U.S. patent application number 14/882540 was filed with the patent office on 2016-02-11 for gel technology suitable for use in cosmetic compositions.
The applicant listed for this patent is Avon Products, Inc.. Invention is credited to John C. Brahms, Steven E. Brown, Michael J. Fair, John R. Glynn, Jr., Prithwiraj Maitra, Jason Rothouse.
Application Number | 20160038384 14/882540 |
Document ID | / |
Family ID | 40795847 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160038384 |
Kind Code |
A1 |
Maitra; Prithwiraj ; et
al. |
February 11, 2016 |
Gel Technology Suitable for Use in Cosmetic Compositions
Abstract
A gel system comprising a fractal network of nanoparticles and
macroscopic particles is disclosed. The gel system is capable of
forming an "optical gel" effective to blurrfine lines and wrinkles
as a consequence of the size domain differences between the fractal
particles and the macroscopic particles. Cosmetic compositions
comprising such gels and methods for their use are also
disclosed.
Inventors: |
Maitra; Prithwiraj;
(Hillsborough, NJ) ; Brown; Steven E.; (Oak Ridge,
NC) ; Glynn, Jr.; John R.; (Ridgewood, NJ) ;
Rothouse; Jason; (Grand Rapids, MI) ; Brahms; John
C.; (Morris Plains, NJ) ; Fair; Michael J.;
(Ridgewood, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Avon Products, Inc. |
Suffern |
NY |
US |
|
|
Family ID: |
40795847 |
Appl. No.: |
14/882540 |
Filed: |
October 14, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12747469 |
Jun 10, 2010 |
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PCT/US2008/083490 |
Nov 14, 2008 |
|
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14882540 |
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61014846 |
Dec 19, 2007 |
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Current U.S.
Class: |
424/401 ;
424/691; 424/78.03 |
Current CPC
Class: |
A61K 8/492 20130101;
A61K 8/447 20130101; A61K 2800/412 20130101; A61K 8/4986 20130101;
A61Q 19/08 20130101; A61K 8/042 20130101; A61K 8/26 20130101; A61K
8/4953 20130101; A61K 8/25 20130101; A61P 17/00 20180101; A61K
8/4946 20130101; A61K 31/325 20130101; A61K 8/49 20130101; A61K
8/891 20130101; A61K 2800/413 20130101; A61K 8/4913 20130101; A61K
8/4926 20130101; A61K 8/494 20130101; A61K 8/4973 20130101; A61K
2800/262 20130101 |
International
Class: |
A61K 8/04 20060101
A61K008/04; A61K 8/891 20060101 A61K008/891; A61K 8/25 20060101
A61K008/25; A61Q 19/08 20060101 A61Q019/08; A61K 8/26 20060101
A61K008/26 |
Claims
1. A method for optically blurring the appearance of skin
imperfections selected from the group consisting of wrinkles, fine
lines, and pores comprising the step of applying to the skin gel
comprising (a) a fractal network of nanoparticles dispersed in a
suitable medium such that the nanoparticles coalesce to form the
fractal network; and; (b) translucent macroscopic elastomeric
particles enveloped in said fractal network of nanoparticles; where
the refractive index of the nanoparticles does not match the
refractive index of the macroscopic particles; and wherein the gel
is anhydrous.
2. The method according to claim 1, wherein the first and second
nanoparticles have a particles size of between about 50 to about
900 nm.
3. The method according to claim 1, wherein the first and second
nanoparticles have a refractive index of from about 1.38 to about
2.
4. The method according to claim 1, wherein the translucent
macroscopic elastomeric particles have particle size of between
about 1-200 microns.
5. The method according to claim 1, wherein translucent macroscopic
elastomeric particles have a refractive index of from about 1.38 to
about 1.6.
6. The method according to claim 1, wherein the first nanoparticles
comprise alumina, and the second nanoparticles comprise silica.
7. The method according to claim 1, wherein the translucent
macroscopic elastomeric particles comprise a silicone
elastomer.
8. The method according to claim 1, wherein the weight ratio of the
fractal particles to the macroscopic particles is from about 1:10
to about 10:1.
Description
RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 12/747,469, filed Jun. 10, 2010, which is a
national stage application of International Application Serial No.
PCT/US08/83490 filed Nov. 14, 2008, which claims priority U.S.
Provisional Patent Application Ser. No. 61/014,846, filed Dec. 17,
2007, the contents of which are hereby incorporated by reference in
their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to gel technology comprising
macroscopic particles dispersed/suspended/interspersed within a
network of fractal particles, more particularly to cosmetic
compositions containing such gels to obtain efficient optical
blurring of wrinkles, fine lines, pores, skin imperfections, and
the like, and most particularly to such cosmetic compositions in
which the fractal network is a fractal gel.
BACKGROUND OF THE INVENTION
[0003] A number of methods have been developed to reduce wrinkles
and minimize fine lines. Some of these methods include active
ingredients such as antioxidants; agents that act by
neurotransmission inhibition in nerve cells such as botulinum toxin
(Botox.TM.) (Allergan, Irvine, Calif.), thereby relaxing contracted
muscles; agents that accelerate the cell renewal process such as
hydroxy and fruit acids like retinoic acid; emollients such as shea
butter; skin plumpers such as hyaluronic acid; fillers such as
collagen; light-diffusing pigments and microspheres which create
the illusion that wrinkles have disappeared. Other methods have
been developed to reduce the appearance of pores, skin surface
unevenness and imperfections and the like. Some of these methods
include skin lightening agents, filling and camouflaging the
skin.
[0004] Unfortunately, many cosmetic foundations and make-ups
actually accentuate wrinkles and fine lines due to migration of the
pigments into the wrinkle crevices. Other products cover skin
imperfections but create an unnatural, caked-on appearance. Others,
such as mica, reflect rather than diffuse and scatter light,
thereby resulting in an unnatural shiny appearance. Additionally,
some of these methods are not immediate, requiring days and weeks
of continued use to see effects. Others are invasive, requiring
injections, patent discomfort, and may entail redness, swelling and
other side effects.
[0005] Novel, safe and effective topical "optical blurring"
technology to treat wrinkles and skin imperfections are needed.
Therefore, the need exists for alternative methods to provide a
natural and smooth appearance to the skin with visible reduction in
wrinkles, fine lines, pores and skin imperfections but which
overcomes the problems associated with previous methods and
compositions and which would represent a significant advance in
cosmetic art.
[0006] The optical reduction of wrinkles is due to the light
diffusing properties of the applied particles. At the margins and
in the creases of wrinkles, particles that scatter and thus diffuse
light away minimize the depressions in the skin. To the observer,
the wrinkles appear blurred, hence the terms "soft focus effect"
"blurring effect." In the past, the blurring effect was based on
the diffuse reflection of spherical particles such as microspheres
and fibers. One such composition is that described by Nakamura, N.
et al, "Blurring of Wrinkles Through Control of Optical
Properties", XIVth I.F.S.C.C. Congress, Barcelona, Spain, 1986.
[0007] The incorporation of inorganic nanoscale particles into a
polymeric matrix is known for industrial uses to provide clear
coatings, for example, mobile phones or skies.
SUMMARY OF THE INVENTION
[0008] The present invention provides for the use of fractal
particles with unique optical properties and surface chemistry,
combined with micron dimension organic or inorganic particles such
that the fractal network wrap around the macroscopic particles
increasing the interfacial area over which lateral light diffusion
occurs. It has been found that such technology is useful to
optimize the optical diffusion effect of light, i.e., optical
blurring, and consequently, cause the appearance of wrinkles, fine
lines, pores and skin imperfections to vanish while allowing the
skin to appear natural and flawless.
[0009] It is an object of the present invention to provide a gel
system (as hereinafter further described) comprising macroparticles
within a fractal network of nanoparticles.
[0010] Another object of the present invention is to provide such
gel system comprising macroparticles that are translucent, for
example silicone crosspolymers.
[0011] A further object of the invention is to provide the gel
system in which the fractal network is a fractal gel (as
hereinafter further described).
[0012] It is yet another object of the present invention to provide
cosmetic compositions comprising the gels of the present invention
that are efficient in blurring fine lines, wrinkles, pores, and
skin imperfections.
[0013] It is a further object of the present invention to provide
gels that leverage the differences in size domain and optical
properties between fractal particles and macroscopic particles. The
presence of macroscopic particles increase the spatial distribution
of fractal particles increasing the interfacial area over which
light bending/lateral scattering occurs. Accordingly, the gels are
seen to have superior optical properties when used especially in
cosmetic products. Macroscopic particles can be organic or
inorganic. Non-limiting examples of macroscopic particles are
silicone elastomers, hydrocarbon elastomers, silicone
crosspolymers, polymeric spheres, metal oxide spheres, or
combinations thereof.
