Solid detergent composition

Abstract

The present invention relates to the field of solid detergent composition, especially solid detergent agglomerated composition. The present inventors have found that when a solid detergent composition includes an agglomerate particle having a surfactant, silica, and alkali metal silicate then the composition provides an agglomerate detergent particle which has low bulk density having good powder sensorial. The powder is free flowing and maintains its free-flowing properties and is anticaking over extended storage periods. The agglomerate particle also has good powder color.

Description

[0001] Solid detergent composition

[0002] Field of the Invention

[0003] The present invention relates to the field of solid detergent composition, especially solid agglomerated detergent composition.

[0004] Background of the Invention

[0005] Laundry detergent composition in the form of powers or granules are widely used. There are two primary types of processes by which detergent granules or powders can be prepared. The first type of process involves spray-drying an aqueous detergent slurry in a spray-drying tower to produce highly porous detergent granules. In the second type of process, the various detergent components are dry mixed after which they are preferably agglomerated with a binder such as a nonionic or anionic surfactant. The second process is generally referred to as a nontower process.

[0006] The spray-drying process is widely used as it provides good quality powders. However, the spray-drying process has certain disadvantages such as the process is not cost-effective, it is an energy intensive process and less amenable to environmental conditions as it tends to emit particulate and volatile organic compounds into the atmosphere.

[0007] The non-tower process on the other hand is economical and flexible and a variety of detergent composition can be produced in the process and is also more amenable to environmental conditions. However, the disadvantage of a non-tower process is that powder produced by this process involves high levels of fillers and has a higher bulk density compared to spray-dried powders.

[0008] It is thus desired to provide a laundry detergent particle and a solid laundry detergent composition thereof which has a low bulk density, is crisp, free-flowing while being produced by a process which is cost-effective and environmentally amenable.

[0009] Some work in this direction has been carried out in the past. One such agglomerate particle is disclosed in European patent application EP 0915959 B1 (2001, P&G) which discloses a process for preparing a low-density detergent composition having the step of agglomerating a liquid acid precursor with silica material and an alkaline inorganic material to form agglomerates having density less than 500g / L.

[0010] Agglomerate detergent particles with lower bulk density of 600g / L have been prepared in the past. However, these powder are susceptible to crushing and damage during transit and storage. This results in a change in their bulk density and the appearance as the powder appears to have higher levels of fine dust-like particle which are not preferred by the consumers and have health impact.

[0011] More recently, EP 2123743 A1 (P&G, 2009) discloses a low bulk density agglomerate having light density silicate with BD 120g / L and average particle size 240 micrometers. This solid laundry detergent composition typically has a cake strength of from 5N to 20N.

[0012] However, it is still desired to provide agglomerate laundry detergent particle with low bulk density having good powder sensorial. The consumer correlates the colour and the brightness of the powder to its performance.

[0013] There is a need to provide agglomerate detergent particles having higher surfactant activity and low moisture content which can preferably be prepared by a dry neutralization process without subsequent drying steps.

[0014] It is also desired to provide an agglomerate detergent particle and a detergent composition having a reduced amount of oversized particle which are undesirable and may require further steps of size reduction.

[0015] Summary of the Invention

[0016] The present inventors have found that when an agglomerate detergent particle has a first region and a second region where the second region is at least partially enveloping the first region, and where the first region has a first composition which includes the detersive anionic surfactant and the second region has a second composition different from the first composition and where the second composition includes silicate and silica it provides an agglomerate detergent particle which provides lower bulk density, improved powder strength, and shelf life while maintaining good powder properties for prolonged periods. The agglomerated detergent particle also does not change its particle size during transit and storage due to the strength of the particle, more particularly the second region maintains good particle structure. The laundry detergent composition comprising the agglomerate detergent particle also has lower bulk density, improved powder strength and shelf life while maintaining good powder properties.

[0017] The present inventors have found that the alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 4, still preferably from 2 to 3.5 where M represents an alkali metal, more preferably where M is sodium provides at least one or more of the above-mentioned benefits. Preferably the alkali metal silicate has desired bulk density, liquid carrying capacity, and porosity.

[0018] According to a first aspect of the present invention disclosed is an agglomerate detergent particle comprising: i. 1 wt.% to 40 wt.% anionic surfactant; ii. 0 wt.% to 25 wt.% alkali metal carbonate; iii. 3 wt.% to 10 wt.% silica; iv. 5 wt.% to 30 wt.% alkali metal silicate; and, wherein the alkali metal silicate has a molar ratio of SiC>2 to M2O ranging from 2 to 4 where the M represents an alkali metal, and wherein the agglomerate detergent particle has a first region and second region, where the second region is at least partially enveloping the first region.

[0019] The term "bulk density" as used herein refers to the uncompressed, untapped powder bulk density, as measured by the Bulk Density Test specified hereinafter.

[0020] The term "particle size distribution" as used herein refers to a list of values or a mathematical function that defines the relative amount, typically by mass or weight, of particles present according to size, as measured by the Sieve Test specified hereinafter.

[0021] As used herein, the term "substantially neutralized" refers to at least 95 wt.% neutralization of the acid precursor of anionic surfactant, more preferably the HLAS.

[0022] As used herein, the term "substantially free of” means that that the specific ingredient is present in an amount less than 0.1 wt.% in the composition. As used herein, the term “non-tower route” means a process for preparing the agglomerate detergent particle by dry mixing the ingredients rather than the slurry process in a spray-drying tower, it may however include ingredients which themselves are prepared by a spray-drying method.

[0023] As used herein, the term "agglomerate" refers to particles formed by agglomerating detergent granules or particles which typically have a smaller mean particle size than the formed agglomerates.

[0024] Detailed Description of the Invention

[0025] According to the first aspect, the present invention provides an agglomerate detergent particle.

[0026] Agglomerate detergent particle

[0027] Disclosed agglomerate detergent particle includes anionic surfactant, 0 wt.% to 25 wt.% alkali metal carbonate, silica, alkali metal silicate and the agglomerate particle has a first region and a second region where the second region is at least partially enveloping the first region.

[0028] Detersive surfactant

[0029] Disclosed agglomerated detergent particle includes from 1 wt.% to 40 wt.% anionic surfactant. Still preferably the anionic surfactant includes at least those which exists in their acid precursor form and may be neutralized to their salt form in presence of an alkaline material, preferably the alkaline material comprises an alkali metal silicate, alkali metal carbonate or mixtures thereof, still more preferably alkali metal silicate. The surfactant may preferably include further detersive surfactant selected from the group consisting of cationic surfactant, amphoteric surfactant, zwitterionic surfactant, nonionic surfactant, or combinations thereof.

[0030] Anionic surfactant:

[0031] Examples of anionic surfactant are given in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). Suitable anionic surfactants include those selected from the group consisting of alkyl sulfates, alkyl sulfonates, alkylaryl sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkyl sulfosuccinamates, alkyl amidosulfosuccinates, alkyl carboxylates, alkyl amido ether carboxylates, alkyl succinates, fatty acyl sarcosinates, fatty acyl amino acids, fatty acyl taurates, fatty alkyl sulfoacetates, alkyl phosphates, and mixtures of two or more thereof. Non-limiting examples of the preferred anionic surfactant includes linear alkyl benzene sulphonate, primary alkyl sulfate, methyl ester sulphonate or combinations thereof.

[0032] Sulphate surfactant:

[0033] Suitable sulphate surfactant includes Cs to C20 alkyl sulphate, preferably Cs to C18 alkyl sulphate, still preferably C12 to C14 alkyl sulphate, more preferably it is predominantly C12 alkyl sulphate. The alkyl sulphate surfactant may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. Preferably the alkyl sulphate surfactant is linear. Still preferably it is preferred that the alkyl sulphate surfactant is a C10 to C14 alkyl sulphate surfactant, most preferably a lauryl sulphate surfactant.

[0034] Conventional primary alkyl sulfate surfactant has the general formula: R"OSOs'M+wherein R" is typically a Cs to C20 alkyl group, which may be straight chain or branched chain, and M is a water-solubilizing cation. In specific embodiments, R" is a C10 to C15 alkyl group, and M is alkali metal, more specifically R" is C12 to C14 alkyl and M is sodium. Specific, non-limiting examples of anionic alkyl sulphate surfactant useful herein include: C10 to C20 primary, branched-chain and random alkyl sulfates (AS); or C10 to Cis secondary (2,3)-alkyl sulfates having following formulae: wherein M is hydrogen or a cation which provides charge neutrality, and all M units, can either be a hydrogen atom or a cation depending upon the form isolated or the relative pH of the system wherein the surfactant is used, with non-limiting examples of preferred cations including sodium, potassium, ammonium, and mixtures thereof, and x is an integer of at least about 7, preferably at least about 9, and y is an integer of at least 8, preferably at least about 9.

