A translucent extruded soap bar composition

Abstract

The present invention relates to an extruded soap bar composition of the present invention comprises 40 to 80 wt% total fatty matter, 0.1 to 4 wt% electrolyte, 1 to 15 of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, 0.1 to 6 wt% propylene carbonate, 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total non-soap surfactant is anionic surfactant, and 10 to 30 wt% water.

Description

[0001] A TRANSLUCENT EXTRUDED SOAP BAR COMPOSITION

[0002] Field of the invention

[0003] The invention relates to translucent extruded soap bar compositions. More particularly, it relates to extruded soap bar compositions having polyols or polyol derivatives.

[0004] Background of the invention

[0005] Three main types of soap bars are known: opaque (non-transparent) soap; translucent soap; and transparent soap, which has ultimate translucency.

[0006] Translucent soap bars are popular among consumers for their aesthetic appeal and their connotation of purity and high moisture content. Generally, a translucent bar soap is composed largely of one single homogeneous crystalline phase known as the “beta phase.” The beta phase is one of four known crystalline phases of soap and imparts translucence, generally due to the small size of the soap crystals, which are too small to diffract light.

[0007] As used herein, the meaning of “translucent” is that which is generally employed and is generally in accordance with the usual dictionary definition. For example, a translucent soap is one that allows light to pass through it but the light may be so scattered, as by a small proportion of crystals or insolubles, such that it will not be possible to clearly identify objects behind the translucent soap. Furthermore, translucent soaps may include clear, colorless, and colored transparent soaps.

[0008] Various types of processes are used in making translucent soap. Casting or pouring by batch processing are the most traditional methods of making translucent soap, but are not widely used. Over the last decades, manufacturing of translucent soaps by extrusion has become possible. This method is gaining popularity because of the relative simplicity of the process, reducing the cost of manufacturing to an acceptable level. This lower cost of the product permits its availability to a larger group of consumers who are very much interested in this kind of soap because of its aesthetically very attractive form. Translucent soaps have been formulated using several well-known methods, either by adding transparency-enhancing additives or agents to inhibit soap crystallization. For example, clarifying agents such as lower alkanols, glycerin and / or sugar were added to inhibit soap crystallization, and the soaps were framed, not milled and plodded. Other methods include low temperature saponification of fats and oils pre-dissolved in warm alcohol, water, and glycerine, followed by evaporation of part of the alcohol / water azeotrope. Yet another method involves the addition of a polyhydric alcohol, such as glycerol, glycol, sugar or the like to a "neat soap" or semi-boiled soap, or to soap prepared by the cold process technology. Numerous other transparent and translucent soap bars are also known in the art which are prepared using additives or specialized equipment.

[0009] Soap bars for cleansing are typically prepared by saponifying or neutralizing triglyceride and free fatty acids. In this saponification process, various fats (e.g., tallow, palms and coconut oil blends) are saponified in the presence of alkali (typically NaOH) to yield alkaline salts of fatty acid (derived from the fatty acid chains forming the glyceride) and glycerol. Glycerol is then typically extracted with brine to yield dilute fatty acid soap solution containing soap and aqueous phase (e.g., 70% soap and 30% aqueous phase, especially water). The soap solution is then typically dried (e.g., to about 12% water) and the remaining mass is milled, plodded and stamped into bars. Alternatively, the soap solution can be cast into moulds, blisters etc.

[0010] Soap transparency levels vary depending on the composition and production method. Cast melt soap bars are soap bars which are typically made by casting the melted composition into moulds and letting the composition cool. Extruded soap bars are usually made by producing an extruded billet of soap and cutting it into small pieces, having a bar shape; the bars are further stamped, giving the bar its desired shape. For mass market, extrusion is more economical and yields higher amounts of processed bars per minute.

[0011] Typically, compositions that yield transparent soap bars are made using cast melt processing due to the flexibility in the process and compositions which can be used. Cast melting allows very high levels of soluble material, e.g., polyols, soluble soaps, and even non-soap detergents, to be used. Conversely, extruded soap bars compositions usually provide opaque bars. It is desirable to have extruded soaps which have higher transparency.

[0012] Generally however, particularly because of the composition required to produce a transparent soap bar (i.e., having a transparency index of at least 15%, preferably at least 16%), the production of a transparent soap bar by extrusion (e.g., forming a billet and stamping the bar) is considered extremely difficult.

[0013] When extruded translucent soap bar formulations are made of a high load of palm soap (e.g., soap produced by saponification of palm oil), typically the soap bar is opaque due to the proportion of the types of fatty acids introduced from the palm blend.

[0014] U.S. Patent No. 6,706,675 discloses a translucent soap bar composition that includes a soap mixture, a polyalkylene glycol, at least one of glycerin and sorbitol, water and optionally, free fatty acid. The soap bar composition exhibits translucent properties; the reference defines a translucent soap as one that allows light to pass through it but, as the light may be scattered by a small proportion of crystals or insolubles, it is not possible to clearly identify objects behind the translucent soap (column 1 , lines 30-34). This is not the case in the present invention in which transparent bars are produced. Furthermore, the soap bar composition includes a soap mixture, a polyalkylene glycol, at least glycerin and / or sorbitol, water and optionally free fatty acid, having 0.5 to about 5.0% of a polyethylene glycol with a molecular weight in the range of about 300 to about 800 (column 2, lines 2-4), and the soap is a blend with sodium tallowate, palm oil and palm kernel oil (column 2, lines 37-39). Such oils provide soaps with amounts of palmitic to Cis (Stearic acid) acids such that ratios range from 2.17 to 18.92; according to The Lipid Handbook, Gunstone et. al., Second Edition, herein incorporated as reference. Applicants have found that these are not desired ratios for achieving transparency in fatty acid based soap bars in which fatty acid blend comes primarily from vegetable based oils. For this reason, it is believed, the reference discloses use of a polyalkylene glycol having a relatively low molecular weight to enhance the translucent properties of the soap bar composition (Column 3, lines 25-31). In particular, PEG 8 (column 5, lines 10 to 14) is used to improve translucency. By contrast, the subject invention utilizes a balance between palmitic and Cis (stearic acid) acids to ensure that a ratio of substantially 1 in final bar is obtained (since little or no Ci6 and Cis in bar is introduced except through fatty acid blends, the ratio obtained from balancing the blend practically defines the ratio in the final bar). The reference also uses fatty acid blends derived from animal source, such as tallow, which are well known in the art for the production of transparent bars, while the subject invention uses fatty acid blends derived primarily from vegetal based oils which were then balanced via addition of Cis (stearic acid) or Ci6 (palmitic acid) acids to provide a ratio of Cis to Ci6 of 1 :1. In short, fatty acids derived primarily from tallow (animal based oil known for production of transparent bars) and PEG 8 appear to be required in the reference to create greater translucency; this is not the case of the present invention (see Comparative 2 for lack of results from the incorporation of PEG 8 into Comparative 1 of the present invention).

