Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-11-16
2002-12-24
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...
C510S376000, C510S445000, C510S446000, C510S452000, C510S499000, C510S500000, C510S504000, C510S511000
Reexamination Certificate
active
06498133
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to particulate bleach activators based on acetonitriles, to a process for their preparation which consists in applying acetonitriles to silicon-containing carrier materials, and to the use of these products as bleach activators in solid laundry detergents and cleaning compositions.
Bleach activators are important constituents in compact detergents, stain-removal salts and machine dishwashing detergents. At temperatures as low as 40 to 60° C., they permit a bleaching result comparable with that of a boil wash by reacting with hydrogen peroxide-donors (in most cases perborates, percarbonates, persilicates and perphosphates) to release peroxy acids.
Many substances are known as bleach activators in the prior art. They are usually reactive organic compounds with an O-acyl or N-acyl group which, in alkaline solution together with a source of hydrogen peroxide, form the corresponding peroxy acids.
Representative examples of bleach activators are N,N,N′,N′-tetraacetylethylenediamine (TAED), glucose pentaacetate (GPA), xylose tetraacetate (TAX), sodium 4-benzoyloxybenzenesulfonate (SBOBS), sodium trimethylhexanoyloxybenzenesulfonate (STHOBS), tetraacetylglucoluril (TAGU), tetraacetylcyanic acid (TACA), di-N-acetyidimethylglyoxine (ADMG) and 1-phenyl-3-acetylhydantoin (PAH).
Ammonium nitrites form a particular class of cationic bleach activators. Compounds of this type and the use thereof as bleach activators in bleaches are described in EP-A-0 303 520, EP-A-0 464 880, EP-A-0 458 396, EP-A-0 897 974 and EP-A-0 790 244.
For the use of the ammonium nitrites as bleach activator in laundry detergents and cleaning compositions, the hygroscopicity of the ammonium nitrites and the sensitivity to hydrolysis in the presence of alkaline laundry detergent constituents and a correspondingly low storage stability associated therewith are highly disadvantageous.
WO 98/23531 and WO 00/36061 describe that acetonitrile derivatives, in particular cyclic acetonitrile compounds, are converted into a solid form for incorporation into solid laundry detergents and cleaning compositions by stirring a carrier material having the largest possible surface area, for example silica, into an aqueous acetonitrile solution, or by spraying the aqueous solution onto the carrier, and subjecting the resulting mixture to drying under reduced pressure at elevated temperatures. The granules or particles described in these specifications have water contents of up to 20% by weight, preferably less than 1 percent by weight. An unsatisfactory aspect is the hygroscopicity and, consequently, the storage stability of the products, in particular of the linear acetonitrile derivatives at fluctuating atmospheric humidity, and the partial decomposition of the hydrolysis-sensitive acetonitrile compounds during the thermal drying process.
SUMMARY OF THE INVENTION
Surprisingly, it has been found that formulating in the form of granules or particles of the acetonitrile derivatives can be carried out in a manner which is very gentle to the active ingredient, but is also very advantageous with regard to costs and environment, by spraying aqueous solutions, saturated at room temperature, of acetonitrile derivatives onto a silicon-containing carrier material, in particular silica, without subsequent drying. This gives solid products with a water content of from 20 to 30% by weight. A drying process, which is energy-intensive and unfavorable for the active ingredient, can be dispensed with. The active ingredient concentration of the products prepared by the process according to the invention is greater than that of conventional products, and the hygroscopicity of the acetonitrile derivatives formulated in accordance with the invention is significantly lower.
The invention provides particulate bleach activators comprising 15 to 60% by weight, preferably 20 to 50% by weight, in particular 35 to 45% by weight, of an acetonitrile, 20 to 70% by weight, preferably 30 to 50% by weight, in particular 35 to 45% by weight, of a silicon-containing carrier matieral, and 20 to 30% by weight, preferably 22 to 25% by weight, of water.
