An aluminum halohydrate is formed by first preparing a reactive aluminum by permeating highly pure aluminum with mercury in the presence of a hydrogen ion source and then contacting the reactive aluminum with a source of iodine, chlorine, bromine or fluorine in the presence of water. The products obtained show high stability, uniformity from batch to batch, and a pH of about 4.3.

Reference is made to the following co-pending applications: Reactive 
Metals, Ser. No. 211,979 filed Dec. 27, 1971, now abandoned; Aluminum 
Hydrates and Salts of Carboxylic Acids, Ser. No. 255,757 filed May 22, 
1972, now abandoned; Metal Hydrates and Salts of Carboxylic Acids, Ser. 
No. 255,758 filed May 22, 1972, now abandoned; and Composition of Matter 
and Apparatus and Method for the Same, Ser. No. 176,907 filed Sept. 1, 
1971. 
BACKGROUND OF THE INVENTION 
The present invention relates to methods of forming selected aluminum 
halohydrates and to the aluminum halohydrates formed thereby. 
The present invention relates more particularly to the methods of forming 
aluminum iodohydrate, aluminum chlorohydrate, aluminum bromohydrate, and 
aluminum fluorohydrate. 
Generally, aluminum halohydrates have found substantial commercial usages 
in a wide variety of fields, including use as an active ingredient in body 
deodorants, tawing salts, and for this impregnation of textiles to impart 
water repelling properties. In addition, aluminum halohydrates are also 
used for the preparation of absorption agents or catalytically active 
substances. Many other commercial uses for the chemicals are well known. 
Prior art methods for preparing aluminum halohydrates often include the 
step of reacting an aluminum halide salt, such as aluminum fluoride, 
aluminum chloride, aluminum bromide or aluminum iodide with water and 
metallic aluminum. The process described in the U.S. Pat. No. 3,476,509 
includes the use of water soluble thallium compound with a pH of between 
2.5 and 4.4 at an elevated temperature in the order of 70.degree. C. to 
105.degree. C. The aluminum hydrate formed from an aluminum halide usually 
shows traces of the aluminum halide. This has been recognized to be a very 
serious problem especially for aluminum chlorohydrate when used as an 
antiperspirant because the aluminum chloride hydrolyzes to hydrochloric 
acid and results in severe skin irritation. The presence of the aluminum 
halide also tends to make the aluminum halohydrates hydroscopic. 
The article entitled, "Basic Aluminum Compounds" by Hideo Tanabe in The 
American Perfumer and Cosmetics, Vol. 77, August 1962 pages 25-30 provides 
a review of known methods for preparing aluminum halohydrates. On page 26, 
Tanabe presents four methods by way of equations (5), (6), (7), and (8). 
The four methods are briefly given herein for reference: 
1. More than an equivalent amount of metallic aluminum is reacted with an 
acid, or metallic aluminum is reacted with an aluminum salt with a 
catalyst of mercury, iron, or copper: 
2. More than an equivalent amount of aluminum hydroxide is reacted with an 
acid; 
3. An alkali is added to an aluminum salt solution; and 
4. An aqueous solution of an aluminum halide is passed through an anion 
exchange resin. 
On page 26, Tanabe presents the general formula Al.sub.2+n OH.sub.3n 
X.sub.6 and indicates that when "n" is large, the soluton is slightly 
turbid but can be made clear by filtration with carbon powder. Tanabe 
continues with an analysis of the aluminum chlorohydrate and states that 
each of the four reactions results in a basic aluminum ion which condenses 
gradually into a polynuclear ion and this condensation is influenced by 
various conditions such as temperature, time and the the value of "n". 
Thus, the aluminum chlorohydrate reported by Tanabe appears to show 
instability with both temperature and time. An eariler Tanable article in 
Pharm. Soc. Japan, 75 page 868 (1955) is directed to the study of these 
instabilities. 
Another earlier article by Tanabe, in Pharm. Soc. Japan, 74, page 868 
(1954) states explicitly that the properties of aluminum chlorohydrate 
varies with the method of preparation. 
SUMMARY OF THE INVENTION 
One of the principal objects of the Invention is to provide a method for 
preparing aluminum iodohydrate, aluminum chlorohydrate, aluminum 
bromohydrate and aluminum fluorohydrate by the steps of first permeating 
aluminum having a purity by weight of at least 99.98% with mercury in the 
presence of a hydrogen ion source, such as an acid, and then contacting 
the permeated aluminum with an appropriate halogen ion source in the 
presence of an excess of water compared to the halogen, in accordance with 
the formula Al.sub.2 (OH).sub.5 X where "X" corresponds to the selected 
halogen. 
