CN1473193A - Remixing of detergent tablets - Google Patents

Abstract

The present invention relates to a multi-phase detergent composition of compressed particulate material wherein the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least one other phase by at least 300 microns. The phases of the composition of the invention are easily separated and avoid excessive contamination which would cause problems for the remixing operation. The present invention also relates to a process for the phase separation of multi-phase detergent compositions of compressed particulate material, wherein the geometric mean particle diameter of the first phase differs from the geometric mean particle diameter of the second phase by at least 300 microns, said process comprising the steps of: fragmenting the compressed composition into particles, and (b) separating the phases according to their particle size.

Description

Remixing of detergent tablets

technical field

The present invention relates to a method of tablet remixing and detergent tablets suitable for use in this method.

Background technique

Detergent tablet compositions are known in the art and they are known to have several advantages over detergent compositions in particulate form, such as ease of dosing, handling, transport and storage. Consumers especially appreciate the convenience of shaped detergent compositions since they can be administered through a dispensing container.

Multiphase tablets have the advantage of allowing essentially incompatible ingredients to be formulated in the same dosage unit. Tablets can be designed so that incompatible ingredients are kept physically separated and those ingredients are released sequentially. For example, it may be desirable to formulate a single-use composition comprising surfactant and fabric softener. However, many commonly used surfactants form complexes with fabric softeners resulting in poor cleaning, poor softening and possible residue on fabrics. Therefore, any composition containing these two classes of substances must be formulated with a limited number of compatible substances or designed to release the ingredients sequentially, so as to avoid incompatibility problems.

Tablets are usually prepared by premixing the ingredients of a detergent composition and forming a tablet from the premixed detergent components using any suitable equipment, preferably a tablet press. Multi-phase tablets are typically prepared by compressing the first composition in a tablet press to form a first substantially planar layer. Another detergent composition is then delivered into the tablet press to be placed on top of the first layer. The second composition is then compressed to form another second substantially planar layer.

Either method will produce a certain number of tablets that do not meet the quality standards that allow them to be shipped in trade. For example, damaged tablets, unattractive tablets, tablets with unacceptable levels of chemicals, etc. To minimize costs and make efficient use of resources, off-spec tablets should be recycled. When the tablet has a uniform composition, the off-spec tablet can simply be crushed and the particulate matter added back to its premix. However, when there are two or more distinct phases consisting of compressed particulate material and containing different materials, the remixing process becomes more complicated because the phases must be separated and remixed with their respective premixes.

It is an object of the present invention to provide a heterogeneous detergent composition of compressed particulate matter which is designed to ameliorate the problems associated with remixing such tablets. The present invention also provides a method of separating the phases of a multiphase detergent tablet.

Contents of the invention

The present invention relates to a multiphase detergent composition of compressed particulate material wherein, after comminution, the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least one other phase by at least 300 microns. The phases are thus easily separated, thereby avoiding excessive contamination between the phases which would cause problems in remixing operations.

The present invention also relates to a process for the separation of phases of a multiphase detergent composition made from compressed particulate material, wherein the geometric mean particle diameter of the first phase differs from the geometric mean particle diameter of the second phase by at least 300 microns, said The method includes the following steps:

(a) breaking up the compressed composition into particles, and

(b) Separate the phases according to their particle size.

The compressed particulate matter of the present invention may be in various forms such as granules, beads, sticks, pellets, and mixtures thereof. The particles are preferably solid particles, but may also be liquid or gel filled beads.

Detailed ways

The multiphase detergent compositions of the present invention are formed from compressed particulate material wherein the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least another phase by at least 300 microns. Preferably the geometric mean particle diameters differ between the phases by at least 500 microns, more preferably by at least 750 microns, even more preferably by at least 1000 microns, even more preferably by at least 1500 microns.

"Geometric mean particle size" as used herein refers to the geometric mass median diameter of a collection of discrete particles as determined by any standard mass-based particle sizing technique, preferably by dry sieving. Suitable sieving methods are in accordance with ISO 3118(1976). A suitable apparatus is a Ro-Tap Test Sieve Shaker Model B, using a selected size of 8 inch sieve.

The detergent compositions of the present invention may be of any suitable shape, such as hexagonal, square, rectangular, cylindrical, spherical and the like. Compositions of the invention are preferably rectangular or square, as this facilitates their use in dispensing dishes of automatic washing machines.

The phases of the invention may be arranged in any suitable manner. EP-A-055,100 shows some suitable heterogeneous forms. The detergent compositions of the present invention preferably have two phases. The phases are preferably arranged in layers, more preferably with one phase inserted into a mold of the other. If the composition of the invention comprises more than two phases, it is preferred, but not necessary, that each of the phases has a geometric mean particle diameter which differs from the geometric mean particle diameter of each of the remaining phases by at least 300 microns.

The invention is especially useful for heterophasic tablets made of compressed microparticles. Multi-phase detergent tablets are typically prepared by compressing the first composition in a tablet press to form the first phase. The other composition is then delivered to the tablet press and compressed on top of the first phase. Preference is given to using the main ingredient in particulate form. The tablet is preferably compressed with a force of less than 10000 N/cm2, more preferably no more than 3000 N/cm2, even more preferably no more than 750 N/cm2. In fact, a more preferred embodiment of the present invention uses less than 500 N/cm2 for compression. Generally, the compositions of the present invention will be compressed using relatively low forces to enable rapid disintegration. Suitable tabletting equipment includes standard single punch or spin presses (commercially available for example from Courtoy ^_ , Korsch ^_ , Manesty ^_ or Bonals ^_ ) or those described in WO-A-00/10800. Tablets are preferably prepared by compression in a tablet press capable of preparing tablets comprising a former. Multiphasic tablets can be prepared using known techniques. The tableting method preferably using the double punch principle (also described as a ring punch with a second core punch inside) comprises the following steps:

i) lowering the core punch and feeding the core phase of the tablet into the cavity formed,

ii) lowering the entire punch and feeding the annular phase into the cavity formed,

iii) Raising the core punch to the level of the annular punch (this step can be done during the feeding of the annular phase or during the compression step).

iv) Compress both punches against the compression plate. A pre-compression step can be added to this compression phase. At the end of the method, both punches are at the same level.

