HUP9903449A2 - Aqueous liquid cleansing composition containing fatty acid soaps - Google Patents

Abstract

The composition of the preparation according to the invention is as follows: a) at least one short-chain fatty acid soap, which is selected from 6-10 carbon chain fatty acid soaps, b) at least one long-chain fatty acid soap, which is selected from 14-22 carbon chain fatty acid soaps, c) water and the preparation, based on the weight of the aqueous cleaning agent, at most 3 wt.% 12-carbon fatty acid soap, and it contains a maximum of 5 wt.% 12-carbon fatty acid soap based on the weight of all fatty acid soaps, and the weight ratio of a) and b) stone-based polymers is (1 : 20) - (5 : 1). ŕ

Description

86127-2227C TF/SM

PUBLICATION COPY

Aqueous liquid detergents containing fatty acid soaps

The invention relates to aqueous liquid detergents containing specific fatty acid soaps. The invention is particularly directed to human skin and hair cleansing compositions containing certain long and short chain fatty acid soaps. These gentle compositions also exhibit good foaming properties.

Aqueous cleansers are traditionally classified by the amount of soap suds they produce during use. Products with the highest foam volume are considered to be of the highest quality. However, there is a recent demand for products that, in addition to good foaming/lathering, are also gentle on the hair or skin being treated.

The main problem with the production of such products is that the above two properties are mutually incompatible.

Highly foaming surfactants are generally very harsh on the skin, while gentle surfactants do not foam properly.

In the field of toilet soaps, solutions have been developed to overcome the above problems, for example those described in British Patent Specification No. 0 295 275. This discloses a product comprising a tallow soap, a C 6-10 primary or secondary linear alkyl sulfate salt and a C 10-24 fatty acid soap.

In our work, we found that high-foaming, yet gentle liquid detergents can be produced by combining a short-chain fatty acid soap with a long-chain fatty acid soap. Surprisingly, we found that short-chain fatty acid soaps, which do not foam very well on their own, increase the foaming ability of long-chain fatty acid soaps.

The subject of the invention is, as described above, an aqueous liquid preparation having the following composition:

a) at least one short-chain fatty acid soap, which may be a fatty acid soap having 6 to 10 carbon atoms;

b) at least one long-chain fatty acid soap, which may be a fatty acid soap having 14 to 22 carbon atoms;

c) water; and the composition contains up to 3% by weight of C12 fatty acid soap based on the weight of the aqueous cleaning agent and up to 15% by weight of C12 fatty acid soap based on the weight of the total fatty acid soap, and the weight ratio (a) : (b) is (1:20) - (5:1).

The weight ratio of components (a) and (b) is preferably (1:20) (1:1).

The short-chain fatty acid soap is preferably a sodium or potassium salt of a fatty acid or a substituted ammonium ion, such as a triethanolamine salt, which is prepared by fatty acid distillation from animal or vegetable sources. The short-chain fatty acid soap is preferably a C6-C8 fatty acid soap, more preferably a C8 fatty acid soap.

The long-chain fatty acid soap is preferably a sodium or potassium salt of a fatty acid or a substituted ammonium ion, such as a triethanolamine salt, which is produced by fatty acid distillation from animal or vegetable sources. The long-chain fatty acid soap is preferably a C 14 or C 18 fatty acid soap containing 1 unsaturated bond (designation: C ₁₄ or C _18, respectively).

The total amount of fatty acid soap in the composition is preferably 1-40% by weight, more preferably 5-30% by weight. In the most preferred embodiment of the invention, the short-chain fatty acid soap is a C8 material, and the long-chain fatty acid soap is a C14 or C18 fatty acid soap containing 1 unsaturated bond. A system containing such a chain mixture not only has a milder effect than systems based on C12 fatty acid soaps, but also exhibits comparable foaming ability. The amount of C12 fatty acid soap that can be added to the mixed soap system is up to 3% by weight, preferably up to 2% by weight, based on the total weight of the composition, and up to 15% by weight, based on the total amount of fatty acid soap. The amount of C12 fatty acid soap further improves the foaming ability without reducing the mild effect of the composition.

The compositions of the invention preferably also contain a co-surfactant. The co-surfactant can be any known surfactant suitable for topical treatment of the human body. Such substances include, for example, nonionic, zwitterionic and cationic surfactants. Particularly preferred are those which are gentle, i.e. do not damage the outer layer of the skin, the stratum corneum.

