Patents by Inventor Thomas Lieser

Thomas Lieser 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: 5902682
    Abstract: Coated sodium percarbonate particles contain, in the coating, sodium carbonate and also one or more magnesium compounds, preferably magnesium sulfate, optionally in a partially hydrated form, in a single layer or in separate layers in the coating. Preferred coated sodium percarbonate particles contain two layers. Particles are prepared by spraying aqueous solutions containing the coating components onto sodium percarbonate in a fluidized bed with simultaneous evaporation of the water. The particles are suitable for use in detergents, bleaches and cleansing agents.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: May 11, 1999
    Assignee: Degussa Aktiengesellschaft
    Inventors: Birgit Bertsch-Frank, Martin Bewersdorf, Claas-Juergen Klasen, Thomas Lieser, Klaus Mueller, Juergen Rollmann
  • Patent number: 5658873
    Abstract: Sodium percarbonate is often used in the form of coated particles to increase its storage stability in detergents.Sodium percarbonate particles coated in accordance with the invention have a coating containing reaction products from the reaction of a dialkali metal tetraborate or alkali metal pentaborate with aqueous hydrogen peroxide. Preferred coating components are: perborax with the formula Na.sub.2 B.sub.4 O.sub.7 .multidot.H.sub.2 O.sub.2, where n =2 or 4.The coated sodium percarbonate particles are produced by coating the percarbonate particles using a solution containing the reaction products mentioned above.Detergent, bleaching and cleaning compositions containing sodium percarbonate particles coated in accordance with the invention are distinguished by very high stability in storage.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: August 19, 1997
    Assignee: Degussa Aktiengesellschaft
    Inventors: Birgit Bertsch-Frank, Claas-Juergen Klasen, Thomas Lieser, Klaus Mueller, Martin Bewersdorf
  • Patent number: 5632965
    Abstract: The invention relates to a method for increasing the storage stability of sodium percarbonate (2 Na.sub.2 CO.sub.3.3 H.sub.2 O.sub.2) by coating with a sodium perborate.According to the present invention wet sodium percarbonate salt, obtained by reacting sodium carbonate with hydrogen peroxide in aqueous phase and separating the salt from the aqueous phase, is treated with a solution or suspension containing sodium perborate in a solid-liquid separator by a kind of displacement wash. In contrast to previously known methods, according to the present invention a greater storage stability is attained with smaller quantities of perborate coating.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: May 27, 1997
    Assignee: Degussa Aktiengesellschaft
    Inventors: Claas-Juergen Klasen, Birgit Bertsch-Frank, Thomas Lieser, Peter Schubert, Klaus Mueller
  • Patent number: 5560896
    Abstract: Sodium percarbonate is produced by means of fluidized bed granulation. The process includes spraying an aqueous sodium carbonate solution and a hydrogen peroxide solution onto nuclei in a fluidized bed and evaporating the water. In the process of the invention, it is not necessary to use a phosphorus-containing crystallization inhibitor in order to avoid cloggings and incrustations in and on the nozzle. This is accomplished by spraying the solutions through separate channels in a single ternary atomizer nozzle, to provide external mixing of the solutions with respect to the nozzle.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: October 1, 1996
    Assignee: Degussa Aktiengesellschaft
    Inventors: Martin Bewersdorf, Claas-Jurgen Klasen, Petra Look-Herber, Birgit Bertsch-Frank, Thomas Lieser, Klaus Muller
  • Patent number: 5395602
    Abstract: The invention relates to sodium perborate hydrate granulates and a method for producing sodium perborate hydrate granulates with an available oxygen content of 14 to 18% by weight, especially 15 to 16% by weight; an abrasion index according to ISO test 5937 of not more than 10%; with a rate of dissolution of below 1.5 minutes, preferably below 1.0 minutes (for 1 gram of the granulate in 500 cm.sup.3 water, at 15.degree. C.); and with a bulk weight in the range of 0.6 to 1.2 kg/dm.sup.3. The sodium perborate hydrate granulate can be produced by compacting spray-dried, essentially amorphous sodium perborate hydrate starting material which exhibits a bulk weight below that of the granulate product, and a particle size of 90% less than 100 micrometers. The hydrate starting material is further characterized in that it loses 0.2 to 2.0% of its weight when stored at 60.degree. C. and 100 Pa for 30 minutes. The starting material is compacted between rollers at a contact pressure of 5.times.10 to 2.times.10.sup.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: March 7, 1995
