JP7623100B2 - Aerosol product and hair treatment method - Google Patents

Description

The present invention relates to an aerosol product suitable for hair washing applications, and a hair treatment method using said product.

The hair washing composition in the product for washing hair contains an anionic surfactant with excellent cleaning effect and a cationic polymer that improves the smoothness of hair when the composition is washed off from the hair.

In response to the demand for a cool feeling, especially in the summer, there are also hair washing compositions (shampoos) containing menthol, as proposed in Patent Document 1, for example.

JP 2013-133319 A

As mentioned above, there are cases where a cool feeling is desired when washing hair, and in recent years, with the high summer temperatures in Japan, there is a need for proposals for hair washing methods that provide an excellent cool feeling.

In view of the above circumstances, the present invention aims to provide an aerosol product and a hair treatment method that can provide an excellent cooling sensation when washing hair.

The aerosol product according to the present invention is characterized in that the concentrate and the propellant are filled in a container, the concentrate contains an anionic surfactant and/or an amphoteric surfactant, water, and ethanol, the propellant is dimethyl ether, and the product is used for washing hair.

The aerosol product according to the present invention is preferably one in which the temperature of the foam discharged from the container is 15°C or less. Such a foam temperature provides an improved cooling sensation.

The aerosol product according to the present invention is preferably one in which the gauge pressure of the container at 25°C is 0.80 MPa or less. If the gauge pressure is 0.80 MPa or less, safety is increased even when used in a bathroom where temperatures tend to be high.

In the aerosol product according to the present invention, the mass ratio D/B of the dimethyl ether to the mass of the concentrate is preferably 5/95 or more. A D/B of 5/95 or more is suitable for improving the cooling sensation.

In the aerosol product according to the present invention, the amount of ethanol in the concentrate is preferably 0.5% by mass or more. If the amount of ethanol is 0.5% by mass or more, it becomes easier to set the above D/B to 5/95 or more.

The hair treatment method according to the present invention is characterized by using the aerosol product according to the present invention.

The aerosol product used for washing hair according to the present invention further contains ethanol in a concentrate containing an anionic surfactant and/or an amphoteric surfactant, and a propellant containing dimethyl ether is filled into the container, providing an excellent cooling sensation.

In addition, according to the hair treatment method of the present invention, ethanol is further blended into the concentrate containing an anionic surfactant and/or an amphoteric surfactant, and hair is washed with an aerosol product whose propellant contains dimethyl ether, providing an excellent cooling sensation.

The present invention will be described below based on the embodiments of the present invention.
The aerosol product according to the present embodiment is a product in which a concentrate and a propellant are filled in a container, and is used for the purpose of washing hair with the discharged foam.

The concentrate of this embodiment is a mixture of an anionic surfactant and/or an amphoteric surfactant, ethanol, and water (the amount of water in this concentrate is, for example, 65% by mass or more). The concentrate may optionally contain ingredients contained in known hair washing compositions.

As described above, the concentrate of this embodiment contains an anionic surfactant and an amphoteric surfactant, an anionic surfactant, or an amphoteric surfactant. These surfactants are components that remove dirt from the hair and scalp, and also contribute to the foaming properties of the concentrate. From the viewpoint of effective dirt removal and foaming properties, the total amount of anionic surfactants and amphoteric surfactants in the concentrate of this embodiment is preferably 3.0% by mass or more and 25% by mass or less, more preferably 5.0% by mass or more and 20% by mass or less, and even more preferably 7.0% by mass or more and 15% by mass or less.

