HIGH SOLVENT CONTENT EMULSIONS
FIELD OF THE INVENTION
The present invention is directed to a high solvent content emulsion. More
particularly, the present invention is directed to an emulsion comprising at least
20% by weight solvent, functionalized polymer and particles having an isoelectric
point below the pH of the emulsion whereby the emulsion is suitable for use as a
cosmetically acceptable vehicle that unexpectedly yields excellent sensory
benefits.

BACKGROUND OF THE INVENTION
Emulsions are typically defined to mean heterogeneous systems which have two
immiscible liquids or phases. One liquid is in dispersed form while the other forms
droplets within the dispersed liquids. Emulsions can be employed as carriers for
actives, especially those targeted for application to skin.
It is customary to use emulsifiers in order to achieve permanent dispersion of one
liquid in another. While emulsifiers are customarily used in vehicles for topical
compositions, emulsifiers are linked to both allergic and non-allergic reactions of
consumers using such compositions. Moreover, use of customary emulsifiers can
result in formulations that do not deliver excellent sensory benefits, are difficult to
apply, and are generally not environmentally friendly.
Attempts at avoiding the need for traditional emulsifiers have been made. These
attempts require the use of micro fine particles (like inorganic pigment) to produce
what is known as a Pickering emulsion. Such emulsions are, however, known for
their low water content and are not characteristically known to deliver excellent
sensory and deliverability characteristics.
It is of increasing interest to develop emulsions comprising a high solvent content,
and preferably, emulsions that are substantially free of emulsifier or surfactant.
Particularly, it is desirable to develop emulsions that deliver excellent sensory
benefits and that do not have a negative impact on the environment. This
invention, therefore, is directed to an emulsion comprising at least 20% by weight
solvent. The emulsion comprises a functionalized polymer and particles having
an isoelectric point below the pH of the emulsion whereby the same delivers
excellent sensory and active deliverability benefits when applied or used by a
consumer even after being formulated substantially free of emulsifier or surfactant.
ADDITIONAL INFORMATION
Efforts have been disclosed for making emulsions. In US 6 379 680, US 6 767
547 and US 6 838 088, Pickering emulsions are described.
Still other efforts have been disclosed for making emulsions. In US 5 9 10 467,
solids-stabilized emulsions are described.
Even other efforts have been disclosed for making emulsions. In US 6 7 10 092,
emulsions stabilized with polymer resin precursors are described.
None of the additional information above describes an emulsion comprising at
least 20% by weight solvent, functionalized polymer and particles having an
isoelectric point below the pH of the emulsion.

SUMMARY OF THE INVENTION
In a first aspect, the present invention is directed to an emulsion comprising:
(a) particles having an isoelectric point below a pH of the emulsion;
(b) functionalized polymer suitable to hydrogen and/or ionically bond to the
particles; and
(c) solvent.
The emulsion of the first aspect is preferably substantially free of surfactant.
In a second aspect, the present invention is directed to an end use composition
comprising the emulsion of the first aspect of this invention.
In a third aspect, the present invention is directed to a method for treating a
condition by applying the composition of the second aspect of this invention.
All other aspects of the present invention will more readily become apparent upon
considering the detailed description and examples which follow.
High solvent content emulsion, as used herein, means an emulsion having at least
20% by weight solvent, the same suitable for use as a vehicle or carrier for an end
use composition. A particle having an isoelectric point below a pH of the emulsion
means a particle within the emulsion suitable to complement hydrogen and/or
ionic bonding tendencies of the functional ized polymer. Typically, the particle has
an isoelectric point under 11, and preferably, under 7.5. End use composition
means a composition ready for use by a consumer and comprising the emulsion
of this invention whereby the high solvent content emulsion of this invention is
preferably a high (water-in-oil) internal phase emulsion which is preferably
prepared substantially free of surfactant. Illustrative examples of the types of end
use compositions that may comprise the high solvent content emulsion of this
invention include leave-on skin lotions and creams, shampoos, hair conditioners,
shower gels, toilet bars, antiperspirants, deodorants, shaving creams, depilatories,
lipsticks, foundations, mascara, sunless tanners, and sunscreen lotions. End use
compositions made with the high solvent content emulsion of this invention may
also include a product associated with oral, laundry or household care such as
laundry detergents, fabric conditioners or hard surface cleaners. In a preferred
embodiment, however, the end use composition of this invention is applied to hair,
skin or both, and most preferably skin, where skin is meant to include skin on the
face, body and scalp. Deliverability means suitable to carry an active to a surface
like a body surface through topical application.
