Depilatory composition

Abstract

To provide a depilatory composition which is easily rinsed off after use and has reduced burden on the skin.SOLUTION: A depilatory composition of the present invention contains the following components (A), (B) and (C): (A) thioglycolic acid or thioglycolic acid salts; (B) high-polymerized polyethylene glycol having an average molecular weight of 600,000 or more; and (C) water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a hair removal agent composition, and particularly to a hair removal agent composition having excellent rinsability after use.

Background Art

[0002] Conventionally, a method of removing body hair using a hair removal agent containing a reducing agent such as thioglycolate has been practiced. When this hair removal agent is applied to a site where hair removal is desired, the reducing agent in the hair removal agent cuts the bonds of the keratin protein that constitutes the body hair, so that the body hair is softened and removed. At this time, in order to enhance the action of the reducing agent, which is the hair removal component, and improve the hair removal effect, the pH of the hair removal agent is set to a highly alkaline level of about 11 to 13. Further, as the dosage form of the hair removal agent, from the viewpoints of ease of handling (easy to apply and difficult to drip) and enhancing the adhesion to body hair to surely exhibit the hair removal effect, many are cream types. However, such a highly alkaline cream-type hair removal agent is difficult to wash off from the skin with hot or cold water after use, and therefore, the hair removal agent remaining on the skin may cause skin irritation.

[0003] Therefore, in Patent Document 1, a hair removal agent composition containing a keratin-reducing compound such as thioglycolate and guanidine or a compound having a guanidine skeleton has been proposed as a hair removal agent having a high hair removal effect, suppressing stickiness during washing, and having no residue after rinsing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the depilatory composition of Patent Document 1 described above, guanidine or a compound having a guanidine skeleton is blended in the depilatory composition, and all of these are compounds having skin irritation, so there is a problem that the burden on the skin is large.

[0006] Therefore, the present invention has been made in view of the above points, and an object thereof is to provide a depilatory composition that is excellent in rinsability after use and reduces the burden on the skin.

Means for Solving the Problems

[0007] In order to solve the above problems, the present inventors have found that by blending a reducing agent such as thioglycolate and a highly polymerized polyethylene glycol having a predetermined molecular weight, a depilatory composition with less burden on the skin and excellent rinsability after use can be obtained. Based on this finding, the present invention has been completed.

[0008] That is, the depilatory composition of the present invention contains the following components (A), (B), and (C). (A) Thioglycolic acid or thioglycolate, (B) Highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more, (C) Water. By blending highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more as component (B) in the depilatory composition, the rinsability of the depilatory composition after use can be improved. In addition, since highly polymerized polyethylene glycol has no skin irritation and is a highly safe component, a depilatory composition with less burden on the skin can be obtained. Furthermore, highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more as component (B) also has the effect of increasing the viscosity of the depilatory composition, improving the adhesion of the depilatory composition to body hair, and enhancing the hair removal effect by component (A). In the present invention, the average molecular weight refers to the weight average molecular weight.

[0009] Further, in the hair removal composition of the present invention, it is also preferable that component (B) is a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more. Thereby, a more suitable range is selected as the average molecular weight of the highly polymerized polyethylene glycol of component (B). By setting the average molecular weight within this range, the rinsability of the hair removal composition after use can be further improved, and a hair removal composition that is easily removed from the skin and difficult to remain on the skin can be obtained.

[0010] Further, in the hair removal composition of the present invention, it is also preferable that component (B) is a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more and 5,000,000 or less. Thereby, a more suitable range is selected as the average molecular weight of the highly polymerized polyethylene glycol of component (B). By setting the average molecular weight within this range, the rinsability of the hair removal composition after use can be further improved, and a hair removal composition that is easily removed from the skin and difficult to remain on the skin can be obtained.

[0011] Further, in the hair removal composition of the present invention, it is also preferable that the content of component (A) is 2 to 10% by mass and the content of component (B) is 0.01 to 1% by mass. Thereby, a suitable range is selected as the content of thioglycolic acid or thioglycolate of component (A) and the highly polymerized polyethylene glycol of component (B).

