CN111511890B - Detergent particles with high anionic surfactant content - Google Patents

Abstract

The present invention provides a detergent particle having a relatively high total anionic surfactant content, for example from 40% to 90% by total weight of the detergent particle, the detergent particle comprising a core and a coating thereon. The core comprises one or more anionic surfactants and a non-quaternized alkoxylated polyethyleneimine having a polyalkyleneimine core with one or more alkoxy side chains bonded to at least one nitrogen atom in the polyalkyleneimine core. The coating comprises silica. The detergent granules, despite having a high anionic surfactant content, retain satisfactory flow properties and are therefore easier to process into the final granular detergent product.

Description

Detergent particles with high anionic surfactant content

Technical Field

The present invention relates to detergent granules having a relatively high total anionic surfactant content for use in granular detergent compositions.

Background

Today's granular detergent compositions are increasingly moving towards high densities, which brings many benefits including excellent cleaning, environmental sustainability, convenience and efficiency. Such high density granular detergent compositions are formed from detergent particles having a high concentration of cleaning active or surfactant, especially detergent particles having a high concentration of anionic surfactant and mixtures thereof.

Currently, the desired surfactant concentration can be as high as 40% to 90%, preferably 50% to 80%, by total weight of the detergent particle. However, challenges exist in both the manufacture and end-use of products comprising detergent particles having such high surfactant concentrations, particularly if the surfactant is predominantly an anionic surfactant. First, when an anionic surfactant is a main component in a detergent particle, the physical strength of the detergent particle is significantly deteriorated as compared to a detergent particle having a lower content of the anionic surfactant. Second, the particle surface is significantly more sticky. Both of these factors can lead to poor flow properties of the resulting granules, which in turn can lead to challenges in batch processing of such detergent granules during manufacture.

Therefore, there is a continuing need to improve the flowability of high-concentration anionic detergent particles without reducing the concentration of anionic surfactant therein.

Disclosure of Invention

The present inventors have surprisingly and unexpectedly found that the addition of non-quaternized alkoxylated polyethyleneimine to detergent particles having a high anionic surfactant concentration and the formation of a silica coating thereon can significantly increase the flowability of such detergent particles.

In one aspect, the invention relates to a detergent granule characterized by a total anionic surfactant content in the range of from about 40% to about 90% by weight. Specifically, such detergent particles comprise:

a core, comprising: (a) one or more anionic surfactants; and (b) a non-quaternized alkoxylated polyethyleneimine having a polyalkyleneimine core wherein one or more alkoxy side chains are bonded to at least one nitrogen atom in the polyalkyleneimine core; and a coating on the core, wherein such coating comprises silica.

In another aspect, the present invention relates to a detergent granule comprising:

a core, comprising: (i) from about 40% to about 9% by total weight of the detergent granule of C₁₂-C₁₄A linear Alkyl Ethoxylated Sulfate (AES) surfactant having a weight average degree of ethoxylation of from about 0.5 to about1; (ii) from about 10% to about 50% by total weight of the detergent granule of C₁₂-C₁₄Linear alkyl benzene sulphonate (LAS) surfactant; (iii) from about 1% to about 10% by total weight of the detergent particle of a non-quaternized alkoxylated polyethyleneimine having an empirical formula (I) of (PEI) x- (EO) y-R₃Wherein x is the average number average Molecular Weight (MWPEI) of the polyalkyleneimine core of the alkoxylated polyalkyleneimine and is in the range of from about 500 to about 1000 daltons, wherein y is the weight average degree of ethoxylation in the one or more side chains of the alkoxylated polyalkyleneimine and is in the range of from about 10 to about 30, and wherein R is₃Is hydrogen; and (iv) from about 20% to about 40% by total weight of the detergent particle of silica; and

a coating on the core, wherein such coating comprises from about 1% to about 10% by total weight of the detergent particle of silica.

In another aspect, the present invention relates to a granular detergent composition comprising from about 1% to about 99% of the detergent granules described above.

In another aspect, the present invention relates to a process for preparing the above detergent particles by: (a) forming an aqueous paste comprising one or more anionic surfactants, a non-quaternized alkoxylated polyethyleneimine, and water; (b) mixing the aqueous paste of step (a) with a solid carrier to form core particles; and (c) coating silica on the core particle.

These and other aspects of the invention will become more apparent upon reading the following drawings and detailed description of the invention.

Detailed Description

The features and advantages of various embodiments of the present invention will become apparent from the following description, which includes examples intended to give a broad representation of specific embodiments of the invention. Various modifications will be apparent to those skilled in the art from this description and from practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed, and the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, 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".

As used herein, articles 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 "comprising," "including," and "containing" are intended to be non-limiting.

As used herein, the term "particle" refers to a minute amount of a solid substance, such as a powder, granule, encapsulate, microcapsule, and/or granulation. The particles of the invention may be regularly or irregularly shaped spheres, rods, plates, tubes, cubes, cuboids, discs, stars or flakes, but they are non-fibrous. The particles of the present invention can have a median particle size of about 2000 μm or less as measured according to the median particle size test described herein. Preferably, the particles of the present invention have a median particle size in the range of from about 1 μm to about 2000 μm, more preferably from about 10 μm to about 1800 μm, still more preferably from about 50 μm to about 1700 μm, still more preferably from about 100 μm to about 1500 μm, still more preferably from about 250 μm to about 1000 μm, most preferably from about 300 μm to about 800 μm, as measured according to the median particle size test described herein.

As used herein, the term "detergent particle" refers to a particle comprising at least one surfactant, preferably at least one anionic surfactant.

As used herein, the term "composite detergent particle" or "mixed detergent particle" refers to a particle comprising two or more surfactants, preferably at least two anionic surfactants.

As used herein, the term "primary surfactant" refers to a surfactant present in an article in an amount of about 50% or more by total weight of all surfactants in the article.

As used herein, the term "coating" refers to a partial or complete coating of a layered material on the outer surface of a particulate material or on at least a portion of such outer surface.

As used herein, the term "granular detergent composition" refers to solid compositions, such as multipurpose or heavy duty detergents in granular or powder form, e.g., for cleaning fabrics, dishes, and/or hard surfaces, as well as cleaning adjuncts, such as bleaching agents, rinse aids, additives, or pretreatment types.

As used herein, the term "water soluble" refers to the ability of a sample material of at least about 25 grams, preferably at least about 50 grams, more preferably at least about 100 grams, and most preferably at least about 150 grams, to be completely dissolved or dispersed in water without leaving visible solids or forming a distinct separate phase when such material is placed in one liter (1L) of deionized water at 20 ℃ and thoroughly stirred at atmospheric pressure.

As used herein, the term "substantially free" means that the component of interest is present in an amount less than about 0.1% by weight.

As used herein, the term "consisting essentially of …" means that the composition does not contain ingredients that would interfere with the benefits or functions of those ingredients specifically disclosed. Furthermore, the term "substantially free of means that the indicated material is present in an amount of 0 wt.% to about 5 wt.%, preferably 0 wt.% to 3 wt.%. The term "substantially free" means that the indicated material is present in an 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 0.1 wt%, most preferably it is not present at analytically detectable levels.

As used herein, all concentrations and ratios are by weight unless otherwise specified. All temperatures herein are in degrees Celsius (. degree. C.) unless otherwise indicated. All conditions herein are at 20 ℃ and atmospheric pressure unless otherwise specifically indicated. All polymer molecular weights are determined as weight average molecular weights unless otherwise specifically indicated.