Active means a component typically delivered to a surface including a body
surface of an animal or human, preferably human, in order to enhance/improve a
characteristic (e.g. appearance, cleanliness, odor) of the surface. Such an active
can include, for example, a skin whitening or lightening ingredient like niacinamide
as well as a hair conditioning agent and moisturizing agent like glycerine as well
as those generally classified as silicon copolymers and quaternary ammonium
salts. Functionalized polymer suitable to hydrogen and/or ionically bond means a
polymer able to non-covalently interact with a particle in a donor and/or acceptor
capacity. Substantially free of means less than 3%, and preferably, less than
1.5%, and most preferably 0.0% by weight, based on total weight of the emulsion.
Excellent sensory benefits means yielding a silky sensation.
Comprising, as used herein, is meant to include consisting essentially of and
consisting of. All ranges identified herein are meant to include, implicitly, all
ranges subsumed therein if reference to the same is not explicitly made.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The only limitations with respect to the type of particle that may be used in this
invention is that the same can be employed in a composition suitable for use by
consumers and is able to complement the hydrogen and/or ionic bonding
capabilities of the functionalized polymer used herein. Illustrative yet non-limiting
examples of the type of particle that may be used in this invention include oxides
of silicon, zinc, iron, cerium, zirconium, titanium or aluminum, as well as stearates
of zinc, magnesium, or calcium, including any mixtures thereof or the like. Still
other particles suitable for use include metal silicates like calcium and/or
magnesium silicate whereby the same may be used alone or in combination with
any of the particles described herein.
In a preferred embodiment, particle used in this invention comprises at least 0.1 %
by weight silicon dioxide (i.e. silica), preferably at least 25% by weight silicon
dioxide, and most preferably at least 50% to 100% by weight silicon dioxide based
on total weight of particle in the emulsion and including all ranges subsumed
therein. In an often preferred embodiment, the particle used is silica, especially
pyrogenically produced silica comprising at least one of the following groups:
- O - Si (CH3)3 (I)
or
O— Si— C8 H 1 (in)
Such silicas are described in US 7 282 236 and made commercially available from
suppliers like Evonik Degussa GmbH under the names Aerosil R812, R81 28,
R202, MS202 and R805. Silica of the octylsilane type and comprising the group
represented by formula III is sold under the name Aerosil R805 and is especially
preferred.
The high solvent content emulsion of the present invention often comprises from
0.25 to 45%, preferably from about 1 to 25%, and most preferably from 1.5 to 15%
by weight particle based on total weight of the emulsion and including all ranges
subsumed therein.
The particle used typically has a diameter of less than three microns, preferably
less than two microns, and most preferably from 10 nm to 1.5 microns including all
ranges subsumed therein.
The functionalized polymer suitable to hydrogen and/or ionically bond to the
particle is limited only to the extent that the same may be used in an emulsion
suitable for consumer use. The polymer, therefore, may have anionic, cationic or
zwitterionic character. Illustrative yet non-limiting examples of the type of polymer
suitable for use in this invention includes polymers comprising primary, secondary,
tertiary and/or quaternary amine groups which may either form part of the main
polymer chain or be carried by a side or pendant group carried by the polymeric
backbone. Among such polymers are quaternarized polysiloxanes, polymers of
the quaternary polyamines, polyaminoamides, polyammonium type compounds,
polyalkyleneimines like polyethyleneimine, polyvinylimidazoles or mixtures
thereof.
Other functionalized polymers suitable for use include polysiloxanes,
polyalkylenes and polyesters functionalized with sulfoxonium, phosphonium,
carboxylate, sulfonate and/or sulphate groups. Groups comprising N+ and COO
are suitable for use when zwitterionic polymers are desired.
In a preferred embodiment, however, the functionalized polymers are of the
amodimethicone type having the general formula:
where:
each R is independently H, or a Ci-4 alkyl;
each R1 is independently OR or a Ci-4 alkyl; and
each x is independently an integer from 1 to 4 and each y is greater than
zero and independently an integer to yield a polymer having a molecular
weight from 500 to 1 million, and preferably, from 750 to 25,000, and most
preferably from ,000 to 5,000.
Other suitable functionalized polymers suitable for use include silicone cationic
polymers represented by the formula:
R2
aZ 3-a-Si(OSiZ2)n-(OSiZbR22-b)m-O-SiZ3-a-R2a (V)
where:
Z is hydrogen, phenyl, OH or a - o alkyl group;
each a is independently an integer from 0 to 3;
b is an integer from 0 to ; and
m and n are integers whereby the sum of n+m ranges from 1 to 3,500, and
preferably, from 0 to 60;
each R2 is independently a monovalent radical of formula - CqH2qL where
each q is independently a number from 2 to 0 and L is an amine or a
quaternized amine represented by one of the following groups:
-NR3-CH2-CH2-N(R 3)2
-N(R 3)
-N (R )3A
-N(R 3)-CH2-CH2-N+R3(H)2A
where:
each R3 is independently hydrogen, phenyl, benzyl or a Ci to Ci2 alkyl; and
each A is independently fluoride, chloride, bromide or iodide anion.
