Pigment-material-microsphere complexes and their production

New cosmetic raw materials are provided in the form of complexes of pigment materials coupled to small microspheres providing complexes that impart richness and feel, with low oil absorbency while displaying the optical and other properties of the pigment. Improvements in spatial disposition of small pigment particles provide a better dispersion of pigment in and products such as makeups, creams, lipsticks, blushers, nail enamels, and the like. Preferred embodiments include talc, nylon, silica, starches and iron oxide pigments coupled by a liquid titanate coupling agent to microspheres of polyvinylidene chloride copolymer, polyethylene, nylon and silica. Simple methods of manufacture include spraying a liquid titanate in solution on a blended mixture of pigment and microsphere and drying the product while blending, to cure it.

TECHNICAL FIELD 
The present invention relates to new cosmetic raw materials in the form of 
novel complexes of microspheres with cosmetic materials and the 
manufacture of such raw materials. The new complexes impart unique and 
desirable characteristics to cosmetic end-product formulations in which 
they are employed as ingredients. The invention can utilize either organic 
or inorganic microspheres. 
BACKGROUND 
Since prehistoric times, when body paint was first being applied, 
separation of pigments and other components in paints and dyes has led to 
inconsistent colors and non-uniform applications of make-up. Separation 
and settling is a well-known phenomenon in liquid, or fluid-phase systems, 
that results in diminished shelf-life, non-uniform colors and ineffectual 
application of make-up. Separation can also take place in powder mixtures 
with the less dense material tending to concentrate in the upper volume of 
the mixture. 
Advances in the cosmetic arts, and the choice of possible cosmetic 
formulants, are constrained and delimited by, among others, the following 
requirements: 
compatibility, both physical and chemical, with customary cosmetic 
formulants and pre-cursor materials which can include both hydrophilic and 
lipophilic materials; 
stability, again both physical and chemical and also biological, in 
end-product formulations for extended distribution and shelf-life, 
especially against settling, loss of volume and spoilage; 
end-product stability for the consumer after opening; 
end-use functionality which, in addition to the more or less subtle 
ornamental functions required of, for example, lipstick, mascara, face 
powder and nail polish, includes the more elusive qualities of feel, ease 
of application as well as an appropriate range of adhesion; and, most 
importantly, 
non-toxicity, non-comedogenicity, hypoallergenicity and the like, in other 
words, dermatological innocuity. 
Many, but not all, of these properties can be related to dispersibility of 
the pigment materials and the art is replete with proposals for improving 
pigment dispersibility. Noting that a pigment can be considered as a 
concentrated particle of colorant or other material providing a useful 
visual effect, including pigment extending, techniques to improve 
dispersibility usually comprise grinding or milling pigment materials to a 
fine particle size and coating the particles. 
Milling of course increases the available surface area and visual effect of 
the pigment, and thus its effectiveness. There are many prior art 
teachings relating to the coating of pigment materials to improve their 
dispersibility. Most pigment materials tend to have a hydrophilic surface 
character making them hard to disperse in organic media, and it is 
accordingly well-known to treat pigment materials to give them a 
hydrophobic character and to use surfactants, anti-flocculants and the 
like to improve the dispersibility of the pigment materials. 
The present invention takes a new approach to the improvement of 
dispersibility, providing striking results of great value to the cosmetics 
industry. Indeed the invention Succeeds in providing some control over the 
spatial distribution of particulate pigment materials in subsequent 
cosmetic formulations. 
In U.S. Pat. No. 4,877,604 to M. Schlossman there are described a number of 
methods to coat pigments and pigment materials with titanate coupling 
agents including isopropyl triisostearoyl titanate. M. Schlossman provides 
valuable improvements in the art of pigment material dispersibility. 
In a different industry, with different constraints, the plastics industry, 
materials known as spherical polymeric particulates in powder form and 
hollow spheres in powder form, either of which materials may be called 
microspheres, are known as valuable fillers and are prized for their 
sphericity, controlled particle size and low density, see for example, 
Ruhno "Handbook of fillers for plastics", edited by H. S. Katz et al , pp. 
437-438 Van Nostrand Reinhold (1978). 
According to Ruhno, there are major advantages to the plastics industry in 
the ability of microspheres to act as fillers in composite materials, 
displacing high-priced polymers with lower density, and better density 
control than solid mineral fillers. Some end product advantages are 
uniform shrinkage, improved sandability and increased impact resistance. 
A brief review of the history and development of spherical polymeric 
powders or microspheres, including hollow spheres, sized under 1000 
micron, can be found in the Ruhno reference. Inorganic and organic hollow 
spheres are described and referred to as "microspheres" the term being 
used for materials which are spherical, small and light, and in the 
context of this reference, hollow and polymeric. Obviously, the 
above-described end-product advantages are not of general use in 
cosmetics. 
Native organic polymeric microspheres have been incorporated in cosmetic 
compositions to impart desirable texture characteristics of smoothness and 
feel, as well as pourability to powder cosmetics, notably makeup, see for 
example UK Patent Application GB 2 191 945. An important drawback is high 
oil absorption causing excessive drying and caking. Another problem is 
that small round microspheres do not adhere well to the skin. 
Inert microspherical materials, especially organic polymeric materials, for 
example spherical nylon or polyethylene powder, have been employed as a 
cosmetic raw material, see for example, the Journal of The Society of 
Cosmetic Chemists, 41, 197-207, May/June 1990 ("Cosm. Chem." hereinafter). 
Here, hybridized powders are disclosed in which fine-chemical deodorant 
powders, specifically zinc oxide and aluminum chlorhydrate are 
mechanically layered on such microspheres by mixing and percussion in a 
centrifugal ball mill. The active, chemical quenching power of the 
deodorants is retained and improved physical properties of the deodorant 
powders result, including better texture and lower coefficients of kinetic 
friction, the latter correlating with smoothness. 
Mechanofusion processes are expensive and difficult to use on a commercial 
scale for bulk raw materials. A drawback of such cosmetics-containing 
microspherical particles produced by mechanofusion processes, especially 
organic polymeric particles, is that they can have too high an oil 
absorption capacity, giving an unacceptable drying effect to the skin. 
Furthermore, the mechanical layering technique results in the outer 
powders being partially buried, reducing their exposed surface area, a 
drawback for pigment materials. Another difficulty may arise during 
pulverization when too much heat can cause polymeric microspheres to melt. 