As noted above, high concentrations of anionic detergent particles (i.e. those having anionic surfactant concentrations of up to about 40% to about 90%, preferably from about 50% to about 80% by total weight of the detergent particle) have poor flowability because such detergent particles have poorer physical strength and more sticky surfaces than detergent particles having lower anionic surfactant concentrations. Poor flow properties in turn lead to challenges in batch handling of such high concentration anionic detergent particles during manufacture.

It has been found that the flowability of such detergent particles can be significantly improved by adding non-quaternised alkoxylated Polyethyleneimine (PEI) to such high concentration anionic detergent particles followed by the formation of a silica coating thereon, particularly when such detergent particles comprise one or more high concentrations of Alkyl Alkoxylated Sulphate (AAS) surfactants.

Without being bound by any theory, the inventors believe that the alkoxylated PEI functions as a surfactant structurant to increase the particle strength of the detergent particle, while the silica coating functions to reduce the surface tackiness of the detergent particle. The alkoxylated PEI and silica coating combination can significantly improve the flowability of the detergent particles, while the flowability improvement achieved by adding alkoxylated PEI alone or forming the silica coating alone is less significant.

Core

The core of the detergent particles of the present invention may be characterized by a median particle size in the range of from about 100 microns to about 900 microns, preferably from about 300 microns to about 800 microns, and more preferably from about 400 microns to about 700 microns.

One or more anionic surfactants: first, the core of the high-concentration anionic detergent particle of the present invention comprises one or more anionic surfactants present in an amount of from about 40% to about 90%, preferably from about 50% to about 80%, by weight of such detergent particle.

Any suitable anionic surfactant can be used in the practice of the present invention. Preferably, one or more anionsThe surfactant is selected from the group consisting of: (1) c₁₀-C₂₀Linear or branched Alkyl Alkoxylated Sulfate (AAS) surfactants; (2) c₆-C₂₀Linear or branched non-alkoxylated Alkyl Sulfate (AS) surfactants; (3) c₁₀-C₂₀Linear alkyl benzene sulphonate (LAS) surfactant; and (4) combinations thereof.

In a preferred embodiment of the present invention, the core of the high concentration anionic detergent particle of the present invention comprises C₁₀-C₂₀Linear or branched Alkyl Alkoxylated Sulfate (AAS) surfactants having a weight average degree of alkoxylation of from about 0.1 to about 10, preferably from about 0.1 to about 5. A particularly preferred AAS surfactant for use in the practice of the present invention is C₁₂-C₁₈Linear Alkyl Ethoxylated Sulfate (AES) having a weight average degree of ethoxylation of from about 0.5 to about 3.0, preferably from about 0.5 to about 2, more preferably from about 0.5 to about 1. More preferably, the AAS surfactant is C₁₂-C₁₄A linear Alkyl Ethoxylated Sulfate (AES) surfactant having a weight average degree of ethoxylation of from about 0.5 to about 1.

Such AAS surfactants may be present in the core in an amount of from about 20% to about 90%, preferably from about 30% to about 90%, more preferably from about 40% to about 80%, most preferably from about 50% to about 70%, by total weight of the core. In a particularly preferred, but not essential, embodiment of the invention, the core comprises only one surfactant, which is an AAS surfactant. In another preferred embodiment of the invention, the core comprises two or more surfactants, but the AAS surfactant is present as the primary surfactant in such core, while one or more other surfactants (anionic, nonionic, amphoteric and/or cationic) are present as co-surfactants.

The core of the high concentration anionic detergent particles of the present invention may comprise C alone or in combination with the above AAS₁₀-C₂₀Linear Alkylbenzene Sulphonate (LAS) surfactant as anionic surfactant.

LAS surfactants are well known in the art and may be usedThe persulphonated commercial linear alkylbenzenes are readily available. Exemplary C that can be used in the present invention₁₀-C₂₀Linear alkyl benzene sulfonates including C₁₀-C₂₀Alkali, alkaline earth or ammonium salts of linear alkyl benzene sulphonic acids, preferably C₁₁-C₁₈Or C₁₁-C₁₄Sodium, potassium, magnesium and/or ammonium salts of linear alkyl benzene sulphonic acid. More preferably C₁₂Sodium or potassium salt of linear alkyl benzene sulphonic acid, and most preferably C₁₂Sodium salt of linear alkyl benzene sulphonic acid i.e. sodium dodecylbenzene sulphonate. The amount of LAS in the core, if present, may range from about 5% to about 90%, preferably from about 10% to about 70%, and more preferably from about 15% to about 45%, by total weight of the core.

In a particularly preferred, but not essential, embodiment of the invention, the core of the high concentration anionic detergent particle of the invention comprises both AAS surfactant and LAS surfactant, wherein the weight ratio of AAS to LAS is in the range of from about 1:3 to about 10:1, preferably from about 1:2 to about 8:1, more preferably from about 1:1 to about 5:1, most preferably from about 2:1 to about 4: 1.

The core of the high concentration anionic detergent particles of the present invention may comprise C alone or in combination with the above AAS and/or LAS₁₀-C₂₀Linear or branched non-alkoxylated Alkyl Sulphate (AS) surfactants AS anionic surfactants. The amount of AS in the core may range from about 50% to about 90%, preferably from about 60% to about 90%, and more preferably from about 65% to about 85%, by total weight of the core.

The core may comprise additional anionic surfactants (other than AAS, LAS and/or AS), such AS C₁₀-C₂₀Straight or branched chain alkylsulfonic acid salts, C₁₀-C₂₀Linear or branched alkyl phosphates, C₁₀-C₂₀Linear or branched alkylphosphonates, C₁₀-C₂₀Straight or branched chain alkyl carboxylates and their salts and mixtures.

One or more other surfactants: in addition to the above anionic surfactant, the core of the high concentration anionic detergent particle of the present invention may further comprise one selected from the group consisting ofOne or more surfactants: nonionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, and combinations thereof.

Suitable nonionic surfactants include alkoxylated fatty alcohols. The nonionic surfactant can be selected from the group consisting of formula R (OC)₂H₄)_nOH, wherein R is selected from the group consisting of aliphatic hydrocarbon groups containing from about 8 to about 15 carbon atoms and alkylphenyl groups wherein the alkyl group contains from about 8 to about 12 carbon atoms, and n has an average value of from about 5 to about 15. Non-limiting examples of nonionic surfactants useful herein include: c₈-C₁₈Alkyl ethoxylates, such as from Shell

A nonionic surfactant; c₆-C₁₂An alkylphenol alkoxylate, wherein the alkoxylate unit may be an ethyleneoxy unit, a propyleneoxy unit, or mixtures thereof; c₁₂-C₁₈Alcohol and C₆-C₁₂Condensates of alkylphenols with ethylene oxide/propylene oxide block polymers, such as from BASF

C₁₄-C₂₂Mid-chain branched alcohols, BA; c₁₄-C₂₂Mid-chain branched alkyl alkoxylates, BAE_xWherein x is 1 to 30; an alkyl polysaccharide; in particular alkyl polyglycosides; polyhydroxy fatty acid amides; and ether-terminated poly (alkoxylated) alcohol surfactants. Suitable nonionic detersive surfactants also include alkyl polyglucosides and alkyl alkoxylated alcohols. Suitable nonionic surfactants also include BASF under the trade name BASF

Those that are sold.