[0035] A preferred sulphate surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a Cs to Cis is alkyl alkoxylated sulphate, preferably a Cs to Cis alkyl ethoxylated sulphate, preferably the alkyl alkoxylated sulphate has an average degree of alkoxylation of from 0.5 to 20, preferably from 0.5 to 10, preferably the alkyl alkoxylated sulphate is a Cs to Cis alkyl ethoxylated sulphate having an average degree of ethoxylation of from 0.5 to 10, preferably from 0.5 to 5, more preferably from 0.5 to 3 and most preferably from 0.5 to 1.5. The alkyl alkoxylated sulphate surfactant may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. Preferably the sulphate surfactant is a linear or branched, substituted or unsubstituted Cs to Cis alkyl sulphate surfactant, Cs to Cis alkyl ether sulphate surfactant or mixtures thereof.

[0036] Sulphonate surfactant:

[0037] Suitable sulphonate anionic surfactant include methyl ester sulphonate, alpha olefin sulphonates, alkyl aryl sulphonate, especially alkyl benzene sulphonate, preferably Cw to C14 alkyl benzene sulphonate. Suitable alkyl benzene sulphonate (LAS) is obtainable, preferably obtained, by sulphonating commercially available linear alkyl benzene (LAB); suitable LAB includes low 2-phenyl LAB, other suitable LAB includes high 2-phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®. The sulphonate surfactant may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. The sulphonate surfactant is preferably a linear or branched, substituted or unsubstituted C to C14 alkyl benzene sulphonate. The sulphonate surfactant may also be selected from the modified alkylbenzene sulfonate (MLAS) as discussed in WO 99 / 05243, WO 99 / 05242, and WO 99 / 05244; methyl ester sulfonate (MES); and alpha-olefin sulfonate (AOS). Preferably the sulphonate surfactant is a Cw to C20 linear alkyl benzene sulphonate surfactant.

[0038] Anionic surfactants may exist in an acid form and the acid form may be neutralized to form a surfactant salt. Preferably the anionic surfactant includes a mixture of

[0039] Cw to C20 linear alkyl benzene sulphonate surfactant and Cw to C20 linear or branched alkylethoxy sulfate surfactant.

[0040] Preferably the anionic surfactant is a non-soap anionic surfactant. The term “soap” is used herein in its popular sense, i.e. , the alkali metal or alkanol ammonium salts of aliphatic, alkanes, or alkene monocarboxylic acids.

[0041] In an agglomeration process, the first ingredients added are typically concentrated into the interior of the particle, with subsequently added ingredients appearing on concentric, successive outer layers of the particle. Due to the specific choice of the levels and type of alkali metal silicate, and preferably the alkali metal carbonate, and preferably the zeolite in the agglomerate particle and preferably where in the present process substantially all of the acid precursor of the detersive surfactant is added onto to the alkali metal silicate, preferably along with one or more of the alkali metal carbonate and the zeolite in the mixer ensuring that the agglomerate particle has 95 parts to 100 parts of the acid precursor of the anionic surfactant present in the interior of the agglomerated particle which is neutralized immediately. Without wishing to be bound by any theory it is believed that the agglomerate detergent particle of the present invention having the anionic surfactant in a first region which is formed by almost complete neutralization of the acid precursor of the detersive surfactant in the agglomerate detergent particle and where preferably not more than 5 parts of the acid precursor of the anionic surfactant is present on the exterior of the agglomerate particle this ensure that the agglomerate detergent particle requires very little to no further addition of fillers and layering agents and thus provides an agglomerate detergent particle which has low bulk density and is also having good flow properties and extended storage life without any undue caking issues during storage.

[0042] Preferably during the agglomeration process the anionic surfactant which is in the form of an acid precursor of the anionic surfactant comes in contact with an excess of alkali metal silicate where the alkali metal silicate has a molar ratio of SiC>2 to M2O ranging from 2 to 4 to form the in-situ silica. Preferably in the agglomerate detergent particle the silica is predominantly present in the second region.

[0043] Preferably the agglomerated detergent particle of the present invention includes from 1 wt.% to 40 wt.% of anionic surfactant, most preferably from 2 wt.% to 35 wt.% anionic surfactant. Preferably the agglomerated detergent particle comprises at least 4 wt.%, still preferably at least 5 wt.%, still preferably at least 8 wt.%, still preferably at least 10 wt.%, still more preferably at least 12 wt.% of the anionic surfactant, most preferably at least 15 wt.% of the anionic surfactant, but typically not more than 38 wt.%, still preferably not more than 35 wt.%, still further preferably not more than 30 wt.%, still more preferably not more than 28 wt.% and most preferably not more than 25 wt.%, still more preferably not more than 20 wt.% of an anionic surfactant based on the weight of the agglomerated detergent particle.

[0044] Non-ionic surfactant:

[0045] Preferably the agglomerate detergent particle may include non-ionic surfactant. Non-limiting examples of nonionic surfactants include: C12 to C18 alkyl ethoxylates, Ce to C12 alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units; C12 to Cis alcohol and Ce to C12 alkyl phenol condensates with ethylene oxide / propylene oxide block alkyl polyamine ethoxylates alkyl polysaccharides and ether capped poly(oxyalkylated) alcohol surfactants. Preferably the nonionic surfactant is branched or linear non-ionic surfactant. Cationic surfactant:

[0046] Preferably the agglomerate detergent particle may include a cationic surfactant. Non-limiting examples of cationic surfactants include: the quaternary ammonium surfactants, which can have up to 26 carbon atoms include: alkoxylate quaternary ammonium (AQA) surfactants, dimethyl hydroxyethyl quaternary ammonium, dimethyl hydroxyethyl lauryl ammonium chloride; polyamine cationic surfactants and cationic ester surfactants.

[0047] Amphoteric surfactant:

[0048] Preferably the agglomerate detergent particle may include an amphoteric surfactant.

[0049] As used herein, the term “amphoteric” includes (a) surfactant molecules that contain both an acidic and basic site such as, for example, an amino acid containing both amino (basic) and acid (e.g., carboxylic acid, acidic) functional groups; or (b) zwitterionic surfactant molecules which possess both positive and negative charges within the same molecule. The charges of the zwitterionic molecule may be either dependent or independent of the pH of the composition. The term “amphoteric surfactant,” as used herein, is also intended to encompass zwitterionic surfactants, which are well known to formulators skilled in the art as a subset of amphoteric surfactants.

[0050] Non-limiting examples of amphoteric surfactants useful in the composition of the present invention are disclosed in McCutcheon's, Detergents and Emulsifiers, North American edition (1986), published by allured Publishing Corporation; and McCutcheons, Functional Materials, North American Edition (1992); both of which are incorporated by reference herein in their entirety.

[0051] Examples of amphoteric surfactant suitable for use in the present invention include, but are not limited to, amphocarboxylates such as alkylamphoacetates (mono or di); alkyl betaines; alkylamidoalkyl betaines; alkylamidoalkyl sultaines; alkylamphophosphates; phosphorylated imidazolines such as phosphobetaines and pyrophosphobetaines; carboxyalkyl alkyl polyamines; alkylimino-dipropionates; alkylamphoglycinates (mono or di); alkylamphoproprionates (mono or di); N-alkyl [3-aminoproprionic acids; alkylpolyamino carboxylates; and mixtures thereof. Specific examples of the amphoteric surfactant include those given hereinbelow.

[0052] The amphoteric surfactant is preferably selected from the group consisting of betaines, sultaines, amine oxide or mixtures thereof. Preferably the betaines includes alkyl betaines, alkylamidoalkyl betaines, alkyl phosphobetaines, alkyl sulphobetaines, alkyl sultaines, alkyl hydroxy sultaines, alkylamidoalkyl sultaines, alkylamidoalkyl hydroxy sultaines, alkyl amine oxide, alkylamidoalkyl amine oxide, alkyl iminoacetates, imino dialkanoates, amino alkanoates alkyl ammonium propionates, or mixtures thereof. More preferably the amphoteric surfactant are betaines or amine oxide. Preferably the betaine type amphoteric surfactant is selected from alkyl betaines, alkylamidoalkyl betaines and alkyl sulphobetaines. Preferably the amine oxide type amphoteric surfactant is selected from alkyl amine oxide, alkylamidoalkyl amine oxide or mixtures thereof. Most preferably the amphoteric surfactant is a cocamidopropyl betaine (CAPB).

