Note: Descriptions are shown in the official language in which they were submitted.
1038295
Background of the Invention
Field of the Invention
Aerosol systems per se are not new, the first record
of such a system being recorded as early as the late 1800's.
Since the introduction of the early aerosol systems, a
variety of aerosol systems have been developed which have
resulted in numerous aerosol consumer products.
Of the aerosol systems which have appeared on the
market since the time aerosol containers became commercially
feasible, one such aerosol system which has become extremely
popular in recent years is the powder aerosol antiperspirant,
which basically consists of a suspension of powdered anti-
perspirant salts in one or more liquefied propellants.
; While it is generally conceded that the powder suspension
aerosol offers a great many advantages over solution or
foam type aerosol products and has met with a high degree
.,
of commercial success, it is also recognized that many
problems are associated with the use of this type of
,
! aerosol product.
~'''` '
.
-~,
~',
, ":
.'. -- 1 --
A~
~0382g5
Foremost of the problems associated with the powder
aerosol compositions is the agalomeration and settling of
the suspended powder particles. This phenomenon most often
occurs immediately after the suspension is prepared or within
a short period of time thereafter. This ag~lomeration, or
clumping together and settling of the powder particles, causes
difficulty of redispersion, valve clogging, and uneven distri-
,
- bution of the powder to the desired surface.
While the effects of agglomeration and settling can
be remedied to some extent by shaking the aerosol container
prior to use, this is not a satisfactory solution to the
: .
problem, since surveys indicate that many aerosol users do
not adequately shak2, or fail to shake, the containers prior
to use.
Some advantages attributed to the use of powder
aerosols, apart from convenience, are: Making possible the
spraying of antiperspirant salts evenly and economically onto
a required area uniformly with a minimum of waste; ease of ap- -
. . .
plication to otherwise inaccessible or difficult-to-reach
areas; and protection from atmospheric deterioration due to
~ humidity or oxidation, thereby resulting in a product having
-~ an extended shelf life.
.j . .
-~ A considerable amount of work has been done in an
~ . attempt to remed~ the aforementioned problems, including the
- 25 utilization of bulking or suspending agents to assist in
~! . .
. ~ .
i
-- 2 --
' -
.
1038295
filling the void space between suspended particles, the
introduction of materials into the suspension for the purpose
of providing slippage between particles and to lubricate
the component parts of the aerosol valve, and the regulation
of particle size, depending upon the nature of the powder
suspensiod. While this work has improved the stability of
powder aerosol antiperspirant products to some extenk,
it is clear that the powder aerosol compositions currently
available are still beset by the problems discussed above.
The Prior Art
There is a considerable amount of art relating to the
use of clay type suspending agents in powder aerosol
systems. See, for example, British Patent 1,167,173, Spitzer
et al.; U.S. Patent 3,088,874 which issued on May 7 , 1963 to
Geary et al.; U.S. Patent 3,218,263 which issued on November
16, 1965, to Boyle et al.; and U.S. Patent 3,773,683 which
issued on November 20, 1973 to Aubert.
SUMMARY OF THE INVENTION
According to the present invention, it has been found
that the ability of certain bulking or suspending agents to
keep antiperspirant salts suspended in aerosol antiperspirants
is appreciably improved when the suspendinc agents are
`~ utilized in combination with specific mixtures of ethanol
;, and water. Specifically, improved suspensions are obtained
witn aerosol antiperspirant compositions comprising: from about
0.2% to about 12% of an astringent antiperspirant salt; from
about 0.1% to about 7% of a suspending agent selected from
the group consisting of montmorillonite clays and hydro-
phobically treated montmorillonite clays; from about 0~
.~
to about 15% of a carrier liquid; a 60/40 to 80/20 parts by
weight mixture of ethanol and water wherein the weight ratio
~ 3 ~
. . .
. - . .
of ethanol/water mixture t~ Q ~ e~ ~ g agent is from about
1.5:1 to about 4:1; and balance, propellant.
