Low TFM high moisture polymeric silica soap bars

Abstract

Disclosed is a soap composition comprising from 18 to 55% by weight of total fatty matter; 0.1 to 5 wt% of an electrolyte; 0.2% to 10% by weight of polymeric silica; 5 to 45% by weight of starch; and 15 to 45% by weight of moisture. The present invention also provides a method of preparing a high moisture soap bar having good hardness by generating polymerized silica in situ during soap preparation.

Description

TECHNICAL FIELD

[0001] The present invention relates to extruded soap-based products, such as noodles and bars. More specifically, the present invention relates to such compositions having significantly higher moisture than conventional products. The present invention provides soap bars with low TFM and contributes to sustainability by reducing the palm oil content in the soap. BACKGROUND

[0002] Surfactants have been used in personal washing applications for a long time. There are many categories of products in the personal washing market, such as body wash, facial wash, hand wash, soap bar, shampoo, etc. Products sold as body wash, facial wash, and shampoo are usually in liquid form and made from synthetic anionic surfactants. They are usually sold in plastic bottles / containers. Soap bars and hand wash products usually contain soap. Soap bars do not need to be sold in plastic containers and are able to hold their own shape by being structured in the form of a rigid solid. Soap bars are usually packaged in cartons made of hard paperboard or plastic laminated wrapping paper.

[0003] Soap bars are usually prepared by one of two routes. One is called the cast bar route, while the other is called the milled and pressed bar route (also known as the extrusion route). The cast bar route is inherently well suited to making low TFM (total fatty matter) bars. Total fatty matter is a common way of qualifying soap mass. TFM is defined as the total amount of fatty matter (mainly fatty acids) that can be isolated from a soap sample after decomposition with a mineral acid (usually hydrochloric acid). In cast bar soaps, the soap mixture is mixed with a polyol and poured into a mold and allowed to cool, and then the soap bar is removed from the cast. The cast bar route enables production at a relatively low production rate.

[0004] The bars of soap are usually made from noodles, which are usually having 40 to 80 wt% or more of total fatty matter (TFM), 10 to 35 wt% of water (moisture), and additives such as fillers, salts, other surfactants, and fragrances. These bars are mainly prepared by mixing the noodles with other ingredients and then going through milling, extrusion, and stamping steps.

[0005] In the milling and plodding approach, a soap with high water content is prepared and then spray dried to reduce the water content and cool the soap, after which other ingredients are added, and then the soap is extruded through a plodder and optionally cut and stamped to make the final soap bar. Milling and plodding soaps typically have a high TFM in the range of 60 to 80 wt%. Most soap compositions contain water insoluble soap as well as water soluble soap. Their structure is typically characterized as a brick and mortar type structure. The insoluble soap, referred to as the brick, is typically composed of longer chain C16 and C18 soaps (stearic and palmitic acid soaps). They are typically included in the soap bar to provide a structuring benefit, i.e. they impart shape to the soap bar. The soap bar is also composed of water soluble soap, which acts as the mortar, typically a combination of unsaturated C18:1 and 18:2 sodium soaps (oleic acid soaps) with short chain fatty acids, typically C8 to C12 or even up to C14 soaps. The water soluble soap typically contributes to cleaning.

[0006] Typically, soap bars contain an excess of active soap compared to what is needed for cleaning or surfactant properties. This is because there is a lot of sodium soap to structure the soap. A portion of the total soap content can be replaced with solvents (e.g. glycerol and water) or particulates. This approach can reduce the cost of production of the bar and can also bring additional benefits to the consumer, such as mildness. However, an increase in the water content can result in a softer and stickier bar and can cause problems during extrusion and stamping and can reduce the production speed.

[0007] In addition to about 40 to 80 wt% TFM, soap bars for personal washing currently made by the extrusion approach contain about 12 to 25 wt% water. There is a need to develop sustainable technologies, one approach of which is to develop soaps with lower TFM content and by increasing the water or moisture content without compromising other properties and desired characteristics. The inventors of the present invention are aware of various approaches to structured soap bars, such as including aluminium phosphates. These technologies are useful for making bars for laundry applications, but such materials are not very skin friendly and therefore not suitable for personal washing. If the TFM is simply replaced with a higher amount of water, problems arise during the extrusion process of the soap mass and the extruded bar is sticky and cannot be easily stamped. The inventors of the present invention are also aware of various other approaches, such as including natural silico-aluminate clays, such as bentonite or kaolinite, but found that they are not as effective in structured bars at low amounts.

[0008] To counteract the effects of increasing the water content, electrolytes can be added to the composition. Electrolytes are used to “shrink” the soap, which means that the hardness of the soap bar is increased and becomes less sticky. However, the addition of electrolytes can result in a greater degree of cracking or splitting in the extruded bar (up to a level that is unacceptable to the consumer); and can also result in the formation of a visible layer of electrolyte on the surface of the bar, a phenomenon known as “weathering”.

[0009] One strategy that has been used to reduce the soap content of bars is to replace some of the fatty acid soap with inorganic fillers and / or higher levels of water. However, the use of high levels of inorganic fillers and / or high levels of water results in several negative properties, which include significant shrinkage of the bar during storage due to evaporation of water, and smaller bar volume due to the higher density of inorganic fillers.

[0010] Another approach that has been used to reduce the surfactant content of bars is to use coagulated gels formed in a melt-cast process. Here, a molten surfactant solution is poured into a mold and cooled. The surfactant solution forms a highly extended three-dimensional network. Although the melt-cast technique produces bars with lower surfactant content, the process is not as efficient as high throughput extrusion. In addition, the melt-cast bars have a high amount of water and solvents, are prone to drying, and their abrasion rate is much higher than milled toilet bars. Thus, such bars are not as economical in use as milled soaps.

[0011] Examples of approaches based on the above concepts include the following.

[0012] GB 2238316 A (Unilever, 1991) discloses a toilet or laundry bar comprising 30 to 70 wt% of soap or a mixture of soap and synthetic detergents considered to be non-aqueous; 0.1 to 20 wt% of an inorganic or organic acid; 5 to 30 wt% of an alkaline silicate; and 10 to 40 wt% of water.

[0013] US 2014378363 Al (Henkel) discloses a low TFM soap bar containing talc, starch and silicate. The talc, starch and silicate constitute a structuring system.

[0014] WO 01 / 42418 to Chokappa et al. discloses a detergent bar containing 0.5 to 30% of amorphous alumina, an alkali metal salt of a carboxylic / sulphonic acid, 5 to 70% of a detergent active and 10-55% of water.

[0015] WO 2006 / 094586 to Gangopadhayay et al. discloses a low TFM detergent bar comprising soap (15% to 30% TFM); 25% to 70% of inorganic particulate including talc and calcium carbonate; 0.5% to 10% of aluminosilicate; and 3% to 20% of water.

[0016] US 6,440,908 to Racherla discloses a high moisture content bar composition which includes a borate compound that enables retention of a high amount of moisture without compromising the performance of the bar.

[0017] Wise et al. WO 96 / 35772 discloses laundry bar compositions comprising from about 20% to about 70% surfactant; from about 12% to about 24% water; from about 6.25% to about 20% calculated excess alkali metal carbonate; from about 2% to about 20% water soluble inorganic strong electrolyte salt; and various optional ingredients including whole-cut starch.

[0018] Rahamann et al. WO 98 / 18896 discloses laundry bar compositions comprising a structured soap composition; from about 5% to about 50% starch; and from about 25% to about 45% moisture.

[0019] Salvador et al. US 2007 / 0021314 and US 2007 / 0155639 disclose cleaning bar compositions comprising (a) at least about 15% water; (b) from about 40% to about 84% soap; and (c) from about 1% to about 15% inorganic salt. The bar compositions further comprise a component selected from the group consisting of a carbohydrate structurant, a humectant, a free fatty acid, a synthetic surfactant, and mixtures thereof.

[0020] Sachdev et al. U.S. 6,838,420 B2 discloses a translucent or transparent composition comprising a. from about 3 to about 40 wt% soap, b. from about 4 to about 40 wt% at least one synthetic surfactant, c. from about 14 to about 45 wt% water, d. from 0 to about 3 wt% lower monohydric alcohol, e. from about 5 to about 60 wt% humectant, f. from 0 to about 5 wt% structurant, g. from 0 to about 10 wt% gellant, with the proviso that the structurant and gellant are not both 0.

[0021] James McLaughlin US 4,808,322 discloses a non-foaming skin cleansing conditioning bar consisting essentially of from 14% to 18% of a particular anionic surfactant material; from about 40% to 72% of a particular water-insoluble emollient; from 0% to 25% of a starch-derived filler; and from 2% to 12% of water.

[0022] WO08055765 by Jagdish Gupta discloses soaps made from fatty materials having 8 to 22 carbon atoms, 30% to 60%, total fatty material (TFM). Of the total fatty material, it is preferred that 70 to 90% by weight of the total fatty material is unsaturated. The soap bar has less than 30% by weight of the total fatty material as saturated fatty material. Prior work described in patent application GB806340.6 established that extrudable soap bar compositions of lower TFM, comprising starch, specific polyols and optionally water insoluble particulates, did not require high levels of water and inorganic fillers. However, the technology was limited to compositions having a total fatty acid soap content of no less than 45%. It was found that when the fatty acid soap content was less than about 45%, particularly less than 40%, the processing and performance properties became increasingly sensitive to small changes in composition. As the total fatty acid soap content was reduced to 20% soap, this sensitivity increased, making mass production problematic.

