AU699818B2 - Process for the production of high bulk density detergent composition - Google Patents

Description

WO 95/01418 PCT/EP94/02064 -1- Process for the Production of High Bulk Density Detergent Composition This invention relates to a process for the production of a detergent composition, in particular to a process for the production of a detergent composition having a high bulk density and which contains a hydrophobic material.

Spray-drying has been emloyed for many years in the production of detergent compositions. In the spray-drying process an aqueous slurry of heat-stable components of the detergent composition is formed and fed to a spray-drying tower at elevated temperature in order to provide a substantially homogeneous mixture of the components. The water in the slurry is then removed by evaporation in the spray-dry tower to produce a spray-dried detergent powder. This powder may then be processed further and/or further components added as desired.

1 EP-A-337523 (Unilever) discloses a process in which a hydrophobic material is incorporated into a detergent composition produced by a spray-drying process in order to provide improved dispensing and powder properties. The hydrophobic material may be incorporated either in the slurry which is to be spray-dried or it may be sprayed in liquefied form onto the spray-dried detergent composition powder. However, **see.

25 the spray drying process has several drawbacks, in particular, it is very energy intensive and requires significant capital investment.

In recent years there has been a trend towards high bulk density detergent powders in which bulk densities in excess of 700g/1 have been achieved. Detergent compositions having a high bulk density, for example in excess of 700 g/l, may be produced without a spray-drying step, herein referred to as a non-tower process, by mixing together the components of the detergent i composition in a h

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w.-1 C3541 la DE3617756 discloses a process for producing a granular detergent composition having a high bulk density comprising the steps of kneading detergent ingredients to form a kneaded mixture, disintegrating the solid mixture and then coating the disintegrated mixtu-e with a water-insoluble finely divided powder having a specified particle diameter.

JP-A-62228000 discloses a granular detergent composition which is coated with a) a fine aluminosilicate powder, and b) a hydrophobic fine pulverised powder wherein the ratio of a) to b) is 3:1 to 1:3 and a) and b) are present at a combined level of 1 to 5 weight percent. The composition is said to provide improved solubility by preventing conglutination of detergent particles due to the coating of components a) and b).

In recent years there has been a trend towards high bulk density detergent powders in which bulk densities in excess of..70.0g/l. hav.,.been achieved. Detergent compositions having a high bulk density, for example in excess of 700 g/l, may be produced without a spray-drying step, herein referred to as a non-cower process, by mixing together the components of the detergent composition in a .1j r i -is p.DEDSHEET Vi 1 i F WO 95/01418 PCT/EP94/02064 2 mixing apparatus, densifying and optionally granulating the components to produce a high density detergent composition.

EP-A-367339 (Unilever) discloses a process for preparing a high bulk density granular detergent composition.

However powders having a high bulk density may be prone to poor dispersion in the wash. A need exists for the dispersion properties of high bulk density deterge., powders produced by mixing the components of the composition rather than by spray-drying (thus avoiding the drawbacks of spray-drying) be improved further.

We have now surprisingly found that by introducing a hydrophobic material into the mixing process, that is, prior to formation of the detergent composition, a detergent composition or component therefor having a high bulk density and improved dispersion properties may be secured.

Accordingly, a first aspect of the invention provides a process for the production of a high bulk density detergent composition or a component therefor, comprising a particulate material which is not the direct product of a spray-drying process, and a hydrophobic material which process comprises mixing the hydrophobic material with the particulate material, densifying the resulting mixture during or subsequent to the said mixing and optionally granulating the said mixture thereby to form a particulate high bulk density detergent composition or component.

The term "composition" as employed herein with regard |I to this invention also includes components may be processed further for inclusion in such compositions or included as I' is in such compositions. jg

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Ii 4 WO 95/01418 PCTEP94/02064 3 Preferably a composition produced by the present invention has a bulk density of at least 700g/l. The process of the present invention may be a continuous or a batch process as desired.

The particulate material may comprise all of the components of the detergent composition excluding the hydrophobic material or alternatively it may comprise at least one of the said components and the other components may be incorporated into the composition during or subsequent to the mixinq of the particulate material and the hydrophobic material. The components of the detergent composition will be selected to provide the desired characteristics and will generally include a surfactant and a builder in addition to the hydrophobic material.

