WO1999014307A1

WO1999014307A1 - Structured high moisture solid compositions with improved physical properties

Info

Publication number: WO1999014307A1
Application number: PCT/US1997/016414
Authority: WO
Inventors: Liben Hailu; Rodolfo Uri Dimayacyac; Ulpiano Bonifacio Ii Dulguime; Natalie Ann Concepcion Saluta Lioanag; Fernando Ray Tollens
Original assignee: The Procter & Gamble Company
Priority date: 1997-09-17
Filing date: 1997-09-17
Publication date: 1999-03-25
Also published as: AU4419197A; CN1215748A; JPH11166200A

Abstract

The present invention is directed to a solid composition in the shape of a bar of from about 25 % to about 95 % structured soap composition, by weight of the final solid composition; wherein the structured soap composition includes a premixture of soap, a cellulose material, and structured soap moisture; and from about 10 % to about 40 % solid composition moisture, by weight of the final solid composition; wherein the ratio of the cellulose material to the solid composition moisture is from about 1:1 to about 1:80. Such a detergent composition satisfies the need for a solid composition with acceptable physical properties, such as improved processing, good bar in-use properties, and good storage physical properties, while maintaining acceptable sudsing characteristics. The process for making the high moisture solid composition described above is also described herein.

Description

STRUCTURED HIGH MOISTURE SOLID COMPOSITIONS WITH IMPROVED PHYSICAL PROPERTIES

FIELD The present invention relates to high moisture solid compositions in the shape of a bar having improved physical properties.

BACKGROUND

For many reasons, it is desirable that solid compositions such as laundry bars and personal cleansing bars contain high levels of moisture. Formulations containing high levels of moisture have physical, aesthetic, and economic advantages. For example, high amount of moisture in solid bar compositions provide bars with increased solubility and dispersion characteristics.

Additionally, high moisture bars can give better colorant/dye dispersion which results in desirable aesthetics. High moisture bars also generate a high amount of sudsing, which is desirable especially in countries where the amount of suds generated during the wash is equated with the cleaning ability of the bars.

High moisture bars are also more economically desirable from a per-unit- production standpoint, because water is inexpensive compared to many detersive ingredients. However, the amount of moisture in the solid composition formulation must be carefully balanced, as too much moisture creates undesirable physical characteristics such as easy deformation of the bar, bar mushiness, stickiness, and unacceptable wear rates of the bar during use.

Fillers and other inorganic materials can be added to solid compositions to harden the composition or otherwise improve the physical properties of the solid composition. However, adding such materials can also have adverse effects, such as increasing formulation and processing costs. Additionally, many fillers are incompatible for use in personal cleansing bars.

In order to form personal cleansing or toilet bar compositions, the conventional process involves reducing moisture from the soap and other conventional ingredients before mixing, milling, and plodding into desired, solid shapes. This reduction in moisture usually requires the use of a drying unit, such as a vacuum flash dryer. A technology that allows processing of the soap without first having to reduce the moisture content would eliminate the need for an extra piece of equipment such as a dryer, simplifying the process and reducing capital cost.

It has now been found that a high moisture solid composition having desirable physical properties can be achieved by including therein a structured soap composition. It has also been found that a structured soap composition can be used with other optional ingredients to form laundry detergent bars, personal cleansing bars, and other solid soap forms. It has also been found that high moisture bars can be produced by using a structured soap composition, which substantially eliminates the need to reduce and/or remove the moisture before forming solid shapes in the bar production process.

SUMMARY

A solid composition in the shape of a bar including from about 25% to about 95% structured soap composition, by weight of the final solid composition; wherein the structured soap composition includes a premixture of soap, a cellulose material, and structured soap moisture; and from about 10% to about 40% solid composition moisture, by weight of the final solid composition; wherein the ratio of the cellulose material to the solid composition moisture is from about

1 :1 to about 1 :80.

Such a detergent composition satisfies the need for a solid composition with acceptable physical properties, such as improved processing, lower formulation costs, good bar in-use properties, and good aesthetic characteristics, while also maintaining acceptable sudsing characteristics. The process for making the high moisture solid composition described above is also described. These and other features, aspects, and advantages of the present invention will become evident to those skilled in the art from a reading of the present disclosure with the appended claims. DETAILED DESCRIPTION In accordance with the present invention it has been found that solid compositions can possess acceptable physical properties, through the addition of a structured soap composition.

All percentages, ratios and proportions herein are by weight, unless otherwise specified. Furthermore, all percentages herein are by weight of the final solid composition, unless specified. All temperatures are in degrees Celsius

(°C) unless otherwise specified. All documents cited are incorporated herein by reference.

As used herein, the term "alkyl" means a hydrocarbyl moiety which is straight or branched, saturated or unsaturated. Unless otherwise specified, alkyl moieties are preferably saturated or unsaturated with double bonds, preferably with one or two double bonds. Included in the term "alkyl" is the alkyl portion of acyl groups.

