Note: Descriptions are shown in the official language in which they were submitted.
CA 02295533 2000-O1-11
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DECORATIVE COSMETIC O/4~T EMULSION
The present invention relates to a cosmetic 0/W emulsion with a
long-lasting effect and which is usable in all areas of decorati-
ve cosmetics, especially for cosmetic foundations.
Generally, O/W emulsions for makeup products are produced
with anionic, non-ionic or amphoteric emulsifiers. A wide variety
l0 of emulsifiers is known for this purpose, such as hydrophile
amphoteric block copolymers with cationic and anionic groups (US-
A-5252692) and copolymers with monomers containing nitrile groups
(EP-A-290166). Generally, such conventional emulsions containing
emulsifiers often lead to irritations of the skin, especially in
the event of frequent or long-term use.
US-A-4913743 deals with treating ceratinic material using a
combination of an anionic and a cationic polymer in order to
stabilize and support the fibre-like cell structures. US-A-
5618522 discloses an 0/W emulsion having an oil phase of 3,000
cps and a thickener, which may be a polymethacrylate polymer, and
an aqueous phase as well as an emulsifier which has to be contai-
ned in at least one phase. W094/23693 relates to an 0/W emulsion
for self-tanning comprising a cationic emulsifier besides DHA, a
sunlight protecting agent and a cationic network polymer. EP-A-
615741 describes an o/w emulsion comprising an amphiphile compo-
nent and an agent being active on the surface together being able
to form a gel, oil and water, wherein the total amount of the
amphiphile component and the agent being active on the surface
are located at the interface of the emulsion particles.
The invention is based on the objective to develop new
decorative O/W emulsions with which the aforementioned disadvan-
tages do not occur and which form long-lasting products having at
the same time a sufficient capacity of accepting pigments in the
emulsions.
According to the invention, the decorative cosmetic O/W
emulsion is characterised in that the emulsion comprises 0.1 to
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3 % by weight of a cationic gel selected among polyquaternium-31,
polyquaternium-16, polyquaternium-24, polyquaternium-7, polyqua-
ternium-22, polyquaternium-39, polyquaternium-28, polyquaternium-
2, polyquaternium-l0, polyquaternium-11, polyquaternium-37 &
mineral oil & PPG trideceth, PVP dimethylaminoethylmethacrylate
copolymer, Guar hydroxypropyltriammonium chloride, calcium
alginate, ammonium alginate, Chitosan PCA and mixtures thereof,
which in case of being mixed with water and with 8 to 10 ~ by
weight (in relation to the total weight of the emulsion) of gel-
l0 compatible powdery components used for decorative purposes provi-
des a positive zeta potential of the emulsion ranging from +5 to
+45 mV at a pH value between 3.0 and 8.0; and
that in the aqueous gel phase 5 to 30 ~ by weight of an oil phase
are permanently dispersed without adding an emulsifier with the
~5 oil phase being selected among those triglycerides, fatty alco
hols, linear and branched esters, esters of polyhydroxy alcohols,
vegetable oils or mixtures thereof providing in a mixture with
the cationic gel and the powdery components a positive zeta
potential.
20 The emulsion may comprise other agents, carrier substances,
or mixtures thereof wherein, depending upon the isoelectric
point, the component ratios of all raw substances used are adap-
ted towards each other in a way to provide an overall positive
zeta potential.
25 The employment of 0.3 to 2.5 ~ by weight of gelatinising
agent in the aqueous phase, which decisively contributes to the
provision of a positive zeta potential in the emulsion, is parti-
cularly advantageous. Especially preferred gels are polyquaterni-
um-l0 and -37, Chitosan PCA, Guar hydroxypropyltriammonium chlo-
30 ride alone or as a mixture of one or several of these substances.
At the same time, the gelatinising agents act as emulsifiers
and thus are to be selected with a view to their own zeta poten
tial as well as to their emulsifying properties, especially in
decorative O/W emulsions.
