Low TFM pour and cast soap bar

Abstract

Disclosed is a melt and pour soap bar composition comprising 6 to 20 wt% soap, 4 to 20 wt% of sodium aluminosilicate; and 60 to 80% of water.

Description

[0001] LOW TFM POUR AND CAST SOAP BAR

[0002] Field of the invention

[0003] The invention relates to a high moisture soap bar. More particularly the invention relates to a high moisture, low Total Fatty Matter (TFM) soap bar made by a pour and cast route and which can be conveniently prepared even by a consumer.

[0004] Background of the invention

[0005] Conventional cleansing bars based on soap for personal washing usually contain over about 70% by weight total fatty matter, the remainder being water (about 10-20%) and other ingredients such as colour, perfume, preservatives, etc. Structurants are also present in such compositions in amounts, which replace some of the soap in the bar while retaining the desired hardness of the bar. A few known structurants include starch, kaolin and talc.

[0006] Soaps are conventionally prepared in factories, packaged, sent to warehouses and shops and to finally reach consumer homes to be used by them. Tons and tons of raw material enters the factories and undergoes intensive processing and leave as finished products with a lot of side products as waste. Furthermore, the finished goods such as soap reach the consumers months after being manufactured after incurring significant transit, supply chain costs and possible transit wear and tear.

[0007] Hard non-milled cleansing bars containing moisture of less than 35% are also available. These bars have a TFM of about 30 to 65%. The reduction in TFM has usually been achieved by the use of insoluble particulate materials and / or soluble silicates. Milled bars generally have a water content about 8 to15%, and the hard non-milled bars have a water content of about 20 to 35%.

[0008] It is important to deliver sensory properties such as lather and skin feel, preferably by incorporating benefit agents in the formulation without altering the process, ability and physical properties of the bar. Currently most of the extruded cleansing bars contain some amount of soluble oil soap content which helps for lathering, and cleansing and insoluble oil soap content for structuring the cleansing bar. Normally any soap bar composition contains 5% to 20% of soluble soap and rest is insoluble soap. Essentially any cleansing bar will have 60 to 95% of insoluble soap used only for structuring the cleansing bar which does not play any role in cleansing. There are some cleansing bars with 40 to 50 TFM where TFM is compensated by skin beneficiary agents, moisturizers etc. Overall normal soap contains 60 to 70% of soap which only helps for structuring cleansing bar. Generally, cast melt cleansing bars available in the market range from with 40 to 60 TFM.

[0009] As a result, the trend is towards lower TFM soaps, being a cost-effective measure. Though the soap industry has tried many ways to achieve this, but this has mostly faced with one or the other roadblocks including compromising on the cleansing, lather, physical properties or sensorial properties of the soap bar besides the manufacturing difficulties.

[0010] Recently, handmade soaps are quite common among consumers as they make the consumers believe that the soap has no harsh chemicals, is mild and is fresh for use. This also allows consumers to choose from the fragrances or additives of their choice.

[0011] CN104651101 (LIU XIAOHUI) discloses a preparation method of a handmade soap prepared by adopting a transparent packaging box as a mould, and the handmade soap is packaged with the transparent packaging box together after being frozen.

[0012] Most soap bars contain in excess of 70% total fatty matter (TFM) making them some of the most high carbon-footprint products in skin cleansing.

[0013] Unlike commercial soaps, handmade soaps aren't made in bulk, but in small batches. Handmade soaps also contain a natural skin emollient called glycerin. Glycerin is responsible for attracting moisture in the air and the deeper layers of your skin to the outer layer of your skin. Glycerin is derived from animal fat and vegetable oil. Too much of glycerin can cause the soap to break quickly and become lumpy. While too little of it can dry your skin out and cause irritation. There's a lot of effort and care that goes into making handmade soaps. Along with the soap base, essential oils, carrier oils and natural colourants are added to the soap. The hot mix is then poured into a mould and left to sit for 24 hours. It takes a few more weeks later to cure and harden. Whereas, commercial soaps are produced in large quantities and come straight from factories. Chemicals, machinery and artificial fragrances hamper the quality of the product.

[0014] Although many consumers are tempted by the very idea of hand-made soap but do not attempt because of the time and effort and hassle it involves. And even on attempting if such a soap bar does not perform at par with the commercial soap and costs significantly higher, it is a dampener for the consumer who sets to attempt making a hand-made soap.

[0015] Therefore, there is a need to provide a good hand-made soap bar which is low TFM, good in sensorial qualities, does not crack, does not become soggy on attracting moisture over time, provides good lather and is gentle on the skin at the same time. Such a soap should be capable of being made without much effort and time at home.

[0016] Summary of the invention

[0017] First aspect of the present invention provides melt and pour soap bar composition comprising, a. 6 to 20 wt% soap; b. 4 to 20 wt% of sodium aluminosilicate; and c. 60 to 80% of water.

[0018] Second aspect of the present invention provides premix composition to make a soap bar composition according to the first aspect, the premix composition comprising, i. 20 to 60 wt% soap, ii. 15 to 55 wt% of sodium aluminosilicate, by weight of the premix composition.

[0019] Third aspect of the present invention provides method of making a soap bar composition according to the first aspect, the steps comprising: a. providing a premix composition according to the second aspect; b. heating water in the range of 80 to 100 °C and adding the premix composition from step (a) to it to and stirring to form a soap solution; c. pouring the soap solution of step (b) into a mould and leaving it undisturbed for a predetermined amount of time to set and form a shaped solid soap; and d. removing the shaped solid soap of step (c) from the mould to obtain the soap bar composition according to the first aspect.

[0020] Fourth aspect of the present invention provides kit for making a soap according to the first aspect, wherein the kit comprises: a. a premix composition according to the second aspect; and b. a set of instructions to make the soap.

[0021] Fifth aspect of the present invention provides use of the premix according to the second aspect to make a handmade soap.

