CLIAMS:1) An enrobed compatible composition for preparing floating bathing bar comprising
a. surfactants in the range of 45-70% by wt;
b. polymers in the range of 1-11% by wt; and
c. binders in the range of 2-15% by wt;
wherein the surfactant to polymer ratio is 10:1; and
wherein the viscosity is in the range of 2500-10,000 cps at 80-850C.

2) The composition as claimed in claim 1, wherein ratio of surfactant to polymer in the present enrobed compatible composition is 4:1.

3) The composition as claimed in claim 1, wherein the viscosity of the enrobed compatible composition ranges from 500-2000 cps at 80-850C.

4) The composition as claimed in claim 1, wherein the enrobed compatible composition further comprises fatty acid.

5) The composition as claimed in claim 4, wherein the fatty acid is present in the range of 1-10% by wt.

6) The composition as claimed in claim 4, wherein the fatty acid is selected from group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid.

7) The composition as claimed in claim 1, wherein said enrobed floating bathing bar is adapted to provide an improved lather generation, cleansing efficacy and surface finish.

8) The composition as claimed in claim 1, wherein said enrobed compatible composition is maintained in liquid state at 75-920C.

9) The composition as claimed in claim 1, wherein said surfactants are chosen from a group comprising anionic surfactants, amphoteric surfactants, nonionic surfactants, and any combinations thereof.

10) The composition as claimed in claim 1, wherein said polymers are selected from a group consisting of starches, silicone polymers and water soluble polymers.

11) The composition as claimed in claim 1, wherein said binders are selected from a group consisting of high molecular weight poly acrylates, high molecular weight poly-ox, silicates, fatty alcohols, lanolin, sugars, tallow alcohol ethoxylates, and mixtures thereof.

12) A process for preparing enrobed compatible composition comprises the steps of
a. mixing free fatty acids, polymers, waxes and emulsifier in mixer at 65-750C
b. mixing for sufficient time (20-30mins) post melting and,
c. adding soap at a temperature of 85-900C;
d. adding pH regulator followed by surfactants at a temperature between 90-950C;
e. adding other additives once soap and surfactants are mixed completely;
f. adding binders, emollients, minerals at high mixing speed followed by homogenization;
g. maintaining the final mass at 85-900C temperature to achieve enrobing machine compatible mass of pouring consistency in mixer; and
h. dipping floating soap into enrobing machine compatible mass to obtain enrobed floating soap bar.

13) The process as claimed in claim 10, wherein said additives are selected from TiO2, EDTA, and fragrances.

14) The process as claimed in claim 10, wherein said homogenization in the process is maintained between 300 to 6000 rpm.

15) The process as claimed in claim 10, wherein the surfactant to polymer ratio is 10:1. and wherein the viscosity is in the range of 2500-10,000 cps at 80-850C. ,TagSPECI:Field of Invention
The present invention relates to a floating bathing bar. More particularly the invention relates to enrobe machine compatible soap composition which has similar characteristic as that of bathing bar in terms of lather generation, cleansing efficacy and surface finish of the bar during use. The superior surface finish of the bar helps to provide good bar glide during application.

Background and prior art
Floating bathing bars differs from the normal soap bar both in terms of formulation and preparation process. Further, processing floating soap requires use of specialized instruments. State of the art describes various processes for preparation of floating bathing bars. However, these processes have certain disadvantages like they require high processing energy and also high processing temperature.

With high energy and high proceeding temperature it becomes very difficult to obtain a floating soap bar with superior surface finish as present in conventional opaque and transparent soap bar.
Surface finish is an important parameter as it is directly related to customer acceptability and bar aesthetics.

Floating soap bar processing involves large quantity of air which is responsible for the soap surface defects, one way to overcome defect is to have a detailed down-stream process. However detailed downstream process is not very effective in improving the surface finish of floating soap. Moreover, incorporation of additional processing step leads to poor production yield.

Floating bathing bars are basically low density soap bars and it is very difficult to obtain a good surface finish for low density soaps. So, improving floating soap bar surface finish is a challenge. Therefore there exists a need to improve floating soap bar surface finish. It is further desired to have a low processing temperature (> 100 0C) during production of floating soap bar.

EP 2100515 relates to enrobing machines usable for coating food products - such as, for example sweets - with a coating layer of food material such as, for example, chocolate, possibly with the addition of hazelnut granules or similar granular materials. EP’515 teaches that in the employment of enrobing machines, the need may arise for the successive treatment of different lots of products destined to be coated with different coating materials. When the coating material is changed, it is usually desirable to do this so that the coating material for the products in the "new" lot is not contaminated by traces of the coating material used for the "old" lot, that is, for the lot of products previously coated: in this regard it is sufficient to consider the case in which the shift is made from a dark chocolate coating to a white chocolate coating.

US3167035 relates to coating of sugar or ready to eat cereal products. This enrobing machine accomplishes enrobing of such products in continuous manner. This invention acknowledges that one of the problems in enrobing of cereal products is that said materials sticks or agglomerate. Thus an apparatus was required that maintains the product in an individual or free flowing state during coating or enrobing process.

The prior arts disclose enrobed confectionaries and related products. The flow behavior and characteristics of products such as confectionaries is totally different from personal wash based products.

