TRANSPARENT/TRANSLUCENT
MOISTURIZING/COSMETIC/PERSONAL
CLEANSING BAR
FIELD OF THE INVENTION
The present invention is directed to transparent/translucent moisturizing/cosmetic/personal cleansing bars (hereinafter "cleansing bars") having a melting point of at least 55 °C and increased hardness/durability, primarily due to the bars containing polyhydric solvents, in an amount of about 15% to about 65% by weight, preferably about 25% to about 65 % by weight, including (A) one or more polyhydric solvents that include at least three hydroxyl groups, in an amount of 5% by weight to about 35% by weight, and (B) one or more polyhydric solvents that include two hydroxyl groups, e.g., diols or glycols, in an amount of about 10% by weight to about 30% by weight. The transparent/translucent cleansing bars contain about 4% to about 13% by weight water, preferably about 4% to about 12% water, most preferably about 7% to about 12% water. The transparent/translucent cleansing bars lose less water with time via atmospheric evaporation and have increased durability and avoid melting and deformation during shipping and handling while maintaining transparency /trans lucency. The bars are manufactured by forming a molten composition in liquid form, and pouring the molten composition into a mold to harden, upon cooling. The bar can be manufactured without a monohydric alcohol, or may contain a monohydric alcohol in relatively small amounts, e.g., 0.1 % to 4%, preferably 0.5 % to 2% by weight, for increased clarity. The bars can be manufactured to include relatively high foam, as personal
cleansing/moisturizing bars, or may contain low foam surfactants as moisturizing/facial cleansing/cosmetic bars.
BACKGROUND OF THE INVENTION AND PRIOR ART
Transparent personal cleansing bars are well known in the art. They are prepared by dissolving soap in a combination of water soluble solvents (normally urea and/or polyhydric alcohols) with the addition of surfactants to improve the cleansing and lathering characteristics of the product. Water is also part of the composition and is incorporated into the bars by the direct addition of water or added from the surfactants or soap that form part of the cleansing bars.
A common problem with transparent personal cleansing bars is that they have a melting point of about 50 °C, which is too close to the temperatures that are reached during shipping or storage of the products. When shipped or stored at temperatures approaching 50°C, the solid personal cleansing bars either melt or become sufficiently soft to deform. Another common problem of the personal cleansing bars is that they lose more weight than regular, opaque cleansing bars due to their relatively higher content of water, and the presence of volatile solvents, such as monohydric alcohols, e.g., ethanol.
U.S. Patent No. 5,041 ,234 to Instone, et al. discloses a transparent personal cleansing bar which contains greater than 40 percent by weight of soap (high soap bar). Like other "high soap" transparent bars, the bars disclosed by Instone et al. have good lather, low smear, and good bar hardness. Such high soap level transparent bars, however, are rather harsh to the skin. Another drawback to such bars is that their processing generally require the use of at least about 5% by weight volatile, short chain monohydric alcohols, or require special milling to obtain transparency.
Transparent bars which contain lower levels of soap are also known in the art. "Lower soap" transparent bars contain less than 40 percent by weight of soap. U.S. Patent No. 5,002,685 to Chambers et al. discloses a transparent bar made with 25% to 34% by weight soap, 5% to 15% by weight monohydric alcohol, 15% to 30% by weight sugar and/or cyclic polyol, and 15% to 30% by weight water. Unfortunately, transparent bars which require the use of at least about 5% by weight monohydric alcohols are prone to excessive weight loss due to the volatile nature of most monohydric alcohols. Such transparent bars are also more expensive to prepare and require special equipment designed to accommodate the explosion hazard associated with most monohydric alcohols.
Zyngier et al. U.S. Patent No. 5,703,025 discloses a monohydric alcohol-free process for making pour molded transparent and translucent cleansing bars that have good hardness, are mild to the skin, low smearing and good lathering. These bars, however, require at least 14% by weight water, particularly 14% to 32% by weight water, and preferably more than 20% by
weight water, so that the bars melt and deform at a relatively low temperature, e.g. , about 50°C, and readily lose weight via water evaporation at room temperature and pressure. As stated in the '025 patent, "The water level within the personal cleansing bars prepared by the process of the present invention is critical to obtain a transparent bar having desirable hardness characteristics. When the water is less than about 14 parts by weight of the bar, the bar may not be transparent."
A transparent/translucent cleansing bar containing 20% by weight water loses about 17% of its original weight when exposed to room temperature for three weeks, whereas a bar containing only 10% by weight water only loses about 7.5 % of its original weight under the same, standard temperature (room temperature) and pressure conditions.
SUMMARY OF THE INVENTION
In brief, the present invention is directed to a composition and a method of preparing a transparent/translucent moisturizing/cosmetic/personal cleansing bar containing polyhydric solvents, in an amount of about 15% to about 65 % by weight, preferably about 25 % to about 65 % by weight, including one or more polyhydric solvents that include at least three hydroxyl groups, in an amount of 5 % by weight to about 35% by weight, and one or more polyhydric solvents that include two hydroxyl groups, e.g., diols or glycols, in an amount of about 10% by weight to about 30% by weight. The transparent/translucent cleansing bars contain a final water content of about 13 % by weight or less, preferably about 4% to about 12% , more preferably about 7% to about 12% water, thereby increasing the melting temperature of
the bar to prevent melting and reduce deformation during storage and handling, increasing its hardness and durability, and substantially reducing the tendency of the bar to lose weight over time by evaporation of water by exposure to room temperature.
