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Expired Canadian patentCanada

Bleaching with improved whitening

CA 2579770 C · Owner: Van Buskirk, Gregory · Inventors: Van Buskirk, Gregory

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

The invention provides methods, compositions and kits for increasing the brightness retention of a fabric laundered using a hypohalite-generating bleach by employing an amount of bromide-releasing compound sufficient to provide between 0.1 to about 1.5 moles of bromine ion to mole of available chlorine in a wash liquor to mitigate the negative effects of said hypohalite bleach on the optical brightener present in either the wash liquor or on said fabric. The invention also applies to fabrics washed using commercial laundry detergents which typically deliver an optical brightener into said wash liquor, said optical brightener generally exhibiting instability in the presence of said …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed August 3, 2005 and granted April 8, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 3, 2025.
  • Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 3, 2005
GrantedApril 8, 2014
Term endedAugust 3, 2025
Patent numberCA 2579770 C
Classification (IPC)C11D1/00 +2 more

Timeline

Timeline From CIPO dates

2006200820102012201420162018202020222024Application filedAug 3, 2005Patent grantedApril 8, 2014Term endedAug 3, 2025

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.