[0023] WO2010089269 Al (Unilever) discloses a low TFM extruded personal washing bar having a continuous phase comprising: a. 20% to less than 45% of a fatty acid soap, wherein the fatty acid soap comprises at least 30% of saturated fatty acid soap, based on the total weight of the soap, and wherein the fatty acid soap has a ratio ROL defined as the total weight of oleic acid soap divided by the total weight of lauric acid soap, which satisfies equation (1): ROL = (-0.00063(TS2) + 0.297(TS) - 1.95) ± 15% (1), wherein TS is the weight % of fatty acid soap in the composition; b. a structuring system comprising: i) 10 wt% to 40 wt% of a polysaccharide structuring agent of the continuous phase selected from starch, cellulose and mixtures thereof, ii) 8.0 wt% to 30 wt% of a polyol of the continuous phase selected from glycerol, sorbitol and mixtures thereof, and iii) 0 to 15 wt% of a water insoluble particulate material of the continuous phase weight, wherein the weight of the polysaccharide structuring agent divided by the weight of the polyol, referred to as Rsp, is in the range of 0.3 to 5.0, and wherein the continuous phase is an extrudable mass having a penetrometer hardness of 3 to 8 Kg and a yield stress of 350 to 2000 kPa measured at a temperature of 40°C.

[0024] WO2019115435 Al (Unilever) discloses a structuring system having a combination of hydrated sodium carbonate and hydrated aluminium material, a silica material can be used to provide a detergent bar capable of holding a high water content.

[0025] WO202258605 (Unilever) discloses an extruded soap-based product having high moisture.

[0026] However, there is still a need for low TFM bars with high moisture content which have qualities that consumers desire, such as good lathering and good hardness, which do not become soggy when used. SUMMARY

[0027] A first aspect of the present application provides a soap composition comprising: 18 to 75 wt% of total fatty material; 0.1 to 5 wt% of electrolyte; 0.2 wt% to 10 wt% of polymeric silica; 1 to 45 wt% of organic filler; and 15 to 45 wt% of moisture.

[0028] A second aspect of the present application provides a process for preparing the soap composition according to the first aspect, the process comprising the steps of: i) saponifying a fatty material with a base to produce a saponified material, wherein 0.1 to 5 wt% of electrolyte by weight of the resulting soap composition is added during the saponification process; ii) adding a bicarbonate salt in the range of 0.5 to 5 wt% by weight of the resulting soap composition to the saponified material obtained from step (i) and mixing; iii) adding water to the mixture of step (ii), iv) adding an alkaline silicate heated to 40 to 80 °C in the range of 0.25 to 5 wt% by weight of the resulting soap composition; v) adding an organic filler in the range of 1 to 45 wt% by weight of the resulting soap composition; and vi) extruding the composition resulting from step (v) into a soap composition according to the first aspect; A third aspect of the present application provides a process for preparing the soap composition according to the first aspect, the process comprising the steps of: i) saponifying a fatty material with a base to produce a saponified material, wherein 0.1 to 5 wt% of electrolyte by weight of the resulting soap composition is added during the saponification process; ii) adding polymeric silica in the range of 0.2 wt% to 10 wt% by weight of the resulting soap composition; iii) adding an organic filler in the range of 1 to 45 wt% by weight of the resulting soap composition; and iv) extruding the composition resulting from step (iii) into a soap composition according to the first aspect.

[0029] A fourth aspect of the present application provides the use of polymeric silica and starch in a soap composition according to the first aspect having a moisture in the range of 15 to 45 wt% for achieving a hardness of at least 3 Kg-F measured at 40 °C.

[0030] As used herein, the term "comprising" encompasses the terms "consisting essentially of" and "consisting of." Where the term "comprising" is used, listed steps or options need not be exhaustive. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When a range of values is designated, unless otherwise stated the maximum value can be combined with each and every minimum value. All numbers or quantities mentioned herein are understood to be modified by the word "about," unless otherwise specified. All percentages and ratios contained herein are calculated by weight unless otherwise indicated. As used herein, the indefinite articles "a" or "an" and their corresponding plural forms "at least one" and "one or more" mean "at least one" or one or more, unless otherwise stated. The various features of the application referred to in individual sections above are applicable to any aspect of the application. Thus, aspects of the application can be combined with features of other aspects of the application as appropriate and not just in the particular combinations explicitly mentioned. Any section headings herein are for convenience only and not to be construed as limiting the disclosure in any way. The application is not limited to the embodiments disclosed in the figures. Thus, it is understood that, in the claims, features recited in the means-plus-function format are equivalent to disjunctively recited corresponding features specified in the specification. It is further understood that any disjunctive word or phrase, such as "among others," "including, but not limited to," or "including, and / or the like" in the claims, is intended in the inclusive sense as used in the specification, and not the exclusive sense.

[0031] Throughout the specification, unless otherwise indicated, weight % means the weight percent of the total weight of the soap composition of the application.

[0032] The various components of the composition are described in more detail below. DETAILED DESCRIPTION

[0033] Soap-based products, such as noodles and bars, need to have physical strength so that they maintain their structural integrity during handling, shipping, and use. Bar hardness is a particularly important property at the time of manufacture and subsequently.

[0034] Inclusion of certain ingredients, such as minerals, to make the bars harder typically results in higher density bars, making the bars significantly smaller, thus less attractive to the consumer and feeling gritty.

[0035] A soap composition is typically made from an oil or fat or blend by methods well known in the art. One such method is direct saponification of the oil / fat, wherein the oil / fat is reacted with a base (typically sodium hydroxide) to form glycerol and a soap matrix (which contains fatty acid alkali metal salts, e.g. fatty acid sodium salts, which are also sodium carboxylate salts). The soap matrix is the material containing the fatty acid alkali metal salts. Thus, the material after removal of glycerol (if it is to be removed) and further processing is an example of a soap matrix. Another method involves neutralisation of the fatty acids with a base (e.g. NaOH) to form a soap matrix. During soap production, the soap matrix can be dried and cut into noodles or pieces. As used herein, the term "soap noodles" refers to pellets or pieces of soap (whether they are pellets, pieces, chunks or other shapes). Soap noodles are typically the result of drying and extruding the raw soap into unit form, such that the soap units or pieces can be further processed into finished soap bars by mixing with additives, as is known to those skilled in the art of soap production.

[0036] During saponification, various fats (e.g. tallow, palm and / or coconut or PKO oil blend) are saponified in the presence of a base (typically NaOH) to produce fatty acids (derived from the fatty acid chains forming glycerides) and alkali salts of glycerol. The glycerol is then typically extracted with brine to produce a dilute fatty acid soap solution containing soap (the soap formed after saponification and before extrusion into final bars is often referred to as soap "noodles") and an aqueous phase (e.g. 70% soap and 30% aqueous phase).

[0037] In the present invention, the inventors have determined that by using a combination of polymeric silica and organic filler, it is possible to produce soap compositions, such as in the form of cells, pellets, bars, tablets, with the ability to hold and structure 15 to 45 wt% moisture in a simple but effective way. The inventors have also determined that such products, e.g. bars, can be produced by very small changes to conventional processes or machinery or equipment. The inventors have also surprisingly found that using the appropriate combination of ingredients according to the first aspect results in soap bars with a TFM as low as 18, without compromising on bar hardness or any other sensory attributes desired by consumers.

[0038] Typically, commercially available soap bars have a moisture content in the range of 14 to 16 wt%. If any filler is added at higher levels, this moisture content is further reduced due to the lower moisture content of the filler. Furthermore, mixing large amounts of filler at lower moisture content makes it unprocessable. The inventors were able to reduce the TFM of soap bars to a certain extent, such as about 50 TFM, using polymeric silica technology. However, surprisingly, very low TFM bars, such as as low as 40 or even 30 or even 20, can be achieved using the ingredients in the soap composition according to the first aspect of the present aspect, despite having a higher moisture content. Thus, the compositions of the present invention were found to reduce the TFM in soap bars, which leads to a reduction in cost of soap bars and reduction in palm oil consumption.

[0039] High moisture will cause processing problems.

[0040] Reducing palm oil consumption also enables the use of sustainably sourced palm oil for the soap composition.

[0041] The present invention relates to a soap composition comprising: 18 to 75 wt% of total fatty material by weight of the soap composition; 0.1 to 5 wt% of electrolyte; 0.2 wt% to 10 wt% of polymeric silica; 1 to 45 wt% of organic filler; and 15 to 45 wt% of moisture.

[0042] moisture The soap composition comprises 15 to 45 wt% of water. It can be preferred that the soap composition comprises 18 to 45 wt%, preferably 20 to 45 wt%, or even 21 to 45 wt%, preferably 25 to 45 wt%, or even 26 to 45 wt% of water.

[0043] soaps The present invention relates to a soap composition. By soap composition is meant a cleansing composition comprising soap in a shaped solid form. It is preferred that the composition is shaped into the form of a stick or bar. More preferably, the composition of the present invention is in the form of a bar. The bar can in turn have a variety of shapes including rectangular, square or oval cross-section. The composition of the present invention is in the form of a shaped solid, for example a bar. The cleansing soap composition is typically a rinse-off product, wherein it comprises a sufficient amount of surfactant for the intended local surface, for example the whole body, hair and scalp or face, to be cleaned. It is applied on the local surface and left thereon for only a few seconds or minutes, and then washed off with a large amount of water.

[0044] The present invention provides a soap composition comprising: 18 to 75 wt% of total fatty material by weight of the soap composition; 0.1 to 5 wt% of electrolyte; 0.2 wt% to 10 wt% of polymeric silica; 1 to 45 wt% of organic filler; and 15 to 45 wt% of moisture.

[0045] The soap composition of the present invention is particularly suitable for personal cleansing. The soap composition is preferably a soap stick or a soap bar. The soap composition of the present invention preferably comprises a total amount of TFM from soap of 18 to 75 wt%, preferably 20 to 65 wt%, and more preferably 20 to 55 wt% of TFM from soap. Even more preferably, the TFM from soap is 20 to 50 wt%, or even 20 to 48 wt%, or even more preferably 20 to 45 wt%, even more preferably 20 to 42 wt%. By the term soap is meant a salt of a fatty acid. Preferably, the soap is a soap of a C8 to C24 fatty acid.

[0046] The cation can be an alkali metal, an alkaline earth metal or an ammonium ion, preferably an alkali metal. Preferably, the cation is selected from sodium or potassium, more preferably sodium. The soap can be saturated or unsaturated. Saturated soaps are superior to unsaturated soaps in terms of stability. The oil or fatty acid can be of vegetable or animal origin.

