CZ356597A3 - Aqueous cleansing preparation - Google Patents

Abstract

An aqueous liquid cleansing composition comprising (a) at least one short chain C6-C10 fatty acid soap in combination with (b) at least one long chain C14-C22 fatty acid soap where the weight ration of (a) to (b) is within the range 1:20 to 5:1, and in which any C12 fatty acid soap is only present in low levels, is mild and provides good lather in use.

Description

The present invention relates to aqueous liquid cleaning compositions containing soaps of specific fatty acids. In particular, it relates to skin and hair cleansing compositions comprising a combination of fatty acid soaps with certain long and short chains.

BACKGROUND OF THE INVENTION

Aqueous cleaning agents have traditionally been classified according to the amount of foam they produce during use; those that provided the largest volume of foam were considered the best products. However, it was later demanded to provide products which were not only good foaming but also gentle to the treated skin and hair.

The main difficulty in securing such products is that these two characteristics are incompatible with each other. While highly foaming surfactants (surfactants) are generally very unprofessional, fine surfactants tend to provide insufficient foam.

Recently, attempts have been made to overcome these difficulties in soap bar soaps, for example by using the system described in GB 1295275, comprising making a product containing tallow soap in combination with salts of a primary or secondary C ₆ -C ₁₀ alkyl sulfate and a C ₁₀ -C soap ₂₄ fatty acids.

It has now been found that liquid cleaning compositions that are delicate and exhibit good foaming can be formed by using short chain fatty acid soap in combination with long chain fatty acid soap. Surprisingly, a short-chain fatty acid soap which, used alone, does not exhibit any effective lather, can improve foaming with a long-chain fatty acid soap.

SUMMARY OF THE INVENTION

The present invention provides a liquid aqueous cleaning composition comprising (a) at least one short chain fatty acid soap selected from C ₆ to C ₁₀ fatty acid soaps;

(b) at least one long chain fatty acid soap selected from C ₁₄ to CL soaps; and (c) water;

wherein the composition comprises no more than 3 weight percent _C12 fatty acid soap relative to the aqueous detergent composition, no more than 15 weight percent _C12 fatty acid soap relative to total fatty acid soap, and the weight ratio (a) to (b) lies ranging from 1:20 to 5: 1.

Preferably, the weight ratio of (a) to (b) ranges from 1:20 to 1: 1.

The short-chain fatty acid soap is preferably

a sodium or potassium salt, or a substituted ammonium ion (e.g., triethanolamine) of a fatty acid, for example from animal or plant sources, obtained through the fatty acid distillation. The short chain fatty acid soap is preferably a C ₆ -C ₈ fatty acid soap, and most preferably a C ₈ fatty acid soap.

The long chain fatty acid soaps are preferably sodium or potassium salts or substituted ammonium ion (e.g., triethanolamine) fatty acids, for example from animal or plant sources, obtained through the fatty acid distillation. Fatty acid soap · the short chain soap is preferably a C ₁₄ or C _{1S: 1 (C-1S} mono unsaturated) fatty acids.

The total amount of fatty acid soap present in the composition should preferably be in the range of 1 to 40 weight percent, and more preferably 5 to 30 weight percent.

In a more preferred embodiment of the invention therein is fatty acid soap short chain C _{and a} compound of a fatty acid soap and a long chain compound C _u and C _8; -. This chain mixture system is not only finer than the C ₁₂ fatty acid soap composition, but also has a comparable foaming ability. The mixed soap system, it is possible to add small amounts of fatty acid soap C _{£ 1,} and not more than 3 percent by weight, preferably not more than 2 weight percent relative to the total composition and up to 15 weight percent of the total amount of fatty acid soap. Using these amounts, the presence of a C ₁₂ fatty acid soap may further enhance the foamability without adversely affecting the fineness of the composition.

The compositions of the invention will preferably also contain a surfactant (wetting agent). This can be selected from all known surfactants suitable for topical application to the human body and is selected from anionic, nonionic, zwitterionic and cationic surfactants and mixtures thereof. Particularly preferred are fine surfactants, i.e. those which do not damage the stratum corneum, the outer layer of the skin.

Preferred anionic surfactants include long chain aliphatic acyl isethionates, alkyl ether sulfates, alkyl glyceryl ether sulfate, sulfosuccinates, taurates, sarcosinates, sulfoacetates, alkyl phosphate, alkyl phosphate esters, acyllactylate, alkylglutamates, and mixtures thereof.