[0014] It is a further object of the present invention to provide
cosmetic compositions containing aqueous gels according to the
invention comprising macroscopic particles present in a fractal
particle network obtained by using a mixture of fractal particles
with opposite zeta potential at a given pH. Such aqueous gels may
be used as prepared, may be modified to include other ingredients,
or may be incorporated as a phase in an emulsion cosmetic
composition. Preferred macroscopic particles in the present
invention are silicone elastomers and silicone crosspolymers.
[0015] It is another object of the present invention to provide
cosmetic compositions containing anhydrous gels of the invention
comprising macroscopic particles dispersed in a network of fractal
particles, typically with a compatible anhydrous solvent. Such
anhydrous gels may be used as prepared, may be modified to include
other ingredients, or may be incorporated as a phase in an emulsion
cosmetic composition.
[0016] A further object is to provide methods for producing the
gels of the invention and cosmetic compositions containing
same.
[0017] The invention also has as its object a cosmetic treatment
process allowing wrinkles, fine lines, pores and skin imperfections
to be blurred in human beings, particularly the skin of the face,
neck, and lips, this process being characterized by applying an
effective quantity of a composition of the present invention to the
skin.
[0018] Further according to this and other objects and advantages
of the present invention, there are provided methods for blurring
wrinkles and fine lines. A method includes applying to the skin
and/or lips a gel composition which leverages the relative
size/domains and refractive indices of the fractal network and
macroscopic particles to obtain efficient blurring.
[0019] In another aspect of the invention the present invention is
applicable to the skin in a cosmetically acceptable vehicle.
[0020] These novel features of the present invention will become
apparent to those skilled in the art from the following detailed
description, which is simply, by way of illustration, various modes
contemplated for carrying out the invention. As will be realized,
the invention is capable of additional, different obvious aspects,
all without departing from the invention. Accordingly, the Figures
and specification are illustrative in nature and not
restrictive.
BRIEF DESCRIPTION OF THE FIGURES
[0021] FIG. 1 is a schematic representation of the spatial
arrangement of the gel structure comprising the macroparticles and
the fractal nanoparticles.
[0022] FIG. 2 is a schematic representation illustrating the
diffusion on light incident on the surface of skin treated with a
cosmetic composition of the present invention.
[0023] FIG. 3 is a graphical plot of the zeta potential of various
metal oxides as a function of pH.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention utilizes gel systems to provide
compositions having unique optical and space filling properties. As
a consequence to the optical properties, thin films of the
compositions applied to a substrate, in particular, a biologic
surface, change the way light incident on the surface of the film
is refracted and improves the diffusion of incident light on the
surface of the film. When the composition is a cosmetic composition
and the film is on the surface of the skin of an individual, the
imperfections of the skin are less noticeable, i.e., less "visible"
because of the way reflected light is being seen by an observer. In
addition the gels of the present invention provide a fractal
network with macroscopic particles, thus further providing
beneficial optical properties, especially when the refractive
indices are non-matching. The gels are capable of filling voids in
the surface of the biologic substrate, especially, wrinkles, lines,
pores, and other imperfections present in the surface of an
individual's skin or lips. Unless indicated otherwise, the term
"gel" refers to the gels as set forth in this paragraph and as
further described in this specification.
[0025] As shown schematically in FIG. 1, it is believed that gel 10
comprises a plurality of translucent macroparticles 15 surrounded
by a multiplicity of nanoparticles 20, which nanoparticles
aggregate or otherwise coalesce to form a fractal gel network,
represented generally by numeral 30.
[0026] FIG. 2 illustrates a film 100 of a cosmetic composition of
the present invention applied to skin 105, as well as an enlarged
view A of the gel 110 taken from a small area of the film 100. Gel
110 comprises a plurality of translucent macroparticles 115
surrounded by a multiplicity of nanoparticles 120, whereby fractal
gel network 130 is formed. Actives and/or adjuvants 135 are present
within the gel network 130. Light 140 entering the gel 110 is
diffused by the translucent macroparticles, as shown schematically
by the plurality of light vectors 145, 146, and 147, whereby the
skin is provided with an optical blurring benefit.
[0027] Another beneficial aspect of the invention is the ability of
the gel network to display unique rheological properties, which are
especially useful in cosmetic applications. The gel network is
highly thixotropic. That is to say, the viscosity of the gel
rapidly diminishes under increasing shear stress, yet the gel
network reforms quickly once the shear stress is removed.
Effectively, this imparts an effect wherein the composition
transforms from viscous, non-flowing compositions to a free flowing
liquid when the composition is applied, e.g., with a brush or other
applicator. The speed at which the network reforms to a gel is a
function of particle concentration, and, in the instance where the
fractal network is a fractal gel, on the magnitude of the
attractive interaction between the oppositely charged particles
(refer to section "Surface Charge of Particulate Dispersions").
Hyperthixotropic compositions are particularly useful in
foundations, mascaras, hair care, lip compositions, and personal
care compositions where low viscosity is desired during
application, yet a rapid increase in viscosity is important to
prevent migration of the applied composition.
[0028] The gel system of the present invention comprises one or
more translucent macroparticles and includes a fractal network of
nanoparticles. Translucent materials allow light to pass through
them but scatter light so that the material distorts the image.
Suitably translucent macroparticles are those whose diffuse
transmittance is greater than zero for a 10 micron film cast on a
glass plate as measured using a color(i) spectrophotometer. Films
can be prepared by dispersing macroparticles in a suitable binder,
polymer, or solvent. A dispersion can prepared by dispersing
macroparticles in a binder, polymer or solvent followed by casting
a 10 micron film on a glass (normalized with % solids in the
solution) using a drawdown bar. A color (i) spectrophotometer can
be used to measure total transmittance and direct transmittance.
Diffused transmittance can be obtained by subtracting direct
transmittance from total transmittance.
[0029] In the present invention the fractal network comprises one
or more types of fractal particles. In the preferred embodiment the
fractal network is a fractal gel. While not wishing to be bound by
any particular theory or mechanism, the fractal network is believed
to envelop the macroparticles, with gelation occurring when
dispersed in a suitable medium.
[0030] The phrase "cosmetically acceptable vehicle" refers to a
medium that is compatible with keratin materials, such as human
skin.
[0031] The term "optical blurring" as used herein refers to optical
reduction of wrinkles, fine lines, skin surface unevenness and
imperfections.
[0032] The term "macroscopic particles" or "macroparticles" as used
herein refers to particles that have a size range of 1 to 200
microns.
[0033] The term "nanoparticle" refers to particles with a size of
up to about 900 nm.
[0034] The term "fractal particles" as used herein refers to
nanoparticles of varying fractal dimension or in-built reticulated
structure; that is, having Hausdorff-Besicovitch dimensions greater
than their topological dimensions. As used herein, "nanoparticles"
is synonymous with "fractal particles", unless specifically
indicated otherwise.
[0035] By "gel" is meant any co-continuous phases of macroscopic
particles and a fractal particle network that forms a composite gel
structure.
[0036] The terms "blurring" and "optical blurring" as used herein
refers to optical reduction of wrinkles, fine lines, pores and skin
surface unevenness and imperfections.
[0037] Reference to "particle size" means the mean diameter of
particles measured under an appropriate imaging technique for the
size domain under consideration, for example, scanning electron
microscopy or transmission electron microscopy.
[0038] Except where specific examples of actual measured values are
presented, numerical values referred to herein should be considered
to be qualified
[0039] The terms "a" and "an", as used herein and in the appended
claims, mean "one or more" unless otherwise indicated herein.
[0040] All percentages and ratios referred to herein are by weight
of total composition (i.e., the sum of all components present),
unless otherwise indicated.
The Fractal Network
[0041] In one embodiment the fractal network comprises at least one
type of submicron sized fractal particle (i.e., nanoparticles). The
fractal particles may have a positive, neutral or negative net
surface charge (zeta potential. When dispersed in a suitable medium
the fractal particles coalesce to form the fractal network.
Depending on the medium, the coalescing takes place in light of van
der Waals forces (hydrophilic dispersant), electrostatic
attraction, or because of hydrogen bonding (lipophilic dispersant).
As explained in more detail below, the macroparticles may be added
to this dispersion under shear to form the gels of the present
invention.
[0042] In one embodiment the fractal network is a fractal gel. The
fractal gel comprises first and second submicron sized fractal
particles having opposite surface charges at a given pH. By way of
example and referring to FIG. 3, at pH below 7-8 the metal oxides
silica and alumina have opposite surface charge or zeta potential.
The first or second fractal particles that form the fractal gel may
each comprise two or more different fractal particles having the
same charge. The two or more different first or second fractal
particles of the same charge may have different sizes, different
net surface charges (of the same type, however), or different
refractive indices. The use of fractal gels in the formation of
gels of the present invention is preferred. The fractal gels,
because of their oppositely charged particles, have stronger
attraction between the fractal particles.
