PARTICULATED DETERGENT COMPOSITIONS WITH PERFUME PARTICLES AND METHODS FOR THEIR USE

Description

FIELD OF THE INVENTION

[0001] The present invention relates to particulate laundry detergent compositions comprising perfume particles for use in laundering fabrics, especially for hand-washing fabrics.BACKGROUND OF THE INVENTION

[0002] It is known to incorporate functional particles (such as colored aesthetic particles, enzyme particles, bleach particles, perfume particles, and the like) in particulate laundry detergent products to enhance the cleaning performance or consumer delight of such products. Conventional wisdom believes that successful incorporation of such functional particles into the particulate laundry detergent products requires fast dissolution, i.e., such function particles should dissolve or disperse or disintegrate in water at about 25°C within about 5 minutes, preferably within about 3 minutes, more preferably within about 1 minute. Preferably, such functional particles will dissolve or disperse or disintegrate in water at the same or similar speed as the base granules of such particulate laundry detergent products. Therefore, functional particles typically incorporated into particulate laundry detergent products are either relatively small and thin, or contain a surfactant or a disintegrant, so as to ensure that they can quickly dissolve or disperse or disintegrate upon contact with water.

[0003] In contrast, relatively large and thick functional particles (e.g., perfume particles with a diameter of 3 mm or more and an aspect ratio of 5 or less) that contain little or no surfactant / disintegrant are typically sold as a separate product. They are not incorporated into particulate laundry detergent products, for fear that the slow dissolution of such functional particles will adversely affect the overall consumer perception and acceptance of the particulate laundry detergent products. Relevant background knowledge is described in the following prior art documents: US 2010 / 298191 A1 discloses a functionalized substrate, comprising a. a composition susceptible to aqueous attack; b. a plurality of perfume microcapsules; c. a total perfume loading level of from about 1% to about 95%. US 4 209 417 A discloses a detergent composition having both immediate and long-term perfume emittance consisting essentially of: (a) from 0.05%% to 35% of a water- soluble organic surfactant selected from the group consisting of anionic, nonionic, amphoteric, and zwitterionic surfactants and mixtures thereof; (b) from 0.01% to 1.0% of the perfumed particles; and (c) a detergency adjunct material. WO 2007 / 124371 A1 discloses a solid particulate laundry detergent composition comprising: (a) from 0.2 wt% to 20wt % perfume particle; and (b) to 100% wt of the remainder of the solid particulate laundry detergent composition. WO 2007 / 130684 A1 discloses an article comprising a functionalized substrate comprising at least two substantially planar water-soluble films carrying a coating of a functional composition, wherein the coating is between the two films, and wherein the functional composition comprises a microcapsule. WO 99 / 55819 A1 discloses a granular detergent composition comprising: I) from about 0.01% to about 50% by weight, of an encapsulated perfume particle comprising (a) a water-soluble modified starch solid matrix; (b) a perfume oil; II) from about 50% to about 99.99%, of conventional laundry ingredients. SUMMARY OF THE INVENTION

[0004] It is a surprising and unexpected discovery of the present invention that incorporation of relatively large and thick perfume particles with relatively slow dissolution rates into particulate laundry detergent products not only do not adversely affect consumer perception and acceptance of such products, but instead provide a significantly improved freshness experience that delights the consumers both visually and olfactorily when they are hand-washing the fabrics. Further, the consumers, when seeing any undissolved perfume particles during wash, are inclined to use them as a scrubbing aid to treat a selected area of the fabrics. Therefore, such undissolved perfume particles are viewed by the consumers as an advantage, rather than a disadvantage, of the products. Based on such surprising and unexpected consumer test results, the present invention provides a particulate laundry detergent product that incorporates such relatively large and thick perfume particles of relatively slow dissolution rates.

[0005] In one aspect, the present invention relates to a particulate laundry detergent composition comprising a major proportion of detergent particles and a minor proportion of perfume particles, wherein each of said perfume particles have a longest dimension of no less than about 3 mm and an aspect ratio of no more than about 5, wherein said perfume particles are characterized by a dissolution rate of no less than about 8 minutes as measured in deionized water at 25°C, wherein each of said perfume particles has a hemispherical or compressed hemispherical shape, wherein said perfume particles are characterized by a density ranging from 0.5 g / cm 3< to 0.98 g / cm 3< and wherein each of said perfume particles have a longest dimension ranging from 3 mm to 10 mm, and an aspect ratio from 1 to 5, wherein said perfume particles are essentially free of surfactants, wherein each of said perfume particles comprises from 0.1 wt% to 20 wt% of a perfume ingredient; wherein said perfume ingredient is selected from the group consisting of free perfumes, pro-perfumes, encapsulated perfumes, perfume microcapsules, and combinations thereof, and wherein each of said perfume particles further comprises from 5 wt% to 99.9 wt% of polyethylene glycol; wherein said polyethylene glycol has a weight average molecular weight (Mw) from 2,000 to 20,000 Daltons.

