Patents Assigned to EKA AB
  • Patent number: 4900399
    Abstract: Chemimechanical pulp is produced from lignocellulosic material in a process in which the material is impregnated in two stages. The material is treated in the first stage with alkaline and, subsequent to passing an intermediate draining and reaction step, in the second stage with a solution that contains peroxide. The quantities of alkali and peroxide charged are fully optional and are independent of one another. The material is then optionally subjected to a further drainage and reaction step, and thereafter pre-heated at a temperature of between 50.degree. C. and 100.degree. C., whereafter the material is refined in one or two stages.The optimal brightness of the processed pulp for a given peroxide consumption is achieved by a balanced division of the peroxide charge between chip impregnation and bleaching.
    Type: Grant
    Filed: May 16, 1988
    Date of Patent: February 13, 1990
    Assignees: Eka AB, Goran Bengtsson, Rune Simonson
    Inventors: Goran Bengtsson, Rune Simonson, Roland Agnemo
  • Patent number: 4756799
    Abstract: In accordance with the invention a chemimechanical pulp is produced from lignocellulosic material, for example wood chips, by subjecting the material to a process in which it is steamed, impregnated with alkali and peroxide, drained, pre-heated, refined and bleached. The material is impregnated in a single stage with a solution containing alkali and peroxide. Subsequent to passing an intermediate drainage and reaction stage, the material is pre-heated to a temperature of from about 50.degree. C., but not above 100.degree. C. The material is then refined in one or two stages. The material can be impregnated by immersing the same in the impregnating solution for a period of up to 20 minutes at a temperature of 15.degree.-60.degree. C., or by compressing the material in a screw press and permitting the compressed material to expand in the impregnating solution.
    Type: Grant
    Filed: March 12, 1986
    Date of Patent: July 12, 1988
    Assignees: Eka AB, Goran Bengtsson, Rune Simonson
    Inventors: Goran Bengtsson, Rune Simonson, Roland Agnemo
  • Patent number: 4600735
    Abstract: A soil-repellent coating composition comprising silica, polyvinyl alcohol and a wetting agent in an aqueous carrier medium. The composition is characterized in that it, in addition to the aqueous carrier medium, contains 0.5-30% by weight of silica and 0.01-6% by weight of polyvinyl alcohol, and 0.05-2.5% by weight of a wetting agent, based on the total weight of the composition. The ready-made coating composition comprises 0.05-5% by weight of silica, 0.05-0.5% by weight of polyvinyl alcohol and 0.05-0.5% by weight of the wetting agent. The silica is present in the form of an alkali stabilized, preferably ammonium stabilized silica sol with an average particle size of 4-30 nm. The polyvinyl alcohol preferably has a hydrolysis degree of 85-100% and an average molecular weight of 15,000-100,000. The weight ratio of silica to polyvinyl alcohol is above 3:1 and preferably from 5:1 to 40:1. The wetting agent preferably is nonionic.
    Type: Grant
    Filed: February 15, 1985
    Date of Patent: July 15, 1986
    Assignee: EKA AB
    Inventors: Bernt Larsson, Gunilla Nobelius, Elisabet Johansson
  • Patent number: 4552748
    Abstract: A method in the production of hydrogen peroxide is described, utilizing the so-called anthraquinone process in which alkylated anthraquinones dissolved in organic solvents to form a liquid working solution, are alternately reduced and oxidized. The working solution is subjected to catalytic hydrogenation by contacting it with hydrogen in the presence of a hydrogenation catalyst. The contact with hydrogen is established in a fixed catalyst bed comprising one or more solid catalyst bodies, each of which consists of a thin-walled, coherent, solid body of a structure forming parallel channels through which the working solution and hydrogen gas are allowed to pass. The channels of the catalyst bed are of equal length and parallel to the direction of flow of the working solution. The catalyst preferably is provided in a thin layer on the walls of the structure, preferably by means of a porous carrier.
    Type: Grant
    Filed: September 6, 1983
    Date of Patent: November 12, 1985
    Assignee: EKA AB
    Inventors: Carl T. Berglin, Wolfgang Herrmann
  • Patent number: 4541997
    Abstract: A process of reducing the oxygen content in gas mixtures to 0.0-1.5% by volume, in which process the gas is contacted with a solution containing anthrahydroquinone derivatives capable of being oxidized with molecular oxygen under formation of hydrogen peroxide. The supply of oxygen is so adjusted that the amount of oxygen supplied, upon quantitative formation of hydrogen peroxide, stoichiometrically corresponds to not more than 90%, preferably 50%, of the supplied amount of anthrahydroquinone derivative. The hydrogen peroxide content at the contact surfaces between the solution and the gas must not exceed 100 millimols per liter at a simultaneous oxygen gas pressure of not more than 100 millibars. The oxygen-poor gas mixture in accordance with the process of this invention may be used as a protective or inert gas in chemical process industries where use is made of inflammable gases.