[0053] Preferably 100% of the anionic surfactant present in the agglomerate detergent particle is prepared in-situ by neutralizing the corresponding acid precursor of the anionic surfactant, more preferably at least 95% of the anionic surfactant in the agglomerate detergent particle is prepared in-situ by neutralizing the acid precursor of the anionic surfactant with the alkali metal silicate. Preferably the anionic surfactant is a non-soap anionic surfactant. Non-limiting examples includes sulphonate surfactant, sulfate surfactant, alkoxylated sulphate surfactant or mixtures thereof. A particularly preferred sulphonate surfactant is an alkyl benzene sulphate surfactant, still preferably linear alkyl benzene sulphonate surfactant.

[0054] Preferably the amount of anionic soap based detersive surfactant in the agglomerate detergent particle according to the present invention is from 0 wt.% to 10 wt.%, still preferably from 0 wt.% to 5 wt.% and further preferably from 0 wt.% to 3 wt.% and most preferably from 0 wt.% to 1 wt.% based on the weight of the agglomerate detergent particle. The term "soap" is used herein in its popular sense, i.e. , the alkali metal or alkanol ammonium salts of aliphatic, alkane or alkene monocarboxylic acids. The soap may be from any of the triglycerides conventionally used in soap manufacture. Preferably the carboxylate anion in the soap may contain from 8 to 22 carbon atoms, more preferably from 12 to 18 carbon atom fatty acids. The alkali metal or alkanol ammonium salt being preferably selected from sodium, potassium, magnesium, mono-, di- and tri-ethanol ammonium cations, or combinations thereof. Alkali metal silicate

[0055] Disclosed agglomerate detergent particle includes from 5 wt.% to 30 wt.% alkali metal silicate where the alkali metal silicate has a molar ratio of SiC>2 to M2O ranging from 2 to 4 wherein the M represents an alkali metal, more preferably sodium. Still preferably the alkali metal silicate has a molar ratio SiC>2 to M2O ranging from 2 to 3.5, still more preferably from 2 to 3.35, still preferably from 2 to 2.6, more preferably the alkali metal silicate has a molar ratio SiC>2 to M2O ranging from 2.05 to 3.5, still more preferably from 2.05 to 3.35, still preferably from 2.05 to 2.6. Preferably the alkali metal silicate is a water-soluble silicate salt. More preferably the alkali metal silicate is sodium silicate.

[0056] The alkali metal silicate is preferably in solid form. Still preferably the alkali metal silicate is heat dried, more preferably a spray-dried alkali metal silicate. The alkali metal silicate may be preferably in the form of powders or granules. The alkali metal silicate may also be a hydrous silicate.

[0057] Preferably the alkali metal silicate salt has an average bulk density less than 750 g / L, still preferably less than 700 g / L and preferably ranging from 80 g / L to 750 g / L, still preferably 80 g / L to 500 g / L, further preferably from 80 g / L to 200 g / L. Preferably the alkali metal silicate has a weight average bulk density ranging from 100 to 700 g / L, still more preferably from 200 g / L to 700 g / L, further preferably from 300 g / L to 700 g / L, also preferably are those with higher weight average bulk density ranging from 400 g / L to 700 g / L. Preferably the alkali metal silicate may be selected from those having lower weight average bulk density ranging from 80 g / L to 400 g / L, still preferably from 100 g / L to 400 g / L, also preferably from 200 g / L to 400 g / L, more preferably from 100 g / L to 200 g / L. Preferably the alkali metal silicate salt has a mean average particle size ranging from 80 micrometers to 250 micrometers, still preferably 90 to 250 micrometers.

[0058] Preferably the alkali metal silicate has a liquid carrying capacity of 150% and preferably the alkali metal silicate typically has the nitrogen surface area of 2.74 m2 / g and the total porosity determined at a pressure of 15,000 psi by a mercury porosimetry test of 3.18 cc. of mercury per gram of sample.

[0059] Preferably the alkali metal silicate is in a solid form, still preferably the light density silicate salt is obtainable, or obtained, by a flash-drying process, preferably a spray drying process. Preferably the agglomerate detergent particle includes from 10 wt.% to 25 wt.% alkali metal silicate, more preferably from 5 wt.% to 25 wt.% alkali metal silicate, still more preferably from 10 wt.% to 15 wt.% alkali metal silicate. Still preferably the agglomerate detergent particle includes not less than 12 wt.%, still preferably not less than 13 wt.%, still preferably not less than 15 wt.%, further preferably not less than 18 wt.% alkali metal silicate by weight of the agglomerate detergent particle. Still preferably the agglomerate detergent particle includes not more than 24 wt.%, still preferably not more than 22 wt.%, still preferably not more than 21 wt.% further preferably not more than 20 wt.% alkali metal silicate by weight of the agglomerate detergent particle.

[0060] Silica

[0061] Disclosed agglomerate detergent particle includes from 0.3 wt.% to 10 wt.% silica. Preferably from 3 wt.% to 10 wt.% silica. Preferably, the agglomerate particle includes from 3.5 wt.% to 10 wt.% silica, more preferably from 4 wt.% to 10 wt.% silica, still more preferably from 4.5 wt.% to 8 wt.% silica. Still preferably the agglomerate detergent particle includes not less than 3.5 wt.%, still preferably not less than 3.8 wt.%, still preferably not less than 4 wt.% further preferably not less than 4.5 wt.% silica by weight of the agglomerate detergent particle. Still preferably the agglomerate detergent particle includes not more than 9.8 wt.%, still preferably not more than 9.5 wt.%, still preferably not more than 8.5 wt.% further preferably not more than 8 wt.% silica by weight of the agglomerate detergent particle.

[0062] Preferably the silica as disclosed herein is formed in-situ. The in-situ formed silica involves the step of contacting an acid precursor of the detersive surfactant with the alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 4 to form in-situ silica. Preferably acid precursor of the detersive surfactant is acid precursor of alkyl aryl sulphonate surfactant, still preferably from acid precursor of linear alkyl benzene sulphonate surfactant. Preferably the acid precursor of C10 to C20 linear alkyl benzene sulphonate surfactant.

[0063] Zeolite salt

[0064] Preferably the agglomerate detergent particle includes a zeolite. Preferably the zeolite is present in a mixture along with the alkali metal silicate, still preferably the zeolite is present along with alkali metal silicate and the alkali metal carbonate which reacts with the acid precursor of the detersive surfactant. Zeolite includes zeolite A, zeolite P, zeolite 4A. Advantageously, aluminium zeolite P (zeolite MAP) described and claimed in EP 384 070A (Unilever) may be used. 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, and more preferably not exceeding 1.07. Zeolite are preferably present at relatively low levels, for example less than 5 wt.%, still preferably less than 3 wt.%, further preferably less than 1 wt.% in the agglomerate particle.

[0065] Alkali metal carbonate

[0066] Disclosed agglomerate detergent particle includes from 0 wt.% to 25 wt.% alkali metal carbonate.

[0067] Preferred alkali metal carbonate are sodium carbonate, potassium carbonate or mixtures thereof, of which sodium carbonate is particularly preferred. It is further preferred that sodium carbonate makes up at least 75 wt.%, more preferably at least 85 wt.% and even more preferably at least 90 wt.% of the total weight of the alkali metal carbonate.

[0068] More preferably the alkali metal carbonate is sodium carbonate in solid form more preferably light soda ash. Preferably the alkali metal carbonate is synthetically prepared from known process which includes the Solvay process or Hou process. The bulk density of the alkali metal carbonate is preferably from 400 Kg / m3to 800 Kg / m3, still preferably 400 Kg / m3to 800 Kg / m3, more preferably 600 Kg / m3to 800 Kg / m3, still more preferably from 600 Kg / m3to 700 Kg / m3.

[0069] Preferably the alkali metal carbonate salt is in a solid form.

[0070] Preferably the liquid acid precursor of the anionic surfactant is mixed with the alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 4 where the M represents an alkali metal, and more preferably sodium and 0 wt.% to 25 wt.% solid alkali metal carbonate and more preferably along with zeolite. More preferably, the liquid acid precursor of anionic surfactant is sprayed onto the alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 4, preferably along with specific levels of zeolite in a mixer.

[0071] More preferably, the liquid acid precursor of anionic surfactant is sprayed onto the mixture of alkali metal carbonate salt and the alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 4, preferably along with specific levels of zeolite in a mixer. The alkali metal carbonate salt reacts with and effects complete neutralization of the liquid acid precursor of anionic surfactant to form the salt form of anionic surfactant. Preferably the resulting agglomerated detergent particle after the neutralization process includes from 0 wt.% to 25 wt.% alkali metal carbonate. Still preferably the amount of alkali metal carbonate is from 0 wt.% to 10 wt.%. Still more preferably the agglomerated particle includes 0 wt.% alkali metal carbonate salt. Most preferably the alkali metal carbonate is sodium carbonate.