Also, while deodorants may be embraced by some interpretations of the term 
"cosmetic" their properties are obviously not those required for 
decorative cosmetics as a material used to adorn embellish or beautify the 
wearer, to enhance the visible appearance of exposed surfaces of the 
wearer, and they are not usually applied to normally exposed skin 
surfaces. 
The Cosm. Chem. disclosure is silent as to the suitability of small inert 
spherical powders for inclusion in appearance-enhancing cosmetics, 
especially for topical application where the oil absorption and 
light-reflective properties of cosmetics are paramount. Nor is the Cosm. 
Chem. disclosure relevant to liquid phase dispersions for manual 
application by spreading. Certain additional properties are vital for 
appearance-enhancing cosmetics. These properties include not only their 
appearance and their ability to sustain and develop pigments, but also 
end-product characteristics such as spreadability. 
Additionally, while the physical properties of feel and smoothness that can 
be contributed by microspheres in some formulations may be desirable out 
of the container, these are of no value if the product lacks adequate 
adhesion to remain on the skin. This is a further drawback of 
microspheres. 
Broad usage of microspheres is contraindicated by high cost in addition to 
technical factors. Formulators may encounter difficulties during 
processing, for example, blending inconsistencies arising from bulk 
density differences; pressing problems in which oil can come out, and 
stability problems because prolonged oil absorption can cause dried cake, 
cracking, and impair the texture of the product. In addition, smooth, 
round particles do not adhere well to the skin. 
SUMMARY OF THE INVENTION 
This invention solves a problem. One of the problems it solves is the 
provision of an improved pigment material which is readily dispersible in 
cosmetic compositions and which has improved bulk density and specific 
surface area characteristics. 
Another object of the invention is to provide a new class of cosmetics 
having richer, more luxurious qualities than have heretofore been 
obtainable. 
It is a further object of this invention to provide improved pigment 
materials having excellent dispersibility which materials are notable for 
comprising a wide class of both inorganic and organic pigments pigment 
extenders and other special, visual-effects materials, and are also 
notable for enhancing the cosmetic properties of these pigments and 
pigment materials. 
A still further object of the invention relates to providing an improved 
cosmetic material which enables microspherical powders to be employed in 
decorative cosmetics without being subject to the drawbacks of known 
materials. 
Additional objects relate to the provision of improved processes for 
formulating cosmetics and to novel processes for the manufacture of the 
novel cosmetic ingredient materials of this invention. 
Broadly stated, the invention provides novel pigment-material complexes for 
use in commercial formulations, especially cosmetics, in which a 
particulate pigment material is chemically coupled to a microsphere 
material. To simplify the coupling reaction and reduce possible chaining 
or polymerization, where the pigment material is inorganic, polar or 
hydrophilic, an organic, non-polar hydrophobic and preferably polymeric 
microsphere material is used as a carrier for the pigment material. 
Similarly, hydrophobic organic materials are preferably coupled to 
inorganic microparticulate carriers, for example by hydroxyl groups on 
adsorbed water molecules. 
However, "homo" complexes in which microspheres are cross-linked are also 
contemplated as being useful embodiments of the present invention, for 
example nylon-nylon complexes or silica-silica complexes. 
Preferably, the pigment material size is less than that of the 
microspheres, nearly all the particles of which should have diameters less 
than 1000 microns, and a number of pigment particles is coupled to each 
microspherical particle to create what can be thought of as a pincushion 
effect in which a plurality of smaller pigment particles is chemically 
bonded or tethered to the surface of a microsphere in a manner providing 
general coverage of the surface of the microsphere with the pigment 
particles distributed in a shell-like zone close to the surface of the 
microsphere particle to which they are attached, like the heads of pins 
sticking out of a pin cushion. This novel material can be described as a 
pigment-material-microsphere complex and is an excellent raw material for 
use in ornamental cosmetics. 
In one aspect, the invention provides an improved hydrophobic, dispersible, 
high-loading cosmetic material with a low surface area-to-volume ratio, 
low bulk density comprising a pulverized inorganic cosmetic pigment 
material coating and coupled to from 5 to 35 percent of an organic 
polymeric microspherical powder of diameter less than 1000 microns by from 
1 to 5 percent of a titanate coupling agent wherein the inorganic pigment 
material is smaller than the organic microspheres and the coupled product 
has a generally spherical particulate shape, said inorganic cosmetic 
material and said cosmetic material being capable of being coupled by said 
titanate coupling agent. 
In another aspect the invention provides an pigment-material-microsphere 
complex of low specific density comprising: 
a) microsphere-material particles having a particle size less than 1000 
microns; 
b) a plurality of pigment-material particles covalently bonded to said 
polymeric particles; and 
c) a coupling agent residue extending between said pigment materials and 
said microsphere particles whereby they are covalently bonded; 
one of said microsphere or said pigment materials being an organic material 
and the other being inorganic and said coupling agent residue being 
derived from a coupling agent reactive with said microsphere particles and 
reactive with said pigment material particles. 
While some ionic attraction or van der Waal's bonding may be a component of 
the chemical bonds providing the coupling, it is preferred for the 
coupling to be by covalent bonding, or electron sharing. 
A particularly desirable complex has a substantially uniform layer of 
pigment particles coupled to each microsphere so as fully to coat it and 
present the pigment's visual properties more or less substantially 
uniformly in all directions from the complex particle, in the manner of an 
outer skin. 
Such inventive complexes are useful when incorporated in liquid phase or 
semi-solid dispersions for manual application by spreading, including 
make-up, nail enamel eye shadow and the like. The complexes can impart 
valuable additional properties to appearance-enhancing cosmetics. These 
properties include not only good appearance and ability to sustain and 
develop pigments, but also end-product characteristics such as 
spreadability. Additionally, the novel cosmetic-material complexes of this 
invention can provide valuable processing advantages in the manufacture of 
such cosmetic end products, and the invention extends to such improved 
manufacturing process which use microsphere-complexed pigment materials in 
place of conventional pigments and the invention further relates to the 
new cosmetic end-products that result. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In a preferred embodiment, the invention relates to novel complexes of 
discrete, particulate cosmetic materials, especially irregularly shaped 
materials, such as pigments and what may be called pigment materials, 
which term is often used to include pigment extenders and other materials 
that modify the characteristics, especially the visual characteristics, of 
the end product cosmetic, for example, talc, silica, sericites and 
pearlescents and mica. 
