JP2975450B2 - Detergent composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a solid detergent composition for skin cleansing containing an acyl isethionate.

Traditionally, soap has been used as a skin cleanser. However, soap is a very unpleasant chemical. Especially in cold climates, the use of soap can cause itchy or cracked skin. Nevertheless, the use of soap has the advantages of being low in cost, easy to manufacture into bars, and good foaming.

[0003] Attempts to replace soap with less irritating surfactants are commercially vigorous. Low-irritating stick-shaped synthetic cosmetic detergent, especially sodium cosyl isethionate
tes) has been particularly successful. Patents relating to this technology are published PCT application number WO
90/12860, which is incorporated herein by reference.

[0004] US Patent No. 4,335,025 discloses a bar detergent containing a limited amount of components. This includes, for example, alkali metal salts of _C8-16 alkyl sulfosuccinates, _C10-16 acyl isethionates, wax fillers (such as _C12-22 fatty acids or alcohols) and any other fillers. Selected water-soluble anionic detergents which can include an agent.

[0005] US Patent No. 3,901,832 discloses a bar detergent comprising a monoalkyl sulfosuccinate and a specific plasticizer in a detergent cake.

US Pat. No. 3,989,642 discloses a bar-shaped synthetic cosmetic detergent containing alkane sulfonate, fatty acid and a binding modifier such as alkyl sulfosuccinate in selected amounts. I have.

[0007] US Patent No. 4,812,253 discloses a polymer which assists hypoallergenicity to the skin, a humectant, a soap, and selected surfactants including acyl isethionates and alkyl sulfosuccinates. Disclosed are various compositions containing

It is an object of the present invention to provide a composition which is excellent in that it has low skin irritation and is excellent in foaming, softening (mush) and workability.

The present invention relates to: i) the acyl chain length distribution is at least about 90% by C ₆
-C ₁₈ a is and about 30% or more acyl ester of isethionate is _{C 14} or less, and ii) the weight ratio of said acyl ester to sulfosuccinate is 10: 1 to 2: at least one 1 The present invention provides a skin cleansing bar-like cosmetic detergent composition containing the sulfosuccinate of the present invention.

A preferred skin cleansing composition has an acyl isethionate as a main active ingredient and a monoalkyl sulfosuccinate as a secondary active ingredient used in combination therewith. The use of such a composition may result in substantially less skin irritation than previously known compositions.

[0011] The compositions of the present invention may contain certain free fatty acids, and these may include certain non-acylated free isethionate salts.
e) and may also contain certain soaps.

Preferred solid compositions for skin cleansing are: (i) an acyl ester of isethionate in an amount of 20-70%; (ii) a weight ratio of said acyl ester to sulfosuccinate of 10: 1 to 2: At least one sulfosuccinate which is 1; (iii) free fatty acids in an amount of 2-40%; (iv) unacylated isethionate in an amount of 2-20%; (v) 0-25% of (Vi) water in an amount of 2-20%, and (vii) various other ingredients in an amount of 0-20%.

The preferred weight ratio of acyl isethionate to sulfosuccinate is from 6: 1 to 2: 1, most preferably 2: 1 to 4.5: 1 to maintain mildness. .

In the present invention, the irritation caused by acyl isethionate, which is already the main active ingredient having low irritation, can be further remarkably reduced by adding sulfosuccinate.

The detergent obtained by mixing the active ingredients has excellent low irritation to the skin and excellent properties of a bar detergent such as processability, low degree of softening, good foaming and good feel. Have. Furthermore, they can be easily manufactured using standard manufacturing equipment. In general, it is necessary for the composition to have appropriate hardness and tackiness in order to have excellent processability.

Isethionate salts in the range of about C _{6 to} C ₁₈ , such as those derived from coconut fatty acids, are used, for example, in a number of commercial cleaning products and produce rich amounts of smooth foam. It is known. The active ingredient itself has been shown to be extremely irritating to the skin. Such active ingredients are solid at room temperature and, when used in rod compositions, are excellent structural formers (Structu).
acts as (r.

