WO2012049178A1

WO2012049178A1 - Laundry detergent particles

Info

Publication number: WO2012049178A1
Application number: PCT/EP2011/067735
Authority: WO
Inventors: Judith Maria Bonsall; Stephen Thomas Keningley; Philip Ronald Moore
Original assignee: Unilever Plc; Unilever N.V.; Hindustan Unilever Limited
Priority date: 2010-10-14
Filing date: 2011-10-11
Publication date: 2012-04-19
Also published as: EP2627749B1; CN103154225A; ES2537714T3; IN2013MN00625A; BR112013009129A2; BR112013009129B1; EP2627749A1; ZA201302293B; CN103154225B

Abstract

A coated detergent particle having perpendicular dimensions x, y and z, wherein x is from 1 to 2mm, y is from 2 to 8mm, and z is from 2 to 8mm, wherein the particle comprises: (i) from 40 to 90 wt% surfactant selected from: anionic surfactant; and, non-ionic surfactant; (ii) from 20 to 40 wt% water soluble inorganic salts, the water soluble inorganic salts a mixture of sodium carbonate and sodium silicate; and, (iii) from 0 to 3 wt% of a perfume, wherein the inorganic salts are present on the detergent particle as a coating and the surfactant is present as a core, and sodium carbonate and sodium silicate comprise from 70 to 100 wt% of the coating and the ratio of sodium carbonate: sodium silicate is in the range from 4:1 to 2:3.

Description

Laundry Detergent Particles

Field of Invention The present invention relates to large laundry detergent particles. Background of Invention

W09932599 describes a method of manufacturing laundry detergent particles, being an extrusion method in which a builder and surfactant, the latter comprising as a major component a sulphated or sulphonated anionic surfactant, are fed into an extruder, mechanically worked at a temperature of at least 40 °C, preferably at least 60°C, and extruded through an extrusion head having a multiplicity of extrusion apertures. In most examples, the surfactant is fed to the extruder along with builder in a weight ratio of more than 1 part builder to 2 parts surfactant. The extrudate apparently required further drying. In Example 6, PAS paste was dried and extruded. Such PAS noodles are well known in the prior art. The noodles are typically cylindrical in shape and their length exceeds their diameter, as described in example 2.

US 7,022,660 discloses a process for the preparation of a detergent particle having a coating.

Summary of the Invention

We have found that large detergent particles flow better after storage in humid conditions by the incorporation of silicate into a carbonate. We have found that the water ingress of carbonate coated particles is reduced by the incorporation of silicate into the coating; this aids stability of the particles. In a further aspect, the present invention provides a coated detergent particle that is a concentrated formulation with more surfactant than inorganic solid. Only by having the coating encasing the surfactant which is soft can one have such a particulate concentrate where the unit dose required for a wash is reduced.

Adding solvent to the core would result by converting the particle into a liquid formulation. On the other hand, having a greater amount of inorganic solid would result in a less concentrated formulation; a high inorganic content would take one back to conventional low surfactant concentration granular powder. The coated detergent particle of the present invention sits in the middle of the two

conventional (liquid and granular) formats.

In one aspect the present invention provides a coated detergent particle having perpendicular dimensions x, y and z, wherein x is from 1 to 2 mm, y is from 2 to 8mm, and z is from 2 to 8 mm, wherein the particle comprises:

(i) from 40 to 90 wt % surfactant selected from: anionic surfactant; and, non-ionic surfactant;

(ii) from 20 to 40 wt% water soluble inorganic salts, the water soluble inorganic salts a mixture of sodium carbonate and sodium silicate; and,

(iii) from 0 to 3 wt % of a perfume,

wherein the inorganic salts are present on the detergent particle as a coating and the surfactant is present as a core and sodium carbonate and sodium silicate comprise from 70 to 100 wt % of the coating and the ratio of sodium

carbonate:sodium silicate in the coating is in the range from 4: 1 to 2:3. Preferably, the ratio of sodium carbonate:sodium silicate in the coating is preferably 2: 1 .

Preferably sodium carbonate and sodium silicate comprise from 80 to 100 wt %, preferably 90 to 100 wt %, and most preferably 95 to 100 wt % of the coating. Unless otherwise stated all wt % refer to the total percentage in the particle as dry weights.

