JPH0631426B2 - Light transparent makeup soap - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent cosmetic soap with improved coloring, a method for reducing the color of transparent cosmetic soap, and a novel reducing agent system.

(Prior Art) Commercially available transparent makeup soap tends to be rather deeply colored. This coloration can be caused by the properties inherent in unsaturated fatty acid soaps and is therefore inherent in the raw materials. Alternatively, this coloration may be due to reactions during the manufacturing process.

Formulations that undergo discoloration due to the manufacturing process, especially thermosensitive formulations, are those that contain alkanolamines and / or alkanolamine salts. It is during heating that alkanolamines and their salts oxidize to give small amounts of strongly colored compounds. The soap bar obtained thus has a characteristic brown color. Many consumers consider brown to be aesthetically unattractive for cosmetic soaps.

The reducing agent is expected to react with the chromophore of the chromophore to prevent discoloration. In fact, the patent literature records numerous transparent soap formulations with reducing agents.

U.S. Pat. Nos. 3,926,828 and 3,793,214 (O'Neill
For other), 0. Sodium hydrosulfite is added to transparent soap.
It is disclosed to be used in a concentration range of 01 to 0.05% by weight. US Pat. No. 4,207,198 (Kenkare) shows that sodium bisulfite can be added as a chemical stabilizer to clear or opaque squeezable elastic detergent bars at a concentration of 0.5% by weight. These detergent bars are substantially anhydrous and consist essentially of gelatin and synthetic detergents. U.S. Pat. No. 4,468,338 (Lindberg) reports that sulfite, bisulfite, and alkali metal metabisulfite can be used as discoloration-preventing additives for transparent soaps in a concentration range of 0.2-1.0% by weight. These sulfur additives are only effective when citric acid and / or related compounds are also present. Japanese Patent No. 59-6300 (Shiseido) reports that transparent soap mixed with 0.05 to 1.0% by weight of sodium sulfide has a medicinal effect on acne. A pleasant light yellow or brown color is said to be characteristic of this soap. Finally, German (West German) Patent Nos. 1,938,177 and 1,938,178 (He
nkel) includes hydrazine, hydroxylamine or 2 to
Alkyl metal salts of tetravalent sulphoxo acids, such as sodium sulfite, are preferably used as reducing agents.
Lightly colored fatty acid soaps are disclosed which are contained in amounts of 0.01 to 5% by weight.

One of the problems with known reducing agents is that these compounds have a finite solubility in soap systems. Above this solubility, the reducing agent will precipitate as solid crystals, which will adversely affect transparency.
In addition, electrolytes are known to reduce the solubility of soap in water. Thus, if the reducing agent is also an electrolyte, the tendency of the soap itself to precipitate as solid crystals increases, which also adversely affects transparency. Therefore, it is desirable to find reducing systems that work at lower concentrations than known in the art. If the amount of reducing agent is reduced, then the transparency is improved.

Therefore, one of the objects of the present invention is to provide a color reduction system for make-up soap bars that is effective at lower electrolyte levels than previously known.

Another object of the present invention is to substantially reduce the coloration of the currently known transparent soap bars and improve their transparency.

Furthermore, it is an object of the present invention to provide a method for inhibiting discoloration of soap bars in general and to provide an improved reducing system.

SUMMARY OF THE INVENTION (i) 1 to 99 wt% C _{12 to} C ₂₂ fatty acid salt; (ii) 0.03 to less than 0.2 wt% sulfur containing +4 in the oxidation state and a negative oxidation potential with respect to hydrogen. And (iii) 0.0001 to less than 0.2% by weight of a second reducing agent containing hydrogen in the oxidation state of −1 and exhibiting a negative oxidation potential with respect to hydrogen. Toilet bar is provided.

DETAILED DESCRIPTION OF THE INVENTION Many transparent cosmetic soaps are made using ingredients that cause discoloration of the soap stock during manufacture. Although reducing agents can prevent this discoloration, their inclusion in transparent soap formulations can be expected to reduce transparency. The present invention includes the use of a combination of reducing agents within a particular concentration range to prevent this discoloration without adversely affecting transparency.

Examples of the first group of reducing agents include compounds containing sulfur having an oxidation state of +4 and exhibiting a negative oxidation potential with respect to hydrogen. Examples of this group include bisulfite, hydrosulfite, metabisulfite, sulfite salts and mixtures thereof. Suitable salt counterions include alkali metal, alkaline earth metal, ammonium, alkyl or hydroxyalkyl ammonium cations and mixtures thereof.
0.03 to 0.2 of at least one compound of Group 1 in soap
Must be present in a concentration range of less than wt%. Preferably, the concentration should be in the range 0.03 to 0.1% by weight, with the optimum range being 0.03 to 0.06% by weight.