Pigments coupled according to the invention are held in a novel spatial 
distribution which avoids agglomeration and reduces settling and 
furthermore facilitates dispersion in hydrophobic media. The resultant 
approximately spherical single-particle layers exhibited by preferred 
embodiments of the invention provide a very efficient spatial distribution 
of the pigment with good fill in formulations and excellent display of the 
pigment's visual properties. 
The novel complexed pigment materials of this invention are valuable 
ingredients when substituted for standard pigments in many cosmetic 
formulations, to which they bring richness, smoothness and other desirable 
properties. Of particular interest are: powder make-up compositions, where 
controlled oil absorption is important so that the make-up does not dry 
the skin; and aqueous or oil-phase cosmetics where the improved 
dispersibility of the pigment complexes is valuable . 
In a liquid system, improved dispersion may be achieved through reduction 
of surface area of the material being dispersed, i.e., spherical particles 
disperse more uniformly than cubic or irregular shaped particles. Improved 
dispersion also allows higher levels of pigment material to be loaded into 
the dispersant. 
Many diverse coupling agents can be used to provide a bond between the 
pigment material and the microsphere material. The coupling agent must be 
capable of bonding So both the pigment material and the microspheres under 
reaction conditions that will not be deleterious to either ingredient. 
Preferably, the coupling agent has one functional group that is reactive 
with the pigment material and a different group that is reactive with the 
microsphere material. The residual linking group should be inactive or 
innocuous in cosmetic compositions and in their processing. Preferably 
also, the coupling agent coats the pigment material to improve its 
dispersibility without unduly detracting from its pigmenting properties. 
In general, organofunctional coupling agents are preferred, especially 
those with a hydrolyzable moiety that will couple to an inorganic material 
and a non-hydrolyzable moiety that will couple to an organic material. 
While the parameters of suitable coupling agents will be discussed more 
fully below, many suitable agents can be found in the various chemical 
arts and they include classes of compounds such for example as of 
organofunctional aluminates, titanates and zirconates as well as 
organofunctional silanes. 
A preferred class of coupling agents comprises titanate coupling agents, 
and these are effective in coating inorganic pigment materials, giving 
them a hydrophobic character rendering them more compatible with oily 
phase dispersants. 
The invention relates to the coupling of particulate components of a 
make-up. An organic particulate material can be coupled with an inorganic 
particulate material to provide a combination or complex that is a 
homogeneous, uniform material that resists separation and disperses better 
than an uncoupled mixture of the same materials. 
Microspheres are value-added ingredients in today's formulations. In a 
preferred embodiment, the invention extends and adapts some of the 
desirable properties of microspheres to irregularly shaped organic and 
inorganic pigments, using an isopropyl triisostearoyl titanate to couple 
pigment materials to microspheres. The new complexed compounds of this 
invention offer increased applications not achievable by the uncoupled 
components whether used singly or together. 
Microspheres disperse more uniformly than most pigments in both oil and 
aqueous-based systems and also in emulsions, having the lowest specific 
surface area per unit volume. Produced to a narrow particle size range, 
microsphere complexes blend more uniformly in pressed and loose powder 
systems. The pigment-complexed microsphere materials of this invention 
have many of these advantages while, depending upon the particular pigment 
and microsphere material chosen, avoiding many of the drawbacks of 
employing microsphere materials, especially organic polymeric microsphere 
materials in cosmetic compositions. 
The inventive cosmetic pigment-material-microsphere complexes have markedly 
improved and useful characteristics for cosmetics including: a low surface 
area to volume ratio; improved dispersion; improved viscosity and better 
flow; and uniform reflectivity. 
Commercially available microspherical powders useful in the preparation of 
the cosmetic materials of this invention include organic polymeric 
materials such as polyethylene, polypropylene and copolymers thereof, 
polyurethane, polyesters, polyamides, polymethylmethacrylate, nylon, 
ethylene acrylates copolymers and polyvinylidene copolymers. Substantially 
any non-toxic, non-irritant, cosmetically compatible organic polymeric 
material that can be satisfactorily coupled, can be used. Inorganic 
microsphere powders including, for example., silica, magnesium carbonate, 
and titanium dioxide can also be used. 
Both organic and inorganic microspheres can be solid, porous or hollow or 
mixtures thereof. Such microspherical powders generally have diameters of 
less than 1000 microns and preferred powders have diameters of from 1 to 
100 microns. Effective results can be obtained with microspheres of from 2 
to 50 microns with many useful, commercially available microsphere 
materials falling in the range of from 2 to 20 microns. Although useful 
results can be obtained with microspheres having an average size of about 
2 microns, larger diameters for better spatial distribution of coupled 
pigments are preferred. 
The characteristics of some commercially available microspherical powders 
useful in the practice of this invention are set forth in Tables: 
TABLE 1 
______________________________________ 
Typical Values of Quantitative Microsphere Properties. 
Avg. Particle 
Apparent Oil Melting 
Size Density Absorption 
Point 
microns g/in.sup.3 
g/100 g .degree.C. 
______________________________________ 
Ethylene 5-15 2.4 60 104 
Acrylates Co- 
polymer 
Polyethylene 
10 .+-. 2 2.9 90 109 
Nylon I 5 3.9 55 165-171 
Nylon II 2-20 -- 90 -- 
Polymethyl- 
2-15 5.4 60 N/A 
methacrylate 
(PMMA) 
Silica 9 .+-. 2 5.5 150 N/A 
Polyvinylidene 
5-35 0.2 1270 N/A 
copolymer 
(PVDC) 
Polyurethane 
10 8.3 60 N/A 
______________________________________ 
Apparent density is determined on the loose material. Oil absorption is 
determined by ASTM D28184. "N/A" is "not applicable". 
1 An example of a suitable class of polyvinylidene copolymers is 
2 that of acrylonitrile vinylidene chloride copolymers. 