The improvements of the present invention are evinced
by significantly higher suspension levels, lower settling
rates and less agglomeration, the net effect being less
clogging, less button build-up,and more uniform product
distribution, even when the aerosol container is not shaken
well or at all. Also, in instances where there has been some
settling due to nonuse over an extended period of time,
powder aerosol antiperspirant compositions oontaining the
-` suspending agents and ethanol/water mixtures of the present
t invention are more easily redispersed by normal shaking than
are products known in the art which do not contain the com-
~t bination of suspending agent and ethanol/water mixtures -i-~
disclosed herein. -
. The suspending agents suitable for use in the com-
t positions of the present invention are selected from the
~ group consisting of montmorillonite clays and hydrophobically
't~ treated montmorillonite clays. Montmorillonite clays are
~ 20 those which contain the mineral montmorillonite and are
;~ characterized by having a suspending lattice. Examples of
these clays include the bentonites, hectorites, and colloidal
t magnesium aluminum silicates.
'`~t Bentonite is colloidal, hydrated aluminum silicate
obtained from montmorillonite and has the formula
g A1234si2 H2O. A more detailed discussion of bentonites
can be found in the Kirk-Othmer Encyclopedia of Chemical
Technology, 2nd Edition, Vol. 3 (1964), pp. 339-360, pub-
- lished by Interscience Pub]ishers, which is incorporated
. 30 herein by reference.
- Hectorite, also a montmorillonite clay, differs
4 --
Ai~
.
., , - ,
,:~
~38Z9S
from bentonite in that there is almost a complete sub-
stitution of aluminum in the lattice structure of bentonite
by magnesium and in addition, the presence of lithium and
fluorine.
The magnesium aluminum silicates are cor,plexes of
colloidal magnesium aluminum silicate richer in magnesium
than aluminum. Magnesium aluminum silicates are commercially
available as Veegu ~ (R.T. Vanderbilt Co).
Preferred suspending agents for use in the present
invention are certain hydrophobically treated montmorillonite
clays, e.g., hydrophobic bentonites available under the
trade mark of "Bentone". Bentone is prepared by reacting
bentonite in a cation exchange system with an amine. Dif-
ferent amines are reacted to obtain a variety of Bentones
; which may also differ in proportions of SiO2, MgO and A12O3.
Specific examples of Bentones within the scope of the present
invention are Bentone 38, Bentone 34, Bentone 27, Bentone 14,
and Bentone LT, all of which have a particle size of below
i about 5 microns and are commercially available from the
National Lead Company. Bentone 38 is most preferred.
The individual astringent antiperspirant salts of
this invention can be any of those generally recognized as
~ suitable for use in antiperspirant compositions. Such
:~
--~ salts are
..!
~'
;10:~B295
acidic metallic salts, usually salts of aluminum, zirconium
or zinc. Probably aluminum chlorhydroxide, which has the
emperical formula A12(OH)5Cl and is also called ACH, is the
~ost widely used, though many others are suitable. For
example, aluminum chloride, aluminum sulfate, aluminum oxy-
chloride, aluminum oxysulfate, zirconyl hydroxychloride,
- (which has the emperical formula ~rOOHC1 and is also called
-ZHC), zirconyl chloride (ZrOC12), also called ZC, zinc sulfate
and zinc sulfocarbolate may also be used. .
In addition to these simple salts, many inorganic/
organic mixtures and complexes containing these salts have
been suggested as antiperspirant agents. Among these are
zirconium salt/amine/amino acid complexes as-taught by Sie~al
et al. in U.S. 3,407,254 (Oct. 22, 1968), e.g., co~plexes
of the formula:
a )b(ZrO)~H2O)c]n, in which;
~1) R is a nucleophilic co~pound;
~2~ R' is an amino acid compound;
(3) n is a number of from 1 to 32 inclusive, and corresponds
to the number of zirconium atoms in the molecules of
the complex;
~ (4) a is a number of from 1 to 5 inclusive;
-, (5) b is a number of from 1 to 5 inclusive;
.; .
