Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SKIN COSMETICS COMPRISING COCOON-SHAPED POLYMER FINE
PARTICLES
[Technical Field]
[0001]
The present invention relates to skin cosmetics having an effect of
making fine wrinkles on the skin unnoticeable, letting the skin appear
smooth and fair.
[Background Art]
[0002]
Conventionally, various cosmetics, for example makeup cosmetics
such as foundation, face powder, rouge and eye shadow, body cosmetics such
as body powder and baby powder, and. lotions such as pre-shave lotion and
body lotion have been proposed as fine particle containing skin cosmetics.
These skin cosmetics have been compounded with spherical resin particles
such as nylon particles and polymethyl methacrylate particles for the purpose
of improving extendability on the skin, improving feel, and making fine
wrinkles unnoticeable (Patent Documents 1 to 3). However, these particles
are insufficient in their effect of making fine wrinkles on the skin
unnoticeable, and there has been demand for fine particles that let the skin
appear smoother and fairer.
[Prior document]
[0003]
Patent Document 1: JP-A 9-48,707
Patent Document 2: JP-A 2001-206,814
Patent Document 3: JP-A 2003-192538
[Summary of the invention]
[Technical Problem]
[0004]
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There are number of wrinkles on the skin. When the skin cosmetics
compounded with spherical resin fine particles as described above are rubbed
into the skin, not all the spherical fine particles have a shape suitable for
filling furrows of wrinkles therewith. That is, the particles settled in
furrows are relatively easily released out of the furrows even when sweat is
wiped off with a handkerchief for example.
[Solution of Problem]
[0005]
The present inventors previously established a method for producing
new cocoon-shaped polymer fine particles, and filed it with the Japanese
Patent Office as Patent Application No. 2006-353783, and published on July
17, 2008 as Publication No. JP 2008-163171 Al. They also found that the
cocoon-shaped polymer fine particles obtained by the above method was quite
suitable for the component of the skin cosmetics which could make fine
wrinkles on the skin unnoticeable and let the skin appear finer and brighter.
They filed the invention of the skin cosmetics with the Japanese Patent Office
on April 26, 2007 as Application No.JP 2007-116760 and it was published on
November 11, 2008 as Publication No. 2008-273854 Al. Based on these
findings, the present inventors have completed the invention.
That is, the present invention relates to:
(1) skin cosmetics comprising cocoon-shaped polymer fine particles having
an average particle size of 1 to 8 m,
(2) the skin cosmetics according to (1), wherein the cocoon-shaped polymer
fine particles are cross-linked or non-cross-linked polyacrylates,
(3) the skin cosmetics according to (1), wherein the content of the
cocoon-shaped fine particles in the skin cosmetics is 0.5 to 50% by weight,
and
(4) the skin cosmetics according to (1), wherein the shape of the
cocoon-shaped polymer fine particles is a body of rotation in the form of a
capsule-like cylinder having one and the other ends formed respectively into
hemispheres or a part thereof, and when a projected figure of the
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cocoon-shaped fine particle drawn by irradiating the fine particle with light
in
a direction perpendicular to the side of the cylinder of the fine-particle is
superimposed on a basal line B drawn by the following numerical formulas (1)
and (2):
(1) 1.1 L/W <_ 3
(2)0.3R/W<_0.6
wherein L is the distance between one and the other ends in rotation axis X of
the body of rotation, W is the diameter of the cylindrical rotation body, and
R
is the radius of the hemisphere,
so that the outline P of the projected figure of the cocoon-shaped fine
particle
will enlarge as large as possible unless it will protrude out of the basal
line B,
the inside area of the outline B of the projected figure makes up 85% or more
of the inside area of the basal line B.
[Description of the preferred embodiments]
[0006]
The cocoon-shaped polymer fine particles used in the present
invention are particles in the shape of a body of rotation in the form of a
capsule-like cylinder having one end and the other end formed respectively
into a hemisphere or a part thereof, and when a projected figure of the
cocoon-shaped microparticle drawn by irradiating the fine particle with light
in a direction perpendicular to the side of the cylinder of the fine particle
is
superimposed on a basal line B drawn by the following formulas (1) and (2):
(1) 1.15L/W53 and
(2) 0.3<_R/W<_0.6
wherein L is the distance between one end and the other end in rotation axis
X of the body of rotation, W is the diameter of the cylinder, and R is the
radius of the hemisphere, so that the outline P of the projected figure of the
cocoon-shaped fine particle will enlarge as large as possible unless it will
protrude out of the basal line B, the inside area of the outline P of the
projected figure makes up 85% or more of the inside area of the basal line B.