TABLE 2 
______________________________________ 
Qualitative Microsphere Properties 
Organic 
Inorganic 
Solid Hollow Porous 
______________________________________ 
Ethylene Acryl- 
X X 
ates Copolymer 
Polyethylene 
X X 
Nylon X X 
PMMA X X 
Silica X X 
PVDC X X 
Polyurethane 
X X 
______________________________________ 
Of particular interest is the PVDC material listed above which comprises 
hollow microsphere particles and has an exceptionally low apparent or bulk 
density. Such materials, when complexed according to the methods of this 
invention, provide a particularly attractive product whose low density 
imparts a highly desirable bulk density reduction to pigment materials 
with which they are complexed. Further advantages are desirable 
characteristics such as richness and smoothness in cosmetic formulations 
and also high oil-absorption characteristics to the cosmetic. (As noted 
above, the oil absorption of raw, hollow polymeric microspheres may be 
excessive.) Hollow microsphere forms of other organic polymers are 
available and similarly advantageous. Bulk densities below 0.5 g/in.sup.3 
are available and useful. Such materials are extremely hard to process in 
their raw state as they become airborne and fly everywhere. Complexing by 
the method of this invention solves this problem. 
Preferred embodiments of the cosmetic materials include pigment materials, 
both inorganic materials, especially those that are customarily ground 
before use and also inorganic materials that are sometimes irregularly 
shaped, in the sense that they are clearly not spherical, are prone to 
have notably angular surfaces with occlusions and voids between particles 
and tend to include a wide range of particle sizes within samples. Such 
features are characteristic of many inorganic pigment materials. Organic 
pigments tend to be gritty, having sharp angular surfaces. Being small 
relatively high density particles, they are hard to disperse and to keep 
in suspension. 
Some examples of irregularly shaped organic and inorganic pigment materials 
that can be used as particulate cosmetic materials to be coupled to 
microspheres are: boron nitride, D&C red #6 barium lake, D&C Red #7 
calcium lake, D&C red #34, FD&C blue #1 aluminum lake, yellow, black and 
red iron oxide, carmine, ferric ammonium ferrocyanide, ferric 
ferrocyanide, manganese violet, ultramarine blue, ultramarine violet, 
ultramarine pin, silica, mica, talc, bismuth oxychloride, titanium 
dioxide, nylon, flour, starch, complexed metal starches and polyethylene, 
and metallic powders, including for example, aluminum powder and bronze 
powder. Clearly such metallic powders will require a choice of process 
conditions that attaches to the surface of the particles and avoids 
destroying the body of the particle itself. Pigment materials generally 
range in size from about 15 nanometers to 10 microns, with coloring 
pigments not usually exceeding about 2 microns in approximate diameter. 
While the lower limit may appear to be extremely small, it should be noted 
that a commercially available titanium dioxide pigment has an average 
primary particle size of 21 nm and a specific surface area of about 
50m.sup.2 /g and there are common pigments, such as iron oxide pigments 
that are known to be smaller. It can readily be appreciated that a 
substantially continuous shell of such fine-particulate pigment coupled to 
an organic microsphere of several microns diameter achieves an excellent 
spatial distribution of the pigment with much improved covering power and 
apparent bulk density, a quite new material. 
In making the present invention, I have discovered that by coupling 
irregularly shaped or multi-faceted pigment materials to the microspheres 
described above using for example titanate coupling agents, the coupled 
pigment products acquire many of the desirable physical characteristics of 
the microspherical powders while retaining their valuable pigment 
properties. Importantly, the basic spherical shape of the microspheres is 
maintained in the coupled material, so that what were in many cases small, 
irregularly shaped, multi-faceted pigment materials having a tendency to 
agglomerate are now held in an organized spaced relationship. This spacing 
improves many of their cosmetic characteristics, especially the coupled 
pigment materials' dispersibility. Clearly this improvement in 
dispersibility is more than mere improvements in phase compatibility 
obtainable by prior art surface treatments, because reductions in bulk 
density of the rather dense pigment materials which are provided by the 
present invention, help reduce any tendency of the materials to settle 
out. 
Such irregularly shaped complexed pigment materials can be considered as 
being distributed around each microsphere particle on generally spherical 
or spheroidal surfaces or in generally spherical shells, with radii 
greater than the average pigment particle size, preferably at least two or 
three times the size. This distribution is illustrated in a general manner 
in the accompanying micrographs which will be described hereinafter. In 
this way optimal use of the surface properties of the pigment is obtained. 
The complexes display similar reflectivity in all directions. In general, 
these complexes will be much larger in size than any of the cosmetic 
materials with which they are formulated and will naturally tend to 
present an evenly pigmented outer surface at any exposed surface. This of 
course is a highly desirable cosmetic characteristic. The size of the 
generally spherical complexes provides plenty of room for smaller 
particles to be accommodated between them. Their sphericity promotes 
blendability with other cosmetic ingredients. 
A further and surprising advantage is displayed by the inventive complexes 
in that, where adequate pigment material is used in manufacturing the 
complex, the oil absorption characteristics of hydrophilic polymeric 
microspheres, especially very absorbent hollow ones, can be significantly 
reduced. This is important, to avoid undue drying effects of the end 
product caused by excessive absorption of skin oils. 
Thus, the pigment shell or coating on a low-density, organic, polymeric 
microsphere particle, or core, can protect or modify the properties of 
that core, while gaining improved spatial distribution leading to 
isotropic light reflectance, bulk density and specific surface area 
characteristics for the pigment material. There is a synergistic 
relationship, the one material gaining properties from the other. Thus, 
the presence, especially of a hydrophilic or oleophobic pigment coating, 
can reduce the accessibility of an oleophilic organic core to oils, and 
thus control oil absorption. In this context, a shell of silica particles 
can greatly reduce the oil absorbency of organic polymer microspheres, 
especially if it is a more or less solid or closed shell. Inorganic, 
unreactive materials such as silica usually have a small quantity of 
adsorbed water providing available sites for the attachment of hydrophilic 
moieties. 
In some cases, the microspheres may be many times the size of the pigment 
material, 10, 50 or even 100 times, so long as the size of the resultant 
pigment-material-microsphere complex particle does not exceed about 1000 
micron (1 mm.) 
Alterations of the microspheres' qualitative properties may also be made, 
yielding advantages in the resulting composition or processing of the 
composition. For example, they may be treated with surfactants to make 
them more dispersible, of value with silica, or pH-modified by an acid 
treatment or base-catalyst treatment. 
The irregularly shaped coating or pigment materials should be ground, 
milled or pulverized to a size, preferably between 15 nanometers and 10 
microns, in relation to the microspheres, which is such as to enable the 
material to coat the microspheres and provide a coupled product or complex 
having a generally spherical shape. Such comminution of the pigment 
material typically results in particles that have sharp angular faces and 
that are far from spherical. Organic pigments, in particular, are gritty 
when comminuted. Complexing with inorganic microspheres improves the bulk 
texture and blendability of such gritty organic pigments. 