[0043] The fractal gel is obtainable by forming dispersions of the
oppositely charged fractal particles. Combining aqueous dispersions
of each particle type forms a highly structured gel network as a
result of charge neutralization. Alternatively, the zeta potentials
may be of the same sign initially, and the pH of the combined
dispersions adjusted thereafter to give zeta potentials of opposite
signs, thereby allowing integration of the organic particles and
inorganic particles.
[0044] When the fractal network comprises a single fractal particle
or two or more fractal particles of the same or neutral charge
(i.e., not oppositely charged as needed to form the fractal gels),
the network can be formed by providing a dispersion of the fractal
particles as described in the previous paragraph. A network will
form suitable for use in the present invention when the cohesive
interactions among particles is greater than adhesive interactions
between the particles and the medium. The macroscopic particles are
incorporated following network formation.
[0045] A brief description of fractal particle geometry
follows:
[0046] Fractal objects are characterized by a recursive
self-similarity. In general, the fractal nature can be described
mathematically by a power law relationship taking the form:
Y=c*X.sup.d (1)
where c is a constant. Therefore, if data adhere to a power law
relationship, a plot of log (Y) versus log (X) will yield a
straight line with slope d.
[0047] Analogously, self-similar fractals, a class of
Hausdorff-Besicovitch dimensionality, rely on the object being
self-similar at different length scales. The power law is
consistent with this case following:
A=(1/s).sup.D (2)
where A is the number of identical parts, s is the reduction factor
and D is the self-similar dimension measure of the fractal.
Equation 2 can be arranged as the following
D=log(A)/Log(1/s) (3)
[0048] For example, the sides of a unit square are divided in half,
forming 4 pieces, therefore A=4, s=1/2 thus D equals 2. Likewise a
Sierpinski Gasket, wherein the original triangle side is halved,
three triangle pieces are formed. Thus, A=3, s=1/2 and D=1.5850.
Comparatively, consider a unit line segment. Dividing the line in
half results in 2 equal parts, and so on. Therefore, A=2, s=1/2
D=1. It is important to note, the value of D agrees with the
topological dimension of the line, yet a line is not fractal.
Accordingly, fractals are those objects wherein the
Hausdorff-Besicovitch dimension exceeds its topological
dimension.
[0049] Furthermore, fractals can be classified according to their
self-similarity. There are three basic types of self-similarity
expressed in fractals. Exact self-similarity (the strongest type of
self-similarity). The fractal appears identical at different length
scales. Fractals of this type are described by displaying exact
self-similarity.
[0050] Quasi-self-similarity (non-exact form of self-similarity).
The fractal appears approximately identical at different length
scales. Quasi-self-similar fractals are comprised of distorted and
degenerate copies.
[0051] Statistical self-similarity (weakest type of
self-similarity). The fractal is described by statistical measures,
which are preserved across the length scale. Random fractals are
examples of fractals, which are statistically self-similar, but not
exact or quasi self-similar. The nature of similarity of fractals
can also be described by mathematical functions.
[0052] Most fractal objects of interest do not have a readily
apparent self-similar nature. Therefore, a convenient method to
determine the fractal dimension of the object is the box counting
method. This method is widely used and a direct method to measure
the fractal dimension objects via image analysis. An object image
is projected on a grid of known dimensions. Subsequently, the
number of blocks that the image touches is counted. This data
yields the number of blocks (N) and the block size (reduction
factor, s). The grid is resized, and the process is repeated. A
plot of the data, where the x-axis is log (s) and the y-axis is log
(N(s)) using equation 3, yields a slope of value D.
[0053] Image analysis is particularly useful to evaluate the
fractal dimension of particulates. Specifically, transmission
electron spectroscopy (TEM) is well adapted to evaluate the fractal
dimension of complex particulate structures. Of particular interest
are fractal particles that are comprised of non-overlapping primary
particles, which form a larger aggregate structure. Typically,
particles of this nature are manufactured by a fuming process or
complex precipitation process.
[0054] Evaluation of the mass fractal dimension of particles formed
from aggregates of smaller primary particles involves determination
of the number of primary particles per aggregate. Typically, this
is achieved by evaluating TEM micrographs using digital imaging
processing techniques. The number of primary particles per
aggregate (N) is determined by dividing the projected area of the
aggregate (Aa) by the projected area of the monomer unit (Am):
N=(Aa/Am).sup..alpha. (4)
where .alpha. is an empirical fitting parameter, typically 1.0-1.1.
Therefore, the Hausdorff dimension implies the relationship between
the primary particle size (dp), the area radius of gyration (Rg),
and the number of primary particles (N) describes the fractal
dimension (Df) of the aggregate:
N=kf(Rg/dp).sup.Df (5)
where kf is a constant fractal prefactor. A plot of log (N) vs. log
(Rg) results in a linear plot of slope Df. Typical Df values for
fractal particles of the present invention obtained by a fuming
process range from 1.5-1.9, while fractal particles of the present
invention obtained by a precipitation process range from 2-2.8.
[0055] Additional test methods based on rheological measurements
and light scattering measurements can be used to elucidate the
dimensionality of fractal particles, as known in the art.
[0056] The fractal nature of the particles results in a porous
matrix structure of the fractal network. In another embodiment the
porous matrix structure of the fractal network may receive one or
more active substances.
[0057] The size domains and refractive indices of the fractal
particles are chosen to effectively form a barrier between the
macroscopic particles and consequently enhance the ability of the
compositions of the invention to fill wrinkles and mask skin
imperfections. The fractal particle network has an open structure,
which provides a surface smoothing effect. Thus, the composition
fills in imperfections in the surface of the skin, and thus
provides a natural, smooth and youthful appearance with visible
reduction in wrinkles and skin imperfections when applied to the
skin.
[0058] Typically, the fractal particle may comprise between about
5% to about 75%, preferably about 10-40%, most preferably about
20-40% solid fractal particles by weight of the fractal particle
dispersion. In some instances the particles are provided by the
manufacturer as a dispersion. Suitable commercially available metal
oxide dispersions are Cab-o-Sperse.TM. PG01, PG063, PG003, PG0042,
and AeroDisp.TM. W1836, W630 supplied by Cabot Corporation and
Degussa, respectively.
[0059] It is also possible to provide nonaqueous dispersions that
can be used to form a nonaqueous gel phase. Where required, the
dispersion media must be able to maintain the surface charge of the
fractal particle, typically requiring trace quantities of a charge
control agent such as tetrabutyl ammonium benzoate, so that charge
neutralization may occur. Suitable dispersion media that may be
used to provide the dispersion of the fractal particles are
hydrocarbons such as isododecane, simple esters, and silicone
fluids such as cyclomethicone. Ionization of metal oxide surface in
nonaqueous media is discussed in: Labib, M. E.; Williams, R. J.; J.
Colloid Interface Sci. 1984, 97, 356; Labib, M. E.; Williams, R.
J.; J. Colloid Interface Sci. 1987, 115, 330; Fowkes, et al.,
"Mechanism of Electric Charging of Particles In Nonaqueous
Dispersions", Journal of the American Chemical Society, vol. 15,
1982; Fowkes, et al., "Steric And Electrostatic Contributions To
The Colloidal Properties of Nonaqueous Dispersions", Journal of the
American Chemical Society, vol. 21, 1984; Huang, Y. C., Sanders, N.
D., Fowkes, F. M., Lloyd, T. B. "The Impact of Surface Chemistry on
Particle Electrostatic Charging and Viscoelasticity of Precipitated
Calcium Carbonate Slurries". National Institute of Standards and
Technology Special Publication 856, USA Department of Commerce,
180-200 (1993)).
[0060] Any suitable metal oxide fractal particles or derivatives
thereof that achieve result in a reticulated fractal network may be
employed. Preferably, the inorganic nanoparticles particles are
fractal metal oxide particles having a diameter of between about
25-300 nm, preferably about 40-250 nm, and more preferably about
40-200 nm. Diameter as used herein refers to the diameter of a
sphere that encompasses the fractal particle. Diameter may be
determined by methods known in the art, e.g., light scattering and
TEM. Furthermore, each nanoparticle type has a particle surface
area between about 50 to 400 m.sup.2/g, and more particularly
between about 50 to 300 m.sup.2/g. The fractal dimension of the
nanoparticle ranges from about 1.2 to 2.8, preferably from about
1.5 to 2.5. Generally, as fractal dimension increases, the
concentration of solids in the network 1 decreases, and as surface
area increases, fractal dimension also increases.
[0061] While not common, fractal organic particles are known and
can be used in accordance with the present invention, provided the
requisite surface charge characteristics are met. For example,
organic polyacrylates and their derivatives have fractal
dimensionality and may be surface charged. Preferred organic
polyacrylate particles are lauryl methacrylate/dimethyl acrylate
crosspolymer (available from Amcol Health and Beauty
Solutions).
