Abstract: The present invention provides a method, which makes it possible to manufacture aromatic carbonates from dialkyl carbonates and aromatic hydroxy compounds inexpensively and with good efficiency. The method uses a titanium catalyst in a particular amount relative to aromatic polyhydric hydroxy compound impurities in a crude aromatic hydroxy compound solution.

Abstract: Improved performance in high temperature, high vacuum reactors is obtained by quenching alkaline catalyst present in the product a melt polycondensation reaction using a sulfonic acid ester quencher in a carrier. The carrier if formed from a first carrier component effective to solubilize the quencher and having a lower boiling point than the quencher, and a second carrier component soluble in the first carrier component and having a higher boiling point than the quencher. An exemplary carrier composition contains equal parts of diphenylcarbonate and toluene.

Abstract: Increasing the endcap level to a level greater than about 90% for Optical Quality (OQ) Melt Polycarbonate significantly reduces the as-molded static charge for injection molded parts for Optical Disc applications. The use of resins with higher endcap levels in combination with antistatic additives provides a highly robust formulation suitable for even the most demanding emerging formats as Digital Versatile Disc (DVD) and in all commercial Optical media molding machines. Thus, optical quality polycarbonates are prepared by performing a base-catalyzed polymerization of a diaryl carbonate and a dihydric phenol under conditions effective to produce a polycarbonate product having an endcap level of 90% or greater.

Abstract: A phenol and a ketone are reacted to form bisphenol, and the liquid bisphenol obtained or a mixed solution of said solution and a phenol is filtered through a calcined metal filter to obtain bisphenol which makes it possible to efficiently obtain bisphenol which either does not contain fine particulate impurities or contains such impurities only in minute amounts, and a method for manufacturing polycarbonate using bisphenol obtained by this method. The filtration grade of the calcined metal filter should be 1.0 .mu.m or less. After filtering, the calcined metal filter can be backwashed or chemically washed and then reused. The bisphenol should preferably be bisphenol A.

Abstract: A method for determining the effective level of catalyst for the preparation of a polycarbonate polymer by a transesterification reaction is disclosed. The method involves measurement of the leaving group by-product (usually phenol) produced in a test reaction between an aromatic dihydroxy compound and a carbonic acid diester, in the presence of a known amount of transesterification catalyst. The by-product production values can be compared with by-product reference values to calculate the effective level of catalyst. This data can be used to efficiently control catalytic activity in a production scale reaction for producing polycarbonate polymer.

Abstract: A copolycarbonate containing the component units shown in Formula ?I! below in the amount of 50-99 mole %: ##STR1## R1 and R2 are hydrogen atoms or monovalent hydrocarbon groups, and R3 is a bivalent hydrocarbon group.) The Rockwell hardness (M scale) of this polycarbonate should preferably be 45-90.

Abstract: A copolycarbonate and a copolycarbonate composition having oustanding hardness and a method for their manufacture.A copolycarbonate containing the component units shown in Formula ?I!below in the amount of 50-99 mole %: ##STR1## X is ##STR2## R1 and R2 are hydrogen atoms or monovalent hydrocarbon groups, and R3 is a bivalent hydrocarbon group.) The Rockwell hardness (M scale) of this polycarbonate should preferably be 45-90.

Abstract: A manufacturing method for polycarbonate comprising ?I! a process for manufacturing diaryl carbonate from an aromatic hydroxy compound and an aromatic hydroxy compound, ?II! a process for manufacturing polycarbonate by solution polymerization of the diaryl carbonate obtained in ?II! and an aromatic dihydroxy compound in the presence of a catalyst comprising a nitrogen-containing basic compound, and ?III! a process for separating and removing the nitrogen-containing compound from the aromatic hydroxy by-products in ?II! and returning the resultant aromatic hydroxy compounds to process ?I! effectively reuses aromatic hydroxy by-products (e.g., phenols) of polycarbonate manufacturing to manufacture diaryl carbonate, while suppressing the production of alkyl aromatic ethers and then uses this diaryl carbonate to manufacture polycarbonate with good productivity.

Abstract: A method for manufacturing polycarbonate in which an aromatic dihydroxy compound and a carbonic acid diester can be effectively subjected to melt polycondensation using a small amount of a catalyst, making it possible to manufacture polycarbonate having outstanding color matching, outstanding thermal stability, color-matching stability, etc., during molding, and outstanding water resistance is characterized in that when an aromatic dihydroxy compound and a carbonic acid diester are subjected to melt polycondensation in the presence of a catalyst, the catalyst is dissolved or dispersed as a catalyst solution, this catalyst solution is added to the melt polycondensation reaction system, and the aromatic dihydroxy compound and carbonic acid diester are subjected to melt polycondensation.

Abstract: A heat resistant copolycarbonate comprises a component of the formula: ##STR1## and a component selected from: ##STR2## R.sup.1 and R.sup.2 are same or different halogens or monovalent hydrocarbons, R.sup.3, R.sup.4, R.sup.6 and R.sup.7 are hydrogen atoms or monovalent hydrocarbons, R.sup.5 and R.sup.8 are bivalent hydrocarbons,R.sup.a, R.sup.b, R.sup.c R.sup.d, R.sup.e, R.sup.f, R.sup.g R.sup.j, R.sup.k and R.sup.l are the same or different halogen atoms, hydrocarbon groups having 1-10 carbon atoms, or hydrocarbon groups having 1-10 carbon atoms which are at least partially halogen-substituted and R.sup.b and R.sup.c may also be hydrogen,m, n, s, t, u, v and w are integers from 0-4, p and q are integers from 0-3 and r is an integer from 1-10.