Non-limiting examples of cationic surfactants include: quaternary ammonium surfactants, which may have up to 26 carbon atoms, include: alkoxylated Quaternary Ammonium (AQA) surfactants; dimethyl hydroxyethyl quaternary ammonium; dimethyl hydroxyethyl lauryl ammonium chloride; a polyamine cationic surfactant; an ester cationic surfactant; and amino surfactants such as amidopropyl dimethylamine (APA). Suitable cationic detersive surfactants also include alkyl pyridinium compounds, alkyl quaternary ammonium compounds, alkyl quaternary phosphonium compounds, alkyl ternary sulfonium compounds, and mixtures thereof.

Suitable cationic detersive surfactants are quaternary ammonium compounds having the general formula:

(R)(R₁)(R₂)(R₃)N⁺X^-

wherein R is a linear or branched, substituted or unsubstituted C_6-18Alkyl or alkenyl moieties, R₁And R₂Independently selected from methyl or ethyl moieties, R₃Is a hydroxyl, hydroxymethyl, or hydroxyethyl moiety, X is an anion that provides electrical neutrality, and suitable anions include: halide ions (e.g., chloride); sulfate radical; and a sulfonate group. Suitable cationic detersive surfactants are mono-C_6-18Alkyl monohydroxyethyl dimethyl quaternary ammonium chloride. Highly suitable cationic detersive surfactants are mono-C_8-10Alkyl mono-hydroxyethyl bis-methyl quaternary ammonium chloride, mono C_10-12Alkyl mono-hydroxyethyl di-methyl quaternary ammonium chlorides and mono-C₁₀Alkyl mono-hydroxyethyl di-methyl quaternary ammonium chloride.

Suitable examples of zwitterionic surfactants include: derivatives of secondary and tertiary amines, including derivatives of heterocyclic secondary and tertiary amines; derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds; betaines, including alkyl dimethyl betaine, coco dimethyl aminopropylbetaine, sulfo and hydroxy betaines; c₈To C₁₈(preferably C)₁₂To C₁₈) An amine oxide; N-alkyl-N, N-dimethylamino-1-propanesulfonic acid salts, wherein the alkyl group may be C₈To C₁₈。

Suitable amphoteric surfactants include aliphatic derivatives of secondary or tertiary amines, or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical can be straight or branched chain and wherein one of the aliphatic substituents contains at least about 8 carbon atoms, alternatively from about 8 to about 18 carbon atoms, and at least one of the aliphatic substituents contains a water-solubilizing anionic group, e.g., carboxy, sulfonate, sulfate. Suitable amphoteric surfactants also include sarcosinates, glycinates, taurates, and mixtures thereof.

Non-quaternized alkoxylated polyethyleneimines: in addition to the anionic surfactants described above, the core of the high concentration anionic detergent particle of the present invention comprises a non-quaternized alkoxylated polyethyleneimine having a polyalkyleneimine core with one or more alkoxy side chains bonded to at least one nitrogen atom in the polyalkyleneimine core, which may be present in an amount ranging from about 0.5% to about 10%, preferably from about 1% to about 5%, by total weight of the detergent particle.

Typically, the non-quaternized alkoxylated polyalkyleneimines are uncharged. The alkoxylated polyethyleneimine is typically non-quaternized at the pH of the concentrated surfactant composition. The non-quaternized alkoxylated polyethyleneimine may be linear, branched, or a combination thereof, preferably branched.

The non-quaternized alkoxylated polyalkyleneimines have a Polyalkyleneimine (PEI) core wherein one or more alkoxy side chains are bonded to at least one nitrogen atom in the polyalkyleneimine core.

Typically, the non-quaternized alkoxylated polyethyleneimine comprises a polyalkyleneimine backbone. The polyalkyleneimine may comprise C₂Alkyl radical, C₃Alkyl groups, or mixtures thereof, preferably C₂An alkyl group. The non-quaternized alkoxylated polyethyleneimine polymer may have a polyethyleneimine ("PEI") backbone. The average number average molecular weight of the PEI backbone may be from about 400 to about 1000, or from about 500 to about 750, or from about 550 to about 650, or about 600 daltons, as determined prior to ethoxylation.

Prior to alkoxylation, the PEI backbone of the polymers described herein may have the empirical formula:

wherein B represents a continuation of the structure by branching. In some aspects, n + m is equal to or greater than 8, or 10, or 12, or 14, or 18, or 22.

Non-quaternized alkoxylated polyethyleneimines typically contain alkoxylated nitrogen groups. The non-quaternized alkoxylated polyethyleneimine may independently comprise an average of up to about 50, or up to about 40, or up to about 35, or up to about 30, or up to about 25, or up to about 20 alkoxylate groups per alkoxylated nitrogen. The non-quaternized alkoxylated polyethyleneimine may independently comprise an average of at least about 5, or at least about 10, or at least about 15, or at least about 20 alkoxylate groups per alkoxylated nitrogen.

The alkoxylate group may be an Ethoxylate (EO) group, a Propoxylate (PO) group or a combination thereof, but is preferably an Ethoxylate (EO) group. For example, the non-quaternized alkoxylated polyethyleneimine may comprise, on average, from about 1 to about 50 Ethoxylate (EO) groups and from about 0 to about 50 Propoxylate (PO) groups per alkoxylated nitrogen. The non-quaternized alkoxylated polyethyleneimine may comprise an average of about 1 to about 50 Ethoxylate (EO) groups per alkoxylated nitrogen and no Propoxylate (PO) groups. The non-quaternized alkoxylated polyethyleneimine may comprise an average of about 10 to 30 Ethoxylate (EO) groups, preferably about 15 to 25 Ethoxylate (EO) groups per alkoxylated nitrogen.

Suitable non-quaternized alkoxylated polyethyleneimines may include propoxylated polyalkyleneimine (e.g., PEI) polymers. Propoxylated polyalkyleneimine (e.g., PEI) polymers may also be ethoxylated. Propoxylated polyalkyleneimine (e.g., PEI) polymers may have an internal polyethylene oxide block and an external polypropylene oxide block, a degree of ethoxylation and a degree of propoxylation that is not above or below certain limiting values. The ratio of polyethylene blocks to polypropylene blocks (n/p) can be about 0.6, or about 0.8, or about 1 to a maximum of about 10, or a maximum of about 5, or a maximum of about 3. The n/p ratio may be about 2. The propoxylated polyalkyleneimine may have a PEI backbone with a weight average molecular weight (as determined prior to alkoxylation) of from about 200g/mol to about 1200g/mol, or from about 400g/mol to about 800g/mol, or about 600 g/mol. The molecular weight of the propoxylated polyalkyleneimine can be from about 8,000g/mol to about 20,000g/mol, or from about 10,000g/mol to about 15,000g/mol, or about 12,000 g/mol.

Suitable propoxylated polyalkyleneimine polymers may include compounds having the following structure:

where EO is an ethoxylate group and PO is a propoxylate group. The compound shown above is PEI, with a molar ratio of EO to PO of about 10:5 (e.g., 2: 1). Other similar suitable compounds may include EO and PO groups present in a molar ratio of about 10:5 or about 24: 16.

Suitable polyamines include low molecular weight, water soluble and lightly alkoxylated ethoxylated/propoxylated polyalkyleneamine polymers. By "lightly alkoxylated," it is meant that the polymers of the present invention have an average degree of alkoxylation per nitrogen of from about 0.5 to about 20, or from 0.5 to about 10. A polyamine can be "substantially uncharged," meaning that no more than about 2 positive charges per about 40 nitrogens present in the backbone of the polyalkyleneamine polymer at pH 10, or at pH 7; it is recognized, however, that the charge density of the polymer may vary with pH.