[0062] The fractal particles may be selected from the group
consisting of silica, alumina, titania, zirconia, zinc oxide,
indium tin oxide, ceria, and mixtures thereof. Particles may be
formed as part of a fuming process or a precipitation process
wherein the metal oxide particle is fractal in dimension. Particles
formed by the fuming process are preferred. Alumina is known to
impart high diffuse transmittance, high reflectance, high scattered
reflectance and low total reflectance in the visual spectra, and is
a preferred fractal particle. Silica is preferred because it has a
refractive index that is substantially matchable to common cosmetic
media, especially silicone oils.
[0063] When the fractal network is a fractal gel, alumina and
silica are preferred oppositely charged particles. As shown in FIG.
2, silica is available with a net surface charge that is opposite
to that of alumina at a pH value of most cosmetic formulations,
that is, at a pH below about 7-8. Accordingly, silica is a
preferred second fractal particle, especially when used in
conjunction with alumina at a composition pH less than about 7 to
8.
[0064] Examples of suitable fractal particles include, but are not
limited to, fumed silicas sold by Degussa under the tradename
Aerosil, including hydrophilic and hydrophobic fumed silicas, for
example, the Aerosil R-900 series, A380.TM. fumed silica
(manufactured by Degussa), OX50.TM. (manufactured by Degussa),
colloidal silica such as the Cabosil.TM. line (manufactured by
Cabot), fumed alumina such as SpectrAL.TM. (manufactured by Cabot),
and fumed titania. Preferred is fumed silica, fumed alumina, fumed
titania (Degussa W740X) fumed zirconia (Degussa W2650X, W2550X),
fumed ceria (Degussa Adnano) fumed zinc oxide (Degussa Adnano),
fumed indium tin oxide (Degussa Adnano) or mixtures thereof.
[0065] Charged particles are subject to electrophoresis, that is to
say, in the presence of an electric field they move with respect to
the liquid medium in which they are dispersed. The region between
the particle and the liquid is known as the plane of shear. The
electric potential at the plane of shear is called the zeta
potential. The magnitude and sign of this potential can be
experimentally determined using commercially available equipment.
Typically, to achieve colloidal stability, i.e. prevent
flocculation, charged particulates are required to have a minimum
zeta potential of approximately 25 mV.
[0066] Selection of fractal particle pairs for the fractal gel can
be chosen based on the magnitude and sign (positive or negative) of
the zeta potential at a given pH. Preferably, the magnitude and
sign of the zeta potential of each particle type is sufficient,
such that when combined, a non-settling, semi-rigid gel structure
is formed. Preferred dispersions of the first particle type have a
zeta potential values of about +10 mV to +50 mV, more preferably
+10 mV to +30 mV, and most preferably +15 mV to +25 mV. Preferred
dispersions of the second particle type have a zeta potential
values of about -10 mV to -50 mV, more preferably -10 mV to -30 mV,
and most preferably -15 mV to -25 mV. Furthermore, evaluation of
the point of zero charge (isoelectric point) of metal oxides is
useful to pre-select metal oxides of interest, as listed in Table
1.
Surface Charge of Particulate Dispersions
[0067] The presence of charge on dispersed colloidal particles
occurs by two principal mechanisms: dissociations of ionogenic
surface groups or preferential absorption. Each mechanism can occur
simultaneously or independently. Dissociation of acidic groups on
the surface of a particle will give rise to a negatively charged
surface. Conversely, dissociation of basic surface groups will
result in a positively charged surface. In both cases, the
magnitude of the surface charge depends on the strength of the
acidic or basic groups and on the pH of the solution. The surface
charge can be reduced to zero (isoelectric point) by suppressing
the surface ionization. This can be achieved by decreasing the pH
in the case of negatively charged particles or increased the pH in
the case of positively charged particles. Furthermore, if alkali is
added to a dispersion of negatively charged particles, the
particles tend to become more negatively charged. If acid is added
to this dispersion, then a point will be reached where the charge
on the particle is neutralized. Subsequent addition of acid will
cause a build up of positive charge on the particle.
Modification of Surface Charge
[0068] Adsorption of ions and ionic surfactants can be specifically
adsorbed onto the charged particle surface. In the case of cationic
surfactants, adsorption leads to a positively charged surface and
in the case of anionic surfactants, adsorption leads to a
negatively charged surface. Adsorption of single valent or
multivalent inorganic ions (e.g. Na.sup.-, Al.sup.+3) can interact
with charged surfaces in one of two ways: reduction of the
magnitude of charge at a given pH; change in pH of the isoelectric
point (point of neutral charge). The specific adsorption of ions
onto a particle surface, even at low concentrations, can have a
dramatic effect on the surface charge. In some cases, specific ion
adsorption can lead to a charge reversal of the surface. The
addition of surfactants or specific ions to particle dispersions is
a common method to modify the surface charge characteristics.
TABLE-US-00001 TABLE 1 Point of Zero Charge (PZC) for Various
Oxides in Water Oxide PZC Ag.sub.2O 11.2 Al.sub.20.sub.3 9.1 BeO
10.2 CdO 11.6 CeO.sub.2 8.1 CoO 10.2 Co.sub.3O.sub.4 7.4
Cr.sub.2O.sub.3 7.1 CuO 9.3 Fe.sub.2O.sub.3 8.2 Fe.sub.3O.sub.4 6.6
HgO 7.3 La.sub.2O.sub.3 10.1 MgO 12.4 MnO.sub.2 5.3 MoO.sub.3 2
Nb.sub.2O.sub.5 2.8 NiO 10.2 PuO.sub.2 5.3 RuO.sub.2 9
Sb.sub.2O.sub.5 1.9 SiO.sub.2 2 SnO2 5.6 Ta.sub.2O.sub.5 2.8
ThO.sub.2 9.2 TiO.sub.2 Rutile 5.7 TiO.sub.2 Anatase 6.2
V.sub.2O.sub.3 8.4 WO.sub.3 0.4 Y.sub.2O.sub.3 8.9 ZnO 9.2
ZrO.sub.2 7.6
[0069] In one embodiment the fractal network is obtained by using
at least one kind of fractal particle. The fractal particles may be
of the same charge and are not limited by a particular pH.
The Macroscopic Particle
[0070] The macroscopic particles used in the preparation of the
gels of the present invention are translucent, and are within the
matrix of the gel. However, it is understood that the cosmetic
composition may be multiphasic, for example, an emulsion wherein
the gel is dispersed into a continuous external phase.
Alternatively, additional components may be dispersed into the gel
phase. In yet another embodiment, macroscopic particles may have a
charge or surface functionality which increases interaction with
the fractal particles.
[0071] In yet another embodiment, two different fractal particles
are used to form different fractal networks, which are used to
form, along with macroscopic particles, the gels of the invention.
In another embodiment different macroscopic particles can be used
to form the gel, using the same or different fractal networks.
[0072] Preferably, the refractive index of the fractal particle
does not match the refractive index of the macroparticle. Non-match
means as used in this context that the refractive index values are
about 0.05 or more units from one another, preferably more than
about 0.07, and most preferably more than about 0.1.
[0073] The macroscopic particles of the invention have a particle
size of between about 1-200 microns, preferably between about 2-100
microns. Macroscopic particles can be organic or inorganic.
Non-limiting examples of macroscopic particles are silicone
elastomers, hydrocarbon elastomers, silicone crosspolymers,
polymeric spheres, metal oxide spheres, or combinations thereof. In
one preferred embodiment of the invention, the macroscopic
particles are macroscopic organic elastomeric particles. In another
preferred embodiment the macroscopic particles are silicone
crosspolymers having a particle size of from about 1 to about 200
microns.
[0074] Illustrative, non-limiting examples of elastomeric
macroparticles to which this invention may be applied are natural
and synthetic rubbers, for example, natural rubber, nitrile
rubbers, hydrogenated nitrile rubbers, ethylene-propylene rubbers,
polybutadiene, polyisobutylene, butyl rubber, halogenated butyl
rubber, polymers of substituted butadienes. such as chlorobutadiene
and isoprene, copolymers of vinyl acetate and ethylene terpolymers
of ethylene, propylene, and a non-conjugated diene, and copolymers
of butadiene with one or more polymerizable ethylenically
unsaturated monomers such as styrene, acrylonitrile, and methyl
methacrylate; silicone elastomers; fluoropolymers including
fluoropolymers having a silicone backbone; polyacrylates;
polyesters, polyacrylic esters, polyethers; polyamides,
polyesteramides, polyurethanes, and mixtures thereof. Moreover, it
is understood that the elastomeric material may contain additional
organic or inorganic phases to modify the elastomeric and optical
properties of the particle.
[0075] Such particles are prepared by conventional procedures, for
example, by palletizing, cutting, or tearing a bale of the
elastomeric material into shreds or small pieces followed by
chopping or grinding those shreds or small pieces into particles
having the size desired. In addition "wet" chemistry techniques
known in the art may be used to form particles of a particular size
or distribution of particle sizes that are desirable. The practice
of the present invention does not depend on the particular
procedure utilized to prepare the elastomer and elastomeric
particles.