[0015] WO 9958636 (Cognis Corp.) discloses a translucent personal cleansing bar with (a) an alkyl polyglycoside corresponding to formula I: R1O(Z)a wherein R1 is a monovalent organic radical having from 8 to 10 carbon atoms, and a is a number having a value of from 1.40 to 1.55; (b) a soap component derived from a fatty acid having an iodine value from 25 to about 44; and (c) water.

[0016] WO2015 / 169678 (Unilever) relates to extruded soap bars having improved transparency. Specifically, by balancing the amounts of C16 (palmitic acid) and C18 (stearic acid) fatty acids to have a ratio in the final bar of 1, substantially improved transparency is unexpectedly obtained.

[0017] Nowhere is there disclosed compositions providing transparency to the soap bar while processing the bar via extrusion using simple, but unexpected, balanced ratios of the ingredients as provided by applicants’ claimed invention.

[0018] Summary of the invention

[0019] First aspect of the present invention provides extruded soap bar composition comprising, a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water.

[0020] Second aspect of the present invention provides a process for preparing soap, the process comprising steps a. saponifying a fatty matter with an alkali to produce a saponified mass, wherein 0.1 to 4 wt% of an electrolyte by weight of a resulting soap bar composition is added during the saponification process; b. adding 1 to 15 wt% polyol comprising polyethylene glycol by weight of the soap bar composition; and 0.1 to 6 wt% propylene carbonate by weight of the resulting soap bar composition to the saponified mass resulting from step a); and c. extruding the soap mass resulting from step (b) to obtain the resulting soap bar soap bar according to the first aspect; wherein non-soap surfactant is added during step (a) or step (b).

[0021] Third aspect of the present invention provide use of polyethylene glycol and propylene carbonate in an extruded soap bar composition to achieve enhanced translucency, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total non- soap surfactant is anionic surfactant, and f. 10 to 30 wt% water; as compared to equivalent soap bar without polyethylene glycol and propylene carbonate. Fourth aspect of the present invention provides use of polyethylene glycol and propylene carbonate in in an extruded soap bar composition to achieve LUX value greater than 120, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water; as compared to equivalent soap bar without polyethylene glycol and propylene carbonate.

[0022] Fifth aspect of the present invention provides use of polyethylene glycol and propylene carbonate in an extruded soap bar composition to achieve hardness of at least 2.5 Kg-F measured at 40°C, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water; as compared to equivalent soap bar without polyethylene glycol and propylene carbonate.

[0023] Detailed description of the invention

[0024] 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.

[0025] Throughout the specification unless otherwise specified, wt% means weight % of the total weight of soap composition of the present invention.

[0026] Various components of the composition are described in greater detail below.

[0027] Soap Composition

[0028] The present invention relates to a soap composition. By a soap composition it is understood to be a composition which may be used as a soap or a composition which is used to prepare a soap. More preferably the present invention provides a soap composition which is used to prepare soap bars and more preferably extruded soap bars and furthermore preferably soap bars prepared by plough shear mixer. The soap composition of the invention is especially useful for personal cleansing.

[0029] 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 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. The extruded soap bar composition of the present invention comprises 40 to 80 wt% total fatty matter, 0.1 to 4 wt% electrolyte, 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, 0.1 to 6 wt% propylene carbonate, 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total non-soap surfactant is anionic surfactant, and 10 to 30 wt% water.

[0030] The composition of the present invention is preferably used or used to prepare a shaped solid for example a bar. The cleaning soap composition is preferably used or used to prepare a wash off product that generally has sufficient amount 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.

[0031] It has been found, completely surprisingly, that certain combination of polyols, when properly incorporated in a suitable soap base, act as crystallization inhibitors and result in the production of translucent soap bars, using known processes for making commercially available milled and plodded soaps. It is possible to prepare a translucent soap bar without addition of traditional crystalline inhibitors or use of specialized, costly equipment, in an extrudable manner, by combining a suitable, regular opaque soap base with suitable benzoate esters, by shear mixing, milling and plodding, without special treatment steps being necessary after mixing of the constituents, to obtain and maintain a translucent soap bar for personal care applications.

[0032] It has been an endeavor of the scientists of the soap industry to achieve translucent soap bars as it caters to the consumer appeal and gives a perception of mildness. Polyols have been considered in past for transparency, but mere inclusion of polyols did not ensure transparency. Further, raising the levels of polyols also does not help with transparency and may not be acceptable by the consumers for sensory reasons. The present inventors were also faced with a proposition to prepare a cost effective composition. The present inventors worked around a lot of different formulations and polyols such as polyethylene glycol was found to be useful, however higher levels of polyethylene glycol would increase the costs tremendously and caused problems with processing. Therefore, the problem to be solved was many fold: to prepare a soap based cleansing composition which is translucent, cost effective and which lathers well. There was also a problem with using higher levels of polyol or any other solvent as this renders the processing of the soap bar difficult. It was a surprising finding that in the present invention, that when the composition was formulated in a way so as to have critical ratio and proportions of ingredients according to the first aspect of the present invention, the inventors were able to have a composition within a window of ranges of different ingredients when the soap bar composition was translucent while keeping the level of polyol low.

