CA1038295A

CA1038295A - Powder aerosol antiperspirant compositions

Info

Publication number: CA1038295A
Application number: CA225,073A
Authority: CA
Inventors: Roderick C. Browne
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1974-05-07
Filing date: 1975-04-21
Publication date: 1978-09-12
Also published as: BE828809A; JPS5132721A; FR2269923B1; NL7505367A; DE2519860A1; GB1498255A; FR2269923A1; IT1035612B

Abstract

POWDER AEROSOL ANTIPERSPIRANT COMPOSITIONS

Abstract of the Disclosure An aerosol powder antiperspirant composition which contains a suspending agent selected from the group con-sisting of montmorillonite clays and hydrophobically treated montmorillonite clays, and a 60/40 to about 80/20 parts by weight mixture of ethanol and water, wherein the weight ratio of the ethanol/water mixture to suspending agent is from about 1.5:1 to about 4:1. The result is improved suspensions of the antiperspirants salts in the composition, with lower settling rates and less agglomeration.

Description

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.

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~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.
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-~ 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 ~! . .

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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 ~

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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 Ai~
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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;
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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~

-~

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 ., - .

~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 _ 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 , .

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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 -~' ~
, 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.

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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%.

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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.

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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
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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.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Aerosol antiperspirant compositions comprising:
(A) from about 0.2% to about 12% of an astringent antiperspirant salt;
(B) from about 0.1% to about 7% of a suspending agent selected from the group consisting of montmorillonite clays and hydrophobically treated montmorillonite clays;
(C) from about 0% to about 15% of a carrier liquid;
(D) a 60/40 to 80/20 parts by weight mixture of ethanol and water wherein the weight ratio of ethanol/water mixture to suspending agent is from about 1.5:1 to about 4:1, and (E) balance, propellant.

2. The aerosol antiperspirant composition as recited in Claim 1 wherein the weight ratio of ethanol/water is 70/30.

3. The aerosol antiperspirant composition as recited in Claim 1 wherein the suspending agent is a hydrophobically treated montmorillonite clay.

4. The aerosol antiperspirant composition as recited in Claim 1 wherein the astringent antiperspirant salt is present in an amount of from about 2.5% to about 6.0%, the sus-pending agent is present in an amount of from about 0.15%
to about 0.8%, the carrier liquid is present in an amount of from about 0.1% to about 10%, and the alcohol/water mixture to suspending agent ratio is from about 1.5:1 to about 2.5:1.