[0076] Suitable macroscopic particles useful in the invention
especially for skin care applications have a preferred refractive
index generally from about 1.38 to about 2, preferably from about
1.38 to about 1.6.
[0077] The silicone elastomers are (i) cross-linked silicone
polymers derived from room temperature vulcanizable silicone
sealant chemistry, or (ii) addition polymerized silicone elastomers
prepared by the hydrosilylation of olefins or olefinic silicones
with silyl hydrides. Preferred silicone elastomers are crosslinked
organopolysiloxanes such as dimethicone/vinyl dimethicone
crosspolymers, vinyl dimethicone/lauryl dimethicone crosspolymers,
alkyl ceteayl dimethicone/polycyclohexane oxide crosspolymers, and
mixtures thereof. Examples of these elastomers are DC 9040, DC
9040, and DC 9045 available from Dow Corning, dimethicone/phenyl
vinyl dimethicone crosspolymers under the tradenames KSG-15, 16, 18
available from Shin Etsu; lauryl dimethicone/vinyl dimethicone
crosspolymers supplied by Shin Etsu (e.g., KSG-31, KSG-32, KSG-41,
KSG-42, KSG-43, and KSG-44), and the Gransil line of elastomers
available from Grant Industries such as EPSQ.TM.. A preferred
silicone elastomer is EPSQ.TM. (Grant).
[0078] Also suitable are silicone crosspolymers obtained by self
polymerization of bifunctional precursor molecules containing both
epoxy-silicone and silyl hydride functionalities to provide a
silicone copolymer network in the absence of crosslinker molecules.
Such crosspolymers are described in U.S. Pat. Nos. 6,444,745;
6,531,540; 6,538,061; 6,759,479, and in US Appln. 2003/00959935.
Especially suitable are such crosspolymers such as the Velvesil.TM.
line of silicone crosspolymers available from Momentive Performance
Materials, Inc. (formerly GE Silicones). Most preferred is Velvesil
125.TM. (GE), a cyclomethicone and C30-C45 alkyl cetearyl
dimethicone/polycyclohexane oxide crosspolymer.
[0079] The weight ratio of the fractal particles to macroscopic
particles in the gels of the present invention are typically from
about 1:10 to 10:1, preferably from about 1:10 to 2:1, and most
preferably from about 1:5 to 1:1.
[0080] Other preferred macroscopic particles are polymeric spheres
such as nylon (e.g., Nylon 12 available from Cabot as SP-500 and
Orgasol 2002.TM.), cellulose beads, poly(methyl acrylic acid) (also
known as PMMA or methyl methacrylate cross polymer; CAS No.
25777-71-3), boron nitride, barium sulfate, silicates such as
calcium alumina borosilicate, polyethylene, polystyrene,
polyurethane such as HDI/Trimethylhexyl lactone cross polymer sold
by Kobo Industries under the tradename BPD-800, ethylene/acrylic
acid copolymer (e.g. EA-209 supplied by Kobo), Teflon, or
silicone.
Compositions of the Invention
[0081] The cosmetic composition may take on various forms including
powder, cake, pencil, stick, ointment, cream, milk, lotion,
liquid-phase, gel, emulsion, emulsified gel, mousse, foam, spray,
wipes. Preferably, the cosmetic composition is used in a liquid or
powder foundation.
[0082] The gels may be incorporated in cosmetically acceptable
vehicles, such as but not limited to, liquid (e.g., suspension or
solution), gel, emulsion, emulsified gel, mousse, cream, ointment,
paste, serum, milk, foam, balm, aerosol, liposomes, solid (e.g.,
pressed powders), anhydrous oil and wax composition. Preferably,
the cosmetic composition is used in a liquid or powder foundation.
More specifically, the cosmetic include facial skin care cosmetics
such as skin lotion, skin milk, skin cream, gel, and make-ups such
as foundation, foundation primer base, blush, lip stick, eye
shadow, eye liner, nail enamel, concealer, mascara, body make-up
product, or a sunscreen.
[0083] A person skilled in the art can select the appropriate
presentation form, and also the method of preparing it, on the
basis of general knowledge, taking into account the nature of the
constituents used and the intended use of the composition.
[0084] Cosmetic compositions according to the invention may
comprise from about 1 to 100% gel, and typically comprise from
about 2 to about 90%, preferably comprise 10 to 80%, and most
preferably comprise 30 to 55% gel by weight of the cosmetic
composition. The broad range reflects the range of different types
of cosmetic products and the various product forms; namely, gels,
emulsions, and dispersions. Typically, the gel contains about 3% to
about 60% fractal particles by weight of the gel, and more
typically from about 5% to about 40% fractal particles by weight of
the gel. Amounts of the gel in the cosmetic compositions of the
invention are also discussed later. Useful gel compositions may
include alumina and silica, titania and silica, zirconia and
silica, and other combinations of particulates described
within.
[0085] The cosmetic compositions of the present invention may be
formulated as aqueous or nonaqueous compositions, which may be
emulsions or non-emulsions. In one embodiment, the cosmetic
compositions according to the invention are formulated as
emulsions. These emulsions may be oil-in-water (including silicone
in water) emulsions, water-in-oil (including water-in-silicone)
emulsions, or multiple emulsions such as oil-in-water-in-oil
(o/w/o) or water-in-oil-in-water (w/o/w), but are preferably
silicone-in-water emulsions. It is understood that the oil phase
can comprise silicone oils, non-silicone organic oils, or mixtures
thereof. While not preferred, the compositions can comprise two
immiscible phases that are admixed at the time of use by
shaking.
[0086] In a typical embodiment in which a gel having a fractal gel
is employed, the weight ratio of alumina to silica is 1:1 to 9:1
and is present as a dispersion in water wherein the alumina surface
area is between 50 to 200 m2/g and the silica surface area is
between about 50 to 400 m2/g. Suitable gels can be formed by using
Spectral 51 or Spectral 80 (Cabot Corporation) fumed alumina and
Cab-O-Sil M5, Cab-O-Sil EH-5. Furthermore, dispersions of metal
oxides can be chosen based on their surface charge characteristics
as determined by zeta potential measurements. Generally, particle
size, surface area and surface charge determines the ease with
which the gel forms and its physical attributes such as yield
strength. In one embodiment of the invention the gel comprises, as
the only fractal particle, a fumed silica or a fumed alumina,
preferably a combination of fumed silica and fumed alumina in an
anhydrous media, such as a hydrocarbon or silicone fluid. In this
embodiment gel formation is occasioned by interaction between
hydrophilic surface groups in a non-interacting hydrophobic
matrix.
[0087] In addition to the gel phase comprising the fractal
particles and the macroparticles, the compositions of the present
invention may comprise one or more active ingredients adapted to
bestow a cosmetic benefit to the skin when applied to the skin as a
film and/or one or more adjuvants or excipients (adjuvants and
excipients are collectively referred to herein as adjuvants) to
impart to the cosmetic product particular desirable physical
properties, to meet product performance requirements, or to
establish compositional type, e.g., emulsion (of a particular
type), solution, etc. The actives and/or the adjuvants may be
present in the gel phase including the fractal network or the
fractal gel, as the case may be, in another phase, or in either, as
desired, or as mandated by the chemical system.
[0088] Suitable active agents include pigments to impart a color to
the skin or other biologic surface; opacifiers and light diffusers;
sunscreens; uv light absorbers; emollients; humectants; occlusive
agents; antioxidants; exfoliants; antioxidants; anti-inflammatory
agents; skin whitening agents; abrasives; antiacne agents; hair
treatment agents; humectants; emollients; moisturizers;
anti-wrinkle ingredients; concealers; matte finishing agents;
proteins; anti-oxidants; bronzers; solvents; ultraviolet (UVA
and/or UVB) absorbing agents; oil absorbing agents; neutralizing
agents. It is understood to those skilled in the art that any other
cosmetically acceptable ingredient, i.e., those included in the
International Cosmetic Ingredient Dictionary and Handbook, 11th
Edition (2006) (Cosmetic and Toiletries Association) (hereinafter
identified as INCI) may be used and compatible combinations
thereof.
[0089] Suitable adjuvants include film forming agents; solvents;
viscosity and rheology modifiers such as thickeners; surface active
agents including emulsifiers; hydrotropes; emulsion stabilizers;
plasticizers; fillers and bulking agents; pH adjusting agents
including buffers, acids, and bases; chelating agents; binders;
propellants; fragrances; preservatives and antimicrobials, and
compatible combinations thereof.
[0090] Suitable active agents and adjuvants used in cosmetic
compositions of the present invention are tabulated in INCI.