[0012] Further, it is also preferable that the hair removal composition of the present invention further contains component (D) a thickener. Thereby, the handleability such as the ease of application and the difficulty of dripping of the hair removal composition can be improved, and other compounding components can be stably dispersed in the preparation, and the stability of the preparation can be improved.

[0013] Further, it is also preferable that component (D) of the hair removal composition of the present invention is xanthan gum. Thereby, a preferable component is selected as the thickener (D) contained in the hair removal composition of the present invention.

[0014] In addition, it is also preferable that the hair removal composition of the present invention further contains an oily component as component (E). Thereby, an emollient effect can be imparted to the skin, and it can be smoothly applied to the skin to reduce friction against the skin, so that a hair removal composition gentle to the skin can be obtained.

[0015] Moreover, it is also preferable that the component (E) of the hair removal composition of the present invention is at least one oily component selected from the group consisting of hydrocarbon oils, ester oils, and vegetable oils and fats. Thereby, a preferable component is selected as the oily component (E).

Advantages of the Invention

[0016] According to the present invention, it is possible to provide a hair removal composition having the following excellent effects. (1) Since it has excellent rinsing property after use, it hardly remains on the skin, and the burden on the skin is reduced. Also, since it is easy to remove from the skin, it is easy to handle and can be used even by children in the teen generation. (2) By blending the thickener as component (D), the handleability such as ease of application and difficulty of dripping is improved, the stability of the preparation is also enhanced, and the storage stability is sufficient. (3) By blending the oily component as component (E), an emollient effect can be imparted to the skin, and the friction against the skin during application can also be reduced, so that the usability can be improved.

Brief Description of the Drawings

[0017]

Figure 1

Modes for Carrying Out the Invention

[0018] Hereinafter, the hair removal composition according to the present invention will be described in detail. The hair removal composition according to the present invention is composed of (A) thioglycolic acid or a thioglycolate, (B) a highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more, and (C) water.

[0019] [(A) Thioglycolic acid or a thioglycolate] First, the (A) thioglycolic acid or thioglycolate contained in the hair removal agent composition according to the present invention will be described. The thioglycolic acid or thioglycolate of this component (A) is formulated as a hair removal component that brings about a hair removal effect. More specifically, thioglycolic acid or a thioglycolate has the effect of reducing the disulfide bonds of the keratin protein that constitutes body hair, whereby the body hair is softened and removed.

[0020] As the component (A), it is possible to contain either thioglycolic acid or a thioglycolate, or to contain both thioglycolic acid and a thioglycolate. Further, as the thioglycolate, it is also possible to use a combination of a plurality of thioglycolates composed of different salts. Examples of the thioglycolate include calcium thioglycolate, sodium thioglycolate, ammonium thioglycolate, magnesium thioglycolate, potassium thioglycolate, and the like. Among these, in the hair removal agent composition according to the present invention, from the viewpoint of low skin irritation and excellent hair removal effect, calcium thioglycolate, sodium thioglycolate or a combination thereof is preferably used as the component (A).

[0021] From the viewpoint of exerting a hair removal effect and reducing skin irritation, the content of the component (A) formulated in the hair removal agent composition according to the present invention is preferably 2 to 10% by mass, more preferably 3 to 8% by mass, and particularly preferably 4 to 6% by mass with respect to the total amount of the hair removal agent composition.

[0022] [(B) High-polymerized polyethylene glycol] Next, the (B) highly polymerized polyethylene glycol contained in the hair removal agent composition according to the present invention will be described. This highly polymerized polyethylene glycol of component (B) increases the viscosity of the hair removal agent composition of the present invention, improves the adhesion to body hair, enhances the hair removal effect by the above-described component (A), and has the effect of improving the rinsability of the hair removal agent composition after use. Here, in the present invention, among the highly polymerized polyethylene glycols, those having an average molecular weight of 600,000 or more are used. Note that the average molecular weight in the present invention refers to the weight average molecular weight Mw.