Accordingly, one aspect of the present invention is to provide a transparent/translucent moisturizing/cosmetic/personal cleansing bar that is more durable, has a relatively high melting point, and a lower water content than prior art personal cleansing bars, while maintaining clarity (transparency).
Another aspect of the present invention is to provide a transparent/translucent moisturizing/cosmetic/personal cleansing bar that is less susceptible to being deformed by heat and/or pressure and includes a combination of polyhydric solvents (1) having three or more hydroxyl groups; and (2) two hydroxyl groups, while providing a bar having a minimum amount of water (4-13 % by weight) so that hydrolyzable bar components, such as antibacterial components, e.g. , triclocarban (TCC), maintain more of their efficacy, for longer periods of time.
The above and other aspects and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments, taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
The Figure is a graph that compares the hardness, in Newtons, of the preferred bar composition of the present invention (Example
6 - PREFERRED) to the same composition containing 17.7% by weight water, prior to dehydration (Example 6 - FORMED).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The transparent/translucent personal cleansing bars of the present invention include the following components, after manufacture and may contain additional additives, such as antibacterial agents, dyes, perfumes, fillers, polymers, silicones, encapsulated materials, and the like:
Range Preferred More Most
% % Preferred Preferred
% %
water-soluble polyhydric 15-65 25-65 30-55 35-50 solvent(s),
3+-OH, e.g. , 5-35 10-30 15-25 17-22 glycerine, sugar alcohols, e.g. , sorbitol and the like
2-OH, e.g. , 10-30 15-30 20-30 22-27 propylene glycol, polyethylene glycol, dipropylene glycol
monohydric alcohol, 0-4 0.5-3 0.5-2 0.75-1.5 e.g. , ethanol soap 5-35 8-30 10-25 10-15 surfactant(s) 5-40 5-30 8-25 10-20 water 4-13 4-12 7-12 10-12
The term "soap", for purposes of describing this component of the transparent/translucent cleansing bar of the present invention, has the meaning as normally understood by those skilled in the art: monovalent salts of fatty monocarboxylic acids having a carbon chain length of from 12 to 24, preferably from 14 to 18 carbon atoms. These monovalent salts would normally be sodium salts, although some cations, such as K, Mg or alkanolammonium ions could be used. The preferred insoluble fatty acid soap
is at least 90% by weight, more preferably at least 95 % by weight selected from the group consisting of sodium myristate, sodium palmitate, sodium stearate and mixtures of any two or more thereof. Other insoluble soaps, particularly higher fatty acid insoluble soaps, can also be used.
This invention relates to the transparent cleansing/cosmetic compositions of the present invention, in a solid form, and method of manufacturing same. The transparent/ trans lucent cosmetic/moisturizing cleansing bars of the present invention have a reduced water content, thereby increasing the melting point of the bars to at least about 60 °C, preferably at least about 65 °C, with reduced weight loss and increased durability and hardness.
The products of this invention can be prepared with reduced water content, for example, by using anhydrous polyhydric alcohols and/or anhydrous surfactants or by removing water from the composition initially formed with a higher water content.
Significant performance improvements are obtained by combining water-soluble polyhydric solvents having at least three hydroxyl groups (3+-OH) with water-soluble polyhydric solvents having two hydroxyl groups (2-OH). Significant performance improvements also are obtained by reducing the water content to a maximum of about 13 % by weight, preferably in the range of about 4% to about 12% by weight, more preferably about 7% to about 12% by weight, most preferably about 10% to about 12% by weight water. The melting point of the bar is increased to at least 55 °C, which is above
the temperatures that are expected to be reached during shipping and storage, thus avoiding melting and deformation of the personal cleansing bars.
Another benefit to the composition of the present invention is the reduction of weight loss. A bar containing about 20% by weight water loses about 17% of its original weight when exposed to room temperature (25 °C) for three weeks, whereas a bar with a water content of 10% by weight only loses about 7.5% of its original weight under the same conditions.
SURFACTANTS
The bars of the present invention, include about 5% to about 40% by weight surfactants, preferably about 5% to about 30% by weight, more preferably about 8% to about 25 % , most preferably about 10% to about 20% by weight surfactants.
The surfactant can be an anionic surfactant, a cationic surfactant, a nonionic surfactant, an ampholytic or amphoteric surfactant or a compatible mixture of surfactants .
