Patents Assigned to EKA Chemicals AB
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Patent number: 5902783Abstract: The invention relates to particles having a core comprising a peroxy compound with capability of releasing hydrogen peroxide or peroxy acids in aqueous solutions, which particles have a coating containing alkali metal silicate and a chelating agent. The invention also relates to preparation and use of the particles as well as a composition containing such particles.Type: GrantFiled: August 23, 1996Date of Patent: May 11, 1999Assignee: Eka Chemicals ABInventors: Hans Lagnemo, Monica Jigstam
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Patent number: 5886216Abstract: The invention relates to a method for producing peracetic acid by reacting hydrogen peroxide and acetic acid in a water-based reaction medium in a reactor and continuously distilling off the produced peracetic acid. Thermal energy in an in an amount exceeding about 0.2 kW/kg reaction medium.Type: GrantFiled: January 30, 1997Date of Patent: March 23, 1999Assignee: EKA Chemicals ABInventor: Roland Pudas
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Patent number: 5885953Abstract: The invention relates to a composition suitable for cleaning disinfection and bleaching comprising an acidic aqueous solution of hydrogen peroxide, a surfactant, and a phosphonic acid based complexing agent selected from biodegradable 1-aminoalkane-1,1-diphosphonic acids, or salts thereof, of the formula: ##STR1## wherein R.sub.1 is selected from hydrogen, C.sub.1 -C.sub.4 alkyl and phenyl; R.sub.2 and R.sub.3, independently from each other, are selected from hydrogen, C.sub.1 -C.sub.22 alkyl, C.sub.5 -C.sub.6 cycloalkyl, phenyl, C.sub.7 -C.sub.18 alkylphenyl, C.sub.7 -C.sub.18 phenylalkyl, a C.sub.1 -C.sub.10 alkanol radical, a carboxy alkyl radical having up to 10 carbon atoms, wherein R.sub.2 and R.sub.3 together with the nitrogen atom can form a piperidino, pyrrolidino or a morpholino group; and X.sub.1 to X.sub.4, independently from each other, are selected from hydrogen, alkali metal and ammonium.Type: GrantFiled: November 24, 1997Date of Patent: March 23, 1999Assignee: EKA Chemicals ABInventors: Gunilla Jadesjo, Gunnil Jonsson
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Patent number: 5876579Abstract: A process for reducing the content of organic and inorganic halogen in an aqueous solution of a nitrogen-containing epihalohydrin-based resin, in which process the aqueous resin solution is subjected to an electrodialysis treatment. The aqueous resin solutions obtained by the process are used as additives in the production of paper, board and paper board, in particular as wet-strength agents.Type: GrantFiled: April 2, 1997Date of Patent: March 2, 1999Assignee: Eka Chemicals ABInventor: Marek Gorzynski
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Patent number: 5876562Abstract: An aqueous anionic sizing dispersion which comprises an anionic dispersion of a cellulose-reactive sizing agent and colloidal anionic aluminum modified silica-based particles. The dispersion is used in the production of paper, board or cardboard whereby the dispersion is either added to the stock or applied as a surface size.Type: GrantFiled: May 28, 1997Date of Patent: March 2, 1999Assignee: Eka Chemicals ABInventor: Hans Johansson
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Patent number: 5858174Abstract: The invention relates to a process for the production of paper from a suspension of cellulose containing fibers, and optional fillers, comprising adding to the suspension a low molecular weight cationic organic polymer, a high molecular weight cationic or amphoteric polymer and anionic inorganic particles, forming and draining the suspension on a wire, wherein the low molecular weight polymer has a molecular weight below 700,000 and the high molecular weight polymer has a molecular weight above 1,000,000, said polymers being simultaneously added to the suspension.Type: GrantFiled: July 8, 1996Date of Patent: January 12, 1999Assignee: Eka Chemicals ABInventors: Michael Persson, Joakim Carlen, Hans Johansson, Carlos Cordoba
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Patent number: 5846384Abstract: A process for the production of paper from a suspension of cellulose containing fibers, and optional fillers, which comprises adding an aluminum compound and anionic inorganic particles to the suspension, forming and draining the suspension on a wire, wherein the aluminum compound and anionic inorganic particles are mixed immediately prior to addition to the suspension.Type: GrantFiled: June 10, 1996Date of Patent: December 8, 1998Assignee: Eka Chemicals ABInventors: Zaid Schold, Hans Johansson
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Patent number: 5846922Abstract: The invention relates to particles having a core comprising a peroxy compound with capability of releasing hydrogen peroxide or peroxy acids in aqueous solutions, which particles have a coating containing a chelating agent selected from alkali metal salts or alkaline earth metal salts of a hydroxy carboxylic acid satisfying the formula: RC.sub.n H.sub.m (OH).sub.n COOH in which R is CH.sub.2 OH or COOH, n is 2-6 and m is 0-n. The invention also relates to preparation and use of the particles, as well as a composition containing such particles.Type: GrantFiled: August 23, 1996Date of Patent: December 8, 1998Assignee: Eka Chemicals ABInventors: Hans Lagnemo, Monica Jigstam