The tablet is then ejected from the die cavity by raising the punch system to the level of the turret head. The order of the steps can be varied depending on the desired end result. Tablets can also be prepared using a two-punch system (one lower punch and one upper punch).

Another preferred form of the compositions of the present invention is the particulate material contained by a membrane material, commonly referred to as capsules. The term "capsule" as used herein refers to a sealed structure made of a water-soluble film containing two or more phases of particulate matter. The capsule can be of any form, shape and material suitable for retaining the composition, eg, not allowing substantial release of the composition from the capsule until the capsule is contacted with water. The exact implementation will depend on factors such as the type and amount of composition in the capsule, the number of compartments in the capsule, the desired properties of each phase to be held, protected and delivered or released by the capsule. Preferably, the bladder as a whole is stretched during formation and/or closure of the bladder such that the resulting bladder is at least partially stretched.

Preferred water-soluble films for use in the present invention include polymers, copolymers or derivatives thereof selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene oxide, acrylamide, acrylic acid, cellulose, cellulose ether, fiber Vegetarian esters, cellulose amides, polyvinyl acetate, polycarboxylic acids and salts, polyamino acids or peptides, polyamides, polyacrylamides, maleic/acrylic acid copolymers, polysaccharides including starch and gelatin, natural gums , such as xanthan gum and carrageenan. More preferred are polyvinyl alcohol, polyvinyl alcohol copolymers and hydroxypropylmethylcellulose (HPMC). A highly preferred water-soluble film is one comprising a PVA polymer and having similar properties to the following commercially available films: commercially available as M8630, sold by Chris-Craft Industrial Products, Gary, Indiana, USA, and PT- 75.

The particulate material used to prepare the compositions of the present invention may be prepared by any granulation or granulation method. An example of such a process is spray drying (in a co-current or counter-current spray drying tower), which typically provides bulk densities of 600 g/L or less. Higher bulk density granular materials can be produced by continuous granulation and densification methods (eg using ^Lodige_CB and/or ^Lodige_KM mixers). Other suitable methods include fluidized bed methods, compaction methods (such as roll compaction), extrusion methods, and any particulate material produced by any chemical method such as flocculation, crystallization sentering, and the like.

The phases of the present invention may comprise any suitable material. The invention is especially useful when the phases contain ingredients that are substantially incompatible with each other or have different consumer-visible characteristics such as odor or color, as this makes it important to avoid contamination during remixing.

Materials typically added to detergent compositions include, but are not limited to, surfactants, fabric softeners, perfumes, chelating agents, suds suppressing systems, color fixing agents, polymeric dye transfer inhibiting agents, polymeric agents, wrinkle reducers, disintegration aids, enzymes, bleaches, builders, and mixtures thereof. These ingredients are described in more detail below.

Preferably the phase with the larger geometric mean particle diameter comprises one or more agents selected from the group consisting of fabric softeners, fragrances, foam suppressing systems, wrinkle reducing agents, chelating agents, color fixing agents, fabric abrasion reducing polymers, and mixtures thereof. More preferably the phase with the larger geometric mean particle diameter comprises one or more agents selected from the group consisting of fabric softeners, perfumes, suds suppressing systems, and mixtures thereof.

The compositions of the present invention preferably comprise a surfactant. Any suitable surfactant can be used. Preferred surfactants are selected from the group consisting of anionic surfactants, amphoteric surfactants, zwitterionic surfactants, nonionic surfactants (including semi-polar nonionic surfactants), cationic surfactants, and mixtures thereof. The compositions of the present invention comprise preferably from 0.5% to 75%, more preferably from 1% to 50%, most preferably from 5% to 30% by total weight of surfactants, based on the total weight of the composition. Detersive surfactants are well known and well described in the art (see, for example, "Surface Active Agents and Detergents", Vol. I & II, Schwartz, Perry and Beach). Some non-limiting examples of surfactants suitable for use in the present invention are:

1. Essentially any nonionic surfactant useful for detersive purposes can be included in the detergent compositions of the present invention. Preferred, non-limiting classes of useful nonionic surfactants include nonionic ethoxylated alcohol surfactants, capped alkyl alkoxylated surfactants, ether capped poly(alkoxylated ) alcohols, nonionic ethoxylated/propoxylated fatty alcohol surfactants, nonionic EO/PO and propylene glycol condensation products, nonionic EO and propylene oxide/ethylenediamine adduct products of condensation.

In a preferred embodiment of the present invention, the detergent composition comprises a mixed nonionic surfactant system comprising at least one low cloud point nonionic surfactant and at least one high cloud point nonionic surfactant agent.

The "cloud point" used in the present invention is a well-known characteristic of nonionic surfactants, that is, the solubility of the surfactant becomes worse as the temperature increases, so the temperature at which the second phase can be observed to appear is called "cloud point" (see Kirk Othmer's Encyclopedia of Chemical Technology, 3rd Ed. Vol.22, pp.360-379).

A "low cloud point" nonionic surfactant as used herein is defined as a nonionic surfactant system component having a cloud point below 30°C, preferably below 20°C, most preferably below 10°C.

Low cloud point nonionic surfactants additionally include polyoxyethylene, polyoxypropylene block polymers. Blocked polyoxyethylene-polyoxypropylene polymers include those based on ethylene glycol, propylene glycol, glycerol, trimethylolpropane and ethylenediamine as initiator reactive hydrogen compounds. Certain block polymeric surfactant compounds known as PLURONIC ^(TM) , REVERSED PLURONIC( ^TM ), and TETRONIC ^(TM) , available from BASF-Wyandotte Corporation of Wyandotte, Michigan, are suitable for use in the ADD compositions of the present invention. Preferred examples include REVERSED PLURONIC ^™ 25R2 and TETRONIC ^™ 702. Such surfactants are typically used herein as low cloud point nonionic surfactants.

A "high cloud point" nonionic surfactant as used herein is defined as a nonionic surfactant system component having a cloud point above 40°C, preferably above 50°C, most preferably above 60°C.

2. Essentially all anionic surfactants used for detersive purposes are suitable for use herein. These may include anionic sulfates, sulfonates, carboxylates, and sarcosinates (including, for example, sodium, potassium, ammonium, and substituted ammonium salts such as monoethanolammonium, diethanolammonium, and triethanolammonium Salt). Anionic sulfate surfactants are preferred.