The isethionate ester salt which can be used in the present invention is preferably an isethionate acyl ester, and most preferably a cocoyl ester. These preferred esters are
₈ the following proportion of the fatty acid chain can be 95% or more carbon chains less prepared from normal cocoyl fatty acid of further more than half a C ₈ -C ₁₈ is C ₁₂ or less. The acyl chain length of the ester is at least about 90% C
₆ is -C _18, preferably about 30% or more is _{C 14} or less. A typical cocoil fraction is including.

Skin tests have shown that the mixed active ingredient system of the present invention further significantly reduces the irritation of the naturally mild acyl isethionate base. Skin testing and use characterization showed that the preferred ratio of isethionate to sulfosuccinate was 2: 1 to 6: 1.

The sulfosuccinates useful in the present invention are any suitable sulfosuccinate salts, ie, mono-esters (half-esters) or di-esters and any alkali metal, alkaline earth metal or ammonium salts. Preferably, the sulfosuccinate is a monoester, which is preferably prepared via an alkanolamine intermediate to introduce an amide group into the molecule. Preferably, the sulfosuccinic acid monoester salt is prepared via a monoethanolamine intermediate to provide processability, mildness and other use properties.

The most preferred sulfosuccinate has the structure 1

[0021]

Embedded image Disodium cocoamide monoethanolamide sulfosuccinate.

R in Structural Formula 1 is derived from coconut fatty acids, but in other classes can be any convenient alkyl group. The chain length distribution of the coconut fatty acids is similar to that of the coco group on isethionate.
Chain length distribution is at least 90% _C 8 _{-C 18,}
More than half is _C 8 _{-C 14.} A typical fatty acid distribution of the cocoyl moiety is as follows: The sulfosuccinate of structural formula 1 is conveniently a two-stage reaction, namely: 1. ester condensation reaction between cocoalkanolamide and maleic anhydride, and It can be prepared by sulfonation of a double bond using sodium sulfite described below.

[0023]

Embedded image The relative amount of isethionate to sulfosuccinate is preferably in a weight ratio of 2: 1 to 4.5: 1, but 6:
1, and preferably from 3: 1 to 4: 1.
And the optimum is about 3.5: 1.

As mentioned above, the soap is somewhat unpleasant to the skin, and when present in the compositions of the present invention, has a
%, Preferably less than 5%, advantageously not at all.

It is desirable to incorporate free fatty acids having about 8 to 22 carbon atoms into the compositions of the present invention. Some of these fatty acids are superfatting agents (superfattin).
agents, and others are present to act as skin feel and smoothness enhancers.
Fatty alcohols, fatty amides and the like can also be used. The superfatting agent enhances foaming properties and has 8 to 8 carbon atoms.
Selected from 18, preferably 10 to 18 fatty acids,
It can be used in amounts up to 40% by weight of the composition.
The most important of the skin feel and smoothness enhancers is stearic acid, which is desirably present in the composition.

Other efficacious chemicals and additives may be required, and such materials may be used in the composition. The amounts of these chemicals and additives can range from about 0% to 20% by weight of the total composition, and include, for example, humectants (eg, glycerin), antiwear agents (eg, polymer JR And natural and synthetic rubbers), disinfectants, fragrances, colorants, dyes, pigments (eg, titanium dioxide), electrolytes, and water.

The hypoallergenicity of the active ingredient on the skin was evaluated by the following test method.

Bend washing test Dove bar cosmetic detergent, a commercially available bar detergent with extremely low irritation (Dove is Lever Brothers)
Co. Was compared with the following test methods to evaluate the hypoallergenicity of the product of the present invention on the skin. The flexion cleaning method consists of washing the anterior fossa (elbow flexion) three times a day for 2 minutes each. This method
This is an "overuse" devised to distinguish very mild products. Since the erythema reaction changes only slightly with changes in temperature and humidity, this test method is a suitable test year round.