[0033] For the purposes of the present invention translucency means a composition having a LUX value about 120 and preferably in the range of 125 to 145 for a soap bar of 75 gm or less.

[0034] For the purposes of this invention, translucency can be measured by placing a photosensor, such as a LUX meter inside a closed box with 200 W LED bulb as a light source and in absence of light interference from an external source.

[0035] Soap

[0036] When the soap composition of the present invention is for personal washing application it comprises 40 to 80 wt% total amount of soap, preferably 45 to 75 wt%, more preferably 45 to 70 wt% and most preferably 50 to 70 wt% by weight of the soap composition. When the soap composition of the invention is for laundering fabrics, it comprises from 15 wt.% to 60 wt.% fatty acid soap. Preferred aspects of such soap compositions comprise at least 20 wt.%, preferably at least 25 wt.%, still preferably at least 30 wt.% and most preferably at least 35 wt.%, but typically not more than 58 wt.%, still preferably not more than 55 wt.%, still further preferably not more than 53 wt.%, still more preferably not more than 50 wt.%, and most preferably not more than 45 wt.% fatty acid soap in the soap composition.

[0037] The term soap means salt of fatty acid. Preferably, the soap is soap of C8 to C24 fatty acids.

[0038] 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.

[0039] The soap may be obtained by saponification of oils, fats or fatty acids. The fats or oils generally used to make soap compositions 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.

[0040] 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.

[0041] The soap compositions of the present invention preferably include low molecular weight soaps (C8 to C14 soaps) which are generally water soluble, which are in the range of 2 to 20% by weight of the composition. It is preferred that the soap composition includes 15 to 55 wt% of the soap of C16 to C24 fatty acid, which are generally water insoluble soaps. Unsaturated fatty acid soaps preferably at 15 to 42% may also be included in the total soap content of the composition. Unsaturated soaps are preferably oleic acid soaps.

[0042] It is preferred that in the soap composition of the present invention the composition comprises 1.7 to 6.5 wt% polyethylene glycol by weight of the soap bar composition.

[0043] It is preferred that in the soap composition of the present invention the composition comprises 0.1 to 6 wt% propylene carbonate by weight of the soap bar composition.

[0044] It is preferred that the % weight ratio of polyethylene glycol to propylene carbonate is in the range of 0.05: 1 to 15: 1.

[0045] It is preferred that in the soap composition of the present invention the electrolyte is selected from the group of sodium carbonate, sodium citrate, sodium sulphate, sodium chloride and mixtures thereof. It is preferred that in the soap composition of the present invention the iodine value of the soap composition is 30 to 45 g / lodine per 100 g of the soap composition.

[0046] It is preferred that in the soap composition of the present invention the composition has a pH in the range from 9 to 13, when measured in a 4% solution with distilled water at 25°C.

[0047] Preferably, the soap bar comprises 40% to 80% by weight of fatty acids. No more than 3% by wt. of bar composition should be fatty acid derived from non-vegetal source. Fatty acids in the blend comprise at least a combined 25% of Ci6 (palmitic acid) and Cis (stearic acid) fatty acids, their salts or their mixtures thereof. Bars also comprise 3 to 25%, preferably 3 to 10% by weight of the soap bar composition polyols, preferably sugars, like sorbitol; 0.1 to 40% by weight of the soap composition may be co-adjuvants selected from the group of polymers, organic and inorganic adjuvants, electrolytes, benefit agents and other minor ingredients; and the remainder of water. The soap bar composition is substantially made from vegetable based oil having a ratio by weight of saturated Ci6 (palmitic acid) to saturated Cis (stearic acid) fatty acids substantially in the range from 0.7 to 1.4, preferably 0.8 to 1.1 , preferably 0.9 to 1.1.

[0048] The extruded soap compositions of the present invention comprise polyols 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, preferably freely soluble in water.

[0049] 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 polyethylene glycol (PEG) and polypropylene glycol (PPG). Especially preferred polyols are glycerol, sorbitol and their mixtures. Preferred levels range from 1 to 15% by weight of the soap composition, more preferred levels range from 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0050] 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; and polymeric synthetic polyols such as polyalkylene glycols, for example polyethylene glycol (PEG) and polypropylene glycol (PPG); and alkanolamine, for example trialkanolamine such as triethanolamine (TEA).

[0051] Especially preferred polyols are glycerine, propylene glycol, butylene glycol (1 ,3 ), myristyl glycol, lauryl glycol, caprylyl glycol, decylene glycol, pentylene glycol, hexylene glycol, 1 ,2,6 hexane triol, phytan triol, 1 ,2,4 butane triol, sorbitol and their mixtures. Another polyol which may be used is trialkanolamine such as triethanolamine (TEA), this is both a triol and an amine.

[0052] The polyol of the present invention preferably comprises glycols in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition. It is preferable that the glycols are selected from the group of propylene glycol, butylene glycol, myristyl glycol, lauryl glycol, caprylyl glycol, decylene glycol, pentylene glycol and hexylene glycol and mixtures thereof.

[0053] The polyol of the present invention preferably comprises propylene glycol in the range of 0.5 to 6 wt% by weight of the composition, more preferably 0.75 wt% to 5.8 wt% and most preferably from 1 wt% to 5.5 wt% by weight of the composition.

[0054] The polyol of the present invention preferably comprises glycerol or glycerin in the range of 0.5 to 6 wt% by weight of the composition, more preferably 0.75 wt% to 5.8 wt% and most preferably from 1 wt% to 5.5 wt% by weight of the composition.

[0055] The polyol of the present invention preferably comprises sorbitol in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0056] The present invention preferably comprises propylene glycol, it is present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0057] The present invention preferably comprises triethanolamine, it is present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0058] The present invention preferably comprises alkylene glycols preferably selected from the group of Propylene Glycol , Butylene Glycol , Pentylene Glycol, Hexylene Glycol, Caprylyl Glycol, Lauryl Glycol, myristyl glycol. The glycols when present in the composition of the present invention are present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0059] The present invention preferably comprises polypropylene glycol (PPG) preferably in the range of 200 to 4000 Da, polypropylene glycol is preferably present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition. In a highly preferred aspect PPG 400, PPG 1000, PPG 2000 and PPG 4000 are preferred.

