DE69424506T2 - Detergent composition - Google Patents

Description

FIELD OF INVENTION

The present invention relates to a novel capsule capable of protecting sensitive active ingredients (e.g. enzymes, peracid bleaches or bleach catalysts) in liquid detergent compositions and to liquid detergent compositions comprising the capsules.

BACKGROUND AND STATE OF THE ART

It is well known in the art that liquid detergent compositions can present a hostile environment for sensitive ingredients (e.g. enzymes, peracid bleaches, bleach catalysts or perfumes) used in these detergents. For example, enzymes are attacked by anionic actives, extreme pH conditions and/or by other enzymes. Bleaching agents, particularly peracid bleaches (as taught in US Patent 4,909,953 and WO/90/14336, for example), are known to be particularly harsh against enzyme components. Encapsulation has been used to protect these sensitive ingredients in liquid detergent.

One proposal to protect these sensitive ingredients is to use a polymer shell around the active component to protect the component. This proposal has been implemented, for example, in GB 1 390 503, Unilever, in EP 266 796, Showa Denko, and in US Patent No. 4 777 089 (Lion Corp.).

While such an attempt is effective in protecting active components, such as enzyme or enzymes, that are attacked by other enzymes or harsh surfactants, this type of capsule does not provide an effective barrier to protect the com component by attack by bleach. Bleach molecules can quickly penetrate the polymer coating and interact with the sensitive component.

In WO-A-93 22417, applicants teach an encapsulated polymer system comprising a hydrophilic water-soluble polymer or polymers chemically or physically bonded to a hydrophobic polymer core particle. Although these applications teach a type of "mesh-like" encapsulation created by entangling the hydrophilic molecules and forming an encapsulation mesh over the core, this "mesh" is still too porous to protect the active component, particularly when the liquid composition is a liquid composition containing a bleaching agent.

Another method that has been used to protect the active components from the liquid medium is to place the active ingredient in a hydrophobic oil so that the active ingredient is protected by the oil diffusing into the composition where it is subject to degradative attack.

For example, each of US Patent 4,906,396, Falholt et al.; EP 356,239, Allied Colloid; and EP 273,775, provide enzymes protected by hydrophobic oils.

However, the use of a hydrophobic oil alone does not provide sufficient protection, especially if the composition also contains strong degrading components, such as the peracid bleaches mentioned above. This may be because the hydrophobic oils have simply not been chosen carefully enough to stop the migration of the degrading components to the active or, conversely, the migration of the active to the degrading component.

U.S. Patent No. 4,906,396, Falholt et al., discloses a detergent enzyme dispersed in a hydrophobic oil. As can be seen in the examples below, the hydrophobic oil is simply not able to slow down the degradation of the enzyme, for example when placed in a bleach containing a liquid composition. Whether this is again due to the hydrophobic oil not being suitably selected to migrate sufficiently slowly from the enzyme to the bleach, or vice versa, is unknown. However, the hydrophobic oil alone is simply not as effective as the capsules of the invention.

In WO 92/20771, Allied Colloids Limited teaches a particulate composition comprising particles having a substantially anhydrous core comprising a matrix polymer containing an active ingredient, a layer of hydrophobic oil around the core and a polymer shell around the oil. It is stated that the matrix polymer (containing the active ingredient) should be sufficiently hydrophobic so that it disperses in the oil rather than the water.

The problem addressed by the patent is that without the hydrophobic matrix polymer, the active ingredient would migrate out of the oil too quickly and would not remain in the oil. In other words, the oil layer is not able to hold a hydrophilic particle without the hydrophobic matrix polymer. Although the retention of a hydrophilic active ingredient by the oil can be enhanced by entrapping the active ingredient with a hydrophobic matrix polymer, this requires modifying the active ingredient with hydrophobic matrix polymer prior to creating the capsule. This, in turn, is costly and causes the problem of not releasing the active ingredient quickly and effectively upon use.

The present invention differs from the reference in that the oil layer of the present invention is selected to be capable of holding a hydrophilic active in the absence of matrix polymer. As further noted above, since the active is not associated with the hydrophobic matrix polymer, it will be more rapidly and released more effectively during use (e.g. when the polymer shell is dissolved).

Consequently, there is a need in the art for a capsule composition that more effectively protects the active ingredients, particularly hydrophilic ingredients, from bleaches or other harsh components present in the detergent composition.

There is also a need to find such a capsule that also releases the active ingredients quickly and effectively during use, for example when the polymer shell is dissolved or burst.

SUMMARY OF THE INVENTION

The present invention relates to a novel capsule system which protects the active ingredients in detergent compositions (i.e. in particular compositions containing bleach) and which effectively releases the active ingredients during use, the capsule system comprising: (1) an oil dispersion containing the active ingredient and in which the oil is selected by satisfying certain defined criteria; and (2) a specific outer polymer shell surrounding the oil dispersion.

According to the present invention there is provided a capsule composition, preferably for use in a liquid cleaning composition, comprising:

(a) an active ingredient not associated with a hydrophobic matrix polymer;

(b) an oil dispersion containing the active ingredient, the oil being defined: (1) by its ability to retain at least 80% of the active ingredient in the oil after one hour when the dispersion of the active ingredient in oil is added to an aqueous solution containing 0.5% by weight of sodium lauryl sulfate; (2) the ability to suspend the active ingredient with less than 10% phase separation when stored at 37°C for one week; and (3) the ability to retain more than 50% of the active ingredient substance after 5 minutes of a wash cycle when measured at 40ºC; and

(c) a polymer shell surrounding the oil dispersion of (b);

wherein the oil is selected from at least one of the groups consisting of petrolatum, hydrophobic silica modified hydrocarbon oil, hydrophobic silica modified silicone oil, fat, fat derivatives, and fatty alkyl phosphate esters; and wherein the polymer of (c) is a water-soluble or water-dispersible polymer selected from the group consisting of synthetic non-ionic water-soluble polymers, modified polysaccharides, proteins, and modified proteins.

