Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2002-02-21
2004-11-30
Wyrozebski, Katarzyna (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S451000, C524S430000, C524S404000, C523S105000
Reexamination Certificate
active
06825259
ABSTRACT:
TECHNICAL FIELD
The present invention relates to scale-like inorganic particles each having the resin-coated surface as well as to cosmetics with the resin-coated scale-like inorganic particles blended therein.
BACKGROUND TECHNOLOGY
Conventionally, the scale-like inorganic particles such as mica, talc, and sericite are blended in makeup cosmetics such as powder foundation. The effects provided by blending the scale-like inorganic particles in such cosmetics include the excellent extendibility on human skin, improved dispersibility of color pigments, and high adhesivity to human skin, all of which are properties indispensable for makeup cosmetics. However, as most of the scale-like inorganic particles are made from inorganic oxides such as silica, alumina, and magnesia, the feel is rather hard. In association with recent progress in the field of pulverization, it has become possible to manufacture the scale-like inorganic particles as flakes with improved feels such as lightness, excellent extendibility, and smoothness, but still the scale-like inorganic particles can not provide soft and moist feels.
On the other hand, just because the scale-like inorganic particles have a scale-like form, the contact area to skin is large, and the adhesivity to the human skin is advantageously higher than that of those having any form other than the scale-like one, but as the particles can not follow extension and shrinkage of skin which occur when an expression of a human face changes, so that, with the particles, it has been impossible to prevent the phenomenon generally called “kinking” in which the particles move on the human skin or separation and drop thereof from the human skin.
Japanese Patent Laid-Open Publication No. HEI 7-291834 proposes the coated pigment with at least a portion of a surface thereof coated with multilayered resin particles with an organic ultraviolet ray absorbent contained in the core material section. However, the resin used in this coated pigment is a (meta)acrylic or a styrene-based one, so that the feel is hard, and although the resin particles are effective in diminishing luster of body colors or pearl colors such as mica when unevenly applied thereon, but the soft feel can not be obtained, and the adhesivity to human skin is not sufficient.
Japanese Patent Laid-Open Publication No. HEI 11-92688 proposes the composite powder comprising flake-like powder such as mica titanium with the surface coated with hollow and spherical powder made from, for instance, styrene-acrylic copolymer resin. Although the flake-like composite can hide defects of human skin and give natural finish, the styrene-acrylic copolymer resin is hard in its feel, so that soft feel can not be obtained and the adhesivity to human skin is not sufficient.
Further Japanese Patent Laid-Open Publication No. HEI 6-32996 proposes the surface-modified pearl-like luster pigment coated with a specific polymer or melamine resin, and describes that the surface-modified pearl-like luster pigment is effective in improving dispensability or solubility in various types of media. However the melamine resin does not have elasticity like rubber, and is not intended to give soft feel to flake-like inorganic particles such as mica.
DISCLOSURE OF THE INVENTION
The present invention was made to solve the problems as described above, and it is an object of the present invention to provide scale-like inorganic particles having soft feel and adhesivity to human skin because of its capability to follow movement of the human skin and also effective in suppressing excessive luster. Further it is another object of the present invention to provide cosmetics which can give soft feel to human skin when applied thereon and is excellent in its adhesivity to the human skin because the scale-like powder is blended therein.
The resin-coated scale-like inorganic particles according to the present invention are those with the surface coated with resin, and are characterized in that the 100% modulus of the resin in the tensile test is in a range from 50 to 3000 N/cm
2
. The resin is preferably one or more selected from the group consisting of polyurethane, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, a silicone-based elastomer, and a polyolefin-based elastomer.
The resin-coated scale-like inorganic particles are blended in the cosmetics according to the present invention.
Therefore the resin-coated scale-like inorganic particles according to the present invention have soft feel and excellent adhesivity to human skin and are effective in suppressing excessive luster. Further the cosmetics according to the present invention have soft feel to human skin when applied thereon and is excellent in its adhesivity to human skin.
BEST MODE FOR CARRYING OUT THE INVENTION
Preferable embodiments of the present invention are described below. At first, the resin-coated scale-like inorganic particles are described. The resin-coated scale-like inorganic particles according to the present invention are those having a resin-coated surface.
1. Scale-Like Inorganic Particles
The scale-like inorganic particles which ay be used in the present invention include natural minerals such as mica, talc, and sericite, synthetic mica, synthetic sericite, plate-formed titanium oxide, plate-formed silica, plate-formed aluminum oxide, boron nitride, barium sulfate, plate-formed titania-silica composite oxide, and bismuth oxychloride. Further, scale-like inorganic particles comprise those described above as a base material and one or more inorganic oxides coating the base material such as titanium oxide, aluminum oxide iron oxide, silicon dioxide, cerium oxide, and zirconium oxide. The scale-like inorganic particles carried organic dye or pigment thereon may be used. Further, one of the various types of scale-like inorganic particles may be used, and also two or more thereof may be used in a mixed form.
An average diameter of the scale-like inorganic particles as described above should preferably be in a range from 1 to 50 &mgr;m, more preferably in a range from 5 to 30 &mgr;m, and most preferably in a range from 6 to 20 &mgr;m. The thickness of the scale-like inorganic particles should preferably be in a range from 0.01 to 1 &mgr;m, and more preferably in a range from 0.1 to 0.5 &mgr;m. When the average diameter of the scale-like inorganic particles is less than 1 &mgr;m, the excellent extendibility and improved dispersibility of the scale-like inorganic particles may be lost. When the average diameter of the scale-like inorganic particles is more than 50 &mgr;m, glittering due to the excessive luster may occur, which is not preferable.
2. Resin
The 100% modulus in the tensile test of the resin used in the present invention is required to be in a range from 50 to 3000 N/cm
2
. When the 100% modulus of the resin is less than 50 N/cm
2
, adhesivity of the resultant resin-coated scale-like inorganic particles becomes higher, and in that case blocking between the particles easily occurs, which causes coagulation and is not preferable for obtaining the good feels such as excellent extendibility. On the other hand, when the 100% modulus of the resin is over 3000 N/cm
2
, flexibility of the resin is not enough, and in this case, the effect of giving soft feel and excellent adhesivity to human skin may sometimes be insufficient. The 100% modulus in the tensile test of the resin should preferably be in a range from 100 to 1500 N/cm
2
, and more preferably in a range from 100 to 1000 N/cm
2
. In the range from 100 to 1500 N/cm
2
or from 100 to 1000 N/cm
2
, the effects of giving the excellent extendibility, soft feel, and high adhesivity to human skin are shown most remarkably.
When the 100% modulus in the tensile test of the resin is within the ranges described above, there is not specific restriction over the resin, and resins having elasticity like that of rubber including a polyurethane, a styrene-butadiene copolymer, acrylonitril-butadiene copolymer, a modified acrylic acid ester, silicon rubber, natural rubber, a nylon-based elastomer, a polyes
Miyazaki Takumi
Tanaka Hirokazu
Catalysts & Chemicals Industries Co. Ltd.
Kanesaka Manabu
Wyrozebski Katarzyna
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