Still other functionalized polymers suitable for use include those having the
formula:
where:
each R4 is independently a Ci to C20 alkyl or C2 to C20 alkenyl;
R5 is a divalent C1-C18 group;
A is as previously defined;
r is an integer from 2 to 20; and
s is an integer from 15 to 75.
It is also within the scope of this invention for the functionalized polymer to
comprise trimethylsilylamodimethicone.
Such polymers are described, for example, in US 4 185 087. Typically, the
functionalized polymers make up from 0.1 to 75%, preferably from 0.3 to 50%,
and most preferably from 0.75 to 20% by weight of the high solvent content
emulsion, including all ranges subsumed therein. The often most preferred
functionalized polymer is amodimethicone represented by formula (IV) and made
commercially available, for example, as ADM 656 by Wacker-Belsil ® and DC 8500
by Dow Corning.
The solvent suitable for use in this invention is one which may be used in an end
use product targeted to provide a benefit to consumers and one which is
preferably capable of hydrogen bonding. Illustrative yet non-limiting examples of
the types of solvent that may be used in this invention include water, Ci-6 alkanols
or a mixture thereof. In a preferred embodiment, the solvent used is at least 50%
by weight water, and most preferably, water.
Solvent typically makes up from 20 to 85%, preferably from 30 to 75%, and most
preferably from 40 to 70% by weight of the high solvent content emulsion,
including all ranges subsumed therein.
Oils and/or fatty acids may optionally be mixed with the functionalized polymer to
make the desired emulsion. Illustrative yet non-limiting examples of the types of
oils that may be used in the emulsion generation include cyclic siloxanes like D5,
as well as alkyl substituted and unsubstituted dimethicones. Especially preferred
are C26-C28 alkyl dimethicones, lauryl dimethicone, mixtures thereof or the like
where the same are commercially available from suppliers like Wacker-Belsil.
Fatty acids preferred for use include C8-C20 fatty acids, especially caprylic or
octanoic acid. When such oils or fatty acids are used in the generation of
emulsion, they typically make up from 3 to 85%, preferably from 4 to 75%, and
most preferably from 4 to 65% by weight of the total weight of mixture of oil and/or
fatty acid, and functionalized polymer in the emulsion, including all ranges
subsumed therein.
End use compositions comprising the high solvent content emulsion of this
invention may optionally comprise co-vehicles or carriers like emollients, fatty
acids, fatty alcohols, thickeners or combinations thereof.
Emollient materials may serve as optional cosmetically acceptable co-carriers along
with the high solvent content emulsion of this invention. These may be in the form of
silicone oils, natural or synthetic esters and hydrocarbons. Amounts of the
emollients when used in addition to the high solvent content emulsion of this
invention may range anywhere from 0.0 to about 30%, preferably between 1 and
25% by weight of the end use composition.
Silicone oils may be divided into the volatile and non-volatile variety. The term
"volatile" as used herein refers to those materials which have a measurable vapor
pressure at ambient temperature. Volatile silicone oils are preferably chosen from
cyclic (cyclomethicone) or linear polydimethylsiloxanes containing from 3 to 9,
preferably from 4 to 5, silicon atoms. DC 245, made commercially available by
Dow Corning, is often preferred.
Non-volatile silicone oils useful as an emollient material include polyalkyl
siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers. The
essentially non-volatile polyalkyl siloxanes useful herein include, for example,
polydimethylsiloxanes with viscosities of from about 5 x 10 6 to 0.1 m2/s at 25°C.
Among the preferred non-volatile emollients useful in the present end use
composition are the polydimethyl siloxanes having viscosities from about 1 x 10 5
to about 4 x 10 4 m2/s at 25°C.
Another class of non-volatile silicones are emulsifying and non-emulsifying
silicone elastomers. Representative of this category is Dimethicone/Vinyl
Dimethicone Crosspolymer available as Dow Corning 9040 and Shin-Etsu KSG-
18 . Emulsifying silicone waxes such as Silwax WS-L (Dimethicone Copolyol
Laurate) may also be useful. Other silicones suitable for use are blends sold as
Dow Corning 9045.
Among the ester emollients are:
a) Alkyl esters of saturated fatty acids having 10 to 24 carbon atoms. Examples
thereof include behenyl neopentanoate, isononyl isonanonoate, isopropyl
myristate, isopropyl palmitate and octyl stearate.
b) Ether-esters such as fatty acid esters of ethoxylated saturated fatty alcohols.
c) Polyhydric alcohol esters. Ethylene glycol mono- and di-fatty acid esters,
diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200-
6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty
acid esters, polypropylene glycol 2000 monostearate, ethoxylated propylene
glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol
poly-fatty esters, ethoxylated glyceryl mono-stearate, 1,3-butylene glycol
monostearate, 1,3-butylene glycol distearate, polyoxyethylene polyol fatty
acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid
esters are satisfactory polyhydric alcohol esters. Particularly useful are
pentaerythritol, trimethylolpropane and neopentyl glycol esters of C 1-C30
alcohols.
d) Wax esters such as beeswax, spermaceti wax and tribehenin wax.
e) Sugar ester of fatty acids such as sucrose polybehenate and sucrose
polycottonseedate.