Abstract: A copolycarbonate and a copolycarbonate composition having oustanding hardness and a method for their manufacture.A copolycarbonate containing the component units shown in Formula [I]below in the amount of 50-99 mole %: ##STR1## X is ##STR2## R1 and R2 are hydrogen atoms or monovalent hydrocarbon groups, and R3 is a bivalent hydrocarbon group.) The Rockwell hardness (M scale) of this polycarbonate should preferably be 45-90.

Abstract: The purpose of the present invention is to provide a method for manufacturing polycarbonate in which polycarbonate having outstanding color matching, outstanding thermal properties, particularly retention stability during molding, and outstanding water resistance can be effectively and easily manufactured.In the method for manufacturing polycarbonate of the present invention, an aromatic dihydroxy compound and a carbonic acid ester are subjected to melt condensation polymerization in the presence of a catalyst composed of(a) an aliphatic amine with 24-60 carbon atoms, and (b) an alkali metal compound and/or alkaline earth metal compound.The (a) aliphatic amine having 24-60 carbon atoms should preferably be an aliphatic tertiary amine and be used in the amount of 1.times.6.sup.-6 -1.times.10.sup.-1 moles for each mole of the aromatic dihydroxy compound, and the (b) alkali metal compound and/or alkaline earth metal compound should be used in an extremely minute specified amount.

Abstract: The present invention provides copolymerized copolyester-carbonates having improved flow and formability, in addition to excellent mechanical properties, heat resistance, transparency, and water resistance obtained by copolymerization of two or more aromatic dihydroxy compounds and a compound capable of reacting with those aromatic dihydroxy compounds to form carbonate linkages, characterized in that, of all the constituent repeating units derived from aromatic dihydroxy compounds, 2-40 mole % are derived from resorcin and/or substituted resorcins.

Abstract: According to the present invention, there is provided an improvement which comprises adding an acid compound and if necessary an epoxy compound to a reaction product resulting from melt polycondensation reaction of an aromatic dihydroxy compound with a carbonic acid diester in the presence of an alkaline compound catalyst.

Abstract: To provide novel polycarbonates and a manufacturing method for them.Copolycarbonates obtained by copolymerizing at least two aromatic dihydroxy compounds and a compound capable of introducing carbonate links. Preferably, they contain, as the components derived from the aromatic dihydroxy compounds, constituent units described by formulas [I] and [II] in proportions of from 8.times.10.sup.-5 to 3.times.10.sup.-2 moles of [II] per mole of [I], and preferably they have a limiting viscosity number [.eta.] of from 0.2 to 1.2 dL/g, as measured in methylene chloride at 20.degree. C. ##STR1## (X, Y,: Alkylene, cycloalkylene, --O--, --S--, --SO--, OR --SO.sub.2 --. R.sup.1, R.sup.2, R.sup.7, R.sup.8 : hydrocarbon group with from 1 to 10 carbon atoms which may be substituted with halogen; or a halogen atom. m, n, p: Integers ranging from 0 to 4, indicating the number of substituents. q: Integer ranging from 0 to 3, indicating the number of substituents. R.sup.

Abstract: A copolymeric polycarbonate containing repeating constituent units having formula [I] below and repeating constituent units having formula [II] below in a molar ratio of from 98:2 to 40:60. ##STR1## The above-described copolymeric polycarbonates have excellent resistance to chemicals, heat resistance and flame retardancy without compromising the impact resistance and good hues intrinsic to polycarbonates.

Abstract: Aromatic polycarbonates manufactured by polycondensation of a dihydric compound and a carbonic acid diester using at least two reactors in series have improved color and low impurities content when filtered before the final reactor and again before the final reactor outlet.

Abstract: The method of the present invention is a hot-melt polycondensation for an aromatic dihydroxy compound and a dicarbonate in the presence of a basic catalyst, adding sulfur-containing acid compound with a pKa value less than 3 or the derivative thereof, and 5-1,000 ppm of water, and additives as needed for the polycarbonate while the reaction product polycarbonate is still in a molten state, and kneading the material.

Abstract: The object of the present invention is to provide a method of producing copolymerized polycarbonates having improved flow and formability, in addition to excellent mechanical properties, heat resistance, transparency, and color tone.A method of producing copolymerized polycarbonates by melt polycondensation of two or more aromatic dihydroxy compounds with a carbonate diester, characterized in that(i) resorcin and/or substituted resorcins are used as 2-90 mole % of the aromatic dihydroxy compounds, where the sum of all the aromatic dihydroxy compounds is taken as 100 mole %, and(ii) an alkali metal compound and/or an alkaline-earth metal compound (a) is used as the catalyst.

Abstract: Object: The present invention was conceived in light of the above-described prior art. The object of this invention is to provide a method for preparing optical-grade polycarbonate compositions, which method is able to prepare with good productivity optical-grade polycarbonate compositions that have not only excellent clarity and water resistance, but also excellent retention stability such as heat stability and hue stability when molten and a low content of inclusions and impurities, and that undergo little heat deterioration.Constitution: The method for preparing optical-grade polycarbonate compositions according to this invention, which method comprises the melt-polycondensation of an aromatic dihydroxy compound and a diester carbonate in the presence of a catalyst, followed by the addition of additives B! while the polycarbonate A! obtained as the reaction product is in a molten state, and mixing.