WO1993014633A1

WO1993014633A1 - Low bromine vapor pressure compositions of organic ammonium perhalides and a solvent

Info

Publication number: WO1993014633A1
Application number: PCT/US1993/000473
Authority: WO
Inventors: Nicolai A. Favstritsky; Dennis M. Borden; L. Jane Likens
Original assignee: Great Lakes Chemical Corporation
Priority date: 1992-01-31
Filing date: 1993-01-19
Publication date: 1993-08-05
Also published as: AU3479293A

Abstract

Low bromine vapor pressure compositions are disclosed which contain perhalides of formula (I) in which R1 and R2 are independently hydrogen, hydroxyethyl, alkyl, cycloalkyl, (alpha, omega)-alkyl, alkyl ether, polyether, polyoxyalkylene, heterocyclic ring-substituted alkyl, and halogenated alkyl; X is chlorine, bromine or iodine; and at most one of R1 and R2 is hydrogen; and a solvent comprising a water soluble, bromine stable, organic solvent. The solvent may optionally include water.

Description

LOW BROMINE VAPOR PRESSURE COMPOSITIONS

OF ORGANIC AMMONIUM PERHALIDES AND A SOLVENT

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to compositions including organic ammonium perhalides and a bromine stable, organic solvent, and which are characterized by a low bromine vapor pressure. The compositions are stable and possess high concentrations of easily available oxidizing bromine, and have utility as water sterilization agents.

Description of the Prior Art

The preparation and utility of ammonium perhalides as are useful in the present invention are described in U.S. Patent No. 4,886,915, issued to Favstritsky on December 12, 1989. These compounds have been found to be particularly desirable in view of their stability, water solubility and high

concentrations of easily available oxidizing bromine.

The perbromide ion (Br₃ ) in solution is in equilibrium with bromide ion (Br-) and bromine (Br₂). The perbromide ion has no measurable vapor pressure, while dissolved bromine (Br₂) will give a distinct bromine odor. It is desirable that compositions containing the ammonium perhalides have a low bromine vapor pressure. U.S. Patent No. 4,898,975, issued to Favstritsky on February 6, 1990, describes

formulations which use the addition of organic and inorganic halide salts to reduce bromine vapor pressure through a common ion effect. The additional halide, especially

bromide, serves to inhibit perbromide dissociation to bromide ion and bromine.

The foregoing organic ammonium compositions, optionally including halide salts to reduce bromine vapor pressure, have been shown to be useful for controlling biofouling in

recirculating water systems. Such use may occur in water cooling Lowers, air conditioning systems and the like, and is described in U.S. Patent No. 4,935,153, issued to Favstritsky et al. on June 19, 1990, and U.S. Patent No. 4,966,716, issued to Favstritsky et al. on October 30, 1990.

Bromine compositions of the aforedescribed type will desirably have low vapor pressure while having a high bromine content. It has surprisingly been discovered that reduction of bromine vapor pressure is obtained by adding a water soluble, bromine stable, organic solvent to an organic perbromide formulation.

The use of organic solvents as stabilizing mediums for hydrogen perbromide and sodium perbromide has been identified in the prior art. For example, it has been reported that the equilibrium constant for the interaction:

K = (Br₃ )/(Br-)(Br₂) increases with the volume percent of acetic acid in aqueous solution. This evaluation was performed to quantitatively interpret the inhibition of aromatic bromination reactions by bromide ion in acetic acid and in aqueous acetic acid

solutions, due to tribromide formation. See T.W. Nakagawa, L.J. Andrews, R.M. Keefer, J.Phys. Chem. 61, pp. 1007-1009 (1957). Similar observations as to inorganic perbromide stability in methanol are set forth in J.E. Dubois, F.

Gamier, Bull. Soc. Chim. Fr., pp. 1715-1718 (1965).

There remains a need for cost effective, low bromine vapor pressure bromine carriers with good water

dispersibility. However, the reduction of bromine vapor pressure for organic perbromides by the addition of a water soluble, bromine stable, organic solvent has not been previously recognized. SUMMARY OF THE INVENTION

The present invention is directed to organic perbromide compositions including (1) water soluble mono- and

disubstituted ammonium perhalide compounds of the formula R₁R₂NH₂XBr_n where R₁ and R₂ are independently

hydrogen or organic substituents, with only one of R₁ and R₂ being hydrogen; X is chlorine, bromine or iodine; and n is 2 to 6; and (2) a bromine stable, organic solvent. More particularly, the compounds of the present invention include compounds in which the organic substituents for R₁ and R₂ may include hydrogen, hydroxyethyl, alkyl, cycloalkyl,

(alpha, omega)-alkyl, alkyl ether, polyether, heterocyclic ring-substituted alkyl, polyoxyalkylene, and halogenated alkyl. These mono- and disubstituted ammonium perhalides possess high concentrations of oxidizable bromine, are stable, have good water solubility and can be easily

prepared. The organic solvents are selected to be stable with the perhalides and to provide reduced bromine vapor pressure.