[0006] In another aspect, the present invention relates to use of the above-mentioned particulate detergent composition for hand-washing fabrics.

[0007] In yet another aspect, the present invention relates to a method of using the above-mentioned particulate detergent composition for hand-washing fabrics, comprising the steps of: (a) providing such particulate detergent composition; (b) forming a laundry liquor by diluting the particulate detergent composition with water at a weight ratio of from about 1:100 to about 1: 1000; (c) hand-washing fabrics in the laundry liquor; and (d) rinsing the fabric with water, wherein during step (c), the perfume particles or an undissolved portion thereof are used for treating a selected area of the fabrics.

[0008] These and other aspects of the present invention will become more apparent upon reading the following detailed description of the invention.DETAILED DESCRIPTION OF THE INVENTION

[0009] Features and benefits of the various embodiments of the present invention will become apparent from the following description, which includes examples of specific embodiments intended to give a broad representation of the invention.

[0010] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0011] As used herein, terms such as "a" and "an" when used in a claim, are understood to mean one or more of what is claimed or described. The terms "comprise," "comprises," "comprising," "contain," "contains," "containing," "include," "includes" and "including" are all meant to be nonlimiting.

[0012] The term "particulate laundry detergent composition" refers to a solid powdery or granular laundry detergent composition, preferably a free-flowing powdery or granular laundry detergent composition, such as an all-purpose or heavy-duty washing agent for fabrics, as well as laundry auxiliaries such as bleach actives, rinse aids, additives, or pre-treat products.

[0013] The term "detergent particle" refers to a particle comprising one or more detersive actives, such as surfactants, builders, bleach actives, enzymes, polymers, chelants, softeners, suds suppressors, suds boosters, brighteners, dye transfer inhibitors, and the like. Preferably, such detergent particles contain one or more surfactants, especially an anionic surfactant and / or a nonionic surfactant.

[0014] The term "perfume particle" refers to a particle comprising one or more perfume ingredients, such as free perfumes, pro-perfumes, encapsulated perfumes, perfume microcapsules, and the like. Preferably, such perfume particles contain perfume microcapsules, especially friable perfume microcapsules.

[0015] The term "aspect ratio" refers to the ratio of the longest dimension of the perfume particles over its shortest dimension. For example, when such perfume particles have a hemispherical or compressed hemispherical shape, the aspect ratio is the ratio between the based diameter of the perfume particles over its height.

[0016] The term "consisting essentially of" means that the composition contains less than about 1%, preferably less than about 0.5%, of ingredients other than those listed.

[0017] Further, the term "substantially free of" or "substantially free from" means that the indicated material is present in the amount of from 0 wt% to about 1 wt%, preferably from 0 wt% to about 0.5 wt%, more preferably from 0 wt% to about 0.2 wt%. The term "essentially free of" means that the indicated material is present in the amount of from 0 wt% to about 0.1 wt%, preferably from 0 wt% to about 0.01 wt%, more preferably it is not present at analytically detectable levels.

[0018] As used herein, all concentrations and ratios are on a weight basis unless otherwise specified. All temperatures herein are in degrees Celsius (°C) unless otherwise indicated. All conditions herein are at 20°C and under the atmospheric pressure, unless otherwise specifically stated. All polymer molecular weights are determined by weight average number molecular weight unless otherwise specifically noted.Perfume Particles

[0019] The particulate laundry detergent composition of the present invention comprises a minor proportion of perfume particles, e.g., in an amount ranging from about 0.1% to about 30%, preferably from about 0.5% to about 20%, more preferably from about 1% to about 15%, by total weight of such particulate laundry detergent composition.

[0020] The perfume particles of the present invention are characterized by the following three (3) key features: (1) a longest dimension of no less than about 3 mm, e.g., from about 3 mm to 10 mm, preferably from about 4 mm to about 9 mm, more preferably from about 5 mm to about 8 mm; (2) an aspect ratio of no more than about 5, e.g., from about 1 to about 5, preferably from about 1.5 to about 4, more preferably from about 2 to about 4; and (3) a dissolution rate of no less than about 8 minutes, e.g., from about 8 minutes to about 60 minutes, preferably from about 10 minutes to about 45 minutes, more preferably from about 15 minutes to about 30 minutes, as measured in deionized water at 25°C using the Dissolution Rate Test described hereinafter.