Such acetonitriles are compounds of the formula
in which R
1
, R
2
, R
3
are identical or different and are linear or branched C
1
-C
24
-alkyl groups, C
2
-C
24
-alkenyl groups or are C
1
-C
4
-alkoxy-C
1
-C
4
-alkyl groups, substituted or unsubstituted benzyl, or in which R
1
and R
2
, together with the nitrogen atom to which they are bonded, form a ring having 4 to 6 carbon atoms which may be substituted by C
1
-C
5
-alkyl, C
1
-C
5
-alkoxy, C
1
- to C
5
-alkanoyl, phenyl, amino, ammonium, cyano, cyanamino, chlorine or bromine, and, in addition to the nitrogen atom, may contain one or two oxygen or nitrogen atoms, a group N—R
6
or a group R
3
—N—R
6
instead of carbon atoms, in which R
6
is hydrogen, C
1
- to C
5
-alkyl, C
2
- to C
5
-alkenyl, C
2
- to C
5
-alkynyl, phenyl, C
7
- to C
9
-aralkyl, C
5
- to C
7
-cycloalkyl, C
1
- to C
6
-alkanoyl, cyanomethyl or cyano, R
4
and R
5
are hydrogen, C
1
-C
4
-alkyl, C
2
-C
4
-alkenyl, C
1
-C
4
-alkoxy-C
1
-C
4
-alkyl, phenyl or C
1
-C
3
-alkylphenyl, preferably hydrogen, methyl or phenyl, where, in particular, R
4
is hydrogen if R
5
is not hydrogen, and A is any desired anion, for example chloride, bromide, iodide, fluoride, sulfate, hydrogensulfate, carbonate, hydrogencarbonate, phosphate, mono- and di-hydrogenphosphate, pyrophosphate, metaphosphate, nitrate, methylsulfate, phosphonate, methylphosphonate, methanedisulfonate, methylsulfonate, ethanesulfonate or is an anion of the formulae RSO
3
⊖
, R
1
SO
4
⊖
or R
2
COO
⊖
, where R, R
1
and R
2
are C
8
-C
20
-alkyl, preferably C
10
-C
18
-alkyl, and R
1
is additionally also substituted aryl, preferably C
1
-C
18
-alkylphenyl. Particular preference is given to cumenesulfonate and C
12/18
-alcohol sulfate as anion.
Particular preference is given to compounds of the above formula in which R
1
, R
2
and R
3
are C
1
-C
4
-alkyl, and R
4
and R
5
are hydrogen, and A is any desired cation, preferably chloride, methosulfate, cumenesulfonate, lauryl sulfate or fatty acid alkyl carboxylates or mixtures of these cations.
The synthesis of these acetonitriles can be carried out by known processes, as published, for example, by Abraham in Progr. Phys. Org. Chem. 11 (1974), p. 1 ff, or by Arnett in J. Am Chem. Soc. 102 (1980), p. 5892 ff.
These acetonitriles are used to prepare a saturated aqueous solution which is applied to the silicon-containing carrier material, preferably by spraying, for example via a two-material nozzle. The temperature of this saturated aqueous solution is preferably 10 to 40° C., particularly preferably 20 to 25° C. The material can then be after-mixed. The amount of saturated aqueous solution is measured such that the limits given above for acetonitrile, carrier material and water are observed.
Preferred silicon-containing carrier materials are preferably those whose internal surface area is in the range from 10 m
2
/g to 500 m
2
/g, in particular 100 m
2
/g to 450 m
2
/g. Examples of suitable materials are silicates, silicas, silica gels and clays, and mixtures thereof. The carrier material is preferably free from strongly alkaline constituents.
Silicas which have been prepared by the thermal process (flame hydrolysis of SiCl
4
) (so-called pyrogenic silicas) can be used as well as silicas prepared by wet processes. Silica gels are colloidal silicas with elastic to solid consistency and a largely loose pore structure, resulting in a high liquid absorption capacity. They can be prepared by reacting mineral acids on water glass. Clays are naturally occurring crystalline or amorphous silicates of aluminum, iron, magnesium, calcium, potassium and sodium, for example kaolin, talc, pyrophyllite, aftapulgite, sepiolite, montmorillonite and bauxite. The use of aluminum silicate as carrier material or as component of a carrier material mixture is also possible. The carrier material preferably has particle sizes in the ran
Borchers Georg
Milbradt Robert
Mogck Oliver
Weinelt Frank
Clariant GmbH
Delcotto Gregory
Silverman Richard P.
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