It is an objective of the present invention to provide a cost effective composition of organic perbrornides having a high bromine content and a low bromine vapor pressure.

A further object of the present invention is to provide an organic perhalide composition having good water

dispersibility, and being useful for controlling biofouling in recirculating water systems.

Further objects and advantages will be apparent from the description of the preferred embodiment which follows. DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the preferred embodiment of the invention and specific language will be used to describe the same. It will

nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations,

modifications and further applications of the principles of the invention being contemplated as would normally occur to one skilled in the art to which the invention relates.

The present invention provides useful organic perhalide compositions which are characterized by significantly reduced bromine vapor pressures. It has been discovered that the addition of a bromine stable, water soluble, organic solvent to the organic perhalide compound, with or without the further addition of water, will reduce the bromine vapor pressure while providing a cost effective and readily water dispersed product. In fact, the present invention reduces the vapor pressure of the perhalide composition by as much as an order of magnitude, while keeping the bromine content at least as much as 10% by weight.

The resulting perhalide compositions are useful in the same manner as the perhalide compositions disclosed in the Favstritsky et al. patents cited in the "Description of the Prior Art", the pertinent portions of which are hereby incorporated by reference. In addition, the use of suitable organic solvents can eliminate the need for the use of additional halide salts, and also is inexpensive and

environmentally acceptable.

In accordance with the present invention, mono- and disubstituted ammonium perhalides are combined with organic solvents, with the result being a reduction in the bromine vapor pressure of the composition. A favorable shift in the equilibrium toward the perbromide ion apparently results from the lower dielectric strength of the organic medium, as suggested by the following relationship:

Br- + Br₂ → Br₃

high dielectric low dielectric

medium medium

The compositions therefore maintain a high bromine content, but provide cost effective, low bromine vapor pressure bromine carriers with good water dispersibility.

The present invention involves the combination of bromine stable, organic solvents with the perhalides. The prior art indicates that it may be convenient to blend the perhalide compounds used in this invention with water to produce a liquid mixture which can easily be handled by pumping and metering devices. However, while water is the preferred diluent for making formulations with excellent shelf life, there are instances where it is desirable to make

formulations with very low bromine partial vapor pressures. In these instances, water soluble, bromine stable solvents alone or in combination with water produce the desired liquid formulations.

Solvents which may be used in this fashion include aliphatic nitro, nitrile and carboxylic acids, some alcohols and some amides. While considerations such as cost,

toxicity, and shelf life will affect the decision as to which solvent to choose, suitable solvents will include one or more of the following solvents: nitromethane, acetonitrile, acetic acid, propionic acid, tertiary butanol, methanol, N,N-dimethyl acetamide and N-methyl pyrrolidinone. From this group of organic solvents, acetic acid and methanol, which are inexpensive and environmentally safe, are especially preferred.

The water soluble mono- and disubstituted ammonium perhalides useful in this invention are compounds of the following structure:

where R₁ and R₂ are independently hydrogen, hydroxyethyl, alkyl, cycloalkyl, (alpha, omega)-alkyl, alkyl ether,

polyether, heterocyclic ring-substituted alkyl,

polyoxyalkylene, and halogenated alkyl, at most one of R₁ and R₂ being hydrogen; X is chlorine, bromine or iodine;

and n is 2 to 6. As known in the art, these perhalide compounds may be prepared by reacting the corresponding raono- or disubstituted ammonium hydrohalide salt with bromine.

The solubility and bromine content of the perhalide compounds depend on the bulk and nature of the substituents. The most preferred substituents are R₁ = hydroxyethyl or C₁, to C₈ alkyl groups, and R₂ = hydrogen, hydroxyethyl, or C₁ to C₈ alkyl groups.