The term "coconut oil" is used herein in connection with materials with fatty acid mixtures which typically are linear and have an approximate carbon chain length distribution of about 8% Cβ, 7% CIQ_> 48% C^<|2. 17% C14, 9% C^Q, 2% C18. 7% oleic, and 2% linoleic (the first six fatty acids listed being saturated). Other sources having similar carbon chain length distribution in their fatty acids, such as palm kernel oil and babassu oil, are included within the term coconut oil. The term "final solid composition" is used to indicate the final bar product at the end of the production process.

The term "the premixture" as used herein refers to the soap, cellulose material, and moisture mixture.

The term "solid composition moisture" is used herein to indicate the moisture in the final solid composition."

The term "structured soap moisture" is used herein to indicate the moisture in the structured soap composition. The term "tallow" is used herein in connection with materials with fatty acid mixtures which are typically linear and have an approximate carbon chain length distribution of 2% C14, 29% C-|6- 23% C^<|8- 2% palmitoleic, 41% oleic, and 3% linoleic (the first three fatty acids listed are saturated). Other mixtures with similar distribution, such as those from palm oil and those derived from various animal tallow and lard, are also included within the term "tallow." The tallow can also be hardened (i.e., hydrogenated) to convert part or all of the unsaturated fatty acid moieties to saturated fatty acid moieties.

Structured Soap Composition The structured soap composition of the present invention comprises a premixture of soap, a cellulose material, and structured soap moisture. The structured soap composition preferably includes, by weight of the structured soap composition:

(a) from about 25% to about 89%, preferably from about 31% to about 85%, more preferably from about 42% to about 79% soap; and

(b) from about 0.5% to about 40%, preferably from about 0.5% to about 24%, more preferably from about 0.5% to about 11% of a cellulose material; and

(c) from about 10% to about 50%, preferably from about 13% to about 45%, more preferably from about 19% to about 40% structured soap moisture. The structured soap composition may contain other optional ingredients such as anionic surfactants and builders. These components are mixed, preferably in a blender, to form a premixture. In a preferred formulation, the structured soap composition contains only soap, cellulose material, and structured soap moisture. In a preferred formulation, the soap is in paste form and already contains the required moisture; accordingly, only cellulose material need be added.

In one preferred process, the cellulose material is dispersed in water before adding it to soap to form the premixture. In another preferred method, neat soap and cellulose material are premixed, and the structured soap moisture is introduced into the premixture as part of the neat soap.

It is preferred that the soap, the cellulose material, and the structured soap moisture be mixed at the very start of the blending step for at least about 3 minutes, preferably from about 3 minutes to about 10 minutes, and more preferably from about 4 minutes to about 6 minutes, in order to homogenize the structured soap composition.

The structured soap composition can be used in forming solid compositions such as laundry detergent bars and personal cleansing bars. The amount of structured soap composition useful in forming the solid compositions herein is from about 25% to about 95%, preferably from about 30% to about 90%, more preferably from about 45% to about 90% by weight of the final solid composition.

Soap As used herein, "soap" means salts of fatty acids. The fatty acids useful herein are linear or branched carbon chains containing from about 8 to about 24 carbon atoms, preferably from about 10 to about 20 carbon atoms. The average carbon chain length for the fatty acid soaps is from about 12 to about 18 carbon atoms, preferably from about 14 to about 16 carbon atoms. Preferred salts of the fatty acids are alkali metal salts, such as sodium and potassium, especially sodium. Also preferred salts are ammonium and alkylolammonium salts.

The fatty acids of soaps useful in the subject invention bars are preferably obtained from natural sources such as plant or animal esters; non-limiting examples include coconut oil, palm oil, palm kernel oil, olive oil, peanut oil, corn oil, sesame oil, rice bran oil, cottonseed oil, babassu oil, soybean oil, castor oil, tallow, whale oil, fish oil, grease, lard, and mixtures thereof. Preferred fatty acids are obtained from coconut oil, tallow, palm oil (palm stearin oil), palm kernel oil, and mixtures thereof. Fatty acids can be synthetically prepared, for example, by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process.

Alkali metal soaps can be made by direct saponification of fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process or prepared in situ just prior to the structuring step. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium and potassium tallow and coconut soaps.

Preferred soap raw materials for the solid compositions herein are soaps made from mixtures of fatty acids from tallow and coconut oil. Typical mixtures have tallow to coconut fatty acid ratios of 85:15, 80:20, 75:25, 70:30, 50:50 and 0:100; preferred ratios are from about 80:20 to about 0:100.

A preferred soap for use herein are neat soaps made by kettle (batch) or continuous saponification. Neat soaps typically comprise from about 65% to about 75%, preferably from about 67% to about 72%, alkali metal soap; from about 24% to about 34%, preferably from about 27% to about 32%, water; and minor amounts, preferably less than about 1% total, of residual materials and impurities, such as alkali metal chlorides, alkali metal hydroxides, alkali metal carbonates, glycerin, and free fatty acids. Another preferred soap raw material is soap noodles or flakes, which are typically neat soap which has been dried to a water content of from about 10% to about 20%. Another preferred soap is one that is prepared via in situ neutralization of the fatty acids mentioned above.