Preferably, the polymer shell consists of a water-soluble polymer or water-dispersible polymers selected from at least one of the group consisting of polyvinyl alcohol, a polyacrylamide, polyvinylpyrrolidone, carrageenan, guar gum, xanthan gum, cellulose and protein.

The present invention further relates to detergent compositions comprising such capsules.

Accordingly, the present invention provides a detergent composition comprising:

(a) 2 to 60 percent by weight of a surfactant, selected from the group consisting of anionic, nonionic, cationic, zwitterionic surfactants, soap and mixtures thereof; and

(b) a capsule composition as described above for use in the composition.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a new capsule system which protects active ingredients in detergent compositions and also rapidly and effectively releases the encapsulated active ingredient for use. Furthermore, the invention relates to compositions comprising these capsules.

Capsule system

The capsule system is embodied as a combination of (1) an oil dispersion that holds the actives in place, thus preventing the actives from diffusing into the solution and also providing a barrier that prevents bleach or other harsh factors/components (anionic surfactants or pH conditions) from coming into contact with the active; and (2) an outer polymer shell that surrounds the oil dispersion to prevent deformation of the oil dispersion during and after addition to the liquid detergent.

The oil in component (1) is selected to satisfy a combination of defined criteria as defined in claim 1 and further detailed below.

The oil component

The first component of the capsule system is the hydrophobic oil component. The oil components of the invention are defined by meeting each of the three defined criteria set out below: (1) their ability to retain the active ingredient in dispersion in an aqueous solution; (2) their ability to resist phase separation at ambient or elevated temperatures over time; and (3) their ability to rapidly and effectively release the encapsulated active ingredient upon use. As stated, the oils must meet all three defined criteria to be selected as the oil component of the invention.

According to the first criterion, the oil component is defined by its ability to retain at least 80% active ingredient, preferably 90%, after adding the active ingredient in the oil dispersion to an aqueous solution containing 0.5% by weight of surfactant for one hour without mixing. Testing was carried out using sodium lauryl sulfate, although any suitable surfactant may be used.

A second criterion by which the oil component is defined is its ability to hold the active in place and prevent the active from diffusing out or precipitating from the oil phase. The stability of the active in the oil dispersion can be determined by adding the active to the oil dispersion in a 10 ml graduated cylinder and measuring the phase separation of the active from the hydrophobic oil. It should be less than 10%, preferably less than 5%, phase separation when measured for 1 week at 37ºC.

The final criterion used to define the oil component is its ability to quickly and effectively release the active ingredient upon use. The oil release property can be determined by a standard Terg-O-Meter wash procedure. Terg-O-Meters are known in the art as such, for example Terg-O-Tometer UR7227. In these devices, generally 500 ml of wash liquor is stirred at above 70 rpm for about 20 minutes using the desired wash liquor.

The capsules of the invention were tested using 1000 ml at 100 rpm for 15 minutes at 40ºC.

The capsule should release more than 50%, preferably more than 70%, of the active ingredient after the first five minutes of the wash cycle when measured at 40ºC.

The hydrophobic oil component may be a liquid or a semi-solid at room temperature. Liquid oils alone having a viscosity of less than 10,000 centipoise (cP), such as mineral oils, silicone oils or vegetable oils, are not suitable for the invention and require modification. These oils do not have the ability to hold and retain the hydrophilic actives and do not provide sufficient protection of the active in a liquid detergent. The preferred liquid oil components are oils containing hydrophobic particles having a particle size of less than 3 µm, preferably less than 1 µm, more preferably less than 0.1 µm. Examples of such hydrophobic The preferred hydrophobic particles are hydrophobic silica, such as Cab-O-Sil TS 720 and Cab-O-Sil TS 530 from Cabot or Aerosil 200 from Degussa; and hydrophobic clay, such as Bentone SD-1 from Rheox. These hydrophobic particles can be incorporated into the oil physically, that is, simply by mixing the oil with the hydrophobic particles, or chemically, that is, by chemical interaction of the oil with the surface of the particles. The preferred hydrophobic particles are hydrophobically modified, fumed silica in the sub-micron size range, such as Cab-O-Sil TS 720. These hydrophobic particles can enhance the suspension of the active in the oil and also increase the ability of the oil to hold the active in an aqueous solution. Generally, the amount of hydrophobic particles in the oil is less than 15%, preferably less than 10%, more preferably less than 5%, but more than 0.5% should be used.

In preferred embodiments of the invention, the oil component is defined by the fact that it is a semi-solid rather than a liquid at room temperature. In particular, when the component has a melting temperature of about 35°C to 70°C, preferably 40°C to 65°C, the semi-solids have been found to hold the active better. Moreover, such materials release actives quickly enough under wash conditions to give wash performances comparable to compositions in which enzymes are re-added. Since these semi-solid oils also slow migration of the active from the oil phase or slow migration of the bleach or other harsh components against the active, they are again preferred.

The semi-solid oils are petrolatum, such as Pereco's Pereco Snow, Mineral Jelly and Tro-Grees; Witco's Multiwax; and fats (e.g. glyceryl esters of C₁₂-C₂₄ fatty acids) or fat derivatives such as mono-, di- or triglycerides. Hydrophobic particles such as hydrophobic fumed silica are also desirable to be incorporated into these semi-solid oils. to further increase their ability to retain active ingredients, particularly when the capsule according to the invention is processed or stored at a temperature close to or above the melting point of the semi-solid oils.

The oil around the active will generally comprise about 98% to 40%, preferably 90% to 70%, of the active in the oil dispersion.

Polymer coating

The second component of the capsule system is the polymer coating that surrounds the active ingredient in the oil dispersion.

The polymer suitable for this invention must be insoluble in the liquid cleaning product composition and must break down or dissolve during use of the product simply by dilution with water, pH change or mechanical forces such as agitation or abrasion. The polymers are water-soluble or water-dispersible polymers which are insoluble or can be made insoluble in the liquid detergent composition. Such polymers are described in EP 1 390 503, US 4 777 089, US 4 898 781, US 4 908 233, US 5 064 650 and WO-A-93 22417.