[0072] Sulphate salt

[0073] According to the first aspect of the present invention disclosed agglomerated detergent particle preferably includes a sulphate salt.

[0074] Preferably the agglomerate detergent particle includes from 3 wt.% to 30 wt.% sulphate salt, more preferably from 5 wt.% to 25 wt.% sulphate salt, still more preferably from 10 wt.% to 23 wt.% sulphate salt. Still preferably the agglomerate detergent particle includes not less than 7 wt.%, still preferably not less than 10 wt.%, still preferably not less than 15 wt.%, further preferably not less than 18 wt.% sulphate salt by weight of the agglomerate detergent particle. Still preferably the agglomerate detergent particle includes not more than 28 wt.%, still preferably not less than 25 wt.%, still preferably not less than 23 wt.% further preferably not less than 22 wt.% sulphate salt by weight of the agglomerate detergent particle by weight of the agglomerate detergent particle. More preferably the agglomerate detergent particle has 0 wt. to 10 wt.% alkali metal sulphate.

[0075] Porosity of the agglomerated detergent particle of the present invention is in the range from 0 to 0.2 volume fraction, more preferably from 0.01 to 0.1, still preferably from 0.04 to 0.1 , most preferably from 0.05 to 0.1. It is surprisingly found that the agglomerated detergent particle having intra-particle porosity in the range from 0 to 0.1 volume fraction is capable of providing low bulk density and good particle strength without altering the flow properties of the agglomerated detergent particle.

[0076] Porosity measurement:

[0077] The porosity of the agglomerated detergent particle of the present invention was determined using a Quantachrom Helium Pycnometer, Model Ultra pycnometer 1000. The intra particle porosity was calculated Ep using the following equation wherein;

[0078] BD = bulk density of the solid (detergent particle)

[0079] II =absolute density of the solid as measured in a Helium pycnometry (measure of the volume excluding the pores and the void spaces between particles of the solid) Eb = bed porosity

[0080] Ep = solid porosity

[0081] The intra particle porosity Epfor the agglomerate detergent particle was calculated to be 0 to 0.2, more preferably 0 to 0.18, more preferably 0 to 0.1.

[0082] Preferably the agglomerate detergent particle has a particle size distribution D50 ranging from 100 micrometers to 1000 micrometers. The agglomerate detergent particle according to the present invention has a unimodal particle distribution.

[0083] Preferably the agglomerate detergent particle has a UCT which ranges from 200 grams to 800 grams. UCT refers to the unconfined compressibility test (UCT) which provides a measure of the cohesiveness or "stickiness" of a particle and provides for predicting its storage properties, such as the storage properties in silos.

[0084] Preferably the agglomerate detergent particle has a VCT which ranges from 10% to 25%.

[0085] Preferably the agglomerate detergent particle has a dynamic flow rate (DFR) which ranges from 60 mL / seconds to 120 mL / seconds. DFR refers to the dynamic flow rate (DFR) which provides a measure of the flow properties of the agglomerate particle.

[0086] Preferably the agglomerate detergent particle has a bulk density ranging from 300 g / L to 900 g / L, more preferably 400 g / L to 860 g / L more preferably 400 g / L to 650 g / L.

[0087] Preferably the agglomerate detergent particle has a weight average particle size ranging from 100 micrometers to 1400 micrometers, more preferably 300 micrometers to 500 micrometers.

[0088] Preferably the agglomerate detergent particle has a moisture content ranging from 0 wt.% to 3 wt.%. Preferably the agglomerate detergent particle has a moisture ingress ranging from 5 wt.% to 15 wt.% in a sample which was stored for 84 days at a temperature of 45°C and a relative humidity of 80RH.

[0089] Preferably the agglomerate detergent particle is substantially free of phosphorous containing compound. Preferably the agglomerate detergent particle is substantially free of phosphate builder. More preferably the agglomerate detergent particle is substantially free of STPP and orthophosphate builder. More preferably the agglomerate particle is substantially free of STPP.

[0090] Disclosed agglomerate detergent particle may be spherical shaped or have other shapes in which agglomerate particle are commonly designed.

[0091] Disclosed agglomerate detergent particle has a first region and a second region where the second region is at least partially enveloping the first region. Preferably the first region has higher levels of the anionic surfactant, and a second region which has higher levels of alkali metal silicate.

[0092] More preferably at least 80% by weight of the agglomerated detergent particle has a second region partially enveloping the first region, still preferably at least 85%, still more preferably at least 90%, still more preferably at least 95%, still further preferably at least 98% and most preferably 100% by weight of the agglomerated particle has a second region partially enveloping the first region.

[0093] More preferably at least 40% of the surface area of the first region is covered with the second region, still preferably at least 50%, still more preferably at least 60%, still more preferably at least 70%, still further preferably at least 80%, still further preferably at least 90% and most preferably 100% of the surface area of the first region is covered with the second region.

[0094] First region

[0095] The agglomerate detergent particle has a first region.

[0096] According to the first aspect of the present invention the first region is at least partially enveloped by the second region. Preferably the first region predominantly comprises anionic surfactant. Preferably the first region comprises from 55 parts to 100 parts anionic surfactant, still more preferably from 60 parts to 100 parts anionic surfactant, still further preferably from 80 parts to 100 parts anionic surfactant, still further preferably from 95 parts to 100 parts anionic surfactant. Preferably the first region has at least 55 parts of the anionic surfactant, preferably the first region has at least 60 parts of the anionic surfactant, more preferably at least 65 parts of the anionic surfactant, still more preferably 70 parts of the anionic surfactant, more preferably 80 parts of the anionic surfactant and further more preferably 85 parts of the anionic surfactant, still further more preferably 90 parts of the anionic surfactant, still more preferably 95 parts of the anionic surfactant, still further preferably 98 parts of the anionic surfactant, and most preferably 100 parts of the anionic surfactant.

[0097] Also preferred is an agglomerate detergent particle where the first region comprises from 95 parts to 100 parts of the anionic surfactant; preferably from 95 parts to 100 parts of the total alkali metal carbonate; and, preferably from 70 parts to 80 parts of the total silica by weight of the agglomerate detergent particle.

[0098] Preferably the first region comprises an inorganic material selected from the group consisting of zeolite, alkali metal sulphate and mixtures thereof.

[0099] Preferably the first region (by weight of the agglomerate detergent particle) comprises: i. anionic surfactant; ii. alkali metal carbonate; iii. silica; and, iv. preferably zeolite.

[0100] Preferably the first region comprises at least 55 parts of the total anionic surfactant present in the agglomerate detergent particle. More preferably the first region comprises at least 65 parts of the total anionic surfactant present in the agglomerate detergent particle.

[0101] Preferably the first region (by weight of the agglomerate detergent particle) comprises: i. 95 parts to 100 parts of the anionic surfactant; ii. preferably 95 parts to 100 parts of the total alkali metal carbonate; and, iii. preferably 70 parts to 80 parts of the total silica. Preferably the agglomerate detergent particle has one or more discrete first region. Preferably the first region comprises from 30 parts to 40 parts zeolite (by weight of the agglomerate detergent particle).

[0102] Preferably the first region includes a flow aid. Preferably the flow aid is selected from the group consisting of zeolite, dolomite, calcite, and mixtures thereof. Preferably the first region includes a filler selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal sulphate and mixtures thereof.

[0103] Preferably the anionic surfactant present in the agglomerate detergent particle is in its neutralized salt form. Preferably at least 80 wt.%, still preferably at least 85 wt.%, further preferably at least 90 wt.%, still more preferably 95 wt.% and furthermore preferably 98 wt.%, still more preferably 99 wt.% and most preferably the entire anionic surfactant present in the agglomerate detergent particle is in its neutralized salt form. Preferably the neutralized salt form of the anionic surfactant is linear alkyl benzene sulphonate.

[0104] Second region

[0105] The agglomerate detergent particle includes a second region.

[0106] According to the first aspect of the present invention the agglomerate detergent particle has a second region, where the second region is at least partially enveloping the first region.

[0107] Preferably the second region predominantly comprises an alkali metal silicate.