[0023] The highly polymerized polyethylene glycol of component (B) is a polymer of ethylene oxide and generally refers to a high molecular weight compound having an average molecular weight of 20,000 or more. Among these, in the present invention, a highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more is used. As the highly polymerized polyethylene glycol, it is also possible to use a single highly polymerized polyethylene glycol or a combination of multiple types of highly polymerized polyethylene glycols having an average molecular weight of 600,000 or more.

[0024] In the present invention, as the highly polymerized polyethylene glycol blended as component (B), from the viewpoint of its action effect, a highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more is used. From the viewpoint of improving the rinsability of the hair removal agent composition after use, it is preferable to use a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more, more preferably a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more and 5,000,000 or less, and particularly preferably a highly polymerized polyethylene glycol having an average molecular weight of 1,500,000 or more and 3,000,000 or less. Although not particularly limited, as commercially available highly polymerized polyethylene glycol materials, for example, Alcox (registered trademark) E-45 (average molecular weight 600,000 to 1,000,000), Alcox E-60 (average molecular weight 1,000,000 to 1,500,000), Alcox E-75 (average molecular weight about 2,000,000), Alcox E-100 (average molecular weight about 3,000,000), Alcox E-160 (average molecular weight about 4,000,000), and Alcox E-240 (average molecular weight about 5,000,000) and other Alcox (registered trademark) series (Meisei Chemical Industry Co., Ltd.) can be used.

[0025] In addition, from the viewpoint of enhancing the rinsability of the depilatory composition after use and adjusting the viscosity of the depilatory composition to a range that is easy to handle, the content of component (B) blended in the depilatory composition according to the present invention is preferably 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, and particularly preferably 0.05 to 0.5% by mass based on the total amount of the depilatory composition.

[0026] [(D) Thickening agent] Next, the (D) thickening agent that may be contained in the depilatory composition according to the present invention will be described. The depilatory composition according to the present invention may contain a (D) thickening agent in order to improve the coatability of the depilatory composition, enhance handleability such as resistance to dripping, or improve the stability of the preparation. Although the highly polymerized polyethylene glycol of component (B) also has an effect of increasing the viscosity of the depilatory composition, combining it with the thickening agent of component (D) makes it easier to adjust the depilatory composition to a more easily handleable property.

[0027] In the present invention, as the thickening agent of component (D), any material can be used as long as it has a thickening effect, but natural thickening agents are preferably used from the viewpoint of being low-irritant and gentle to the skin. Although not particularly limited, examples of natural thickening agents include xanthan gum, locust bean gum, guar gum, tamarind gum, or gum arabic. Among these, xanthan gum is particularly preferably used from the viewpoint of high thickening stability even in an alkaline region and excellent compatibility with the thioglycolate of component (A). The content of component (D) blended in the depilatory composition according to the present invention is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and particularly preferably 0.05 to 1% by mass based on the total amount of the depilatory composition.

[0028] [(E) Oil component] Next, the (E) oily component that can be contained in the hair removal composition according to the present invention will be described. In the hair removal composition according to the present invention, an (E) oily component may be contained in order to impart an emollient effect to the skin, apply it smoothly to the skin, and reduce friction against the skin. In the present invention, the oily component of component (E) refers to a component that is insoluble in water. Specifically, examples include hydrocarbon oils, ester oils, vegetable oils and fats, higher fatty acids, higher alcohols, waxes, or silicone oils, etc., and one or a combination of two or more of these can be used. In the present embodiment, an oily component raw material that is usually used as a raw material for cosmetics can be preferably used.