In general, the compounds of this invention include mono- and disubstituted perhalides where X may be bromine, chlorine or iodine. It is preferred, however, to employ compounds where X is bromine, i.e., perbroπiides of the formula

R₁R₂NH₂Br_n+1, such as R₁R₂NH₂Br₃.

Specific stable, water soluble perhalides useful with the present invention include ethanolammonium perbromide, propylammonium perbromide, diethanolammonium perbromide, butylammonium perbromide, methylethanolammonium perbromide, ethylethanolammυnlum perbromide, hexylammonium perbromide octylammonium perbromide, dipropylammonium perbromide, dibutylammonium perbromide, diethylammonium perbromide, and 1,6-hexanediammonium perbromide, as well as the corresponding chloro and iodo-dibromides. If desired, the shelf life of aqueous solutions of the compounds of this invention may be stabilized by increasing the amount of ammonium hydrohalide in relation to bromine. More particularly, up to four moles of mono- or disubstituted ammonium hydrohalide salt may be admixed with one mole of bromine. Perhalides with lower apparent vapor pressure and lower oxidizable bromine content are produced when two moles of salt in aqueous solution are added to one mole of

elemental bromine. Mono- and disubstituted ammonium

hydrohalide salts which may be used include those of the formula:

where R₁, R₂ and X are as previously defined.

Shelf life stability may also be increased by replacing part of the substituted ammonium hydrohalide salt with other stability enhancing salts such as alkali metal and ammonium bromides, especially ammonium bromide and sodium bromide, preferably in a molar ratio of about 1:1. Preferably, the substituted ammonium hydrohalide salt and other stability enhancing salt, if any, are provided in a ratio lying in the range of about 1 to 4 moles of salt to 1 mole of bromine.

The compositions of this invention can be easily prepared by mixing the organic solvent with perhalide compounds formed by various known processes as exemplified by the following. For example, the perbromides may be prepared by first

reacting the corresponding amines with hydrogen halide

(Equation 1), followed by the addition of bromine (Equation 2):

R₁R₂NH + HX → R₁R₂NH₂X (1)

R₁R₂NH₂X + Br₂ → R₁R₂NH₂XBr₂ (2) Alternatively, anhydrous perbromides can be easily prepared by gently heating the dry amine hydrobromide salt with bromine.

Conveniently, an aqueous solution of lower alkyl- or dialkyl-ammonium perbromides can be prepared by reacting the readily available and inexpensive aqueous 48% hydrobromic acid with neat amine. The resulting aqueous amine

hydrobromic salt is then readily converted to the perbromide by the addition of bromine. A simple one-pot procedure produces aqueous solutions of perbromides with exceedingly high bromine content. The organic solvent is then added thereto.

Another method of preparing the perhalide compounds consists of first dissolving the bromine in hydrobromic acid (Equation 3), followed by the addition of the neat amine (Equation 4):

HBr + Br₂ → HBr₃ (3)

HBr₃ + R₁R₂NH → R₁R₂NH₂XBr₂ (4)

Still another method for the preparation of the perhalide compounds used in the present invention, especially if higher bromine content in the final solution is desired, consists of reacting a more concentrated hydrobromic acid with amine, followed by bromine addition. Alternatively, the

corresponding aqueous solution of the amine hydrobromide can be concentrated by evaporating water, followed by the

addition of an appropriate amount of bromine.

Analogous procedures may be employed to produce the chlorine and iodine containing perhalides useful in this invention by employing the corresponding hydrogen halide in the foregoing reactions.

The perhalides used in this invention may also include those containing additional bromine. The bromine content of these perhalides may be increased by adding more than one mole of bromine to the substituted-ammonium hydrobromide, yielding a higher perbrominated salt, as illustrated by

Equation (5). R₁R₂NH₂Br + 2Br₂ → R₁R₂NH₂Br₅ (5)

Although four or more moles of bromine can be added to the aqueous amine hydrobromide, the solution, upon contact with excess water, releases elemental bromine. However, it is possible to prepare solutions of perbromides in which the bromine content approaches R₁R₂NH₂Br₅ and which does

not release bromine upon contact with excess water.

The inventive solutions of perhalides have good shelf life stability. Generally, in aqueous solution

monoalkylammonium perbromides are more stable than

dialkylammonium perbromides. Furthermore, the more dilute the perbromide solution, the lower its stability unless stabilized with additional stabilizer additives.