Cellulose Material

A cellulose material is added to the soap to form the structured soap composition of the invention. This cellulose material can be in any physical form, such as, for example, powders, liquids, dispersions, suspensions, or solutions. In a preferred embodiment of the invention, the cellulose material is premixed with moisture before adding to the soap. In a more preferred embodiment, the cellulose material is premixed with hot water (at least 40°C) prior to addition to the soap.

Preferred cellulose materials useful herein include cellulosic polymers, cellulosic co-polymers, and mixtures thereof. Non-limiting examples of cellulose materials useful herein include cellulosic derivatives such as the hydroxyether cellulosic polymers available as METHOCEL from Dow; the C1-C4 alkyl celluloses and C4 hydroxyalkyl celluloses, see U.S. 4,000,093, issued December 28, 1976 to Nicol, et al.; and the methyl cellulose ethers. Such materials are available as, for example, METOLOSE SM100 and METOLOSE SM200, which are the trade names of methyl cellulose ethers manufactured by Shin-etsu Kagaku Kogyo KK.

The methyl cellulose ether described above is preferably represented by the following formula:

wherein R represents a hydrogen atom or a methyl group, respective Rs may be the same or different; and n represents the degree of polymerization. More preferably, the methyl cellulose ethers described herein have an average degree of substitution (methyl) per anhydroglucose unit from about 1.6 to about 2.3 and a solution viscosity of from about 80 to about 120 centipoise measured at 20°C as a 2% aqueous solution.

More preferred cellulose materials are carboxymethyl cellulose, carboxymethylhydroxyethyl cellulose, cellulose gums, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, microcrystalline cellulose and carboxymethyl cellulose sodium NF, nonoxynyl hydroxyethyl cellulose, xanthan gums, and mixtures thereof. As stated above, one preferred method is to dissolve or disperse the cellulose material in water or other solvent before adding the soap in order to form the structured soap composition.

Moisture

The structured soap composition comprises structured soap moisture. Some structured soap moisture must be present when premixing the soap and the cellulose material, to facilitate formation of the structured soap composition. Without intending to be limited by theory, it is believed that the structured soap moisture present at the premixing step leads to improved dispersion of the cellulose material within the structured soap composition. Moisture can be introduced into the premixture separately; for example, by adding free water, or can be brought into the mixture with an ingredient, such as with neat soap or the cellulose material, or a combination of both.

The structured soap composition comprises from about 10% to about 50%, preferably from about 13% to about 45%, more preferably from about 19% to about 40% structured soap moisture, by weight of the structured soap composition.

The solid compositions in the shape of a bar contain moisture, specifically, an amount of solid composition moisture, which includes the structured soap moisture. The amount of solid composition moisture useful herein is in from about 10% to about 40%, preferably from about 12% to about 35%, more preferably from about 17% to about 23%, by weight of the final solid composition. The weight ratio of cellulose material to solid composition moisture present in the final solid composition is from about 1 :1 to about 1 :80, preferably from about 1 :5 to about 1 :50, and more preferably from about 1 :5 to about 1 :15. Optional Ingredients

The structured soap composition as well as the solid compositions comprising the structured soap composition may contain other optional ingredients. Detergent builder is an optional ingredient. Varying levels of detergent builders can be used herein, according to the final form and desired characteristics. For example, laundry bars of the invention can contain from about 1% to about 50%, preferably from about 5% to about 30% detergent builder. These detergent builders can be, for example, phosphate builders such as water-soluble alkali-metal salts of phosphate, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof. Preferred detergent builders are a water-soluble alkali-metal salt of tripolyphosphate, and a mixture of tripolyphosphate and pyrophosphate. Specific preferred examples of detergent builders include sodium tripolyphosphates (STPP), tetra sodium pyrophosphates (TSPP), and mixtures thereof. The detergent builder can also be a non-phosphate detergent builder. Specific examples of non-phosphate, inorganic detergency builders include water-soluble inorganic carbonate and bicarbonate salts. The alkali metal (e.g., sodium and potassium) carbonates, bicarbonates, and silicates are particularly useful herein. Other specifically preferred examples of detergent builders include zeolites and polycarboxylates.

Sodium carbonate is a particularly preferred ingredient in the subject invention compositions, because in addition to its use as a detergent builder, it can also provide alkalinity to the composition for improved detergency, and can also serve as a neutralizing agent for acidic components during processing. Sodium carbonate is particularly preferred as a neutralizing inorganic salt for an acid precursor of a synthetic anionic surfactant used in such compositions, such as the alkyl ether sulfuric acid and alkyl benzene sulfonic acid.

Co-polymers of acrylic acid and maleic acid are preferred as auxiliary builders in laundry bar compositions of the present invention, because their use in combination with fabric softening clay and clay flocculating agents further stabilizes and improves the clay deposition and fabric softening performance.

