Patents by Inventor Dietrich Arntz
Dietrich Arntz 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: 5852217Abstract: This invention relates to a process for the production of primary and/or secondary amines from oxo compounds by catalytic imination of the oxo compound with ammonia or a primary amine and subsequent hydrogenation. Imination proceeds according to the invention in the presence of a novel imination catalyst, namely an organopolysiloxane containing sulphonate groups. This imination catalyst is distinguished by elevated activity. The process is in particular suitable for the production of isophorone diamine from isophorone nitrile, wherein it has proved possible to reduce the content of secondary products and to increase yield.Type: GrantFiled: July 7, 1997Date of Patent: December 22, 1998Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Dietrich Arntz, Karl-Ludwig Weber, Willi Hofen, Stefan Wieland
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Patent number: 5831121Abstract: 3-hydroxy propionic acid is obtained in high yield through the catalytic oxidation of 3-hydroxy propionaldehyde with O.sub.2 or an O.sub.2 -containing gas in the aqueous phase in the presence of a platinum-group catalyst, in particular a Pd or Pt supported catalyst. The catalyst is used in a quantity corresponding to at least 10 percent by weight of the platinum-group metal relative to 3-hydroxy propionaldehyde.Type: GrantFiled: July 21, 1997Date of Patent: November 3, 1998Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Martin Meier, Christoph Brossmer, Dietrich Arntz, Andreas Freund
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Patent number: 5817870Abstract: Malonic acid or a salt of the same is obtained at high yield according to the invention through the catalytic oxidation with oxygen or an O.sub.2 -containing gas of 3-hydroxy propionaldehyde or 3-hydroxy propionic acid in the aqueous phase. The conversion takes place in the presence of at least 10 percent by weight, relative to the C.sub.3 building block used, of a precious metal from the platinum group. Pd and Pt supported catalysts are preferred.Type: GrantFiled: July 21, 1997Date of Patent: October 6, 1998Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Martin Meier, Christoph Brossmer, Dietrich Arntz, Andreas Freund
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Patent number: 5785942Abstract: A process for the highly efficient production of hydrocyanic acid by reacting methane and ammonia to yield hydrocyanic acid in a reactor heated by the combustion of fuel gases and coated with a catalyst. The process is characterized in that the reactor consists of a monolithic arrangement of heating and reaction channels, wherein the fuel gas and a gas containing oxygen pass through the heating channels and the reactants pass through the reaction channels, the internal walls of which are coated with the catalyst. The fuel gas is burned in the heating channels. The monolithic structure of the reactor is such that the heating channels and reaction channels are in intimate contact. The cross-section of the channels and the wall thicknesses thereof may be reduced without any loss of mechanical stability. Wall thicknesses of 0.1 to 1 mm are completely adequate.Type: GrantFiled: June 28, 1996Date of Patent: July 28, 1998Assignee: Degussa AktiengesellschaftInventors: Lukas Von Hippel, Christian Bussek, Dietrich Arntz
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Patent number: 5741904Abstract: A method of producing .epsilon.-caprolactam from cyclohexanone in the gaseous phase using MFI catalysts on whose surface symmetrically arranged OH groups are present.Type: GrantFiled: May 6, 1996Date of Patent: April 21, 1998Assignee: Degussa AktiengesellschaftInventors: Wolfgang Hoelderich, Joerg Roeseller, Dietrich Arntz
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Patent number: 5705706Abstract: 2-(Alkoxymethyl)acrolein of the formula ##STR1## is produced from acrolein, an alcohol ROH and formaldehyde, in one step, with a good yield being obtained. The acrolein is reacted with a substantially equimolar quantity of a source of formaldehyde in the presence of at least an equimolar quantity of the alcohol ROH and a catalytic quantity of a catalyst system based on a secondary amine and a mineral acid at a pH value of the reaction mixture in the range of 1 to less than 7.Type: GrantFiled: July 23, 1996Date of Patent: January 6, 1998Assignee: Degussa AktiengesellschaftInventors: Mathias Hoepp, Klaus Koehler, Dietrich Arntz
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Patent number: 5688973Abstract: Process for the production of 2-vinyl-1,3-dioxolane reacting acrolein with ethylene glycol in the presence of a solid, acidic catalyst and recovery of the reaction mixture. Selectivity may be increased in comparison with known prior art processes by performing the reaction in the presence of a solid acidic catalyst at a temperature of below 50.degree. C.; the reaction mixture, from which the catalyst has been removed, is treated by extraction using an organic solvent which substantially does not dissolve ethylene glycol and has a boiling point of above 130.degree. C.; the two phases obtained on extraction are treated for recovery by distillation and recovered educts and the organic solvent are recycled.Type: GrantFiled: September 5, 1995Date of Patent: November 18, 1997Assignee: Degussa AktiengesellschaftInventors: Mathias Hoepp, Dietrich Arntz, Wolfgang Boeck, Andreas Bosse-Plois, Klaus Raible
