Patent application number | Description | Published |
20080221302 | Catalyst and Process for the Polymerization of Cyclic Ethers - The present invention provides a catalyst comprising a mixture of at least one acid-activated sheet silicate with a transition metal oxide of groups 8 and/or 9 of the Periodic Table of the Elements and also a process for preparing polytetrahydrofuran, polytetrahy-drofuran copolymers, diesters or monoesters of these polymers, in which tetrahydrofuran is polymerized in the presence of at least one telogen and/or comonomer over such a catalyst. | 09-11-2008 |
20090131657 | PROCESS FOR ALKENYLATING CARBOXAMIDES - The present invention relates to a process for preparing N-(1-alkenyl)carboxamides of the formula I, which comprises reacting a carboxamide of the formula II with an alkyne of the formula III in the presence of a catalyst selected from among carbonyl complexes, halides and oxides of rhenium, manganese, tungsten, molybdenum, chromium and iron. | 05-21-2009 |
20090215971 | METHOD FOR THE PRODUCTION OF POLYTETRAHYDROFURANE OR TETRAHYDROFURANE COPOLYMERS - The present invention relates to a process for preparing polytetrahydrofuran or tetrahydrofuran copolymers by polymerization of tetrahydrofuran in the presence of a telogen and/or a comonomer over a fixed bed of an acid catalyst, in which the temperature of the polymerization mixture increases in the direction of flow through the catalyst bed. | 08-27-2009 |
20100240864 | METHOD FOR CHANGING THE PREDEFINED MEAN MOLECULAR WEIGHT MN DURING THE CONTINUOUS PRODUCTION OF POLYTETRAHYDROFURANES OR THE COPOLYMERS - The present invention provides a process for changing the given mean molecular weight M | 09-23-2010 |
Patent application number | Description | Published |
20090215971 | METHOD FOR THE PRODUCTION OF POLYTETRAHYDROFURANE OR TETRAHYDROFURANE COPOLYMERS - The present invention relates to a process for preparing polytetrahydrofuran or tetrahydrofuran copolymers by polymerization of tetrahydrofuran in the presence of a telogen and/or a comonomer over a fixed bed of an acid catalyst, in which the temperature of the polymerization mixture increases in the direction of flow through the catalyst bed. | 08-27-2009 |
20100240864 | METHOD FOR CHANGING THE PREDEFINED MEAN MOLECULAR WEIGHT MN DURING THE CONTINUOUS PRODUCTION OF POLYTETRAHYDROFURANES OR THE COPOLYMERS - The present invention provides a process for changing the given mean molecular weight M | 09-23-2010 |
20110224401 | APPARATUS FOR SEPARATION BY DISTILLATION - The invention relates to an apparatus for separating a liquid substance mixture by distillation, a method for producing a tetrahydrofuran homopolymer and copolymer in which the oligomers in a liquid starting mixture containing oligomers are separated by distillation in such an apparatus, tetrahydrofuran homopolymers and copolymers which can be obtained using said method and have a narrow distribution of the relative molar mass, and the use thereof. | 09-15-2011 |
20120059142 | PREPARING POLYESTER ALCOHOLS - A process for preparing polyester alcohols by condensation of polytetrahydrofuran with aromatic dicarboxylic acids and/or their anhydrides and/or their esters, preferably isophthalic acid, phthalic acid and terephthalic acid and more preferably isophthalic acid, in the presence of a transesterification catalyst in a multi-stage operation at different pressure levels with at least one reaction stage at atmospheric pressure and at least one reaction stage at reduced pressure, where distillate is removed from the reaction system, comprises deactivating the catalyst after the polycondensation by using phosphoric acid in a molar ratio of 1:1 to 1:3.5 for catalyst to phosphoric acid. | 03-08-2012 |
20120059143 | PREPARING POLYESTER ALCOHOLS - The subject of the present invention is a process for preparing polyester alcohols by condensation of polytetrahydrofuran with aromatic dicarboxylic acids and/or their anhydrides in the presence of a transesterification catalyst in a multi-stage operation at different pressure levels with at least one reaction stage at atmospheric pressure and at least one reaction stage at reduced pressure, where distillate is removed from the reaction system, which process comprises heating the reaction mixture in two or more phases in the atmospheric-pressure reaction stage wherein the heating phases are interrupted by at least one phase in which the temperature is kept constant. | 03-08-2012 |