[0047] The soap composition can be obtained by saponification of an oil, fat or fatty acid. The fat or oil commonly used to make soap bars can be selected from tallow, tallow hard stearine, palm oil, palm hard stearine, soybean oil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil, babassu oil and palm kernel oil. The fatty acid can be from coconut, rice bran, peanut, tallow, palm, palm kernel, cottonseed or soybean.

[0048] Fatty acid soaps can also be made synthetically (for example by oxidation of petroleum or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids such as those found in tall oil can also be used. Naphthenic acids can also be used.

[0049] The soap composition can additionally comprise synthetic surfactants selected from one or more of the anionic, non-ionic, cationic or zwitterionic surfactant classes, preferably selected from anionic surfactants. According to the present application, the content of these synthetic surfactants in the composition is less than 8%, preferably less than 4%, more preferably less than 1% and sometimes absent.

[0050] The soap composition of the present application preferably includes a low molecular weight soap (C8 to C14 soap) which is typically water soluble in the range of 2 to 20% by weight of the composition. It is preferred that the soap bar contains 15 to 55% by weight of a C16 to C24 fatty acid soap which is typically a water insoluble soap. Also included in the total soap content of the composition can be preferably 15 to 35% of an unsaturated fatty acid soap. The unsaturated soap is preferably an oleic acid soap.

[0051] The chain length of the soap depends on the fat or oil feedstock which is typically a blend. For the purposes of this specification, "oil" and "fat" are used interchangeably unless the context requires otherwise. Longer chain fatty acid soaps (e.g. C 16 palm acid soaps or C16 stearic acid soaps) are typically obtained from tallow and palm oil and shorter chain soaps (e.g. C 12 lauric acid soaps) can typically be obtained from, for example, coconut oil or palm kernel oil. The resulting fatty acid soaps can also be saturated or unsaturated (e.g. oleic acid).

[0052] Typically, longer chain fatty acid soaps (e.g. C 14 to C 22 soaps), particularly the longer saturated soaps, are insoluble and do not produce sufficient lather on use, but they can make the lather more creamy and stable. Conversely, shorter chain soaps (e.g. C8 to C 12) and unsaturated soaps (e.g. oleic or linoleic acid soaps) foam rapidly. However, longer chain soaps (which are typically saturated, although they can contain a level of unsaturated soap such as oleic acid) are required to hold the structure and not dissolve easily. Unsaturated soaps (e.g. oleic acid) are soluble and foam as rapidly as short chain soaps, but form a denser, creamier lather like longer chain soaps.

[0053] Iodine value is an indicator of unsaturation and there are well known methods of measuring IV. One method is gas chromatography. In this method, the methyl ester of the fatty acid is formed and analysed by chromatographic techniques. In addition, there are wet chemical analysis methods. The iodine value of a fat blend can be measured prior to saponification. In addition, the iodine value of the soap (saponified oil or fatty acid) present in the finished product (e.g. soap bar or soap noodles) can be determined.

[0054] Preferably, the fatty material is obtained by saponification of a saponifiable fat blend, wherein the iodine value of the soap composition is from 30 to 45 grams of iodine per 100 grams of soap composition.

[0055] Preferably, the free base content of the soap is from 0.01 to 0.1 % by weight of the soap composition.

[0056] Preferably, the free fatty acid content of the soap is from 0.01 to 1.0 % by weight of the soap composition.

[0057] Preferably, the pH of the soap composition is in the range of from 9 to 13 when measured in a 4% solution prepared with distilled water at 25°C.

[0058] polymeric silica According to a first aspect of the present application, there is disclosed a soap bar composition having a polymeric silica.

[0059] The polymeric silica can be a pre-formed polymeric silica or the generation of the polymeric silica can be carried out in situ during the manufacturing process. However, it is preferred that the polymeric silica is formed in situ in the process of the present application. It will be appreciated that the polymeric silica is a porous form of silica. The polymeric silica is an amorphous solid. The partial dipoles in the Si-O bonds allow the polymeric silica to hydrogen bond with water molecules, whilst the porous nature and large surface area of the polymeric silica enable the material to readily adsorb water. According to embodiments of the present application, the metal silicate can form the polymeric silica in situ during the manufacture of the laundry soap bar composition.

[0060] Preferably, the polymeric silica is formed in situ by acidification of an alkali metal silicate. Any metal silicate that can be converted to polymeric silica is suitable for use in the present application. For example, alkali metal silicates such as sodium silicate, potassium silicate, lithium silicate, calcium silicate or any combination thereof are suitable for use in the present application. The alkali metal silicate can be added either in solid form alone or in wet form such as a slurry or solution. The alkali metal silicate component is preferably sodium silicate, or alternatively a combination of sodium silicate with another metal silicate. Sodium silicate is a water-soluble, alkaline inorganic compound, and is usually sold as an aqueous solution.

[0061] Sodium silicate is usually referred to or characterised by its ratio of alkali metal oxide to silica, such as its ratio of Na20 to Si02. Orthosilicate with the formula Na4Si04 is the most basic, with a Na20 to Si02 ratio of 2:1. Metasilicate Na2Si03 has a Na20 to Si02 ratio of 1 :1. The so-called "water glass" silicates that are soluble in water have a Na20 to Si02 ratio in the range of about 1 :2 to 1 :3. Preferably, the Na20 to Si02 ratio used in the present application is 1 :2 to 1 :2.5. Examples of silicates that can be used for the purposes of the present application are basic sodium silicate (Na20 to Si02 ratio of 1 :3.0), orthosilicate (Na20 to Si02 ratio of 2:1) and potassium silicate (K20 to Si02 ratio of 1 :2.50). Preferably, the alkali metal silicate is basic.

[0062] Preferably, the polymeric silica is formed in situ by acidification of an alkali metal silicate. Any metal silicate that can be converted to polymeric silica is suitable for use in the present application. For example, alkali metal silicates such as sodium silicate, potassium silicate, lithium silicate, calcium silicate or any combination thereof are suitable for use in the present application. The alkali metal silicate can be added either in solid form alone or in wet form such as a slurry or solution. The alkali metal silicate component is preferably sodium silicate, or alternatively a combination of sodium silicate with another metal silicate. Sodium silicate is a water-soluble, alkaline inorganic compound, and is usually sold as an aqueous solution.

[0063] It is within the scope of the present application to form the polymeric silica in situ by reacting a water-soluble or water-dispersible silicate with an organic acid. Preferably the organic acid is an anionic detergent-forming acid. Non-limiting examples of acids are saturated and unsaturated fatty acids having carbon chains containing from about 8 to 22 carbon atoms, exemplified by lauric acid, stearic acid, oleic acid and linoleic acid. Non-soap detergent-forming acids, such as alkyl aryl sulfonic acids, wherein the alkyl group (straight chain and branched) has a carbon chain length of at least 4 carbon atoms, preferably 10 to 12 carbon atoms, which are capable of forming water-soluble non-soap detergents upon neutralisation with a base such as sodium hydroxide or potassium hydroxide.

[0064] The degree of polymerisation of the silicate to polymeric silica is preferably 50% or more (i.e. a ratio of 1 :1), more preferably 60% or more, further preferably 70% or more, still further preferably 80% or more, yet further preferably 90% or more, further preferably 95% or more, and most preferably 99% or more. Preferably, the alkali metal silicate is fully polymerised to polymeric silica.

[0065] Preferably, the composition according to the present application comprises from 0.2% to 10% by weight of polymeric silica, preferably from 0.5 to 8% by weight, and more preferably from 1 to 5% by weight. Preferably, the bar composition comprises at least 0.2% by weight, preferably at least 0.3% by weight, more preferably at least 0.5% by weight, and most preferably at least 0.7% by weight, but typically no more than 10% by weight, more preferably no more than 7% by weight, still more preferably no more than 5% by weight, and most preferably no more than 3% by weight, of the bar composition of polymeric silica.

[0066] The silicate polymerisation reaction can be thought of as an acid-base reaction. The reaction can be represented as follows: k(Na2O:RmSi02) + xAHn --> xANan + (k-y)[Na2O:(kRm / (k-y))Si02] + yH20, wherein, Rm is the ratio of Si02 to Na20, k is the number of moles of sodium silicate, x is the number of moles of acid (salt of acid), n is the number of protons in the acid, and y = nx / 2.

[0067] Typically, in the reaction, the acid neutralises the base (Na20) associated with the basic silicate, thus increasing Rm, i.e. partial polymerisation of the silicate to silica and formation of a "salt". Preferably, the degree of polymerisation of the silicate to polymeric silica is from 50% to 99% of complete polymerisation, preferably greater than 90%, more preferably greater than 95%, and most preferably greater than 99%.

[0068] alkali silicate The present application uses a basic silicate as one of the reactants in the process of making the bar of the present application. Preferably, the basic silicate is used in the range of from 0.25 to 5% by weight, more preferably from 0.5 to 3% by weight, and most preferably from 0.7 to 2.25% by weight, based on the dry weight of the composition of the present application. Preferably, the basic silicate is an alkali metal silicate, and most preferably a sodium silicate, calcium silicate, lithium silicate or potassium silicate salt. Highly preferably, the basic silicate is sodium silicate or potassium silicate, and more preferably sodium silicate.

[0069] When sodium silicate is used, it is in the range of 0.25 to 5 wt%, more preferably 0.5 wt% to 3 wt%, and most preferably 0.7 to 2.25 wt%, based on the dry weight of the composition weight of the present application.

[0070] When potassium silicate is used, it is in the range of 0.25 to 5 wt%, more preferably 0.5 wt% to 3 wt%, and most preferably 0.7 to 2.25 wt%, based on the dry weight of the composition weight of the present application.

[0071] It is preferred that the sodium silicate comprises a compound having the formula (Na20) x • Si02.

[0072] It is preferred that in the alkali silicate, the ratio of alkali metal oxide to silicon oxide is in the range of 1 : 1.8 to 1 :2.8, more preferably 1 : 1.8 to 1 :2.6, and most preferably 1 : 1.7 to 1 :2.5, even more preferably 1 : 1.5 to 1 :2.3. Preferably, when sodium silicate is used, the ratio of Na20:Si02is in the range of 1 : 1.8 to 1 :2.8, more preferably 1 : 1.8 to 1 :2.6, most preferably 1 : 1.7 to 1 :2.5, even more preferably 1 : 1.5 to 1 :2.3.

