Note: Descriptions are shown in the official language in which they were submitted.
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SBELI~AC-CONTAINING COSMETIC PRODUCT
The invention relates to a cosmetic emulsion or a gel containing
shellac.
It is~known that shellac has been used as a resin component in
cosmetic hair sprays, hair setting lotions, shampoos and even
l0 nail varnish. Shellac was present as a film-forming agent in
alcoholic compositions. Shellac has been largely replaced by a
number of modern copolymers that have assumed this role.
Nevertheless, shellac is still being used for certain applica-
tions such as hair spray and shampoo, not least of all because it
is available as a very pure natural product in good quality.
U. S . Patent No. 5, 614, 200 A describes W/0 emulsions that are used
as mascara and contain solids, including resins such as shellac,
liquid vehicles such as alcohol and a hardening retarder in
addition to other cosmetic additives.
Use of shellac as a parting compound between layers to be set off
from one another in a light protectant formed from three or more
layers is also known from International Patent WO 96/41630, so
that a multilayer structure of the light protectant is formed on
the skin, and the skin comes in contact only with the layer
containing the inorganic light protectant which is tolerated well
by the skin.
The object of this invention is to improve upon the feeling of
traditional emulsions and gels on the skin by preventing an oily
or sticky feeling while at the same time improving on the water
resistance and achieving stabile emulsions and gels.
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It has been found that addition of an aqueous shellac dispersion
to O/W or W/O emulsions or hydrogels may under certain conditions
lead to a cosmetic product (emulsion or gel) having a different
type of structure and thus also different properties.
The prerequisite for preparation of such emulsions and gels is
the use of pure aqueous shellac solutions or dispersions . Shellac
is normally soluble only in solvents such as alcohols, ketones
and organic acids. Shellac is insoluble in hydrocarbons, and is
to soluble in water only in the form of saponified shellac. It has
been found that unsaponified shellac is also up to approximately
30 wt% soluble in water under certain conditions, and dispersions
in water containing up to approximately 60 wt% are possible. Such
solutions/dispersions consist of
shellac in the range of 1 to 60 wt%, preferably l0 to 60 wt%,
especially 15-60 wt~;
a water-soluble film-forming agent in the range of 0.1 to 3 wt%;
a gel-forming agent that is stable in the acidic range, in the
2o range of 0.1 to 1 wt%;
an acid to adjust the pH to a value of 2 to 4.2,,preferably 2 to
3.5;
and water up to 100 wt%.
These solutions or dispersions are prepared by placing solid,
purified, dewaxed shellac in an aqueous acidic solution of the
film-forming substance and the gel-forming substance at a pH of
2 to 4.2, while stirring at a temperature in the range of 5°C to
20°C, and then homogenizing the ingredients of the solution or
3o dispersion together well.
Thus, this invention makes available a cosmetic product contai-
ning shellac, comprising a pure shellac content in the aqueous
phase, wherein the shellac component is
in the range of 0.1 to 20 wt% in an 0/W emulsion,
in the range of 0.1 to 15 wt% in a W/0 emulsion,
in the range of 0.1 to 10 wt% in a hydrogel,
and the oily phase or the aqueous phase or both phases may con-
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tain additional cosmetic active ingredients or vehicles in the
range of 1 to 20 wt%. All amounts here are based on the weight of
the total composition.
The new cosmetic product permits an especially smooth distribu-
tion on the skin without having an oily effect, produces a very
pleasant soft feeling on the skin and is not sticky.
Another object of this invention is the above cosmetic product
l0 containing shellac, comprising a pure shellac content in the
aqueous phase, wherein the shellac component
is in the range of 0.1 to 20 wt% in an O/W emulsion,
is in the range of o.l to 15 wt% in a W/O emulsion,
is in the range of 0.1 to 10 wt% in a hydrogel,
and the oily phase or the aqueous phase or both phases may con-
tain additional cosmetic active ingredients or vehicles in the
range of 1 to 20 wt%,
prepared by
a) preparing an emulsion or a hydrogel in the usual way by mixing
a primary emulsion phase, containing the cosmetic active ingre
dients and additives provided therein, with a secondary emulsion
phase, containing the cosmetic active ingredients and additives
provided therein;
or mixing a gel-forming substance with water and adding the
cosmetic active ingredients and additives provided therein;
and
b) preparing a 5 wt% to 60 wt% aqueous shellac solution or dis-
persion by mixing pure shellac dry solids having a molecular
weight of approximately 1000 to 1010 with water in the presence
of a water-soluble film-forming substance and a gel-forming
substance that is stable in an acidic pH range at a temperature
of 5°C to 20°C and a pH of 2 to 4.2;
and
c) heating the emulsion or the gel from step a) to a temperature
in the range of 35°C to 45°C while stirring;
and
d) adding the shellac solution or dispersion from step b) to the
former
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while stirring at 150 to 1000 rpm for a period of 5 to 60
minutes at 20 °C to 45 °C; and then
e) cooling the resulting product to ambient temperature.