Other anionic surfactants include isethionates such as acyl isethionates, N-acyl taurates, fatty acid amide compounds of methyl taurates, alkyl succinates and sulfo Succinates, monoesters of sulfosuccinates (especially saturated and unsaturated C ₁ 2 -C ₁₈ monoesters), diesters of sulfosuccinates (especially saturated and unsaturated C ₆ -C ₁₄ diesters), N-acyl sarcosinates. Resin acids and hydrogenated resin acids are also suitable, such as rosin, hydrogenated rosin, and resin acids and hydrogenated resin acids present in or derived from tallow.

Secondary alkyl sulfate surfactants are also suitable for use herein. These include those disclosed in US-A-6,015,784. Preferred secondary alkyl sulfate surfactants are those having sulfate moieties randomly distributed along the hydrocarbyl "backbone" of the molecule. Such substances can be described by the following structures:

CH ₃ (CH ₂ ) _n (CHOSO ₃ ⁻ M ⁺ )(CH ₂ ) _m CH ₃ where m and n are integers of 2 and greater than 2, and the sum of m+n is typically 9 to 17, and M is Water-soluble cations. Preferred secondary alkyl surfactants for use in the present invention have the following formula:

CH ₃ (CH ₂ ) _x (CHOSO ₃ ^- M ⁺ )CH ₃ , and

CH ₃ (CH ₂ ) _y (CHOSO ₃ ⁻ M ⁺ )CH ₂ CH ₃ wherein x and (y+1) are integers of at least 6, preferably 7 to 20, more preferably 10 to 16. M is a cation such as an alkali metal, ammonium, alkanolammonium, alkaline earth metal or the like. Typically the sodium salt is used. Further details of secondary alkyl surfactants suitable for use in the present invention are described in US-A-6015784.

3. Amphoteric surfactants suitable for use in the present invention include amine oxide surfactants and alkyl amphocarboxylic acids.

4. Zwitterionic surfactants may also be incorporated into the detergent compositions of the present invention. These surfactants can be broadly described as derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. Betaine and sulphobetaine surfactants are examples of zwitterionic surfactants useful in the present invention.

Suitable betaines are compounds of the formula: R(R ¹ ) ₂ N ⁺ R ² COO ^- , where R is a C ₆ -C ₁₈ hydrocarbyl group and each R ¹ is typically C ₁ -C ₃ An alkyl group, and R ² is a C ₁ -C ₅ hydrocarbon group. Preferred betaines are C ₁₂ -C ₁₈ dimethylammonium hexanoate and C ₁₀ -C ₁₈ amidopropane (or ethane) dimethyl (or diethyl) betaine. Complexed betaine surfactants are also suitable for use in the present invention.

5. Cationic ester surfactants for use in the present invention are preferably water-dispersible compounds having surfactant properties comprising at least one ester (ie -COO-) linkage and at least one cationic charge group. Other suitable cationic ester surfactants, including choline ester surfactants, are disclosed, for example, in US-A-4228042, US-A-4239660 and US-A-4260529.

Suitable cationic surfactants include quaternary ammonium surfactants selected from the group consisting of mono C ₆ -C ₁₆ , preferably C ₆ -C ₁₀ N-alkyl or alkenyl ammonium surfactants, wherein the remaining N positions have formazan substituted with hydroxyethyl or hydroxypropyl.

Preferred surfactants for use in the present invention are selected from the group consisting of anionic sulfonate surfactants (especially linear alkylbenzene sulfonates), anionic sulfate surfactants (especially C ₁₂ -C ₁₈ alkyl sulfates), Secondary alkyl sulfate surfactants, nonionic surfactants and mixtures thereof.

Highly preferred agents for use in the present invention are fragrances. In the context of this specification the term "perfume" refers to any odoriferous substance or any substance which acts as an odor counteractant. In general, such materials are characterized by a vapor pressure above atmospheric pressure at ambient temperature. Perfumes or deodorants useful in the present invention are mostly liquids at ambient temperature, but may also be solids known in the art, such as various camphoraceous fragrances. Many chemicals are known for their use as fragrances, including substances such as aldehydes, ketones, esters and their analogs. Most commonly used, naturally occurring vegetable and animal oils and exudates, including complex mixtures of various chemical components, are also known for use as fragrances, and such materials are useful in the present invention. Perfumes of the present invention may be relatively simple in their composition or may comprise highly elaborate mixtures of natural or synthetic chemical components, all of which are selected to provide any desired scent.

The perfume components of the present invention may comprise encapsulated perfumes, pro-perfume, pure perfume substances, and mixtures thereof.

Perfumes, which are usually solids, are also useful in the present invention. These materials can be mixed with a liquefier such as a solvent before being incorporated into the granule, or can simply be melted or incorporated, as long as the flavor does not sublime or decompose when heated.

Fragrances also include substances used as odor counteractants. These substances, although also referred to herein as "fragrances", do not have a discernible odor themselves, but can mask or reduce any unpleasant odors. Examples of suitable malodor counteractants are disclosed in US Patent No. 3,102,101.

The fragrance component may also comprise a fragranceogen. Fragrances are precursors of fragrances that release fragrances upon interaction with external stimuli such as moisture, pH, chemical reactions. Fragrances suitable for use in the present invention include those known in the art. Examples can be found in US-A-4,145,184, US-A-4,209,417, US-A-4,545,705, US-A-4,152,272, US-A-5,139,687 and US-A-5,234,610.

The compositions of the invention preferably comprise from 0.05% to 15%, preferably from 0.1% to 10%, most preferably from 0.5% to 5%, by weight of a perfume component.

Preferably the compositions of the present invention comprise a disintegration aid. The term "disintegration aid" used in the present invention refers to a substance or a mixture of substances which has the effect of accelerating the dispersion of the matrix of the composition of the present invention when in contact with water. This may take the form of substances which accelerate the disintegration itself or substances which enable the composition to be formulated or processed in such a way as to accelerate the disintegration effect of the water itself. For example, suitable disintegration aids include clays that swell on contact with water (thereby disrupting the matrix of the composition) and coatings that allow the use of lower pressures during processing to improve tablet integrity (thus breaking the matrix of the composition). making the tablet less dense and easier to disperse). Any suitable disintegration aid may be used, but they are preferably selected from disintegrants, coating agents, effervescent agents, binders, clays, highly soluble compounds, adhesive compounds, and mixtures thereof.