Suitably, the particulate material comprises an adjunct, that is, a particle comprising at least 2 components of the composition. Components of the detergent composition which are liquid may be added to the particulate material during or subsequent to the mixing step or incorporated by means of an adjunct as desired.

Preferably, the hydrophobic material is incorporated into the particulate material in a flowable form, for example as a melt, solution, suspension, or a slurry.

According to a second aspect of the invention there is provided a non-tower process for the production of a detergent composition which comprises mixing a hydrophobic material in a flowable form with a particulate material, densifying the resulting mixture during or subsequent to the said mixing step and optionally granulating the said mixture thereby to form a high density particulate detergent composition.

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'4 WO 95/01418 PCT/EP9402064 4 Suitably the hydrophobic material is in the liquid phase when it is mixed with the base material. The hydrophobic material may be heated to a temperature above its melting point and then mixed with the particulate material. The hydrophobic material is suitably mixed with the particulate material at a rate sufficient to permit efficient mixing between the two components. Preferably the hydrophobic material is substantially uniformly dispersed within the particles of the composition.

Suitably, the hydrophobic material has a viscosity of no more than O1000mPa and preferably no more than 500mPa at a shear rate of 200 at the temperature at which it is mixed with the base material.

It is especially preferred that the hydrophobic material be mixed in the liquid phase with a liquid component, preferably a surfactant and more preferably a non-ionic surfactant to form a flowable premix prior to mixing with the particulate material. The premix may then be mixed with the particulate material. Preferably, the hydrophobic material in flowable form is dribbled or sprayed onto the particulate material to provide a substantially even distribution of the flowable material over the particulate material during the mixing step.

By incorporating a hydrophobic material into the detergent composition excellent dispersion properties may be secured without any significant drawbacks being introduced as regards dissolution. This is particularly surprising in that a hydrophobic material would be expected to hinder dissolution in water. A practical benefit is that there is less powder residue in the washing machine 35 and on the washed articles following the washing process.

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;3 r vr' nClnIAIR PCT/EP94/02064 WO 95/01418 PCTJEP94/02064 The hydrophobic material may be a substantially pure material or may be a mixture of different materials.

Suitably the hydrophobic material is substantially insoluble in water and has a contact angle to water of at least 750 and preferably at least 850. The hydrophobic material is suitably solid at ambient temperature and preferably has a melting point in the range 25 to 110 0

C,

more preferably in the range 30 to 80 0 C, especially 35 to 0 C and optimally 35 to 50 0 C. It is particularly preferred that the hydrophobic material is solid at ambient temperature for ease of handling but has a melting point below the wash temperature as this reduces undesirable deposition of the material.

Suitable hydrophobic materials include silicone oils; long chain esters preferably having at least 9 carbon atoms in both the acid and the alcohol parts thereof for example stearyl stearate; and preferably hydrocarbon waxes.

Suitably, the hydrophobic material is present in an amount of up to 5 preferably from 0.1 to more preferably from 0.2 to especially 0.4 to 1.8% by weight based on the detergent composition. Where the hydrophobic material is introduced in a flowable form with a liquid component, the amount of hydrophobic material which may be present in the premix may be limited in order to ensure that the premix is sufficiently mobile to allow for an even distribution of the hydrophobic material during mixing with the particulate material.

Where a continuous process is employed, the mixing and densification steps may be carried out simultaneously using a high speed mixer, suitable examples include a Shugi (trademark) Granulator, a Drais (trade mark) K-TTP Granulator and the Lodige (trade mark) CB30 recycler. The residence time in the mixing step is suitably about 5 to 4- n W Q~l9141R PCT/EP9410626 WO 95/01418 PCTJEP94/02064 -6seconds and the rate of mixing in the apparatus is suitably in the range 100 to 2500rpm depending upon the degree of densification'and the particle size required. The granulation step if present may be carried out using a lower speed mixer for example, the Drais (trade mark) K-T 160 and the Lodige (trade mark) KM300 mixer. The residence time in the granulation step is suitably about 1 to minutes and the rate of mixing in the apparatus is about to 160 rpm.