The temperature for process step b) is advantageously in the
range of 5 °C to 15 °C.
For example, a polyvinylpyrrolidone such as PVPK30° may be used
to as the water-soluble film-forming substance. Other possible film-
forming substances include chitosan, microcrystalline chitosan,
quaternary chitosan, polymers of the acrylic acid series,
quaternary cellulose derivatives, hyaluronic acid and the salts
thereof, as well as mixtures thereof.
An example of a gel-forming substance that is stable in the
acidic range is a modified natural polysaccharide such as guar
hydroxypropyltrimonium chloride (Jaguar C14S'). Other possible
gel-forming substances include agar, alginates, alginic acid as
well as mixtures thereof.
The shellac used here may be a processed product. Shellac is a
natural lac resin secreted by the female lac insect Laccifer
lacca Kerr. The purified wax-free resin used for cosmetic pur-
poses has a molecular weight of approximately 1000, consists of
a series of hydroxymono- or dicarboxylic acids in the form of
lactones, lactides and intramolecular esters. The main components
are aleuritic acid, shellolic acid and jalaric acid (C~SHzo05) with
molecular weights of 304, 296 and 280, respectively. Shellac is
3o therefore more like an oligomer of hydroxycarboxylic acids than
a polymer. Impurities can be removed by means of a solvent
extraction method, e.g., with an alcohol, and after
decolorization with activated carbon and evaporating the alcohol,
shellac can be converted to a yellowish to faintly yellowish
solid.
Such a solid is a starting material for the aqueous solutions or
dispersions used with this invention.
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The present invention makes possible for the first time the use
of shellac in pure form as an aqueous solution or dispersion with
a viscosity of >l00 mPa~s (cP) in aqueous cosmetic products in an
advantageous manner, in particular in 0/W emulsions.
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These shellac solutions/dispersions have a viscosity of approx.
500 mPa~s (cP) at a shellac content of 10 wt%, approx. 1000 mPa~s
( cP ) at 20 wt% and approx. 2500 mPa ~ s ( cP ) at 35 wt% . Shellac
solutions or dispersions of approx. 400-500 mPa~s (cP) and higher
l0 are preferred. Thus, dispersions of 55-60 wt% shellac have a
viscosity of approx. 100,000 mPa~s (cP), have a creamy to pasty
consistency and can still be processed well with existing equip-
ment. Since the viscosity depends on the shellac concentration in
an aqueous dispersion or solution, it is expedient to work with
these viscosities in practical implementation of this invention.
In the case of an O/W emulsion, the structure of an emulsion
according to this invention is presumably such that the shellac
is distributed in the continuous aqueous phase, or in a W/O
emulsion, water droplets axe surrounded by a layer of the natural
shellac resin, or in a hydrogel, shellac droplets are present in
a random distribution in the gelled aqueous phase.
The shellac content in the emulsion or in the hydrogel is in the
range of 0.5 to 20 wt%, preferably in the range of 0.5 to 8 wt%.
In the O/W emulsion, the oil content is in the range of 3 to 20
wt%, preferably 3.5 to 7.7 wt%, and the water content is in the
range of 50 to 80 wt%, preferably 50 to 65 wt%.
In the W/O emulsion, the water content is in the range of 40 to
65 wt%, preferably 40 to 55 wt%, and the oil content is in the
range of 5 to 20 wt%, preferably 4.5 to 10 wt%. In the hydrogel,
the water content is in the range of 40 to 80 wt%, preferably 50
to 80 wt%.
In addition, it is preferable for the concentration of the aque-
ous shellac solution or dispersion to be 15 to 50 wt%.
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The cosmetic product according to this invention may also be a
multiple emulsion of the W/O/W type or the O/W/O type.
The shellac content in the finished cosmetic product in an O/W
emulsion is preferably in the range of 5-20 wt%, in a W/O emul-
sion it is in the range of 5-15 wt%, and in a hydrogel it is in
the range of 3 to 10 wt%.
The cosmetic product containing shellac according to this inven-
tion is advantageously in the form of a cream, lotion, sunscreen
preparation, lipstick, makeup, mask, lip gloss, spray or gel.
The oily phase or the aqueous phase or both phases may contain
additional active cosmetic ingredients and cosmetic vehicles or
additives.