    Assignee: Degussa Aktiengesellschaft
    Inventors: Joerg Herzig, Wolfgang Zikofsky, Birgit Bertsch-Frank, Thomas Lieser
  • Patent number: 5094827
    Abstract: The spray drying of a solution containing hydrogen peroxide and sodium metaborate to obtain primary particles which are immediately conveyed after leaving the drying zone to a granulating device and are then granulated in the presence of free and/or perborate water of crystallization. The granulated materials are dried, if necessary. The generally amorphous primary particles are converted into granulated materials with at least partially crystalline structure and significantly improved shelf life. The work is performed with advantage in a spray dryer with integrated fluid bed or in a compressing granulating device. The method is suitable for preparing perborate granulated materials with an active oxygen content of over 10% by weight, especially perborate monohydrate granular materials with 14 to 16% by weight active oxygen. A rapidly dissolving product is produced with an acceptable apparent weight for ease in packaging.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: March 10, 1992
    Assignee: Degussa Aktiengesellschaft
    Inventors: Birgit Bertsch-Frank, Klaus Mueller, Thomas Lieser
  • Patent number: 4968500
    Abstract: The spray drying of a solution containing hydrogen peroxide and sodium metaborate to obtain primary particles which are immediately conveyed after leaving the drying zone to a granulating device and are then granulated in the presence of free and/or perborate water of crystallization. The granulated materials are dried, if necessary. The generally amorphous primary particles are converted into granulated materials with at least partially crystalline structure and significantly improved shelf life. The work is performed with advantage in a spray dryer with integrated fluid bed or in a compressing granulating device. The method is suitable for preparing perborate granulated materials with over 10% by wt., especially perborate monohydrate granular materials with 14-16% by wt. active oxygen.
    Type: Grant
    Filed: May 17, 1989
    Date of Patent: November 6, 1990
    Assignee: Degussa Aktiengesellschaft
    Inventors: Birgit Bertsch-Frank, Klaus Mueller, Thomas Lieser
  • Patent number: 4879057
    Abstract: Aqueous bleaching agent suspensions based on a water-soluble peroxycarboxylic acid suspended in a carrier liquid in the presence of an organic thickening agent and of an acidifying agent exhibit an improved storage resistance over known suspensions with this base. This is achieved by means of pourable to pasty bleaching agent suspensions which contain a xanthan polysaccharide or agar polysaccharide as thickening agent and, in addition, a hydrate-forming neutral salt which desensitizes peroxycarboxylic acids. Preferred suspensions exhibit a pH of 2-5 and contain 10-30% by wt. diperoxydodecanedioic acid, 5-20% by wt. sodium sulfate and 0.1-1.0% by wt. xanthan. The use of non-dried, hydrophilized and optionally in situ desensitized peroxycarboxylic acids is especially preferred.The bleaching agent suspensions are prepared by homogeneously suspending the peroxycarboxylic acid in the thickened carrier liquid.
    Type: Grant
    Filed: March 16, 1988
    Date of Patent: November 7, 1989
    Assignee: Degussa Aktiengesellschaft
    Inventors: Manfred Dankowski, Thomas Lieser, Gunter Prescher, Wolfgang Leonhardt, Manfred Diehl
  • Patent number: 4790949
    Abstract: Aqueous bleaching agent suspensions based on a water-insoluble peroxycarboxylic acid suspended in a carrier liquid in the presence of a colloidal silicic acid and of an acidifying agent which exhibit, in comparision to known suspensions with this base, an improved storage resistance and are more economical to prepare. This result is achieved by means of pourable-to-pasty bleaching agent suspensions which contain 0.1 to 9% by weight silicic acid in relation to the suspension and contain a hydrate-forming neutral salt which desensitizes peroxycarboxylilc acids, in an amount of 10 to 400% by weight, calculated hydrate-free and in relation to peroxycarboxylic acid added. Preferred bleaching agent suspensions contain 10-30% by weight diperoxydodecanedioic acid, 5-20% by weight sodium sulfate and 2 to 6% by weight pyrogenic silicic acid, each in relation to the suspension. The use of non-dried, hydrophilized and optionally in situ-desensitized peroxycarboxylic acids is especially preferred.
    Type: Grant
    Filed: March 16, 1988
    Date of Patent: December 13, 1988
    Assignee: Degussa Aktiengesellschaft
    Inventors: Manfred Dankowski, Thomas Lieser, Gunter Prescher, Wolfgang Leonhardt