The invention further provides a particulate detergent composition comprising a hydrophobic material, a surfactant and a detergency builder obtainable by a non-tower process wherein the hydrophobic material is mixed with the surfactant or builder prior to or whilst the surfactant and builder are mixed.

Preferably the detergent composition is produced by a non-tower process in which the hydrophobic material is mixed with a liquid surfactant, preferably a nonionic surfactant, to produce a solution. The hydrophobic material is preferably melted to aid formation of a solution with the surfactant.

Although, it is preferred that the hydrophobic material be distributed substantially uniformly through the detergent particle, a composition having an inner core which optionally contains a hydrophobic material and which has an outer coating comprising the hydrophobic material is also within the scope of the invention.

Another aspect of the invention provides a particulate detergent composition comprising a hydrophobic material, a I surfactant and a detergency builder wherein the detergent particle comprises an inner core not being the direct Si product of a spray-drying process which comprises the WO 95/01418 PCT/EP94/02064 -7surfactant, builder and optionally a part of the hydrophobic material and, on the inner core, a coating which comprises the hydrophobic material.

Preferably the distribution of components in the inner core is substantially homogeneous.

Preferably the hydrophobic material in the coating is the major component of the coating and more preferably the coating consists essentially of the hydrophobic material.

It is further preferred that the proportion of hydrophobic material in the coating is not in excess of 10% and more preferably not in excess of 5% by weight of the total amount of the hydrophobic material in the particle.

Compositions produced according to the present invention will generally contain detergent-active compounds and detergency builders, and may optionally contain bleaching components and other active ingredients to enhance performance and properties. The detergent-active compounds (surfactants) may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent-active compounds, and mixtures thereof. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch.

The preferred detergent-active compounds that can be I 30 used are soaps and synthetic non-soap anionic and nonionic compounds.

Anionic surfactants are well-known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C 8

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5 primary and secondary alkyl I I 00--ma I H

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A WO 95/01418 PC 1/EP94/02064 8 sulphates, particularly C 12 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.

Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the

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0 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of.alcohol, and more especially the C 0 5 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to moles of ethylene oxide per mole of alcohol.

Non-ethoxylated nonionic surfactants include alkylpolyglycosides also glycerol monoethers, and polyhydroxyamides (glucamide).

The choice of detergent-active compound (surfactant), and the amount present, will depend on the intended use of the detergent composition. For example, for machine dishwashing a relatively low level of a low-foaming nonionic surfactant is generally preferred. In fabric washing compositions, different surfactant systems may be chosen, as is well known to the skilled formulator, for handwashing products and for products intended for use in different types of washing machine.

The total amount of surfactant present will also depend on the intended end use and may be as low as wt%, for example, in a machine dishwashing composition, or as high as 60 wt%, for example, in a composition for washing fabrics by hand. In compositions for machine washing of fabrics, an amount of from 5 to 40 wt% is generally appropriate.

Detergent compositions suitable for use in most automatic fabric washing machines generally contain anionic WO 95/C1418 PCT/EP94/02064 9non-soap surfactant, or nonionic surfactant, or combinations of the two in any ratio, optionally together with soap.

The detergent compositions of the invention will generally also contain one or more detergency builders.

The total amount of detergency builder in the compositions will suitably range from 10 to 80 wt%, preferably from to 60 wt%.

Inorganic builders that may be present include sodium carbonate, if desired in combination with a crystallisation seed for calcium carbonate, as disclosed in GB 1 437 950 (Unilever); crystalline and amorphous aluminosilicates, for example, zeolites as disclosed in GB 1 473 201 (Henkel), amnorphous aluminosilicates as disclosed in GB 1 473 202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter Gamble); and layered silicates as disclosed in EP 164 514B (Hoechst). Inorganic phosphate builders, for example, sodium orthophosphate, pyrophosphate and tripolyphosphate, may also be present, but on environmental grounds those are no longer preferred.

Zeolite builders may suitably be present in amounts of "from 10 to 45 wt%, amounts of from 15 to 35 wt% being especially suitable for (machine) fabric washing compositions. The zeolite used in most commercial particulate detergent compositions is zeolite A.

