Patents by Inventor Kurt Hoffmann
Kurt Hoffmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5807932Abstract: The invention relates to a process for increasing the molecular weight of polycondensates, which comprises heating a polycondensate in the temperature range below the melting point and above the glass transition temperature in the solid phase of the polymer with additionof at least one sterically hindered hydroxyphenylalkylphosphonic ester or monoester.Type: GrantFiled: April 9, 1997Date of Patent: September 15, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Rudolf Pfaendner, Kurt Hoffmann, Heinz Herbst
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Patent number: 5804623Abstract: Recycled plastics, predominandy thermoplastics, from domestic, commercial and industrial waste can be stabilized against thermooxidative degradation by adding a combination of a sterically hindered phenol with an organic phosphite or phosphonite and a metal salt of a fatty acid.Type: GrantFiled: November 25, 1996Date of Patent: September 8, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Kurt Hoffmann, Heinz Herbst, Rudolf Pfaendner, Hans-Jurgen Sander, Franciszek Sitek
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Patent number: 5789470Abstract: The invention relates to stabilized recycled plastics, which can be obtained from domestic, commercial and industrial waste or valuable material collections, comprising a macrocyclic compounds containing a radical of formula (I) or (II), in the macrocycle or in a side group of the macrocycle, where the macrocycle comprises at least 8 atoms and in which the substituents R, independently of one another, are methyl, ethyl or propyl, or two radicals R on the same carbon atom are, together, a pentamethylene radical, and a is the number 0, 1 or 2. The invention also relates to a process for the stabilization of recycled plastics and to the use of the above macrocyclic compounds as stabilizer.Type: GrantFiled: March 20, 1997Date of Patent: August 4, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Heinz Herbst, Kurt Hoffmann, Franca Masina, Rudolf Pfaendner, Franciszek Sitek
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Patent number: 5774014Abstract: An integrated buffer circuit includes a first series circuit connected between a first supply potential and a second supply potential (ground). The first series circuit has a voltage-controlled first constant current source, a first field effect transistor having a gate forming an input of the buffer circuit, a circuit node between the first current source and the first field effect transistor forming an output of the buffer circuit, and a first control input for controlling the first current source with a reference potential having a constant potential difference relative to the first supply potential. A second series circuit is connected between the first supply potential and the second supply potential.Type: GrantFiled: April 4, 1996Date of Patent: June 30, 1998Assignee: Siemens AktiengesellschaftInventors: Johannes Stecker, Klaus Luther, Kurt Hoffmann, Oskar Kowarik
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Patent number: 5765521Abstract: A supply pump for lubricant or heat transfer liquid of a conventional design is driven by a drive unit independently of the consumer of the lubricant or of the heat transfer liquid. In the event of the failure of the drive unit a forced connection occurs between the pump and the rotating parts of the consumer in order to ensure its supply with the lubricant or the heat transfer liquid at least for a sufficient emergency period. By the independent drive of the supply pump the supply to the consumer can be controlled according to the consumption of lubricant or heat transfer liquid independently of its individual operating characteristic or operating state.Type: GrantFiled: October 15, 1996Date of Patent: June 16, 1998Assignee: Schwaebische Huettenwerke GmbHInventors: Gunther Stutzle, Bernd Schrelber, Wolfgang Bruttel, Franz Maucher, Kurt Hoffmann
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Patent number: 5756596Abstract: An increase in the molecular weight of a polyamide or recycled polyamide, essentially without crosslinking, can be achieved by blending said polyamide with a polyfunctional epoxy resin and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester and heating the blend to above the melting point (or the glass transition temperature) of the polyamide, in the absence of a catalyst of the type used in the polymerization of polyamides.Type: GrantFiled: April 7, 1997Date of Patent: May 26, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Rudolf Pfaendner, Heinz Herbst, Kurt Hoffmann
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Patent number: 5747606Abstract: An increase in the molecular weight of polyester and recycled polyester can be achieved by blending said polyester with a difunctional epoxy resin and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester and heating the blend to above the melting point (glass transition temperature) of the polyester.Type: GrantFiled: July 11, 1997Date of Patent: May 5, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Rudolf Pfaendner, Kurt Hoffmann, Heinz Herbst