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The average particle size of the polymer fine particles is usually 1 to 8
pm, preferably 2 to 6 m.
The average particle size is measured with a precision particle size
distribution measuring instrument Multisizer TIE (manufactured by
Beckman Coulter, Inc.).
[0007]
The cocoon-shaped polymer fine particles show special optical
diffusivity by their unique shape and the orientation generated by easy
rolling in a direction perpendicular to the rotation axis X thereof.
The cocoon-shaped polymer fine particles, when compounded into
cosmetics, can make fine wrinkles on the skin more unnoticeable and let the
skin appear finer and brighter than by spherical particles.
[0008]
A method for producing the cocoon-shaped polymer fine particles used
in the present invention is described.
A polymerizable monomer mixture containing a polymerizable vinyl
monomer and a crosslinkable monomer in an amount of 0.05 to 1% by weight
based on the vinyl monomer is subjected to dispersion polymerization to give
a dispersion of seed particles, followed by adding, to the dispersion of seed
particles, a polymerizable vinyl monomer that is 1 to 5 times larger than the
weight of the seed particles and subjecting the mixture to seed
polymerization,
whereby the cocoon-shaped polymer fine particles can be obtained.
[0009]
A method of synthesizing the seed particles by using a polymerizable
monomer is described.
For synthesizing the seed particles in the present invention from a
polymerizable monomer mixture containing a polymerizable vinyl monomer
and a crosslinkable monomer, a solvent in which the polymerizable monomer
is dissolved but a polymer after polymerization is not dissolved is used. The
crosslinkable monomer is added in an amount of usually 0.05 to 1% by weight,
preferably 0.1 to 0.6% by weight, more preferably 0.2 to 0.5% by weight, based
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on the polymerizable vinyl monomer.
[0010]
When the amount of the crosslinkable monomer added, based on the
polymerizable vinyl monomer, is lower than the amount defined above,
another polymerizable vinyl monomer to be added later is easily absorbed
into the inside of seeds to cause swelling of the seeds, thereby rendering
formed particles liable to be spherical. On the other hand, when the amount
of the crosslinkable monomer added is higher than the above, aggregation is
easily caused during dispersion polymerization, and thus seed particles with
even particle size distribution cannot be obtained.
More specifically, a polymerization initiator is dissolved in a solvent
and then heated to a temperature suitable for the initiator used, a monomer
mixture containing a polymerizable vinyl monomer and a crosslinkable
monomer is added thereto, and the mixture is polymerized for 10 to 24 hours
under an inert gas stream, for example, a nitrogen gas stream, whereby a
dispersion of the objective seed particles can be obtained. On this occasion,
various surfactants, or dispersion stabilizers such as polymer protective
colloids, may be used to improve the dispersion stability of the polymer
particles.
[00111
The polymerizable vinyl monomer includes, for example,
styrene-based monomers such as styrene, p-methylstyrene, p-chlorostyrene,
chloromethylstyrene and a-methylstyrene; acrylate ester-based monomers
such as ethyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate,
dimethylaminoethyl acrylate and diethylaminoethyl acrylate, methacrylate
ester-based monomer such as methyl methacrylate, ethyl methacrylate,
lauryl methacrylate, dimethylaminoethyl methacrylate and
diethylaminoethyl methacrylate; ethylene glycol mono(meth)acrylate,
polyethylene glycol mono(meth)acrylate; alkyl vinyl ethers such as methyl
vinyl ether and ethyl vinyl ether; vinyl ester-based monomers such as vinyl
acetate and vinyl butyrate; N- alkyl- substituted (meth)acrylamides such as
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N- methylacrylamide, N-ethylacrylamide, N-methylmeacrylamide,
N-ethylmethacrylamide; and nitrile-based monomers such as acrylonitrile
and methacrylonitrile. However, usable monomers are not limited to the
above-mentioned monomers as long as they are hydrophobic and soluble in an
organic solvent.
[0012]
The cross-linkable monomer includes compounds having 2 or more
polymerizable unsaturated bonds in one molecule, for example, aromatic
divinyl compounds such as divinyl benzene and divinyl toluene, glycol
di(meth)acrylates such as ethylene glycol di(meth)acrylate and diethylene
glycol di(meth)acryl.ate, and tri(meth)acrylates and tetra(meth)acrylates such
as trimethylol propane tri(meth)acrylate and pentaerythritol
tetra(meth)acrylate. These monomers can be used alone or as a mixture of
two or more thereof.