It has been discovered that a titanate coupling agent can join an inorganic 
material to an organic microspherical powder and join organic material to 
an inorganic microspherical powder. In joining the materials, moisture and 
air voids on the irregularly shaped material can be eliminated when these 
materials are coupled to the microsphere, thus tremendously reducing the 
surface area. 
An improved method is to solubilize the titanate coupling agent in a 
volatile solvent such as isopropyl alcohol, heptane or, preferably, a 
high-purity, fractionated isoparaffinic solvent, and then mix it with or 
spray it on the materials to be coupled. 
Liquid monalkoxy (C.sub.1 to C.sub.20) isostearoyl titanates, especially 
isopropyl triisostearoyl titanate, have been found effective as coupling 
agents in accordance with the invention. 
Titanate coupling agents are well known materials and they can be used in a 
number of different coupling processes that are described in relevant 
literature, for example a chapter entitled "The Chemistry of Titanate 
Coupling Agents", pages 2-9 and 26-29 in "Ken-React Reference 
Manual--Titanate, Zirconate and Aluminate Coupling Agents", Monte et al., 
and M. Schlossman U.S. Pat. No. 4,877,604. 
In general terms, a titanate coupling reaction mechanism is believed to 
proceed as follows. 
A monohydrolyzable group attaches to a proton on the surface of an 
inorganic pigment material, followed by hydrolysis or solvolysis, and then 
transesterification and transalkylation, whereupon the water of hydration 
and air voids on the inorganic pigment surface are replaced by a 
monomolecular layer of organofunctional titanium, the titanate forming a 
covalent bond (electron sharing) with a proton on the inorganic surface. 
The titanium is bonded to oxygen atoms and to the inorganic surface. The 
coated inorganic material is then able to be joined to a microspherical 
surface, especially an organic surface, by the coating. 
Monte et al. U.S. Pat. No. 4,098,758, the disclosure of which is herein 
incorporated by reference thereto, describes one class of titanate 
coupling agents which can be used to couple inorganic pigments to organic 
polymers and which have the advantage of avoiding multi-layer coatings on 
the pigment. These coupling agents can be used in the practice of the 
present invention. Furthermore, analogous titanate coupling agents having 
different proportions of hydrolyzable to non-hydrolyzable groups from 
those required by Monte, can be used. There is a great diversity of 
substituents that can be present on the coupling agent. Many of these are 
set forth in Monte. Such titanate coupling agents can also be used to 
couple organic pigment materials to an inorganic microsphere carrier. 
Clearly other coupling agents can be used with similar effect and 
advantage, for example, zirconate or aluminate coupling agents such as 
neopentyl (diallyl) oxyl, tri(dioctyl) phosphito zirconate and equivalent 
aluminates. However, titanates constitute a preferred species, whose 
effectiveness and desirability for the purposes of this invention have 
been demonstrated by experiment, as disclosed herein and are known to 
cosmetically compatible with few, if any, undesirable side effects. The 
use of titanium in the form of titanium dioxide is of course a standard 
practice in the cosmetic arts and its safeness is well established. 
A number of surfactants having a polar terminus for attachment to or 
coating inorganic pigments having a hydrophilic surface, such as those 
disclosed in Ayala U.S. Pat. No. 4,952,651, can also be used as coupling 
agents. These surfactant-type coupling agents include, for example, 
triols, especially trimethylol ethane and propane and dimethyl 
polysiloxanes. Ayala's surfactants have, in addition to a reactive polar 
terminus capable of attachment to active sites on hydrophilic pigment 
particles, a non-polar terminus for compatibility with a non-polar matrix 
such as a polyolefin. While such agents could be used in the practice of 
the present invention to complex polar and non-polar particles, and can be 
effective for example where the polar terminus comprises an extensive 
alkyl or alkyl-substituted ligand that binds to polymer microspheres 
reasonably well by van der Waal's forces, it is preferred that the 
non-polar terminus be reactive and be capable of being chemically 
covalently bound to an organic microsphere without disturbing the bonding 
to the pigment. 
In summary, a coupling agent for coupling polar particles having active 
sites to non-polar particles can have the general formula: 
EQU X.sub.n (M)Y.sub.m 
where M is a carrier moiety with a valency state of from 2 to 6, preferably 
from 2 to 4; n and m is each from 1 to 5 with n+m equaling said valency 
state; X is a polar-reactive ligand reactable with said active sites on 
said polar particles and Y is a non-polar-reactive ligand reactable with 
said non-polar particles. 
M can be selected from the group consisting of metallo moieties including 
titano, zircono and alumino, phosphato or phosphito moieties, secondary, 
tertiary or quaternary substituted ammonium moieties and bi-, tri- or 
quadri-functional organic groups, including aliphatic, cyclic, 
heterocyclic and polycyclic organic moieties. 
X preferably includes a hydroxyl or alkoxy moiety of from one to five 
carbon atoms and is hydrolyzable, but other polar-binding ligands can be 
used. 
Y can be any ligand which will couple to the desired non-polar particle, be 
it pigment material or microsphere without interfering with the X-bond to 
the polar particle. Examples of suitable Y ligands include alkoxy groups 
having from 1 to 24 carbon atoms, such as stearoyl, oleyl, and palmitoyl, 
straight, branched chain and cyclic homologues there of, either saturated 
or unsaturated, and substituted homologues thereof with halo, amino or 
nitro substituents. 
Thus, in general terms, a preferred class of coupling agents comprises a 
monohydrolyzable ligand for attachment to inorganic pigment materials by 
hydrolysis, a metallo carrier moiety and an organofunctional ligand or 
ligands for attachment to the organic polymeric microspheres. 
Conveniently, the organofunctional ligand can comprise an ester-like 
moiety that can attach to paraffinic chains or groups in the polymeric 
microspheres by trans-esterification and trans-alkylation. 
Many other variants of M, X and Y that can serve the general purposes of 
this invention will be apparent to those skilled in the art from the 
disclosure herein and from the literature cited herein, as well as from 
other literature known to those skilled in the art. Isopropyl 
triisostearoyl titanate, the preferred coupling agent used herein, 
exemplifies the formula above. Another class of possible coupling agents, 
not discussed above, comprises organofunctional silanes, especially those 
possessing both organic and inorganic reactivity, (the possession of which 
is a feature of preferred coupling agents) for example, Dow Corning Z-6020 
silane which is designated 
N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane of formula (CH.sub.3 
O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2 NH.sub.2. Notable are the 
aminoalkyl organic group and the trimethoxy silyl inorganic group which 
can serve as coupling moieties in a variety of coupling agents. Other 
usable silanes include amine, epoxy, vinyl, chloralkylamine and 
vinylbenzylamine homologs of the above Z-6020 silane. 