The water soluble polymers exhibit an upper separation temperature or cloud point. As is known in the art (P. Molyneaux, Water Soluble Polymers CRC Press, Boca Raton, 1984), the solubility or cloud point of such polymers is sensitive to electrolyte and they can be "salted out" by the appropriate type or amount of electrolyte. Such polymers can generally be effectively salted out by realistic amounts of electrolyte (< 10%). Suitable polymers in this class are synthetic nonionic, water soluble polymers including: polyvinyl alcohol, polyvinylpyrrolidone and their various copolymers with styrene and vinyl acetate and polyacrylamide and their various modifications as appropriate. ne discussed by Molyneaux (see above) and McCormick (in Encyclopedia of Polymer Science Volume 17, John Wiley, New York). Another class of useful polymers are modified polysaccharides such as carrageenan, guar gum, pectin, xanthan gum, particularly hydrolyzed cellulose acetate, hydroxyethyl, hydroxypropyl and hydroxybutyl cellulose, methyl cellulose and the like. Proteins and modified proteins such as gelatin are another class of polymer useful in the present invention, particularly selected for an isoelectric pH close to the liquid composition in which the polymers are to be used.

From the above discussion it is clear that a variety of hydrophilic polymers have potential applicability as a polymer coating for the capsules of the invention. The solution is to select a suitable hydrophilic polymer which would be essentially insoluble in the composition (preferably a concentrated liquid system) under which the prevailing electrolyte concentration would be, but which dissolves or decomposes when that composition is under conditions of use. The adjustment of such polar polymers is within the discretion of one of ordinary skill in the art, aware of the general requirements and the principles cited.

The capsule

The capsule of the present invention can be prepared by a variety of known encapsulation processes. For example, the capsule can be prepared according to the coacervation process in which the active ingredient in oil dispersion is dispersed into an aqueous solution of a water-soluble or water-dispersible polymer. In this process, a non-solvent of the polymer or an electrolyte is added or a pH change or a pressure change is caused to produce the capsule. Examples of this coacervation process are given in US 4,777 089, US 3,943,063 and US 4,978,483. Similarly, the capsule can be formed by adding the emulsion of active in oil in polymer solution to the non-solvent. In this process, the oil composition and the emulsification method are critical because the active must remain within the oil rather than diffusing out during emulsification of the active in the oil dispersion to a polymer solution. Hydrophobic particles, particularly sub-micron fumed silica, are particularly useful to assist in retaining actives in the oil during emulsification. The oil should contain a sufficient amount of hydrophobic particles to prevent diffusion of the hydrophilic active from the oil. The amount of hydrophobic particles in the oil is greater than 0.5%, preferably greater than 3% and less than 10%. The emulsification process should be carried out in a mild state to prevent overmixing of the active ingredient in the oil dispersion with the polymer solution and to ensure that the resulting oil droplet size is larger than the particle size of the active ingredient.

The capsule of the invention can also be prepared by extrusion dies as taught in US 3,310,612, US 3,389,194 or US 2,799,897 and GB 1,390,503. In these processes, the active ingredient in oil dispersion is extruded through the inner orifice of the die. Simultaneously, the water-soluble polymer solution is extruded through the outer orifice of the die to form a uniform coating on the surface of the active ingredient in the oil dispersion. The capsule is then formed by breaking up the coextrudate at the end of the die orifice by air, centrifugal force, blade or carrier force to form droplets which are hardened in a non-solvent of the water-soluble polymer to form the capsule.

The active ingredient

The active materials desired to be encapsulated by the capsule of the invention are those materials which will lose their activity in a cleaning product, particularly a liquid cleaning product containing a bleach, unless a hydrophobic oil coating is added in accordance with this invention. The active materials to be protected by the oil layer may be a hydrophilic active (e.g. enzyme or bleach catalyst) or a hydrophobic active (e.g. perfume) and may be solid, liquid or in aqueous solution. If it is a solid material, the particle size of the active should be less than 200 µm, preferably less than 50 µm. Of course, since the hydrophobic active can generally be easily protected by an oil layer and is generally not easily degraded by the harsh components in the composition, the advantages of the invention are more readily apparent when the active is a hydrophilic one. Hydrophilic active materials include enzymes, bleach catalysts, peracid bleaches, bleach activators and optical brighteners.

A preferred component of the capsules disclosed herein is an enzyme. The enzymes may be amylases, proteases, lipases, oxidases, cellulases or mixtures thereof. The amylolytic enzymes for use in the present invention may be those derived from bacteria or fungi. Preferred amylolytic enzymes are those described in British Patent Specification No. 1 296 839 which are cultured from the strains of aacillus Bicheniformis, NCIB 8061, NCIB 8059, ATCC 6334, ATCC 6598, ATCC 11 945, ATCC 8480 and ATCC 9945A. A particularly preferred enzyme is an amylolytic enzyme manufactured and sold under the trade name Termamyl by Novo Industri A/S, Copenhagen, Denmark. These amylolytic enzymes are generally solid granules and can tivities of about 2 to 10 maltose units/milligram. The amylolytic enzyme is normally included in an amount of 1% to 40% by weight of the capsule, especially 5 to 20% by weight.

The active ingredient may also be a proteolytic enzyme. Examples of suitable proteolytic enzymes are the subtilisins obtained from certain strains of B. subtilis and B. licheniformis, such as those commercially available under the trade names Maxatase, marketed by Gist-Brocades NV, Delft, the Netherlands, and Alcalase, marketed by Novo Industri A/S, Copenhagen, Denmark. Particularly preferred are the proteases obtained from a strain of Bacillus with a maximum activity through the pH range of 8-12, which are commercially available under the trade names Esperase and Savinase, marketed by Novo Industri A/S. These proteolytic enzymes are generally marketed as granules and may have enzyme activities of about 500 to 50,000 glycine units/milligram. The proteolytic enzyme is normally included in an amount of 1% to 40% by weight of the capsule, especially 5% to 20% by weight.

Lipolytic enzymes may also be included to enhance the removal of fatty soils. The lipolytic enzymes are preferably included in an amount of 1% to 40%, preferably 5% to 20% by weight. Cellulase enzymes may be used in an amount of 1% to 40% by weight of the capsule.