Advantageously, however, maximum aluminium zeolite P (zeolite MAP) described and claimed in EP 384 070A (Unilever) may be use$. Zeolite MAP is an alkali metal aluminosilicate of the P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 1.15, t 35 and more preferably not exceeding 1.07.

.1 I WO 95/01418 PCT/EP94/02064 Organic builders that may be present include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts. This list is not intended to be exhaustive.

Especially preferred organic builders are citrates, nitrolotriacetic acid and oxydisuccinate and are suitably used in amounts of from 5 to 30 wt%, preferably from 10 to wt%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used iii amounts of from to 15 wt%, preferably from 1 to 10 wt%.

Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.

Detergent compositions according to the invention may also suitably contain a bleach system. Machine dishwashing compositions may suitably contain a chlorine bleach system, while fabric washing compositions may more desirably contain peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution.

Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates. Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, aid sodium percarbonate.

INTERNATIONAL SEARCH REPORT Intea ^A on No PCT/EP 94/02064 to form a particulate high ulk density detergent composition or component therefor.

WO 95/01418 PCTIEP94/02064 11 Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture.

Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao).

The peroxy bleach compound is suitably present in an amount of from 5 to 35 wt%, preferably from 10 to 25 wt%.

The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 1 to 8 wt%, preferably from 2 to 5 wt%.

Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and peroxybenzoic acid precursors; and peroxycarbonic acid precursors. An especially preferred bleach precursor suitable for use in the present invention is N,N,N',N'-tetracetyl ethylenediamine (TAED).

The novel quaternary ammonium and phosphonium bleach precursors disclosed in US 4 751 015 and US 4 818 426 (Lever Brothers Company) and EP 402 971A (Unilever) are also of great interest. Especially preferred are peroxycarbonic acid precursors, in particular cholyl-4-sulphophenyl carbonate. Also of interest are peroxybenzoic acid precursors, in particular, N,N,N-trimethylammonium toluoyloxy benzene sulphonate; and the cationic bleach precursors disclosed in EP 284 292A and EP 303 520A (Kao).

A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include r

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WO 95/01418 PCT/EP94/02064 12 ethylenediamine tetraacetate (EDTA) and the polyphosphonates such as Dequest (Trade Mark), EDTMP.

An especially preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate optionally together with a bleach activator), and a transition metal bleach catalyst as described and claimed in EP 458 397A, EP 458 398A and EP 509 787A (Unilever).

Fluorescer is preferably present in an amount within the range of from 0.02 to 0.8 wt%, more preferably from 0.03 to 0.5 wt%.

The compositions of the invention may contain alkali metal, preferably sodium, carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in amounts ranging from 1 to 60 wt%, preferably from 2 to 40 wt%. However, compositions containing little or no sodium carbonate are also within the scope of the invention.

Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate polymer, or sodium silicate.

One preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt%.

Other materials that may be present in detergent compositions of the invention include sodium silicate and sodium metasilicate; antiredeposition agents such as cellulosic polymers; fluorescers; inorganic salts such as sodium sulphate; lather control agents or lather boosters as appropriate; proteolytic and lipolytic enzymes; dyes; coloured speckles; perfumes; foam controllers; and N981" 11 WO 95/01418 PCT/EP94/02064 13 fabric softening compounds. This list is not intended to be exhaustive.

The invention is illustrated by the following nonlimiting Examples.

Example 1 to 4 A particulate detergent composition was prepared by feeding a particulate material and a flowable premix to a Lodige CB30 recycler high speed mixer/densifier. The flowable premix comprised the wax and nonionic surfactant components listed in Table 1. The particulate material comprised particles of the other solid components listed in Table 1. The hydrocarbon wax was melted prior to mixing with the nonionic surfactant to provide a sprayable solution. The premix was introduced to the mixer and the components mixed and densified for 15 seconds at about 1400rpm. The mixture was then fed to a Lodige Ploughshare granulator operated at about 120 rpm for granulation to form granules of the detergent composition. The residence time was about 2 minutes.

Comparative Examples A to D Compositions not according to the invention as listed in Table 1 were produced by the same method as in Examples 1 to 4 except that hydrophobic material was not included in the formulation.