[0021] Perfume particles with the above-described longest dimension, aspect ratio and dissolution rate can provide a significantly improved freshness experience that delights consumers both visually and olfactorily when they are hand-washing the fabrics, and may also more likely to be used by the consumers as a scrubbing aid to treat a selected area of the fabrics during the wash. If the longest dimension is less than 3mm or if the aspect ratio is greater than 5, the perfume particles may not be readily seen by the consumers during the hand-washing process, or they may not be perceived as strong enough for use as a scrubbing aid, thereby reducing or limiting their freshness experience. If the dissolution rate of such perfume particles is less than 5 minutes, a majority of them may become completely dissolved before the consumers notice them, which also will lead to reduced or limited freshness experience.

[0022] The perfume particles of the present invention may be formed into tablets, pills, spheres, and the like. The perfume particles have a hemispherical or compressed hemispherical shape Compressed hemispherical refers to a shape corresponding to a hemisphere that is at least partially flattened such that the curvature of the curved surface is less, on average, than the curvature of a hemisphere having the same radius. A compressed hemispherical particle can have an aspect ratio (i.e., the ratio of its base diameter over its height that is orthogonal to the base) of from about 2.0 to about 5, alternatively from about 2.1 to about 4.5, alternatively from about 2.2 to about 4.

[0023] Because the perfume particles are significantly different from the detergent particles in size, it is inevitable that they are likely to segregate from the detergent particles during shipment and storage. Such segregation may lead to significant variations in the amount of perfume particles in the particulate laundry detergent composition from dosage to dosage. It has been discovered that such hemispherical or compressed hemispherical shape helps to significantly reduce segregation of the perfume particles in the particulate laundry detergent composition, e.g., by nearly half in comparison with spherical perfume particles.

[0024] Individual perfume particles of the present invention can each have a mass from about 0.1 mg to about 5 g, alternatively from about 1 mg to about 1 g, alternatively from about 5 mg to about 500 mg, alternatively from about 10 mg to about 250 mg, alternatively from about 15 mg to about 125 mg, alternatively combinations thereof and any whole numbers or ranges of whole numbers of mg within any of the aforementioned ranges.

[0025] Perfume particles of the present invention have a density lower than water, so that they can float on water and are more noticeable by the consumers and more likely to be picked up by the consumers for use as a scrubbing aid during wash. Perfume particles have a density ranging from about 0.5 g / cm 3< to about 0.98 g / cm 3< , preferably from about 0.7 g / cm 3< to about 0.95 g / cm 3< , more preferably from about 0.8 g / cm 3< to about 0.9 g / cm 3< .

[0026] A plurality of perfume particles of the present invention can have different shapes, sizes, mass, and / or density.

[0027] The perfume particles of the present invention comprise from about 0.1 wt% to about 20 wt%, preferably from about 0.5 wt% to about 15 wt%, more preferably from about 1 wt% to about 10 wt% of one or more perfume ingredients, such as free perfumes, pro-perfumes, encapsulated perfumes, perfume microcapsules, and the like. The perfume particle comprise free perfumes, encapsulated perfumes, and / or perfume microcapsules. In one embodiment, the perfume particles comprise free perfumes and are substantially or essentially free of encapsulated perfumes or perfume microcapsules. In yet another embodiment, the perfume particles comprise encapsulated perfumes (i.e., perfumes carried by a carrier material such as starch, cyclodextrin, silica, zeolites or clay) or perfume microcapsules, but are substantially or essentially free of free perfumes. In yet another embodiment, the perfume particles comprises both free perfumes and encapsulated perfumes or perfume microcapsules, e.g., at a weight ratio ranging from about 1:5 to about 5:1, alternatively from about 1:4 to about 4: 1, further alternatively from about 1:3 to about 3: 1.

[0028] Preferably, such perfume particles contain perfume microcapsules (PMCs), especially friable PMCs. For purpose of the present invention, the term "perfume microcapsules" or PMCs cover both perfume microcapsules and perfume nanoparticles. In one embodiment, the PMCs comprise melamine / formaldehyde shells, which are commercially available from Appleton, Quest International, International Flavor & Fragrances, or other suitable sources. In a preferred embodiment, the shells of the PMCs are coated with polymer to enhance the ability of the PMCs to adhere to fabric. The perfume particles of the present invention may comprise from about 0.1 wt% to about 20 wt%, preferably from about 1 wt% to about 18 wt%, more preferably from about 5 wt% to about 15 wt% of perfume microcapsules.

[0029] The perfume particles of the present invention further comprises as water-soluble polymer, polyethylene glycol (PEG). Each of the perfume particles comprises from about 5 wt% to about 99.9 wt%, preferably from about 10 wt% to about 99 wt%, more preferably from about 30 wt% to about 95 wt% of PEG, and such PEG is characterized by a weight average molecular weight (Mw) ranging from about 2,000 to about 20,000 Daltons, preferably from about 3,000 to about 18,000 Daltons, more preferably from about 4,000 to about 16,000 Daltons. A particular suitable PEG is commercially available from BASF under the tradename PLURIOL E 8000.

