MXPA96005438A - Emulsifying agent for use in explosi compositions - Google Patents

Abstract

An emulsifying, explosive emulsifying agent comprising a first lipophilic group, a second lipophilic group and a hydrophilic group, all of which are linked to a linking group, in which the second lipophilic group has more than one olefinic unsaturation in its hydrocarbon chain. Preferred compounds of the present invention have the structure shown in Formula IA: where L1 is a lipophilic first chain, L2 is a second lipophilic unsaturated chain having an olefinic unsaturated level greater than 1, R is hydrogen or a group hydrophilic, and n esú1, and m0. The emulsification agent allows emulsion explosives to have improved stability when produced.

Description

EMULSIPING AGENT FOR USE IN EXPLOSIVE COMPOSITIONS DESCRIPTION This invention relates to a suitable emulsifying agent for use in water explosives in fuel and fuel melt. Explosives in water-in-fuel emulsion and fuel-melt are well known in the explosives industry and are routinely used in civil, mine and quarry excavations. Water-in-fuel emulsions comprise a discontinuous phase of drops of a component that supplies oxygen, such as an aqueous oxidizing salt solution, dispersed in a continuous phase of oil / waxes in the presence of one or more emulsifying agents. The discontinuous phase that supplies oxygen from a melt emulsion in fuel comprises only a small proportion of water or advantageously only water. The discontinuous phase can be a eutectic composition, ie the melting point of the composition is either in the eutectic region or in the eutectic region of the component salts of the discontinuous phase. When used herein, the term "emulsion" refers to both of the emulsions water in fuel and melt in fuel.

In general, emulsions suitable for use in emulsion explosives are relatively inert until they are mixed with sensitizing agents such as self-detonating compounds (for example nitroglycerin) or a material to form voids such as glass microballoons, glass bubbles or similar. Water-in-fuel emulsion explosive compositions were first described by Bluhm in U.S. Patent 3,447,978 and comprise (a) a discontinuous aqueous phase comprising discrete drops of an aqueous solution of inorganic oxygen release salts; (b) an organic phase immiscible with water, continuous throughout which the droplets are dispersed; and (c) an emulsifier, which forms an emulsion of the droplets of the oxidizing salt solution throughout the continuous organic phase. They may also include sensitizing agents such as the discontinuous aqueous phase. Subsequently, numerous documents have been published, which provide modifications and / or improvements on the formulations originally described by Bluhm. A key component in the formulation of an explosive emulsion composition is the selection of the suitable emulsifying agent. The type of emulsification agent chosen will have an effect on many properties of the emulsion, including, for example, the ease of formation of the emulsion, the discontinuous phase drop size and the tendency of the drops to crystallize or bind. These properties are particularly important for the stability during storage of the emulsion and finally, the effectiveness of the composition as an explosive. The Australian Patent Application no. 40006/85 (Cooper &Baker) discloses explosive emulsion compositions, in which the emulsifier is a product of the reaction of a poly [alk (en) yl] species (for example, an alkylated succinic anhydride) and amines such as ethylene diamine , diethylenetriamine and mono- and di-ethanilamines. McKenzie in U.S. Patent No. 4,931,110 discloses the use of bis (alkanolamine or polyol) amide and / or ester derivatives, for example poly (al) (en) ylsuccinic anhydride compound as a suitable emulsifying agent. The polyalq (en) ilsuccinic anhydride compounds are described by Baker in Canadian Patent No. 1,244,463. Forsberg et al, in the United States Patent No. 4,840,687 describes an explosive emulsion composition, in which the emulsifier is an emulsifier containing nitrogen derived from at least one carboxylic acylating agent, a polyamine and an acid compound.

Additionally, Chattopadhyay, in Canadian Patent Application No. 2No. 076,987 describes the use of a mixed emulsification agent system for emulsion explosives, comprising a surfactant and a co-surfactant, each having branched chain hydrocarbon tails. However, identification of additional emulsifying agents is still desirable to bring the emulsification agent or properties of the improved emulsion. The emulsifying agents perform various functions during the formation and subsequent stabilization of an explosive emulsion composition. As an emulsion is being formed, the emulsifying agent must be able to decrease the interfascial tension between the discontinuous and continuous phases and thereby stabilize the interfaces between the oxidant salt of the drops and the fuel. The emulsifying agent must also form a structured bilayer at the interface to aid in the elimination of the binding or coalescence of the drop and to inhibit the crystallization of salts in the drops. It is also important that the emulsifying agent be able to preserve the integrity of the bilayer dynamically, when an emulsion explosive is subjected to shear stress, such as the shear stress which occurs during pumping.