EP 0912706 discloses a bar composition comprising
(a) 30% to 85% by weight of total composition of fatty acid soaps, other than lithium soaps;
(b) 0 to 30% of an synthetic surfactant;
(c) 0% to 40% by weight of the composition of a structurant selected from the group consisting of alkylene oxide components having a molecular weight of from about 2,000 to about 25,000; C8-C22 free fatty acids; C2 to C20 alkanols, paraffin waxes; and water-soluble starches; and
(d) 1% to 25% by weight of total composition of a polyoxyethylene polyoxypropylene nonionic polymer surfactant (EO-PO polymer) wherein the ratio by weight total composition of fatty acid soaps and anionic surfactants to EO-PO polymer is between 1.2:1 to 15:1.
The applicants of EP’706 have found that the use of relatively low levels of specific nonionic polymeric surfactants can be used to obtain these goals. That is, at levels no higher than 25% by wt. of the bar composition, the polymers provide enhanced mildness without sacrificing processability or lather, and have the added benefit of reducing mushing.
EP 1108005 provides a bar composition comprising a synthetic non-soap surfactant, a hydrophilic structurant, a water insoluble structurant, an oil/emollient benefit agent and a cationic polymer. The cationic polymer has a charge of density greater than 0.007 and is used in a specific ratio to the surfactant. The amount of cationic polymer is such that ratio of cationic polymer to surfactant is 0.06:1 to 1:1; and wherein charge density of cationic polymer is greater than 0.007; and wherein the ratio of hydrophilic to hydrophobic structurant is at least 1:2 according to the invention claimed in EP’005.

WO 1997/040132 discloses a bar composition comprising
(a) 10% to 70% by weight of total composition of a surfactant system selected from the group consisting of anionic surfactants, nonionic surfactants other than the nonionic polymer surfactant of item (c) below, cationic surfactants, amphoteric surfactants and mixtures thereof, wherein the anionic surfactant comprises 50% or greater of the surfactant system, and wherein anionic comprises no more than about 60% by wt. of the total composition.
(b) 20% to 85% by wt. of the composition of a bar structurant selected from the group consisting of alkylene oxide components having a molecular weight of from about 2,000 to about 25,000; C8-C2_ free fatty acids; C2 to C10 alkanols; paraffin waxes; water- soluble starch; and
(c) 2 to 30% to 30% by wt. total composition of a hydrophobically modified polyalkylene glycol polymeric surfactant wherein ratio by weight total composition of hydrophobically modified polyalkylene nonionic polymer to anionic surfactant s between 1:1.5 to 1:10.
The present invention is distinct from WO '132 in that the enrobing soap mass of the present invention does not require any hydrophobically modified polyalkylene glycol polymeric surfactant, non-ionic surfactants or cationic surfactants. The present invention only requires anionic surfactants and amphoteric surfactants for its working. Amphoteric surfactants are also added in very less quantity.

Enrobing technology is widely used in foods, detergents, Pharmaceutical industry. However, enrobing technology has never been used with respect to soap formulations due to various reasons as mentioned below.

1. It is difficult to bind two different soap formulations into one as it is difficult to coat soap uniformly through formulation approach.

2. Melting any ordinary opaque soap requires temperature of around 250oC and to keep the soap in melted state high temperature has to be maintained also it requires large quantity of solvents. Full process has to be operated at high temperature and any variation in temperature will choke the entire process.

3. At high temperature fragrance and temperature sensitive actives are lost.

Thus there is a need to provide enrobing machine compatible mass and to improve the surface finish of the soap bar. The enrobe machine compatible mass has similar characteristic as that of bathing bar in terms of lather generation, cleansing efficacy and surface finish of the bar during use.

The present invention thus aims at improving the surface finish of floating soap bar by using mechanism of bulk surface coating using enrobing technology (machine).

The present invention is distinct from EP '706 in that the enrobing soap mass of present invention does not require any nonionic polymer surfactant for its functioning, whereas EP '706 essentially requires the presence of element d) nonionic polymer surfactant and that too in fixed ratio with anionic surfactant for its functioning. Additionally soap formulation as per EP '706 has more of soap and less than 30% synthetic surfactant, whereas synthetic surfactants as may be incorporated into the enrobing soap mass of the present invention are more than 30% and also does not employs use of any nonionic polymer surfactant as compared to EP’706. Further the mass of present invention can be melted effectively at 750C.

EP '005 relates to the use of hydrophillic and hydrophobic structurants in specific ratios. Unlike that of prior art present invention on enrobing soap mass essentially does not relate to the use of hydrophillic structurants. Also present invention does not require the use of cationic polymers as compared to EP’005. Further the mass of present invention can be melted effectively at 750C. The soap mass of prior art cannot be used in the enrobing machine as the desired characteristics in terms of viscosity and physical properties (liquid at 75-920C) are not met.

The compatibility of the soap mass with the enrobing machine is pre-tested. There has been lot of experimentation to come up with a unique formulation that has desired polymer: surfactant ratio, desired viscosity and meting properties in order to achieve the required coating on the surface of the soap. It is challenging to adapt any conventional soap formulation into enrobing machine.