The total content of the enzyme in the capsule of the present invention is 1% to 40%, preferably 5% to 20%.

It should be understood that the enzyme may also be a genetically engineered variant of one of the enzymes described, engineered with a characteristic (e.g. stability) that is superior to its natural counterpart.

The protected active ingredient can also be peroxygen compound activators, peracid bleaches, bleach catalysts, optical brighteners and perfumes.

Peroxygen compound activators are organic compounds that react with peroxygen salts (e.g., sodium perborate, percarbonate, persilicate) in solution to form an organic peroxygen acid as the active bleaching agent. Preferred activators include tetraacetylethylenediamine, tetraacetylglycoluril, glucose pentaacetate, xylose tetraacetate, sodium benzoyloxybenzenesulfonate, and choline sulfophenyl carbonate. The activators can be released from the capsule to combine the peroxygen compound in the composition.

When the activator is included, the ratio between the peroxygen in solution and the activator is in the range of 8:1 to 1:3, preferably 4:1 to 1:2, and most preferably 2:1.

Although peroxyacids are generally conceivable for use in the composition rather than in the capsule, peroxyacid compounds can be used as the active ingredient in the capsule and especially in compositions where the conditions are so severe that the peroxyacid is deactivated.

Generally, the peroxyacids are amido or imidoperoxyacids and are present in the range of 0.5 to 50%, preferably 15 to 30%, by weight of the capsule. Preferably, the peroxyacid is an amide peracid. More preferably, the amide is selected from the group of amidoperacids consisting of N,N'-terephthaloyldi(6-aminopercarboxycaproic acid (TPCAP), N,N'-di(4-percarboxybenzoyl)piperazine (PCBPIP), N,N'-di(4-percarboxybenzoyl)ethylenediamine (PCBED), N,N'-di(4-percarboxybenzoyl)-1,4-butanediamine (PCBBD), N,N'-di(4-percarboxyaniline)terephthalate (DPCAT), N,N'-di(4-percarboxybenzoyl)-1,4-diaminocyclohexane (PCBHEX), N,N'-terephthaloyldi-(4-aminoperoxybutanoic acid) (C₃-TPCAP analogue, called TPBUTY), N,N'-terephthaloyldi(8-aminoperoxyoctanoic acid) (C�7;- TPCAP analogue, called TPOCT), N,N'-di(percarboxyadipoyl)phenylenediamine (DPAPD) and N,N'-succinoyldi(4-percarboxy)aniline (SDPCA). Such compounds are described in WO 90/14 336.

Other peroxyacids that may be used include the amidoperoxyacids disclosed in U.S. Patent No. 4,909,953 to Sadowski and U.S. Patent No. 5,055,210 to Getty.

Also, the active ingredient within the compounds can be a bleach catalyst (i.e., to activate peracids found in the composition outside the capsule).

Examples of such catalysts include manganese catalysts of the type described in U.S. Patent No. 5,153,161 or U.S. Patent No. 5,194,416, both of which are incorporated by reference into the present application; sulfonamine catalysts and derivatives as described in U.S. Patent No. 5,041,232, Batal, U.S. Patent No. 5,045,223, Batal, and U.S. Patent No. 5,047,163, Batal.

In particular, manganese catalysts include for example manganese complexes of the formula:

[LMnIV (OR)₃]Y

in which:

Mn is manganese in the oxidation state +4;

R represents a C₁-C₂₀ radical selected from the group consisting of alkyl, cycloalkyl, aryl, benzyl and combinations of radicals thereof, wherein at least two R radicals may also be linked together to form a bridging unit between two oxygen atoms coordinating with manganese;

L represents a ligand selected from a C₃-C₆₀ residue with at least 3 nitrogen atoms which coordinate with the manganese and

Y represents an oxidatively stable counterion.

The sulfonomines include compounds with the structure:

R¹R²C=NSO₂R³

in which:

R¹ can represent a substituted or unsubstituted radical, selected from the group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl and cycloalkyl radicals;

R² may represent a substituted or unsubstituted radical, selected from the group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl, R¹C=NSQ₂R³, nitro, halogen, cyano, alkoxy, keto, carbon and carboalkoxy radicals;

R³ may represent a substituted or unsubstituted radical, selected from the group consisting of phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl, nitro, halogen and cyano radicals;

R¹ with R² and R² with R³ can together form a cycloalkyl, heterocyclic and aromatic ring system.

Sulfonomine derivatives include compounds of the structure:

in which:

R¹ may represent a substituted or unsubstituted radical, selected from the group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl and cycloalkyl radicals;

R² is a substituted or unsubstituted radical selected from the group consisting of hydrogen, phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl,

nitro, halogen, cyano, alkoxy, keto, carbon and carboalkoxy radicals;

R³ may represent a substituted or unsubstituted radical, selected from the group consisting of phenyl, aryl, heterocyclic ring, alkyl, cycloalkyl, nitro, halogen and cyano radicals;

R¹ with R² and R² with R³ can together form a cycloalkyl, heterocyclic and aromatic ring system.

Bleach activators are particularly good candidates for bleach encapsulation because they can be used in very small quantities and because they are easily deactivated in solution.

In particular, the bleach activators are applied in an amount of about 1% to 30% by weight of the capsule composition, preferably 3% to 15% by weight.

As mentioned above, the active ingredients can also be optical brighteners or perfumes.

Compositions

The invention is further directed to the use of the capsules in compositions, in particular in liquid detergent compositions, most particularly in aqueous liquid detergent compositions. Preferably, the compositions are bleach-containing aqueous detergent compositions. Indeed, it is with those aqueous bleach-containing detergent compositions that the advantages of the present invention become more apparent, since it has hitherto been very difficult, if not impossible, to formulate capsules for use in aqueous bleach-containing compositions in which the actives are well protected in the capsule (for example, more than 80% active as defined above) and yet are readily released upon dilution.