Suitable anionic surfactants include, but are not limited to, compounds in the classes known as alkyl sulfates, alkyl ether sulfates, alkyl ether sulfonates, sulfate esters of an alkylphenoxy polyoxyethylene ethanol, alpha-olefin sulfonates, beta-alkoxy alkane sulfonates, alkylaryl sulfonates, alkyl monoglyceride sulfates, alkyl monoglyceride sulfonates, alkyl carbonates, alkyl ether carboxylates, fatty acids, sulfosuccinates, sarcosinates, oxtoxynol or nonoxynol phosphates, taurates, fatty taurides, fatty acid amide
polyoxyethylene sulfates, isethionates, or mixtures thereof. Additional anionic surfactants are listed in McCutcheon's Emulsifiers and Detergents, 1993 Annuals, (hereafter McCutcheon's), McCutcheon Division, MC Publishing Co. , Glen Rock, NJ, pp. 263-266, incorporated herein by reference. Numerous other anionic surfactants, and classes of anionic surfactants, are disclosed in Laughlin et al. U.S. Patent No. 3,929,678, incorporated herein by reference.
The cleansing bars of the present invention also can contain nonionic surfactants. Typically, a nonionic surfactant has a hydrophobic base, such as a long chain alkyl group or an alkylated aryl group, and a hydrophilic chain comprising a sufficient number (i.e., 1 to about 30) of ethoxy and/or propoxy moieties. Examples of classes of nonionic surfactants include ethoxylated alkylphenols, ethoxy lated and propoxy lated fatty alcohols, polyethylene glycol ethers of methyl glucose, polyethylene glycol ethers of sorbitol, ethylene oxide-propylene oxide block copolymers, ethoxylated esters of fatty (C8-Cι8) acids, condensation products of ethylene oxide with long chain amines or amides, and mixtures thereof. Fatty alcohol ethoxy lates (FAE) are preferred for dissolving antibacterial compounds, such as triclocarban (TCC).
Exemplary nonionic surfactants include, but are not limited to, methyl gluceth-10, PEG-20 methyl glucose distearate, PEG-20 methyl glucose sesquistearate, C1M5 pareth-20, ceteth-8, ceteth-12, dodoxynol-12, laureth-15, PEG-20 castor oil, polysorbate 20, steareth-20, poly oxy ethylene- 10 cetyl ether, polyoxy ethylene- 10 stearyl ether, polyoxyethylene-20 cetyl ether, polyoxyethylene-10 oleyl ether, polyoxyethylene-20 oleyl ether, an ethoxylated
nonylphenol, ethoxylated octylphenol, ethoxylated dodecylphenol, or ethoxylated fatty (C6-C22) alcohol, including 3 to 20 ethylene oxide moieties, polyoxyethylene-20 isohexadecyl ether, polyoxyethylene-23 glycerol laurate, polyoxy-ethylene-20 glyceryl stearate, PPG-10 methyl glucose ether, PPG-20 methyl glucose ether, polyoxyethylene-20 sorbitan monoesters, polyoxyethylene-80 castor oil, polyoxyethylene-15 tridecyl ether, polyoxy- ethylene-6 tridecyl ether, laureth-2, laureth-3, laureth-4, PEG-3 castor oil, PEG 600 dioleate, PEG 400 dioleate, and mixtures thereof.
Numerous other nonionic surfactants are disclosed in McCutcheon's Detergents and Emulsifiers, 1993 Annuals, published by McCutcheon Division, MC Publishing Co., Glen Rock, NJ, pp. 1-246 and 266- 272; in the CTFA International Cosmetic Ingredient Dictionary, Fourth Ed., Cosmetic, Toiletry and Fragrance Association, Washington, D.C. (1991) (hereinafter the CTFA Dictionary) at pages 1-651; and in the C77vl Handbook, at pages 86-94, each incorporated herein by reference.
In addition to anionic and nonionic surfactants, cationic, ampholytic, and amphoteric surfactants can be used in the cleansing bars of the present invention. Cationic surfactants include amine oxides, for example.
Ampholytic surfactants can be broadly described as derivatives of secondary and tertiary amines having aliphatic radicals that are straight chain or branched, and wherein one of the aliphatic substituents contains from about
8 to 18 carbon atoms and at least one of the aliphatic substituents contains an anionic water-solubilizing group, e.g. , carboxy, sulfonate, or sulfate.
Examples of compounds falling within this description are sodium 3-(dode- cylamino)propionate, sodium 3-(dodecylamino)-propane-l-sulfonate, sodium 2-(dodecylamino)ethyl sulfate, sodium 2-(dimethylamino)octadecanoate, disodium 3-(N-carboxymethyl-dodecylamino)propane-l-sulfonate, disodium octadecyliminodiacetate, sodium l-carboxymethyl-2-undecylimidazole, and sodium N,N-bis(2-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine.
More particularly, one class of ampholytic surfactants include sarcosinates and taurates having the general structural formula
0 R1 - C -N- ( CH 2 ) n-Y R2
wherein R1, for the above, as well as the following classes of ampholytic surfactants, is Cn through C21 alkyl, R2 is hydrogen or C C2 alkyl, Y is CO2M or SO3M, M is an alkali metal, and n is a number 1 through 3.