When an anionic surfactant is added to the above-mentioned stock solution, it is preferable to add one or more known anionic surfactants. Examples of the anionic surfactant include carboxylate-based anionic surfactants such as N-acylamino acid salts and alkyl ether carboxylates; sulfonic acid-based anionic surfactants such as N-acylmethyl taurine salts; sulfate-based anionic surfactants such as alkyl sulfates and polyoxyethylene alkyl ether sulfates; and sulfosuccinate-based anionic surfactants such as polyoxyethylene alkyl sulfosuccinates. (Examples of the salt form of the anionic surfactant include sodium salts, potassium salts, triethanol salts, and monoethanol salts.) In order to effectively remove dirt and foam, the amount of the anionic surfactant in the stock solution of this embodiment is preferably 3.0% by mass or more and 25% by mass or less, more preferably 5.0% by mass or more and 20% by mass or less, and even more preferably 7.0% by mass or more and 15% by mass or less.

When an amphoteric surfactant is added to the above-mentioned stock solution, it is preferable to add one or more known amphoteric surfactants. Examples of the amphoteric surfactant include acetate betaine-type amphoteric surfactants such as alkyl dimethyl amino acetate betaine, fatty acid amidopropyl dimethyl amino acetate betaine, and alkyl dihydroxyethyl amino acetate betaine; and sulfobetaine-type amphoteric surfactants such as N-alkyl-N,N-dimethyl ammonium-N-propyl sulfonate, N-alkyl-N,N-dimethyl ammonium-N-(2-hydroxypropyl) sulfonate, and N-fatty acid amidopropyl-N,N-dimethyl ammonium-N-(2-hydroxypropyl) sulfonate. The amount of amphoteric surfactant added to the stock solution of this embodiment is, for example, 3.0% by mass or more and 10% by mass or less.

As described above, the concentrate of this embodiment contains ethanol. When ethanol is added to the concentrate, the tendency for the container gauge pressure to increase due to the increased amount of dimethyl ether filled can be reduced. The amount of ethanol in the concentrate of this embodiment is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, more preferably 1.5% by mass or more, even more preferably 2.0% by mass or more, and even more preferably 2.5% by mass or more, from the viewpoint of increasing the amount of dimethyl ether filled to improve the cool feeling while suppressing the gauge pressure of the container. On the other hand, the upper limit of the amount of ethanol in the concentrate is preferably 20% by mass, more preferably 15% by mass, more preferably 10% by mass, and even more preferably 5.0% by mass, from the viewpoint of suppressing irritation to the scalp and suppressing fading of dyed hair.

As described above, the concentrate of this embodiment can contain any of the components contained in known hair washing compositions. Examples of such optional components include cationic polymers, lower alcohols, polyhydric alcohols, nonionic surfactants, sugars, amino acids, animal and plant extracts, inorganic compounds, fragrances, and preservatives.

By adding a cationic polymer to the above-mentioned stock solution, the finger-combing properties of the stock solution when it is rinsed off from the hair are improved. Examples of such cationic polymers include cationic cellulose, cationic guar gum, vinylpyrrolidone/N,N-dimethylaminoethyl methacrylic acid copolymer diethyl sulfate, acrylamide/acrylic acid/dimethyldiallylammonium chloride copolymer, N,N-dimethylaminoethyl methacrylic acid diethyl sulfate/N,N-dimethylacrylamide/polyethylene glycol dimethacrylate copolymer, etc. The amount of cationic polymer in the stock solution is, for example, 0.1% by mass or more and 1.0% by mass or less.

The formulation of the concentrate in this embodiment is preferably liquid. When the viscosity of the concentrate in liquid form is measured using a B-type viscometer (temperature: 25°C, rotor: set appropriately according to viscosity, rotor rotation speed: set appropriately according to viscosity), for example, the value 60 seconds after the start of viscosity measurement is 10 mPa·s or more and 500 mPa·s or less.

The pH of the concentrate in this embodiment is, for example, 4.0 or more and 7.5 or less.

In the foaming aerosol product of this embodiment, the amount of concentrate filled in the container is set appropriately. The amount is, for example, 40 g to 65 g per 100 ml of container volume, and preferably 40 g to 60 g. A filling amount of 40 g or more extends the product's shelf life, while a filling amount of 65 g or less is preferable for increasing the amount of propellant filled in the container.