Another object of the present invention is to obtain novel aluminum 
iodohydrate, aluminum chlorohydrate, aluminum bromohydrate and aluminum 
fluorohydrate compounds exhibiting novel properties. 
A further object of the present invention is a method of preparing selected 
aluminum halohydrates having a desired ratio between the aluminum and 
halogen atoms. 
Yet another object of the present invention is to provide a method for 
preparing aluminum iodohydrate, aluminum chlorohydrate, and aluminum 
bromohydrate by the use of the corresponding gas in the presence of water. 
Yet another object of the present invention is a method for preparing 
aluminum iodohydrate from iodine crystals in water. 
Further objects and advantages of the invention will be set forth in part 
in the following specification and in part will be obvious therefrom 
without being specifically referred to, the same being realized and 
attained as pointed out in the claims hereof. 
The present invention accordingly comprises the several steps and the 
relation of one or more of such steps with respect to each of the others, 
all as exemplified in the following detailed disclosure, and the scope of 
the application of which will be indicated in the claims. Furthermore, the 
products obtained are novel and exhibit properties which are superior to 
known corresponding products. For example, the products obtained are 
water-clear when dried to a solid, are soluble in water, and are not 
hygroscopic. In addition, the aluminum iodohydrate, aluminum 
chlorohydrate, and aluminum bromohydrate exhibit superior bacterialcidal 
properties.

THE INVENTION 
The present invention if focused on the utilization or the remarkable 
properties of a reactive aluminum described in application Ser. No. 
211,979, now abandoned. 
Generally, a reactive aluminum is prepared by permeating highly pure 
aluminum in the presence of a hydrogen ion source with mercury. The 
hydrogen ion source can be an inorgaic acid, such as hydrochloric acid or 
hydrobromic acid or the like, or an organic acid, such as citric acid or 
acetic acid, or the like. The reactive aluminum in an alkali solution such 
as water and sodium hydroxide will serve as an hydrogen ions source for 
the formation of another reactive aluminum. 
It should be understood that the term "highly pure" herein means a purity 
greater than 99.98% by weight. 
The concentration of the acid employed can cover the broadest range. The 
choice of the hydrogen ion source such as an acid will depend upon the 
product to be formed and the concern over impurities. 
It is preferable to prepare a highly pure aluminum rod for the reaction by 
at least partially stripping the aluminum oxide coating which usually has 
formed on the surface due to exposure to air and moisture. Of course, 
other than a rod shape can be used. If the aluminum rod has been stripped, 
hot water can serve as a hydrogen ion source, although the reaction time 
is long. Otherwise, it may be desirable to start out with an acid to strip 
off the oxide coating on the aluminum rod in order to initiate the 
reaction as quickly as possible. Of course, the aluminum rod may be 
stripped mechanically with sandpaper or a file or the like. 
The inter-reaction which occurs between the aluminum, the mercury and the 
acid, gives rise, at the start, to the formation of large bubbles which 
rise up to the surface through the acid. After a while, it will be 
observed that instead of large bubbles forming at the top of the aluminum 
rod and then breaking free and rising to the surface of the acid, tiny 
bubbles will be eminating from many parts of the upper surface of the rod. 
The occurrence of the multitude of tiny bubbles indicates that the rod is 
becoming converted to receive aluminum as herein used. 
Generally, the rod will take up or absorb from 0.1% to 5% by weight of the 
mercury depending upon the length of time the reaction is permitted to 
continue. A range of 2% to 3% by weight of the mercury is satisfactory for 
many application. The maximum mercury content is about 5% by weight. 
The reaction can be stopped on the one hand due to increase in weight or 
the rod due to the absorption of the metal or on the other hand due to the 
production of a multitude of tiny bubbles for a period of ten to fifteen 
minutes. Another basis is to test the rod by immersing it in water 
hydrolysis of the water to absence. 
A reactive aluminum as described, displays surprisingly active catalytic 
properties not at all suggested by the prior art. The reactive aluminum 
possesses an altered physical structure and my be used as an activator or 
initiator. After grain alignment, the reactive aluminum becomes an open 
matrix where the boundaries have expanded. 
The amount of the mercury in the aluminum can be varied in accordance with 
applications. In general, if a high percent of the mercury of weight is 
desired, quick cooling of the reactive aluminum after formation will 
prevent the squeezing out of the mercury due to an exothermic reaction and 
lattice expansion. Water or alcohol is convenient for this purpose. In 
cases where it is desired to reduce the amount of, mercury from several 
percent by weight to 0.1% by weight, for example the reactive aluminum can 
be heated to squeeze out the mercury. 
