CA1317188C - Detergent powders and process for preparing them - Google Patents
Detergent powders and process for preparing themInfo
- Publication number
- CA1317188C CA1317188C CA000593788A CA593788A CA1317188C CA 1317188 C CA1317188 C CA 1317188C CA 000593788 A CA000593788 A CA 000593788A CA 593788 A CA593788 A CA 593788A CA 1317188 C CA1317188 C CA 1317188C
- Authority
- CA
- Canada
- Prior art keywords
- powder
- weight
- paraffin wax
- water
- spray
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/16—Organic compounds
- C11D3/18—Hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D11/00—Special methods for preparing compositions containing mixtures of detergents ; Methods for using cleaning compositions
- C11D11/02—Preparation in the form of powder by spray drying
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
- C11D17/06—Powder; Flakes; Free-flowing mixtures; Sheets
- C11D17/065—High-density particulate detergent compositions
Abstract
C 3224 (R) ABSTRACT
Dispensing of certain spray-dried detergent powders in automatic washing machines is substantially improved by the incorporation of 0.1-6.0% by weight of a hydrophobic additive having a contact angle to water of at least 75°
and a melting point of 30-100°C. The additive may be included in the slurry from which the powder is prepared, or sprayed, preferably dispersed in nonionic surfactant, onto the powder. The preferred additive is paraffin wax.
Dispensing of certain spray-dried detergent powders in automatic washing machines is substantially improved by the incorporation of 0.1-6.0% by weight of a hydrophobic additive having a contact angle to water of at least 75°
and a melting point of 30-100°C. The additive may be included in the slurry from which the powder is prepared, or sprayed, preferably dispersed in nonionic surfactant, onto the powder. The preferred additive is paraffin wax.
Description
`` 1 3 1 7 1 ~
c 3224 (R) DETERGENT POWDERS AND PROCESSES FOR PREPARING THEM
TECHNICAL FIELD
The present invention relates to detergent powders prepared at least in part by spray-drying and intended for use in drum-type front-loading washing machines.
The invention is oE especial applicability to powders containing no, or reduced levels o-f, phosphate builders and to powders of high bulk density.
BACKGROUND
In recent years the trend in detergent compositions has been towards reducing or eliminating phosphate builders.
The replacement of sodium tripolyphosphate as a builder in detergent powders by its most popular zero-phosphate su~stitute, crystalline sodium aluminosilica~e (zeolite~, has led to a number of difficulties with the structure and physical properties of the powder. One such problem that has been encountered is the tendency of zeolite-built powders to dispense less well in front-loading automatic washing machines than do their phosphate-built counterparts; a higher proportion of the powder dosed into the machine is left behind in the dispenser, leading to product wastage and clogging. This proklem is especially marked at low wash temperatures.
The tendency towards poor dispensing has been exacerbated by the recent trend in the detergents industry towards higher bulk density powders.
We have now found that the dispensing behaviour of those powders that are especially prone to this problem may be substantially improved by including in the powders low levels of certain hydrophobic materials, either via the slurry or by subsequent spray-on.
1 3 1 7 1 S~, Surprisingly, the incorporation of these materials via the slurry also improves powder structure and, when anionic surfactant is present, raises the bulk density.
DEFINITION OF THE INVENTION
In a first aspect, the invention comprises a spray-dried detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weigh-t of one or more anionic surfactants, from 20 to 80~ by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkali metal silica-te and further comprising from 0.1 to 6.0% by weight of a paraffin wax which is water-insoluble and substantially insoluble in anionic and nonionic surfactants and which has a melting point within the range of from 30 to 100C and a contact angle to water of at least 75, said detergent powder giving a dispenser residue of at least 10% by weight less than that of a comparative powder without the paraffin wax, as measured in a Philips (Trade Mark) AWB 126/7 washing machine using lO0 g powder and 5 litres of water a 20C
flowing in ov~r a period of 1 minute.
In a second aspect, the invention provides a process for the preparation of a detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weight of one or more anionic surfactants, from 20 to 80%
by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkalimetal silicate, the process including the step of spray-drying an aqueous slurry, characterised in that the powder further comprises a paraffin wax which is water-insoluble and substantially insoluble in anionic and non-ionic surfactants and has a melting point within the range of from 30 to 100C and a contact angle to water of at least 75, in that this paraffin wax is incorporated in the slurry or sprayed onto the powder in an amount of from 0.1 to 6.0%
by weight based on the powder, and in tha-t the powder thus obtained gives a dispenser residue at least 10% by weight 3 1 3 1 7 1 ~
less than that of a compara~ive powder withou-t the additive, as measured in a Philips (Trade Mark) AWB 126/7 washing machine using 100 g powder, and 5 litres of water at 20C flowing in over a period o~ 1 minute.
PRIOR ART
Detergent compositions containing foam control systems that include hydrocarbon waxes are disclosed in EP 87 233A
published Aug 31/83, EP 109 2~7A published May ~3/84, and EP 206 522A published Dec 30/86 (Unilever); GB 1 492 ~38 published Nov 23/77, GB 1 492 939 published Nov 23/77, GB 2 040 982B published 25 Aug/82l ~P 8 829A published Nar 19/80, EP 8 830A published Mar 19/80 and JP 56 034797A
published April 7/81 (Procter & Gamble); DE 3 436 194A
published April 10/~6, US 4 590 194 issued May 20/86 and EP 150 386A published Aug 7/85 (Henkel). US 4 196 104 issued April 1/80 (Procter & Gamble) discloses spraying an antistatic composition comprising a quaternary ammonium compound and a paraffin wax (as dispersion inhibitor) onto detergent base granules.
DETAIL~D DESC~IPTION OF THE INVENTION
The first aspect of the invention is a detergent powder prepared at least in part by spray-drying. The composition of the invention may be a fully formulated detergent composition prepared wholly by spray-drying; a spray-dried base to which other ingredients may be admixed to form a finished product; or a finished product of that type, comprising a spray-dried base in admixture with other ingredients.
As essential ingredients, the detergent powder of the invention contains one or more anionic and/or nonionic surfactants~ and a specified hydrophobic material that influences its dispensing behaviour in a particular manner.
The composition of the invention may also contain any of the materials conventionally included in detergent compositions. These are described in more detail below.
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C 3224 (R) The surfactant com~nent The total amount of surfactant present in -the composikion of the invention will generally range from 5 to 40% by weight, more preferably from 10 to 30% by weight and especially from 12 to 20% by weight. These figures are typical for fully formulated detergent compositions, and where a spray-dried base forms only part of such a composition the surfactant content of that base, as a percentage, may of course be higher.
