Patents Assigned to Warwick International Group Limited
  • Patent number: 9587205
    Abstract: A peracid bleaching species is formed in situ in aqueous wash liquor by reaction of a peroxygen bleach precursor, such as perborate or percarbonate, and a bleach activator. The bleach activator is an acetylated ethylene diamine, that comprises at least 25% triacetyl ethylene diamine. The peracid is formed more rapidly even at low temperatures (F2) compared to use of conventional pure tetracetyl ethylene diamine (F1) and better disinfectant properties result.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: March 7, 2017
    Assignee: Warwick International Group Limited
    Inventors: Matthew Brian Skett, Gary Miller
  • Patent number: 6569286
    Abstract: Wood and non-wood pulp is bleached by: a) adding an aliquot of agglomerate from a bulk solids dispensing means, advantageously a hopper, to a dilute solution of hydrogen peroxide which is desirably agitated to keep the agglomerate in suspension, the agglomerate comprising: a bleach activator, advantageously tetraacetyl ethylene diamine (TAED); a peroxide soluble binder, preferably polyvinyl alcohol (PVOH); a dispersing system comprising a wetting agent which is a low foaming and does not discolour on exposure to temperatures of up to 120° C. and optionally a salt, preferably sodium acetate, which is highly soluble in hydrogen peroxide; and sequestrant which may additionally or alternatively be added directly to the hydrogen peroxide; b) allowing the TAED to substantially completely react with the hydrogen peroxide; c) adjusting the pH of the bleach solution by adding alkali, preferably caustic soda; and d) bleaching the pulp by contacting it with the bleaching solution under alkaline conditions.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: May 27, 2003
    Assignee: Warwick International Group Limited
    Inventors: John David Withenshaw, Jane Williams, Mark Ardern Chadwick, Neil Anthony Turner
  • Patent number: 6080710
    Abstract: A process for making a coated bleach component which may be incorporated into a detergent composition comprising hydrogen peroxide solution. The process includes the steps of dispersing the bleach component in a continuous liquid phase to form discrete islands of dispersed phase and subsequently forming a polymeric coating at the interface between the dispersed phase and the continuous phase. The coating formed is resistant to hydrogen peroxide solution and is removable when the liquid continuous phase is diluted with aqueous wash liquor. In this way particulate material which reacts with hydrogen peroxide can be incorporated into an aqueous detergent liquid which contains dissolved hydrogen peroxide, whilst maintaining stability.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: June 27, 2000
    Assignee: Warwick International Group Limited
    Inventors: John David Withenshaw, Mark Alexander France
  • Patent number: 5985815
    Abstract: New compounds useful as bleach activators as well as new percarboxylic acids, which may be formed as intermediates upon reaction of such activators with peroxygen bleach source in aqueous solution, include nitrogen-containing heterocyclic groups. Preferred activators are symmetrical derivatives of dibasic carboxylic acids, having N,N'diacyl N-heterocyclic groups usually lactams. They are produced by reaction of 2 moles of the lactam with one mole of dibasic acid chloride or anhydride.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: November 16, 1999
    Assignee: Warwick International Group Limited
    Inventors: John Townend, Jan Darrel Crowther
  • Patent number: 5801138
    Abstract: A liquid concentrate peroxide composition contains a combination of sequestrants which together are capable of universal sequestration of transition metal ions which would otherwise cause decomposition of the peroxide. The combination preferably includes a sequestrant capable of sequestering cobalt and a sequestrant capable of sequestering metal ions other than cobalt. A particularly preferred combination includes a poly(methylene phosphonic acid) and nitrogen-donor type sequestrants such as dipyridylamine or triazacyclononane.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: September 1, 1998
    Assignee: Warwick International Group Limited
    Inventors: Vincent Brian Croud, Stephen James Tompsett, Susan Jane Scarborough
  • Patent number: 5800755
    Abstract: An agglomerated active with controlled release comprising a particulate solid active material and a binder characterised in that the binder comprises from 0.02 to 5% by weight of a polyvinyl alcohol, based on the total weight of the agglomerate. The binder system simultaneously provides the desired hardness and release characteristics while maintaining a high level of actives. The active may be a bleach activator such as Tetraacetylethylenediamine.A process for manufacturing the agglomerate comprises the steps of mixing a particulate solid active material and optionally a portion of polyvinyl alcohol and optionally also a co-binder and then adding an agglomerating solution which optionally contains polyvinyl alcohol binder while mixing and agglomerating and drying the agglomerates to obtain an agglomerate with average particle size in the range 1-2000 microns wherein the agglomerate comprises from 0.02 to 5% by weight based on the total weight of the agglomerate of polyvinyl alcohol.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: September 1, 1998
    Assignee: Warwick International Group Limited
    Inventors: John David Withenshaw, Mark Ardern Chadwick, William John Wilson
  • Patent number: 5433881
    Abstract: An improvement in the process of granulating bleach activator using an organic binder selected from starch and cellulose derivatives polyacrylates, polymaleates and polyvinyl pyrrolidone, the process comprising dry mixing particulate activator and at least a portion of the binder in particulate form and then moistening the mixture with a granulating liquid, comprises using as granulating liquid an aqueous solution of a granulating aid which is a sequestrant optionally combined with a water-soluble inorganic salt. The granules are then dried. The product has improved activity in laundry detergents especially in low temperature wash and cold fill conditions.
    Type: Grant
    Filed: December 2, 1992
    Date of Patent: July 18, 1995
    Assignee: Warwick International Group Limited
    Inventors: John Townend, Anthony J. Gradwell, John D. Withenshaw