Suitable alkoxylated polyalkyleneimines such as PEI₆₀₀EO₂₀From BASF (Ludwigshafen, Germany).

Ethylene oxide-propylene oxide-ethylene oxide (EO/PO/EO) triblock copolymers: in addition to the anionic surfactant and PEI polymer described above, the core of the high concentration anionic detergent particle of the present invention may further comprise an ethylene oxide-propylene oxide-ethylene oxide (EO/PO/EO) triblock copolymer having an average propylene oxide chain length of from about 20 to about 70, preferably from about 30 to about 60, more preferablyPreferably about 45 and about 55 propylene oxide units.

Preferably, the ethylene oxide-propylene oxide-ethylene oxide (EO/PO/EO) triblock copolymer has a weight average molecular weight of from about 1000 to about 10,000 daltons, preferably from about 1500 to about 5000 daltons, more preferably from about 2000 to about 4500 daltons, even more preferably from about 2500 to about 4000 daltons, and most preferably from about 3500 to about 3800 daltons.

Preferably, the average chain length of each ethylene oxide block or chain is independently from about 2 to about 90, preferably from about 3 to about 50, more preferably from about 4 to about 20 ethylene oxide units.

Preferably, the copolymer comprises from about 10% to about 90%, preferably from about 15% to about 50%, most preferably from about 15% to about 25%, by weight of the copolymer of the combined ethylene oxide blocks. Most preferably, the total ethylene oxide content is equally divided over the two ethylene oxide blocks. Equally divided herein means that each ethylene oxide block comprises from about 40% to about 60%, preferably from about 45% to about 55%, even more preferably from about 48% to about 52%, most preferably about 50% of the total number of average ethylene oxide units, the% of the two ethylene oxide blocks adding up to 100%.

Most preferably, the weight average molecular weight of the copolymer is from about 3500 to about 3800 daltons, the propylene oxide content is from about 45 to about 55 propylene oxide units, and the ethylene oxide content is from 4 to 20 ethylene oxide units per ethylene oxide block.

Suitable ethylene oxide-propylene oxide-ethylene oxide triblock copolymers are commercially available from BASF under the trade name Pluronic PE series or from dow chemical as Tergitol L series. A particularly suitable material is Pluronic PE 9200.

Solid support: furthermore, the core of the high concentration anionic detergent particle of the present invention may comprise a solid carrier selected from the group consisting of: zeolites, silicas, carboxymethylcellulose, modified starches, and combinations thereof. Preferably, such solid carrier is present in an amount ranging from about 5% to about 50%, preferably from about 15% to about 45%, more preferably from about 20% to about 30%, by total weight of the detergent particle.

In a particularly preferred embodiment of the invention, the solid support is silica, and more preferably is hydrophilic silica. Silica has both an inner surface area and an outer surface area, which makes it easy to adsorb liquid and has a large liquid carrying capacity. Hydrophilic silica is particularly effective in adsorbing water. Any silica particle having a suitable particle size can be used in the practice of the present invention. Specifically, the silica particles have a dry particle size distribution DW50 in the range of about 0.1 μm to about 100 μm, preferably about 1 μm to about 50 μm, more preferably about 2 μm to about 40 μm, and most preferably 4 μm to about 20 μm.

Preferably, but not necessarily, the silica particles are comprised of hydrophilic silica that is hydratable to expand volume upon contact with the wash liquor. Without being bound by any theory, it is believed that the volume expansion of the hydrophilic silica helps to accelerate the breakdown of the detergent particles and allows the anionic surfactant to disperse and dissolve more quickly into the wash liquor. Thus, hydrophilic silica, preferably precipitated hydrophilic silica, is incorporated into the core of the detergent particle of the present invention together with anionic surfactant therein to provide higher surfactant activity and faster dispersion or dissolution benefits. Particularly preferred hydrophilic precipitated silica materials for use in the practice of the present invention are available under the trade name

340 are commercially available from Evonik Corporation.

The silica is preferably present in the core of the detergent particle in an amount in the range from about 10 wt% to about 50 wt%, more preferably from about 15 wt% to about 45 wt% and most preferably from about 20 wt% to about 30 wt%, based on the total weight of the detergent particle.

Water-soluble inorganic salt: further, the core of the high concentration anionic detergent particle of the present invention may comprise water soluble inorganic salts selected from the group consisting of: sodium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and combinations thereof. Particular preference for water-soluble inorganic salts for use in the practice of the inventionExamples of (b) include sodium sulfate and sodium carbonate, with sodium sulfate being most preferred. Such water-soluble inorganic salts may be present in an amount ranging from about 1% to about 20%, preferably from about 2% to about 15%, more preferably from about 3% to about 10%, by total weight of the detergent granule.

Optionally, the particle size of the one or more salts may be reduced by a grinding, milling or pulverizing step using any equipment known in the art for grinding, milling or pulverizing of granular or particulate compositions.

Other cleaning actives: in addition to the above ingredients, the core may, but need not, further comprise one or more other cleaning actives such as chelants, polymers, enzymes, bleaches, and the like. In a particularly preferred embodiment of the invention, the core of the high-strength anionic detergent particle of the invention is substantially free of such other cleaning actives.

Coating layer

A coating layer comprising silica is formed on the core of the detergent particle of the present invention. Such a coating may cover only a portion of the core, or the entire outer surface of the core. The coating is preferably a continuous layer, but it may also be discontinuous and cover discrete areas of the outer surface of the core. Such silica coatings may be present in an amount ranging from about 1% to about 10%, preferably from about 2% to about 5%, by total weight of the detergent particle.

The silica used to form the coating may be the same as or different from the silica used as the solid support in the core. Preferably, the silica in the coating is the same as the silica used in the core. More preferably, the silica in the coating is a hydrophilic silica, in particular a precipitated hydrophilic silica. Particularly preferred hydrophilic precipitated silica materials for use in the practice of the present invention are available under the trade name

340 are commercially available from Evonik Corporation.

Detergent granules

The particle size distribution of the detergent particles of the present invention may be such that D50 is from greater than about 150 microns to less than about 1700 microns. The particle size distribution of the detergent particles may be such that D50 is greater than about 212 microns to less than about 1180 microns. The particle size distribution of the detergent particles may be such that D50 is greater than about 300 microns to less than about 850 microns. The particle size distribution of the detergent particles may be such that D50 is greater than about 350 microns to less than about 700 microns. The particle size distribution of the detergent particles may be such that D20 is greater than about 150 microns and D80 is less than about 1400 microns. The particle size distribution of the detergent particles may be such that D20 is greater than about 200 microns and D80 is less than about 1180 microns. The particle size distribution of the detergent particles may be such that D20 is greater than about 250 microns and D80 is less than about 1000 microns. The particle size distribution of the detergent particles may be such that D10 is greater than about 150 microns and D90 is less than about 1400 microns. The particle size distribution of the detergent particles may be such that D10 is greater than about 200 microns and D90 is less than about 1180 microns. The particle size distribution of the detergent particles may be such that D10 is greater than about 250 microns and D90 is less than about 1000 microns.

In another aspect, the detergent particles may be used in bead detergents or derivatives thereof. The particle size distribution of the detergent particles may be such that D50 is greater than about 1mm to less than about 4.75 mm. The particle size distribution of the detergent particles may be such that D50 is greater than about 1.7mm to less than about 3.5 mm. The particle size distribution of the detergent particles may be such that D20 is greater than about 1mm and D80 is less than about 4.75 mm. The particle size distribution of the detergent particles may be such that D20 is greater than about 1.7mm and D80 is less than about 3.5 mm. The particle size distribution of the detergent particles may be such that D10 is greater than about 1mm and D90 is less than about 4.75 mm. The particle size distribution of the detergent particles may be such that D10 is greater than about 1.7mm and D90 is less than about 3.5 mm.

