Patent application number | Description | Published |
20090209703 | Methods for Modulated Degenerative Transfer Living Polymerization and Isotactic-Atactic Stereoblock and Stereogradient Poly(Olefins) Thereby - Methods for modulated degenerative transfer living polymerization and isotactic-atactic stereoblock and stereogradient poly(olefins) thereby Abstract A method of producing a multiblock, stereoblock polyolefin having substantially uniform microstructure is disclosed. The method includes contacting a Ziegler-Natta pre-catalyst with a co-catalyst and an olefin to polymerize the olefin and form a first stereoblock, adding a methyl donator that changes the stereoregularity of the polymerization, and polymerizing the olefin to form a second stereoblock. The methods of the present invention allow for the production of poly(olefin)s having predictable degrees of incorporation of stereoerrors of a known type. The methods allows for the production of a variety of poly(olefin) microstructures, ranging from stereoblock to stereogradient poly(olefin)s and poly(olefin)s having fully isotactic to fully atactic microstructures. | 08-20-2009 |
20090220786 | Methods for Modulated Degenerative Transfer Living Polymerization and Isotactic-Atactic Stereoblock and Stereogradient Poly(Olefins) Thereby - Methods for modulated degenerative transfer living polymerization and isotactic-atactic stereoblock and stereogradient poly(olefins) thereby Abstract A method of producing a multiblock, stereoblock polyolefin having substantially uniform microstructure is disclosed. The method includes contacting a Ziegler-Natta pre-catalyst with a co-catalyst and an olefin to polymerize the olefin and form a first stereoblock, adding a methyl donator that changes the stereoregularity of the polymerization, and polymerizing the olefin to form a second stereoblock. The methods of the present invention allow for the production of poly(olefin)s having predictable degrees of incorporation of stereoerrors of a known type. The methods allows for the production of a variety of poly(olefin) microstructures, ranging from stereoblock to stereogradient poly(olefin)s and poly(olefin)s having fully isotactic to fully atactic microstructures. | 09-03-2009 |
20110028654 | Process for Preparation of Polyolefins Via Living Coordinative Chain Transfer Polymerization - Disclosed is a method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst, co-catalyst, and a stoichiometric excess of a metal alkyl; adding a first olefin monomer; and polymerizing the first monomer for a time sufficient to form the polyolefin. The method allows for the use of minimum amounts of activating co-catalyst and metallocene pre-catalyst. Also disclosed is a method of producing a block polyolefin composition comprising contacting a metallocene pre-catalyst, a co-catalyst, and a stoichiometric excess of a metal alkyl; adding a first olefin monomer; polymerizing the first monomer for a time sufficient to form the polyolefin; adding a second monomer; and polymerizing the second olefin monomer for a time sufficient to form said block polyolefin composition. Also disclosed are amorphous atactic polymer and copolymer compositions made according to the present invention. | 02-03-2011 |
20130109900 | Scalable Production of Precision Hydrocarbons from Trialkylaluminum via Ternary Living Coordinative Chain Transfer Polymerization | 05-02-2013 |
20140073752 | Living Coordinative Chain Transfer Polymerization with Dynamic Counterion Exchange - Disclosed is a method of producing a polyolefin composition comprising contacting a metal alkyl and a first olefin monomer, then adding a first co-catalyst, a second co-catalyst, a pre-catalyst, and a second olefin monomer. The method allows for the production of a series of copolymers with tunable incorporation ratios of the first olefin monomer. The method also allows for the production of polyolefins of low molecular weights and narrow molecular weight distributions. | 03-13-2014 |
20140221586 | Methods for Stereoselective Coordinative Chain Transfer Polymerization of Olefins - The present invention provides a method of producing a polyolefin composition comprising contacting a binuclear metallocene pre-catalyst and a co-catalyst, adding a excess of a metal alkyl, then adding a first olefin monomer. The method allows for the production of polyolefins with a highly stereoregular stereochemical micrsostructure through living coordination polymerization in which rapid reversible chain transfer between a racemic mixture of a chiral active transition metal propagating center and multiple equivalents of inert main group metal alkyl is competitive with chain-growth propagation at the active center. By virtue of the slower rate of chain-transfer relative to propagation that can be achieved with a binuclear catalyst relative to the corresponding mononuclear catalyst, the present invention provides a work-around solution to the intrinsic limitation on product volume imposed by a traditional living polymerization, as well as a work-around solution to the stereochemically random microstructure that is normally obtained as the result of rapid and reversible chain-transfer between two populations of chiral active propagating centers, of opposite absolute configuration, when a racemic mixture of the pre-catalyst is employed. In essence, the field of invention is defined as stereoselective living coordinative chain-transfer polymerization. | 08-07-2014 |
Patent application number | Description | Published |
20080310080 | Solid State Capacitors and Method of Manufacturing Them - The present invention concerns the field of solid state capacitors and is directed more particularly to a method for manufacturing solid state electrolytic capacitors formed from porous conductive metal oxide anode bodies and having a cathode layer of conducting polymer, and capacitors thereby formed. There is disclosed a solid state capacitor comprising a porous anode body, a dielectric layer formed on surfaces of the porous anode body and a cathode layer formed on the dielectric layer, characterised by the combination of the anode body being formed from an electrically conducting ceramic material and the cathode layer being formed from an electrically conductive polymer material. The conducting ceramic material may be a metal oxide or nitride. | 12-18-2008 |
20090244812 | Hermetically Sealed Capacitor Assembly - A capacitor assembly that includes a conductive polymer electrolytic capacitor that is enclosed and hermetically sealed within a ceramic housing in the presence of an inert gas is provided. Without intending to be limited by theory, the present inventors believe that the ceramic housing is capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the conductive polymer is less likely to oxidize in high temperature environments, thus increasing the thermal stability of the capacitor assembly. | 10-01-2009 |
20100025876 | BINDER REMOVAL FROM PARTICULATE BODIES - The present invention relates to a method of manufacturing a porous article, in particular the anode of a valve action material based solid state capacitor, comprising the steps of combining a water soluble polymeric binder and particulate material before pressing the particulate material and the subsequent step of removing the binder form the pressed pellet. Thus, the present invention also relates to a method of removing a water soluble polymeric binder from pressed particulate material and to a composition comprising a water soluble polymeric binder for forming the anode of a valve action material based solid state capacitor. | 02-04-2010 |
20120113567 | Hermetically Sealed Capacitor Assembly - A capacitor assembly that includes a conductive polymer electrolytic capacitor that is enclosed and hermetically sealed within a ceramic housing in the presence of an inert gas is provided. Without intending to be limited by theory, the present inventors believe that the ceramic housing is capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the conductive polymer is less likely to oxidize in high temperature environments, thus increasing the thermal stability of the capacitor assembly. | 05-10-2012 |