Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-10-04
2002-04-30
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...
C510S309000, C510S372000, C510S500000, C548S259000, C548S302400, C548S304400, C548S361100, C548S469000, C252S186290, C252S186310, C252S186390
Reexamination Certificate
active
06380142
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to novel storage-stable formulations that comprise at least one peroxide compound, at least one mediator, and at least one pH stabilizer, to their preparation, and to their use in enzymatic bleaching systems, to specific enzymatic two-component bleaching systems, and to the use of such enzymatic bleaching systems.
The use of enzymatic bleaching systems is a method known to the person skilled in the art for the oxidative breakdown and/or for the alteration of wide varieties of substances. WO-A 92/18687 describes the decoloring of dyes, for example, as a field of application for such enzymatic bleaching systems. WO-A 94/29425, furthermore, discloses their use together with detersive substances. Moreover, enzymatic bleaching systems are much employed for pulp bleaching in the paper industry. See
Journal of Biotech.,
53 163-202 (1997).
Enzymatic bleaching systems are multi-component systems and are commonly composed of an enzyme, an oxidant, an auxiliary component termed a mediator, and further additives such as, pH regulators or auxiliary mediators, for example. Frequently described mediators come from the group of the aliphatic, cycloaliphatic, heterocyclic and aromatic NO—, NOH—, or H—RN—OH-containing compounds. 1-Hydroxy-benzotriazole (“HOBT”), in particular, is widely mentioned as a mediator. Examples of oxidants are hydrogen peroxide itself or peroxide sources such as perborate, persulfate, or percarbonate.
WO-A 94/29425 describes, for example, a multi-component bleaching system for use with detersive substances, the system comprising an oxidation catalyst (in the form of an enzyme, for example), an oxidant, and a mediator. A common formulation in a washing solution is prepared from these three components.
WO-A 99/34054, furthermore, discloses a method of removing excess dye from a freshly dyed textile material. This method comprises treating the dyed textile material with a washing solution comprising at least one enzyme having laccase or peroxidase activity, an oxidant, at least one mediator, and, optionally, further additives. As far as the practical implementation of the method is concerned, it is merely stated that the said multi-component system is added to the washing solution in at least one of the washing steps. The state of the individual components is not critical; i.e., the individual components may each be used in the form of a solution, slurry, or granules. It is further stated that in one embodiment a common formulation of the two components enzyme and mediator is prepared in the form, for example, of a cogranulated formulation, a solution, or a slurry. In another embodiment, the multi-component system constitutes a mixture of granules, one granule component containing the enzyme, and another granule component containing the mediator. According to the examples of WO-A 99/34054, a preferred embodiment of the method comprises adding first a phosphate buffer to the wash liquor in one of the washing steps, then rinsing with this wash liquor for a certain time, and subsequently adding the components peroxidase, hydroxy-benzotriazole, and hydrogen peroxide, simultaneously but individually. This individual but simultaneous metered addition of the necessary components imposes stringent requirements on the accuracy and the moment of metered addition when the method is implemented on the industrial scale.
For optimum utilization of enzymatic bleaching it is therefore important in practice to control the process with exactitude in terms of the reaction conditions such as pH, temperature, moment of addition, and amounts of the components of the bleaching system. Precise observation of the process parameters is essential to successful bleaching. For example, even a local excess of hydrogen peroxide or a locally excessive pH leads to deactivation of the enzyme, which is synonymous with a reduction in or failure of the desired bleaching effect.
Against this background, in order to provide access for enzymatic bleaching systems to industrial application, i.e., to provide a product which is easy and reliable to use, it is necessary to bring the system comprising the above-mentioned individual components into an application-friendly form comprising as few components as possible.
In particular, liquid product forms are desirable since these can be metered precisely and reproducibly in automatic installations. Moreover, good stability on storage, including storage at relatively high temperatures, is an important factor for successful industrial deployment.
The object of the present invention was therefore to find storage-stable and application-friendly formulations of enzymatic bleaching systems for industrial use.
