| Patent Number |
Title Of Patent |
Date Issued |
| 7129315 |
Process for the production of polycarbonate |
October 31, 2006 |
| A process for the isolation of polycarbonate produced by the interfacial polymerization process is disclosed. Accordingly, the process entails (a) evaporating the organic solvent from the solution that contains solvent and polycarbonate to obtain a material system that contains 90 to 99. |
| 7091302 |
Process for the preparation of polycarbonate |
August 15, 2006 |
| The invention describes a process for the preparation of polycarbonate. The process includes (a) transesterifying at least one aromatic dihydroxyaryl compound and a diaryl carbonate in the melt in the presence of a catalyst, (b) mixing the melt obtained in step (a) with a foaming age |
| 6855794 |
Polycarbonate substrates |
February 15, 2005 |
| Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from |
| 6855390 |
Optical data carriers and method for producing the same |
February 15, 2005 |
| A process for the preparation of optical data carriers made of a particualr polycarbonate is disclosed. The polycarbonate is prepared by the phase boundary process that entails reacting at least one dihydroxydiarylalkane in the form of its alkali metal salts with phosgene in the heteroge |
| 6835798 |
Method of producing polycarbonates |
December 28, 2004 |
| A process for the preparation of polycarbonate by the phase boundary process is disclosed. The process entails reacting at least one dihydroxydiarylalkane in the form of its alkali metal salts with phosgene in the heterogeneous phase in the presence of sodium hydroxide solution and a |
| 6815524 |
Polycarbonate substrates |
November 9, 2004 |
| Polycarbonate substrates having low concentration of defects are disclosed. The substrates are suitable for producing molded articles characterized by low cloudiness. |
| 6720406 |
High-purity polymer granules and method for the production thereof |
April 13, 2004 |
| A process for producing polymer pellets is disclosed. The process that is particular suitable for making polycarbonate pellets entails extruding a polymer melt, cooling the extrudate by contacting it with a cooling fluid and pelletizing the solidified polymer. The process is characterize |
| 6710154 |
Polycarbonate substrates |
March 23, 2004 |
| A method for producing polycarbonate based on 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexanone and 4,4-(metaphenylene diisopropyl) diphenol is disclosed. The method is characterized in that the recovery and/or further processing of the polycarbonate is performed at temperatures |
| 6703473 |
Process for producing polycarbonate |
March 9, 2004 |
| An improvement to the melt transesterification reaction of diaryl carbonate with dihydroxy aryl compound is disclosed. The improvement entails the following steps (i) introducing the resulting vapor stream at the mid-height of a first distillation column, and (ii) separating the vapor |
| 6696542 |
Polycarbonate substrates |
February 24, 2004 |
| Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from |
| 6689464 |
Method and device for producing bisphenol a prills and bisphenol a prills produced according to |
February 10, 2004 |
| A method for producing bisphenol A in prill form is disclosed. Molten bisphenol is top-fed into a prilling tower via a plate containing a plurality of nozzles. A gas coolant guided through a circuit is led into said tower in a counter flow direction. The prills are cooled to about ro |
| 6682794 |
Polycarbonate containers |
January 27, 2004 |
| A container made of polycarbonate resin is disclosed. The container is characterized in that the polycarbonate is prepared by the phase interface process that is characterized in that the aqueous solution of an alkali salt of a bisphenol used, contains dissolved oxygen in an amount less |
| 6680400 |
Continuous process for the production of carboxylic acid diaryl esters |
January 20, 2004 |
| An improvement to the interfacial boundary process for continuous production of carbonic acid diaryl esters is disclosed. The process that entails a reaction of monophenols in an inert solvent, in the presence of an alkaline solution and a nitrogen base catalyst, is carried out in two |
| 6646101 |
Use of copolycarbonates |
November 11, 2003 |
| The present invention provides the use of impact resistant, stress cracking resistant copolycarbonates with particularly good low temperature properties for applications in which particularly good low temperature properties are required, e.g., for automobile construction or external |
| 6586556 |
Use of copolycarbonates |
July 1, 2003 |
| The present invention provides the use of impact resistant, stress cracking resistant copolycarbonates with particularly good low temperature properties for applications in which particularly good low temperature properties are required, e.g., for automobile construction or external |
| 6548691 |
Process for producing carbonic acid diaryl ester |
April 15, 2003 |
| An improvement to the interfacial boundary process for producing carbonic acid diaryl esters is disclosed. In the two-stage process that entails phosgene and monophenols reaction in an inert solvent, in the presence of alkali and in the presence of a nitrogen base catalyst, the improveme |
| 6531623 |
Continuous process for producing carbonic acid diaryl ester |
March 11, 2003 |
| A two stage interfacial polycondensation process for the production of carbonic acid diaryl ester is disclosed. The invention concerns an improvement to the process that entails forming in a first stage a reaction mixture that contains an inert solvent, at least one monophenol, phosg |
| 6414198 |
Method for producing bisphenol-A |
July 2, 2002 |
| A process of preparing bisphenol A having low residual contents of oxygen and phenol is described. The process involves: (a) melting mixed crystals of bisphenol A and phenol under a nitrogen atmosphere at a temperature of 100.degree. C. to 120.degree. C.; (b) feeding continuously the mel |
