Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-06-29
2002-11-12
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S424000, C510S426000, C510S446000, C510S447000, C510S492000, C134S040000
Reexamination Certificate
active
06479452
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to solid laundry detergents, dishwashing detergents and cleaning compositions and, more particularly, to new surfactant granules distinguished by improved solubility in cold water, to a process for their production and to their use.
PRIOR ART
Nowadays, surfactants are preferably used in granular, substantially water-free form for the production of solid laundry detergents, dishwashing detergents and cleaning compositions. Various processes have been found to be suitable for the production of granular surfactants. However, one feature common to all commercially available surfactant granules is that they have an unsatisfactory dissolving rate, particularly in cold water. For this reason, detergent tablets based on anionic or nonionic surfactants cannot be directly introduced into the dispensing compartment of washing machines despite the use of considerable quantities of disintegrating agents; instead, they have to be directly added to the wash liquor. Anionic surfactants are important ingredients of detergents/cleaners. Where they are to form part of powder-form cleaners of high bulk density or compacted detergents, for example detergent tablets, alkyl sulfates—also known as fatty alcohol sulfates (FAS)—are preferably used in powder or granular form. These FAS powders or granules are normally produced by spray drying or drying in a continuous fluidized bed. C
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fatty alcohol sulfate granules in particular, which have been produced by drying and granulation in a continuous fluidized bed, show inadequate solubility and dispersibility at low temperatures. There is a risk of traces of detergent being left behind, particularly in the case of colored washing which has to be washed at low temperatures.
Since the solution to this problem is very important for cold washing and for the use of detergent compactates, the problem addressed by the present invention was to provide long-chain alkyl sulfate granules with improved dissolving and dispersing behavior at low temperatures and to improve the dissolving behavior of detergent compactates through the use of these granules.
DESCRIPTION OF THE INVENTION
The present invention relates to surfactant granules consisting of
(a) 75 to 97% by weight of an alkyl sulfate,
(b) 3 to 25% by weight of an alkenyl sulfate,
with the proviso that the quantities add up to 100% by weight with water and optionally electrolyte salts, and to a process for the production of these surfactant granules.
The present invention also relates to the use of the surfactant granules according to the invention in laundry detergents, dishwashing detergents and cleaning compositions.
It has surprisingly been found that the preparations according to the invention dissolve spontaneously in water, even at low temperatures. Detergent compactates containing the granules according to the invention have a considerably shorter disintegration time and dissolving rate. Even the addition of small quantities of alkenyl sulfate leads to a distinctly better dissolving rate at low temperatures (temperatures of 25° C.±10° C.).
Alkyl sulfate granules produced in a continuous fluidized bed also show this improved dissolving behavior. The improved dissolving behavior also leads to improved disintegration of disintegrator-containing detergent tablets (cellulose-based disintegrator systems).
Alkyl Sulfates
Alkyl sulfates, which are often referred to as fatty alcohol sulfates and which form surfactant component (a), are the sulfation products of primary saturated alcohols which correspond to formula (I):
R
1
O—SO
3
X (I)
where R
1
is a linear or branched, aliphatic alkyl group containing 6 to 22 and preferably 12 to 18 carbon atoms and X is an alkali metal and/or alkaline earth metal, ammonium, alkyl ammonium, alkanolammonium or glucammonium. Typical examples of alkyl sulfates which may be used for the purposes of the invention are the sulfation products of caproic alcohol, caprylic alcohol, capric alcohol, 2-ethyl hexyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol and erucyl alcohol and the technical mixtures thereof obtained, for example, by the high-pressure hydrogenation of technical methyl ester fractions or aldehydes from Roelen's oxo synthesis. The sulfation products may advantageously be used in the form of their alkali metal salts, more particularly their sodium salts. Alkyl sulfate powders or needles based on C
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tallow fatty alcohols or vegetable fatty alcohols of comparable C-chain distribution in the form of their sodium salts are particularly preferred.
Alkenyl Sulfates
Alkenyl sulfates, which are often referred to as ocenol sulfates, are understood to be the sulfation products of primary mono- and polyunsaturated alcohols which correspond to formula (Il):
R
2
O—SO
3
X (II)
in which R
2
is a linear or branched, mono- or polyunsaturated aliphatic alkenyl group containing 12 to 22 and preferably 16 to 18 carbon atoms and X is an alkali metal and/or alkaline earth metal, ammonium, alkyl ammonium, alkanolammonium or glucammonium. Alkenyl sulfates with an iodine value in the range from 5 to 60 and preferably in the range from 10 to 20 (palmocenol) or 50-55 (HD-ocenol), preferably based on C
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alcohols, are particularly preferred.
Residual Moisture and Electrolyte Salts
The surfactant granules according to the invention have residual moisture contents of 0.5 to 7% by weight and preferably 0.5 to 1.5% by weight, depending on the production process, the drying conditions and the storage conditions
The surfactant granules also contain free sodium hydroxide (0.2 to 1.2% by weight, preferably 0.4 to 0.8% by weight), free fatty alcohols (0.5 to 6% by weight, preferably 0.5 to 4% by weight) and varying amounts of electrolyte salts, for example sodium sulfate (0.2 to 10% by weight, preferably 0.5 to 5% by weight) and/or sodium chloride (0 to 2% by weight, preferably 0 to 0.5% by weight), from their production process.
Production Processes
The surfactant granules are produced by known processes, including SKET granulation, spray drying and droplet formation (“dropletization”). The granules may also be produced by compacting which includes press agglomeration, extrusion, roll compacting, pelleting and tabletting as operations.
Fluidized Bed Granulation
A particularly preferred process for the production of the surfactant granules according to the invention comprises subjecting the mixtures to fluidized bed granulation (“SKET” granulation). SKET fluidized bed granulation is understood to be a simultaneous granulation and drying process preferably carried out in batches or continuously. The mixtures of surfactants and disintegrating agents may be used both in dried form and in the form of a water-containing preparation. Preferred fluidized-bed arrangements have base plates measuring 0.4 to 5 m. The SKET granulation is preferably carried out at fluidizing air flow rates of 1 to 8 m/s. The granules are preferably discharged from the fluidized bed via a sizing stage. Sizing may be carried out, for example, by means of a sieve or by an air stream flowing in countercurrent (sizing air) which is controlled in such a way that only particles beyond a certain size are removed from the fluidized bed while smaller particles are retained in the fluidized bed. The inflowing air is normally made up of the heated or unheated sizing air and the heated bottom air. The temperature of the bottom air is between 80 and 400° C. and preferably between 90 and 350° C. A starting material, preferably surfactant granules from an earlier test batch, is advantageously introduced at the beginning of the granulation process.
Drying and Granulation in a Flash Dryer
The simultaneous drying and granulation process may also be carried out in a horizontally arranged thin-layer evaporator or dryer with rotating internals of the type marketed, for exampl
Kischkel Ditmar
Weuthen Manfred
Cognis Deutschland GmbH & Co. KG
Drach John E.
Ogden Necholus
Trzaska Steven J.
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