The invention is of especial applicahility to compositions containing anionic surfactant. When such powders are prepared by spray-drying, the high-foaming anionic surfactant tends to cause "puffing'l (entrainment of air) in the slurry, so that highly porous particles are formed in the spray-drying tower. These particles may be very crisp and free-flowing, but may be of lower bulk density than desired. Surprisingly, the incorporation in the slurry of an additive such as paraffin wax, in accordance with the present invention, has been fsund to result in an increase in bulk density.
The amount of anionic surfactant present is desirably at least 5% by weight, and may suitably be in the range of from 5 to 30% by weight, preferably from 5 to 10% by weight, these figures again being based on a fully formulated detergent composition.
Anionic surfactants are well known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly sodium linear alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary and secondary alkyl sulphates, particularly sodium C12-C15 primary alcohol sulphates; olefin sulphonates; alkane sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.
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C 322~ (R) Preferably, the composition of the invention also contains one or more nonionic surfactants. Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C12-Cl5 primary and secondary alcohols ethoxylated with an average of from 3 to 20 moles of ethylene oxide per mole of alcohol.
The weight ratio of anionic surfactant to nonionic surfactant is preferably at least 0.67:1, more preferably at least l:l, and most preferably within the range of from l:l to 0:1, in order to obtain the optimum detergency and foaming properties appropriate for front-loading automatic washing machines. These ratios of course apply to fully formulated products. A spray dried base that is to form only part of a product may contain a lower proportion of, or no, nonionic surfa~tant, the balance of the nonionic surfactant being added after the spray-drying tower.
The hvdroPhobic_material The characterising feature of the composition of the present invention is the presence of a low level (0.1-6.0% by weight) of a hydrophobic material. The hydrophobicity of the material is expressed in terms of its contact ang]e to water, which must be at least 75, preferably at least 85. Hydrocarbons are especially preferred.
The melting point of the material is also important: it appears that the additive should be solid at ambient temperature but liquid at slurry-processing temperature (generally in the range of from 60 to 100C). The melting point of the additive should lie within the range of from 30 to 100C, preferably from 40 to 80C.
Preferred materials are paraffin waxes melting within ~ 31 7 ~ a~ C 3224 (R) the specified range, and preferably melting within the range of from 50 to 60~C. Paraffin oil liquid at ambient temperature has been found to be ineffective in the context of the present invention, and also tends to give wet, sticky powders with unacceptable flow properties.
It is also essential that the hydrophobic material be substantially insoluble in the anionic and nonionic surfactant system present in the composition: the microcrystalline waxes of GB 1 492 938 and GB 1 492 939 published November 23/77 (Procter & Gamble) are stated to be chosen for their solubility in the surfactant present, and are unsuitable for use in the present invention for that reason as well as or the reason that their melting points are too high.
The hydrophobic material is preferably present in an amount of from 0.2 to 4~ by weight. In a fully formulated product the optimum level for paraffin wax appears to be from 0.3 to 2% by weight.
Incorporation of the hYdro~_bic material 2S The composition of the inven~ion is prepared by a process which includes the step of spray-drying an aqueous crutcher slurry. This slurry will normally contain all those desired ingredients sufficiently heat-stable to survive the spray-drying process, notably anionic surfactants, builders, inorganic salts, sodium silicate, polym~rs and fluorescers. More heat-sensitive ingredients can be postdosed to, or sprayed onto, the spray--dried baseO
There are two methods by means of which the hydrophobic material characteristic of the invention may be incorporated. It may be included in the slurry, in which l3l7~sa C 3224 (R) case it is preferably used in an amount oE from 0.2 to 4.0% by weight, more preferably from 0.3 to 2.0% by weight, based on the final powder including any postdosed ingredients. It may be advantageous to premix the hydrophobic material with surfactant, especially nonionic surfactant, before admixture with other slurry ingredients.
It has surprisingly been found that incorporation of paraffin wax via the slurry not only improves dispensing behaviour, but also improves powder structure and, when anionic surfactant is present, also raises the bulk density. Flow properties are not detrimentally affected.
The second method by which the hydrophobic material may be incorporated in a detergent composition of the invention is by spraying it in liquefied form onto the spray-dried powder. If the final product is to include postdosed solid ingredients, for example, sodium perborate, bleach activator granules, enzyme granules or antifoam granules, the hydrophobic material should be sprayed on after addition of ~hose ingredients so as to cover the whole powder.
If desired, the hydrophobic material may be melted and sprayed directly onto the powder. The hydrophobic material is then preferably used in an amount of from 2.0 to 6.0% by weight, more preferably from 3.0 to 4.0%
by weight.
According to a preferred embodiment of the invention, however, the hydrophobic material is premixed with nonionic surfactant to form a coating composition which may then be sprayed onto the detergent powder. Lower levels of the hydrophobic material, for example, 0.2 to 4.0%, preferably 0.3 to 2.0%, are then found to be effective. The coating composition consists essentially 1 31 7 1 S~3 C 322~ (R) of 2-50% by weight of the hydrophobic material and 50-98% by weight of nonionic surfactant. In the preferred embodiment of the invention in which the hydrophobic material is paraffin wax, the coating composition desirably contains 8-15% by weight of paraffin wax and 85-92% by weight of nonionic surfactant. The para~fin wax, and if necessary the nonionic surfactant, are melted to form the coating composition, which is applied as a liquid, suitably at a temperature of 40-60C.
The coating composition should be substantially free of other ingredients that might interfere with the beneficial effect of the hydrophobic material on dispensing.
Dispensinq behaviour It is an essential feature of the detergent powder of the invention that the incorporation as specified above of a hydrophobic material such as paraffin wax should bring about an improvement in dispensing behaviour. Dispensing is assessed by means of a standard test using a Philips (Trade Mark) AWB 126/7 washing machine using a 100 g powder dose and a water fill of 5 litres at 20C flowing in over a period of 1 minute. The dry weight of powder remaining in the dispenser, in grams, then represents the weight percentage of powder not dispensed into the machine (the residue). It will be appreciated that this test is stringent, using a low water inlet temperature and flow rate, and a machine with a drawer-type dispenser which is particularly vulnerable to high residues and clogglng. According to the invention, the incorporation of the hydrophobic material should effect a reduction in the residue of at least 10 percentage points, preferably at least 20 percentage points. For the 13171~
C 3224 (R) purposes of comparison, a powder having essentially the same composition but with an inorganic salt (sodium carbonate or sodium sulphate) to make up the difference should be used.
Clearly an improvement of this magnitude can only be observed if the control powder exhibits poor dispensing properties. The present invention is therefore especially applicable to powders which, without the additive, give dispenser residues of at least 10%, more especially at least 20%, by weight. That is especially likely to be the case if the powder is a zero-phosphate composition built with crystalline (zeolite) or amorphous sodium aluminosilicate; if it contains less than 10% sodium silicate; or if it has a bulk density of 550 g/litre or more.