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Patent number: 5681973Abstract: Heteropolyoxometallates of tungsten, molybdenum and vanadium with a structurally defined micropore volume, a method of production by means of the hydrothermal reaction of the appropriate metal with an associated oxide, a diamine, phosphoric acid and water, and the use of the novel compounds as catalysts.Type: GrantFiled: July 13, 1995Date of Patent: October 28, 1997Assignee: Degussa AktiengesellschaftInventors: Wolfgang Hoelderich, Markus Hoelscher, Goetz-Peter Schindler, Ulli Englert, Bodo Zibrowius, Dietrich Arntz
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Patent number: 5679860Abstract: A process for producing 3-aminomethyl-3,5,5-trimethylcyclohexyl amine (isophorone diamine) from isophorone nitrile. Isophorone nitrile is iminated in a first stage and then the reaction mixture is subjected to aminating hydrogenation in a second stage in the presence of a fixed bed hydrogenation catalyst based on Raney cobalt. The fixed bed hydrogenation catalyst is produced in a special manner by mixing a powdery Co--containing Raney alloy with powdery cobalt, sintering the powdery mixture to shaped moldings and then activating by leaching with alkali hydroxide solution. The yield and/or space-time yield in isophorone diamine production can be increased.Type: GrantFiled: October 28, 1996Date of Patent: October 21, 1997Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Roland Burmeister, Dietrich Arntz, Karl-Ludwig Weber, Monika Berweiler
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Patent number: 5658844Abstract: A method of producing cyanopyridines by means of the catalytic reaction of methylpyridines with ammonia and oxygen at elevated temperature using catalysts consisting of compounds of the elements antimony, vanadium, silicon, titanium and oxygen and compounds of one or more of the alkali metals as well as a method of producing the catalysts and the catalysts themselves.Type: GrantFiled: February 1, 1996Date of Patent: August 19, 1997Assignee: Degussa AktiengesellschaftInventors: Lukas V. Hippel, Armin Neher, Dietrich Arntz
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Patent number: 5583260Abstract: A method of controlling the cis/trans isomer ratio in the preparation of isophoronediamine by the aminating hydrogenation of isophoronenitrile in the presence of ammonia, H.sub.2 and a catalyst. The reaction takes place in two temperature steps, initially at 10.degree. to 90.degree. C. and then at above 90.degree. to 150.degree. C. with a temperature difference of at least 30.degree. C. between the two steps, the contact time being shorter in the first step than in the second. The cis/trans ratio is increased by lowering the temperature of the first step.Type: GrantFiled: December 22, 1994Date of Patent: December 10, 1996Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Dietrich Arntz, Dieter Most
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Patent number: 5504254Abstract: A process is disclosed for the continuous preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine) in high yield and high purity from 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile) by aminating hydrogenation with hydrogen and ammonia in the presence of a fixed bed catalyst. The aminating hydrogenation is carried out by allowing a mixture of isophoronenitrile, ammonia and a C.sub.1 -C.sub.3 -alcohol, in the presence of hydrogen, to trickle over a trickle bed reactor provided with a Co and/or Ru fixed bed catalyst, at 3 to 8 MPa and at a temperature of 40.degree. to 150.degree. C., preferably 90 to 130.degree. C., and working up the reaction mixture by distillation. Preferably, a high-boiling by-product fraction, containing a bicyclic amidine, is added to the mixture to be hydrogenated, thereby appreciably increasing the yield.Type: GrantFiled: December 22, 1994Date of Patent: April 2, 1996Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Dietrich Arntz, Dieter Most
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Patent number: 5426249Abstract: A process is described for the simultaneous production of 1,2- and 1,3-propanediol from glycerol. The process involves the reaction stages (a) dehydration of glycerol by feeding a gaseous glycerol-water mixture with 10 to 40 wt % glycerol at 250.degree. to 340.degree. C. over a solid catalyst with an H.sub.0 value (Hammett acidity function) of less than 2, preferably between -3 and -8.2, (b) hydration of the acrolein contained in the reaction mixture of stage (a), and (c) catalytic hydrogenation of the reaction mixture, containing 3-hydroxypropionaldehyde and hydroxyacetone, of stage (b). Two valuable products, namely 1,2- and 1,3-propanediol, can be obtained simultaneously and in high total yield from glycerol in a simple process.Type: GrantFiled: November 12, 1993Date of Patent: June 20, 1995Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Armin Neher, Dietrich Arntz, Herbert Klenk, Walter Girke
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Patent number: 5387720Abstract: A process for the production of acrolein by dehydration of glycerol in the liquid phase or in the gaseous phase, in each case on acidic solid catalysts, is described. Compared with previously known processes, the space-time yield and catalyst service life may be surprisingly increased with higher selectivity by treating a glycerol-water mixture with a glycerol content of 10 to 40 wt. % at 180.degree. to 340.degree. C. (liquid phase) or at 250.degree. to 340.degree. C. (gaseous phase) on a solid catalyst with an H.sub.o value (Hammett acidity function) of less than +2, preferably less than -3.Type: GrantFiled: November 12, 1993Date of Patent: February 7, 1995Assignee: Degussa AktiengesellschaftInventors: Armin Neher, Thomas Haas, Dietrich Arntz, Herbert Klenk, Walter Girke
