Patents by Inventor Stefan Dreher
Stefan Dreher 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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Publication number: 20240077305Abstract: A measurement apparatus (10) for interferometrically measuring a shape of a surface (12) of a test object (14) in relation to a reference shape includes a diffractive optical element (30) generating a test wave (32) from measurement radiation (22), whereas a wavefront of the test wave is adapted to a target shape of the surface of the test object and the target shape is configured as a first non-spherical surface, and a reference element (38) with a reference surface (40) having the reference shape, the reference shape being configured as a further non-spherical surface and the reference element including a low thermal expansion material with a mean coefficient of thermal expansion having an absolute value of no more than 200×10?6 K?1 in the temperature range from 5° C. to 35° C.Type: ApplicationFiled: September 25, 2023Publication date: March 7, 2024Inventors: Jochen HETZLER, Stefan SCHULTE, Matthias DREHER
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Patent number: 7767130Abstract: The invention relates to a method and device for production of a three-dimensional article from a material, by means of layered application. According to the invention, a dropwise application is carried out, whereby drops of reaction components are ejected by a nozzle arrangement (3) and applied to a base reaction component (2), arranged on a substrate (1). The material for the three-dimensional article is formed in layers, with reaction of the base reaction component (2) with reaction components on contact, whereby the material is formed on a reaction of the base reaction component with one of the reaction components to give a material with one material property and on another reaction of the base reaction component with another of the reaction components to give a material with another material property. On production of the three-dimensional article, an article section is produced in which a gradual transition between the one material property and the other material property is generated.Type: GrantFiled: May 24, 2005Date of Patent: August 3, 2010Assignee: Voxeljet Technology GmbHInventors: Philip Elsner, Stefan Dreher, Ingo Ederer, Brigitte Voit, Janke Gudrun, Michael Stephan
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Publication number: 20080233302Abstract: The invention relates to a method and device for production of a three-dimensional article from a material, by means of layered application. According to the invention, a dropwise application is carried out, whereby drops of reaction components are ejected by a nozzle arrangement (3) and applied to a base reaction component (2), arranged on a substrate (1). The material for the three-dimensional article is formed in layers, with reaction of the base reaction component (2) with reaction components on contact, whereby the material is formed on a reaction of the base reaction component with one of the reaction components to give a material with one material property and on another reaction of the base reaction component with another of the reaction components to give a material with another material property. On production of the three-dimensional article, an article section is produced in which a gradual transition between the one material property and the other material property is generated.Type: ApplicationFiled: May 24, 2005Publication date: September 25, 2008Applicants: TECHNISCHE UNIVERSITÄT BERLIN, VOXELJET TECHNOLOGY GMBH, INSTITUT FÜR POLYMERFORSCHUNG DRESDEN E.V.Inventors: Philip Elsner, Stefan Dreher, Ingo Ederer, Brigitte Voit, Janke Gudrun, Michael Stephan
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Patent number: 6897256Abstract: A description is given of a polymer dispersion comprising i) polymer particles dispersed in an aqueous medium and composed of units of ethylenically unsaturated monomers, ii) a water-soluble polymeric polyelectrolyte which along a polymeric backbone carries a large number of ionic groups of uniform charge character or groups which can be ionized to such groups, and iii) an ionic surfactant which carries an ionic group having a charge character opposite to that of the polymeric polyelectrolyte, or a group which can be ionized to such a group. The polymer dispersion can be coagulated by simple dilution with water.Type: GrantFiled: January 7, 2000Date of Patent: May 24, 2005Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Bernd Reck, Michael Seufert, Christian Pfaff
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Patent number: 6841608Abstract: An aqueous polymer dispersion, a process for preparing it, and substrates bound on the basis of it are described.Type: GrantFiled: October 13, 2000Date of Patent: January 11, 2005Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Bernd Reck, Michael Seufert, Johannes Türk
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Patent number: 6716922Abstract: The invention relates to a thermally hardenable polymer dispersion powder and the use of said powder as a binding agent in particular for fibrous and grainy materials. The binding agent in powder form is obtained by drying a polymer dispersion which comprises a carboxyl-group-containing polymerization component in addition to, optionally, a hydroxy-alkylated amine.Type: GrantFiled: April 15, 2002Date of Patent: April 6, 2004Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Bernd Reck, Michael Seufert, Johannes Türk, Matthias Laubender, Matthias Gerst, Heinrich Sack
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Publication number: 20040047694Abstract: The invention relates to polymer-modified earthwork materials, containing a) a mineral main constituent based on sand, grit and/or gravel and b) at least one hydrophobic synthetic polymer that is uniformly distributed in the mineral main constituent. The invention also relates to a method for the production of said materials and to a method for the fortification of earth.Type: ApplicationFiled: June 16, 2003Publication date: March 11, 2004Inventors: Mario Sandor, Stefan Dreher, Joachim Pakusch, Hans-Jurgen Denu