Strong, unsafe surfactants such as primary alkanesulfonate or alkylbenzenesulfonate will generally not be used.

Suitable nonionic surfactants include alkyl polysaccharides, lactobionamides, ethylene glycol esters, glycerol monoethers, polyhydroxyamides (glucamide), primary and secondary alcohol ethoxylates, especially aliphatic alcohols, ethoxylated on average 1 to 20 moles of ethylene oxide per mole of alcohol.

Preferred zwitterionic detergents are those having an alkyl or alkenyl group of 7 to 18 carbon atoms and corresponding to the overall structural

formula:

R ²

II I

R ¹ - [- C-NH (CH, V) _n -N ⁺ -XY

Wherein R ¹ is alkyl or alkenyl of 7 to 18 carbon atoms, R and R ³ are each independently hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms, m is 2 to 4, n is 0 or 1,

X is alkylene of 1 to 3 carbon atoms, optionally substituted with hydroxyl, and

Y is -CO ₂ 'or -SO 2.

The bi-surfactants corresponding to the above formula include simple betaines of the formula:

R ²

AND

R ¹ - N * - ch ₂ co;

AND

R ³ and amido betaines of formula:

R ²

AND

R ¹ - CONH (CH) m -N ⁺ -CH2COJ

R ³ wherein m is 2 or 3.

In both formulas R ^1, R ² and R ^J are as defined previously. In particular, R ¹ may be a mixture of C ₂ -C ₁₄ alkyl groups derived from coconut so that at least half and preferably at least three quarters of the R ^x groups have 10 to 14 carbon atoms. R ² and R ^J are preferably methyl groups.

Another option is sulfobetaine of the formula:

R ²

R ² -N _{'(CH) 3} with /

R ^; or

R ²

R ¹ - CONH (CH _{2) m} -N + - _(CH) SO-. '

R ³ where m is 2 or 3, or variants of these formulas in which - (CH ₂ ) ₃ SO 6 is replaced by

OH

AND

-CH ₂ CHCH ₂ SO ₃ 'wherein R ¹ , R ² and R ³ in this formula are as previously defined.

The compositions of the invention may contain a structuring agent, i.e., a substance added to increase low shear viscosity, such as shear less than 1 sec. Suitable materials include swellable clays such as laponite; fatty acids and derivatives thereof, and in particular polyglycol ethers of monoglycerides of fatty acids crosslinked polyacrylates such as Carbopol ^m . (registered trademark) (polymers available from Goodrich); acrylates and copolymers of acrylates, polyvinylpyrrolidone and copolymers thereof; polyethylenimines; salts such as sodium chloride and ammonium sulfate; sucrose esters; gellants and mixtures thereof.

Of the clays, synthetic hectorite (laponite) clay used in conjunction with an electrolyte salt capable of thickening the clay is particularly preferred. Suitable electrolytes include alkali and alkaline earth salts, such as halides, ammonium salts and sulfates.

The compositions of the invention may also contain a thickening agent, i.e., a substance that maintains the viscosity of the composition such that its shear value increases during use. Suitable materials include cross-linked polyacrylates such as Carbopol ¹¹¹ (registered trademark) (polymers available from Goodrich); fatty acids and derivatives thereof, and in particular polyglycol ethers of fatty acid monoglycerides; natural gums including alginates, guar, xanthan and polysaccharide derivatives including hydroxyethylcellulose, carboxymethylcellulose and hydroxypropylguar; propylene glycols and propylene glycol oleate; salts such as sodium chloride and ammonium sulfate; tallow glycerol derivatives and mixtures of the above.

Further examples of structuring and thickening agents are given in International Cosmetic Ingredient Dictionary, 5th Edition, 1993, issued by CTFA (The Cosmetic, Toiletry and Fragrance Association), which is incorporated herein by reference. .

Examples of other additives which may be added to the compositions of the invention include an opacifying _f i.e. opacifiers; preservatives such as parahydroxybenzoate esters; antimicrobial agents such as antioxidants such as butylhydroxytoluene; bactericidal agents; moisture stabilizers such as glycerol and sorbitol; waxes; plant extracts such as aloe vera with hazelnut or elderberry extract; dyes and perfumes. The compositions of the invention may be formulated for washing the skin, e.g., as bath or shower gels; hand washing preparations; facial cleansing preparations; pre- and post-shave products and skin cleansing and facial cleansing products.

The compositions of the invention will generally be liquid or semi-liquid, for example pastes, and preferably will have a viscosity range of n from 100 to 100,000 mPa · s, measured at a shear value of 10 sec ^-1 and at 25 ° C in a Haak RV20 rotoviscometer.