[0013]
The solvent in which the monomers used in synthesis of seed particles
are dissolved but a polymer after polymerization is not dissolved includes,
for
example, alcohols such as methanol, ethanol, propanol and isopropyl alcohol.
The amount of the solvent used is preferably about 3 to 25 times larger than
the weight of the monomers.
[0014]
Examples the dispersion stabilizer that is used include surfactants
such as sodium dodecylbenzenesulfonate and sodium laurylsulfate,
water-soluble polymers such as gelatin, methyl cellulose, hydroxyethyl
cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and polyacrylates, and
water-sparingly- soluble inorganic materials such as tricalcium phosphate and
magnesium carbonate. These dispersion stabilizers are used alone or in
combination of two or more thereof. Polymerization can be conducted
preferably with these dispersion stabilizers in an amount used in usual
dispersion polymerization.
[00151
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Examples of the polymerization initiator that is used include organic
peroxides such as benzoyl peroxide, o-methoxybenzoyl peroxide,
o-chlorobenzoyl peroxide, lauroyl peroxide and cumene hydroperoxide and azo
compounds such as 2,2'-azobisisobutyronitrile and
2,2'-azobis-2,4-dime thylvarelonitrile. The amount of the polymerization
initiator used is about 0.5 to 5% by weight relative to the monomer mixture.
[00161
The synthesized particles are removed by filtration or centrifugation
and used in the subsequent step. The average particle size of the seed fine
particles is 0.6 to 6 m, preferably 1.2 to 4.5 m.
[00171
For preparing the cocoon-shaped fine particles from the obtained seed
particles, the seed fine particles are dispersed completely in an aqueous
medium. For this purpose, the seed fine particles are added to an aqueous
medium such as water and dispersed desirably by ultrasonic dispersion, if
necessary in the presence of a dispersion stabilizer.
A polymerizable vinyl monomer which is 1 to 5 times (preferably 1.5
to 3.5 times) larger than the weight of the seed fine particles in the aqueous
seed particle dispersion, and an oil-soluble initiator, are dissolved and
subjected to dispersion with a homomixer or the like or ultrasonic dispersion
in an aqueous solution of a surfactant such as sodium lauryl sulfate, to form
a
monomer emulsion. This monomer dispersion is added to the seed particle
dispersion and stirred thereby absorbing the monomer onto the seeds. For
improving the solvent tolerance of the polymer fine particles obtained by
polymerization reaction, a cross-linkable monomer can be added in an amount
of 20% by weight or less, preferably 5 to 15% by weight, based on the
polymerizable vinyl monomer, to the monomer emulsion. The conclusion of
absorption can be confirmed with an optical microscope or the like. When
the amount of the polymerizable monomer relative to the seeds is lower than
the above-defined amount, the particles obtained after polymerization are
nearly spherical and not preferable. When the amount of the monomer
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added is higher than the above-defined amount, the particles obtained after
polymerization are irregular particles with unevenness, and given the
monomer in large excess, become spherical and are not preferable. After it is
confirmed that the monomer has been completely absorbed, the reaction
mixture is heated and polymerized. At this time, various dispersion
stabilizers may be used to improve the dispersion stability of the polymer
particles.
[0018]
In seed polymerization in the present invention, a chain transfer
agent, a polymerization inhibitor etc. may be used in suitable amounts in
addition to a polymerization initiator.
The polymerization initiator is that which is usually used in this type
of reaction. Examples of such polymerization initiator include organic
peroxides such as benzoyl peroxide and lauroyl peroxide and azo
polymerization initiators such as 2,2'-azobisisobutyronitrile and
2,2'-azobisvarelonitrile. The polymerization initiator is used by dissolving
it
in the polymerizable monomer. The chain transfer agent may also be one
usually used in this type of reaction. Examples of the chain transfer agent
that can be preferably used include monothiol, polythiol, xanthogen disulfide,
thiuram disulfide, 2-ethylhexyl mercaptoacetate ester, 2-methylmercaptoethyl
octanoate ester, methoxybutyl mercaptoacetate ester, methoxybutyl
mercaptopropionate ester, a-methylstyrene dimer, and terpirenone. As the
polymerization inhibitor, a usually used polymerization initiator such as
sodium nitrite, sodium nitrite or cupric chloride is used in a suitable
amount.