The aqueous detergent compositions of the present invention are generally structured (duotropic) or unstructured (isotropic) detergent compositions as described in U.S. Patent No. 5,089,163, Aronson et al., or 4,908,150, Hessel et al., (for isotropic liquids), or U.S. Patent No. 4,992,194, Liberati et al., or U.S. Patent No. 5,147,576, Montague et al. (for structured liquids).

Such compositions will generally comprise water, surfactants, electrolyte (for structuring and/or builder purposes) and other ingredients as described below.

The surfactants may be anionic, nonionic, cationic, zwitterionic or soap or mixtures thereof such as those described, for example, in U.S. Patent No. 4,642,198 in columns 3 to 4.

The total amount of surfactant in the liquid composition of the invention may vary from 2 to 60% by weight, preferably 10 to 50% by weight, depending on the intended use. In the case of suspending liquids comprising anionic and a nonionic surfactant, the ratio thereof may vary from about 10:1 to 1:10. The term "anionic surfactant" as used in this context includes the alkali metal soaps of synthetic or natural long chain fatty acids having normally 12 to 20 carbon atoms in the chain.

The total amount of electrolyte(s) present in the composition for providing patterning may vary from about 1.5 to about 30%, preferably 2.5 to 25 weight percent.

In addition to the components discussed above, the liquid heavy-duty detergent compositions of the present invention may also contain certain optional ingredients in minor amounts. Typical examples of optional ingredients are foam control agents, fluorescers, perfumes, colorants, abrasives, hydrotropes, Masking agents, enzymes and the like in varying amounts.

Bleaching agents used in the invention may be any of those described above in U.S. Patent No. 4,992,194 to Liberati.

Peroxygen salts include salts such as sodium perborate, tetrahydrate or monohydrate, percarbonate, persilicate, persulfate, dipersulfate and the like. Other peroxygen compounds include perphosphates, peroxide and perpolyphosphates. As indicated above, the peroxygen salts can be activated by activators, which can be encapsulated actives.

The uncoupling polymer is also disclosed in U.S. Patent No. 4,992,194, Liberati. The bleaching agents can also be any of the peracid bleaching agents described in the Actives section (i.e., the mono- or dipercarboxylic acid amido or imido acids) or the amidoperoxyacids disclosed in U.S. Patent Nos. 4,409,953 and 5,055,210.

In a preferred embodiment of the invention, the composition is a peracid bleach-containing composition and the capsule of the invention (first embodiment) protects the active ingredient (e.g. enzyme or bleach catalyst) from the action of the peracid bleach (and other harsh components) in the liquid compositions. In this embodiment of the invention, the peracid bleach may be any of the peracid bleaches described above and are preferably amides selected from amidoperacids such as TPCAP, PCBPIP, PCBED and any of the other amides of peracids cited above when used in the composition, the peracid comprising from 0.1% to 50% by weight, preferably from 0.5% to 25% by weight, more preferably from 1% to 10% by weight of the composition.

The following examples are intended to further explain and describe the invention and are not intended to limit the invention in any way.

EXAMPLES Production of capsule and detergent composition

The capsule of the invention was prepared as described below using an enzyme slurry available from NOVO.

One part of a commercially available silicone enzyme slurry, Savinase 16SL/SR (ex Novo, 3.5 x 106 GU/g savinase activity), was added to two parts of neutralized Acrysol ASE-95 (which is a carboxylic acid-containing polyacrylate latex) aqueous solution (ex Rohm & Haas, 1.5 wt.%, pH = 7.3-8.0). The mixture was stirred with an overhead stirrer for 20 minutes to form an enzyme-in-oil-in-water emulsion. The emulsion was added and cured in an acid bath (98% water and 2% conc. H2SO4) using a micro-dropper (Thies Technology) to form a matrix enzyme capsule of approximately 1,000 microns with 2.4 x 106 GU/g enzyme activity. The capsule was cured in the acid bath for 40 minutes and stored in glycerin for further use.

This capsule was incorporated into the liquid detergent formulation with the composition shown in Table 1 below:

TABLE 1 BASIC FORMULATION FOR LIQUID DETERGENT

Water 24.8

Sorbitol (70%) 15.8

Glycerine 4.76

Sodium borate 10 H₂O 4.76

Sodium citrate 2 H₂O 9.52

Narlex DC-1 (from National Starch & Chem.)* 3.0

50% NaOH 5.43

DB100 (Dow Chem.) (antifoam agent) 0.1

Alkylbenzenesulfonic acid 21.83

Neodol 25-9 (non-ionic surfactant) 10.0

Total 100.00

The composition additionally contained a sufficient amount of peracid SBPB for 1000 ppm active oxygen and was stored at 37ºC.

* Hydrophobically modified aqueous polyacrylic acid solution with a molecular weight of about 4000. Similar polymers are taught in US Patent No. 5,147,576 to Montague et al.

example 1

To demonstrate that the capsule prepared as described above was superior to the silicone enzyme slurry alone (i.e., the non-encapsulated silicone enzyme slurry), applicants prepared the same silicone enzyme slurry according to the procedure set forth in U.S. Patent No. 4,906,396 by mixing the same silicone enzyme slurry (Savinase 16SL/SR (ex Novo)) in the detergent composition set forth in Table 1 above.

The applicants additionally compared the residual enzyme activity of the enzyme after 2 and 6 days, both when the enzymes were unprotected (i.e. the liquid composition alone) and when the enzyme was in a PVA/PS (i.e. Po lyvinyl alcohol-polystyrene) capsule as described in US-A-5 281 365, published January 25, 1994. The results are shown in the table below: % Residual Activity

* Liquid - Savinase 16, 0L

** Slurry - Savinase 16SL/SR

Capsule

Stability studies were performed at 37ºC using duotropic HDL (heavy duty liquid composition) from Table 1 containing SBPB (4,4'-sulfonylbisperoxybenzoic acid) with 1000 ppm active oxygen and enzymes with 18 GU/mg activity.

As can be seen from the table above, the stability of the enzyme in the composition alone or in the composition encapsulated by polymer (PVA/PS) but without oil or slurry was almost zero after 2 days. Some improvement was observed with slurry alone. However, the results using the combination of slurry encapsulation were far superior to slurry alone.