Hence the present invention provides a composition which is compatible with the enrobing machine and hence provides a good surface finish to the soap bar of the present invention.

Objects of the present invention

It is an object of the invention to overcome the drawbacks of the prior art.
It is another object of the invention to provide an enrobed floating soap bar composition.
It is yet another object of the invention to provide a process of preparing the enrobed floating soap bar composition.

Summary of the present invention

An aspect of the present invention provides an enrobed compatible composition for preparing floating bathing bar comprising
a. surfactants in the range of 45-70% by wt;
b. polymers in the range of 1-11% by wt; and
c. binders in the range of 2-15% by wt;
wherein the surfactant to polymer ratio is 10:1; and
wherein viscosity is in the range of is in the range of 2500-10,000 cps at 80-850C.

Another aspect of the present invention provides a process for preparing enrobed compatible composition comprises the steps of
a. mixing free fatty acids, polymers, waxes and emulsifier in mixer at 65-750C;
b. mixing for sufficient time (20-30mins) post melting;
c. adding soap at a temperature of 85-900C;
d. adding pH regulator followed by surfactants at a temperature between 90-950C;
e. adding other additives once soap and surfactants are mixed completely;
f. adding binders, emollients, minerals at high mixing speed followed by homogenization;
g. maintaining the final mass at 85-900C temperature to achieve enrobing machine compatible mass of pouring consistency in mixer; and
h. dipping floating soap into enrobing machine compatible mass to obtain enrobed floating soap bar.

Brief Description of Accompanying Drawings
Figure 1 illustrates the difference in feature of the enrobed floating soap bar of present invention from conventional soap of prior art.
Figure 2 illustrates images comparing the surface finish for Coated floating soap bar, Coated non floating soap bar and Floating soap bar

Detailed Description of the Invention
The present invention discloses surface coating soap mass to be used for coating surface of the floating soap bar by mechanism of bulk surface coating using enrobing machine. Uniform coating in enrobing can potentially eliminate multi step process during down-stream operation. Present process is also very efficient and leads to greater yield. The enrobed mass/ surface coating mass of floating soap provides excellent surface finish and brightness. This technology is new and efficient for personal care industry.

The term “personal care industry” as used herein refers to the industry which manufactures consumer products used in personal hygiene and for beautification. Example soaps, liquid soaps, shampoo, cream, lotions and the like.

The present invention provides enrobing machine compatible mass which can be use to enrobe any soap/syndet/combi bar like opaque soap, transparent soap, translucent soap, floating soap, syndet mass combi bar and to improve the surface finish of the soap bar. The enrobe machine compatible mass has similar characteristics as that of bathing bar in terms of lather generation, cleansing efficacy and aesthetics during in use.

The expression “Enrobing machine compatible mass” as used in the present invention is related to the mass which is used by the enrobing machine to coat the surface of soap. The soap mass has certain characteristics that make it compatible so that it can be used with the machine as it gets melted at lower temperature (~75 –80 0C). This helps to make the soap composition more compatible with the conventional enrobing machine used in the food industry. The composition can also be used with any other machine similar to enrobing for coating the soap surface.

The expression “enrobed compatible composition for preparing floating soap bar” as used herein is meant by the coating of floating soap bar prepared by an enrobed compatible composition by enrobing machine. The enrobing machine compatible mass is liquid at 75-920C.

The following are the various essentials features of the enrobed mass of present invention:
1. It remains liquid at 75-920C.
2. It has viscosity in the range of 500-2000 cps.
3. The enrobed mass starts getting solidified at < 65 0C.
4. It gets solidified on the surface of the soap within 30 -120 seconds at ambient conditions.

In accordance with the present invention, there is provided a enrobed compatible composition for preparing floating soap bar comprising
a. surfactants in the range of 45-70% by wt;
b. polymers in the range of 1-11% by wt; and
c. binders in the range of 2-15% by wt;
wherein the surfactant to polymer ratio is 10:1 and viscosity is in the range of is in the range of 2500-10,000 cps at 80-850C.

The ratio of surfactant to polymer ratio in the present enrobed compatible composition is preferably 4:1. The viscosity of the enrobed compatible mass or composition preferably ranges from 500-2000 cps at 80-850C. The enrobed floating soap of the present invention is as single phase soap bar.

The soap mass of the present invention which is adopted for floating soap bar is different from any other soap mass. The soap mass of present invention maintains the desired density, aeration and physical form such that when it is coated over floating soap it maintains the floating characteristic of the main soap body. Further the soap mass also maintains the aesthetic in terms of lather generation and cleansing profile. The composition of the present invention may comprise one or more surfactants selected from natural, natural-derived, or synthetic or a combination thereof. Preferably, the soap composition of the present invention may comprise alkali metal salts of fatty acids such as sodium palmitate and sodium oleate (i.e. anionic surfactants). Among the soaps that are used herein may be saponified glycerides such as sodium palmate, sodium palm kernelate and sodium cocoate. The soaps that are used in the soap bar compositions of the present invention may be present in an amount from approximately 50% to approximately 80%, preferably from approximately 55% to approximately 70% by weight.