Preferred anionic cosurfactants include fatty acid isothionates, alkyl ether sulfates, alkyl glyceryl ether sulfate, sulfosuccinates, taurates, sarcosinates, sulfoacetates, alkyl phosphate, alkyl phosphate esters, acetylates, alkyl glutamates, and mixtures thereof.

The use of strong surfactants, such as primary alkane sulfonate or alkylbenzene sulfonate, should generally be avoided.

Suitable nonionic surfactants include, for example, alkyl polysaccharides, lactobionamides, ethylene glycol esters, glycerol monoethers, poly(hydroxyamines) (glucamide), primary and secondary alcohol ethoxylates, primarily aliphatic alcohols having 8 to 20 carbon atoms ethoxylated with an average of 1 to 20 moles of ethylene oxide per mole of alcohol.

Preferred zwitterionic detergents are compounds of formula (I) containing an alkyl or alkenyl group of 7 to 18 carbon atoms, in which

R ¹ is an alkyl or alkenyl group having 7-18 carbon atoms;

R ² and R ³ are independently C 1-3 alkyl, hydroxyalkyl or carboxyalkyl;

m is 2-4;

n is 0 or 1;

X is an alkylene group having 1-3 carbon atoms, optionally substituted with hydroxyl; and

Y represents a -CO2 or -SO3' group.

The zwitterionic detergents of the above general formula include simple betaines of the general formulae (II) and (III) in which m is 2 or 3. In these formulae, R ¹ , R ² and R ³ have the same meanings as defined above.

R ¹ may in particular be a mixture of coco alkyl groups having 12 and 14 carbon atoms, such that at least half, preferably three quarters, of the R ¹ group has 10 to 14 carbon atoms. R ² and R ³ are preferably methyl.

This also includes sulfobetaines of general formula (IV) or (V) in which m is 2 or 3 or variants thereof in which the (ChhhSOs'-group is replaced by the group of formula (a). In the formulae, R ¹ , R ² and R ³ have the same meanings as defined above.

The compositions of the invention may also contain a structuring agent, i.e. an agent suitable for increasing viscosity at low shear rates, for example less than 1 s' ¹ . Examples of such materials include: swelling clays, such as laponite; fatty acids and their derivatives, and in particular fatty acid monoglyceride poly(glycol ethers) crosslinked with polyacrylates, such as Carbopol, a product manufactured by Goodrich; acrylates and their copolymers; poly(vinylpyrrolidone) and its copolymers; poly(ethyleneimine)s; salts, such as sodium chloride and ammonium sulfate; sucrose esters; gelling agents; and mixtures thereof.

Of the clays, synthetic hectorite (laponite) clay is particularly preferred, which is used in combination with an electrolyte salt suitable for thickening the clay. Suitable electrolytes are alkali metal and earth metal salts, such as halides, ammonium salts and sulfates. The compositions of the invention may also contain thickening agents. These are materials which maintain the viscosity of the composition even when the shear rate increases during use. Suitable materials are crosslinked polyacrylates, such as the polymers manufactured by Goodrich under the trade name Carbopol, fatty acids and their derivatives, especially fatty acid monoglyceride polyglycol ethers; natural gums, including alginates, guar and xanthan gums; polysaccharide derivatives, including hydroxyl ethyl cellulose, carboxymethyl cellulose and hydroxypropyl guar; propylene glycols and propylene glycol oleates; salts such as sodium chloride and ammonium sulfate; glycerol tallow esters; and mixtures thereof.

Further examples of structuring agents and thickening agents can be found in the following literature: International Cosmetic Ingredient Dictionary, Fifth Edition, 1993, published by CTFA (The Cosmetic, Toiletry & Fragrance Association).

The compositions of the invention may also include opacifying agents, preservatives, such as para-hydroxybenzoate esters; antimicrobial agents, such as antioxidants, such as butylhydroxytoluene; bactericides; humectants, such as glycerin and sorbitol; waxes; plant extracts, such as Aloe Vera, witch hazel and elderberry vinegar; colorants and perfumes.

The compositions of the invention may be skin cleansers, such as bath or shower gels; hand washes; face washes; pre- and after-shaves; and skin care products such as skin rinses and wipes.

