CA1140765A - Explosive compositions based on time-stable colloidal dispersions - Google Patents
Explosive compositions based on time-stable colloidal dispersionsInfo
- Publication number
- CA1140765A CA1140765A CA000342098A CA342098A CA1140765A CA 1140765 A CA1140765 A CA 1140765A CA 000342098 A CA000342098 A CA 000342098A CA 342098 A CA342098 A CA 342098A CA 1140765 A CA1140765 A CA 1140765A
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- Canada
- Prior art keywords
- water
- explosive composition
- oil
- microemulsion
- composition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B47/00—Compositions in which the components are separately stored until the moment of burning or explosion, e.g. "Sprengel"-type explosives; Suspensions of solid component in a normally non-explosive liquid phase, including a thickened aqueous phase
- C06B47/14—Compositions in which the components are separately stored until the moment of burning or explosion, e.g. "Sprengel"-type explosives; Suspensions of solid component in a normally non-explosive liquid phase, including a thickened aqueous phase comprising a solid component and an aqueous phase
- C06B47/145—Water in oil emulsion type explosives in which a carbonaceous fuel forms the continuous phase
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Colloid Chemistry (AREA)
- Liquid Carbonaceous Fuels (AREA)
Abstract
Abstract CIL 601 Explosive Compositions Based on Time-Stable Colloidal Dispersions A water-in-oil explosive composition based on colloidal dispersions is provided, Unlike conventional emul-sion explosive compositions, the microemulsion composition of the invention displays exceptional long term storage stability retaining sensitivity to propagation even in small diameter charges. The composition is also tolerant to doping with further fuel and energy enhancing ingredients, The micro-emulsion-producing component of the composition comprises a combination of at least one conventional water-in-oil emulsi-fier and at least one amphiphatic synthetic polymeric emulsifier selected from graft, block or branch polymers.
Description
7~
~x~osive C_mpositions Based on Time-Stable Cnlloid~1 Dispersions : This invention relates to waterproof explosive compositi-S ons based on ultra-stable colloidal dispersions, More particularly, this invention relates to explosive compo-sitions comprising, in part or in whole, a water-in-oil micro-emulsion which results from the use oE blends of specific emulsifiers and co-surfactants.
Conventional low cost commercial explosives rely on am-monium nitrate as the primary source of energy for blasting.
Ammonium nitrate/fuel oil compositions-(ANFO) and thickened water-based a~onium nitrate-containing explosives (slurries) are widely used blasting compositions, However, these compo-15 sitions may not produce optimum results under conditions fre-quently encountered in the field nor are these compositions always acceptable l'rom other standpoints, The use of ANFO, for example, is generally restricted to ~airly dry boreholes, Also, ANFO does not perform well in blasting hard rock because 20 of its low brisance and low bulk energy, The development of the pumpable water-based slurries has overcome some of the problems, but the need to incorporate special thickening and cross-linking agents in the slurries increase their cost, Also, for these slurry compositions to perform well, especi-ally in small diameter charges, their density and hence their 25 bulk energy must be appreciably lowered if the incorporation ~1~0~7~iS
" :
- la -of large amounts of self-explosive sensitizing agents is to be avoided.
The discovery of water-in-oil emulsion explosives in which the oil/fuel phase is external or continuous and the oxidizer salt phase comprising dispersed small supersaturated droplets is discontinuous, has resulted in a pumpable, fluid explosive which in many instances displays improved perform-ance over the water-based slurries. This improvement results 10 principally because the surface area of contact between the oxidizer phase and the fuel phase is increased. This en-hanced intimacy produces a more sensitive and ~aster reacting mixture and provides a high brisance explosive, Water-in-oil emulsion explosives are now well known in . . . , . . . .. . . . /
/
~L~4C~7~
the explosives art. Bluhm, in United States patent No.
3,447,978 discloses a composition comprising an aqueous dis-continuous phase containing dissolved oxyyen-supplying salts, a carbonaceuous fuel continuous phase, an occluded gas and a water-in-oil emulsifier. Cattermole et al., in United States patent ~o. 3,674,578 describe a similar composition containing as part of the inorganic oxidizer phase, a nitro-gen-base salt such as an amine nitrate. Tomic, in United 10 States patent ~o. 3,770,522 also descxibes a similar composi-tion wherein the emulsifier is an alkali or ammonium stearate.
Wade, in United States patent ~o. 3,715,247 describes a small-diameter cap-sensitive emulsion type explosive composition comprising carbonaceous fuel, water, inorgànic salts, an 15 emulsifier, gas bubbles, and a detonation catalyst consisting of a water-soluble salt containing selected metals. In United States patent No. 3,765,964, Wade describes an improvement in the composition of United States patent No 3,715,247 by in-cluding therein a water-soluble strontium compound to provide 20 ~urther sensitivity. Wade again, in united States patent ~o. 4,110,134 describes an emulsion type explosive composition devoid of any self explosive ingredient and containing a closed-cell ~oid-containing material as a density controller.
Wade further describes, in United Statas patent No. 4,149,916,a 25 cap sensitive emulsion type explosive composition containing perchlorates and occluded air and in United States patent No.
4,119,917 he describes a similar composition without any sen-sitizer other than occluded air. Sudwe~ks and Jessop i~
United States patent ~o. 4,141,767 describe a cap-insensitive 30 water-in-oil emulsion e~plosive composition containing a fatty acid amine or ammonium salt emulsifier having a chain length ranging from 14 to 22 carbon atoms. In applicant's copending Canadian application Serial No 317,649, filed on December 8, 1978, there is described a sensitive emulsion type explosive 35 composition containing fuel, water, salts, gas bubbles, an emulsifier and an emulsification promoter comprising a highly chlorinated paraffinic hydrocarbon. Clay, in United States patent No. 4,111,727 describes a blasting composition con-sisting of a greasy, water-in-oil emulsion admixed with a sub-stantially undissolved particulate solid oxidizer salt consti-tuent so as to fill the interstices between salt particles to increase the bulk density of the mass. Similar blasting com-positions had also been disclosed by Egly and Neckar in United States patent No. 3,161,551 and by Butterworth in South African lO patent specification No. 71/3355 Mullay, in United States patent ~o. 4,104,092 describes an aqueous gel explosive composi-tion wherein a water-in-oil emulsion is uniformly distributed in the gPl portion While all of the aforementioned emulsion compositions 15 are meritorious, they are not without some disadvantages.
The composition of Bluhm, for example, is only suitable for use in large diameter charges and requires strong primer initi-ation The compositions of Cattexmole et al. while useful in small diameter charges, require the use of expensive raw mate-20 rials, demand extra handling precautions because of the sensi-tive nature of some of the ingredients used and hence lead to increase costs.
The compositions of Wade, and other prior art water-in-oil emulsion-based explosives exhibit limited stability. These 25 compositions quickly tend to become dry and hard upon aging which condition deleteriously affects their handling character-istics and their explosive performance. The emulsifying agents used heretofore have not been sufficiently effective in permanantly suppressing the coalescence of the supersaturated 30 oxidizer salt droplets. Fairly large quantities of per-chlorate salts or other sensitizing agentsmust be incorporated in the mixtures in order to retain cap~sensitivity at densities above 1.10 g/cc for any appreciable period of time. Tha compo-sitions of clay are substantially similar to and behave like 35 ANF0 and can not be expected to offer much improved water resistance. Furthermore, any of the compositions containing (376~
_ ~ _ added excess salts would exhibit very limited stability because of the seeding or precipitation effect of the salt crystals leading to a fairly rapid breakdown of the emulsion, Thus, there remains a need in the explosives art for a low cost, high velocity and relatively high density explosive which is easy to manufacture, pumpable, water resistant and moxe importantly, which is safe to handle, stable over long periods of storage and sufficiently sensitive to propagate . 10 in very small diameter boreholes, The present invention pro-vides an improved water-in-oil emulsion explosive composition which meets all the above-mentioned objectives, The efectiveness of emulsification of the aqueous salts and liquid fuels as a promoter of explosive performance is 15 crucially dependent on the a,ctivity of the emulsifying agent chosen. The emulsifying agent aids the process o droplets subdivision and dispersion in the continuous phase by reducing the surface tension and the energy required to create new sur-faces. The emulsification agent also reduces the ratP of 20 coalescence by coating the surface of the droplets with a molecular layer of th~ emulsifying agent, The emulsifiers employed in the aforementioned prior art explos~ve composi-tions are somewhat effective in performing these functions but they are limited in their utility because the droplet 25 surfaces still contain energy and coalescence of the droplets and breakdown of the emulsion takes place over time.
.
The emulsifier systems of the present invention are of a novel and distinct class of materials which function to produce 30 a water-in-oil microemulsion, In the context of the present inven-tion, the term 'microemulsion' is intended to denote a liquid-liquid foam of very small cell size ranging normally from less than 1 micron to about 15 microns, These microemulsions demonstra-- tea surprising sta~ility and retention of initiation sensitivity, 35 and they possess extreme intimacy of mixing which is achievable under a variety of mixing conditions. The novel emulsifier sys-tems of this invention provide means whereby water-in-oil micro-emulsions may be formed with concentrated oxidizer salt(s) coommon in explosive formulations, The water-in-oil microemulsion explosive compositions of the invention comprise essentially an aqueous solution of at least one oxygen-supplying salt as a discontinuous phase, an insoluble liquid or liquefiable carbonaceous fuel as a con-tinuous phase, at least one sensitizing component distributed substantially homogeneously throughout the composition as a further discontinuous phase and a distinct definable blend of emulsifying agents capable of producing a time-stable micro-10 emulsion. The compositions may optionally contain particulateoxygen-supplying salts, ANFO, particulate light metals, par-ticulate fuels, particulate solid explosives, soluble and partly soluble self-explosives, explosive oils and the like or purposes of augmenting the strength and sensitivity or 15 decreasing the cost of the compositions. The specific blends of emulsifie~ capable of producing a time-stable, water-in-oil microemulsion explosive composition comprise a mixture of at least one amphiphatic synthetic polymeric emulsifier selected from graft, block or branch polymers and at least 20 one conventional water-in-oil emulsifier Optionally a phos-phatide emulsion stabili~er may be included in the blend.
By "amphiphatic graft, block or branch polymers" is meant a polymer comprising at least two or more segments, one of which is only soluble in an oil phase and the other only 25 soluble in an aqueous phase, each segment having a molecular weight of at least 500. By "conventional water-in-oil emulsifier" is meant herein the relatively low molecular weight emulsifiers which are capable of producing a water-in-oil emulsion. Most of these emulsifiers are listed in the 30 well known publication "McCutcheon's Detergents & E~ulsifiers".
Exemplary of the synthetic polymeric emulsifiers used in the combinations are:
A. Copolymers of the general formula (A-COO)m~B wherein m is 2, wherein each polymeric component A has a molecular weight 35 of at leasb 50Q and is the residue of an oil soluble complex monocarboxylic acid having the general structural formula:
~4~76~
Rl R
R-C0 -o-C-(R2)n~C -O-C-(R~)n-COOH (I) S _ _ P
in which R is hydrogen or a monovalant hydrocarbon or substituted hydrocarbon group;
Rl is hydrogen or a monovalent Cl to C2 4 hydrocarbon group;
R2 is a divalent Cl to C2 4 hydrocarbon group;
n is zero or l;
p is an integer from zero up to 200:
15 and wherein each polymeric component B has a molecular weight of at least 500 and is the divalent residue of a water-soluble polyalkylene glycol having the general formula:
r R3 1 R3 H _ -0-C-CH2¦ 0-C-CH20H (II) _ q in which R3 is hydrogen or Cl to C3 alkyl group;
q is an integer from 10 up to 500.
The units of the formula 1~1 - 0 - IC - (R2)n - C0 -H
which are present in the molecule of the complex monocarboxylic acid as represented by Fonmula I may all be the same or they may be different in respect of Rl, Rz and n.
35 Similarly, the units of the formula 3765i l3 - o - C - CH2 -H
which are present in the polyalkylene glycol as represented by Formula II may all be the same or they may be different in respect of R3.
The complex monocarboxylic acid, from which the poly-meric components A are derived by the notional removal of 10 the carboxyl group, is structurally the product o inter-esterification of one or more monohydroxy-monocarboxylic acids together with a monocarboxylic acid free from hydroxyl groups which acts as a chain terminator. The hydrocarbon chains R, Rl and R2 may be linear or branched. R is prefer-15 ably an alkyl gro~pcontaining up to 25 carbon atoms, forexample a straight-chain C17H35-group derived from stearic acid. Rl is preferably a straight-chain alkyl group, and R~ is prefexably a straight-chain alkylene group; for example, the unit containing Rl and R2 may be derived from 20 12-hydroxystearic acid.
The polyalkylene glycol of the Formula II, from which the polymeric component B is derived by the notional removal of the two terminal hydroxyl groups, may be, for example, a polyethylene glycol, a polypropylene glycol, a mixed poly 25 (ethylene-propylene) glycol ox a mixed poly(ethylene-buty-lene? glycol, but preferably a polyethylene glycol.
Preferably each of the polymeric components A has a molecular weight o~ at least 1000 (by "mQlecular weight" is meant number average molecular weight). Thus where, for 30 example, the group R is derived from stearic acid and the unit cvntaining Rl and R2 together is derived from 12-hydroxy-stearic, p will have a value of at least 2. Similarly, it is preerred that the polymeric component B has a molecular weight of at least 1000. Thus where that component is the 35 residue of a polyal~ylene glycol which is derived from ethyl-ene oxide exclusively, q will preferably have a value of at ~4~
least 23, For optimum results for purposes of the present inven-tion the proportion of polymeric component B in the copolymer is between about 20% to 50%, preferably 25% to 35% by weight of the total copolymer.
B, Polyesters obtained by the condensation of i) an alk(en)yl succinic anhydride of the formula CHz- CO ~
where R is a saturated or unsaturated hydrocarbon substituent derived from a polymer of a mono-olefin, the said polymer comprising a chain containing from 40 - 500 carbon atoms, 15 and ii) a polyalkylene glycol which has a molecular weight of 500 to 20,000. The polyester so obtained contains 10% to 80%, preferably 20% to 60%, by weight of residues of the polyaLkylene glycol (ii).
2Q The alk(en)yl succinic anhydrides which are used in making the polyester are known commercial materials, For making the anhydrides (i), suitable polyolefins include those obtained by polymerising a mono-olefin containing from
~x~osive C_mpositions Based on Time-Stable Cnlloid~1 Dispersions : This invention relates to waterproof explosive compositi-S ons based on ultra-stable colloidal dispersions, More particularly, this invention relates to explosive compo-sitions comprising, in part or in whole, a water-in-oil micro-emulsion which results from the use oE blends of specific emulsifiers and co-surfactants.
Conventional low cost commercial explosives rely on am-monium nitrate as the primary source of energy for blasting.