[0060] The present invention preferably comprises polyethylene glycol (PEG) preferably in the range of 200 to 4000 Da, polyethylene glycol is preferably present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition. In a highly preferred aspect PEG 200, PEG 400 and PEG 600 are preferred. It is preferred that the PEG has a molecular weight below 100000 Dalton. Preferably, the polyethylene glycol has a molecular weight in the range of 100-10000 Dalton, and is preferably 400-4000 Dalton. The preferred PEG'S are miscible with water. PEG'S with molecular weights above 10000 are markedly less water soluble and form increasingly viscous liquids above their melting points. This leads to processing difficulties.

[0061] PEG- polyethylene glycol

[0062] It is preferred that the polyol comprises 1.7 to 6.5 wt% polyethylene glycol, more preferably 1.8 wt% to 5.8 wt% and most preferably from 1.9 to 5.5 wt% and further most preferably from 2 to 5.5 wt%.

[0063] In a highly preferred aspect the polyol comprises of at least 80wt% of polyethylene glycol, more preferably at least 85 wt% and most preferably at least 90 wt% of polyethylene glycol. It is most preferred that the polyol is polyethylene glycol.

[0064] Lower levels of said polymer do not give the mildness / skinfeel benefit of the present invention, whereas at higher levels of polymer the processability of the product is deleteriously influenced. Typically, the PEG has a molecular weight below 100000 Dalton. Preferably, the polyethylene glycol has a molecular weight in the range of 100- 10000 Dalton, and is preferably 200-5000 Dalton. The preferred PEG'S are miscible with water. PEG'S with molecular weights above 10000 are markedly less water soluble and form increasingly viscous liquids above their melting points. This leads to processing difficulties.

[0065] While it is envisaged that products can be prepared by dry mixing of high molecular weight PEG and a dry soap base, this would not give the molecular-level mixing believed necessary to achieve the required properties. An advantage of the low molecular weight PEG'S is that they can be added as melted liquids or as low viscosity aqueous solutions. Addition of the PEG can occur at any stage in the soap making process, including addition to the dried soap or to the wet soap prior to drying.

[0066] Other translucency enhancers The present invention may comprise caprylyl alcohol, when present it is in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0067] The present invention may comprise benzyl alcohol, when present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0068] The present invention may comprise polyalkylene glycol ether, more preferably polyethylene glycol ether, having molecular weight in the range of 200 to 800 Da, polyalkylene glycol ether when present is preferably present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition. In a highly preferred aspect PEG-25 propylene glycol stearate, PEG-75 propylene glycol stearate and PEG-8 propylene glycol cocoate are preferred.

[0069] The present invention may comprise propylene carbonate, when present it is in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0070] Propylene carbonate (C4H6O3.) is a cyclic organic ester and more particularly carbonate ester derived from propylene glycol. The Chemical Abstract Service Registry Numbers for propylene carbonate is 108-32-7.

[0071] The present invention may comprise ethylene carbonate, when present it is in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0072] Propylene carbonate Propylene carbonate (C4H6O3.) is a cyclic organic ester and more particularly carbonate ester derived from propylene glycol. The Chemical

[0073] Propylene Ca rbonate Abstract Service Registry Numbers for propylene carbonate is 108-32-7. The chemical structures is shown below:

[0074] Mo l . Wt . 102 . 09

[0075] It is preferred that the prevent invention comprises propylene carbonate in the range of 0.1 to 6 wt%, more preferably in the range of 0.5 to 6 wt% and most preferably in the range of 0.8 to 5 wt% by weight of the soap bar composition.

[0076] It is preferred that the weight ratio of polyethylene glycol to propylene carbonate is in the range of 0.05: 1 to 15: 1 , more preferably in the range of 0.1 to 13: 1 and most preferably in the range of 0.8 to 12:1.

[0077] Other translucency enhancers

[0078] The present invention may comprise caprylyl alcohol, when present it is in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0079] The present invention may comprise benzyl alcohol, when present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0080] The present invention may comprise polyalkylene glycol ether, more preferably polyethylene glycol ether, having molecular weight in the range of 200 to 800 Da, polyalkylene glycol ether when present is preferably present in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition. In a highly preferred aspect PEG-25 propylene glycol stearate, PEG-75 propylene glycol stearate and PEG-8 propylene glycol cocoate are preferred.

[0081] Propylene carbonate (C4H6O3.) is a cyclic organic ester and more particularly carbonate ester derived from propylene glycol. The Chemical Abstract Service Registry Numbers for propylene carbonate is 108-32-7.

[0082] The present invention may comprise ethylene carbonate, when present it is in the range of 0.5 to 15 wt% by weight of the composition, preferably 1 to 12 wt%, more preferably from 1.5 to 11 wt%, further more preferably from 2 to 10 wt% and most preferably from 2 to 8 wt% by weight of the composition.

[0083] The polyols, propylene carbonate and the translucency enhancers may be present in the composition of the present as combinations and mixtures thereof.

[0084] Non-soap Surfactant

[0085] The bar compositions can optionally include non-soap synthetic type surfactants (detergents) - so called syndets. Syndets can include anionic surfactants, nonionic surfactants, amphoteric or zwitterionic surfactants and cationic surfactants.

[0086] The level of synthetic surfactant present in the bar is generally less than 25%, preferably less than 15%, preferably up to 10% and most preferably from 0 to 7% based on the total weight of the bar composition.