The synthetic surfactants used in the present invention may be selected from a group comprising anionic surfactants, amphoteric surfactants, nonionic surfactants, and any combinations thereof. As it is well known in the art that surfactant materials can also be an emulsifier, the term “surfactant” does not exclude materials which also have emulsification properties. The synthetic surfactants that are used in the soap bar compositions of the present invention may be present in an amount from approximately from 40 to 60wt%.

The anionic surfactants that may be used in the present invention include but are not limited to alkyl sulfates, anionic acyl sarcosinates, anionic alkyl sarcosinates, methyl acyl taurates, N-acyl glutamates, acyl isethionates, alkyl ether sulfates, alkyl sulfosuccinates, alkyl phosphate esters, ethoxylated alkyl phosphate esters, trideceth sulfates, protein condensates, mixtures of ethoxylated alkyl sulfates and the like. Alkyl chains for these surfactants are C8-22, preferably C10-18 and, more preferably, C12-14 alkyls.

The amphoteric surfactants which can be used in the compositions of the present invention are those which can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, sodium 3-dodecylaminopropane sulfonate. Other amphoterics such as betaines are also useful in the present composition. Examples of betaines useful herein include the high alkyl betaines such as coco betaine, coco dimethyl carboxymethyl betaine, lauryl dimethyl carboxy-methyl betaine, lauryl dimethyl alpha-carboxyethyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, stearyl bis-(2-hydroxypropyl)carboxymethyl betaine, oleyl dimethyl gamma-carboxypropyl betaine, lauryl bis-(2-hydro-xypropyl)alpha-carboxyet-hyl betaine, etc. The sulfobetaines may be represented by coco dimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, amido betaines, amidosulfobetaines, and the like.

The nonionic surfactants useful in this invention can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. Non-limiting examples of preferred nonionic surfactants for use herein are those selected form the group consisting of glucose amides, alkyl polyglucosides, sucrose cocoate, sucrose laurate, alkanolamides, ethoxylated alcohols and mixtures thereof. In a preferred embodiment the nonionic surfactant is selected from the group consisting of glyceryl monohydroxystearate, isosteareth-2, trideceth-3, hydroxystearic acid, propylene glycol stearate, PEG-2 stearate, sorbitan monostearate, glyceryl laurate, laureth-2, cocamide monoethanolamine, lauramide monoethanolamine, decyl glucoside and mixtures thereof. The composition of the present invention may also comprise one or more sugar based surfactants selected from but not limited to condensation products of long chain alcohols with sugar or starch polymers (e.g. decyl polyglucoside and lauryl polyglucoside), amides (e.g. cocoamide diethanolamine and cocoamide monoethanolamine), alkylene oxide derived surfactants (e.g. ceteth-6, ceteareth6, steareth-6, PEG-12 stearate, and PEG-200 glyceryl tallowate), Maltooligosyl Glucoside/Hydrogenated Starch Hydrolysate and mixtures thereof. Preferred sugar based surfactants include Maltooligosyl Glucoside/Hydrogenated Starch Hydrolysate and Alkyl polyglucoside. The sugar based surfactants of the present invention may be present in an amount from approximately 0.1 % to 5% by weight, preferably from about 0.5 – 3% by wt.

According to the present invention polymers are starches such as corn starch, silicone polymers; water soluble polymers such as polyurethanes, polyacrylates, polyalkylene glycol with molecular weight between 200 and 20,000, preferably between 400 and 10,000 such as PEG 200, PEG 400, PEG600, PEG 1500, PEG 4000, PEG 6000, PEG 8000 and the like; anionic, zwitterionic, amphoteric and nonionic polymers that can be used are, for example, vinylacetate/crotonic acid-copolymers, vinylpyrrolidone/vinylacrylate-copolymers, vinylacetate/butylmaleate/ isobornylacrylate-copolymers, methylvinylether/maleic acid anhydride-copolymers and their esters, which are not cross-linked and with polyoles linked polyacrylacids which are cross-linked, acrylamidopropyltrimethylammonium chloride/ acrylate-copolymers, octylacrylamide/ methylmethacrylate/tert.butylaminoethylmethacrylate/2-hydroxypropylmethacrylate-copolymers, polyvinylpyrrolidone, vinylpyrrolidone/vinylacetate-copolymers, vinylpyrrolidone/ dimethylaminoethylmethacrylate/vinyl caprolactam-terpolymers as well as optionally derivatized cellulose ethers and silicones. Typically polymers are present in amounts 1 to 11 % by weight, preferably 1 to 8% by wt. of the total formulation.

Binders according to the present invention include high molecular weight poly acrylates, high molecular weight poly-ox, silicates, fatty alcohols, lanolin, sugars, tallow alcohol ethoxylates, and mixtures thereof. Other plastic binders are identified in the published literature (J. Amer. Oil Chem. Soc. 1982, 59, 442). Binders can be present in amount of 0.2 to 15% by wt, preferably 0.2 to 4 % by weight in the final product.

The soap composition of present invention optionally comprises fatty acids in the range of 1-10% by wt.

The “free fatty acids” as used herein are selected from fatty acids with alkyl chain lengths of from C8 – C18. These may be selected from group of linear chained fatty acids, branched chain fatty acids, saturated and unsaturated fatty acids such as Caprylic, Capric, Lauric, Myristic, Palmitic, Stearic, Oleic, etc and mixtures thereof. The free fatty acids that are used in the soap bar compositions of the present invention may be present in an amount from approximately 5% to approximately 10% by weight.

