Patents Assigned to Kemira
  • Patent number: 4045453
    Abstract: Furfuryl acetate is reacted at 0.degree.-20.degree. C with a mixture containing strong nitric acid and less than 7 mole, preferably less than 5 mole, acetic anhydride per 1 mole furfuryl acetate, in order to produce an intermediate of nitration, whereafter water is added and the aqueous solution is neutralized to a pH of 4.7-6.5 and finally the mixture is heated to 40.degree.-60.degree. C.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: August 30, 1977
    Assignee: Kemira Oy
    Inventors: Ilkka Renvall, Tapio Mattila
  • Patent number: 4008256
    Abstract: Furfuryl alcohol is esterified by means of an aliphatic anhydride or its halogen derivative using aliphatic, tertiary amines as catalysts.
    Type: Grant
    Filed: August 7, 1975
    Date of Patent: February 15, 1977
    Assignee: Kemira Oy
    Inventors: Ilkka Renvall, Tapio Mattila
  • Patent number: 3983222
    Abstract: A continuous process for removing nitrates from nitrate containing aqueous solutions having a pH of about 0-7, which comprises: (1) extracting the nitrate containing aqueous solution with an organic amine salt dissolved in an organic solvent phase whereby the nitrate ion goes into the organic solvent, (2) separating the organic phase, (3) stripping the organic extraction solvent phase from the extraction with a stripping salt solution of pH at least 0.
    Type: Grant
    Filed: November 18, 1974
    Date of Patent: September 28, 1976
    Assignee: Kemira Oy
    Inventor: Timo Kalevi Lehto
  • Patent number: 3981737
    Abstract: In the process for manufacturing a light-resisting titanium dioxide pigment suitable for matting artificial fibers, by adding to a suspension of titanium dioxide pigment some water-soluble vanadium compound plus possibly a compound of aluminum, silicon and/or, phosphorus, which are precipitated onto the surface of the titanium dioxide particles, whereafter the suspension is filtered, washed, thermally dried, and ground, the thermal drying and the grinding are carried out at such a low temperature that the pigment temperature at no stage rises above 300.degree.C and for such a short period that the vanadium remains on the surface of the titanium dioxide pigment particles without being substantially calcinated into the particles, which consequently remain white.
    Type: Grant
    Filed: February 14, 1974
    Date of Patent: September 21, 1976
    Assignee: Kemira Oy
    Inventors: Toivo Evilampi, Virpi Laamanen