EP0807160A1

Automatic dishwashing compositions comprising cobalt (iii) catalysts

Abstract

Automatic dishwashing detergent compositions comprising certain cobalt catalysts are provided. More specifically, the invention relates to automatic dishwashing detergents which provide enhanced cleaning/bleaching benefits (especially tea stain removal) through the selection of cobalt (III) catalysts having the formula:Co[(NH3)nMmBbTtQqPp]YyPreferred automatic dishwashing compositions comprise amylase and/or protease enzymes. Included are methods for washing tableware in domestic automatic dishwashing appliances using the cobalt catalysts.

Term

Term ended

Projected expiry passed 30 January 2016, 10.7 years ago.

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13 claims: 11 independent, 2 dependent

  1. 1
    Claims of equivalent WO 9623861 A1 WHAT IS CLAIMED IS:1. An automatic dishwashing detergent composition comprising: (a) a catalytically effective amount of a cobalt catalyst having the formula: Co[(NH3)nMmBbTtQqPp] Yy wherein cobalt is in the +3 oxidation state;n is an interger from 0 to 5;M represents a monodentate ligand;m is an integer from 0 to 5;B represents a bidentate ligand;b is an integer from 0 to 2;T represents a tridentate ligand;t is 0 or 1;Q is a tetradentae ligand;q is 0 or 1;P is a pentadentate ligand;p is 0 or 1 ;and n + m + 2b + 3t + 4q + 5p = 6;Y is one or more appropriately selected counteranions present in a number y, where y is an integer from 1 to 3 to obtain a charge-balanced salt;and wherein further at least one of the coordination sites attached to the cobalt is labile under automatic dishwashing use conditions and the remaining coordination sites stabilize the cobalt under automatic dishwashing conditions such that the reduction potential for cobalt (III) to cobalt (II) under alkaline conditions is less than 0.4 volts versus a normal hydrogen electrode;(b) an effective amount of a source of hydrogen peroxide;and (c) automatic dishwashing detergent adjunct materials.
  2. 3
    An automatic dishwashing detergent composition according to any of Claims 1 or 2 comprising as part or all of the automatic dishwashing adjunct material one or more low foaming nonionic surfactants.
  3. 4
    An automatic dishwashing detergent composition according to any of Claims 1-3 comprising as part or all of the automatic dishwashing adjunct material one or more material care agents.
  4. 5
    An automatic dishwashing detergent composition according to any of Claims 1-4 comprising as part or all of the automatic dishwashing adjunct material one or more water soluble silicates.
  5. 6
    An automatic dishwashing detergent composition according to any of Claims 1-5 comprising as part or all of the automatic dishwashing adjunct material one or more bleach activators, preferably TAED.
  6. 7
    An automatic dishwashing detergent composition according to any of Claims 1-6 having a 1% aqueous solution pH of less than 11.
  7. 8
    A method of washing tableware in a domestic automatic dishwashing appliance, said method comprising treating the soiled tableware in an automatic dishwasher with an aqueous alkaline bath comprising a source of hydrogen peroxide and a cobalt catalyst having the formula:Co[(NH3)nMmBbTtQqPp] Yy wherein cobalt is in the +3 oxidation state;n is an interger from 0 to 5;M represents a monodentate ligand;m is an integer from 0 to 5;B represents a bidentate ligand;b is an integer from 0 to 2;T represents a tridentate ligand;t is 0 or 1 ;Q is a tetradentate ligand;q is 0 or 1 ;P is a pentadentate ligand;p is 0 or 1 ;and n + m + 2b + 3t + 4q + 5p = 6;Y is one or more appropriately selected counteranions present in a number y, where y is an integer from 1 to 3 to obtain a charge-balanced salt;and wherein further at least one of the coordination sites attached to the cobalt is labile under automatic dishwashing use conditions and the remaining coordination sites stabilize the cobalt under automatic dishwashing conditions such that the reduction potential for cobalt (III) to cobalt (II) under alkaline conditions is less than 0.2 volts versus a normal hydrogen electrode.