[0019]
Polymer fine particles having an average particle size that is 1.3 to
1.5 times larger than the particle size of the seeds used are obtained by
subsequent polymerization reaction. Accordingly, the particle size of the
polymer fine particles can be regulated in the range of 1 to 8 m by
arbitrarily
changing the particle size of the seeds used.
[0020]
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The polymerization temperature in the polymerization reaction in the
present invention, though varying depending on the polymerization initiator,
the monomers, the polymerization inhibitor added if necessary, the chain
transfer agent etc., is usually 30 to 100 C, preferably 50 to 90 C. After
polymerization, the polymer fine particles are separated by filtration, washed
with water and then dried thereby giving dry powder consisting of
cocoon-shaped polymer fine particles.
[0021)
According to the method described above, cocoon-shaped fine particles
shown in electron microscope photographs in FIGS. 1 to 3 are obtained. The
fine particles in the photographs contain those which seem spherical, but
many of these particles merely seem spherical or elliptical due to the angle
at
which their photograph was taken, and they are actually cocoon-shaped.
As shown in FIG. 4 and FIG 5, the shape of the cocoon-shaped
polymer fine particles is a body of rotation in the form of a cylinder having
one end and the other end formed respectively into a hemisphere or a part
thereof, and when a projected figure of the cocoon-shaped fine particle
obtained by irradiating the microparticle with light in a direction
perpendicular to the side of the cylinder of the microparticle is superimposed
on a basal line drawn by the numerical formulas (1) and (2):
(1) 1.1 _< L/W _<<3
(2)0.3<_R/W<_0.6
wherein L is the distance between one end and the other end in rotation axis
X of the rotation body, W is the diameter of the rotation body, and R is the
radius of the hemisphere, so that the outline P of the projected figure will
enlarge as large as possible unless it will protrude from the basal line P,
the area within the outline P of the projected plan is 85% or more, preferably
90% or more, of the area within the basal line B.
The basal line B is drawn preferably by the numerical figures (3) and
(4):
(3) 1.2_<L/W_<2.3
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(4)0.35<_R/W<_0.55,
and the area within the outline P of the projected figure can be 90% or more
of the area within the basal line B.
The polymer fine particles produced by the production method of the
present invention have an almost uniform average particle size, and at least
80%, and usually 90%, of the fine particles are cocoon-shaped polymer fine
particles.
[0022]
The content of the spherical composite polymer particles in cosmetics
varies depending on the preparation form etc. and is not particularly limited.
Usually, the content is 0.1 to 50% by weight, preferably 0.5 to 40% by weight,
1 to 40% by weight for liquid or cream cosmetics, 2 to 40% by weight for solid
cosmetics such as a powder. The cocoon-shaped powder fine particles when
contained in the above range is superior in an effect of making fine wrinkles
etc. on the skin unnoticeable, is excellent in sense of use, and is thus
preferable.
Other components than the cocoon-shaped polymer fine particles in
the cosmetics of the present invention may be a liquid or solid vehicle for
cosmetics and additives mentioned below usually incorporated in cosmetics,
as long as the effect of making fine wrinkles on the skin unnoticeable,
achieved by optical extendability resulting from the unique shape of the
cocoon-shaped polymer fine particles, is not impaired.
As the liquid vehicle, there may be exemplified by a liquid vehicle
such as water, hydrous alcohol and oils, solid vehicles such as an extender
pigment or solid filler. As the additives, there may be exemplified by fat or
oil, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal
soup,
moisture conditioners, surfactants, polymer substances, thickening agents,
colorants, perfumes, preservatives and bactericides, antioxidants, ultraviolet
absorbers and special compounding ingredients
[0023]
An oil solution may be one which is used in cosmetics. Examples of
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the oil solution include hydrocarbon oils such as liquid paraffin, squalane,
petrolatum Vaseline and paraffin wax, higher fatty acids such as lauric acid,
myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid,
undecylenic
acid, oxystearic acid, linolic acid, lanolin fatty acid, and synthetic fatty
acids,
ester oils such as glyceryl trioctanoate, propylene glycol dicaprate, cetyl
2-ethylhexanoate, and isocetyl stearate, waxes such as beeswax, whale wax,
lanolin, carnauba wax, and candelilla wax, fats and oils such as linseed oil,
cottonseed oil, caster oil, egg-yolk oil and palm oil, metal soaps such as
zinc
stearate and zinc laurate, and higher alcohols such as cetyl alcohol, stearyl
alcohol, and oleyl alcohol.