Another class of ampholytic surfactants is the amide sulfosuccinates having the structural formula
0 S03 "Na+
R ,1 -NHC11CH 2 - C IH- C0 2 "Na+
The following classes of ampholytic surfactants also can be used:
O CH2C02 ~Na+
R1C IINHCH 2CH2N i
CH2CH2OH
alkoamphoglycinates
alkoamphocarboxyglycinates
alkoamphopropionates
O CH2CH2C02 "Na+
II I
R1CNHCH2 H2 CH2C02H CH2CH2OH
alkoamphocarboxypropionates
OH
O CH2CHCH2S03-Na+
R1ClNHCH2CH2N I
CH2CH2OH
alkoamphopropylsulfonates
O CH3
R1C IINH (CH2) 3N I+-CH2C02- CH3
alkamidopropyl betaines
alkamidopropyl hydroxysultaine
alkylaminopropionates
CH2CH2C02 -
I
RNH CH2CH C02H
alkyliminopropionates .
Additional classes of ampholytic surfactants include the phosphobetaines and the phosphitaines.
Specific, nonlimiting examples of ampholytic surfactants useful in the present invention are sodium coconut N-methyl taurate, sodium oleyl N-methyl taurate, sodium tall oil acid N-methyl taurate, sodium palmitoyl N-methyl taurate, cocodimethylcarboxymethylbetaine, lauryldimethyl- carboxymethylbetaine, lauryldimethylcarboxyethylbetaine, cetyldimethyl- carboxymethylbetaine, lauryl-bis-(2-hydroxyethyl)carboxymethylbetaine, oleyldimethylgammacarboxypropylbetaine, lauryl-bis-(2-hydroxypropyl)- carboxyethylbetaine, cocoamidodimethylpropylsultaine, stearylamidodimethyl- propylsultaine, laurylamido-bis-(2-hydroxyethyl)propylsultaine, disodium oleamide PEG-2 sulfosuccinate, TEA oleamido PEG-2 sulfosuccinate, disodium oleamide ME A sulfosuccinate, disodium oleamide MIPA sulfosuccinate, disodium ricinoleamide MEA sulfosuccinate, disodium undecylenamide ME A sulfosuccinate, disodium wheat germamido MEA sulfosuccinate, disodium wheat germamido PEG-2 sulfosuccinate, disodium isostearamideo MEA sulfosuccinate, cocoamphoglycinate, cocoamphocarboxyglycinate, lauroamphoglycinate, lauroamphocarboxyglycinate, capryloampho- carboxy gly cinate , cocoamphopropionate , cocoamphocarboxypropionate , lauroamphocarboxypropionate, capryloamphocarboxypropionate, dihydroxy ethyl tallow glycinate, cocamido disodium 3-hydroxypropyl phosphobetaine, lauric myristic amido disodium 3-hydroxypropyl phosphobetaine, lauric myristic amido glyceryl phosphobetaine, lauric myristic amido carboxy disodium 3-hydroxypropyl phosphobetaine, cocoamido propyl monosodium phosphitaine, lauric myristic amido propyl monosodium phosphitaine, and mixtures thereof.
POLYHYDRIC SOLVENT(S):
The transparent bar prepared according to the process of the present invention comprises from about 15 % to about 65 % by weight, preferably about 25% to about 65 % by weight, more preferably from about 30% to about 55% by weight, most preferably about 35 % to about 50% by weight of a combination of water-soluble polyhydric organic solvents including (A) about 5% to about 35% by weight water-soluble polyhydric solvent(s) having three or more hydroxyl groups (3+-OH), and (B) about 10% to about 30% by weight polyhydric solvent(s) having two hydroxyl groups (2-OH). Preferred water soluble organic polyols having two hydroxyl groups (2-OH) include those selected from the group consisting of: propylene glycol; dipropylene glycol; butylene glycol; ethylene glycol; 1,7-heptanediol; monoethylene glycols, polyethylene glycols, polypropylene glycols of up to 8,000 molecular weight; mono- .4 alkyl ethers of any of the foregoing; and mixtures thereof. Preferred water-soluble polyhydric solvents that have at least three hydroxyl groups (3+-OH) include glycerine, and any sugar alcohol, such as sorbitol.
Examples of suitable sugar alcohols include:
Tetritols:
Erythritol, threitol, D-threitol, L-threitol, and D,L-threitol.
Pentitols:
Ribitol, arabinitol, D-arabinitol, L-arabinitol, D,L-arabinitol and xylitol.
Hexitols:
Allitol, dulcitol (galacitol), glucitol, sorbitol, (D-glucitol), L-glucitol, D,L- glucitol, D-mannitol, L-mannitol, D,L-mannitol, altritol, D-altritol, L-altritol, D,L-altritol, iditol, D-iditol, and L-iditol.
Disaccharide alcohols:
Maltitol, lactitol and isomalt.
SOAP
The fatty acid soap used in the present invention comprises sodium soaps. However, low levels of non-sodium soaps such as potassium, magnesium, and/or triethanolammonium (TEA) soaps are permissible. Such non-sodium soaps, when used, are preferably used at a level of from 0% to
10% by weight, preferably from 0% to 5 % by weight of the bar soap.
OPTIONAL INGREDIENTS
The transparent/translucent bars of the present invention also can contain optional ingredients well known to persons skilled in the art. Such optional ingredients typically are present, individually, from 0% to about 5 % , by weight, of the composition, and, collectively, from 0% to about 20% , by weight, of the composition.
Suitable optional ingredients include dyes, fragrances and one or more antibacterial compounds(s), that are present in a sufficient amount to perform their intended function and do not substantially adversely affect the transparency of the composition.