Ammonium nitrate/fuel oil compositions-(ANFO) and thickened water-based a~onium nitrate-containing explosives (slurries) are widely used blasting compositions, However, these compo-15 sitions may not produce optimum results under conditions fre-quently encountered in the field nor are these compositions always acceptable l'rom other standpoints, The use of ANFO, for example, is generally restricted to ~airly dry boreholes, Also, ANFO does not perform well in blasting hard rock because 20 of its low brisance and low bulk energy, The development of the pumpable water-based slurries has overcome some of the problems, but the need to incorporate special thickening and cross-linking agents in the slurries increase their cost, Also, for these slurry compositions to perform well, especi-ally in small diameter charges, their density and hence their 25 bulk energy must be appreciably lowered if the incorporation ~1~0~7~iS
" :
- la -of large amounts of self-explosive sensitizing agents is to be avoided.
The discovery of water-in-oil emulsion explosives in which the oil/fuel phase is external or continuous and the oxidizer salt phase comprising dispersed small supersaturated droplets is discontinuous, has resulted in a pumpable, fluid explosive which in many instances displays improved perform-ance over the water-based slurries. This improvement results 10 principally because the surface area of contact between the oxidizer phase and the fuel phase is increased. This en-hanced intimacy produces a more sensitive and ~aster reacting mixture and provides a high brisance explosive, Water-in-oil emulsion explosives are now well known in . . . , . . . .. . . . /
/
~L~4C~7~
the explosives art. Bluhm, in United States patent No.
3,447,978 discloses a composition comprising an aqueous dis-continuous phase containing dissolved oxyyen-supplying salts, a carbonaceuous fuel continuous phase, an occluded gas and a water-in-oil emulsifier. Cattermole et al., in United States patent ~o. 3,674,578 describe a similar composition containing as part of the inorganic oxidizer phase, a nitro-gen-base salt such as an amine nitrate. Tomic, in United 10 States patent ~o. 3,770,522 also descxibes a similar composi-tion wherein the emulsifier is an alkali or ammonium stearate.
Wade, in United States patent ~o. 3,715,247 describes a small-diameter cap-sensitive emulsion type explosive composition comprising carbonaceous fuel, water, inorgànic salts, an 15 emulsifier, gas bubbles, and a detonation catalyst consisting of a water-soluble salt containing selected metals. In United States patent No. 3,765,964, Wade describes an improvement in the composition of United States patent No 3,715,247 by in-cluding therein a water-soluble strontium compound to provide 20 ~urther sensitivity. Wade again, in united States patent ~o. 4,110,134 describes an emulsion type explosive composition devoid of any self explosive ingredient and containing a closed-cell ~oid-containing material as a density controller.
Wade further describes, in United Statas patent No. 4,149,916,a 25 cap sensitive emulsion type explosive composition containing perchlorates and occluded air and in United States patent No.
4,119,917 he describes a similar composition without any sen-sitizer other than occluded air. Sudwe~ks and Jessop i~
United States patent ~o. 4,141,767 describe a cap-insensitive 30 water-in-oil emulsion e~plosive composition containing a fatty acid amine or ammonium salt emulsifier having a chain length ranging from 14 to 22 carbon atoms. In applicant's copending Canadian application Serial No 317,649, filed on December 8, 1978, there is described a sensitive emulsion type explosive 35 composition containing fuel, water, salts, gas bubbles, an emulsifier and an emulsification promoter comprising a highly chlorinated paraffinic hydrocarbon. Clay, in United States patent No. 4,111,727 describes a blasting composition con-sisting of a greasy, water-in-oil emulsion admixed with a sub-stantially undissolved particulate solid oxidizer salt consti-tuent so as to fill the interstices between salt particles to increase the bulk density of the mass. Similar blasting com-positions had also been disclosed by Egly and Neckar in United States patent No. 3,161,551 and by Butterworth in South African lO patent specification No. 71/3355 Mullay, in United States patent ~o. 4,104,092 describes an aqueous gel explosive composi-tion wherein a water-in-oil emulsion is uniformly distributed in the gPl portion While all of the aforementioned emulsion compositions 15 are meritorious, they are not without some disadvantages.
The composition of Bluhm, for example, is only suitable for use in large diameter charges and requires strong primer initi-ation The compositions of Cattexmole et al. while useful in small diameter charges, require the use of expensive raw mate-20 rials, demand extra handling precautions because of the sensi-tive nature of some of the ingredients used and hence lead to increase costs.
The compositions of Wade, and other prior art water-in-oil emulsion-based explosives exhibit limited stability. These 25 compositions quickly tend to become dry and hard upon aging which condition deleteriously affects their handling character-istics and their explosive performance. The emulsifying agents used heretofore have not been sufficiently effective in permanantly suppressing the coalescence of the supersaturated 30 oxidizer salt droplets. Fairly large quantities of per-chlorate salts or other sensitizing agentsmust be incorporated in the mixtures in order to retain cap~sensitivity at densities above 1.10 g/cc for any appreciable period of time. Tha compo-sitions of clay are substantially similar to and behave like 35 ANF0 and can not be expected to offer much improved water resistance. Furthermore, any of the compositions containing (376~
_ ~ _ added excess salts would exhibit very limited stability because of the seeding or precipitation effect of the salt crystals leading to a fairly rapid breakdown of the emulsion, Thus, there remains a need in the explosives art for a low cost, high velocity and relatively high density explosive which is easy to manufacture, pumpable, water resistant and moxe importantly, which is safe to handle, stable over long periods of storage and sufficiently sensitive to propagate . 10 in very small diameter boreholes, The present invention pro-vides an improved water-in-oil emulsion explosive composition which meets all the above-mentioned objectives, The efectiveness of emulsification of the aqueous salts and liquid fuels as a promoter of explosive performance is 15 crucially dependent on the a,ctivity of the emulsifying agent chosen. The emulsifying agent aids the process o droplets subdivision and dispersion in the continuous phase by reducing the surface tension and the energy required to create new sur-faces. The emulsification agent also reduces the ratP of 20 coalescence by coating the surface of the droplets with a molecular layer of th~ emulsifying agent, The emulsifiers employed in the aforementioned prior art explos~ve composi-tions are somewhat effective in performing these functions but they are limited in their utility because the droplet 25 surfaces still contain energy and coalescence of the droplets and breakdown of the emulsion takes place over time.
.
The emulsifier systems of the present invention are of a novel and distinct class of materials which function to produce 30 a water-in-oil microemulsion, In the context of the present inven-tion, the term 'microemulsion' is intended to denote a liquid-liquid foam of very small cell size ranging normally from less than 1 micron to about 15 microns, These microemulsions demonstra-- tea surprising sta~ility and retention of initiation sensitivity, 35 and they possess extreme intimacy of mixing which is achievable under a variety of mixing conditions. The novel emulsifier sys-tems of this invention provide means whereby water-in-oil micro-emulsions may be formed with concentrated oxidizer salt(s) coommon in explosive formulations, The water-in-oil microemulsion explosive compositions of the invention comprise essentially an aqueous solution of at least one oxygen-supplying salt as a discontinuous phase, an insoluble liquid or liquefiable carbonaceous fuel as a con-tinuous phase, at least one sensitizing component distributed substantially homogeneously throughout the composition as a further discontinuous phase and a distinct definable blend of emulsifying agents capable of producing a time-stable micro-10 emulsion. The compositions may optionally contain particulateoxygen-supplying salts, ANFO, particulate light metals, par-ticulate fuels, particulate solid explosives, soluble and partly soluble self-explosives, explosive oils and the like or purposes of augmenting the strength and sensitivity or 15 decreasing the cost of the compositions. The specific blends of emulsifie~ capable of producing a time-stable, water-in-oil microemulsion explosive composition comprise a mixture of at least one amphiphatic synthetic polymeric emulsifier selected from graft, block or branch polymers and at least 20 one conventional water-in-oil emulsifier Optionally a phos-phatide emulsion stabili~er may be included in the blend.
By "amphiphatic graft, block or branch polymers" is meant a polymer comprising at least two or more segments, one of which is only soluble in an oil phase and the other only 25 soluble in an aqueous phase, each segment having a molecular weight of at least 500. By "conventional water-in-oil emulsifier" is meant herein the relatively low molecular weight emulsifiers which are capable of producing a water-in-oil emulsion. Most of these emulsifiers are listed in the 30 well known publication "McCutcheon's Detergents & E~ulsifiers".
Exemplary of the synthetic polymeric emulsifiers used in the combinations are:
A. Copolymers of the general formula (A-COO)m~B wherein m is 2, wherein each polymeric component A has a molecular weight 35 of at leasb 50Q and is the residue of an oil soluble complex monocarboxylic acid having the general structural formula:
~4~76~
Rl R
R-C0 -o-C-(R2)n~C -O-C-(R~)n-COOH (I) S _ _ P
in which R is hydrogen or a monovalant hydrocarbon or substituted hydrocarbon group;
Rl is hydrogen or a monovalent Cl to C2 4 hydrocarbon group;
R2 is a divalent Cl to C2 4 hydrocarbon group;
n is zero or l;
p is an integer from zero up to 200:
15 and wherein each polymeric component B has a molecular weight of at least 500 and is the divalent residue of a water-soluble polyalkylene glycol having the general formula:
r R3 1 R3 H _ -0-C-CH2¦ 0-C-CH20H (II) _ q in which R3 is hydrogen or Cl to C3 alkyl group;
q is an integer from 10 up to 500.
The units of the formula 1~1 - 0 - IC - (R2)n - C0 -H
which are present in the molecule of the complex monocarboxylic acid as represented by Fonmula I may all be the same or they may be different in respect of Rl, Rz and n.
35 Similarly, the units of the formula 3765i l3 - o - C - CH2 -H
which are present in the polyalkylene glycol as represented by Formula II may all be the same or they may be different in respect of R3.
The complex monocarboxylic acid, from which the poly-meric components A are derived by the notional removal of 10 the carboxyl group, is structurally the product o inter-esterification of one or more monohydroxy-monocarboxylic acids together with a monocarboxylic acid free from hydroxyl groups which acts as a chain terminator. The hydrocarbon chains R, Rl and R2 may be linear or branched. R is prefer-15 ably an alkyl gro~pcontaining up to 25 carbon atoms, forexample a straight-chain C17H35-group derived from stearic acid. Rl is preferably a straight-chain alkyl group, and R~ is prefexably a straight-chain alkylene group; for example, the unit containing Rl and R2 may be derived from 20 12-hydroxystearic acid.
The polyalkylene glycol of the Formula II, from which the polymeric component B is derived by the notional removal of the two terminal hydroxyl groups, may be, for example, a polyethylene glycol, a polypropylene glycol, a mixed poly 25 (ethylene-propylene) glycol ox a mixed poly(ethylene-buty-lene? glycol, but preferably a polyethylene glycol.
Preferably each of the polymeric components A has a molecular weight o~ at least 1000 (by "mQlecular weight" is meant number average molecular weight). Thus where, for 30 example, the group R is derived from stearic acid and the unit cvntaining Rl and R2 together is derived from 12-hydroxy-stearic, p will have a value of at least 2. Similarly, it is preerred that the polymeric component B has a molecular weight of at least 1000. Thus where that component is the 35 residue of a polyal~ylene glycol which is derived from ethyl-ene oxide exclusively, q will preferably have a value of at ~4~
least 23, For optimum results for purposes of the present inven-tion the proportion of polymeric component B in the copolymer is between about 20% to 50%, preferably 25% to 35% by weight of the total copolymer.
B, Polyesters obtained by the condensation of i) an alk(en)yl succinic anhydride of the formula CHz- CO ~
where R is a saturated or unsaturated hydrocarbon substituent derived from a polymer of a mono-olefin, the said polymer comprising a chain containing from 40 - 500 carbon atoms, 15 and ii) a polyalkylene glycol which has a molecular weight of 500 to 20,000. The polyester so obtained contains 10% to 80%, preferably 20% to 60%, by weight of residues of the polyaLkylene glycol (ii).
2Q The alk(en)yl succinic anhydrides which are used in making the polyester are known commercial materials, For making the anhydrides (i), suitable polyolefins include those obtained by polymerising a mono-olefin containing from
2 to 6 carbon atoms, for example ethylene, propylene, bu-25 tylene, isobutylene and mixtures thereof, the derived polymers containing from 40 to 500 carbon atoms in the chain as stated heretofore.
A preferred alk(en)yl succinic anhydride is (polyiso-butenyl) succir.ic anhydride containing from 50 to 200 carbon 30 atoms in the alkenyl chain, The alk(en)yl succinic anhydrides (i) may, however, if desired be a mixture of two or more different compounds which respectively satisfy the foregoing de~initions, A minor pro-portion of a monobasic carboxylic acid may be included to 35 adjust the functionality and/or degree of branching of the ~40~65 .
- 8a -derived polyesters.
The polyalkylene glycols (ii) which are used in making the polyesters may be, for example, polyethylene glycols, mixed poly(ethylene-propylene) glycols or mixed poly(ethyl-/
/
~4~7 Ei5 g ene-butylene) glycols, provided that they satisfy the mole-lar weight requirement hereinbefore stated. The polyalkyl-ene glycols are also commercially available materials, and a single such compound or a mixture of two or more such com-pounds differing in composition and/or molecular weight may be used in making the polyeste~ i~ desired.
Preferred polyalkylene glycols for use in making the polyesters are polyethylene glycols of average molecular weight 10 500 to 1,500.
In addition to the polyalkylene glycol(s), other polyols such as glycerol, trimethylol propane, pentaerythritol and sorbitol may be incorporated in order to adjust the overall functionality of the components and/or increase the degree 15 of branching of the polymers.
C. Copolymers as described in A but with the polyoxyethyl-ene chain of the polyalkylene glycol moiety replaced by a polyethylene-imine chain (i.e. replacing the oxygen atom in the polyoxyethylene hy a ~-H group).
20 D. Polyesters as described in B but with the polyoxyethylene chain of the polyalkylene glycol moiety replaced by a poly-ethylene imine chain.
The substitution of the polyoxyethylene chain of the poly-alkylene glycol of the block copolymers A and of the polyes-25 ters B by a polyethylene-imine chain does not significantly alter the emulsifying ability of these resins. The propor-tion of polymeric components in the block copolymer and in the polyester of these polyethylene-imine based polymers are as described in the types A and B. Also these polymers can 30 be largely a salt or an amide depending on the conditions present during their synthesis.
