Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-05-07
2003-09-02
Webb, Gregory E. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S313000, C510S372000, C510S376000, C510S424000, C510S427000, C510S475000, C008S137000
Reexamination Certificate
active
06613726
ABSTRACT:
TECHNICAL FIELD
The present invention relates to bleaching compositions. The compositions of the present invention are particularly useful for laundry bleaching.
BACKGROUND
Compositions for the bleaching of laundry have been extensively described in the art. Bleaching compositions can be classified into peroxide bleaching compositions and hypochlorite bleaching compositions. Peroxide bleaching compositions have the advantage over hypochlorite bleaching compositions in that they are generally considered as being somewhat safer to fabrics, specifically to colored fabrics. Peroxide compositions however have the inconvenience that they are often chemically unstable, which makes it difficult to formulate peroxide bleaching compositions which are sufficiently stable for sufficiently long periods of time to be commercialized. A possible solution to this problem consists in formulating compositions with a high level of peroxide, to extend the “effective” period of the composition. However, a potential drawback of this solution is that compositions may reach consumers which still comprise a high amount of peroxide, possibly causing skin irritation (e.g. itching) in contact with the peroxide composition. This irritation, specifically itching phenomenon is quite moderate and fully reversible, but does constitute potential discomfort for the user.
Furthermore peroxide species are in general poor bleaching agents at lower temperatures, so that it is required to formulate activated peroxide bleaching compositions if they are to be used across a wider range of temperatures. Activated bleaching compositions comprise a bleach activator, typically a peracid precursor, which will react in an aqueous medium with hydrogen peroxide to form the corresponding peracid. This peracid is an effective bleaching agent at lower temperatures.
It is thus an object of the present invention to formulate a peroxide bleaching composition which is stable, without having to resort to using higher amounts of peroxide, and which can be activated in a stable manner.
It is also an object of the present invention to formulate a bleaching composition with superior bleaching performance.
In response we have now found that this object can be met by formulating an aqueous emulsion as described herein.
Bleaching compositions formulated as emulsions have been disclosed in EP 598 170 and a co-pending patent application number EP-A-687 726. The compositions as described in '170 are emulsions comprising hydrogen peroxide in one phase and a hydrophobic liquid ingredient in the other phase. This hydrophobic liquid ingredient can be a peracid precursor. The compositions as described in '726 comprise at least two nonionic surfactants and benzoyl peroxide.
SUMMARY OF THE INVENTION
The present invention relates to a composition in the form of an aqueous emulsion and/or microemulsion comprising a diacyl peroxide and a surfactant system, wherein the surfactant system comprises at least one anionic surfactant and at least one nonionic surfactant.
DETAILED DESCRIPTION OF THE INVENTION
Aqueous Emulsion
The compositions according to the present invention are stable aqueous emulsions and/or microemulsions. By “stable emulsion” it is meant a liquid composition comprising polar and non polar components which does not macroscopically separate into distinct layers, upon standing for at least two weeks at 20° C., more preferably at least six months. The emulsion can alternatively be microemulsions. By “microemulsion” it is meant an emulsion that is thermodynamically stable.
The Applicants have found that diacyl peroxide (or DAP) is not stable in aqueous solution. However, when the DAP is formulated with a mixture of at least one anionic surfactant and at least one nonionic surfactant the stability of the DAP is improved. It is believed that this phenomenon exists because the surfactants form micelles in which the DAP is retained, thus protecting the DAP from decomposition. Moreover, it has additionally been found that the stability of the composition is improved even further when the composition comprises a hydrophobic solvent.
The compositions according to the present invention are aqueous. Accordingly, the compositions according to the present invention preferably comprise from 10% to 95% by weight of the total composition of water, preferably from 30% to 90%, most preferably from 60% to 85%. Deionized water is preferably used.
Diacyl Peroxide
The compositions of the present invention comprise a diacyl peroxide (or DAP). The DAP may be selected from the group consisting of dialiphatic peroxide, diaromatic peroxide, aliphatic-aromatic peroxide or mixtures thereof. Generally, the DAP has the general formula:
R—C(O)—O—O—C(O)—R
1
wherein R and R
1
can be the same or different and are selected from either aliphatic or aromatic groups having from 6 to 20 carbon atoms.
Where R and/or R
1
is an aliphatic group it may be branched, but is preferably linear. Preferred aliphatic groups have from 8 to 14 carbon atoms, most preferably 10 to 12 carbon atoms. Particularly, preferred dialiphatic peroxides include dioctanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, dimyristoyl peroxide or mixtures thereof. Dilauroyl peroxide is available from Akzo Nobel under the tradename Laurox®. Dodeconoy peroxide is availabe from Akzo Nobel under the tradename Perkadox SE 10.
An example of a suitable diaromatic peroxide is dibenzoyl peroxide. However for the purposes of the present invention although useful, these species are not preferred because they are more noticeably aggressive to colours, causing fabric colour loss.
Particulary preferred DAP's are aliphatic-aromatic peroxides wherein one of either R or R′ is aliphatic and the other is aromatic. In these species the aromatic moiety is preferably benzoyl. In an alternative embodiment, the aromatic species may be a substituted benzoyl wherein the substituent is preferably an alkyl group having from 1 to 20 carbon atoms. The aliphatic moiety preferably comprises from 8 to 14 carbon atoms, more preferably from 10 to 12 carbon atoms and although it may be branched, it is preferably linear.
A particularly preferred aliphatic-aromatic peroxide is benzoyl-lauroyl peroxide. Typically the DAP is preferably at a level of from 0.01% to 20% by weight of the composition, more preferably 0.05% to 10%, most preferably 0.5% to 3%.
Surfactant
The compositions according to the present invention are emulsions of at least one anionic and at least one nonionic surfactant.
Suitable anionic surfactants for use in the compositions herein include water-soluble salts or acids of the formula ROSO
3
M wherein R preferably is a C
8
-C
20
hydrocarbyl, preferably linear or branched alkyl having a C8-C
20
alkyl component, more preferably a C
10
-C
14
linear or branched alkyl, and M is H or a cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium), or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium cations and quaternary ammonium cations, such as tetramethyl-ammonium and dimethyl piperdinium cations and quaternary ammonium cations derived from alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like).
Other suitable anionic surfactants for use herein are water-soluble salts or acids of the formula RO(A)
m
SO
3
M wherein R is an unsubstituted C
6
-C
24
linear or branched alkyl group having a C
6
-C
24
alkyl component, preferably a C
10
-C
20
linear or branched alkyl, more preferably C
12
-C
18
linear or branched alkyl, A is an ethoxy or propoxy unit, m is greater than zero, typically between about 0.5 and about 30, more preferably between about 0.5 and about 5, and M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium, lithium, calcium, magnesium, etc.), ammonium or substituted-ammonium cation. Alkyl ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein. Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl-ammonium and quaternary
Gagliardi Leo
Scialla Stefano
Van Spaendonk Vincentius Henricus Adrianus Maria
Zanazzi Silvia
McBride James F.
Miller Steve W.
Webb Gregory E.
Zerby Kim W.
LandOfFree
Bleaching compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bleaching compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bleaching compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3107819