[0030] The perfume particles of the present invention may optionally comprise one or more colorants, e.g., dyes, pigments, and combinations thereof, in an amount ranging from about 0.0001 wt% to about 1 wt%, preferably from about 0.001 wt% to about 0.5 wt%, more preferably from about 0.005 wt% to about 0.1 wt%. More preferably, the colorants impart to the perfume particles a color selected from the group consisting of blue, green, yellow, orange, pink, red, purple, grey, and the like, so that such perfume particles are visually contrasting with detergent particles of a white or light-colored appearance in the particulate laundry detergent composition of the present invention.

[0031] The perfume particles of the present invention may further comprise a water-soluble or water-dispersible filler, e.g., sodium chloride, sodium sulfate, sodium carbonate, sodium bicarbonate, sugar, starch, modified cellulose, silica, zeolite, clay, and the like.

[0032] The perfume particles of the present invention are essentially free of surfactants, because the presence of such surfactants may speed up dissolution of the perfume particles in water, which is undesirable in the context of the present invention. More preferably, the perfume particles of the present invention are substantially free of or essentially free of any detersive actives.

[0033] In a most preferred embodiment of the present invention, the perfume particles are present in the particulate laundry detergent composition an amount ranging from 1% to 15% by total weight of such particulate laundry detergent composition, while each of the perfume particles has a hemispherical or a compressed hemispherical shape and is characterized by: (a) a longest dimension ranging from 4 mm to 9 mm; (b) an aspect ratio ranging from 2 to 4; and (c) a density ranging from 0.8 g / cm 3< to 0.9 g / cm 3< . Such perfume particles used in such a specific amount provide a good balance between maximizing consumer freshness experience and minimizing segregation of the perfume particles from the detergent particles.Detergent Particles

[0034] The particulate laundry detergent composition of the present invention comprises a major proportion of detergent particles, e.g., in an amount ranging from about 50% to about 99.9%, preferably from about 55% to about 99.5%, more preferably from about 60% to 99%, by total weight of such particulate laundry detergent composition.

[0035] The detergent particles of the present invention may comprise one or more detersive actives, such as surfactants, builders, bleach actives, enzymes, polymers, chelants, softeners, suds suppressors, suds boosters, brighteners, dye transfer inhibitors, and the like. The detergent particles can be spray-dried particles and / or agglomerated particles and / or extruded particles. Such detergent particles may be selected from: surfactant particles, including surfactant agglomerates, surfactant extrudates, surfactant needles, surfactant noodles, surfactant flakes; polymer particles such as cellulosic polymer particles, polyester particles, polyamine particles, terephthalate polymer particles, polyethylene glycol polymer particles; builder particles, such as sodium carbonate and sodium silicate co-builder particles, phosphate particles, zeolite particles, silicate salt particles, carbonate salt particles; filler particles such as sulphate salt particles; dye transfer inhibitor particles; dye fixative particles; bleach particles, such as percarbonate particles, especially coated percarbonate particles, such as percarbonate coated with carbonate salt, sulphate salt, silicate salt, borosilicate salt, or any combination thereof, perborate particles, bleach catalyst particles such as transition metal bleach catalyst particles, or oxaziridinium-based bleach catalyst particles, pre-formed peracid particles, especially coated pre-formed peracid particles, and co-bleach particles of bleach activator, source of hydrogen peroxide and optionally bleach catalyst; bleach activator particles such as oxybenzene sulphonate bleach activator particles and tetra acetyl ethylene diamine bleach activator particles; chelant particles such as chelant agglomerates; hueing dye particles; brightener particles; enzyme particles such as protease prills, lipase prills, cellulase prills, amylase prills, mannanase prills, pectate lyase prills, xyloglucanase prills, bleaching enzyme prills, cutinase prills and co-prills of any of these enzymes; clay particles such as montmorillonite particles or particles of clay and silicone; flocculant particles such as polyethylene oxide particles; wax particles such as wax agglomerates.

[0036] Preferably, such detergent particles are surfactant particles containing from about 10 wt% to about 90 wt%, preferably from about 15 wt% to about 80 wt%, more preferably from about 20 wt% to about 70 wt%, of a surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, and combinations thereof. Preferably, the detergent particles of the present invention comprise an anionic surfactant and / or a nonionic surfactant.

[0037] The detergent particles may be characterized by a Median Weight Particle Size (Dw50) of from about 250 µm to about 1000 µm, preferably from about 300 µm to about 950 µm, more preferably from about 400 µm to about 850 µm.