[0029] Here, examples of the hydrocarbon oil as the oily component of the component (E) according to the present invention include squalane, squalene, petrolatum, liquid paraffin, and the like. Examples of the ester oil include dimer acid esters such as dimer dilinoleyl dimer dilinoleate, di(isostearyl / phytosteryl) dimer dilinoleate, or (phytosteryl / isostearyl / cetyl / stearyl / behenyl) dimer dilinoleate, oligomer type sterol esters, isopropyl myristate, glyceryl tri(caprylate / caprate), and the like. Examples of the vegetable oils and fats include jojoba oil, shea butter, cocoa butter, coconut oil, palm oil, palm kernel oil, macadamia seed oil, hydrogenated castor oil, avocado oil, camellia oil, corn oil, olive oil, rapeseed oil, sesame oil, sasanqua oil, castor oil, linseed oil, safflower oil, cottonseed oil, soybean oil, tea seed oil, rice bran oil, and the like. Examples of the higher fatty acids include oleic acid, isostearic acid, lauric acid, myristic acid, palmitic acid, stearic acid, linoleic acid, linolenic acid, and the like. Examples of the higher alcohols include lauryl alcohol, stearyl alcohol, cetanol, oleyl alcohol, lanolin alcohol, cholesterol, phytosterols, hexyl dodecanol, isostearyl alcohol, and the like. Examples of the waxes include cotton wax, beeswax, candelilla wax, carnauba wax, barberry wax, ivy wax, and the like. Examples of the silicone oils include methyltrimethicone, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, cyclopentasiloxane, and the like. The content of the component (E) formulated in the hair removal composition according to the present invention is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, and particularly preferably 5 to 15% by mass with respect to the total amount of the hair removal composition.

[0030] In addition, when the depilatory composition contains the above-described component (E) an oily component, it is preferably further contained with a surfactant for emulsifying this (E) oily component. The surfactant is not particularly limited as long as it can emulsify and disperse the oily component related to component (E), but from the viewpoint of excellent emulsifying power, a nonionic surfactant is preferably selected. As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene glycol fatty acid ester, alkyl glucoside, etc. or a combination thereof is preferably used.

[0031] [(C) Water] Component (C) water contained in the depilatory composition according to the present invention is a component used as a dispersion medium for the above-described compounding components. The content of component (C) water is not particularly limited, but is preferably 30 to 90% by mass, more preferably 50 to 80% by mass, based on the total amount of the depilatory composition.

[0032] In addition, the pH of the depilatory composition of the present invention is preferably pH = 11 or more in order to enhance the reducing action of component (A) thioglycolic acid or thioglycolate, that is, the depilatory action, and more preferably in the range of pH = 11 to 13 in order to reduce the burden on the skin. In adjusting the pH of the depilatory composition, it can be easily carried out by blending an alkaline agent such as sodium hydroxide.

[0033] The depilatory composition according to the present invention can contain, within a range not impairing the effects of the present invention, in addition to the above-described compounding components, other components that can be compounded in a normal depilatory composition. Such other components include chelating agents, pH adjusters, skin conditioning agents, perfumes, preservatives, antioxidants, brighteners, colorants, emulsion stabilizers, etc.

[0034] The dosage form of the hair removal composition of the present invention is not particularly limited. From the viewpoint of handleability such as ease of application, in addition to a viscous liquid or emulsion, a gel form, a cream form, a mousse form, etc. are preferable. Among these, from the viewpoint of more highly exhibiting the action and effect of the present invention, it is more preferable to be in a cream form or a gel form, and particularly preferably in a cream form.

[0035] The hair removal composition of the present invention can be produced by a known method for producing a hair removal composition. For example, components (A) to (C) and other compounding components are weighed in predetermined amounts, each component is added to component (C) water which is a base material, and stirred and mixed with a mixer or the like to be homogenized.

[0036] The usage method of the hair removal composition of the present invention is as follows. When the hair removal composition of the present invention is applied to the part where hair removal is desired and left for 2 to 20 minutes, preferably 5 to 15 minutes, the hair removal component (A) attached to the body hair cuts the bond of the keratin protein of the body hair, and the body hair softens. Then, when the hair removal composition is washed away with hot or cold water, the softened body hair is cut off from near the hair follicles and removed. At this time, the hair removal composition of the present invention is excellent in the washability after use and has little residue on the skin, so it is excellent in usability and also reduces the burden on the skin.