Synthetic anionic surfactants which are suitable for use herein include the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cs-18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the sodium and potassium alkyl benzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099 to Guenther, et al., issued November 5, 1940, and 2,477,383 to Lewis, issued July 26, 1949. Especially valuable are linear straight chain alkyl benzene sulfonates (LAS) in which the average number of carbon atoms in the alkyl group is from about 11 to 13, abbreviated as C-j ι.13 LAS. The alkali metal salts, particularly the sodium salts of these surfactants are preferred. Alkyl benzene sulfonates and processes for making them are disclosed in U.S. Patents 2,220,099 to Guenther, et al., issued November 5, 1940, and 2,477,383 to Lewis, issued July 26, 1949.

Other synthetic anionic surfactants suitable for use herein are the sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates. Preparation of alkyl glyceryl ether sulfonates (AGS) are described in detail in U.S. Pat. 3,024,273 to Whyte, et al., issued March 6, 1962. Another suitable synthetic anionic surfactant for use herein are sodium or potassium salts of alkyl ethoxy ether sulfates (AES) having the following formula:

RO(C2H4θ)_xSθ3M In the above structure R is an alkyl of from about 10 to about 20 carbon atoms. On average, R is from about 13 to about 16 carbon atoms. R is preferably saturated and linear. In the above structure, x is an integer from 0.5 to about 20 and M is a water-soluble cation, for example, an alkali metal cation (e.g., sodium, potassium, lithium), preferably sodium or potassium, especially sodium. The preferred AES surfactant has a saturated linear alkyl with an average of 14 to 15 carbon atoms, an average of about one ethoxy unit per molecule, and is a sodium salt (Ci4-isAEiSO3Na).

In addition, suitable synthetic anionic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1 -sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane moiety.

Preferred synthetic anionic surfactants are C<ιo-18 linear alkyl benzene sulfonates, C13-I6 alkyl ethoxy ether sulfates, Cιo-14 alkyl glyceryl ether sulfonates, and C-ιo-18 ^a'^ky' sulfates (AS). The amount of synthetic anionic surfactant in the composition herein is from about 1% to about 30%, preferably from about 2% to about 25%, by weight of the final solid composition.

Optional surfactants, in addition to the structured soap composition, can be optionally included at levels up to a total of about 25%, preferably about 0.5% to about 20%. The preferred total surfactant level (structured soap + synthetic anionic surfactants + any other surfactants) useful herein is from about 25% to about 80%, by weight of the final solid composition.

In addition, a hydrotrope, or mixture of hydrotropes, can be present herein. Preferred hydrotropes include the alkali metal, preferably sodium, salts of toluene sulfonate, xylene sulfonate, cumene sulfonate, sulfosuccinate, and mixtures thereof. Preferably, the hydrotrope is added to the linear alkyl benzene sulfonic acid prior to its neutralization. The hydrotrope, if present, will preferably be present at from about 0.5% to about 5%, by weight of the final solid composition.

A preferred optional ingredient in solid compositions is an oxygen bleach component. The oxygen bleaching component can be a source of ^_OOH groups, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate. Sodium percarbonate (2Na2CO3-3H2O2) is preferred because it has a dual function of serving as both a source of HOOH and as a source of sodium carbonate. Another optional bleaching ingredient is a peracid p_er se, such as is represented by the formula:

CH3(CH2)w-NH-C(O)-(CH2)zCO3H wherein z is from 2 to 4 and w is from 4 to 10. The bleaching component can contain, as a bleaching component stabilizer, a chelating agent of polyaminocarboxylic acids, polyaminocarboxylates such as ethylenediaminotetraacetic acid, diethylenetriaminopentaacetic acid, and ethylenediaminodisuccinic acid, and their salts with water-soluble alkali metals. When oxygen bleach is used, it is preferred that the dihydric alcohol be one wherein the two hydroxyl groups are separated by at least one carbon atom. The oxygen bleach components, if any, can be added to the composition at a level up to 20%, preferably from about 1% to about 10%, and more preferably from about 2% to about 6%, by weight of the final solid composition.

Another optional ingredient of the subject invention, especially in laundry detergent bars, is a photobleach material, particularly phthalocyanine photobleaches which are described in U.S. Patent 4,033,718 issued July 5, 1977 to Holcombe, et al. Preferred photobleaches are metal phthalocyanine compounds, the metal preferably having a valance of +2 or +3; zinc and aluminum are preferred metals. Such photobleaches are available, for example, under the tradename TINOLUS or as zinc phthalocyanine sulfonate. Photobleach components, if included, are typically at levels up to about 0.02%, preferably from about 0.001% to about 0.015%, more preferably from about 0.002% to about 0.01%, by weight of the final solid composition.

Soil suspending agents can be optionally used herein. In the present invention, their use can be balanced with the fabric softening clay/clay flocculating agent combination to provide optimum cleaning and fabric softening performance. One such soil suspending agent is an acrylic/maleic copolymer, commercially available as Sokolan®, from BASF Corp. Other soil suspending agents include polyethylene glycols having a molecular weight of about 400 to 10,000, and ethoxylated mono- and polyamines, and quaternary salts thereof. Soil suspending agents should be used at levels up to about 5%, preferably from about 0.1 % to about 1 %, by weight of the final solid composition.