Emollients are substance which soften or improve the elasticity, appearance, and youthfulness of the skin (stratum corneum) by increasing its water content, and keeps it soft by retarding the decrease of its water content. Emollients that may be used in the present invention include but are not limited to silicone oils and modifications thereof such as linear and cyclic polydimethylsiloxanes; polyols such as glycerol, sorbitol; amino, alkyl, alkylaryl, and aryl silicone oils; fats and oils including natural fats and oils such as jojoba, soybean, sunflower, rice bran, avocado, almond, olive, sesame, persic, castor, coconut, mink oils; cacao fat; beef tallow, lard; hardened oils obtained by hydrogenating the aforementioned oils; and synthetic mono, di and triglycerides such as myristic acid glyceride and 2-ethylhexanoic acid glyceride; waxes such as carnauba, spermaceti, beeswax, lanolin, and derivatives thereof; hydrophobic plant extracts; hydrocarbons such as liquid paraffin, petrolatum, microcrystalline wax, ceresin, squalene, pristan and mineral oil; higher fatty acids such as lauric, myristic, palmitic, stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic, arachidonic and poly unsaturated fatty acids (PUFA); higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2-hexydecanol alcohol; esters such as cetyl octanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristyl myristate, isopropyl palmitate, isopropyl adipate, butyl stearate, decyl oleate, cholesterol isostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate; essential oils and extracts thereof such as mentha, jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine, cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay, clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint, rose, sage, sesame, ginger, basil, juniper, lemon grass, rosemary, rosewood, avocado, grape, grapeseed, myrrh, cucumber, watercress, calendula, elder flower, geranium, linden blossom, amaranth, seaweed, ginko, ginseng, carrot, guarana, tea tree, jojoba, comfrey, oatmeal, cocoa, neroli, vanilla, green tea, penny royal, aloe vera, menthol, cineole, eugenol, citral, citronelle, borneol, linalool, geraniol, evening primrose, camphor, thymol, spirantol, penene, limonene and terpenoid oils; and mixtures of any of the foregoing components, and the like. Advantageously emollients may be used from about 0.5 to about 3 % by weight in the final product.

Preservatives according to the present invention include BHT, EDTA, phenoxy ethanol. Preservatives can be present in amounts 0.01 to 0.1 % by weight in the final product.

pH regulator according to the present invention includes citric acid, lactic acid, oxalic acid, acetic acid etc. pH regulator can be present in amounts 0.2 to 2 % by weight in the final product.

Hydrotropes according to the present invention include but are not limited to cumene sulphonate, xylene sulphonates and combinations thereof. Hydrotropes can be present in amounts 0.5 to 5 % by weight in the final product

Further the composition of the present invention can comprise 0.1 to 2 % by weight of fragrance, 0.1 to 2% by weight of emotives.

Secondary emulsifiers that may be added to compositions of the present invention can be of the W/O type or O/W type. The addition of an emulsifier allows the incorporation of hydrophilic components or agents into the wax phase. Preferred are non-ionic emulsifiers which typically have good skin compatibility. Non-ionic emulsifiers of the present invention may be selected from group comprising addition products of 2 to 50 mole of ethylene oxide and/or 0 to 20 moles propylene oxide to linear fatty alcohols having 8 to 40 C-atoms, to fatty acids with 12 to 40 C-atoms and to alkylphenols with 8 to 15 C-atoms in the alkyl rest; C12-18-fatty acid mono- and -diesters of addition products of 1 to 50 mole of ethylene oxide and glycerine; glycerine mono- and -diesters and sorbitan mono- and -diesters of saturated and unsaturated fatty acids with 6 to 22 C-atoms and their ethylene oxide addition products; alkyl mono- and -oligoglycosides with 8 to 22 C-atoms in the alkyl rest and their ethoxylated analogs; addition products of 7 to 60 mole of ethylene oxide to castor oil and/or hardened castor oil; Polyol- and in particular polyglycerine esters, such as e.g. polyol poly-12-hydroxystearate, polyglycerine polyricinoleate, polyglycerine diisostearate or polyglycerine dimerate. Also applicable are mixtures of compounds of several of these substance classes; addition products of 2 to 15 mole of ethylene oxide to castor oil and/or hardened castor oil; partial esters derived from linear, branch chained, unsaturated or saturated C6-C22-fatty acids, ricinoleic acid as well as 12-hydroxystearic acid and glycerine, polyglycerine, pentaerythrite, dipentaerythrit, sugar alcohols (e.g. sorbitol), alkylglucosides (e.g. methylglucoside, butylglucoside, laurylglucoside), as well as polyglucosides (e.g. cellulose), or mixed esters such as e.g. glyceryl stearate/citrate and glyceryl stearate/lactate;Wool wax alcohols; Polysiloxane-polyalkyl-polyether-copolymers and derivatives thereof; Mixed esters from pentaerythrite, fatty acids, citric acid and fatty alcohols and/or mixed esters of fatty acids with 6 to 22 C-atoms with methylglucose and polyoles, respectively glycerine or polyglycerine; Polyalkylene glycols. Emulsifiers can be present in amounts 0.5 to 5 % by weight in the final product.