Examples

[0037] Hereinafter, the present invention will be described in detail using examples and comparative examples. The evaluation methods of the hair removal compositions in the following examples and comparative examples are as follows.

[0038] (1) Removal rate (Washability 1) Approximately 0.2 g of each depilatory composition prepared in the examples and comparative examples was taken and applied to the entire one side of a glass plate (25 mm × 75 mm × 1.2 mm). The mass of the glass plate after application was measured from the mass of the glass plate measured before application, and the exact mass of the depilatory composition applied to the glass plate was calculated. Next, 500 mL of distilled water at 30 °C was placed in a 1000 mL capacity vat, and the glass plate coated with the depilatory composition was placed with the coated surface facing up at the bottom of this vat and immersed. The entire vat was placed on a rotary shaker and shaken at 42 rpm for 5 minutes to wash away the depilatory composition applied to the glass plate. After 5 minutes, the glass plate was taken out of the vat, leaned at a 45-degree angle in the longitudinal direction of the glass plate, and left to dry at room temperature for 24 hours. After 24 hours, the mass of the glass plate was measured, and the exact mass of the depilatory composition remaining on the glass plate was calculated. From the mass of the depilatory composition on the glass plate before and after washing, the mass of the washed-away depilatory composition was determined, and the removal rate (%) was calculated. The number of samples was n = 10, and the average value of the removal rate was shown.

[0039] (2) Ease of removal (washability 2) Each depilatory composition prepared in the examples and comparative examples was taken on the finger, and on the forearm and the shin of the leg of the subject, one portion each, an amount of the depilatory composition was applied in a range of about 3 cm × 3 cm so that the skin could not be seen. Ten minutes after application, the depilatory composition was washed away with warm water at 30 °C. The ease of washing away from the skin at this time was evaluated. The number of subjects was 3, and the average value of the three was shown. The evaluation criteria were as follows. ◎: Easy to remove from the skin (easy to wash away), ○: Slightly easy to remove (slightly easy to wash away), △: Slightly difficult to remove (slightly difficult to wash away), ×: Difficult to remove (difficult to wash away).

[0040] (3) Depilatory power During the evaluation of the above-mentioned "(2) Ease of removal", the depilatory power was also evaluated simultaneously. The evaluation criteria were as follows. ◎: Completely depilated, ○: Slightly remaining depilation but no problem, △: Remaining depilation, ×: Not depilated.

[0041] (4) Skin irritation Each depilatory composition prepared in the examples and comparative examples was taken on the finger, and on the forearm and the shin of the leg of the subject, an amount of the depilatory composition sufficient to make the skin invisible was applied to one place each in an area of about 3 cm × 3 cm. Ten minutes after application, the depilatory composition was washed off with warm water at 30 °C. The irritation of the skin 10 minutes after application was evaluated. Six subjects were used for the skin irritation test, and the average value of the six subjects was shown. The evaluation criteria are as follows. ◎: No irritation is felt at all, ○: Slightly irritated but no problem, △: Irritation is felt, ×: Strong irritation is felt

[0042] [Example 1] The depilatory composition of Example 1 shown in Table 1 below was produced by the following procedure. Among the components shown in Table 1, calcium thioglycolate of component (A) was added to the purified water of component (C) and dissolved, and then the other components were added and mixed to obtain the depilatory composition of Example 1. In Example 1, as component (B), high-polymer polyethylene glycol (B1) with an average molecular weight of about 2 million was used. In addition, when adding the oily component of component (E), it was added after mixing with a nonionic surfactant. The depilatory composition of Example 1 thus obtained was evaluated for its effects based on the above-described evaluation methods (1) to (4). The evaluation results are shown in Table 1 below and the graph of FIG. 1.