The supply of a single emulsification agent, which satisfies all these criteria is not direct. Therefore, an emulsifier system which contains a mixture of emulsifying agents is often employed; each of which satisfies different criteria. A mixed, particularly preferred emulsifier system of the prior art was described in Cooper & Baker and Chattopadhyay mentioned in the above and by Yates et al. in U.S. Patent No. 4,710,248, which discloses the use of a derivatized polyisobutensuccinic anhydride surfactant, in combination with a co-surfactant such as sorbitan mono-oleate. Emulsification agents of the prior art are relatively effective in performing some functions, but improvements are still sought. For example, it has proven particularly difficult to identify suitable emulsifying agents for certain types of emulsions, for use in emulsion explosive compositions. In particular, emulsifying agents of the prior art have proven to be unsuitable for the formation of emulsions, which can be formed with stable, stable, oxygen-balanced emulsion compositions. In the field of emulsion explosives, it is said that a composition is balanced in oxygen at the point at which the adequate oxygen of the components is made available for the detonation of the explosive, without leaving unreacted material. The oxygen balanced compositions are particularly advantageous, because they provide maximum energy and minimal smoke. Many explosive compositions in emulsion currently in use, are negative in oxygen, ie there is insufficient oxidant salt present to achieve the total reaction of all materials. In these oxygen-negative formulations, the ratio of the oxidant phase to the fuel oil phase is commonly between 90:10 and 94: 6 and the detonation of these materials tends to produce N0? toxic Ideally, the release of maximum energy and minimum smoke would be provided by a composition balanced in oxygen. Typically, these oxygen balanced compositions have an oxidant: fuel oil ratio of between about 95: 5 and 96: 4. However, oxygen balanced compositions can be difficult to prepare, in practice, due to the lack of suitable emulsifying agents, which can stabilize such compositions with low fuel phase content. Thus, an object of the present invention is to provide an improved emulsifying agent capable of providing the desired properties described in the foregoing. It has now been found that a particular class of emulsifier is particularly suitable for use in emulsion explosive compositions and in particular, for use in explosive emulsion compositions balanced in oxygen. Accordingly, the present invention provides a suitable emulsifying agent for use in an explosive emulsion composition, comprising a hydrophilic species, a first lipophilic chain which is attached to the hydrophilic species, a first linker portion and a second linker lipophilic, which is attached to the hydrophilic species by a second binding portion and in which the second lipophilic chain has more than one unsaturated, olefinic bond in its hydrocarbon chain. As is known to those skilled in the art, the degree of olefinic unsaturation for the second lipophilic chain may be an average value for the individual lipophilic molecules. Accordingly, the level of unsaturation of the second lipophilic chain can approach the value of 1, but preferably, the second lipophilic chain comprises at least two unsaturated, olefinic bonds in its hydrocarbon chain, and preferably these two unsaturated bonds are separated by at least one saturated carbon bond (for example -CH2 ~). In addition, the present invention also provides an emulsion suitable for use in an explosive emulsion composition, having a continuous hydrocarbon phase, a discontinuous aqueous salt or eutectic phase and at least one emulsifying agent, wherein the emulsifying agent is an emulsification agent as described above, with respect to the present invention. In a particularly preferred embodiment, the emulsifying agent is as described above with respect to the present invention and has the structure shown for formula I; Ll R, / Ml - N Formula I wherein: L1 is a first lipophilic chain, L2 is a second, lipophilic, unsaturated chain having an olefinic unsaturated level greater than 1, R is hydrogen or a hydrophilic group, or a direct link to M1 when x is 0, M1 is a ester, amide or imide bond, M2 is an ester bond, and m is = O, and x is O or l. The first lipophilic chain (L1) can be any monomeric or polymeric chain by nature. The chain structure must incorporate a skeletal sequence of at least 10 and preferably not more than 500 attached atoms. These bound atoms may be completely carbon atoms or they may be predominantly carbon atoms interrupted by heteroatoms such as oxygen or nitrogen. A preferred type of the first lipophilic chain is a saturated or unsaturated