Optional components As indicated previously, the detergent powder of the invention can contain any of the ingredients conventionally present in compositions intended for the washing of fabrics in front-loading automatic washing machines. Examples of such components include inorganic and organic detergency builders, other inorganic salts, sodium silicate, bleaches, fluorescers, polymers, lather control agents, enzymes and perfumes.
If desired, the powder of the invention may contain one or more soaps of fatty acids, in addition to the non-soap anionic surfactant mentioned above.
The powder will also contaln one or more de-tergency builders. The invention is of especial applicability, as previously mentioned, to low- or zero-phosphate powders containing crystalline (zeolite) or amorphous aluminosilicate. Zeolite may suitably be present in an 13171~
C 322~ (R) amount of from 20 to 80% by weight. Other, supplementary, builders may also be present, for example, polycarboxylate polymers such as polyacrylates, acrylic-maleic copolymers, or acrylic phosphinates; momomeric polycarboxylates such as nitrilotriacetates and ethylene diamine tetraacetates;
inorganic salts such as sodium carbonate; and many other materials ~amiliar to the skilled detergent formulator.
If desired, the powder of the invention may contain sodium silicate. High levels of silicate can in themselves have a beneficial effect on dispensing, as well as on powder structure and prevention of machine corrosion, but are undesirable in powders containing aluminosilicate because the two components react together to form insoluble siliceous species. The present invention enables the dispensing behaviour of zeolite-built powders to be improved without a corresponding increase in the level of insoluble material. Accordingly, the invention is of especial applicability to powders containing less that 10% by weight, more especially less than 5~ by weight, of sodium silicate.
Other materials that may be present in the powder of the invention include fluorescers, antiredeposition agents, inorganic salts such as sodium sulphate, enzymes, lather control agents, bleaches, bleach activators, and bleach stabilisers. These may be included in the spray-dried base powder or postdosed according to their known suitability for undergoing spray-drying processes and their compatibility with other slurry ingredients.
The invention is further illustrated by the following non limiting Examples, in which parts and percentages are by weight unless otherwise stated.
1 3 1 7 1 ~ .3 c 3224 ~R) EXAMPLES
Examples 1 to 4 Zero-phosphate detergent base powders containing various amounts of paraf~in wax (melting point 52-54C~
or paraffin oil were prepared, by slurry-making and spray-drying, to the following nominal composition:
Parts Sodium linear alkylbenzene sulphonate 9.0 Nonionic surfactant 1.0 Zeolite (anhydrous) 24.0 Acrylic/maleic copolymer* 4.0 15 Sodium carbonate 2.0 Minor ingredients 0.83 Moisture 10.0 Paraffin wax 0, 0.25, 0.5, 1.0, 2.0 or paraffin oil 1.0 Total 51 53 parts *Sokalan (Trade Mark) CP5 ex BASF.
To the base powder were postdosed the following ingredients:
Parts Burkeite/nonionic surfactant adjunct* 13.0 Sodium perborate monohydrate 8.0 TAED granules 3.0 Dequest 0.2 30 Enzvme granules 0.6 Lather control granules 3.0 Sodium alkaline silicate 5.0 Sodium carbonate 5.4 Sodium sulphate to 100.0 *as described and claimed in EP 221 776A (Unilever) 2 13171~
c 3224 (R) The following table shows the six compositions prepared, their dispenser residues measured in accordance with the defined test given above, and their powder properties:
Paraffin wax 0 0.25 0~5 1.02.0 0 Paraffin oil 0 0 0 0 0 l.0 Sodium sulphate 11.65 11.32 10.87 10.62 9.82 10.62 10 Dispenser residue 42 20 0 0 0 33 Bulk density (g/l~ 680 609 755 724 685 Dynamic flow rate 109 111 109 109 90 Compressibility (%) 34 16 24 25 21 It will be noted that even the low level of 0.25 parts of paraffin wax effected a substantial improvement in dispensing behaviour, and no dispenser residues at all were observed when higher levels of paraffin wax were used. The higher levels also brought about increases in bulk density, and improvements in powder structure (compressibility) were observed at all levels.
The dispensing and powder properties of the spray-dried base powders of Examples 2-4 and Comparative Example A
were also examined. The full formulations of these base powders were as follows:
Sodium LAS 17.9617.6717.59 17.30 30 Nonionic surfactant1.99 1.96 1.95 1.92 Zeolite (anhydrous)47.8947.13 ~6.89 46.17 Copolymer 7.897.85 7.82 7.70 Sodium carbonate 3.99 3.93 3.91 3.85 Minor ingredients 1.66 1.63 1.62 1.60 35 Moisture 18.5318.8518.27 17.61 Paraffin wax 0 0.98 1.9 3.85 Total100.0100.0 100.0 100.0 13171~
C 3224 (R) The full formulation of the base powder of Comparative Example B was identical to that of Example 3, except that the paraffin wax was replaced by paraffin oil. The dispensing residues of the base powders, determined by the test described above, and their powder properties were as follows:
Dispenser residue (%) 46 0 0 0 Bulk density (g/l)540585 525 586 10 DFR (ml/s) 108 115 117 109 Compressibility (% v/v)36 29 31 30 The dispenser residue of the base powder of Comparative Example B was 15%.
Example 5 Zero-phosphate detergent powders similar to those of Examples 1-4 but containing a higher level of anionic surfactant were prepared, to the following formulations (in weight %):
Spray~dried base powder Sodium linear alkylbenzene sulphonate 11.1 11.1 25 Nonionic surfactant 1.2 1.2 Zeolite (anhydrous) 24.0 24.0 Acrylic/maleic copolymer* 4.0 4.0 Sodium carbonate 2.0 2.0 Sodium alkaline silicate 0.5 0.5 30 Sodium sulphate 1.3 1.3 Minor ingredients 0.83 0.83 Paraffin wax (m.pt. 52-54C) 0 1.0 Moisture g.50 9.95 *Sokalan (Trade Mark) CP5 ex BASF.
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C 3224 (R) Postdosed inq_edients Burkeite/nonionic surfactant adjunct 16.09 16.09 Sodium perborate monohydrate 8.0 8.0 TAED granules 3.0 3.0 Dequest 0.75 0.75 Enzyme granules 0.5 0.5 Lather control granules 2.4 2.4 Sodium carbonate 3.27 3.27 Sodium sulphate 11.43 9.98 Total 100.0 100.0 The dispensing and powder properties of these products were as follows~
15 Dispenser residue (%):
of base 80 0 of whole product 55 3 Bulk density (g/l) 660 648 Dynamic flow rate (ml/s) 91 97 20 Compressibility (% v/v) 10 17 With this product, which already exhibited a very high bulk density and excellent powder properties, no further improvement in these respects resulted from the inclusion of paraffin wax in the base powder. A marked improvement in dispensing behaviour was, however, observed.