This object has been achieved by virtue of the provision of a common formulation comprising at least one mediator, at least one peroxide compound, and a pH stabilizer.
SUMMARY OF THE INVENTION
The invention provides aqueous formulations comprising, based on the overall formulation,
(a) 0.1 to 20% by weight of at least one mediator comprising compounds of formula (I)
wherein
M denotes hydrogen, alkali metal (preferably sodium or potassium), alkaline earth metal (preferably calcium or magnesium), ammonium, C
1
-C
4
-alkylammonium, or C
1
-C
4
-alkanolammonium,
the radicals R
1
, R
2
, R
3
and R
4
are identical or different and denote hydrogen, halogen (preferably fluorine, chlorine, or bromine), hydroxyl, formyl, amino, nitro, straight-chain or branched C
1
-C
12
-alkyl, straight-chain or branched C
1
-C
6
-alkoxy, carbonyl-C
1
-C
6
-alkyl, phenyl, benzyl, phenyloxy, —COOR
5
, —SO
2
OR
5
, —SO
2
NH
2
, —NHSO
2
, —CONH
2
, —PO(OR
5
)
2
, —PO
2
(OR
5
), or —OPO(OR
5
)
2
,
X represents a group (—N═N—), (—N═CR
6
—)
m
, (—CR
6
═N—)
m
, or (—CR
7
═CR
8
—)
m
,
m is 1 or 2,
R
6,
R
7
and R
8
are identical or different and denote hydrogen, halogen (preferably fluorine, chlorine, or bromine), hydroxyl, formyl, amino, nitro, straight-chain or branched C
1
-C
12
-alkyl, straight-chain or branched C
1
-C
6
-alkoxy, carbonyl-C
1
-C
6
-alkyl, phenyl, benzyl, phenyloxy, —COOR
5
, —SO
2
OR
5
, —SO
2
NH
2
, —NHSO
2
, —CONH
2
, —PO(OR
5
)
2
, —PO
2
(OR
5
), or —OPO(OR
5
)
2
, and
each R
5
is identical or different and denotes hydrogen, alkali metal (preferably sodium or potassium), alkaline earth metal (preferably calcium or magnesium), ammonium, C
1
-C
4
-alkylammonium, C
1
-C
4
-alkanolammonium, straight-chain or branched C
1
-C
18
-alkyl (preferably C
2
-C
15
-alkyl, especially C
3
-C
10
-alkyl), or the radical —(CH
2
—CH
2
—O)
x
—H in which x denotes an integer 1 to 25 (preferably 2 to 20, more preferably 3 to 15),
(b) 0.1 to 20% by weight of at least one peroxide compound, and
(c) 60 to 99.8% by weight of an aqueous solution of at least one pH stabilizer,
wherein the formulations contain no enzymes.
DETAILED DESCRIPTION OF THE INVENTION
The common formulations of components (a), (b), and (c) of the invention exhibit an unexpectedly good storage stability. This is particularly surprising in view of the fact that it is known that peroxide compounds in aqueous formulations generally exhibit poor storage stabilities. Especially at relatively high storage temperatures, degradation occurs more or less rapidly and is accompanied by oxygen elimination of the peroxide compounds. In order to retard the decomposition of the peroxide compounds during storage, it is already known from the prior art to add stabilizers such as sodium phosphates or complexing agents, for example, to aqueous peroxide formulations. However, the formulations of the invention exhibit a further unexpectedly improved storage stability relative to formulations that are stabilized solely with sodium phosphate.
The aqueous formulations of the invention comprise, based on the overall formulation,
(a) preferably 0.1 to 10% by weight (with particular preference for 1 to 5% by weight) of at least one mediator comprising a compound of the above-mentioned formula (I),
(b) preferably 0.1 to 10% by weight (with particular preference 1 to 8% by weight
Schindler Markus
Vogt Uwe
Bayer Aktiengesellschaft
Delcotto Gregory
Gil Joseph C.
Henderson Richard E. L.
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