hydrocarbon chain derived, for example, from a polymer of a monoolefin, in which the polymer chain contains from 40 to 500 carbon atoms. Suitable polyolefins include those derived from olefins containing from 0.2 to 6 carbon atoms, in particular ethylene, propylene, butene-1 and isoprene, but especially isobutene. It has been observed that during the selection of the second lipophilic chain, a higher degree of olefinic unsaturation generally results in an increased stability of the emulsion formed and generally leads to a smaller droplet size in the emulsion. Accordingly, it is preferred that the second lipophilic chain (L2) is preferably a hydrocarbon chain, comprising more than one, and preferably more than two, or preferably 3, olefinic unsaturated bonds. It is also preferred that the second lipophilic chain comprises a long chain hydrocarbon, which comprises between 8-36 carbon atoms, preferably 10-26 carbon atoms and more preferably between 16 and 22 carbon atoms. A preferred material for use as the second lipophilic chain is based on the residue of a polyunsaturated fatty acid. The polyunsaturated fatty acids include fatty acids having an average olefinic unsaturation level greater than 1 (for example 1.1) and may include mixtures of fatty acids. Examples of these fatty acids include linoleic acid (cis, cis-9, 12-octadecadienoic acid), linolenic acid (cis, cis, cis-9, 12, 14-octadecatrienoic acid) or mixtures thereof and between them, and rusic acid . In addition, it is preferred that the second lipophilic chain is an aliphatic chain, which preferably may not be significantly branched. The hydrophilic species (R) of the preferred emulsifying agent of the present invention is hydrogen or a hydrophilic group. However, when x is 0, R can be a second direct link to M1. When R is a hydrophilic group, it is preferred that the group be polar in character and suitably comprise an organic residue having a molecular weight not exceeding 450 and preferably not exceeding 200. In the determination of the molecular weights mentioned in US Pat. the above, any contribution of an ionic portion will not be considered. The organic residue is advantageously onomeric although the oligomeric groups - containing, for example, no more than about 10 periodic units - can be used, provided that their molecular weight is within the limit mentioned in the above. In a preferred embodiment, suitable monomeric groups can be chosen from the group comprising hydroxyl, aminohydroxyl, alkylhydroxypyridine, alkylhydroxypyrimidine and polyhydroxycarboxylic acid. A preferred formula for R is - (CH2) -4? H wherein j is 1, 2 or 3. Preferably, either of the two linking portions (M1 or M2) may consist of hydroxyl, amino, carboxylic acid groups or carboxylic acid anhydride and each acts to bind either the first and second lipophilic chain to the hydrophilic portion. Conveniently, the first linker portion (M1) and the first lipophilic chain (L1) may be present in the same species. For example, the first linker portion and the first lipophilic chain may both be a compound based on the poly [al (en) yl] succinic anhydride (or its acid form) in which the lipophilic carbon chain is terminated by a portion of succinic anhydride bond.

A preferred material for use in this embodiment is a material based on the polyisobutylene succinic anhydride. Similarly, the second binding portion (M2) and the hydrophilic species can be combined into a common species. For example, the second linking portion and the hydrophilic species can form a material, such as a dialkanolamine. It is preferred that the emulsifying agent of the present invention, which consists of ester linkages between the second linking portion (M2) and the second lipophilic chain (L2) It is also preferred that the emulsifying agent comprises ester, amide or imide linkages between the first linking portion (M1) and the first lipophilic chain (L1). Preferably, M ^ - has one of the following formulas: V O - (CH *) »- // OH when x is 0 in Formula 1 preferably, M2, has the formula: - O - C \ A particularly preferred emulsifying agent has the formula IA: i Formula? A where L1, L2 and R are as defined in the above and n is = l, and m = O. In addition, a particularly preferred emulsifying agent has the formula IA shown above, in which L1 and M1 combined are the residue of the polyisobutylene succinic anhydride having a backbone structure of less than 500 carbon atoms in the polyisobutylene moiety, n and m are 1, R is hydrogen or - (CH 2) -OH, where j is 1, 2 or 3 and L 2 is acid linoleic or linolenic acid, or mixtures thereof, or rusic acid. The formation of the emulsifying agent of the present invention can be carried out by conventional methods depending on the chemical nature of the lipophilic chains and hydrophilic species involved.