1. The compositions of the present invention may contain a disintegrant which swells when in contact with water. Disintegrants useful in the present invention include those described in Handbook of Pharmaceutical Excipients (1986). Examples of suitable disintegrants include clays such as bentonite; starches: native, modified or pregelatinized starch, sodium starch gluconate; resins: agar, guar gum, locust bean gum, karaya gum, Pectin, Gum Tragacanth; Croscarmellose Sodium, Crospovidone, Cellulose, Carboxymethylcellulose, Alginic Acid and Its Salts (including Sodium Alginate), Silicon Dioxide, Polyvinylpyrrolidone , soybean polysaccharides, ion exchange resins, and mixtures.

2. The composition of the present invention can be coated. Coatings can improve the mechanical properties of shaped compositions while maintaining or improving dissolution. This applies very advantageously to multilayer tablets, whereby the mechanical constraints of multiphase processing can be relieved by using a coating, thus improving the mechanical integrity of the tablet. Preferred coatings and methods for use in the present invention are described in EP-A-846,754, which is incorporated herein by reference. Preferred coating agent ingredients are dicarboxylic acids as described in EP-A-846,754. Particularly suitable dicarboxylic acids are selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecane Diacids, tridecanedioic acid and mixtures thereof. Adipic acid is most preferred. The coating preferably contains a disintegrant as described above which, on contact with water, will swell and break the coating into small pieces. Preferably the coating comprises a cation exchange resin ^{, such as the sodium salt of sulfonated poly(styrene-divinylbenzene) copolymer and Purolite _ C100CaMR} sulfonated poly (styrene-divinylbenzene) copolymers are marketed as calcium salts.

3. The compositions of the invention may contain an effervescent agent. Effervescent as used in the present invention refers to the generation of carbon dioxide gas as a result of the chemical reaction between the soluble acid source and the alkali metal carbonate, thereby emanating bubbles from the liquid. Addition of such effervescent agents to detergents shortens the disintegration time of the composition. The amount added is preferably 0.1% to 20% by weight of the composition, more preferably 5% to 20%. Preferably the effervescent agent should be added as an agglomerate of different particles or as a compact but not as individual particles.

4. Additional dispersion aids can be provided by using compounds such as sodium acetate, nitrilotriacetic acid and its salts or urea. A list of suitable dispersing aids is found in Pharmaceutical Dosage Forms: Tablets, Volume 1, 2nd Edition, edited by H.A. Lieberman et al., ISBN 0-8247-8044-2.

5. To aid dispersion, non-gelling binders may be added to the tablet-forming granules. They are preferably selected from synthetic organic polymers such as polyethylene glycols, polyvinylpyrrolidones, polyacetates, water-soluble acrylate copolymers, and mixtures thereof. The Pharmaceutical Excipients 2nd Edition brochure has the following binder classes: Gum Arabic, Alginic Acid, Carbomer, Sodium Carboxymethylcellulose, Dextrin, Ethylcellulose, Gelatin, Guar Gum, Type I Hydrogenated Vegetable Oil, Hydroxyethyl Cellulose, hydroxypropylmethylcellulose, liquid dextrose, magnesium aluminosilicate, maltodextrin, methylcellulose, polymethacrylate, povidone, sodium alginate, starch and zein. Most preferred binders also have an active cleaning function in the wash, such as cationic polymers. Examples include ethoxylated hexamethylene diamine quaternary compounds, bis-hexamethylene triamine or others such as pentamine, ethoxylated polyethylene amine, maleic acrylic polymers.

6. The compositions of the present invention may also comprise expandable clays. As used herein, the term "swellable" refers to clays that have the ability to swell (or swell) when in contact with water. These are usually three-layer clays such as aluminosilicates and magnesium silicates having an ion exchange capacity of at least 50 meq/100 g of clay. The three-layer expandable clays used in the present invention are geologically classified as smectites. Examples of clays that can be used in the present invention include montmorillonite, volmolite, nontronite, hectorite, saponite, sauconite, vermiculite, and mixtures thereof. Clays in the present invention are available under different trade names such as Thixogel #1 and Gelwhite GP (from Georgia Kaolin Co., Elizabeth, NJ, USA); Volclay BC and Volclay #325 (from American Colloid Co., Skokie, IL, USA); Black Hills Bentonite BH450 (from International Minerals and Chemicals); and Veegum Pro and Veegum F (from R.T.Vanderbilt). It should be recognized that the smectite-like minerals available under the above trade names may comprise a mixture of various discrete ore entities. Mixtures of such smectite minerals are suitable for use in the present invention.

7. The compositions of the present invention may comprise highly soluble complexes. Such complexes may be formed from mixtures or single compounds. Examples include acetate, urea, citrate, phosphate, sodium diisobutylbenzenesulfonate (DIBS), sodium toluenesulfonate, and mixtures thereof.

8. The compositions of the present invention may contain a compound which has a binding effect on the detergent matrix forming the composition. The cohesion on the particulate material forming the detergent matrix of the tablet is characterized by the force required to break a tablet or layer based on the detergent matrix under consideration compressed under controlled compression conditions. For a given compression force, a high tablet or layer strength indicates that the granules are highly cohesive together when the granules are compressed and thus stronger cohesion occurs. Methods for assessing tablet or layer strength (also known as diametrical fracture stress) are described in Pharmaceutical dosage forms: tablets, volume 1, edited by H.A. Lieberman et al., 1989. Adhesion is determined by comparing the tablet or layer strength of the original base powder without the adhesive compound to the tablet or layer of a powder mixture containing 97 parts of the original base powder and 3 parts of the adhesive compound strength for comparison. The compound having a binding effect is preferably added to the matrix in a substantially water-free form (moisture content below 10%, preferably below 5%). The adding temperature is between 10 and 80°C, more preferably between 10 and 40°C. When a tablet containing 50 grams of detergent granular material and having a diameter of 55 mm is increased by 30% due to the presence of 3% of a binding compound in the matrix granular material under a given pressure of 3000 Newtons % (preferably 60%, more preferably 100%), the compound is defined as having a binding effect on the particulate material according to the invention. An example of a compound having a binding effect is sodium diisoalkylbenzenesulfonate.