Preferably, the coupling agent is chosen to favor the coupling of a number 
of pigment particles to a single microsphere without chaining or layering 
of the coupling agent. Depending upon their relative particle sizes, this 
number is preferably at least four and even at the outer limits of 
relative proportions is probably not in excess of a thousand, while 100 is 
a more practical maximum. An optically continuous layer of pigment 
particles is desirable. 
It is also preferred that the coupling agent be capable of coating 
inorganic pigment particles having a hydrophilic surface to render that 
surface hydrophobic and the particles dispersible. Using such a coupling 
agent and appropriate process conditions, a pigment-material-microsphere 
complex can be produced which presents hydrophobic, non-polar surfaces 
regardless of the character of the inorganic pigment coating the complex; 
which has isotropic reflectivity displaying the optical character of the 
pigment material; which is dispersible in,oils and has desirable density 
and specific surface area characteristics. Isopropyl triisostearoyl 
titanate and other organotitanates are examples of such 
microsphere-coupling materials that can also coat inorganic pigment 
particles. 
In a preferred embodiment, the organofunctional group or groups, and there 
can be three such groups per titanium atom, are alkoxy groups, giving the 
coated inorganic pigment material a hydrophobic or lipophilic surface. As 
disclosed and claimed by M. Schlossman, such pigment materials have 
improved dispersibility in cosmetic formulations and, by virtue of their 
titanate coating, provide surprising advantages both to the processor and 
the end user. These advantages perhaps can be attributed to the surface 
characteristics of the titanate-coated particles which, in addition to 
being hydrophobic, are less likely to trap air and moisture between the 
particles. 
The present invention achieves some surprising advantages over the prior 
art, including M. Schlossman, by improving the spatial distribution of 
particulate cosmetic materials. This distribution is obtained by 
chemically bonding or coupling the particulate cosmetic materials to a 
microspherical carrier. One way of doing this is by coupling coated 
particles, such as those described above, to organic polymeric 
microspheres using per se known reaction techniques. 
As a practical matter, using bifunctional coupling agents, for example 
organic titanates having hydrophilic and hydrophobic reactive groups, the 
coupling process can be effected in a single step. In such a one-step 
process, the particulate cosmetic material, the microspheres and the 
coupling agent are mixed under conditions promoting the desired coupling 
reactions, for example by spraying or otherwise mixing a solution of the 
coupling agent with a mixture of the other two ingredients, which can be a 
dry mix in a blender, and drying off the solvent with heat, while mixing 
or blending. In preferred embodiments, the coupling agent or titanate is 
substantially fully reacted to the particulate cosmetic material surface 
by the heat required to dry off the solvent. 
A titanate coupling agent dissolved in an organic solvent, for example, an 
isopropyl triisostearoyl titanate coupling agent, will partially react at 
room temperature, but an elevated temperature, for example in the range of 
from 80.degree. to 300.degree. C. is preferred to effect coupling. The 
solvent can then be removed in a drying step which usually completes the 
coupling reaction steps of hydrolysis, transesterification and 
transalkylation. 
A volatile organic solvent with, for example, a distillation range between 
97.degree.-140.degree. C., is preferred for use in the coupling process, 
especially where the coupling agent is a liquid monoalkoxy titanate, 
especially an alkyl trialkoyl titanate. 
A particularly suitable solvent is an isoparaffinic solvent such as Isopar 
C (trade mark) manufactured by the Exxon Corporation. This has a narrow 
distillation range of from 98.degree. to 106.degree. C., has exceptional 
purity of isoparaffinics with low limits of other hydrocarbons and of 
trace impurities. Isoparaffinic solvents have similarities to heptane, 
which could also be used, but have a lower heat of vaporization, a mild 
odor add are relatively inert. Their freedom from essentially any polar 
compounds is of particular value in carrying out the present invention as 
is their low toxicity. Furthermore, Isopar C has been found to yield 
better coatings than other solvents, for example isopropyl alcohol. 
The solvent can be added to the coupling agent or titanate to comprise 
between 1-99 percent of the formula. A good blend has between 5-50 percent 
solvent, and a preferred ratio between 15-35 percent by weight. In 
practicing the coupling process of this invention, the powdery 
ingredients, namely the particulate cosmetic or pigment material and the 
microspheres can be charged to a vessel provided with a vacuum system 
capable of removing volatile solvents. 
Preferably the solvent is recovered and examined for purity. In a 
well-controlled process with adequate ventilation it can be recycled. 
Preferably the recovered solvent should not contain any titanium. This 
provides a further quality control check and also confirms binding of the 
coupling agent to the particulates. 
When coupling an organic polymer to pigment or extender pigment, the 
organic polymer may comprise as little as 15 percent by weight or less of 
the mixture and the titanate can be present in amounts of at least 0.01 
percent by weight, although from about 1 to 5 percent by weight is more 
practical. Preferred compositions use the microspheres in the amount of 5 
to 35 percent by weight and a coupling agent, for example, isopropyl 
triisostearoyl titanate in amounts of 1 to 3 percent by weight. In 
general, however, the weight of microspheres will be from 5 to 100 percent 
of the weight of pigment material. 
A particularly preferred embodiment of the invention employs 
hydrophilic-surfaced inorganic pigment materials coupled to organic 
polymeric microspheres. 
Specific advantages of preferred pigment-material-microsphere complexes of 
this invention include: improved hydrophobicity; a higher melting point; 
more uniform specific gravity and bulk density; improved dispersibility; 
lower viscosities at comparable use levels; higher solids loading is 
possible; improved adhesion; smoother texture; unique surface area 
characteristics and reduced processing times and clean up is necessary. 
Such coupled microspherical powders and fillers are useful in cosmetic 
compositions, especially oil-based and aqueous-based emulsions and poured 
powders. The advantages include: uniform specific gravity; a controlled 
oil absorption rate; lower specific surface area is achieved; maximum 
solid content for a given viscosity is achieved; minimum viscosity for a 
desired solids load is achieved; improved flowability and ease of 
dispersion; improved spreadability and application; a unique surface 
texture (smooth/creamy) is achieved; and spherical particulate 
characteristics are maintained during processing. Organic polymeric 
microsphere materials can thus be used to better incorporate pigments and 
fillers, or extender pigments, into a cosmetic. 