Examples of the second group of reducing agents include compounds containing hydrogen having an oxidation state of -1 and exhibiting a negative oxidation potential with respect to hydrogen. Examples of this group include sodium hydroxide, calcium hydride, sodium aluminum hydride, lithium hydride, sodium borohydride, sodium amide, diborane, alkyl and alkoxy aluminum hydrides, alkyl and alkoxy borohydrides, hydrogenated There are sodium alkyl and alkoxy aluminums, diimides and mixtures thereof. Particularly preferred among these compounds is borohydride, especially sodium borohydride. The sodium alkoxyaluminum hydride that can be used here is Vitr commercially available from Hexcel Corporation.
There is one known as ide (registered trademark). The concentration of this second group of compounds is about 0.0001 of the total soap composition.
Should be less than ~ 0.2% by weight. Preferably from 0.001
The amount should be in the range of 0.1% by weight, but the optimum range is 0.0
It is from 01 to 0.002% by weight.

The relative weight concentration of the reducing agent of the first group to the second group is about 1000: 1 to
It should be in the range of 1: 100, but preferably 60: 1 to
It is 1: 5, most preferably 40: 1 to 1: 1.

When the concentration of the reducing agent used is lower than the above range, discoloration of the bar occurs during production, while when it is high, crystallization occurs in the transparent soap bar, resulting in loss of transparency.

The term "transparent" as used herein is intended to mean the ordinary dictionary definition. Thus, transparent soap, like glass, can easily see objects behind it. In contrast, translucent soap allows light to pass through, but a small amount of crystals or insoluble material scatters the light, making it impossible to see objects behind it.

In the present invention, a cosmetic soap bar is transparent if the maximum transmittance of light having a wavelength range of 200 to 800 nm in a sample having a thickness of 10 cm is at least 4%. Similarly, a bar is cloudy if the maximum transmittance of such a sample for such a sample is 1-4%. For clear bars, haze is considered undesirable. If the maximum transmittance of such a sample for such light is 0.01-1%,
The bar is translucent. Finally, a bar is opaque if the maximum transmission of such light is less than 0.01%. This transmission is measured using a UV-VIS spectrophotometer (eg, Hewlett-packar) for a solid soap sample of the required thickness.
d 8451A Diode Array Spectrophotometer) for easy measurement. The advantages of this transparency assessment method over previously published methods are:
That is, it is extremely sensitive to optical clarity and is independent of color.

The term "soap" is used herein in its ordinary sense, that is, an alkali metal, ammonium, or substituted ammonium salt of an aliphatic alkane- or alkene monocarboxylic acid. Substituted ammonium term, in the following, are intended to include C ₁ -C ₄ alkyl and hydroxyalkyl substituted nitrogen cations. Sodium, potassium, mono-, di- and triethanolammonium cations or combinations thereof are suitable for the purposes of the present invention. However, when the composition of the invention is to be transparent, organoammonium soaps, especially triethanolammonium type, are employed.

The soaps useful in the present invention are the well known salts of natural or synthetic resin (alkane or alkene) acids having about 12 to 22 carbon atoms, preferably about 12 to 18 carbon atoms. Coconut oil
soaps with a fatty acid distribution of t oil) can provide the lower end of a broad molecular weight range, and soaps with a fatty acid distribution of peanut oil or rapeseed oil or hydrogenated derivatives thereof can provide the upper end of such a range. it can.

The use of soaps having a fatty acid distribution of coconut oil or tallow or mixtures thereof is preferred as they are readily available fats. The proportion of fatty acids having at least 12 carbon atoms in coconut oil is about 85%. This proportion is increased when a mixture of coconut oil and tallow, palm oil, or a fat such as a non-tropical nut oil or fat is used. This is because in these, the main chain length is C ₁₆ or more.

The coconut oil used in the soap may be replaced in whole or in part with other "high uranic acid" oils, i.e. fats in which at least 50% of the total fatty acids consist of uraric acid or myristic acid and mixtures thereof. These oils are generally exemplified by the tropical nut oils of the coconut oil class.
For example, these include palm kernel oil, babassu palm oil,
ouricuri oil, tucum oil, cohn palm nut oil, murmur oil, jaboty kernel oil, khakan kernel oil, dika nut oil, and ucuhub
a butter is included.