Exemplary of the conventional water-in-oil emulsifiers with which the copolymeric and/or polyester emulsifiers of the above-described types A, B, C and D are combined in ord~r 35 to produce the microemulsion explosive compositions of this invention are:
~L~4~7~ii5 E Those derived from sorbitol by esterification such as sorbitan fatty acid esters, for example, sorbitan monooleate, sorbitan sesquioleate, so.rbitan monostearate and the like;
F. Mono and diglycerides of fat-forming fatty acids such as Atmos 300 (Reg. TM), Dur-Em 187 tReg. TM3, Dur-Em 207 (Reg.
TM) and the like;
G. Polyoxyethylene sorbitol esters such as polyoxyethylene sorbitol beeswax darivative materials and the llke;
10 H. Substituted imidazolines such as Witcamine PA-78B (Reg.
TM) and the like, I. Aliphatic amido-amines such as Witcamine 210 tReg~ TM) and the like;
J. Glycerol esters such as glycerol monooleate, glycerol 15 monostearate, decaglyce.rol decaoleate and the like;
K. Fatty acid amines or ammonium salts such as Armac HT
(Reg. TM) and the like;
L. Hydrocarbon sulphonate salts such as the petroleum sul-phonatesand more particularly sodium petroleum sulphonates 20 and the like; and M. Alkali metal or ammonium stearates used alone or in com-bination with stearic acid It has been found that an optional phosphatide emulsion stabilizer in admixture with the polymeric emulsifier(s) and 25 the conventional water-in-oil emulsifier(s) can be employed to yet further improve the long term stability and sensitivity of the emulsion. Particularly effective phosphatides are those having the structural formula ~H2 - O - M
wherein M is selected from the class consisting of fatty acyl radicals and phosphorus-containing radicals having the struct-35 ural grouping ~4~7~5 0 R"
- P - 0 - R' - - R''' b- ~....
wherein R' is a lower alkylene radical having from 1 to about 10 carbon atoms and R", R''' and R'''' are lowex alkyl radi-cals having from 1 to 4 carbon atoms and wherein at least one but no more than two of the M radicals comprise the phospho-rus-containing radical. The fatty acyl radicals are for the 10 most part those derived from fatty acids having from 8 to 30 carbon atoms in the fatty radicals such as, for example, pal-mitic acid, stearic acid, palmitoleic acid, oleic acid and linoleic acid. Especially desirable radicals are those de-rived from commercial fatty compounds such as soybean oil, 15 cotton seed oil, castor s~ed oil and the like. A particularly effective phosphatide is soybean lecithin.
The ratio of polymeric emulsifier(s) to conventional water-in-oil emulsifier(s)isinthe range of 1:25 to 3:1, but preferably in the range of 1:5 to 1:1. The total quantity of 20 the mixed emulsifiers found suitable for use is from 0.4% to 4%, preferably from 0.6% to 1.6% by weight of the total micro-emulsion composition. The quantity of optional phosphatide stabilizer which can be used is from 0.05% to 5.0%, preferably from 0.5% to 1.5% of the total microemulsion composition.
25 The ratio of mixed emulsifiers (polymeric plus conventional) to the phosphatide stabilizer can ba in the range of 1:10 to 100:1 but preferably is in the range of 1:3 to 5:1.
The preerred inorganic oxygen-supplying salt suitable for use in the water-in-oil microemulsion composition is ammo-30 nium nitrate; however a portion of the ammonium nitrate maybe replaced by other oxygen-supplying salts such as alkali or alkaline earth metal nitrates, chlorates, perchlorates or mixtures thareof. The quantity of oxygen-supplying salt used in the water-in-oil microem~lsion may range from 30% to 90%
35 by weight of the total compositionD
Suitable water-immiscible emulsifiable fuels for use in the water-in-oil microemulsion include most hydrocarbons, for example, paraffinic, olefinic, naphthenic, elastomeric, aromatic, satuxated or unsaturated hydrocarbons. Preferred among the water-immiscible emulsifiable uels are the highly refined paraffinic hydrocarbons. The quantity of liquia or liquefiable carbonaceous fuel used in the water-in-oil micro-emulsion may comprise up to ~0% by weight of the total compo-lO sition.
The sensitizing component distributed substantially homo-geneously throughout the composition is preferably occluded gas bubbles which may be introduced in the form of glass or resin mi-rospheres or other gas-containing particulate mate-15 rials. Alternatively, gas bubbles may be generated in-situ by adding to the composition and distributing therein a gas-generating material such as, for example, an aqueous solution of sodium nitrite. Other suitable sensitizing components which may be employed alone or in addition to the occluded 20 or in-situ generated gas bubbles include insoluble particu-late solid self-explosives such as, for example, grained or flaked TNT, D~T, RDX and the like and water soluble and/or hydrocarbon soluble organic sensitizers such as, for example, amine nitrates, alkanolamine nitrates, hydroxyalkyl nitrates, 25 and the like. The explosive compositions of the present in-vention may be formulated for a wide range of applications.
Any combination of sensitizing components may be selected in order to provide an explosive composition of virtually any desired density, weight-strength or critical diameter.
The quantity o~ solid self-explosive ingredients and o~ water-soluble and/or hydrocarbon-soluble organic sensi-tizers may comprise up to 40% by weight of the total compo-sition. The volume of the occluded gas component may comprise up to 50% of the volume of the total explosive composition.
Optional additional materials may be incorporated in the composition of the invention in order to further improve - 1~4C976S
sensitivity, density, strength, rheology and cost of the final explosive. Typical of materials found useful as op-tional additives include, for example, emulsion promotion agents such as highly chlorinated paraffinic hydrocarbons, particulate oxygen-supplying salts such as prilled ammonium nitrate, calcium nitrate, perchlorates, and the like, ammo-nium nitrate/fuel oil mixtures (A~FO), particulate metal fuels such as aluminium, silicon and the like, particulate 10 non-metal fuels such as sulphu~, gilsonite and the like, particulate inert materials such as sodium chloride, barium sulphate and the like, water phase or hydrocarbon phase thickeners such as guar gum, polyacrylamide, carboxymethyl or ethyl cellulose,biopolymers, starches, elastomeric ma-15 terials, and the like, crosslinkers for the thickeners suchas potassium pyroantimonate and the like, bufers or pH
controllers such as sodium borate, zinc nitrate and the like, crystal habit modifiers such as alkyl naphthalene sodium sulphonate and the like, liquid phase extenders such 20 as formamide, ethylene glycol and the like and bulking agents and additives of commsn use in the expLosives art The quantities of optional additiona- materials used may comprise up to 50% by weight of the total explosive composi-tion, the actual quantities employed depending upon their 25 nature and function.
The preferred methods for making the water-in-oil microemulsion explosive compositions of the invention com-prise the steps of (a) mixing the water, inorganic oxidizer salts and, in certain cases, some of the optional water-30 soluble compounds, in a first premix, (b) mixing the carbon-aceous fuel, emulsifying agent and any other optional oil solub-le compounds, in a second premix and (c) adding the first pre-mix to the ~econd premix in a suitable mixing apparatus, to form a water-in-oil microemulsion. The first premix is heated 35 until all the salts are completely dissolved and the solution may be filtered if needed in order to remove any insoluble ~4~S
residue. The second premix is also heated to li~uefy the ingredients. Any type o~ apparatus capable of either low or high shear mixin~ can be used to prepare the microemulsion explosives of the invention. Glass microspheres, solid self-explosive ingredients such as particula-te TNT, solid fuels such as aluminium or sulphur, inert materials such as barytes or sodium chloride, undissolved solid oxidizer salts and other optional materials, if employed, are added to the 10 microemulsion and simply blended until homo~enerously dis-persed throughout the composition The water-in-oil microemulsion of the invention can also be prepared by adding the second premlx liquefied fuel solu-tion phase to the first premix hot aqueous solution phase 15 with sufficient stirring to invert the phases. ~Io~ever, this method usually requires substantially more energy to obtain the desired dispersion than does the preferred reverse procedure. Alternatively, the water-in-oil micro-emulsion is particularly adaptable to preparation by a con-20 tinuous mixing process where the two separately preparedliquid phases are pumped through a mixing device wherein they are combired and emulsified Characteristic of the novel explosive compositions of the invention is the unique nature of the water-in-oil micro-emulsion which results from the use of specific blends ofemulsifiers The microemulsion of the invention is a demon-strably different state of matter than any of previously dis-closed, conven~ional prior art explosive emulsions. Several techniques well known to those experienced in the art, may be 30 employed to differentiate the microemulsions of this inven-tion from the conventional explosive emulsions of the prior art Microcalorimetry:
The novel emulsifiers employed in the composition of 35 this invention differ from prior art systems in that a highly ordered and stable film is produced. This stability is a ~L14('176~i consequence of the energy release on formation of the film which energy release exceeds the newly created surface energy The microemulsions created therefore, have an energy barrier towards coalescence which barrier does not existwith prior art emulsifiers. Microcalorimetry ~ay be used to observe the free energy change of mixing. A typical micxoemulsion of the present invention had a highly negative free energy change of mixing (-5 to -7 ~g of oil phase), on the otiler hand, a re-10 presentative prior art emulsion formed from sorbitan mono-oleate had a much smaller free energy change of mixing closely ap-proaching æero (-0.5 to -0.9 J/g of oil phase). This substan~
tial energy difference help~ explain the stability of the microemulsions of the present invention 15 Ease of Mixing:
As further evidence for ease of formation and for intrinsic - stability, a microemulsion was prepared by simply pouring an aqueous oxidizer salt solution into an hydrocarbon fuel solution containing the emulsifying system of the present 20 invention while stirring by hand with a slow spatula action.
This extremely low shear mixing was sufficient to produce a ~table water-in-oil microemulsion explosive composition which was subsequently aerated to a density of 1.10 g/cc, packaged in a 25 ~m diameter cartridge and detonated at 5C with an 25 ordinary electric blasting cap. After several weeks of storage this composition was still detonator sensitive and no visual signs of destabilization were observed, X-Ray diffraction:
All prior art explosive emulsions show gradually increasing 30 crystal growth and structure upon storage as a consequence of - their instability and slow coalescence of the aqueous oxidizer salt droplets. This increasing crystal structure can be easily detected by X-ray diffraction. The microemulsion explosives of this invention show no sùch X-ray diffraction pa-ttern even 35 at very low temperature or after prolonged storage and/or for f compositions containing extremely low levels of waterO
Sedimentation:
To urther differentiate the microemulsion explosives of 5 this invention from prior art emulsion explosives, centrifuga-tion experiments were conducted to observe sedimentation rates, After 30 minutes of ultracentrifugation at 35000 G's, the microemulsions of the present invention devoid of any insoluble optional additives remained virtually intact as opposed to sub-10 stantial crystallization and/or phase separation for all priorart emulsion explosives tested, The following Examples and Tables demonstrate the uniq~le properties of the microemulsion explosive compositions of the invention.
E.YAMPLES 1-10 To demonstrate the effectiveness of the disclosed blends of polymeric and conventional emulsifiers,with and without an optional phosphatide emulsion stabilizer, in producing the desired microemulsion, a series of compositions were prepared 20 by adding various admixtures of one polymeric emulsifier and several different conventional emulsifiers to similar formula-tions. The results are shown in Table I, below, , . .
7~S
T ~ B L E
. .
Ingredients Ex.l Ex.2 Ex.3 EX,4 Ex,5 .
Ammonium nitrate 6107 61.9 61.9 61,9 61.9 Sodium nitrate 16.6 16.6 16.6 16.6 16.6 Calcium nitrate Sodium borate 0~5 0.5 0.5 0.5 Water 12.6 12.6 12.6 12.6 12,5 Polymeric emulsifier~l) - 0.3 0,3 0.3 0,3 10 Sorbitan sesqui-oleate - 1.1 - - -Sorbitan mono-oleate 1.4 - 1.1 - -Atmos 300 (Reg.TM) (2) _ _ _ 1.1 -Lithium stearate - - - - 1,0 Armac HT (Reg.TM) (3) Drewpol 10-10-0 (Reg~TM)(4) - - - - -Witcamine PA-78B (Reg.TM)(5) Witcamine 210 (Reg.TM) ( ) - - - - -~ecithin - - - - 0,7 Paraffin oil 2.9 2,7 2.7 2.7 4,5 Paraffin wax 2,0 2.0 2,0 2.0 Glass microspheres 2.3 2.3 2O3 2.3 2,5 Density (g/cc) 1,17 1.16 1.18 1.19 1.15 Oxygen balance (%) -0.1 ~0.5 +0,5 +0,5 -0~7 Cartridge diameter (mm) 25 25 25 25 25 Temp, (C) 7 5 5 5 8 Minimum initiatox EB 9 F/C 10 F/C 9 F/C 9 F/C
Failed (7) .
(1) Block copolymer comprising 30% of component B (residue of water-soluble polyalkylene glycol of MW 1500) (2) Mono and diglycerides of fat-forming fatty acids
A preferred alk(en)yl succinic anhydride is (polyiso-butenyl) succir.ic anhydride containing from 50 to 200 carbon 30 atoms in the alkenyl chain, The alk(en)yl succinic anhydrides (i) may, however, if desired be a mixture of two or more different compounds which respectively satisfy the foregoing de~initions, A minor pro-portion of a monobasic carboxylic acid may be included to 35 adjust the functionality and/or degree of branching of the ~40~65 .
- 8a -derived polyesters.
The polyalkylene glycols (ii) which are used in making the polyesters may be, for example, polyethylene glycols, mixed poly(ethylene-propylene) glycols or mixed poly(ethyl-/
/
~4~7 Ei5 g ene-butylene) glycols, provided that they satisfy the mole-lar weight requirement hereinbefore stated. The polyalkyl-ene glycols are also commercially available materials, and a single such compound or a mixture of two or more such com-pounds differing in composition and/or molecular weight may be used in making the polyeste~ i~ desired.
Preferred polyalkylene glycols for use in making the polyesters are polyethylene glycols of average molecular weight 10 500 to 1,500.
In addition to the polyalkylene glycol(s), other polyols such as glycerol, trimethylol propane, pentaerythritol and sorbitol may be incorporated in order to adjust the overall functionality of the components and/or increase the degree 15 of branching of the polymers.
C. Copolymers as described in A but with the polyoxyethyl-ene chain of the polyalkylene glycol moiety replaced by a polyethylene-imine chain (i.e. replacing the oxygen atom in the polyoxyethylene hy a ~-H group).
20 D. Polyesters as described in B but with the polyoxyethylene chain of the polyalkylene glycol moiety replaced by a poly-ethylene imine chain.
The substitution of the polyoxyethylene chain of the poly-alkylene glycol of the block copolymers A and of the polyes-25 ters B by a polyethylene-imine chain does not significantly alter the emulsifying ability of these resins. The propor-tion of polymeric components in the block copolymer and in the polyester of these polyethylene-imine based polymers are as described in the types A and B. Also these polymers can 30 be largely a salt or an amide depending on the conditions present during their synthesis.
