Cosmetic

Abstract

The present invention provides a liquid cosmetic that gives excellent feeling of use and a high ultraviolet protection effect. This cosmetic is a liquid cosmetic containing (A) hydroxystearic acid and (B) a nonvolatile oil component. In the cosmetic, component (B) contains (b1) an oil-based ultraviolet absorber. The content percentage of component (A) based on the total mass of the cosmetic is 1.5 mass% or more to 3.5%. The viscosity measured using a B-type viscometer at 30°C is 7,000 mPa / s or less.

Description

Cosmetic

[0001] The present invention relates to cosmetics, particularly cosmetics having a high ultraviolet absorption effect.

[0002] Various sunscreen cosmetics have been developed to protect the skin from strong ultraviolet radiation. In order to enhance the ultraviolet protection effect of sunscreen cosmetics, it is common practice to increase the content of ultraviolet absorbers or ultraviolet reflecting agents. However, most ultraviolet absorbers are oil-based; increasing the content of such ingredients may lead to insufficient use feeling such as increased stickiness during application, or increase the content of highly polar oils, which raises the risk of chemical attack on containers, thus there remains room for improvement. In addition, ultraviolet reflecting agents are generally powders; increasing the content thereof may cause roughness during application and give the skin an unnatural appearance after application, thus there also remains room for improvement. Therefore, in order to improve ultraviolet protection ability while reducing the content of ultraviolet protective agents, techniques for enhancing the ultraviolet protection effect are desired.

[0003] International Publication No. 2024 / 116842

[0004] According to the present invention, a liquid cosmetic that is excellent in use feeling and has a high ultraviolet protection effect is provided.

[0005] The present invention provides the following: [1] A liquid cosmetic comprising (A) hydroxystearic acid and (B) a non-volatile oil, wherein component (B) comprises (b1) an oily ultraviolet absorber, the content of component (A) based on the total mass of the cosmetic is 1.5% or more and less than 3.5%, and the viscosity measured with a B-type viscometer at 30°C is 7,000 mPa / s or less. [2] The cosmetic according to [1], further comprising (C) a volatile oil. [3] The cosmetic according to [1] or [2], wherein component (A) is 12-hydroxystearic acid. [4] The cosmetic according to any one of [1] to [3], wherein the mass ratio A / B of the total content of component (A) to the total content of component (B) is 0.03 to 0.08. [5] A cosmetic composition according to any one of [1] to [4], further comprising (D) a polar functional group and an oil thickener having an alkyl side chain having 6 to 30 carbon atoms. [6] A cosmetic composition according to [5], wherein component (D) is polyamide-8. [7] A cosmetic composition according to any one of [1] to [6], which is substantially free of powder. [8] A cosmetic composition according to any one of [1] to [7], which is an oil-in-water cosmetic. [9] A cosmetic composition according to any one of [1] to [7], which is an oily cosmetic.

[0006] The present invention provides a liquid cosmetic composition that offers excellent usability and high UV protection. More specifically, the present invention makes it possible to provide a cosmetic composition in which UV protection is improved without increasing the amount of UV absorber, and deterioration of usability due to an increase in oil content is suppressed. Detailed description of the invention

[0007] The liquid cosmetic composition according to the present invention (hereinafter sometimes simply referred to as "cosmetic composition") comprises (A) hydroxystearic acid and (B) a non-volatile oil. The following describes each of these components, as well as any additional components that may be added.

[0008] (A) Hydroxystearic Acid The cosmetic composition according to the present invention comprises hydroxystearic acid (hereinafter sometimes referred to as component (A)). Hydroxystearic acid is obtained in which the hydrogen atoms present in the aliphatic group of stearic acid are replaced with hydroxyl groups. In the present invention, component (A) is obtained in which the hydrogen atoms in the alkyl group of stearic acid are replaced with hydroxyl groups, and the number of substitutions is preferably two or less, and more preferably one. Furthermore, although the position of the hydroxyl group is not limited, it is preferable that the hydroxyl group is attached at the 12 position.Therefore, 12-hydroxystearic acid is particularly preferably used in the present invention.

[0009] 12-Hydroxystearic acid is particularly effective among hydroxy-substituted fatty acids in this invention. Although the reason for this is not fully understood, it is thought that when the cosmetic composition according to this invention is applied to the skin, some of the oil contained in the liquid cosmetic composition is heated by body temperature and volatilizes, causing a change in composition. This leads to rapid gelation of hydroxystearic acid, which makes the formed film uniform, thereby enhancing the UV absorption effect.

[0010] For the effects of the present invention to be clearly evident, it is preferable that hydroxyl groups and carboxyl groups in hydroxystearic acid are present in equal quantities, and that the distance between the hydroxyl groups and carboxyl groups within the hydroxystearic acid molecule is appropriate. Since 12-hydroxystearic acid appropriately satisfies these conditions, it is considered to exhibit particularly excellent effects.