A preferred soap is about 15-20% coconut oil and about 80-85%.
It is a mixture with tallow. These mixtures have approximately
It contains about 95% of 12 to about 18 fatty acids. Can also be prepared from soap Hayashi oil, in this case, the fatty acid content of C ₁₂ -C ₁₈ chain length of about 85%.

The soap may contain unsaturated fatty acids (salts) according to commercially acceptable standards. Excessive unsaturated fatty acids (salts) are usually avoided.

FW Wells describes the manufacturing method of transparent soap as “Soap and Chem.
ical Specialties ”, Vol.XXXI.No.6 and 7 (6, 1955)
Month and July), which is incorporated herein by reference. Another typical method for producing transparent and opaque soaps is U.S. Pat.
3,155,624 and 2,820,768, all of which are incorporated herein by reference.

Another desirable class of ingredients are polyhydric alcohols. Glycerin, sorbitol, maltitol,
There are propylene and ethylene glycol and higher alkoxylated derivatives. Polyhydric alcohols such as propylene glycol can act as diluents to dilute the concentrated mixture of caustic soda and fatty oils. Polyhydric alcohols such as glycerin act as humectants and skin moisturizers. The amount of these materials ranges from about 1 to about 30% by weight of the total composition, preferably from about 2 to about 10%.

Example 1 As an example of the transparent composition of the present invention, the following Table I can be mentioned.

TABLE I Ingredient wt% Triethanolamine 45.0 Opaque Toilet soap 20.4 Lili - amount Lili to stearate 11.6 glycerol 8.3 reducing agent 0-3.0 Water 100 - stearic acid were dissolved reducing agent and a small amount of water to triethanolamine . This mixture is then heated to about 80 ° C
Heated for 10 minutes. Glycerin, remaining water and opaque toilet soap were added. After combining the ingredients, the mixture was stirred at 80 ° C. until all ingredients were dissolved. The mixture was then poured into molds and cooled.

The "opaque toilet soap" used in the examples of the present specification means
A mixture of sodium salt of tallow-oil fatty acid and sodium salt of coconut oil fatty acid, the ratio of both is 82:18 and the water content is 12%.

Example 2 This example compares the performance of various reducing agents and combinations thereof with regard to color formation. Table II below shows the effect of different types of reducing agents in the composition of Example 1 at varying amounts.

From the results in Table II above, 0 for sodium borohydride alone.
It can be seen that 3 to 0.02% cannot substantially reduce the color. 0.1% and 0.3% sodium borohydride also clouded the soap bar. 3% sodium metabisulfite is effective in reducing color but makes the bar translucent. 2.0, 1.3, 0.6, 0.3 and 0.2%
At a concentration, sodium metabisulfite blocks the coloration and eliminates the problem of translucency. However, their clarity is still unacceptable in cloudy conditions. Transparency returns at 0.13% sodium metabisulfite concentration, but in this case it is insufficient in terms of color inhibition. That is, the bar has an orange color.

Table II shows that sodium borohydride and sodium metabisulfite each are not effective at substantially reducing coloration at low levels of content, while high levels of content adversely affect clarity. Shows. In contrast to these, the combination of metabisulfite and borohydride gives unexpectedly transparent uncolored bars. That is, as shown in Table II, by combining 0.04% or 0.06% sodium metabisulfite and 0.001% sodium borohydride, a colorless and sufficiently transparent toilet soap bar was obtained. Similar results have been achieved with the combination of 0.03% sodium metabisulfite and 0.0005% sodium borohydride. In the control experiment (Sample No. 1), sodium metabisulfite and sodium borohydride were omitted. The soap bar formed from this control composition was brown in color but transparent.

The above description and examples of the present invention describe the embodiments of the present invention, and these can be further modified. All of these variations are also within the spirit and scope of the invention.

