Patent Application
20080255022
The present invention relates to a process for producing granular or pulverulent detergent compositions, comprising the production of a detergent base powder by drying an aqueous detergent slurry, and also to detergent slurries and detergent compositions comprising a copolymer obtainable by free-radical copolymerization of
In the production of powder detergents or base powders for further processing to solid detergents (for example extrusion with addition of further components to give granules), up to 30 liquid or solid components, some of them in very different amounts, have to be homogenized very intensively and uniformly, which is done by slurrying in water. In the course of this, various components, for example surfactants and the zeolites used as builders, give rise to highly viscous mixtures. Since very highly concentrated slurries are desired for the subsequent spray-drying, it is necessary to use assistants which lower the viscosity of the slurries.
WO-A-91/09932 describes a process for producing granular detergent compositions in which a deflocculating polymer with a hydrophilic polymer backbone and hydrophobic side chains is added to the detergent slurry. The backbone is based on unsaturated monocarboxylic acids, dicarboxylic acids and/or alcohols as monomer units; the side chains which may comprise polyalkylene oxide blocks are bonded to the backbone via ester, ether or amide functions. In the examples, a copolymer of acrylic acid and dodecyl maleate is used.
Copolymers of acrylic acid and ethoxylated allyl ethers having a mean molecular weight Mw of about 12 000 g/mol are used for this purpose in U.S. Pat. Nos. 5,595,968, 5,618,782 and 5,733,861.
Finally, WO-A-96/17919 describes copolymers of acrylic acid and maleic acid which comprise dodecyl mercaptan radicals as end groups as deflocculating agents for detergent slurries.
It was an object of the invention to enable the production of solid detergent compositions in an advantageous manner by use of viscosity-lowering polymers.
Accordingly, a process has been found for producing granular or pulverulent detergent compositions, comprising the production of a detergent base powder by drying an aqueous detergent slurry, which comprises adding to the slurry a copolymer which is obtainable by free-radical copolymerization of
Also found has been a process for lowering the viscosity of detergent slurries, which comprises adding these copolymers to the slurry.
Moreover, detergent slurries and detergent compositions which comprise these copolymers have been found.
The copolymers used in accordance with the invention comprise, as the copolymerized monomer (A), a monoethylenically unsaturated monocarboxylic acid or dicarboxylic acid or a mixture of these acids. The acids may be used in the form of their water-soluble salts, especially of the alkali metal salts such as potassium salts and in particular sodium salts, or ammonium salts; the dicarboxylic acids may also be present fully or partly in anhydride form. It will be appreciated that it is also possible to use acid mixtures.
The monomers (A) comprise preferably from 3 to 10 carbon atoms.
Specific examples of suitable monomers (A) include: acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride and itaconic acid.
Particularly preferred monomers (A) are acrylic acid, methacrylic acid and maleic acid/anhydride, very particular preference being given to maleic acid/anhydride.
The copolymers used in accordance with the invention comprise from 20 to 80% by weight, in particular from 30 to 70% by weight of monomer (A).
As the copolymerized monomer (B), the copolymers used in accordance with the invention comprise at least one aliphatic or aromatic monoolefin.
Specific examples of suitable monomers (B) are: 1-butene, isobutene, 1-pentene, 1-hexene, diisobutene (2-methyl-4,4-dimethyl-1-pentene), 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, C18-C24-α-olefins such as 1-octadecene, 1-eicosene, 1-docosene and 1-tetracosene, C20-C24-α-olefin mixtures, 1-hexacosene, polyisobutenes having an average of 12 to 100 carbon atoms and styrene.
The copolymers used in accordance with the invention preferably comprise, as component (B), a mixture of (B1) at least one monoolefin having ≦8 carbon atoms and (B2) at least one monoolefin having ≧10 carbon atoms. Suitable monoolefins (B1) are in particular isobutene, diisobutene and styrene. Particularly suitable monoolefins (B2) are 1-dodecene, C18-C24-α-olefins, C20-C24-α-olefin mixtures and polyisobutenes having an average of from 12 to 100 carbon atoms.
The copolymers used in accordance with the invention comprise from 20 to 80% by weight, preferably from 30 to 70% by weight of monomer (B).
Very particularly preferred copolymers used in accordance with the invention are obtainable by free-radical copolymerization of (A) from 30 to 70% by weight of maleic acid/anhydride, (B1) from 20 to 40% by weight of isobutene and (B2) from 5 to 20% by weight of a C18-C24-α-olefin.
The copolymers used in accordance with the invention have a mean molecular weight Mw of from 1000 to 200 000 g/mol, preferably from 2000 to 50 000 g/mol (determined by gel permeation chromatography at room temperature with aqueous eluents).