These materials also yield advantages when incorporated into pressed 
powders. The powders are easier to press; the oil absorption rate is 
better controlled; packing is reduced; adhesion is improved; density is 
uniform; and a smooth surface is achieved. 
The polymer microspheres used in cosmetics such as polyethylene may begin 
to soften at 95.degree. C. to 110.degree. C. and then deform or melt and 
flow. It is not unusual for these temperatures to be realized and exceeded 
in the processing of cosmetics. 
By treating polymer microspheres mixed with an inorganic material such as 
boron nitride with a titanate or other type of coupling agent, insulated 
microspheres are achieved. The coating acts as insulation preventing the 
melting or deforming of the microspheres during processing. Thus, the 
dispersion advantages etc., due to microspherical shape are available in 
the final cosmetic product. 
In accordance with the inventive method of making an improved cosmetic 
component, one selects an organic microspherical material for cosmetic 
use. A pulverized inorganic material to be coupled to and carried by the 
organic microspherical material is combined with the microspherical 
material and the inorganic material to form a mixture. The liquid titanate 
coupling agent is added to the mixture and the resulting mixture is 
thoroughly mixed to form a mixture of microspherical compounds of 
inorganic material coupled to organic microspheres by the titanate 
coupling agent. Tests on specific coupled combinations have been performed 
and scanning electron microscope images have been made for components, 
mixtures and coupled mixtures. 
Polyvinylidene copolymer (PVDC) microspheres have been combined with talc, 
with black iron oxide and with spherical silica. Isopropyl triisostearoyl 
titanate was used as a coupling agent. Polyethylene was coupled with boron 
nitride using isopropyl triisostearoyl titanate. The amount of isopropyl 
triisostearoyl titanate was 2 percent by weight in all cases. 
Talc was mixed with PVDC in a 85 to 15 ratio. The specific surface area of 
the mixture was 5.2 meters.sup.2 /gram, talc alone has a specific surface 
area of 8.0 meters.sup.2 /gram. When the mixture was treated, the specific 
surface area was reduced to 0.57 meters.sup.2 /gram. 
A 20 percent composition of the treated talc-PVDC mixture in mineral oil 
was pourable with a measurable viscosity while a like composition using an 
untreated mixture formed a paste and had no flow property. 
It was found that one gram of the treated material would float on 50 ml of 
water for more than an hour. This was not the situation without treatment. 
The treated mixture thus exhibits greatly increased hydrophobicity. 
When PVDC and silica were combined in a 15 to 85 ratio and treated with 
isopropyl triisostearoyl titanate, a float time for one gram of material 
on the surface of water was also in excess of one hour. When an untreated 
mixture was floated on water, the silica swiftly separated out and sank. 
Polyethylene microspheres having a melt range of 105.degree. to 106.degree. 
C. were combined in a 50 to 50 ratio with boron nitride powder and treated 
with isopropyl triisostearoyl titanate. Again, the titanate amount was two 
percent by weight of the mixture. The melt range for the treated 
microspherical mixture was increased to more than 140.degree. C.

Some preferred embodiments of the invention will now be described, by way 
of illustration, and without limitation, as the scope of the invention is 
limited only by the appended claims, with reference to the following 
examples, in which parts are by weight. 
EXAMPLE 1 
30 parts of nylon II, as described in Table 1, and 70 parts of mica were 
intimately blended in a vacuum blender for 5 minutes with mica ground to 
an average particle size of 5 microns and a specific surface area of 
1.4-1.6 meters squared/gram. Sufficient 34 percent solution of isopropyl 
triisostearoyl titanate in Isopar C (Exxon Corporation) was sprayed onto 
the surface of the blended powders to coat the powder with about 2 percent 
by weight of isopropyl titanium triisostearate. The blender temperature 
was set at 80.degree. C. and the powdered complex reaction product was 
dried for 1 hour. After a five minute post-process blend, and cooling, the 
powder was discharged from the blender. 
The nylon-mica complex reaction product of treated powder has a slightly 
waxy odor, good slip, good adhesion to the skin, is hydrophobic and 
exhibits significantly reduced oil absorption (40 grams oil/100 grams) 
than the base uncomplexed nylon II particles. In addition, the composite 
powder or complex can easily be dispersed in water, like the mica, and 
unlike the nylon, so that the complex or composite powder acquires useful 
characteristics from both its parent powders. 
The recovered solvent is analyzed and has a boiling point elevated by 
2.degree. C. compared with Isopar C. This difference is acceptable. The 
percentage of titanate bound in the composite powder product was 
determined to be 2 percent. No solvent odor could be detected in the 
product. 
Evidence of the coupling treatment and its effects was also determined by 
resistivity measurements by applying a voltage between metal electrodes in 
a dry contained of powder, the powder being lightly tapped to make contact 
at the electrodes. Various nylon microsphere materials exhibited high 
individual resistivities of insulative value in excess of 10.sup.14 
ohm-cm. Mica alone showed a semiconductive resistivity value of about 
1.5.times.10.sup.8 ohm-cm. A 30/70 nylon/mica had a higher resistivity of 
about 6.6.times.10.sup.10 ohm-cm. while that of the reaction product 
complex of Example 1 was about 1.1.times.10.sup.13, only about one order 
of magnitude less than the naked nylon microspheres. Interpreting a higher 
resistance to imply greater hydrophobicity, the complexing process has 
increased the hydrophobicity of the complex, as compared with the mix, by 
more than two orders of magnitude, clearly demonstrating coupling. 
EXAMPLE 2 
15 parts of polyvinylidene copolymer (PVDC) as described in Table 1 were 
added to a vacuum blender followed by 85 parts of talc pigment. The 
powders were intimately blended for 5 minutes. A 17 percent solution of 
isopropyl triisostearoyl titanate in Isopar C (Exxon Corp.) was sprayed 
onto the surface of the powder mix. The blender temperature was set to 
80.degree. C. and the powders were dried for 1 hour. After cooling, the 
treated powder was discharged to a drum and examined. The composite powder 
product was hydrophobic, had a slightly waxy odor, had good slip, improved 
adhesion, and lower oil absorption (180 grams oil/100 grams than untreated 
PVDC. The PVDC powder used was hollow and very lightweight, being easily 
airborne. The treated material complex product or composite powder is 
substantially denser having an apparent density of approximately 1 gram 
per cubic inch, and could readily be dispensed without becoming airborne. 