Examples 6 to 8 A zero-phosphate detergent base powder similar to that of Comparative Example A was prepared, by slurry-making and spray-drying, to the following formulation:
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C 3224 (R) Parts %
Sodium linear alkylbenzene sulphonate 9.0 18. 37 Nonionic surfactant 1.0 2.04 Zeolite (anhydrous) 24.0 48.98 5 Acrylic/maleic copolymer* 4.0 8.16 Sodium carbonate 2.0 4.08 Minor ingredients 0.83 1.69 Moisture 8.17 16.68 *Sokalan (Trade Mark) CP5 ex BASF.
Samples of this base powder were post-sprayed with molten paraffin wax (melting point 52-54C) in various amounts, as shown in the table below. The dispensing properties of the samples, and of the base powder 15 without wax spray-on (Comparative Example D), are also shown in the table.
Paraffin wax sprayed on:
parts 0 0.3 1.0 2.0 %o 0.61 2.0 3.92 Dispenser residue (%) 37 12 10 It will be seen that the sprayed-on paraffin wax effected a substantial reduction in dispenser residues-at the 2 parts (3.92%) level these were negligibly low.
Examples 9 to 11 The procedure of Examples 6 to 8 was repeated, but this time the paraffin wax was melted and dispersed in liquid nonionic surfactant, and the coating composition thus obtained was sprayed onto the base powder. The three coating compositions used were as follows, the parts being on the same basis as those of the base powder D, and the percentages being based on the coating composition:
13~7~&~
C 3224 (R) ~ %
Example 9:
Paraffin wax 0.3 9~1 Nonionic surfactant 3.0 90.9 5 Example 10:
Paraffin wax 1~0 25.0 Nonionic surfactant 3.0 75.0 Example 11:
Paraffin wax 2.0 40.0 Nonionic surfactant 3.0 60.0 Dispensing and powder properties were as follows:
Wax/nonionic spray-on:
Total (parts) o 3.3 4.0 5.0 Total (% on base powder) 0 6.31 7.55 9.26 Dispenser residue (%) 37 0 0 0 Bulk density (g/ml) 450 512 Dynamic flow rate (ml/s) 108 105 Compressibility (% v/v) 27 21 Comparison with Examples 6 to 8 shows that when the paraffin wax was pre-dispersed in nonionic surfactant it was effective at a lower level in improving dispensing behaviour. Bulk density and compressibility were improved even at the low level of 0.3 parts (0.61%) of paraffin wax.
c 3224 (R) DETERGENT POWDERS AND PROCESSES FOR PREPARING THEM
TECHNICAL FIELD
The present invention relates to detergent powders prepared at least in part by spray-drying and intended for use in drum-type front-loading washing machines.
The invention is oE especial applicability to powders containing no, or reduced levels o-f, phosphate builders and to powders of high bulk density.
BACKGROUND
In recent years the trend in detergent compositions has been towards reducing or eliminating phosphate builders.
The replacement of sodium tripolyphosphate as a builder in detergent powders by its most popular zero-phosphate su~stitute, crystalline sodium aluminosilica~e (zeolite~, has led to a number of difficulties with the structure and physical properties of the powder. One such problem that has been encountered is the tendency of zeolite-built powders to dispense less well in front-loading automatic washing machines than do their phosphate-built counterparts; a higher proportion of the powder dosed into the machine is left behind in the dispenser, leading to product wastage and clogging. This proklem is especially marked at low wash temperatures.
The tendency towards poor dispensing has been exacerbated by the recent trend in the detergents industry towards higher bulk density powders.
We have now found that the dispensing behaviour of those powders that are especially prone to this problem may be substantially improved by including in the powders low levels of certain hydrophobic materials, either via the slurry or by subsequent spray-on.
1 3 1 7 1 S~, Surprisingly, the incorporation of these materials via the slurry also improves powder structure and, when anionic surfactant is present, raises the bulk density.
DEFINITION OF THE INVENTION
In a first aspect, the invention comprises a spray-dried detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weigh-t of one or more anionic surfactants, from 20 to 80~ by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkali metal silica-te and further comprising from 0.1 to 6.0% by weight of a paraffin wax which is water-insoluble and substantially insoluble in anionic and nonionic surfactants and which has a melting point within the range of from 30 to 100C and a contact angle to water of at least 75, said detergent powder giving a dispenser residue of at least 10% by weight less than that of a comparative powder without the paraffin wax, as measured in a Philips (Trade Mark) AWB 126/7 washing machine using lO0 g powder and 5 litres of water a 20C
flowing in ov~r a period of 1 minute.
In a second aspect, the invention provides a process for the preparation of a detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weight of one or more anionic surfactants, from 20 to 80%
by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkalimetal silicate, the process including the step of spray-drying an aqueous slurry, characterised in that the powder further comprises a paraffin wax which is water-insoluble and substantially insoluble in anionic and non-ionic surfactants and has a melting point within the range of from 30 to 100C and a contact angle to water of at least 75, in that this paraffin wax is incorporated in the slurry or sprayed onto the powder in an amount of from 0.1 to 6.0%
by weight based on the powder, and in tha-t the powder thus obtained gives a dispenser residue at least 10% by weight 3 1 3 1 7 1 ~
less than that of a compara~ive powder withou-t the additive, as measured in a Philips (Trade Mark) AWB 126/7 washing machine using 100 g powder, and 5 litres of water at 20C flowing in over a period o~ 1 minute.
PRIOR ART
Detergent compositions containing foam control systems that include hydrocarbon waxes are disclosed in EP 87 233A
published Aug 31/83, EP 109 2~7A published May ~3/84, and EP 206 522A published Dec 30/86 (Unilever); GB 1 492 ~38 published Nov 23/77, GB 1 492 939 published Nov 23/77, GB 2 040 982B published 25 Aug/82l ~P 8 829A published Nar 19/80, EP 8 830A published Mar 19/80 and JP 56 034797A
published April 7/81 (Procter & Gamble); DE 3 436 194A
published April 10/~6, US 4 590 194 issued May 20/86 and EP 150 386A published Aug 7/85 (Henkel). US 4 196 104 issued April 1/80 (Procter & Gamble) discloses spraying an antistatic composition comprising a quaternary ammonium compound and a paraffin wax (as dispersion inhibitor) onto detergent base granules.
DETAIL~D DESC~IPTION OF THE INVENTION
The first aspect of the invention is a detergent powder prepared at least in part by spray-drying. The composition of the invention may be a fully formulated detergent composition prepared wholly by spray-drying; a spray-dried base to which other ingredients may be admixed to form a finished product; or a finished product of that type, comprising a spray-dried base in admixture with other ingredients.