Another preferred ingredient suitable for use in the compositions of the present invention is one or more enzymes. Suitable enzymes include enzymes selected from the group consisting of peroxidase, protease, glucoamylase, amylase, xylanase, cellulase, lipase, phospholipase, esterase, cutinase, pectinase, cutinase, Proteases, reductases, oxidases, phenoloxidases, lipoxygenases, lignases, pullulanases, tannases, pentosanases, malanases, beta-glucanases, arabinosidases, hyaluronic acid Enzymes, chondroitinases, glucanases, transferases, laccases, mannanases, xyloglucanases, or mixtures thereof. Detergent compositions generally comprise a mixture of conventionally suitable enzymes such as proteases, amylases, cellulases, lipases. Enzymes are typically incorporated into detergent compositions at a neat enzyme level of from 0.0001% to 2%, preferably from 0.001% to 0.2%, more preferably from 0.005% to 0.1%, by weight of the composition. The above enzymes may be obtained from any suitable source, such as vegetable, animal, bacterial, fungal and yeast origin. The source can also be mesomorphic bacteria or extremophilic bacteria (psychrophilic, psychrotrophic, thermophilic, barophilic, alkalophilic, acidophilic, halophilic, etc.). These enzymes can be used in purified or unpurified form. It is now common practice to modify wild-type enzymes by protein/genetic engineering techniques to optimize their performance efficiency in the detergent compositions of the present invention. For example, variants can be designed such that the compatibility of the enzyme with usual ingredients of such compositions is improved. Alternatively, variants can be designed such that the pH optimum, bleach or chelant stability, catalytic activity, etc. of the enzyme variant can be adjusted to suit a particular cleaning application. With regard to enzyme stability in liquid detergents, attention should be focused on oxidation-sensitive amino acids (in terms of bleach stability) and surface charge (in terms of surfactant compatibility). The isoelectric point of such enzymes can be altered by substituting certain charged amino acids. Enzyme stability can also be further enhanced by creating, for example, additional salt bridges and strengthening metal binding sites to increase chelator stability. Furthermore, the enzyme can be chemically or enzymatically modified, eg PEGylated, cross-linked and/or it can be immobilized, ie the enzyme attached to a support can be used. The enzymes to be incorporated into detergent compositions may be in any suitable form, such as liquids, encapsulates, pellets, granules, or any other form according to well-established art.

The compositions of the present invention preferably comprise a builder. Suitable water-soluble builder compounds for use herein include polycarboxylates of water-soluble monomers or their acid forms, homo- or co-polymeric polycarboxylic acids or salts thereof, wherein the polycarboxylic acids comprise at least two polycarboxylic acids separated from each other by no more than 2 carbon atoms of carboxyl, carbonate, bicarbonate, borate, phosphate, and mixtures thereof. Carboxylate or polycarboxylate builders can be of the monomeric or oligomeric type, although monomeric polycarboxylates are generally preferred. Suitable carboxylates containing one carboxy group include the water soluble lactate, glycolate and ether derivatives thereof. Polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy)diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid, and Fumaric acid, and ether carboxylates and sulfinyl carboxylates. Polycarboxylates containing three carboxyl groups include especially the water-soluble citrate, aconitate and citraconic acid salts and succinate derivatives such as carboxymethyloxysuccinate as described in GB-A-1,379,241 , lactyloxysuccinates described in GB-A-1,389,732, aminosuccinates described in NL-A-7205873, oxypolycarboxylate materials described in GB-A-1,387,447. Polycarboxylates containing 4 carboxy groups suitable for use herein include those disclosed in GB-A-1,261,829. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives disclosed in GB-A-1,398,421, GB-A-1,398,422 and US-A-3,936,448, and the sulfonate derivatives described in GB-A-1,439,000 pyrolyzed citrate. Cycloaliphatic and heterocyclic polycarboxylates include cyclopentane-cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran-cis-dicarboxylates, 2,2,5, 5-tetrahydrofuran-tetracarboxylate, 1,2,3,4,5,6-hexane-hexacarboxylate and carboxymethyl derivatives of polyalcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and phthalic acid derivatives disclosed in GB-A-1,425,343. Preferred polycarboxylates are hydroxycarboxylates containing up to 3 carboxy groups per molecule, especially citrates. Mixtures of monomeric or oligomeric polycarboxylate chelating parent acids or their salts, such as citric acid or citrate/citric acid mixtures, are also contemplated for use as builders. Examples of carbonate builders are alkaline earth and alkali metal carbonates, including sodium carbonate and sodium sesquicarbonate and their mixtures with ultrafine calcium carbonate, such as disclosed in DE-A-2,321,001. Partially water-soluble builder compounds suitable herein include the crystalline layered silicates as disclosed in EP-A-164,514 and EP-A-293,640. Preferred crystalline layered sodium silicates have the general formula:

NaMSi _x O ₂₊₁ .yH ₂ O In the formula, M is sodium or hydrogen, x is a number from 1.9 to 4, and y is a number from 0 to 20. Such crystalline layered sodium silicates preferably have a two-dimensional sheet structure, such as the so-called delta-layer structures described in EP-A-164,514 and EP-A-293,640. The preparation of such crystalline layered silicates is disclosed in DE-A-3,417,649 and DE-A-3,742,043. A more preferred crystalline layered sodium silicate compound has _the structure _of formula 5- _Na2Si2O5 , known as NaSKS-6 ^™ , available from Hoeschst AG.