35 The size of the particles of the emulsion- can be further
reduced by adding ethoxylated glycol or polyethylene glycol ( PEG )
in the aqueous phase. Liponic EG1~ made by Lipo or Lutrol e400'°
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made by BASF are suitable PEGS.
Suitable esters of polyols are esters of Coo-C~5 fatty acids
and alcohols, esters of Coo-C~5 fatty acids and glycols, or esters
of hydroxy fatty acids. Branched C~2-C~5 alkyl esters in con-
s junction with other esters such as di- or tri-esters of polyols
are particularly advantageous in the oil phase, with esters of
linear-chain alcohols and branched acids being particularly
favourable. All these suitable esters are derived from primary
alcohols.
l0 Suitable substances for the oil phase include C~Z_~5 alkylma-
late, neopentyl glycol diheptanoate, propylene glycol dicapryla-
te, dioctyl adipate, diisopropyl dimer dilinoleate, diisostearyl
dimer dilinoleate, C~2-~3 alkyl lactate, di-C~Z_~3 alkyl tartrate,
tri-C~2_~3 alkyl citrate, Ci2_~5 alkyl lactate, PPG dioctanoate,
15 diethylene glycol dioctanoate, meadowfoam oil, babassu oil,
jojoba oil, rice oil, C~2_~5 alkyl oleate, avocado oil, tridecyl
neopentanoate, beeswax, cetearyl alcohol and polysorbate 60,
candelilla wax, C~e_26 triglycerides, cetearyl alcohol & cetearyl
glucoside, acetylated lanolin, glyceryl hydroxystearate, C~g_36
20 acid glycol ester, with substances such as C~8_36 triglycerides,
glyceryl hydroxystearate, candelilla wax, and mixtures thereof
being particularly preferred.
Also, polymers such as polyisobutene, synthetic wax, hydro
genated polyisobutene, phytantriol, PVP/hexadecene copolymer may
25 be comprised therein.
The share of the oil phase is preferably within the range
from l0 to 25~ by weight, based on the total mass of the emul-
sion. The range between 15 to 25o by weight is particularly
preferred.
30 The emulsion for use in decorative cosmetics according to
the invention contains substances in a powder form selected from
the group consisting of pigments such as metal oxides (iron
oxides, TiOZ, ultramarine blue, chromium oxide, micaceous titani-
um oxide, micaceous iron oxide, manganese purple, zinc oxide,
35 mixtures thereof), and of other powdery substances such as SiOZ,
silica, kaolin, kaolin modified with SiOz (as per W096/17588),
polytetrafluoroethylene, nylon°', talcum, mica, polymethylmeth-
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acrylate, polyethylene, natural organic compounds such as encapsulated and non-
encapsulated
grain starch, dulling means such as polymethacrylate and mixtures thereof.
The emulsion may also comprise large shares of active components which
otherwise are
difficult to stabilise in a formulation, such as octylmethoxycinnamate which
is used as an organic
sun protecting agent, or methyl lactate as a refresher.
The emulsion according to the present invention represents a colloidal system.
Depending upon the selected cationic gel or gel mixture, the emulsion
according to the
present invention may be of a visco-plastic type, e.g. using a Polyquaternium
gel such as
Polyquaternium 31. In this case, it has a medium yield point in the range from
15 to 40 Pa. The
viscosity of this emulsion is lower than
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l0 Pa~s. The values were determined by means of a Physica US
200 rheometer on the basis of the Herschel-Buckley~equation.
The conus was MK23 (2°).
An essential characteristic of the present invention is
the positive zeta potential of the emulsion. Zeta potential is
the designation for the galvanic voltage in the diffuse sec
tion of the electrochemical double layer at the interface of
two non-miscible phases. The electrochemical double layer is
known to consist of the Stern layer of firmly adsorbed ions
l0 with their surface or Nernst potential (facing the inner par-
ticles, in this case the oil droplets) and the Stern potential
facing the diffuse layer (Gony-Chapman double layer) . The zeta
potential is the potential externally effective for the elec-
trokinetic appearance of the particles. When this potential
equals zero, the isoelectric point has been reached.