As essential ingredients, the detergent powder of the invention contains one or more anionic and/or nonionic surfactants~ and a specified hydrophobic material that influences its dispensing behaviour in a particular manner.
The composition of the invention may also contain any of the materials conventionally included in detergent compositions. These are described in more detail below.
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C 3224 (R) The surfactant com~nent The total amount of surfactant present in -the composikion of the invention will generally range from 5 to 40% by weight, more preferably from 10 to 30% by weight and especially from 12 to 20% by weight. These figures are typical for fully formulated detergent compositions, and where a spray-dried base forms only part of such a composition the surfactant content of that base, as a percentage, may of course be higher.
The invention is of especial applicahility to compositions containing anionic surfactant. When such powders are prepared by spray-drying, the high-foaming anionic surfactant tends to cause "puffing'l (entrainment of air) in the slurry, so that highly porous particles are formed in the spray-drying tower. These particles may be very crisp and free-flowing, but may be of lower bulk density than desired. Surprisingly, the incorporation in the slurry of an additive such as paraffin wax, in accordance with the present invention, has been fsund to result in an increase in bulk density.
The amount of anionic surfactant present is desirably at least 5% by weight, and may suitably be in the range of from 5 to 30% by weight, preferably from 5 to 10% by weight, these figures again being based on a fully formulated detergent composition.
Anionic surfactants are well known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly sodium linear alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary and secondary alkyl sulphates, particularly sodium C12-C15 primary alcohol sulphates; olefin sulphonates; alkane sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.
1317~
C 322~ (R) Preferably, the composition of the invention also contains one or more nonionic surfactants. Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C12-Cl5 primary and secondary alcohols ethoxylated with an average of from 3 to 20 moles of ethylene oxide per mole of alcohol.
The weight ratio of anionic surfactant to nonionic surfactant is preferably at least 0.67:1, more preferably at least l:l, and most preferably within the range of from l:l to 0:1, in order to obtain the optimum detergency and foaming properties appropriate for front-loading automatic washing machines. These ratios of course apply to fully formulated products. A spray dried base that is to form only part of a product may contain a lower proportion of, or no, nonionic surfa~tant, the balance of the nonionic surfactant being added after the spray-drying tower.
The hvdroPhobic_material The characterising feature of the composition of the present invention is the presence of a low level (0.1-6.0% by weight) of a hydrophobic material. The hydrophobicity of the material is expressed in terms of its contact ang]e to water, which must be at least 75, preferably at least 85. Hydrocarbons are especially preferred.
The melting point of the material is also important: it appears that the additive should be solid at ambient temperature but liquid at slurry-processing temperature (generally in the range of from 60 to 100C). The melting point of the additive should lie within the range of from 30 to 100C, preferably from 40 to 80C.
Preferred materials are paraffin waxes melting within ~ 31 7 ~ a~ C 3224 (R) the specified range, and preferably melting within the range of from 50 to 60~C. Paraffin oil liquid at ambient temperature has been found to be ineffective in the context of the present invention, and also tends to give wet, sticky powders with unacceptable flow properties.
It is also essential that the hydrophobic material be substantially insoluble in the anionic and nonionic surfactant system present in the composition: the microcrystalline waxes of GB 1 492 938 and GB 1 492 939 published November 23/77 (Procter & Gamble) are stated to be chosen for their solubility in the surfactant present, and are unsuitable for use in the present invention for that reason as well as or the reason that their melting points are too high.
The hydrophobic material is preferably present in an amount of from 0.2 to 4~ by weight. In a fully formulated product the optimum level for paraffin wax appears to be from 0.3 to 2% by weight.
Incorporation of the hYdro~_bic material 2S The composition of the inven~ion is prepared by a process which includes the step of spray-drying an aqueous crutcher slurry. This slurry will normally contain all those desired ingredients sufficiently heat-stable to survive the spray-drying process, notably anionic surfactants, builders, inorganic salts, sodium silicate, polym~rs and fluorescers. More heat-sensitive ingredients can be postdosed to, or sprayed onto, the spray--dried baseO
There are two methods by means of which the hydrophobic material characteristic of the invention may be incorporated. It may be included in the slurry, in which l3l7~sa C 3224 (R) case it is preferably used in an amount oE from 0.2 to 4.0% by weight, more preferably from 0.3 to 2.0% by weight, based on the final powder including any postdosed ingredients. It may be advantageous to premix the hydrophobic material with surfactant, especially nonionic surfactant, before admixture with other slurry ingredients.
It has surprisingly been found that incorporation of paraffin wax via the slurry not only improves dispensing behaviour, but also improves powder structure and, when anionic surfactant is present, also raises the bulk density. Flow properties are not detrimentally affected.
The second method by which the hydrophobic material may be incorporated in a detergent composition of the invention is by spraying it in liquefied form onto the spray-dried powder. If the final product is to include postdosed solid ingredients, for example, sodium perborate, bleach activator granules, enzyme granules or antifoam granules, the hydrophobic material should be sprayed on after addition of ~hose ingredients so as to cover the whole powder.
If desired, the hydrophobic material may be melted and sprayed directly onto the powder. The hydrophobic material is then preferably used in an amount of from 2.0 to 6.0% by weight, more preferably from 3.0 to 4.0%
by weight.
According to a preferred embodiment of the invention, however, the hydrophobic material is premixed with nonionic surfactant to form a coating composition which may then be sprayed onto the detergent powder. Lower levels of the hydrophobic material, for example, 0.2 to 4.0%, preferably 0.3 to 2.0%, are then found to be effective. The coating composition consists essentially 1 31 7 1 S~3 C 322~ (R) of 2-50% by weight of the hydrophobic material and 50-98% by weight of nonionic surfactant. In the preferred embodiment of the invention in which the hydrophobic material is paraffin wax, the coating composition desirably contains 8-15% by weight of paraffin wax and 85-92% by weight of nonionic surfactant. The para~fin wax, and if necessary the nonionic surfactant, are melted to form the coating composition, which is applied as a liquid, suitably at a temperature of 40-60C.
The coating composition should be substantially free of other ingredients that might interfere with the beneficial effect of the hydrophobic material on dispensing.
Dispensinq behaviour It is an essential feature of the detergent powder of the invention that the incorporation as specified above of a hydrophobic material such as paraffin wax should bring about an improvement in dispensing behaviour. Dispensing is assessed by means of a standard test using a Philips (Trade Mark) AWB 126/7 washing machine using a 100 g powder dose and a water fill of 5 litres at 20C flowing in over a period of 1 minute. The dry weight of powder remaining in the dispenser, in grams, then represents the weight percentage of powder not dispensed into the machine (the residue). It will be appreciated that this test is stringent, using a low water inlet temperature and flow rate, and a machine with a drawer-type dispenser which is particularly vulnerable to high residues and clogglng. According to the invention, the incorporation of the hydrophobic material should effect a reduction in the residue of at least 10 percentage points, preferably at least 20 percentage points. For the 13171~
C 3224 (R) purposes of comparison, a powder having essentially the same composition but with an inorganic salt (sodium carbonate or sodium sulphate) to make up the difference should be used.