The example clearly shows that the use of both an oil or slurry layer and encapsulation is superior to either one.

Example 2

To ensure the stability of the enzyme used in the compositions comprising bleach peracids when the To determine how the enzyme is protected by the capsules of the invention, the stability of Savinase in the composition comprising one to two peracids, N,N'-di(4-percarboxybenzoyl)piperazine (PCBPIP) or N,N'-terephthaloyldi(6-aminopercarboxycaproic acid) (TPCAP), was tested. Although the presence of peracids would normally destroy almost immediately all enzyme activity, the following results were observed using the capsules of the invention.

Time (days) PCBPIP % residual enzyme activity

0 100

2 99

6 117

13 77

17 57

20 67

31 38

Time (days) TPCAP % residual enzyme activity

0 100

4 68

7 58

16 65

23 44

42 32

The capsule composition is that of the Preparation Example (Table 1 above). Stability studies were carried out at 37ºC in the same HDL as in Table 1, except that it contained one of the two peracids dosed with 1000 ppm of active oxygen instead of SBPB.

The effectiveness of the capsules can be clearly observed. Again, this example demonstrates the effectiveness of encapsulated slurry.

Example 3

To ensure that enzyme is released into the wash liquor from the capsules, the applicants tested the percentage activity released over time and the following results were observed:

Time (minutes) % Activity released

0 14.6

5 75.9

10 100.0

15 96.5

Conditions: 40ºC + 120 ppm Ca²&spplus;

The capsules were added to the liquid composition described above (Table 1).

As can be clearly seen, the release from capsules is more than 70% in the first 5 minutes of washing and is complete after 10 minutes. The example shows again that the encapsulated oils are well released.

Examples 4 and 5 and comparisons A and B

To demonstrate that some hydrophobic oils were superior to others when used in the capsule, protease was tested in various oils. It should be noted that each of the capsules was prepared by the matrix method described in the Preparation Example. The results for yield and percent residual activity are presented below.

In particular, slurry compositions were prepared comprising concentrated Savinase and an oil as follows:

The compositions were then formed from the slurry compositions containing 66.6 weight percent of the slurry composition and 33.4 weight percent of ASE 95 solution (1.5%).

Finally, these compositions were then prepared into capsules using the matrix encapsulation process. The capsules formed from slurry compositions 1 and 4 were referred to as Examples 4, 5 and the capsules formed from slurry compositions 2 and 3 were referred to as Comparative Examples A and B.

Applicants then tested (1) the Savinase activity within the capsule after the capsule was in the composition of Table 1, which additionally contained SBPB, peracid bleach (4,4-sulfonylbisperoxybenzoic acid), to determine what % of the original activity (as listed in the table above) this restored, and (2) the % residual enzyme activity for each capsule when measured after 3 days at 37ºC. The results are shown below.

It can be clearly observed that Examples 4 and 5, which represent oil or oils meeting all three criteria of the invention, retained a high percentage of initial activity (28% and 3.7%) relative to the comparative examples (1.2% and 0.4%), the oils not meeting all criteria. In addition, the residual activity after three days was also clearly superior.

The silicone oil (Comparison A) and mineral oil (Comparison B) showed low entrapment efficiency and also rapid loss of enzyme activity in the bleach-containing liquid. The addition of petrolatum to mineral oil (Example 5) can enhance the oil entrapment efficiency during capsule manufacture and can also dramatically increase the performance of the capsule. The same result was observed using Rhodisil LV461, which is a silicone oil containing hydrophobically modified silica.

The examples show that the oil composition is not only important in the entrapment efficiency of enzyme during the manufacture of the capsule, but is also critical in increasing the enzyme stability when the enzyme is used in a peracid-containing liquid heavy-duty detergent.

Without wishing to be bound by theory, it is believed that those oils with the ability to stop the enzyme from dispersing or diffusing out of the oil and the ability to prevent the penetration of harsh detergent ingredients into the capsule during capsule manufacturing and storage are those that show the greatest yield and residual activity over time.

Examples 6-9 and comparative examples C, D and E

The examples below are used to demonstrate the manufacture of the capsule and the effectiveness of the capsules in protecting active ingredients/enzymes, relative to the closest state of the art.

Preparation of capsule compositions Oil slurries

Enzyme dispersions were first prepared by dispersing Savinase enzyme particles (protease) in various oils using Dispermate (UMA-GETZMANN) at 2000 rpm for 10 minutes: The following seven (7) oil dispersions were prepared:

* This was considered a comparison because the enzyme particle phase separated from the oil during storage.

Capsules

Core shell savinase enzyme capsules (as a difference from matrix capsule preparation) were then prepared by encapsulating the Enzyme dispersions mentioned above with a polymer solution containing polyvinyl alcohol (Airvol 540) and Acrysol ASE-60 (which is an alkali-soluble emulsion thickener from Rohm & Haas) using a concentric triple nozzle.

Specifically, the enzyme-in-oil dispersion was fed through an inner port, the aqueous polymer solution was fed through the middle port, and the compressed air was passed through the outer port to prepare the enzyme capsules of 600 to 800 microns. These capsules were cured and stored in a saline solution containing 15% by weight sodium sulfate and 2% by weight sodium borax with a pH in the range of 6 to 7. The following capsule examples 6-9 and comparative examples C-E were thus prepared from seven dispersions.

Capsule examples Composition of the capsule

Capsule of comparison C 1 part enzyme dispersion 1 (silicone antifoam agent) and 6.7 parts polymer solution A*

Capsule 6 1 part enzyme dispersion 2 (silicone antifoam) and 6 parts polymer solution A*

Capsule of comparison D 1 part enzyme dispersion 3 (silicone oil 10 000) and 6.7 parts polymer solution A*

Capsule of comparison E 1 part enzyme dispersion 4 (mineral oil) and 6 parts polymer solution B**

Capsule 7 1 part enzyme dispersion 5 (mineral oil and Carbosil) and 6 parts polymer solution B**

Capsule 8 1 part enzyme dispersion 6 (Tro- Grees 5) and 6 parts Polymer solution B**

Capsule 9 1 part enzyme dispersion 7 (petrolatum) and 6 parts polymer solution B**

* Polymer solution A contains 2.7% Airvol 540 PVA (Air Product) and 1.3% Acrysol ASE-60 (Rohm & Haas).