[00241
Fats, oils, and waxes include, for example, avocado oil, almond oil,
olive oil, cacao seed oil, beef tallow, sesame oil, wheat germ oil, safflower
oil,
shear butter, turtle oil, camellia oil, pasic oil, caster oil, grape oil,
macadamia
nut oil, mink oil, yolk oil, Japan tallow, palm oil, rose hip oil, hardened
oil,
silicone oil, orange roughy oil, carnauba wax, candelilla wax, whale wax,
jojoba oil, montan wax, beeswax, and lanolin.
Hydrocarbons include, for example, liquid paraffin, petrolatum,
paraffin, ceresin, microcrystalline wax, and squalane.
[00251
Higher fatty acids include, for example, lauric acid, myristic acid,
palmitic acid, stearic acid, oleic acid, behenic acid, undecylenic acid,
oxystearic acid, linolic acid, lanolin fatty acid, and synthetic fatty acids.
Higher alcohols include, for example, lauryl alcohol, cetyl alcohol,
cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin
alcohol, hydrogenated lanolin alcohol, hexyl decanol, octyl decanol,
isostearyl
alcohol, jojoba alcohol, and decyltetradecanol.
Sterols include, for example, lesterol, dihydroxycholesterol, and
phytocholesterol.
[00261
Fatty acid esters include, for example, ethyl linoleate, isopropyl
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myristate, lanolin fatty isopropyl, hexyl laurate, myristyl myristate, cetyl
myristate, octyldodecyl myristate, decyl oleate, octyldodecyl oleate,
hexyldecyl
dimethyloctanoate, cetyl octanoate, cetyl isooctanoate, decyl palmitate,
glycerin trimyristate, glycerin tri(capryl caprylate/caprate), propylene
glycol
dioleate, glycerin tr:iisostearate, glycerin triisooctanoate, cetyl lactate,
myristyl lactate and diisostearyl malate, and cyclic alcohol fatty acid esters
such as cholesteryl isostearate and cholesteryl 1,2-hydroxystearate.
[0027]
Metal soaps include, for example, zinc laurate, zinc stearate,
magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate,
calcium stearate, magnesium stearate, and zinc undecylenate.
Humectants include, for example, glycerin, propylene glycol,
1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidonecarboxylate,
sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylit, and
maltitol.
[0028]
Surfactants include, for example, anionic surfactants such as higher
fatty soaps, higher alcohol sulfates, N-acyl glutamate, phosphates, and alkyl
sulfates, cationic surfactants such as amines and quaternary ammonium salts,
amphoteric surfactants such as those of betaine type, amino acid type,
imidazoline type, and lecithin, and nonionic surfactants such as fatty
monoglyceride, propylene glycol fatty ester, sorbitan fatty ester, sucrose
fatty
ester, polyglycerin fatty ester, alkyl alkanolamide, and an ethylene oxide
condensate.
[0029]
Polymer compounds include, for example, natural polymer compounds
such as gum arabic, tragacanth gum, guar gum, locust bean gum, karaya gum,
iris moss, quince seed, gelatin, shellac, rosin, and casein, semisynthetic
polymer compounds such as sodium carboxymethyl cellulose, hydroxyethyl
cellulose, methyl cellulose, ethyl cellulose, sodium alginate, ester gum,
nitrocellulose, hydroxypropyl cellulose, and crystalline cellulose, and
synthetic polymer compounds such as polyvinyl alcohol, polyvinyl pyrrolidone,
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sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide
resin, silicone oil, and synthetic resin particles, for example nylon
particles,
polymethyl methacrylate particles, crosslinked polystyrene particles, silicone
particles, urethane particles, and polyethylene particles.
[0030]
Colorant materials include, for example, inorganic pigments such as
iron oxide, ultramarine blue, iron blue pigment, chrome oxide, chrome
hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc,
kaolin, mica, calcium carbonate, magnesium carbonate, isinglass, aluminum
silicate, barium silicate, calcium silicate, magnesium silicate, silica,
zeolite,
barium sulfate, burning calcium sulfate (plaster), calcium phosphate,
hydroxyapatite and ceramic powder, and tar dyes of azo type, nitro type,
nitroso type, xanthene type, quinoline type, anthraxquinoline type, indigo
type, triphenylmethane type, phthalocyanine type, and pyrene type.
[0031]
Perfumes include, for example, natural perfumes such as lavender oil,
peppermint oil and lime oil, and synthetic perfumes such as ethyl phenyl
acetate, geraniol, p- tert-butylcyclohexyl acetate.