| 6395864 |
Polycarbonates with a low yellowness index |
May 28, 2002 |
| A process for the preparation of polycarbonate resins having a low yellowness index is described. The process involves converting phosgene with a sodium bisphenolate solution by means of a phase interface process performed with the exclusion of oxygen. The sodium bisphenolate solution |
| 5900501 |
Process for the continuous production of aryl carbonates |
May 4, 1999 |
| The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by the reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts, phosgene still present being removed from the stream of waste ga |
| 5856012 |
Process for the production of multilayer plastic sheets |
January 5, 1999 |
| The invention relates to a process for the production of multilayer plastic sheets from special branched polycarbonates. |
| 5831111 |
Process for the continuous production of aryl carbonates |
November 3, 1998 |
| The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by reacting aromatic hydroxy compounds with phosgene in the gas phase in the presence of heterogeneous catalysts. |
| 5830977 |
Process for the isolation of partially crystalline polycarbonate powder |
November 3, 1998 |
| The present invention provides a process for the isolation of partially crystalline polycarbonate powder or oligocarbonate powder from solutions thereof, in which process the organic solvent of a polycarbonate solution is vaporized in a heat exchanger, optionally with incorporation of st |
| 5783651 |
Process for the production of poly (diorganosiloxane)/polycarbonate block copolymers |
July 21, 1998 |
| The present invention provides a process for the production of poly(diorganosiloxane)/polycarbonate block copolymers in a melt using specific transesterification catalysts. |
| 5767224 |
Two-step process for the production of thermoplastic polycarbonate |
June 16, 1998 |
| The invention relates to a two-step melt process for the production of thermoplastic, solvent-free, low-branching polycarbonates with low --OH terminal group content using a self-cleaning high-viscosity reactor. |
| 5756641 |
Process for producing thermoplastic polycarbonate |
May 26, 1998 |
| The present invention relates to a transesterification process for producing thermoplastic polycarbonates with the use of fixed bed catalysts. |
| 5739258 |
Process for preparing diaryl carbonates and the polycarbonates obtainable therefrom |
April 14, 1998 |
| The invention relates to a process for preparing a diaryl carbonate by oxidative carbonylation of the basic aromatic hydroxy compound, in which the aromatic hydroxy compound is the one which is eliminated during melt polycondensation of this diaryl carbonate with a bisphenol. Accordingly |
| 5734004 |
Process for the purification of carbonic acid diaryl ester |
March 31, 1998 |
| The present invention relates to a distillation process for the purification of carbonic acid diaryl esters. |
| 5710310 |
Process for the continuous production of diaryl carbonates |
January 20, 1998 |
| The present invention relates to a process for the continuous production of diaryl carbonates by reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts. |
| 5652324 |
Process for the production of thermoplastic polycarbonate |
July 29, 1997 |
| The invention relates to a transesterification process for the production of thermoplastic, solventless oligo-/polycarbonates in which aromatic diphenols and carbonic acid diaryl esters are combined and reacted in gaseous form. |
| 5652313 |
Two-stage process for the manufacture of thermoplastic polycarbonate |
July 29, 1997 |
| The present invention provides a two-stage melt process for the manufacture of thermoplastic, solvent-free, low-branched polycarbonates with low OH end-group contents with the use of ammonium or phophonium catalysts in the first stage and alkali and alkaline earth catalysts in the second |
| 5652275 |
Process for the chemical recycling of polycarbonates |
July 29, 1997 |
| The invention relates to a process for the chemical recycling of polycarbonates by catalyzed reaction with diaryl carbonates to oligocarbonates which are crystallized, purified and then polycondensed back to polycarbonates, insoluble constituents optionally being removed before the c |
| 5648437 |
Process for the manufacture of thermoplastic polycarbonate |
July 15, 1997 |
| The present invention provides a melt process for the manufacture of thermoplastic solvent-free polycarbonates with the use of a continuously operated tubular reactor for monophenol vaporization. |
| 5618906 |
Process for the production of thermoplastic polycarbonates |
April 8, 1997 |
| A process is described for preparing solvent-free polycarbonate using phosphazene catalysts. |
| 5440066 |
Process for splitting polycarbonates |
August 8, 1995 |
| A continuous process for splitting an aromatic polycarbonate resin is disclosed. Accordingly there are reacted in a distillation column and in the presence of a catalyst(i) a polycarbonate resin in solution with(ii) methanolto produce a dihydroxy compound and dimethyl carbonate. The solution |
| 5418316 |
Guanidine-derived catalyts for preparing polycarbonates by transesterification |
May 23, 1995 |
| The present invention provides a transesterification process for the production of thermoplastic, solvent-free polycarbonates by the use of catalysts that are derived from guanidine. |
| 5399659 |
Two-stage process for the production of thermoplastic polycarbonate |
March 21, 1995 |
| The invention relates to a two-stage process for the production of thermoplastic, solvent-free lightly branched polycarbonates in the melt using ammonium and/or phosphonium catalysts in the first stage and alkali metal and/or alkaline earth metal catalysts in the second stage. |