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i' d; li 1- C3541 2 1$) *1 r 14 Example aPAS Na bLAS Na A24 Zeolite Carbonate CNonionic 3 EO 7 EO Soap dSCMC 'Wax Water/Salts

A

18.8 0 49.6 3.3 8.27 10.5 0 0.99 0 to 100 1 18.6 0 49.2 3.3 8.3 10.5 0 0.99 0.62 to 100

B

19 0 49.0 3.3 0 19.8 0 0.99 0 to 100 2 18.9 0 48.8 3.3 0 19.8 0 0.99 0.51 to 100

C

0 27.5 45.2 4.8 4.78 8.87 0 0.99 0 to 100 3 0 27.5 45.0 4.8 4.75 8.83 0 0.99 0.49 to 100 D 4 9.48 9.48 0 0 55.2 55.2 1.62 1.62 11.9611.85 9.48 9.4 3.3 3.3 1.49 1.49 0 to 100 1 to 100 Sprimary alkyl sulphate, sodium salt b linear alkyl benzene sulphonate, sodium sale.

c C12-15._alc.hol,.e.thoxylate, 3..and 7 ethylene oxide groups respectively d sodium carboxymethyl cellulose SPRIWAX41 (tradename) The compositions had bulk densities in excess of 700g/l and were formulated with conventional post-dosing materials and then analysed.

Examole 30 Compositions A to D and I to 4 were subjected to the following tests to assess the delivery into the wash, dispersion. ard dissn.utibon.charateris..is..;.Theesults,...

are shown be'low.in Table*2. I :i

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a b~i~i~HEEt i h C3541 I 4 I 1 14a Test 1: caae test Delivery characteristics of the powders were compared using a model system which simulates the delivery of a powder in an automatic washing machine, under more adverse conditions (low temperature, minimal agitation) than those normally encountered in a real wash situation) 0ii.

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1< For this test a cylindrical vessel having a diameter of 4 cm and a height of 7 cm, made of 600 micrometre pore size stainless steel mesh, and having a top closure made of Teflon and a bottom closure of the mesh just described, was 5 used. The top closure had inserted therein a 30 cm metal rod to act as a handle, and this handle was attached to an agitator arm positioned above 1 litre of water at 200C in an open container. By means of this agitator apparatus the cylindrical vessel, held at 45 degrees, could be rotated through a circle with a 10 cm radius over a period of 2 seconds and allowed to rest for 2 seconds, before the start of the next rotation/rest cycle.

A 50 g powder sample was introduced into the cylindrical vessel which was then closed. The vessel was attached to the agitator arm which was then moved down to a position such that the top of the cylindrical vessel was just below the surface of the water. After a 10 second delay, the apparatus was operated for 15 rotation/rest cycles.

The cylindrical vessel and handle were removed from the water and the vessel detached from the handle. Surface water was carefully poured off, and any powder residues transferred to a preweighed container and dried for 24 hours at 100 0 C. The weight of dried residue as a percentage of the initial powder weight (50 g) was then calculated.

Test 2: delivery device test Delivery characteristics of the powders were also compared using a model system which emulates the delivery of a powder in an automatic washing machine from a flexible delivery device of the type supplied with Lever's Persil (TradeMark) Micro System powder in the UK: a spherical

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WO 95/01418 PCTJEP94/02064 16 container of flexible plastics material having a diameter of approximately 4 cm and a top opening of diameter approximately 3 cm.

In this test the. delivery device was attached in an upright position (opening uppermost) to an agitator arm positioned above water. By means of this apparatus the device could be moved vertically up and down through a distance of 30 cm, the lowest 5 cm of this travel being under water. Each up or down journey had a duration of 2 seconds, the device being allowed to rest 5 cm under water for 4 seconds at the lowest position, and at the highest position being rotated through 1000 and allowed to rest in the resulting tilted orientation for 2 seconds before redescending. 5 litres of water at a temperature of 20 0

C

were used.