Preservatives and bactericides include, for example, methylparaben,
ethylparaben, propylparaben, benzalkonium, and benzethonium.
Antioxidants include, for example, dibutyl hydroxy toluene, butyl
hydroxy anisole, propyl gallate, and tocopherol.
[0032]
Ultraviolet absorbers include, for example, inorganic absorbers such
as titanium oxide fine particles, zinc oxide fine particles, cerium oxide fine
particles, iron oxide fine particles and zirconium oxide fine particles, and
organic absorbers such as those of benzoic acid type, p-aminobenzoic acid
type,
anthranilic acid type, salicylic acid type, cinnamic acid type, benzophenone
type, and dibenzoylmethane type.
Special compounding ingredients include, for example, hormones such
as estradiol, estrone, ethinyl estradiol, cortisone, hydrocortisone, and
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prednisone, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E,
skin astringents such as citric acid, tartaric acid, lactic acid, aluminum
chloride, aluminum/potassium sulfate, allantoin chlorohydroxy aluminum,
zinc p-phenolsulfonate, and zinc sulfate, hair growth promoters such as
cantharis tincture, red pepper tincture, ginger tincture, senburi extract,
garlic
extract, hinokitiol, carpronium chloride, glyceride pentadecanoate, vitamin E,
estrogen, and a photosensitive element, and skin-lightening agents such as
magnesium phosphate-L-ascorbate and kojic acid.
The present skin cosmetics include solid type such as powder, cakes,
semi-solid type such as creams, gels, liquid type such as oil dispersion,
aqueous dispersion, water-in-oil emulsion or oil-in water emulsion from
formulation aspect, and creams such as after-shaving cream, cleansing cream,
cold cream, hand cream, sunscreen cream, lotions such as face lotion and body
lotion, foundations, powders such as cake, baby powder, body powder, lip
sticks, eye shadow and mascara, perfumes, bath cosmetics from utility
aspects.
Preparation for the present skin cosmetics from the cocoon-shaped
polymer fine particles and other materials can be conducted according to the
conventional methods for preparing cosmetics employing fine solid particles,
for example, by mixing the cocoon-shaped polymer particles, a vehicle and
other additives at the environment or elevated temperature in an apparatus
having a stirrer.
[Best Mode for Carrying Out the Invention]
[0033]
Hereinafter, the present invention is described in more detail with
reference to the Examples, but the present invention is not limited by these
examples. In the Examples, the term "parts" refers to parts by weight unless
otherwise stated.
Synthesis of cocoon-shaped polymer fine particles
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[0034]
Synthesis Example 1
A solution wherein 24 parts of polyvinyl pyrrolidone (molecular weight
360,000) and 6.5 parts of tricaprylylmethyl ammonium chloride (Aliquot 336,
Cognis Japan Ltd.) had been dissolved in 840 parts of methanol and 94 parts
of ion-exchanged water was heated to 50 C under stirring in a nitrogen
stream. Then, a solution prepared by 2.4 parts of t-butyl peroxypivalate in
100 parts of methyl methacrylate and 0.2 part of ethylene glycol
dimethacrylate was added thereto and stirred at the same temperature for 24
hours to give polymer particles (seeds). The average particle size of the
particles was 3.34 m and the standard deviation of their particle size
distribution was 7.84%.
0.52 part of surfactant Hightenol NF-13 (polyoxyethylene-alkylether
sulfate, Dai-ichi Kogyo Seiyaku Co., Ltd.) and 350 parts of ion-exchanged
water were added to 44 parts of the resulting seed particles which were then
uniformly dispersed. 280 parts of ion-exchanged water and 1.05 parts of
Hightenol NF-13 were mixed with a solution prepared by dissolving 1.4 parts
of benzoyl peroxide in a mixture of 63 parts of methyl methacrylate and 7
parts of ethylene glycol dimethacrylate, and then sonicated. The resulting
emulsion was added to the above seed particle dispersion and stirred for 30
minutes, thereby absorbing the monomer completely into the seed particles.
This dispersion was polymerized at 70 C for 4 hours in a nitrogen stream to
give cocoon-shaped particles having a uniform particle distribution. As a
result of measurement of the resulting particles with a precision particle
size
distribution measuring instrument Multisizer TIE (manufactured by
Beckman Coulter, Inc.), the average particle size was 4.38 m, and the
standard deviation of the particle size distribution was 15.4%. An electron
microscope photograph of the polymer particles is shown in FIG. 1. As a
result of observation with a scanning microscope, the L/W value of the 50
particles was 1.5 to 1.9, and the RIW thereof was 0.41 to 0.55.