[0073] organic fillers The soap composition of the present application comprises an organic filler. Preferably, the organic filler is starch, and preferably the starch is native starch, pregelatinized starch, modified starch, or a mixture thereof.

[0074] It is preferred that the organic filler in the soap composition is in the range of 1 to 45 wt%, preferably 5 to 45 wt%, more preferably 2 to 40 wt%, even more preferably 5 to 40 wt%, more preferably 3 to 35 wt%, even more preferably 5 to 35 wt%, based on the weight of the soap composition.

[0075] Preferably, when the organic filler is starch, the starch in the soap composition is in the range of 1 to 45 wt%, preferably 5 to 45 wt%, more preferably 2 to 40 wt%, even more preferably 5 to 40 wt%, and more preferably 3 to 35 wt%, even more preferably 5 to 35 wt%, based on the weight of the soap composition. The starch is even more preferably present in an amount of 8 to 40 wt%, more preferably 11 to 40 wt%, even more preferably 12 to 40 wt%, even more preferably 12 to 35 wt%, based on the weight of the composition.

[0076] For example, a preferred soap composition of the present application can comprise 11 to 40 wt% starch, a TFM content of 18 to 50 wt%, a moisture content of 18 to 45 wt%, preferably 20 to 45 wt%, or even 21 to 45 wt%, preferably 25 to 45 wt%, or even 26 to 45 wt% moisture.

[0077] Suitable starch materials include native starch (from corn, wheat, rice, potato, tapioca, etc.), pregelatinized starch, various physically and chemically modified starches, and mixtures thereof. The term native starch refers to starch that has not been chemically or physically modified, also known as raw starch or unmodified starch.

[0078] Preferred starches are native or raw starches from corn (maize), tapioca, wheat, potato, rice, and other natural sources. Raw starches with different ratios of amylase and amylopectin: e.g., corn (25% amylase); waxy corn (0%); high amylase corn (70%); potato (23%); rice (16%); sago (27%); tapioca (18%); wheat (30%), etc. Raw starch can be used directly in the process of making the stick composition or modified so that the starch becomes gelatinized, partially or completely.

[0079] Another suitable starch is pregelatinized, which is starch that has been gelatinized prior to its addition as an ingredient in the stick composition of the present invention. Various forms are available that gelatinize at different temperatures, such as cold water dispersible starch. One suitable commercial pregelatinized starch is supplied by National Starch Co. (Brazil) under the trade name FARMAL CS 3400, but other commercially available materials with similar properties are suitable.

[0080] It is preferred that the organic filler is starch, and preferably the starch is native starch, pregelatinized starch, modified starch, or mixtures thereof.

[0081] electrolytes The inclusion of small amounts of electrolytes (in addition to the soap) can affect the liquid and solid phase ratios. Increasing the electrolyte content decreases the solubility of the soap, thereby increasing the amount of the solid phase, on the other hand, decreasing the electrolyte level makes the stick softer.

[0082] It is preferred that the composition of the present invention comprises electrolyte in the range of 0.1 to 5 wt%, more preferably 0.5 to 3 wt%, and most preferably 0.7 to 2.5 wt% by weight of the composition. Preferred electrolytes include sodium sulfate, sodium chloride, sodium citrate, potassium chloride, potassium sulfate, sodium carbonate, and other mono- or di- or tri-salts of alkaline earth metals, more preferred electrolytes are sodium chloride, sodium sulfate, potassium chloride, especially preferred electrolytes are sodium chloride and sodium sulfate, and combinations thereof. For the avoidance of doubt, it is clarified that the electrolyte is a non-soap material.

[0083] Most preferred is sodium sulfate and / or sodium chloride for use as electrolyte in the composition of the present invention.

[0084] Preferably, when present, sodium sulphate is present in the range of 0.1 to 5 wt%, more preferably 0.5 to 3 wt% and most preferably 0.7 to 2.5 wt% of electrolyte of the composition weight. Preferably sodium sulphate is at least 0.1 wt%, more preferably at least 0.5 wt%, most preferably at least 0.7 wt% of the total composition weight and preferably it is no more than 5 wt%, more preferably no more than 3 wt%, further preferably no more than 2.8 wt%, most preferably no more than 2.5 wt%.

[0085] Preferably, when present, sodium chloride is in the range of 0.5 to 1.5 wt%, more preferably 0.7 to 1.3 wt% and most preferably 1.0 to 1.3 wt% of the composition weight. Preferably sodium chloride is at least 0.1 wt%, more preferably at least 0.5 wt%, most preferably at least 0.7 wt% of the total composition weight and preferably it is no more than 5 wt%, more preferably no more than 3 wt%, further preferably no more than 2.8 wt%, most preferably no more than 2.5 wt%.

[0086] organic and inorganic adjuvant materials The total level of adjunct materials used in the bar composition should be no more than 50 wt%, preferably 1 to 50 wt%, more preferably 3 to 45 wt% of the bar composition.

[0087] The adjunct system can optionally include insoluble particles comprising a material or combination of materials. By insoluble particles we mean materials which are present in solid particulate form and are suitable for personal washing. Preferably, mineral (e.g. inorganic) or organic particles are present.

[0088] The insoluble particles should not be perceived as itchy or gritty and therefore the particle size should be less than 300 microns, more preferably less than 100 microns and most preferably less than 50 microns.

[0089] Preferred inorganic particulate materials include talc and calcium carbonate. Talc is a magnesium silicate mineral material having a sheet silicate structure and a composition of Mg3Si4(OH) 22 and can be obtained in a hydrated form. It has a platy morphology and is essentially oleophilic / hydrophobic, i.e. it is wetted by oil rather than water.

[0090] Calcium carbonate or chalk exists in three crystal forms: calcite, aragonite and vaterite. The natural habit of calcite is rhombohedral or cubic, aragonite is acicular or dendritic, and vaterite is spheroidal.

[0091] Examples of other optional insoluble inorganic particulate materials include aluminates, phosphates, insoluble sulphates, borates and clays (e.g. kaolin, china clay) and combinations thereof.

[0092] Organic particulate materials include insoluble polysaccharides such as highly cross-linked or insoluble starch (e.g., by reaction with a hydrophobe such as octyl succinate) and cellulose; synthetic polymers such as various polymeric lattices and suspension polymers; insoluble soaps and mixtures thereof.

[0093] The bar composition preferably comprises 0.1 to 25 wt%, preferably 5 to 15 wt% of the bar composition of these minerals or organic particles.

[0094] Sunscreen agents can optionally be present in the personal care composition. When present, the cleansing bar is typically opaque. Examples of sunscreen agents include titanium dioxide, zinc oxide and the like. A particularly preferred sunscreen agent which can be used when an opaque soap composition is desired is ethylene glycol monostearate or ethylene glycol distearate, for example in the form of a 20% solution in sodium lauryl ether sulphate. An alternative sunscreen agent is zinc stearate.

[0095] The product can take the form of a water-clear, i.e. transparent, bar, in which case it does not contain a sunscreen agent.

[0096] It is preferred that the soap composition of the present application has a pH in the range of 9 to 13 when measured in a 4% solution prepared with distilled water at 25°C.

[0097] Preferred bars can additionally comprise up to 30 wt% of a benefit agent. Preferred benefit agents include moisturizers, emollients, sunscreens, skin lightening agents and anti-aging compounds. The benefit agent can be added at an appropriate step in the process of making the bar. Some benefit agents can be introduced as macrodomains.

[0098] In the compositions of the present application, the polyol can be present in the range of 0.01 to 15 wt%, more preferably in the range of 1 to 10 wt%, and most preferably in the range of 1.5 to 8 wt%. In a highly preferred aspect, the polyol is less than 8 wt%. Preferably, glycerin can be present in the range of 0.01 to 15 wt%, more preferably in the range of 1 to 10 wt%, most preferably in the range of 1.5 to 8 wt%. In a highly preferred aspect, the glycerin is less than 8 wt%.

[0099] Other optional ingredients can be added in the process of the present application in suitable amounts, such as antioxidants, fragrances, polymers, chelating agents, colorants, deodorants, dyes, emollients, moisturizers, enzymes, foam boosters, bactericides, additional antimicrobial agents, lathering agents, pearlescent agents, skin conditioning agents, stabilizers, superfatting agents, sunscreens. Preferably, the ingredients are added after the saponification step. Preferably, sodium metabisulfite, ethylenediaminetetraacetic acid (EDTA), borax or ethylidene hydroxy phosphonic acid (EHDP) are added to the formulation.

[0100] The compositions of the present application can be used to provide antimicrobial benefits. Antimicrobial agents preferably included to provide such benefits include: a micro-kinetic metal or a compound thereof. Preferred metals are silver, copper, zinc, gold or aluminum. Silver is particularly preferred. In ionic form, it can be present as a salt of any applicable oxidation state or any compound. Preferred silver compounds are silver oxide, silver nitrate, silver acetate, silver sulfate, silver benzoate, silver salicylate, silver carbonate, silver citrate and silver phosphate, with silver oxide, silver sulfate and silver citrate being of particular interest in one or more embodiments. In at least one preferred embodiment, the silver compound is silver oxide. The micro-kinetic metal or compound thereof is preferably included at a level of from 0.0001 to 2 wt%, preferably from 0.001 to 1 wt% of the composition. Alternatively, an essential oil antimicrobial active can be included in the compositions of the present application. Preferred essential oil actives that can be included are terpineol, thymol, carvacrol, (E)-2-(prop-1-enyl)phenol, 2-propylphenol, 4-pentylphenol, 4-sec-butylphenol, 2-benzylphenol, eugenol or combinations thereof. Further, more preferred essential oil actives are terpineol, thymol, carvacrol or thymol, most preferably terpineol or thymol, and ideally a combination of the two. The essential oil active is preferably included at a level of from 0.001 to 1 wt%, preferably from 0.01 to 0.5 wt% of the composition.