(6) c is a number from 0 to 4 inclusive;
(7) a+b+c has a value of from 2 to 6 inclusive; and
. (8) wherein R, R', H2O and O, when present, are attached
. . .
~ directly to Zr;
."
- 6 -
.,
. ...
1~)38295
zirconium salt/aluminum chlorhydroxide/glycol complexes as
taught by Jones et al. in U.S. 3,405,153 ~Oct. 8, 1968),
inorganic-organic complexes having the formula:
2 4-5 1-2R 1-4H2- 5-4 wherein Q is a member
of the group consisting of zinc chloride, zinc iodide, zinc
bromide, zinc hydroxychloride, zinc hydroxyiodide, zinc
hydroxybromide, ziroonyl chloride, and zirconyl hvdroxvchloride;
,
A is an anion selected from the group consisting of chloride,
bromide and iodide; R'' is the coordinating moiety of a
polyhydroxy compound having at least two carbon atoms to
which are attached at least two hydroxy groups, and n'
is the number of moles of Q and is at least 0.05; aluminum
chlorhydroxide/glycol complexes as taught by Jones et al.
in U.S. 3,420,932 (Jan. 7, 1969), e.g., complexes having ~-
lS the-formula: Alz(H2O)y z(OH)6 n,,x(A')n,,(R ) , wherein
.' . .
J, - A' is selected from the class consisting of chloride,
.. , . .
-, bromide, iodide, sulfate and sulfamate R is the coordinating
moiety of a polyhydroxy compound having a carbon chain in
which at least two carbon atoms link a hydroxvl group to
said chain; n'' is a positive inteaer of from 1 to 4;
~-~ x is the valence of A', y is a value of about 0.5 to 6 and
is always such that (y-z) does not give a negative value;
and z is the number of available coordinatin~ sites, with
n' 'x being from 2 to 4; zirconyl and aluminum halohydroxy
;;~ 25 complexes as taught by Beekman in U.S. 2,906,668 (Sept. 29,
1959), e.g., complexes having the formula.
2A~ (H)n---(2-2.5~(Cl)n~(0.5-i~
-~
295
is a number within the range 2-10 and the numbers of OH
groups and Cl atoms are so selected, within the ranges
stated, that their total will be 3n'''; alumi~um-zirconium
complexes as disclosed in the copending application of
Raymond E. Bolich, Jr., Ser. No. 59,690, filed July 30, 1973
, . . .
entitled "ALU~INUM-ZIRCONIUM AEROSOL ANTIPERSP~RANT COM- :
POSITION AND PROCESS", e.g., a cpmplex prepared by:
- (A) Heating an aqueous solution containing from
about 1 to about 3.2 parts of aluminum chlorhydroxide
to a temperature of from about 190F. to about 225F;
(B) Adding an aqueous solution containing 1 part --
zirconyl hydroxychloride ratewise to the aluminum
~- chlorhyaroxide solution over a Period of from
about 2 hours to about 5 hours while heating and
agitating, the total solids content at this point
i being at least about 10%, and
~; ~C) Heating and agitating the aluminum chlorhy-
i
~ - droxide-zirconyl hydroxychloride mixture at a tempera-
-l ture of from about 190F. to about 225F. for from
- 20 about 1/2 hour to about 5 hours until a stable complex
P forms,
, .
~ aluminum salt and zirconium hydroxychloride complexes as
.i - .
-~ disclosed in U.S. Patent 3,792,068 (Feb. 12, 1974) issued
to Wilmer L. Luedders et al., e.g., complexes prepared by:
(A) Co-dissolving in water:
tl) one part A12(OH)6 mXm, wherein X is an
anion selected from the group consisting of
.,
- .