Active ingredients according to the present invention can be an optional ingredient in the soap composition. The role of active agent is to provide benefit to the skin. The active ingredients include lipophilic or hydrophilic active ingredients. As used herein an 'active ingredient' is meant to comprise a compound that has a cosmetic or therapeutic effect on the skin, hair, or nails, e.g. lightening agents, darkening agents such as self-tanning agents, anti-acne agents, shine control agents, anti-microbial agents, anti-inflammatory agents, anti-aging agents, in particular anti-wrinkle agents, anti-mycotic agents, anti-parasite agents, external analgesics, sunscreens, photoprotectors, antioxidants, keratolytic agents, detergents/surfactants, moisturizers, nutrients, vitamins, energy enhancers, anti-perspiration agents, astringents, deodorants, hair removers, firming agents, anti-callous agents, and agents for hair, nail, and/or skin conditioning.

Examples of active ingredients are hydroxy acids, benzoyl peroxide, sulfur resorcinol, ascorbic acid, D-panthenol, hydroquinone, octyl methoxycinnimate, titanium dioxide, octyl salicylate, homosalate, avobenzone, polyphenolics, carotenoids, free radical scavengers, spin traps, retinoids such as retinol and retinyl palmitate, ceramides, polyunsaturated fatty acids, essential fatty acids, enzymes, enzyme inhibitors, minerals, hormones such as estrogens, steroids such as hydrocortisone, 2-dimethylaminoethanol, copper salts such as copper chloride, peptides containing copper such as Cu:Gly-His-Lys, coenzyme Q10, peptides such as those disclosed in WO-00/15188, lipoic acid, amino acids such a proline and tyrosine, vitamins, lactobionic acid, acetyl-coenzyme A, niacin, riboflavin, thiamin, ribose, electron transporters such as NADH and FADH2, and other botanical extracts such as aloevera and soy, and derivatives and mixtures thereof. The cosmetically active agent will typically be present in the formulation of the invention in an amount of from about 0.001 % to about 20% by weight of the formulation, e.g., about 0.01% to about 10% by wt such as about 0.1% to about 5% by wt.

Examples of vitamins include, but are not limited to, vitamin A, vitamin Bs such as vitamin B3, vitamin B5, and vitamin B12, vitamin C, vitamin K, and vitamin E and derivatives thereof.

In an embodiment of the present invention, there is provided a process for preparation of the enrobing machine compatible soap mass composition comprising:
1. melting Polymer (s) fatty acid(s), wax (es) and emulsifier(s) and mixing them to obtain a molten mixture;
2. adding soap(s) and surfactant(s) to the molten mixture of step 1 at a temperature of 85-950C to obtain molten soap mix;
3. optionally adding other additives such as pH regulator(s), opacifier(s), chelatant(s), fragrance(s), colourant(s), preservative(s) etc to the well mixed molten soap mix of step 2 to obtain soap mass;
4. mixing binder(s) and other optional ingredients such as emollients, minerals to the soap mass of step 3, homogenizing while maintaining temperature; to achieve enrobing soap mass.
The homogenization speed in the present process is maintained between 300 to 6000 rpm.

The coated soaps of prior art are prepared using melting the soap composition at a very high temperature (greater than 250 0C), further the coating is not as uniform as achieved using enrobing machine. Moreover, the surface finish achieved also depends upon the rate of cooling of the coated mass. In case of coated soaps of the prior art the cooling takes more than 300 seconds while it is less than 30 seconds for the present invention. This helps in achieving superior surface finish as compared to the soap of prior art.
The process of present invention has various advantages:
2. Processing rate is very high.
1. Process is simplified and easy and leads to shiny surface and high processing rate.
2. The process is energy efficient as the process temperature does not exceed beyond 1000C.
3. Machine can be used to coat one part and leave other.
4. The quantity of enrobed mass used per soap is very less i.e. less than 1% w/w.

Enrobing mass is much more flexible which can maintain wide range of viscosity and liquidity.
The expression “wide range of viscosity and liquidity” encompasses the fact that the enrobing mass is flexible as it can maintain its desired characteristic at wide range of viscosity and temperature.

The cleansing product of present invention can be used in personal care industry. The products in personal care industry include grade I soap, grade II soap , grade III soap, bathing bar, transparent bathing bar, low density floating bathing bar and the like.

The invention is now illustrated by non-limiting examples.

Example 1
Enrobing soap mass composition for enrobing opaque bathing bars (melts at 80-950C.)

Table 1
Ingredients Wt %
Surfactant 40-60
Free Fatty Acid (C16-C18) 5-10
Emulsifier 0.5-5
Polymer 1-11
Salt 0.1-1
Aqua 0.1-2
Paraffin 2-15
Soap 10-20
Preservatives 0.01-0.1
pH regulator 0.2-2
Color / Fragrance / Emotive 0.1-2

Specific example of enrobing soap mass composition for enrobing opaque bathing bars
Table 2
Ingredients Wt %
Sodium cocoyl isethionate (65%) 48
Free Fatty Acid (C16-C18) 8.5
Cocamidopropyl betaine 4
PEG 400 6
Corn starch 3
Salt 0.8
Aqua 1.5
Paraffin wax 12
Soap 14
Preservatives 0.05
Citric acid 1.1
Color / Fragrance / Emotive 1.05

Table 2 also exemplifies a soap mass for enrobing opaque soap. The specific composition of table 2 is for enrobing a low pH opaque soap bar.