Classes of optional ingredients include, but are not limited to, dyes, fragrances, pH adjusters, thickeners, fillers, viscosity modifiers, buffering agents, foam stabilizers, antioxidants, foam enhancers, chelating agents, opacifiers, sanitizing or anti-microbial agents, preservatives, polymers, silicones, encapsulated materials, and similar classes of optional ingredients known to persons skilled in the art.
Specific classes of optional ingredients include alkanolamides as foam boosters and stabilizers; gums and polymers as thickening agents; inorganic phosphates, sulfates, and carbonates as buffering agents; EDTA and phosphates as chelating agents; and acids and bases as pH adjusters.
Examples of preferred classes of basic pH adjusters are ammonia; mono-, di-, and tri-alkyl amines; mono-, di-, and tri-alkanolamines; alkali metal and alkaline earth metal hydroxides; and mixtures thereof. However, the identity of the basic pH adjuster is not limited, and any basic pH adjuster known in the art can be used. Specific, nonlimiting examples of basic pH adjusters are ammonia; sodium, potassium, and lithium hydroxide; monoethanolaminε; triethylamine; isopropanolamine; diethanolamine; and triethanolamine.
Examples of preferred classes of acidic pH adjusters are the mineral acids and polycarboxylic acids. Nonlimiting examples of mineral acids are hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid. Nonlimiting examples of polycarboxylic acids are citric acid, glycolic acid, and lactic acid. The identity of the acidic pH adjuster is not limited and any acidic pH adjuster known in the art, alone or in combination, can be used.
In accordance with a preferred embodiment of manufacturing the moisturizing/cosmetic/personal cleansing bars of the present invention, the solvents and surfactants are added in an open agitated reaction vessel at atmospheric pressure and at a temperature sufficient to melt the fatty acids, generally at least about 70°C, e.g. , 70°C to 80°C. The fatty acid(s) then are added, followed by raising the temperature to at least about 80 °C, e.g., 80-90 °C, prior to the addition of a neutralizing agent, preferably a sodium base, e.g. , NaOH, in an amount sufficient to provide 100% neutralization of the fatty acids, to form the soap, in situ. It should be understood that the soap, i.e., sodium myristate, sodium palmitate, and/or sodium stearate, can be added in pre-manufactured form instead of being formed, in situ. At this stage of the manufacturing process, if the water content of the mixture is above 13 % by weight, the temperature of the reaction mixture is raised to at least about 90 °C, preferably 90°C to 100°C to evaporate sufficient water to provide a composition having 4-13 % by weight water, most preferably about 10-12% by weight water. It should be noted that during the above-described water evaporation or dehydration step of the manufacturing process, a small portion of the propylene glycol or other relatively low boiling solvents may evaporate together with the water. However, it has been found in the following examples
that only about 0.5-2.0% of the propylene glycol is lost via evaporation during the dehydration step, and such solvent evaporation can be compensated for by the initial addition of 0.5-2.0% extra propylene glycol or other relatively low boiling polyhydric solvents at any stage of manufacture.
It should also be noted that the above-described dehydration step is unnecessary if one or more of the solvents and/or surfactants is added in anhydrous form (see Examples 3, 4, 7 and 10). Further, the dehydration step can be carried out at much lower temperatures by using a sealed reaction vessel at a pressure below atmospheric (under vacuum).
As well known in the art, the more volatile optional ingredients, such as dyes, fragrances and monohydric alcohols, should be added to the composition after cooling the molten composition, e.g., to 70° C or below, so that the volatile components are not lost to evaporation.
The cleansing bars of the present invention can be manufactured by adding the soap in sodium salt form, or the fatty acid(s) can be added together with a sodium base, such as sodium hydroxide to form the soap in situ. As shown in the following examples, the moisturizing/cosmetics cleansing bars of the present invention have sufficient clarity to provide at least 85 % light transmission, generally 85-95 % light transmission. In accordance with another important feature of the present invention, when the bars are frozen and then thawed (Freeze/Thaw), the clarity remains at least 90% , preferably at least 95% of its original clarity compared to about 80% clarity after Freeze/Thaw of prior art bars containing 17.7% water (see Example 6 - PREFERRED vs. Example
>
6 -FORMED). The following examples show the compositions in percentages by weight of materials added to an agitated reaction vessel designated as "ADDED"; the composition formed from the materials added, designated "FORMED" ; and the final composition after removal of water, if any, designated "FINAL":
In the following examples, when the soap is made in situ by reaction of fatty acid(s) with a caustic solution, e.g. , NaOH, it is preferred to add the caustic solution before the addition of the fatty acid(s) to prevent formation of gels or lumps, which would increase manufacturing time. It has also been found that color degradation is minimized by adding any sorbitol only when the percent free fatty acid(s) is in the range of about 0.1 % to about 2% , preferably in the range of 0.2% to 1.5%, more preferably in the range of 0.5% to 1.0% free fatty acid(s), based on the total weight of free fatty acids and neutralized fatty acids. The following is the preferred sequence of addition:
1- Mix the non-sorb itol polyhydric solvent(s), e.g. , propylene glycol and glycerine and the surfactant(s);
2- Raise batch temperature to 70 to 80 °C;
3- Add less than the required amount of the caustic solution needed to fully neutralize the later-added fatty acids, e.g., about 95 % of the required amount of caustic solution, e.g. , NaOH;
4- Add the fatty acids, ensuring that the temperature remains above about 80°C but below 100°C;
5- Analyze for free fatty acid, e.g., titrate with NaOH, using a pH indicator, and adjust, if required, to 0.1 to 2.0% by weight, preferably 0.2 to
1.5 % (most preferred 0.5 % to 1.0%) based on the total weight of free fatty acids and neutralized fatty acids, as lauric acid, adding more caustic solution or more fatty acid, e.g. , stearic acid;
6- Add the sorbitol solution, if sorbitol is one of the polyhydric solvents, and mix well;
7- Start the water evaporation step, e.g. , by raising the temperature of the batch to about 99 to 102°C with good agitation while preventing the batch from boiling. Of course, water removal under reduced pressure would require lower temperatures, the temperature depending upon the degree of applied vacuum;
8- When the desired amount of water has been removed, cool the batch to 75 to 80 °C. Add the remaining caustic solution for complete neutralization of the fatty acids and any optional ingredients.