[0038] Preferably, such detergent particles have a white or light-colored appearance, while the perfume particles have a blue, green, yellow, orange, pink, red, purple or grey color so that they are visually contrasting with the detergent particles.Particulate Laundry Detergent Composition

[0039] In addition to the perfume particles and detergent particles described hereinabove, the particulate laundry detergent composition of the present invention may comprise one or more detergent ingredients. Suitable detergent ingredients include: detersive surfactants including anionic detersive surfactants, non-ionic detersive surfactants, cationic detersive surfactants, zwitterionic detersive surfactants, amphoteric detersive surfactants, and any combination thereof; polymers including carboxylate polymers, polyethylene glycol polymers, polyester soil release polymers such as terephthalate polymers, amine polymers, cellulosic polymers, dye transfer inhibition polymers, dye lock polymers such as a condensation oligomer produced by condensation of imidazole and epichlorhydrin, optionally in ratio of 1:4:1, hexamethylenediamine derivative polymers, and any combination thereof; builders including zeolites, phosphates, citrate, and any combination thereof; buffers and alkalinity sources including carbonate salts and / or silicate salts; fillers including sulphate salts and bio-filler materials; bleach including bleach activators, sources of available oxygen, pre-formed peracids, bleach catalysts, reducing bleach, and any combination thereof; chelants; photobleach; hueing agents; brighteners; enzymes including proteases, amylases, cellulases, lipases, xylogucanases, pectate lyases, mannanases, bleaching enzymes, cutinases, and any combination thereof; fabric softeners including clay, silicones, quaternary ammonium fabric-softening agents, and any combination thereof; flocculants such as polyethylene oxide; perfume including starch encapsulated perfume accords, perfume microcapsules, perfume loaded zeolites, schif base reaction products of ketone perfume raw materials and polyamines, blooming perfumes, and any combination thereof; aesthetics including soap rings, lamellar aesthetic particles, geltin beads, carbonate and / or sulphate salt speckles, colored clay, and any combination thereof: and any combination thereof.

[0040] In a preferred embodiment of the present invention, the particulate laundry detergent composition comprises one or more builders (not including the carbonate as described hereinabove) in the amount ranging from about 1 wt% to about 40 wt%, typically from 2 wt% to 25 wt%, or even from about 5 wt% to about 20 wt%, or from 8 wt to 15 wt% by total weight of such composition. Builders as used herein refers to any ingredients or components that are capable of enhancing or improving the cleaning efficiency of surfactants, e.g., by removing or reducing "free" calcium / magnesium ions in the wash solution to "soften" or reducing hardness of the washing liquor.

[0041] It is particularly desirable that such particulate laundry detergent composition has relatively low levels of phosphate builder, zeolite builder, and silicate builder. Preferably, it contains at most 15 wt% by weight of phosphate builder, zeolite builder, and silicate builder in total. More preferably, such particulate laundry detergent composition contains from 0 wt% to about 5 wt% of phosphate builder, from 0 wt% to about 5 wt% of zeolite builder, and from 0 wt% to about 10 wt% of silicate builder, while the total amounts of these builders add up to no more than 10 wt% by total weight of the composition. Still more preferably, the particulate laundry detergent composition contains from 0 wt% to about 2 wt% of phosphate builder, from 0 wt% to about 2 wt% of zeolite builder, and from 0 wt% to about 2 wt% of silicate builder, while the total amounts of these builders add up to no more than 5 wt% by total weight of the composition. Most preferably, the particulate laundry detergent composition contains from 0 wt% to about 1 wt% of phosphate builder, from 0 wt% to about 1 wt% of zeolite builder, and from 0 wt% to about 1 wt% of silicate builder, while the total amounts of these builders add up to no more than 2 wt% by total weight of the composition. The composition may further comprise any other supplemental builder(s), chelant(s), or, in general, any material which will remove calcium ions from solution by, for example, sequestration, complexation, precipitation or ion exchange. In particular, the composition may comprise materials having at a temperature of 25°C and at a 0.1M ionic strength a calcium binding capacity of at least 50 mg / g and a calcium binding constant log K Ca 2+< of at least 3.50.

[0042] The particulate laundry detergent composition of the present invention may contain one or more solid carriers selected from the group consisting of sodium chloride, potassium chloride, sodium sulphate, and potassium sulphate. In a preferred, but not necessary embodiment, such particulate laundry detergent composition includes from about 20 wt% to about 65 wt% of sodium chloride and / or from about 20 wt% to about 65 wt% of sodium sulphate. When the particulate laundry detergent composition is in a concentrated form, the total amount of sodium chloride and / or sodium sulphate in such composition may sum up, for example, to a total amount of from about 0 wt% to about 60 wt%.Methods of Using the Particulate Laundry Detergent Composition

[0043] The particulate laundry detergent composition of the present invention is typically used for cleaning and / or treating fabrics. It can be used for machine-washing fabrics (using either top-loading or front-loading washing machines, which can be either fully automatic or semi-automatic) as well as hand-washing fabrics, but it is particularly suitable for hand-washing fabrics. Such hand-washing method may include the steps of: (a) providing a particulate laundry detergent composition as described hereinabove;(b) forming a laundry liquor by diluting the particulate detergent composition with water at a weight ratio of from about 1:100 to 1:1000; (c) hand-washing fabrics in the laundry liquor; and (d) rinsing the fabric with water, while during step (c), the perfume particles or an undissolved portion thereof are used for treating a selected area of the fabrics. As a result, the consumers can readily appreciate an enhanced freshness experience during such hand-washing process.