Clearly an improvement of this magnitude can only be observed if the control powder exhibits poor dispensing properties. The present invention is therefore especially applicable to powders which, without the additive, give dispenser residues of at least 10%, more especially at least 20%, by weight. That is especially likely to be the case if the powder is a zero-phosphate composition built with crystalline (zeolite) or amorphous sodium aluminosilicate; if it contains less than 10% sodium silicate; or if it has a bulk density of 550 g/litre or more.
Optional components As indicated previously, the detergent powder of the invention can contain any of the ingredients conventionally present in compositions intended for the washing of fabrics in front-loading automatic washing machines. Examples of such components include inorganic and organic detergency builders, other inorganic salts, sodium silicate, bleaches, fluorescers, polymers, lather control agents, enzymes and perfumes.
If desired, the powder of the invention may contain one or more soaps of fatty acids, in addition to the non-soap anionic surfactant mentioned above.
The powder will also contaln one or more de-tergency builders. The invention is of especial applicability, as previously mentioned, to low- or zero-phosphate powders containing crystalline (zeolite) or amorphous aluminosilicate. Zeolite may suitably be present in an 13171~
C 322~ (R) amount of from 20 to 80% by weight. Other, supplementary, builders may also be present, for example, polycarboxylate polymers such as polyacrylates, acrylic-maleic copolymers, or acrylic phosphinates; momomeric polycarboxylates such as nitrilotriacetates and ethylene diamine tetraacetates;
inorganic salts such as sodium carbonate; and many other materials ~amiliar to the skilled detergent formulator.
If desired, the powder of the invention may contain sodium silicate. High levels of silicate can in themselves have a beneficial effect on dispensing, as well as on powder structure and prevention of machine corrosion, but are undesirable in powders containing aluminosilicate because the two components react together to form insoluble siliceous species. The present invention enables the dispensing behaviour of zeolite-built powders to be improved without a corresponding increase in the level of insoluble material. Accordingly, the invention is of especial applicability to powders containing less that 10% by weight, more especially less than 5~ by weight, of sodium silicate.
Other materials that may be present in the powder of the invention include fluorescers, antiredeposition agents, inorganic salts such as sodium sulphate, enzymes, lather control agents, bleaches, bleach activators, and bleach stabilisers. These may be included in the spray-dried base powder or postdosed according to their known suitability for undergoing spray-drying processes and their compatibility with other slurry ingredients.
The invention is further illustrated by the following non limiting Examples, in which parts and percentages are by weight unless otherwise stated.
1 3 1 7 1 ~ .3 c 3224 ~R) EXAMPLES
Examples 1 to 4 Zero-phosphate detergent base powders containing various amounts of paraf~in wax (melting point 52-54C~
or paraffin oil were prepared, by slurry-making and spray-drying, to the following nominal composition:
Parts Sodium linear alkylbenzene sulphonate 9.0 Nonionic surfactant 1.0 Zeolite (anhydrous) 24.0 Acrylic/maleic copolymer* 4.0 15 Sodium carbonate 2.0 Minor ingredients 0.83 Moisture 10.0 Paraffin wax 0, 0.25, 0.5, 1.0, 2.0 or paraffin oil 1.0 Total 51 53 parts *Sokalan (Trade Mark) CP5 ex BASF.
To the base powder were postdosed the following ingredients:
Parts Burkeite/nonionic surfactant adjunct* 13.0 Sodium perborate monohydrate 8.0 TAED granules 3.0 Dequest 0.2 30 Enzvme granules 0.6 Lather control granules 3.0 Sodium alkaline silicate 5.0 Sodium carbonate 5.4 Sodium sulphate to 100.0 *as described and claimed in EP 221 776A (Unilever) 2 13171~
c 3224 (R) The following table shows the six compositions prepared, their dispenser residues measured in accordance with the defined test given above, and their powder properties:
Paraffin wax 0 0.25 0~5 1.02.0 0 Paraffin oil 0 0 0 0 0 l.0 Sodium sulphate 11.65 11.32 10.87 10.62 9.82 10.62 10 Dispenser residue 42 20 0 0 0 33 Bulk density (g/l~ 680 609 755 724 685 Dynamic flow rate 109 111 109 109 90 Compressibility (%) 34 16 24 25 21 It will be noted that even the low level of 0.25 parts of paraffin wax effected a substantial improvement in dispensing behaviour, and no dispenser residues at all were observed when higher levels of paraffin wax were used. The higher levels also brought about increases in bulk density, and improvements in powder structure (compressibility) were observed at all levels.
The dispensing and powder properties of the spray-dried base powders of Examples 2-4 and Comparative Example A
were also examined. The full formulations of these base powders were as follows:
Sodium LAS 17.9617.6717.59 17.30 30 Nonionic surfactant1.99 1.96 1.95 1.92 Zeolite (anhydrous)47.8947.13 ~6.89 46.17 Copolymer 7.897.85 7.82 7.70 Sodium carbonate 3.99 3.93 3.91 3.85 Minor ingredients 1.66 1.63 1.62 1.60 35 Moisture 18.5318.8518.27 17.61 Paraffin wax 0 0.98 1.9 3.85 Total100.0100.0 100.0 100.0 13171~
C 3224 (R) The full formulation of the base powder of Comparative Example B was identical to that of Example 3, except that the paraffin wax was replaced by paraffin oil. The dispensing residues of the base powders, determined by the test described above, and their powder properties were as follows:
Dispenser residue (%) 46 0 0 0 Bulk density (g/l)540585 525 586 10 DFR (ml/s) 108 115 117 109 Compressibility (% v/v)36 29 31 30 The dispenser residue of the base powder of Comparative Example B was 15%.
Example 5 Zero-phosphate detergent powders similar to those of Examples 1-4 but containing a higher level of anionic surfactant were prepared, to the following formulations (in weight %):
Spray~dried base powder Sodium linear alkylbenzene sulphonate 11.1 11.1 25 Nonionic surfactant 1.2 1.2 Zeolite (anhydrous) 24.0 24.0 Acrylic/maleic copolymer* 4.0 4.0 Sodium carbonate 2.0 2.0 Sodium alkaline silicate 0.5 0.5 30 Sodium sulphate 1.3 1.3 Minor ingredients 0.83 0.83 Paraffin wax (m.pt. 52-54C) 0 1.0 Moisture g.50 9.95 *Sokalan (Trade Mark) CP5 ex BASF.