[0101] The soap composition can be made into bars by a process which first involves saponifying a fat charge with a base, and then extruding the mixture in a conventional padder. The padder mass can then be optionally cut to the desired size and stamped with the desired indicia. A particularly important benefit of the present application is that, despite the high water content of the soap bars, it is found that compositions so prepared by extrusion are readily stamped with the desired indicia.

[0102] The present application also relates to a process for making the soap bars of the present application, including the step of including substantially all of the structuring system in the soap at the time the soap is produced in the saponification step. Preferably, the polymer is included at least during the saponification stage.

[0103] The present application will now be illustrated by the following non-limiting examples.

[0104] The expression total fatty material is used very widely in the soap and detergent art. The term, abbreviated as "TFM", is used to indicate the weight percent of fatty acid and triglyceride residues present in a soap composition, without regard to the accompanying cation. For a soap having 18 carbon atoms, the accompanying sodium cation typically accounts for about 8 weight percent. Other cations such as zinc, potassium, magnesium, alkylammonium and aluminum can be used as desired.

[0105] It is preferred that the composition of the present application comprises 18 to 75 wt% TFM, more preferably 20 to 70 wt% TFM, and most preferably 20 to 65 wt% TFM, by weight of the soap composition. Even more preferably, the composition comprises 20 to 50 wt%, or even 20 to 48 wt%, or even more preferably 20 to 45 wt%, and even more preferably 20 to 42 wt% TFM, by weight of the soap composition.

[0106] The term soap refers to a salt of a fatty acid, wherein the accompanying cation can be an alkali metal, an alkaline earth metal or an ammonium ion, preferably an alkali metal. Preferably, the cation is sodium or potassium. The soap can be saturated or unsaturated, and it depends on the nature of the respective fatty acid and / or oil used for the saponification.

[0107] It is preferred that the fatty blend comprises 10 to 20 parts by weight lauric fatty acid, 35 to 50 parts by weight saturated non-lauric fatty acid and 20 to 45 parts by weight unsaturated non-lauric fatty acid, wherein the sum of all fatty acids is 100 parts by weight.

[0108] Lauric fatty acid refers to fatty acids derived from, for example, coconut or palm kernel oil and comprising C12 acids, i.e. lauric acid, but can contain small amounts, up to 5 wt%, of shorter or longer chain fatty acids, e.g. C10 to C14. Preferably, the lauric fatty acid is derived from coconut or palm kernel oil.

[0109] Saturated non-lauric fatty acid refers to those fatty acids having a higher carbon chain length than C14 and being saturated. It is preferred that the saturated non-lauric fatty acid comprises at least one of palmitic acid, myristic acid or stearic acid. Such fatty acids can comprise up to 2 to 3 wt% of other longer or shorter chain fatty acids, e.g. C20.

[0110] Unsaturated non-lauric fatty acid refers to those fatty acids being unsaturated and having a higher carbon chain length than C14. It is preferred that the unsaturated non-lauric fatty acid comprises one or more of oleic acid, linoleic acid, palmitoleic acid or linolenic acid. Such fatty acids can comprise up to 2 to 3 wt% of other longer or shorter chain fatty acids, e.g. C 12 or C8. It is preferred that the unsaturated non-lauric fatty acid is obtained from at least one of beef tallow, lard, soybean oil, sunflower oil, rice bran oil, linseed oil, olive oil, rapeseed oil, peanut oil or fish oil. A variety of other alternative sources can be used, such as bioengineered oils. 20

[0111] Commercially available blends (with appropriate modifications or additional oils / fats) that can be used include 80 / 20, 85 / 15 blends, wherein the larger number indicates the parts by weight of non-lauric fatty acid and the smaller number indicates the parts by weight of lauric fatty acid.

[0112] form and style ​ The soap composition of the present application can be in any physical form. It is preferably in the form of noodles, tablets, flakes, chips or powder, more preferably noodles.

[0113] The term "noodles" is used to refer to generally cylindrical particles prepared by extrusion and cutting or breaking up of noodles which typically contain soap as the main ingredient.

[0114] Soap-based noodles are typically produced by mixing dry soap chips with colorants and other minor ingredients, homogenizing by processing in a mill or refiner, and then extruding through a perforated plate having fine holes. They are typically extruded continuously and then allowed to weather sufficiently to break up into chips of 3 to 15 mm in length. A series of rotating blades can be fitted to the surface of the plate to automatically cut the extruded noodles into the appropriate length, but these tend to cause some amount of bunching to occur. The degree of bunching depends on the geometry of the cutting blades and the holes, and is also greatly affected by the plasticity and stickiness of the noodles themselves. Even without the use of rotating blades, the quality of the noodles depends on the physical properties of the extruded soap. Ideally, the soap should be sufficiently plastic to extrude satisfactorily through the holes in the perforated plate, but not so soft and sticky that they bunch together after extrusion. They should also be sufficiently hard and brittle to break up into the desired length range.

[0115] While soap noodles can be used for washing and cleaning purposes, in practice such noodles are used as an input or raw material to make bars or tablets which are sold in stores and supermarkets and used by consumers as personal washing compositions.

[0116] Thus, according to another aspect of the present application, there is disclosed a soap bar comprising the soap composition of the first aspect of the present application. The bar can be of any shape and size, but is preferably rectangular with rounded edges and of a size which allows it to be comfortably held in one hand.

[0117] other ingredients In addition to the saponified fatty material and the polymeric gel, the soap composition of the present application, for example the noodles, and in particular the soap bar, preferably comprises one or more of the following further ingredients. The choice of ingredients and the amounts thereof depend to a large extent on the formulator and the purpose for which such noodles or bars are prepared.

[0118] non-soap surfactants The composition of the present application preferably comprises a non-soap surfactant which acts as a co-surfactant and is selected from anionic, non-ionic, zwitterionic, amphoteric or cationic surfactants. Preferably, the composition comprises 0.1 to 15 wt% of non-soap surfactant. More preferably, the composition comprises 2 to 10 wt% and most preferably 3 to 6 wt% of non-soap surfactant based on the weight of the soap composition.

[0119] Suitable anionic surfactants include water-soluble salts of organic sulfuric acid reaction products having alkyl groups containing 8 to 22 carbon atoms and groups selected from sulfonic acid or sulfate ester groups in their molecular structure, and mixtures thereof.

[0120] Examples of suitable anionic surfactants are sodium and potassium alcohol sulfates, especially those obtained by sulfation of higher alcohols produced from reduced glycerides of tallow or coconut oil; sodium and potassium alkylbenzene sulfonates, such as those in which the alkyl group contains 9 to 15 carbon atoms; sodium alkyl glycerol ether sulfates, especially those ethers derived from higher alcohols of tallow and coconut oil; sodium monoglyceride sulfates of coconut oil fatty acids; sodium and potassium salts of sulfates of the reaction products of 1 mole of higher fatty alcohols with 1 to 6 moles of ethylene oxide; sodium and potassium salts of alkylphenol ethylene oxide ether sulfates having 1 to 8 ethylene oxide molecular units and in which the alkyl group contains 4 to 14 carbon atoms; and reaction products of fatty acids esterified with ethanesulfonate and neutralized with sodium hydroxide, wherein, for example, the fatty acids are derived from coconut oil and mixtures thereof.

[0121] Preferred water-soluble synthetic anionic surfactants are alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of higher alkylbenzene sulfonic acids, as well as mixtures with olefin sulfonates and higher alkyl sulfates, and higher fatty acid monoglyceride sulfates.

[0122] Suitable nonionic surfactants can be broadly described as compounds produced by the condensation of an olefinic group (which is hydrophilic in nature) with an organic hydrophobic compound (which may be aliphatic or alkyl aromatic in nature). The length of the hydrophilic or polyoxyalkylene group condensed with any particular hydrophobic group can be easily tuned to produce a water-soluble compound with the desired balance between hydrophilic and hydrophobic elements.

[0123] Specific examples include condensation products of an aliphatic alcohol containing from 8 to 22 carbon atoms in a straight or branched chain configuration with ethylene oxide, such as coconut oil ethylene oxide condensates having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; condensates of an alkyl phenol containing an alkyl group having from 6 to 12 carbon atoms with from 5 to 25 moles of ethylene oxide per mole of alkyl phenol; condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, containing from 40 to 80 weight percent polyoxyethylene groups and having a molecular weight of from 5,000 to 11,000; tertiary amine oxides of the structure R3NO, wherein one group R is an alkyl group of from 8 to 18 carbon atoms and the other R groups are each methyl, ethyl or hydroxyethyl, such as dimethyl dodecyl amine oxide; tertiary phosphine oxides of the structure R3PO, wherein one group R is an alkyl group of from 10 to 18 carbon atoms and the other R groups are each an alkyl or hydroxyalkyl group of from 1 to 3 carbon atoms, such as dimethyl dodecyl phosphine oxide; and dialkyl sulfoxides of the structure R2SO, wherein one group R is an alkyl group of from 10 to 18 carbon atoms and the other R group is methyl or ethyl, such as methyl tetradecyl sulfoxide; fatty acid alkanolamides; alkylene oxide condensates of fatty acid alkanolamides and alkyl mercaptans.

[0124] Suitable cationic surfactants that can be incorporated are alkyl substituted quaternary ammonium halide salts such as bis(hydrogenated tallow)dimethyl ammonium chloride, cetyl trimethyl ammonium bromide, benzalkonium chloride and dodecyl methyl polyoxyethylene ammonium chloride, and amine and imidazoline salts such as primary, secondary and tertiary amine hydrochlorides and imidazoline hydrochlorides.

[0125] Suitable amphoteric surfactants are derivatives of aliphatic secondary and tertiary amines containing an aliphatic radical and an anionic water-soluble radical, such as sodium 3-dodecylamino propionate, sodium 3-dodecylamino propanesulfonate and sodium N-2-hydroxyethyl dodecyl taurate.

[0126] Suitable zwitterionic surfactants are derivatives of aliphatic quaternary ammonium, sulfonium and phosphonium compounds containing an aliphatic radical and an anionic water-soluble radical, such as 3-(N-N-dimethyl-N-hexadecylammonium) propane-1-sulfonate betaine, 3-(dodecylmethyl sulfonium) propane-1-sulfonate betaine and 3-(hexadecylmethyl phosphonium) ethane sulfonate betaine.

