound and a quaternary phosphonium salt, (2) a tetraarylphosphonium salt having a specific chemical structure, or (3) a quaternary phosphonium salt having a specific chemical structure and containing a branched alkyl group; and a process for producing a polycarbonate which comprises the steps of preparing a polycarbonate prepoplymer by preliminary polymerization and thereafter polymerizing the resultant prepolymer in a state of a solid phase by the use of a quaternary phosphonium salt as a catalyst.By using any of these processes it is made possible to produce, in extremely high efficiency, a high-quality polycarbonate being excellent in appearance, heat resistance, hydrolysis resistance and the like.
摘要:
Granules collected from a solution of a polycarbonate, an integrated structure of independent fine particles constituting the granules being formed at least on the surfaces of the granules; and a process for preparing the granules of the polycarbonate which comprises the steps of adding a poor solvent to the polycarbonate solution, and then agitation-granulating fine particles of the polycarbonate into the granules, while stirring involving a shear force-imparting function is carried out under heating. According to the present invention, the polycarbonate or the like can be collected from its organic solvent solution as the granules having good drying properties.
摘要:
Disclosed herein is a polycarbonate copolymer comprising repeating units respectively made of a bisphenol A and a tetrahalogenobisphenol A and having a trihalogenophenoxy group as an end group at the terminal, particularly both terminals thereof and a method for efficiently producing said polycarbonate copolymer. This polycarbonate copolymer is superior in impact resistance, flame retardance, molding thermostability and the like, is good in hydrolytic resistance, is much less liable to cause a mold rust and has high quality. Therefore, this polycarbonate copolymer will be extensively used in various industrial materials, for example as the flame retardant parts for household electric appliances, office automation apparatuses and the like.
摘要:
Provided is a method for washing an impurities-containing polycarbonate/organic solvent solution with an aqueous washing solution, which comprises monitoring the viscosity of the mixture dispersion of the polycarbonate/organic solvent solution and the aqueous washing solution, and controlling the blend ratio of the aqueous washing solution in the system on the basis of the relation between the phase condition and the viscosity of the mixture dispersion. In the method of washing a polycarbonate/organic solvent solution with an aqueous washing solution, the amount of the washing solution to be used is reduced, and the mixture dispersion of the two solutions is stabilized at a high level of washing efficiency. The washing method is economical in practical use.
摘要:
A phase difference compensation film formed of a polycarbonate, which can be used in a liquid crystal display and which shows a decreased change in retardation caused by a temperature change at a stretch forming time due to the use of a polycarbonate having a branched structure and having a viscosity-average molecular weight of 40,000 or less as the above polycarbonate.
摘要:
Provided a process for producing a polycarbonate which comprises reacting an aqueous alkali solution of a dihydric phenol with phosgene in the presence of an organic solvent to produce a polycarbonate oligomer and subsequently polycondensing the oligomer, wherein an emulsion solution of a polycarbonate oligomer-containing organic solvent obtained in the polycarbonate oligomer production step is introduced into a coalescer to separate the emulsion solution into a polycarbonate oligomer-containing organic solvent phase and an aqueous phase, and the polycarbonate oligomer-containing organic solvent phase is subjected to polycondensation. Thus the emulsion solution of a polycarbonate oligomer-containing organic solvent obtained in the polycarbonate oligomer production step is efficiently separated to reduce the content of impurity-containing water in the oligomer for producing a polycarbonate having excellent quality and to a obtain wastewater having a low content of organic materials.
摘要:
A process for the production of a polycarbonate powder comprising introducing an organic solvent solution of polycarbonate and steam into a mixing nozzle and obtaining the polycarbonate powder from a mixture ejected from the mixing nozzle, wherein the organic solvent solution contains 3 to 45% by weight of the polycarbonate, and the ratio of the weight of steam/the weight of an organic solvent in the organic solvent solution is 1/10 to 1/5.
摘要:
A process for producing polycarbonates which comprises transesterifying by reacting (A) at least one compound selected from the group consisting of aromatic dihydroxy compounds, aliphatic dihydroxy compounds, bisesters of aromatic dihydroxy compounds, bisesters of aliphatic dihydroxy compounds, carbonates of aromatic dihydroxy compounds and carbonates of aliphatic dihydroxy compounds, with (B) at least one compound selected from the group of diaryl carbonates, dialkyl carbonates, and alkylaryl carbonates, at a transesterification temperature of 100.degree. C. to 330.degree. C. in the presence of an inert solvent in an amount of 1 to 60% by weight based on the total of the theoretical amount of polycarbonate produced from the said compounds (A) and (B) and the amount of the inert solvent. According to the present invention, a polycarbonate which is excellent in color tone (transparency), heat resistance, and water resistance can be efficiently and simply produced at a low cost.