[0044] The laundry liquor pH is chosen to be the most complimentary to the fabrics to be cleaned spanning broad range of pH, e.g., from about 5 to about 11, preferably from about 8 to about 10. The composition is preferably employed at concentrations of from about 200 ppm to about 15,000 ppm in solution. The water temperatures preferably range from about 5 °C to about 100 °C. The water to fabric ratio is typically from about 1:1 to about 30:1.

[0045] The wash liquor may comprise 40 litres or less of water, or 30 litres or less, or 20 litres or less, or 10 litres or less, or 8 litres or less, or even 6 litres or less of water. The wash liquor may comprise from above 0 to 15 litres, or from 2 litres, and to 12 litres, or even to 8 litres of water. For dilute wash conditions, the wash liquor may comprise 150 litres or less of water, 100 litres or less of water, 60 litres or less of water, or 50 litres or less of water, especially for hand-washing conditions, and can depend on the number of rinses.

[0046] Typically, from 0.01 Kg to 2 Kg of fabric per litre of wash liquor is dosed into the wash liquor. Typically, from 0.01 Kg, or from 0.05 Kg, or from 0.07 Kg, or from 0.10 Kg, or from 0.15 Kg, or from 0.20 Kg, or from 0.25 Kg fabric per litre of wash liquor is dosed into the wash liquor.

[0047] Optionally, 50 g or less, or 45 g or less, or 40 g or less, or 35 g or less, or 30 g or less, or 25 g or less, or 20 g or less, or even 15 g or less, or even 10 g or less of the composition is contacted to water to form the wash liquor.TEST METHODS

[0048] The following techniques must be used to determine the properties of the perfume particles, the detergent particles, and the particulate laundry detergent compositions of the invention in order that the invention described and claimed herein may be fully understood.Test 1: Dissolution Rate Test

[0049] The Dissolution Rate Test is used to measure the speed of dissolution of the particles.

[0050] This test is conducted by adding 400ml of de-ionized water into a 400ml transparent glass beaker at room temperature (25°C), then dispersing about 1 gram of test particles into the deionized water. Use stop watch to count the total time needed before the particles are fully dissolved.Test 2: Sieve Test

[0051] This test method is used herein to determine particle size distribution of the detergent particles of the present invention. The particle size distribution of the detergent particles is measured by sieving the particles through a succession of sieves with gradually smaller dimensions. The weight of material retained on each sieve is then used to calculate a particle size distribution.

[0052] This test is conducted to determine the Median Particle Size of the subject particle using ASTM D 502 - 89, "Standard Test Method for Particle Size of Soaps and Other Detergents", approved May 26, 1989, with a further specification for sieve sizes used in the analysis. Following section 7, "Procedure using machine-sieving method," a nest of clean dry sieves containing U.S. Standard (ASTM E 11) sieves #8 (2360 µm), #12 (1700 µm), #16 (1180 µm), #20 (850 µm), #30 (600 µm), #40 (425 µm), #50 (300 µm), #70 (212 µm), and #100 (150 µm) is required. The prescribed Machine-Sieving Method is used with the above sieve nest. The detergent granule of interest is used as the sample. A suitable sieve-shaking machine can be obtained from W.S. Tyler Company of Mentor, Ohio, U.S.A. The data are plotted on a semi-log plot with the micron size opening of each sieve plotted against the logarithmic abscissa and the cumulative mass percent (Q3) plotted against the linear ordinate.