Substantially water-insoluble builders suitable for use herein include sodium aluminosilicates. Suitable aluminosilicates include aluminosilicate zeolites having the unit cell unit of the formula Na _z [(AlO ₂ ) _z (SiO ₂ ) _y ].xH ₂ O, where z and y are at least 6, and the combination of z and y The molar ratio is 1 to 0.5, x is at least 5, preferably 7.5 to 276, more preferably 10 to 264. The aluminosilicate material is in hydrated form and is preferably crystalline, containing 10% to 28%, more preferably 10% to 22%, water in bound form. Aluminosilicate zeolites may be naturally occurring materials, but are preferably synthetically derived. Synthetic crystalline aluminosilicate ion exchange materials are available under the designations Zeolite A, Zeolite B, Zeolite P, Zeolite X and Zeolite HS. Preferred aluminosilicate zeolites are colloidal aluminosilicate zeolites. When used as a component of detergent compositions, colloidal aluminosilicate zeolites, especially colloidal Zeolite A, provide enhanced builder performance, especially in terms of improved soil removal performance, reduced fabric fouling and improved fabric whiteness. In terms of maintenance. Mixtures of colloidal Zeolite A and colloidal Zeolite Y are also suitable in the present invention to provide excellent calcium ion and magnesium ion sequestration properties.

Fabric softeners can be used in the present invention. Any suitable softening agent may be used in the present invention, but quaternary ammonium agents and/or clay softening systems are preferred.

The term "quaternary ammonium agent" used in the present invention refers to a compound or a mixture of compounds having one quaternary nitrogen atom and one or more, preferably two, groups containing 6 or more carbon atoms. The quaternary ammonium agents used in the present invention are preferably selected from those substances having one quaternary nitrogen atom substituted by two groups each comprising 10 or more, preferably 12 or more carbon atoms . Preferred examples of quaternary ammonium compounds suitable for use in the compositions of the present invention are N,N-bis(canolyl-oxyl-ethyl)-N,N-dimethylammonium chloride, N,N-bis(canolyl -Oxy-ethyl)-N-methyl-N-(2-hydroxyethyl)ammonium, N,N-di(canolyl-oxy-ethyl)-N-methyl-N-(2 -Hydroxyethyl)ammonium and mixtures thereof. Especially preferred for use in the present invention is N,N-di(canolyl-oxy-ethyl)-N-methyl-N-(2-hydroxyethyl)ammonium methylsulfate. While quaternary ammonium compounds derived from "canolyl" fatty acyl groups are preferred, other suitable examples of quaternary ammonium compounds are derived from fatty acyl groups, wherein the term "canolyl" in the above examples is replaced by the term "tallow, coco, palm Palmyl, lauryl, oleyl, castoryl, stearyl, palmyl" instead, which correspond to the triglyceride source from which the fatty acyl units are derived. These alternative fatty acyl sources may contain fully saturated or preferably at least partially unsaturated chains.

Any suitable clay softening system may be used, but clay softening systems comprising a clay mineral compound and optionally a clay flocculant are preferred. If present, the forming compositions of the invention preferably comprise from 0.001% to 10% of the clay softening system by weight of the total composition. The clay inorganic compound is preferably a smectite clay compound. Smectite clays are disclosed in US-A-3,862,058, US-A-3,948,790, US-A-3,954,632 and US-A-4,062,647. Additionally EP-A-299,575 and EP-A-313,146 describe suitable organopolymeric clay flocculants.

The compositions of the present invention may comprise a chelating agent/heavy metal ion sequestering agent. The so-called heavy metal ion sequestering agent refers to a component for sequestering (chelating) heavy metal ions in the present invention. These components may also have calcium and magnesium chelating capacity, but preferentially exhibit selectivity for binding heavy metal ions such as iron, manganese and copper. Heavy metal ion sequestrants are used in amounts of from 0.005% to 20%, preferably from 0.1% to 10%, more preferably from 0.25% to 7.5%, most preferably from 0.5% to 5%, by weight of the composition. Suitable heavy metal ion sequestrants for use in the present invention include organic phosphonates such as aminoalkylene poly(alkylene phosphonates), alkali metal ethane 1-hydroxydiphosphonates, and nitrilotriethylene Methylphosphonate. Preferred among the above classes are diethylenetriaminepenta(methylenephosphonate), ethylenediaminetris(methylenephosphonate), hexamethylenediaminetetrakis(methylenephosphonate) and hydroxy-ethylene-1,1-diphosphonate. Other heavy metal ion sequestrants suitable for use in the present invention include nitrilotriacetic acid and polyaminocarboxylic acids such as ethylenediaminetetraacetic acid, ethylenetriaminepentaacetic acid, ethylenediamine disuccinic acid, ethylenediamine diamine Glutaric acid, 2-hydroxypropylenediamine disuccinic acid or any salt thereof. Especially preferred is ethylenediamine-N,N'-disuccinic acid (EDDS) or its alkali metal, alkaline earth metal, ammonium or substituted ammonium salts, or mixtures thereof. Preferred EDDS compounds are the free acid form and its sodium, magnesium or complexes.

The compositions of the present invention may comprise a suds suppressing system. Suds suppressing systems suitable for use in the present invention can include substantially all known antifoam compounds including, for example, silicone antifoam compounds, 2-alkyl and alcanol antifoam compounds. Preferred foam suppressing systems and antifoam compounds are disclosed in WO-A-93/08876 and EP-A-705324.

The compositions according to the invention may comprise color fixing agents (fixatives). These are well known commercially available materials which are intended to improve the appearance of dyed fabrics by minimizing fabric dye loss through washing. Many fixatives are cationic and are based on quaternized nitrogen compounds or nitrogen compounds with a strong cationic charge which forms in situ under the conditions of use. Cationic fixatives are commercially available under various trade names from several suppliers. Representative trade names include CROSCOLOR PMF and CROSCOLOR NOFF from Crosfield, INDOSOL E-50 from Sandoz, SANDOFIX TPS from Sandoz, SANDOFIX SWE from Sandoz, REWIN SRF, REWIN SRF-O and REWIN DWE from CHT-Beitlich GmbH , Tinofix ECO, Tinofix FRD and Solfin from Ciba-Geigy.

Other cationic color fixing agents are described in "Aftertreatments for Improving the Fastness of Dyes on Textile Fibers", Christopher C. Cook, Rev. Prog. Coloration, Vol. XII (1982). Color fixing agents suitable for use in the compositions of the present invention include ammonium salt compounds such as fatty acid-diamine condensates, especially diamine ester hydrochloride, acetate, monomethyl sulfate and benzyl hydrochloride. Non-limiting examples include oleyldiethylaminoethylamide, monomethylsulfate oleylmethyldiethylenediamine, monomethylsulfate-stearylethylenediamine-trimethylamine. Also included are N-oxides of tertiary amines, derivatives of polymeric alkyldiamines, polyamine cyanuric chloride condensates, aminated glycerol dichlorohydrins, and mixtures thereof.