Active cosmetic ingredients include, for example, emulsifiers
2o such as 1-decane homopolymer, polyglycerine ester and other known
emulsifiers for W/O emulsions, as well as C12-C15 alkyl
benzoates, beeswax, steareth, shea butter and other known O/W
emulsifiers.
Other possible additives include isopropyl myristate, isopropyl
palmitate, isopropyl stearate, carbomer, cetearyl alcohol,
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lecithin, copolymers, paraffin oil, cetyl alcohol, propylene
glycol, polyglycol, jojoba oil, silicone oil, coconut oil, palm
oil, mineral oil, cetyl palmitate, acrylates, C10-C30 alkyl
acrylate crosspolymer, magnesium aluminum silicate, hydroxyethyl-
cellulose and other substances with which those skilled in the
art are familiar and which are adapted to the specific applica-
tions such as lipstick, eye makeup, other cosmetics, etc.
As additional active ingredients, the preparation may contain
l0 1, 3- and 1, 6-f3-glucan, CM-glucan° , allantoin, Tio2, ZnO, Zro2,
Sio2 and additional UVA and UVB blocking substances such as or-
ganic sunscreens. For example, benzophenone derivatives, 3-benzy-
lidene camphor derivatives, esters of cinnamic acid or salicylic
acid, 4-aminobenzoic acid derivatives, such as benzophenone-3,
butylmethoxydibenzoylmethane, octyl methoxycinnamate, octyl
salicylate and also water-soluble products such as phenylbenzimi-
dazolesulfonic acid or benzophenone sulfonic acid derivatives may
be used for this purpose. Combinations with WA filters are also
possible.
An emulsion according to this invention may also contain powdered
substances selected from the group consisting of pigments such as
metal oxides (iron oxides, Ti02, ultramarine blue, chromium oxi-
de, mica-titanium oxide, mica-iron oxide, mixtures thereof) and
also other powdered substances such as Sio2, silica, Zno, kaolin,
~Si02-modified kaolin (according to Wo96/17588), polytetrafluoro
ethylene, nylon, talc, mica, polymethyl methacrylate, polyethyle
ne, natural organic compounds such as encapsulated or unencapsu
lated grain starch and mixtures thereof.
In addition, cosmetically beneficial additives that can also be
used include water, monohydric and polyhydric alcohols, such as
ethanol, isopropanol, propylene glycol, glycerol, ethylene gly-
col, C9-C» alcohols, etc.; methyl, ethyl or butyl ether with
ethylene glycol; propylene glycol or diethylene glycol; gel-
forming substances; vitamins such as vitamin A, E, B2, B6, BIZ, C;
panthenol, aloe vera, allantoin, bisabolol; coloring agents;
preservatives; protective agents, radical scavengers; enzymes,
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plant ingredients; natural anti-inflammatory agents; moisturi-
zers; antioxidants; pIi regulators; pigments such as soluble
melanin; perfume; copper gluconate, etc.
In addition, the emulsion or the gel may contain oxygen-loaded
asymmetrical lamellar aggregates according to W094/00109 or
dispersed or magnetically hard, single-crystal particles contai-
ned in the asymmetrical lamellar aggregates or in liposomes and
having a high coercive field strength according to W095/03061.
to Digestion products of yeasts or plant substances produced by a
gentle ultrasonic digestion method according to W094/13783 are
also very advantageous.
The invention has the following advantages:
1. Incorporating shellac into emulsions or hydrogels leads to
an improved feeling on the skin, which has been proven by
tests,
2. Adhesion to the skin is improved for decorative cosmetics,
i.e., lipstick, tinted daily creames, makeup-cosmetics,
powder and all products containing pigments and pigment-like
substances such as magnetically hard single-crystal parti-
cles of barium or strontium hexaferrite (see W095/03061).
3. Stability in water is increased in sun care products, i.e.,
sun lotions, sun emulsions, after-sun care lotions, sun
gels, etc.
4. In sun care products it acts as an anti-salt water/anti-sand
agent, because it does not leave any oily film on the skin.
5. No stickiness on the skin is detected with any products.
6. Homogeneous emulsions are also obtained with large amounts
of inorganic pigments such as Ti02 or Zn0 or combinations of
Ti02, Zno and Si02, which is advantageous for sun care pro-
ducts with a high sunscreen factor in particular.
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7. An especially permanent (long-lasting) product is achieved
with lipstick and lip gloss with a special gloss that can be
described as matt brilliance.
The invention will be explained in greater detail below on the
basis of examples. All amounts are based on weight unless ex-
plicitly stated otherwise.
Example 1
l0 Preparation of an O/W Emulsion
An 0/W emulsion was prepared from the following ingredients.