Detailed Description of the Invention

Shape

Preferably the coated laundry detergent particle is curved. The coated laundry detergent particle may be lenticular (shaped like a whole dried lentil), an oblate ellipsoid, where z and y are the equatorial diameters and x is the polar diameter; preferably y = z.

The coated laundry detergent particle may be shaped as a disc.

Preferably the coated laundry detergent particle does not have hole; that is to say, the coated laundry detergent particle does not have a conduit passing there though that passes through the core, i.e., the coated detergent particle has a topologic genus of zero.

CORE

SURFACTANT

The coated laundry detergent particle comprises between 40 to 90 wt%, preferably 50 to 90 wt% of a surfactant, most preferably 70 to 90 wt %. In general, the nonionic and anionic surfactants of the surfactant system may be chosen from the surfactants described "Surface Active Agents" Vol. 1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the current edition of "McCutcheon's Emulsifiers and Detergents" published by

Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981 . Preferably the surfactants used are saturated.

Anionic Surfactants

Suitable anionic detergent compounds which may be used are usually water- soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher Cs to Ci8 alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl Cg to C20 benzene sulphonates, particularly sodium linear secondary alkyl C10 to C15 benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum. Most preferred anionic surfactants are sodium lauryl ether sulfate (SLES), particularly preferred with 1 to 3 ethoxy groups, sodium C10 to C15 alkyl benzene sulphonates and sodium C12 to C18 alkyl sulphates. Also applicable are surfactants such as those described in EP-A-328 177 (Unilever), which show resistance to salting-out, the alkyl polyglycoside surfactants described in EP-A-070 074, and alkyl monoglycosides. The chains of the surfactants may be branched or linear.

Soaps may also be present. The fatty acid soap used preferably contains from about 16 to about 22 carbon atoms, preferably in a straight chain configuration. The anionic contribution from soap is preferably from 0 to 30 wt% of the total anionic.

Preferably, at least 50 wt % of the anionic surfactant is selected from: sodium Cn to C-I 5 alkyl benzene sulphonates; and, sodium C12 to C18 alkyl sulphates. Even more preferably, the anionic surfactant is sodium Cn to C15 alkyl benzene sulphonates.

Preferably the anionic surfactant is present in the coated laundry detergent particle at levels between 15 to 85 wt%, more preferably 50 to 80 wt% on total surfactant.

Nonionic Surfactants Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Preferred nonionic detergent compounds are C6 to C22 alkyl phenol- ethylene oxide condensates, generally 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule, and the condensation products of aliphatic Cs to C18 primary or secondary linear or branched alcohols with ethylene oxide, generally 5 to 50 EO. Preferably, the non-ionic is 10 to 50 EO, more preferably 20 to 35 EO. Alkyl ethoxylates are particularly preferred.

Preferably the nonionic surfactant is present in the coated laundry detergent particle at levels between 5 to 75 wt% on total surfactant, more preferably 10 to 40 wt% on total surfactant. Cationic surfactant may be present as minor ingredients at levels preferably between 0 to 5 wt% on total surfactant.

Preferably all the surfactants are mixed together before being dried. Conventional mixing equipment may be used. The surfactant core of the laundry detergent particle may be formed by extrusion or roller compaction and subsequently coated with an inorganic salt.

Calcium Tolerant Surfactant System

In another aspect the surfactant system used is calcium tolerant and this is a preferred aspect because this reduces the need for builder.

Surfactant blends that do not require builders to be present for effective

detergency in hard water are preferred. Such blends are called calcium tolerant surfactant blends if they pass the test set out hereinafter. However, the invention may also be of use for washing with soft water, either naturally occurring or made using a water softener. In this case, calcium tolerance is no longer important and blends other than calcium tolerant ones may be used.

Calcium-tolerance of the surfactant blend is tested as follows:

The surfactant blend in question is prepared at a concentration of 0.7 g surfactant solids per litre of water containing sufficient calcium ions to give a French hardness of 40 (4 x 10^"3 Molar Ca²⁺). Other hardness ion free electrolytes such as sodium chloride, sodium sulphate, and sodium hydroxide are added to the solution to adjust the ionic strength to 0.05M and the pH to 10. The adsorption of light of wavelength 540 nm through 4 mm of sample is measured 15 minutes after sample preparation. Ten measurements are made and an average value is calculated. Samples that give an absorption value of less than 0.08 are deemed to be calcium tolerant.