13171~3~
C 3224 (R) Postdosed inq_edients Burkeite/nonionic surfactant adjunct 16.09 16.09 Sodium perborate monohydrate 8.0 8.0 TAED granules 3.0 3.0 Dequest 0.75 0.75 Enzyme granules 0.5 0.5 Lather control granules 2.4 2.4 Sodium carbonate 3.27 3.27 Sodium sulphate 11.43 9.98 Total 100.0 100.0 The dispensing and powder properties of these products were as follows~
15 Dispenser residue (%):
of base 80 0 of whole product 55 3 Bulk density (g/l) 660 648 Dynamic flow rate (ml/s) 91 97 20 Compressibility (% v/v) 10 17 With this product, which already exhibited a very high bulk density and excellent powder properties, no further improvement in these respects resulted from the inclusion of paraffin wax in the base powder. A marked improvement in dispensing behaviour was, however, observed.
Examples 6 to 8 A zero-phosphate detergent base powder similar to that of Comparative Example A was prepared, by slurry-making and spray-drying, to the following formulation:
l3l7la~
C 3224 (R) Parts %
Sodium linear alkylbenzene sulphonate 9.0 18. 37 Nonionic surfactant 1.0 2.04 Zeolite (anhydrous) 24.0 48.98 5 Acrylic/maleic copolymer* 4.0 8.16 Sodium carbonate 2.0 4.08 Minor ingredients 0.83 1.69 Moisture 8.17 16.68 *Sokalan (Trade Mark) CP5 ex BASF.
Samples of this base powder were post-sprayed with molten paraffin wax (melting point 52-54C) in various amounts, as shown in the table below. The dispensing properties of the samples, and of the base powder 15 without wax spray-on (Comparative Example D), are also shown in the table.
Paraffin wax sprayed on:
parts 0 0.3 1.0 2.0 %o 0.61 2.0 3.92 Dispenser residue (%) 37 12 10 It will be seen that the sprayed-on paraffin wax effected a substantial reduction in dispenser residues-at the 2 parts (3.92%) level these were negligibly low.
Examples 9 to 11 The procedure of Examples 6 to 8 was repeated, but this time the paraffin wax was melted and dispersed in liquid nonionic surfactant, and the coating composition thus obtained was sprayed onto the base powder. The three coating compositions used were as follows, the parts being on the same basis as those of the base powder D, and the percentages being based on the coating composition:
13~7~&~
C 3224 (R) ~ %
Example 9:
Paraffin wax 0.3 9~1 Nonionic surfactant 3.0 90.9 5 Example 10:
Paraffin wax 1~0 25.0 Nonionic surfactant 3.0 75.0 Example 11:
Paraffin wax 2.0 40.0 Nonionic surfactant 3.0 60.0 Dispensing and powder properties were as follows:
Wax/nonionic spray-on:
Total (parts) o 3.3 4.0 5.0 Total (% on base powder) 0 6.31 7.55 9.26 Dispenser residue (%) 37 0 0 0 Bulk density (g/ml) 450 512 Dynamic flow rate (ml/s) 108 105 Compressibility (% v/v) 27 21 Comparison with Examples 6 to 8 shows that when the paraffin wax was pre-dispersed in nonionic surfactant it was effective at a lower level in improving dispensing behaviour. Bulk density and compressibility were improved even at the low level of 0.3 parts (0.61%) of paraffin wax.
Claims (15)
1. A spray-dried detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weight of one or more anionic surfactants, from 20 to 80%
by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkali metal silicate and further comprising from 0.1 to 6.0% by weight of a paraffin wax which is water-insoluble and substantially insoluble in anionic and nonionic surfactants and which has a melting point within the range of from 30 to 100°C and a contact angle to water of at least 75°, said detergent powder giving a dispenser residue of at least 10%
by weight less than that of a comparative powder without the paraffin wax, as measured in a Philips (Trade Mark) AWB
126/7 washing machine using 100 g powder and 5 litres of water a 20°C flowing in over a period of 1 minute.
by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkali metal silicate and further comprising from 0.1 to 6.0% by weight of a paraffin wax which is water-insoluble and substantially insoluble in anionic and nonionic surfactants and which has a melting point within the range of from 30 to 100°C and a contact angle to water of at least 75°, said detergent powder giving a dispenser residue of at least 10%
by weight less than that of a comparative powder without the paraffin wax, as measured in a Philips (Trade Mark) AWB
126/7 washing machine using 100 g powder and 5 litres of water a 20°C flowing in over a period of 1 minute.
2. A powder as claimed in claim 1, characterised in that it gives a dispenser residue in the defined test at least 20%
by weight less than that of the comparative powder without the paraffin wax.
by weight less than that of the comparative powder without the paraffin wax.
3. A powder as claimed in claim 1, characterised in that the comparative powder without the paraffin wax gives a dispenser residue of at least 10% by weight in the defined test.
4. A powder as claimed in claim 1, characterised in that the comparative powder without the paraffin wax gives a dispenser residue of at least 20% by weight in the defined test.
5. A powder as claimed in claim 1, characterised in that the paraffin wax has a contact angle to water of at least 85°C.
C 3224 (R) CA
C 3224 (R) CA
6. A powder as claim in claim 1, characterised in that the paraffin wax has a melting point within the range of from 40 to 80°C.
7. A powder as claimed in claim 1, characterised in that the amount of additive incorporated in the powder is within the range of from 0.2 to 4.0% by weight.
8. A powder as claimed din claim 1, characterised in that it has a bulk density of at least 450 g/litre.
9. A powder as claimed in claim 1, having a bulk density of at least 600 g/litre.
10. A process for the preparation of a detergent powder being substantially free from inorganic phosphate and comprising at least 5% by weight of one or more anionic surfactants, from 20 to 80% by weight of crystalline or amorphous aluminosilicate detergency builder and no more than 10% by weight of alkalimetal silicate, the process including the step of spray-drying an aqueous slurry, characterised in that the powder further comprises a paraffin wax which is water-insoluble and substantially insoluble in anionic and nonionic surfactants and has a melting point within the range of from 30 to 100°C and a contact angle to water of at least 75°, in that this paraffin wax is incorporated int he slurry or sprayed onto the powder in an amount of from 0.1 to 6.0% by weight based on the powder, and in that the powder thus obtained gives a dispenser residue at least 10%
by weight less than that of a comparative powder without the additive, as measured in a Philips (Trade Mark) AWB
126/7 washing machine using 100 g powder, and 5 litres of water at 20°C flowing in over a period of 1 minute.
by weight less than that of a comparative powder without the additive, as measured in a Philips (Trade Mark) AWB
126/7 washing machine using 100 g powder, and 5 litres of water at 20°C flowing in over a period of 1 minute.