Another class of fixing agents suitable for use in the present invention are cellulosic reactive fixing agents. To comprise a "fixing agent system", cellulosic reactive fixing agents may suitably be used in combination with one or more of the above-mentioned fixing agents. In the present invention, the term "cellulosic reactive fixative" is defined as a fixative which reacts with cellulosic fibers when heated or heat-treated in situ or by the formulator. Cellulose-active fixatives are described in detail in WO-A-00/15745.

The compositions of the present invention may comprise polymeric dye transfer inhibiting agents. If present, the shaped compositions of the invention preferably comprise from 0.01% to 10%, preferably from 0.05% to 0.5%, by weight of the total composition, of a polymeric dye transfer inhibiting agent. The polymeric dye transfer inhibiting agents are preferably selected from polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone polymers or combinations thereof.

Compositions of the present invention may comprise polymers which reduce fabric abrasion. Any suitable fabric abrasion reducing polymer may be used in the present invention. Some examples of suitable polymers are described in WO-A-00/15745.

Compositions of the present invention may contain a wrinkle reducing agent. Any suitable wrinkle reducing agent can be used in the present invention. Some examples of suitable wrinkle reducing agents are described in WO-A-99/55953.

Another ingredient that may be present is a bleach system, such as percarbonate, especially sodium salt, and/or organic peroxyacid bleach precursors, and/or transition metal bleach catalysts, especially those comprising Mn or Fe . It has been found that when the capsule or compartment is formed from a material containing free hydroxyl groups, such as PVA, preferred bleaching agents include percarbonate and preferably do not contain any perborate or borate. Borates and perborates have been found to interact with these hydroxyl containing species and reduce their solubility, also resulting in reduced performance. Inorganic perhydrates are a preferred source of peroxide. Examples of inorganic perhydrate salts include percarbonates, perphosphates, persulfates and persilicates. Inorganic perhydrate salts are generally alkali metal salts. Alkali metal percarbonates, especially sodium percarbonate, are the preferred perhydrates herein. Compositions according to the invention preferably comprise a peroxyacid or precursor thereof (bleach activator), preferably an organic peroxyacid bleach precursor. It is preferred that the composition comprises at least two peroxyacid bleach precursors, preferably at least one hydrophobic peroxyacid bleach precursor and at least one hydrophilic peroxyacid bleach precursor, as defined herein . The organic peroxyacid is then generated by in situ reaction of this precursor with a source of hydrogen peroxide. The hydrophobic peroxyacid bleach precursor preferably comprises a compound having an oxy-benzenesulfonic acid group, preferably NOBS, DOBS, LOBS and/or NACA-OBS as described herein. The hydrophilic peroxyacid bleach precursor preferably comprises TAED. Amide substituted alkyl peroxyacid precursor compounds are useful in the present invention. Suitable amide-substituted bleach activator compounds are described in EP-A-0170386.

The composition may contain a preformed organic peroxyacid. A preferred class of organic peroxyacid compounds is described in EP-A-170,386. Other organic peroxyacids include diacyl and tetraacyl peroxides, especially diperoxydodecanedioic acid, diperoxytetradecanedioic acid and diperoxyhexadecandioic acid. Mono- and diperazelaic acid, mono- and dipertridecanedioic acid, and N-phthaloylaminoperoxycaproic acid are also suitable for use in the present invention.

Other ingredients that may be added to the compositions of the present invention include optical brighteners, organic polymers, alkali metal silicates, colorants and lime soap dispersants.

The compositions of the present invention are not preferably formulated to have an excessively high pH. The pH of the composition of the invention is preferably from 7.0 to 12.5, more preferably from 7.5 to 11.8, most preferably from 8.0 to 11.5, measured as a 1% solution in distilled water.

Separation method

The present invention includes methods for the separation of two or more phases of compositions made from compressed particles. The method comprises the steps of:

(a) breaking up the compressed composition into particles, and

(b) Separate the phases according to their particle size.

The compressed composition may be comminuted by any suitable method, but the resulting particles must have substantially the same particle size as the original phase. That is, the crushing method must be a method of reacquiring each phase with a geometric mean particle diameter similar to that at the time of initial addition. The composition is preferably crushed using a pair of cylindrical drums with built-in knives (examples of these devices are Telschig shears and Opbouw Messen's Cru-cut ^- shears). The composition is then passed on to a conventional rotary screen to separate the plastic flow packs, and then to a block breaker (e.g., Kemutec ^K1350 Screener_ ) to further break down the last tablet fragments that were not broken by the shears .

After micronization, the phases of the composition (each having a different particle size) can be separated by any suitable method. Preferably, the granules are fed into a screening machine, such as a Rotex Gradex ^2000® , available from Rotex Corporation, Cincinnati, Ohio, USA.

Once the phases are separated, they can be fed into their respective premixes and recompressed.

Example

A composition was prepared using the following procedure:

first phase:

% by weight, based on

Total weight of composition

Anionic agglomerates 1 7.1

Anionic agglomerates 2 17.5

Non-ionic agglomerates 9.1

Cationic agglomerates 4.6

Layered silicate 9.7

Sodium percarbonate 12.2

Bleach activator agglomerates 6.1

Sodium Carbonate 7.27

EDDS/Sulphate Granules 0.5

Hydroxyethane diphosphonic acid tetrasodium salt 0.6

Soil Release Polymer 0.3

Fluorescent agent 0.2

Zinc Phthalocyanine Sulfonate Encapsulations 0.03

Soap powder 1.2

Foam suppressant 2.8

Citric acid 4.5

Protease 1

Lipase 0.35

Cellulase 0.2

Amylase 1.1

Binder sprayed on the system 3.05

Spray Fragrance 0.1

DIBS (sodium diisobutylbenzenesulfonate) 2.1

Anionic agglomerate 1 comprises 40% anionic surfactant, 27% zeolite and 33% carbonate.

Anionic agglomerate 2 comprised 40% anionic surfactant, 28% zeolite and 32% carbonate.