Commonly this would involve (1) the reaction of the first lipophilic chain with the first binding portion, (2) condensation of the hydrophilic species containing the second binding portion, with the first binding portion and (3) derivatization of the second lipophilic chain with the second binding portion. For example, where the first lipophilic chain and the first linking portion together comprise a compound based on poly (al) (en) yl] succinic anhydride and the hydrophilic species / second linking portion together are a dialkanolamine, the anhydride group can be reacted with the hydroxyl or amino group by heating the two components together in a suitable solvent, in the presence of a catalyst, if desired. Where the succinic anhydride and the amino groups are present in a molar ratio of 1: 1 there is imide / amide formation. The compound thus formed can then be heated with a cis-polyunsaturated fatty acid to promote esterification. This reaction sequence may be presented as follows: wherein L1, L2, R, m and n are as previously defined. The emulsifying agents of the present invention, as described above, are suitable for use in explosive emulsion compositions. These compositions comprise a hydrocarbon phase, water immiscible, continuous, a discontinuous aqueous salt or eutectic phase and at least one emulsifying agent, wherein the emulsifying agent is as described above. Typically, the total emulsifying component of the emulsion, consists of up to 5% by weight of the emulsion. A greater proportion of the emulsifying component can be used or can serve as a supplementary fuel for the composition, but in general it is not necessary to add more than 5% by weight of the emulsifying component to achieve the desired effect. Stable emulsions can be formed using relatively low levels of the emulsifier component and for reasons of economy, it is preferable to maintain the minimum amounts of emulsifier, necessary to achieve the desired effect. The preferred level of the emulsifier component used in the practice of the present invention is preferably in the range of 0.4 to 3.0% by weight of the emulsion, and more preferably in the range of between 1.5 to 2.5% by weight. The remaining components of the explosive emulsion composition are described in detail in the prior art. However, the following describes, in general, formulation parameters, typical for emulsion explosives. The oxidizing salt to be used in the discontinuous phase of the emulsion is preferably selected from the group consisting of nitrates and ammonium perchlorates and alkaline earth metal and mixtures thereof. It is particularly preferred that the oxidizing salt of ammonium nitrate or. a mixture of ammonium nitrate and sodium nitrate or calcium nitrate. The oxidizing salt for use in the discontinuous phase of the emulsion, may contain depressants of melting point suitable for use with ammonium nitrate in the discontinuous phase, include inorganic salts such as lithium nitrate, sodium nitrate, potassium nitrate; alcohols such as methyl alcohol, ethylene glycol, glycerol, mannitol, sorbitol, pentaerythritol; carbohydrates such as sugars, starches and dextrins; aliphatic carboxylic acids and their salts such as formic acid, acetic acid, ammonium formate, sodium formate, sodium acetate and ammonium acetate; glycine; chloroacetic acid; Glycolic Acid; succinic acid; tartaric acid; adipic acid; lower aliphatic amides such as formamide, acetamide and urea; Urea nitrate; nitrogenous substances such as nitroguanidine, guanidine nitrate, methylamine nitrate and ethylendia dinitrate; and its mixtures. Typically, the discontinuous phase of the emulsion consists of 60 to 97% by weight of the emulsion explosive and preferably from 86 to 95% by weight of the emulsion explosive. The water-immiscible, continuous phase of the emulsion consists of an organic fuel. Preferred organic fuels for use in the continuous phase include aliphatic, alicyclic and aromatic compounds and their mixtures, which are in the liquid state at the temperature of the formulation. Suitable organic fuels can be chosen from fuel oil, diesel oil, distillate, furnace oil, kerosene, naphtha, waxes (for example microcrystalline wax, paraffin wax and paraffin wax), paraffin oils, benzene, toluene, xylenes, asphalt materials , polymeric oils such as low molecular weight polymers of olefins, animal oils, fish oils, vegetable oils, corn oil and other mineral, hydrocarbon or fatty oils and their mixtures. Preferred organic fuels are liquid hydrocarbons, generally preferred as petroleum distillates, such as gasoline, kerosene, fuel oils and paraffin oil. Typically, the continuous water immiscible fuel phase of the emulsion (including the emulsifier) consists of more than 3 to less than 30% by weight of the emulsion and preferably 5 to 15% by weight of the emulsion. For acceptable production properties, however, the immiscible, continuous, total fuel phase of the emulsions