Example 2
Enrobing soap mass composition for enrobing transparent soaps (melts at 70-90 0C)
Table 3
Ingredients Wt %
Soap 20-40
Surfactants 5-10
Aqua 15-20
Solvents 20-40
Sucrose 1-10
Organic oil 0.5-5
Polymer 1-5
Hydrotopes 0.5-5
Preservative 0.05
Color / Fragrance / Emotive 1.05

Specific example of enrobing soap mass composition for enrobing transparent soap
Table 4
Ingredients Wt %
Soap 28.5
Surfactants 10
Aqua 20
Solvents (Gycerine, Polyol) 33
Sucrose 1
Organic oil 2
Polymer 3
Hydrotopes 1.5
Preservative 0.05
Color / Fragrance / Emotive 1.05

Example 1 relates to an enrobing mass that may be used for enrobing opaque soaps and Example 2 relates to an enrobing mass that may be used for enrobing transparent soaps. The temperature difference in the enrobing mass compositions of example 1 and example 2 is essentially to suit the specific melting requirements of the soaps to be enrobed.

Example 3
Process of preparing enrobed soap mass
I. Mixing fatty acids, polymers, waxes and emulsifier in mixer at 65-750C;
II. Mixing for sufficient time (20-30mins) post melting and, adding soap at a temperature of 85-900C;
III. Adding pH regulator followed by surfactants at a temperature between 90-950C;
IV. Adding other additives like TiO2, EDTA, fragrance etc once soap and surfactants are mixed completely;
V. Adding binders, emollients, minerals at high mixing speed followed by homogenization; and
VI. Maintaining the final mass in 85-900C temperature to achieve pouring consistency in mixer.

Example 4
Process for preparation of enrobed opaque soap
I. Mixed fatty acids, PEG 400, paraffin waxes and CAPB in mixer at 65-750C;
II. Mixed for sufficient time (20-30mins) post melting and, added soap at a temperature of 85-900C;
III. Added citric acid followed by Sodium cocoyl isethionate at a temperature between 90-950C;
IV. Added other additives like TiO2, EDTA, fragrance etc once soap and surfactants are mixed completely;
V. Added corn starch, emollients, minerals at high mixing speed followed by homogenization; and
VI. Maintained the final mass at 85-900C temperature to achieve enrobing machine compatible mass of pouring consistency in mixer.
VII. Dipped an opaque soap (prepared using conventional method of preparation) into enrobing machine compatible mass to obtain enrobed opaque soap.

Example 5
Process of preparation of enrobed transparent soap bar.
I. Mixed fatty acids, polymers, waxes and emulsifier in mixer at 65-750C;
II. Mixed for sufficient time (20-30mins) post melting and, added soap at a temperature of 85-900C;
III. Added pH regulator followed by surfactants at a temperature between 90-950C;
IV. Added other additives like TiO2, EDTA, fragrance etc once soap and surfactants are mixed completely;
V. Added binders, emollients, minerals at high mixing speed followed by homogenization; and
VI. Maintained the final mass at 85-900C temperature to achieve enrobing machine compatible mass of pouring consistency in mixer.
VII. Dipped a transparent soap (prepared using conventional method of preparation) into enrobing machine compatible mass to obtain enrobed transparent soap bar.

Example 6
Table 5
Ingredients % w/w
Surfactant 16
In situ soap (FFA blend + NaOH solution) 42.2
Polymer 0.5
Salt 0.5
Aqua 12
Solvents (PG, Sorbitol etc) 28
Preservatives 0.05
Additives like color, fragrance etc 0.75

Example 7
Process of preparation of floating soaps:
Step 1: mixing all the solvents and free fatty acids (FFA) in the mixer at a specified temperature. The required temperature ranges from 70-75°C.
Step 2: Adding surfactants after Step 1
Step 3: Generation of in-situ soap after step 2 and carrying out homogenization at temperature 75 to 95 °C.
Step 4: Mixing to obtain a homogenous mass.
Step 5: adding other additives like BHT, EDTA, and fragrance etc once the product of step 4 is obtained.

Example 8
Table 6-
Ingredients % w/w
Surfactant 48
Free Fatty Acid (C16-C18) 8.5
Emulsifier 4.0
Polymer 9
Salt 0.8
Aqua 1.5
Paraffin 12
Soap 14
Preservatives 0.05
pH regulator 1.1
Color / Fragrance / Emotive 1.05

Example 9
Process of preparation of enrobed mass to coat the floating soap bar prepared above.

