Patents by Inventor Helmut Lask
Helmut Lask 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: 4924084Abstract: A device for determining surface moisture, especially of absorbent materials, comprises a Dove reflection prism, a radiation source of such a design that its beams, which are aligned parallel, perpendicularly strike one of the two small surfaces of the prism, a light trap which traps the light beams emanating from the other small surface, and a photoelectric transducer which is located in the angle formed by the two small surfaces and is arranged such that its measurement surface is located parallel and opposite to the hypotenuse surface of the prism.Type: GrantFiled: October 13, 1988Date of Patent: May 8, 1990Assignee: Hoechst AktiengesellschaftInventors: Helmut Lask, Arno Holst, Kurt Dryczynski, deceased
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Patent number: 4250306Abstract: This invention relates to a process for preparing swellable cross-linked carboxyalkylcelluloses by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers, textile sheet materials containing these fibers, or sheet materials of other kinds, having a base of cellulose hydrate or of natural cellulose, by contacting said fibers or sheet materials with an ample quantity of an aqueous alkaline reaction mixture, removing part of the reaction mixture from the fibers or sheet materials contacted therewith, so that at least the quantity required for reaction is still present, and treating the fibers or sheet materials containing the remainder of the aqueous alkaline reaction mixture with heat energy. The invention also relates to equipment for performing the process.Type: GrantFiled: May 29, 1979Date of Patent: February 10, 1981Assignee: Hoechst AktiengesellschaftInventors: Helmut Lask, Arno Holst, Ehrenfried Nischwitz, Hans Sommer
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Patent number: 4248595Abstract: This invention relates to a process for preparing swellable cross-linked carboxyalkylcelluloses in the form of fibers, by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers of cellulose hydrate or fiber-based textile sheet materials which contain these fibers, by contacting said fibers or textile sheet materials which contain these fibers with an ample quantity of an aqueous alkaline reaction mixture, removing part of the reaction mixture from the fibers or the textile sheet materials contacted therewith, so that at least the quantity required for reaction is still present, and treating the fibers or the textile sheet materials containing the remainder of the aqueous alkaline reaction mixture with heat energy.Type: GrantFiled: May 29, 1979Date of Patent: February 3, 1981Assignee: Hoechst AktiengesellschaftInventors: Helmut Lask, Arno Holst
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Patent number: 4200558Abstract: Hydrophilic films, fibers and spongy articles of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, are produced by distributing in a mass of the polymer up to 50% of pulverulent or granular amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent. The resulting mixture is then processed by conventional methods into the desired article.Type: GrantFiled: May 8, 1978Date of Patent: April 29, 1980Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask
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Patent number: 4194024Abstract: This invention relates to a hydrophilic shaped article of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, said article containing amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent.Type: GrantFiled: May 8, 1978Date of Patent: March 18, 1980Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask
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Patent number: 4187342Abstract: This invention relates to a bonded fiber web capable of absorbing water vapor and composed of synthetic, natural or regenerated fibers with a uniformly incorporated additive of at least one polymer, said additive comprising fibrous particles of at least one swellable carbohydrate derivative or a swellable modified carbohydrate derivative. The invention also relates to a process for the manufacture of the bonded fiber web.Type: GrantFiled: March 10, 1978Date of Patent: February 5, 1980Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask, Ehrenfried Nischwitz, Wilhelm Fischer
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Patent number: 4186238Abstract: This invention relates to a hydrophilic shaped article of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, said article containing amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent.Type: GrantFiled: September 30, 1977Date of Patent: January 29, 1980Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask
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Patent number: 4171705Abstract: This invention relates to a cigarette filter of cellulosic material composed at least partially of modified cellulose modified with at least one fatty acid group containing at least 14 carbon atoms in the molecule selected from the group consisting of a complex compound of a fatty acid containing basic chromium chloride and a melamine resin precondensate containing a fatty acid group.Type: GrantFiled: December 17, 1976Date of Patent: October 23, 1979Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask
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Patent number: 4144886Abstract: An absorbent laminate comprising a first layer of absorbent material and at least one layer comprising a tissue having an absorbent carbohydrate derivative on at least one face.Type: GrantFiled: October 26, 1976Date of Patent: March 20, 1979Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask
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Patent number: 4136218Abstract: Process for improving the water-absorbing capacity and absorptivity of fibrous materials consisting of, or containing, synthetic fibers or filaments, which comprises applying modified, highly absorbing cellulose ethers onto the fibrous materials and fixing these cellulose ethers on the fibrous material with the aid of finishing agents, resins or binders.Type: GrantFiled: August 27, 1975Date of Patent: January 23, 1979Assignee: Hoechst AktiengesellschaftInventors: Ehrenfried Nischwitz, Arno Holst, Ottokar Smerz, Michael Kostrzewa, Helmut Lask