Phases A and B were prepared separately at 60°C while stirring
and were combined at the aforementioned temperature and then
cooled to 40°C. Phases C and D were added to the total mixture
while stirring.
Phase A
C12-C15 alkyl benzoate 3.5%
Steareth 1.5%
Phase B
water q.s. ad 100
Glycerol 1.5%
Coloring pigments 2.0%
Phase C .
Babassu oil 2.5%
Silicone oil 1.5%
Preservative 0.3%
Phase D
Perfume oil 0'.2% ,
Example 2
Preparation of an Aqueous Shellac Solution/Dispereion
While stirring, the pH was adjusted to 3.3 with citric acid
in 100 mL water. Then 1.3 g polyvinylpyrrolidone (PVPK30°) and
0.6 g guar hydroxypropyltrimonium chloride (CTFA name) (Jaguar
C14S°) were added while stirring further. To the resulting sol-
ution was added 15 g purified, dewaxed, particulate shellac at
approximately 13-15'C and at less than 1000 rpm, and the solution
was homogenized at 1450 rpm.
The shellac solution prepared in this way had a viscosity of
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54o cP~s. Solutions and-dispersions with higher viscosities and
concentrations of shellac were prepared in the same way, varying
the pH, the amount of shellac used and the amounts of the other
components.
Examgle 3
Preparing a W/O Emulsion
A W/O emulsion was prepared from the
following ingredients.
Phases A and B were prepared separate ly at 85C while stirring
and combined at the same temperature and cooled to 40'C while
stirring. Then phase C was added to the total mixture while
stirring.
Phase A
1-Decane 11.0%
Polyglycerol ester 3.0%
Mineral oil 5.0%
UV filter TiOZ/Zn0/benzophenone-3 3.5%
Si02 (monodisperse) (Merck) .1.0%
Phase B
Distilled water q.s. ad 100
Glycerol 6.0%
Phase C
Preservative 0.2%
Perfume oil 0.1%
Example 4
Preparation of the Gel
Phases A through C were prepared and
mixed together in succession
in this order at room temperature and homogenized.
Phase A
Distilled water q.s. ad 100
Crosspolymer 1.0%
Glycerol 2.0%
Phase B
Triethanolamine 1.0%
Phase C '
Perfume oil 0.2%
Preservative, chamomile extract 2.0%
Vitamin E 0.5%
Vitamin C 0.5%
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Vitamin B2 1.0%
Example 5
Tanning Day Cream
A shellac solution with a shellac content of 20%, prepared accor
5 ding to Example 2, was added as phase E in the amount of 15.0% to
the mixture from Example 1 at 35°C while stirring until the
mixture was homogeneous.
Example 6
Sun emulsion
to A shellac solution with a shellac content of l0%, prepared accor-
ding to Example 2, was added as phase D in the amount of 20.5% of
the total composition to the mixture from Example 3 at 35'C while
stirring until the mixture was homogeneous.
Example 7
Skin care gel
A shellac solution or dispersion with a shellac content of 1%,
prepared according to Example 2, was added as a component of
phase C in the amount of 20.5% of the total composition to the
.mixture from Example 4 at ambient temperature while stirring
until the mixture was homogeneous.
Example 8
Lipstick .
Phase A
Wax WM300/46 (CTFA name) 70%
Castor oil 12%
PPG 1-glyceryl oleostearate paraffin 0.5%
Coloring agents 4.5%
Phase B
DMDM hydantoin ~ 0.6%
PPG 518MDI copolymer (CTFA name) 1.0%
Water q.s. ad 100
Phase C
Perfume oil 0.5%
Phase A was melted while stirring at 80'C. Phase A was added
to phase B at 80'C while stirring. Then the mixture was cooled to
5o'C, and phase C was added at this temperature while stirring.
Then a shellac dispersion with a shellac content of 50%, prepared
according to Example 2, was added in the amount of 5% of the
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total composition while stirring until the mixture was homogene-
ous, and then the product was solidified.
Experimental Example 1
A product that was designated as " product A" was prepared
according to Example 6. A similar product like that in Example 6
was prepared, but no shellac solution was added. This product was
designated as "product B."
For the purpose of testing while sunbathing, the two prod
ucts were applied to the entire body of ten volunteers who were
to already pre-tanned.
Product A gave adequate W protection on all volunteers. The
product was applied only once each time over the period of the
daily four-hour sunbath, and it had a sufficient water resistance
with three interruptions by a l0-minute water bath each time.
Product B was applied at least twice by eight volunteers
during the period of the daily four-hour sunbath to achieve the
same UV protection. Its stability in water was not adequate.