[0087] It is preferred that the soap bar comprises non-soap surfactants in the range from 0.1 to 5 wt% non-soap surfactant, more preferably 0.8 to 4.5 wt% and most preferably from 1 to 4 wt%, wherein at least 60%, more preferably at least 70 wt%, further more preferably 80 wt% and most preferably at least 90 wt% of the total non-soap surfactant is anionic surfactant. It is highly preferred that the non-soap surfactant is an anionic surfactant. It is preferred that the anionic surfactant is range from 60 to 100 wt% by weight of the total non-soap surfactants. It is preferred that the soap bar comprises anionic surfactants in the soap range from 0.1 to 5 wt% non-soap surfactant, more preferably 0.8 to 4.5 wt% and most preferably from 1 to 4 wt%,

[0088] The anionic surfactant may be, for example, an aliphatic sulfonate, such as a primary alkane (e.g.. C8-C22) sulfonate, primary alkane (e.g.. C8-C22) disulfonate, C8-C22 alkene sulfonate, C8-C22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate (AGS); or an aromatic sulfonate such as alkyl benzene sulfonate, Alpha olefin sulfonates are another suitable anionic surfactant.

[0089] The anionic may also be an alkyl sulfate (e.g. C12-C18 alkyl sulfate), especially a primary alcohol sulfate or an alkyl ether sulfate (including alkyl glyceryl ether sulfates).

[0090] The anionic surfactant can also be a sulfonated fatty acid such as alpha sulfonated tallow fatty acid, a sulfonated fatty acid ester such as alpha sulfonated methyl tallowate or mixtures thereof.

[0091] The anionic surfactant may also be alkyl sulfosuccinates (including mono- and dialkyl, e.g.. C6-C22 sulfosuccinates); alkyl and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates, C8-C22 alkyl phosphates and phosphates, alkyl phosphate esters and alkoxyl alkyl phosphate esters, acyl lactates or lactylates, C8-C22 monoalkyl succinates and maleates, sulphoacetates and acyl isethionates.

[0092] Another class of anionics is Cs to C20 alkyl ethoxy (1-20 EO) carboxylates.

[0093] Another suitable anionic surfactant is Cs-Cis acyl isethionates. These esters are prepared by reaction between alkali metal isethionate with mixed aliphatic fatty acids having from 6 to 18 carbon atoms and an iodine value of less than 20. At least 75% of the mixed fatty acids have from 12 to 18 carbon atoms and up to 25% have from 6 to 10 carbon atoms. The acyl isethionate may also be alkoxylated isethionates

[0094] Acyl isethionates, when present, will generally range from about 0.5% to about 25% by weight of the total composition. In general, the anionic component will comprise the majority of the synthetic surfactants used in the bar composition.

[0095] Amphoteric detergents which may be used in this invention include at least one acid group. This may be a carboxylic or a sulphonic acid group. They include quaternary nitrogen and therefore are quaternary amido acids. They should generally include an alkyl or alkenyl group of 7 to 18 carbon atoms. Suitable amphoteric surfactants include amphoacetates, alkyl and alkyl amido betaines, and alkyl and alkyl amido sulphobetaines.

[0096] Amphoacetates and diamphoacetates are also intended to be covered in possible zwitterionic and / or amphoteric compounds which may be used.

[0097] Suitable nonionic surfactants include the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols or fatty acids, with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Examples include the condensation products of aliphatic (Cs-Cis) primary or secondary linear or branched alcohols with ethylene oxide and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxides.

[0098] The nonionic may also be a sugar amide, such as alkyl polysaccharides and alkyl polysaccharide amides.

[0099] Examples of cationic detergents are the quaternary ammonium compounds such as alkyldimethylammonium halides.

[0100] Water

[0101] The soap compositions of the present invention can moisture or water content upto 30wt% of the weight of the soap bar. The soap compositions of the present invention have 10 to 30 wt% of water, preferably 12 to 28 wt%, and most from preferably 15 to 25 wt% by weight of the soap composition. Electrolyte

[0102] 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.

[0103] It is preferred that composition of the invention comprises 0.1 to 4 wt%, preferably 0.5 to

[0104] 3.8 wt %, more preferably in the range of 0.5 to 3 wt % electrolyte, and most preferably 0.7 to 2.8% 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.

[0105] It is most preferred that sodium sulphate and sodium chloride are used as electrolytes for the composition of the present invention.

[0106] It is preferred that sodium sulphate is present in the range of 0.1 to 4 wt% of the weight of composition, more preferably 0.5 to 3.8 wt %, and most preferably in the range of 0.5 to 3 wt %. It is preferred that sodium sulphate is at least 0.1 wt%, more preferably at least 0.5wt%, and most preferably at least 1wt% and it is preferred that it is not more than 4wt%, more preferably not more than 3 wt%, further, more preferably not more than

[0107] 2.8 wt% and most preferably not more than 2.5wt% of the total weight of composition of the present invention.

[0108] It is preferred that when sodium chloride is present in the range of 0.1 to 4 wt% of the weight of composition, more preferably 0.5 to 3.8 wt %, and most preferably in the range of 0.5 to 3 wt %. It is preferred that sodium chloride is at least 0.1 wt%, more preferably at least 0.5wt%, and most preferably at least 1wt% and it is preferred that it is not more than 4wt%, more preferably not more than 3 wt%, further, more preferably not more than

[0109] 2.8 wt% and most preferably not more than 2.5wt% of the total weight of composition of the present invention. The composition of the present invention is targeted to compositions which are substantially free of free fatty acids. By the phrase ‘substantially free of free fatty acids is meant that free fatty acids is present in an amount less than 1.0 percent, preferably less than 0.5 percent, furthermore preferably less than 0.1 percent and optimally absent from the composition. It is most preferred that the composition is free of free fatty acids.

[0110] The soaps bar composition may optionally comprise 0.1 to 15%, preferably 0.2 to 12% by weight of free fatty acids. By free fatty acids is meant a carboxylic acid comprising a hydrocarbon chain and a terminal carboxyl group bonded to an H. Suitable fatty acids are C8 to C22 fatty acids. Preferred fatty acids are C12 to C18, preferably predominantly saturated, straight-chain fatty acids. However, some unsaturated fatty acids can also be employed.

[0111] The soap composition generally comprises electrolyte and water. 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. Electrolyte is preferably included in 0.1 to 6%, more preferably 0.5 to 6%, even more preferably 0.5 to 5%, furthermore preferably 0.5 to 3%, and most preferably 1 to 3% by weight of the composition. It is preferred that the electrolyte is included in the soap composition during the step of saponification to form the soap.