The perhalide compositions of this invention, though high in bromine content, show surprisingly low vapor pressure of bromine. Liquid elemental bromine has a vapor pressure of approximately 220 mm Hg at 26°C and bromine water (containing approximately 3.5% by weight of bromine) shows a vapor pressure of 210 mm Hg at 26°C. For comparison, aqueous

NaBr₃ containing roughly 40% Br₂ has a bromine partial vapor pressure of about 80 mm Hg . Aqueous solutions of organic perhalides such as described by Favstritsky in U.S. Patent No. 4,886,915 further reduce this bromine partial vapor pressure to less than 20 mm Hg at roughly the same bromine content (these numbers differ from Favstritsky because total vapor pressure is not being measured).

Finally, in accordance with this invention the dilution of these organic perhalides with bromine stable solvents and/or stabilizer salts reduces the bromine partial vapor pressure to less than half that of the undiluted organic perhalides. This is important for containment, corrosion minimization and reduction of personnel exposure during shipment, storage, and application.

The following examples will detail the preparation, properties and stability of the preferred perbromide/solvent compositions in accordance with the present invention.

EXAMPLE 1

Preparation of Ammonium Perbromides In a 5.01, four-necked round-bottom flask, immersed in an ice bath and equipped with a mechanical stirrer, reflux condenser, addition funnel, and thermometer, HBr (48%)

(1940 g, 11.5 moles) was placed. Ethanolamine (703 g, 11.5 moles) was slowly added at a rate such that the temperature did not exceed 50°C, to ensure minimal loss of HBr.

After the addition of the ethanolamine was completed, the reaction mixture (61.8% ethanolamine hydrobromide) was allowed to cool to room temperature. Then, bromine (1840 g, 11.5 moles) was carefully added via the addition funnel, and the temperature was maintained below 50°C. The yield of the dark red aqueous ethanolammonium perbromide (Compound #1) was 4483 g.

The perbromide was then titrated for oxidizable bromine via the method described in "Standard Methods for the

Examination of Water and Waste Water," 15th edition: Method 408A. Data for Compound #1 is given in Table 1.

Other water soluble organic ammonium perbromides

identified as Compounds #2-9 in Table 1 were prepared via the procedure used for Compound #1, but on a reduced scale. Data for these compounds is also reported in Table 1.

A series of additional perbromides identified as

Compounds #10-14 were prepared using the procedure described above. However, after the addition of the bromine was completed, two liquid phases were produced. The top phase was an aqueous layer and contained a minimal amount of bromine. The bottom phase, a viscous liquid, represented the perbromide, which in most instances contained oxidizable bromine very close to the theoretical oxidizable bromine content of the neat compound. Data for Compounds #10-14 is given in Table 2.

TABLE 2

PARTIALLY SOLUBLE PERBROMIDES PREPARED FROM AQUEOUS SOLUTION

Compound Tit. Ox. Br₂ Theo. Ox. Br₂** Solubility

# Name Structure % by Weight % by Weight (g/100 g H₂O)

10 Dipropyla-mmonium (CH₃(CH₂)₂)₂NH₂Br₃ 45.1 46.7 10 Perbromide

11 Dibutylammonium (CH₃(CH₂)₃)₂NB₂Br₃ 40.9 43.3 1.0

Perbromide

12 Tributylammonium (CH₃(CH₂)₃)₃NHBr₃ 36.0 37.5 0.01

Perbromide

13 Triethylammonium (CH₂CH₂) NHBr 45.6 46.7 0.1

Perbromide

14 Diethylethanolammonium (CH₃CH₂)₂(HOCH₂CH₂)NHBr₃ 42.3 44.7 0.1

** Theoretical oxidizable bromine content of the neat compound,

Compounds #15 and #16 were prepared using the foregoing procedure. The perbromides produced were crystalline solids which precipitated as the bromine addition proceeded. Data for Compounds #15 and #16 is shown in Table 3.

TABLE 3

PERBROMIDES WHICH PRECIPITATED OUT OF AQUEOUS SOLUTION

Compound Tit. Ox. Br₂ Theo. Ox. Br₂** Solubility # Name Structure % by Weight % by Weight (g/100 g H₂O)

15 Diethylammonium (CH₃CH₂)₂NH₂Br₃ 47.9 50.9 15

Perbromide

16 1,6-Hexanediammonium Br₃H₃N(CH₂)₆NH₃Br₃ 51.8 53.5 50

Perbromide ** Theoretical oxidizable bromine content of the neat compound.