- 8 -
~038295
chloride, bromide and iodide and m is an
integer from about 0.8 to about 1.2;
(2) n4 parts ZrY wherein Y is an anion selected
from the group consisting of -O(OH)Cl and
OCl , and where n has a value of from about-
.16 to about 1.2;
~3) p parts neutr,al amino acid selected from
the group consisting of glycine, dl-tryptophane,
dl-p -phenylalanine, dl-valine, dl-methionine
and ~-alanine, and where p has a value of
from about 0.06 to about .53;
(B) Co-drying the resultant mixture at a temperature
of from about 100F. to about 230F. to a moisture
level of from about 0.5% to about 15~ by weight; and
- (C) Comminuting the resultant dried inorganic-organic
. antiperspirant compl~x into the form of an impalpable
-, powder; and
.~
aluminum salt/zirconyl hydroxychloride/amino acid complexes
as described in U.S. Patent 2,854,382 (Sept. 30, 1958), to
.: . .
Grad, All of these patents and applications are incorporated
-~ by referenc~ herein.
'~ Particularly preferred astringent antiperspirant
salts for use herein are aluminum chlorhydroxide, zirconyl
hydroxychloride, complexes of these two salts with each
other and complexes o' these two salts together with amino
acidS~ the most suitable amino acids being glycine, dl-
,. . .
, tryptophane, dl-~ -phenylalanine, dl-valine, dl-methionine
and ~-alanine, Glycine is most preferred.
;'- ,
_ g _
103829S
The amount of antiperspirant salts or complexes
of such salts in the compositions of the present invention
can range from about 0.2% to about 12~ by weight of the com-
position (all percentages and ratios herein are by weight
unless otherwise specified).
Typical dry powder aerosol antiperspirant composi-
tions, for example, can be formulated by combining the fol-
.
lowing components:
~A) from about 0.2% to about 12% by weight of an
astringent antiperspirant salt;
. . ,
~ (B) from about 0.1% to about 7~ by weight of a
, i -
~ suspending agent selected from the group consisting
`3 - of montmorillonite and hydrophobically treated
i~ montmorillonite clays;
, .. ~ .
3 15 (Cl from about 0% to about 15% by weight of a
carrier liquid;
.... . .
~D) a 60/40 to about 80/20 parts by weight mixture
of ethanol and water wherein the weight ratio of
ethanol/wa,er mixture to suspending agent is from
s 20 a~Oht ~ to aDGut ~:1; a~l~
(E) balance, an anhydrous gas propellant
i to produce an aerosol spray. - -`
-s Component (A)
-~ The astringent antiperspirant salts described here-
~ :.~ , . . .
inbefore are all suitable for use in dry aerosol antiperspi-
rant compositions. The usage level of these salts in such
~ compositions is generally between about 0.2% and about 12~ by
-~'
: ~ '
..
;., -- 10 --
, . .
.~
,
~038295
weight, preferably from about 2.5~ to about 6~ by weight.
Below about 0.2%, the antiperspirant effectiveness falls off.
- Above 12% is not practical economically because the antiper-
spirant effectiveness does not increase commensurate with ad-
ditional quantities used, and in addition, these higher ievelstend to cause handling and atomization problems.
Component (B~
. , ,
The suspending agent keeps the antiperspirant salt
in suspension within the composition. Although some slight
amount of settling may occur, the antiperspirant salt remains
. .
in a readily redispersible state. Suitable suspending agents
are the montmorillonite clays and hydrophobically treated
montmorillonite clays listed hereinbefore.
The suspendins agents described supra or mixtures
-~ 15 thereof can be used in amounts of from about 0.1% to about 7%
.~ . .
by weight in the aerosol composition. Amounts of suspending
agents of from about 0.15% to about 0.8% are preferred. The
st preferred suspending agents for the purpose of this
. O .
invention are the hydrophobically treated montmorillonite
clays ~for example, Bentone 38).
:-i
Component (C)
A carrier liquid of low volatility is used in the
- dry aerosol antiperspirant compositions of the invention so
, ~ .
that the stream issuing from the aerosol container is a moist
spray rather than a gritty, dusty cloud. This imparts a
cosmetic feeling to the skin when applied thereto and reduces
the likelihood of breathing the otherwise dry powder. The
,
.