[0112] The various optional ingredients that make up the final soap composition are as described below: The total level of the adjuvant materials used in the bar composition generally is in an amount not higher than 50%, preferably 1 to 50%, more preferably 3 to 45% by wt. of the soap composition.

[0113] 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.

[0114] 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.

[0115] 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 Mg3Si4(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.

[0116] 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.

[0117] Examples of other optional insoluble inorganic particulate materials include aluminates, silicates, phosphates, insoluble sulfates, borates and clays (e.g., kaolin, china clay) and their combinations.

[0118] Organic particulate materials include: insoluble polysaccharides such as highly crosslinked or insolubilized starch (e.g., by reaction with a hydrophobe such as octyl succinate) and cellulose; synthetic polymers such as various polymer lattices and suspension polymers; insoluble soaps and mixtures thereof.

[0119] It is preferred that the compositions of the invention comprise polymers. Polymers of the acrylate class are especially preferred. Preferred bars include 0.05 to 5% acrylates. More preferred bars include 0.01 to 3% acrylates. Examples of acrylate polymers include polymers and copolymers of acrylic acid crosslinked with polyallylsucrose as described in US Patent 2,798,053 which is herein incorporated by reference. Other examples include polyacrylates, acrylate copolymers or alkali swellable emulsion acrylate copolymers, hydrophobically modified alkali swellable copolymers, and crosslinked homopolymers of acrylic acid. Examples of such commercially available polymers are: ACULYN®, CARBOPOL®, and CARBOPOL® Ultrez grade series.

[0120] 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.

[0121] 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 composition is desired is ethylene glycol mono- or distearate, for example in the form of a 20% solution in sodium lauryl ether sulphate. An alternative opacifying agent is zinc stearate.

[0122] The product can take the form of a water-clear, i.e. transparent soap, in which case it will not contain an opacifier.

[0123] The pH of preferred soaps compositions of the invention is from 8 to 11 , more preferably 9.5 to 11.

[0124] A preferred bar may additionally include up to 30 wt% benefit agents. Preferred benefit agents include moisturizers, emollients, sunscreens 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.

[0125] Other optional ingredients like anti-oxidants, perfumes, polymers, chelating agents, colourants, deodorants, dyes, enzymes, foam boosters, germicides, anti-microbials, lathering agents, pearlescers, skin conditioners, stabilizers or superfatting agents, 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.

[0126] The composition of the invention could be used to deliver antimicrobial benefits. Antimicrobial agents that are preferably included to deliver this benefit 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 or 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.

[0127] In soap compositions for laundering fabric, one or more of the above described optional ingredients may be included. However, in laundry bars, antimicrobial agents are generally not added. Laundry bars generally include chelating agents that are generally not included in soap compositions for personal cleansing. Chelating agents may be selected from but not limited to ethylene diamine tetra acetic acid (EDTA), ethylene hydroxy diphosphonic acid (EHDP) or mixtures thereof. The chelating agent is preferably present in an amount ranging from 0.01 wt.% to 1 wt.%. Non-phosphate chelating agents like methylglycinediacetic acid and salts thereof are also preferred.

[0128] The present invention provides use of soap bar composition according to the first aspect to provide soap bars having a bar hardness of 2.7 to 5.0 Kg when measured at 40°C, using 15 mm penetration value. The present invention also provides use of amorphous form of aluminosilicate in soap compositions having moisture in the range of 15 to 45wt% for achieving hardness of at least 2.5 Kg-F measured at 40°C.

[0129] Process

[0130] Second aspect of the present invention provides for preparing soap, the process comprising steps: a. saponifying a fatty matter with an alkali to produce a saponified mass, wherein 0.1 to 4 wt% of an electrolyte by weight of a resulting soap bar composition is added during the saponification process; b. adding 1 to 15 wt% polyol comprising polyethylene glycol by weight of the soap bar composition; and 0.1 to 6 wt% propylene carbonate by weight of the resulting soap bar composition to the saponified mass resulting from step a); and c. extruding the soap mass resulting from step (b) to obtain the resulting soap bar soap bar according to the first aspect; wherein non-soap surfactant is added during step (a) or step (b).

[0131] It is preferred that in the process for preparing soap composition according to the first aspect, the polyol comprises 1.7 to 6.5 wt% polyethylene glycol by weight of the soap bar composition.

[0132] It is preferred that in the process for preparing soap composition according to the first aspect, the composition comprises 0.5 to 5.5 wt% propylene carbonate by weight of the soap bar composition.

[0133] Present invention provides use of polyethylene glycol and propylene carbonate in the weight ratio 0.05:1 to 15:1 to achieve enhanced translucency in an extruded soap bar composition according to the first aspect, as compared to an equivalent soap bar without polyethylene glycol and propylene carbonate in the weight ratio 0.05:1 to 15:1. Present invention provides use of polyethylene glycol and propylene carbonate in in an extruded soap bar composition according to the first aspect, having LUX value greater than 120 as compared to an equivalent soap bar composition without polyethylene glycol and propylene carbonate for a soap bar of 75 gm or less.

[0134] Present invention provides use of polyethylene glycol and propylene carbonate in in an extruded soap bar composition according to the first aspect, for achieving enhanced translucency as compared to an equivalent soap bar composition without polyethylene glycol and propylene carbonate.

[0135] Present invention provides use of polyethylene glycol; and propylene carbonate in an extruded soap bar composition according to the first aspect, for achieving hardness of at least 3 Kg-F measured at 40°C as compared to an equivalent soap bar composition without polyethylene glycol and propylene carbonate.