The compositions of the invention are generally pourable liquids or semi-liquids, such as pastes, having a viscosity of 100-100,000 mPa-s at 10 s' at ¹ °C, measured with a Haake Rotoviscometer RV20.

The following examples are presented to further illustrate the compositions of the invention.

In the examples:

1. all fatty acids used are Aldrich products with a purity of more than 99.5%;

2. the betaine used is 30% cocosamidopropyl betaine BDF-H dispersion manufactured by Nippon Oils and Fats.

1-3, examples

In these experiments, the effect of chain length on foaming ability is investigated. The following formulations are prepared by combining fatty acids, and then potassium hydroxide is slowly added to the formulations in sufficient quantity to completely neutralize the acids. Mixing is continued until the resulting mixture becomes homogeneous.

The table

Example Weight (g) KOH Cg C14 Water 1 5.61 4.81 7.61 500 ml, 25 °C 2 5.61 7.21 11.42 500 ml, 25 °C 3 5.61 9.61 15.23 500 ml, 25 °C

Table B

Comparative example Weight (g) KOH Fatty acid Water The 5.61 14.42 500 ml at 25 °C B 5.61 17.22 500 ml at 25 °C C 5.61 20.04 500 ml at 25 °C D 5.61 22.84 500 ml at 25 °C

The foaming properties of the different formulations were evaluated by a group of 20 participants. Each participant wore medical gloves that had been washed to remove talc.

2.5 ml of the test formulations were applied directly to dry gloves and participants rubbed their hands together to create a foam. The volume of the foam was measured. The measurement was performed by immersing the participants' hands in a calibrated collecting funnel.

The results obtained are summarized in Table C. The compositions of Comparative Examples A, B, C and D were prepared with soap of the same chain length.

Table C

Example Average chain length Foam volume 1 10 45.3 2 11 46.2 3 12 47.6 The 8 0 B 10 0 C 12 39.8 D _______14____________ 30.7

The results show that the best foaming of the comparative compositions is that containing only C12 soap (Example C). The C14 soap composition of Example D foams much less than the C12 system, and the C8 and C10 systems (Examples A and B) do not foam.

The foam produced by the systems containing a mixture of C8 and C14 is better than that produced by the systems containing C12 soap alone. The results show that C8 soap improves the foaming ability of C14 soap.

Example 4

In this experiment, we examined whole preparations.

The following preparations are prepared by combining the fatty acids and slowly adding enough potassium hydroxide to neutralize 97% of the acids. Stirring is continued until a homogeneous mixture is obtained. The soap solution is then added to the solution while stirring. In the case of preparations containing sodium chloride, this addition is made either as a 25% distilled aqueous solution or as a crystalline substance. In both cases, the substances are stirred into the hot solution until they are completely dissolved, and stirring is continued. The desired concentration is then adjusted by adding water.

Table D

Example 4 This example Example F Caprylic acid 1.7 - - Lauric acid - - 6.80 Myristic acid 8.50 10.20 3.40 Oleic acid 6.80 6.80 6.80 In beta 5.00 5.00 5.00 KOH 3.99 3.75 3.98 NaCl 1.50 - 1.00 Water 100%

Examples E and F are comparative compositions.

The foaming ability of the above compositions was determined by the method described in Examples 1-3, except that 0.5 g of sample was added to the wet gloves.

The results obtained are summarized in the following table.

This table

Example Foam volume 4 66.6 This 49.3 F .56.1

The results show that when a C8 soap is associated with the composition, foaming is advantageously improved.

5-6, example

In this experiment, two compositions of the invention and one comparative composition (Example F above) not containing C8 soap were used for skin washing (the compositions are described below). The viscosity of the compositions of Examples 5 and 6 was adjusted with sodium chloride to a viscosity similar to that of the composition of 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 In beta 5.00 5.00 _____5.00

KOH 3.99 4.00 3.98 NaCl 1.70 1.00 1.00 Water 100%

The skin-friendly effect of the test samples was measured using the standard Flex Wash test, in a defined system. The Flex Wash test consists of three one-minute washes of the elbow crease per day. In this test, the “increased use” serves to differentiate products with a very gentle effect. The skin redness that develops changes only slightly with changes in temperature and humidity, therefore allowing testing throughout the year.

The study group consists of approximately 25 people. The elbows of the participants must be free of any skin conditions (eczema, dryness, irritation, cuts, abrasions).