[0022] As used herein the term “comprising” encompasses the terms “consisting essentially of” and “consisting of”. Where the term “comprising” is used, the listed steps or options need not be exhaustive. Unless otherwise specified, numerical ranges expressed in the format "from x to y" are understood to include x and y. In specifying any range of values or amounts, any particular upper value or amount can be associated with any particular lower value or amount. Except in the examples and comparative experiments, or where otherwise explicitly indicated, all numbers are to be understood as modified by the word “about”. All percentages and ratios contained herein are calculated by weight unless otherwise indicated. As used herein, the indefinite article “a” or “an” and its corresponding definite article “the” means at least one, or one or more, unless specified otherwise. The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added only for convenience and are not intended to limit the disclosure in any way. The invention is not limited to the embodiments illustrated in the drawings. Accordingly, it should be understood that where features mentioned in the claims are followed by reference numerals, such numerals are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting to the scope of the claims. Throughout the specification unless otherwise specified, wt% means weight % of the total weight of soap bar composition of the present invention.

[0023] Various components of the composition are described in greater detail below.

[0024] Detailed description of the invention

[0025] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0026] Throughout the specification unless otherwise specified, wt% means weight % of the total weight of soap bar composition of the present invention.

[0027] Various components of the composition are described in greater detail below.

[0028] The present invention provides a soap bar composition comprising a melt and pour soap bar composition comprising 6 to 20 wt% soap, 4 to 20 wt% of sodium aluminosilicate; and 60 to 80% of water.

[0029] The present inventors were faced with the problem of achieving a low TFM soap bar and at the same time having functional and sensorial properties of a conventional soap bar. The goal of inventors was also to achieve a soap bar that is extremely easy to make so that it can be prepared at home without any special equipment. Such a soap bar would be highly sustainable carrying the lowest possible carbon footprint and the simplicity of the formulation and process would also make it a low cost hygiene product that can be made available to all. However, the inventors were faced with lot of challenges, such as it was difficult to lower the TFM without affecting the lather, sensorial properties of the bar and it was either too soft or too hard or would not set. After a lot of experimentation with various permutations and combinations, different ingredients, the inventors arrived at the composition of the present invention which had the optimal hardness, rate of wear and lather properties commensurate with current toilet bars. The inventors finally and unexpectedly found that a soap bar composition having a defined content of long chain fatty acid soap and having with a moisture content between 60 to 80%, containing appropriate structurants such as sodium alumino silicate at a given wt% range along with the combination of non-soap surfactants was able to result in a soap bar with the desired characteristics.

[0030] Soap

[0031] The present invention relates to a soap composition. By a soap composition is meant a cleansing composition comprising soap which is in the form of a shaped solid. It is preferred that the composition is shaped in the form of noodles or bars. More preferably the composition of the invention is in the form of a bar. The bars in turn, could 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 cleaning soap composition is generally a wash off products have sufficient amounts of surfactants included therein that it is used for cleansing the desired topical surface e.g. the whole body, the hair and scalp or the face. It is applied on the topical surface and left thereon only for a few seconds or minutes and washed off thereafter with copious amounts of water.

[0032] The present invention provides a melt and pour soap bar composition comprising 6 to 20 wt% soap, 4 to 20 wt% of sodium aluminosilicate; and 60 to 80% of water. The soap bar composition preferably further comprises up to 10 wt% of a non-soap surfactant.

[0033] The soap composition of the invention is especially useful for personal cleansing. The soap composition is preferably soap noodles or a soap bar. The soap bar composition of the present invention preferably comprises 6 to 20% total amount of TFM from soap, preferably 8 to 18% and more preferably 10 to 16 wt% TFM from soap. The term soap means salt of fatty acid. Preferably, the soap is soap of C8 to C24 fatty acids.

[0034] The cation may be an alkali metal, alkaline earth metal or ammonium ion, preferably alkali metals. Preferably, the cation is selected from sodium or potassium, more preferably sodium. The soap may be saturated or unsaturated. Saturated soaps are preferred over unsaturated soaps for stability. The oil or fatty acids may be of vegetable or animal origin.

[0035] The soap bar composition may be obtained by saponification of oils, fats or fatty acids. The fats or oils generally used to make soap bars may be selected from tallow, tallow stearins, palm oil, palm stearins, soya bean oil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil, babassu oil, and palm kernel oil. The fatty acids may be from coconut, rice bran, groundnut, tallow, palm, palm kernel, cotton seed or soyabean.

[0036] The fatty acid soaps may also be synthetically prepared (e.g. by the oxidation of petroleum or by the hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids, such as those present in tall oil, may also be used. Naphthenic acids may also be used.

[0037] The chain length of soaps depends on the fat or oil feedstock which is usually a blend. For purposes of this specification, "oil" and "fat" are used interchangeably, except where context demands otherwise. Longer chain fatty acid soaps (e.g., Ci6 palmitic or Cis stearic) are typically obtained from tallow and palm oils, and shorter chain soaps (e.g., C12 lauric) may typically be obtained from, for example, coconut oil or palm kernel oil. The fatty acid soaps produced may also be saturated or unsaturated (e.g., oleic acid).

[0038] Typically, longer chain fatty acid soaps (e.g., C14 to C22 soaps) especially longer, saturated soaps are insoluble and do not generate enough foam upon use but they can make the foam creamier and more stable. Conversely shorter chain soaps (e.g., Cs to C12) and unsaturated soaps (e.g., oleic or linoleic acid soap) lather quickly. However, the longer chain soaps (typically saturated, although they may also contain some level of unsaturated such as oleic) are desirable to maintain structure and not dissolve as readily. Unsaturated soaps (e.g., oleic) are soluble and lather quickly, like short-chained soaps, but form a denser, creamier foam, like the longer chained soaps. It is preferred that the soap in the soap bar composition of the present invention is preferably a saturated fatty acid soap, in the range of 6 to 20 wt%, more preferably in the range of 8 to 18 wt% and most preferably in the range of 10 to 16 wt% by weight of the soap bar composition of the present invention.