The bulk density of such detergent particles may range from about 300g/L to about 900g/L, preferably from about 400g/L to about 800g/L, more preferably from about 450g/L to about 550 g/L.

The total moisture content of the detergent particles of the present invention preferably does not exceed about 5%, preferably does not exceed about 3%, more preferably does not exceed about 2.5% by total weight of such detergent particles.

Granular detergent composition

The detergent particles described above are particularly useful in forming high active granular detergent compositions with improved water hardness tolerance, fast surfactant release and better dissolution or dispersion. Such detergent particles may be provided in the granular detergent composition in an amount in the range of from about 1% to about 99%, preferably from about 2% to about 80%, and more preferably from about 5% to about 50%, by total weight of the granular detergent composition.

The granular detergent composition may comprise one or more additional surfactants added directly thereto, i.e. independently of the detergent granules described above. The additional surfactant may be the same as those already included in the detergent particle, or they may be different. Anionic surfactants and other surfactants of the same type as described above are also suitable for direct addition to the granular detergent composition.

The granular detergent composition of the present invention may further comprise a water-swellable cellulose derivative. Suitable examples of water-swellable cellulose derivatives are selected from: substituted or unsubstituted alkylcelluloses and salts thereof, such as ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, methylcellulose, carboxymethylcellulose (CMC), crosslinked CMC, modified CMC, and mixtures thereof. Preferably, such cellulose derivative materials can rapidly swell within about 10 minutes, preferably within about 5 minutes, more preferably within about 2 minutes, even more preferably within about 1 minute, and most preferably within about 10 seconds after contact with water. Water-soluble cellulose derivatives may be incorporated into the structured particles of the present invention with hydrophilic silica, or they may be incorporated into the granular detergent composition separately from the structured particles, at levels ranging from about 0.1% to about 5%, and preferably from about 0.5% to about 3%. Such cellulose derivatives may also enhance the mechanical cleaning benefits of the granular detergent compositions of the present invention.

The granular detergent composition may optionally include one or more other detergent adjunct materials for assisting or enhancing cleaning performance, treating the substrate to be cleaned, or improving the aesthetics of the detergent composition. Illustrative examples of such detergent builder materials include: (1) inorganic and/or organic builders,such as carbonates (including bicarbonates and sesquicarbonates), sulphates, phosphates (e.g. tripolyphosphates, pyrophosphates and glassy polymeric metaphosphates), phosphonates, phytic acid, silicates, zeolites, citrates, polycarboxylates and their salts (such as mellitic acid, succinic acid, disuccinic oxide, polymaleic acid, benzene 1,3, 5-tricarboxylic acid, carboxymethoxysuccinic acid and its soluble salts), ether hydroxypolycarboxylates, copolymers of maleic anhydride and ethylene or methyl vinyl ether, 1,3, 5-trihydroxybenzene-2, 4, 6-trisulfonic acid, 3-dicarboxyl-4-oxa-1, 6-adipate, polyacetates (such as ethylenediaminetetraacetic acid and nitrilotriacetic acid) and their salts, fatty acids (such as C.C.₁₂-C₁₈Monocarboxylic acids); (2) chelating agents, such as iron and/or manganese chelating agents selected from the group consisting of amino carboxylates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents, and mixtures thereof; (3) clay-removal/anti-redeposition agents such as water-soluble ethoxylated amines (particularly ethoxylated tetraethylene-pentamine); (4) polymeric dispersants such as polymeric polycarboxylates and polyethylene glycols, acrylic acid/maleic acid based copolymers and water soluble salts thereof, hydroxypropyl acrylate, maleic acid/acrylic acid/vinyl alcohol terpolymers, polyethylene glycol (PEG), polyaspartates and polyglutamates; (5) optical brighteners, including but not limited to derivatives of stilbene, pyrazolines, coumarins, carboxylic acids, methinecyanines, dibenzothiophene-5, 5-dioxides, azoles, 5-and 6-membered ring heterocycles, and the like; (6) suds suppressors, such as monocarboxylic fatty acids and soluble salts thereof, high molecular weight hydrocarbons (e.g., paraffins, halogenated paraffins, fatty acid esters of monovalent alcohols, aliphatic C' s₁₈-C₄₀Ketones, etc.), N-alkylated aminotriazines, propylene oxide, monostearyl phosphates, silicones or derivatives thereof, secondary alcohols (e.g., 2-alkyl alkanols), and mixtures of such alcohols with silicone oils; (7) foam boosters, such as C₁₀-C₁₆Alkanolamide, C₁₀-C₁₄Monoethanol and diethanolamide, high foaming surfactants (e.g., amine oxides, betaines, and sultaines), and soluble magnesium salts (e.g., MgCl)₂、MgSO₄Etc.); (8) fabric softeners, such as montmorillonite clay, amine softeners and cationic softenersA softening agent; (9) pigment transfer inhibitors such as polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, manganese phthalocyanines, peroxidases, and mixtures thereof; (10) enzymes such as proteases, amylases, lipases, cellulases and peroxidases, and mixtures thereof; (11) enzyme stabilizers including water-soluble sources of calcium and magnesium ions, boric acid or borates (such as boric oxide, borax, and other alkali metal borates); (12) bleaching agents such as percarbonates (e.g., sodium carbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide), persulfates, perborates, magnesium monoperoxyphthalate hexahydrate, the magnesium salt of m-chloroperbenzoic acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanedioic acid, 6-nonylamino-6-oxoperoxyhexanoic acid, and photoactivated bleaching agents (e.g., zinc sulfonate and/or aluminum phthalocyanine); (13) bleach activators such as Nonanoyloxybenzenesulfonate (NOBS), Tetraacetylethylenediamine (TAED), amide-derived bleach activators including (6-octanamido caproyl) oxybenzenesulfonate, (6-nonanamido caproyl) oxybenzenesulfonate, (6-decanamido caproyl) oxybenzenesulfonate, and mixtures thereof, benzoxazine activators, acyllactam activators (especially acylcaprolactams and acylvalerolactams); and (9) any other known detergent builder ingredients including, but not limited to, carriers, hydrotropes, processing aids, dyes or pigments, and solid fillers.

Process for preparing detergent particles

The detergent granules of the present invention may be formed by well known processes, preferably by an agglomeration process, using suitable mixing equipment known in the art. Any suitable mixing device capable of handling viscous pastes may be used as the mixer described above for practicing the present invention. Suitable equipment includes, for example, high-speed pin mixers, ploughshare mixers, paddle mixers, twin-screw extruders, Teledyne compounders, and the like. The mixing process may be carried out batchwise or continuously.

In a preferred embodiment of the invention, the detergent particle is formed in at least two steps, including a first step, i.e. forming a core, and a second step, i.e. then forming a silica coating on the core.

In a particularly preferred, but not essential, embodiment of the invention, the detergent particles are formed in at least three steps, including a first step of forming an aqueous paste comprising one or more anionic surfactants, a non-quaternized alkoxylated polyethyleneimine and water; a second step of mixing the aqueous paste of the first step with a solid carrier to form core particles; and a third step of coating silica on the core particle to form a coating layer.