of the prior art, typically consist of more than 5% by weight of the emulsion, to effectively process the emulsion in a "Jet" mixer. commonly used for production. Due to the requirement of improved emulsification (the ability of the emulsifying agent to form an emulsion) of the emulsifiers of the present invention, however, it is now possible to reduce the emulsification agent level of the emulsion and thus decrease the level of the total fuel phase required for the production processing of the emulsion. Accordingly, with the emulsifiers of the present invention, the amount of fuel oil for the acceptable production properties is reduced, thus creating emulsions having a lower, total oil-fuel phase content. This allows the practical production of emulsion explosives, which are essentially balanced in oxygen (for example having less than 5% of the total content of the fuel oil phase) or which are not significantly oxygen deficient. Accordingly, in a preferred embodiment, the emulsion comprises a combined total level of the hydrocarbon phase immiscible in water, continuous and the emulsifying agent less than or equal to 5% by weight of the emulsion. If desired, additional, optional combustible materials, mentioned in the following as secondary fuels, may be mixed in the emulsion. Examples of such secondary fuels include finely divided materials such as: sulfur, aluminum, carbonaceous materials such as gilsonite, crushed coke or charcoal, carbon black, resin acids such as abietic acid, sugars such as glucose or dextrose and other plant products such as starch, nut shell flour, grain flour and wood pulp; and its mixtures. Typically, the optional secondary fuel component of the emulsion is used in an amount of up to 30% by weight based on the weight of the emulsion. The emulsion may be sensitized to provide an explosive emulsion by combination with a self-blowing compound or composition or by the addition of finely dispersed void-forming agents. The agents for the formation of voids can also be used to vary the density and / or sensitivity of an explosive composition. For example, the explosive composition may consist of a discontinuous gaseous component as a space-forming agent. The methods of incorporating a gaseous component and the increased sensitivity of the explosive compositions comprise gaseous components that are well known to those skilled in the art. The gaseous components can, for example, be incorporated into the explosive composition as fine gas bubbles dispersed throughout the composition, as hollow particles which are often referred to as microballoons or microspheres, as porous particles for example of pearlite or their mixtures.

A discontinuous phase of fine gas bubbles can be incorporated into the explosive composition by mechanical agitation, injection or bubbling of the gas through the composition by chemical generation of the gas in situ. Chemical agents suitable for in situ generation of gas bubbles include peroxides, such as hydrogen peroxide nitrites such as sodium nitrite, nitrosoamines, such as N, N'-dinitrosopentamethylene-tetraamine, alkali metal borohydride, such as borohydride of sodium and carbonates, such as sodium carbonate. The preferred chemicals for in situ generation of gas bubbles are nitrous acid and its salts, which decompose under acid pH conditions to produce nitrogen gas bubbles. Preferred nitrous acid salts include alkali metal nitrite such as sodium nitrite. These may be incorporated as an aqueous solution, an aqueous solution pre-emulsified in an oil phase or as a water-in-oil microemulsion, comprising oil and a nitrite solution. Catalytic agents such as thiocyanate or thiourea can be used to accelerate the decomposition of a nitrite gasification agent. Suitable small hollow particles include hollow, small microspheres of glass materials or resinous materials, such as phenol-formaldehyde, urea-formaldehyde and copolymers of vinylidene chloride and acrylonitrile. Suitable porous materials include expanded minerals such as perlite and expanded polymers such as polystyrene. Gas bubbles may also be added to the emulsion as a preformed air foam, carbon dioxide, nitrogen or nitrous oxide in the liquid, preferably an oil phase. As described above, preferred emulsion explosive compositions formed using the emulsion of the present invention, preferably are oxygen balanced or are not significantly oxygen deficient. The additional components can be added to the explosive composition to control the oxygen balance of the explosive composition, such as particulate ammonium nitrate, solid, such as dust or porous granules. The emulsion can also be mixed with ANFO. Emulsions and emulsion explosives of the present invention are preferably formed by preparing a first premix of water and inorganic oxidizing salt and a second fuel / oil premix and a mixture of the surfactant and the co-surfactant (if desired) in accordance with the present