[0053] An example of the above data representation is given in ISO 9276-1:1998, "Representation of results of particle size analysis - Part 1: Graphical Representation", Figure A.4. The Median Weight Particle Size (Dw50) is defined as the abscissa value at the point where the cumulative weight percent is equal to 50 percent, and is calculated by a straight line interpolation between the data points directly above (a50) and below (b50) the 50% value using the following equation: D w 50 = 10 Log D a 50 − Log D a 50 − Log D b 5 o * Q a 5 o − 50 % / Q a 50 − Q bso where Q a50 and Q b50 are the cumulative weight percentile values of the data immediately above and below the 50 th< percentile, respectively; and D a50 and D b50 are the micron sieve size values corresponding to these data. In the event that the 50 th< percentile value falls below the finest sieve size (150 µm) or above the coarsest sieve size (2360 µm), then additional sieves must be added to the nest following a geometric progression of not greater than 1.5, until the median falls between two measured sieve sizes.Test 3: Particle aspect ratio

[0054] For non-spherical particles, the particle's longest dimension and shortest dimension can be measured by using Vernier calipers. To reduce the variation of the data, typically 10 particles can be measured and then use the average result. The particle aspect ratio herein is calculated by using this formula: Aspect ratio = Longest dimension / Shortest dimension.Test 4: Segregation test

[0055] Prepare 600g normal laundry detergent powder sample which contains desired target percentage of particles of different shapes. Mix the above-mentioned powder detergent in a rocking mixer for 5 mins, then discharge it to a plastic bag.

[0056] Use a lab sampler (CAPCO rotary whole-stream sample divider) to split the powder sample into 6 x 100g sub-samples.

[0057] Put each 100g sub-sample in a plastic bag, followed by mixing each sub-sample by hand along a tumbling figure-eight motion for one minute. Provide two stainless steel conical-shape funnels. The angle between the side wall of the funnels and the vertical direction is about 55 degrees. The bottom of each of the funnels has a round-shape hole with a diameter of about 3 cm and a moveable slide gate valve (stopper) to block / stop the flow. The top funnel is placed about 10cm above the bottom funnel, while each funnel has an approximate volume of about 1.5 liters. Block the outlet of the top funnel with the stopper, and pour one 100g sub-sample into the funnel. Block the outlet of the lower funnel with the stopper and allow the sub-sample to flow from the upper funnel to the lower funnel. Allow the sub-sample to then flow from the lower funnel into a small beaker ("the 1 st< beaker") until the total weight of the sub-sample in the 1 st< beaker reaches around 25 + / - 3g. Stop the sample flow from the lower funnel, and place another beaker ("the 2 nd< beaker") underneath the 1 st< beaker. Repeat the above steps to allow the sub-sample to flow from the lower funnel into the 2 nd< beaker until the total weight of the sub-samples in the 2 nd< beaker reaches around 25 + / - 3g. Repeat the above steps to fill 4 beakers with 4 x 25g of the sub-sample.

[0058] Then put another 100g sub-sample to the top funnel, repeat the above steps to collect another 4 x 25g of the sub-sample from the bottom of the lower funnel.

[0059] After all 6 x 100g sub-samples have been processed, measure the weight of sub-samples in each beaker, select the ones have sub-sample weights within the pre-defined 25+ / -3g limits, then sieve out and weigh the shaped particles in each sub-sample.

[0060] Calculate the shaped particles wt% as = shape particles weight / total sub-sample weight. Calculate the standard deviation and relative standard deviation (RSD) of the shape particles wt% in all sub-samples, while RSD is calculated as = Standard deviation of shape particle wt% / Average shape particle wt%.EXAMPLESExample 1: Comparative Test Showing Enhanced Freshness Experience

[0061] An inventive particulate laundry detergent formulation containing about 11.1 wt% of red perfume particles and about 88.9 wt% of detergent particles is provided. The red perfume particles in turn contain about 87.5 wt% of PEG 9000, about 9.2 wt% of free perfumes, about 1.2 wt% of friable perfume microcapsules, and balance of dyes and water. The red perfume particles all have a compressed hemispherical shape with a base diameter of about 5 mm to about 6 mm and an aspect ratio of about 2.2 to 2.3, and they are characterized by a dissolution rate of no less than 10 minutes as measured in deionized water at 25°C.

[0062] A comparative particulate laundry detergent formulation is also provided, which contains about 97.32 wt% of the same detergent particles, about 1.30 wt% of aesthetic particles (nil perfume) of pink, red or green colors, about 1.02 wt% of the same free perfume, and about 0.36 wt% of the same friable perfume microcapsules. The total levels of free perfume and friable perfume microcapsules are the same in the inventive and comparative compositions.

[0063] The inventive and comparative compositions are given to two consumer panels of 8 panelists each for a one-week hand-wash use study. At the end of the week, the panelists are called back to provide their feedback on the freshness experience of using these two samples. The inventive particulate detergent composition is rated significantly higher than the comparative particulate laundry detergent formulation in the overall freshness experience from start to finish of the laundering process and the overall enjoyability of the laundering process.Example 2: Comparative Test Showing Reduced Segregation

[0064] A first inventive particulate laundry detergent formulation containing about 5 wt% of first perfume particles and about 95 wt% of detergent particles is provided. Each of the first perfume particles has a compressed hemispherical shape with a base diameter of about 5.5 mm and an aspect ratio of about 2.3. Compositional breakdown of these first perfume particles is the same as those in Example 1.