[0043] [Example 2] In Example 2, as component (B), high-polymer polyethylene glycol (B2) with an average molecular weight of 600,000 to 1 million was used, and the depilatory composition of Example 2 was produced by the same procedure and materials as in Example 1 above. The depilatory composition of Example 2 thus obtained was evaluated for its effects based on the above-described evaluation method (1). The evaluation results are shown in Table 1 below and the graph of FIG. 1.

[0044] [Comparative Example 1] In Comparative Example 1, a depilatory composition of Comparative Example 1 was produced by the same procedure and materials as in Example 1 described above, except that a highly polymerized polyethylene glycol (B3) with an average molecular weight of 400,000 to 550,000 was used as component (B). The depilatory composition of Comparative Example 1 thus obtained was evaluated for its effects based on the evaluation method (1) described above. The evaluation results are shown in the graph of Table 1 and Figure 1 below.

[0045] [Comparative Example 2] In Comparative Example 2, a depilatory composition of Comparative Example 2 was produced by the same procedure and materials as in Example 1 described above, except that the formulation did not contain component (B). The depilatory composition of Comparative Example 2 thus obtained was evaluated for its effects based on the evaluation methods (1) to (4) described above. The evaluation results are shown in the graph of Table 1 and Figure 1 below.

[0046] [Table 1]

[0047] According to the results of Table 1 and Figure 1, the depilatory compositions of Examples 1 and 2 had a removal rate by washing exceeding 75%, indicating that they were superior in washability compared to Comparative Examples 1 and 2. From these results, it became clear that by blending a highly polymerized polyethylene glycol in the depilatory composition, the washability was improved, and for the improvement of washability, it was preferable that the molecular weight of the highly polymerized polyethylene glycol was 600,000 or more. Among these, by blending a highly polymerized polyethylene glycol with a molecular weight of about 2,000,000, a higher removal rate was confirmed. Therefore, it was found that it was preferable to blend a highly polymerized polyethylene glycol with a molecular weight of about 1,000,000 or more, and more preferably to blend a highly polymerized polyethylene glycol with a molecular weight of about 2,000,000 or more.

[0048] Also, according to the results in Table 1, in the application test by the panelists, the hair remover composition of Example 1 was highly evaluated as being easier to remove from the skin compared to the hair remover composition of Comparative Example 2 (without addition of highly polymerized polyethylene glycol). Further, the hair remover composition of Example 1 was highly evaluated for its hair removal power compared to the hair remover composition of Comparative Example 2, and was also excellently evaluated for its skin irritation.

[0049] The present invention is not limited to the above-described examples, and various forms with design changes are also included in the technical scope without departing from the gist of the invention described in the claims.

Industrial Applicability

[0050] The hair remover composition according to the present invention is excellent in rinsability after use, is gentle to the skin, and is easy to handle, and is mainly used in the field of beauty.

Claims

1. A depilatory composition characterized by containing the following components (A), (B) and (C). (A) Thioglycolic acid or a thioglycolate (B) A highly polymerized polyethylene glycol having an average molecular weight of 600,000 or more (C) Water

2. The depilatory composition according to Claim 1, wherein the component (B) is a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more.

3. The depilatory composition according to Claim 1, wherein the component (B) is a highly polymerized polyethylene glycol having an average molecular weight of 1,000,000 or more and 5,000,000 or less.

4. The content of the component (A) is 2 to 10% by mass, The depilatory composition according to any one of Claims 1 to 3, wherein the content of the component (B) is 0.01 to 1% by mass.

5. The depilatory composition according to Claim 4, further comprising a component (D) thickener.

6. The depilatory composition according to Claim 5, wherein the component (D) is xanthan gum.

7. The depilatory composition according to Claim 4, further comprising a component (E) oil component.

8. The depilatory composition according to Claim 7, wherein the component (E) is at least one oil component selected from the group consisting of hydrocarbon oils, ester oils and vegetable oils.

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