Natural ester emollients principally are based upon mono-, di- and tri- glycerides.
Representative glycerides include sunflower seed oil, cottonseed oil, borage oil,
borage seed oil, primrose oil, castor and hydrogenated castor oils, rice bran oil,
soybean oil, olive oil, safflower oil, shea butter, jojoba oil and combinations
thereof. Animal derived emollients are represented by lanolin oil and lanolin
derivatives. Amounts of the natural esters may optionally range from about 0.1 to
about 20% by weight of the end use compositions.
Hydrocarbons can optionally be employed as acceptable co-carriers with the high
solvent content emulsions of this invention and they include petrolatum, mineral
oil, C 11-C1 3 isoparaffins, polybutenes, and especially isohexadecane, available
commercially as Permethyl 10 1A from Presperse Inc.
Fatty acids having up to 30 carbon atoms may also be employed as cosmetically
acceptable co-carriers. Illustrative of this category are pelargonic, lauric, myristic,
palmitic, stearic, isostearic, oleic, linoleic, linolenic, hydroxystearic and behenic
acids.
Fatty alcohols having from 10 to 30 carbon atoms are another useful category of
cosmetically acceptable carrier. Illustrative of this category are stearyl alcohol,
lauryl alcohol, myristyl alcohol, oleyl alcohol and cetyl alcohol.
Thickeners can be utilized along with the high solvent content emulsion of this
invention in the end use compositions according to the present invention. Typical
thickeners include crosslinked acrylates (e.g., Carbopol 982® and Carbopol Ultrez
2 1) , hydrophobically-modified acrylates (e.g. Carbopol 1382®), polyacrylamides
(e.g. Sepigel 305®), acryloylmethylpropane sulfonic acid/salt polymers and
copolymers (e.g. Aristoflex HMB® and AVC®), cellulosic derivatives and natural
gums. Among useful cellulosic derivatives are sodium carboxymethylcellulose,
hydroxypropyl methocellulose, hydroxypropyl cellulose, hydroxyethyl cellulose,
ethyl cellulose and hydroxymethyl cellulose. Natural gums suitable for the present
invention include guar, xanthan, sclerotium, carrageenan, pectin and
combinations of these gums. Inorganics may also be utilized as thickeners,
particularly clays such as bentonites and hectorites, fumed silicas, talc, calcium
carbonate and silicates such as magnesium aluminum silicate (Veegum®).
Amounts of the thickener may optionally range from 0.0001 to 10%, usually from
0.001 to 1%, optimally from 0.01 to 0.5% by weight of the end use composition.
Adjunct humectants may be employed in the end use compositions of the present
invention. These are generally polyhydric alcohol-type materials. Typical
polyhydric alcohols include glycerol, propylene glycol, dipropylene glycol,
polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol,
hexylene glycol, 1,3-butylene glycol, isoprene glycol, 1,2,6-hexanetriol,
ethoxylated glycerol, propoxylated glycerol and mixtures thereof. If used, the
amount of adjunct humectant may range anywhere from 0.5 to 20%, preferably
between 1 and 15% by weight of the end use composition.
Surfactants, while not required or desired to prepare or make the high solvent
content emulsion of this invention, may be present in end use compositions
comprising the high solvent content emulsion of the present invention. Total
concentration of the surfactant when present may range from 0.1 to 20%,
preferably from 1 to 15%, optimally from 1 to 10% by weight of the end use
composition. The surfactant may be selected from the group consisting of
anionic, nonionic, cationic and amphoteric actives. Particularly preferred nonionic
surfactants are those with a C10-C20 fatty alcohol or acid hydrophobe condensed
with from 2 to 100 moles of ethylene oxide or propylene oxide per mole of
hydrophobe; C2-C10 alkyl phenols condensed with from 2 to 20 moles of alkylene
oxide; mono- and di-fatty acid esters of ethylene glycol; fatty acid monoglyceride;
sorbitan, mono- and di- C8-C20 fatty acids; and polyoxyethylene sorbitan
(e.g.Tweens, like Tween 20 and Tween 40) as well as combinations thereof. Alkyl
polyglycosides and saccharide fatty amides (e.g. methyl gluconamides) and
trialkylamine oxides are also suitable nonionic surfactants.
