Patents Assigned to EKA Chemicals AB
  • Patent number: 5902783
    Abstract: 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: Grant
    Filed: August 23, 1996
    Date of Patent: May 11, 1999
    Assignee: Eka Chemicals AB
    Inventors: Hans Lagnemo, Monica Jigstam
  • Patent number: 5886216
    Abstract: 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: Grant
    Filed: January 30, 1997
    Date of Patent: March 23, 1999
    Assignee: EKA Chemicals AB
    Inventor: Roland Pudas
  • Patent number: 5885953
    Abstract: 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: Grant
    Filed: November 24, 1997
    Date of Patent: March 23, 1999
    Assignee: EKA Chemicals AB
    Inventors: Gunilla Jadesjo, Gunnil Jonsson
  • Patent number: 5876579
    Abstract: 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: Grant
    Filed: April 2, 1997
    Date of Patent: March 2, 1999
    Assignee: Eka Chemicals AB
    Inventor: Marek Gorzynski
  • Patent number: 5876562
    Abstract: 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: Grant
    Filed: May 28, 1997
    Date of Patent: March 2, 1999
    Assignee: Eka Chemicals AB
    Inventor: Hans Johansson
  • Patent number: 5858174
    Abstract: 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: Grant
    Filed: July 8, 1996
    Date of Patent: January 12, 1999
    Assignee: Eka Chemicals AB
    Inventors: Michael Persson, Joakim Carlen, Hans Johansson, Carlos Cordoba
  • Patent number: 5846384
    Abstract: 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: Grant
    Filed: June 10, 1996
    Date of Patent: December 8, 1998
    Assignee: Eka Chemicals AB
    Inventors: Zaid Schold, Hans Johansson
  • Patent number: 5846922
    Abstract: 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: Grant
    Filed: August 23, 1996
    Date of Patent: December 8, 1998
    Assignee: Eka Chemicals AB
    Inventors: Hans Lagnemo, Monica Jigstam
  • Patent number: 5842150
    Abstract: 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: Grant
    Filed: April 11, 1997
    Date of Patent: November 24, 1998
    Assignee: Eka Chemicals AB
    Inventors: Lars Renberg, Anders Sparen
  • Patent number: 5827811
    Abstract: 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: Grant
    Filed: March 21, 1997
    Date of Patent: October 27, 1998
    Assignee: EKA Chemicals AB
    Inventors: Hans Lagnemo, Monica Jigstam, Cecilia Oddstig
  • Patent number: 5810939
    Abstract: 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: Grant
    Filed: November 27, 1996
    Date of Patent: September 22, 1998
    Assignee: EKA Chemicals AB
    Inventors: Charlotte Angel, Troy Berglind, Arne Frestad, Sven-Eric Lunner, Anders Waleij
  • Patent number: 5808053
    Abstract: 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: Grant
    Filed: January 17, 1997
    Date of Patent: September 15, 1998
    Assignee: Eka Chemicals AB
    Inventors: Hans Johansson, Tomas Lund, Ake Larsson
  • Patent number: 5800603
    Abstract: 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: Grant
    Filed: March 24, 1997
    Date of Patent: September 1, 1998
    Assignee: Eka Chemicals AB
    Inventors: Ylva Cruslock, Maj-Lis Dahlgren, Lars Lindahl
  • Patent number: 5792315
    Abstract: 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: Grant
    Filed: February 20, 1996
    Date of Patent: August 11, 1998
    Assignee: Eka Chemicals AB
    Inventors: Johan Landfors, Christin Persson
  • Patent number: 5788815
    Abstract: 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: Grant
    Filed: January 8, 1997
    Date of Patent: August 4, 1998
    Assignee: Eka Chemicals AB
    Inventors: Maria Norell, Lennart Nilsson
  • Patent number: 5747171
    Abstract: 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: Grant
    Filed: April 17, 1996
    Date of Patent: May 5, 1998
    Assignee: Eka Chemicals AB
    Inventors: Marek Tokarz, Michael Persson, Roman Kozlowski