Patents by Inventor Karl Gaa

Karl Gaa 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: 6491853
    Abstract: The present application relates to storage-stable plastics additives which are prepared by cooling a mixture of 99.9 to 10% by weight of molten additive material and 0.1 to 90% by weight of crystalline additive material after a shaping process. The shaping process is carried out by forcing the mixture out of a tool provided with die openings, and cooling can be carried out on a cooled conveyor belt. Even after prolonged storage and/or handling, these plastics additives remain free-flowing and do not stick.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: December 10, 2002
    Assignee: Clariant GmbH
    Inventors: Karl Gaa, Günter Nowy, Gerhard Pfahler, Matthias Zäh
  • Patent number: 6225385
    Abstract: The present invention relates to a stabilizer mixture prepared by partially condensing PCl3 with 2,2′-dimethyl-4,4′-dihydroxy-5,5′-di-tert-butyldiphenyl sulfide, where the phosphorus content is from 2 to 4% by weight and the content of 2,2′-dimethyl-4,4′-dihydroxy-5,5′-di-tert-butyldiphenyl sulfide is from 0.5 to 50% by weight. The stabilizer mixture has very good solubility in organic solvents and in the polymer and has very good stabilizing action.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: May 1, 2001
    Assignee: Clariant GmbH
    Inventors: Thomas Stährfeldt, Alexander Lichtblau, Gerhard Pfahler, Karl Gaa
  • Patent number: 5919933
    Abstract: The present invention relates to novel UV stabilizers of the formula (I) ##STR1## where the substituents are as defined in the description. These compounds are highly suitable for stabilizing organic material, such as plastics, surface coatings, paints and oils, against the action of light, radiation, oxygen and heat.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: July 6, 1999
    Assignee: Clariant GmbH
    Inventors: Karl Gaa, Matthias Zah, Mathias Mehrer, Gerhard Pfahler, Thomas Stahrfeldt
  • Patent number: 5852159
    Abstract: The present invention relates to plastics comprising a high molecular weight, sterically hindered amine, wherein the sterically hindered amine is at least one amine from the group consisting ofI: oligomerized 2,2,4,4-tetramethyl-20(oxiranylmethyl)-7-oxa-3,20-diazadispiro?5.1.11.2!he neicosan-21-one,II: condensation product of 2-chloro-4,6-di(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triaz ine and 1,2-bis(3-aminopropylamino)ethane, andIII: condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid.These plastics exhibit a reduced rate of uptake of sulfur compounds.The invention further relates to shaped articles made from these plastics.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: December 22, 1998
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Matthias Zah, Gerhard Pfahler, Karl Gaa, Klaus Keck-Antoine
  • Patent number: 5633378
    Abstract: Polyalkylpiperidine compounds of the formula I ##STR1## in which Y is the group ##STR2## are very effective stabilizers for organic materials.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: May 27, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karl Gaa, Matthias Z ah, Josef Wiedemann
  • Patent number: 5594142
    Abstract: The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in a solvent mixture of at least one alcohol and if appropriate an inert organic solvent in the presence of solid alkali metal hydroxide or a corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by using a solvent mixture and dispensing with a phase transfer catalyst, a higher rate of reaction and therefore higher product quality with the same yield are achieved. By dispensing with a phase transfer catalyst, which remains in the waste water and must be disposed of expensively, and by the reusability of the solvent mixture, the process is more environment-friendly and more economical than processes known to date.
    Type: Grant
    Filed: February 16, 1995
    Date of Patent: January 14, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karl Gaa, G unter Nowy, Georg Schmailzl
  • Patent number: 5550234
    Abstract: Polyalkylpiperidine compounds of the formula I ##STR1## in which Y is one of the groups ##STR2## are distinguished by very low volatility at elevated temperature and are very effective stabilizers for organic substances.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: August 27, 1996
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karl Gaa, Matthias Z ah
  • Patent number: 5550242
    Abstract: The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in an inert organic solvent in the presence of solid alkali metal hydroxide or of the corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by changing the reaction procedure in a multiphase system and avoiding the use of a phase transfer catalyst, equally good results are achieved with regard to product quality and yield. Additionally, it is possible to reduce the reaction time from over 6 hours to 30 minutes. This results in a considerable rise in the space-time yield and consequently contributes, in addition, to an increase in the economy of the process of the invention.
    Type: Grant
    Filed: February 16, 1995
    Date of Patent: August 27, 1996
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karl Gaa, Matthias Z ah