More preferably, the detergent granules of the present invention are formed according to a paste-agglomeration process comprising the steps of: (a) adding the powdered raw ingredients to a mixer-granulator, wherein the powdered raw ingredients may comprise one or more of solid carriers, water-soluble inorganic salts, buffering agents, dispersant polymers or chelating agents, necessary powder processing aids, and fines recovered from the agglomeration process; (b) adding a paste comprising a premix of concentrated anionic surfactant (i.e., AAS and/or LAS, optionally with other surfactants) and non-quaternized alkoxylated polyethyleneimine (optionally with ethylene oxide-propylene oxide-ethylene oxide (EO/PO/EO) triblock copolymer); (c) operating the mixer-granulator to provide a suitable mixing flow field to disperse the paste with the powder and form agglomerates; and (d) adding additional powder ingredients (i.e., silica and optionally other dry powders) to at least partially coat the agglomerates to form a coating; (e) optionally drying the resulting agglomerates in a fluid bed dryer to remove excess moisture; (f) optionally cooling the agglomerates in a fluidized bed cooler; (g) removing any excess fines from the agglomerate size distribution, preferably by elutriation from the fluidized bed of step (e) and/or (f), and recycling the fines back to step a; (h) removing excess oversize particles from the agglomerate size distribution, preferably by sieving; (i) milling the oversized particles and recycling the milled particles to step (a), (e) or (f). The paste-agglomeration process may be a batch process or a continuous process.

When the LAS surfactant is included in the detergent granule, it is preferably added in a separate stream from the pre-mixed surfactant paste containing the AAS. The method selection comprises adding pre-neutralized LAS as a solid powder in step (a), adding a neutralized or partially neutralized LAS paste as a supplement in step (b), or adding a liquid acid precursor (HLAS) as a supplement in step (b). In the latter case, sufficient free basicity must be present in the powder added in step (a) to effectively neutralize HLAS during the agglomeration process. Alternatively, HLAS neutralization may be performed in a separate pre-treatment step, first premixing HLAS with alkaline buffer powder ingredients and other optional solid carriers to form a neutralized pre-mixture of LAS and alkaline buffer powder in powder form, and then adding the pre-mixture in step (a) above. In another embodiment using a concentrated aqueous paste comprising a mixture of AAS surfactant and non-quaternized alkoxylated polyethyleneimine, an extrusion process may be used. The extrusion process comprises the following steps: (a) optionally adding a fine powder to the paste, dispersing the powder into the paste to form a harder paste; (b) extruding the paste mixture through a die plate opening of suitable size to obtain the desired particle size, thereby forming an extrudate; (c) dividing the extrudate into particles by cutting the extrudate directly as it leaves the die opening or by breaking it in a stirred mixer after the extrusion process; (d) optionally rounding the particles in a spheronization process to form spherical particles; (e) optionally drying the resulting granules in a fluid bed dryer to remove excess moisture; (f) optionally cooling the granules in a fluidized bed cooler; (g) removing any excess fines from the particle size distribution, preferably by elutriation from the fluidized bed of step (e) and/or (f), and recycling the fines back to step (a); (h) removing excess oversize particles from the particle size distribution, preferably by sieving; (i) milling the oversized particles and recycling the milled particles to step (a), (e) or (f).

In another embodiment, the non-quaternized alkoxylated polyethyleneimine detergent particle. The binder-agglomeration process comprises the steps of: (a) adding a powder feedstock to a mixer-granulator, wherein the powder comprises the AAS surfactant in the form of a fine powder, optionally with additional solid carrier, water soluble inorganic salt, buffering agent, dispersant polymer or chelating agent, necessary powder processing aids and the fine powder recovered from the granulation process; (b) adding a binder comprising a non-quaternized alkoxylated polyethyleneimine; (c) operating the mixer-granulator to provide a suitable mixing flow field to disperse the binder with the powder to form agglomerates; optionally, (d) adding additional powder ingredients (i.e., silica and other dry powder ingredients) to at least partially coat the agglomerates to form a coating; (e) optionally drying the resulting agglomerates in a fluid bed dryer to remove excess moisture; (f) optionally cooling the agglomerates in a fluidized bed cooler; (g) removing any excess fines from the agglomerate size distribution, preferably by elutriation from the fluidized bed of step (e) and/or (f), and recycling the fines back to step (a); (h) removing any excess oversize particles from the agglomerate size distribution, preferably by sieving; (i) milling the oversized particles and recycling the milled particles to step (a), (e) or (f). In this embodiment, achieving sufficient micromixing of the non-quaternized alkoxylated polyethyleneimine with the AAS surfactant requires that the surfactant-containing powder material have an initial particle size with a D50 particle size of less than about 100 microns and a D90 particle size of less than about 200 microns, more preferably a D50 particle size of less than about 50 microns and a D90 particle size of less than about 100 microns. A pre-milling step may be added to obtain a finer surfactant-containing powder material. To facilitate the milling, the surfactant-containing material may be combined with other dry materials such as builders and buffers. Alternatively, low temperature milling of the surfactant-containing material may be used. An example of particles prepared using this procedure is given in the examples section.

The concentrated surfactant paste is an intermediate composition that can be combined with other ingredients to form the detergent particles of the present invention. The concentrated surfactant composition may comprise, consist essentially of, or may consist of: a surfactant system, which may include an AAS surfactant and/or a LAS surfactant; alkoxylated amines, preferably alkoxylated polyamines; an organic solvent system; and water.

Preferably, the concentrated surfactant composition may comprise: from about 70% to about 90%, by weight of the composition, of a surfactant system, wherein the surfactant system comprises from about 50%, or about 60%, or about 70%, or about 80% to about 100% of an AAS surfactant; from about 0.1% to about 25%, by weight of the composition, of an alkoxylated Polyethyleneimine (PEI); less than about 5%, by weight of the composition, of an organic solvent system; and water.

Process for preparing a granular detergent composition comprising detergent particles

Granular detergent compositions provided in finished form may be prepared by mixing the detergent particles of the invention with a variety of other particles comprising the additional surfactants, cellulose derivatives and detergent adjunct materials described above. Such other particles may be provided in the form of spray-dried particles, agglomerated particles, and extruded particles. Alternatively, additional surfactants, cellulose derivatives and detergent adjunct materials may be incorporated into the granular detergent composition in liquid form by spray coating methods.

Process for using granular detergent composition

The granular detergent composition of the present invention can be used for washing fabrics in machine or hand. It is particularly suitable for hand washing. For hand washing, the laundry detergent is typically diluted by a factor of about 1:100 to about 1:1000, or about 1:200 to about 1:500, by weight, by placing the laundry detergent in a container with wash water to form a laundry wash liquor. The wash water used to form the laundry wash liquid is generally any readily available water, such as tap water, river water, well water, and the like. The temperature of the wash water may range from about 0 ℃ to about 40 ℃, preferably from about 5 ℃ to about 30 ℃, more preferably from about 5 ℃ to about 25 ℃ and most preferably from about 10 ℃ to about 20 ℃, although higher temperatures may be used for soaking and/or pretreatment.

