JP2022027367A - Impalpable powder of plant charcoal and cosmetics containing the same - Google Patents

Abstract

To provide impalpable powder of plant charcoal that can exhibit sufficient functions as a substitute for black iron oxide and carbon black, can maintain excellent properties even when blended in cosmetics, has reduced environmental load, and achieves improved safety for the human body.SOLUTION: The inventive impalpable powder of plant charcoal is produced by crushing, in which the average particle size is controlled in a range of 0.15-0.7 μm and the minimum particle size is controlled to 0.1 μm or more; and the carbon content is 96 mass% or more; and the L* value is 20 or less when measured with a spectral color difference meter.SELECTED DRAWING: None

Description

The present invention relates to fine vegetable charcoal powder and cosmetics containing the same.

Conventionally, black pigments have been widely used in make-up cosmetics such as foundations, eye shadows, mascaras, and blushers, and black iron oxide and carbon black are often used as the black pigments to be used.

Among them, carbon black is often used because its particles are much finer than those of black iron oxide and its coloring power is high.

On the other hand, it has been pointed out that carbon black has a problem of safety to the human body because its particles are very fine, and an alternative material has been desired.

Furthermore, in recent years, carbon black obtained by incomplete combustion of natural gas or petroleum has been increasingly required to be replaced with a material having a low environmental load due to consideration for the environment.

Patent Documents 1 to 3 disclose examples of using vegetable charcoal such as medicinal charcoal as a black pigment, but these have a problem in terms of safety because the particle size is too small. Further, in Patent Documents 2 to 3, it is a dispersion in which vegetable charcoal is dispersed in water, and its use is limited to liquid cosmetics.

Japanese Unexamined Patent Publication No. 2001-48747 Japanese Unexamined Patent Publication No. 2006-8757 Japanese Unexamined Patent Publication No. 2006-22008

The present invention has been made in view of the above-mentioned problems, and can exhibit sufficient coloring power as a substitute for black iron oxide or carbon black, and has good properties when blended in cosmetics. The purpose is to provide a black pigment that can be exerted, reduce the environmental load, and improve the safety to the human body, and a vegetable charcoal fine powder that can be used, and also to provide a cosmetic containing the vegetable charcoal fine powder. It is something to do.

As a result of diligent research to solve the above-mentioned problems, the present inventors have shown a high degree of blackness in the fine powder of vegetable charcoal obtained by controlling the particle size of the vegetable charcoal and pulverizing it, and the user. We have found that it can be used as an environmentally friendly black pigment, and have completed the present invention.

That is, the vegetable charcoal fine powder according to the first invention has an average particle size of 0.15 to 0.7 μm and a minimum particle size of 0.1 μm or more is controlled by pulverization, and the carbon content is 96% by mass or more. It is characterized by being.

In the first invention, the vegetable charcoal fine powder preferably has an L * value of 20 or less measured by a spectrocolorimeter (second invention).

The cosmetic according to the third invention is characterized by containing the vegetable charcoal fine powder of the first invention or the second invention.

According to the present invention, since the average particle size of the vegetable charcoal is controlled to 0.15 μm to 0.7 μm, it is higher than black iron oxide and blackness equivalent to carbon black can be obtained. Further, since the minimum particle size is controlled to 0.1 μm or more, it is possible to avoid the problem of safety of fine particles to the human body. In this way, it can sufficiently function as a substitute for black iron oxide and carbon black. In addition, good properties can be maintained even when this fine vegetable charcoal powder is blended into cosmetics, and a cosmetic that is effective in reducing the environmental load and improving safety for the human body can be obtained.

Next, a specific embodiment of the fine vegetable charcoal powder according to the present invention and the cosmetic containing the same will be described.

As the vegetable charcoal used in the present invention, plant-derived charcoal such as Bincho charcoal, bamboo charcoal, plum charcoal, plum seed charcoal, pine charcoal, birch charcoal, and maple charcoal, and activated carbon produced from coconut husk can be used. However, it is necessary to use one having a carbon content of 96% or more (strong heat residue of 4% or less).

The fine vegetable charcoal powder of the present invention is characterized in that the particle size is controlled, and by setting the average particle size to 0.15 μm to 0.7 μm, it is higher than black iron oxide and a blackness equivalent to carbon black can be obtained. Can be done. Further, in order to avoid the problem of fine particles, the minimum fine particle diameter needs to be controlled to 0.1 μm or more.

