Patents by Inventor Thomas Gerdau

Thomas Gerdau 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).

  • Patent number: 5719284
    Abstract: The invention relates to a process for the preparation of substituted 3-arylquinazoline-2,4-diones of the formula (I) ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in claim 1 and Ar is ##STR2## where R.sup.5 to R.sup.9 are as defined in claim 1, by reacting a compound of the formula (II) ##STR3## with a compound Z in the presence of a catalyst, a ligand and a solvent, where Z isa) an anthranilic acid derivative of the formula (III) ##STR4## or b) an alcohol R.sup.10 --OH and where, in case b), the resulting carbamate is then reacted with an anthranilic acid derivative of the formula III.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: February 17, 1998
    Assignee: Hoecht Aktiengesellschaft
    Inventors: Jens Weiguny, Holger Borchert, Thomas Gerdau
  • Patent number: 5650537
    Abstract: A process for the preparation of N-acylglycine derivatives of the formula (I) ##STR1## which comprises reacting a carboxylic acid amide with an aldehyde in the presence of a solvent and an acid to give an acylaminomethylol and then carbonylating the acylaminomethylol in the presence of a cobalt carbonyl catalyst.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: July 22, 1997
    Assignee: Hoechst AG
    Inventors: Matthias Beller, Hartmut Fischer, Thomas Gerdau, Peter Gross
  • Patent number: 5648551
    Abstract: The invention relates to a process for the preparation of halobenzaldehydes of the formula (I): ##STR1## in which Hal is fluorine, chlorine, bromine or iodine and z=1, 2, 3 or 4, by catalytic gas-phase oxidation of a substituted toluene of the formula (II), ##STR2## by oxygen, which comprises carrying out the oxidation in the presence of a catalyst of the formula (III)Me.sup.1.sub.a Me.sup.2.sub.b Me.sup.3.sub.c O.sub.x (III),in which Me.sup.1 is bismuth or vanadium, Me.sup.2 is at least one of the elements selected from the group consisting of lithium, sodium, potassium, rubidium and cesium, Me.sup.3 is at least one element selected from the group consisting of iron, cobalt, nickel, niobium, molybdenum, arsenic, tin, antimony, tungsten, tantalum, phosphorus, chromium, manganese, palladium, copper, zinc, cerium, silver, boron, samarium, barium, calcium, magnesium and rhenium, and the letters a, b and c represent an atomic ratio of the respective elements such that when a=1, b has a value in the range from 0.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: July 15, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Holger Borchert, Thomas Gerdau, Jens Weiguny
  • Patent number: 5585523
    Abstract: Process for the preparation of aldehydes by catalytic gas phase hydrogenation of carboxylic acid or their derivatives with the aid of a tin catalystThe invention relates to a process for the preparation of aldehydes by catalytic gas phase hydrogenation of carboxylic acids or carboxylic acid derivatives at elevated temperature, which comprises employing at tin catalyst supplied to an oxidic support material.
    Type: Grant
    Filed: September 6, 1995
    Date of Patent: December 17, 1996
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jens Weiguny, Holger Borchert, Thomas Gerdau
  • Patent number: 5231224
    Abstract: The invention relates to alkyl ether carboxylic acid taurides of the formulaR.sup.2 --(OC.sub.2 H.sub.4).sub.n --O--CH.sub.2 --CO--NR.sup.1 --C.sub.2 H.sub.4 --SO.sub.3 M,in which n is greater than 0, R.sup.1 =H or C.sub.1 -C.sub.4 alkyl, R.sup.2 =C.sub.5 -C.sub.22 alkyl and M=H, Na, K, Ca/2 or Mg/2.Processes for their preparation and their use as surface-active substances, especially as mild cleaning agents for cosmetic purposes, are also described.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: July 27, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Alwin Reng, Walter Kunz
  • Patent number: 5189132