[0039] It is preferred that the soap bar composition of the present invention comprises at least 6 wt% of long chain (C16-C20) fatty acid soap, more preferably at least 7 wt% and most preferably at least 8 wt% by weight of the soap bar of the present invention. It is preferred that the long chain (C16-C20) fatty acid soap in the soap bar composition of the present invention is in the range of 6 to 18 wt%, more preferably 7 to 16 wt% and most preferably from 7.5 to 15 wt% by weight of the soap bar composition of the present invention.

[0040] The short chain fatty acid soap (C8 to C12) may be optionally present in the soap, when present they may be present in the range of 0.01 to 10 wt%, more preferably 1 to 10 wt% and most preferably from 1.5 to 8 wt% by weight of the soap bar composition of the present invention.

[0041] When short chain fatty acid soap is present, the ratio of short chain to long chain fatty acid soap is in the range of 0.01 :1 to 0.6:1 , more preferably in the range of 0.15:1 to 0.4:1 and most preferably in the range of 0.2:1 to 0.3:1.

[0042] The soap bar compositions of the present invention may also comprise unsaturated fatty acid soap preferably in the range of 0.01 to 3 wt%, more preferably 0.1 to 2.8 wt% and most preferably from 1 to 2.5 wt% by weight of the soap bar composition of the present invention.

[0043] Iodine value is an indicator of unsaturation and there are well known methods of measurement of IV. One method is gas chromatography. In this method, methyl esters of the fatty acids are formed and analysed by the chromatographic technique. In addition, there are wet chemical methods of analyses. It is possible to measure iodine value of a fat blend before saponification. Additionally, it is possible to determine the iodine value of a soap (saponified oil or fatty acids) present in a finished good like a bar of soap or noodles of soap.

[0044] It is preferred that the soap bar composition has pH in the range from 8 to 13, when measured in a 8% solution with distilled water at 25°C. NonSurfactant

[0045] The composition of the invention preferably includes a non-soap surfactant, which acts as a co-surfactant and which is selected from anionic, non-ionic, zwitterionic, amphoteric or cationic surfactant or a combination thereof. Preferably the soap bar composition of the present invention comprises non-soap surfactant upto 10wt%. Preferably the soap bar composition of the present invention comprises 0.01 to 10 wt % non-soap surfactant. More preferably the composition comprises 1 to 9 wt % non-soap surfactant and most preferably 2 to 8 wt % by weight of the soap bar composition.

[0046] Suitable anionic surfactants include water soluble salts of organic sulphuric reaction products having in the molecular structure an alkyl radical containing from 8 to 22 carbon atoms, and a radical chosen from sulphonic acid or sulphuric acid ester radicals, and mixtures thereof.

[0047] Examples of suitable anionic surfactants are sodium and potassium alcohol sulphates, especially those obtained by sulphating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium and potassium alkyl benzene sulphonates such as those in which the alkyl group contains from 9 to 15 carbon atoms; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphates; sodium and potassium salts of sulphuric acid esters of the reaction product of one mole of a higher fatty alcohol and from 1 to 6 moles of ethylene oxide; sodium and potassium salts of alkyl phenol ethylene oxide ether sulphate with from 1 to 8 units of ethylene oxide molecule and in which the alkyl radicals contain from 4 to 14 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil and mixtures thereof.

[0048] The preferred water-soluble synthetic anionic surfactants are the alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of higher alkyl benzene sulphonates and mixtures with olefin sulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates.

[0049] Suitable nonionic surfactants can be broadly described as compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

[0050] Particular examples include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a coconut oil ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; condensates of alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol; condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensate containing from 40 to 80 percent of polyoxyethylene radicals by weight and having a molecular weight of from 5,000 to 11,000; tertiary amine oxides of structure R3NO, where one group R is an alkyl group of 8 to 18 carbon atoms and the others are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; tertiary phosphine oxides of structure R3PO, where one group R is an alkyl group of from 10 to 18 carbon atoms, and the others are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyldodecylphosphine oxide; and dialkyl sulphoxides of structure R2SO where the group R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyltetradecyl sulphoxide; fatty acid alkylolamides; alkylene oxide condensates of fatty acid alkylolamides and alkyl mercaptans.

[0051] Suitable cationic surfactants that can be incorporated are alkyl substituted quarternary ammonium halide salts e.g. bis (hydrogenated tallow) dimethylammonium chlorides, cetyltrimethyl ammonium bromide, benzalkonium chlorides and dodecylmethylpolyoxyethylene ammonium chloride and amine and imidazoline salts for e.g. primary, secondary and tertiary amine hydrochlorides and imidazoline hydrochlorides.

[0052] Suitable amphoteric surfactants are derivatives of aliphatic secondary and tertiary amines containing an alkyl group of 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance sodium 3-dodecylamino-propionate, sodium 3- dodecylaminopropane sulphonate and sodium N-2-hydroxydodecyl-N-methyltaurate. Suitable zwitterionic surfactants are derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3-(N-N-dimethyl-N-hexadecylammonium) propane-1 -sulphonate betaine, 3-(dodecyl methyl sulphonium) propane-1 -sulphonate betaine and 3-(cetylmethylphosphonium) ethane sulphonate betaine.

[0053] Further examples of suitable detergent-active compounds are compounds commonly used as surface-active agents given in the well-known textbooks “Surface Active Agents”, Volume I by Schwartz and Perry and “Surface Active Agents and Detergents”, Volume II by Schwartz, Perry and Berch.