Certain impurities such as copper and iron, inhibit the formation of a 
reactive aluminum and so should be avoided in the aluminum. Some of the 
impurities which inhibit or promote the reaction are given in the 
aforementioned Reactive Metals application. But, small amounts of the 
inhibitors can be tolerated for certain applications. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
For a fuller understanding of the invention certain embodiments have been 
selected for more detailed description. 
Generally, a reactive aluminum is reacted with water and a selected source 
of chlorine, bromine, iodine or fluorine. In many cases, it is convenient 
to use an acid form of the selected halogen. Sometimes, it is convenient 
to use a gaseous form of the selected halogen, such as chlorine gas, or 
bromine gas iodine vapors. A further possibility in the use of ground 
iodine crystals in water. 
Basically, the amount of water present compared to the available halogen 
atoms can be determined from the formula: Al.sub.2 (OH).sub.5 Q; Q 
corresponds to the halogen: chlorine, bromine, iodine of fluorine. It is 
preferable to use more water than the stoichiometric equivalent of the 
formula in order to be assured of having sufficient hydroxyl groups 
available. 
The ratio of the aluminum atoms to the halogen atoms varies from the ratio 
of 2:1. It is highly significant that the ratio of 2.2:1 for aluminum 
chlorohydrate and 2.4:1 for aluminum bromohydrate can be obtained by the 
present invention. Also, a ratio of 2.7:1 for aluminum iodohydrate has 
been obtained by the present methods. Surprisingly, the product obtained 
by the present methods even for high ratios of aluminum to halogen is 
water clear. 
In addition, the products obtained by the present methods show a stable pH 
of about 4.2 to about 4.3 in contrast to products obtained by prior art 
methods which have a pH of approximately 3.9. 
In carrying out the present methods, it is desirable to cool the reaction 
to below 100.degree. F. in order to avoid the incidental formation of an 
aluminum halide. The presence of an aluminum halide in prior art products 
is considered highly undesirable. However, products obtained by the 
present methods are non-hydroscopic and are therefore far more suitable 
for many applications where prior art products were unsuitable. For 
example, the present aluminum chlorohydrate is well suited use as an 
underarm deordorant even in for high concentrations, since the absence of 
aluminum chloride avoids the formation of hydrochloric acid and irritation 
to human skin. Tests with even relatively concentrated solutions have 
verified this for human use. 
Another significant advantage of the present product is that the present 
products become micronized after spray drying and at least 99% will pass a 
325 mesh. Prior art products require additional treatment in order to 
become micronized after spray drying. This may be related to the fact that 
prior art products have at least 14% moisture content after spray drying 
in contrast to the present products which have only about an 8% moisture 
content after spray drying. 
The aluminum used in the present method preferably is high purity aluminum 
having a purity of 99.99% by weight and is readily available in rod form 
but, of course, other shapes can be used. It is preferable to prepare the 
reactive aluminum with the halogen acid corresponding to the aluminum 
halohydrate to be formed in order to maintain high purity. Repeated 
washing of a reactive aluminum can be used for cleansing the reactive 
aluminum of potential impurities. Usually, it is highly desirable to form 
the aluminum halohydrate with a high degree of assurance that no mercury 
will appear in the product. This can easily be achieved by using a 
reactive aluminum having a mercury content by weight such that the mercury 
by weight in the initial reactive aluminum corresponds to less than 
approximately 3% by weight of the reactive aluminum after completion of 
the reaction. It is known that the reactive aluminum retains mercury up to 
the approximate saturation point of about 5% by weight. Thus, calculations 
can show the amount of aluminum which will be consumed to obtain the 
desired aluminum to halogen ratio for the available halogen and these 
calculations can guide the selection of the total weight of the reactive 
aluminum used and the mercury content thereof. This is another surprising 
feature contributing to the high purity of the product obtained by the 
present methods. 
The aluminum iodohydrate, aluminum bromohydrate, and aluminum chlorohydrate 
prepared by the present methods exhibit surprisingly good anti-microbial 
properties. Standard tests are used to determine the anti-microbial 
number, namely the concentration to completely destroy pseudomonas and 
aeruginosia in 10 minutes but not 5 minutes. The aluminum iodohydrate was 
effective at dilutions in the order of 1000:1 to 600:1 and the aluminum 
chlorohydrate was effective at a dilution in the order of 1000:1. The 
Aluminum bromohydrate was effective at a dilution of approximately 100:1. 