[0108] Preferably the second region comprises from 55 parts to 100 parts alkali metal silicate, still more preferably from 60 parts to 100 parts alkali metal silicate, still further preferably from 80 parts to 100 parts alkali metal silicate, still further preferably from 95 parts to 100 parts alkali metal silicate. Preferably the second region has at least 55 parts of the alkali metal silicate, preferably the first region has at least 60 parts of the alkali metal silicate, more preferably at least 65 parts of the alkali metal silicate, still more preferably 70 parts of the alkali metal silicate, more preferably 80 parts of the alkali metal silicate and further more preferably 85 parts of the alkali metal silicate, still further more preferably 90 parts of the alkali metal silicate, still more preferably 95 parts of the alkali metal silicate, still further preferably 98 parts of the alkali metal silicate, and most preferably 100 parts of the alkali metal silicate. Preferably the second region comprises from 95 parts to 100 parts of the total alkali metal silicate and preferably from 20 parts to 30 parts of the total silica by weight of the agglomerate detergent particle.

[0109] Preferably the second region comprises less than 3 parts of the anionic surfactant by weight of the agglomerate detergent particle.

[0110] Preferably the second region comprises an inorganic material selected from the group consisting of zeolite, alkali metal carbonate and mixtures thereof.

[0111] Preferably the second region has a sulphur content ranging from 5 wt.% to 10 wt.%.

[0112] Preferably the second region (by weight of the agglomerate detergent particle) comprises: i. alkali metal silicate; and, ii. silica.

[0113] Preferably the second region comprises at least 55 parts of the total alkali metal silicate present in the agglomerate detergent particle. More preferably the first region comprises at least 65 parts of the total alkali metal silicate present in the agglomerate detergent particle. Preferably the first region comprises at least 55 parts of the total alkali metal silicate present in the agglomerate detergent particle. More preferably the second region comprises at least 65 parts of the total alkali metal silicate present in the agglomerate detergent particle.

[0114] Preferably the second region (by weight of the agglomerate detergent particle) comprises: i. 95 parts to 100 parts of the total alkali metal silicate; and, ii. 20 parts to 30 parts of the total silica.

[0115] Preferably the agglomerate detergent particle has one or more discrete second region. Preferably the second region comprises from 60 parts to 70 parts zeolite (by weight of the agglomerate detergent particle).

[0116] Preferably the second region has a sulphur content in the second region ranging from 5 wt.% to 10 wt.%. The first region and the second region may separately constitute individual layers within the agglomerate detergent particle.

[0117] Preferably the agglomerate detergent particle, may have a third region which includes 100% alkali metal silicate having a molar ratio of SiC>2 to M2O ranging from 2 to 3.5.

[0118] Preferably the second region includes a flow aid. Preferably the flow aid is selected from the group consisting of zeolite, dolomite, calcite, or mixtures thereof. Preferably the first region includes a filler selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal sulphate or mixtures thereof.

[0119] Without being bound by any theory, it is believed that the spatial arrangement of the detersive surfactant, silica, alkali metal silicate, and alkali metal carbonate, preferably zeolite in the agglomerate detergent particle and in specific amounts according to the invention enables the formation of free-flowing, low moisture content agglomerate detergent particles by a simple dry neutralization process without the need for subsequent drying. Further, the agglomerate detergent particle so formed are characterized by a significantly reduced amount of oversized particles therein (i.e., particles having a particle size greater than 1180mm), which are undesirable for incorporating into the finished detergent composition and therefore need to be removed prior thereto.

[0120] Laundry detergent composition

[0121] According to a second aspect of the present invention disclosed is a laundry detergent composition including an agglomerate detergent particle of the first aspect.

[0122] The laundry detergent composition preferably comprises from 30 wt.% to 100 wt.% agglomerate detergent particle. The laundry detergent composition comprising the agglomerate detergent particle comprises 5 wt.% to 20 wt.% alkali metal silicate; 5 wt.% to 20 wt.% alkali metal carbonate; and 10 wt.% to 50 wt.% laundry ingredient.

[0123] Preferably the laundry detergent composition includes: i. 50 wt.% to 80 wt.% agglomerate detergent particle; ii. unreacted alkali metal silicate; iii. unreacted alkali metal carbonate; iv. optionally flow aid; v. optionally fillers; and, vi. optionally laundry ingredient selected from the group consisting of soil release polymers, enzymes, colorants, shading dye, foaming agent, antifoaming agent, visual cues, optical brighteners, further surfactants, polymers, builder, antiredeposition agents and mixtures thereof.

[0124] Preferably the laundry detergent composition according to the present, comprises at least 80% by weight of the agglomerated detergent particle which has a second region partially enveloping the first region, still preferably at least 85%, still more preferably at least 90%, still more preferably at least 95%, still further preferably at least 98% and most preferably 100% by weight of the agglomerated particle has a second region partially enveloping the first region.

[0125] Preferably the laundry detergent composition according to the present, comprises at least 40% of the surface area of the first region is covered with the second region, still preferably at least 50%, still more preferably at least 60%, still more preferably at least 70%, still further preferably at least 80%, still further preferably at least 90% and most preferably 100% of the surface area of the first region is covered with the second region.

[0126] It is also preferred that the laundry detergent composition comprising the agglomerated detergent particle may also include a second particle comprising detersive surfactant which may be spray-dried detergent particle, extruded detergent particle and mixtures thereof.

[0127] Optional Laundry ingredients

[0128] Inorganic builder:

[0129] Zeolite builders used in most commercial particulate detergent compositions is zeolite A. Advantageously, aluminium zeolite P (zeolite MAP) described and claimed in EP 384 070A (Unilever) may be used. Zeolite MAP is an alkali metal aluminosilicate of the P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 30 1.15, and more preferably not exceeding 1.07. Zeolite builders are preferably present at relatively low levels, for example less than 5 wt.%, still preferably less than 3 wt.%, further preferably less than 1 wt.% in the agglomerate particle. Most preferably the agglomerate particle has 0 wt.% zeolite.

[0130] Organic builder: Non-limiting examples of organic builder 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. Preferably the organic builder is selected from monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and tri succinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates, more preferably alkali metal citrate, most preferably it is sodium citrate. Organic builders may be used in minor amounts as supplement to carbonate builder.

[0131] Preferred supplementary organic builders are citrates, suitably used in amounts of from 0.1 wt.% to 30 wt.% more preferably of alkaline metal compounds, preferably from 10 wt.% to 25 wt.%; and acrylic polymers, more especially acrylic / maleic copolymers, suitably used in amounts of from 0.5 wt.% to 15 wt.%, preferably from 1 wt.% to 10 wt.%.

[0132] Polymers:

[0133] The agglomerate particle may preferably include from 0 wt.% to 4 wt.% polymer, preferably the polymer is selected from antiredeposition polymer, soil release polymer, structuring polymer or mixtures thereof. Preferably the polymer is a polymeric carboxylate, preferably polyacrylate or a copolymer of acrylic acid and maleic acid. However other polymers may also be suitable such as polyamines (including the ethoxylated variants thereof), polyethylene glycol and polyesters. Polymeric soil suspending aids and polymeric soil release agents are particularly suitable.

[0134] Non-limiting examples of the post-dosed polymers include cleaning polymers, antiredeposition polymers, soil release polymers structuring polymers. Some examples include PET-PEOT polymer (Repel-o-Tex® SF2 ex.Solvay), copolymer of acrylic acid and maleic acid (Sokalan CP5 ex. BASF).

[0135] Non-limiting examples of the optional post-dosed benefit ingredients includes but is not limited to enzymes, anti-redeposition polymers, perfumes, additional surfactant selected from amphoteric surfactant, zwitterionic surfactant, cationic surfactant and non-ionic surfactant, optical brighteners, antifoaming agent, foam boosters, fabric softeners such as smectite clays, amine softeners and cationic softeners; bleach and bleach activators; dyes or pigments, fillers, fluorescers, salts, soil release polymers, dye transfer inhibitors. These optional ingredients are well known to be used in a laundry detergent composition and added preferably by post-dosing.

[0136] Fluorescers:

[0137] Suitable fluorescent brighteners include dis-styryl biphenyl compounds example Tinopal® CBS- X, di-amino stilbene di-sulfonic acid compounds, e.g. Tinopal® DMS 10 pure Xtra and Blankophor® HRH, and Pyrazoline compounds, e.g. Blankophor® SN, and coumarin compounds, e.g. Tinopal® SWN. Preferred brighteners are: sodium 2 (4- styry)-3-sulfophenyl)- 2H-napthol(1,2-d]triazole, disodium 4,4’bis{[4-anilino-6-(N methylN-2 hydroxyethyl)amino 1 ,3,5- triazin-2-yl)]amino]stilbene-2-2' disulfonate, disodium 4,4’bis([(4-anilino-6-morpholino-l,3,5- triazin-2-yl)]amino} stilbene-2-2'disulfonate, and 15 disodium 4,4’- bis(2-sulfostyryl)biphenyl. A suitable fluorescent brightener is S C.l. Fluorescent Brightener 260, which may be used in its beta or alpha crystalline forms, or a mixture of these forms.