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Patent number: 5744554Abstract: A polyester/polycarbonate (PES/PC) blend having enhanced properties as virgin material and as recyclate comprisesa) at least one phosphite,b) at least one sterically hindered phenol,c) at least one compound promoting the reaction of an epoxy resin with a PES/PC blend which is a Lewis base, andd) at least one difunctional epoxy resin, with 0.01 to 10 parts of component c) being used per 100 parts of PES/PC blend.Type: GrantFiled: November 25, 1996Date of Patent: April 28, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Rudolf Pfaendner, Kurt Hoffmann, Heinz Herbst
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Patent number: 5726234Abstract: The invention relates to stabilized PVDC-containing PVC, preferably a PVC recyclate, comprising as polymer at least 50% by weight of polyvinyl chloride (PVC) and 0.05-50% by weight of PVDC and additionally comprising at least one inorganic compound of the series of the metal oxides, metal hydroxides or metal carbonates.Type: GrantFiled: February 12, 1997Date of Patent: March 10, 1998Assignee: Ciba Specialty Chemicals CorporationInventors: Heinz Herbst, Kurt Hoffmann, Rudolf Pfaendner
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Patent number: 5693681Abstract: A process is disclosed for increasing the molecular weight of polyesters, polyester copolymers or polyester blends, which comprises heating a polyester blended with a tetracarboxylic acid dianhydride and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester to above the melting point (glass transition temperature) of the polyester.Type: GrantFiled: August 28, 1996Date of Patent: December 2, 1997Assignee: Ciba Specialty Chemicals CorporationInventors: Rudolf Pfaendner, Heinz Herbst, Kurt Hoffmann
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Patent number: 5643985Abstract: Recycled plastics, predominanty thermoplastics, from domestic, commercial and industrial waste can be stabilized against thermooxidative degradation by adding a combination of a sterically hindered phenol with an organic phosphite or phosphonite and a metal salt of a fatty acid.Type: GrantFiled: March 21, 1995Date of Patent: July 1, 1997Assignee: Ciba-Geigy CorporationInventors: Kurt Hoffmann, Heinz Herbst, Rudolf Pfaendner, Hans-Jurgen Sander, Franciszek Sitek
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Patent number: 5496920Abstract: An increase in the molecular weight of newly produced polyamides and recycled polyamide materials can be achieved by heating to above the melting point or glass transition point and adding of a bismaleimide and a sterically hindered hydroxyphenyl-alkyl-phosphonic acid ester or half-ester.Type: GrantFiled: May 27, 1994Date of Patent: March 5, 1996Assignee: Ciba-Geigy CorporationInventors: Rudolf Pfaendner, Kurt Hoffmann, Heinz Herbst
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Patent number: 5395217Abstract: The invention relates to a gear pump for oil for an internal-combustion engine, in particular for motor vehicles, comprising a pump housing mounted on the motor and an outer rotor which is arranged in the pump housing, an inner rotor additionally being arranged within the outer rotor or within the pump housing and at least one suction and/or at least one pressure passage being provided in the pump housing, a drive further being present; the pump according to the invention is integrated in a drive wheel or guide pulley of the internal-combustion engine and the outer rotor or the outer rotors are driven by the drive wheel or the guide pulley.Type: GrantFiled: April 28, 1994Date of Patent: March 7, 1995Assignee: Schwabische Huttenwerke GmbHInventors: Kurt Hoffmann, Franz Maucher
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Patent number: 5276643Abstract: An integrated semiconductor circuit includes word lines and bit lines. A memory region has at least one memory cell field with memory cells addressable through the word lines and the bit lines, and a number of evaluator circuits corresponding to the number of the bit lines. Each of the evaluator circuits is connected with one of the bit lines and divides the one bit line into two at least approximately identical bit line halves. Logic units of a block perform digital processing of data read-out of the memory region through the bit lines and evaluated. Each of the logic units is connected to the two bit line halves of one of the bit lines. Various operating modes of the block of logic units are selected with mode select signals.Type: GrantFiled: November 26, 1991Date of Patent: January 4, 1994Assignee: Siemens AktiengesellschaftInventors: Kurt Hoffmann, Rainer Kraus, Oskar Kowarik
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Patent number: 5270435Abstract: Polyarylene ethers which, based on the total amount of the structural units present in the polyether resin, contain 2-100 mol % of a recurring structural unit of formula I ##STR1## and 0-98 mol % of a recurring structural unit of formula II wherein each a is 1 or 2, 10 to 100% of X, based on the total number of the bonds X present in the structural units of formulae I and II, are --SO.sub.2 --, and 0 to 90% of X are --CO--, and A is a group of formula IIIa-IIIg: ##STR2## wherein Y is --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 --, --S--, --SO--, --SO.sub.2 --, --O-- or --CO--, and the aromatic rings in the structural units of formulae I and II are unsubstituted or substituted by one or more alkyl groups of 1 to 4 carbon atoms, have good solubility in organic solvents and are suitable preferably for modifying other plastics materials or for use as matrix resins for the production of fibrous composite structures.Type: GrantFiled: January 9, 1992Date of Patent: December 14, 1993Assignee: Ciba-Geigy CorporationInventors: Rudolf Pfaendner, Thomas Kainmuller, Kurt Hoffmann, Andreas Kramer, Friedrich Stockinger