[0029] About 15 subjects were used as a test group. The bend in the subject must be free of any signs of skin (eczema, dryness, irritation, cuts or abrasions). Antihistamine, anti-inflammatory (8 per week)
More than one dose) or regularly taking topical, oral or injectable cortisone were excluded from the study. The population was divided into two subgroups so that left-handers averaged. Group I was assigned composition "A" to the left bend and composition "B" to the right bend, while Group II was the opposite.

First, after the evaluation, the subject was instructed to wet the left bent portion, and the sponge and the test composition formulated in the cosmetic bar were moistened with tap water (100 ppm calcium / magnesium ion). The evaluator then reciprocated the sponge 10 times on the test bar detergent and handed the "detergent-laden" sponge to the right hand of the subject. The subject then washed the left bend exactly 2 minutes, rinsed the bend, and patted dry with a towel. This washing process was repeated for the right arm with the assigned composition. Thus, both arms were tested simultaneously. Washing by this method three times a day,
Repeated for 5 consecutive days, a total of 15 washes were performed.
The treatment time was set at 1.5 hour intervals. Each test site
Evaluation was made immediately before washing and 4 hours after the third washing in one day.

One trained examiner was asked before each wash and 15
The test site was evaluated 4 hours after the third wash on day 5 as an overall evaluation of the wash. The scores are as follows: 0-no erythema 0.5-almost unrecognizable erythema 1-mild uneven erythema / no edema 1.5-mild / moderate erythema / with or without edema 2-medium Each test site was tested in the manner described above until a score of "2" or greater was reached or 15 washes were completed. When a score of "2" or greater was reached, treatment at the flexion was discontinued and this final score was assigned to all remaining ratings. The remaining flexure was washed until a score of at least "2" was reached or 15 treatments were completed, whichever was earlier. In the example of the present specification, the final evaluation, that is, the average score (Mean Rank S)
cores) was the average of the scores obtained from all subjects, and was the total score of 15 evaluations per subject. Thus, theoretically the average score is 0-30, a lower score indicates no irritation to the skin, and a score of 30 indicates the worst irritation. Average final erythema score (Mean Endpoint Erythema S
cores) is the average of the scores in each subject when the first arm receives an erythema score of "2" or greater or when 15 washes have been completed.

[0032]

The following examples will more fully illustrate embodiments of the present invention. All parts, percentages, and proportions in the examples and the claims are by weight relative to the total composition unless otherwise specified.

Example 1 This example illustrates the use of Dove and a bar cosmetic cleaner using an acyl isethionate / alkyl sulfosuccinate active ingredient system with an isethionate to sulfosuccinate ratio of 2.20: 1. Shows the difference in hypoallergenicity.

[0034] Example 2 Even if a small amount of ethylene oxide polymer PEG-150 was added,
There was no adverse effect on the mildness of the bar cleaner formulated as 2.87: 1 isethionate to sulfosuccinate.

[0035] (Wilcoxon 2 sample) Example 3 In this example, it was proved that the hypoallergenic property was superior to Dove. Here, the ratio of isethionate to sulfosuccinate was 2.89: 1.

[0036] Example 4 In this example, the ratio of cocoyl isethionate to amidosulfosuccinate was 3.64: 1. Do
Hypoallergenicity over ve was demonstrated by flexion cleaning.

Composition 4 Example 5 The ratio of isethionate to sulfosuccinate is 5.12:
As a value of 1, much lower hypoallergenicity than Dove was obtained with 90% reliability. The average final erythema is Dov for the isethionate / sulfosuccinate mixed active ingredient system
It was much lower than e.

[0038] Example 6 In the above-mentioned composition, the measurement of the foaming amount and the evaluation of softening (mush) of the bar detergent were carried out. Foaming and softening are briefly described below.

