Abstract: Polycarbonates are prepared by inducing the melt polycondensation of an aromatic dihydroxy compound and a diester carbonate in the presence of alkali metal compounds and/or alkaline earth metal compound droxy and adding to the polycarbonate which is the reaction product thereof: a sulfonic acid compound having the formula ##STR1## in an amount of 0.05-10 ppm, based on the polycarbonate, an epoxy compound in an amount of 1-2000 ppm, based on the polycarbonate and a phosphorus compound in an amount of 10-1000 ppm, based on the polycarbonate.

Abstract: Thermosetting resin compositions with low shrinkage are provided, which when molded show low shrinkage rates, good dimensional stability (little cracking or warping), and excellent surface smoothness, mechanical strength, and dispersion stability.The thermosetting resin compositions with low shrinkage in accordance with the present invention comprise:(a) 100 wt. parts by weight thermosetting resins, and(b) 3 to 200 parts by weight polycarbonates containing constituent units derived from aromatic dihydroxy compounds.The polycarbonates preferably have at least 5% (of all the terminal groups) terminal hydroxyl groups derived from aromatic dihydroxy compounds. The polycarbonates also preferably have an intrinsic viscosity of 0.05 to 0.65 dL/g.

Abstract: The present invention relates to a method for preparing copolymeric polycarbonates which comprises melt polycondensing a mixture of an aromatic dihydroxy compound containing an amount of 2-90 mol % of hydroquinone or substituted hydroquinones and a diester carbonate in the presence of a catalyst containing an alkali metal compound or an alkaline earth metal compound in an amount of 1.times.10.sup.-8 to 5.times.10.sup.-6 mole per mole of the total amount of the aromatic dihydroxy compound, then adding an acidic compound to the melt polycondensation product.

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: The method of this invention prepares copolymeric polycarbonates which have excellent mechanical properties, heat resistance and transparency, and which also have improved chemical resistance, hue, and residence stability by inducing the melt polycondensation of an aromatic dihydroxy compound containing an amount of 2-90 mol % of hydroquinone and/or substituted hydroquinones with a diester carbonate in the presence of a catalyst containing alkali metal compounds and/or alkaline earth metal compounds in an amount of 1.times.10.sup.-8 to 5.times.10.sup.-6 mole per mole of the total amount of the aromatic dihydroxy compound.

Abstract: The present invention provides copolymerized polycarbonates 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: 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: [Purpose] The object of the present invention is to provide a method of product copolymerized polycarbonates having improved flow and formability, in addition to excellent mechanical properties, heat resistance, transparency, and color tone.[Constitution] 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: Polycarbonates are prepared by inducing the melt polycondensation of an aromatic dihydroxy compound and a diester carbonate in the presence of alkali metal compounds and/or alkaline earth metal compound droxy and adding to the polycarbonate which is the reaction product thereof: a sulfonic acid compound having the formula ##STR1## in an amount to 0.05-10 ppm, based on the polycarbonate, and also an epoxy compound in an amount of 1-2000 ppm, based on the polycarbonate.

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.

Abstract: The present invention relates to a method of preparing a copolymeric polycarbonate which comprises melt-polycondensing a mixture of an aromatic dihydroxy compound comprising hydroquinone or substituted hydroquinones and a diester carbonate in the presence of a catalyst containing alkali metal compounds and/or alkaline earth metal compounds.

Abstract: The present invention relates to a polycarbonate production method. More specifically, it relates to a polycarbonate production method that is capable of preparing polycarbonates which have excellent residence stability such as hue stability and heat stability at the time of molding, and which have particularly outstanding water resistance.

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: The present invention relates to an optical polycarbonate composition comprising a polycarbonate resin and a boron compound wherein the resulting composition undergoes little coloration during molding, and is capable of forming molded products having excellent transparency.

Abstract: Disclosed herein are processes for the production of polycarbonates by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester or a diphenyl carbonate compound wherein said polycondensation is carried out in the presence of from 0.05 to 15 mol %, based on 1 mole of the aromatic dihydroxy compound, of a phenol having from 10 to 40 carbon atoms, a carbonic acid diester having from 17 to 50 carbon atoms or a carbonic acid diester having from 13 to 16 carbon atoms, using a catalyst comprising (a) a nitrogen containing basic compound, (b) from 10.sup.-8 to 10.sup.-3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound, and (c) boric acid or boric ester. Also disclosed is a polycarbonate in which from 5 to 30% of its terminal groups are hydroxy groups and it has a sodium content of not more than 1 ppm and a chlorine content of not more than 20 ppm.

Abstract: A polycarbonate composition which contains 60-95 parts by weight of a polycarbonate with a terminal hydroxyl group concentration of 5-95 mol % and 40-5 parts by weight of polyester.

Abstract: Disclosed herein are processes for the production of polycarbonates by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester or a diphenyl carbonate compound wherein said polycondensation is carried out in the presence of from 0.05 to 15 mol %, based on 1 mole of the aromatic dihydroxy compound, of a phenol having from 10 to 40 carbon atoms, a carbonic acid diester having from 17 to 50 carbon atoms, or a carbonic acid diester having from 13 to 16 carbon atoms, using a catalyst comprising (a) a nitrogen containing basic compound, (b) from 10.sup.-8 to 10.sup.-3 mole, based on 1 mole of the aromatic dihydroxy compound, of an alkali metal or alkaline earth metal compound, and (c) boric acid or boric ester. Also disclosed is a polycarbonate in which from 5 to 30% of its terminal groups are hydroxy groups and it has a sodium content of not more than 1 ppm and a chlorine content of not more than 20 ppm.

Abstract: A process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using an aromatic dihydroxy compound and a carbonic acid diester, wherein the combined content of hydrolyzable chlorine in those monomers falls within the particular range. Another process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using a catalyst comprising (a) a nitrogen containing basic compound and (b) aromatic dihydroxy compound of an alkali metal or alkaline earth metal compound, or (a) and (b) and (c) boric acid or boric ester.

Abstract: A process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using an aromatic dihydroxy compound and a carbonic acid diester, wherein the combined content of hydrolyzable chlorine in those monomers falls within the particular range. Another process for preparing polycarbonates according to the invention by melt polycondensation of aromatic dihydroxy compounds and carbonic acid diesters, is characterized by using a catalyst comprising (a) a nitrogen containing basic compound and (b) aromatic dihydroxy compound of an alkali metal or alkaline earth metal compound, or (a) and (b) and (c) boric acid or boric ester.

Abstract: The novel fluorine-containing mono- or poly-alkylene glycol of this invention is a mono- or poly-alkylene glycol of the formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.