The invention is further illustrated by the following non-limiting Examples.

DETAILED DESCRIPTION OF THE INVENTION

In the Examples;

All fatty acids were from Aldrich, having a purity greater than 99.5%.

2. Betaine was coconut amidopropyl betaine BDF-H as a 30% dispersion from Nippon Oils and Fats.

Examples 1-3

In these examples, the effect of chain length on foam-forming capacity was tested. The following preparations were prepared by mixing fatty acids. Potassium hydroxide was then slowly added in an amount that fully neutralized the acid. Stirring was continued until the resulting mixture was homogeneous.

Table A

example  weight / g KOH C ₆ ' c ₁₄ water 1 5, 61 4.81 7, 61 to 500 ml at 25 ° C 2 . 5, 61 7.21 11.42 ll 3 5, 61 9, 61 15.23 Π

Table B

comparative example weight / g KOH oily acid water AND 5, 61 14.72 up to 500 ml at 25´C (B) 5, 61 17.22 II C 5, 61 20, 04 II D 5, 61 22.84 ir

The foaming properties of the various compositions were evaluated by a group of twenty people. Each assessor wore surgical gloves that had been previously washed with soap to remove any talc.

2.5 ml of the test composition was measured directly on φφφφ «φ * φ •

φ φφ φ φ

φφφ dry gloves and each assessor rubbed his hands together to form foam. The foam volume was measured by dipping the hands of the scoring under

calibrated collecting funnel. The results shown in Table C were obtained, wherein Comparative Examples A, B, C and D were carried out with soaps o uniform chain length of the fatty acid.

Table C

example Avg. string length foam volume (cm ³ ) 1 10 45, 3 2 11 46.2. 3 12 47.6 AND 8 0 (B) 10 0 C 12 39, 8 D 14 30.7

The results show that preparations containing exclusively C fatty acid soap _; (Example C), were the most potent foaming system of the comparative formulations. The Example D system (C ₁₄ soap) foamed less than the C ₁₂ system and the C ₃ and C _{10 systems} (Examples A and B) produced no foam. System C mixture of _G / C ₁₄ creating the volume of foam above the foam volume of the system itself with C _12th The results show that fatty acid soap _C8 boosts the lather performance of the soap C _l4 fatty acids.

Example 4

In this example. the tests were performed with fully formulated products.

φ * φ

φ φ

• ΦΦΦ *

»»

·· • * φ φ · ♦ ·

The following preparations were prepared by mixing fatty acids. Potassium hydroxide was then slowly added in an amount ensuring 97% neutralization of the acids. Stirring was continued until the resulting mixture was homogeneous. Betaine was then added to the soap solution with stirring. To formulations containing sodium chloride, it was added as a 25% solution in distilled water or as crystals. In both cases, it was stirred into the hot solution until complete dissolution and mixing. Subsequently, water was added to create the correct concentration of the mixture.

Table D

Example 4 Example E Example F caprylic acid 1.70 - - lauric acid - - 6, 80 myristic acid 8.50 10.20 3.40 oleic acid 6.80 6.80 6, 80 betaine 5, 00 5.00 5.00 KOH 3.99 3.75 3.98 NaCl 1.50 - 1.00 water up to 100 percent

E and F are comparative examples.

The foaming capability of these formulations was determined using the same method as described in Examples 1-3, except that 0.5 g of the test article was measured on wet gloves.

The following results were obtained:

- 12 Table E

example foam volume (cm ³ ) 4 66.6 E 49, 3 F 56.1

Results show benefit on enhancing lathering soap provides inclusion _Cg fatty acids in the formulation.

Examples 5-6

In these examples, the two compositions of the invention and the comparative composition (Example F above), not containing the Cs component (full composition is shown below), were used to wash the skin. The viscosities of Formulations 5 and 6 were adjusted using sodium chloride to be similar to those of Comparative Example F.

Table F

Example 5 Example 6 Example F caprylic acid 1.70 1.53 - lauric acid - 1.00 6, 80 myristic acid 8.50 7, 66 3, 40 oleic acid 6, 80 6, 80 6, 80 betaine 5, 00 5, 00 5, 00 KOH 3.99 4.00 3.98 NaCl 1.70 1.70 1, 00 water up to 100 percent

J • ···

Skin softness properties of the test products were tested using a block arrangement in a standardized flexible wash test. The flexible wash test procedure consists of a one minute wash of the forearm well (flexible, flexible elbow region) three times a day. This method is an over-use method ”designed to distinguish very fine products. The redness response differs only slightly in temperature and humidity variations, making the experimental protocol suitable for testing throughout the year.