The laundry detergent and wash water are typically agitated to uniformly disperse and/or partially or completely dissolve the detergent, thereby forming a laundry wash liquor. Such agitation forms a foam, typically a voluminous and creamy foam. Soiled laundry is added to the laundry wash liquor and optionally soaked for a period of time. Such soaking in the laundry wash liquor may be overnight, or for about 1 minute to about 12 hours, or for about 5 minutes to about 6 hours, or for about 10 minutes to about 2 hours. In one variation herein, the laundry is added to the container before or after the wash water, and then the laundry detergent is added to the container before or after the wash water. The methods herein optionally include a pre-treatment step wherein the user pre-treats the laundry with a laundry detergent to form a pre-treated laundry. In such a pretreatment step, the laundry detergent may be added directly to the laundry to form a pretreated laundry, which may then optionally be scrubbed, e.g., rubbed against a surface with a brush, or rubbed upon itself, prior to addition to the wash water and/or laundry wash liquor. In the case of adding pre-treated laundry to water, a dilution step may then be performed when laundry detergent from the pre-treated laundry is mixed with wash water to form laundry wash liquor.

The laundry is then hand washed by a user who may or may not use one or more hand-held washing devices, such as a washboard, brush, or wand. The actual hand wash duration may range from about 10 seconds to about 30 minutes, preferably from about 30 seconds to about 20 minutes, more preferably from about 1 minute to about 15 minutes, and most preferably from about 2 minutes to about 10 minutes. Once the laundry is hand washed, it can then be wrung out and put aside while the laundry washing liquid is used for other laundry, poured off, etc. Rinse water may then be added to form a rinse bath, and then it is common practice to agitate the laundry to remove surfactant residue. The laundry may be soaked in rinse water, then wrung out and set aside. When the liquid laundry detergents herein are used, the rinse number is typically from about 1 to about 3, or from about 1 to about 2. In a particularly preferred embodiment of the invention, the rinsing is carried out in a single rinsing step or cycle.

Test method

The following techniques must be used to determine the performance of the detergent particles and detergent compositions of the present invention so that the invention described and claimed herein can be fully understood.

Test 1: moisture content measurement

Two (2) grams of sample detergent particles were tested in a Mettler Toledo HR73 halogen moisture analyzer at 120 ℃ for 30 minutes. The percent (%) mass loss at the end of the measurement was recorded as the moisture content of the sample detergent particles.

And (3) testing 2: particle size distribution test

The particle size distribution of the detergent particles was determined by using ASTM D502-89, "Standard test method for particle size of soaps and other detergents", approved on 26.5.5.1989, and further illustrating the sieve size and sieve time used in the analysis. Following section 7 "procedure using machine sieving method", a clean set of dry sieves is required: 1400 microns, 1180 microns, 850 microns, 600 microns, 425 microns, 250 microns, 150 microns to cover the particle size ranges cited herein. The above described set of screens is used for a given machine screening method. Suitable screen shakers are available from the w.s.tyler Company, Ohio, u.s.a. The sieve shakes the test sample to about 100 grams and for 5 minutes.

Data are plotted on a semi-logarithmic graph, where the micron-sized openings of each sieve are plotted against the logarithmic abscissa, and the cumulative mass percent (Q)₃) Plotted against the linear ordinate. An example of the above data Representation is given in FIG. A.4 of ISO 9276-1:1998, "reproduction of results of particulate size analysis-Part 1: Graphical reproduction". For the purposes of the present invention, the characteristic particle size (Dx) is defined as the abscissa value of the point for which the cumulative mass percentage is equal to x%, and is calculated by linear interpolation between the data points directly above (a) and directly below (b) the value of x%, using the following formula:

Dx＝10^[Log(Da)-(Log(Da)-Log(Db))*(Qa-x％)/(Qa-Qb)]

wherein Log is a base-10 logarithm, Qa and Qb are the cumulative mass percentile values of the measured data directly above and below the xth percentile, respectively; and Da and Db are micron sieve size values corresponding to these data.

For example, for the following exemplary data sets:

sieve size (micron)	Mass percent (g) of sample from each sieve	Finer Cumulative Mass Percent (CMPF)
			1400	0％	99.9％
1180	13.6％	86.3％
			850	17.7％	68.6％
600	19.9％	48.7％
			425	21.1％	27.6％
250	24.1％	3.5％
			150	3.1％	0.4％
Base plate	0.4％	0.0％

The corresponding D50(x 50%) can then be calculated using the above formula. Specifically, the micron sieve size with CMPF directly above 50% (Da) is 850 microns, while the sieve size below (Db) is 600 microns. The cumulative mass directly above 50% (Qa) was 68.6%, and the cumulative mass below (Qb) was 48.7%. Thus, D50 ^ 10 [ Log (850) - (Log (850) -Log (600)) × (68.6% -50%)/(68.6% -48.7%) ] ^ 614 microns.

Examples

Example 1: exemplary detergent granule formulations：

TABLE I

*Sipernat@340

Including NaOH, salts and solvents from surfactant stock.

Example 2: comparative testing shows improved flowability

Providing four sample detergent particles comprising: (1) a control sample ("control") comprising neither the alkoxylated PEI polymer nor the silica coating; (2) the first comparative sample ("C1") contained alkoxylated PEI polymer only in the core, without silica coating. (3) A second comparative sample ("C2") comprising only a silica coating, and no alkoxylated PEI polymer in the core; and (4) a sample of the present invention ("S1") comprising an alkoxylated PEI polymer in the core and comprising a silica coating. The formulations of such sample detergent particles are listed below:

TABLE II

*Sipernat@340

Including NaOH, salts and solvents from surfactant stock.

The sample detergent particles listed above may be prepared by a suitable binder-agglomeration process. The process may be batch or continuous. Particle size distribution is one of the key factors affecting particle flowability. Therefore, it is important to ensure that all sample detergent particles have the same or substantially similar particle size distribution in order to minimise any potential impact of changes in particle size distribution on the results of the flowability test. The same or substantially similar particle size distribution of all sample detergent particles can be obtained by sieving the sample detergent particles with a complete set of clean dry sieves using a sieve shaker. The screened samples from each screen can then be combined to form sample detergent granules characterized by a desired particle size distribution. For example, all sample detergent particles tested herein were characterized by a D50 of about 614 microns, as measured by test 2 described above.

Before running the flowability test, each sample detergent particle was left in a thin layer in an open petri dish at ambient conditions (20-22 ℃ and 35-40% RH) enabling it to absorb water from the environment for about 1 day. Before running the flowability test, the samples required to reach an eRH of 30-35%.

Flowability (ff) of detergent particles for each sample_c) Is the ratio of σ 1 (consolidation stress) to σ c (unconfined yield strength) that is used to numerically characterize flowability: a larger ffc indicates a better flowability of the bulk solid. Fluidity (ff)_c) The data were generated by the Schulze Loop shear tester RST-XS (shown in FIG. 1), and the detailed test procedure for the Loop shear tester is described in detail in ASTM Standard D-6773.

The specific operating conditions of the Schulze Ring shear tester RST-XS are described below. To run the flowability test, sufficient preconditioned detergent particles are first filled into the shear unit and then excess material is scraped off with a doctor blade to form a flat powder bed. The mass of the filled bottom ring was then weighed and recorded. The filled bottom ring was placed on a ring shear tester and the lid was placed on the stack solid sample concentrically with the bottom ring. For pre-shearing, the bottom ring is rotated clockwise (as viewed from the top) to prevent the tie rod from rotating the cap. The consolidation stress at pre-shear was set to 16000Pa and five different other consolidation stresses (3200Pa, 4800Pa, 6400Pa, 8000Pa and 9600Pa) were also applied in the same test. The minimum shear stress required to shear the heap sample (shear to failure) at each consolidation stress was then measured to yield a yield trace (see figure 4.10 in d.schulze, Powder and Bulk Solid: Behavior, characteristics, Storage and Flow, Springer, 2008). Then, the yield trajectory is used to calculate consolidation stress σ 1 and unconfined yield strength σ c; and the ratio of σ 1 to σ c is the fluidity ff_c. The following are the flowability test results for the sample detergent granules:

TABLE III

The above flowability data shows that the combination of the alkoxylated PEI polymer in the core and the silica coating thereon in the sample detergent particle of the present invention, S1, surprisingly and unexpectedly improved the flowability of such detergent particles, significantly higher than the flowability improvement observed by the addition of the alkoxylated PEI polymer alone or the provision of the silica coating alone.