The pH value of the emulsion according to the invention
is preferably in the rage from 5.5 to 6.5.
It was found that o/W emulsions with positive zeta poten
tial of a composition in accordance with the invention possess
an excellent skin adhesion and thus may be processed into
highly long-lasting cosmetic products without the fear of skin
irritations due to the effects of emulsifiers: This is parti-
cularly surprising as it may be deduced from J. Biomat. Appl. ,
Vol. 3, April 1989, p. 554, that hydrogels generally have a
low propensity to adhere to tissues, etc. due to their non-
specific absorption of proteins at the hydrogel surfaces,
specifically due to the lack of protein absorption due to
hydrophobic interactions. Excellent skin adhesion is one of
the fundamental advantages of the invention.
Furthermore, the emulsions according to the invention
provide a better colour stability than decorative emulsions
already known, a fact that could not easily be deduced from
their composition.
It was also found that the special gel phase of the emul
sions in accordance with the invention can accept a high share
of pigments or powdery substances, and that this viscoplastic
CA 02295533 2000-O1-11
emulsion thus is especially suited for use in decorative cos-
metics. The preferred shares of pigments and/or powdery sub-
stances range between 8 - 20 % by weight, preferably l0 - 20
% by weight, in particular 12 - 20 % by weight. It was also
5 found that even small amounts of cationic gelatinising agents
with a positive zeta potential ranging from o.l to 0.8 % by
weight form stable emulsions.
In order to obtain a generally positive zeta potential in
the claimed range, it is necessary to use such raw materials
l0 which contribute to the same accordingly. To this, end, the
person skilled in the art has to determine the surface load,
i.e. the isoelectric point of all raw materials used and to
adjust the various shares of the components in a way providing
an overall positive zeta potential.
Pigments, for example, slightly reduce the zeta potential
as mineral substances often feature a negative load at the pH
values of the emulsion according to the present invention
ranging between 5.5 and 6.5 while this pH value lies mostly
near the isoelectric points of the pigments. Therefore, the
2o person skilled in the art has to select appropriate cationic
gels together with the other agents and/or carrier substances
in order to achieve an overall positive zeta potential. Struc-
tural similarities between e. g. Polyquaternium-31 (quaternary
ammonia salt comprising DMAPA acrylates/acrylic acid/acryloni-
trogene copolymer, and diethyl sulphate) and an acrylate block
copolymer can very well produce quite different zeta potenti-
als in the emulsion, e. g. +38 mV in case of Polyquaternium-31
and -21 mV in case of an acrylate block copolymer.
Finally, it was found that the humidity characteristics
of the emulsion according to the present invention are
somewhat better than those of comparable emulsions containing
additional humidity-keeping substances. Thus, CorneometerA
measurements of skin hydration indicated a value of 12 % 1
hour after applying the emulsion, compared with 11 % in case
of the comparative emulsion which contained humidity-keeping
substances. After 3 hours the emulsion of the invention indi-
cated a value of 4, 5 % compared with 2 % of the comparative
emulsion. The comparative emulsion was a so-called "no-tran-
CA 02295533 2000-O1-11
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sfer foundation" . Significantly better results are expected in
comparison with a so-called "transfer-proof foundation". Such
emulsions are known to be dehydrating cosmetic substances.
The better humidity characteristics of the emulsion ac
s cording to the present invention are probably due to the capa
bility of the hydrogel to keep water within its network over.
a long period of time.
The particularly favourable long-lasting adhesion to be
achieved by the invention may be documented by investigation,
to e.g. of the colour change DE in a formulation in accordance
with the invention containing pigments, which is applied onto
one half of the face of a test person, in comparison to a
formulation with the same composition but a negative zeta
potential of the emulsion . While the DE value of approximately
15 22 drops to around 18 after 8 hours in the formulation with
the negative zeta potential, the DE value of the emulsion with
a positive zeta potential according to the invention applied
onto one half of the face remains nearly constant at its in-
itial level throughout the period. A feature of the long-la-
2o sting effect characteristic for this invention is the skin
adhesion without noticeable impairment of the colour or other
conditions of the emulsion applied onto the skin over a mini-
mum period of 3 hours.