Generally, reference to specific materials utilizes the INCI
adopted name nomenclature. The active agents and adjuvants are
incorporated in the compositions of the present invention in
amounts that provide their intended functions, as those skilled in
the cosmetic arts are knowledgeable. Generally, this amount is from
about 0.001 to 25%, more usually 0.01 to 15%, and especially 0.1 to
10% by weight of the composition.
[0091] The cosmetic compositions may contain polymeric light
diffusers such as nylon (e.g., Nylon 12 available from Cabot as
SP-500 and Orgasol 2002.TM.), cellulose beads, poly(methylacrylic
acid) (also known as PMMA or methyl methacrylate crosspolymer; CAS
No. 25777-71-3), polyethylene, polystyrene, ethylene/acrylic acid
copolymer (e.g., EA-209 supplied by Kobo), and fluorinated
hydrocarbons such as Teflon. The polymeric light diffusers,
preferably nylon, are present in a concentration in the range of
between about 0.01-10%, preferably about 0.1-5% by weight of the
composition. Inorganic light diffusers can also be used, e.g.,
boron nitride, barium sulfate, and silicates such as calcium
alumina borosilicate, and are typically present in an amount of
from about 0.01 to about 10%, preferably about 0.1 to about 5% by
weight.
[0092] The cosmetic composition of the present invention may
contain a viscosity modifier such as a thickener together with
emulsifiers to modify the viscosity of the composition, for example
to form creams, pastes, and lotions that enhance skin feel.
Suitable viscosity modifiers are starches, cellulose derivatives
such as sodium carboxymethyl cellulose, methyl cellulose, ethyl
cellulose, cationized cellulose, hydroxyethyl cellulose,
hydroxypropyl cellulose, hydroxypropylmethyl cellulose; silicates
such as Veegum or clays; polysaccharides such as xanthan or guar
gums, hydrophilic polymers, such as carboxyvinyl polymers, for
example carbomers. Viscosity/rheology modifiers may be present in
the composition in an amount of from about 0.1 to about 10% by
weight of the composition.
[0093] The cosmetic emulsifier should preferably be an oil-in-water
or water-in-oil emulsifier. Preferably, the oil phase is a silicone
oil, and the emulsifier is a silicone emulsifier. The emulsifiers
may be chosen advantageously to match the refractive index of the
fractal particle whose refractive index is matched, but are not
substitutes for the refractive index matching polymer.
[0094] Emulsifying agents may be present in a concentration of from
about 0-10%, preferably about 0.1-6%, more preferably about 3-5%.
Nonlimiting examples of suitable emulsifiers are glycerol
monostearate, PEG 12 Dimethicone (Dow Corning), RM 2-2051.TM. (Dow
Corning), an emulsion of aqueous polyacrylate emulsified into
silicone (dimethicone and cyclopentasiloxane), alkylmethyl
siloxanes copolyol (Dow Corning 5200), PEG 11 methylether
dimethicone (Shin Etsu), cyclopentasiloxane/PEG/PPG 18/18
dimethicone (Dow Corning 5225C).
[0095] The cosmetic composition of the present invention may
contain non-occlusive film-forming agents such as, but not limited
to, cosmetic fluids, i.e., silicone compounds containing various
combinations of elastomers in a variety of diluents. Examples of
suitable cosmetic fluids are cyclopentasiloxane and amino
propyldimethicone (Cosmetic fluid 1486-NH) (manufactured by
Chemisil), cyclomethicone and dimethicone (Cosmetic Fluid 1684-DM)
(manufactured by Chemisil), and a blend of low and high viscosity
polydimethylsiloxane (e.g. Dow Corning 1413 Fluid.TM.) (Dow
Corning). Preferred is a blend of high viscosity
polydimethylsiloxane in low viscosity polydimethylsiloxane (e.g.
Dow Corning 1413 Fluid.TM.) (Dow Corning).
[0096] In one embodiment the cosmetic composition is
nonpigmented.
[0097] In one embodiment the cosmetic compositions contain one or
more pigments, which are typically present in a different phase
from the gel phase. The pigment used herein can be inorganic and/or
organic. Cosmetic compositions according to the invention comprise
greater than or equal to 0.1% pigments by weight of the cosmetic
composition to provide a pigmenting effect. Typically, the pigments
may be present from about 0.1% to 25%, preferably from about 0.5 to
15%, and most preferably from about 1 to 10% by weight The pigments
are not fractal particles in accordance with the invention because
they do not have the proper size domain, do not have the proper
dimensionality, or are not charged particles. As used herein the
term "pigments" includes lakes, and a single pigment or pigment
combinations. Other colorants such as D&C dyes and self-tanning
agents such as carbonyl derivatives or food colorants such as
dihydroxyacetone (DHA) or erythrulose may be used. Pigments and
colorants are used interchangeably herein.
[0098] Preferably, the pigments are selected from the group
consisting of titanium oxides such as rutile titanium dioxide,
anatase titanium dioxide, zinc oxide, zirconium oxide, iron oxides
such as ferric oxide, ferrous oxide, yellow iron oxide, red iron
oxide, bismuth oxy chlorides, black iron oxide, acylglutamate iron
oxides, chromium oxide, chromium hydroxide, manganese violet,
cerium oxide, ultramarine blue, carmine, and derivatives and
mixtures thereof. More preferably, the pigment is titanium oxide,
yellow iron oxide, red iron oxide, black iron oxide, and mixtures
thereof. The pigments can be surface modified to render them either
hydrophobic or hydrophilic to interact synergistically with the
fractal particle network.
[0099] The cosmetic composition may also include opacifying agents
(pearlescent agents) to add optical shimmer and luster or for
tactile silkiness to the touch such as, but not limited to mica,
sericite (a fine grained variety of muscovite). These agents may be
present in amounts from about 0.1-10%, preferably about 0.5-5%.
[0100] The cosmetic composition may also include oil phase solvents
useful as base fluids for spreading and lubrication properties or
as a vehicle to provide a medium for one or more of the other
constituents of the cosmetic composition. Solvents include water,
organic fluids, especially alcohols and hydrocarbon fluids,
silicone fluids, hydrophilic and hydrophobic polymers, and the
like, and may be present in a concentration of about 0.5-90%,
preferably about 5-50%, most preferably 10-35%. Preferred oil phase
solvents are cyclomethicones such as cyclotetrasiloxane (e.g.
Cyclo-2244 Cosmetic Grade Silicone (D4) (manufactured by Clearco),
cyclopentasiloxane (e.g. Cyclo-2245 Cosmetic Grade Silicone (D5)
(manufactured by Clearco), a cyclopentasiloxane/cyclohexasiloxane
blend (D5/D6 Blend) Cyclo-2345 Cosmetic Grade Silicone
(manufactured by Clearco), and a cyclomethicone/dimethiconol blend
(D5/D4 Blend) Cyclo-1400 Cosmetic Grade Silicone (manufactured by
Clearco). More preferred is D5.
[0101] Water typically is present in amounts ranging from about 10%
to about 95% water by weight of the composition, preferably from
about 40% to about 80%, and most preferably from about 40% to about
70%. Also suitable as aqueous phase solvents are low molecular
weight alcohols having less than 8 carbons, for example ethanol,
propanol, hexanol, and the like, and polyhydric alcohols,
especially glycols. Suitable glycols are propylene glycol,
pentylene glycol, hexylene glycol, and 1,2-octanediol. Suitable
polyhydric alcohols include sorbitol and glycerin. These may be
present in amounts of from about 1% to about 50%, preferably 5% to
35% by weight.
[0102] In another embodiment the compositions are substantially
anhydrous suspensions of the macroscopic particles and the fractal
particles in accordance with the present invention. Preferably, the
fractal particles are fumed alumina, fumed silica, fumed titania,
or combinations thereof, and the macroscopic particle is a silicone
elastomer or cross polymer as previously described. The silicone
elastomer or crosspolymer may also be swelled in a suitable
nonaqueous solvent such as dimethicone or cyclomethicone. In this
embodiment the composition typically contains from about 1 to about
80% macroparticles, from about 1 to about 10% fractal particles and
from about 3 to about 80% nonaqueous solvent. Suitable solvents
include silicone fluids such as dimethicone and cyclomethicone, and
hydrocarbon fluids such as isododecane. The composition may further
contain adjuvants and excipients such as optical diffusers, waxes,
pigments, and the like. By substantially anhydrous is meant that
the compositions contain an insufficient amount of water to form a
separate aqueous phase, which is typically less than about 1%
water, and preferably less than about 0.5% water.
[0103] Optionally, electrolytes such as sodium chloride may be
added in amounts ranging from about 0-5%, preferably from about
0.5-2%.
[0104] The compositions of the invention further typically contain
an amount of a pH adjusting agent to provide the desired pH of the
composition, e.g., the pH at which the fractal particles will have
the requisite opposite net surface charges. Suitable pH adjusting
agents are organic and mineral acids as is well known in the
cosmetic arts. Buffers to maintain the established pH may also be
incorporated, for example sodium lactate.