Objective foaming- 95 ° F. for this test
Under a running water of 15 times, the stick-like detergent was turned 15 and a half times, and then the stick-like detergent was set aside, and the obtained foam was thoroughly foamed by hand for 10 seconds. Next, the weighing funnel is placed on both hands, and both the funnel and both hands are placed in a water tank filled with water.
It was lowered to the mark of ml. When both hands were completely submerged, they were removed from under the funnel. Next, the funnel was lowered to the bottom of the water tank, and the foaming amount was measured.

And the rod-like detergent which has been measured previously by weight was immersed in water for 2 hours - The softening. Note that the weight increases. The softened portion was removed and the remaining portion of the detergent bar was dried. It weighed again to calculate the degree of softening as weight of softening portions of the surface 50 cm ² per the softened.
A smaller value indicates better performance.

[0041] All compositions in Table 1 have excellent foaming values and low softening values.

Example 7 In this example, six mixed active ingredient bar detergents and a commercial Dove were panel tested. Panel is Dove
There were 15 highly reputed female users. Each respondent was asked to set the water temperature and then wet both hands. The bar detergent was removed from the soap dish, held in both hands, foamed, and returned to the soap dish. Respondents then rinsed their hands and tapped dry with a nonwoven towel. At the end of the wash, respondents filled out a questionnaire. This process was repeated for each of the remaining six bar detergents. The questionnaire is divided into two parts, the first of which investigates the use characteristics and gives the respondents the ease of foam generation, subjective foaming volume,
The smoothness of the foam and the ease of rinsing were asked. The second part asked about the skin after use, for example dryness, softness, irritability, smoothness and cleanliness.

The results of these tests show that the isethionate / sulfosuccinate formulation has excellent consumer properties.

The bar detergent tested had the following composition:

[0045]

[Table 1] Foaming was evaluated based on the following scale.

[0046] The above results clearly show that bar detergents 1-6 are as acceptable to consumers as commercial bar detergents.

The feel of the skin after use was evaluated based on the following scale.

[0048]

[0049]

[Table 2] From the above results, it can be seen that the performance of the composition of the present invention is not only equal to that of a commercially available bar detergent, but in some cases is clearly better.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Frederik Silvio Osmer, New Jersey 07054, United States of America, Parsippani, Citroen Way 5 10973, Slate Hill, Woodward Road 9 (56) References JP-A-1-287017 (JP, A) JP-A-4-502624 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61K 7/50 C11D 1/28 C11D 3/20

Claims (10)

(57) [Claims] 1. i) The acyl chain length distribution is at least about 90% C ₆ -C ₁₈ and at least about 30% C _14.
An acyl ester of isethionate, which is: ii)
The weight ratio of the acyl ester to the sulfosuccinate is 1
A cosmetic bar composition for skin cleansing comprising at least one sulfosuccinate in a ratio of 0: 1 to 2: 1. 2. The composition according to claim 1, wherein said sulfosuccinate is a monoester. 3. The composition of claim 1, wherein said sulfosuccinate is derived from monoethanolamide. 4. The composition according to claim 2, wherein said sulfosuccinate is amide sulfosuccinate. 5. The composition according to claim 4, wherein said sulfosuccinate is cocoamide sulfosuccinate. 6. The composition according to claim 1, wherein the ratio of isethionate to sulfosuccinate is from 6: 1 to 2: 1. 7. The method of claim 1, wherein the ratio of isethionate to sulfosuccinate is from 4.5: 1 to 3: 1.
A composition according to any one of the preceding claims. 8. The method according to claim 1, wherein the acyl chain length has a distribution: The composition according to any one of claims 1 to 7, comprising: 9. The composition of claim 1, wherein the amount of the acyl ester of isethionate is 20 to 70% by weight of the composition.
A composition according to any one of the preceding claims. 10. The composition of claim 2, further comprising 2 to 40% by weight of free fatty acid, 2 to 20% by weight of sodium isethionate,
20% by weight of water, the amount of soap in the composition does not exceed 25% by weight and the amount of any other material in the composition exceeds 20% by weight 10. The composition of claim 9, wherein there is no.