[0138] The present inventors have surprisingly found that the agglomerate particle having a core and shell structure and where the shell comprises a mixture of alkali metal silicate and silica and wherein the alkali metal silicate is in an amount ranging from 10 to 25 wt.% and silica in an amount ranging from 3 to 10 wt.% by weight of the total agglomerate particle weight, then the particle appears whiter and requires lower levels of fluorescers for improving the powder appearance. It is known to add fluorescers in the conventional non-tower route powders to impart powder whiteness.

[0139] Preferably the agglomerate particle of the present invention includes less than 1 wt.% fluorescers, still preferably less than 0.5 wt.%, most preferably 0 wt.% fluorescers from petroleum sources or non-biodegradable and non-renewable sources.

[0140] Fragrance:

[0141] Fragrances are well known in the art and are preferably incorporated into compositions described herein at level of 1 to 5 wt%.

[0142] Microcapsules:

[0143] One type of microparticle suitable for use in the invention is a microcapsule.

[0144] Microencapsulation may be defined as the process of surrounding or enveloping one substance within another substance on a very small scale, yielding capsules ranging from less than one micron to several hundred microns in size. The material that is encapsulated may be called the core, the active ingredient or agent, fill, payload, nucleus, or internal phase. The material encapsulating the core may be referred to as the coating, membrane, shell, or wall material. Microcapsules typically have at least one generally spherical continuous shell surrounding the core. The shell may contain pores, vacancies or interstitial openings depending on the materials and encapsulation techniques employed. Multiple shells may be made of the same or different encapsulating materials, and may be arranged in strata of varying thicknesses around the core. Alternatively, the microcapsules may be asymmetrically and variably shaped with a quantity of smaller droplets of core material embedded throughout the microcapsule.

[0145] The shell may have a barrier function protecting the core material from the environment external to the microcapsule, but it may also act as a means of modulating the release of core materials such as fragrance. Thus, a shell may be water soluble or water swellable and fragrance release may be actuated in response to exposure of the microcapsules to a moist environment. Similarly, if a shell is temperature sensitive, a microcapsule might release fragrance in response to elevated temperatures. Microcapsules may also release fragrance in response to shear forces applied to the surface of the microcapsules.

[0146] A preferred type of polymeric microparticle suitable for use in the invention is a polymeric coreshell microcapsule in which at least one generally spherical continuous shell of polymeric material surrounds a core containing the fragrance formulation (f2). The shell will typically comprise at most 20% by weight based on the total weight of the microcapsule. The fragrance formulation (f2) will typically comprise from about 10 to about 60% and preferably from about 20 to about 40% by weight based on the total weight of the microcapsule. The amount of fragrance (f2) may be measured by taking a slurry of the microcapsules, extracting into ethanol and measuring by liquid chromatography.

[0147] Polymeric core-shell microcapsules for use in the invention may be prepared using methods known to those skilled in the art such as coacervation, interfacial polymerization, and polycondensation.

[0148] The process of coacervation typically involves encapsulation of a generally water-insoluble core material by the precipitation of colloidal material(s) onto the surface of droplets of the material. Coacervation may be simple e.g. using one colloid such as gelatin, or complex where two or possibly more colloids of opposite charge, such as gelatin and gum arabic or gelatin and carboxymethyl cellulose, are used under carefully controlled conditions of pH, temperature and concentration.

[0149] Interfacial polymerisation typically proceeds with the formation of a fine dispersion of oil droplets (the oil droplets containing the core material) in an aqueous continuous phase. The dispersed droplets form the core of the future microcapsule and the dimensions of the dispersed droplets directly determine the size of the subsequent microcapsules. Microcapsule shell-forming materials (monomers or oligomers) are contained in both the dispersed phase (oil droplets) and the aqueous continuous phase and they react together at the phase interface to build a polymeric wall around the oil droplets thereby to encapsulate the droplets and form core-shell microcapsules. An example of a core-shell microcapsule produced by this method is a polyurea microcapsule with a shell formed by reaction of diisocyanates or polyisocyanates with diamines or polyamines.

[0150] Polycondensation involves forming a dispersion or emulsion of the core material in an aqueous solution of precondensate of polymeric materials under appropriate conditions of agitation to produce capsules of a desired size, and adjusting the reaction conditions to cause condensation of the precondensate by acid catalysis, resulting in the condensate separating from solution and surrounding the dispersed core material to produce a coherent film and the desired microcapsules. An example of a core-shell microcapsule produced by this method is an aminoplast microcapsule with a shell formed from the polycondensation product of melamine (2,4,6-triamino-1 ,3,5-triazine) or urea with formaldehyde. Suitable cross-linking agents (e.g. toluene diisocyanate, divinyl benzene, butanediol diacrylate) may also be used and secondary wall polymers may also be used as appropriate, e.g. anhydrides and their derivatives, particularly polymers and co-polymers of maleic anhydride.

[0151] One example of a preferred polymeric core-shell microcapsule for use in the invention is an aminoplast microcapsule with an aminoplast shell surrounding a core containing the fragrance formulation (f2). More preferably such an aminoplast shell is formed from the polycondensation product of melamine with formaldehyde.

[0152] Polymeric microparticles suitable for use in the invention will generally have an average particle size between 100 nanometers and 50 microns. Particles larger than this are entering the visible range. Examples of particles in the sub-micron range include latexes and mini-emulsions with a typical size range of 100 to 600 nanometers. The preferred particle size range is in the micron range. Examples of particles in the micron range include polymeric core-shell microcapsules (such as those further described above) with a typical size range of 1 to 50 microns, preferably 5 to 30 microns. The average particle size can be determined by light scattering using a Malvern Mastersizer with the average particle size being taken as the median particle size D (0.5) value. The particle size distribution can be narrow, broad, or multimodal. If necessary, the microcapsules as initially produced may be filtered or screened to produce a product of greater size uniformity.

[0153] Polymeric microparticles suitable for use in the invention may be provided with a deposition aid at the outer surface of the microparticle. Deposition aids serve to modify the properties of the exterior of the microparticle, for example to make the microparticle more substantive to a desired substrate. Desired substrates include cellulosics (including cotton) and polyesters (including those employed in the manufacture of polyester fabrics).

[0154] The deposition aid may suitably be provided at the outer surface of the microparticle by means of covalent bonding, entanglement, or strong adsorption. Examples include polymeric coreshell microcapsules (such as those further described above) in which a deposition aid is attached to the outside of the shell, preferably by means of covalent bonding. While it is preferred that the deposition aid is attached directly to the outside of the shell, it may also be attached via a linking species.

[0155] Deposition aids for use in the invention may suitably be selected from polysaccharides having an affinity for cellulose. Such polysaccharides may be naturally occurring or synthetic and may have an intrinsic affinity for cellulose or may have been derivatized or otherwise modified to have an affinity for cellulose. Suitable polysaccharides have a 1-4 linked glycan (generalized sugar) backbone structure with at least 4, and preferably at least 10 backbone residues which are pi -4 linked, such as a glucan backbone (consisting of pi -4 linked glucose residues), a mannan backbone (consisting of pi -4 linked mannose residues) or a xylan backbone (consisting of pi -4 linked xylose residues). Examples of such pi -4 linked polysaccharides include xyloglucans, glucomannans, mannans, galactomannans, P(1-3),(1-4) glucan and the xylan family incorporating glucurono-, arabino- and glucuronoarabinoxylans. Preferred pi -4 linked polysaccharides for use in the invention may be selected from xyloglucans of plant origin, such as pea xyloglucan and tamarind seed xyloglucan (TXG) (which has a (31-4 linked glucan backbone with side chains of a-D xylopyranose and p-D-galactopyranosyl-(1-2)-a-D-xylo- pyranose, both 1-6 linked to the backbone); and galactomannans of plant origin such as loc ust bean gum (LBG) (which has a mannan backbone of (31-4 linked mannose residues, with single unit galactose side chains linked a1 -6 to the backbone).

[0156] Also suitable are polysaccharides which may gain an affinity for cellulose upon hydrolysis, such as cellulose mono-acetate; or modified polysaccharides with an affinity for cellulose such as hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxypropyl guar, hydroxyethyl ethylcellulose and methylcellulose.