[0105] It is further understood that the other cosmetic actives and
adjuvants introduced into the composition must be of a kind and
quantity that are not detrimental to the advantageous effect which
is sought herein according to the invention.
[0106] The composition of the present invention improves the
optical properties of films of cosmetic composition (as compared to
those which merely reflect light producing a shiny appearance,
those which merely cover the skin and impart a white cast to the
skin, or those which either result in optical blurring or space
filling, but not both). The resulting composition when applied to
the skin, makes the skin appear more youthful, smoother and even in
tone.
[0107] The physical arrangement of the gel structure, high particle
loading and network formation, provides a smooth surface for
topcoat (optical layer) applications of any foundation. The optical
layer provides a unique "light releasing" effect from the skin when
used as a primer for pigmented cosmetics. The optical layer mimics
and enhances the skin's natural transparent qualities. When light
penetrates the optical layer, diffuse reflection through the
pigmented layer provides a "back lighting" effect, brightening
foundations to give a more natural and youthful look
Methods of Use
[0108] The methods of use for the cosmetic compositions disclosed
and claimed herein concern the improvement in the aesthetic
appearance of skin and include, but are not limited to: methods of
blurring or masking one or more of wrinkles, fine lines, pores,
skin imperfections, especially in the facial, neck or on or around
the lip areas; methods to correct imperfections in skin such as
blotches, freckles, redness, spider veins, and dark rings around
the eyes; methods of enhancing or modifying skin color; and methods
to improve finished makeup, and methods for application to the
hair, eyelashes, and eyebrows.
[0109] The compositions of the present invention are suitable for
use as a hair cosmetic, in particular as a mascara, in light of the
unique rheological properties exhibited by the gels, as mentioned
above. Thus, the compositions of the invention are free-flowing
under shear, which allows them to be applied with a brush or
suitable applicator. When the shear is removed the compositions
return rapidly to the more viscous gel condition. Because the
compositions are fractal, that is, they are porous, reticulated
structures capable of maintaining geometric shape, they are able to
coat hair and provide a volumizing benefit. Accordingly, they are
ideal as mascaras, especially when formulated with a film former
(as previously described), and as hair volumizers for treating
thinning hair.
[0110] Examples of facial lines and skin imperfections which can be
improved using the fractal gels of the present invention include,
but are not limited to; frown lines that run between the eyebrows
known as glabellar lines; perioral or smoker's lines which are
vertical lines on the mouth; marionette lines at the corner of the
mouth known as oral commissures; worry lines that run across the
forehead; crow's feet at the corner of the eyes known as
periorbital lines; deep smile lines that run from the side of the
nose to corners of the mouth known as nasolabial furrows; cheek
depressions; acne scars; some facial scars; wound or burn scars;
keloids; to reduce dark rings around the eyes; to reduce the
appearance of pores or blemishes, age spots, moles, birthmarks; to
redefine the lip border; for artificial or self-tanning, and to
reduce skin color unevenness or dullness.
[0111] In another embodiment the resulting gel can be employed as
it is and can itself constitute a skin care or make-up composition
for blurring wrinkles, fine lines, pores, and skin
imperfections.
[0112] Therefore, the gels may comprise from about 1% to about 100%
by weight, relative to the total weight of the composition.
[0113] Facial lines and wrinkles can be present anywhere on the
face, and occur most frequently on the lips and in the eye area.
However, it is understood by those skilled in the art that the
composition can be applied to any part of the body where a blurring
effect is desired such as to reduce wrinkles, fine lines, poses and
skin imperfections. Non-limiting examples include to conceal
imperfections in the skin, such as to mask the appearance of
cellulite or vitiligo, to mask the appearance of spider vessels,
moles, age spots, blemishes, scars, freckles, birth marks and
varicose veins, to conceal damage incurred to the skin as a result
of trauma such as cosmetic surgery, burns, stretching of skin, to
conceal the appearance of villus hair on the skin; to provide UV
protection to the skin.
[0114] The compositions herein can be used by topically applying to
the areas of the skin an effective amount of the compositions. The
effective amount can easily be determined by each user. As used
herein the term "effective amount" refers to an amount sufficient
to result in "optical blurring" of the appearance of the skin.
[0115] The composition can be applied for several days, weeks,
months or years at any intervals. The compositions are generally
applied by light massaging the composition onto the skin. However,
the method of application may be any method known in the art and is
thus not limited to the aforementioned.
[0116] The invention also relates to a method for therapeutic
treatment of the skin. It is further understood that the gel of the
present invention may be used together with therapeutic agents
together with or adjunctive to pharmaceutical compositions
including, but not limited to, anti-acne agents, sunscreens,
self-tanning ingredients, anti-inflammatory agents,
anti-bacterials, anti-fungals, anti-virals, anti-yeast agents, eye
treatments, age spot treatments, analgesics, antidandruff and
antiseborrhetic agents, hyperkeratolytics, antipsoriatic agents,
skin lightening agents, depigmenting agents, wound healing agents,
burn treatments, tanning agents, hair treatment agents, hair growth
products, wart removers, antipuretics, and hormones.
Preparation
[0117] Sol-gel chemistry techniques can be used to effect the
formation of the gels of the present invention, as described in C.
J. Brinker and W. Scherer, Acad. Press, Boston, 1990, which is
incorporated by reference in its entirety herein.
[0118] The compositions useful for the methods of the present
invention are generally prepared by conventional methods such as
are known in the art of making topical cosmetic compositions. Such
methods typically involve mixing of the ingredients in one or more
steps to a relatively uniform state, with or without heating,
cooling, application of vacuum, and the like.
[0119] Typically, the network of fractal particles is made by
preparing a dispersion of each fractal particle in a suitable
solvent (dispersant), adjusting the dispersion pH with a pH
adjusting agent, if needed, e.g., when the fractal network is a
fractal gel, and admixing the dispersions with shear to permit the
formation of the fractal network. In some instances owing to the
properties of the constituents it may be necessary to preheat the
dispersant. Where fractal gels are being used to form the fractal
network, the pH adjusting agent may also be provided into the
admixed dispersions rather than into each dispersion individually.
The macroparticles may then be incorporated into the dispersion,
along with any actives and adjuvants that are desired. Certain of
the adjuvants may require addition as premixes with a solvent, as
generally known in the cosmetic art. The resulting gel can be
employed as it is and can itself constitute a skin care or make-up
composition for blurring wrinkles and skin imperfections.
[0120] Alternatively, the fractal gel may be incorporated into a
multiphase cosmetic composition as previously mentioned. The other
phase may be prepared in accordance with known methods, for example
forming one or more premixes of the ingredients for combination
with the gel. As previously mentioned the polymer in whole or in
part may be incorporated into this other phase. Where premixes have
been formed at elevated temperatures appropriate cooling of the
composition to establish the emulsion will be necessary.
[0121] The following examples describe specific aspects of the
invention to illustrate the invention and provide a description of
the present methods for those skilled in the art. The Examples
should not be construed as limiting the invention as the examples
merely provide specific methodology useful in the understanding and
practice of the invention and its various aspects.
EXAMPLES
General Example
[0122] The present invention is further illustrated by the
following nonlimiting example.
TABLE-US-00002 TABLE 1 Illustrative Compositions Component WEIGHT %
Polydimethylsiloxane and Cetearyl Dimethicone .sup. 5-50
Crosspolymer .sup.1 Cellulose Beads (spherical) .sup. 1-20 Fumed
Alumina (SpectrAL 51 from Cabot) 0.1-10 Amino Phenyltrimethicone
0.1-10 Ethylhexylmethoxy Cinnamate 0.1-7.5 Acrylates/Dimethicone
copolymer/cyclomethicone .sup. 0.1-10.0 Decamethyl
cyclopentasiloxane 0.1-30 Fragrance 0-1 Fumed Silica (Cabosil EH-5
from Cabot) 0.1-10 Preservative 0.1-2 Nylon Powder (spherical)
0.1-10 HDI/Trimethylol Hexyllactone Crosspolymer and Silica .sup.2
0.1-10 Polyethylene 1-20 um .sup.3 (spherical) 0.1-10 Boron Nitride
(spherical) 0.1-10 Ethylhexyl Salicylate 0.1-5 POE (24M)
Cholesterol Ether .sup.4 0.1-5 Lauryl PEG-9 Polydimethylsiloxane
Dimethicone .sup.5 0.1-5 .sup.1 Available from Dow Corning under
the tradename DC 9041. .sup.2 Available from Kobo Products under
the tradename BPD 800. .sup.3 Available from Presperse under the
tradename Micropoly 220L. .sup.4 Available from Croda under the
tradename Crodalan C24. .sup.5 Available from Shin Etsu under the
tradename KF6038.
[0123] In the method of making of the preferred compositions of the
present invention, the gel emulsifying agent, and sunscreens are
premixed in a vessel. To a separate vessel, the solvent, film
formers, wax, and preservative are added and heated to 180 to 190
degrees F. with mixing. Once the temperature is constant and the
materials are well mixed, the fumed alumina and silica are added.