The aluminum iodohydrate showed suprisingly superior anti-microbial 
activity even compared to IOPREP (trademark), a well known pre-surgical 
antiseptic. The antimicrobial dilution of the aluminum iodohydrate against 
stabhylococcus and pseudomonas was 400:1 in each case as compared to the 
IOPREP which was 100:1 in each case. Furthermore, one part of a 25% 
concentration aluminum iodohydrate was combined with 4 parts of Ivory 
(trademark) soap and was found effective against staphylococcus even after 
being diluted 80 times. The solution was also effective against 
pseudomonas but only for a dilution of 40 times. 
Therefore, a further step in the present invention includes using aluminum 
iodohydrate prepared in accordance with the present invention for its 
anti-microbial properties. 
With regard to usual properties, it is noted that the aluminum bromohydrate 
is suprisingly well suited for fireproofing such things as wood, clothes 
and paper. The fireproofing properties can be imparted either by spraying 
a solution of the aluminum bromohydrate on the object or soaking the 
object therein. Naturally, other methods may be use. 
After preparing an aluminum halohydrate according to the present methods, 
it may be desirable to enrich the hydroxyl content of the aluminum 
halohydrate. The enrichment of the hydroxyl content may be carried out by 
utilizing the product obtained as described in applicant's co-pending 
patent application Ser. No. 176,907. Briefly, the product of application 
Ser. No. 176,907 is obtained by placing highly pure aluminum in contact 
with mercury and an acid with a part of the aluminum exposed to air. The 
aluminum can be in the form of a rod with the mercury covering about half 
of the rod lying therein. A novel product forms on the aluminum exposed to 
the air. The temperature of the rod should preferably be maintained below 
105.degree. F. Cooling can be accomplished many different ways but one 
convenient way is to contact the aluminum with a large pool of mercury and 
use only a small amount of acid to just bearly cover the mercury. The 
mercury helps to conduct heat away from the rod and therefore cools the 
rod. An operating temperature of about 90.degree. F. is preferable. The 
novel product obtained is extremely rich in hydroxyl groups and can be 
added to the aluminum halohydrate and mixed with or without heating to 
obtain a hydroxyl enriched aluminum halohydrate. 
Sometimes it is desirable to obtain an aluminum halohydrate involving at 
least two different halogen atoms. This can be easily accomplished by the 
present methods by using, for example, two different acids such as 
hydrochloric acid and hydrobromic acid. Other variations include, for 
example, hydrofluoric acid with chlorine gas pumped therethrough in the 
presence of an immersed reactive aluminum. 
The products obtained by the present method are polymeric in nature and the 
above noted formula should not be considered restrictive because the 
number of aluminum atoms in a unit may exceed the number two and can 
easily be 4 or 6 with a corresponding increase, but not necessarily 
proportional, number of hydroxyl and halogen atoms included. Furthermore, 
with regard to the formula, the hydroxyl content could be less than "5" 
depending upon the available quantity of hydroxyl groups. 
Sometimes an alcohol soluble product is desired. Such a product can be 
obtained by the use of water and alcohol but some instabilities over 
extended periods of time have been noted for aluminum chlorohydrate. 
EXAMPLES 
Illustrative non-limiting examples of the practice of the invention are set 
forth below. Numerous other examples can readily be evolved in the light 
of the guiding principles and teachings contained herein. The examples are 
intended merely to illustrate the invention and not in any sense to limit 
the manner in which the invention can be practiced. The parts and 
percentages recited herein and all through this specification, unless 
specifically provided otherwise, refer to parts by weight and percentages 
by weight. 
EXAMPLE 1 
The procedure for preparing an aluminum chlorohydrate illustrates some 
general rules. Typically, it is convenient to use a mass of aluminum equal 
to that needed to obtain a desired ratio. The aluminum chlorohydrate is 
prepared by first forming a mercury treated reactive aluminum rod and then 
reacting the reactive aluminum with hydrochloric acid. A rod of 54 grams 
of aluminum having a purity of 99.98% by weight is permeated in the 
presence of hydrochloric acid with mercury so that the permeated mercury 
is between 1% to 3% by weight of the rod. Then, the reactive aluminum is 
immersed in 87 grams of 1.5N hydrochloric acid. Generally, the acid can 
range between 0.5N and 2N or higher. It is preferable to maintain the 
temperature of the reaction below about 100.degree. F. in order to avoid 
the possibility of forming aluminum chloride or a product which does 
exhibit a stable chemical property. Generally, a temperature of 
200.degree. F. or higher should be avoided so that halides are not formed. 
EXAMPLE 2 
The reactive aluminum rod of Example 1 is immersed in a solution of 126 
grams of approximately 38% concentration hydrochloric acid and 300 grams 
of water. Again, the reaction temperature is maintained below 100.degree. 