[0054] Water- Moisture content

[0055] The soap bar compositions of the present invention have moisture or water content of at least 60wt% of the weight of the soap bar. The soap bar compositions of the present invention have 60 to 80 wt% of water, preferably 63 to 78 wt%, and most from preferably 65 to 78 wt% by weight of the soap bar composition.

[0056] Electrolyte

[0057] Inclusion of small amount of an electrolyte (other than soap) can influence the liquid and solid phase ratio. Increasing the electrolyte content lowers the solubility of soap thereby increasing the solid phase amount, on the other hand lowering the electrolyte levels make the bars softer.

[0058] Electrolytes as per this invention include compounds that substantially dissociate into ions in water. Electrolytes as per this invention are not an ionic surfactant. Suitable electrolytes for inclusion in the soap making process are alkali metal salts. Preferred alkali metal salts include sodium sulfate, sodium chloride, sodium acetate, 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, sodium citrate, potassium chloride and especially preferred electrolyte is sodium chloride sodium sulphate, sodium citrate or a combination thereof. For the avoidance of doubt, it is clarified that the electrolyte is a non-soap material. It is preferred that the electrolyte is included in the soap bar composition during the step of saponification to form the soap.

[0059] It is preferred that composition of the invention comprises electrolyte in the range of 0.001 to 4 wt %, more preferably 0.01 to 3.8 wt %, and most preferably 0.1 to 3% 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 and especially preferred electrolytes are sodium chloride and sodium sulfate and combinations thereof. For the avoidance of doubt is clarified that the electrolyte is a non-soap material.

[0060] It is most preferred that sodium sulphate and / or sodium chloride and or sodium citrate or combinations thereof are used as electrolytes for the composition of the present invention.

[0061] It is preferred when sodium sulphate is present, it is present in the range of 0.01 to 4 wt %, more preferably 0.5 to 3.8 wt %, and most preferably 0.7 to 3% by weight of the composition. It is preferred that sodium sulphate is at least 0.1 wt%, more preferably at least 0.5wt%, and most preferably at least 0.7 wt% and it is preferred that it is not more than 5wt%, more preferably not more than 3 wt%, furthermore preferably not more than 2.8 wt% and most preferably not more than 2.5wt% of the total weight of composition of the present invention.

[0062] It is preferred that when sodium chloride is present, it is in the range of 0.01 to 4 wt %, more preferably 0.5 to 3.8 wt %, and most preferably 0.7 to 3% by weight of the composition of the present invention. It is preferred that sodium chloride is at least 0.1 wt%, more preferably at least 0.5wt%, and most preferably at least 0.7 wt% and it is preferred that it is not more than 5wt%, more preferably not more than 3 wt%, furthermore preferably not more than 2.8 wt% and most preferably not more than 2.5wt% of the total weight of composition of the present invention.

[0063] It is preferred that when sodium citrate is present, it is in the range of 0.01 to 4 wt %, more preferably 0.5 to 3.8 wt %, and most preferably 0.7 to 3% by weight of the composition of the present invention. It is preferred that sodium citrate is at least 0.1 wt%, more preferably at least 0.5wt%, and most preferably at least 0.7 wt% and it is preferred that it is not more than 5wt%, more preferably not more than 3 wt%, furthermore preferably not more than 2.8 wt% and most preferably not more than 2.5wt% of the total weight of composition of the present invention.

[0064] Sodium alumino silicate

[0065] The composition of the invention comprises sodium alumino silicate, preferably selective amount of a sodium alumino silicate preferably having a specific molar ratio of SiCh / AI2O3. Sodium alumino silicate is preferably included in 3 to 20%, more preferably 4 to 18% and most preferably 4 to 17% by weight of the composition. The sodium alumino silicate is carefully prepared such that preferably the molar ratio of SiCh / AI2O3 is less than 5.0, preferably less than 3.5.

[0066] Premix composition

[0067] The present invention provides a premix composition to make a soap according to the first aspect, the premix composition comprising i. 20 to 60 wt% fatty acid soap, ii. 15 to 55 wt% of sodium aluminosilicate, by weight of the premix composition.

[0068] It is preferred that in the premix composition the soap is a fatty acid saturated soap.

[0069] It is preferred that the premix composition comprises upto 30 wt% of non-soap surfactant by weight of the premix composition.

[0070] It is preferred that the premix composition comprises 25 to 70 wt% of long chain (C16-C20) fatty acid soap by weight of the premix composition.

[0071] It is preferred that the premix composition comprises 0.01 to 25 wt% of short chain (C8-C12) fatty acid soap by weight of the premix composition.

[0072] It is preferred that the premix composition comprises up to 10 wt% of unsaturated fatty acid soap by weight of the premix composition.

[0073] It is preferred that the premix composition comprises 0.01 to 4 wt% of electrolyte fatty acid soap by weight of the premix composition. It is preferred that in the premix composition the ratio of sodium aluminosilicate to soap is in the range of 0.5:1 to 1.5:1.

[0074] Method of making the soap bar

[0075] The present invention provides a method of making a soap bar of the first aspect, the steps comprising: a. providing a premix composition comprising: i. 20 to 60 wt% fatty acid soap, ii. 15 to 55 wt% of sodium aluminosilicate, by weight of the premix composition; b. heating water in the range of 80 to 100 °C and adding the premix composition from step (a) to it to and stirring to form a soap solution; c. pouring the soap solution of step (b) into a mould and leaving it undisturbed for a predetermined amount of time to set and form a shaped solid soap; and b. removing the shaped solid soap of step (c) from the mould to obtain the soap bar composition according to the first aspect.

[0076] The present invention provides a soap bar prepared by the method according to the third aspect of the present invention. It is preferred that the soap bar prepared by this method comprises 6 to 20 wt% soap; 4 to 20 wt% of sodium aluminosilicate; and 60 to 80% of water.

[0077] It is preferred that in the method of preparing a soap bar by the premix composition, the water is added in the range of 60 to 80wt% by weight of the soap bar composition.