Exemplary of the conventional water-in-oil emulsifiers with which the copolymeric and/or polyester emulsifiers of the above-described types A, B, C and D are combined in ord~r 35 to produce the microemulsion explosive compositions of this invention are:
~L~4~7~ii5 E Those derived from sorbitol by esterification such as sorbitan fatty acid esters, for example, sorbitan monooleate, sorbitan sesquioleate, so.rbitan monostearate and the like;
F. Mono and diglycerides of fat-forming fatty acids such as Atmos 300 (Reg. TM), Dur-Em 187 tReg. TM3, Dur-Em 207 (Reg.
TM) and the like;
G. Polyoxyethylene sorbitol esters such as polyoxyethylene sorbitol beeswax darivative materials and the llke;
10 H. Substituted imidazolines such as Witcamine PA-78B (Reg.
TM) and the like, I. Aliphatic amido-amines such as Witcamine 210 tReg~ TM) and the like;
J. Glycerol esters such as glycerol monooleate, glycerol 15 monostearate, decaglyce.rol decaoleate and the like;
K. Fatty acid amines or ammonium salts such as Armac HT
(Reg. TM) and the like;
L. Hydrocarbon sulphonate salts such as the petroleum sul-phonatesand more particularly sodium petroleum sulphonates 20 and the like; and M. Alkali metal or ammonium stearates used alone or in com-bination with stearic acid It has been found that an optional phosphatide emulsion stabilizer in admixture with the polymeric emulsifier(s) and 25 the conventional water-in-oil emulsifier(s) can be employed to yet further improve the long term stability and sensitivity of the emulsion. Particularly effective phosphatides are those having the structural formula ~H2 - O - M
wherein M is selected from the class consisting of fatty acyl radicals and phosphorus-containing radicals having the struct-35 ural grouping ~4~7~5 0 R"
- P - 0 - R' - - R''' b- ~....
wherein R' is a lower alkylene radical having from 1 to about 10 carbon atoms and R", R''' and R'''' are lowex alkyl radi-cals having from 1 to 4 carbon atoms and wherein at least one but no more than two of the M radicals comprise the phospho-rus-containing radical. The fatty acyl radicals are for the 10 most part those derived from fatty acids having from 8 to 30 carbon atoms in the fatty radicals such as, for example, pal-mitic acid, stearic acid, palmitoleic acid, oleic acid and linoleic acid. Especially desirable radicals are those de-rived from commercial fatty compounds such as soybean oil, 15 cotton seed oil, castor s~ed oil and the like. A particularly effective phosphatide is soybean lecithin.
The ratio of polymeric emulsifier(s) to conventional water-in-oil emulsifier(s)isinthe range of 1:25 to 3:1, but preferably in the range of 1:5 to 1:1. The total quantity of 20 the mixed emulsifiers found suitable for use is from 0.4% to 4%, preferably from 0.6% to 1.6% by weight of the total micro-emulsion composition. The quantity of optional phosphatide stabilizer which can be used is from 0.05% to 5.0%, preferably from 0.5% to 1.5% of the total microemulsion composition.
25 The ratio of mixed emulsifiers (polymeric plus conventional) to the phosphatide stabilizer can ba in the range of 1:10 to 100:1 but preferably is in the range of 1:3 to 5:1.
The preerred inorganic oxygen-supplying salt suitable for use in the water-in-oil microemulsion composition is ammo-30 nium nitrate; however a portion of the ammonium nitrate maybe replaced by other oxygen-supplying salts such as alkali or alkaline earth metal nitrates, chlorates, perchlorates or mixtures thareof. The quantity of oxygen-supplying salt used in the water-in-oil microem~lsion may range from 30% to 90%
35 by weight of the total compositionD
Suitable water-immiscible emulsifiable fuels for use in the water-in-oil microemulsion include most hydrocarbons, for example, paraffinic, olefinic, naphthenic, elastomeric, aromatic, satuxated or unsaturated hydrocarbons. Preferred among the water-immiscible emulsifiable uels are the highly refined paraffinic hydrocarbons. The quantity of liquia or liquefiable carbonaceous fuel used in the water-in-oil micro-emulsion may comprise up to ~0% by weight of the total compo-lO sition.
The sensitizing component distributed substantially homo-geneously throughout the composition is preferably occluded gas bubbles which may be introduced in the form of glass or resin mi-rospheres or other gas-containing particulate mate-15 rials. Alternatively, gas bubbles may be generated in-situ by adding to the composition and distributing therein a gas-generating material such as, for example, an aqueous solution of sodium nitrite. Other suitable sensitizing components which may be employed alone or in addition to the occluded 20 or in-situ generated gas bubbles include insoluble particu-late solid self-explosives such as, for example, grained or flaked TNT, D~T, RDX and the like and water soluble and/or hydrocarbon soluble organic sensitizers such as, for example, amine nitrates, alkanolamine nitrates, hydroxyalkyl nitrates, 25 and the like. The explosive compositions of the present in-vention may be formulated for a wide range of applications.
Any combination of sensitizing components may be selected in order to provide an explosive composition of virtually any desired density, weight-strength or critical diameter.
The quantity o~ solid self-explosive ingredients and o~ water-soluble and/or hydrocarbon-soluble organic sensi-tizers may comprise up to 40% by weight of the total compo-sition. The volume of the occluded gas component may comprise up to 50% of the volume of the total explosive composition.
Optional additional materials may be incorporated in the composition of the invention in order to further improve - 1~4C976S
sensitivity, density, strength, rheology and cost of the final explosive. Typical of materials found useful as op-tional additives include, for example, emulsion promotion agents such as highly chlorinated paraffinic hydrocarbons, particulate oxygen-supplying salts such as prilled ammonium nitrate, calcium nitrate, perchlorates, and the like, ammo-nium nitrate/fuel oil mixtures (A~FO), particulate metal fuels such as aluminium, silicon and the like, particulate 10 non-metal fuels such as sulphu~, gilsonite and the like, particulate inert materials such as sodium chloride, barium sulphate and the like, water phase or hydrocarbon phase thickeners such as guar gum, polyacrylamide, carboxymethyl or ethyl cellulose,biopolymers, starches, elastomeric ma-15 terials, and the like, crosslinkers for the thickeners suchas potassium pyroantimonate and the like, bufers or pH
controllers such as sodium borate, zinc nitrate and the like, crystal habit modifiers such as alkyl naphthalene sodium sulphonate and the like, liquid phase extenders such 20 as formamide, ethylene glycol and the like and bulking agents and additives of commsn use in the expLosives art The quantities of optional additiona- materials used may comprise up to 50% by weight of the total explosive composi-tion, the actual quantities employed depending upon their 25 nature and function.
The preferred methods for making the water-in-oil microemulsion explosive compositions of the invention com-prise the steps of (a) mixing the water, inorganic oxidizer salts and, in certain cases, some of the optional water-30 soluble compounds, in a first premix, (b) mixing the carbon-aceous fuel, emulsifying agent and any other optional oil solub-le compounds, in a second premix and (c) adding the first pre-mix to the ~econd premix in a suitable mixing apparatus, to form a water-in-oil microemulsion. The first premix is heated 35 until all the salts are completely dissolved and the solution may be filtered if needed in order to remove any insoluble ~4~S
residue. The second premix is also heated to li~uefy the ingredients. Any type o~ apparatus capable of either low or high shear mixin~ can be used to prepare the microemulsion explosives of the invention. Glass microspheres, solid self-explosive ingredients such as particula-te TNT, solid fuels such as aluminium or sulphur, inert materials such as barytes or sodium chloride, undissolved solid oxidizer salts and other optional materials, if employed, are added to the 10 microemulsion and simply blended until homo~enerously dis-persed throughout the composition The water-in-oil microemulsion of the invention can also be prepared by adding the second premlx liquefied fuel solu-tion phase to the first premix hot aqueous solution phase 15 with sufficient stirring to invert the phases. ~Io~ever, this method usually requires substantially more energy to obtain the desired dispersion than does the preferred reverse procedure. Alternatively, the water-in-oil micro-emulsion is particularly adaptable to preparation by a con-20 tinuous mixing process where the two separately preparedliquid phases are pumped through a mixing device wherein they are combired and emulsified Characteristic of the novel explosive compositions of the invention is the unique nature of the water-in-oil micro-emulsion which results from the use of specific blends ofemulsifiers The microemulsion of the invention is a demon-strably different state of matter than any of previously dis-closed, conven~ional prior art explosive emulsions. Several techniques well known to those experienced in the art, may be 30 employed to differentiate the microemulsions of this inven-tion from the conventional explosive emulsions of the prior art Microcalorimetry:
The novel emulsifiers employed in the composition of 35 this invention differ from prior art systems in that a highly ordered and stable film is produced. This stability is a ~L14('176~i consequence of the energy release on formation of the film which energy release exceeds the newly created surface energy The microemulsions created therefore, have an energy barrier towards coalescence which barrier does not existwith prior art emulsifiers. Microcalorimetry ~ay be used to observe the free energy change of mixing. A typical micxoemulsion of the present invention had a highly negative free energy change of mixing (-5 to -7 ~g of oil phase), on the otiler hand, a re-10 presentative prior art emulsion formed from sorbitan mono-oleate had a much smaller free energy change of mixing closely ap-proaching æero (-0.5 to -0.9 J/g of oil phase). This substan~
tial energy difference help~ explain the stability of the microemulsions of the present invention 15 Ease of Mixing:
As further evidence for ease of formation and for intrinsic - stability, a microemulsion was prepared by simply pouring an aqueous oxidizer salt solution into an hydrocarbon fuel solution containing the emulsifying system of the present 20 invention while stirring by hand with a slow spatula action.
This extremely low shear mixing was sufficient to produce a ~table water-in-oil microemulsion explosive composition which was subsequently aerated to a density of 1.10 g/cc, packaged in a 25 ~m diameter cartridge and detonated at 5C with an 25 ordinary electric blasting cap. After several weeks of storage this composition was still detonator sensitive and no visual signs of destabilization were observed, X-Ray diffraction:
All prior art explosive emulsions show gradually increasing 30 crystal growth and structure upon storage as a consequence of - their instability and slow coalescence of the aqueous oxidizer salt droplets. This increasing crystal structure can be easily detected by X-ray diffraction. The microemulsion explosives of this invention show no sùch X-ray diffraction pa-ttern even 35 at very low temperature or after prolonged storage and/or for f compositions containing extremely low levels of waterO
Sedimentation:
To urther differentiate the microemulsion explosives of 5 this invention from prior art emulsion explosives, centrifuga-tion experiments were conducted to observe sedimentation rates, After 30 minutes of ultracentrifugation at 35000 G's, the microemulsions of the present invention devoid of any insoluble optional additives remained virtually intact as opposed to sub-10 stantial crystallization and/or phase separation for all priorart emulsion explosives tested, The following Examples and Tables demonstrate the uniq~le properties of the microemulsion explosive compositions of the invention.
E.YAMPLES 1-10 To demonstrate the effectiveness of the disclosed blends of polymeric and conventional emulsifiers,with and without an optional phosphatide emulsion stabilizer, in producing the desired microemulsion, a series of compositions were prepared 20 by adding various admixtures of one polymeric emulsifier and several different conventional emulsifiers to similar formula-tions. The results are shown in Table I, below, , . .
7~S
T ~ B L E
. .
Ingredients Ex.l Ex.2 Ex.3 EX,4 Ex,5 .
Ammonium nitrate 6107 61.9 61.9 61,9 61.9 Sodium nitrate 16.6 16.6 16.6 16.6 16.6 Calcium nitrate Sodium borate 0~5 0.5 0.5 0.5 Water 12.6 12.6 12.6 12.6 12,5 Polymeric emulsifier~l) - 0.3 0,3 0.3 0,3 10 Sorbitan sesqui-oleate - 1.1 - - -Sorbitan mono-oleate 1.4 - 1.1 - -Atmos 300 (Reg.TM) (2) _ _ _ 1.1 -Lithium stearate - - - - 1,0 Armac HT (Reg.TM) (3) Drewpol 10-10-0 (Reg~TM)(4) - - - - -Witcamine PA-78B (Reg.TM)(5) Witcamine 210 (Reg.TM) ( ) - - - - -~ecithin - - - - 0,7 Paraffin oil 2.9 2,7 2.7 2.7 4,5 Paraffin wax 2,0 2.0 2,0 2.0 Glass microspheres 2.3 2.3 2O3 2.3 2,5 Density (g/cc) 1,17 1.16 1.18 1.19 1.15 Oxygen balance (%) -0.1 ~0.5 +0,5 +0,5 -0~7 Cartridge diameter (mm) 25 25 25 25 25 Temp, (C) 7 5 5 5 8 Minimum initiatox EB 9 F/C 10 F/C 9 F/C 9 F/C
Failed (7) .
(1) Block copolymer comprising 30% of component B (residue of water-soluble polyalkylene glycol of MW 1500) (2) Mono and diglycerides of fat-forming fatty acids
(3) Acetic acid salts of n-alkyl amines
(4) Decaglycerol decaoleate
(5) Oil-soluble imidazoline
(6) Alkyl amidoamine
(7) Fulminate/chlorate cap ~L~4(~7~iS
T A_B L_E I cont'd Ingredients Ex.6 Ex.7 Ex.8 Ex.9 Ex.10 . . .. . ~
Ammonium nitrate 61.8 55.7 61.9 61,9 61.9 Sodium nitrate 16.6 15.0 16.6 16.6 16.6 Calcium nitrate - 5.7 Sodium borate - 0.5 Water 12.6 14.1 12.5 12.5 12.5 Polymeric emulsifier(l) 0.3 0.3 0.3 0,3 0.3 10 Sorbitan sesqui-oleate - - - - O.7 Sorbitan mono-oleate - - - - -Atmos 300 (Reg.TM) (2) _ _ _ _ _ Lithium stearate Armac HT (Reg. TM) (3) 0.7 15 Drewpol 10-10-0 (Reg, TM)(4) - 0.7 Witcamine PA-78 (Reg.TM)(5) - - 0.7 Witcamine 210 (Reg.TM) (6) _ _ _ 0.7 Lecithin 0.7 0.7 0.7 0.7 0.7 Paraffin oil 2.8 2.8 208 2~8 208 20 Paraffin wax 2,0 2.0 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2.5 2.5 2.5 Density (g/cc) 1.16 1.16 1.16 1.17 1.15 Oxygen balance (%) -0.6 +0.2 -0.6 -0.6-0.6 25 Cartridge diameter (mm) 25 25 25 25 25 -Temp. (C) 5 5 5 5 5 Minimum initiator 9 F/C EB(8)9 F/C 9 F/C 6 F/C
(1) Block copolymer comprising 30% of component B (residue of water-soluble polyalkylene glycol o MW 1500) 30 (2) Mono and diglyc erides of fat-forming fatty acids 53) Acetic acid salts of n-alkyl amines (4) Decaglycerol decaoleate (5) Oil-soluble imida201ine (6) Alkyl amidoamine 35 (7) Fulminate/chlorate cap
T A_B L_E I cont'd Ingredients Ex.6 Ex.7 Ex.8 Ex.9 Ex.10 . . .. . ~
Ammonium nitrate 61.8 55.7 61.9 61,9 61.9 Sodium nitrate 16.6 15.0 16.6 16.6 16.6 Calcium nitrate - 5.7 Sodium borate - 0.5 Water 12.6 14.1 12.5 12.5 12.5 Polymeric emulsifier(l) 0.3 0.3 0.3 0,3 0.3 10 Sorbitan sesqui-oleate - - - - O.7 Sorbitan mono-oleate - - - - -Atmos 300 (Reg.TM) (2) _ _ _ _ _ Lithium stearate Armac HT (Reg. TM) (3) 0.7 15 Drewpol 10-10-0 (Reg, TM)(4) - 0.7 Witcamine PA-78 (Reg.TM)(5) - - 0.7 Witcamine 210 (Reg.TM) (6) _ _ _ 0.7 Lecithin 0.7 0.7 0.7 0.7 0.7 Paraffin oil 2.8 2.8 208 2~8 208 20 Paraffin wax 2,0 2.0 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2.5 2.5 2.5 Density (g/cc) 1.16 1.16 1.16 1.17 1.15 Oxygen balance (%) -0.6 +0.2 -0.6 -0.6-0.6 25 Cartridge diameter (mm) 25 25 25 25 25 -Temp. (C) 5 5 5 5 5 Minimum initiator 9 F/C EB(8)9 F/C 9 F/C 6 F/C
(1) Block copolymer comprising 30% of component B (residue of water-soluble polyalkylene glycol o MW 1500) 30 (2) Mono and diglyc erides of fat-forming fatty acids 53) Acetic acid salts of n-alkyl amines (4) Decaglycerol decaoleate (5) Oil-soluble imida201ine (6) Alkyl amidoamine 35 (7) Fulminate/chlorate cap
(8) Electric blasting cap (containing 0.78 g of PET~) ~L4~6~ii In Table I, the cap-sensitivity at low temperature shows the utility of these microemulsions as sensitive explosive compositions even in small diameter Example ~o. 1, not con-taining the polymeric emulsifier, fails thecap-sensitivity test and is significantly inferior to compo-sitions containing the polymeric emulsifier. Further, the benefits of the optional phosphatide emulsion stabilizer can be seen in Examples 5-10 inclusive. Although beneficial to 10 the present invention, the phosphatide stabilizer is not es-sential as is obvious from Example~ 2-4 inclusive.