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[00351
Synthesis Example 2
A solution wherein 24 parts of polyvinyl pyrrolidone (molecular weight
360,000) and 5.8 parts of Aliquot 336 (Cognis Japan Ltd.) had been dissolved
in 649 parts of methanol and 114 parts of ion-exchange water was heated to
50 C under stirring in a nitrogen stream. Then, a solution prepared by 1.2
parts of 2,2'-azobisisobutyronitrile in 79.8 parts of methyl methacrylate and
0.4 part of ethylene glycol dimethacrylate was added thereto and stirred at
the same temperature for 24 hours to give polymer particles. The average
particle size of the particles was 2.50 m and the standard deviation of their
particle size distribution was 20.8%.
0.52 part of Hightenol NF-13 (Dai-ichi Kogyo Seiyaku Co., Ltd.) and
350 parts of ion-exchange water were added to 35 parts of the resulting seed
particles which were then uniformly dispersed. 280 parts of ion-exchange
water and 1.05 parts of Hightenol F-13 were mixed with a solution prepared
by dissolving 1.05 parts of benzoyl peroxide in a mixture of 63 parts of
methyl
methacrylate and 7 parts of ethylene glycol dimethacrylate, and then
sonicated. The resulting emulsion was added to the above seed particle
dispersion and stirred for 30 minutes, thereby absorbing the monomer
completely into the seed particles. 0.14 part of sodium nitrite was added to
this dispersion which was then polymerized at 70 C for 4 hours in a nitrogen
stream to give cocoon-shaped particles having a uniform particle distribution.
The average particle size of the resulting particles was 3.58 m, and the
standard deviation of the particle size distribution was 19.3%. It was
observed under a scanning microscope that among the 50 particles, there
were 3 particles that did not satisfy 1.1 5 L/W <_ 3.0 and 0.3<_ RA V<_ 0.6,
and
the L/W value of the other particles was 1.2 to 1.4, and the R/W thereof was
0.35 to 0.52.
An electron microscope photograph of the polymer particles is shown
in FIG. 2.
16
CA 02665402 2009-05-04
[0036]
Synthesis Example 3
0.5 part of surfactant Prisurf A2 10G (Dai-ichi Kogyo Seiyaku Co.,
Ltd.) and 350 parts of ion-exchange water were added to 35 parts of seed
particles obtained in the same manner as in Example 2, and the mixture was
uniformly dispersed. 280 parts of ion-exchange water and 1.5 parts of
Prisurf A210G were mixed with a solution prepared by dissolving 1.05 parts
of benzoyl peroxide in 70 parts of methyl methacrylate, and then sonicated.
The resulting emulsion was added to the above seed particle dispersion and
stirred for 30 minutes, thereby absorbing the monomer completely into the
seed particles. 0.14 part of sodium nitrite and 15 parts of 10% aqueous
solution of polyvinyl alcohol (GH-17, manufactured by Nippon Synthetic
Chemical Industry Co., Ltd.) were added to this dispersion which was then
polymerized at 70 C for 4 hours in a nitrogen stream to give cocoon-shaped
particles having a uniform particle distribution. The average particle size of
the resulting particles was 3.82 m, and the standard deviation of the
particle
size distribution was 20.1%. It was observed under a scanning microscope
that among the 50 particles, there were 3 particles that did not satisfy 1.1
<_
LAV _<3 and 0.3<_ R/`V <_ 0.6, and the L/W value of the other particles was
1.2
to 1.45, and the R/W thereof was 0.43 to 0.55.
[0037]
Synthesis Example 4
The same operation as described above was conducted except that
70.0 parts of the seed particles obtained in Synthesis Example 2 were used.
The resulting fine particles were spherical fine particles having an average
particle size of 2.78 m.
Example 1
[0038]
Oily compact foundation
Carnauba wax 4.0 parts
Solid paraffin 4.0 parts
17
CA 02665402 2009-05-04
Cetanol 4.0 parts
Lanolin 7.0 parts
Liquid paraffin 6.0 parts
Behenyl alcohol 4.0 parts
Titanium oxide 13.0 parts
Iron oxide 10.0 parts
Cocoon-shaped polymer fine particles
(Synthesis Example 1, particle size 4.4 m) 40.0 parts
Sericite 8.0 parts
From the above composition, an oily compact foundation was
produced.
