Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2002-02-05
2004-02-24
Gupta, Yogendra N. (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, C510S375000
Reexamination Certificate
active
06696403
ABSTRACT:
FIELD OF INVENTION
This invention relates to compositions and methods for catalytically bleaching substrates with air or a peroxyl species using a defined class of ligand or complex as catalyst.
BACKGROUND OF INVENTION
The use of bleaching catalysts for stain removal has been developed over recent years. The recent discovery that some catalysts are capable of bleaching effectively in the absence of an added peroxyl source has recently become the focus of some interest, for example: WO9965905; WO0012667; WO0012808; WO0029537, and, WO0060045. The compounds found in the aforementioned application are, in many instances, also useful as bleach catalysts for use with peroxyl species.
The search for new classes of compounds that are suitable as air bleaching catalyst is ongoing. In addition, the selection within known groups for classes of compounds that are surprisingly effective as air bleaching catalysts and peroxyl bleaching catalysts is sought.
SUMMARY OF INVENTION
We have found that a selected class of ligand or complex is surprisingly effective in catalysing the bleaching of substrates using either air or a peroxyl species.
We have selected a group of ligands that are surprisingly effective as bleach catalysts. The ligand group selected has at least two imidazol groups as described herein.
The present invention provides a laundry bleach composition, capable of bleaching in an air bleaching mode or peroxyl bleaching mode, comprising a ligand of general formula (L):
R
1
R
1
N—X—NR
1
R
1
(L),
wherein:
X is selected from —CH
2
CH
2
—, —CH
2
CH
2
CH
2
—, —CH
2
C(OH)HCH
2
—; and,
R
1
independently represents a group selected from: alkyl, cycloalkyl, heterocycloalkyl, heteroaryl, aryl and arylalkyl groups optionally substituted with a substituent selected from hydroxy, alkoxy, phenoxy, carboxylate, carboxamide, carboxylic ester, sulphonate, amine, alkylamine and N
+
(R
4
)
3
, wherein R
4
is selected from hydrogen, alkanyl, alkenyl, arylalkanyl, arylalkenyl, oxyalkanyl, oxyalkenyl, aminoalkanyl, aminoalkenyl, alkanyl ether, alkenyl ether, and —CY
2
—R
2
, in which Y is independently selected from H, CH3, C2H5, C3H7 and R
2
is independently selected from: an optionally substituted:
wherein R3 is independently selected from: H, alkyl, and benzyl, and wherein at least two of R
1
are —CY
2
—R
2
and R
2
. The optionally substituted imidazole is not so substituted that it forms a benzimidazol group per se.
It is essential that the ligand (L) has at least two imidazole substituents as defined above, preferably at least three imidazole substituents. The nature of the remaining R1 substituent(s) has not been found to be significant to activity of the selected ligand.
A present invention also provides a method of bleaching a substrate comprising applying to the substrate, in an aqueous medium, a bleaching composition as defined herein.
The present invention also extends to use of a ligand or complex as defined below in the manufacture of a bleaching composition, the bleaching composition containing effective amounts of a peroxygen bleach or a peroxy-based or peroxy-generating bleach system. An effective amount of a peroxygen bleach may be provided by a composition containing at least 1%, preferably at least 5%, of a peroxyl species. In the present invention, it is preferred that the composition contains the range of about 1-35% by weight, preferably from 5-25% of a peroxyl species.
The present invention also extends to a commercial package comprising a bleaching composition according to the present invention together with instructions for its use.