[0078] Kit for making the soap

[0079] The present invention provides a kit for making the soap bar of the first aspect, wherein the kit comprises: a. a premix composition comprising: i. 20 to 60 wt% fatty acid soap, ii. 15 to 55 wt% of sodium aluminosilicate, by weight of the premix composition; and b. a set of instructions to make the soap.

[0080] The kit may optionally comprise of at least one mould. Use

[0081] The present invention provides use of premix according to according to the first aspect, to make a handmade soap.

[0082] Organic and Inorganic Adjuvant Materials

[0083] The total level of the adjuvant materials used in the bar composition should be in an amount not higher than 50%, preferably 1 to 50%, more preferably 3 to 45% by wt. of the soap bar composition.

[0084] The adjuvant system may optionally include insoluble particles comprising one or a combination of materials. By insoluble particles is meant materials that are present in solid particulate form and suitable for personal washing. Preferably, there are mineral (e.g., inorganic) or organic particles.

[0085] The insoluble particles should not be perceived as scratchy or granular and thus should have a particle size less than 300 microns, more preferably less than 100 microns and most preferably less than 50 microns.

[0086] Preferred inorganic particulate material includes talc and calcium carbonate. Talc is a magnesium silicate mineral material, with a sheet silicate structure and a composition of MgaSi4(OH)22 and may be available in the hydrated form. It has a plate-like morphology, and is essentially oleophilic / hydrophobic, i.e., it is wetted by oil rather than water.

[0087] Calcium carbonate or chalk exists in three crystal forms: calcite, aragonite and vaterite. The natural morphology of calcite is rhombohedral or cuboidal, acicular or dendritic for aragonite and spheroidal for vaterite.

[0088] Examples of other optional insoluble inorganic particulate materials include aluminates, phosphates, insoluble sulfates, borates and clays (e.g., kaolin, china clay) and their combinations. Organic particulate materials include: insoluble polysaccharides such as cellulose; synthetic polymers such as various polymer lattices and suspension polymers; insoluble soaps and mixtures thereof.

[0089] Bar compositions preferably comprise 0.1 to 25% by wt. of bar composition, preferably 5 to 15 by wt. of these mineral or organic particles.

[0090] An opacifier may be optionally present in the personal care composition. When opacifiers are present, the cleansing bar is generally opaque. Examples of opacifiers include titanium dioxide, zinc oxide and the like. A particularly preferred opacifier that can be employed when an opaque soap bar composition is desired is ethylene glycol mono- or di-stearate, for example in the form of a 20% solution in sodium lauryl ether sulphate. An alternative opacifying agent is zinc stearate.

[0091] The product can take the form of a translucent or transparent soap, in which case it will not contain an opacifier.

[0092] It is preferred that the soap bar composition of the present invention has a pH in the range from 9 to 13, when measured in a 4% solution with distilled water at 25°C.

[0093] A preferred bar may additionally include up to 30 wt% benefit agents. Preferred benefit agents include moisturizers, emollients, sunscreens, skin lightening agents and anti-ageing compounds. The agents may be added at an appropriate step during the process of making the bars. Some benefit agents may be introduced as macro domains.

[0094] Other optional ingredients like anti-oxidants, perfumes, polymers, chelating agents, colourants, deodorants, dyes, emollients, moisturizers, enzymes, foam boosters, germicides, additional anti-microbials, lathering agents, pearlescers, skin conditioners, stabilisers, superfatting agents, sunscreens may be added in suitable amounts in the process of the invention. Preferably, the ingredients are added after the saponification step. Sodium metabisulphite, ethylene diamine tetra acetic acid (EDTA), borax or ethylene hydroxy diphosphonic acid (EHDP) are preferably added to the formulation. The composition of the invention could be used to deliver antimicrobial benefits. Antimicrobial agents that are preferably included to deliver this benefits include oligodynamic metals or compounds thereof. Preferred metals are silver, copper, zinc, gold or aluminium. Silver is particularly preferred. In the ionic form it may exist as a salt or any compound in any applicable oxidation state. 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. Oligodynamic metal or a compound thereof is preferably included in 0.0001 to 2%, preferably 0.001 to 1% by weight of the composition. Alternately an essential oil antimicrobial active may be included in the composition of the invention. Preferred essential oil actives which may be included are terpineol, thymol, carvacol, (E) -2(prop-1-enyl) phenol, 2- propylphenol, 4- pentylphenol, 4-sec-butylphenol, 2-benzyl phenol, eugenol or combinations thereof. Furthermore preferred essential oil actives are terpineol, thymol, carvacrol or thymol, most preferred being terpineol or thymol and ideally a combination of the two. Essential oil actives are preferably included in 0.001 to 1%, preferably 0.01 to 0.5% by weight of the composition.

[0095] The soap bar composition may be made into a bar by a process that first involves saponification of the fat charge with alkali followed by extruding the mixture in a conventional plodder. The plodded mass may then be optionally cut to a desired size and stamped with a desirable indicia. An especially important benefit of the present invention is that, notwithstanding the high amount of water content of the soap bar, compositions thus prepared by extrusion are found to be easy to stamp with a desirable indicia.

[0096] The present invention also relates to a process to prepare the soap bar of the invention comprising the step of including substantially all of the structuring system to the soap when it is being produced during the saponification step. Preferably, at least, the polymer is included during the saponification stage.

[0097] The invention will now be illustrated by means of the following non-limiting examples.

[0098] An expression called total fatty matter is used very widely in the field of soaps and detergents. The term abbreviated to “TFM”, is used to denote the wt% of fatty acid and triglyceride residues present in the soap bar composition without taking into account the accompanying cations. For a soap having 18 carbon atoms, an accompanying sodium cation will generally amount to about 8 wt%. Other cations may be employed as desired, for example zinc, potassium, magnesium, alkyl ammonium and aluminium.