    Abstract: The invention relates to novel polymeric hydridochlorosilazanes, to their preparation, to their processing to form ceramic materials containing silicon nitride, and to said materials themselves. The polymeric hydridochlorosilazanes are prepared by reacting oligohydridoorganosilazanes of the general formula (R.sup.1 SiHNH).sub.n, in which n is about 3 to about 12, with at least one of the chlorosilanes R.sup.2 SiHCl.sub.2, R.sup.3 SiCl.sub.3, Cl.sub.2 R.sup.4 Si--CH.sub.2 CH.sub.2 --SiR.sup.4 Cl.sub.2 or Cl.sub.3 Si--CH.sub.2 CH.sub.2 --SiR.sup.5 Cl.sub.2 at 30.degree. C. to 300.degree. C., where the radicals independently of one another have the following meanings:R.sup.1 =a C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkenyl group,R.sup.2 =a C.sub.2 -C.sub.6 alkenyl group if R.sup.2 SiHCl.sub.2 is reacted with the oligosilazanes by itself, orR.sup.2 =a C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkenyl group if R.sup.2 SiHCl.sub.2 is reacted with the oligosilazanes as a mixture with other chlorosilanes, andR.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: February 23, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Tilo Vaahs, Thomas Gerdau, Hans-Jerg Kleiner, Marcellus Peuckert, Martin Bruck
  • Patent number: 5176941
    Abstract: The invention relates to a process for the production of a ceramic/fiber composite.The process comprises impregnating fibers with a molten polysilazane in a first step, converting the polysilazane in the fibers into the infusible state in a second step and, in a third step, heating the impregnated fibers to 800.degree. to 2000.degree. C. in an atmosphere of nitrogen, noble gas, or ammonia.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: January 5, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Marcellus Peuckert, Martin Bruck, Thomas Gerdau, Tilo Vaahs, Hans-Jerg Kleiner, Fritz Aldinger
  • Patent number: 5081080
    Abstract: The invention relates to novel polymeric hydridosilazanes, their preparation, their conversion into silicon nitride-containing ceramic material, and this material itself. To prepare the polymeric hydridosilazanes, polymeric hydridothiosilazanes are reacted with NH.sub.3. To prepare the silicon nitride-containing ceramic material, the polymeric hydridosilazanes are then pyrolyzed.
    Type: Grant
    Filed: April 20, 1990
    Date of Patent: January 14, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Tilo Vaahs, Thomas Gerdau, Marcellus Peuckert, Martin Bruck
  • Patent number: 5081078
    Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation, to its processing to form silicon nitride ceramic and to said material itself and its use. The sinterable ceramic powder is prepared by dissolving the polysilazane of formula (I)[CH.sub.3 SiHNH].sub.n [CH.sub.3 SiN].sub.nwhere n is about 10 to 12, in an organic solvent, suspending a pulverulent sinter aid in this solution and then evaporating the solvent and pyrolyzing the residue in an inert gas atmosphere at 500.degree. to 1600.degree. C.The resulting ceramic powder can be used to form a shaped article and then to manufacture silicon nitride ceramic by sintering. It is also possible, however, to form a shaped article from the as yet unpyrolyzed residue obtained after evaporation of the solvent, and then to pyrolyze and sinter said article.The ceramic obtained can be used to manufacture components subject to high mechanical, thermal and corrosive stress.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: January 14, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Marcellus Peuckert, Martin Bruck, Thomas Gerdau, Hans-Jerg Kleiner, Tilo Vaahs, Fritz Aldinger
  • Patent number: 5075266
    Abstract: The invention relates to a process for the production of ceramic material containing silicon nitride, such as fibers, coatings or moldings. In this process, polymeric hydridochlorosilazanes are rendered infusible at a temperature below their softening point by treatment with gaseous NH.sub.3 and are then pyrolyzed in an atmosphere containing NH.sub.3 at 700.degree. to 1500.degree. C. Fibers, coatings or moldings containing silicon nitride are produced by first producing appropriate structures from a melt of the polymeric hydridochlorosilazane and then rendering them infusible and pyrolyzing them.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: December 24, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Hans-Jerg Kleiner, Martin Bruck, Marcellus Peuckert, Fritz Aldinger
  • Patent number: 5066623
    Abstract: The invention relates to novel polymeric hydridosilazanes, processes for their preparation and their use for the preparation of ceramic material containing silicon nitride. To prepare the polymeric hydridosilazanes, polymeric hydridochlorosilazanes are reacted with NH.sub.3. To prepare the ceramic material containing silicon nitride, the polymeric hydridosilazanes are then pyrolyzed.