. ~ ~ , . .
1038295
carrier liquid also aids efficacy by keeping the anti-
perspirant compound in contact with the s};in so that it does
not flake off or wash off. Thus, the carrier liquid is
highly desirable for practical use of the dry aerosol anti-
perspirants, though it is not required per se for purposes
of preparing such compositions.
Any of the carrier liquids that are known in the
aerosol antiperspirant art are suitable for the dry aerosol
compositions herein. Examples are: Lanolin; silicone oils
such as polysiloxanes having the formula [-R2SiO-]n where
R can be Cl-C4 alkyl or phenyl, and the polysiloxane can
have a viscosity at 25C. of from about 5 to about 2,000
centistokes; fatty alcohols containing from about 12 to
about 18 carbon atoms such as lauryl, myristyl, hexadecyl,
octadecyl, and oleyl alcohols; fatty acid esters of aliphatic
. ~:
monoalcohols where said esters contain from about 12 to
about 26 carbon atoms such as ethyl laurate, isopropyl
` myristate, isopropyl palmitate, isopropyl behenate, decyl
acetate, behenyl butyrate, hecadecyl acetate, decyl decanoate
methyl oleate, lauryl laurate, and oleyl acetate; aliphatic
hydrocarbons such as mineral oil having a specific gravity
~: at 60F. of from about 0.8 to about 0.9 and aliphatic hydro-
. .
} carbons containing from about 12 to ahout 26 carbon atoms
such as tetradecane, hexadecane, nonane, tetracosane,etc.;
esters containing multiple ester groups such as those dis-
closed in U.S. Patent 4,045,548 issued August 30, 1977, i.e.
a multiple carboxylic ester organic compound of from about
12 to about 16 carbon atoms having a ratio of ester groups
to carbon atoms of from about 0.125 to about 0.214 and having
a solubility in water of from about 0.0005% to about 0.1% at
30C., examples being di-n-octyl-n-decyl phthalate, di-n-octyl
~- - 12 -
~' ~
,
1038295
phthalate, di-n-hexyl phthalate, di-n-butyl phthalate,
diethyl sebacate, diisopropyl adipate, and ethyl ethyl-
carbomethyl phthalate lortho C2H5OOC-0-COOCIS2COOC2H5].
The carrier liquid is utilized at levels of from 0% to
about 15% in the aerosol compositions.
Among these various caI~rier liquids, carboxylic
esters having from about 12 to about 26 carbon atoms are
preferred. As described supra, they can be either aliphatic
or aromatic and can contain either one ester group or multiple
ester groups (the aromatic multiple esters containing from
about 12 to 18 carbon atoms). Especially preferred are
di-n-butyl phthalate, diethyl sebacate, diisopropyl adipate,
and ethyl ethylcarbomethyl phthalate.
Any of the carrier liquids described supra can be
used in dry aerosol compositions. The level of the carrier -
liquid is adjusted to give a moist spray which is not
undesirably dusty and gritty, but not undesirably oily
and greasy either. Amounts of carrier liquid from about 0.1%
to about 10% are preferred, and amounts of from about 1%
. , .
to about 7% are most preferred.
..
's
' ~
-,
.,
,
:,
- 13 -
"~
.: . . . - . ,
. . . .
. .
Component (D) 10382~5
As described above, Component (D) in the aerosol
antiperspirant compositions herein is the 60/40 to about 80/20
parts by weight ethanol/water mixture wherein the weight
ratio of the ethanol/water mixture to suspending agent is from
about 1.5:1 to about 4:1. The preferred ratio is from about
1.5:1 to about 2.5:1.