[0099] It is preferred that the composition of the invention comprises 18 to 75 wt% TFM, more preferably 20 to 70 wt% TFM and most preferably 20 to 65 wt% by weight of the soap bar composition.

[0100] The term soap means salts of fatty acids in which the accompanying cation may be an alkali metal, alkaline earth metal or ammonium ion, preferably an alkali metal. Preferably, the cation is sodium or potassium. The soap may be saturated or unsaturated and it depends on the nature of the corresponding fatty acid and / or oil used for saponification.

[0101] Other ingredients

[0102] In addition to the saponified fatty matter and the polymeric gel, the soap bar composition of the invention, example noodles, and in particular the bars of soap, preferably comprises one or more of the following other ingredients. Choice of the ingredients and the amounts thereof are largely dependent on the formulation scientists and the purpose for which such noodles or bars are made.

[0103] Opacifier

[0104] An opacifier may be optionally present in the composition. When opacifiers are present, the cleansing bar is generally opaque, i.e. “opacification”. Examples of opacifiers include titanium dioxide, zinc oxide and the like. A particularly preferred opacifier that can be employed when an opaque rather than a transparent soap bar composition is desired is ethylene glycol mono- or di-stearate, for example in the form of a 20% solution in sodium lauryl ether sulphate. An alternative opacifying agent is zinc stearate.

[0105] Benefit agents

[0106] Preferably the soap bar composition of the invention comprises one or more benefit agent not already disclosed earlier. Preferably the benefit agent is an emollient, sunscreen, anti- ageing compounds or moisturizers and humectants. The agents may be added at an appropriate step during the process. Some benefit agents may be introduced as macro domains.

[0107] Examples of moisturizers and humectants include cetyl alcohol, ethoxylated castor oil, paraffin oils, lanolin and its derivatives. Silicone compounds such as silicone surfactants like DC® 3225C (Dow Corning) and / or silicone emollients, silicone oil (DC-200® ex. Dow Corning) may also be included. Further examples include glycerin, oat kernel flour, Petrolatum, Aquaporin and hydroxyethyl urea.

[0108] Sunscreens such as 4-tertiary butyl-4'-methoxy dibenzoylmethane (available under the trade name PARSOL®1789 from Givaudan) or 2-ethyl hexyl methoxy cinnamate (available under the trade name PARSOL® MCX from Givaudan) or other IIV-A and IIV-B sun-screens may also be added. Further examples include Helioplex® (Diethylhexyl naphthylate), Ensulizole®, Ethylhexyl salicylate, Tinosorb® (S & M), Octocrylene® and Mexoryl®.

[0109] Lipids such as cholesterol, ceramides, and pseudoceramides, and exfoliant particles such as polyethylene beads, walnut shells, apricot seeds, flower petals and seeds may also be present.

[0110] The composition can also optionally include other ingredients conventionally used in soap such as lather boosters, colourants and opacifiers and skin tone agents such as hexyl resorcinol, Soybean extract (Bowman Birk inhibitor), Octadecenedioic acid, (Ariatone® DC), niacinamide, Seppiwhite®, Acetylglucosamine, Pitera Extract, Symwhite® and Melano- block® (Calcium pantothenate). Further, the composition of the invention may comprise antiaging ingredient such as retinol, hyaluronic acid, Collagen, CoQ10 (ubiquinone), retinyl propionate, peptides, retinyl palmitate, Jasmonic acid derivatives and Proxylane®.

[0111] Other adjunct materials may include germicides and preservatives. These ingredients normally will be in amounts less than 2 wt %, usually less than 0.5 wt % and may include silver salts and silver compounds, thymol, terpineol and their analogues, ZPTO, chloroxylenol, PCMX, triclosan and trichlorocarbanilide. The composition preferably comprises a polyhydric alcohol (also called polyol) or mixture of polyols. Polyol is a term used herein to designate a compound having multiple hydroxyl groups (at least two, preferably at least three) which is highly water soluble. Many types of polyols are available including: relatively low molecular weight short chain polyhydroxy compounds such as glycerol and propylene glycol; sugars such as sorbitol, manitol, sucrose and glucose; modified carbohydrates such as hydrolyzed starch, dextrin and maltodextrin, and polymeric synthetic polyols such as polyalkylene glycols, for example polyoxyethylene glycol (PEG) and polyoxypropylene glycol (PPG). Especially preferred polyols are glycerol, sorbitol and their mixtures. Most preferred polyol is glycerol. In a preferred embodiment, the bars of the invention comprise 0 to 8%, preferably 1 to 7.5% by wt. polyol.

[0112] The soap bar composition may include structurants. These may include water insoluble particulate material. Structurants may, individually or combined, support 0 to 25 wt%. Preferred inorganic particulate material includes talc and calcium carbonate. Talc is a magnesium silicate mineral material, with a sheet silicate structure represented by the chemical formula Mg3Si4(O) (OH)2 and may be available in the hydrated form. Talc has a plate-like morphology and is substantially oleophilic / hydrophobic.

[0113] Examples of other optional insoluble inorganic particulate materials include zeolites aluminates, silicates, phosphates, insoluble sulfates, clays (e.g., kaolin, china clay), titanium oxide, zinc oxide and their combinations.

[0114] The compositions of the invention may additionally comprise anti-cracking agents such as acrylate polymers.

[0115] The term “slip modifier” is used herein to designate materials that when present at relatively low levels (generally less than 1.5% based on the total weight of the bar composition) will significantly reduce the perceived friction between the wet bar and the skin. The most suitable slip modifiers are useful, individually or combined, at a level of 1% or less, preferably from 0.05 to 1% and more preferably from 0.05 to 0.5%.