Suitable anionic surfactants include soap, alkyl ether sulfates and sulfonates, alkyl
sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyi sulfosuccinates,
C8-C20 acyl isethionates, C8-C20 alkyl ether phosphates, C8-C20 sarcosinates, Cs-
C20 acyl lactylates, sulfoacetates and combinations thereof.
Useful amphoteric surfactants include cocoamidopropyl betaine, C12-C20 trial kyl
betaines, sodium lauroamphoacetate, and sodium laurodiamphoacetate.
Perfumes may optionally be used in the end use composition of this invention.
Illustrative non-limiting examples of the types of perfumes that may be used
include those comprising terpenes and terpene derivatives like those described in
Bauer, K., et al., Common Fragrance and Flavor Materials , VCH Publishers
( 1990).
Illustrative yet non-limiting examples of the types of fragrances that may be used
in the (end use) compositions of this invention include myrcene, dihydromyrenol,
citral, tagetone, cis-geranic acid, citronellic acid, mixtures thereof or the like.
Preferably the amount of fragrance employed in the end use composition of this
invention is in the range from 0.0% to 10%, more preferably 0.00001 % to 5 wt %,
most preferably 0.0001 % to 2% of the end use composition.
Sunscreen agents may optionally be included in end use compositions of the
present invention. Particularly preferred are such materials as ethylhexyl pmethoxycinnamate,
available as Parsol MCX®, Avobenzene, available as Parsol
1789® and benzophenone-3, also known as Oxybenzone. Inorganic sunscreen
actives may be employed such as microfine titanium dioxide and zinc oxide.
Amounts of the sunscreen agents when present may generally range from 0.0 to
20%, preferably from 0.1 to 12%, optimally from 2 to 8% by weight of the end use
composition.
In the event the end use composition comprising the high solvent content
emulsion is an antiperspirant or deodorant composition, the same may comprise
astringent actives. Examples include aluminum chlorohydrate, aluminum
chlorhydrex, aluminum-zirconium chlorhydrex glycine, aluminum sulfate, zinc
sulfate, zirconium and aluminum chlorohydroglycinate, zirconium hydroxychloride,
zirconium and aluminum lactate, zinc phenolsulfonate and combinations thereof.
Amounts of the astringents may range anywhere from 0.5 to 12% by weight of the
end use composition.
Oral products formulated with the high solvent content emulsion according to the
present invention will optionally contain a fluoride source to prevent dental caries.
Typical anti-caries actives include sodium fluoride, stannous fluoride and sodium
monofluoro phosphate. Amounts of these materials will be determined by the
amount of fluoride releasable which should range between about 500 to about
8800 ppm of the end use composition. Other components of dentifrices can
include desensitizing agents such as potassium nitrate and strontium nitrate,
sweeteners such as sodium saccharine, aspartame, sucralose, and potassium
acesulfam.
Preservatives can desirably be incorporated into the end use compositions of this
invention to protect against the growth of potentially harmful microorganisms.
Particularly preferred preservatives are phenoxyethanol, methyl paraben, propyl
paraben, imidazolidinyl urea, dimethyloldimethylhydantoin,
ethylenediaminetetraacetic acid salts (EDTA), sodium dehydroacetate,
methylchloroisothiazolinone, methylisothiazolinone, iodopropynbutylcarbamate
and benzyl alcohol. The preservatives should be selected having regard for the
use of the composition and possible incompatibilities between the preservatives
and other ingredients. Preservatives are optionally employed in amounts ranging
from 0.01 % to 2% by weight of the end use composition.
End use compositions of the present invention may include vitamins. Illustrative
vitamins are Vitamin A (retinol), Vitamin B2, Vitamin B6, Vitamin C, Vitamin E, Folic
Acid and Biotin. Derivatives of the vitamins may also be employed. For instance,
Vitamin C derivatives include ascorbyl tetraisopalmitate, magnesium ascorbyl
phosphate and ascorbyl glycoside. Derivatives of Vitamin E include tocopheryl
acetate, tocopheryl palmitate and tocopheryl linoleate. DL-panthenol and
derivatives may also be employed. Total amount of vitamins when present in the
end use compositions according to the present invention may range from 0.001 to
10%, preferably from 0.01 % to 1%, optimally from 0.1 to 0.5% by weight of the
end use composition.
Another type of useful substance for optional use is that of an enzyme such as
amylases, oxidases, proteases, lipases and combinations. Particularly preferred
is superoxide dismutase, commercially available as Biocell SOD from the Brooks
Company, USA. Still other optional additives suitable for use include sunless
tanning agents like dihydroxyacetone, antioxidants like lycopene as well as the
skin benefit agents like conjugated linoleic acid, and/or petroselinic acid. Even
other optional additives include pH modifiers like HCI and NaOH as well as
microspheres to scatter light like those made available by Kobo as, for example,
MSP-825 and CL-2080.
