Abstract: A method of making polycarbonate comprises polymerizing, in a melt polymerization reaction, an aromatic dihydroxy compound and a diaryl carbonate in a presence of a polymerization catalyst and producing a by-product vapor stream comprising the dihydroxy compound, the diaryl carbonate and a diaryl carbonate by-product, adding a low vapor pressure compound to the by-product vapor stream to produce a modified by-product vapor stream, introducing the modified by-product vapor stream to a separation unit, removing the volatile diaryl carbonate by-product from the modified by-product vapor stream in the separation unit to form a treated by-product stream and returning the treated by-product stream to the polymerization reaction. Alternatively, the low vapor pressure compound can be added directly to the separation unit.

Abstract: A method of making polycarbonate comprises polymerizing, in a melt polymerization reaction, an aromatic dihydroxy compound and a diaryl carbonate in a presence of a polymerization catalyst and producing a by-product vapor stream comprising the dihydroxy compound, the diaryl carbonate and a diaryl carbonate by-product, adding a low vapor pressure compound to the by-product vapor stream to produce a modified by-product vapor stream, introducing the modified by-product vapor stream to a separation unit, removing the volatile diaryl carbonate by-product from the modified by-product vapor stream in the separation unit to form a treated by-product stream and returning the treated by-product stream to the polymerization reaction. Alternatively, the low vapor pressure compound can be added directly to the separation unit.

Abstract: The system (1) for the continuous vacuum coating of a continuously suppliable material in web form (2) provided with feed means; at least one inlet chamber (4), wherein the transition between the inlet atmospheric pressure and the vacuum pressure of a coating chamber (5) incorporating at least one vacuum deposition module (6) for depositing metallic and/or dielectric components on the material in web form is carried out; at least one outlet chamber (7); and collecting means (8) which collect the coated material in web form. The system further comprises drive and support means (9), on which the material in web form is fixed for its transport and by one of its faces, which material follows a preferably straight path at least through the coating chamber.

Abstract: A method of forming polycarbonate includes the steps of introducing a plurality of reaction components to a reactor operating under melt polymerization conditions and removing ester-substituted phenol from the reactor. The plurality of reaction components include a dihydroxy compound, an ester-substituted diaryl carbonate, and a melt transesterification catalyst. The reaction components are introduced in a plurality of reaction component streams. A first reaction component streams includes a melt transesterification catalyst dissolved or suspended in a liquid carrier containing an ester-substituted phenol. The composition of the first reaction component stream is selected such that ester-substituted phenol is not generated as a reaction product in the first reaction component stream.

Abstract: A method of making polycarbonate includes the steps of forming polycarbonate by a melt transesterification method using an activated diaryl carbonate, and compounding the polycarbonate with a phosphorus-containing compound that has an abstractable proton or hydrolyzable group. The phosphorus-containing compound is compounded with the polycarbonate in an amount sufficient to result in an improvement in the color properties of the polycarbonate as compared to pellets formed from the same polycarbonate without addition of the phosphorus-containing compound.

Abstract: A method of forming polycarbonate includes the steps of introducing a plurality of reaction components to a reactor operating under melt polymerization conditions and removing ester-substituted phenol from the reactor. The plurality of reaction components include a dihydroxy compound, an ester-substituted diaryl carbonate, and a melt transesterification catalyst. The reaction components are introduced in a plurality of reaction component streams. A first reaction component streams includes a melt transesterification catalyst dissolved or suspended in a liquid carrier containing an ester-substituted phenol. The composition of the first reaction component stream is selected such that ester-substituted phenol is not generated as a reaction product in the first reaction component stream.

Abstract: A method of producing a polycarbonate is provided. In an embodiment of the present invention the method includes the steps of: (i) introducing to a melt polymerization reactor system a reaction mixture having a first dihydroxy compound and an acid stabilizer, a carbonate source, and a polymerization catalyst system containing K2HPO4; and (ii) allowing the reaction mixture to polymerize thereby forming polycarbonate.

Abstract: A method of preparing polycarbonate includes a steps of providing a melt reaction mixture and allowing the melt reaction mixture to react to build molecular weight, thereby preparing the polycarbonate. The melt reaction mixture has a dihydroxy compound, an ester substituted diaryl carbonate mixture, and a melt transesterification catalyst where the ester substituted diaryl carbonate mixture may contain acid-substituted phenol. The method also includes the step of adjusting the molar ratio of acid-substituted phenol, if present, to melt transesterification catalyst (acid-substituted phenol/catalyst) in the melt reaction mixture to an amount of less than 10.

Abstract: A method of producing a polycarbonate is provided. In an embodiment of the present invention the method includes the steps of: (i) introducing to a melt polymerization reactor system a reaction mixture having a first dihydroxy compound and an acid stabilizer, a carbonate source, and a polymerization catalyst system containing K2HPO4; and (ii) allowing the reaction mixture to polymerize thereby forming polycarbonate.