[0136] The soap 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 composition, compositions thus prepared by extrusion are found to be easy to stamp with a desirable indicia. By “easy to extrude” is meant that the hardness of the bar as it is extruded is high enough that it exits the extruder in a firm enough form that it can be called a rigid bar. The hardness of the bar is preferably higher than 1.2 kg, more preferably in the range of 1.2 to 5.0 kg (at 40°C). The hardness is preferably measured using the TA-XT Express apparatus available from Stable Micro Systems. The hardness is measured using this apparatus with a 30° conical probe - Part #P / 30c to a penetration of 15 mm. If the soap mass is too soft and is passed through the extruder it will not extrude out of the extruder in a cohesive enough mass to be called a bar. By “easy to stamp” is meant that the soap composition is of such a consistency and low enough stickiness that it does not stick to the die that is used to stamp any desired indicia on the bar. The soap composition prepared by the process of the invention therefore preferably comprises an indicium stamped thereupon. The specific process that may be employed using the above described general process for soap composition manufacture comprises one of the following processes.

[0137] EXAMPLES

[0138] Example 1- Soap Compositions

[0139] The soap compositions for the examples were prepared in accordance with the present invention.

[0140] Soap Noodle preparation- Required quantity of fatty acids & all other raw materials were weighed and charged fatty acids were put into the mixer, salt was added, polyols were added, non-soap surfactant, Alpha Olefin Sulphonate- AOS 70% paste was added and neutralization was started using sodium hydroxide. The completion of neutralization was checked through phenolphthalein indicator test and if required caustic was added to complete the neutralization reaction.

[0141] Preservatives were added and free fatty acid content was checked, if if required caustic was added to complete the neutralization reaction. The soap mass was conveyed to the chilled rolls & further to refiner to get the noodles.

[0142] Soap Finishing- The noodle added the noodle to sigma mixer and crushed, requisite colour and fragrance was dissolved in water and mixed. A batch was dropped and conveyed to refiner for further processing. The refined mass is then conveyed to triple roll mill & then to plodder where the soap mass is converted into a shape. These plodded bars are pushed for stamping where final shape is given to the soap along with the logo.

[0143] For measurement of translucency Lux meter, Model No - Fluke 941 Light Meter was used. The experiment was set up with one closed box with Lux meter and 200 W LED bulb was used as a light source. The Fluke 941 measures the visible light from fluorescent, metal halide, high pressure sodium or incandescent sources. The 200W bulb fixed inside the dark chamber was illuminated. The voltage regulator knob was adjusted, so that light source reads certain fixed number. When the Light source lux value is fixed even when there is voltage fluctuation results for test sample remains unaffected. The light lux value was fixed to 3600 lux . The light path was blocked and directed to sensor by placing the soap between the light source and the sensor. It was ensured that the soap blocks light falling directly on the sensor. The value on the LUX Meter was recorded, which indicates the amount of translucency of soap bar.

[0144] 5 One LUX (Lumen) is the illumination from a one candela lamp perpendicular to a surface one meter squared at a distance of one meter. One foot-candle (Fc) is the illumination from a one candela lamp perpendicular to a surface one foot squared at a distance of one foot.

[0145] Distance between light source and soap top surface was kept to be about 35 mm. 0 Distance between soap bottom surface and Lux meter was kept about -100 mm. And readings were taken. The readings of above 120 lx were considered acceptable for transparency.

[0146] The compositions E1, E2 and E3 in Table 1 were prepared according to the first aspect (Examples inside the scope of the present invention)in accordance with the methodology 5 as given above. Similar compositions E4-E6 were prepared according to the methodology as given above but which were not according to the first aspect (Examples outside the scope of the present invention). Composition E4 was prepared with a high level of polyethylene glycol and composition E5 was prepared with high level of propylene carbonate. E6 was prepared with low level of polyethylene glycol. 0 Table 1

[0147] It is clearly evident from data of Table 1 that the compositions E1, E2 and E3 prepared according to the first aspect have good processability, good bar hardness and had good transparency reported in terms of acceptable LUX values. Composition E4 which was 5 prepared with a high level of polyethylene glycol which did not show good translucency and the composition E5 which was prepared with high level of propylene carbonate was not processable. E6 was prepared with low level of polyethylene glycol and was not processable. Therefore, it is clear how the combination of propylene carbonate and polyethylene glycol resulted in processable soap bars with good hardness and 0 translucency values.

[0148] Therefore, it was seen that any digression from the compositions of the present invention according to the first aspect results in compromising translucency or difficulty in processing.

[0149] Hardness Testing Protocol 5 Principle

[0150] 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 0 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.

[0151] Apparatus and Equipment

[0152] TA-XT Express (Stable Micro Systems)

[0153] 30° conical probe - Part #P / 30c (Stable Micro Systems)

[0154] Sampling Technique

[0155] 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.

[0156] Procedure

[0157] Setting up the TA-XT Express

[0158] 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.

[0159] Set test method

[0160] Press MENU

[0161] Select TEST SETTINGS (Press 1)

[0162] Select TEST TPE (Press 1)

[0163] Choose option 1 (CYCLE TEST) and press OK

[0164] Press MENU

[0165] Select TEST SETTINGS (Press 1)

[0166] Select PARAMETERS (Press 2)

[0167] Select PRE TEST SPEED (Press 1)

[0168] Type 2 (mm s-1) and press OK

[0169] Select TRIGGER FORCE (Press 2)

[0170] Type 5 (g) and Press OK

[0171] Select TEST SPEED (Press 3)

[0172] Type 1 (mm s-1) and press OK

[0173] Select RETURN SPEED (Press 4)

[0174] Type 10 (mm s-1) and press OK

[0175] Select DISTANCE (Press 5)

[0176] Type 15 (mm) for soap billets or 3 (mm) for soap pastilles and press OK Select TIME (Press 6)

[0177] Type 1 (CYCLE)

[0178] Calibration

[0179] Screw the probe onto the probe carrier.

[0180] Press MENU

[0181] Select OPTIONS (Press 3)

[0182] Select CALIBRATE FORCE (Press 1) - the instrument asks for the user to check whether the calibration platform is clear

[0183] Press OK to continue and wait until the instrument is ready.

[0184] Place the 2kg calibration weight onto the calibration platform and press OK

[0185] Wait until the message “calibration completed” is displayed and remove the weight from the platform.