EXAMPLE 1
ADDED
Propylene Glycol 22.8
Glycerine 15.3
Sorbitol (70%) 15.8
Sorbitol (100%) 0.0
SLES (70%) 12.0 AOS* (40%) 0.0 FAE** ( 100%) 0.0
Myristic acid 7.3 Stearic acid 11.1
H2O 9.9
NaOH (50%) 5.8
TOTAL 100.0
FORMED
Propylene Glycol 22.8
Glycerine 15.3
Sorbitol (100%) 11.1
SLES (100%) 8.4
AOS* (100%) 0.0
FAE** (100%) 0.0
NaMyristate 8.0 NaStearate 12.0
Total Water 22.5
TOTAL 100.0
CLARITY 86/90
MELTING POINT (°C) 50
FINAL
H,O Removed 13.0
Propylene Glycol 26.2
Polyhydric Solvents: 54.5% 2-OH: 26.2%
Glycerine 17.6 3+-OH: 28.3 % Sorbitol 12.7
SLES 9.7 AOS* 0.0 FAE** 0.0
NaMyristate 9.2 NaStearate 13.8
Final Water 10.9
TOTAL 100.1
* alpha olefin sulfonate ** fatty alcohol ethoxylate CLARITY 84/90
MELTING POINT (°C) 60
EXAMPLE 2
Dry Sorbitol (no need to remove water)
ADDED
Propylene Glycol 26.0
Glycerine 17.0
Sorbitol (70%) 0.0
Sorbitol (100%) 13.7
SLES (70%) 12.7
AOS* (40%) 0.0
FAE** (100%) 0.0
Myristic acid 10.0
Stearic acid 12.7
H2O 0.0
NaOH (50%) 7.3
TOTAL 99.4
FORMED
Propylene Glycol 26.0
Glycerine 17.0
Sorbitol (100%) 13.7
SLES (100%) 8.9 AOS* (100%) 0.0 FAE** (100%) 0.0
NaMyristate 11.0 NaStearate 13.7
Total Water 9.1
TOTAL 99.4
FINAL H,O Removed Propylene Glycol 26.0
Polyhydric Solvents: 56.7% 2-OH: 26.0%
Glycerine 17.0 3+-OH: 30.7% Sorbitol 13.7
SLES 8.9 AOS* 0.0
FAE** 0.0 8.9 Surfactants
NaMyristate 11.0 NaStearate 13.7 24.7 Soap
Final Water 9.1 9.1 Water
TOTAL 99.4 99.4 Total
* alpha olefin sulfonate ** fatty alcohol ethoxylate CLARITY 85/90
MELTING POINT (°C) 60
EXAMPLE 3
High Level Of Surfactant
ADDED
Propylene Glycol 20.4
Glycerine 5.0
Sorbitol (70%) 0.0
Sorbitol (100%) 10.6
SLES (70%) 13.4
AOS* (40%) 0.0
FAE** (100%) 25.0
Myristic acid 8.5 Stearic acid 10.8
H2O 0.0
NaOH (50%) 6.2
TOTAL 99.9
FORMED
Propylene Glycol 20.4
Glycerine 5.0
Sorbitol (100%) 10.6
SLES (100%) 9.4
AOS* (100%) 0.0
FAE** (100%) 25.0
NaMyristate 9.3 NaStearate 11.7
Total Water 8.5
TOTAL 99.9
FINAL
H2O Removed 0
Propylene Glycol 20.4
Polyhydric Solvents: 36.0% 2-OH: 20.4%
Glycerine 5.0 3+-OH: 15.6% Sorbitol 10.6
SLES 9.4 AOS* 0.0
FAE** 25.0 34.4 Surfactants
NaMyristate 9.3 NaStearate 11.7 21.0 Soap
Final Water 8.5 8.5 Water
TOTAL 99.9 99.9 TOTAL
* alpha olefin sulfonate ** fatty alcohol ethoxylate
CLARITY 82/90
MELTING POINT (°C) 62
EXAMPLE 4
Very Low Water Content, Low Foaming, Facial Cleanser
ADDED
Propylene Glycol 26.1
Glycerine 17.2
Sorbitol (70%) 0.0
Sorbitol (100%) 12.6
SLES (70%) 0.0
AOS* (40%) 0.0
FAE** (100%) 12.4
Myristic acid 10.6
Stearic acid 13.4
H2O 0.0
NaOH (50%) 7.7
TOTAL 100.0
FORMED
Propylene Glycol 26.1
Glycerine 17.2
Sorbitol (100%) 12.6
SLES (100%) 0.0
AOS* (100%) 0.0
FAE** (100%) 12.4
NaMyristate 11.6 NaStearate 14.5
Total Water 5.6
TOTAL 100.0
FINAL
