Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
1997-04-01
2001-05-22
Medley, Margaret (Department: 1714)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S421000, C510S457000, C510S470000
Reexamination Certificate
active
06235703
ABSTRACT:
TECHNICAL AREA
The present invention is concerned with mobile surfactant blends containing alkylpolyglycosides, processes for preparing them, their use in the preparation of particulate detergent compositions and components.
BACKGROUND
Alkylpolyglycosides have been widely disclosed in the art as environmentally friendly carbohydrate-derived nonionic surfactants, and are used in various detergent and personal care products. Disclosures in the prior art include EP 75 995A (Procter & Gamble), EP 238 638B (Staley/Henkel), EP 487 262A (Unilever) and EP 374 702 A (Kao).
These materials are currently supplied as aqueous pastes containing only about 50 wt % of active matter, the balance being water. The water is present as a result of the manufacturing process, and is also important as a medium for the subsequent hydrogen peroxide bleaching step which is always required in order to obtain a light-coloured product. For example, EP 306 650A (Hals AG) discloses a process for the preparation of alkylpolyglycosides by glycosidation in alcoholic solution, followed by purification with active charcoal, removal of the alcohol by distillation, addition of further water, and bleaching with hydrogen peroxide. The product is an aqueous paste having an active matter content of about 50 wt %.
The aqueous paste possesses a number of disadvantages. Viscosity is too high for processability at 20° C. and heating to 30° C. or above is required. If the water is surplus to the requirements of the final detergent product, it must be removed by the detergent manufacturer either before or during its incorporation.
Traditional low- and medium-density detergent powders were and are prepared by spray-drying an aqueous slurry of all ingredients that are sufficiently heat-insensitive. This is a high temperature process in which large amounts of water are driven off. In this process the water associated with the polymer is a minor contributor to the total slurry moisture and makes little or no difference to the efficiency or energy consumption of the process.
The compact or concentrated powders which now form a substantial part of the market, however, are prepared by non-tower mixing and granulation processes which generally avoid high-temperature processing where water will be driven off. In such processes it is generally desirable that the moisture content should be kept as low as possible, both to facilitate granulation, which requires a carefully controlled balance of liquid and solid ingredients, and to ensure that the final product also has as low as possible a moisture content. Low moisture content is especially important for compositions to which moisture-sensitive bleach ingredients, especially sodium percarbonate, are to be added.
Mixing and granulation may be followed by a separate drying step, for example, in a fluidised bed, but that requires additional plant and the expenditure of additional energy.
Accordingly, for the preparation of compact high bulk density powders of low moisture content, the incorporation of alkylpolyglycosides in the form of aqueous pastes is not ideal.
The present inventors have now succeeded in preparing alkylpolyglycosides in a mobile, processable form having low water content, as blends with ethoxylated nonionic surfactants and strictly controlled amounts of water. The blends may readily be mixed and granulated with detergent solids by non-spray-drying processes to form particulate detergent compositions or components of high surfactant content and low water content, no further drying step being required.
PRIOR ART
EP 75 995A and EP 75 996A (Procter & Gamble) disclose detergent compositions containing alkylpolyglycosides and ethoxylated nonionic surfactants. The combination of surfactants is said to give improved detergency on certain soils.
EP 265 203B (Unilever) discloses sprayable mobile liquid blends of anionic surfactants (alkylbenzene sulphonates or primary alcohol sulphates) and ethoxylated nonionic surfactants containing less than 10 wt % of water. The blends may be sprayed onto solid absorbent particulate carrier materials to form particulate detergent compositions.
WO 94 22997A (Henkel) discloses synergistic surfactant mixtures of alkylpolyglycosides and nonionic surfactants.
EP 662 511A (Huls) relates to the use of nonionic surfactants to liquefy the hexagonal liquid crystalline phase of surfactant mixtures, and discloses isotropic liquid surfactant mixtures of alkylpolyglycosides, ethoxylated nonionic surfactants and water.
WO 93 19155A (Henkel) discloses the production of granular detergent compositions or components from aqueous alkylpolyglycoside pastes: the pastes are dried and granulated with a cosurfactant (which may be nonionic) and with solid detergent ingredients in a turbo-dryer, to give a granular product having a high alkylpolyglycoside content and a low water content.
EP 694 608A (Procter & Gamble) discloses the production of granular laundry detergent compositions or components containing a polyhydroxy fatty acid amide sugar surfactant. A pumpable premix of the sugar surfactant with ethoxylated nonionic surfactant and a glyceride fat is prepared and then mixed and granulated with solid detergent ingredients, for example, zeolite or sodium citrate, to form the desired granular product.
DEFINITION OF THE INVENTION
In its first aspect, the present invention provides a mobile liquid surfactant blend having a viscosity at 65° C., measured at 50 s
−1
, not exceeding 1 Pas, the blend consisting essentially of an alkylpolyglycoside and an ethoxylated nonionic surfactant in a ratio within the range of from 35:65 to 65:35 and from 2 to 25 wt % water.
In its second aspect, the invention provides various processes for the preparation of this blend.
In its third aspect, the present invention provides a process for the preparation of a particulate detergent composition or component which comprises mixing a surfactant blend as defined in the previous paragraph with a particulate carrier material.
In its fourth aspect, the present invention provides a detergent granule consisting essentially of alkylpolyglycoside, ethoxylated nonionic surfactant and one or more detergent-functional inorganic salts, having a total content of alkylpolyglycoside and ethoxylated nonionic surfactant of at least 20 wt %, a ratio of alkylpolyglycoside to ethoxylated nonionic surfactant within the range of from 35:65 to 65:35, and a water content not exceeding 20 wt %.
In its fifth aspect, the present invention provides the use of a mobile surfactant blend having a viscosity at 65° C., measured at 50 s
−1
, not exceeding
1
Pas, consisting essentially of an alkylpolyglycoside and an ethoxylated nonionic surfactant in a ratio within the range of from 35:65 to 65:35 and from 2 to 25 wt % water, to prepare a particulate detergent composition or component having a water content not exceeding 20 wt %.
DETAILED DESCRIPTION OF THE INVENTION
The Alkyltolyplycoside
Alkylpolyglycosides may be represented by the general formula I
RO(R′O)
t
(G)
x
(I)
in which R is an organic hydrophobic residue containing from 10 to 20 carbon atoms, R′ is an alkylene group containing from 2 to 4 carbon atoms, G is a saccharide residue containing 5 or 6 carbon atoms, t is in the range of from 0 to 25 and x is in the range of from 1 to 10.
The hydrophobic group R may be aliphatic, either saturated or unsaturated, notably linear or branched alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl. However, it may include an aryl group for example alkyl-aryl, alkenyl-aryl and hydroxyalkyl-aryl. The preferred R group is an alkyl or alkenyl group having from 8 to 20 carbon atoms, more preferably from 8 to 16 carbon atoms. The most preferred R group is an alkyl group having from 12 to 14 carbon atoms.
The value of t in the general formula above is preferably zero, so that the -(RO)
t
- unit of the general formula is absent. In that case the general formula becomes
RO(G)
x
(II)
If t is non-zero it is preferred that R′O is an ethylene oxide residue. Other likely possibilities are
Appel Peter Willem
Euser Huig
Rebers Hendricus Anthonius
van Kralingen Cornelis Gerhard
Lever Brothers, Division of Conopco, Inc.
Medley Margaret
Mitelman Rimma
LandOfFree
Surfactant blends, processes for preparing them and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surfactant blends, processes for preparing them and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surfactant blends, processes for preparing them and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2565718