In laundry detergent bars of the present invention, a fabric softening clay is preferably included herein. If present, the fabric softening clay is preferably a smectite-type clay. The smectite-type clays can be described as expandable, three-layer clays; i.e., alumino-silicates and magnesium silicates, having an ion exchange capacity of at least about 50 meq/100 g of clay. Preferably the clay particles are of a size that they can not be perceived tactilely, so as not to have a gritty feel on the treated fabric of the clothes. Fabric softening clays can be added from about 1% to about 50% by weight of the final solid composition, preferably from about 2% to about 20%, and more preferably about 3% to 14%. While any of the smectite-type clays described herein are useful in the present invention, certain clays are preferred. For example, Gelwhite GP is an extremely white form of smectite-type clay and is therefore preferred when formulating white detergent bar compositions. Volclay BC, which is a smectite- type clay mineral containing at least 3% iron (expressed as Fe2θ3) in the crystal lattice, and which has a very high ion exchange capacity, is one of the most efficient and effective clays for use in the instant compositions from the standpoint of product performance. On the other hand, certain smectite-type clays are sufficiently contaminated by other silicate minerals that their ion exchange capacities fall below the requisite range; such clays are of no use in the instant compositions.

It has been found that the use of a clay flocculating agent in conjunction with a fabric softening clay provides surprisingly improved softening clay deposition onto clothes and enhances clothes softening performance, compared to that of compositions comprising softening clays alone. Polymeric clay flocculating agents are selected to provide improved deposition of the fabric softening clay. Typically such materials have a molecular weight greater than about 100,000. Examples of such materials can include long chain polymers and copolymers derived from monomers such as ethylene oxide, acrylamide, acrylic acid, dimethylamino ethyl methacrylate, vinyl alcohol, vinyl pyrrolidone, and ethylene imine. Gums, like guar gums, are suitable as well. The preferred clay flocculating agent is a poly(ethylene oxide) polymer. The amount of clay flocculating agent, if any, is about 0.2 to about 2%, preferably about 0.5 to about 1%, by weight of the final solid composition. Fillers may optionally be added. The use of the structured soap composition may allow a significant reduction in the amount of filler traditionally used to achieve a certain desired hardness. Starch and sodium sulfate are fillers that are compatible with the compositions of this invention. Sodium sulphate can be produced in situ as a by-product of the surfactant sulfation and sulfonation processes, or it can be added separately. Other filler materials include bentonite and talc.

Calcium carbonate is also a well known and often used filler ingredient of laundry bars. Fillers include minerals, such as talc and hydrated magnesium silicate-containing minerals, where the silicate is mixed with other minerals, e.g., old mother rocks such as dolomite. Filler materials are typically used, herein, at levels up to 40%, preferably from about 5% to about 25%, by weight of the final solid composition.

Binding agents for holding the bar together in a cohesive, soluble form can also be used, and include natural and synthetic starches, gums, thickeners, and mixtures thereof. Such materials, if included, are typically at levels up to about 8%, preferably from about 0.5% to about 6%, by weight of the final solid composition.

A particularly preferred optional ingredient of the present invention is a detergent chelant. Such chelants are able to sequester and chelate alkali cations (such as sodium, lithium and potassium), alkali metal earth cations (such as magnesium and calcium), and most importantly, heavy metal cations such as iron, manganese, zinc and aluminum. Preferred cations include sodium, magnesium, zinc, and mixtures thereof. The detergent chelant is particularly beneficial for maintaining good cleaning performance and improved surfactant mileage, despite the presence of the softening clay and the clay flocculating agent.

The detergent chelant is preferably a phosphonate chelant, particularly one selected from the group consisting of diethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methylene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetra(acetic acid) (EDTA), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof. Preferably such salts or complexes have a molar ratio of metal ion to chelant molecule of at least 1 :1 , preferably at least 2:1.

The detergent chelant can be included herein at a level up to about 5%, preferably from about 0.1% to about 3%, more preferably from about 0.2% to about 2%, even more preferably from about 0.5% to about 1.0%, by weight of the final solid composition.

Another preferred additional ingredient of the laundry bar is a fatty alcohol having an alkyl chain of 8 to 22 carbon atoms, more preferably from 12 to 18 carbon atoms. A preferred fatty alcohol has an alkyl chain predominantly containing from 16 to 18 carbon atoms, so-called "high-cut fatty alcohol," which can exhibit less base odor of fatty alcohol relative to broad cut fatty alcohols. Typically, a fatty alcohol, if present herein, is present at a level of from about 0% to about 10%, preferably from about 0.75% to about 6%, more preferably from about 2% to about 5%, by weight of the final solid composition. The fatty alcohol is generally added as free fatty alcohol. However, low levels of fatty alcohol can be introduced into the bars as impurities or as unreacted starting material. For example, laundry bars based on coconut fatty alkyl sulfate can contain, as unreacted starting material, from 0.1% to 3.5%, more typically from 2% to 3%, by weight of free coconut fatty alcohol on a coconut fatty alkyl sulfate basis. Another preferred optional ingredient in laundry bars of the current invention is a dye transfer inhibiting (DTI) ingredient to prevent diminishing of color fidelity and intensity in fabrics. A preferred DTI ingredient can include polymeric DTI materials capable of binding fugitive dyes to prevent them from depositing on the fabrics, and decolorization DTI materials capable of decolorizing the fugitives dye by oxidation. An example of a decolorization DTI is hydrogen peroxide or a source of hydrogen peroxide, such as percarbonate or perborate. Non-limiting examples of polymeric DTI materials include polyvinylpyrridine N-oxide, polyvinylpyrrolidone (PVP), PVP-polyvinylimidazole copolymer, and mixtures thereof. Copolymers of N-vinylpyrrolidone and N- vinylimidazole polymers (referred to as "PVPI") are also preferred for use herein. The amount of DTI included in the subject compositions, if any, is about 0.05 to about 5%, preferably about 0.2 to about 2%, by weight of the final solid composition.