Examples of surfactant blends that satisfy the above test for calcium tolerance include those having a major part of LAS surfactant (which is not of itself calcium tolerant) blended with one or more other surfactants (co-surfactants) that are calcium tolerant to give a blend that is sufficiently calcium tolerant to be usable with little or no builder and to pass the given test. Suitable calcium tolerant co- surfactants include SLES 1 -7EO, and alkyl-ethoxylate nonionic surfactants, particularly those with melting points less than 40°C.

A LAS/SLES surfactant blend has a superior foam profile to a LAS nonionic surfactant blend and is therefore preferred for hand washing formulations requiring high levels of foam. SLES may be used at levels of up to 30 wt% of the surfactant blend.

Water Soluble Inorganic Salts

The water-soluble inorganic salt is present as a coating on the particle. The water- soluble inorganic salt is preferably present at a level that reduces the stickiness of the laundry detergent particle to a point where the particles are free flowing.

It will be appreciated by those skilled in the art that while multiple layered coatings, of the same or different coating materials, could be applied, a single coating layer is preferred, for simplicity of operation, and to maximise the thickness of the coating.

The coating is preferably applied to the surface of the surfactant core, by deposition from an aqueous solution of the water soluble inorganic salt. In the alternative coating can be performed using a slurry. The aqueous solution preferably contains greater than 50g/L, more preferably 200 g/L of the salt. An aqueous spray-on of the coating solution in a fluidised bed has been found to give good results and may also generate a slight rounding of the detergent particles during the fluidisation process. Drying and/or cooling may be needed to finish the process. A preferred calcium tolerant coated laundry detergent particle comprises 15 to 100 wt% on surfactant of anionic surfactant of which 20 to 30 wt% on surfactant is sodium lauryl ether sulphate. Preferably the coating is applied as a solution rather than a suspension.

The coated laundry detergent particle

Preferably, the coated laundry detergent particle comprises from 10 to 100 wt %, more preferably 50 to 100 wt %, even more preferably 80 to 100 wt %, most preferably 90 to 100 wt % of a laundry detergent formulation in a package.

The package is that of a commercial formulation for sale to the general public and is preferably in the range of 0.01 kg to 5 kg, preferably 0.02 kg to 2 kg, most preferably 0.5 kg to 2 kg.

Preferably, the coated laundry detergent particle is such that at least 90 to 100 % of the coated laundry detergent particles in the in the x, y and z dimensions are within a 20 %, preferably 10%, variable from the largest to the smallest coated laundry detergent particle.

Water content

The particle preferably comprises from 0 to 15 wt % water, more preferably 0 to 10 wt %, most preferably from 1 to 5 wt % water, at 293K and 50% relative humidity. This facilitates the storage stability of the particle and its mechanical properties. Other Adjuncts

The adjuncts as described below may be present in the coating or the core. These may be in the core or the coating.

Fluorescent Agent

The coated laundry detergent particle preferably comprises a fluorescent agent (optical brightener). Fluorescent agents are well known and many such

fluorescent agents are available commercially. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt %, more preferably 0.01 to 0.1 wt %. Suitable Fluorescer for use in the invention is described in chapter 7 of Industrial Dyes edited by K. Hunger 2003 Wiley-VCH ISBN 3-527-30426-6.

Preferred fluorescers are selected from the classes distyrylbiphenyls,

triazinylaminostilbenes, bis(1 ,2,3-triazol-2-yl)stilbenes, bis(benzo[b]furan-2- yl)biphenyls, 1 ,3-diphenyl-2-pyrazolines and courmarins. The fluorescer is preferably sulfonated.

Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. Preferred fluorescers are: sodium 2 (4-styryl-3-sulfophenyl)- 2H-napthol[1 ,2-d]triazole, disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2

hydroxyethyl) amino 1 ,3,5-triazin-2-yl)]amino}stilbene-2-2' disulfonate, disodium 4,4'-bis{[(4-anilino-6-morpholino-1 ,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'-bis(2-sulfostyryl)biphenyl. Tinopal® DMS is the disodium salt of disodium 4,4'-bis{[(4-anilino-6-morpholino- 1 ,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate. Tinopal® CBS is the disodium salt of disodium 4,4'-bis(2-sulfostyryl)biphenyl. Perfume

Preferably the composition comprises a perfume. The perfume is preferably in the range from 0.001 to 3 wt %, most preferably 0.1 to 1 wt %. Many suitable examples of perfumes are provided in the CTFA (Cosmetic, Toiletry and

Fragrance Association) 1992 International Buyers Guide, published by CFTA Publications and OPD 1993 Chemicals Buyers Directory 80th Annual Edition, published by Schnell Publishing Co.

It is commonplace for a plurality of perfume components to be present in a formulation. In the compositions of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components.

In perfume mixtures preferably 15 to 25 wt% are top notes. Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]).

Preferred top-notes are selected from citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol.

The perfume serves to disaggregate the dye to make the dye more visible.

It is preferred that the coated laundry detergent particle does not contain a peroxygen bleach, e.g., sodium percarbonate, sodium perborate, and peracid. Polymers

The composition may comprise one or more further polymers. Examples are carboxymethylcellulose, poly (ethylene glycol), polyvinyl alcohol), polyethylene imines, ethoxylated polyethylene imines, water soluble polyester polymers polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers and lauryl methacry late/acrylic acid copolymers.

Enzymes

One or more enzymes are preferred present in a composition of the invention.

Preferably the level of each enzyme is from 0.0001 wt% to 0.5 wt% protein on product.

Especially contemplated enzymes include proteases, alpha-amylases, cellulases, lipases, peroxidases/oxidases, pectate lyases, and mannanases, or mixtures thereof. Suitable lipases include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Examples of useful lipases include lipases from Humicola (synonym Thermomyces), e.g. from H. lanuginosa (7. lanuginosus) as described in EP 258 068 and EP 305 216 or from H. insolens as described in WO 96/13580, a Pseudomonas lipase, e.g. from P. alcaligenes or P. pseudoalcaligenes (EP 218 272), P. cepacia (EP 331 376), P. stutzeri (GB

1 ,372,034), P. fluorescens, Pseudomonas sp. strain SD 705 (WO 95/06720 and WO 96/27002), P. wisconsinensis (WO 96/12012), a Bacillus lipase, e.g. from B. subtilis (Dartois et al. (1993), Biochemica et Biophysica Acta, 1 131 , 253-360), B. stearothermophilus (JP 64/744992) or B. pumilus (WO 91/16422). Other examples are lipase variants such as those described in WO 92/05249, WO 94/01541 , EP 407 225, EP 260 105, WO 95/35381 , WO 96/00292, WO 95/30744, WO 94/25578, WO 95/14783, WO 95/22615, WO 97/04079 and WO 97/07202, WO 00/60063, WO 09/107091 and WO09/1 1 1258.

Preferred commercially available lipase enzymes include Lipolase™ and Lipolase Ultra™, Lipex™ (Novozymes A/S) and Lipoclean™.

The method of the invention may be carried out in the presence of phospholipase classified as EC 3.1 .1 .4 and/or EC 3.1 .1 .32. As used herein, the term

phospholipase is an enzyme which has activity towards phospholipids.

Phospholipids, such as lecithin or phosphatidylcholine, consist of glycerol esterified with two fatty acids in an outer (sn-1 ) and the middle (sn-2) positions and esterified with phosphoric acid in the third position; the phosphoric acid, in turn, may be esterified to an amino-alcohol. Phospholipases are enzymes which participate in the hydrolysis of phospholipids. Several types of phospholipase activity can be distinguished, including phospholipases Ai and A₂ which hydrolyze one fatty acyl group (in the sn-1 and sn-2 position, respectively) to form

lysophospholipid; and lysophospholipase (or phospholipase B) which can hydrolyze the remaining fatty acyl group in lysophospholipid. Phospholipase C and phospholipase D (phosphodiesterases) release diacyl glycerol or

phosphatidic acid respectively. Suitable proteases include those of animal, vegetable or microbial origin. Microbial origin is preferred. Chemically modified or protein engineered mutants are included. The protease may be a serine protease or a metallo protease, preferably an alkaline microbial protease or a trypsin-like protease. Preferred commercially available protease enzymes include Alcalase™, Savinase™, Primase™,

Duralase™, Dyrazym™, Esperase™, Everlase™, Polarzyme™, and Kannase™, (Novozymes A/S), Maxatase™, Maxacal™, Maxapem™, Properase™,

Purafect™, Purafect OxP™, FN2™, and FN3™ (Genencor International Inc.).