[0011] Hydroxystearic acid is known to function as a thickening agent. In contrast, in the present invention, hydroxystearic acid is thought to exert its effect through rapid gelation, as described above, and therefore functions more as a gel-forming agent than a thickening agent. To achieve this function, the cosmetic composition is initially liquid, and to rapidly harden it, hydroxystearic acid is contained in the cosmetic composition at a relatively high concentration. Specifically, in the cosmetic composition according to the present invention, the hydroxystearic acid content, based on the total mass of the cosmetic composition, is 1.5% by mass or more and less than 3.5% by mass, preferably 2.0% by mass or more and less than 3.0% by mass.

[0012] (B) Non-volatile oil The cosmetic composition according to the present invention comprises a non-volatile oil (hereinafter sometimes referred to as component (B)). In the present invention, component (B) is an oil that does not exhibit volatility at 25°C. Component (B) can be classified into various types based on its properties and molecular structure, but since the cosmetic composition intended for the present invention has the function of a sunscreen, it comprises at least a part of component (B) an oily ultraviolet absorber (hereinafter sometimes referred to as component (b1)).

[0013] (b1) Examples of components include the following: t-butyl methoxydibenzoylmethane, ethylhexyl methoxycinnamate, homomenthyl salicylate (homosalate), octyl salicylate, octocrylene, 2-hydroxy-4-methoxybenzophenone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, 2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine, polysilicone-15, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, avobenzone, drometrizole trisiloxane, etc.

[0014] The cosmetic composition according to the present invention contains component (b1) as an essential component, but may also contain a non-volatile oil other than component (b1) (hereinafter referred to as component (b2)). Component (b2) may be a polar oil or a non-polar oil, and may be any of the following: ester oil, hydrocarbon oil, higher alcohol, higher fatty acid, silicone oil, etc.

[0015] The cosmetic composition according to the present invention can be applied to both oil-in-water and oil-based cosmetic compositions, as described later. Therefore, the content of component (B) and component (b1) can be appropriately adjusted according to the purpose, and are not particularly limited. Generally, the content of component (B) is preferably 20 to 70% by mass, more preferably 30 to 60% by mass, based on the total mass of the cosmetic composition, and the content of component (b1) is preferably 5 to 30% by mass, more preferably 10 to 20% by mass.

[0016] Furthermore, in the present invention, since component (A) is considered to have the function of gelling component (B), the ratio of component (A) to component (B) is important. Specifically, it is preferable that the mass ratio A / B of the total content of component (A) to the total content of component (B) is 0.03 to 0.08.

[0017] (C) Volatile oil The cosmetic composition according to the present invention contains components (A) and (B) as essential components, but may further contain a volatile oil (hereinafter referred to as component (C)). Component (C) is an oil that exhibits volatility at 25°C, corresponding to component (B). Examples of such component (C) include: lower alcohols such as ethanol and propanol; silicone oils such as low molecular weight dimethylsiloxane and alkyl-modified silicone oil; and low molecular weight hydrocarbons such as isododecane.

[0018] The volatile oil component has the function of maintaining the cosmetic composition according to the present invention in a liquid state, as well as stably dissolving each component in the cosmetic composition, and, in the case of the cosmetic composition according to the present invention being an oil-in-water type cosmetic composition, stably maintaining its dispersion state.

[0019] The cosmetic composition according to the present invention can be applied to both oil-in-water and oil-based cosmetic compositions. Therefore, when using component (C), the content of component (C) can be appropriately adjusted according to the purpose. Generally, when using component (C) in an oil-in-water cosmetic composition according to the present invention, its content is preferably 1 to 20% by mass, and more preferably 3 to 10% by mass, based on the total mass of the cosmetic composition. When using component (C) in an oil-based cosmetic composition according to the present invention, its content is preferably 10 to 70% by mass, and more preferably 20 to 60% by mass, based on the total mass of the cosmetic composition.

[0020] (D) Oily thickener The cosmetic composition according to the present invention may further contain an oily thickener (hereinafter sometimes referred to as component (D)). In the present invention, component (A) is a compound having a polar functional group and an alkyl group side chain having 6 to 30 carbon atoms.

[0021] In addition to appropriately adjusting the viscosity of the cosmetic composition of the present invention, component (D) also exhibits the effect of improving stability over time. Specifically, the cosmetic composition of the present invention contains a relatively large amount of component (A). The higher the amount of component (A), the more the UV protection effect tends to improve, but on the other hand, precipitation of component (A) is more likely to occur in low-temperature environments. However, by combining component (D) with the cosmetic composition of the present invention, precipitation of component (A) is suppressed, and as a result, the stability of the cosmetic composition is improved, and the content of component (A) can be increased, thereby achieving even better properties.

[0022] Various components are known for (D), but examples include polyamide-8, dibutyllauroyl glutamine, dibutylethylhexanoyl glutamine, (behenate / eicosanoate) glyceryl, dextrin palmitate, and (palmitate / ethylhexanoate) dextrin, with polyamide-8 being particularly preferred.

