Colloid systems and wetting agents; subcombinations thereof; pro – Compositions containing an agent for breaking ; processes of... – Continuous liquid phase colloid system and discontinuous gas...
Reexamination Certificate
2000-10-10
2003-08-26
Lovering, Richard D. (Department: 1712)
Colloid systems and wetting agents; subcombinations thereof; pro
Compositions containing an agent for breaking ; processes of...
Continuous liquid phase colloid system and discontinuous gas...
C510S226000, C510S313000, C510S315000, C510S316000, C510S317000, C510S442000, C510S446000, C516S120000, C516S123000
Reexamination Certificate
active
06610752
ABSTRACT:
BACKGROUND OF THE INVENTION
Detergents for domestic laundry and for industrial laundry, but also dishwashing detergents and cleaners, generally contain organic surfactants, builders and numerous organic and inorganic additives. The surfactants used for washing normally tend to foam in use which has an adverse effect on the cleaning result. Accordingly, there is a practical need to control foaming in use. Silicones have proven to be particularly suitable defoamers. They are generally applied to support materials and are optionally coated with other organic defoaming substances for use in solid laundry detergents, dishwashing detergents and cleaners.
Thus, the production of foam-suppressed detergents containing microencapsulated silicone defoamers is known from DE 3128631 A1. According to this document, the silicone is dispersed in an aqueous dispersion of a film-forming polymer and the dispersion is delivered to the spray-drying tower through a separate pipe, i.e. separately from the other detergent ingredients dissolved or dispersed in water. The two streams are then combined in the vicinity of the spray nozzle. Suitable film-forming polymers are, for example, cellulose ethers, starch ethers and synthetic water-soluble polymers. Microcapsules are spontaneously formed in the spray nozzle. The described process is limited in its application to the production of spray-dried detergents and does not appear to lend itself to detergents produced by other methods, for example by granulation. European patent application EP 0496510 A1 describes silicone-containing defoamers which are characterized in that a mixture of silicones and fatty alcohols, fatty acids or glycerol monoesters having special melting points is applied to starch as the support material. To produce these defoamer granules, the silicones and the other organic ingredients are mixed with the starch in liquid form or granulated by the fluidized bed process. A problematical aspect of this process is the spraying of the silicones and the organic materials onto the support during the granulation process. Thus, in view of their viscosity and their tacky, oily consistency, the silicones on the one hand are difficult to pump and, on the other hand, lead to stringing and tacky deposits in the spray nozzle, so that the fine spraying required is virtually impossible.
Accordingly, the problem addressed by the present invention was to provide new defoamer granules for solid laundry detergent, dishwashing detergent and cleaning compositions which would be distinguished in particular by their flowability and by the absence of dust emissions. Finally, the associated production process would be designed in such a way that the silicones would be easy to pump and could be finely sprayed on.
BRIEF SUMMARY OF THE INVENTION
This invention relates generally to solid laundry detergent, dishwashing detergent and cleaning compositions and, more particularly, to new silicone-containing defoamer granules for solid laundry detergent, dishwashing detergent and cleaning compositions which are obtained by simultaneous granulation and drying, to a process for their production and to the use of the granules for the production of solid surface-active compositions.
The present invention includes defoamer granules containing support materials and silicones for solid laundry detergent, dishwashing detergent and cleaning compositions which can be obtained by applying silicones in the form of aqueous emulsions to an added intermediate product of support materials and simultaneously drying and granulating the products in a fluidized bed, with the proviso that at least 85% by weight, preferably at least 90% by weight and more preferably at least 95% by weight of the particles have a mean diameter below 1.5 mm, preferably below 1.3 mm and more preferably between 0.1 and 1.5 mm.
It has surprisingly been found that the new defoamer granules fully satisfy the desired requirement profile.
The present invention also includes a process for the production of defoamer granules containing support materials and silicones for solid laundry detergent, dishwashing detergent and cleaning compositions, characterized in that silicones are applied in the form of aqueous emulsions to an added intermediate product of support materials and the products are simultaneously dried and granulated in a fluidized bed, with the proviso that at least 85% by weight, preferably at least 90% by weight and more preferably at least 95% by weight of the particles have a mean diameter below 1.5 mm, preferably below 1.3 mm and more preferably between 0.1 and 1.5 mm.
DETAILED DESCRIPTION OF THE INVENTION
Suitable silicones in the context of the present invention are typical organopolysiloxanes containing fine-particle silica which, in turn, may even be silanized. Corresponding organopolysiloxanes are described, for example, in U.S. Pat. No. 5,238,596, the entire contents of which are incorporated herein by reference. Polydiorganosiloxanes known from the prior art are particularly preferred. Suitable polydiorganosiloxanes have an almost linear chain and a degree of oligomerization of 40 to 1500. Examples of suitable substituents are methyl, ethyl, propyl, isobutyl, tert.butyl and phenyl. The polydiorganosiloxanes generally contain fine-particle silica which may even be silanized. Silica-containing dimethyl polysiloxanes are particularly suitable for the purposes of the present invention. The polydiorganosiloxanes advantageously have a Brookfield viscosity at 25° C. (spindle 1,10 r.p.m.) of 5000 mPas to 30,000 mPas and, more particularly, 15,000 mPas to 25,000 mPas. A key criterion of the present invention is that the silicones are sprayed in as aqueous emulsions. In general, the silicone is added with stirring to water. If desired, so-called thickeners known from the prior art may be added to increase the viscosity of the aqueous silicone emulsions. The thickeners may be inorganic and/or organic, particularly preferred thickeners being nonionic cellulose ethers, such as methyl cellulose, ethyl cellulose and mixed ethers, such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, methyl hydroxybutyl cellulose, and anionic carboxy cellulose types, such as carboxymethyl cellulose sodium salt (abbreviation: CMC). Particularly suitable thickeners are mixtures of CMC with nonionic cellulose ethers in a ratio by weight of 80:20 to 40:60 and, more particularly, 75:25 to 60:40. In general and particularly where the described thickener mixtures are added, it is advisable to use concentrations of around 0.5 to 10% by weight and, more particularly, 2.0 to 6% by weight, expressed as thickener mixture and based on aqueous silicone emulsion. The content of silicones of the described type in the aqueous emulsions is advantageously in the range from 5 to 50% by weight and, more particularly, in the range from 20 to 40% by weight, expressed as silicones and based on aqueous silicone emulsion. In another advantageous embodiment, the aqueous silicone solutions contain starch-from natural sources, for example rice, potatoes, corn and wheat, as thickener. The starch is advantageously present in quantities of 0.1 to 50% by weight, based on silicone emulsion, and more particularly in the form of a mixture with the above-described thickener mixtures of sodium carboxymethyl cellulose and a nonionic cellulose ether in the quantities already mentioned. The aqueous silicone emulsions are preferably prepared by allowing any thickeners present to preswell in water before the silicones are added. The silicones are preferably incorporated using effective stirrers and mixers.
Suitable support materials in the context of the present invention are any known inorganic and/or organic support materials. Examples of typical inorganic support materials are alkali metal carbonates, aluminosilicates, water-soluble layered silicates, alkali metal silicates, alkali metal sulfates, for example sodium sulfate, and alkali metal phosphates. The alkali metal silicates are preferably a compound with a molar ratio of alkali metal oxide to
Borntraeger Andrea
Koren Karin
Neuss Michael
Schmid Karl Heinz
Stanislowski Detlef
Cognis Deutschland GmbH
Drach John E.
Ettelman Aaron R.
Lovering Richard D.
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