Compounds #7, #12, #13, #14, which are all trisubstituted amine hydroperbromides, were used for comparison purposes. All except Compound #7 are only sparingly soluble in water, and thus are unsuitable for use where high water solubility is required. The water solubilities of the perbromides which separated from the solution are shown in Tables 2 and 3.

Again, with the exception of Compound #7, they are all significantly more soluble than the trisubstituted ammonium hydrotribromides. EXAMPLE 2

Concentrated Organic Ammonium Perbromides

By concentrating the salt solution used, aqueous

perbromides are obtained with higher oxidizable bromine concentrations. These concentrated salt solutions may be prepared in two different ways: (1) the aqueous salt solution may be evaporated to the desired concentration; or (2) a more concentrated HBr may be used. The procedure for preparing a perbromide using concentrated HBr (62%) is described below and the compound is listed as Compound #17 in Table 4.

Compound #17: Concentrated Aqueous

Ethanolammonium Perbromide

Using the setup described in the preparation of Compound #1, HBr (62%) (500 g, 3.8 moles) was placed in a round-bottom flask. Ethanolamine (234 g, 3.8 moles) was slowly dripped into the flask. After the neutralization was complete, yielding a 74.1% salt solution, bromine (612 g, 3.8 moles) was carefully dripped into the reaction flask. TABLE 4

CONCENTRATED AND ANHYDROUS ORGANIC AMMONIUM PERBROMIDES

Compound Concentration of Tit. Ox. Br₂ Calc. Ox. Br₂

Name Hydrobromide, % % by Weight % by Weight M.P. (ºC)

17 Ethanolammonium Perbromide 74.1 47.3 45.5 Liquid

18 Ethanolammonium Perbromide 100 51.8 52.9 47-53

19 Propylammonium Perbromide 100 53.2 53.4 25-29

20 Diethanolammonium Perbromide 100 45.3 46.2 35-45

By using a completely anhydrous amine hydrobromide salt, it was possible to produce solid organic ammonium

perbromides. The preparation of Compound #18, shown in Table 4, is described below. Compound #18: Solid Anhydrous

Ethanolammonium Perbromide

Ethanolammonium bromide (10 g, 0.07 moles), prepared by the neutralization of HBr (48%) by ethanolamine and

evaporated to dryness, was placed in a beaker. Bromine

(11.2 g, 0.07 moles) was added, and the beaker was covered with parafilm to minimize bromine loss. The beaker was carefully heated to 35 °C, at which point the contents of the beaker became a homogenous liquid. The beaker was allowed to sit overnight at room temperature (24°C). By morning, the perbromide had crystallized.

Two other solid perbromides, solid propylammonium

perbromide (Compound #19) and solid diethanolammonium

perbromide (Compound #20), were very soluble in water and were prepared in the same manner (see Table 4).

EXAMPLE 3

Perbromides with lower apparent vapor pressure and lower oxidizable bromine content are produced when two moles of the hydrobromide salt are added to one mole of elemental

bromine. If the second mole of salt is the same

corresponding amine hydrobromide, then the perbromides are exemplified by Compounds #21-23. The procedure for preparing a 2:1 (salt : bromine) aqueous ethanolammonium perbromide

(Compound #21) is described below. However, if the second salt is different, as exemplified by Compounds #24 and #25, then the desired second salt can be added either as a solid or as an aqueous solution, followed by the addition of bromine. The procedure for preparing Compound #24 is given below. Data for Compounds #21-#25 is given in Table 5. TABLE 5

STABILIZED AQUEOUS ORGANIC AMMONIUM PERBROMIDES

Compound Tit. Ox. Br₂ Calc. Ox. Br₂

Name Stab. Salt Used % by Weight % by Weight

21 Ethanolammonium Perbromide HOCH₂CH₂NH₃Br 25.4 25.8 22 Propylammonium Perbromide CH₃(CH₂)₂NH₃Br 26.9 28.6 23 Piethanolammonium Perbromide (HOCH₂CH₂)₂NH₂Br 20.5 22.6 24 Ethanolammonium Perbromide NaBr 24.4 24.8 25 Ethanolammonium Perbromide NH₄Br 23.6 24.8

Cornpound #21: Aqueous 2:1 (Salt:Bromine)

Ethanolammonium Perbromide

The ethanolamine hydrobromide salt is prepared via the neutralization of HBr (48%) with ethanolamine as described by Compound #1. Ethanolamine hydrobromide (459.2 g, 2.0 moles) was placed in a 500 ml round-bottom flask, equipped with a mechanical stirrer, thermometer, and addition funnel.