A further series of compositions were prepared similar to those of Examples 1-10 but employing a number of different 15 polymeric emulsifiers in combination with sorbitan sesqui-f _ __ , , _, _ , . , . ., . ~ ., ., . .. ... ,_, _, . , T A B L E II
. ~ , Ingredients Ex.ll Ex.12 Ex.13 Ex.14 , . .. _ _ .
Ammonium nitrate 61.7 61.7 61.6 61.9 Sodium nitrate 16.6 16.6 16.6 16.6 5 Calcium nitrate - - -Sodium borate 0.5 0.5 0.5 Water 12.6 12.6 12.6 12.5 Polymeric emulsifier - 1 0.4 - ~ -" " - 2 - 0.4 - -" " - 3 - - 0.3 " " - 4 - - - 0.3 " " - 5 - _ _ _ ll - 7 15 Sorbitan sesqui-oleate0.6 0.6 0.7 0.7 Lecithin 0.6 0.6 0.7 0.7 Parafin oil 2.7 2.7 2,7 2.8 Paraffin wax 2.0 2.0 2.0 2.0 Glass microspheres 2.3 2.3 2.3 2~5 Density (g/cc) 1.10 1.10 1.10 1.12 oxygen balance (%) 0.0 0.0 -0.3 -0.6 Cartridge diameter (mm) 25 25 25 25 Temperature ~C) 5 5 5 9 25 Minimum initiator 7 F/C 7 F/C 6 F/C 6 F/C
1 - ~lock copolymer comprising 25% of component B (residue of a polyalkylene glycol of MW 1000 - 1500) 2 - Block copol~mer comprising 30% of component ~ as in 1 3 - Block copolymer comprising 35% of component B as in 1 30 4 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 5 - Polyester from polyisobutenyl succinic anhydride and 39% of a polyalkylene glycol of MW 600 6 - Block copolymer comprising 20% of component B (residue of a polyethylene imine of MW 5000Q). The resin was formulated to be largely as an amide 7 - Blcck copolymer comprising 20% o component B as in 6.
The resin was formulated to be largely as a salt.
114(.~7 Ei5 T A B L E II cont'd _ IngredientsEx.lS Ex.16 Ex.17 Ammonium nitrate 61.9 55.7 55.7 Sodium nitrate 16.6 15.0 15.0 Calcium nitrate - 5.7 5.7 Sodium borate - 0.5 0.5 Water 12.6 14.1 14Ol Polymeric emulsifier - 1 - - -" - 2 " - 4 - 5 0.2 - 6 - 0.3 " " - 7 - - 0.3 Sorbitan sesqui-oleate 0.7 0.7 0.7 Lecithin 0~7 0 7 0 7 Paraffin oil 2.8 2.8 2,8 Paraffin wax 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2O5 Density (g/cc) 1.16 1.15 1.15 Oxygen balance (%) -0.3 +0.2 +0.2 Cartridge diameter (mm)25 25 2S
2 Temperature (C) 6 15 15 5 Minimum initiator 7 F/C EB EB .
1 ~ Block copolymer comprising 25% of component B (residue of a polyalkylene glycol of MW 1000 - 1500) 2 - Block copolymer comprising 30% of component B as in 1 3 - Block copolymer comprising 35% of component B as in 1 4 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 5 - Po~yester fxom polyisobutenyl succinic anhydride and 3~/O of a polyalkylene glycol of MW 600 6 - Block copolvmer comprising 20% of component B (residue of a polyethylene-imine of MW 50000)~ The resing was formulated to be largely as an amide.
7 - Block copolymer comprising 20% of component B as in 6, The resin was formulated to ba largely as a salt.
7~
From Tab~e II it can be seen that cap-sensitivity at low temperature was maintained with all the polymeric emulsifier combinations employed.
EXAMPLES_18-21 A further series of compositions were prepared similar to those of Examples 1-17 but employing either a blend of polymeric emulsifiers in combination with a conventional emulsifier, or a polymeric emulsifier in combination with 10 a blend of conventional emulsifiers, or other different blends of polymeric and conventional emulsifiers, with and without an optional phosphatide emulsion stabilizer~ The results are shown in Table III, bel~w.
/
~14~
T A B L E III
_______________ Ingredlents Ex.18 Ex.l9 Ex.20 Ex.21 Ammonium nitrate 61.9 62.1 61.7 61.7 Sodium nitrate 16.6 16.6 16.5 16.6 Water 12O6 12.6 12.6 12.5 Polymeric emulsifier - l0 . 2 " " - 2 0 .2 - - -" " - 3 - 0.2 0,2 0,2 Atmos 300 (Reg, TM) - 4 0 . 5 0 . 5 Sodium stearate - 0. 5 Witcamine 3164 (Reg. TM) - 5 - - 0.7 -Armac ~T (Reg. TM) - 6 - - - 0.7 Lecithin 0.5 ~ 0.7 0 7 Cereclor 70 L (Reg. TM) - 7 - - - 0,5 Paraf~in oil 3.0 3.0 2.8 2.6 Paraffin wax 2.0 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2.8 2.5 20 Density (g/cc) 1.15 1.15 1.05 1.16 oxygen balance (%) -0.6 0.0 -0.4 -0.1 Cartridge diametex (mm) 25 25 25 25 Temperature (C) 5 5 5 5 Minimum initiator 6 F/C EB 7 F/C EB
_ _ _ _ .
1 - Block copolymer comprising 30% of component B (residue of a water-soluble polyalkylene glycol of MW 1500) 2 - Polyester from polyisobutenyl succinic anhydride and 30% o~ a polyalkylene glycol of MM 600 3 - Polyester from polyisobutenyl succinic anhydride and 39O/o of a polyalkylene glycol of MW 600 4 - Mono and diglycerides of fat-forming fatty acids 5 - Alkyl amidoamine 6 - Acetic acid salts of n-alkyl amines 7 - Highly chlorinated paraffin~ hydrocarbon ~14~7~i5 From Table III it can be seen that cap-sensitivity at low temperature was maintained with any of the further polymeric emulsifier(s)/conventional emulsifier(s) combina-tions employed in these examples, EX~MPLES 22-29 To demonstrate that a variety of oxidizer salts can be utilized in the microemulsion explosive compositions of the invention and further, to show various methods of incoxpo-10 rating occluded air ih the composition and thus controllingthe final density, a series of compositions were prepared using various oxidizer salts and dansity reducing methods.
The results are given in Table IV, below.
_ . /
~14C?76~5 T A B L E IV
IngredientsEx.22 Ex.23 Ex.24Ex.25 .. . ... - .
Ammonium nitrata 75,9 65.7 58.559.4 5 Sodium nitrate - 17.7 7.0 Calcium nitrate - - 9,0 9.1 Sodium borate Water 17.2 7,3 13.113.2 Polymeric emulsifier - 1 0,3 0,3 0.3 0.3 10 Sorbitan sesqui-oleate 0.7 0.7 0.7 0.7 Lecithin 0.7 0.7 0.7 0,7 Paraffin oil 2.2 4,0 3.2 2.5 Paraffin wax 1.0 1.0 - 1.6 Glass microspheres2.0 2.6 2.5 2.5 Gassing solution - 2 Porous glass agglomerates - - - -Particulate aluminium - - 5.0 Density (g/cc) 1.17 1.10 1.161.17 Oxygen balance (%)0.0 0,0 -0.3 0,0 20 Cartridge diametsr (mm) 25 25 25 25 Temperature (C) 5 8 8 5 Minimum initiator 7 F/C 6 F/C 5 F/C 7 F/C
Minimum initiator after 25 storage at - 40~C - - - 7 F/C
Minimum initiator at -40C -, _ . _ , , , , 1 - Block copolymer comprising 30% of component B
(residue of a water-soluble polyalkylene glycol of MW 1500) 2 - 50% water, 20% sodium nitrite, 30% sodium thiocyanate by weight S
T A B L E IV cont' d ____________________ Ingredients Ex, 2 6Ex ~ 2 7Ex, 2 8Ex, 2 9 Ammonium nitrate 61.1 58.7 63,3 61.5 Sodium nitrate 16.5 7,2 16.9 16,5 Calcium nitrate - 10.8 Sodium borate 0,5 - - -Water 12.5 13,8 12,8 12,5 Polymeric emulsifier - 1 0,3 0,3 0,3 0,3 10 Sorbitan sesqui-oleate 0,7 0,7 0,7 0.7 ~ecithin 0.7 0.7 0.7 0.7 Paraffin oil 2,7 4.8 2,8 4,6 Paraffin wax 2,0 - 2~0 Glass microspheres 3.0 3,0 15 Gassing solution - 2 - - 0,5 -Porous glass agglomerates - - - 3.2 Particulate aluminium - - - - .
Density (g/cc) 1.05 1,10 1.05 1.10 20 Oxygen balance (%) -0,4 -0,4 -0,2 0,0 Cartridge diameter (mm) 25 25 25 25 Temperature (C) 5 5 5 6 Minim~m initiator 6 F/C 6 F/C 7 F/C 6 F/C
Minimum initiator after Failed 25 storage at -40C EB 7 F/C
Minimum initiator at Failed -40C EB EB - - .
30 1 - Block copolymer comprising 30% of component B
(residue of a water-soluble polyalkylene glycol of MW 1500) 2 - 50% water, 20% sodium nitrite, 30% sodium thiocyanate by weight ~ ~C'-~6~i From the results in Table IV it can be observed that a variety of oxidizer salts can be utili2ed in the formulation of the water-in-oil microemulsion explosives, Of particular interest is the surprisin~ effect of calcium nitrate in pro-ducing exceptional cap-sensitivity at extremely low tempera-ture, as exemplified in Examples 25 and 27.
Also evident from Examples 28 and 29 is the fact that porous glass agglomerates and chemical generation of in-situ 10 gas bubbles are equally effective density reducing methods.
~a .
In order to demonstrate the exceptional stability o the microemulsion explosive compositions o~ this invention, a fu~ther series of compositions were prepared. The cap 15 sensitivity of these compositions was determined within one week of manufacture and approximately every month thereafter up to about one year, at which time the supply of material was exhausted. The results are shown in Table V, the quan-tities shown being in weight percent.
/
T A B L E V
Ingredients Ex. 30 Ex~ 31 _ _ Ammonium nitrate 61.7 61.7 Sodium nitrate 16.6 16.6 Sodium borate 0.5 0.5 Water 12.6 12.6 Polymeric emulsifier - 1 0.4 " " - 2 - 0.4 10 Sorbitan sesqui-oleate 0.6 0.6 Lecithin 0.6 0.6 Paraffin oil 2.7 2.7 Paraffin wax 2.0 2.0 Glass microspheres 2.3 2.3 Density tg/cc) 1.10 1.10 Oxygen balance (%) o.o 0.0 Cartridge diameter (mm) 25 25 Temperature (C) 5 5 20 Minimum initiator (fresh) 7 F/C 7 F/C
Aging period (months) 1 3 123 1 - Block copolymer comprising 30% of component B (re idue of water-soluble polyalkylene glycol of MW 1500) 2 - Block copolymer comprising 25% of component B (residue of a water-soluble polyalkylene glycol of MW 1000 - 1500) 3 - Pexiod during which cartridges were successfu~ly detonated with electric detonator at 5C until the supply of the material was exhausted after 12 months s A further aspect of the mi~roemulsion explosive compo-tion of the present invention is that doping with substanti-ally large proportions of, for example, energy enhancing solid materials such as solid ~ prills, does not signifi-cantly alter the sensitivity or the stability of the compo-sition Furthermore, if the microemulsion composition is formulated so as to possess a suitably high fluidity, a very large proportion of these solid materials may be added without 10 significant loss of pumpability. Retention of fluidity is not usually the case with water-gel explosives; the addition of extra amounts of high energy content ingredients such as AN prills is severely restricted because of rapid loss of pumpability, reduction in initiator sensitivity levels and 15 in water resistance qualities. Doping of the microemulsion compositions of this invention at levels up to 50% addition of extra A~ prills or ANF0, nevertheless produces waterproo~
pumpable explosive compositions which retain booster sensi-tivity at densities up to 1.35 g/cc. These new explosive 20 compositions have weight strengths which are substantially higher than the weight strength of the undoped microemulsion and, more importantly, the raw material costs are at the same time substantially reduced. Furthermore, the blasting per-formance which is in part determined by calculable gas evola-25 t~on volumes, is substantially higher than that of otherpumpable, waterproof explosive compositions because of the much higher proportion of gas producing A~ contained in these new explosive cQm~ositions. In addition, the other unique explosive properties associated with the microemulsion com-30 positions su~h as high velocities of detonation, very smallcritical diametexs, temperature independent sensitivity, and storage stability, are substantially retained b~ the doped microemulsion compositions.