F. After approximately 72 hours, the liquor contains about 50% by weight 
solid aluminum chlorohydrate with the balance being water. The aluminum to 
chlorine ratio is approximately 2.04:1. 
EXAMPLE 3 
The reactive aluminum rod of Example 1 is immersed in 250 grams of 50% by 
weight methanol with the balance being water; then, 36 grams of chlorine 
gas is bubbled therethrough over a period of approximately 24 hours. The 
product obtained had an aluminum to chlorine ratio of approximately 
1.86:1. 
EXAMPLE 4 
The reactive aluminum of Example 1 is immersed in 87 grams of 38% by weight 
concentration of hydrochloric acid mixed with 150 grams of methanol and 
300 grams of water. The temperature is maintained below 100.degree. F. by 
cooling. After 72 hours, the liquor contained approximately 50% by weight 
aluminum chlorohydrate with the balance being mainly methanol. The 
aluminum to chlorine ratio was approximately 1.92:1. When the liquor was 
permitted to dry, alcohol soluble crystals were obtained. 
EXAMPLE 5 
An aluminum chlorohydrate is prepared with the reactive aluminum of Example 
1 is immersed in 250 grams of water which has been twice distilled and 
then chlorine gas is bubbled through the water, preferably so that the 
bubbles collide with the reactive aluminum. It may be desirable to 
recirculate the gas which has not been reacted. 36 grams of chlorine 
reacted over a period of approximately 72 hours producing a liquor having 
46% by weight of aluminum chlorohydrate. A reactive aluminum of 59 grams 
yields a product with a ratio of aluminum to chlorine 2.2:1. 
EXAMPLE 6 
An aluminum iodohydrate is prepared by using 59 grams of the reactive 
aluminum of Example 1 in 435 grams of water and 127 grams of powdered 
iodine. The water and iodine are agitated so that the iodine contacts the 
reactive aluminum. A product with an aluminum to iodine ratio of 2.7:1 is 
obtained. 
EXAMPLE 7 
An aluminum bromohydrate is prepared by immersing a 64 gram reactive 
aluminum in 600 grams of water and introducing 80 grams of bromine gas 
into the water so that the bubbles contact the reactive aluminum. The gas 
flow should be regulated to occur over a period of several days. A product 
with an aluminum to bromine ratio of 2.4:1 is obtained. 
EXAMPLE 8 
An aluminum bromohydrate is prepared by immersing 59 grams a reactive 
aluminum in 307 grams of water and 162 grams of hydrobromic acid and 
continuing the reaction until an aluminum to bromine ratio of 2.0:1 is 
obtained. It is preferable to provide cooling. 
EXAMPLE 9 
An aluminum fluorohydrate is prepared by immersing a reactive aluminum of 
54 grams in 307 grams of water and 40 grams of hydrofluoric acid and 
providing cooling. A teflon lined reactor is preferable. 
EXAMPLE 10 
A stable hydroxyl augmented aluminum chlorohydrate is formed by taking 150 
grams of the aluminum chlorohydrate of Example 1 and combining it with 40 
grams of the oxygen-bearing aluminum complex of application Ser. No. 
176,907 and 40 grams of methanol. After the mixture is heated to 
approximately 200.degree. F. a stable product is obtained. This product is 
soluble in alcohol. 
EXAMPLE 11 
An hydroxyl augmented aluminum chlorohydrate is obtained by adding to 150 
grams of the aluminum chlorohydrate of Example 1 40 grams of the 
aforementioned oxygen-bearing aluminum complex, which is an aluminum 
complex including hydroperoxy groups. After mixing, the combination is 
left for 24 hours. Then, 10 grams of ethanol are added to the liquor and a 
reactive aluminum is immersed therein for between 12 to 24 hours. The 
resulting product is an aluminum oxychlorohydrate which is soluble in 
alcohol. 
EXAMPLE 12 
Example 12 is repeated except that no reactive aluminum is used after the 
ethanol has been added. 
EXAMPLE 13 
When the procedure of any of Examples 1 to 12 is repeated for an aluminum 
having a purity of at least 99.99% a purer product having a superior 
quality and preferable for pharmaceutical and like applications is 
obtained. 
Examples 1 to 12 will result in elemental mercury at the bottom of the 
reactor. This mercury can be easily avoided by standard techniques for 
recovery the desired product. But, some mercury may be held in the liquor 
obtained and may be highly undesirable. A further step can be used to 
purge the mercury from the liquor. The purging can be accomplished by 
using a reactive aluminum having 500 to 2000 parts per million. Such a 
reactive aluminum accumulates and holds mercury so that the liquor purity 
is remarkably improved.