11. A process as claimed in claim 10, characterised in that the paraffine wax is incorporated via the slurry, in an amount C 3224 (R) CA
of from 0.2 to 4.0% by weight based on the powder.
of from 0.2 to 4.0% by weight based on the powder.
12. A process as claimed in claim 10, characterised in that the paraffin wax is premixed with nonionic surfactant before admixture with other slurry ingredients.
13. A process as claimed in claim 10, characterised in that the paraffin wax in liquefied form is sprayed onto the spray-dried powder, in an amount of from 0.2 to 4.0% by weight based on the powder thus obtained.
14. A process as claimed in claim 10, characterised in that it comprised spraying onto the powder a coating composition consisting essentially of:
(i) from 2 to 50% by weight of the paraffin wax dispersed in (ii) from 50 to 98% by weight of nonionic surfactant, the percentages being based on the coating composition.
(i) from 2 to 50% by weight of the paraffin wax dispersed in (ii) from 50 to 98% by weight of nonionic surfactant, the percentages being based on the coating composition.
15. A powder as claimed din claim 14, characterised in that the coating composition consists essentially of from 8 to 15%
by weight of paraffin wax and from 85 to 92% by weight of nonionic surfactant.
by weight of paraffin wax and from 85 to 92% by weight of nonionic surfactant.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8806702 | 1988-03-21 | ||
| GB888806702A GB8806702D0 (en) | 1988-03-21 | 1988-03-21 | Detergent powders & processes for preparing them |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1317188C true CA1317188C (en) | 1993-05-04 |
Family
ID=10633813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000593788A Expired - Fee Related CA1317188C (en) | 1988-03-21 | 1989-03-15 | Detergent powders and process for preparing them |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0337523B2 (en) |
| AU (1) | AU620381B2 (en) |
| CA (1) | CA1317188C (en) |
| DE (1) | DE68906949T3 (en) |
| ES (1) | ES2042963T5 (en) |
| GB (1) | GB8806702D0 (en) |
| TR (1) | TR26791A (en) |
| ZA (1) | ZA892134B (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9025673D0 (en) * | 1990-11-26 | 1991-01-09 | Unilever Plc | Detergent powders and process for preparing them |
| EP0679178A1 (en) * | 1993-01-18 | 1995-11-02 | The Procter & Gamble Company | Machine dishwashing detergent compositions |
| US5776874A (en) * | 1993-01-18 | 1998-07-07 | The Procter & Gamble Company | Anti-tarnishing machine dishwashing detergent compositions containing a paraffin oil |
| AU6086494A (en) * | 1993-01-18 | 1994-08-15 | Procter & Gamble Company, The | Detergent compositions |
| WO1995001416A1 (en) * | 1993-07-01 | 1995-01-12 | The Procter & Gamble Company | Machine dishwashing composition containing oxygen bleach and paraffin oil and benzotriazole compound silver tarnishing inhibitors |
| JPH08512072A (en) * | 1993-07-02 | 1996-12-17 | ユニリーバー・ナームローゼ・ベンノートシヤープ | Method for producing detergent composition |
| EP0634478B1 (en) * | 1993-07-16 | 2000-05-17 | The Procter & Gamble Company | Machine dishwashing detergent compositions |
| ES2141336T3 (en) * | 1994-02-18 | 2000-03-16 | Henkel Ecolab Gmbh & Co Ohg | PROCEDURE FOR OBTAINING SPRAY DRY GRANULATES. |
| WO1996003485A1 (en) * | 1994-07-21 | 1996-02-08 | The Procter & Gamble Company | Bleaching agents containing paraffin oil or wax in a particle separate from the bleach |
| DE19615824A1 (en) * | 1996-04-20 | 1997-10-23 | Igus Gmbh | bearings |
| DE19857204A1 (en) | 1998-12-11 | 2000-06-15 | Henkel Kgaa | Aqueous foam regulator emulsion |
| DE10108459A1 (en) | 2001-02-22 | 2002-09-12 | Henkel Kgaa | Stability of foam-regulator granulates for use in detergents is improved by using a carrier containing alkali carbonate and a Bronsted acid |
| WO2013093877A2 (en) | 2011-12-23 | 2013-06-27 | Koninklijke Philips Electronics N.V. | Encapsulation system for controlled release of a bleaching agent |
| WO2013128328A2 (en) | 2012-02-28 | 2013-09-06 | Koninklijke Philips N.V. | System and method for whitening teeth |
| WO2014097053A1 (en) | 2012-12-18 | 2014-06-26 | Koninklijke Philips N.V. | Enhanced tooth whitening method combining sustained release varnish with light activation |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2423450A (en) * | 1941-04-17 | 1947-07-08 | Colgate Palmolive Peet Co | Preparation of synthetic organic detergent particles having only slight dust-forming tendencies |
| AU496849B2 (en) * | 1974-01-11 | 1978-11-02 | Procter & Gamble Company, The | LOW sudsing DETERGENT COMPOSITIONS |
| US4363740A (en) * | 1980-07-29 | 1982-12-14 | Lever Brothers Company | Process for making controlled sudsing detergent powder |
| GB8513074D0 (en) * | 1985-05-23 | 1985-06-26 | Unilever Plc | Antifoam ingredient |
-
1988
- 1988-03-21 GB GB888806702A patent/GB8806702D0/en active Pending
-
1989
- 1989-03-09 EP EP89200587A patent/EP0337523B2/en not_active Expired - Lifetime
- 1989-03-09 ES ES89200587T patent/ES2042963T5/en not_active Expired - Lifetime
- 1989-03-09 DE DE68906949T patent/DE68906949T3/en not_active Expired - Lifetime
- 1989-03-15 CA CA000593788A patent/CA1317188C/en not_active Expired - Fee Related
- 1989-03-20 AU AU31498/89A patent/AU620381B2/en not_active Ceased
- 1989-03-21 TR TR00242/89A patent/TR26791A/en unknown
- 1989-03-21 ZA ZA892134A patent/ZA892134B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU620381B2 (en) | 1992-02-20 |
| ZA892134B (en) | 1990-11-28 |
| EP0337523B2 (en) | 2002-05-29 |
| AU3149889A (en) | 1989-09-21 |
| DE68906949T3 (en) | 2002-09-05 |
| DE68906949D1 (en) | 1993-07-15 |
| EP0337523B1 (en) | 1993-06-09 |
| GB8806702D0 (en) | 1988-04-20 |
| ES2042963T5 (en) | 2002-12-16 |
| TR26791A (en) | 1994-08-08 |
| EP0337523A1 (en) | 1989-10-18 |
| ES2042963T3 (en) | 1993-12-16 |
| DE68906949T2 (en) | 1993-09-16 |
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