Another preferred optional ingredient in the laundry bars of the current invention is a secondary fabric softener ingredient in addition to the softening clay. Such materials can be used, if at all, at levels of about 0.1% to about 5%, more preferably from 0.3% to about 3%, by weight of the final solid composition, and can include: amines of the formula R4R5R6N, wherein R4 is a C5 to C22 hydrocarbyl, and R5 and RQ are independently C1 to C10 hydrocarbyls. One preferred amine is ditallowmethyl amine; complexes of such amines with fatty acid of the formula R7COOH, wherein R7 is a Cg to C22 hydrocarbyl, as disclosed in EP No. 0,133,804 A to Burckett and Busch, published March 6, 1985; complexes of such amines with phosphate esters of the formula RδO- P(O)(OH)-ORg and HO-P(O)(OH)-ORg, wherein Rs and R9 are independently C1 to C20 alkyls of alkyl ethoxylate of the formula -alkyl-(OCH2CH2); cyclic amines such as imidazolines of the general formula 1 -(higher alkyl) amido (lower alkyl)-2-(higher alkyl)imidazoline, where higher alkyl is from 12 to 22 carbons and lower alkyl is from 1 to 4 carbons, such as described in U.K. Patent Application GB 2,173,827 A to de Buzzaccarini, et al., published October 22, 1986; and quaternary ammonium compounds of the formula Ri 0R11 Rl 2R13N⁺X", wherein R10 is an alkyl having 8 to 20 carbons, Rn is an alkyl having 1 to 10 carbons, R12 and R13 are alkyls having 1 to 4 carbons, preferably methyl, and X is an anion, preferably Cl^" or Br, such as C12-13 alkyl trimethyl ammonium chloride. Glycerine can be incorporated in the compositions described herein. If included in laundry detergent bars, glycerine is typically at concentrations up to about 3%, preferably about 0.5 to about 1.5%, by weight of the final solid composition. If present in personal cleansing bars of the invention, then glycerine is typically at concentrations up to about 15%, preferably up to about 7%, by weight of the final solid composition. Optical brighteners are also preferred optional ingredients in laundry bars of the present invention. Preferred optical brighteners are diamino stilbene, distyrilbiphenyl-type optical brighteners. Preferred as examples of such brighteners are 4,4'-bis{[4-anilino-6-bis(2-hydoxyethyl) amino-1 ,3,5-trizin-2- yl]amino}stilbene-2,2'-disulfonic acid disodium salt, 4-4'-bis(2-sulfostyryl) biphenyl and 4,4'-bis[(4-anilino-6-morpholino-1 ,3,5-triazin-2-yl) amino]stilbene-2,2'- disulfonic acid disodium salt. Such optical brighteners, or mixtures thereof, can be used at levels in the bar of from about 0.01% to about 1.0%, by weight of the final solid composition.

Dyes, pigments, germicides, and perfumes can also be added herein, if desired. If included, they are typically at levels up to about 0.5%, by weight of the final solid composition.

Another useful optional ingredient of the subject compositions are detergent enzymes. In laundry compositions, particularly preferred enzymes include celiulase, lipase, protease, amylase, and mixtures thereof. Enzymes, if included, are typically at levels up to about 5%, preferably about 0.05 to about 3%, by weight of the final solid composition.

Bar Physical Properties

Solid compositions of the present invention possess acceptable physical properties such as hardness, a smooth feel, and good in-use properties. A preferred method to measure the hardness of the solid composition is to measure the penetration of a needle through the surface under a standard weight, for 5 seconds using a cone penetrometer. One such penetrometer is made by Associated Instrument Manufacturers India Pvt. Ltd. (Model number AIM 512). The weight of the rod and the cone is 149 grams and an additional 50 gram weight is placed on the cone. The penetration reading of a fresh, acceptable laundry bar will typically be about 35-50 (1/10 mm) immediately after plodding. Acceptable laundry bars aged about 3 days at ambient conditions will typically have a bar penetration reading of about 5-25 (1/10 mm).

Processing

The laundry bars and solid compositions of the present invention can be processed in conventional soap or detergent bar making equipment with some or all of the following key equipment: blender/mixer, amalgamator, mill, refining plodder, two-stage vacuum plodder, logo printer/cutter, cooling tunnel and wrapper.