[0065] A second comparative particulate laundry detergent formulation containing about 5 wt% of second particles and about 95 wt% of detergent particles is also provided. Each of the second particles has a spherical shape with a diameter of about 3.4 mm and an aspect ratio of about 1.

[0066] Segregation of the first and second compositions is measured by taking multiple samples (25±3 grams each) of said first or second compositions and then measure the actual wt% of said first or second perfume particles in each sample. The greater the wt% variations from sample to sample, the more severe the segregation. The measurement results are summarized as follows: TABLE 11 st< Inventive Composition2 nd< CompositionPerfume particle shapeCompressed hemisphericalSphericalTarget perfume particle wt%5%5%Count of sub-samples (about 25 ± 3 grams each)712Average wt% of perfume particles (measured from samples)5.395.01Standard Deviation of wt%0.731.51Relative SD of wt%13.54%30.20%

[0067] The first inventive composition containing perfume particles of compressed hemispherical shape exhibits significantly less segregation than the second composition containing spherical particles.

Claims

1. A particulate laundry detergent composition comprising a major proportion of detergent particles and a minor proportion of perfume particles, wherein each of said perfume particles have a longest dimension of no less than 3 mm and an aspect ratio of no more than 5, and wherein said perfume particles are characterized by a dissolution rate of no less than 8 minutes as measured in deionized water at 25°C, wherein each of said perfume particles has a hemispherical or compressed hemispherical shape, wherein said perfume particles are characterized by a density ranging from 0.5 g / cm3 to 0.98 g / cm3 and wherein each of said perfume particles have a longest dimension ranging from 3 mm to 10 mm, and an aspect ratio from 1 to 5, wherein said perfume particles are essentially free of surfactants, wherein each of said perfume particles comprises from 0.1 wt% to 20 wt% of a perfume ingredient; wherein said perfume ingredient is selected from the group consisting of free perfumes, pro-perfumes, encapsulated perfumes, perfume microcapsules, and combinations thereof, wherein each of said perfume particles further comprises from 5 wt% to 99.9 wt% of polyethylene glycol; wherein said polyethylene glycol has a weight average molecular weight (Mw) from 2,000 to 20,000 Daltons.

2. The particulate laundry detergent composition of claim 1, wherein each of said perfume particles further comprises from 0.0001 wt% to 1 wt%, preferably from 0.001 wt% to 0.5 wt%, more preferably from 0.005 wt% to 0.1 wt% of a colorant; wherein preferably said colorant is selected from the group consisting of dyes, pigments, and combinations thereof.

3. The particulate laundry detergent composition according to any one of the preceding claims, wherein said perfume particles are present in an amount ranging from 0.1% to 30%, preferably from 0.5% to 20%, more preferably from 1% to 15%, by total weight of said particulate laundry detergent composition.

4. The particulate laundry detergent composition according to any one of the preceding claims, wherein each of said detergent particles comprises from 10 wt% to 90 wt% of a surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, and combinations thereof; and wherein preferably said detergent particles are characterized by a Median Weight Particle Size (Dw50) ranging from 250µm to 1000µm.

5. The particulate laundry detergent composition according to any one of the preceding claims, wherein said detergent particles are present in an amount ranging from 50% to 99.9%, preferably from 55% to 99.5%, more preferably from 60% to 99%, by total weight of said particulate laundry detergent composition.

6. The particulate laundry detergent composition according to any one of the preceding claims, wherein said detergent particles have a white or light-colored appearance; wherein the perfume particles are visually contrasting with said detergent granules, and preferably said perfume particles are colored in blue, green, yellow, orange, pink, red, purple, or grey.

7. The particulate laundry detergent composition according to any one of the preceding claims, wherein said perfume particles are present in an amount ranging from 1% to 15% by total weight of said particulate laundry detergent composition, and wherein each of said perfume particles has a hemispherical or a compressed hemispherical shape and is characterized by: (a) a longest dimension ranging from 4 mm to 9 mm; (b) an aspect ratio ranging from 2 to 4; and (c) a density ranging from 0.8 g / cm3 to 0.9 g / cm3.

8. Use of the particulate laundry detergent composition according to any one of the preceding claims for hand-washing fabrics.

9. A method of using the particulate detergent composition according to any one of the preceding claims for hand-washing fabrics, comprising the steps of: (a) providing said particulate detergent composition; (b) forming a laundry liquor by diluting the particulate detergent composition with water at a weight ratio of from about 1:100 to 1: 1000; (c) hand-washing fabrics in the laundry liquor; and (d) rinsing the fabric with water, wherein during step (c), the perfume particles or an undissolved portion thereof are used for treating a selected area of the fabrics.