The propellant in this embodiment contains dimethyl ether. Any known propellant other than dimethyl ether may also be used.

As described above, the container in the aerosol product of this embodiment is filled with dimethyl ether. The dimethyl ether ejects foam from the container and also reduces the temperature of the foam, which is necessary to improve the cool feeling when washing hair. In the aerosol product of this embodiment, the mass ratio D/B of dimethyl ether to the mass of the concentrate is preferably 5/95 or more, preferably 10/90 or more, more preferably 15/85 or more, even more preferably 20/80 or more, even more preferably 25/75 or more, and most preferably 30/70 or more. On the other hand, the upper limit of D/B is 40/60 from the viewpoint of suppressing the gauge pressure of the container to a certain extent.

Increasing the amount of dimethyl ether filled tends to increase the gauge pressure of the container. Hair washing products are often used indoors in bathrooms where the temperature is relatively high, so dimethyl ether is likely to cause an increase in gauge pressure. For this reason, it is technically common knowledge not to fill hair washing products with dimethyl ether. However, in this embodiment, this can be reduced by blending ethanol into the concentrate, so the increase in gauge pressure can be reduced while setting the D/B (the mass ratio of dimethyl ether to the mass of the concentrate) to 5/95 or more.

In this embodiment, carbon dioxide, which is known to promote blood circulation, may be used as an optional propellant. The amount of carbon dioxide to be filled in this case is preferably 0.3 parts by mass or more, and more preferably 0.5 parts by mass or more, per 100 parts by mass of the original liquid. On the other hand, the upper limit of the amount of carbon dioxide to be filled is 1.5 parts by mass per 100 parts by mass of the original liquid from the viewpoint of suppressing an increase in the container gauge pressure.

In this embodiment, liquefied gas, isopentane, or liquefied gas and isopentane may be any propellant for sustaining the foam. However, regarding the temperature of the foam discharged from the container, since liquefied gas and isopentane inhibit the temperature drop caused by dimethyl ether, the total amount of liquefied gas and isopentane to be filled is preferably less than 1.0 part by mass, preferably less than 0.5 part by mass, more preferably less than 0.3 part by mass, and even more preferably less than 0.1 part by mass, per 100 parts by mass of the concentrate. On the other hand, the upper limit of the amount of carbon dioxide to be filled is 1.5 parts by mass per 100 parts by mass of the concentrate, from the viewpoint of suppressing an increase in the container gauge pressure.

The container in the aerosol product of this embodiment may be a known pressure-resistant container, and may be made of a metal such as aluminum, aluminum alloy, tinplate, or steel. This container may have a resin layer laminated on the inner surface or may have an inner bag inside.

From the viewpoint of safety, the gauge pressure of the container in the aerosol product of this embodiment is 0.80 MPa or less at a temperature condition of 25°C, preferably 0.75 MPa or less, preferably 0.70 MPa or less, more preferably 0.65 MPa or less, even more preferably 0.60 MPa or less, and even more preferably 0.55 MPa or less. Even if such an upper limit of the gauge pressure is set, since ethanol is blended in the concentrate, the gauge pressure in a bathroom where the indoor temperature is high can be reduced. On the other hand, the lower limit of the gauge pressure at 25°C is preferably 0.25 MPa, preferably 0.30 MPa, more preferably 0.35 MPa, and even more preferably 0.40 MPa in order to increase the amount of dimethyl ether filled in the container.

The aerosol product of this embodiment is used in a hair treatment method for washing hair. When used in this manner, foam discharged from a container is applied to the head, followed by a process of rinsing with water. From the viewpoint of enhancing the cool or refreshing sensation, the temperature of the discharged foam is preferably 15°C or less, more preferably 10°C or less, more preferably 5°C or less, and even more preferably 0°C or less. The temperature of the foam can be lowered by increasing the amount of dimethylethanol filled.

The present invention will be described in detail below with reference to examples, but the present invention should not be construed as being limited to the descriptions in these examples.

