Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Particulate form
Reexamination Certificate
2000-07-06
2002-11-19
Pryor, Alton (Department: 1616)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Particulate form
Reexamination Certificate
active
06482441
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel coated powder exhibiting super-dispersibility and, more particularly, it relates to surface-treated powder comprising a powder usable for cosmetics, and coating layers of surface treating agents containing a layer A that is a solid at room temperature and a layer B that is a liquid at room temperature, each formed on at least a portion of the powder particle surface, and to a cosmetic containing the surface-treated powder. More particularly, it relates to a surface-treated powder having coating layers of surface treating-agents, in which the coating layer of a surface treating agent of layer A as a first layer, and the coating layer of a surface treating agent of layer B as a second layer, are each formed on at least a portion of the powder particle surface. Layer A is a coating layer of a surface treating agent that is a solid at room temperature and contains at least one compound selected from the compounds contained in reactive organo polysiloxane, polyolefin, hydrogenated lecithin, including its salt forms, N-acylamino acid, including its salt forms, fatty acid, including its salt forms, and dextrin fatty acid esters. Layer B is a coating layer of a surface treating agent that is a liquid at room temperature, and contains at least one compound selected from the compounds contained in organo polysiloxane modified at its sole terminal end with a functional group, alkylsilane modified at its sole terminal end with a functional group, and branched fatty acid, and to a cosmetic containing the surface-treated powder.
The surface-treated powder of the present invention exhibits super-dispersibility, so that, when the surface-treated powder of the present invention is mixed into a formula (composition for cosmetics) not containing an oleophilic liquid, that is a system containing only powders, it exhibits superior dispersibility. Moreover, if the surface-treated powder of the present invention is mixed into a system containing oleophilic liquid; the surface-treated powder is superior in affinity to the liquid and hence superior in dispersibility and dispersion stability. Moreover, the surface-treated powder of the present invention drastically improves the functions of the powder base that vary according to the dispersed state, for example, adhesion to the skin, aesthetic feeling (using touch), covering power, coloring power, shielding power against UV or IR rays and optical characteristics (properties), as compared to those of conventional surface-treated powders.
Therefore, the cosmetic containing the surface-treated powder according to the present invention can be appreciably improved as to the functions as cosmetics.
The powder obtained in this manner can be applied not only to cosmetics, but also to surface-treated powders that finds application in a variety of other technical fields such as additives for plastics, inks, paints, toners (magnetic powders) and the like.
2. Description of the Related Art
Powders mixed into cosmetics are oleophilized in order to eliminate the powdery feeling, reduce physical stimuli to the skin, improve adhesiveness to the skin, improve dispersibility in an oleophilic liquid and improve wear on the skin. These oleophilized powders are usually mixed with an oily component and used in formulations. As the powder materials approaches its primary particles when mixed or dispersed, the powder material exhibits its optimum potential of its functional properties. In order to reach this optimum point of functionality, which relates to adhesion, aesthetic feeling (using touch), covering power, coloring power, optical properties, absorption and/or scattering of UV and IR rays to the fullest extent, excellent affinity as well as excellent dispersibility of the powder to an oily agent is necessary, because poor affinity with the oily agent leads to flocculation to render it impossible to display its maximum potential characteristics.
In order to solve this problem, it has been proposed to have the surface of the powder material coated with an oleophilic material. Although the adhesion to the skin of the powder material, as well as its rough feeling is improved by this method to some extent, the powder material becomes flocculated by the surface treating agent itself such that dispersibility does not reach its optimum state. Furthermore, in order to disperse the powder material into an oleophilic liquid, it is necessary to assort a large quantity of surfactants to improve its affinity into the oil and to achieve dispersion stability.
On the other hand, powdered organic materials, exemplified by polyethylene powder, nylon powder, polystyrene powder and methyl methacrylate powder, etc. is itself oleophilic such that it is in many cases better in dispersibility into an oleophilic liquid than the inorganic material. However, organic material suffers from drawbacks such as extremely poor adhesion to the skin and a tendency to be statically charged and therefore become flocculated, which lowers its dispersibility, etc., significantly. In order to improve upon this, a variety of surface treating methods have so far been proposed.
This kind of surface treating method routinely coats the material with organic surface treating agents, such as silicones, organic silanes, N-acylamino acids, fatty acids, hydrogenated lecithin, fluorine compounds, polyethylene, ester-based oily agents and the like. Specifically, there have been proposed a surface treating method with methyl hydrogen polysiloxane (Refer to Japanese Patent Kokai Publications JP-A-60-163973, JP-A-61-127767, JP-A-61-190567, JP-A-61-215216, JP-A-63-30407, JP-A-63-139015, JP-A-63-165461, JP-A-1-110540, JP-A-3-163172 and JP-A-4-246474, and Japanese Patent Kokoku Publications JP-B-1-54379, JP-B-1-54380 and JP-B-1-54381.), a surface treating method with various silane coupling agents (Refer to Japanese Patent Kokai Publications JP-A-62-177070, JP-A-2-218603 and JP-A-4-193816.), a method for surface-treating with other silicones (Refer to Japanese Patent Kokai Publications JP-A-4-202109, JP-A-4-202110, JP-A-4-202111, JP-A-5-86368, JP-A-7-206637, JP-A-7-206638, JP-A-7-207187 and JP-A-11-80588.), and a method for surface-treating with alkylsilane (Refer to Japanese Patent Kokai Publications JP-A-61-204112, JP-A-64-90111, JP-A-8-92052, JP-A-8-104606 and JP-A-8-104612.).
Further, a method for surface-treating with N-acylamino acids has been proposed in, for example Japanese Patent Kokai Publications JP-A-61-737775, JP-A-61-69709, JP-A-3-200879, JP-A-5-186706, JP-A-9-328413, JP-A-10-226626 and the like, whilst a method for coating with fatty acids is proposed in Japanese Patent Kokai Publications JP-A-60-69011 and the like, and a method for surface-treating with hydrogenated lecithin is proposed in Japanese Patent Kokai Publications JP-A-60-184571, JP-A-60-190705 and the like.
There are also known methods of enhancing the function of the powdered base material by coating the powder material with plural surface treating agents in combination. Specifically, powder material coated with methyl hydrogen polysiloxane and trimethyl siloxy silicic acid (Refer to Japanese Patent Kokai Publications JP-A-7-62263 and the like.), powder material coated with a titanium coupling agent or an alkylsilane compound, and an oleophilic material not having a functional group (Refer to Japanese Patent Kokai Publications JP-A-11-29719 and the like.) and powder material coated with methyl hydrogen polysiloxane, trimethyl siloxysilicic acid and cross-linked methyl polysiloxane in combination (Refer to Japanese Patent Kokai Publications JP-A-11-80588 and the like.).
SUMMARY OF THE INVENTION
1. Problem to be Solved by the Invention
However, there are as yet left problems to be solved in the aforementioned conventional surface treating methods.
First, the aforementioned surface treating agents are mostly solid at ambient room temperature on the surface of the powder particle material, so that, when the surface treating agent is applied to the powder parti
Hasegawa Yukio
Ohara Ryo
Armstrong Westerman & Hattori, LLP
Miyoshi Kasei, Inc.
Pryor Alton
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