A specific embodiment of the present invention comprises
25 a cosmetic emulsion in which the aqueous phase contains 0.1 to
0.8 ~ by weight of a cationic gel or gel mixture which, if
mixed with water and with o .1 to 20 ~ by weight of powdery
components and possibly other agents, carrier substances or
mixtures thereof, produces a positive zeta potential of the
3o emulsion ranging between +5 and +45 mV at a pH value between
3.0 and 8.0, preferably 5.5 to 6.5, an wherein 5 to 30 ~ by
weight of an oil phase are dispersed in a stable manner in the
aqueous gel phase without adding an emulsifier.
The present invention is to be described in greater de
35 tail by the examples below. All amounts specified are in per
cent by weight.
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Glycereth 26 or PEG 8 4.0
Polyquaternium 10 0.5
propylene glycol dicaprilate dicaprate o.3
PPG-1-Trideceth-6
tocopheryl acetate 0.2
C~z-C~3 alkyl malate 25.0
The emulsion was produced in the usual manner, i. e. by
stirring and heating the water to reach 80 ° C and then adding
Polyquaternium to to be homogenized at around 8,000 rpm. The oil
phase was heated up to 80 °C, and the emulsification with a
aqueous phase was carried out at 8,000 rpm. Finally, the resul-
ting product was slowly stirred (at about 200 rpm), deaerated and
cooled down.
The resulting emulsion had a zeta potential of +2B mV, a pH
value of 6 and a volume-related average particle size of 2.56 ~.m,
with 90 % of the particles being smaller than 6.33 um.
The zeta potential was measured using a " Zeta Sizer 3" of
Malvern Instruments Ltd., Worcs, Great Britain. The zeta potenti-
al was determined on the basis of a laser Doppler microelectro-
phoresis. According to this method, the thinned emulsion is
injected into a measuring cell; then, a current having a known
voltage is applied, and the speed of the particles in a fluid
flow is measured by means of laser Doppler velocimetry (LDV) and
determined according to the known formula taking into account the
viscosity, the migration speed in the direct current field, the
dielectric constant and the field strength.
The measurement of the particle sizes was carried out using
a "Mastersizer" of Melvern Instruments Ltd.
Example 2: Cosmetic foundation with sun protector
deionised water q.s. ad 100
preservative 0.5 ; titanium dioxide 5.0
PE 4.0 ; tocopheryl acetate 0.2
glycereth-25 4 . 0 i C~2-C13 alkyl octanoate 18 . 0
Polyquaternium l0 0.4 ; octylmethoxycinnamate 7.0
iron oxides 1.25
The emulsion was produced in a manner similar to that in
Example 1, except that the pigments were added in Glycereth-25 or
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PEG-8 prior to adding the aqueous phase. Octylmethoxycinnamate
was added during the cooling-down phase at a temperature of about
60 C.
In vitro, the resulting emulsion
had a sun protection factor
(SPF) of 10 and a zeta potent ial of +35.8 mV 1.2 mV, with 80
%
of the particles having a par ticle size of less than 8.80 Vim.
Example 3: Cosmetic foundation
deionised water q.s. ad 100
preservative 0.5
l0 kaolin modified with Sio2* 2.5
Polyquaternium l0 0.4
Chitosan PCA 1.5
Glycereth 26 4.0
silica l.o
Di-Cj2-C~3-alkyl malate 11.0
iron oxides 1.25
titanium dioxide 5.0
neopentyl glycol diheptanoate 3.0
diethylene glycol dioctanoate / diisononanoate 3.5
tridecyl neopentanoate 2.0
tocopheryl acetate 0.2
myristyl lactate 2.0
cyclomethicone & dimethyconol 1.0
porphyridium cruentum extract 5.0
fragrance 0.4
The emulsion was produced in a manner similar to
Example 2. The resulting emulsion had a zeta potential of +32.4
mV ~1.5 mV and a pH value of 6.