Members taking antihistamines or anti-inflammatory medications regularly (for more than 8 weeks) or taking topical, oral or injectable cortisone should be excluded from the study. 3 products are applied to the areas to be washed (right and left arms) in a specific order.

During the test, the group members wet their left elbow and a sponge. 0.5 g of the product is then applied to the sponge and the “dosed” sponge is placed in the examiner’s right hand. The examiner then washes the left elbow for exactly 1 minute. The elbow is then rinsed and patted dry. This washing procedure is repeated on the right arm using the appropriate product. Thus, both arms are tested simultaneously.

The above washing procedure was repeated three times on 5 consecutive days, i.e. a total of 15 washings were performed. The washings were separated by 1.5 hours. Each of the tested surfaces was examined immediately before washing and 4 hours after washing on the 3rd day.

The assessment, which was based on a total of 20 estimates, was assessed by a qualified expert. The assessment scale is as follows:

- no skin redness;

0.5 - skin redness corresponding to the detection threshold;

mild patchy redness of the skin without edema;

1.5 - mild/moderate skin redness without edema or with edema;

- moderate associated skin redness/edema with or without blistering.

The treatment of the test surfaces as described above was continued until a grade of “2” was reached or 15 washes were completed. If a grade of “2” or higher was reached, the treatment was terminated in that area. Each treatment was carried out similarly.

The final evaluation of the compositions of Examples 5 and 6 and Comparative Example F was carried out by summing the results estimated over 5 days. The classification values obtained based on the average of 20 evaluations made by one participant were added up and then the results of all participants were averaged. Accordingly, the theoretically obtainable average cumulative scale ranges from 0 to 30; the lower value of the scale means that there is no skin irritation at all and the value 30 indicates the most severe effect.

The results of the study are as follows:

Table G

Example Cumulative results of the 5-day test 5 8.51 6 9.04 F 15.60

The results obtained show that the compositions according to the invention are much more gentle on the skin than the comparative composition, which contains no C8 fatty acid soap and more than 3% by weight of C12 fatty acid soap. The results also show that the use of a small amount (1% by weight) of C12 fatty acid soap does not reduce the strong effect of the product.

Claims (7)

Patent claims 1. An aqueous cleaning composition, characterized in that its composition is as follows: a) at least one short-chain fatty acid soap selected from fatty acid soaps having 6-10 carbon atoms; b) at least one long-chain fatty acid soap selected from fatty acid soaps having 14 to 22 carbon atoms; c) water; and the composition contains up to 3% by weight of C12 fatty acid soap based on the weight of the aqueous cleaning agent and up to 15% by weight of C12 fatty acid soap based on the weight of the total fatty acid soap, and the weight ratio of the polymers of components a) and b) is (1:20) to (5:1). 2. A cleaning composition according to claim 1, characterized in that it comprises a co-surfactant which may be an anionic, nonionic, cationic or zwitterionic surfactant or mixtures thereof. 3. A cleaning composition according to claim 2, characterized in that it contains as co-surfactant a zwitterionic surfactant, which may be alkyl betaine, amidopropyl betaine, amidopropyl sultain or mixtures thereof. 4. A cleaning composition according to any one of claims 1-3, characterized in that the fatty acid soap according to point a) comprises a C6-C8 fatty acid soap or mixtures thereof. 5. A cleaning composition according to any one of claims 1-3, characterized in that the fatty acid soap according to point b) comprises a 14-carbon fatty acid soap or a 18-carbon fatty acid soap containing 1 unsaturated bond, or mixtures thereof. 6. A cleaning composition according to any one of claims 1-5, characterized in that it also contains a thickening agent. 7· A method for applying an aqueous liquid composition to human skin and hair as a cleanser, characterized in that a composition having the following composition is used: a) at least one short-chain fatty acid soap selected from fatty acid soaps having 6 to 10 carbon atoms; b) at least one long-chain fatty acid soap selected from fatty acid soaps having 14 to 22 carbon atoms; c) water; and the composition contains up to 3% by weight of C12 fatty acid soap based on the weight of the aqueous cleaning agent and up to 15% by weight of C12 fatty acid soap based on the weight of the total fatty acid soap, and the weight ratio of the polymers of components a) and b) is (1:20) to (5:1). The authorized person: "DANUBIA" Patent and Trademark Office Ltd. 2a L· Ferenc Török, patent attorney