The method of the invention may be carried out in the presence of cutinase.

classified in EC 3.1 .1 .74. The cutinase used according to the invention may be of any origin. Preferably cutinases are of microbial origin, in particular of bacterial, of fungal or of yeast origin.

Suitable amylases (alpha and/or beta) include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Amylases include, for example, alpha-amylases obtained from Bacillus, e.g. a special strain of B. licheniformis, described in more detail in GB 1 ,296,839, or the Bacillus sp. strains disclosed in WO 95/026397 or WO 00/060060. Commercially available amylases are Duramyl™, Termamyl™, Termamyl Ultra™, Natalase™,

Stainzyme™, Fungamyl™ and BAN™ (Novozymes A/S), Rapidase™ and

Purastar™ (from Genencor International Inc.).

Suitable cellulases include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Suitable cellulases include cellulases from the genera Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia,

Acremonium, e.g. the fungal cellulases produced from Humicola insolens, Thielavia terrestris, Myceliophthora thermophila, and Fusarium oxysporum disclosed in US 4,435,307, US 5,648,263, US 5,691 , 178, US 5,776,757, WO 89/09259, WO 96/029397, and WO 98/012307. Commercially available cellulases include Celluzyme™, Carezyme™, Endolase™, Renozyme™ (Novozymes A/S), Clazinase™ and Puradax HA™ (Genencor International Inc.), and KAC-500(B)™ (Kao Corporation).

Suitable peroxidases/oxidases include those of plant, bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Examples of useful peroxidases include peroxidases from Coprinus, e.g. from C. cinereus, and variants thereof as those described in WO 93/24618, WO 95/10602, and WO 98/15257. Commercially available peroxidases include Guardzyme™ and

Novozym™ 51004 (Novozymes A/S).

Further enzymes suitable for use are disclosed in WO2009/087524,

WO2009/090576, WO2009/148983 and WO2008/007318.

Enzyme Stabilizers

Any enzyme present in the composition may be stabilized using conventional stabilizing agents, e.g., a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol, lactic acid, boric acid, or a boric acid derivative, e.g., an aromatic borate ester, or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid, and the composition may be formulated as described in e.g. WO 92/19709 and WO 92/19708.

Where alkyi groups are sufficiently long to form branched or cyclic chains, the alkyi groups encompass branched, cyclic and linear alkyi chains. The alkyi groups are preferably linear or branched, most preferably linear.

The indefinite article "a" or "an" and its corresponding definite article "the" as used herein means at least one, or one or more, unless specified otherwise. The singular encompasses the plural unless otherwise specified.

Sequesterants may be present in the coated laundry detergent particles.

It is preferred that the coated detergent particle has a core to shell ratio of from 3 to 1 : 1 , most preferably 2.5 to 1.5: 1 ; the optimal ratio of core to shell is 2: 1 . EXPERIMENTAL

Example 1 : (particle manufacture)

Preparation of core of particle 1 & 2

Core particle 1 -1962.5g of dried, milled surfactant blend (LAS/PAS/SLES.3eo (58.3-14.6-27.1 by weight) was thoroughly mixed with 37.38g of perfume oil and 30.1 g of Sodium Carboxymethyl cellulose. Core particle 2- 1962.5g of dried, milled surfactant blend LAS/Ni-30eo (85-15 by weight) was thoroughly mixed with 37.38g of perfume oil and 30.1 g of Sodium Carboxymethyl cellulose.

The mixtures were then extruded using a ThermoFisher 24HC twin screw extruder, operated at a rate of 8kg/hr. Inlet temperature of the extruder was set at 20°C, rising to 40°C just prior to the die-plate. The die-plate used was drilled with 6 circular orifices of 5mm diameter.

The extruded products were cut after the die-plate using a high speed cutter set up to produce particle with a thickness of ~1 .1 mm.