I. Mixed free fatty acids, polymers, waxes and emulsifier in mixer at 65-750C;
II. Mixed for sufficient time (20-30mins) post melting and, add soap at a temperature of 85-900C;
III. Add pH regulator followed by surfactants at a temperature between 90-950C;
IV. Add other additives like TiO2, EDTA, fragrance etc once soap and surfactants are mixed completely;
V. Add binders, emollients, minerals at high mixing speed followed by homogenization; and
VI. Maintained the final mass at 85-900C temperature to achieve enrobing machine compatible mass of pouring consistency in mixer.
VII. Dipping floating soap (prepared using process given above) into enrobing machine compatible mass to obtain enrobed floating soap bar.

Example 10
Comparative data of a soap enrobed with enrobing machine compatible mass with that of normal soap in terms of aesthetics is shown by way of figure 1.
Observation: As depicted in Figure 1, enrobed floating bar soap has pleasing aesthetics and improved surface finish as compared to a conventional floating soap bar.

Example 11
Cleaning efficacy of enrobed floating soap bar of present invention:
Two soap compositions were made to evaluate the cleansing efficacy. The composition of the two soap varieties is given as below:
Composition A: Normal conventional floating soap
Table 7
Ingredients %
AOS 10
CAPB 5
Aqua 5
Soap 47
Sorbitol 15
PEG 400 6
Propylene glycol 10
EDTA 0.1
Preservative 0.4
Colour, Fragrance 1.5

Composition B: Enrobed floating soap bar
Table 8
Ingredients % by wt
Floating soap
AOS 6
CAPB 3
Aqua 3
Soap 28
Sorbitol 9
PEG 400 3.25
Propylene glycol 6
EDTA 0.6
Preservative 0.25
Colour, Fragrance 0.9
Coating composition
Sodium cocoyl isethionate (65%) 19.2
Free Fatty Acid (C16-C18) 3.4
Cocamidopropyl betaine 1.6
PEG 400 2.4
Corn starch 1.2
Salt 0.32
Aqua 0.6
Paraffin wax 4.8
Soap 5.6
Preservatives 0.02
Citric acid 0.44
Color / Fragrance / Emotive 0.42

Cleansing efficacy of the soap composition
Table 9
Samples/Parameters Lather (ml) at 30 FH Mush (g/50 cm2) Cleansing efficacy(1-5 score)*
Composition A: Normal conventional floating soap bar 350-360 4.5-5.5 4
Composition B: Enrobed floating soap bar 350-380 4.5-5.0 4

*Score definition: Score based on 10 panelist data. Score scale is provided below:
1 2 3 4 5
Poor cleaning Not at par cleaning Optimum cleaning Good cleaning Very good cleaning

Example 12
For good quality and accurate weight control, the enrobed mass must have the correct flow properties and which is liquid at 750C and it is important to maintain the surfactant to polymer ratio. Preferably the surfactant to polymer ratio is maintained at 4:1.

Table 10: Comparative data to show that desired effect is achieved when surfactant is to polymer ratio is from 10:1 to 4:1.

Surfactant : Polymer 5.7 (<4:1) 3.35 (>10:1) 14
S. No. Ingredients Wt% Wt% Wt%
1 Sodium cocoyl isethionate (65%) 48 43 53
2 Free Fatty Acid (C16-C18) 8.5 8.5 8.5
3 Cocamidopropyl betaine 4 4 4
4 PEG 400 (Polymer 1) 6 11 2
5 Corn starch (Polymer 2) 3 3 2
6 Salt 0.8 0.8 0.8
7 Aqua 1.5 1.5 1.5
8 Paraffin wax 12 12 12
9 Soap 14 14 14
10 Preservatives 0.05 0.05 0.05
11 pH regulator 1.1 1.1 1.1
12 Color / Fragrance / Emotive 1.05 1.05 1.05
Observation Desired soap mass that is compatible with enrobing machines. Soap mass does not melt at 75 - 90ºC and hence enrobing is not possible. Soap is very soft with a very high mush.

Table 11: Comparative data to show that desired effect is achieved when viscosity is not in maintained at the range of 500-2000 cps at 80 to 85 0C.

Viscosity 1700 450 2500
S. No. Ingredients Wt% Wt% Wt%
1 Sodium cocoyl isethionate (65%) 48 38.15 51
2 Free Fatty Acid (C16-C18) 8.5 16 6
3 Cocamidopropyl betaine 4 7 2
4 PEG 400 (Polymer 1) 6 7 1
5 Corn starch (Polymer 2) 3 1 11
6 Salt 0.8 0.8 .8
7 Aqua 1.5 5 0
8 Paraffin wax 12 15 8
9 Soap 14 8 18
10 Preservatives 0.05 .05 0.05
11 pH regulator 1.1 1 1.1
12 Color / Fragrance / Emotive 1.05 1 1.05
Observation Desired soap mass that is compatible with enrobing machines. Viscosity of the mass is very low and the mass is not compatible with the enrobing machine Due to high viscosity the mass is not suitable for enrobing. Uneven covering of the mass observed.

Example 13
Table 11 shows the difference in the surface finish and lather profile of a coated floating soap bar of present invention and coated non-floating soap bar.

Table 12
Soap mass Surface finish of the soap bar (Score) (figure 1) Lather profile
Coated floating soap bar 5 Creamy lather
Coated non-floating soap bar 5 Creamy lather
Floating soap bar 2 Airy/loose lather