[0023] Component (D) functions effectively when the content of component (A) is high in the cosmetic composition according to the present invention, and its effect is particularly strong when the cosmetic composition according to the present invention is an oil-based cosmetic composition. Therefore, when the cosmetic composition according to the present invention is an oil-based cosmetic composition, it is preferable to include component (D). Note that the effects of the present invention will not be exhibited in a cosmetic composition that does not contain component (A) but contains component (D).

[0024] In the present invention, the content of component (D) is not particularly limited, but if the cosmetic composition according to the present invention contains component (D), its content is preferably 0.1 to 5% by mass, and more preferably 0.2 to 3% by mass, based on the total mass of the cosmetic composition.

[0025] (E) Other optional components The cosmetic composition according to the present invention comprises the above components (A) and (B) as essential components, and may optionally contain component (C) or (D), but may also contain other optional components.

[0026] For example, if the cosmetic composition according to the present invention is an oil-in-water cosmetic composition, it further contains water that forms an aqueous phase. As the water, water used for cosmetics, quasi-drugs, etc., can be used, for example, purified water, ion-exchanged water, tap water, etc.

[0027] The cosmetic composition according to the present invention may contain ingredients commonly used in cosmetics, particularly sunscreens, such as whitening agents, moisturizers, antioxidants, surfactants, and aqueous thickeners. In addition, sunscreens may use powder as an ultraviolet reflector to enhance their ultraviolet protection effect. Powder can also be used in the cosmetic composition according to the present invention, but since the ultraviolet protection effect provided by components (A) and (B) is high, there is no need to use powder components. Rather, since powder components may lead to a decrease in usability, it is preferable that the cosmetic composition of the present invention has a low powder component content, and preferably substantially contains no powder components.

[0028] The cosmetic composition according to the present invention can be provided as a liquid cosmetic composition such as a sunscreen cream, sunscreen lotion, or sunscreen emulsion, as a cosmetic composition having a very high ultraviolet protection effect. Here, since the ultraviolet protection effect according to the present invention is thought to be brought about by the liquid cosmetic composition forming a film on the skin, it is necessary that the form is liquid. Specifically, the viscosity measured with a B-type viscometer at 30°C must be 7,000 mPa / s or less, and preferably 3,000 mPa / s or less.

[0029] The method for producing the cosmetic composition according to the present invention is not particularly limited and can be produced by the same method as conventionally known cosmetic compositions.

[0030] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples. Unless otherwise specified, the content is expressed as mass % of the total amount.

[0031] [Examples 1-3, Comparative Examples 1-8] Oil-in-water cosmetic compositions for each example and comparative example were prepared using the formulations shown in Table 1.

[0032] Furthermore, the performance of these cosmetics was evaluated as follows.

[0033] [Viscosity] The viscosity of each cosmetic product at 30°C was measured using a B-type viscometer.

[0034] [Integrated Apparent Absorbance at 280–400 nm] For each cosmetic product, the absorption spectrum in the wavelength range of 280–400 nm was measured, and the integrated absorbance (area in the absorption spectrum) was calculated (in arbitrary units).

[0035] [Increase in Integrated Absorbance Value] Using the integrated apparent absorbance value obtained from the above measurements, the increase or decrease in the integrated absorbance value was calculated, with Comparative Example 1 as the baseline. A positive value indicates an improvement in UV protection, and a larger value indicates a higher UV protection effect.

[0036]

[0037] [Examples 4-5, Comparative Examples 9-16] Oily cosmetic compositions for each example and comparative example were prepared using the formulations shown in Table 1. All of the prepared cosmetic compositions were liquid.

[0038] Furthermore, the performance of these cosmetic compositions was evaluated in the same manner as in Example 1. However, the standard for the rate of increase in the integrated absorbance value was set to Comparative Example 10.

[0039] The following are examples of suitable formulations for cosmetics according to the present invention. The amounts are expressed in mass percent.

[0040]

Claims

1. A liquid cosmetic comprising (A) hydroxystearic acid and (B) a non-volatile oil, wherein component (B) contains (b1) an oily ultraviolet absorber, the content of component (A) based on the total mass of the cosmetic is 1.5% by mass or more and less than 3.5%, and the viscosity measured with a B-type viscometer at 30°C is 7,000 mPa / s or less.

2. (C) The cosmetic composition according to claim 1, further comprising a volatile oil.

3. The cosmetic composition according to claim 1 or 2, wherein component (A) is 12-hydroxystearic acid.

4. The cosmetic composition according to claim 1 or 2, wherein the mass ratio A / B of the total content of component (A) to the total content of component (B) is 0.03 to 0.

08.

5. (D) The cosmetic composition according to claim 1 or 2, further comprising a polar functional group and an oil thickener having an alkyl side chain having 6 to 30 carbon atoms.

6. The cosmetic composition according to claim 5, wherein component (D) is polyamide-8.

7. A cosmetic composition according to claim 1 or 2, which is substantially free of powder.

8. The cosmetic composition according to claim 1 or 2, which is an oil-in-water cosmetic composition.

9. The cosmetic composition according to claim 1 or 2, which is an oil-based cosmetic composition.

Images