invention. The aqueous premix is heated to ensure dissolution of the salts and the fuel premix is heated as may be necessary to provide liquidity. Premixes are mixed together and emulsified. Common emulsification methods use a mechanical blade mixer, a rotary cylinder mixer or a duct via a static in-line mixer. Then, property modifying materials such as, for example, glass microspheres, may be added together with any auxiliary fuel, for example aluminum particles or any particulate ammonium nitrate, desired. Accordingly, in another aspect the present invention provides, a method of manufacturing an emulsion explosive comprises emulsifying an oxidative salt phase in an emulsifying / fuel mixture using the emulsifying agent of the present invention and then adding a sensitizing agent. In another aspect, the present invention also provides an explosion method, comprising placing an explosive emulsion as described above, in operational contact with an initiation system that includes a detonator and initiating the detonator and therefore the explosive emulsion. . Examples The emulsifier of the invention of the present application will now be further explained with reference to the following examples: Example 1 Triethanolamine (32 parts by volume) is added to the polyisobutylene-succinic anhydride (300 parts by volume); ex-Mobil) at 100 ° C and the components are stirred together for one hour. The linoleic acid (55 parts) is slowly added to the hot reaction mixture and the stirring is continued at 100 ° C for an additional 1 hour, until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction to form a 50% active emulsifying agent. Example 2 Diethanolamine (32 parts by volume) is added to the polyisobutylene-succinic anhydride (300 parts by volume, ex-Mobil) at 100 ° C and the components are stirred together for one hour. The linoleic acid (55 parts) is slowly added to the hot reaction mixture and the stirring is continued at 100 ° C for another hour until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction mixture to form a 50% active emulsifying agent. Example 3 Aminopropylene glycol (20 parts by volume) is added to the polyisobutylene succinic anhydride (300 parts by volume, ex-Mobil) at 100 ° C and the components are stirred together for one hour. The linoleic acid (55 parts) is slowly added to the hot reaction mixture and the stirring is continued at 100 ° C for another hour until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction mixture to form a 50% active emulsifying agent. Example 4 Triethanolamine (32 parts by volume) is added to the polyisobutylene succinic anhydride (300 parts by volume, ex-Mobil) at 100 ° C and the components are stirred together for one hour. The linoleic acid (55 parts) is slowly added to the hot reaction mixture and the stirring is continued at 100 ° C for another hour until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction mixture to form a 50% active emulsifying agent. Conpartative Example 5 (EC 5) Triethanolamine (32 parts by volume) is added to the polyisobutylene succinic anhydride (300 parts by volume, ex-Mobil) at 100 ° C and the components are stirred together for one hour. The oleic acid (55 parts) is added slowly to the hot reaction mixture and the stirring is continued at 100 ° C for another hour until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction mixture to form a 50% active emulsifying agent.

Comparative Example 6 Triethanolamine (32 parts by volume) is added to the polyisobutylene succinic anhydride (300 parts by volume, ex-Mobil) at 100 ° C and the components are stirred together for one hour. The stearic acid (55 parts) is slowly added to the hot reaction mixture and the stirring is continued at 100 ° C for another hour until the end of the reaction. The paraffin oil (120 parts by volume) is then added to the reaction mixture to form a 50% active emulsifying agent. Example 7 The water-in-oil emulsion is formed by slowly adding the emulsifying agent of Example 1 and the fuel oil mixture to a solution of aqueous ammonium nitrate. The emulsion formed was of the following composition: Component Proportion (weight /%) Example 7A Example 7B Ammonium nitrate 79.05 79.05 Water 16.20 16.20 Emulsification agent; as for Example 1 2.30 as for Example 4 2.30 fuel oil 2.45 2.45 Comparative Example 8 A water-in-oil emulsion is formed by slowly adding the emulsifying agent of Comparative Example 5 and the fuel oil mixture to a nitrate solution of aqueous ammonium. The emulsion formed was of the following composition: Component Proportion (weight /%) ammonium nitrate 79.05 water 16.20 emulsification agent: as for EC 5 2.30 fuel oil 2.45 Comparative Example 9 A water-in-oil emulsion is formed by slowly adding the emulsifying agent of Comparative Example 6 (EC 6) and the fuel oil mixture to a solution of aqueous ammonium nitrate. The emulsion formed was of the following composition: Component Proportion (weight /%) ammonium nitrate 79.05 water 16.20 emulsifying agent: as for EC 6 2.30 fuel oil 2.45 The water-in-oil emulsions of Examples 7A and 7B, and Comparative Examples 8 and 9 were subjected to microscopic and physical examination and the results were recorded in Table 1 TABLE 1 Notes: (1 - viscosity measured at 20 ° C using a Brookfield spindle number 7 at 50 rpm) (2 - stability measured by the emulsion examined microscopically, stored at room temperature) (3 - stability of the emulsions mixed with % by weight of granules of ammonium nitrate). The emulsions of Examples 7A and 7B comprise emulsifiers having a second lipophilic chain (L2) derived from polyunsaturated fatty acids, having olefinic unsaturation, such as linoleic acid or linolenic acid. The emulsion of Comparative Examples 8 and 9 comprises an emulsifier having a second lipophilic chain (L2) derived from a monounsaturated fatty acid (oleic acid) or a saturated fatty acid (stearic acid). The recorded results, in Table 1, illustrate the superior storage stability of the emulsions of the present invention, even though the three examples all have essentially constant interfacial tension. Comparative Example 10 A water-in-oil emulsion is formed by slowly adding an emulsifying agent and the fuel oil mixture to a solution of aqueous ammonium nitrate. The emulsification agent of the prior art consists of a product of the condensation of the reaction of the succinic anhydride with an alpha-olefin mixed with sorbitan mono-oleate. The emulsion formed was of the following composition: Component Proportion (weight /%) ammonium nitrate 76.20 water 19.05 emulsification agent: 2.30 fuel oil 2.45 Comparative Example 11 A water-in-oil emulsion is formed by slowly adding an emulsifying agent of the Prior art, comprising a condensation product of the reaction of the succinic anhydride with an alpha-olefin and a mixture of fuel oil, to a solution of aqueous ammonium nitrate. The emulsion formed was of the following composition: Component Proportion (weight /%) ammonium nitrate 73.90 water 18.50 emulsification agent: 2.30 fuel oil 5.30 The emulsion of Example 7A, which comprises the emulsifying agent of the present invention, was compared with the emulsions of Comparative Examples EC 10 and EC 11, which comprises emulsification agents of the prior art. The emulsions are mixed by hand with granules of ammonium nitrate and then subjected to greater shear stress by mixing at about 60 rpm in a Hobart mixer at 60 ° C for 5 minutes. The mixed material was stored at room temperature and subjected periodically to photomicroscopic examination. The results are shown in Table 2. It can be seen that the emulsion of Example 7 showed greater stability than the emulsion either EC 10 or EC 11.

Table 2: Stability with Ammonium Nitrate * - Examined emulsion photomicroscopically mixed with 30% by weight of granules of ammonium nitrate. ** - Crystallization rate (0 = no crystallization, 5 = fully crystallized). Having described the specific embodiments of the present invention, it will be understood that modifications thereto, may be suggested to those skilled in the art and are intended for cover all such modifications as fall within the scope of the appended claims.

Claims (27)

1. CLAIMS 1.- An emulsification agent suitable for use in an emulsion explosive composition, characterized in that it comprises a hydrophilic species, a first lipophilic chain, which is attached to the hydrophilic species by a first binding portion and a second lipophilic chain which is attached to the hydrophilic species by a second binding portion, and wherein the second lipophilic chain has more than one unsaturated olefinic bond in its hydrocarbon chain.
2. The emulsification agent according to claim 1, characterized in that the second lipophilic chain comprises at least two unsaturated, olefinic bonds in its hydrocarbon chain, which unsaturated bonds are separated by at least one saturated carbon atom.
3. 3. The emulsification agent according to claim 1, characterized in that the second binding portion comprises an ester linkage.
4. 4. The emulsifying agent according to claim 1, characterized in that the first binding portion comprises an ester, imide or amide linkage.
5. 5. The emulsifying agent according to claim 1, characterized in that the emulsifying agent is of Formula I: Ml- N Formula i N (CHi) B- M2 2 wherein L1 is a first lipophilic chain, L2 is a second unsaturated lipophilic chain, having an unsaturated, olefinic level greater than 1, R is hydrogen or a hydrophilic group, or a direct link to M1, when x is 0, M1 is an ester, amide or imide bond, M2 is an ester bond, and m is = O, and x is O or l.
6. 6. The emulsifying agent according to claim 5, characterized in that: M ^ is when x is 0 you. Ma is - O - c /? and, n is > 1, and m > 0
7. 7. The emulsification agent according to claim 5, characterized in that R is - (CH 2) -: OH wherein j is 1, 2 or 3, when x is 1.