[0186] Sample Measurements

[0187] Place the billet onto the test platform.

[0188] Place the probe close to the surface of the billet (without touching it) by pressing the UP or DOWN arrows.

[0189] Press RUN

[0190] Take the readings (g or kg) at the target distance (Fin).

[0191] After the run is performed, the probe returns to its original position.

[0192] Remove the sample from the platform and record its temperature.

[0193] Calculation & Expression of Results

[0194] Output

[0195] 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)

[0196] The force reading can be converted to extensional stress, according to the equation given below.

[0197] The equation to convert the TX-XT readout to extensional stress is where: o = extensional stress C = "constraint factor" (1.5 for 309cone)

[0198] Gc= acceleration of gravity

[0199] A = projected area of cone = d = penetration depth

[0200] 0 = cone angle

[0201] For a 30° cone at 15 mm penetration, Equation 2 becomes a (Pa) = RT(g) x 128.8

[0202] This stress is equivalent to the static yield stress as measured by penetrometer.

[0203] The extension rate is: where E = extension rate (s-1)

[0204] V = cone velocity

[0205] For a 30° cone moving at 1mm / s, E = 0.249 s-1

[0206] Temperature Correction

[0207] 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:

[0208] R<o = RT x exp[a(T-40)]

[0209] 20 where R40 = reading at the reference temperature (40°C)

[0210] RT = reading at the temperature T a = coefficient for temperature correction

[0211] T = temperature at which the sample was analyzed.

[0212] The correction can be applied to the extensional stress.

[0213] Raw and Processed Data

[0214] The result is the temperature-corrected force or stress, but it is advisable to record the instrument reading and the sample temperature also.

[0215] A hardness value of at least 1.2 kg (measured at 40°C), preferably at least 2.7 kg is acceptable.

Claims

Claims1. An extruded soap bar composition comprising a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprise 1.7 to 6.5 wt% polyethylene glycol by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water.

2. A soap bar composition according to claim 1, wherein the % weight ratio of polyethylene glycol to propylene carbonate is in the range of 0.05:1 to 15:1.

3. A soap bar composition according to claim 1 or 2, wherein the polyethylene glycol has molecular weight in the range of 200 to 10,000 KDa.

4. A soap bar composition according to anyone of the preceding claims from 1 to 3, wherein the electrolyte is selected from the group of sodium carbonate, sodium citrate, sodium sulphate, sodium chloride and mixtures thereof.

5. A soap bar composition according to anyone of the preceding claims from 1 to 4, wherein the propylene carbonate is 0.5 to 5.5 wt% by the weight of the soap bar composition.

6. A soap bar composition according to anyone of the preceding claims from 1 to 5, wherein the polyethylene glycol is 2 to 5.5 wt% by the weight of the soap bar composition.

7. A soap bar composition according to anyone of the preceding claims 1 to 6, wherein the iodine value of the soap composition is 30 to 45 g / lodine per 100 g of the soap composition.

8. A soap bar composition according to any one of the preceding claims from 1 to 7, wherein the composition has a pH in the range from 9 to 13, when measured in a 4% solution with distilled water at 25°C.

9. A process for preparing soap, the process comprising steps: a. saponifying a fatty matter with an alkali to produce a saponified mass, wherein 0.1 to 4 wt% of an electrolyte by weight of a resulting soap bar composition is added during the saponification process; b. adding 1 to 15 wt% polyol comprising 1.7 to 6.5 wt% polyethylene glycol by weight of the soap bar composition; and 0.1 to 6 wt% propylene carbonate by weight of the resulting soap bar composition to the saponified mass resulting from step a); and c. extruding the soap mass resulting from step (b) to obtain the resulting soap bar soap bar according to any one of the preceding claims from 1 to 8; wherein 0.1 to 5 wt% non-soap surfactant by weight of the resulting soap bar composition is added during step (a) or step (b); wherein at least 60 wt% of the total non-soap surfactant by weight of the resulting soap bar composition is anionic surfactant; and wherein 10 to 30 wt% water by weight of the resulting soap bar composition is added during step (a) or step (b).

10. A process according to claim 9, wherein weight ratio of the polyethylene glycol to the propylene carbonate is in the range of 0.05:1 to 15:1.

11. A process for preparing soap bar composition according to anyone of the claims 9 or 10, wherein, the polyethylene glycol is in the range of is 0.5 to 6 wt%.

12. Use of polyethylene glycol and propylene carbonate in an extruded soap bar composition to achieve enhanced translucency, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprises 1.7 to 6.5 wt% polyethylene glycol, by the weight of the soap bar composition,d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water; wherein the translucency is measured by placing a photo-sensor inside a closed box with 200 W LED bulb as a light source and in absence of light interference from an external source.

13. Use according to claim 12, wherein the % weight ratio of polyethylene glycol to propylene carbonate is in the range of 0.05:1 to 15:1.

14. Use of polyethylene glycol and propylene carbonate in in an extruded soap bar composition to achieve LUX value greater than 120, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte, c. 1 to 15 wt% of total polyols, wherein polyol comprises 1.7 to 6.5 wt% polyethylene glycol, by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water; wherein the LUX value is measured by placing a photo-sensor inside a closed box with 200 W LED bulb as a light source and in absence of light interference from an external source.

15. Use of polyethylene glycol and propylene carbonate in an extruded soap bar composition to achieve hardness of at least 2.5 Kg-F measured at 40°C, the soap bar composition comprising: a. 40 to 80 wt% total fatty matter, b. 0.1 to 4 wt% electrolyte,c. 1 to 15 wt% of total polyols, wherein polyol comprises 1.7 to 6.5 wt% polyethylene glycol, by the weight of the soap bar composition, d. 0.1 to 6 wt% propylene carbonate, e. 0.1 to 5 wt% non-soap surfactant, wherein at least 60 wt% of the total nonsoap surfactant is anionic surfactant, and f. 10 to 30 wt% water; wherein the hardness of the soap bar is measured by penetrometer method using TA- XT Express apparatus having a 30° conical probe which penetrates to depth of 15 mm.

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