[0116] The composition of the present invention optionally comprises modified poly ethylene glycol in the range of 0.01 to 0.08% as a slip modifier and / or for other sensory benefits. The composition of the present invention may also optionally comprise modified ethylene acrylate copolymer in the range of 0.1 to 0.05% as a benefit agent.

[0117] Suitable slip modifier include petrolatum, waxes, lanolins, poly-alkane, poly-alkene, polyalkyene oxides, high molecular weight polyethylene oxide resins, silicones, polyethylene glycols and mixtures thereof.

[0118] Free fatty acids (FFA) up to 3% such as coconut fatty acid, PKO fatty acid, lauric acid are commonly used in soap bars for overall quality and process improvement. Free fatty acid higher than 3% could lead to soft and sticky mass and could negatively impact one or more physical feature. In at least one form, level of FFA in compositions of the invention is 0.05 to 3%, preferably 0.1 to 2%, more preferably 0.1 to 1.5 wt%.

[0119] A variety of test method have been used to determine properties of the soap bar compositions.

[0120] The test methods are hardness testing protocol, using a 30° conical probe which penetrates to depth of 15 mm. Another test is the rate of wear (RoW) which relates to the amount of material which is lost by a soap bar product under controlled conditions. These conditions for use, mimic approximately the way consumers use the product. A further test is done to check for the extent of as the physical damage which may result (or not) from the sequence of washdown and drying of the bar. Yet another test is to determine “mush” defined as the jelly, creamy material that forms when toilet soap bars absorb water. The Mush Immersion Test gives a numerical value of the amount of mush formed on a bar.

[0121] All the aforesaid test methods have been described in US20190016994 A1 (Unilever).

[0122] EXAMPLES

[0123] The soap bar compositions for the examples were prepared in accordance with the present invention.

[0124] The soap premix is prepared by adding all the ingredients and blending into a powder in a mixer. Foam Quality- For checking the foam quality, hands were pre wet with water. Soap bars were rubbed for 10 times under running tap water for pre conditioning the soap bar. Hands were again washed to remove soap / foam. Soap was rubbed for 10 times on hands under running water. Foam was generated by rubbing hands for 10 times without soap. The generated foam was compared visually and rated on a scale of 5.

[0125] Scale: 5: Very good, 4: good, 3: acceptable, 2: poor & 1 : very poor

[0126] The bars were called processable when by pouring hot water into the premix powder & with stirring a homogeneous solution could be obtained, which could be casted in moulds to get the soap bar.

[0127] Hardness value above 1 kgF was considered as acceptable.

[0128] The compositions E1, E2 and E3 were prepared according to the soap bar compositions of the present invention. Compositions E4, E5 and E6 were prepared to study the effect of sodium alumino silicate from similar respective compositions E1, E2 and E3, where it was absent. Compositions E7 to E12 were also prepared to study the effects of sodium aluminosilicate in varying wt% concentrations by the weight of soap, such as 4wt%, 8wt%, 12wt%, 16wt%, 20wt% and 24wt% respectively. E11A was prepared with low water concentration. Compositions E13 to E16 were also prepared to study the effects of sodium aluminosilicate by replacing it with other structurants such as E13 had talc in place of sodium alumino silicate, E14 had starch, E15 had calcium carbonate and E16 had sodium alumino silicate.

[0129] Table 1

[0130] The data of table 1 clearly show that when compositions E1, E2 and E3 were prepared according to the present invention, the soap bars were processable, with good hardness and foam quality. Similar bars E4, E5 and E6 in absence of sodium alumino silicate were not able to foam well and E4 was too soft. Similarly E7 to E11 when prepared according to the present invention with varying sodium alumino silicate weight percentages, performed well in terms of foam, hardness and processability. E11 A was prepared with low water concentration and surprisingly showed that the soap bar composition with desired properties is only possible with the given concentrations of the ingredients of the first aspect and if water concentration is lowered the soap bar was not processible. Similarly, E12 with higher level of sodium alumino silicate was not processable.

[0131] Table 2

[0132] Table 2 shows effect of different structurants on the soap bar in terms of hardness of the soap bar composition of the present invention. It is seen that only soap bar compositions such as E16 with sodium aluminosilicate was able to provide the desired hardness for the soap bar and others with talc (E13), Starch (E14) and Calcium carbonate (E15) did not have acceptable hardness value.

[0133] Hardness Testing Protocol

[0134] Principle

[0135] A 30° conical probe penetrates into a soap / syndet sample at a specified speed to a predetermined depth. The resistance generated at the specific depth is recorded. There is no size or weight requirement of the tested sample except that the bar / billet be bigger than the penetration of the cone (15mm) and have enough area. The recorded resistance number is also related to the yield stress and the stress can be calculated as noted below. The hardness (and / or calculated yield stress) can be measured by a variety of different penetrometer methods. In this invention, as noted above, we use probe which penetrates to depth of 15 mm.

[0136] Apparatus and Equipment

[0137] TA-XT Express (Stable Micro Systems)

[0138] 30° conical probe - Part #P / 30c (Stable Micro Systems)

[0139] Sampling Technique

[0140] This test can be applied to billets from a plodder, finished bars, or small pieces of soap / syndet (noodles, pellets, or bits). In the case of billets, pieces of a suitable size (9 cm) for the TA-XT can be cut out from a larger sample. In the case of pellets or bits which are too small to be mounted in the TA-XT, the compression fixture is used to form several noodles into a single pastille large enough to be tested.

[0141] Procedure

[0142] Setting up the TA-XT Express

[0143] These settings need to be inserted in the system only once. They are saved and loaded whenever the instrument is turned on again. This ensures settings are constant and that all experimental results are readily reproducible.