8. The emulsification agent according to claim 5 , characterized in that the agent of where L1, L2 and R are as defined in claim 5 and n is yes, and m is = 0.
9. 9. The emulsifying agent according to any of claims 1 to 8, characterized in that the hydrophilic species is polar in character and comprises an organic residue having a molecular wt not exceeding 450.
10. 10. The emulsifying agent according to claim 9, characterized in that the hydrophilic species comprises components selected from the group consisting of hydroxyl, aminohydroxyl, alkylhydroxypyridine, or polyhydroxycarboxylic acid.
11. 11. The emulsifying agent according to any of claims 1 to 8, characterized in that the first lipophilic chain is either monomeric or polymeric in nature and has a chain structure that incorporates a skeletal sequence of at least 10 and no more than 500 atoms attached.
12. The emulsification agent according to claim 11, characterized in that the first lipophilic chain is a saturated or unsaturated hydrocarbon chain, derived from a polymer of a mono-olefin and in which the polymer chain contains from 40 to 500 carbon atoms.
13. The emulsifying agent according to any of claims 1 to 8, characterized either in that the first or second linking portions, may consist of functional groups selected from the group consisting of hydroxyl, amino or carboxylic acid groups.
14. The emulsification agent according to claim 13, characterized in that the first binding portion and the first lipophilic chain are present in the same species.
15. 15. The emulsifying agent according to claim 14, characterized in that the first binding portion and the first lipophilic portion are present in a compound based on poly [alk (en) yl] succinic anhydride or its acid form.
16. 16. The emulsifying agent according to claim 15, characterized in that the first binding portion and the first lipophilic portion are present in the residual form of the polyisobutylene succinic anhydride.
17. 17. The emulsifying agent according to any of claims 1 to 8, characterized in that the second lipophilic chain is derived from a polyunsaturated fatty acid.
18. 18. The emulsifying agent according to claim 17, characterized in that the second lipophilic chain is linoleic acid or linolenic acid, or mixtures thereof, or rusic acid.
19. 19. The emulsifying agent according to claim 8, characterized in that combined L1 and M1 are polyisobutylene succinic anhydride residue, having a backbone structure of less than 500 carbon atoms in the polyisobutylene portion, n and m are 1, R is hydrogen or - (CH2) -0H wherein j is 1, 2 or 3 and L2 is linoleic acid or linolenic acid, or mixtures thereof, or rusic acid.
20. A process for producing an emulsion suitable for use in an emulsion explosive composition comprising emulsifying a component that supplies oxygen and a fuel to form an emulsion, in which the oxygen-supplying component forms at least part of the phase discontinuous and the fuel forms at least part of the continuous phase, wherein the emulsification is carried out in the presence of the emulsifying agent according to any of claims 1 to 19.
21. 21. An emulsion suitable for use in an explosive composition in emulsion, having a continuous water-immiscible hydrocarbon phase, a discontinuous aqueous salt or eutectic phase and at least one emulsifying agent, wherein the emulsifying agent is an emulsifying agent according to any one of claims 1 to 19.
22. 22. The emulsion according to claim 21, characterized in that the em Total emulsifier of the emulsion, consisting of up to 5% by weight of the emulsion explosive composition, the discontinuous phase of the emulsion comprises 60 to 97% by weight of the emulsion and the water immiscible hydrocarbon phase, continuous of the emulsion it consists of 3 to 30% by weight of the emulsion.
23. 23. The emulsion according to claim 21, characterized in that the combined total level of the hydrocarbon phase immiscible in water, continuous and the emulsifying agent is = to 5% by weight of the emulsion.
24. 24. The explosive emulsion composition formed by the emulsion combination according to any of claims 21 to 23, with a self-blowing compound or with agents for the formation of voids.
25. 25. The explosive emulsion composition according to claim 24, characterized in that the emulsion explosive composition comprises a discontinuous gaseous component as an agent for the formation of empty spaces.
26. 26. The explosive emulsion composition according to claim 24, characterized in that the composition is essentially oxygen balanced or not significantly oxygen deficient.
27. 27. An explosion method comprising placing the emulsion explosive composition according to any of claims 24 to 26 in operative contact with an initiation system, including a detonator and initiating the detonator and the emulsion explosive.