H,O Removed
Propylene Glycol 26.1
Polyhydric Solvents: 55.9% 2-OH: 26.1 %
Glycerine 17.2 3+-OH: 29.8% Sorbitol 12.6
SLES 0.0 AOS* 0.0
FAE** 12.4 12.4 Surfactants
NaMyristate 11.6 NaStearate 14.5 26.1 Soap
Final Water 5.6 5.6 Water
TOTAL 100.0 100.0 TOTAL
* alpha olefin sulfonate ** fatty alcohol ethoxylate
CLARITY 84/90
MELTING POINT (°C) 62
EXAMPLE 5
PEG-2ME
ADDED
Propylene Glycol 16.4
Glycerine 0.0
Sorbitol (70%) 19.5
Sorbitol (100%) 0.0
PEG-2ME* 10.4
SLES (70%) 19.6
AOS** (40%) 0.0
FAE*** (100%) 0.0
Myristic acid 11.0 Stearic acid 14.1
H2O 0.0
NaOH (50%) 8.0
Ethanol 1.0
TOTAL 100.0
FORMED
Propylene Glycol 16.4
Glycerine 0.0
Sorbitol (100%) 13.7
PEG-2ME* 10.4
SLES (100%) 13.7
AOS** (100%) 0.0
FAE*** (100%) 0.0
NaMyristate 12.1 NaStearate 15.2
Ethanol 1.0
Total Water 17.6
TOTAL 100.0
FINAL HiO Removed 7.0
Propylene Glycol 17.6
Polyhydric Solvents: 43.5%
2-OH: 28.8%
Glycerine 0.0 3+-OH: 14.7%
Sorbitol 14.7
PEG-2ME* 11.2
SLES 14.8 AOS** 0.0 Λ p Ψ •!» Ψ 0.0 14.8 Surfactants
NaMyristate 13.0 NaStearate 16.4 29.4 Soap
Ethanol 1.0
Final Water 11.3 11.3 Water
TOTAL 100.0 100.0 TOTAL
* polyethylene 2 glycol methyl ether ** alpha olefin sulfonate *** fatty alcohol ethoxylate CLARITY 83/90
MELTING POINT (°C) 62
EXAMPLE 6
(Preferred Embodiment)
ADDED
Propylene Glycol 25.1
Glycerine 6.0
Sorbitol (70%) 18.4
Sorbitol (100%) 0.0
SLES (70%) 18.4
AOS* (40%) 0.0
FAE** (100%) 0.0
Myristic acid 10.3 Stearic acid 13.1
H2O 1.2
NaOH (50%) 7.5
TOTAL 100.0
FORMED
Propylene Glycol 25.1
Glycerine 6.0
Sorbitol (100%) 12.9
SLES (100%) 12.9
AOS* (100%) 0.0
FAE** (100%) 0.0
NaMyristate 11.3
NaStearate 14.2
Total Water 17.7
TOTAL 100.0
FINAL PREFERRED H7O Removed 5.0 7.5 10.0
Propylene Glycol 26.4 Polyhydric 27.1 Polyhydric 27.9 Polyhydric
Solvents: 46.3 % Solvents: 47.5 % Solvents: 47.9%
2-OH: 26.4% 2-OH: 27.1 % 2-OH : 27.9%
Glycerine 6.3 3+-OH: 19.9% 6.5 3+-OH: 20.4% 6.7 3+-OH: 20.0%
Sorbitol 13.6 13.9 14.3
SLES 13.6 13.9 14.3 I
FAE** 0.0 0.0 0.0
NaMyristate 11.9 12.2 12.5 NaStearate 14.9 15.3 15.7
Final Water 13.3 11.0 8.5
100.0 100.0 100.0
TOTAL
FORMED 0% H,0 5% H,0 7.5% H,0 10.0% H,0
REMOVED REMOVED REMOVED REMOVED
CLARITY 85/90 83/90 81/90 79/90
MELTING POINT 50 56 62 64
(°C)
HARDNESS (N) 16.2 22.5 Freeze/Thaw 72/90 78/80
Weight Loss 10% 4%
* alpha olefin sulfonate ** fatty alcohol ethoxylate
EXAMPLE 7
Dry Sorbitol (no need to remove water)
ADDED
Propylene Glycol 27.1
Glycerine 6.5
Sorbitol (70%) 0.0
Sorbitol (100%) 13.9
SLES (70%) 18.6
AOS* (40%) 0.0 FAE** (100%) 0.0
Myristic acid 11.3
Stearic acid 14.4
H2O 0.0
NaOH (50%) 8.2
TOTAL 100.0
FORMED
Propylene Glycol 27.1
Glycerine 6.5
Sorbitol (100%) 13.9
SLES (100%) 13.0
AOS* (100%) 0.0
FAE** (100%) 0.0
NaMyristate 12.4 NaStearate 15.6