Claims (28)

[Claims] 1. A first compound containing (i) 1 to 99% by weight of a fatty acid salt of C _{12 to} C ₂₂ carbon atoms, (ii) sulfur in the oxidation state of +4 and exhibiting a negative oxidation potential with respect to hydrogen. 0.03 to 0.2% by weight of a reducing agent of (iii) -1 and a second reducing agent of 0.0001 to 0.
A makeup soap bar containing 2% by weight. 2. The makeup soap bar according to claim 1, wherein the first reducing agent is selected from the group consisting of bisulfite, hydrosulfite, metabisulfite, salts of sulfite and mixtures thereof. 3. The makeup soap bar according to claim 1, wherein the amount of the first reducing agent is 0.03 to 0.1% by weight. 4. The cosmetic soap bar according to claim 1, wherein the amount of the first reducing agent is 0.03 to 0.06% by weight. 5. The second reducing agent is sodium hydride, calcium hydride, lithium hydride, sodium aluminum hydride, sodium borohydride, sodium amide, diborane, alkyl hydride and alkoxy aluminum, alkyl hydride and Alkoxy boron, alkyl hydride and alkoxy aluminum sodium,
The soap bar of claim 1 selected from the group consisting of diimides and mixtures thereof. 6. The makeup soap bar according to claim 1, wherein the amount of the second reducing agent is 0.001 to 0.1% by weight. 7. The amount of the second reducing agent is 0.001 to 0.00.
The cosmetic soap bar according to claim 1, which is 2% by weight. 8. The cosmetic soap bar according to claim 1, wherein the first reducing agent is sodium metabisulfite. 9. The cosmetic soap bar according to claim 1, wherein the second reducing agent is sodium borohydride. 10. A cosmetic soap bar according to claim 1, which comprises a combination of metabisulfite and a borohydride salt. 11. A first reducing agent 0.0 which contains sulfur in the oxidation state (i) +4 and exhibits a negative oxidation potential with respect to hydrogen.
A second reducing agent 0.0001 to 0.2 containing 3 to 0.2% by weight and hydrogen in the oxidation state of (ii) -1 and exhibiting a negative oxidation potential with respect to hydrogen.
% Of a C ₆ -C ₂₂ alkyl fatty acid salt in combination with a reducing system consisting of 10% by weight and a reducing system consisting of 1% to 99.9%. 12. The method of claim 11 wherein the first reducing agent is selected from the group consisting of bisulfite, hydrosulfite, metabisulfite, inorganic alkali metal salts of sulfite, and mixtures thereof. 13. The method of claim 11, wherein the amount of the first reducing agent is 0.03 to 0.1% by weight. 14. The amount of the first reducing agent is 0.03 to 0.06.
12. The method of claim 11 which is weight percent. 15. The second reducing agent is sodium hydride, calcium hydride, lithium hydride, sodium aluminum hydride, sodium borohydride, sodium amide, diborane, alkyl hydride and alkoxy aluminum, alkyl hydride and Alkoxy boron, alkyl hydride and alkoxy aluminum sodium,
The method of claim 11 selected from the group consisting of diimides and mixtures thereof. 16. The amount of the second reducing agent is 0.001 to 0.1.
12. The method of claim 11 which is weight percent. 17. The amount of the second reducing agent is 0.001-0.0.
The method of claim 11, which is 02% by weight. 18. The method of claim 11, wherein the first reducing agent is sodium metabisulfite. 19. The method of claim 11, wherein the second reducing agent is sodium borohydride. 20. The method of claim 11, wherein the metabisulfite and the borohydride salt are combined. 21. A first reducing agent containing (i) +4 sulfur in the oxidation state and having a negative oxidation potential with respect to hydrogen; and (ii) -1 containing hydrogen in the oxidation state and hydrogen. A second reducing agent exhibiting a negative oxidation potential with respect to, and the ratio of the first reducing agent to the second reducing agent is 1000: 1 to 1: 100.
A reducing agent composition. 22. The ratio of the first reducing agent to the second reducing agent is 6
22. The reducing agent composition according to claim 21, which is 0: 1 to 1: 5. 23. The ratio of the first reducing agent to the second reducing agent is 4
22. The reducing agent composition of claim 21, which is 0: 1 to 1: 1. 24. The reducing agent composition according to claim 21, wherein the first reducing agent is selected from the group consisting of bisulfite, hydrosulfite, metabisulfite, salts of sulfite, and mixtures thereof. 25. The second reducing agent is sodium hydride, calcium hydride, lithium hydride, sodium aluminum hydride, sodium borohydride, sodium amide, diborane, alkyl hydride and alkoxy aluminum, alkyl hydride and Alkoxy boron, alkyl hydride and alkoxy aluminum sodium,
22. The reducing agent composition of claim 21, selected from the group consisting of diimides and mixtures thereof. 26. The reducing agent composition of claim 21, wherein the first reducing agent is sodium metabisulfite. 27. The reducing agent composition of claim 21, wherein the second reducing agent is sodium borohydride. 28. The reducing agent composition according to claim 21, which comprises a combination of metabisulfite and a borohydride salt.