Abstract: A surface of a melt polymerization reactor system having residual reaction components of a melt polymerization reaction thereon can be cleaned by introducing a cleaning agent having a phenolic compound to the polymerization reactor system and into contact with the surface of the melt polymerization reactor system having the residual reaction components of a melt polymerization reaction thereon. The residual reaction components of the melt polymerization reaction include polycarbonate oligomers or polymers or their degradation products. Further, the cleaning agent is maintained in contact with the surface for a period of time and at a temperature sufficient to substantially remove the residual reaction components from the surface.

Abstract: A method for preparing a membrane to be assembled in a membrane, electrode assembly includes the step of swelling an ion-conducting membrane in a liquid containing at least one solvent or to an atmosphere containing the vapor phase of at least one solvent by controlling the content of the solvent in the ion-conducting membrane. A method for manufacturing a membrane electrode assembly using an ion conducting membrane includes the steps of: providing an ion-conducting membrane in a pre-swollen state; coating the ion-conducting membrane on both sides with an electrode layer to form a sandwich; and hot-pressing the sandwich to form an ion-conducting bonding of the layers of the sandwich. Furthermore, a membrane electrode assembly is disclosed including a hot pressed sandwich having an electrode layer, a ion-conducting membrane and again an electrode layer, thereby using the ion-conducting membrane in its pre-swollen status prior to the hot-pressing.

Abstract: According to the present invention a method for grafting a chemical compound to a predetermined region of a support substrate (4) is disclosed, comprising: a) irradiating selectively the support substrate with electromagnetic radiation and/or particle radiation in order to both define said predetermined region and to form at least one reactive functional group or a precursor thereof in said predetermined region of the support substrate; b) exposing the irradiated support substrate to said chemical compound or to a precursor thereof. Therefore, only these very few steps are needed to effectively grafting the desired chemical compound, such as an organic compound, to the predetermined regions of the support substrate. Moreover, the irradiation step can be carried out in a vastly flexible manner and allows to generate numerous distinct shapes of the predetermined regions.

Abstract: Alkyl ester end-capped polycarbonates have improved release properties and may be produced by a method comprising the step of combining a polycarbonate having free terminal OH groups with an end-capping reagent comprising a symmetrical activated carbonate and an alkyl ester, whereby the end-capping reagent reacts with at least some of the free hydroxyl end groups of the polycarbonate to produce an end-capped polycarbonate comprising optionally substituted aliphatic ester end groups.

Abstract: Alkyl ester end-capped polycarbonates have improved release properties and may be produced by a method comprising the step of combining a polycarbonate having free terminal OH groups with an end-capping reagent comprising a symmetrical activated carbonate and an alkyl ester, whereby the end-capping reagent reacts with at least some of the free hydroxyl end groups of the polycarbonate to produce an end-capped polycarbonate comprising optionally substituted aliphatic ester end groups.

Abstract: A process for the production of polycarbonate having increased end-cap levels, the process comprising adding a terminal blocking agent of the formula: 1

Abstract: A method for preparing a polycarbonate comprises preparing a free hydroxyl-containing polycarbonate and reacting the hydroxyl-containing polycarbonate with a mixture of (B) a symmetrical optionally activated aromatic carbonic acid diester and (C) an optionally substituted aromatic hihydroxy compound, diol or diacid. A copolymerization reagent comprises a mixture of (B) a symmetrical optionally activated aromatic carbonic acid diester and (C) an optionally substituted aromatic hihydroxy compound, diol or diacid. A copolymer comprises [polycarbonate]x moieties; (B) [symmetrical optionally activated aromatic carbonic acid diester]y moieties and (C) [optionally substituted aromatic hihydroxy compound, diol or diacid]z moieties, wherein x, y and z are mole percents of the copolymer.

Abstract: Polycarbonate compositions incorporating long chain alkylphenol endgroups, for example cardanol, show enhanced pit replication characteristics when molded into optical disks. The enhancement in molding performance is especially pronounced at the shortest mold cycle times tested. Thus, a blend of 75 parts by weight bisphenol A polycarbonate 92 percent encapped with phenol, and 25 parts by weight bisphenol A polycarbonate about 100 percent endcapped with cardanol showed enhanced pit replication performance in optical disk molding trials relative to the same bisphenol A polycarbonate alone and analogous blends utilizing short chain alkylphenols.

Abstract: A method for end-capping polycarbonate resins, comprising the step of processing a mixture comprising a polycarbonate having free hydroxyl-end groups and an end-capping reagent in a melt transesterification reaction to produce a polycarbonate resin, wherein the end-capping reagent comprises a mixture of: (a) at least one species of a symmetrical activated aromatic carbonate, and (b) at least one species of an optionally-substituted phenol, whereby said end-capping reagent reacts with at least some of the free hydroxyl end-groups of the polycarbonate to produce an end-capped polycarbonate resin.