The nonionic agglomerate comprised 26% nonionic surfactant, 6% Lutensit K-HD 96 (ex BASF), 40% anhydrous sodium acetate, 20% carbonate and 8% zeolite.

The cationic agglomerate contained 20% cationic surfactant, 56% zeolite and 24% sulfate.

Phyllosilicate contains 95% SKS 6 and 5% silicate.

Bleach activator agglomerates comprised 81% tetraacetylethylenediamine (TAED), 17% acrylic/maleic copolymer (acid form) and 2% water.

EDDS/sulfate granules comprised 58% ethylenediamine-N,N-disuccinic acid sodium salt, 23% sulfate and 19% water.

Zinc phthalocyanine sulfonate encapsulates are 10% active ingredients.

The suds suppressor comprised 11.5% silicone oil (ex Dow Corning), 59% zeolite and 29.5% _H2O .

The binder sprayed on the system contains 0.5 parts of Lutensit K-HD 96 and 2.5 parts of polyethylene glycol (PEG).

Second phase:

% by weight, based on group

Total weight of compound

Softener and Fragrance Beads 8.4

The fragrance bead composition contains 56% expancel 091DE80, 7% silica, 8% fragrance, 5% cross-linked polyvinyl alcohol (PVA)-borate, 5% water, 18% cationic softener monomethyl sulfate N , N-di(candyl-oxy-ethyl)-N-methyl-N-(2-hydroxyethyl)ammonium and 1% of laundry-compatible Zeneca Monastral Blue.

manufacture:

Manufacturing of the first phase:

The detergent active composition of the first phase is prepared by mixing the granular components in a mixing tank for 5 minutes to form a homogeneous granular mixture. During this mixing, the above-mentioned binder composition is sprayed by means of a nozzle and a stream of hot air. The average particle size is 560 microns. Manufacturing of phase 2:

Second phase beads were made using a Braun food processor with a standard blender to which the above dry mixture was added. The mixer was run at high speed for 1 minute and the mixture was poured into a Fuji Paudal Dome Gran DGL1 (Japan) extruder having a 3 mm diameter hole in the extrusion end plate and operating at 70 revolutions per minute. speed running. The resulting product was added to Fuji Paudal Marumerizer QJ-230, and the machine was operated at a speed of 1000 revolutions per minute for 5 minutes to obtain a good spheroidization.

In the next step, the beads are coated with the partially insoluble coating agent. Apply as follows: 4% (based on the weight of the beads) of 80% cross-linked polyvinyl alcohol-borate and 20% water in a conventional mixing tank at a temperature of 70°C using spray nozzles and hot air. The mixture sprays the beads. The beads were then mixed in a tumbler mixer for 60 minutes and injected with hot air to evaporate part of the water contained in the PVA coating. The final water content in the beads is mentioned in the bead composition above.

The particle size of the obtained beads was 2110 microns.

Manufacture of tablets:

Multiphase tablet compositions were prepared using an Instron 4400 testing machine and standard dies for manual tablet manufacturing. 35 grams of the detergent active composition of the first phase are fed into a 41 x 41 mm die with rounded edges having a scale of 2.5 mm. The mixture is compressed with a force of 1,500 Newtons using a punch of suitable shape to form a concave pattern of 25 mm diameter and 10 mm depth in the tablet. Carefully remove the forming punch leaving the tablet in the die. 4 grams of beads to form the second phase were introduced into the former remaining in the shape of the first tablet and a final pressure of 1,700 Newtons was applied using a flat common punch to produce multi-phase tablets. The tablets are then manually ejected from the die.

In the next step, the tablets prepared as described above were manually dipped into the molten coating mixture at 170°C and then allowed to cool to room temperature to allow the coating to harden for coating. The composition and percentages of the coating agent are described in the composition of the tablet above.

The material equivalent to 1 kg of flow-packed tablets was processed by an Opbouw Messen shear and then transferred to a cylindrical rotary sieve with 10 mm x 10 mm openings to separate the plastic flow-packs from the crushed tablets. After flow pack separation, the mixture was transferred to a Kemutec K1350 Lump Breaker to convert tablet remaining fragments into powder.

To sort the particles according to their density, a laboratory-scale apparatus was prepared with 10 cm diameter transparent plastic columns. The column was connected at the top to a standard vacuum cleaner and had a screen with 50 micron openings on each side of the column. The system is set up in such a way that the airflow is controlled by the vacuum cleaner's own controls to return particles with a lighter density to the top of the column and denser particles to the bottom of the column.

To separate the large particle size phase from the smaller particle size phase, the powder stream was fed to a Rhewum WA 8/270 x 180V sieve with 1500 x 1500 micron openings. Two powder streams were recovered using this method: a coarse particle fraction with a geometric mean particle diameter of 2137 microns and a fine particle fraction with a geometric mean particle diameter of 691 microns.

These two fractions were then reblended at 10% by weight (in each phase) into the original powder stream and a new composition was prepared following the same procedure as indicated above.

Claims (10)

CLAIMS 1. A multiphase detergent composition of compressed particulate matter wherein the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least another phase by at least 300 microns. 2. A detergent composition according to claim 1, wherein the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least another phase by at least 750 microns. 3. A detergent composition according to claim 1 or 2, wherein the geometric mean particle diameter of one phase differs from the geometric mean particle diameter of at least one other phase by at least 1000 microns. 4. A detergent composition according to any preceding claim, wherein the composition has two phases. 5. A detergent composition according to any one of the preceding claims, wherein the phases are arranged in layered form. 6. A detergent composition according to any preceding claim, wherein the phases are arranged with one phase inserted into a mold of the other. 7. A detergent composition according to any preceding claim, wherein the composition is in the form of a tablet. 8. A method of phase separation of a multiphase detergent composition of compressed particulate matter, wherein the geometric mean particle diameter of the first phase differs from the geometric mean particle diameter of the second phase by at least 300 microns, said method comprising the steps of: (a) breaking up the compressed composition into particles, and (b) Separating the phases according to their particle size. 9. A method as claimed in claim 8, wherein the particles are separated by a screening machine. 10. A method as claimed in claim 8 or 9, wherein the separated phases are returned to their respective premixes and compressed again.