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Patent number: 5253209Abstract: An integrated semiconductor memory includes a memory cell field having memory cells disposed in matrix form, word lines and internal bit lines forming pairs of internal bit lines for triggering the memory cells. Internal weighting circuits are each assigned to a respective one of the internal bit line pairs. An external pair of bit lines is commonly assigned to the internal bit lines. Pairs of separation transistors are each assigned to a respective one of the internal bit line pairs for electrical separation of the respective internal bit line pair from the external pair of bit lines. A bit line decoder triggers the pairs of separation transistors. An external weighting circuit is provided. A discriminator device and a precharging device are connected to the external bit line pair. The internal bit lines of each pair of internal bit lines are triggered separately from one another.Type: GrantFiled: July 26, 1991Date of Patent: October 12, 1993Assignee: Siemens AktiengesellschaftInventors: Kurt Hoffmann, Oskar Kowarik, Rainer Kraus, Bernhard Lustig, Hans D. Oberle
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Patent number: 5229710Abstract: A band gap reference circuit configuration includes first and second bipolar transistors having base-to-emitter voltages. An emitter resistor is connected to the first bipolar transistor. An operational amplifier is connected to the bipolar transistors for processing a difference generated between the base-to-emitter voltages of the first and second bipolar transistors to generate a largely temperature-independent reference voltage. The bipolar transistors are parasitic transistors, and the operational amplifier is constructed in MOS technology.Type: GrantFiled: September 30, 1991Date of Patent: July 20, 1993Assignee: Siemens AktiengesellschaftInventors: Rainer Kraus, Kurt Hoffmann
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Patent number: 5212264Abstract: There are disclosed substantially linear polyarylene ether sulfones having a reduced viscosity of having a reduced viscosity of ca. 0.25 to ca. 1.5 dl/g (measured in a 1% solution in DMF at 25.degree. C.) and consisting essentially of 95-99.8% by weight of segments of formula I and of 5-0.2% by weight of segments of formula IIa, formula IIb and/or formula IIc ##STR1## the percentages by weight being based on the entire polymer and the molecular weight (number average) of the segments of formula I being 6000 to ca. 60 000, if the polymer contains solely structural units of formula IIa and/or IIb, and 1000 to ca. 60 000 if the polymer contains more than 0.1% by weight of structural units of formula IIc, and R consists of the recurring structural units of formula Ia and/or of up to 99.8% by weight, based on the total polymer, of recurring structural units of formula Ib ##STR2## wherein R.sub.1 is C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.10 alkenyl, phenyl or halogen, p is an integer from 0 to 4 Ar.sub.1 and Ar.Type: GrantFiled: March 16, 1992Date of Patent: May 18, 1993Assignee: Ciba-Geigy CorporationInventors: Kurt Hoffmann, Thomas Kainmuller, Rudolf Pfaendner
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Patent number: 5212278Abstract: The invention relates to polyarylene ethers which contain, based on the total amount of structural elements present in the polyether resin, 5-100 mol % of a recurring structural element of the formula I ##STR1## and 0-95 mol % of a recurring structural element of the formula II ##STR2## in which X and X' independently of one another are --SO--, --SO.sub.2 -- or --CO--, one of the radicals R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is phenyl or phenyl which is substituted by one to three (C.sub.1 -C.sub.4)alkyl groups and the remaining radicals R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently of one another are hydrogen, (C.sub.1 -C.sub.4)alkyl, phenyl or phenyl which is substituted by one to three (C.sub.1 -C.sub.4)alkyl groups, and A is an aromatic radical, at least 25% of the bonds X and/or Y and/or the bridge members contained in A being --SO.sub.2 --.These industrial materials are distinguished by very good mechanical properties and good solubility.Type: GrantFiled: March 13, 1990Date of Patent: May 18, 1993Assignee: Ciba-Geigy CorporationInventors: Rudolf Pfaendner, Thomas Kainmuller, Kurt Hoffmann, Andreas Kramer, Friedrich Stockinger
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Patent number: 5184326Abstract: An integrated semiconductor memory of the DRAM type includes word lines and bit line pairs. Memory cells in a matrix are connected to the word lines and the bit lines. One evaluator circuit per bit line pair is connected to the bit lines. Each of the bit line pairs is divided into one bit line and one reference bit line during operation. A control line is provided. At least one coupling capacitor is provided for each of the bit lines and each of the reference bit lines having a first lead connected to the bit line pair and a second lead connected to the control line. A method for testing an integrated semiconductor memory of the DRAM type includes reading data stored in memory cells out of the memory cells, precharging bit line pairs to a precharge level before reading out, and feeding an additional potential to each bit line pair after precharging.Type: GrantFiled: March 15, 1990Date of Patent: February 2, 1993Assignee: Siemens AktiengesellschaftInventors: Kurt Hoffmann, Rainer Kraus, Oskar Kowarik