Bromine (159.8 g, 1 mole) was slowly added. A dark red liquid (612 g, 98.9% yield based on mass balance) with very low visible vapor pressure was obtained.

Compound #24: Aqueous Ethanolammonium

Perbromide Stabilized with NaBr

NaBr (26 g, 0.25 moles) was dissolved in water (38 g). The resulting solution was added to 100 g of an

ethanolammonium perbromide solution containing 0.25 moles ethanolammonium hydrobromide and 0.25 moles of bromine. The perbromide produced had a very low vapor pressure.

EXAMPLE 4

Further addition of bromine to the aqueous organic ammonium perbromides is possible. These perbromides have a higher available oxidizable bromine content and are still soluble in water. Data for these perbromides is listed in

Table 6. The calculated n of the HOCH₂CH₂NH₃BrBr_n

molecule is also shown. Compound #29, which had an added bromine concentration of approximately 51%, was the only perbromide that formed pools when a one-ml sample was placed in 200 ml of water. TABLE 6

HIGHER AQUEOUS ETHANOLAMMONIUM PERBROMIDE

Compound Grams Br₂ Added Tit. Ox. Br₂ Calc. Ox. Br₂

to 100 g Cpd #1 % by Weight % by Weight n¹ H₂O Solubility

26 24.6 52.6 52.5 3.2 Completely 27 46.9 57.7 59.7 4.3 Completely 28 69.0 63.9 65.0 5.5 Completely 29 106.0 72.6 71.3 7.3 Formed pools 1n calculated for formula HOCH₂CH₂NH₃BrBr_n

Perbromide Shelf Life Stability Studies

In order to determine the shelf life stability of the perbromide solutions, a series of studies was conducted to determine the percent bromine lost over time. The following tables shown below list the perbromides studied and the percent oxidizable bromine lost over time. The perbromides studied were kept in closed bottles in ambient conditions (Table 7) and at 50°C. (Table 8).

TABLE 7

PERBROMIDE CLOSED-BOTTLE STABILITY AT AMBIENT TEMPERATURE

Compound Initial Ox. Br₂ Final Ox. Br₂ Relative Change Time Elapse # Name of Perbromide % by Weight % by Weight Change in % Br₂ in % Br₂ (months)

1 Ethanolammonium 40.1 38.5 1.6 4.0 24

3 Propylammonium 41.3 41.0 0.3 0.7 17

4 Diethylammonium 37.0 35.0 2.0 5.4 24 11 Dibutyla-mmonium 43.2 41.1 2.1 4.9 16

21 Stabilized Ethanolammonium 25.4. 24.9 0.5 2.0 24

22 Stabilized Propylammonium 25.6 25.0 0.6 2.3 24

23 Stabilized Diethanolammonium 22.1 19.7 2.4 10.9 22

30 Diluted Compound #1 20.0 18.0 1.0 5.0 24

31 Diluted Compound #3 20.0 18.2 1.8 9.0 24

32 Diluted Compound #4 20.0 16.6 3.4 17.0 24

TABLE 8

PERBROMIDE CLOSED-BOTTLE STABILITY AT 50º C

Compound Initial Ox. Br₂ Final Ox. Br₂ Relative Change Time Elaps # Name of Perbromide % by Weight % by Weight Change in % Br₂ in % Br ₂ (months)

1 Ethanolammonium 40.8 39.0 1.8 4.4 40

3 Propylammonium 41.0 39.0 2.0 4.9 40

4 Diethylammonium 37.0 30.0 7.0 18.9 40

21 Stabilized Ethanolammonium 25.8 25.0 0.8 3.1 40

22 Stabilized Propylammonium 25.6 24.9 0.7 2.7 40

23 Stabilized Di ethanolammonium 22.5 16.6 5.9 26.2 40

30 Diluted Compound #1 20.0 17.2 2.8 14.0 40

31 Diluted Compound #2 20.0 17.0 3.0 15.0 40

32 Diluted Compound #3 20.0 10.6 9.4 47.0 40

Vapor Pressure of Perbromides

In accordance with the present invention, useful

perbromide formulations are formed by the combination of the foregoing perhalides of Examples 1 and 2 with water soluble, bromine stable, organic solvents. Table #9 illustrates the effect of various exemplary additives and diluents on the bromine partial vapor pressure. The data in Table #9 was determined as follows. 10 milliliters of the formulation were added to a 50 milliliter disposable polypropylene syringe held upright (plunger down) . Then 40 milliliters of air were drawn into the syringe. The syringe was sealed and immersed in a temperature controlled bath at 25°C for two hours to allow equilibration. After equilibration, a