Abstract: Catalyst component for the polymerization of alpha-olefins in solution, in suspension, in gas phase at low and high pressure and temperature or in mass at high pressures and high or low temperatures, characterized in that is defined by general formulas I or II wherein: R, equal to or different from each other, is hydrogen or a radical which contains from 1 to 20 carbon atoms; this group optionally contains heteroatoms of groups 14 to 16 of the periodic table of the elements and boron; at least one group R contains a group OSiR?3, Q is selected from a group comprising: boron or an element from groups 14 or 16 of the periodic table; m value can change from 1 to 4 and it preferably is 1 or 2; L, equal to or different from each other, is a cyclic organic group united to M through a ? bond, or it is an atom from groups 15 or 16 of the periodic table; L1 and L2, equal to or different from each other, have the same meaning of L; M is a metal from groups 3, 4, 10 of the periodic table, lanthanide or actinide.

Abstract: A method of making polycarbonates comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate phenol, wherein the separated phenol has a phosphorus concentration of less than or equal to about 3 part per million, based upon the total weight of the phenol separated.

Abstract: A method of making polycarbonate comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate the carbonic acid diester, wherein the separated carbonic acid diester has a phosphorous concentration of less than or equal to about 30 parts per million.

Abstract: A method of making polycarbonates comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate phenol, wherein the separated phenol has a phosphorus concentration of less than or equal to about 3 part per million, based upon the total weight of the phenol separated.

Abstract: A method of making polycarbonate comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate the carbonic acid diester, wherein the separated carbonic acid diester has a phosphorous concentration of less than or equal to about 30 parts per million.

Abstract: Catalyst component for the polymerization of alpha-olefins in solution, in suspension, in gas phase at low and high pressure and temperature or in mass at high pressures and high or low temperatures, characterised in that is defined by general formulas I or II 1

Abstract: Heterogeneous catalytic component obtainable by reacting a porous inorganic support with a metallocene compound characterized in that the metallocene compound is defined by the following general formulas:

Abstract: Acidic impurities in dihydroxyaromatic compounds such as bisphenol A, as illustrated by sulfonic acids and mercaptocarboxylic acids, can have an adverse effect on the molecular weight of a polycarbonate prepared therefrom by transesterification. The same is true of acidic impurities in diaryl carbonates such as diphenyl carbonate, as illustrated by salicylic acid and ferric chloride. The reagents are analyzed for these impurities. Based on the analysis, the reagents are discarded or recycled, or a compensatory amount of alkali metal hydroxide is employed as a catalyst in the reaction.

Abstract: Catalytic systems particularly suitable for the polymerization of &agr;-olefins containing from two to 20 carbon atoms, as well as for the copolymerization of ethylene with &agr;-olefins containing from three to 20 carbon atoms, dienes, and cycloalkenes in processes wherein the catalyst is suspended in a solvent, in processes in gas phase, as well as in mass polymerization processes at high temperatures and pressures, are disclosed. The catalytic system is a mixture of a catalyst component A and a co-catalyst component B. The catalyst component A is formed by a functionalized inorganic porous oxide, by an organoaluminium compound and by an organometallic compound of a metal of the groups 3, 4, 5, or 6 of the periodic table. Functionalization of the inorganic oxide is by introduction of functional groups to be used to strongly fix the organoaluminium compound and the organometallic compound.

Abstract: Catalytic systems particularly suitable for the polymerization of .alpha.-olefins containing from two to 20 carbon atoms, as well as for the copolymerization of ethylene with .alpha.-olefins containing from three to 20 carbon atoms, dienes, and cycloalkenes in processes wherein the catalyst is suspended in a solvent, in processes in gas phase, as well as in mass polymerization processes at high temperatures and pressures, are disclosed. The catalytic system is a mixture of a catalyst component A and a co-catalyst component B. The catalyst component A is formed by a functionalized inorganic porous oxide, by an organoaluminium compound and by an organometallic compound of a metal of the groups 3, 4, 5, or 6 of the periodic table. Functionalization of the inorganic oxide is by introduction of functional groups to be used to strongly fix the organoaluminium compound and the organometallic compound.

Abstract: A catalyst comprising a cocatalyst and a catalyst component obtained by contacting a silicon-containing metallocene compound with an inorganic support to chemically bond the metallocene compound to the inorganic support, wherein the silicon-containing metallocene compound has a formula (I): ##STR1## wherein: M is a metal selected from [the group consisting of] group 4, 5, or 6 of the periodic table;each X is independently selected from the group consisting of hydrogen, halogen, C.sub.1 -C.sub.10 alkyl, C.sub.1 -C.sub.10 alkoxy, C.sub.6 -C.sub.10 aryl, C.sub.6 -C.sub.10 aryloxy, C.sub.2 -C.sub.10 alkenyl, C.sub.7 -C.sub.40 arylalkyl, C.sub.7 -C.sub.40 alkylaryl, and C.sub.8 -C.sub.40 arylalkenyl;A.sub.1 and A.sub.2 are independently selected from the group consisting of cyclopentadienyl, substituted cyclopentadienyl, indenyl, fluorenyl, substituted indenyl, and substituted fluorenyl, wherein the substituents are independently C.sub.1 -C.sub.10 linear or branched alkyl, C.sub.5 -C.sub.