  8. 10
    A method of washing tableware in a domestic automatic dishwashing appliance, said method comprising treating the soiled tableware in an automatic dishwasher with an aqueous alkaline bath comprising an automatic dishwashing detergent composition according to any of Claims 1 - 7.
  9. 11
    A method for removing tea and/or coffee stains from tableware in a domestic automatic dishwashing appliance, said method comprising treating tea-stained tableware in an automatic dishwasher with an aqueous alkaline bath comprising a source of hydrogen peroxide and the cobalt catalyst of the formula:Co[(NH3)nMmBbTtQqPp] Yy wherein cobalt is in the +3 oxidation state;n is an interger from 0 to 5;M represents a monodentate ligand;m is an integer from 0 to 5;B represents a bidentate ligand;b is an integer from 0 to 2;T represents a tridentate ligand;t is 0 or 1 ;Q is a tetradentate ligand;q is 0 or 1 ;P is a pentadentate ligand;p is 0 or 1;and n + m + 2b + 3t + 4q + 5p = 6;Y is one or more appropriately selected counteranions present in a number y, where y is an integer from 1 to 3 to obtain a charge-balanced salt;and wherein further at least one of the coordination sites attached to the cobalt is labile under automatic dishwashing use conditions and the remaining coordination sites stabilize the cobalt under automatic dishwashing conditions such that the reduction potential for cobalt (III) to cobalt (II) under alkaline conditions is less than 0.4 volts versus a normal hydrogen electrode.
  10. 12
    An automatic dishwashing rinse aid composition comprising:(a) a catalytically effective amount of a cobalt catalyst having the formula: Co[(NH3)nMmBbTtQqPp] Yy wherein cobalt is in the +3 oxidation state;n is an interger from 0 to 5;M represents a monodentate ligand;m is an integer from 0 to 5;B represents a bidentate ligand;b is an integer from 0 to 2;T represents a tridentate ligand;t is 0 or 1 ;Q is a tetradentate ligand;q is 0 or 1 ;P is a pentadentate ligand;p is 0 or 1 ;and n + m + 2b + 3t + 4q + 5p = 6;Y is one or more appropriately selected counteranions present in a number y, where y is an integer from 1 to 3 to obtain a charge-balanced salt;and wherein further at least one of the coordination sites attached to the cobalt is labile under automatic dishwashing use conditions and the remaining coordination sites stabilize the cobalt under automatic dishwashing conditions such that the reduction potential for cobalt (III) to cobalt (II) under alkaline conditions is less than 0.4 volts versus a normal hydrogen electrode;(b) automatic dishwashing detergent adjunct materials, preferably comprising one or more low foaming nonionic surfactants.
  11. 13
    A method for washing tableware in a domestic automatic dishwashing appliance, said method comprising treating the soiled tableware during a wash cycle of an automatic dishwasher with an aqueous alkaline bath comprising a source of hydrogen peroxide, followed by treating the tableware during the subsequent rinse cycle with an aqueous bath comprising a cobalt having the formula:Co[(NH3)nMmBbTtQqPp] Yy wherein cobalt is in the +3 oxidation state;n is an interger from 0 to 5;M represents a monodentate ligand;m is an integer from 0 to 5;B represents a bidentate ligand;b is an integer from 0 to 2;T represents a tridentate ligand;t is 0 or 1 ;Q is a tetradentae ligand;q is 0 or 1 ;P is a pentadentate ligand;p is 0 or 1 ;and n + m + 2b + 3t + 4q + 5p = 6;Y is one or more appropriately selected counteranions present in a number y, where y is an integer from 1 to 3 to obtain a charge-balanced salt;and wherein further at least one of the coordination sites attached to the cobalt is labile under automatic dishwashing use conditions and the remaining coordination sites stabilize the cobalt under automatic dishwashing conditions such that the reduction potential for cobalt (III) to cobalt (II) under alkaline conditions is less than 0.4 volts versus a normal hydrogen electrode.