(Coating)

1200g of the extrudates above were charged to the fluidising chamber of a Strea 1 laboratory fluid bed drier (Aeromatic-Fielder AG) and spray coated using 1714g of a solution containing 342.8g of sodium carbonate with 342.8g @50% alkaline silicate solution (defined as 2.1 to 2.6 Sio2 to 1 Na20) in 1028.4g of water, using a top-spray configuration. The coating solution was fed to the spray nozzle of the Strea 1 via a peristaltic pump (Watson-Marlow model 101 U/R) at an initial rate of 3.3g/min, rising to 9.1 g/min during the course of the coating trial. The Fluid bed coater was operated with an initial air inlet air temperature of 55°C increasing to 90 °C during the course of the coating trial whilst maintaining the outlet temperature in the range 45-50°C throughout the coating process.

Storage method and results

Coated granules, 200g, were put into a plain card box, open at the lid. The samples were stored in an environment set at 27 °C 70% rh for either 2 weeks or 4 weeks. After that time the boxes were removed and tested for pouring and crystal feel.

Storage results (ash = sodium carbonate).

Sample 2 Wee ks Storage 4 Weeks Storage

LAS/Ni-30oe base

30% Ash coated slightly Moderately Slightly Moderately

sluggish Crisp sluggish Crisp

20% Ash 10% Silicate Free Crisp Slightly Moderately coated flowing sluggish Crisp

LAS/PAS/ SLES base

30% Ash coated Free Soft No Flow Soft

flowing

20% Ash 10% Silicate Free Crisp Free Crisp

coated flowing flowing Key to Symbols used in Classifying Storage Behaviour

Flow of powder is assessed after Feel Determined by touch pack is opened and inverted

F=Free flowing C=Crisp

SS=Slightly sluggish MC=Moderately crisp

S=Sluggish MS=Moderately soft

L=Lumps S=Soft

SC=Slightly creepy M=Moist

No Flow W=Wet

Claims

We claim:

1 . A coated detergent particle having perpendicular dimensions x, y and z, wherein x is from 1 to 2 mm, y is from 2 to 8mm, and z is from 2 to 8 mm, wherein the particle comprises:

(iii) from 0 to 3 wt % of a perfume,

carbonate:sodium silicate in the coating is in the range from 4: 1 to 2:3.

2. A coated detergent particle according to claim 1 , wherein ratio of sodium carbonate:sodium silicate 2:1 .

3. A coated detergent particle according to claim 1 or 2, wherein sodium carbonate and sodium silicate comprise from 80 to 100 wt % of the coating.

4. A coated detergent particle according to claim 3, wherein sodium carbonate and sodium silicate comprise from 90 to 100 wt % of the coating.

5. A coated detergent particle according to claim 4, wherein sodium carbonate and sodium silicate comprise from 95 to 100 wt % of the coating.

6. A coated detergent particle according to any one of the preceding claims, wherein the coated detergent particle comprises from 15 to 85 wt % anionic surfactant on surfactant and from 5 to 75 wt % non-ionic surfactant on surfactant.

7. A coated detergent particle according to any one of claims 1 to 6, wherein the coated detergent particle comprises 15 to 100 wt % anionic surfactant on surfactant of which 20 to 30 wt % is sodium lauryl ether sulphate.

8. A coated detergent particle according to any one of the preceding claims, wherein the anionic surfactant is selected from alkyi benzene sulphonates; alkyi ether sulphates; alkyi sulphates.

9. A coated detergent particle according to claim 8, wherein the anionic surfactant is selected from sodium lauryl ether sulfate with 1 to 3 ethoxy groups, sodium do to C15 alkyi benzene sulphonates and sodium C12 to C18 alkyi sulphates.

10. A coated detergent particle according to any one of the preceding claims, wherein the non-ionic surfactant is 10 to 50 EO.

1 1 . A coated detergent particle according to claim 10, wherein the non-ionic surfactant is the condensation products of aliphatic Cs to C18 primary or secondary linear or branched alcohols with 20 to 35 ethylene oxide groups.

12. A coated detergent particle according to any one of the preceding claims, wherein the particle comprises from 0 to 15 wt % water.

13. A coated detergent particle according to claim 12, wherein the particle comprises from 1 to 5 wt % water.