Skin lightening compounds may optionally be included in the end use
compositions of the invention. Illustrative substances are placental extract, lactic
acid, vitamin B3 (niacinamide), arbutin, kojic acid, ferulic acid, resorcinol and
derivatives including 4-substituted resorcinols and combinations thereof. Amounts
of these agents may range from 0.1 to 10%, preferably from 0.5 to 2% by weight
of the end use composition.
Desquamation promoters may optionally be present. Illustrative are the alphahydroxycarboxylic
acids and beta-hydroxycarboxylic acids. The term "acid" is
meant to include not only the free acid but also salts and C 1-C30 alkyl or aryl
esters thereof and lactones generated from removal of water to form cyclic or
linear lactone structures. Representative acids are glycolic, lactic and malic acids.
Salicylic acid is representative of the beta-hydroxycarboxylic acids. Amounts of
these materials when present may range from about 0.01 to about 15% by weight
of the end use composition.
A variety of herbal extracts may optionally be included in compositions of this
invention. The extracts may either be water soluble or water-insoluble carried in
a solvent which respectively is hydrophilic or hydrophobic. Water and ethanol are
the preferred extract solvents. Illustrative extracts include those from green tea,
yarrow, chamomile, licorice, aloe vera, grape seed, citrus unshui, willow bark,
sage, thyme and rosemary.
Also included may be such materials as lipoic acid, retinoxytrimethylsilane
(available from Clariant Corp. under the Silcare 1M-75 trademark),
dehydroepiandrosterone (DHEA) and combinations thereof. Ceramides (including
Ceramide 1, Ceramide 3, Ceramide 3B and Ceramide 6) as well as
pseudoceramides may also be useful. Amounts of these materials may optionally
range from 0.000001 to 10%, preferably from 0.0001 to 1% by weight of the end
use composition.
Colorants, opacifiers and abrasives may optionally be included in the end use
compositions of the present invention. Each of these substances may range from
0.05 to 5%, preferably between 0.1 and 3% by weight of the end use composition.
Colorant often preferred is carbon black.
Especially preferred but optional additives suitable for use in this invention include
quaternary ammonium compounds such as 1,2-dihydroxypropyl trimonium
chloride as well as derivatives thereof and moisturizing agents such as substituted
ureas like hydroxymethyl urea, hydroxyethyl urea, hydroxypropyl urea;
bis(hydroxymethyl) urea; bis(hydroxyethyl) urea; bis(hydroxypropyl) urea; ,'-
dihydroxymethyl urea; N,N'-di-hydroxyethyl urea; N,N'-di-hydroxypropyl urea;
N,N,N'-tri-hydroxyethyl urea; tetra(hydroxymethyl) urea; tetra(hydroxyethyl) urea;
tetra(hydroxypropyl urea; N-methyl, N'-hydroxyethyl urea; N-ethyl-N'-hydroxyethyl
urea; N-hydroxypropyl-N'-hydroxyethyl urea and N,N'dimethyl-N-hydroxyethyl
urea or mixtures thereof. Where the term hydroxypropyl appears, the meaning is
generic for either 3-hydroxy-n-propyl, 2-hydroxy-n-propyl, 3-hydroxy-i-propyl or 2-
hydroxy-i-propyl radicals. Most preferred is hydroxyethyl urea. The latter is
available as a 50% aqueous liquid from the National Starch & Chemical Division
of ICI under the trademark Hydrovance.
Amounts of optional quaternary ammonium compound and/or substituted urea,
when used, in the end use composition of this invention range from 0.01 to 20%,
preferably from 0.5 to 15%, and most preferably from 2 to 10% based on total
weight of the end use composition and including all ranges subsumed therein.
In a preferred embodiment, the end use composition of this invention comprises at
least 50% by weight of high solvent content emulsion, and most preferably 60 to
95% by weight of the high solvent content emulsion. The same is expected to
display excellent active deliverability. Furthermore, the emulsion of this invention
is suitable to retain high amounts of water and displays a diffusion coefficient of
water of less than 1.5 x 10 9 m/s, preferably less than 1.0 x 10 10 m/s, and most
preferably less than 9 x 10 11 m/s.
A wide variety of packaging, including biodegradable packaging, can be employed
to store and deliver the end use compositions. Packaging is often dependent
upon the type of personal care end-use. For instance leave-on skin lotions and
creams, shampoos, conditioners and shower gels generally employ plastic
containers with an opening at a dispensing end covered by a closure. Typical
closures are screw-caps, non-aerosol pumps and flip-top hinged lids. Packaging
for antiperspirants, deodorants and depilatories may involve a container with a
roll-on ball on a dispensing end. Alternatively these types of personal care
products may be delivered in a stick composition formulation in a container with
propel-repel mechanism where the stick moves on a platform towards a
dispensing orifice. Metallic cans pressurized by a propellant and having a spray
nozzle serve as packaging for antiperspirants, shave creams and other personal
care products. Toilette bars may have packaging constituted by a cellulosic or
plastic wrapper or within a cardboard box or even encompassed by a shrink wrap
plastic film.