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Patent number: 5364984Abstract: Disclosed is a process for the preparation of 1,3-propanediol by the hydrogenation of hydroxypropionaldehyde (HPA) in aqueous solution on a formed carrier catalyst in a solid bed, the concentration of HPA in the solution being from 5 to 100% by weight and hydrogenation being carried out at temperatures of from 30.degree. to 180.degree. C. and hydrogen pressures of from 5 to 300 bar and at a pH of from 2.5 to 6.5. The carrier catalyst is formed principally of titanium oxide on which platinum is applied in a finely divided form in a quantity of from 0.1 to 5.0% by weight, based on the carrier.Type: GrantFiled: September 24, 1992Date of Patent: November 15, 1994Assignee: Degussa AktiengesellschaftInventors: Dietrich Arntz, Thomas Haas, Adolf Schafer-Sindlinger
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Patent number: 5364987Abstract: 1,3-propanediol (PD) is obtained by hydration of acrolein to 3-hydroxypropionaldehyde (HPA) with subsequent catalytic hydrogenation; 3,3'-oxybis-1-propanol (OD) occurs as a yield-reducing by-product. Disclosed is a process which increases the 1,3-propanediol yield. The OD which is separated by distillation during treatment of the reaction mixture containing PD and OD is treated in aqueous solution at from 100 to 300.degree. C. with an acid solid catalyst, in particular an acid zeolite, and the reaction mixture from which the solid catalyst has been removed is returned into the treatment stage of the reaction mixture containing PD and OD.Type: GrantFiled: July 6, 1993Date of Patent: November 15, 1994Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Dietrich Arntz
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Patent number: 5334778Abstract: 1,3-Propanediol produced in a known manner by catalytic hydrogenation of 3-hydroxypropionaldehyde (HPA) obtainable from acrolein has a high residual carbonyl content and leads to problems in the production of poly(1,3-propylene glycol terephthalate). Disclosed is a process for producing 1,3-propanediol having a residual carbonyl content, expressed as propionaldehyde, below 500 ppm and generally below 100 ppm produced in the presence of a fixed-bed or suspension hydrogenation catalyst under an H.sub.2 pressure of 5 to 300 bar providing the hydrogenation is carried out at 30.degree. to 80.degree. C. to an HPA conversion of 50 to 95% and is then continued at 100.degree. to 180.degree. C. to an HPA conversion of substantially 100%.Type: GrantFiled: May 19, 1993Date of Patent: August 2, 1994Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Norbert Wiegand, Dietrich Arntz
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Patent number: 5284979Abstract: A process is disclosed for the preparation of 3-hydroxyalkanals having 3 to 12 carbon atoms, in particular 3 or 4 carbon atoms, by hydration of the underlying 2-alkenals with water in a homogeneous phase in the presence of an acid catalyst. The previously known hydration using mineral acids or carboxylic acids as catalyst results in low volume/time yields and/or low selectivities. These disadvantages can be avoided by using in the present invention, as catalyst, a dissolved acid-base buffer which results in a pH of from 2 to 5 in the reaction mixture; the acid component and corresponding base of which are present in a total quantity of from 0.5 to 40% by weight in the reaction mixture. The preferred buffers composed of a lower monobasic carboxylic acid and a tertiary amine can easily be recycled.Type: GrantFiled: November 24, 1992Date of Patent: February 8, 1994Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Georg Bohme, Dietrich Arntz
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Patent number: 5276201Abstract: A process for the production of 3-hydroxyalkanals, more particularly 3-hydroxypropionaldehyde, by hydration of the basic 2-alkenals, more particularly acrolein, in the presence of a solid catalyst containing acid functional groups. The catalysts are based on an inorganic support containing basic activity centers (which are at least partly occupied by a polybasic acid, of which the first pK.sub.s value is between 0 and 3, in a form in which it cannot be removed by water) enables the hydration to be carried out with high selectivity. At the same time, the disadvantages of known organic fixed-bed catalysts are avoided. Preferred catalyst are based on pyrogenic titanium dioxide with phosphoric acid fixed thereon.Type: GrantFiled: November 24, 1992Date of Patent: January 4, 1994Assignee: Degussa AktiengesellschaftInventors: Thomas Haas, Dietrich Arntz, Reinhold Brand
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Patent number: 5234883Abstract: A catalyst for hardening unsaturated fatty acids obtained from the decomposition of fat is described, formed of an intimate mixture of titanium oxide and finely divided palladium metal, wherein the titanium oxide is pyrogenic titanium oxide obtained from titanium tetrachloride by flame hydrolysis.Type: GrantFiled: March 18, 1992Date of Patent: August 10, 1993Assignee: Degussa AktiengesellschaftInventors: Adolf Schaefer-Sindlinger, Dietrich Arntz