Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2002-05-09
2003-11-25
Delcotto, Gregory (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S302000, C510S303000, C510S312000, C510S220000, C510S224000, C510S372000, C510S376000, C008S111000, C008S137000, C252S186330
Reexamination Certificate
active
06653270
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to stabilized bleaching and detergent compositions which comprise a catalytically effective amount of a transition-metal bleach catalyst which is a complex of a transition-metal and a cross-bridged macropolycyclic ligand and an anti-oxidant or reducing agent which serves to stabilize said catalyst. The present invention further relates to a method for bleaching/cleaning fabric with a catalytically effective amount of said stabilized transition-metal bleach catalyst wherein the method is performed substantially free of any organic or inorganic peroxygen compound or precursors to any organic or inorganic peroxygen compound.
BACKGROUND OF THE INVENTION
Bleaching of fabric is essentially exposing soiled or stained fabric to a chemical reaction the purpose of which is to eliminate the soil or stain. At one point in time, bleaching involved exposure of fabric to a solution of hypochlorite. Therefore, fabric which was colored or dyed via sensitive pigments were excluded from treatment with bleach. To the benefit of the consumer, formulators developed various forms of bleach inter alia peroxygen bleaching systems which typically comprise a source of hydrogen peroxide and a bleach activator. This combination of source of hydrogen peroxide and activator plays a dominating role in effective, safe bleaching compositions. An effective example of this peroxygen bleaching system employs perborate (peroxygen source) and nonanoyloxybenzene sulfonate (activator).
In order to boost the performance of bleaching agents and to develop bleaching systems which are safe to any type of dyed or colored fabric inter alia silk, polyester blends, cotton, nylon, formulators have continued to develop peroxygen bleaching systems, as well as new methods of forming activated oxygen.
However, there still remains a need in the art for a stable bleaching system which will effectively bleach fabric without the need for reactive chemicals such as peroxides, sources of peroxide, and/or mixtures thereof. Said stable bleaching system will comprise a transition-metal catalyst which does not loose its effectiveness due to the instability of the catalyst to oxidation and/or reduction post formulation.
SUMMARY OF THE INVENTION
The present invention meets the aforementioned needs in that it has been surprisingly discovered that bleaching systems comprising a transition-metal catalyst which are capable of bleaching soils and stains in the absence of a source of hydrogen peroxide or other peroxygen bleaching agent can be successfully stabilized against the unwanted degradation of the transition-metal catalyst. In other words, it has been surprisingly discovered that the addition of an effective amount of an anti-oxidant and/or free radical scavenger or an reducing agent can stabilize a nil hydrogen peroxide bleaching system.
A first aspect of the present invention relates to stabilized bleaching compositions comprising:
A) a catalytically effective amount of a transition-metal bleach catalyst which is a complex of a transition-metal and a cross-bridged macropolycyclic ligand;
B) an effective amount of a stabilizing agent, said agent selected from
i) one or more anti-oxidants;
ii) one or more reducing agents;
iii) and mixtures thereof; and
C) the balance carriers and other adjunct ingredients;
provided said composition is substantially free of any organic or inorganic peroxygen compounds.
The present invention further relates to a method for cleaning and/or bleaching soils and stains on fabrics, said method comprising the step of contacting the fabric in need of cleaning and/or bleaching with an aqueous solution containing a composition which is substantially free of a peroxygen source and which comprises:
a) a catalytically effective amount of a transition-metal bleach catalyst which is a complex of a transition-metal and a cross-bridged macropolycyclic ligand;
b) an effective amount of a stabilizing agent, said agent selected from
i) one or more anti-oxidants;
ii) one or more reducing agents;
iii) and mixtures thereof; and
c) the balance carriers and other adjunct ingredients;
provided the concentration of said transition metal bleach catalyst in the aqueous solution is at least about 0.01 ppb and said composition is substantially free of any organic or inorganic peroxygen compounds.
The compositions and methods of the present invention are suitable for cleaning/bleaching any surface in need of stain removal. For example, hard surface cleaners and automatic dishwashing compositions can employ the bleach catalysts of the present invention in applications which are substantially free of any organic or inorganic peroxygen compounds.
These and other objects, features, and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims.
All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (° C.) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the surprising discovery that transition-metal catalysts which are capable of bleaching of soils and stains in the absence of an added peroxygen bleach can be suitably stabilized by the addition of one or more stabilizing agents. The stabilizing agents suitable for use in the present invention are present at varying level depending upon the formulation inter alia liquid, solid, gel, and the concentration of the transition-metal present.
Absence of Peroxygen Sources
The compositions of the present invention, as well as the methods for cleaning and/or bleaching of fabric which utilize the compositions of the present invention are substantially free of any peroxygen source such as hydrogen peroxide, peroxyacid etc. The compositions of the present invention need only have an effective amount of the herein below described catalyst present for effective bleaching. For the purposes of the present invention the term “substantially free” is defined as “the formulator does not include in the composition any peroxygen compound or source of peroxygen at a level required for either effective bleaching without a transition metal catalyst, or which would provide an increase in effectiveness of bleaching in the presence of a transition metal catalyst as defined herein.” Therefore, as will be further described herein below, effective bleaching of stains can be accomplished by simply adding an aqueous or non-aqueous solution of a catalyst as described herein to fabric which is stained, preferably the fabric is in an aqueous solution when contacted with the catalyst. However, it is recognized that because of factors outside the control of the formulator inter alia source of product raw materials, unwanted decomposition of one or more ingredients, that a source of peroxygen may be introduced and/or formed unknowingly in the product. The compositions of the present invention do not require any peroxygen source, but the presence of any minor amounts will not effect the performance of the bleaching compositions described herein.
Formulators may typically include a small amount of a source of hydrogen peroxide into compositions for the purposes of stabilizing enzymes, for example, a minor amount of perborate may be added. However, this amount of perborate is typically so minor that it has no effect on the bleaching capacity of the compositions of the present invention. In cases where the formulator has added a minor amount of an oxidant, or other source of peroxide for the purposes of stabilizing an adjunct ingredient, for the purposes of the present invention, those compositions are still defined as “substantially free” of a source of peroxygen as defined herein above if they do not provide additional bleaching activity on stains under typical use conditions. For example, a “substantially free” composition can include an amount of peroxygen source provided the degree to which the
Delcotto Gregory
McBride James F.
Miller Steve W.
Procter & Gamble Company
Zerby Kim W.
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