[0144] Set test method

[0145] Press MENU Select TEST SETTINGS (Press 1)

[0146] Select TEST TPE (Press 1)

[0147] Choose option 1 (CYCLE TEST) and press OK

[0148] Press MENU

[0149] Select TEST SETTINGS (Press 1)

[0150] Select PARAMETERS (Press 2)

[0151] Select PRE TEST SPEED (Press 1)

[0152] Type 2 (mm s-1) and press OK

[0153] Select TRIGGER FORCE (Press 2)

[0154] Type 5 (g) and Press OK

[0155] Select TEST SPEED (Press 3)

[0156] Type 1 (mm s-1) and press OK

[0157] Select RETURN SPEED (Press 4)

[0158] Type 10 (mm s-1) and press OK

[0159] Select DISTANCE (Press 5)

[0160] Type 15 (mm) for soap billets or 3 (mm) for soap pastilles and press OK

[0161] Select TIME (Press 6)

[0162] Type 1 (CYCLE)

[0163] Calibration

[0164] Screw the probe onto the probe carrier.

[0165] Press MENU

[0166] Select OPTIONS (Press 3)

[0167] Select CALIBRATE FORCE (Press 1) - the instrument asks for the user to check whether the calibration platform is clear

[0168] Press OK to continue and wait until the instrument is ready.

[0169] Place the 2kg calibration weight onto the calibration platform and press OK

[0170] Wait until the message “calibration completed” is displayed and remove the weight from the platform.

[0171] Sample Measurements

[0172] Place the billet onto the test platform.

[0173] Place the probe close to the surface of the billet (without touching it) by pressing the UP or DOWN arrows. Press RUN

[0174] Take the readings (g or kg) at the target distance (Fin).

[0175] After the run is performed, the probe returns to its original position.

[0176] Remove the sample from the platform and record its temperature.

[0177] Calculation & Expression of Results

[0178] Output

[0179] The output from this test is the readout of the TA-XT as “force” (RT) in g or kg at the target penetration distance, combined with the sample temperature measurement. (In the subject invention, the force is measured in Kg at 40°C at 15 mm distance)

[0180] The force reading can be converted to extensional stress, according to the equation given below.

[0181] The equation to convert the TX-XT readout to extensional stress is where: o = extensional stress

[0182] C = “constraint factor” (1.5 for 30° cone)

[0183] Gc= acceleration of gravity . . . , ,

[0184] A = projected area of cone = d = penetration depth 0 = cone angle

[0185] For a 30° cone at 15 mm penetration, Equation 2 becomes ct (Pa) = RT(g) x 128.8

[0186] This stress is equivalent to the static yield stress as measured by penetrometer. The extension rate is:

[0187] F E = where E = extension rate (s-1) V = cone velocity

[0188] For a 30° cone moving at 1mm / s, E = 0.249 s-1

[0189] Temperature Correction The hardness (yield stress) of skin cleansing bar formulations is temperature-sensitive. For meaningful comparisons, the reading at the target distance (RT) should be corrected to a standard reference temperature (normally 40°C), according to the following equation:

[0190] R40= R ■■ exp[a(T-40)] where R40 = reading at the reference temperature (40°C) RT = reading at the temperature T a = coefficient for temperature correction

[0191] T = temperature at which the sample was analyzed.

[0192] The correction can be applied to the extensional stress.

Claims

Claims:

1. A melt and pour soap bar composition comprising, a. 6 to 20 wt% fatty acid soap; b. 4 to 20 wt% of sodium aluminosilicate; and c. 60 to 80% of water.

2. A soap bar composition according to claim 1 , wherein the soap bar composition comprises up to 10wt% of non-soap surfactant.

3. A soap bar composition according to claims 1 or 2, wherein the soap is a fatty acid saturated soap.

4. A soap bar composition according to anyone of the preceding claims 1 to 3, wherein the soap bar composition comprises 6 to 20wt% of long chain (C16 to C20) fatty acid soap by weight of the soap bar composition.

5. A soap bar composition according to anyone of the preceding claims 1 to 4, wherein the soap bar composition comprises 1 to 10 wt% of short chain (C8-C12) fatty acid soap by weight of the soap bar composition.

6. A soap bar composition according to anyone of the preceding claims 1 to 5, wherein ratio of the sodium aluminosilicate to the fatty acid soap is in the range of 0.5:1 to 1.5:1.

7. A soap bar composition according to anyone of the preceding claims 1 to 6, wherein the soap bar composition further comprises upto 3 wt% unsaturated fatty acid soap by weight of the soap bar composition.

8. A premix composition to make a soap bar composition according to anyone of the preceding claims 1 to 7, the premix composition comprising, i. 20 to 60 wt% fatty acid soap, ii. 15 to 55 wt% of sodium aluminosilicate, by weight of the premix composition.

9. A premix composition according to claim 8, wherein the composition comprises upto 30 wt% of non-soap surfactant.

10. A premix composition according to anyone of the claims 8 or 9, wherein the premix composition comprises 25 to 70 wt% of long chain (C16-C20) fatty acid soap.

11. A premix composition according to anyone of the preceding claims from 8 to 10, wherein ratio of the sodium aluminosilicate to the fatty acid soap is in the range of 0.5:1 to 1.5:1.

12. A method of making a soap bar composition according to anyone of the preceding claims 1 to 7, the steps comprising: a. providing a premix composition according to claims 8 to 11 ; b. heating water in the range of 80 to 100 °C and adding the premix composition from step (a) to it to and stirring to form a soap solution; c. pouring the soap solution of step (b) into a mould and leaving it undisturbed for a predetermined amount of time to set and form a shaped solid soap; and d. removing the shaped solid soap of step (c) from the mould to obtain the soap bar composition according to claims 1 to 7.

13. A soap bar prepared by the method according to claim 12.

14. A kit for making a soap bar composition according to anyone of the preceding claims 1 to 7, wherein the kit comprises: i. a premix composition according to claims 8 to 11 ; and ii. a set of instructions to make the soap bar according to claims 1 to 7.

15. Use of premix according to according to anyone of the preceding claims 8 to 11 , to make a handmade soap.

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