A preweighed powder sample was introduced into the device in its highest position, and the apparatus then allowed to operate for six cycles and stopped when the device was again in its highest position. Surface water was carefully poured off, and any powder residues transferred to a preweighed container. The container was then dried at 100 0 C for 24 hours, and the weight of dried residue as a percentage of the initial powder weight calculated.

Test 3: black pillowcase test A washing machine test was also used to determine the extent that insoluble residues were deposited on washed articles. The machine used was a Siemens Siwamat (TradeMark) Plus 3700 front-loading automatic washer.

A 100 g dose of powder was placed in a flexible delivery device as described previously. The delivery WO 95/01418 PCT/EP94/02064 17 device was placed inside a black cotton pillowcase having dimensions of 30 cm by 60 cm, taking care to keep it upright, and then pillowcase was then closed by means of a zip fastener. The pillowcase containing the (upright) delivery device was then placed on top of a 3.5 kg dry cotton washload in the drum of the washing machine.

The machine was operated on the "heavy duty cycle" at a wash temperature of 40 0 C, using water of 150 French hardness and an inlet temperature of 20 0 C/ At the end of the wash cycle the pillowcase was removed, opened and turned inside out, and the level of powder residues on its inside surfaces determined by visual assessment using a scoring system of 1 to 5: a score of 5 corresponds to a residue of approximately 75 wt% of the powder, while 1 indicates no residue. A panel of five assessors was used to judge each pillowcases and allot a score. With each powder the wash process was carried out ten times and the scores were averaged over the ten repeats.

Test 4: Insolubles 4g of powder was stirred ii 1 litre of water at 20 0 C for 1 minute. The mixture was .hen filtered through a 50 um sieve and dried to cons .Ant weight. The residue was weighed to determine the level of 'insolubles'.

Test 5: Dispensing For the purposes of the present invention, dispensing is assessed by means of a standard procedure using a test rig based on the main wash compartment of the dispenser drawer of the Philips (Trade Mark) AWB 126/7 washing machine. This drawer design provides an especially stringent test of dispensing characteristics especially WO 95/01418 PCT/EP94/02064 18 when used under conditions of low temperature, low water pressure and low rate of water flow.

In the test, a 100 g dose of powder is placed in a heap at the front end of the main compartment of the drawer, and subjected to a water fill of 5 litres at 10 0

C

and an inlet pressure of 50 kPa, flowing in over a period of 1 minute.

After 1 minute the flow of water is ceased, and the powder remaining is then collected and dried to constant weight. The dry weight of powder recovered from the dispenser drawer, in grams, represents the weight percentage of powder not dispensed into the machine (the residue). Every result is the average of two duplicate measurements.

TABLE 2 Example A 1 2 1 D A Test 1 19.1 20.8 31.4 17.0 16.3 16.1 28.8 25.8 Test 2 57.1 0 38.1 0 23.6 0 50.5 0 Test 3 0.8 0.5 2.1 1.7 2.6 1.8 0.8 0.2 Test 4 2.3 2.0 1.8 2.1 6.8 6.3 3.4 2.1 Test 5 0 0 15 6 11 8 11 0 For tests 1, 2, 4 and 5 the figures denote wt% residue. For test 3 the figure is a score on a scale of 0 to The results in Table 2 show that the dispensing dispersion and delivery characteristics of powders containing a hydrophobic material incorporated into a Non- |i Tower powder in accordance with the present invention are WO 95/01418 PCT/EP94/02064 19 significantly superior to those of equivalent powders without the hydrophobic material.

Claims (9)