End use compositions of the present invention, therefore, may be in a variety of
forms. These forms may also include mousses, aerosol and non-aerosol sprays
and fabric (e.g. non-woven textile)-applied formulations.
The following examples are provided to facilitate an understanding of the present
invention. The examples are not intended to limit the scope of the claims.
Example 1
All samples were made by mixing the mentioned ingredients under conditions of
moderate shear, atmospheric pressure and ambient temperature.
Materials Sample Sample Sample Sample Sample Sample Sample Sample Sampl
1 2 3 4 5 6 7 8 9
Silica R805 8% 5% 2% 8% 5% 5% 5% 5% 5%
Amodimethicone 72% 45% 18% 7.3% 4.5% 4.5% 4.5% 4.5% 4.5%
(ADM 656)
Lauryl 6.38% 4.05% 4.05%
dimethicone
Dimethicone 40.5% 36.45%
Cyclomethicone 58.32% 36.45%
(D5)
Mineral oil 40.5%
Isopropyl 40.5°/
palmitate
20 20% 50% 80% 20% 50% 50% 50% 50% 50%
Silica R805, Evonik Degussa
ADM 656, Waker-Belsil
Neobee CLA80, Conjugated Linoleic Acid - Stepan Company
RA 200 HS, Evonik Degussa
A380, Evonik Degussa
The samples made in this experiment were assessed for appearance and stability.
Samples 1-19 displayed an excellent and uniform white appearance. The same
samples displayed no syneresis after preparation. Samples 20-23 were not made
consistent with this invention. Samples 20-23 were not stable and resulted in
phase separation almost immediately after mixing. Coherent anti-Stokes Raman
Scattering Spectroscopy revealed that the samples made according to this
invention in this experiment were in fact water-in-oil emulsions.
Example 2
The following were assessed for water diffusion rates.
Samples 28-31 correspond to samples 1, 2, 4 and 5 of Example 1,
respectively.
Fumed silica R972 is made available by Evonik Degussa.
Water diffusion for samples 28-31 shows multiple water diffusion rates
observed. Such rates are significantly lower than those observed for
conventional Pickering emulsions. The lower water diffusion rates are an
indication that the compositions made according to this invention can
comprise high water content because water is hydrogen-bonded to the
amino group on amodimethicone.
300MHz Bruker DSX spectrometer with pulsed-field gradient and diffSe (spin
echo sequence) and Topspin software.
Example 3
Water-in-oil and oil-in-water compositions consistent with this invention were
made by mixing the ingredients identified below.
A. Water-in-oil composition
Ingredient Weight %
Silica R805 2.88
Amodimethicone DC 8500 2.60
Silicone volatile DC 245* 23.36
Water Balance
Cyclopentasiloxane and dimethicone 38.46
crosspolymer DC 9045
Glycerol 3.85
*made available by Dow Corning
B. Oil-in-water composition
Ingredient Weight %
Water Balance
EDTA 0.05
Phenoxyethanol 0.40
Carbopol Ultrez 2 1 (cross-linked 0.40
acrylate thickener)
Xanthum gum 0.1 0
NaOH (20%) 0.42
Methylparaben 0.20
Propylparaben 0.1
Silica R805 1.0
Amodimethicone DC 8500 0.9
Dimethicone * 8.1
Glycerol 20.0
Kobo MSP-825 2.0
* Mixture, 40% with viscosity of 5 centistokes and 60% with viscosity at 50
centistokes, taken at 25°C; DC 200
Assessment of the water-in-oil and oil-in-water compositions made above and
consistent with this invention revealed excellent sensory benefits after topical
application to skin.
Compositions similar to the water-in-oil composition described above were made
except that no particle was used in one set of compositions and no functional ized
polymer was used in a second set of compositions. Water was used to make up
the balance. The compositions made inconsistent with the compositions of this
invention resulted in poor silky sensory characteristics.
Compositions similar to the ones made according to this invention were made with
traditional surfactant (e.g. Tween 40, 2% by weight or PEG-10 Dimethicone
[KF601 7 by Shin Etsu]) in lieu of particle and functionalized polymer. Water was
used to make up the balance. The compositions made consistent with this
invention had silky sensory characteristics, surprisingly, at least as good as those
compositions made with traditional surfactant.
Example 4
Compositions were prepared by mixing the ingredients below.