capillary PTFE syringe needle was affixed to the syringe and the 40 milliliters of air were carefully displaced into 20 grams of 1.0 N NaOH solution. The bromine content of the air was then titrated using the method described in "Standard Methods for Examination of Water and Waste Water," 15th edition: Method 408A. The partial pressure was then

calculated to ± 1 torr using the ideal gas law (PV = nRT).

TABLE 9

VAPOR PRESSURE MEASUREMENTS OF ORGANIC AMMONIUM PERBROMIDE FORMULATIONS

Br₂ Partial

Compound Name of Weight % Weight % Name of Solvent Weight % Vapor Pressure

# Perbromide as Bromine Water or Additive Solvent or Additive (torr at 25ºC)

1 Ethanolammonium 40.8 22.6 16

30.6 34.2 25

25.0 52.5 34

20.0 62.0 41

30.0 16.6 Acetic Acid 26.5 7

25.0 13.9 Acetic Acid 38.7 4

20.0 11.1 Acetic Acid 51.0 3

20.0 11.1 Propionic Acid 51.0 3

20.0 11.1 Acetonitrile 51.0 <1

20.0 30.3 Ethanolammonium 31.8 4

bromide

25.4 28.4 Ethanolammonium 23.5

bromide

3 Propylammonium 39.3 23.4 12

20.0 30.8 Propylammonium 30.2 1

bromide

20.0 11.9 Acetic Acid 49.1 3

20,0 11.9 Methanol 49.1 <1

20.0 11.9 N-methyl 49.1 <1

Pyrrolidinone

33 Sodium (NaBr₃) 41.7 31.5 80 35 Pure Bromine 100 223

The water, perhalide and organic solvent mixtures of this invention can be easily and economically prepared. They are surprisingly stable and have a high concentration of

oxidizable bromine. These compositions are useful in many water treatment and other sterilization and disinfection applications where stability and low bromine partial

pressure, high bromine content and good water dispersibility are desirable.

Claims

I claim:

1. A stabilized, perhalide composition comprising:

an ammonium perhalide of the formula:

in which R₁ and R₂ are independently selected from the group consisting of hydrogen, hydroxyethyl, alkyl,

cycloalkyl, (alpha, omega)-alkyl, alkyl ether,

polyoxyalkylene, and halogenated alkyl, wherein said alkyl has 1-8 carbon atoms; X is chlorine, bromine or iodine; and n = 2-6; and at most one of R₁ and R₂ is hydrogen; and

a liquifying agent comprising a water soluble, bromine stable, organic solvent selected from the group consisting of: nitromethane, acetonitrile, acetic acid, propionic acid, tertiary butanol, methanol, N,N-dimethyl acetamide and

N-methyl pyrrolidinone.

2. The composition of claim 1 in which said liquifying agent further includes water.

3. The perhalide composition of claim 1 in which the organic solvent is acetic acid.

4. The perhalide composition of claim 1 in which the organic solvent is methanol.

5. The perhalide composition of claim 1 in which R₁ is selected from hydroxyethyl and C₁-C₈ alkyl and in

which R₂ is selected from hydrogen, hydroxyethyl and C₁-C₈ alkyl.

6. The perhalide composition of claim 1 in which said ammonium perhalide is selected from the group consisting of ethanolammonium perbromide, propylammonium perbromide, diethanolammonium perbromide, butylammonium perbromide, methylethanolammonium perbromide, ethylethanolammonium perbromide, hexylammonium perbromide octylammonium

perbromide, dipropylammonium perbromide, dibutylammonium perbromide, diethylammonium perbromide, and

1, 6-hexanediammonium perbromide, and the corresponding chloro and iodo perbromides.

7. The perhalide composition of claim 1 and which further includes a stabilizing salt selected from the group consisting of ammonium hydrohalide salt, alkali metal

bromides and ammonium bromides, said ammonium hydrohalide salt having the formula R₁R₂NH₂X in which R₁, R₂

and X are as previously defined.

8. The perhalide composition of claim 7 in which said stabilizing salt is selected from the group consisting of ammonium bromide and sodium bromide.