The device for pulverizing into fine powder having such a particle size is not particularly limited, and a hammer mill, a pin mill, a roll mill, a jet mill, a dry media mill, a wet media mill and the like are used. In consideration of safety such as electrostatic explosion, wet pulverization treatment is preferable, and continuous pulverization treatment by a media mill such as a wet bead mill is more preferable. In particular, by using this kind of crushing device and controlling the circulation time, it is possible to obtain fine vegetable charcoal powder having a desired particle size.

The solvent used for the wet pulverization treatment is not particularly limited as long as it is a volatile solvent, but it is preferable to use water for safety.

The device for removing the solvent is not particularly limited, and a vacuum dryer, a freeze dryer, a hot air dryer, a spray dryer and the like are used.

Next, specific examples of the fine vegetable charcoal powder according to the present invention and the cosmetics containing the same will be given and will be described in more detail, but the present invention is not limited to the examples described below.

Wet bead mill (Dynomill KDL-Pilot manufactured by Symmar Enterprises) by adding 85% by mass of ion-exchanged water to 15% by mass of Bincho charcoal powder (Bincho charcoal US grade JM / average particle diameter 5.3 μm manufactured by Latest) as vegetable charcoal. Wet pulverization treatment was carried out at. Grinding was carried out with zirconia beads having a diameter of 0.5 mm to an average particle diameter of 0.51 μm and a minimum particle diameter of 0.11 μm. The particle size distribution measurement was performed using a laser scattering type particle size distribution measuring device (Microtrac MT3300).

(Comparative Example 1)
In the same manner as in Example 1, wet pulverization was carried out to an average particle diameter of 1.17 μm and a minimum particle diameter of 0.27 μm to obtain a vegetable charcoal fine powder having a larger particle diameter than that of Example 1.

The vegetable charcoal fine powder obtained as described above is undiluted with titanium oxide (CR-50 / L * value 88.2 manufactured by Ishihara Sangyo Co., Ltd.) to 10% by mass, 5% by mass, and 1% by mass. After mixing and diluting, these coloring powers were evaluated by the L * value measured by a spectrophotometer SE6000 manufactured by Nippon Denshoku Kogyo Co., Ltd. In the color space called CIEL * a * b * formulated by the International Commission on Illumination (CIE), all colors visible to the human eye can be described and used as a standard for device-specific models. In this definition, L * is a measure of color lightness, L * = 0 is black, and L * = 100 is a diffuse color of white. It is considered that the lower the L * value, the higher the degree of blackness. These results are shown in Table 1.

As described above, even with the same charcoal, the smaller the average particle size, the higher the blackening power. In addition, the effect of reducing the average particle size became more remarkable when the concentration of vegetable charcoal used was low, which was higher than that of black iron oxide, and the coloring power equivalent to that of carbon black could be obtained.

Next, each black powder was blended so as to have a black powder concentration of 5% by mass to prepare a pen-shaped eyeliner. The color tone was evaluated by preparing a coating film and measuring the L * value with a spectrocolorimeter. We also confirmed the writing performance of the pen-type eyeliner. These results are shown in Table 2.

As described above, even with the same charcoal, the smaller the average particle size, the higher the blackness. In addition, by reducing the average particle size, clogging in the felt of the pen-type eyeliner was eliminated, and writing performance could be improved.

As described above, by controlling the particle size of the charcoal, even with the same charcoal, there is a difference in the blackness when used as a cosmetic, and the smaller the average particle size, the higher the coloring power tends to be. In addition, it was higher than black iron oxide, and it was possible to obtain a blackness equivalent to that of carbon black. Furthermore, it was confirmed that not only the color tone but also the characteristics such as writability are improved when the average particle size becomes smaller as seen in the example of the pen-type eyeliner.

The fine vegetable charcoal powder of the present invention exhibits a high degree of blackness, can exhibit a sufficient function as a substitute for black iron oxide and carbon black, and maintains good properties even when blended in cosmetics. Since it is very effective in reducing the environmental load and improving the safety to the human body, it has great practical value when applied to various cosmetics.

Claims (3)

A fine vegetable charcoal powder having an average particle size of 0.15 to 0.7 μm and a minimum particle size of 0.1 μm or more controlled by crushing and having a carbon content of 96% by mass or more. The vegetable charcoal fine powder according to claim 1, wherein the L * value is 20 or less. A cosmetic comprising the fine powder of charcoal according to claim 1 and 2.