Ingredients Weight % Weight %
Water Balance Balance
EDTA 0.05 0.05
Phenoxyethanol 0.4 0.4
Carbopol Ultrez 2 1 (cross- 0.4 0.4
linked acrylate thickener)
NaOH (50%) 0.2 0.14
Xanthum gum 0.1 0.1
Tween 40 1.0 1.0
Glycerol 5.0 30.0
Methylparaben 0.2 0.2
Propylparaben 0.1 0.1
Silica R805 1.0 1.0
Amodimethicone DC 8500 0.9 0.9
Dimethicone * 8.0 8.0
Kobo MSP-825 3.0 2.0
* Mixture, 40% viscosity of 5 centistokes and 60% with viscosity at 50 centistokes,
taken at 25°C; DC200
Results demonstrated that compositions made according to this invention may,
optionally, be formulated with surfactant. Upon application, panelists concluded
that the compositions made according to this example had excellent silky sensory
attributes.
Claims
An emulsion comprising:
(a) particles having an isoelectric point below a pH of the emulsion;
(b) a functionalized polymer suitable to hydrogen and/or ionically bond to
the particles; and
(c) a solvent.
An emulsion according to claim 1 wherein the particles comprise hydrogen
and/or ionic bonding capabilities with the functionalized polymer.
An emulsion according to claim 1 or claim 2 wherein the particles comprise
at least 0.1 % by weight silica.
An emulsion according to any one of the preceding claim wherein the
particles comprise pyrogenically produced silica, pyrogenically produced
silican comprising at least one group selected from
- O - Si (CH3)3 (I)
and
O— Si — C8 H 17 (in) •
o
An emulsion according to any one of the preceding claims wherein the
particles have a diameter of less than 3 microns.
An emulsion according to any one of the preceding claims wherein the
functionalized polymer has anionic, zwitterionic and/or cationic character.
An emulsion according to any one of the preceding claims wherein the
functionalized polymer comprises primary, secondary and/or quaternary
amine groups.
An emulsion according to claim 6 wherein the functionalized polymer is
selected from the group consisting of polysiloxane, polyalkylane and
polyester each one of which is functionalized with sulfoxarium, phosphorium,
carboxylate sulfonate and/or sulfate groups.
An emulsion according to claim 6 wherein the functionalized polymer
comprises groups with N+ and COO .
An emulsion according to any one of the preceding claims wherein the
functionalized polymer comprises polymer of the formulae:
where:
each R is independently H, or a Ci-4 alkyl;
each R1 is independently OR or a Ci-4 alkyl; and
each x is independently an integer from 1 to 4 and each y is independently
an integer to yield a polymer having a molecular weight from 500 to 1 million,
R2
aZ 3- a-Si(OSiZ 2 ) n-(OSiZ bR22- b)m -O-SiZ3-a-R2 a (V)
where:
Z is hydrogen, phenyl, OH or a Ci-Cs alkyl group;
each a is independently an integer from 0 to 3;
b is an integer from 0 to 1;
m and n are integers such that the sum of n+m may vary from 1 to 3,500;
and
each R2 is independently a monovalent radical of formula - CqH2qL where
each q is independently a number from 2 to 10 and L is an amine or a
quaternized amine group chosen from the groups:
-N(R3)2
-N (R3)3A
-N(R>CH 2-CH2-N+R3(H)2A ,
where:
each R3 is independently hydrogen, phenyl, benzyl or a Ci to Ci2 alkyl; and
each A is independently fluoride, chloride, bromide or iodide
and/or
where:
each R4 is independently a Ci to C20 alkyl or C2 to C20 alkenyl;
R5 is a divalent C1-C18 group;
A is as previously defined;
r is an integer from 2 to 20; and
s is an integer from 15 to 75.
11. An emulsion according to any one of claims 1 to 8 wherein the functionalized
polymer is amodimethicone.
12 . An emulsion according to any one of the preceding claims wherein the
emulsion further comprises at least one oil and/or fatty acid.
13 . The emulsion according to claim 12 wherein the oil is pentasiloxane,
dimethicone and/or mineral oil, and the fatty acid is octanoic acid.
14. An emulsion according to claim 12 or claim 13 wherein the oil makes up from
3 to 85% by weight of the mixture of oil and functionalized polymer.
15 . An emulsion according to any one of the preceding claims wherein the
emulsion comprises at least 20% by weight solvent and the solvent is water.
16 . An emulsion according to any one of the preceding claims wherein the
emulsion further comprises carbon black.
17 . An end use composition comprising the emulsion of claim 1.
18 . A composition according to claim 16 wherein the end use composition is
topically applied.
19 . A composition according to claim 17 or claim 18 wherein the composition
further comprises niacinamide, a quaternary ammonium compound or both.
20. A method for treating a skin condition comprising the step of topically
applying the end use composition of any one of claims 16 to 18 to skin.