1. 3. A process according to claim 1 in which the steps (ii) and (iii) are carried out simultaneously using a a high speed mixer.
2. 4. A process according to any preceding claim in which step (iv) is carried out in a separate lower speed mixer. A process according to any preceding claim in which the particulate material comprises a detergent active compound and optionally a detergency builder.
3. 6. A process according to any preceding claim in which the liquid component comprises a nonionic surfactant. -4 C3541-AU -21-
4. 7. A process according to any preceding claim in which the flowable premix consists essentially of nonionic surfactant and the hydrophobic material.
5. 8. A process according to any preceding claim in which the hydrophobic material has a contact angle to water of at least 750.
6. 9. A process according to any preceding claim in which the 1 0 hydrophobic material has a melting point in the range 25 to 110 0C and preferably comprises a hydrocarbon wax.
7. 10. A particulate detergent composition or component therefor having a high bulk density comprising a detergent active compound, a detergency builder and a hydrophobic material dispersed substantially uniformly within the particles obtained by a non-tower process wherein the hydrophobic material is mixed with the said detergent active or builder prior to or whilst the detergent active and builder are mixed whereby a substantially uniform dispersion of the said material within the particles is obtained. t i t C
8. 11. A composition or component therefor according to claim 10 which further comprises a nonionic surfactant.
9. 12. A composition or component therefor according to any of claims 10 or 11 wherein the hydrophobic material comprises a hydrocarbon wax. DATED 4A q\q9% for and on behalf of UNILEVER PLC by UrQAlfer Australia Limited INTERNATIONAL SEARCH REPORT ntema icati InPEma Application No PCT/EP 94/02064 A. CLASSIFICATION OF SUBJECT MATTER IPC 6 C11D17/06 C11D11/00 According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) IPC 6 C11D Documentation searched other thn minimum documentation to the exten that such documents are included in the fields searched Electronic data base consulted during the international search (name of data base and, where practical, search terms used) C. DOCUMENTS CONSIDERED TO BE RELEVANT Category Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. A EP,A,O 337 523 (UNILEVER) 18 October 1989 1-10 cited in the application see the whole document A EP,A,O 492 679 (UNILEVER) 1 July 1992 1-10 see page 3, line 55 page 4, line 26; claims; examples A DE,A,36 17 756 (LION CORP.) 11 December 1,2,7-10 1986 see claims 1,5; examples 1-4 SFurther documents are listed in the continuation of box C. Patent family members are listed in annex. *Special cateories of cited documents: T" later document published ater the international filing date A doc entdefingthe eneral state of the art which is not not in conflict with the applicaton but A document defining the general e of th which is not ted to understand the principle or theory underlying the considered to be of particular relevance invention E' earlier document but published on or after the international document of particular relevance; the claimed invention filing date cannot be considered novel or cannot be considered to "L document which may throw doubts on priority claim(s) or involve an inventive step when the document is taken alone which is cited to establish the publicaton date of another *Y document of particular relevance; the claimed inve.ition citation or other special reason (as specified) cannot be considered to involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other meanr ments, such combination being obvious to a person sddlled document published prior to the international filing date but in the art. later than the priority date claimed document member of the ame patent farmly Date of the actual completion of the international search Date of mailing of the intenational search report 8 November 1994 8. 11. Name and mailing addres of the ISA Authorized officer European Patent Office, P.B. 5818 Patentlaan 2 NL 2280 HV Rijswik Te. (+31-70) 3402040, 31 65 1 epo l, Gri n, Fa (+31.70) 340-3016 Grittern, A a ii I: ii 4 Z B Ci ti iii Fom PCTSA/210 (tsmnd sent (July IM) mmomm-AIN INTERNATIONAL SEARCH REPORT Inena Application No PCT/EP 94/02064 C.(Continuation) DOCUMENTS CONSIDERED TO BE RELEVANT Category Citation of docwnt, with indication, where appropriate, of the rele*'ant passages X DATABASE WPI Derwent Publications Ltd., London, GB; AN 87-318719 JP,A,62 228 000 (KAO CORP.) 6 October 1987 see abstract IRelevant to claim No, 7-10 Form PCTI/lSN31O (conzuaon of sewnd sheet) (July 1992) INTERNATIONAL SEARCH REPORT nemalApitonN inforrnaton on patent family nicinbers PCT/EP 94/02064 Patent document I Publication IPatent family I Publication cited in search report jT date member(s) dt EP-A-0337523 18-10-89 AU-A- 3149889 21-09-89 CA-A- 1317188 04-05-93 ES-T- 2042963 16-12-93 EP-A-0492679 01-07-92 AU-A- 8810991 28-05-92 DE-A-3617756 11-12-86 JP-B- 6031430 27-04-94 JP-A- 61272300 02-12-86 JP-B- 6031431 27-04-94 JP-A- 62000598 06-01-87 US-A- 4970017 13-11-90