** Polymer solution B contains 2.3% Airvol 540 and 1.2% Acrysol ASE-60.

Compositions

Enzyme Capsules 6-9 and Comparative Capsules C-E were then formulated into a liquid detergent composition containing 95.4 wt% of a stable liquid detergent formulation having the following composition.

BASIC FORMULATION OF LIQUID DETERGENT

Water 24.8

Sorbitol (70%) 15.8

Glycerine 4.76

Sodium borate 10 H₂O 4.76

Sodium citrate 2 H₂O 9.52

Narlex DC-1 (by National Starch & Chem.) 3.0

50% NaOH 5.43

DB100 (Dow Chem.) (antifoam agent) 0.1

Alkylbenzenesulfonic acid 21.83

Neodol 25-9 (non-ionic surfactant) 10.0

Total 100.00

and additionally contains 4.6 wt.% of stable peracid, N,N'-terephthaloyldi(6-aminopercarboxycaproic acid) (TPCAP), which was prepared as described in WO patent application 90 14 336.

The enzyme capsules were incorporated into the formulation indicated above to give 16,000 GU enzyme activity per gram of formulated liquid detergent. These formulated samples were stored at 37ºC and the residual Savinase activity from these stored samples was determined and entered in the left hand column of the table shown below: Table Residual enzyme activity of examples

To demonstrate that the capsules of the invention work by retaining enzyme activity, whereas the enzyme slurry alone (i.e., not encapsulated) did not and could not retain the same enzyme levels, applicants prepared the same Examples 6-9 and Comparative Examples C-E, but not encapsulated (i.e., right column of the table). The slurry corresponds only to examples of the system used in U.S. Patent No. 4,906,396, Falholz.

The slurry-only examples were prepared by stirring the prepared enzyme-in-oil dispersion into the same liquid detergent as used in the capsule examples, containing 4.6% TPCAP peracid, and were stored at 37°C. As noted, the residual Savinase enzyme activity of these slurry-only examples was shown in the right column of the table.

The enzyme stability data summarized in the table clearly show that the proprietary enzyme system according to US 4 906 396 did not provide any protection to the enzyme in the bleach-containing liquid detergent. Almost 0% enzyme activity activity remained overall from the slurry-only examples after storage for less than 1 week at 37°C. Depending on the oil used in the capsule composition of the invention, 22 to 78% enzyme activity remained after this bleach-containing liquid was stored for 2 weeks.

Example 10 - Performance

The performance of 3 Savinase enzyme capsules (Examples 6, 8 and 9) of this invention was compared with a liquid Savinase in the wash liquor for stain removal. A test cloth (AS10 Cloth, from Center for Test Material) stained with casein, pigments and oils was used. The performance of these Savinase capsules containing liquid detergent and the control containing liquid Savinase was summarized in Table 2 below. ΔΔ R values, which indicate the whiteness of the washed cloth, show that the capsule of the invention had released the encapsulated enzyme and performed the same as free Savinase. Table 2 is shown below:

TABLE 2 ENZYME RELEASE IN WASHING SOLUTION Enzyme sample ΔΔ R

Control (Savinase liquid) 11.0

Capsule of Example 6 7.9

Capsule of Example 8 9.3

Capsule of Example 9 10.5

Example 11

Another example using encapsulated lipase is described below:

A Lipolase enzyme particle was prepared by spray drying a mixture of 30 wt% Lipolase 100L (Novo) and 70 wt% Airvol 1603/polystyrene latex to give an enzyme particle with 210 x 103 LU/g Lipolase activity.

A Lipolase-in-oil dispersion was prepared by dispersing 25% by weight of this Lipolase particle into 75% by weight of Rhodosil LV461 silicone antifoam (from Rhone-Poulenc). One part of the Lipolase-in-oil dispersion was mixed with 3 parts of Acrysol ASE-95 solution (1.8% by weight, pH 7.5-8.0) with an overhead stirrer to prepare an enzyme-in-oil-in-water emulsion. A matrix enzyme capsule was prepared by adding the Lipolase-in-oil-in-water emulsion dropwise to an acid bath containing 98% water and 2% concentrated H₂SO₄. The capsule had a particle size of about 1,000 micrometers and 19 x 103 LU/g of Lipolase activity. A liquid detergent containing 88% by weight of the basic liquid detergent of Examples 6-9, 10% by weight benzoyl peroxide and 2% Lipolase capsule was formulated and stored at 37°C. A comparative example containing the non-encapsulated Lipolase 100L was also formulated with the same liquid detergent containing 10% by weight benzoyl peroxide and stored at 37°C for 1 week: 0% for the comparative example and 58% for the Lipolase capsule of the invention.

Examples 12-14

The examples below were used to demonstrate the preparation and effectiveness of the capsules in protecting PAP in a liquid laundry detergent.

Production of capsule components: PAP-in-oil dispersions:

PAP (phthalamidoperoxycaproic acid) dispersions were prepared by mixing PAP crystal in the various oils meeting the criteria stated in the invention using Dispermat (F1, VMA-Getzmann) at 2000 rpm for 10 minutes. Three dispersions were prepared as shown in the table below: TABLE PAP-in-oil dispersions

Each of these oils had the properties defined by the oils of the invention (i.e., retains more than 80% crystals, preferably more than 90% crystal after capsule manufacture; suspends actives with less than 10% phase separation under defined conditions; and releases under defined conditions).

Capsules

Core-shell PAP capsules were then prepared by encapsulating the above PAP dispersions with a polymer solution containing 3.3 wt% polyvinyl alcohol (Airvol 540, Air Products) and 1.7 wt% alkali-soluble polymer (ASE-60, Rohm & Haas) using a concentric triple die.