The aerosol products of the examples and comparative examples capable of foam ejection were manufactured by filling a container with the concentrate and propellant. The details are as follows.

(undiluted solution)
A liquid stock solution containing 4% by weight of olefin (C14-16) sodium sulfonate, 3% by weight of sodium laureth-11 acetate, 2% by weight of sodium cocoyl glutamate, 1% by weight of disodium laureth sulfosuccinate, 3% by weight of lauryl betaine, 79% by weight of water, 3% by weight of ethanol, 0.6% by weight of citric acid, 0.5% by weight of aluminum lactate, 0.4% by weight of polyquaternium-10, 0.1% by weight of polyquaternium-52, 0.3% by weight of PEG-32, 0.6% by weight of menthol, 0.2% by weight of orange oil, 0.7% by weight of preservative, and 0.4% by weight of fragrance was prepared. The pH of this stock solution was adjusted to about 5.

The above stock solutions were used as the stock solutions of Examples 1a and 2a to 2b. The stock solution of Example 1b was prepared by adding 5 parts by mass of ethanol to 100 parts by mass of the stock solution of Example 1a (the ethanol concentration in the stock solution of Example 1b was 7.6% by mass). The stock solution of Example 1c was prepared by adding 10 parts by mass of ethanol to 100 parts by mass of the stock solution of Example 1a (the ethanol concentration in the stock solution of Example 1c was 11.8% by mass). The stock solution of Example 1d was prepared by adding 20 parts by mass of ethanol to 100 parts by mass of the stock solution of Example 1a (the ethanol concentration in the stock solution of Example 1d was 19.2% by mass).

(container)
A metal container with a diameter of 53 mm and a height of 17 cm.

Examples 1a to 1d
A total of 160 g of the concentrate and propellant (only dimethyl ether) were filled into a container to produce the aerosol products of Examples 1a to 1d. The mass ratio of the propellant to the concentrate (propellant/concentrate) was as shown in Table 1 below.

The container gauge pressure of the aerosol products of Examples 1a to 1d was measured at ambient temperatures of 25° C. and 50° C. The gauge pressures are as shown in Table 1 below, and it can be confirmed that increasing the blending amount of ethanol is effective in decreasing the gauge pressure.
In Table 1 below,

(Examples 2a to 2b)
A total of 160 g of the concentrate and propellant (only dimethyl ether) were filled into a container to produce the aerosol products of Examples 2a to 2b. The mass ratio of the propellant to the concentrate (propellant/concentrate) was as shown in Table 2 below.

The temperature of the ejected foam was measured using a digital thermometer "TM-150" manufactured by AS ONE Corporation. In this measurement, foam ejected from the aerosol products of Examples 2a to 2b was poured into a stainless steel container (contents approximately 500 ml) with the rod-shaped sensor of the digital thermometer inserted. The minimum temperature displayed by the digital thermometer was then recorded. The temperatures are as shown in Table 2 below, and it can be confirmed that increasing the amount of dimethyl ether filled is effective in lowering the temperature of the foam.

Claims (6)

An aerosol product in which a concentrate and a propellant are filled in a container,
The stock solution contains an anionic surfactant and/or an amphoteric surfactant, water, and ethanol;
The propellant comprises dimethyl ether,
The aerosol product is characterized in that the temperature of the foam discharged from the container is 15°C or lower, and the foam is used for washing hair. 2. The aerosol product of claim 1, wherein the incorporation of ethanol reduces the gauge pressure in the container. The aerosol product according to claim 1 or 2, wherein the gauge pressure of the container at 25°C is 0.80 MPa or less. The aerosol product according to any one of claims 1 to 3, wherein the mass ratio D/B of the dimethyl ether to the mass of the concentrate is 5/95 or more. The aerosol product according to any one of claims 1 to 4, wherein the amount of ethanol in the concentrate is 0.5% by mass or more. A hair treatment method comprising using the aerosol product according to any one of claims 1 to 5.