* White kaolin modified according to W096/17588 with 0.5 to 10
by weight of spherical Si02 having a particle size < 5 ~,m.
Example 4: Mascara (not pertaining to the invention)
deionised water q.s. ad 100
preservative 0.7
PVP 4.0
Polyquaternium l0 0.2
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fragrance 0.4
The emulsion was produced in a
manner similar to that in
Example 2. The resulting emuls ion had a zeta potential of
+32.4 mV 1.5 mV and a pH value of 6.
Example 4: Mascara
deionised water q.s. ad 100
preservative 0.7
PVP 4.0
Polyquaternium 10 0.2
l0 Guar hydroxypropyltriammonium 0.9
chloride
Glycereth 26 2.0
triethanolamine 99 g 2.4
magnesium aluminium silicate 1.0
talcum 1.0
wheat germ oil 1.0
PVP/eicosene copolymer 2.0
iron oxides 12.0
hydrogenated polyisobutene 0.2
cetearyl alcohol 0.1
stearic acid 7.0
carnauba 4.0
sorbitan sesquioleate 1.3
beeswax 4.0
C~8-36 acid triglycerides 8.5
lecithin 1.0
tocopheryl acetate 0.2
All gels and polymers were dispersed in the aqueous pha-
se. Then, the pigments were dispersed.
The emulsion was com-
pleted at 85 C.
The resulting emulsion had a zeta potential of 29.1 mV
1.6 mV; due to the high wax concentration,
it contains an
emulsifier.
Example 5: Eyeliner
deionised water q.s. ad 100
CA 02295533 2000-O1-11
The emulsion was produced in a manner similar to that in Example
2. The resulting emulsion had a zeta potential of +18.1 mV ~4.5
mV.
Example 6: Cosmetic foundation
5 This cosmetic foundation has the advantage of not being trans-
ferred onto textiles.
deionised water q.s. ad 100
preservative 0.5
10 Glycereth 26 4.0
C12-C73-alkyl malate 4.2
iron oxides 10.5
Polyquaternium 31 0.4
diethylene glycol dioctanoate / diisononanoate 4.5
tocopheryl acetate 0.2
myristyl lactate 3.5
dicaprylyl ether 3.0
cetearyl alcohol 4.0
jojoba ester 1.5
polymethyl methacrylate 2.5
fragrance 0.4
The emulsion was produced in a manner similar to that
in Example 2. At a pH value of 6, the resulting emulsion had a
zeta potential of +35.8 mV ~1.2 mV.
Comparative Example 1:
An emulsion similar to that in Example 3 was produced with the
following composition:
deionised water q.s. ad 100
preservative 0.5
kaolin modified with Si02 * 1.0
xanthan gum 0.3
silica 1.0
Di-C~Z-C~3-alkyl malate 11.0
propylene glycol 6.25
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Example 2. At a pH value of 6, the resulting emulsion had a
zeta potential of +35.8 mV 1.2 mV.
Comparative Example 1:
An emulsion similar to that in Example
3 was produced with the
following composition:
deionised water q.s. ad 100
preservative 0.5
kaolin modified with Si02 * 1.0
xanthan gum 0.3
l0 silica 1.0
Di-C~2-C~3-alkyl malate 11.0
propylene glycol 6.25
iron oxides 1.25
titanium dioxide 5.0
neopentyl glycol diheptanoate 3.0
diethylene glycol dioctanoate
/ diisononanoate 3.5
tridecyl neopentanoate 2.0
acrylic acid / acrylonitrogen 3.4
copolymer
myristyl lactate 2.0
cyclomethicone & dimethyconol 1.0
fragrance 0.4
* as per W096/17588
The emulsion was produced in a manner similar to that in
Example 3. At a pH value of 5.5, the resulting emulsion had a
zeta potential of -41.4 mV ~7.9 mV.
The emulsion of Example 3 and the Comparative Example 1
3o were subjected to a colour test to determine ~E over a period
of 8 hours. The results described earlier were achieved.