[0157] Deposition aids for use in the invention may also be selected from phthalate containing polymers having an affinity for polyester. Such phthalate containing polymers may have one or more nonionic hydrophilic segments comprising oxyalkylene groups (such as oxyethylene, polyoxyethylene, oxypropylene or polyoxypropylene groups), and one or more hydrophobic segments comprising terephthalate groups. Typically, the oxyalkylene groups will have a degree of polymerization of from 1 to about 400, preferably from 100 to about 350, more preferably from 200 to about 300. A suitable example of a phthalate containing polymer of this type is a copolymer having random blocks of ethylene terephthalate and polyethylene oxide terephthalate.

[0158] Mixtures of any of the above-described materials may also be suitable.

[0159] Deposition aids for use in the invention will generally have a weight average molecular weight (Mw) in the range of from about 5 kDa to about 500 kDa, preferably from about 10 kDa to about 500 kDa and more preferably from about 20 kDa to about 300 kDa.

[0160] One example of a particularly preferred polymeric core-shell microcapsule for use in the invention is an aminoplast microcapsule with a shell formed by the polycondensation of melamine with formaldehyde; surrounding a core containing the fragrance formulation (f2); in which a deposition aid is attached to the outside of the shell by means of covalent bonding. The preferred deposition aid is selected from (31-4 linked polysaccharides, and in particular the xyloglucans of plant origin, as are further described above. Enyzme:

[0161] The composition of the present invention preferably includes an enzyme. It may preferably include one or more enzymes. Preferred examples of the enzymes include those which provide cleaning performance and / or fabric care benefits.

[0162] Examples of suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, xyloglucanase, phospholipases, esterases, cutinases, pectinases, mannanases, pectate lyases, keratinases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, G-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof. A typical combination is an enzyme cocktail that may comprise, for example, a protease and lipase in conjunction with one or more of amylase, mannanase and cellulase. When present in a detergent composition, the enzymes may be present at levels from about 0.00001% to about 2% from about 0.0001% to about 1% or from 0.001% to about 0.5% enzyme protein by weight of the detergent composition.

[0163] Packaging and dosing

[0164] The agglomerate particle or the laundry composition having the agglomerate particle prepared according to the invention may be packaged as unit dose composition in polymeric film soluble in the wash water. Alternatively, the spray-dried detergent particle or a composition including the particle of the invention may be supplied in multidose plastics packs with a top or bottom closure.

[0165] A dosing measure may be supplied with the pack either as a part of the cap or as an integrated system. The packaging material suitable for packaging may include but not limited to multilayer polyethylene film, laminate, paper based, and other materials known to a person skilled in the art. Preferably the packaging material is selected from material which are biodegradable or recyclable.

[0166] According to another aspect of the present invention, provided is a method of laundering fabric using an agglomerate particle or a laundry composition comprising a agglomerate particle according to the present invention which involves the step of diluting the dose of detergent composition with water to obtain a wash liquor and washing fabrics with the wash liquor so formed. In automatic washing machines the dose of detergent composition is typically put into a dispenser and from there it is flushed into the machine by the water flowing into the machine, thereby forming the wash liquor. From 5 up to about 65 litres of water may be used to form the wash liquor depending on the machine configuration. The dose of detergent 25 composition may be adjusted accordingly to give appropriate wash liquor concentrations. The dilution step preferably provides a wash liquor which comprises inter alia from about 3 to about 20 g / wash of detersive surfactants (as are further defined above).

[0167] Water-insoluble inorganic material:

[0168] Preferably the amount of the insoluble in the agglomerate particle or the laundry detergent composition comprising the agglomerate particle is less than 1 wt.%, still preferably less than 0.5 wt.% and more preferably 0 wt.%. Insoluble (flow aids) are added to conventional non-tower route powders to increase the flowability by layering the sticky agglomerates however inventors have found that when the benefit agent is present in the core in accordance with the agglomerate particle according to the present invention the stickiness on the surface of the shell is significantly reduced and this makes agglomerate particle surface dry enough to reduce the amount of flow aids for a desired flowability to powder.

[0169] Reserve Alkalinity of the agglomerate detergent particle:

[0170] The reserve alkalinity of the present invention is reduced as the levels of the alkali metal carbonate is reduced. Sodium carbonate that serves as carrier and alkalinity source for conventional detergent particle (agglomerate) however the invented process contains alkali metal silicate having a ratio of SiC>2 to M2O ranging from 2 to 4 which acts as an alternate carrier and source of alkalinity for the powder.

[0171] Examples

[0172] Example 1 : Evaluation of the agglomerate detergent particle according to the present invention

[0173] Agglomerate detergent particle according to the present invention was prepared by a method as provided herein below and using the ingredients as provided in table 1.

[0174] Solid sodium silicate having a molar ratio of SiC>2 to M2O of 3, sodium carbonate, zeolite, and zeolite in amounts as shown in table 1 were added into a mixer and was mixed vigorously with high-speed agitator (speed was 80 rpm to 100rpm with a tip speed of 5 to 7 m / s with a Froud number of 4 to 6) to obtain a homogeneous dry mixture.

[0175] Table 1

[0176] To the dry mixture LAS acid was sprayed using a flat spray nozzle at room temperature into the mixer over a bed of solid dry mixture composed of sodium silicate (SiC>2 to Na2 of 2), sodium carbonate, sodium sulphate and Zeolite 4A. LAS acid was neutralized to the salt form NaLaS upon reaction with sodium carbonate and sodium silicate (SiC>2 to Na2O of 2), the mixing is continued for 2 minutes to 3 minutes. A portion (0.080 Kg) of the total zeolite content was added before the addition of the LAS acid and the remaining portion of the zeolite (1.89 Kg) was added after the LAS neutralization.

[0177] After the neutralization reaction agglomerate detergent particle was formed which was composed of Na LAS, in-situ formed silica, unreacted sodium carbonate, sodium sulphate, zeolite, and sodium silicate. In the agglomerate particle the Na-LAS, sodium carbonate, sodium sulphate and zeolite were present in the first region and were at least partially enclosed by the second region which was composed of silica and alkali metal silicate.

[0178] The prepared agglomerate detergent particle according to the present invention were evaluated for the VCT, UCT, Moisture ingress and other properties as provided in the table 1 below.

[0179] Determination of VCT: This test provides a measure of the behavior of detergent powders in storage in factory silos and when considered along with the measurement of dynamic flow rate values provides an indication of the powder flow properties.

[0180] For the measurement of the VCT, a fixed volume (0.0389 cm3) of the agglomerate detergent particle of Table 1 is compressed by a constant load (25Kg) for a fixed interval of time (120 seconds), where the powder undergoes a decrease in volume. This decrease in volume expressed as a percentage of the original volume is a measure of the compressibility of the powder. The VCT is expressed in %.

[0181] T, , >.... Initial volume- Final volume v olumecompressihlity = - x 100

[0182] Initial volume

[0183] Determination of UCT: This test provides a measure of the cohesiveness of a detergent powder and gives an indication of the storage properties of the powder in silos.

[0184] For the measurement of UCT, the powder is compressed into a compact using a force of 10 Kg for 2 minutes followed by application of force in increments of 200 gm for 2 minutes till the compact is broken and total force required is measured. The force required to break the cake is correlated with the cohesivity of powder as provided below. W < 1kg Good flowing < W < 2kg Moderate flowing < W < 5kg Cohesive < W Very cohesive

[0185] Determination of moisture ingress: This method determines the %volatile present in a powder by drying a known weight of powder under constant temperature and recording the loss in weight over time. The sample under test is spread thinly in a dish provided and put on the top loading balance. The dish and contents are tarred and the infra-red light source / halogen lamp is switched on. The sample is dried at 130°C to 135°C for a period of time estimated from a previously prepared drying curve. After completion of the drying time, the loss of weight can be read directly from the balance. The procedure yields an approximate value for the water content of detergent powder or detergent paste, since any ingredients, volatile at the 130°C to 135°C range of temperature recommended, will also be included and the results must therefore, be interpreted cautiously. The % loss is calculated based on the formula given below where Wi is the weight of the dish, W2 is the weight of the dish and sample; W3 is the weight of the dish and dry residue.

[0186] Determination of bulk density: A pre-weighed rectangular metal box of known volume is filled with the powder same under standard conditions that simulate those encountered during agglomerate detergent composition packaging. The weight of the powder in the box is measured and the bulk density of the powder is calculated in g / cm3using the formula

[0187] Bulk Density of Powder where,

[0188] V (in cm3) = volume of the box

[0189] BE (in grams) = weight of the empty box

[0190] BE (in grams) = weight of the powder filled in the box

[0191] Determination of flowability: To determine the flowability, a known volume of powder was allowed to flow through a calibrated, standardized orifice and the flow time was recorded. A glass tube with a length of 50 cm and an internal diameter of 3.5cm was calibrated using water, an upper point and a lower point were marked on the glass tube such that the volume between the upper and the marked points was 287 mL. A brass or a stainless orifice with a diameter of 2.25 cm was fixed at the bottom of the tube with a metal slide to hold the powder.