Inverted phase slusries such as described in United 35 States patent ~o. 4,141,767 have virtually no storage sta-bility and are not able to support large proportions of ~4~
extra added salts. On cooling to ambient temperature, some of the oxidizer salt already precipitates from the solution and this rapidly desensitizes the composition, making it less fluid and increasingly more difficult to load into boreholes by pump or to package by extrusion methods.
These inverted phase compositions have limited use in that they must be pumped immediately after manufacture and deto-nated within a relatively limited period of time The micro-10 emulsion compositions of the present invention, on the otherhand, retain their fluidity and pumpability for long periods of time even when doped with large proportions o additional oxidizer salts.
All known prior art water-in-oil emulsion explosives 15 also suffer from lack of stability. The presence of solid oxidizer salts act as seeding crystals and rapidly destabi-lizes the basic emulsion~ This is illustrated in the fol-lowing Examples 32 - 33.
A prior art emulsion based explosive composition and a microemulsion based explosive composition were prepared and then doped with ground AN to compare their sensitivity and more particularly their stability. Both compositions were submitted to a temperature cycling test consisting of 3 days 25 of storage at 50C followed by 2-3 days of storage at -17C.
The results axe shown in Table VI the quantities shown being in parts by weight ~:~L4~3765 - T A B L E VI
. . _ . .
Inyredients Ex. 32 Ex. 33 .. .. __ Ammonium nitrate 61.4 61.2 Sodium nitrate 17.0 16.9 Water 12.6 12.5 Sorbitan mono-oleate 1.0 Sorbitan sesqui-oleate - 0,7 Lecithin _ o 7 10 Polymeric emulsifier (1) ~ 0 3 Paraffin oil 4.8 S.5 Paraffin wax . 2.0 l.O
Glass microspheres 3.0 3.0 Dopes Ammonium nitrate - ground 31.5 31.5 Total (parts) 133.3 133.3 _ ===== = ===_ ===== ====_ Properties at 5C in 25mm Oxygen balance (%) ~0,3 -0,3 Density (g/cc) 1.17 1.17 Minimum initiator - fresh ( ) EB 7 F/C
Minimum initiator after 1 cycle Failed 2,5 g ~ F/C
primer Minimum initiator after 2 cycles - 9 F/C
Minimum initiator after 3 cycles - EB
1 - Block copolymer compxising 30% of component B
(residue of a water-soluble polyalkylene ~lycol of MW 150~) 2 - One cycle consisted of: 3 days of storage at 50C
followed by 2-3 days of storage at -17C. Samples were warmed up to 5C before testing ~14C3765 In Table VI, it can be seen that the A~ crystal doping quickly resulted in a rapid loss of initiator sensitivity of the prior art emulsion. On the other hand, the doped micro-emulsion was much more sta~le to this seeding crystal effectand remained cap-sensitive for a relatively long period of tim~ under unusually severe storage conditions.
EXAMoeLES 34-52 In order to demonstrate the various optional materials, 10 especially oxidizer salts, which can be dispersed in the microemulsion explosive compositions of this invention to form cap-sensitive and/or boostex-sen9itive explosive mix-tures, a series of compositions were prepared using various combinations of oxidizer salts, fuels and inert materials.
15 The results are presented in Table VII.
~ . . _ . ... . .
~4~:~7 EiS
_ 33 -T A B L E VII
. ~ ~ .
Ingredients Ex.34 Ex.35 Ex.36 Ex.37 . . . _ .
Ammonium nitrate 45,68 49.18 49.14 46.83 Sodium nitrate 15.36 13,16 13.25 12.98 Calcium nitrate Sodium borate - - 0,36 -Water 12.0 9.98 10.05 9.57 Polymeric emulsifier~0.24 0.24 0.24 0,23 10 Polymeric emuls.ifier2 - - - -Sorbitan sesqui-oleate 0.56 0.56 0.56 0,52 Lecithin 0.56 0.56 0.56 0.52 Cereclor 70 1 (Reg.TM)4 Paraffin oil 2.72 2,72 2.84 2.10 15 Paraffin wax 2.0 1.2 1.6 1.5 Glass microspheres 2,0 2,4 2,0 Gassing solution3 - - - 0,75 Dopes Ammonium nitrate - prills " " - ground 18.88 17.0 ANFO - - - 25.0 Sodium nitrate - prills - - 14,4 Calcium nitrate - prills5 : Particulate alum.inium - 3.0 5,0 Sodium chloride Barium sulfate Properties at 5C
Oxygen balance (%) +0.4 -0,1 -0.3 0.O
Density (g/cc) 1.15 1.18 1.21 1.18 30 Cartridge diameter (mm) 50 25 50 50 Minimum initiator 8 F/C7 F/C 7 F/C 8 F/C
Primer (g - pentolite) ~OD (km/sec) 4.44.0 4.7 4.3 Total ammonium nitrate 64.6666.18 49.14 70.44 35 content (%) i7~S
-- 3~ --T A B L E VII Cont.'d , Ingredients Ex.38 Ex.39 Ex.40 Ex.41 ~Imnonium nitrate 56.57 51.61 46.21 45,5 Sodium nitrate - - 12.37 12.2 Calcium nitrate - 6.75 - -Sodium borate - - - -Water 12.83 9.82 9.38 9.2 Polymeric emulsifier1 0~21 0.23 - 0.2 Polymeric emulsifier2 - - 0.23 -Sorbitan se~ui-oleate 0.53 0.52 0.52 0.5 ~ecithin 0.53 0.52 0.52 0.5 Cereclor 70 1 (Reg.TM)4 Para~fin oil 3.03 3.71 4.16 3.9 Paraffin wax 0,75 0.75 0.75 1.0 Glass microsph~res 1.87 2.48 2,25 2.0 Gassing solution3 - - - -Dopes Ammonium nitrate - prills - - - 25.0 " " - ground 23.68 23.61 23.61 A~FO
Sodium nitrate - prills - - - -Calcium nitrate - prills5 - - - -particulate aluminium - - ~ ~
Sodium chloride - - - -Barium sulfate - - ~ -Pro,~erties at 5C
Oxygen balance (%) -0.1 -0.2 -0.3 -0"6 Density (g/cc) 1.20 1.19 1.20 1.21 Cartridge diameter (mm) 25 25 25 75 Minimum initiator 9 F/C 7 F/C 9 F/C 9 F/C
Primer (g - pentolite) - - - -tlOD (km/sec~ 4.0 3,8 3.6 5.2 Total ammonium nitrate 80.25 75.22 69.82 70,5 content (%) . ~ .
7~5 T A B ~ E VII cont.'d _________._____ ______.
. .
IngredientS Ex. 42 Ex. 43 Ex. 44 . -Ammonium nitrate 50.53 43.09 46.16 Sodium nitrate 13,52 11.62 12,35 Calcium nitrate - - -Sodium borate - 0,32 Water 10.25 8.81 9.37 : Polymeric emulsifier 0.25 0.21 0.23 10. Polymeric emulsi~ier2 ~ - -Soxbitan sesqui-oleate 0.58 0.49 0.52 Lecithin 0.58 0.49 0.52 . Cereclor 70 1 (Reg.TM)4 0.41 Paraffin oil 2.64 3.93 2.85 Paraffin wax 1.24 1.05 0O75 Glass microspheres 2.47 1.61 2,25 Gassing solution Dopes i Ammonium nitrate - prills " " - ground 17.53 28.38 A~FO - - -Sodium nitrate - prills - - _ ' Calcium nitrate - prills ¦ Particulate aluminium 25l Sodium rhloride - - 25,0 ¦ Barium sul~ate I Properties at 5C
I
! Oxygen balance (%) ~3.0 -0.4 -0.5 Density (g/cc) 1~12 1.21 1.26 Cartridge diameter (mm) 25 50 25 Minimum initiator 5 F/C 9 F/C 5 F/C
Primer ~g - pentolite) VOD (km/sec) 4.2 4.1 4.0 Total ammonium nitrate68.06 71.47 46.16 35 content (%) _ . _ S
- 36 _ T A B L E VII ContO'd ______________ _______ Ingredients EXo45 Ex,46 Ex,47 Ex.48 . ._ . . .
Ammonium nitrate 54.53 47.24 60,743,33 Sodium nitrate 6.53 12.67 - 11.68 Calcium nitrate 8.41 Sodium borate - 0.37 . - 0.32 Water 12,16 9,82 8.38.86 Polymeric emulsifierl 0.27 0.22 0,200.21 Polymeric emulsifier Sorbitan sesqui-oleate 0.63 0.53 0.60.49 Lecithin 0.63 0~53 0.60.49 Cereclor 70 1 (Reg.TM)4 Paraffin oil 2.34 3.50 - 3.36 Paraffin wax 1.80 1.50 3.91.40 Glass microspheres 2.70 - 1.01.26 Gassing solution Dopes Ammonium nitrate - prills - 23.6224,7 " " - ground - - - -A~FO
Sodium nitrate - prills Calcium nitrate - prills5 - - - 23,6 Particulate aluminium - - - 5,0 Sodium chloride Barium sulfate 10.0 . Pxopexties at 5C
Oxygen balance (%) ~0.2 -0.4 ~0.2~0,3 Density (g/cc) 1.22 1.25 1.271.25 Cartridge diametex (mm)25 75 75 75 Minimum initiator 6 F/C
Primer (g - pentolite) _ 160 160 160 VOD ~km/sec) 4.1 4.9 4O9 4.5 Total ammonium nitrate54.53 70,86 85,443.33 35 content (/O) _ _ ~4(376S
T A B L E VII Cont 'd Ingredients Ex.49 Ex.50 Ex.51 Ex.52 _ _ .
Ammonium ni~rate 40.32 40.67 35~86 31,56 Sodium nitrate 13.51 11.27 11.03 8~74 Calcium nitrate Sodium borate - - - -Water 10.64 8,31 8.28 6.45 -Polymeric emulsifierl0,21 0,19 0.18 0.15 Polymeric emulsifier2 Sorbitan sesqui-oleate0.84 0.46 0.41 0.35 Le~ithin 0.14 0.46 0.41 0.35 Cexeclor 70 1 (Reg.TM)4 - - - -Paraffin oil 1.89 2.47 3.8663.25 1 1~ Paraffin wax 1.40 0065 1.18 1.15 ~
Glass microspheres 1.05 - 1.18 - ¦
Ga~sing solution3 - 0.5~ - -Dopes Ammonium nitrate - prills - - 37.61 " " - ground ANF0 30.0 35.0 - 48.o7 Sodium nitrate - prills Calcium nitrate - prills5 - - _ _ Particulate aluminium Sodium chloride Barium sulfate - - _ Properties at 5C
Oxygen balance (%) +0.1 -0.1 +0.3 -0.6 Density (g/cc) 1.29 1.26 1.25 1.338 Cartridge diameter (mm) 150 75 75 75 Minimum initiator Primer (g - pentolite) 450 160 80 80 VQD (hm/sec) 4.6 4,0 1.5 3.5 Total ammonium nitrate68.6473.78 73.47 78.81 content (%) , . .
~L~4Q~
T A B L E VII Cont 'd 1 - Block copolymer comprising 3~% component ~ (residue of polyalkylene glycol of MW 1500) 2 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 3 - 15 parts sodium nitrite, 20 parts ammonium nitrate, 20 parts sodium thiocyanate, 45 parts water by weight 4 - Highly chlorinated paxaffinic hydrocarbon 5 - Norsk-Hydro calcium nitrate prills 6 - Fuel oiL~o. 2 7 - Oil-deficient ANFO - 47.25% AN and 0.75% Fuel oil No, 2 8 - Contains whipped-in air bubbles From the results in Table VII lt can be seen that various combinations of oxidizer salts, fuels and/or inerts can be utilized to dope the basic microemulsion compositions and that cap-sensitivity and/or primer sensitivity is well r~-tained even at up to fairly high levels of addition. It is 20 equally evident that the other explosive properties such as velocity of detonation and small critical diameter, for example, are also fairly well retained by these new explosive composi-tions.
In order to demonstrate that various solid self explosi-ve ingredients and various water-soluble and/or hydrocarbon-soluble organic sensitizers may be used as sensitizing agents, in either the base microemulsion or the doped microemulsion compositions, a ~eries of compositions were prepared using 30 various agents representative of the above class of sensitizers, The results are shown in Table VIII.
~4~7~iS
T A B L E VIII
_______________ .
Ingredients Ex.53Ex,54 Ex.55Ex. 56 EX, 57 Ex,58 Ammonium nitrate59.160.366.338.536.2 37,79 5 Sodium nitrate 15.212.8 - 11.814.0 10.11 Calcium nitrate - - 8.7 - - -Zinc nitrate - 0.3 - 0,3 Sodium borate Ethylene glycol mono-nitrate4.6 - - - - -Ethanolamine nitrate - 7.2 - 6.6 Methylamine nitrate - - - - 9.3 Water 13.412,6I2.611.410.67,67 Polymeric emulsifierl 0,3 0.3 0.3 0.2 Q.2 0.18 Sorbitan sesqui-oleate0.7 0.7 0,7 0.7 0.6 0,42 Lecithin 0,7 0.7 0.7 0,7 0.60.42 Paraffin oil2.2 1.6 - 2.3 2O5 Fuel oil No. 2 - - - - - 1~66 Paraffin wax1.5 1.5 2,7 2.0 1.01.19 20 ~-propyl nitrate - - 6.0 Glass microspheres 2,3 2,0 2.0 0.5 Dop~s Ammonium nitrate prills - - - 25,0 25.0 25.56 TWT prills - - - - 15.0 Properties at 5C in 25 mm Oxygen balance (%) -~1.4 -0.4 -1.9 -3.9 0.0 -8.1 Density (g/cc) 1.15 1.17 1.18 1.32 1.31 1,47 Cartridge diameter (mm) 25 25 25 75 75 75 Minimum initiator5 F/C 6 F/C 8 F/C
Booster (g pentolite) - - - 160 160 160 Velocity of detonation 4.8 4,9 4.4 4.3 4.8 4.0 (km/sec) ~ _ , 1 - Block copolymer comprising 30% of component B (residue of a polyalkylene glycol of MW 1500) 2 - Contains whipped-in air bu~bles s As can be seen from the results of Tab1e VIII a variety ) of cap or booster sensitive compositions may be prepared over a broad range of densities (i e at various levels o~ occluded gas bubbles) by using various self-explosive ingredients such as TNT or water-soluble and/or hydrocarbon-soluble organic sensitizers such as ethylene glycol mononitrate, methylamine nitrate, n-propyl nitra-te, ethanolamine nitrate and the like.
