Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Solid – shaped macroscopic article or structure
Reexamination Certificate
2001-01-12
2002-09-24
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Solid, shaped macroscopic article or structure
C510S446000, C510S447000, C510S426000, C510S428000
Reexamination Certificate
active
06455488
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a process for the production of substantially odorless granules of alkyl sulfates and to their use for the production of laundry detergents, dishwashing detergents and cleaners and for the production of cleansing cosmetics.
Alkyl sulfates are conventional surfactants which are mostly used in detergents. In the method used for their production, they accumulate in the form of water-containing pastes with water contents of 35 to 65% by weight. In order to obtain solid free-flowing products, the water-containing pastes are dried, for example in a spray drying tower, to form spray-dried powders which, unfortunately, only have a low bulk density. An alternative to spray drying is granulation, more particularly in a fluidized bed. For example, it is known from European patent EP-B-603 207 that water-containing pastes of alkyl sulfates can be converted into granules of high bulk density by granulation and simultaneous drying in a continuous fluidized bed. It is also possible by this process to incorporate inorganic or organic carrier materials.
Accordingly, although it is known in principle that granules can be produced from water-containing pastes of alkyl sulfates, the problem posed by the unpleasant odor of water-containing alkyl sulfate pastes and spraydried powders or granules thereof remains unsolved. This unpleasant odor occurs above all with alkyl sulfates which contain 8 to 14 carbon atoms in the alkyl moeity. On account of their unpleasant odor, alkyl sulfates such as these have hitherto only been used in small quantities in cosmetics and, even then, have been heavily perfumed.
The problem addressed by the present invention was to provide free-flowing, dust-free and, above all, substantially odorless alkyl sulfates.
The problem stated above has surprisingly been solved by granulating and, at the same time, drying conventionally obtainable water-containing alkyl sulfate pastes in a fluidized bed until the content of unsulfonated components in the granules has fallen below 0.2% by weight, based on active substance content.
BRIEF SUMMARY OF THE INVENTION
Accordingly, the present invention relates to substantially odorless granules of alkyl sulfates corresponding to formula (I):
R—O—SO
3
X (I)
in which R is an alkyl group containing 6 to 18 carbon atoms and
X is an alkali metal, alkaline earth metal, ammonium, alkyl ammonium, alkanolammonium or glucammonium ion,
with a content of unsulfonated components of less than 0.2% by weight, based on active substance content.
The substituent R in formula (I) is derived from alcohols with the formula ROH, where R is as defined above. Accordingly, R may be derived from the alcohols, such as caproic alcohol, caprylic alcohol, 2-ethyl hexyl alcohol, capric alcohol, lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, linoyl alcohol, linolenyl alcohol, elaeostearyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol and brassidyl alcohol and the technical mixtures thereof obtained, for example, in the high-pressure hydrogenation of technical methyl esters based on fats and oils. R is preferably derived from alcohols containing 8 to 14 carbon atoms and more preferably from technical mixtures of such alcohols. In one particular embodiment, R is derived from technical mixtures of octanol so that the alkyl groups R in formula (I) have in particular the following composition:
0 to 10% by weight C
6
alkyl groups,
50 to 100% by weight C
8
alkyl groups,
0 to 10% by weight C
10
alkyl groups,
0 to 10% by weight C
12
alkyl groups,
0 to 10% by weight C
14
alkyl groups,
0 to 10% by weight C
16
alkyl groups,
0 to 10% by weight C
18
alkyl groups.
The present invention also relates to a process for the production of substantially odorless granules of alkyl sulfates corresponding to formula (I) with a content of unsulfonated components of less than 0.2% by weight, based on active substance content, characterized in that water-containing pastes of alkyl sulfates with a content of unsulfonated components of more than 0.3% by weight are granulated and, at the same time, dried in a fluidized bed, optionally in the presence of carrier materials.
DETAILED DESCRIPTION OF THE INVENTION
In the context of the present invention, the expression “active substance content” means the content of detersive alkyl sulfate as determined by the Epton method.
Conventional water-containing alkyl sulfate pastes obtained after sulfation of the corresponding alcohols and subsequent neutralization are used in the process according to the invention. Since the sulfation is not complete, above all in industrial plants, and yields partly unidentified secondary products without any sulfate groups, conventional alkyl sulfate pastes also always contain so-called “unsulfonated components”. These unsulfonated components are understood to be both the unreacted alcohols and the secondary products. The water-containing alkyl sulfate pastes normally contain the unsulfonated components in quantities of more than 3% by weight and generally between 0.5 and 2.5% by weight, based on active substance content. For example, water-containing technical octyl sulfate pastes contain between 0.5 and 2.5% by weight of unsulfonated components and 35 to 65% by weight and preferably 35 to 45% by weight of technical octyl sulfates with the chain distribution shown above for the technical octyl moiety and—in small quantities of generally below 3% by weight—alkali metal salts, such as sodium chloride and/or sodium sulfate. The balance of the pastes to 100% by weight is water.
These conventional alkyl sulfate pastes may be granulated and, at the same time, dried in the fluidized bed either on their own or in the presence of solid carrier materials. In the fluidized bed, the water evaporates from the paste, leaving partly to fully dried “nuclei” which are coated with more water-containing paste introduced or with the carrier materials added, granulated and, again, simultaneously dried.
In the most simple case, they are granulated and, at the same time, dried in the fluidized bed on their own. In this case, the water-containing pastes are introduced simultaneously or successively through one or more nozzles. If carrier materials are to be added, they are introduced at the same time as, but separately from, the water-containing pastes, preferably through an automatically controlled solids metering system.
Preferred fluidized beds have circular base plates (diffusor plates) between 0.4 and 5 m in diameter, for example 1.2 m or 2.5 m in diameter. The base plate may be a perforated plate, a Conidur plate (a product of Hein & Lehmann, Federal Republic of Germany) or a perforated plate of which the perforations (throughflow openings) are covered by a gauze with mesh widths smaller than 600 &mgr;m. The gauze may be arranged in or above the throughflow openings. However, the gauze is preferably located immediately below the throughflow openings of the diffusor plate. This is preferably done by sintering on a metal gauze with the appropriate mesh width. The metal gauze preferably consists of the same material as the diffusor plate, more particularly stainless steel. The mesh width of the gauze mentioned is preferably between 200 and 400 &mgr;m.
According to the invention, the process is preferably carried out at fluidizing air flow rates of 1 to 8 m/s and, more particularly, 1.5 to 5.5 m/s. The granules are preferably discharged via a grading stage. Grading is preferably carried out by a stream of drying air flowing in countercurrent (grading air) which is controlled in such a way that only particles beyond a certain particle size are removed from the fluidized bed while smaller particles are retained therein. In one preferred embodiment, the inflowing air is made up of the heated or unheated grading air and the heated bottom air. The bottom air temperature is preferably between 80 and 400° C. The fluidizing
Assmann Georg
Blochwitz Olaf
Kischkel Ditmar
Syldath Andreas
Cognis Deutschland GmbH
Drach John E.
Ogden Necholus
Trzaska Steven J.
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