[0127] Further examples of suitable detergent active compounds are compounds which are commonly used as surfactants and are given in the well-known textbooks "Surface Active Agents" with an introduction to their application", by Schwartz and Perry and "Surface Active Agents and Detergents", Vol. II, by Schwartz, Perry and Berch.

[0128] sunscreen agents An opacifier can optionally be present in the composition. When present, the cleansing bar is typically opaque, i.e. "opacified". Examples of opacifiers include titanium dioxide, zinc oxide and the like. A particularly preferred opacifier which can be used when opacity rather than transparency of the soap composition is desired is ethylene glycol monostearate or ethylene glycol distearate, for example in the form of a 20% solution in sodium lauryl ether sulphate. An alternative opacifier is zinc stearate.

[0129] benefit agents Preferably, the soap composition of the present application comprises one or more previously undisclosed benefit agents. Preferably, the benefit agent is an emollient, a sunscreen, an anti-aging compound or a humectant and a moisturiser. The benefit agent can be added at an appropriate step during the process. Some benefit agents can be introduced as macrodomains.

[0130] Examples of humectants and moisturisers include cetyl alcohol, ethoxylated castor oil, paraffin oil, lanolin and its derivatives. Silicone compounds such as silicone surfactants, such as DC® 3225C (Dow Corning), and / or silicone emollients, silicone oils (DC-200®, from Dow Corning) can also be included. Further examples include glycerol, oat kernel flour, petrolatum, aquaporin modulators and hydroxyethyl urea.

[0131] Sunscreen agents such as 4-tert-butyl-4'-methoxydibenzoylmethane (available as PARSOL® 1789 from Givaudan) or 2-ethylhexyl methoxy cinnamate (available as PARSOL® MCX from Givaudan) or other UV-A and UV-B sunscreen agents can also be added. Further examples include Helioplex® (diethylhexyl

[0132] Lipids such as cholesterol, ceramides and pseudoceramides, and exfoliating particles such as polyethylene beads, walnut shells, apricot kernels, flower petals and seeds can also be present. Structuring agents such as maltodextrin or starch can be used to structure the bar.

[0133] The compositions can also optionally contain other ingredients conventionally used in soaps, such as lathering boosters, colorants and opacifiers, and skin tone agents such as hexyl resorcinol, soy extract (Bowman Birk inhibitor), octadecenedioic acid (Ariatone® DC), niacinamide, Seppiwhite®, acetyl glucosamine, Pitera extract, Symwhite®, and Melano-Block® (calcium pantothenate). In addition, the compositions of the present application can contain anti-aging ingredients such as retinol, hyaluronic acid, collagen, CoQlO (ubiquinone), retinyl propionate, peptides, retinyl palmitate, jasmonic acid derivatives, and Proxylane®.

[0134] Other adjunct materials can include bactericides and antiseptics. These ingredients are normally present at less than 2%, often less than 0.5% by weight, and can include silver salts and silver compounds, thymol, terpineol and the like, ZPTO, chloroxylenol, PCMX, triclosan, and triclocarban.

[0135] The soap compositions can contain structuring agents. These can include water insoluble particulate materials. The structuring agents can be present individually or in combination at 0 to 25% by weight. Preferred inorganic particulate materials include talc and calcium carbonate. Talc is a magnesium silicate mineral material represented by the chemical formula Mg3Si4(O) 10 (OH)2, has a sheet silicate structure, and is available in a hydrated form. Talc has a platy morphology and is essentially oleophilic / hydrophobic.

[0136] Examples of other optional insoluble inorganic particulate materials include zeolitic aluminosilicates, silicates, phosphates, insoluble sulfates, clays (e.g., kaolin, china clay), titanium oxide, zinc oxide, and combinations thereof.

[0137] The compositions of the present application can additionally contain anti-caking agents such as acrylate polymers.

[0138] The term "slip modifier" as used herein means a material that significantly reduces the perceived friction between a wet soap bar and the skin when present at relatively low levels (typically less than 1.5% based on the total weight of the bar composition). The most suitable slip modifiers are used individually or in combination at levels of 1% or less, preferably from 0.05 to 1%, more preferably from 0.05 to 0.5%.

[0139] The compositions of the present application optionally contain a modified polyethylene glycol in the range of 0.01 to 0.08% as a slip modifier and / or for other sensory benefits. The compositions of the present application can also optionally contain a modified ethylene acrylic acid ester copolymer in the range of 0.1 to 0.05% as a benefit agent.

[0140] Suitable slip modifiers include petrolatum, waxes, lanolin, polyalkanes, polyalkenes, polyalkylene oxides, high molecular weight polyethylene oxide resins, silicones, polyethylene glycols, and mixtures thereof.

[0141] Up to 3% free fatty acids (FFA), such as coconut fatty acids, PKO fatty acids, lauric acid, are typically used in soap bars to improve overall quality and process. Above 3% free fatty acids can lead to soft and sticky material and can negatively impact one or more physical characteristics. In at least one form, the FFA content in the composition of the present invention is from 0.05 to 3%, preferably from 0.1 to 2%, more preferably from 0.1 to 1.5% by weight.

[0142] Various test methods have been used to determine the properties of soap compositions.

[0143] The test method is a hardness test protocol which uses a 30° cone probe which penetrates to a depth of 15 mm. Another test is the rate of wear (RoW) which relates to the amount of material lost from a soap bar product under controlled conditions. These use conditions roughly mimic the way a consumer uses a product. Further tests are carried out to examine the extent of physical damage which can be caused (or not) by the sequence of rinsing and drying of a soap bar. Yet another test is to determine the "mush" which is defined as the gummy, creamy substance which forms when a bar of toilet soap absorbs water. The mush dip test gives a numerical value for the amount of mushy material which forms on the bar.

[0144] All of the above test methods have been described in US20190016994A1 (Unilever).

[0145] the method of the invention According to a second aspect, there is disclosed a method of making a soap composition according to the first aspect, the method comprising the steps of: i) saponifying a fatty material with a base to produce a saponified material, wherein 0.1 to 5% by weight of an electrolyte is added during the saponification process; ii) adding a bicarbonate salt in the range of 0.5 to 5% by weight of the resulting soap composition to the saponified material obtained from step (i) and mixing, iii) adding water to the mixture of step (ii), iv) adding an alkali silicate heated to 40 to 80°C in the range of 0.25 to 5% by weight of the resulting soap composition; v) adding an organic filler in the range of 1 to 45% by weight of the resulting soap composition of step (iv); and vi) extruding the composition resulting from step (v) into a soap composition according to the first aspect; wherein steps (ii) and (iv) are interchangeable.

[0146] According to a second aspect, a process for preparing a soap composition according to the first aspect is disclosed, the process comprising the steps of: i) saponifying a fatty material with a base to produce a saponified material, wherein an electrolyte is added during the saponification process in an amount of 0.1 to 5 wt.%; ii) adding 0.2 wt.% to 10 wt.% of a polymeric silica; iii) adding an organic filler in an amount ranging from 1 to 45 wt.% of the weight of the resulting soap composition of step (ii); and iv) extruding the composition resulting from step (iii) into a soap composition according to the first aspect.

[0147] Preferably, in the process of the present application, the electrolyte is selected from the group consisting of sodium carbonate, sodium citrate, sodium sulfate, sodium chloride and mixtures thereof, and preferably sodium sulfate and / or sodium chloride, and most preferably sodium sulfate.

[0148] Preferably, in the process of the present application, the soap composition comprises 18 to 75 wt.% of total fatty material and 15 to 45 wt.% of moisture. It can be preferred that the soap composition comprises 20 to 45 wt.%, or even 21 to 45 wt.%, or even 25 to 45 wt.%, or even 26 to 45 wt.% of water.

[0149] Preferably, in the process of the present application, the sodium sulfate is in an amount ranging from 0.1 to 2 wt.% of the total weight of the composition.

[0150] Preferably, in the process of the present application, the bicarbonate is sodium bicarbonate.

[0151] Preferably, in the process of the present application, the alkali silicate is sodium silicate.

[0152] Preferably, in the process of the present application, the polymeric silica is generated in situ by the reaction of the alkali silicate and the bicarbonate.

[0153] Preferably, in the process of the present application, the organic filler is starch, more preferably the organic filler is added in an amount ranging from 1 to 45 wt.% of the weight of the soap composition.

[0154] Preferably, the electrolyte in step (i) is added in an amount ranging from 0.1 to 2 wt.% of the total weight of the composition.

[0155] In the process of the present application, the polymeric silica can be added non-in situ or generated in situ by the reaction of the alkali silicate with an acid or an acidic salt.

[0156] The present application provides the use of polymeric silica and starch in a soap bar having a moisture in the range of 15 to 45 wt.% for achieving a hardness of at least 3 Kg-F measured at 40°C.

[0157] The bar composition according to the present application can be produced on a commercial scale by any method known to the person skilled in the art. Preferably, the bar composition of the present application is prepared using an extrusion route. Preferably a Sigma mixer process (post-dosing route) or a beater / Mazzonni / spray dryer process is used.

[0158] neutralizing the fatty acid or the fat to form a fatty acid soap: The fatty acid used for neutralization can be a single type or a mixture of different fatty acids. Preferably, the fatty acid is a mixture of different fatty acids. The fat used is one that provides a combination of short chain fatty molecules and long chain fatty molecules in the preferred amounts. As used herein, the term fat also includes oils as generally known to the person skilled in the art. The neutralization step is achieved by forming a fatty acid soap using a basic neutralizing agent, preferably selected from silicates, carbonates, hydroxides, basic aluminum containing materials such as aluminates, phosphates or mixtures thereof, preferably the basic neutralizing agent is a hydroxide or a silicate. Also preferably, the basic neutralizing agent used for neutralization is sodium hydroxide or potassium hydroxide.