Component (E)
The propellant gas for the dry aerosol compositions
herein can be any liquefiable gas conventionally used for
aerosol containers. Examples of materials that are suitable
'7. for use as propellants are trichlorofluoromethane, dichloro-
~ difluoromethane, dichlorotetrafluoroethane, monochlorodifluoro-
j methane, trichlorotrifluoroethane, propane, butane, 1,1-
~. lS difluoroethane, l,l-difluoro-l-chloroethane, dichloromono-
~. fluoromethane, methylene chloride, and isobutane, used singly
-~ or admixed. Trichlorofluoromethane, dichlorodifluoromethane,
dichlorotetrafluoroethane, and isobutane, used singly or
.;. .. .
admixed, are preferred.
The amount of the propellant gas is governed by
normal factors as well known in the aerosol art. It is
satisfactory to consider the propellant as constituting the
balance of the compositions of the instant invention that
is not accounted for by the other components as detailed
herein, or other components that may be used in dry powder
aerosol antiperspirant compositions. The preferred limits
of propellant are, therefore, from about 55% to about 95%.
:. ,
- 14 -
:
1038~95
The compositions of the present invention may
also contain optional ingredients such as additional suspending
agents, antimicrobials, coloring agents, perfumes and fillers
such as starch and talc.
The dry powder aerosol antiperspirant compositions
~ of the present invention can be conveniently prepared by
`~ the processes outlined in U.S. Patent 3,773,683, November 20,
l 1973 to Aubert, incorporated herein by reference. The sus-
pending agent is mixed together with a portion of the propellant
~, 10 and the ethanol/water mixture. This mixture is then subjected
. j .
' to shear mixing. The astringent antiperspirant salt, the
carrier liquid and other optional ingredients are then added
to the mixture. The remaining propellant is charged into the
individual aerosol containers containing the appropriate
amounts of the mixture.
The invention will be further illustrated by the
following example.
:-~
~'
;~
.~,
;... :: :~ -. . ,: ~ -
:.;.,.- . : . -, ~ , ,: ,, ,
: ~, :;.: :: - - ., :- : : . - . , ~- : ,. - :
. .. , - ~ , . ~ : - - .
.'.'~ ' ' :
.1,. ~ ,
:" - . : ,
-.~. . .: - : , . .
~`
;
lQ38295
EXA~IPLE I
An aerosol cor.?osition of this invention is pre-
:. pared, ha~ing the following formula:
. . .
n~redient Parts by h~eight
Aluminum chlorhydroxide ~AC~)5.0
`~ , 8entone 38 . 0.25
.,~ .
Isopropyl myristate 2.0
Perfume 0-4
Ethanol~water mixture 0.5
(70/30 parts by weight)
Propellant (CC13F:CC12F2:: 91.85
~ 60:40 weignt ratio)
,,~ i 100.00
J
, .~
-.',: ' : .
,~-- ,. . .
.. "'' ' ' ~ ' -: - '
:''';' , . ' ~ ~ '
- :. ~
1038295
The composition is prepared by premixing the 0.25
parts Bentone 38 in 15 parts of the CC13F propellant, adding
the 0.5 parts of ethanol/water to this mixture, shear
mixing at high speed in a Chemineer ~ in-line mixer for about
5 minutes to form a gel at room temperature , ~hen blending
in the ACH, isopropyl myristate and perfume. This mixture
is placed in clear Wheaton ~ plastic-coated glass aerosol
bottles which are then charged with the remainder of the
propellant. The bottles are shaken and allowed to stand for
24 hours, after which time it is noted that the antiperspirant
salt has been more effectively kept in suspension than is
the case when a composition is similarly prepared using con- ~-
ventional 95% ethanol (i.e., 95~ ethanol/5~ water by volume)
and is shaken and observed in the same manner.
When in this Example Bentone 38 is replaced by
equal amounts of other montmorillonite clays selected from
the group consisting of bentonites , hectorites, colloidal
magnesium silicates, and hydrophobically treated montmorillonite
slays selected from the group consisting of Bentone 34,
Bentone 27, Bentone 14 and Bentone LT, similar results
are obtained, in that the compositions containing the 70/30
ethanol/water mixture maintain the antiperspirant salt in
suspension better than similar compositions containing 95
ethanol.
~: .