The preferred mixer type to be used is a high shear mixer. Suitable equipment can include: Sigma (single arm or double arms) blender, manufactured by Mazzoni; Winkworth RT 25 series, manufactured by Winkworth Machinery Ltd., Berkshire, U.K.; Eirich, series RV, manufactured by Gustau Eirich Hardheim, Germany; Lodige, series FM for batch mixing; series Baud KM for continuous mixing, manufactured by Lodige Machinenbau GmbH. Other types of suitable mixers for this application are Twin Screw Extruders, supplied by APV Bakes (CP series), Werner and Pfleiderer (continua series). In a typical process, the structured soap composition is first formed by premixing soap, cellulose material, and structured soap moisture in a blender. There must be at least some moisture present when the soap and the cellulose materials are premixed. However, it is not always necessary to provide additional moisture by adding free water; for example, structured soap moisture can be introduced by utilizing neat soap. While not required, herein, it is preferred that the cellulose material is first dispersed with water and then mixed with the soap. When free water is added, it can be at room temperature, but is preferably at a temperature of at least 40°C. The premixture is mixed for more than about 3 minutes, preferably from about 3 minutes to about 10 minutes, and more preferably from about 4 minutes to about 6 minutes, until homogenized. This step can take place at ambient temperature, or preferably, at a temperature of between 65°C to 95°C before additional bar ingredients are added.

When forming a solid composition, optional ingredients can be added to the structured soap composition. Typically, synthetic anionic surfactants, alkaline inorganic salts, strong electrolyte salts, and fillers (preferably including sodium carbonate) will be mixed together with the structured soap composition, and the resulting mixture mechanically worked to effect homogeneity. Once any neutralization reactions are completed, other optional surfactants can be added, followed by detergent builders and any additional optional ingredients. If desired, polyphosphate can be used as an alkaline salt in the neutralization. The mixing can take from one minute to one hour, with the usual mixing time being from about ten to twenty minutes. The blender mix is then charged to a surge tank. The product is conveyed from the surge tank to the mill via a multi-screw conveyer. After milling and optionally, preliminary plodding, the product is then conveyed to a double vacuum plodder, operating at high vacuum, e.g. 400 to 740 mm of mercury vacuum, so that entrapped air is removed. The product is extruded and cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage.

Surprisingly, it has been found that the structured soap composition and solid compositions containing the structured soap compositions described herein can have both a high moisture content and acceptable physical properties such that a separate drying step is no longer needed to further process the composition into solid bars. Traditionally, soap bar-making processes, such as those involving personal cleansing soaps, require an additional drying step before processing neat soap pastes and high-moisture soaps. For example, a vacuum flash drier is commonly used before either mixing or before milling, plodding, and/or further processing. However, because of its physical properties, the structured soap composition of the current invention provides a means to bypass this expensive step, if so desired. Accordingly, this provides significant cost savings per unit in the soap production process and a simplification in the manufacturing steps. Because a separate dryer is no longer needed at this step, the process described herein also significantly reduces capital expenditures for equipment and machinery. Although not intending to be limited by theory, utilizing a relatively small amount of cellulose material to form a solid composition containing the structured soap composition provides similar characteristics as the use of large amounts of other common structurants in high moisture solid compositions. Therefore, the solid composition formulation cost is cheaper, due to the low level of cellulose material required as well as the resulting decreased levels of or even elimination of other structurants. In addition, because the solid compositions contain high amounts of moisture, formulation costs are further reduced. Thus, in addition to the significant savings seen in the production process, the current invention provides more cost-effective formulations. The solid compositions of the structured soap composition and process described herein have improved firmness (both initially, and after aging), better mileage wear, less surface penetration and mushiness, and improved sudsing characteristics compared to unstructured soap compositions. These results remain true for both soap/synthetic bars as well as pure soap bars.

Examples of the invention are set forth hereinafter by way of illustration and are not intended to be in any way limiting of the invention.

EXAMPLE 1 A solid composition in the shape of a bar is made from the process described above, wherein 47.5 grams of soap (specifically 80:20 tallow/coconut soap), 0.5 grams of cellulose material, and 23 grams of water are premixed in a blender. The water, cellulose material and soap are mixed for about 5 minutes, at a temperature of 65°C to 95°C. Optional ingredients are then added and the mixture is processed to form a bar as described above.

EXAMPLE 2

An alternative process which leads to the same result as seen in Example

1 involves in situ neutralization of coconut fatty acid followed by addition of water before the soap and cellulose material are combined. In this process, 12 parts of carbonate and 6.5 parts of coconut fatty alkyl sulfate flakes are placed in the blender. 27 parts coconut fatty acid are then added, along with 3 parts of water and mixed for 2 minutes to form a neutralized mass. 2 parts of cellulose material premixed with 12 parts of water are then added to the paste-like mass. The mixture is mixed, for 5 minutes. Other optional ingredients are then added, and the solid composition is further processed into the shape of a bar as described above.