[0159] The process of the present application comprises a first step of heating a fat blend comprising lauric fatty acids and saturated and unsaturated non-lauric fatty acids in a blending tank to 60 to 80°C, wherein the iodine value of the fat blend is 44 to 58 g / iodine / 100 g. The main components of a typical mixer are a jacketed cylinder, an axial rotating shaft rod through the center of the cylinder (longitudinally), a plow blade mounted on the axial shaft rod and a chopper. The plow and the high speed chopper are mixing elements. Since the gap between the plow surface and the cylinder is about 3 to 8 mm, the material is significantly sheared while mixing. A typical mixer has a cylinder volume of 60 liters, a plow rpm of 200 and a chopper rpm of 3000. The ratio of plow blade area to barrel volume is about 0.002 cm -1 .

[0160] About one third of the blend from the melt tank is then transferred to a blending tank kept at 60 to 80°C.

[0161] The process can alternatively be carried out in any mixer conventionally used in soap manufacture. Preferably a high shear kneader mixer is used. Preferred mixers include Sigma type, multi-wiping overlapping, single curve or double arm kneading elements. The double arm kneader mixer can be overlapping or tangential in design. Alternatively, the present application can be carried out in a screw-screw agitator vessel or a multi-head metering pump / high shear mixer and spray dryer combination as in conventional processing.

[0162] The next step involves the addition of at least one reactant from a first set of reactants consisting of a water soluble polycarboxylic acid, a water soluble salt of such acid, calcium chloride, a borate or OHC(CH2) n CHO (where n = 2 to 6) while maintaining the temperature at 60°C to 80°C.

[0163] The third step comprises the addition of a base, preferably under shear, to saponify the fat blend. The saponification is preferably carried out to the extent of 80 to 100%. Preferably, an aqueous solution or dispersion of a base is used. More preferably, the base is caustic soda. Alternatively, any other suitable base can be used in stoichiometrically calculable amounts. Due to the exothermic nature of the saponification reaction, the temperature of the reaction mass increases. Preferably, a portion of the total base is introduced in aqueous form into the mixer.

[0164] Process for the preparation of in-situ polymerized silica: The next step involves the acidification of the alkaline silicate with an acid to form the polymerized silica in-situ. Preferably, the silicate is an alkali metal silicate, more preferably sodium silicate, and the acid is selected from inorganic acids (preferably sodium bicarbonate) or organic acids. Preferably, the acid is selected from carbon dioxide, an organic acid, a bicarbonate or a mixture thereof. Preferably, the bicarbonate is sodium bicarbonate. During the acidification step, the silicate is mixed with the acid in the required concentration, in approximately stoichiometric proportions or in a slight excess. The silicate can be added at room temperature or can be separately subjected to a further step of heating to a temperature of about 45°C to 80°C, preferably about 60°C, prior to mixing.

[0165] The reactants are simultaneously introduced into the reaction vessel under closed vessel conditions, at or substantially at atmospheric pressure, and the reaction mass is subjected to agitation for uniform mixing. The reaction is allowed to proceed to completion, which generally takes about 20 to 30 minutes. Thereafter, the pH of the polymerized silica is adjusted to the required level by the addition of either the acid or the silicate. The pH of the final dough mass is preferably adjusted to the range of 7.2 to 10.0 pH.

[0166] The preparation of the soap bar composition preferably comprises acidifying an excess of an alkali metal silicate with an acid source selected from a bicarbonate, carbon dioxide or an organic acid to form the polymerized silica. Preferably, the bicarbonate reacts with the alkali metal silicate to form the polymerized silica. Preferably, the bicarbonate is sodium bicarbonate and the alkali metal silicate is sodium silicate.

[0167] In one embodiment of the present application, the steps for making the laundry soap bar composition involves a step of in-situ preparation of polymeric silica followed by in-situ preparation of silicate structurant. In this aspect, the step of acidifying excess silicate with an acid, preferably bicarbonate, to form polymeric silica in-situ is followed by contacting the remaining silicate with a magnesium source to form magnesium silicate or with a calcium source to form calcium silicate or with an aluminium source to form sodium aluminium silicate and with water to provide the dough.

[0168] Beater process: Step (i): This is one of the well known processes for making laundry soap bar composition. In the beater process, the step of neutralizing one or more fatty acids or fats with an alkaline neutralizing agent to obtain fatty acid soaps is carried out by adding fatty acids or fats having shorter chain length of fatty acids having C 12 or lower and fatty acids or fats having longer chain length of fatty acids having C 14 or higher in a preferred ratio range to the beater maintained at a temperature in the range of 50°C to 90°C. The oil used can be selected from distilled fatty acids or neutral oils. Next, the alkaline neutralizing agent, preferably sodium hydroxide or potassium hydroxide, is added in an amount required to achieve complete saponification of the fatty acids or fats. Thereafter, the temperature of the beater is increased to a range of 75°C to 120°C. Preferably, during the neutralization step, a required amount of sodium carbonate or sodium chloride solution is added to the neutralization mixture to obtain fatty acid soaps. A sufficient amount of free water is added at this stage, which is required to provide the final bar composition having 15% to 45% by weight of water. A chelating agent is preferably also added during or immediately after the step of neutralizing the fatty acids or soaps. Non-limiting examples of chelating agents include EHDP and EDTA.

[0169] Step (ii): The next step involves the addition of silicate structurant or in-situ generation of silicate structurant. Preferably, the silicate structurant is generated in-situ. Preferably, the silicate structurant is aluminium based. Preferably, the aluminium compound, for example aluminium sulphate, is added to the beater in solid form or in solution form and mixed for 5 to 10 minutes to form a uniform mixture with the fatty acid soaps. An excess stoichiometric ratio of alkaline silicate, preferably sodium silicate, is then added under ambient temperature conditions or slightly heated before being added to the beater. After addition, the contents in the beater are mixed for about 5 to 10 minutes to allow the aluminium compound to react completely with the alkaline silicate, thereby forming the silicate structurant. As mentioned above, preferably the aluminium compound is aluminium sulphate and the alkaline silicate is sodium silicate, which react to form sodium aluminium silicate.

[0170] Step (iii): The next step involves acidifying the silicate to form polymeric silica in situ. First, an acid, preferably sodium bicarbonate, is added to a blender. The sodium bicarbonate is preferably in solid form. Thereafter, the basic silicate is added to the mixture in stoichiometric proportions and the mass is mixed for 5 to 10 minutes to form a billet with polymeric silica formed in situ. The polymeric silica retains excess water.

[0171] Preferably, at this stage, cationic polymers can be added to the billet. The addition of the required cationic polymers at the end of the process avoids any complexation with the anionic soaps. The other optional ingredients that can be added to the laundry soap bar include electrolytes, dyes, acrylic polymers and colorants, glycerol, chelating agents, soluble fillers, inorganic fillers, alkaline materials (carbonates) to form the billet.

[0172] The billet at this stage preferably has a moisture content in the range of 15 to 45% by weight.

[0173] Drying: The formed billet is preferably dried in the next step. In this drying step, the billet is dried to reduce the moisture content of the mixture to 15 to 45% by weight. Commercially practiced drying steps can be achieved by several different methods. One process employs a water cooled roller in combination with a second feed roller to spread the molten neutralized soap into a thin uniform layer. The cooled billet is then scraped off the rollers to form a sheet and dried in a tunnel dryer to a specific moisture level. A modern technique for drying is known as spray drying. This method directs the molten billet through a nozzle to the top of a tower. The spray forms a billet hardening of the dried soap mixture which is then dried in the presence of a hot air stream. A vacuum can be applied to facilitate the removal of water, preferably a vacuum providing at least 50 mm Hg absolute pressure. The dried soap mixture is then extruded to form soap noodles having a water content of 15 to 45% by weight. During the drying step, typically 4 to 7% by weight of moisture is removed from the billet. Preferably, the dryer is a mazzoni vacuum spray dryer which is maintained at a temperature of 85 to 90°C and the vacuum is maintained at 700 mm Hg, and the flow rate is about 3 to 8 tons per hour.

[0174] Stripping: Preferably after drying, the dried soap noodles are transferred to a stripper during the step of stripping the logs in the billets. In the stripping, the step involves converting the soap noodles into shaped laundry soap bar compositions. The conventional strippers are set at a barrel temperature of about 90°F (32°C) and a nose temperature of about 110°F (43°C). The stripper used is a two-stage twin-screw stripper which allows a vacuum of about 40 to 65 mm Hg between the two stages. Preferably, perfume can be added at this stage. The soap logs extruded from the stripper are generally circular or oval in cross-section and are cut into individual plugs. These plugs are then preferably punched on a conventional soap puncher to produce the finished shaped laundry soap bar compositions. After punching, the finished soap bars are packed in the desired packaging material which can be selected from laminates, films, papers or combinations thereof.

[0175] In the preferred process, prior to stripping, the dried soap noodles can be subjected to a mixing step in a simple paddle mixer wherein the noodles are added to the mixer, auxiliary ingredients such as colorants, preservatives, perfumes are added therein and mixed thoroughly to combine all the ingredients together. Further, the mixture from the mixer can preferably be subjected to a grinding step. In a three-roll soap mill, the mixed mixture is passed through rollers set at a temperature of 29°C to 41°C to obtain a uniform mixture which is a intensive mixing step wherein the soap mixture is subjected to compression and intense shearing action. After mixing in the mill, the mixture is transferred to the stripper.

[0176] sigma mixer (post-dosing) process: Another well-known process for making laundry soap bar compositions is known as the post-dosing process or the sigma mixer process. The sigma mixer process involves the use of a whisker or plow shear mixer to make the soap noodles.

[0177] The step of neutralizing the fatty acid or fat with a basic neutralizing agent is carried out in a whisker mixer or a plow shear mixer wherein the fatty acid or oil / fat having a desired level of C 12 or lower shorter chain length fatty acid molecules and C 14 or higher longer chain length fatty acid molecules are added with a basic neutralizing agent, preferably sodium hydroxide. The step is continued i.e. sodium hydroxide is added until the fatty acid or fat / oil is completely neutralized. Preferably, during the neutralization step, a desired amount of sodium carbonate or sodium chloride solution is added to the neutralized mixture to obtain a fatty acid soap. At this stage, sufficient amount of water required to provide a final bar composition having 17% to 40% by weight of water is added. Preferably, a chelating agent is also added during or immediately after the step of neutralizing the fatty acid or soap. Non-limiting examples of chelating agents include EHDP and EDTA.