Specifically, the PAP-in-oil dispersion, polymer solution and compressed air were simultaneously fed to the nozzle tip through the central, middle and outer orifices, respectively. Three PAP capsules of 600-800 µm were prepared from the three dispersions as shown in the table below:

Table 2 PAP core-shell capsules Example capsule composition

Capsule 12 1 part PAP dispersion 1 (silicone antifoam agent) and 5 parts polymer solution

Capsule 13 1 part PAP Dispersion 2 (Tro-Grees) and 5 parts Polymer solution

Capsule 14 1 part PAP dispersion 3 (petrolatum) and 6 parts polymer solution

Composition:

PAP capsules 1-3 were then formulated into a liquid detergent with the following composition:

Table 3 - Basic formulation of liquid detergent Components wt.%

Sorbitol (70%) 15.8

Glycerine 4.8

Sodium borate 10 H₂O 4.8

Sodium citrate 2 H₂O 9.5

Narlex DC-1 (33%) 2.9

Sodium hydroxide (50%) 5.5

DB100 (silicone antifoam agent) 0.1

BDA (alkylbenzenesulfonic acid) 21.8

Neodol 25-9 (non-ionic surfactant) (with medium alkylation of about 9) 10.0

Water 24.9

The PAP capsule was incorporated into the formulation to give 4000 ppm active oxygen per gram of formulated liquid detergent. These formulated samples were stored at 37ºC and the residual PAP activity from these stored samples was determined and reported in the table below. Table 4 - Residual PAP Activity of Examples 12-14

The stability results show that the stability of PAP in a liquid detergent can be dramatically increased by protecting PAP in the capsule according to the invention.

Example 15

The following examples were used to demonstrate the preparation and effectiveness of the capsules in protecting manganese bleach catalyst [MnMeTACN, di- (N,N',N"-trimethyl-1,4,7-triazacyclononane)-tri(u-oxo)dimanganese(IV) di(hexafluorophosphate monohydrate)] in a liquid duty detergent:

Production of capsule components: Catalyst-in-oil dispersions:

Catalyst dispersions were prepared by mixing the manganese bleach catalyst in various oils using Dispermat (F1, VMA-Getzmann) at 2000 rpm for 10 minutes. The dispersion contained 81% Tro-Grees, 9% petrolatum and 10% manganese bleach catalyst.

Capsules:

The core-shell bleach catalyst capsule was then prepared by encapsulating the bleach catalyst dispersions, which were the same as Examples 12-14, with a polymer solution containing 3.3 wt% polyvinyl alcohol (Airvol 540, Air Products) and 1.7 wt% alkali soluble polymer (ASE-60, Rohm & Haas) using a concentric triple die.

Specifically, the catalyst-in-oil dispersion polymer solution and compressed air were simultaneously fed to the nozzle tip through the central, middle and outer orifices, respectively.

Compositions of bleach catalyst capsules Example No. Capsule composition

15 1 part magnesium bleach catalyst dispersion

1 (mixture of petrolatum and tro-grees) and 8 parts polymer solution

The capsules were then formulated into a liquid detergent with the following composition:

Table 3 - Basic formulation of liquid detergent Components wt.%

Sodium metaborate 1.50

Sodium borate 10.00

Sodium citrate 10.00

Narlex DC-1 (33%) 4.50

BDA (97%) 20.10

Neodol 25-9 8.60

Antifoam agent 0.25

Water 35.0

Sodium hydroxide (50%), pH adjusted to 10

The capsule was incorporated into the formulation at 0.2% of the active bleach catalyst in the formulated liquid detergent. The formulated samples were stored at 37ºC and 22ºC and the residual catalyst activity from these stored samples was determined and reported in the table below.

Claims (8)

1. Capsule composition comprising: (a) an active ingredient not associated with a hydrophobic matrix polymer; (b) an oil dispersion containing the active ingredient, wherein the oil is defined: (1) by its ability to retain at least 80% of the active ingredient in the oil after one hour when the dispersion of active ingredient in oil is added to an aqueous solution containing 0.5% by weight of sodium lauryl sulfate; (2) the ability to suspend the active ingredient with less than 10% phase separation when stored at 37ºC for 1 week; and (3) the ability to release more than 50% of the active ingredient after 5 minutes of a wash cycle when measured at 40ºC; and (c) a polymer shell surrounding the oil dispersion of (b); wherein the oil is selected from at least one of the groups consisting of petrolatum, hydrophobic silica modified hydrocarbon oil, hydrophobic silica modified silicone oil, fat, fat derivatives, and fatty alkyl phosphate esters; and wherein the polymer of (c) is a water-soluble or water-dispersible polymer selected from the group consisting of synthetic non-ionic water-soluble polymers, modified polysaccharides, proteins, and modified proteins. 2. Capsule according to claim 1, wherein the active ingredient is a hydrophilic active ingredient. 3. Capsule according to claims 1-2, wherein the active ingredient is selected from the group consisting of enzymes, peracid bleach, bleach catalyst, bleach activators and optical brighteners. 4. Capsule according to claims 1-3, wherein the active ingredient is an enzyme or enzymes selected from the group consisting of proteases, lipases, amylases, cellulases and oxidases. 5. Capsule according to claims 1-3, wherein the bleach activator is selected from the group consisting of tetraacetylethylenediamine, tetraacetylglycoluril, glucose pentaacetate, xylose tetraacetate, sodium benzoyloxybenzenesulfonate and choline sulfophenyl carbonate. 6. Capsule according to claims 1-3, wherein the bleach catalyst is a manganese catalyst or a sulfonomine or sulfonomine derivative catalyst. 7. Capsule according to claims 1-6, wherein the polymer of (c) is a water-soluble polymer or water-dispersible polymer selected from at least one of the group consisting of polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, carrageenan, guar gum, xanthan gum, cellulose and protein. 8. A detergent composition comprising: (a) 2 to 60 percent by weight of a surfactant selected from the group consisting of anionic, nonionic, cationic, zwitterionic surfactants, soap and mixtures thereof; and (b) a capsule composition according to any preceding claim.