Example 3: comparative testing shows that the yield stress of the particles is improved

The following compressive force tests were also performed on four (4) sample detergent particles of example 2 (i.e., control, C1, C2, and S1):

a suitable mechanical testing machine (INSTRON 3369, where the compaction platen and punch and die are set to measure pressures up to at least 10 MPa) is used. The bottom punch is placed into the die. Sufficient sample detergent particles (250-. The top punch was added gently until it stayed on the powder. The die and punch were placed between the platens of a mechanical testing machine. The top platen is moved to a position less than about 1mm from the top of the punch. The compression test was performed on a force corresponding to a pressure limit of at least 10 MPa. After compression, the platens were retracted, the die and punches were removed, the tablets were ejected, and the height and mass of the tablets were measured.

After the above procedure, the compaction curve recorded in the system can be used to calculate yield stress data following the following procedure: the compaction curve start calculation is performed by taking the tangent lines from the particle rearrangement region to the particle deformation region (which are located close to the transition in the curve) and solving for the intersection of the tangent lines. The first derivative of the compaction curve is used to locate the tangent point at each lateral end of the grade transition. The apparent yield stress can be defined by this initial analysis. For a detailed data Analysis, see "Analysis and application of powder compatibility diagnostics," P.Mort in A.Levy, H.Kalman (eds.) Handbook of Conveying and Handling of Particulate Solids, Elsevier Science, 2001. The following is the apparent yield stress (MPa) of the sample detergent particles:

TABLE IV

The yield stress data above shows that the combination of the alkoxylated PEI polymer in the core and the silica coating thereon in the sample detergent particle of the present invention, S1, surprisingly and unexpectedly improved the physical strength of such detergent particles significantly over the improvement observed by the addition of the alkoxylated PEI polymer alone or the provision of the silica coating alone.

Each document cited herein, including any cross referenced or related patent or patent application and any patent application or patent to which this application claims priority or its benefits, is hereby incorporated by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with any disclosure of the invention or the claims herein or that it alone, or in combination with any one or more of the references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (17)

1. A detergent particle characterised in that the total anionic surfactant content is in the range 40% to 90% by weight, the detergent particle comprising:

-a core comprising: (a) one or more anionic surfactants; and (b) a non-quaternized alkoxylated polyethyleneimine having a polyalkyleneimine core, wherein one or more alkoxy side chains are bonded to at least one nitrogen atom in the polyalkyleneimine core; and

-a coating on the core, the coating comprising silica,

wherein the non-quaternized alkoxylated polyethyleneimine has the empirical formula (I) of (PEI) a- (EO) b-R₁Wherein a is the average number average molecular weight of the polyalkyleneimine core of the alkoxylated polyalkyleneimine and is in the range of 100 to 1,000 daltons, wherein b is the alkoxylated polyalkyleneimineAnd in the range of 5 to 40, and wherein R is₁Is a hydrogen atom, and is,

wherein the non-quaternized alkoxylated polyethyleneimine is present in an amount ranging from 0.5% to 10% by total weight of the detergent particle, and

wherein the silica coating is present in an amount in the range of from 1% to 10% by total weight of the detergent particle.

2. The detergent granule of claim 1, wherein the one or more anionic surfactants are selected from the group consisting of: (1) c₁₀-C₂₀Linear or branched alkyl alkoxylated sulfate surfactants; (2) c₆-C₂₀Linear or branched non-alkoxylated alkyl sulfate surfactants; (3) c₁₀-C₂₀Linear alkylbenzene sulfonate surfactants; and (4) combinations thereof.

3. The detergent particle of claim 2, wherein the core comprises only one surfactant which is the C₁₀-C₂₀Linear or branched alkyl alkoxylated sulphate surfactants.

4. The detergent particle of claim 2, wherein the core comprises the C₁₀-C₂₀Linear or branched alkyl alkoxylated sulfate surfactants and said C₁₀-C₂₀Linear alkylbenzene sulfonate surfactant wherein the weight ratio of alkyl alkoxylated sulfate to linear alkylbenzene sulfonate is in the range of 1:3 to 10: 1.

5. The detergent particle of any of claims 2-4, wherein the alkyl alkoxylated sulfate surfactant is C₁₂-C₁₈Linear alkyl ethoxylated sulfate having a weight average degree of ethoxylation of from 0.5 to 3.0.

6. The detergent particle according to claim 1, wherein the non-quaternized alkoxylated polyethyleneimine is present in an amount ranging from 1% to 5% by total weight of the detergent particle.

7. The detergent particle of claim 1, wherein the core of the detergent particle further comprises a solid carrier selected from the group consisting of: zeolites, silicas, carboxymethylcellulose, modified starches, and combinations thereof.

8. The detergent granule of claim 7, wherein the solid carrier is silica.

9. The detergent particle according to claim 7, wherein the solid carrier is present in an amount in the range of from 5% to 50% by total weight of the detergent particle.

10. The detergent particle of claim 1, wherein the core of the detergent particle further comprises a water-soluble inorganic salt selected from the group consisting of: sodium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and combinations thereof.

11. The detergent particle according to claim 10, wherein the water-soluble inorganic salts are present in an amount ranging from 1% to 20% by total weight of the detergent particle.

12. The detergent particle according to claim 1, wherein the silica coating is present in an amount ranging from 2% to 5% by total weight of the detergent particle.

13. The detergent granule of claim 1, wherein the silica is a hydrophilic silica.

14. A detergent particle according to claim 1, characterised in that the total moisture content is not more than 5% by total weight of the detergent particle.

15. A detergent particle comprising:

-a core comprising: (i) from 20% to 50% by total weight of the detergent particle of C₁₂-C₁₄A linear alkyl ethoxylated sulfate surfactant having a weight average degree of ethoxylation of from 0.5 to 1; (ii) from 10% to 50% by total weight of the detergent particle of C₁₂-C₁₄Linear alkylbenzene sulfonate surfactants; (iii) from 1% to 10% by total weight of the detergent particle of a non-quaternised alkoxylated polyethyleneimine having the empirical formula (I) of (PEI) x- (EO) y-R₃Wherein x is the average number average molecular weight of the polyalkyleneimine core of the alkoxylated polyalkyleneimine and is in the range of from 500 to 1000 daltons, wherein y is the weight average degree of ethoxylation in the one or more side chains of the alkoxylated polyalkyleneimine and is in the range of from 10 to 30, and wherein R is₃Is hydrogen; and (iv) from 20% to 40% by total weight of the detergent particle of silica; and

-a coating on the core, the coating comprising from 1% to 10% by total weight of the detergent particle of silica.

16. A granular detergent composition comprising from 1% to 99% of a detergent granule according to any of claims 1-15.

17. A process for making a detergent granule according to any of claims 1 to 15, the process comprising the steps of:

(a) forming an aqueous paste comprising the one or more anionic surfactants, the non-quaternized alkoxylated polyethyleneimine, and water;

(b) mixing the aqueous paste of step (a) with a solid carrier to form core particles; and

(c) silica is coated on the core particle.

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