[0178] In the next step, the neutralized fatty acid soap is dried, preferably in a vacuum spray dryer, as described above in the pug mill process. Soap noodles having a moisture content of 15 wt% to 45 wt% are formed.

[0179] In the next step, 30 wt% to 55 wt% of the dried fatty acid soap and 15 wt% to 45 wt% of the required level of water to obtain the final laundry bar composition is added to the sigma mixer and the mixer is operated preferably for 10 to 15 minutes for homogenization.

[0180] Preferably, in the next step, the silicate structurant and the polymeric silica are formed to form a billet, with reference to the pug mill process as described above. The billet is then subjected to the noodling step as described above. The billet is subjected to the noodling step wherein the billet is transferred to the noodler which involves converting the billet into a shaped laundry soap bar composition.

[0181] According to a third aspect, the present application discloses use of polymeric silica and organic filler (preferably starch) in a soap bar having 15 wt% to 45 wt% water in a laundry soap bar composition having 18 wt% to 75 wt% TFM (more preferably, the composition comprises 18 to 55 wt%, preferably 18 to 50 wt%, or even 20 to 48 wt%, or even more preferably 20 to 45 wt%, and even more preferably 20 to 42 wt% of TFM by weight of the soap composition) for providing good user properties, improved bar performance, foaming properties and / or improved fragrance delivery.

[0182] The present application provides use of polymeric silica and organic filler (preferably starch) in a soap bar having moisture in the range of 15 wt% to 45 wt% for achieving a hardness of at least 3 Kg-F measured at 40°C.

[0183] The present application will now be illustrated by the following non-limiting examples.

[0184] Example Soap compositions (E1, E2, E3 and E4) were prepared according to the present application using formulations as shown in Table 1. The fatty acids / fats according to the required blend were weighed and neutralized using sodium hydroxide. Electrolytes sodium sulfate and sodium chloride were added during the saponification process.

[0185] The required amount of sodium silicate and sodium bicarbonate powder was added either in the soap making stage (PSM / pug mill) or in the finishing line (at the sigma mixer) to make the gel.

[0186] After complete fatty acid neutralization, sodium silicate and sodium bicarbonate powders are added to the PSM / whipper mixer. First, a high moisture soap noodle (24-25%) is prepared. The material is then converted into noodles by passing through a sub-cylinder and noodler. The noodles are converted into bars by adding SLS, starch, minor ingredients, perfumes, etc. to a sigma mixer and then bar pressed through an extruder.

[0187] In another process, after the electrolyte containing soap noodles are comminuted, sodium silicate and sodium bicarbonate are added to a sigma mixer. In the sigma mix, the soap noodles and sodium lauryl sulfate are comminuted for 3 to 5 minutes. Sodium bicarbonate is added as a powder and mixed for 2 minutes. The entire amount of water is added and mixed for 1-2 minutes. Sodium silicate (45% liquid) is then heated to 70°C and added slowly and mixed for 6-10 minutes to allow gel formation to occur. Starch is added and mixed for 2-3 minutes. All minor ingredients and free fatty acids are added and mixed. Colorants and fragrances are also added and mixed. The resulting billet is shaped into soap bars. Similar bars without polymeric silica (E5) are prepared, as well as a high TFM (72 wt%) conventional soap bar for comparison. Formulations E6 and E7 are prepared in the absence of starch. The formulations of the eight bars are shown in Table 1.

[0188] Measurement of bar parameters: bar hardness Bar hardness refers to the hardness of the bar after manufacture, which gives an indication of processability, strength, and retention of structural integrity during handling, shipping, and use.

[0189] Bar hardness is determined by using a TA-XT Express texture analyzer with a 30° cone probe that penetrates into a soap bar sample to a predetermined depth at a specified speed. The resistance generated at the specified depth is recorded. The bar whose hardness is to be measured is placed on the test platform. The probe of the measuring instrument is then placed close to the surface of the soap composition without touching it. Next, the instrument is started and the force required to reach the preset target distance is measured and the observation is recorded (in g, g f force).

[0190] This value can be related to the yield stress, which has long been known to be an important determinant of processability, and also to in-use performance. The hardness of freshly prepared bars and bars after 24 hours of storage is measured.

[0191] Temperature correction The hardness (yield stress) of skin cleansing bar formulations is temperature sensitive. In order to make meaningful comparisons, the reading at the target distance (R T ) should be corrected for a standard reference temperature (usually 40°C) according to the following equation: R40 = R T x exp [a (T - 40)], where R 40 = reading at reference temperature (40°C) R T = reading at temperature T a = temperature correction factor T = temperature at which the sample is analyzed.

[0192] Table 1:

[0193] As can be seen in the above table, low TFM bars E1, E2, E3 and E4 using different TFM of starch and polymeric silica were successfully manufactured with good hardness and no processing issues were perceived when processing the bars.

[0194] Attempts were also made to make low TFM and high moisture bars without starch as in examples E6 and E7. However, it was difficult to make low TFM bars with higher moisture using only polymeric silica as the soap mass was soft and the bar hardness was low.

[0195] In example E5, bars were made without polymeric silica and only with starch, with similar moisture content and similar TFM as E3. It was found that the bar hardness of the starch only bars was low and difficult to process due to the softer mass [bar hardness 3.1 Kg-F (E3) vs 2.1 Kg-F (E5)].

[0196] Low TFM bars were also made with polymeric silica without starch, but the TFM was lower than 55 TFM and the bars with only polymeric silica without starch were difficult to process due to the softer soap mass (E6). Even when the polymeric silica weight % was increased, it was not possible to make soap bars with TFM lower than 50 (E7).

[0197] The lower TFM in the low TFM non-starch bars was adjusted by compensating the starch content with increased water content (E6). However, it was noted that increasing the moisture content made the soap mass soft and unprocessable. Even increasing the polymeric silica content did not solve this problem of bar softness (E7). In E8 and E9, attempts were made to add starch in the absence of polymeric silica. As the starch water content was reduced as in E8, the soap bar composition was unprocessable. On the other hand, if the TFM was reduced and the water content was attempted to be maintained, even then the soap bar composition was unprocessable.

[0198] Therefore, a combination of polymeric silica and starch is required to make low TFM bars.

[0199] Thus, it is observed that the embodiment E3 according to the first aspect has a hardness comparable to the high TFM control bar, but can be made with low TFM and high moisture content, which is not possible in other embodiments in the absence of polymeric silica or starch.

Claims

1. A soap composition comprising: i. 18 to 55% by weight of total fat; ii. 0.1 to 5% by weight of electrolyte; iii. 5 to 45% by weight of starch; iv. 0.2% to 10% by weight of polymeric silica; and v. 15 to 45% by weight of moisture.

2. The soap composition according to claim 1, wherein the starch is natural starch, pregelatinized starch, invert starch, or a mixture thereof.

3. The soap composition according to claim 1 or 2, wherein the electrolyte comprises a compound selected from sodium carbonate, sodium citrate, sodium sulfate, sodium chloride, and mixtures thereof.

4. The soap composition according to any one of claims 1 to 3, wherein the iodine value of the soap composition is 30 to 45 g / iodine per 100 g of soap composition.

5. The soap composition according to any one of claims 1 to 4, wherein the composition has a pH in the range of 9 to 13 when measured at 25°C in a 4% solution prepared with distilled water.

6. The soap composition according to any one of claims 1 to 5, comprising, based on the weight of the composition, 20 to 50% by weight, preferably 20 to 48% by weight, or even more preferably 20 to 45% by weight, and even more preferably 20 to 42% by weight of TFM.

7. The soap composition according to any one of claims 1 to 6, wherein the soap composition comprises 18 to 45% by weight, preferably 20 to 45% by weight, more preferably 21 to 45% by weight, more preferably 25 to 45% by weight, or more preferably 26 to 45% by weight of water.

8. The soap composition according to any one of claims 1 to 7, wherein, based on the weight of the composition, the soap composition contains 10 to 40% by weight, even more preferably 11 to 40% by weight, and even more preferably 12 to 35% by weight of starch.

9. A method for preparing a soap composition according to any one of claims 1 to 8, the method comprising the following steps: i) Saponifying fatty substances with alkali to produce saponified material, wherein 0.1 to 5% by weight of electrolyte is added to the resulting soap composition during the saponification process; ii) Add 0.5 to 5% by weight of the bicarbonate of the resulting soap composition to the saponified material obtained in step (i) and mix. iii) Add water to the mixture from step (ii), iv) Add 0.25 to 5% by weight of the resulting soap composition of an alkaline silicate heated to 40 to 80°C; v) Adding 1 to 45% by weight of organic filler to the resulting soap composition; and vi) Extruding the composition obtained from step (v) into a soap composition according to any one of claims 1-8; Steps (ii) and (iv) are interchangeable.

10. A method for preparing a soap composition according to any one of claims 1 to 8, the method comprising the following steps: i) Saponifying fatty substances with alkali to produce saponified material, wherein 0.1 to 5% by weight of electrolyte is added during the saponification process; ii) Add 0.2% to 10% by weight of the polymeric silica to the resulting soap composition; iii) Add starch ranging from 5 to 45% by weight of the resulting soap composition; and iv) The composition obtained from step (iii) is extruded into a soap composition according to any one of claims 1-8.

11. The method according to claim 9 or 10, wherein the soap composition comprises 18 to 55% by weight of total fatty substances and 15 to 45% by weight of water.

12. The method according to any one of claims 9 to 11, wherein the addition of the polymeric silica in step (ii) can be done ex-situ or generated in situ by reaction of a basic silicate with an acid or an acidic salt.

13. The method according to any one of claims 9 to 12, wherein the electrolyte is selected from sodium carbonate, sodium citrate, sodium sulfate, sodium chloride, and mixtures thereof.

14. Use of polymeric silica and starch in a soap composition according to any one of claims 1 to 8 having a moisture content in the range of 15 to 45% by weight for achieving a hardness of at least 3 kg-F as measured at 40°C.

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