Mixing continues until all of the fumed material is evenly
dispersed. The premixed gel phase is then added to the solvent/film
former/wax mixture. Mixing continues for 10 to 60 minutes, as the
batch cools the remaining powdered components are added. Fragrance
is added when the temperature is below 120.degree. F.
[0124] When wax is used as a structurant in the composition the
processing temperature is maintained above the solidification point
of the wax and a hot fill is used.
TABLE-US-00003 TABLE 2 Illustrative Composition Containing Wax
Component WEIGHT % Polydimethylsiloxane and Cetearyl Dimethicone
.sup. 5-50 Crosspolymer .sup.1 Cellulose Beads (spherical) .sup.
1-20 Fumed Alumina (SpectrAL 51 from Cabot) 0.1-10
Ethylhexylmethoxy Cinnamate 0.1-7.5 Acrylates/Dimethicone
copolymer/cyclomethicone .sup. 0.1-10.0 Decamethyl
cyclopentasiloxane 0.1-30 Fragrance 0-1 Fumed Silica (Cabosil EH-5
from Cabot) 0.1-10 Preservative 0.1-2 Nylon Powder (spherical)
0.1-10 HDI/Trimethylol Hexyllactone Crosspolymer and Silica .sup.2
0.1-10 Polyethylene 1-20 um .sup.3 (spherical) 0.1-10 Boron Nitride
(spherical) 0.1-10 Ethylhexyl Salicylate 0.1-5 C30-45 Alkyl
Methicone/C30-45 Olefin 0.1-5 Lauryl PEG-9 Polydimethylsiloxane
Dimethicone .sup.5 0.1-5 .sup.1 Available from Dow Corning under
the tradename DC 9041. .sup.2 Available from Kobo Products under
the tradename BPD 800. .sup.3 Available from Presperse under the
tradename Micropoly 220L. .sup.5 Available from Shin Etsu under the
tradename KF6038.
[0125] Skin care compositions of the present invention are found to
reduce the visibility of wrinkles to a greater extent than skin
care products not containing the gels of the present invention.
Working Examples (without Pigment)
[0126] Examples I through VI are illustrative of the present
invention in which Examples I-III are aqueous emulsions and
Examples IV-VI are anhydrous compositions, wherein the fractal
particles 3, 4 and 5 are dispersed in D5.
TABLE-US-00004 TABLE 3 Colorless Primer Compositions I II III IV V
VI 1 Dow Corning 1413 Fluid 10 10 10 15 15 15 2 Velvesil 125 30 30
30 35 30 30 3 Fumed Silica 0 0 0 7 10 7 4 Fumed TiO2 0 0 0 0 5 8 5
Fumed Alumina 0 0 0 10 5 5 6 Nylon 0 0 0 3 5 5 7 Dow Corning 5225 C
0 0 9 0 0 0 8 D5 15 15 9 30 30 30 9 RM 2-2051 4 4 0 0 0 0 (Dow
Corning) 10 Water 11 11 11 0 0 0 11 30% Silica/Alumina (1:1) 0 30
15 0 0 0 dispersion in Water 12 30% Silica/Alumina (2:1) 30 0 15 0
0 0 dispersion in Water 13 NaCl 0 0 1 0 0 0 Total 100 100 100 100
100 100 1 Dimethicone (3300 cs.) sold by Dow Corning Corp. as DC
1413 fluid 2 Macroscopic dimethicone/vinyl dimethicone crosspolymer
available from Momentive Performance Materials, Inc. 3 Cabosil EH-5
available from Cabot Company 4 Aeroxide P25 from Degussa 5 SpectrAl
51 from Cabot 6 Orgasol 2002 B Natural Extra COS from Lipa Chemical
7 Cyclopentasiloxane and PEG/PPG-18/18 Dimethicone sold by Dow
Corning Corp. 8 Cyclomethicone available from Dow Corning under the
tradename DC 245 Fluid 9 Thickening agent containing sodium
polyacrylate, dimethicone, cyclopentasiloxane, trideceth-6 and
PEG/PPG-18/18 dimethicone sold by Dow Corning Corp. 11 and 12 are
fractal particle gel dispersions containing fumed silica (Cabosil
EH-5) and fumed alumina (SpectrAl 51) both sold by Cabot
Corporation in the proportions indicated
[0127] The compositions I through III were made as follows:
[0128] Phase A--Silicone Phase: Dow Corning 1413 Fluid, Velvesil
125, DC 5225 C were mixed until homogeneous followed by addition of
D5 and Nylon using a 3 blade propeller mixer. RM 2051 was then
added to the silicone phase and mixed for an additional 10
minutes.
[0129] Phase B--Aqueous phase: A 30 wt % dispersion of fumed
silica/alumina was added to water and NaCl until homogenous for
about 20 minutes at room temperature. Phase B was then slowly added
to phase A with continuous stirring for 10 minutes. The composition
was then mixed further for an additional 20 minutes.
[0130] The compositions IV through VI were made as follows:
[0131] Velvesil 125, D5, and (1413 Fluid are added and heated to
180 to 190.degree. F. with mixing. Once the temperature is constant
and the materials are well mixed, the fumed alumina and silica are
added. Mixing continues until all of the fumed material is evenly
dispersed. Mixing continues for 10 to 60 minutes, as the batch
cools the remaining powdered components (nylon) are added.
Working Examples with Pigment
[0132] The following examples are illustrative of a foundation
composition containing pigments.
TABLE-US-00005 TABLE 4 Foundation Compositions I II III IV V 1 TiO2
5 4 3 5 5 2 Red Iron Oxide 2 3 2 2 3 3 Yellow Iron Oxide 3 2 2 3 2
4 Black Iron Oxide 1 1 1 1 1 5 Sericite 5 4 5 3 3 6 Dow Corning
1413 Fluid 10 10 10 10 12 7 Velvesil 125 25 25 25 30 27 8 Fumed
Silica 0 0 0 8 7 9 Fumed TiO2 0 0 0 5 8 10 Fumed Alumina 0 0 0 5 2
11 Nylon 0 0 0 5 5 12 Dow Corning 5225C 0 0 10 0 0 13 D5 10 10 9 23
25 14 Rm 2-2051 (Dow Corning) 4 4 0 0 0 15 Water 5 7 8 0 0 16 30%
Silica/Alumina (1:1) 0 30 12 0 0 dispersion in Water 17 30%
Silica/Alumina (2:1) 30 0 12 0 0 dispersion in Water 18 NaCl 0 0 1
0 0 Total 100 100 100 100 100 6 Dimethicone (3300 cs.) sold by Dow
Corning Corp. 1431 Fluid is the trade name 7 Macroscopic
dimethicone/vinyl dimethicone crosspolymer available from Momentive
Performance Materials, Inc. 8 Cabosil EH-5 available from Cabot
Company 9 Aeroxide P25 from Degussa 10 SpectrAL 51 from Cabot 11
Orgasol 2002 B Natural Extra COS from Lipa Chemical 12
Cyclopentasiloxane and PEG/PPG-18/18 Dimethicone sold by Dow
Corning Corp. 13 Cyclomethicone available from Dow Corning under
the tradename DC 245 Fluid 14 Thickening agent containing sodium
polyacrylate, Dimethicone, Cyclopentasiloxane, Trideceth-6 and
PEG/PPG-18/18 Dimethicone sold by Dow Corning Corp. 16 and 17 are
fractal particle gel dispersions containing fumed silica (Cabosil
EH-5) and fumed alumina (SpectrAl 51) both sold by Cabot
Corporation in the proportions indicated
[0133] Examples I-III are aqueous emulsions; Examples IV-V are
anhydrous compositions in which the fractal particles 8, 9 and 10
are dispersed in D5.
[0134] The present invention provides a variety of compositions
useful in solid and/or semi-solid forms (including creams, gels and
viscous liquids). Such compositions are preferably foundations, but
also include face sticks, pancakes, and other facial cosmetic
products.
[0135] Although the present invention describes in detail certain
embodiments, it is understood that variations and modifications may
exist that are known to those skilled in the art but, nonetheless,
fall within the scope of the present invention. Accordingly, the
present invention is intended to encompass all such alternatives,
modification and variations that are within the scope of the
invention as set forth in the following claims.
[0136] The contents of all patents, patent applications, published
PCT applications and articles, books, references, reference manuals
and abstracts cited herein are hereby incorporated by reference in
their entirety to more fully describe the state of the art to which
the invention pertains.
[0137] As various changes can be made in the above-described
subject matter without departing from the scope and spirit of the
present invention, it is intended that all subject matter contained
in the above description, or defined in the appended claims, be
interpreted as descriptive and illustrative of the present
invention. Many modifications and variations of the present
invention are possible in light of the above teachings.
* * * * *