Their K values are correspondingly from 10 to 150, preferably from 15 to 60 (measured at pH 7 in 1% by weight aqueous solution at 25° C.; according to H. Fikentscher, Cellulose-Chemie, vol. 13, p. 58-64 and 71-74 (1932)).
The copolymers used in accordance with the invention may be prepared by known processes.
Typically, they are obtained especially in the form of aqueous polymer solutions or dispersions which have a solids content of from 10 to 70% by weight, preferably from 25 to 60% by weight.
It is possible with the copolymers used in accordance with the invention to effectively lower the viscosity of aqueous detergent slurries, especially of the slurries which are dried to produce granular or pulverulent detergent compositions, so that even highly concentrated slurries can be handled without any problem. Thus, the slurry concentrations may be always ≧50% by weight, preferably ≧60% by weight, based on the anhydrous detergent components.
The copolymers used in accordance with the invention additionally bring about stabilization and homogenization of the slurries and prevent separations.
They are added to the slurries generally in amounts of from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight and more preferably from 0.1 to 5% by weight, based on the overall mixture.
They can either be added to the overall mixture or admixed in any portions to individual detergent components, for example to the surfactants or to the builder premixes, whose solids contents may already have been raised in this way.
Inventive solid detergent formulations which comprise the polymers used in accordance with the invention advantageously have, for example, the following composition:
Suitable nonionic surfactants (b) are in particular:
Suitable anionic surfactants are, for example:
The anionic surfactants are added to the detergent preferably in the form of salts. Suitable salts are, for example, alkali metal ions such as sodium, potassium and lithium, and ammonium salts such as hydroxyethylammonium, di(hydroxyethyl)-ammonium and tri(hydroxyethyl)ammonium salts.
Particularly suitable cationic surfactants include:
in which the variables are defined as follows:
Suitable inorganic builders are in particular:
Suitable organic cobuilders are in particular:
Suitable bleaches are, for example, adducts of hydrogen peroxide to inorganic salts, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium carbonate perhydrate, and percarboxylic acids such as phthalimidopercaproic acid.
Suitable bleach activators are, for example, N,N,N′,N′-tetraacetylethylenediamine (TAED), sodium p-nonanoyloxybenzenesulfonate and N-methylmorpholinium acetonitrile methylsulfate.
Enzymes used with preference in detergents are proteases, lipases, amylases, cellulases, oxidases and peroxidases.
Suitable dye transfer inhibitors are, for example, homopolymers, copolymers and graft polymers of 1-vinylpyrrolidone, 1-vinylimidazole and 4-vinylpyridine N-oxide. Homopolymers and copolymers of 4-vinylpyridine reacted with chloroacetic acid are also suitable as dye transfer inhibitors.
Detergent ingredients are otherwise generally known. Detailed descriptions can be found, for example, in WO-A-99/06524 and 99/04313 and in Liquid Detergents, editor: Kuo-Yann Lai, Surfactant Sci. Ser., Vol. 67, Marcel Dekker, New York, 1997, p. 272-304.
The viscosity-lowering action of the copolymer P was investigated in two detergent slurries.
The copolymer P was a copolymer of maleic anhydride, isobutene and 1-octadecene in a weight ratio of 65:26:9, which had a mean molecular weight Mw of 3000 g/mol and a K value of 24 (measured at pH 7 in 1% by weight aqueous solution at 25° C.). The copolymer was used in the form of a 40% by weight aqueous solution.
The two detergent slurries were prepared as follows:
In a 500 ml heatable jacketed stainless steel vessel, two different detergent slurries were produced with stirring. To this end, the liquid components were initially heated at 50° C. for 10 min with stirring. The stirrer used had a torque recorder. Within 4 min, the solid components mixed beforehand were metered in uniformly, in the course of which the slurry continued to be stirred at 150 rpm. After the addition had ended, the slurry continued to be stirred at constant rotational speed while determining the torque.
The torque expresses the force which is required to stir the slurry at constant rotational speed. The lower the torque, the lower the viscosity of the detergent slurry.
Table 1 lists the compositions of the detergent slurries. The amounts reported relate to feedstocks in anhydrous form, i.e. without water fractions or water of crystallization, which are present in the overall water content.
Table 2 compiles the torques obtained after 30 min in each case. For comparison, the results obtained without polymer addition are also listed.
The result nd means that the viscosity of the slurry was very high and the torque was no longer determinable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 047 833.6 | Oct 2005 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP06/66868 | 9/29/2006 | WO | 00 | 4/1/2008 |