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Patent number: 5842150Abstract: A method, based on UV/VIS/NIR/IR (including Raman spectroscopy), is provided for the qualitative and quantitative determination of quality parameters in pulp and paper and/or the organic content in effluents from pulp and paper production, by applying chemometric methods.Type: GrantFiled: April 11, 1997Date of Patent: November 24, 1998Assignee: Eka Chemicals ABInventors: Lars Renberg, Anders Sparen
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Patent number: 5827811Abstract: The invention relates to particles comprising a peroxy compound with capability of releasing hydrogen peroxide or peroxy acids in aqueous solutions and up to 15% by weight of a dicarboxylic acid having from 5 to 10 carbon atoms or a salt thereof. The invention also relates to use of the particles and a composition comprising such particles.Type: GrantFiled: March 21, 1997Date of Patent: October 27, 1998Assignee: EKA Chemicals ABInventors: Hans Lagnemo, Monica Jigstam, Cecilia Oddstig
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Patent number: 5810939Abstract: The invention relates to a method for pickling steel in an acidic aqueous pickling solution containing Fe.sup.3+ and Fe.sup.2+, wherein the steel is contacted with pickling solution that continuously is brought to circulate through a conduit into which hydrogen peroxide is supplied to oxidize Fe.sup.2+ to Fe.sup.3+.Type: GrantFiled: November 27, 1996Date of Patent: September 22, 1998Assignee: EKA Chemicals ABInventors: Charlotte Angel, Troy Berglind, Arne Frestad, Sven-Eric Lunner, Anders Waleij
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Patent number: 5808053Abstract: The invention generally relates to a process for modification of cationic starch at which the cationic starch is treated, in the presence of water, with an aluminium compound. The modified cationic starch is useful as a retention agent. The invention also relates to a method for improving retention and/or dewatering in papermaking at which cationic starch is modified by the process.Type: GrantFiled: January 17, 1997Date of Patent: September 15, 1998Assignee: Eka Chemicals ABInventors: Hans Johansson, Tomas Lund, Ake Larsson
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Patent number: 5800603Abstract: An aqueous dispersion comprising particles of a zeolite having a hydrophobicity of below about 9.0 percent by weight residual butanol as determined by the Residual Butanol Test, which dispersion comprises a stabilizing amount of biogum. Production of the dispersion comprising mixing zeolite particles with a biogum into a dry mixture; and mixing the dry mixture with water under agitation into a homogeneous mixture. Use of the dispersion for binding particles of zeolite to fibers. Production of paper or paperboard by forming and dewatering a suspension of cellulosic fibers wherein dewatering is carried out in the presence of particles of a zeolite, the dispersion being added to the suspension prior to dewatering. Production of dry-laid paper, nonwoven or fluff pulp, in which cellulosic fibers are carried by a gas stream, in which the dispersion is sprayed onto the fibers while they are carried by the gas stream.Type: GrantFiled: March 24, 1997Date of Patent: September 1, 1998Assignee: Eka Chemicals ABInventors: Ylva Cruslock, Maj-Lis Dahlgren, Lars Lindahl
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Patent number: 5792315Abstract: This invention is related to a process for producing pulp from a cellulosic starting material, wherein an aqueous process effluent is purified from metal impurity cations. This process comprises that the effluent is purified by an electro-chemical membrane treatment in an electrochemical membrane device comprising a unit cell through which an electric current is passed between an anode side and a cathode side of said cell, said cell comprising at least two ion permeable membranes forming between them at least one compartment, said effluent being fed into an effluent feed compartment in said cell, in which the effluent is purified by removing with the electric current metal impurity cations from the effluent through a cation selective membrane on the cathode side of said compartment, and withdrawing from said compartment the purified effluent. The purified effluent may be recirculated to the pulp mill process, e.g. as washing water.Type: GrantFiled: February 20, 1996Date of Patent: August 11, 1998Assignee: Eka Chemicals ABInventors: Johan Landfors, Christin Persson
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Patent number: 5788815Abstract: A process for the production of paper by mixing an aqueous phase comprising white water with cellulose containing fibres, and optional fillers, in a mixing stage to form an aqueous suspension, draining the suspension in the presence of a drainage or retention aid to form a fibre containing sheet or web and white water, and recirculating at least part of the white water to the mixing stage, whereby at least part of the white water is subject to electrodialysis before the mixing stage.Type: GrantFiled: January 8, 1997Date of Patent: August 4, 1998Assignee: Eka Chemicals ABInventors: Maria Norell, Lennart Nilsson
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Patent number: 5747171Abstract: A method of protecting a porous material sensitive to corrosion caused by pollutants in the atmosphere. The method comprises treating the surface of the material with an agent containing more than 90% by weight of silica sol. The agent contains substantially no solid particles with a diameter exceeding about 1 micron. Porous building materials comprising a layer of gelled silica sol present in the pores below the material surface are prepared by the method.Type: GrantFiled: April 17, 1996Date of Patent: May 5, 1998Assignee: Eka Chemicals ABInventors: Marek Tokarz, Michael Persson, Roman Kozlowski