EXAMPLE 3 In a preferred process, 2 grams of cellulose material are mixed with 30 grams of hot water (about 70° C) and then added to 60 grams of neat soap (containing - 30% moisture, 65:35 tallow/coconut soap). The resulting premixture is blended to homogeneity in a mixer for 5 minutes to form the structured soap composition. 5% coconut fatty acid by weight of the final composition, and about 2% NaCI by weight of the final composition are then added and the resulting composition blended for a total mixing time of 15 minutes. The resulting mixture is then fed into a roll mill where the mixture is cooled and flaked. The flaked material is then passed to a duplex plodder and extruded to form a personal cleansing bar.

EXAMPLES 4-11 Structured soap compositions of the present invention are described below:

All amounts are shown as weight percentages of the structured soap composition, unless stated. EXAMPLES 12-17 High moisture laundry bars of the present invention, having the following compositions are prepared by the process described above, using the structured soap compositions of Examples 4-11. All numbers are by weight % of the final

EXAMPLES 18-20 Personal cleansing bars of the present invention, having the following compositions are prepared by the process described above, using the structured soap compositions of Examples 4-11. All numbers are by weight % of the final composition, unless otherwise indicated.

herwise listed above.

Claims

WHAT IS CLAIMED IS:

1. A solid composition in the shape of a bar comprising:

A. from about 25% to about 95% structured soap composition, by weight of the final solid composition; wherein the structured soap composition comprises a premixture of soap, a cellulose material, and structured soap moisture; and

B. from about 10% to about 40% solid composition moisture, by weight of the final solid composition; wherein the ratio of the cellulose material to the solid composition moisture is from about 1 :1 to about 1:80.

2. The solid composition of Claim 1 , wherein the structured soap composition comprises, by weight of the structured soap composition, from about 25% to about 89% of a soap, from about 0.5% to about 40% of a cellulose material selected from the group consisting of cellulosic polymers, cellulosic co-polymers, and mixtures thereof, and from about 10% to about 50% of structured soap moisture.

3. The solid composition of Claim 1 , further comprising from about 1% to about 50% of a detergent builder.

4. The solid composition of Claim 1 , further comprising from about 1% to about 30% of a synthetic anionic surfactant selected from the group consisting of CI Q-18 linear alkyl benzene sulfonates, C13-I6 alkyl ethoxy ether sulfates, Ci0-14 alkyl glyceryl ether sulfonates, C-ιo-18 a'kyl sulfates, and mixtures thereof.

5. The solid composition of Claim 2, wherein the cellulose material is selected from the group consisting of carboxymethyl cellulose, carboxymethylhydroxyethyl cellulose, cellulose gums, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, microcrystalline cellulose and carboxymethyl cellulose sodium NF, nonoxynyl hydroxyethyl cellulose, xanthan gums, and mixtures thereof.

6. The solid composition of Claim 3, wherein the detergent builder is selected from the group consisting of water-soluble alkali-metal salts of phosphate, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof.

7. A solid composition in the shape of a bar comprising:

A. from about 30% to about 90% structured soap composition, by weight of the final solid composition; wherein the structured soap composition comprises, by weight of the structured soap

5 composition, a premixture of:

1. from about 25% to about 89% of soap;

2. from about 0.5% to about 40% of a cellulose material selected from the group consisting of cellulosic polymers, cellulosic co-polymers, and mixtures thereof; and o 3. from about 10% to about 50% of structured soap moisture;

B. from about 10% to about 40% solid composition moisture, by weight of the final solid composition; wherein the ratio of the cellulose material to the solid composition moisture is from about 1 :1 to about 1 :80; 5 C from about 1 % to about 50% of a detergent builder, by weight of the final solid composition, selected from the group consisting of water- soluble alkali-metal salts of phosphate, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof; and 0 D. from about 1% to about 30% of a synthetic anionic surfactant, by weight of the final solid composition, selected from the group consisting of C10-I8 linear alkyl benzene sulfonates, C13-I6 alkyl ethoxy ether sulfates, Cio-14 alkyl glyceryl ether sulfonates, C-JO- 18 alkyl sulfates, and mixtures thereof.

8. A process for making a solid composition comprising the steps of:

A. forming a premixture to form a structured soap composition comprising:

1. from about 25% to about 89% of soap; 2. from about 0.5% to about 40% of a cellulose material selected from the group consisting of cellulosic polymers, cellulosic co-polymers, and mixtures thereof; and

3. from about 10% to about 50% of structured soap moisture;

B. adding optional ingredients to the structured soap composition; and C. forming the mixture of B into a solid bar form; wherein the final solid composition has from about 10% to about 40% solid composition moisture, by weight of the final solid composition; and wherein the ratio of the cellulose material to the solid composition moisture is from about 1 :1 to about 1:80.

9. A process for making a solid composition comprising the steps of:

A. forming a premixture to form a structured soap composition, wherein the premixture consists essentially of a soap, a cellulose material, and structured soap moisture; B. adding optional ingredients to the structured soap composition; and

C. forming the mixture of B into a solid bar form; wherein the final solid composition has from about 10% to about 40% solid composition moisture, by weight of the final solid composition; and wherein the ratio of the cellulose material to the solid composition moisture is from about 1 :1 to about 1 :80.

10. A solid composition in the shape of a bar made by the process of Claim 8 or 9.