The versatility of the emulsifier combinations of this lQ invention towards producing stable microemulsions in the pre-sence of a broad range of usually hostile organic nitrate sensitizers is clearly evident in Examples 53-5~3. Further, this versatility provides the formulator with a most useful tool in defining a complete, tailor made range of products //
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, ~ _. _ e ~
11~0'~65 SUPPLEME~TAR~ DISCLOSURE
It has now been found that an additional type of amphiphatic, synthetic pol~meric emulsi~ier possesses parti-lar utility, when combined ;~ith a conventional water-in-oil emulsifier, in the production oftime-stable, emulsion explosive compositions This type of polymeric emulsifier is com~only designated an alkyd resin and is the condensation product of (a) a polybasic acid or anhydride alone or in combina-tion lO with a monobasic acid, and (b) a polyhydric alcohol of mole-cular weight at least 500. More particularly, the polybasic acid component of the alkyd resin may be saturated, or un-saturated either by olefinic or aromatic unsaturation Com-monly used acids arealiphatic or aromat.ic dibasic acids con-15 taining up to 20 carbon atoms, preferably up to 10 carbonatoms such as, for example, orthQ-, iso- or terephthalic acid, maleic acid and fumaric acid. The polybasic acid may also be tri- or tetra-basic, suitably an aromatic acid con-taining up to 20, preferably up to 10 carbon atoms such as, 20 for e~ample, trimellitic acid or pyromellitic acid The optional monobasic acid component of the alkyd resin, which runctior.s as a monofunctional chain terminator, may be derived from a rr2e acid or Erom an ester of the acid, par-ticularly a gl-yceride The acid is preferably an aliphatic 25 saturated or e hylenically unsaturated acid containing up to 30 carbon atoms, ~referably 6 to 22 carbon atoms Mixtures of acids or their esters may also be used to derive the mono-basic acid component, partlcularly naturally-occurring mix-tures such as tall oil acids, or acids derived from linseed 30 oil, soyabean oil, castor oil, cottonseed oil and the like Other monobasic acid chain terminators known to those expert in the field may also be used as may monohydricalcohol chain terminators which are also known for this purpose, for example, Cl to C20 alkanols The polyhydric alcohol is a water-soluble polyalkylene ~14(~7~6~
glycol which has a molecular weight in the range of 500 to 10,000, preferably 500 to 5,000. The water-soluble poly-alkylene glycol is preferably polyethylene glycol, bu-t poly-propylene glycol or polyalkylene glycols containiny a majorproportion of ethyleneoxy groups together with minor pro-portions of randomly distributed propyleneoxy and/or butylene-oxy groups may also be used. One of the terminal hydroxyl groups of the polyalkylene glycol may, if desired, be~etheri-10 fied, for examplej with a lower Cl to C6 alcohol.
The alkyd resins so obtained contain at least 10% byweight of residues of the polyalkylene glycol, and pre~erably from 25% to 50%.
To demonstrate the effectiveness o~ a blend of a poly-meric alkyd resin emulsifier and a conventional emulsifier in producing a time-stable microemulsion explosive composition, a composition was prepared from the ingredients shown in Table IX, below. From an examination of Table IX, it will be 20 seen that the composition produced compares favourably wi-th other previously demonstrated compositions made in accordance with the invention - /
~ . . _ . _ _ , _, . . .
1l4(d7~6s TABLE IX
Ammonium nitrate 61 8 Sodium nitrate 16.6 Water 12.6 Alkyd resin emulsifier - Tall oil fatty acid/trimellitic an-hydride alkyl resin containing 30% of a polyalkylene ~lycol of MW 1500 0,3 Sorbitan sesqui-oleate 0.7 Lecithin 0.7 Paraffin oii 2,8 Paraffin wax 2,0 Glass microspheres 2,5 Density tg/cc) 1.15 Oxygen balance (5) -0.6 Cartridge diameter (mm) 25 Temperature (C) 5 Minimum initiator 7 F/C
A further series of compositions were prepared similar to those of Examples 1-10 but employing a number of different 15 polymeric emulsifiers in combination with sorbitan sesqui-f _ __ , , _, _ , . , . ., . ~ ., ., . .. ... ,_, _, . , T A B L E II
. ~ , Ingredients Ex.ll Ex.12 Ex.13 Ex.14 , . .. _ _ .
Ammonium nitrate 61.7 61.7 61.6 61.9 Sodium nitrate 16.6 16.6 16.6 16.6 5 Calcium nitrate - - -Sodium borate 0.5 0.5 0.5 Water 12.6 12.6 12.6 12.5 Polymeric emulsifier - 1 0.4 - ~ -" " - 2 - 0.4 - -" " - 3 - - 0.3 " " - 4 - - - 0.3 " " - 5 - _ _ _ ll - 7 15 Sorbitan sesqui-oleate0.6 0.6 0.7 0.7 Lecithin 0.6 0.6 0.7 0.7 Parafin oil 2.7 2.7 2,7 2.8 Paraffin wax 2.0 2.0 2.0 2.0 Glass microspheres 2.3 2.3 2.3 2~5 Density (g/cc) 1.10 1.10 1.10 1.12 oxygen balance (%) 0.0 0.0 -0.3 -0.6 Cartridge diameter (mm) 25 25 25 25 Temperature ~C) 5 5 5 9 25 Minimum initiator 7 F/C 7 F/C 6 F/C 6 F/C
1 - ~lock copolymer comprising 25% of component B (residue of a polyalkylene glycol of MW 1000 - 1500) 2 - Block copol~mer comprising 30% of component ~ as in 1 3 - Block copolymer comprising 35% of component B as in 1 30 4 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 5 - Polyester from polyisobutenyl succinic anhydride and 39% of a polyalkylene glycol of MW 600 6 - Block copolymer comprising 20% of component B (residue of a polyethylene imine of MW 5000Q). The resin was formulated to be largely as an amide 7 - Blcck copolymer comprising 20% o component B as in 6.
The resin was formulated to be largely as a salt.
114(.~7 Ei5 T A B L E II cont'd _ IngredientsEx.lS Ex.16 Ex.17 Ammonium nitrate 61.9 55.7 55.7 Sodium nitrate 16.6 15.0 15.0 Calcium nitrate - 5.7 5.7 Sodium borate - 0.5 0.5 Water 12.6 14.1 14Ol Polymeric emulsifier - 1 - - -" - 2 " - 4 - 5 0.2 - 6 - 0.3 " " - 7 - - 0.3 Sorbitan sesqui-oleate 0.7 0.7 0.7 Lecithin 0~7 0 7 0 7 Paraffin oil 2.8 2.8 2,8 Paraffin wax 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2O5 Density (g/cc) 1.16 1.15 1.15 Oxygen balance (%) -0.3 +0.2 +0.2 Cartridge diameter (mm)25 25 2S
2 Temperature (C) 6 15 15 5 Minimum initiator 7 F/C EB EB .
1 ~ Block copolymer comprising 25% of component B (residue of a polyalkylene glycol of MW 1000 - 1500) 2 - Block copolymer comprising 30% of component B as in 1 3 - Block copolymer comprising 35% of component B as in 1 4 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 5 - Po~yester fxom polyisobutenyl succinic anhydride and 3~/O of a polyalkylene glycol of MW 600 6 - Block copolvmer comprising 20% of component B (residue of a polyethylene-imine of MW 50000)~ The resing was formulated to be largely as an amide.
7 - Block copolymer comprising 20% of component B as in 6, The resin was formulated to ba largely as a salt.
7~
From Tab~e II it can be seen that cap-sensitivity at low temperature was maintained with all the polymeric emulsifier combinations employed.
EXAMPLES_18-21 A further series of compositions were prepared similar to those of Examples 1-17 but employing either a blend of polymeric emulsifiers in combination with a conventional emulsifier, or a polymeric emulsifier in combination with 10 a blend of conventional emulsifiers, or other different blends of polymeric and conventional emulsifiers, with and without an optional phosphatide emulsion stabilizer~ The results are shown in Table III, bel~w.
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~14~
T A B L E III
_______________ Ingredlents Ex.18 Ex.l9 Ex.20 Ex.21 Ammonium nitrate 61.9 62.1 61.7 61.7 Sodium nitrate 16.6 16.6 16.5 16.6 Water 12O6 12.6 12.6 12.5 Polymeric emulsifier - l0 . 2 " " - 2 0 .2 - - -" " - 3 - 0.2 0,2 0,2 Atmos 300 (Reg, TM) - 4 0 . 5 0 . 5 Sodium stearate - 0. 5 Witcamine 3164 (Reg. TM) - 5 - - 0.7 -Armac ~T (Reg. TM) - 6 - - - 0.7 Lecithin 0.5 ~ 0.7 0 7 Cereclor 70 L (Reg. TM) - 7 - - - 0,5 Paraf~in oil 3.0 3.0 2.8 2.6 Paraffin wax 2.0 2.0 2.0 2.0 Glass microspheres 2.5 2.5 2.8 2.5 20 Density (g/cc) 1.15 1.15 1.05 1.16 oxygen balance (%) -0.6 0.0 -0.4 -0.1 Cartridge diametex (mm) 25 25 25 25 Temperature (C) 5 5 5 5 Minimum initiator 6 F/C EB 7 F/C EB
_ _ _ _ .
1 - Block copolymer comprising 30% of component B (residue of a water-soluble polyalkylene glycol of MW 1500) 2 - Polyester from polyisobutenyl succinic anhydride and 30% o~ a polyalkylene glycol of MM 600 3 - Polyester from polyisobutenyl succinic anhydride and 39O/o of a polyalkylene glycol of MW 600 4 - Mono and diglycerides of fat-forming fatty acids 5 - Alkyl amidoamine 6 - Acetic acid salts of n-alkyl amines 7 - Highly chlorinated paraffin~ hydrocarbon ~14~7~i5 From Table III it can be seen that cap-sensitivity at low temperature was maintained with any of the further polymeric emulsifier(s)/conventional emulsifier(s) combina-tions employed in these examples, EX~MPLES 22-29 To demonstrate that a variety of oxidizer salts can be utilized in the microemulsion explosive compositions of the invention and further, to show various methods of incoxpo-10 rating occluded air ih the composition and thus controllingthe final density, a series of compositions were prepared using various oxidizer salts and dansity reducing methods.
The results are given in Table IV, below.
_ . /
~14C?76~5 T A B L E IV
IngredientsEx.22 Ex.23 Ex.24Ex.25 .. . ... - .
Ammonium nitrata 75,9 65.7 58.559.4 5 Sodium nitrate - 17.7 7.0 Calcium nitrate - - 9,0 9.1 Sodium borate Water 17.2 7,3 13.113.2 Polymeric emulsifier - 1 0,3 0,3 0.3 0.3 10 Sorbitan sesqui-oleate 0.7 0.7 0.7 0.7 Lecithin 0.7 0.7 0.7 0,7 Paraffin oil 2.2 4,0 3.2 2.5 Paraffin wax 1.0 1.0 - 1.6 Glass microspheres2.0 2.6 2.5 2.5 Gassing solution - 2 Porous glass agglomerates - - - -Particulate aluminium - - 5.0 Density (g/cc) 1.17 1.10 1.161.17 Oxygen balance (%)0.0 0,0 -0.3 0,0 20 Cartridge diametsr (mm) 25 25 25 25 Temperature (C) 5 8 8 5 Minimum initiator 7 F/C 6 F/C 5 F/C 7 F/C
Minimum initiator after 25 storage at - 40~C - - - 7 F/C
Minimum initiator at -40C -, _ . _ , , , , 1 - Block copolymer comprising 30% of component B
(residue of a water-soluble polyalkylene glycol of MW 1500) 2 - 50% water, 20% sodium nitrite, 30% sodium thiocyanate by weight S
T A B L E IV cont' d ____________________ Ingredients Ex, 2 6Ex ~ 2 7Ex, 2 8Ex, 2 9 Ammonium nitrate 61.1 58.7 63,3 61.5 Sodium nitrate 16.5 7,2 16.9 16,5 Calcium nitrate - 10.8 Sodium borate 0,5 - - -Water 12.5 13,8 12,8 12,5 Polymeric emulsifier - 1 0,3 0,3 0,3 0,3 10 Sorbitan sesqui-oleate 0,7 0,7 0,7 0.7 ~ecithin 0.7 0.7 0.7 0.7 Paraffin oil 2,7 4.8 2,8 4,6 Paraffin wax 2,0 - 2~0 Glass microspheres 3.0 3,0 15 Gassing solution - 2 - - 0,5 -Porous glass agglomerates - - - 3.2 Particulate aluminium - - - - .
Density (g/cc) 1.05 1,10 1.05 1.10 20 Oxygen balance (%) -0,4 -0,4 -0,2 0,0 Cartridge diameter (mm) 25 25 25 25 Temperature (C) 5 5 5 6 Minim~m initiator 6 F/C 6 F/C 7 F/C 6 F/C
Minimum initiator after Failed 25 storage at -40C EB 7 F/C
Minimum initiator at Failed -40C EB EB - - .
30 1 - Block copolymer comprising 30% of component B
(residue of a water-soluble polyalkylene glycol of MW 1500) 2 - 50% water, 20% sodium nitrite, 30% sodium thiocyanate by weight ~ ~C'-~6~i From the results in Table IV it can be observed that a variety of oxidizer salts can be utili2ed in the formulation of the water-in-oil microemulsion explosives, Of particular interest is the surprisin~ effect of calcium nitrate in pro-ducing exceptional cap-sensitivity at extremely low tempera-ture, as exemplified in Examples 25 and 27.
Also evident from Examples 28 and 29 is the fact that porous glass agglomerates and chemical generation of in-situ 10 gas bubbles are equally effective density reducing methods.
~a .
In order to demonstrate the exceptional stability o the microemulsion explosive compositions o~ this invention, a fu~ther series of compositions were prepared. The cap 15 sensitivity of these compositions was determined within one week of manufacture and approximately every month thereafter up to about one year, at which time the supply of material was exhausted. The results are shown in Table V, the quan-tities shown being in weight percent.