Total Water 11.5
TOTAL 100.0
FINAL
H,O Removed
Propylene Glycol 27.1
Polyhydric Solvents: 47.5 % 2-OH: 27.1 %
Glycerine 6.5 3+-OH: 20.4% Sorbitol 13.9
SLES 13.0 AOS* 0.0
FAE** 0.0 13.0 Surfactants
NaMyristate 12.4 NaStearate 15.6 28.0 Soap
Final Water 11.5 11.5 Water
TOTAL 100.0 100.0 TOTAL
* alpha olefin sulfonate ** fatty alcohol ethoxylate
CLARITY 81/90
MELTING POINT (°C) 60
EXAMPLE 8
ADDED
Propylene Glycol 24.3
Glycerine 5.7
Sorbitol (70%) 17.5
Sorbitol (100%) 0.0
SLES (70%) 14.3
AmphoAcetate (30%) 8.6
FAE* (100%) 0.0
Myristic acid 9.9 Stearic acid 12.6
H2O 0.0
NaOH (50%) 7.2
TOTAL 100.1
FORMED
Propylene Glycol 24.3
Glycerine 5.7
Sorbitol (100%) 12.3
SLES (100%) 10.0
AmphoAcetate (100%) 2.6
FAE* (100%) 0.0
NaMyristate 10.9 NaStearate 13.6
Total Water 20.8
TOTAL 100.1
FINAL
H2O Removed 9.0
Propylene Glycol 26.7
Polyhydric Solvents: 46.4% 2-OH: 26.7%
Glycerine 6.3 3+-OH: 19.8 % Sorbitol 13.5
SLES 11.0
AmphoAcetate (100%) 2.8 FAE* 0.0 13.8 Surfactants
NaMyristate 11.9 NaStearate 15.0 26.9 Soap
Final Water 12.9 12.9 Water
TOTAL 100.1 100.1 TOTAL
* fatty alcohol ethoxylate
CLARITY 81/90
MELTING POINT (°C) 62
EXAMPLE 9
ADDED
Propylene Glycol 22.4
Glycerine 5.1
Sorbitol (70%) 16.0
Sorbitol (100%) 0.0
SLES (70%) 0.0
AOS* (40%) 29.4
FAE** (100%) 0.0
Myristic acid 9.0 Stearic acid 11.5
H2O 0.0
NaOH (50%) 6.6
TOTAL 100.0
FORMED
Propylene Glycol 22.4
Glycerine 5.1
Sorbitol (100%) 11.2
SLES (100%) 0.0
AOS* (100%) 11.8
FAE** (100%) 0.0
NaMyristate 9.9 NaStearate 12.4
Total Water 27.2
TOTAL 100.0
FINAL
H,O Removed 18.0
Propylene Glycol 27.3
Polyhydric Solvents: 47.2% 2-OH: 27.3%
Glycerine 6.2 3+-OH: 19.9% Sorbitol 13.7
SLES 0.0 AOS* 14.3 FAE** 0.0
NaMyristate 12.0 NaStearate 15.2
Final Water 11.2
TOTAL 99.9
* alpha olefin sulfonate ** fatty alcohol ethoxylate
CLARITY 81/90
MELTING POINT (°C) 58
EXAMPLE 10
High Soap Level - Added In Pellet Form (as Na salt)
ADDED
Propylene Glycol 24.1
Glycerine 5.8
Sorbitol (70%)
Sorbitol (100%) 12.6
SLES (70%) 17.0 AOS* (40%) 0.0
Soap Pellets (75%)** 10.0
Myristic acid 10.1
Stearic acid 13.0
H2O 0.0
NaOH (50%) 7.4
TOTAL 100.0
FORMED
Propylene Glycol 24.1
Glycerine 6.5
Sorbitol (100%) 12.6 SLES (100%) 11.9
AOS* (100%) 0.0
Soap 7.5
NaMyristate 11.1 NaStearate 14.1
Total Water 12.0
TOTAL 99.7
FINAL
H2O Removed 2.0
Propylene Glycol 24.6
Polyhydric Solvents: 44.1 % 2-OH: 24.6%
Glycerine 6.6 3+-OH: 19.5%
Sorbitol 12.9
SLES 12.1
AOS* 0.0 12.1 Surfactants
7.7
NaMyristate 11.3
NaStearate 14.3 33.3 Soap
Final Water 10.2 10.2 Water
TOTAL 99.7 99.7 TOTAL alpha olefin sulfonate
** C12 0.2%
3.0% CLARITY 78/90
16 31.0% MELTING POINT (°C) 62
C 18 16.0% c *** 45.0%
C18.2 *** 4.0% *** number of double bonds in C18 acid c *** 1.0% **** fatty alcohol ethoxylate