SUMMARY OF THE INVENTION
Air Bleaching Mode
In an air bleaching mode the composition of the present invention uses air to bleach a substrate. This is distinct from using pure oxygen or an enriched oxygen source. Air is different to molecular oxygen. The provision of a commercially available air bleaching product negates the requirement of an additional component, namely a peroxyl source. The removal of a peroxyl species, an expensive component, from a bleaching composition results in a reduction in manufacturing costs of the bleaching composition. Of significant importance is that an increased retention of textile strength and less dye damage is found when a bleaching composition without an added peroxyl species is used to clean fabrics. In addition, the provision of a commercially available air bleaching composition that may function without the requirement of saturated oxygen solutions and/or pressure vessels in an aqueous environment is important. Oxygen is relatively insoluble in water when compared to organic solvents. Nitrogen makes up approximately 80% of the volume of air whilst molecular oxygen makes up only approximately 20% of the volume of air.
In the present invention at least 10%, preferably at least 50% and optimally at least 90% of any bleaching of the substrate is effected by oxygen sourced from the air.
In any composition containing organic matter it is difficult to avoid the presence of hydroperoxides which are readily formed from the oxygen in the air. In this regard, the air bleaching composition of the present invention has less that 1%, preferably less than 0.1%, most preferably less than 0.01%, of a peroxyl species present.
Peroxyl Bleaching Mode
The Peroxyl Species or Precursor Thereof
In a peroxyl bleaching mode the composition of the present invention uses a peroxyl species to bleach a substrate. The peroxy bleaching species may be a compound which is capable of yielding hydrogen peroxide in aqueous solution. Hydrogen peroxide sources are well known in the art. They include the alkali metal peroxides, organic peroxides such as urea peroxide, and inorganic persalts, such as the alkali metal perborates, percarbonates, perphosphates persilicates and persulphates. Mixtures of two or more such compounds may also be suitable.
Particularly preferred are sodium perborate tetrahydrate and, especially, sodium perborate monohydrate. Sodium perborate monohydrate is preferred because of its high active oxygen content. Sodium percarbonate may also be preferred for environmental reasons. The amount thereof in the composition of the invention usually will be within the range of about 1-35% by weight, preferably from 5-25% by weight. One skilled in the art will appreciate that these amounts may be reduced in the presence of a bleach precursor e.g., N,N,N′N′-tetraacetyl ethylene diamine (TAED).
Another suitable hydrogen peroxide generating system is a combination of a C1-C4 alkanol oxidase and a C1-C4 alkanol, especially a combination of methanol oxidase (MOX) and ethanol. Such combinations are disclosed in International Application PCT/EP 94/03003 (Unilever), which is incorporated herein by reference.
Alkylhydroxy peroxides are another class of peroxy bleaching compounds. Examples of these materials include cumene hydroperoxide and t-butyl hydroperoxide.
Organic peroxyacids may also be suitable as the peroxy bleaching compound. Such materials normally have the general formula:
wherein R is an alkylene or substituted alkylene group containing from 1 to about 20 carbon atoms, optionally having an internal amide linkage; or a phenylene or substituted phenylene group; and Y is hydrogen, halogen, alkyl, aryl, an imido-aromatic or non-aromatic group, a COOH or
group or a quaternary ammonium group.
Typical monoperoxy acids useful herein include, for example:
(i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-.alpha.-naphthoic acid;
(ii) aliphatic, substituted aliphatic and arylalkyl monoperoxyacids, e.g. peroxylauric acid, peroxystearic acid and N,N-phthaloylaminoperoxy caproic acid (PAP); and
(iii) 6-octylamino-6-oxo-peroxyhexanoic acid.
Typical diperoxyacids useful herein include, for example:
(iv) 1,12-diperoxydodecanedioic acid (DPDA);
(v) 1,9-diperoxyazelaic acid;
(vi) diperoxybrassilic acid; diperoxysebasic acid and diperoxyisophthalic acid;
(vii) 2-decyldiperoxybutane-1,4-diotic acid; and
(viii) 4′-sulphonylbisperoxybenzoic acid.
Also inorganic peroxyacid compounds are s
Carina Riccardo Filippo
Delroisse Michel Gilbert Jose
Hage Ronald
Tetard David
Gupta Yogendra N.
Honig Milton L.
Petruncio John M.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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