Approximately 25 evaluators participated in the evaluation. The elbows of the scoring should not show any skin manifestations (eczema, drying, irritation, scratches, abrasions). Any evaluator taking antihistamines, anti-inflammatory drugs (more than 8 weeks), or cortisone administered topically, orally or by injection, was excluded from the study. Three test products were determined for the wash areas (left or right arm) using a block arrangement.

Following the determination, the assessors were instructed to moisten the left bent portion of the elbow with the aid of a fungus. 0.5 g of product was then applied to the sponge and the dispensed sponge was scooped in the right hand. Then they washed the left bent part of the elbow exactly one minute. Then the bent part was rinsed and tapped dry. The washing procedure was repeated on the right hand with the appropriate detergent. Thus both arms were tested concurrently. Washing with this procedure was repeated three times a day for five consecutive days to a total of 15 washes. Test times were scheduled 1.5 hours apart. Each test site was evaluated immediately before and 4 hours after the third day wash.

One trained assessor evaluated the test sites for a total of 20 determinations. The classification scale was as follows:

no redness

0.5 barely discernible redness faint redness in the form of spots / no swelling

1.5 - mild / medium redness / with or without swelling

- moderate continuous redness / with or without swelling or with blistering

Each test site was affected in the procedure described above until a grade of 2 ”or higher or 15 washes was completed. If Grade 2 or higher was reached, the bending action was discontinued. The final grade was then counted for all remaining determinations. The remaining bend site was washed until a score of at least grade 2 was reached, or until 15 washes were completed, whichever came first. In Examples 5 and 6 and in Comparative Example F, the final score, the cumulative five-day response, is the total sum of the classification scores (scores) for 20 determinations per score, calculated from the average of the scores of all scores. Thus, in theory, the average score may range from 0 to 30; a lower score shows the absolute absence of skin irritation, while a score of 30 corresponds to the greatest roughness.

The following results were obtained:

* »··

- 15 Table G

example cumulative 5-day response 5 8, 51 6 9.04 F 15, 60

The results show that the compositions of the invention are significantly finer than the comparative compositions which do not contain C soap _. fatty acids and more than 3% by weight of C ₁₂ fatty acid soap. The results also show that adding a small amount (1%) of C- ₂ fatty acid soap does not adversely affect the roughness of the product.

Claims (7)

An aqueous cleaning composition comprising (a) at least one short-chain fatty acid soap selected from C ₆ to C ₁₀ soaps; (b) at least one long-chain fatty acid soap selected from C ₁₄ to C ₂₂ fatty acid soaps; and (c) water; wherein the composition comprises no more than 3 weight percent C ₁₂ fatty acid soap relative to the aqueous cleaning composition, no more than 15 weight percent C ₁₂ fatty acid soap relative to the total amount of fatty acid soap, and the weight ratio (a) to (b) lies ranging from 1:20 to 5: 1. The aqueous cleaning composition of claim 1 further comprising a surfactant adjuvant selected from anionic, nonionic, cationic, zwitterionic surfactants and mixtures thereof. The aqueous cleaning composition of claim 2, wherein the surfactant adjuvant comprises a zwitterionic surfactant selected from alkyl betaines, amidopropylbetaines, amidopropylsultaines, and mixtures thereof. ·· »··· The aqueous cleaning composition of any one of claims 1 to 3, wherein the fatty acid soap (a) is selected from C ₆ to C ₈ fatty acids soaps and mixtures thereof. Aqueous cleaning composition according to any one of claims 1 to 3, characterized in that the fatty acid soap (b) is selected from soaps C ₁ and C _{19; 1} fatty acids and mixtures thereof. The aqueous cleaning composition of any one of claims 1 to 5, further comprising a thickening agent. 7. A method of using an aqueous liquid composition as a cleanser for human skin and hair comprising (a) at least one short-chain fatty acid soap selected from C ₆ to C ₁₀ fatty acids soaps; (b) at least one long-chain fatty acid soap selected from C ₁₄ to C ₂₂ fatty acid soaps; and (c) water; wherein the composition comprises no more than 3 weight percent of _C12 fatty acid soap relative to aqueous. % of the soap _C12 fatty acid soap relative to the total fatty acid soap, and the weight ratio (a) to (b) is in the range of 1:20 to 5: 1.