Example 2
[0039]
Powder
Cocoon-shaped polymer fine particles
(Synthesis Example 1)
12.0 parts
Solid paraffin 5.0 parts
Petrolatum 14.0 parts
Liquid paraffin 40.0 part
Glycerin monostearate 2.0 parts
Polyoxyethylene sorbitan monooleate ester 2.0 parts
Purified water 24.7 parts
Soap powder 0.1 part
Borax 0.2 part
From the above composition, powder was produced.
Example 3
[0040]
Lotion
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CA 02665402 2009-05-04
Oil phase
Stearic acid 2.0 parts
Cetyl alcohol 1.2 parts
Vaseline 5.0 parts
Liquid paraffin 1.0 part
Polyoxyethylene oleyl ether (20 E.O.) 3.0 parts
Polyoxyethylene sorbitan monolaurate (4 E.O.) 3.0 parts
Aqueous phase
Propylene glycol 4.0 parts
Triethanolamine 1.0 part
Purified water 64.6 parts
Cocoon-shaped fine particles (Synthesis Example 1) 5.0 parts
Titanium oxide 0.2 part
From the above composition, a lotion was produced.
Comparative Example 1
[0041]
An oily compact foundation was prepared using the same composition
as in Example 1 except that the cocoon-shaped fine particles in Synthesis
Example 4 were used.
Comparative Example 2
[0042)
Powder was prepared using the same composition as in Example 2
except that the cocoon-shaped fine particles in Synthesis Example 4 were
used.
Comparative Example 3
[0043]
A lotion was prepared using the same composition as in Example 3
except that the cocoon-shaped fine particles in Synthesis Example 4 were
19
CA 02665402 2009-05-04
used.
Experimental Example 4
[0044]
When the respective cosmetics were used to do a makeup, a panel of
20 persons evaluated, under the following criteria, whether fine wrinkles etc.
were made unnotice able or not, and whether the makeup was done with
natural finish or not
Evaluation criteria
O: 16 or more persons evaluated that the products were improved as
compared with those in the Comparative Examples.
O : 11 to 15 persons evaluated that the products were improved as compared
with those in the Comparative Examples.
A: 6 to 10 persons evaluated that the products were improved as compared
with those in the Comparative Examples.
x: 5 or less persons evaluated that the products were improved as compared
with those in the Comparative Examples.
The results are shown in Table 1.
[0045]
Table 1
Oily compact powder in Lotion in
foundation in
Example Example 5 Example 6
4
Object of Comparative Comparative Comparative
comparison Examples 1 Examples 2 Examples 3
Degree of
unnoticeable fine OO OO OO
wrinkles
Natural finish OO 0 0
As shown above, the skin cosmetics compounded with the
cocoon-shaped resin fine particles of the present invention, as compared with
the skin cosmetics compounded with spherical resin fine particles, made fine
wrinkles unnoticeable and gave natural finishing effect.
CA 02665402 2009-06-17
[Brief Description of the Drawings]
[0046]
FIG. 1 is a photomicrograph of cocoon-shaped polymer fine particles
obtained in Synthesis Example 1.
FIG. 2 is a photomicrograph of cocoon-shaped polymer fine particles
obtained in Synthesis Example 2.
FIG. 3 is a photomicrograph of cocoon-shaped polymer fine particles
obtained in Synthesis Example 3.
FIG. 4 is a schematic diagram of the cocoon-shaped polymer fine
particles of the present invention.
FIG. 5 is a schematic diagram of superimposed basal line B and
outline P of the projected figure of a cocoon-shape fine particle.
[Description of Symbols]
[0047]
L: Distance between one and the other ends in rotation axis X of the rotation
body of the cocoon-shaped fine particles
W: Diameter of the cylinder of a cocoon-shaped body
R: Radius of hemisphere
X: Rotation axis of cocoon-shaped body
B: Basal line drawn by the numerical formulas (1) and (2)
P: Outline of the projected figure of the cocoon shape fine particle drawn by
irradiating the fine particle with light in a direction perpendicular to the
side
of the cylinder of the fine-particle
[Industrial Applicability]
[0048]
The present skin cosmetics comprising cocoon-shaped polymer fine
particles having an average particle size of 1 to 8 m and cosmetic vehicles
has good extendability on the face skin and show an effect of making fine
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29032-23
wrinkles on the skin unnoticeable, letting the skin appear smooth and fair.
22
