Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – With oxygen or halogen containing chemical bleach or oxidant...
Reexamination Certificate
1999-07-15
2002-04-16
Boyer, Charles (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
With oxygen or halogen containing chemical bleach or oxidant...
C510S276000, C510S283000, C510S285000, C510S286000, C510S289000, C510S290000, C510S304000, C510S302000, C510S308000, C510S309000, C510S329000, C510S338000, C510S356000, C510S371000, C510S407000, C510S421000, C510S504000, C510S509000
Reexamination Certificate
active
06372703
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to non-aqueous liquid detergents which contain nonionic surfactant(s), builder(s) and bleaching agent and which show increased stability of the bleaching agent. The present invention also relates to the use of special stabilizers for stabilizing bleaching agents in non-aqueous liquid detergents.
2. Discussion of Related Art
Liquid detergents are enjoying increasing popularity among consumers because they are easier to dose and generally dissolve better and faster. However, these advantages are offset by technical difficulties which have to be overcome in the production and storage of the detergents. Thus, it is almost impossible to incorporate a bleaching system in aqueous detergents because the bleaching agents steadily lose activity as a result of hydrolysis, so that the effectiveness of the detergents in removing bleachable soils is reduced. However, the incorporation of bleaching agents and bleach activators in non-aqueous liquid detergents is also problematical. Thus, even so-called “water-free” detergents still contain small residues of water, which cause the hydrolysis problems mentioned above, or absorb these quantities of water during storage and use. In addition, the decomposition of bleaching agents is catalyzed by the presence of traces of heavy metals which can even be found in the non-aqueous solvents on which the “water-free” detergents are based.
There are several proposed solutions in the prior art for increasing the stability of bleach-containing non-aqueous liquid detergents, these proposed solutions generally involving the use of certain stabilizers. Thus, EP 340 989 (Colgate), for example, describes the use of C
5-21
fatty acids, fatty acid salts or fatty acid glyceryl monoesters or diesters as stabilizers in non-aqueous liquid detergents containing bleaching agent and bleach activator. The use of vicinal hydroxy compounds for this purpose is disclosed in EP 344 909 (Colgate).
WO 93/06201 (Henkel) describes a non-aqueous liquid or paste-form detergent containing 5 to 20% by weight of hydrated zeolite A, 50 to 80% by weight of anionic and/or nonionic surfactant, 5 to 20% by weight of bleaching agent, up to 6% by weight of bleach activator and up to 6% by weight of a complexing agent for heavy metals.
WO 96/10072 (Procter & Gamble) discloses a process for the production of non-aqueous bleach-containing liquid detergents which show high chemical and physical stability and produce excellent washing and bleaching results, characterized in that fine-particle detergent components are suspended in a non-aqueous liquid matrix of alcohol ethoxylates.
The use of other complexing agents and/or radical scavengers for stabilizing bleaching agents is widely described in the prior art.
However, the effect of the measures described in the prior art for stabilizing bleaching agents in non-aqueous liquid detergents is unsatisfactory. In the event of prolonged storage, the bleaching agents undergo decomposition, despite the use of the stabilizers mentioned, while the detergents lose washing power.
Now, the problem addressed by the present invention was to provide a stable bleach-containing liquid detergent which would contain the solid bleaching agents in the form of a stable dispersion. The bleaching agents would not undergo any loss of activity, even in the event of prolonged storage of the detergent.
The solution to this problem is characterized in that certain cationic compounds are incorporated as stabilizers in the non-aqueous liquid detergents.
DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a non-aqueous liquid detergent containing nonionic surfactant(s), builder(s) and bleaching agent, characterized in that it contains as stabilizer one or more cationic compounds corresponding to formula I, II or III:
in which the groups R
1
independently of one another are each selected from C
1-6
alkyl, alkenyl or hydroxyalkyl groups, the groups R
2
independently of one another are each selected from C
8-28
alkyl or alkenyl groups, R
3
has the same meaning as R
1
or represents (CH
2
)
n
—T—R
2
, R
4
has the same meaning as R
1
or R
2
or represents (CH
2
)
n
—T—R
2
, T represents —CH
2
—, —O—CO— or —CO—O— and n is an integer of 0 to 5.
The expression “non-aqueous” in the context of the present invention is understood to apply to detergents which only contain small quantities of free water, i.e. water which is not bound as water of crystallization or in any other way. Since even non-aqueous solvents and raw materials (particularly those of technical quality) have certain water contents, entirely water-free compositions can only be produced with great difficulty and at high cost on an industrial scale. Accordingly, small quantities of free water of less than 5% by weight and preferably less than 2% by weight, based on the final detergent, are tolerable in the “non-aqueous” detergents according to the present invention.
The liquid detergents according to the present invention can be produced within a broad viscosity range. Thus, it is possible to produce not only low viscosity, readily pumpable detergents according to the invention, but also high-viscosity or even paste-like detergents with relatively high viscosities. Paste-form detergents may even have a spreadable or cuttable consistency. Even in detergents such as these, the use of the cationic stabilizers leads to the bleach-stabilizing effects according to the present invention.
The cationic stabilizers may be introduced into the detergents according to the invention in varying quantities. The content of cationic stabilizers corresponding to the above formulae in the detergents according to the invention is normally from 0.5 to 10% by weight, preferably from 1 to 6% by weight and more preferably from 2 to 4% by weight.
Preferred cationic stabilizers are obtained by esterification of triethanolamine with long-chain fatty acids and subsequent quaternization. Both the esterification step and the quaternization step are carried out in known manner, dimethyl sulfate preferably being used as the quaternizing agent. Preferred detergents contain a quaternized triethanolamine ester as cationic stabilizer.
Other preferred cationic stabilizers are compounds which are derived from formula I above and in which the groups R
1
independently of one another are each selected from methyl, ethyl and 2-hydroxyethyl groups; the groups R
2
independently of one another are each selected from C
8-28
alkyl or alkenyl groups, preferably from C
10-20
alkyl or alkenyl groups and more preferably from C
12-18
alkyl or alkenyl groups, T represents O—CO— and n is the number 1, 2 or 3. Cationic stabilizers such as these are commercially available, for example, under the names of Stepantex® VA 90, Stepantex® VS 90 (trademarks of the Stepan Company) and Dehyquart® AU 46 and Dehyquart® AU 57 (trademarks of Henkel/Pulcra).
The cationic stabilizers to be used in accordance with the invention may be used either on their own or in combination with other stabilizers known from the prior art. The stabilizers described in the prior art can be divided into three large groups, namely: antioxidants, drying agents and complexing agents.
Suitable antioxidants are, for example, phenols, bisphenols and thiobisphenols substituted by sterically hindered groups. Other classes of antioxidants are aromatic amines, preferably secondary aromatic amines, and substituted p-phenylenediamines, phosphorus compounds containing trivalent phosphorus, such as phosphines, phosphites and phosphonites, compounds containing enediol groups, so-called reductones, such as ascorbic acid and derivatives thereof, organic sulfur compounds, such as the esters of 3,3′-thiodipropionic acid with C
1-18
alkanols, more especially C
10-18
alkanols, metal ion deactivators which are capable of complexing autoxidation-catalyzing metal ions, for example copper, such as EDTA, nitrilotriacetic acid etc. and mixtures thereof. A large number of examples of such antioxidants can be found in DE
Pegelow Ulrich
Richter Bernd
Bo Charles
Boyer Charles
Henkel Komanditgesellschaft auf Aktien
Murphy Glenn E. J.
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