    Type: Grant
    Filed: February 16, 1983
    Date of Patent: September 17, 1985
    Assignee: EKA AB
    Inventor: Gustaf F. Bengt
  • Patent number: 4503028
    Abstract: A method in the production of hydrogen peroxide by the anthraquinone process is described, in which method anthraquinone derivatives dissolved in a working solution are subjected alternatingly to hydrogenation and oxidation. To reduce the relative moisture in the working solution to a suitable level of 20-98%, preferably 40-85%, the working solution is dried prior to hydrogenation by contacting it with a gas or a gaseous mixture, the water vapor pressure of which is below that of the working solution. Suitable gases or gas mixtures are air or exhaust gases from the oxidation stage of the anthraquinone process.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: March 5, 1985
    Assignee: Eka AB
    Inventors: Bengt G. Franz/e/ n, Wolfgang Herrmann
  • Patent number: 4409117
    Abstract: Detergent compositions stable to chlorine separation are described, which as main constituents contain alkali metal phosphate, alkali metal silicate, a surfactant and granulate chlorinated triazine trione, the granules of the chlorinated triazine trione being coated with a thin layer of a hydrophobic substance. The surface-treated chlorinated triazine trione which constitutes an agent for producing the composition, is also described as is the use of the composition as a machine dish washing detergent or industrial detergent.
    Type: Grant
    Filed: December 17, 1980
    Date of Patent: October 11, 1983
    Assignee: EKA AB
    Inventors: Krister Holmberg, Ingvar Nilsson
  • Patent number: 4357454
    Abstract: A lignin product-containing binder and a process for its production are described.The lignin product consists of chlorolignin which has been treated with strong alkali (NaOH) for preferably 0.5-3 h. at 50.degree.-100.degree. C. and a pH of 10-13.5. The alkali-treated chlorolignin product can be used on its own as a binder component or, preferably, together with phenol-formaldehyde. The weight ratio phenol/lignin product is suitably from 4:1 to 1:4.
    Type: Grant
    Filed: August 20, 1981
    Date of Patent: November 2, 1982
    Assignee: Eka AB
    Inventors: Krister Holmberg, Jan-Allan Y. Johansson, Gerd E. Wallin
  • Patent number: 4311553
    Abstract: A method of producing peroxide bleached pulp. Lignocellulose fiber material is impregnated with an aqueous silicate solution containing a sequestering agent. The impregnated lignocellulose is preheated with saturated steam at a temperature corresponding to the defibrating temperature to precipitate silic acid on and in the fibers. The preheated fiber mass is defibrated between two grinding disc in an atmosphere of saturated steam at a temperature of 100.degree.-170.degree. C. Alkaline peroxide solution free of silicate is introduced into the grinding space.
    Type: Grant
    Filed: January 14, 1980
    Date of Patent: January 19, 1982
    Assignees: Sunds Defibrator AB, Eka AB
    Inventors: Sven G. Akerlund, Jan-Erik Hook
  • Patent number: 4294885
    Abstract: A surface modified pigment formed from kaolin material and a process of producing same are described.The pigment consists of pigment particles of kaolin material, and on the surface of the particles a primary and a secondary layer are precipitated. The primary layer consists of an anionic Al.sub.2 O.sub.3 --SiO.sub.2 hydrate gel having a molar ratio of SiO.sub.2 :Al.sub.2 O.sub.3 of from 3 to 30 and is present in a quantity corresponding to from 2 to 15% by weight of SiO.sub.2, based upon the original quantity of kaolin material. The secondary layer consists of a polymeric binder which is bonded to the primary layer by hydrogen or ion bonding and which is included in a quantity of at least 2% by weight, based upon the original quantity of kaolin material.The pigment is prepared by dispersing the pigment particles in water and providing them, while they are dispersed, with precipitated primary and secondary layers. The primary layer of anionic Al.sub.2 O.sub.3 --SiO.sub.
    Type: Grant
    Filed: May 14, 1980
    Date of Patent: October 13, 1981
    Assignee: EKA AB
    Inventor: Olof Sunden