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Process of bleaching

  • US 20090205143A1
  • Filed: 04/26/2006
  • Published: 08/20/2009
  • Est. Priority Date: 05/27/2005
  • Status: Abandoned Application
First Claim
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1. A method of catalytically treating a substrate, the substrate being a cellulose-containing substrate or starch containing substrate, with a preformed transition metal catalyst salt, the preformed transition metal catalyst salt having a non-coordinating counter ion, the method comprising the following steps:

  • (i) optionally dissolving a concentrate or solid form of a preformed transition metal catalyst salt in an aqueous medium to yield an aqueous solution of the preformed transition metal catalyst salt;

    (ii) adding the aqueous solution of the preformed transition metal catalyst salt to a reaction vessel; and

    ,(iii) adding hydrogen peroxide to the reaction vessel,wherein the preformed transition metal catalyst salt is a mononuclear or dinuclear complex of a Mn(III) or Mn(IV) transition metal catalyst for catalytically treating the substrate with hydrogen peroxide, the non-coordinating counter ion of said transition metal selected to provide a preformed transition metal catalyst salt that has a water solubility of at least 30 g/l at 20°

    C. and wherein the ligand of the transition metal catalyst is of formula (I);

    wherein;

    p is 3;

    R is independently selected from;

    hydrogen, C1-C6-alkyl, CH2CH2OH, and CH2COOH, or one of R is linked to the N of another Q via an ethylene bridge;

    R1, R2, R3, and R4 are independently selected from;

    H, C1-C4-alkyl, and C1-C4-alkylhydroxy, and the substrate is brought into contact with a mixture of the aqueous solution of the preformed transition metal catalyst salt and the hydrogen peroxide.

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