The composite pigment material contained 2 percent isopropyl 
triisostearoyl titanate by weight had a generally spherical shape, there 
was no odor of solvent detected and the specific surface area was in the 
range of from 0.5 to 2 m.sup.2 /g. 
EXAMPLE 3 
15 parts PVDC as described in Table 1 and 85 parts mica pigment material 
were intimately blended in a vacuum blender. The mica had been ground to 
an average particle size of 5 microns and had a surface area between 
1.4-1.6 meters squared per gram. The powder was blended, treated, and 
dried as described in Example 2. The treated pigment was spherical. The 
treated pigment had good slip, improved adhesion, was hydrophobic, and had 
lower oil absorption (180 grams oil/100 grams). The solvent odor could not 
be detected. The amount of titanate employed was 2 percent by weight of 
the composition. 
EXAMPLE 4 
15 parts polyvinylidene copolymer (PVDC) microspheres and 85 parts of 
silica as described in Table 1 were intimately blended, treated and dried 
as described in Example 2. The microspheres are extremely lightweight and 
easily airborne. In contrast, the coupled powder can be easily dispensed. 
The apparent density of the complexed pigment material is approximately 
1.4 grams/cbi. The oil absorption of the PVDC microspheres decreased to 
approximately 280 grams oil/100 grams. The complexed pigment material is 
hydrophobic, has good slip, improved adhesion, and a slightly waxy odor. 
There was no odor of solvent present. The amount of titanate used was 2 
percent by weight. The spherical shapes were maintained. 
The pigment-material-microsphere complex products of Examples 2, 3 and 4 
all had a spherical appearance under a scanning electron microscope, an 
average particle size of about 20 micron with 90 percent of particles 
falling within the range of from 5 to 35 micron, and a waxy odor. Talc-, 
mica- and silica-PVDC complexes produced by methods generally equivalent 
to those of Examples 2-4 can be advantageously incorporated in anhydrous 
blushers, shadows, lip powders, eye pencils and lip pencils, and pressed 
powders. In liquid foundations such complexes are also effective, 
silica-PVDC complexes being especially so. The latter can also be used, 
with advantage in solvent or aqueous-based mascara. 
In such formulations, customary proportions of pigment are used, although 
because of the benefits of the invention, smaller amounts may be adequate. 
Richer, creamier or smoother products can result with better 
pigment-related appearance qualities. 
EXAMPLE 5 
15 parts PVDC as described in Table 1 and 85 parts black iron oxide pigment 
were intimately mixed. The black iron oxide had been ground to an average 
particle size between 2-5 microns. The mixed powders were blended, 
treated, and dried as described in Example 2. The spherical shape was 
maintained. The treated pigment has good slip, improved adhesion and 
texture. The amount of titanate was 2 percent by weight. There was no odor 
of solvent. The treated pigment was hydrophobic. 
EXAMPLE 6 
5 parts PVDC and 95 parts talc were intimately blended, treated, and dried 
as described in Example 2. The treated powder was spherical, hydrophobic, 
had good slip and improved adhesion. The amount of titanate was 2 percent 
by weight of the composition. There was no odor noticed. The complexed 
pigment could be more readily pressed than polyvinylidene copolymer. 
EXAMPLE 7 
50 parts polyethylene as defined in Table 1 were intimately mixed with 50 
parts of boron nitride. 99 percent of the boron nitride particles had a 
particle size below 10 microns. The pigments were blended, treated, and 
dried as described in Example 2. The complexed pigment had good slip, 
improved adhesion, and was hydrophobic. The melting point of the complex 
was increased to about 140 centigrade. Boron nitride is believed to 
provide insulation to the polyethylene. The pigment complex is 
particularly useful for incorporation as part of a pressed powder blend. 
This blend can be pulverized without the polyethylene component melting. 
The amount of titanate was 2 percent. There was no odor of solvent in the 
product. 
BRIEF DESCRIPTION OF THE DRAWINGS 
The following scanning electron microscope photographs depict various 
microspheres, microsphere-irregular particulate mixtures and microspheres 
coupled with irregular particulates by isopropyl triisostearoyl titanate. 
Photographs 1 to 8 show the shape of the particulate materials to be 
coupled and photographs 9, 10 and 11 depict the non-homogeneity and uneven 
distribution of materials in a non-coupled mixture. Such inhomogeneity 
leads to uneven dispersion, accelerated separation and other problems. 
Photographs 12 to 27 show the coupled mixtures and the spherical nature of 
the microspheres remaining intact after being coated with the irregularly 
shaped material. The materials depicted and the magnification employed in 
the photomicrographs are detailed in the legends accompanying each of 
photographs 1-27. Scales in microns are also shown for approximate 
determination of actual particle size characteristics directly from the 
photographs. Scanning electron micrographs or photographs 28 and 29 show 
70% mica coupled to microspherical ethylene/acrylates copolymer using an 
organofunctional silane coupling agent at magnifications of 500 and 6,000 
respectively. 
The inorganic materials are much denser than the organic polymers and 
therefore significant loading in terms of weight of the inorganic material 
is achievable while maintaining the spherical shape of the coupled 
materials. 
The invention has been described with special reference to the field of 
cosmetics where it provides outstanding benefits, as set forth herein. It 
will be clear, however, to workers in other fields that some of the unique 
benefits of the pigment-material-microsphere complexes of this invention 
are transferable to and realizable in other fields. For example, in 
compounding moldable plastics or rubbers, good dispersibility of pigment 
materials is desirable and the unique three-dimensional control of spatial 
distribution that is afforded by the microsphere-complexed pigment 
materials of this invention is also valuable in those fields. Such control 
affords the prospect of better utilization of pigment materials exploiting 
the advantages described herein. Accordingly, the invention extends to 
plastics and rubber materials, cured and uncured, molded and amorphous, as 
well as paints, inks and artists' materials which incorporate novel 
pigment-material-microsphere complexes such as those described hereinabove 
in a manner equivalent to the cosmetic materials described herein. 
While an illustrative embodiment of the invention has been described above, 
it is, of course, understood that various modifications will be apparent 
to those of ordinary skill in the art. Such modifications are within the 
spirit and scope of the invention, which is limited and defined only by 
the appended claims.