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Patent number: 6656994Abstract: The use is described of polysulfide-free preparations comprising, based on solids content, from 40 to 99.5% by weight of at least one water-dispersible copolymer and from 0.5 to 10% by weight of at least one alkoxylated ionic or nonionic emulsifier, as additives for construction materials based on loam or clay. The building materials based on loam or clay and comprising the preparation are described, as are the use of the construction materials and a process for treating construction materials with the preparation.Type: GrantFiled: November 9, 2001Date of Patent: December 2, 2003Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Joachim Roser, Joachim Pakusch, Dietbert Knöfel, Karl-Georg Boettger
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Patent number: 6617387Abstract: Ammonia-free polymer dispersions containing at least one copolymer which contains, as polymerized monomers, a) from 40 to 80% by weight of at least one ester of acrylic acid with C2-C12-alkanols, b) from 10 to 40% by weight of at least one vinylaromatic monomer and/or at least one ester of methacrylic acid with C1-C4-alkanols, c) from 2 to 15% by weight of at least one monoester of a C2-C10-alkanediol with acrylic acid or methacrylic acid, d) not more than 1% by weight of ethylenically unsaturated monomers which have at least one acid group, or salts thereof, e) less than 5% by weight of &agr;,&bgr;-ethylenically unsaturated nitrites and f) less than 1% by weight of amides of &agr;,&bgr;-ethylenically unsaturated mono- and dicarboxylic acids, and the polymer powders or polymer granules obtainable from the polymer dispersion, are used as additives for building materials based on hydraulic binders.Type: GrantFiled: August 20, 2001Date of Patent: September 9, 2003Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Joachim Pakusch, Bernd Reck
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Publication number: 20030017288Abstract: The disclosure is a water containment bag comprising an at least partially water-pervious wall material enclosing a mixture of sand and a water-insoluble redispersible synthetic polymer powder having a glass transition temperature of below 50° C. It possesses improved mechanical strength and watertightness.Type: ApplicationFiled: June 13, 2002Publication date: January 23, 2003Inventors: Stefan Dreher, Joachim Pakusch, Mario Sandor
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Patent number: 6489381Abstract: Cement-based compositions comprising per 100 parts by weight of cement from 1 to 500 parts by weight of a polymer built up from a) 30-99.5% by weight of at least one alkyl ester of (meth)acrylic acid, b) 0-70% by weight of at least one vinylaromatic, c) 0.5-10% by weight of at least one alkyl polyethoxy(meth)acrylate of the formula where R1 is a hydrogen atom or a methyl group, R2 is a C1 to C4 alkyl group and n is an integer from 1 to 55, d) 0-10% by weight of at least one ethylenically unsaturated mono- or dicarboxylic acid, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, or anhydride, amide or hydroxyalkylamide thereof, e) 0-10% by weight of acrylonitrile or methacrylonitrile, and f) 0-50% by weight of further ethylenically unsaturated compounds other than a) to e).Type: GrantFiled: August 17, 2000Date of Patent: December 3, 2002Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Joachim Pakusch, Mario Sandor, Bernd Reck, Claudia Wood, Hans-Jürgen Denu
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Publication number: 20020049265Abstract: Ammonia-free polymer dispersions containing at least one copolymer which contains, as polymerized monomers,Type: ApplicationFiled: August 20, 2001Publication date: April 25, 2002Applicant: BASF AktiengesellschaftInventors: Stefan Dreher, Joachim Pakusch, Bernd Reck
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Patent number: 6348530Abstract: Heat-curable aqueous compositions which comprise a carboxyl-containing polymer component and optionally a hydroxyalkylated amine are used as binders for shaped articles.Type: GrantFiled: January 4, 2000Date of Patent: February 19, 2002Assignee: BASF AktiengesellschaftInventors: Bernd Reck, Stefan Dreher, Wilhelm Friedrich Beckerle, Eckehardt Wistuba, Michael Seufert, Joachim Roser, Johannes Türk
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Patent number: 6299936Abstract: Thermally curable aqueous compositions comprising a low-acid and an acid-rich polymer component and also a hydroxyalkylated amine are used as binders for shaped articles.Type: GrantFiled: February 17, 2000Date of Patent: October 9, 2001Assignee: BASF AktiengesellschaftInventors: Bernd Reck, Stefan Dreher, Wilhelm Friedrich Beckerle, Eckehardt Wistuba, Joachim Roser, Johannes Türk
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Patent number: 6262159Abstract: Described is a polymer dispersion comprising in an aqueous medium (a) dispersed particles of a polymer containing more than from 5 to 20% by weight of &agr;,&bgr;-ethylenically unsaturated mono- or dicarboxylic acid, (b) a dissolved polymer containing from 60 to 100% by weight of &agr;,&bgr;-ethylenically unsaturated mono- or dicarboxylic acid, and (c) an alkoxylated long-chain amine. Heat-curable compositions are obtained by adding polyfunctional alcohols and, optionally, reaction accelerant. The polymer dispersions and the heat-curable compositions are suitable for use as binders for textile sheetlike structures and for moldings.Type: GrantFiled: January 7, 2000Date of Patent: July 17, 2001Assignee: BASF AktiengesellschaftInventors: Stefan Dreher, Bernd Reck, Michael Seufert, Johannes Türk