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Patent number: 4096289Abstract: Process for the transformation of comminuted and modified cellulose ether swellable with water, into a material that may easily be further processed and may thus be used without difficulty in particular in the production of hygienic pads, napkins, bandages, tampons, wrapping papers, insulating material, household papers and similar articles. In said process the modified cellulose ether is attached by electrostatic flocking to at least one surface of a web-shaped hydrophilic support that has been wetted with water and the support is dried.Type: GrantFiled: December 14, 1976Date of Patent: June 20, 1978Assignee: Hoechst AktiengesellschaftInventors: Ehrenfried Nischwitz, Klaus Uhl, Helmut Lask
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Patent number: 4096312Abstract: Process for the transformation of comminuted cellulose ether, which has been rendered at least largely water-insoluble by modification but is still highly swellable with water, into an easily workable material, comprising wetting a hydrophilic support web, applying the comminuted modified cellulose ether to the wetted web, and drying. This invention also relates to an apparatus for performing the process.Type: GrantFiled: July 28, 1976Date of Patent: June 20, 1978Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask
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Patent number: 4068068Abstract: This invention relates to an improvement in the process for the manufacture of water-adsorbing but at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and reacted with an etherification agent in a manner such that an at least preponderantly water-soluble cellulose ether would be obtained in the case of a mere etherification process and in which, prior to, simultaneously with, or after the etherification process, a reaction is effected with a crosslinking agent which is polyfunctional towards cellulose in an alkaline reaction medium,The improvement comprising employing bis(acrylamido)-acetic acid as the crosslinking agent.Type: GrantFiled: May 3, 1976Date of Patent: January 10, 1978Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask, Michael Kostrzewa
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Patent number: 4068067Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a modification agent reactive with the still free hydroxyl groups of the cellulose anhydro glucose groups, said modification agent having one of the formulae ##STR1## in which R.sub.1 is hydroxyl, an acylamino or esterified carbamino group, andR.sub.2 is hydrogen or a carboxyl group,The improvement comprising effecting alkalization, etherification, and modification in a liquid reaction medium other than isopropyl alcohol.Type: GrantFiled: May 6, 1976Date of Patent: January 10, 1978Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask, Michael Kostrzewa
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Patent number: 4066828Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but at least partially water-insoluble, cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a cross-linking agent which is polyfunctional towards cellulose and selected from the group consisting of acrylamido methylene chloroacetamide, dichloroacetic acid, phosphorous oxychloride, or a compound in which at least two groups functional towards cellulose are ##STR1## the improvement comprising effecting alkalization, etherification, and cross-linking in a liquid reaction medium other than isopropyl alcohol.Type: GrantFiled: May 6, 1976Date of Patent: January 3, 1978Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask, Michael Kostrzewa
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Patent number: 4015611Abstract: This invention relates to a cigarette filter of cellulosic material composed at least partially of cellulose modified with an organic isocyanate or with higher molecular weight fatty acid groups, or of a naturally water-soluble cellulose ether rendered largely or completely insoluble in water by cross-linking or other means of modification, but still capable of adsorbing water.Type: GrantFiled: March 26, 1975Date of Patent: April 5, 1977Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask
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Patent number: 3990851Abstract: Antigen-antibody reactions are measured by passing laser light through the mixture of the antigen solution with the corresponding antibody and measuring the light scattered in the forward direction and determining its intensity. The device used comprises a measuring system consisting of a laser, at least two diaphragms, a system of lenses and a photodetector and a light trap having a diameter corresponding to 1.1 to 1.7 times the diameter of the laser beam.Type: GrantFiled: February 25, 1975Date of Patent: November 9, 1976Assignee: Behringwerke AktiengesellschaftInventors: Jurgen Gross, Arno Holst, Helmut Lask, Axel Sieber
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Patent number: 3965091Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but largely water-insoluble, cellulose ethers, in which cellulose is alkalized in the presence of alkali and isopropanol as a reaction medium and is so reacted with an etherification agent that by etherification only a water-soluble cellulose ether is produced, and in which process a modification agent which is able to react with the still free hydroxyl groups of the cellulose anhydro glucose groups in an alkaline reaction medium is reacted before, during, or after the etherification, the improvement comprising effecting the etherification of cellulose to carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose, or methylhydroxyethyl cellulose, reacting with the modification agent in the presence of 0.8 to 7.5 parts by weight of isopropanol, based upon the cellulose weight, and employing a modification agent being one of the formulae ##EQU1## R.sub.Type: GrantFiled: November 18, 1974Date of Patent: June 22, 1976Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Helmut Lask
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Patent number: 3936441Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but largely water-insoluble, cellulose ethers, in which cellulose is alkalized in the presence of alkali hydroxide and isopropanol as a reaction medium and is so reacted with an etherification agent that by etherification only a water-soluble cellulose ether is produced, and in which process the cellulose is reacted with a cross-linking agent which is polyfunctional towards cellulose in an alkaline reaction medium before, during, or after the etherification of the cellulose, the improvement comprising effecting the etherification of cellulose to carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose, or methylhydroxyethyl cellulose, reacting the cellulose with the polyfunctional cross-linking agent in the presence of 0.8 to 7.Type: GrantFiled: November 11, 1974Date of Patent: February 3, 1976Assignee: Hoechst AktiengesellschaftInventors: Arno Holst, Michael Kostrzewa, Helmut Lask