    Type: Grant
    Filed: March 12, 1990
    Date of Patent: November 19, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Hans-Jerg Kleiner, Marcellus Peuckert, Martin Bruck, Fritz Aldinger
  • Patent number: 5008423
    Abstract: The invention relates to novel polymeric hydridochlorosilazanes and a process for their preparation. The compounds according to the invention can be converted into polyhydridosilaznes by reaction with ammonia, and these can in turn be pyrolyzed to ceramic material containing silicon nitride. To prepare the polymeric hydridochlorosilazanes, oligohydridoalkylsilazanes (R.sup.1 SiHNH).sub.n are reacted with a dichlorohydridoalkylsilane R.sup.2 SiHCl.sub.2.
    Type: Grant
    Filed: September 22, 1988
    Date of Patent: April 16, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Hans-Jerg Kleiner, Marcellus Peuckert, Martin Bruck, Fritz Aldinger
  • Patent number: 4966991
    Abstract: A process for the production of alkali-phosphonoformates which comprises bringing together in a first stage a trialkyl ester of phosphonoformic acid and an aqueous solution of an alkali hydroxide at a temperature in the range from the freezing point of water and about 40.degree. C., either keeping the resulting mixture in a second stage for further progress of the reaction and then heating the reaction mixture in a third stage to a temperature up to about 100.degree. C. for completion of the saponification, or heating the reaction mixture immediately for completion of the saponification to a temperature of up to 100.degree. C.
    Type: Grant
    Filed: July 1, 1988
    Date of Patent: October 30, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Thomas Gerdau
  • Patent number: 4939225
    Abstract: Polymeric hydridosilazanes, processes for the preparation thereof, silicon nitride-containing ceramic materials which can be prepared therefrom, and the preparation thereof.The invention relates to novel polymeric hydridosilazanes, their preparation, their conversion into silicon nitride-containing ceramic material, and this material itself. To prepare the polymeric hydridosilazanes, polymeric hydridothiosilazanes are reacted with NH.sub.3. To prepare the silicon nitride-containing ceramic material, the polymeric hydridosilazanes are then pyrolyzed.
    Type: Grant
    Filed: December 23, 1988
    Date of Patent: July 3, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Tilo Vaahs, Thomas Gerdau, Marcellus Peuckert, Martin Bruck
  • Patent number: 4931513
    Abstract: The invention relates to novel polymeric hydridosilazanes, processes for their preparation and their use for the preparation of ceramic material containing silicon nitride. To prepare the polymeric hydridosilazanes, polymeric hydridochlorosilazanes are reacted with NH.sub.3. To prepare the ceramic material containing silicon nitride, the polymeric hydridosilazanes are then pyrolyzed.
    Type: Grant
    Filed: September 22, 1988
    Date of Patent: June 5, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Hans-Jerg Kleiner, Marcellus Peuckert, Martin Bruck, Fritz Aldinger
  • Patent number: 4859795
    Abstract: Compounds of the general formula ##STR1## wherein X and Y are the same or different and denote oxygen or sulfur,R.sub.1 is an ethylenically unsaturated aliphatic radical containing from 2 to 6 carbon atoms, andR.sub.2 is a saturated aliphatic radical containing from 1 to 6 carbon atoms or an aryl radical containing from 6 to 10 carbon atoms,are intermediate products used for the preparation of photocrosslinkable polymers with lateral (thio)phosphinyl(thio)urethane groups or (thio)phosphinyl(thio)urea groups, which polymers are useful in photosensitive mixtures and recording material.
    Type: Grant
    Filed: May 8, 1987
    Date of Patent: August 22, 1989
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Gerdau, Hans-Jerg Kleiner, Georg Pawlowski
  • Patent number: 4859562
    Abstract: A photosensitive mixture that contains a photosensitive compound, for example, a photoinitiator or a diazo compound, and a reaction product of a polymer containing active hydrogen with an olefinically unsaturated compound represented by the formula ##STR1## wherein X and Y are the same or different and denote oxygen or sulfur,R.sub.1 is an olefinically unsaturated aliphatic radical containing 2 to 8 carbon atoms andR.sub.2 is a saturated aliphatic radical containing 1 to 8 carbon atoms or an aryl radical containing 6 to 10 carbon atoms,is suitable for producing photoresists and printing plates.
    Type: Grant
    Filed: May 8, 1987
    Date of Patent: August 22, 1989
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Georg Pawlowski, Hans-Jerg Kleiner, Thomas Gerdau