[0192] When the slide is moved, the orifice opens, and the time needed for the powder to flow from the upper point to the lower point is recorded and expressed as dynamic flow rate (DFR) in mL / s.

[0193] The Reserve alkalinity refers to the grams of NaOH / 100 grams when titrated till 10 pH with Na2SC>4.The alkali reserve is determined by an acid / base titration of a solution with 0.5 mol / L sulphuric acid till pH of 10.00.

[0194] Table 2

[0195] &the alkali metal silicate used in Ex 1 , 3, 4, 5 and 7 was with a molar ratio of SiO2 to M2O of 2;Athe alkali metal silicate used in Ex 1A was with bulk density 120g / L and weight average particle size of 240 micrometers.

[0196] The data shown in the above table shows that when an agglomerate detergent particle according to the present invention (Ex 1 , 3, 4, 5 and 7) includes Na silicate with a molar ratio of 2 and silica and where the particle has specific first region and second region it provides agglomerate detergent particles with lower bulk density at various NaLAS levels. The composition was found to have low moisture content and good flow properties.

[0197] On the other hand, the agglomerate detergent particle formed by conventional composition without the alkali metal silicate with specific molar ratio of SiO2 to N2O and having Na carbonate as the predominant neutralizing agent resulted in agglomerate detergent particle with higher bulk density and lower particle porosity. Also, the agglomerate detergent particle which was formed using Na silicate with low bulk density but where the SiO2 to N2O molar ratio is outside the claimed ranges the particle was found to have higher moisture content. Example 2: Evaluating an agglomerate detergent particle with a first region and a second region according to the present invention.

[0198] The agglomerate detergent particle of Example 1 as provided in Table 1 was evaluated for the surface characteristics, sub surface morphology and elemental composition using a SEM-EDS analysis technique (ex. Hitachi, S3400-N SEM) which is a surface and below surface measurement technique. In addition to the agglomerated detergent particle the agglomerate detergent particle, and spray-dried detergent particle as shown in table 3 was also studied.

[0199] The Hitachi S3400-N SEM is fitted with a Standard secondary electron (SE) detector, an Environmental secondary electron detector (ESED), a multi-element backscatter electron (BSE) detector and an Oxford Instruments X-Max (EDX) detector.

[0200] 5 grams of the agglomerate detergent particle of the Example 1 was placed on the stub of the SEM-EDS analyzer and the sample chamber was closed and the analysis was conducted using the different detectors under conditions of vacuum.

[0201] The elemental composition of the 3 different detergent particle is provided in the table 3 below. The data has been normalized after excluding the values for carbon from the stub on which the sample was mounted and provided in table 3 below.

[0202] Table 3

[0203] In the above table the sulphur peak corresponds to the presence of LAS active, silica peak corresponds to the presence of in-situ formed silica, the oxygen peak to the combined levels of Na carbonate, Na silicate, Na sulphate and zeolite; similarly the sodium peak corresponds to the combined levels of Na carbonate, Na silicate and Na sulphate, while the aluminium peak corresponds to the presence of zeolite and calcium is from the impurities in zeolite.

[0204] In the agglomerated detergent particle according to the present invention, the analysis of the agglomerate particle after the completion of the agglomeration process in the mixer provided the analysis of the second region which showed no presence of the sulphur. When these particles were crushed, distinct regions of the crushed powder showed sticky appearance, these regions were collected and analyzed which showed an elemental composition (first region) distinct and different than the composition of the second region (before crushing). The first region showed the presence of the sulphur which shows that the neutralized anionic surfactant is enclosed at least partially by the second region. It is believed that the specific spatial arrangement of the first region and the second region reduces the stickiness on the surface of the agglomerated detergent particle which provides the particle with good flow properties.

[0205] Compared to the conventional agglomerate detergent particle the agglomerate detergent particle according to the present invention showed a first region and a second region with specific composition while the conventional agglomerate detergent particle had no such distinct regions.

[0206] Example 3: Study of the dissolution profiles of the agglomerate detergent particle.

[0207] The detergent particle provided in table 3, were studied for dissolution profile. To study the dissolution profile, 100 grams of the detergent particle was added into water at room temperature in a beaker and was continuously stirred, the amount of the powder dissolved was measured at regular intervals by decanting the undissolved particle and weighing the undissolved particles. The amount of the dissolved particle in wt.% was calculated and is provided in table 4 below.

[0208] The data of the dissolution study is provided in table 4 below.

[0209] Table 4

[0210] The dissolution profile of the various detergent particle shows that the agglomerate detergent particle according to the present invention having similar levels of the detersive anionic surfactant shows a dissolution profile which is similar to the spray-dried detergent particle. It is seen that the agglomerate detergent particle according to the present invention is 90% dissolved in a minute which is similar to that of a spray dried particle. On the other hand, the conventional agglomerate detergent particle has a much slower dissolution profile.

Claims

Claims1. An agglomerate detergent particle comprising:(i) 1 wt.% to 40 wt.% anionic surfactant;(ii) 0 wt.% to 25 wt.% alkali metal carbonate;(iii) 0.3 wt.% to 10 wt.% silica; and,(iv) 5 wt.% to 30 wt.% alkali metal silicate; wherein the alkali metal silicate has a molar ratio of SiC>2 to M2O ranging from 2 to 4 where the M represents an alkali metal, and wherein the agglomerate detergent particle has a first region and second region where the second region is at least partially enveloping the first region and wherein the first region of the agglomerate particle predominantly comprises the anionic surfactant.

2. An agglomerate detergent particle according to claim 1 wherein the first region comprises at least 55 parts of the anionic surfactant, preferably 55 parts to 100 parts of the anionic surfactant, still preferably from 80 parts to 100 parts of the anionic surfactant, still more preferably from 90 parts to 100 parts of the anionic surfactant.

3. An agglomerate detergent particle according to claim 1 wherein the first region has at least 55 parts of the anionic surfactant and a second region which has at least 55 parts of alkali metal silicate by weight of the agglomerate detergent particle.

4. An agglomerate detergent particle according to claim 1 to 3 wherein the first region comprises from 95 parts to 100 parts of the anionic surfactant; preferably from 95 parts to 100 parts of the total alkali metal carbonate; and, from 70 parts to 80 parts of the total silica by weight of the agglomerate detergent particle.

5. An agglomerate detergent particle according to claim 1 wherein the second region comprises from 95 parts to 100 parts of the total alkali metal silicate and from 20 parts to 30 parts of the total silica by weight of the agglomerate detergent particle.

6. An agglomerate detergent particle according to any one of the preceding claims wherein the first region comprises an inorganic material selected from the group consisting of zeolite, alkali metal sulphate and mixtures thereof.

7. An agglomerate detergent particle according to any one of the preceding claims wherein the second region comprises less than 3 parts of the anionic surfactant by weight of the agglomerate detergent particle.

8. An agglomerate detergent particle according to any one of the preceding claims wherein the second region comprises an inorganic material selected from the group consisting of zeolite, alkali metal carbonate and mixtures thereof.

9. An agglomerate detergent particle according to any one of the preceding claims wherein the second region has a sulphur content ranging from 5 wt.% to 10 wt.%.

10. An agglomerate detergent particle according to any one of the preceding claims wherein the particle has a bulk density ranging from 300 g / L to 860 g / L, more preferably from 400 g / L to 650 g / L.

11. An agglomerate detergent particle according to any one of the preceding claims wherein the particle has a weight average particle size ranging from 100 micrometers to 1400 micrometers, more preferably from 300 micrometers to 500 micrometers.

12. An agglomerate particle according to any one of the preceding claims wherein the second region at least partially overlays the first region, still more preferably at least 70% of the first region is enclosed within the second region, still more preferably at least 80% of the is enclosed within the second region, furthermore preferably at least 95% of the first region is enclosed within the second region.

13. An agglomerate particle according to any one of the preceding claims wherein the anionic surfactant is a C to C20 alkyl benzene sulphonate surfactant, more preferably a C10 to C20 linear alkyl benzene sulphonate surfactant.

14. A laundry detergent composition comprising agglomerate detergent particle according to any one of the preceding claims 1 to 12, preferably 30 wt.% to 100 wt.% agglomerate detergent particle.

15. A laundry detergent composition according to claim 13 comprising:(i) 5 wt.% to 20 wt.% alkali metal silicate;(ii) 5 wt.% to 20 wt.% alkali metal carbonate;(iii) 10 wt.% to 50 wt.% laundry ingredient.

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