Abstract: A method for end-capping polycarbonate resins, comprising the step of processing a mixture comprising a polycarbonate having free hydroxyl-end groups and an end-capping reagent in a melt transesterification reaction to produce a polycarbonate resin, wherein the end-capping reagent comprises a mixture of: (a) at least one species of a symmetrical activated aromatic carbonate, and (b) at least one species of an optionally-substituted phenol, whereby said end-capping reagent reacts with at least some of the free hydroxyl end-groups of the polycarbonate to produce an end-capped polycarbonate resin.

Abstract: A process for the production of polycarbonate by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding the to polycarbonate under melt conditions a compound of the formula (1): wherein R1 and R3 may be the same or different and are selected from the group consisting of alkoxy, phenoxy, benzoxy, aryloxy, phenyl and aryl groups, R2 is selected from the group consisting of alkyl, phenyl, aryl, or aralkyl groups.

Abstract: Polycarbonate compositions incorporating long chain alkylphenol endgroups, for example cardanol, show enhanced pit replication characteristics when molded into optical disks. The enhancement in molding performance is especially pronounced at the shortest mold cycle times tested. Thus, a blend of 75 parts by weight bisphenol A polycarbonate 92 percent encapped with phenol, and 25 parts by weight bisphenol A polycarbonate about 100 percent endcapped with cardanol showed enhanced pit replication performance in optical disk molding trials relative to the same bisphenol A polycarbonate alone and analogous blends utilizing short chain alkylphenols.

Abstract: A method for preparing a polycarbonate comprises preparing a free hydroxyl-containing polycarbonate and reacting the hydroxyl-containing polycarbonate with a mixture of (B) a symmetrical optionally activated aromatic carbonic acid diester and (C) an optionally substituted aromatic hihydroxy compound, diol or diacid. A copolymerization reagent comprises a mixture of (B) a symmetrical optionally activated aromatic carbonic acid diester and (C) an optionally substituted aromatic hihydroxy compound, diol or diacid. A copolymer comprises [polycarbonate]x moieties; (B) [symmetrical optionally activated aromatic carbonic acid diester]y moieties and (C) [optionally substituted aromatic hihydroxy compound, diol or diacid]z moieties, wherein x, y and z are mole percents of the copolymer.

Abstract: A process for preparing an end-capped polycarbonate comprises melt reacting an aromatic dihydroxy compound, a carbonic acid diester, and optionally a catalyst in a prepolymerization vessel to form a polycarbonate product; transferring the polycarbonate product from the prepolymerization vessel; mixing the polycarbonate product with an end-capping agent under hermetic seal at a pressure of at least about 760 mm Hg; and transferring the polycarbonate product and end-capping agent mixture to a postpolymerization vessel to endcap the polycarbonate product.

Abstract: A method for end-capping polycarbonate resins, comprising the step of processing a mixture comprising a polycarbonate having free hydroxyl-end groups and an end-capping reagent in a melt transesterification reaction to produce a polycarbonate resin, wherein the end-capping reagent comprises a mixture of:

Abstract: Polycarbonate resin containing reduced levels of reaction by-products can be prepared by adding to the polycarbonate a scavenging agent having the formula: wherein R1 is alkoxy, phenoxy, benzyloxy or phenyl, and R2 is a substituted or unsubstituted C1-C30 alkyl group, C6-C30 aryl group, C7-C30 aralkyl group or C6-C30 aryloxy group and processing the resulting mixture at an elevated temperature and for a period of time such that the scavenging agent reacts with linear Fries products to produce capped linear Fries products, and with residual phenols (monohydric or dihydric) to produce capped phenols and ortho-substituted phenols.

Abstract: Polycarbonate having increased end-cap levels is made by adding an end-capping agent to the polycarbonate, preferably after the polycarbonate has reached a number-average molecular weight of about 2,000 to 15,000 Dalton.

Abstract: A method for end-capping polycarbonate resins, comprising the step of processing a mixture comprising a polycarbonate having free hydroxyl-end groups and an end-capping reagent in a melt transesterification reaction to produce a polycarbonate resin, wherein the end-capping reagent comprises a mixture of:(a) at least one species of a symmetrical activated aromatic carbonate, and (b) at least one species of an optionally-substituted phenol, whereby said end-capping reagent reacts with at least some of the free hydroxyl end-groups of the polycarbonate to produce an end-capped polycarbonate resin.

Abstract: Polycarbonate resin containing reduced levels of reaction by-products can be prepared by adding to the polycarbonate a scavenging agent having the formula: 1

Abstract: A process for preparing an end-capped polycarbonate comprises melt reacting an aromatic dihydroxy compound, a carbonic acid diester, and optionally a catalyst in a prepolymerization vessel to form a polycarbonate product; transferring the polycarbonate product from the prepolymerization vessel; mixing the polycarbonate product with an end-capping agent under hermetic seal at a pressure of at least about 760 mm Hg; and transferring the polycarbonate product and end-capping agent mixture to a postpolymerization vessel to endcap the polycarbonate product.