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T A B L E V
Ingredients Ex. 30 Ex~ 31 _ _ Ammonium nitrate 61.7 61.7 Sodium nitrate 16.6 16.6 Sodium borate 0.5 0.5 Water 12.6 12.6 Polymeric emulsifier - 1 0.4 " " - 2 - 0.4 10 Sorbitan sesqui-oleate 0.6 0.6 Lecithin 0.6 0.6 Paraffin oil 2.7 2.7 Paraffin wax 2.0 2.0 Glass microspheres 2.3 2.3 Density tg/cc) 1.10 1.10 Oxygen balance (%) o.o 0.0 Cartridge diameter (mm) 25 25 Temperature (C) 5 5 20 Minimum initiator (fresh) 7 F/C 7 F/C
Aging period (months) 1 3 123 1 - Block copolymer comprising 30% of component B (re idue of water-soluble polyalkylene glycol of MW 1500) 2 - Block copolymer comprising 25% of component B (residue of a water-soluble polyalkylene glycol of MW 1000 - 1500) 3 - Pexiod during which cartridges were successfu~ly detonated with electric detonator at 5C until the supply of the material was exhausted after 12 months s A further aspect of the mi~roemulsion explosive compo-tion of the present invention is that doping with substanti-ally large proportions of, for example, energy enhancing solid materials such as solid ~ prills, does not signifi-cantly alter the sensitivity or the stability of the compo-sition Furthermore, if the microemulsion composition is formulated so as to possess a suitably high fluidity, a very large proportion of these solid materials may be added without 10 significant loss of pumpability. Retention of fluidity is not usually the case with water-gel explosives; the addition of extra amounts of high energy content ingredients such as AN prills is severely restricted because of rapid loss of pumpability, reduction in initiator sensitivity levels and 15 in water resistance qualities. Doping of the microemulsion compositions of this invention at levels up to 50% addition of extra A~ prills or ANF0, nevertheless produces waterproo~
pumpable explosive compositions which retain booster sensi-tivity at densities up to 1.35 g/cc. These new explosive 20 compositions have weight strengths which are substantially higher than the weight strength of the undoped microemulsion and, more importantly, the raw material costs are at the same time substantially reduced. Furthermore, the blasting per-formance which is in part determined by calculable gas evola-25 t~on volumes, is substantially higher than that of otherpumpable, waterproof explosive compositions because of the much higher proportion of gas producing A~ contained in these new explosive cQm~ositions. In addition, the other unique explosive properties associated with the microemulsion com-30 positions su~h as high velocities of detonation, very smallcritical diametexs, temperature independent sensitivity, and storage stability, are substantially retained b~ the doped microemulsion compositions.
Inverted phase slusries such as described in United 35 States patent ~o. 4,141,767 have virtually no storage sta-bility and are not able to support large proportions of ~4~
extra added salts. On cooling to ambient temperature, some of the oxidizer salt already precipitates from the solution and this rapidly desensitizes the composition, making it less fluid and increasingly more difficult to load into boreholes by pump or to package by extrusion methods.
These inverted phase compositions have limited use in that they must be pumped immediately after manufacture and deto-nated within a relatively limited period of time The micro-10 emulsion compositions of the present invention, on the otherhand, retain their fluidity and pumpability for long periods of time even when doped with large proportions o additional oxidizer salts.
All known prior art water-in-oil emulsion explosives 15 also suffer from lack of stability. The presence of solid oxidizer salts act as seeding crystals and rapidly destabi-lizes the basic emulsion~ This is illustrated in the fol-lowing Examples 32 - 33.
A prior art emulsion based explosive composition and a microemulsion based explosive composition were prepared and then doped with ground AN to compare their sensitivity and more particularly their stability. Both compositions were submitted to a temperature cycling test consisting of 3 days 25 of storage at 50C followed by 2-3 days of storage at -17C.
The results axe shown in Table VI the quantities shown being in parts by weight ~:~L4~3765 - T A B L E VI
. . _ . .
Inyredients Ex. 32 Ex. 33 .. .. __ Ammonium nitrate 61.4 61.2 Sodium nitrate 17.0 16.9 Water 12.6 12.5 Sorbitan mono-oleate 1.0 Sorbitan sesqui-oleate - 0,7 Lecithin _ o 7 10 Polymeric emulsifier (1) ~ 0 3 Paraffin oil 4.8 S.5 Paraffin wax . 2.0 l.O
Glass microspheres 3.0 3.0 Dopes Ammonium nitrate - ground 31.5 31.5 Total (parts) 133.3 133.3 _ ===== = ===_ ===== ====_ Properties at 5C in 25mm Oxygen balance (%) ~0,3 -0,3 Density (g/cc) 1.17 1.17 Minimum initiator - fresh ( ) EB 7 F/C
Minimum initiator after 1 cycle Failed 2,5 g ~ F/C
primer Minimum initiator after 2 cycles - 9 F/C
Minimum initiator after 3 cycles - EB
1 - Block copolymer compxising 30% of component B
(residue of a water-soluble polyalkylene ~lycol of MW 150~) 2 - One cycle consisted of: 3 days of storage at 50C
followed by 2-3 days of storage at -17C. Samples were warmed up to 5C before testing ~14C3765 In Table VI, it can be seen that the A~ crystal doping quickly resulted in a rapid loss of initiator sensitivity of the prior art emulsion. On the other hand, the doped micro-emulsion was much more sta~le to this seeding crystal effectand remained cap-sensitive for a relatively long period of tim~ under unusually severe storage conditions.
EXAMoeLES 34-52 In order to demonstrate the various optional materials, 10 especially oxidizer salts, which can be dispersed in the microemulsion explosive compositions of this invention to form cap-sensitive and/or boostex-sen9itive explosive mix-tures, a series of compositions were prepared using various combinations of oxidizer salts, fuels and inert materials.
15 The results are presented in Table VII.
~ . . _ . ... . .
~4~:~7 EiS
_ 33 -T A B L E VII
. ~ ~ .
Ingredients Ex.34 Ex.35 Ex.36 Ex.37 . . . _ .
Ammonium nitrate 45,68 49.18 49.14 46.83 Sodium nitrate 15.36 13,16 13.25 12.98 Calcium nitrate Sodium borate - - 0,36 -Water 12.0 9.98 10.05 9.57 Polymeric emulsifier~0.24 0.24 0.24 0,23 10 Polymeric emuls.ifier2 - - - -Sorbitan sesqui-oleate 0.56 0.56 0.56 0,52 Lecithin 0.56 0.56 0.56 0.52 Cereclor 70 1 (Reg.TM)4 Paraffin oil 2.72 2,72 2.84 2.10 15 Paraffin wax 2.0 1.2 1.6 1.5 Glass microspheres 2,0 2,4 2,0 Gassing solution3 - - - 0,75 Dopes Ammonium nitrate - prills " " - ground 18.88 17.0 ANFO - - - 25.0 Sodium nitrate - prills - - 14,4 Calcium nitrate - prills5 : Particulate alum.inium - 3.0 5,0 Sodium chloride Barium sulfate Properties at 5C
Oxygen balance (%) +0.4 -0,1 -0.3 0.O
Density (g/cc) 1.15 1.18 1.21 1.18 30 Cartridge diameter (mm) 50 25 50 50 Minimum initiator 8 F/C7 F/C 7 F/C 8 F/C
Primer (g - pentolite) ~OD (km/sec) 4.44.0 4.7 4.3 Total ammonium nitrate 64.6666.18 49.14 70.44 35 content (%) i7~S
-- 3~ --T A B L E VII Cont.'d , Ingredients Ex.38 Ex.39 Ex.40 Ex.41 ~Imnonium nitrate 56.57 51.61 46.21 45,5 Sodium nitrate - - 12.37 12.2 Calcium nitrate - 6.75 - -Sodium borate - - - -Water 12.83 9.82 9.38 9.2 Polymeric emulsifier1 0~21 0.23 - 0.2 Polymeric emulsifier2 - - 0.23 -Sorbitan se~ui-oleate 0.53 0.52 0.52 0.5 ~ecithin 0.53 0.52 0.52 0.5 Cereclor 70 1 (Reg.TM)4 Para~fin oil 3.03 3.71 4.16 3.9 Paraffin wax 0,75 0.75 0.75 1.0 Glass microsph~res 1.87 2.48 2,25 2.0 Gassing solution3 - - - -Dopes Ammonium nitrate - prills - - - 25.0 " " - ground 23.68 23.61 23.61 A~FO
Sodium nitrate - prills - - - -Calcium nitrate - prills5 - - - -particulate aluminium - - ~ ~
Sodium chloride - - - -Barium sulfate - - ~ -Pro,~erties at 5C
Oxygen balance (%) -0.1 -0.2 -0.3 -0"6 Density (g/cc) 1.20 1.19 1.20 1.21 Cartridge diameter (mm) 25 25 25 75 Minimum initiator 9 F/C 7 F/C 9 F/C 9 F/C
Primer (g - pentolite) - - - -tlOD (km/sec~ 4.0 3,8 3.6 5.2 Total ammonium nitrate 80.25 75.22 69.82 70,5 content (%) . ~ .
7~5 T A B ~ E VII cont.'d _________._____ ______.
. .
IngredientS Ex. 42 Ex. 43 Ex. 44 . -Ammonium nitrate 50.53 43.09 46.16 Sodium nitrate 13,52 11.62 12,35 Calcium nitrate - - -Sodium borate - 0,32 Water 10.25 8.81 9.37 : Polymeric emulsifier 0.25 0.21 0.23 10. Polymeric emulsi~ier2 ~ - -Soxbitan sesqui-oleate 0.58 0.49 0.52 Lecithin 0.58 0.49 0.52 . Cereclor 70 1 (Reg.TM)4 0.41 Paraffin oil 2.64 3.93 2.85 Paraffin wax 1.24 1.05 0O75 Glass microspheres 2.47 1.61 2,25 Gassing solution Dopes i Ammonium nitrate - prills " " - ground 17.53 28.38 A~FO - - -Sodium nitrate - prills - - _ ' Calcium nitrate - prills ¦ Particulate aluminium 25l Sodium rhloride - - 25,0 ¦ Barium sul~ate I Properties at 5C
I
! Oxygen balance (%) ~3.0 -0.4 -0.5 Density (g/cc) 1~12 1.21 1.26 Cartridge diameter (mm) 25 50 25 Minimum initiator 5 F/C 9 F/C 5 F/C
Primer ~g - pentolite) VOD (km/sec) 4.2 4.1 4.0 Total ammonium nitrate68.06 71.47 46.16 35 content (%) _ . _ S
- 36 _ T A B L E VII ContO'd ______________ _______ Ingredients EXo45 Ex,46 Ex,47 Ex.48 . ._ . . .
Ammonium nitrate 54.53 47.24 60,743,33 Sodium nitrate 6.53 12.67 - 11.68 Calcium nitrate 8.41 Sodium borate - 0.37 . - 0.32 Water 12,16 9,82 8.38.86 Polymeric emulsifierl 0.27 0.22 0,200.21 Polymeric emulsifier Sorbitan sesqui-oleate 0.63 0.53 0.60.49 Lecithin 0.63 0~53 0.60.49 Cereclor 70 1 (Reg.TM)4 Paraffin oil 2.34 3.50 - 3.36 Paraffin wax 1.80 1.50 3.91.40 Glass microspheres 2.70 - 1.01.26 Gassing solution Dopes Ammonium nitrate - prills - 23.6224,7 " " - ground - - - -A~FO
Sodium nitrate - prills Calcium nitrate - prills5 - - - 23,6 Particulate aluminium - - - 5,0 Sodium chloride Barium sulfate 10.0 . Pxopexties at 5C
Oxygen balance (%) ~0.2 -0.4 ~0.2~0,3 Density (g/cc) 1.22 1.25 1.271.25 Cartridge diametex (mm)25 75 75 75 Minimum initiator 6 F/C
Primer (g - pentolite) _ 160 160 160 VOD ~km/sec) 4.1 4.9 4O9 4.5 Total ammonium nitrate54.53 70,86 85,443.33 35 content (/O) _ _ ~4(376S
T A B L E VII Cont 'd Ingredients Ex.49 Ex.50 Ex.51 Ex.52 _ _ .
Ammonium ni~rate 40.32 40.67 35~86 31,56 Sodium nitrate 13.51 11.27 11.03 8~74 Calcium nitrate Sodium borate - - - -Water 10.64 8,31 8.28 6.45 -Polymeric emulsifierl0,21 0,19 0.18 0.15 Polymeric emulsifier2 Sorbitan sesqui-oleate0.84 0.46 0.41 0.35 Le~ithin 0.14 0.46 0.41 0.35 Cexeclor 70 1 (Reg.TM)4 - - - -Paraffin oil 1.89 2.47 3.8663.25 1 1~ Paraffin wax 1.40 0065 1.18 1.15 ~
Glass microspheres 1.05 - 1.18 - ¦
Ga~sing solution3 - 0.5~ - -Dopes Ammonium nitrate - prills - - 37.61 " " - ground ANF0 30.0 35.0 - 48.o7 Sodium nitrate - prills Calcium nitrate - prills5 - - _ _ Particulate aluminium Sodium chloride Barium sulfate - - _ Properties at 5C
Oxygen balance (%) +0.1 -0.1 +0.3 -0.6 Density (g/cc) 1.29 1.26 1.25 1.338 Cartridge diameter (mm) 150 75 75 75 Minimum initiator Primer (g - pentolite) 450 160 80 80 VQD (hm/sec) 4.6 4,0 1.5 3.5 Total ammonium nitrate68.6473.78 73.47 78.81 content (%) , . .
~L~4Q~
T A B L E VII Cont 'd 1 - Block copolymer comprising 3~% component ~ (residue of polyalkylene glycol of MW 1500) 2 - Polyester from polyisobutenyl succinic anhydride and 30% of a polyalkylene glycol of MW 600 3 - 15 parts sodium nitrite, 20 parts ammonium nitrate, 20 parts sodium thiocyanate, 45 parts water by weight 4 - Highly chlorinated paxaffinic hydrocarbon 5 - Norsk-Hydro calcium nitrate prills 6 - Fuel oiL~o. 2 7 - Oil-deficient ANFO - 47.25% AN and 0.75% Fuel oil No, 2 8 - Contains whipped-in air bubbles From the results in Table VII lt can be seen that various combinations of oxidizer salts, fuels and/or inerts can be utilized to dope the basic microemulsion compositions and that cap-sensitivity and/or primer sensitivity is well r~-tained even at up to fairly high levels of addition. It is 20 equally evident that the other explosive properties such as velocity of detonation and small critical diameter, for example, are also fairly well retained by these new explosive composi-tions.
In order to demonstrate that various solid self explosi-ve ingredients and various water-soluble and/or hydrocarbon-soluble organic sensitizers may be used as sensitizing agents, in either the base microemulsion or the doped microemulsion compositions, a ~eries of compositions were prepared using 30 various agents representative of the above class of sensitizers, The results are shown in Table VIII.
~4~7~iS
T A B L E VIII
_______________ .
Ingredients Ex.53Ex,54 Ex.55Ex. 56 EX, 57 Ex,58 Ammonium nitrate59.160.366.338.536.2 37,79 5 Sodium nitrate 15.212.8 - 11.814.0 10.11 Calcium nitrate - - 8.7 - - -Zinc nitrate - 0.3 - 0,3 Sodium borate Ethylene glycol mono-nitrate4.6 - - - - -Ethanolamine nitrate - 7.2 - 6.6 Methylamine nitrate - - - - 9.3 Water 13.412,6I2.611.410.67,67 Polymeric emulsifierl 0,3 0.3 0.3 0.2 Q.2 0.18 Sorbitan sesqui-oleate0.7 0.7 0,7 0.7 0.6 0,42 Lecithin 0,7 0.7 0.7 0,7 0.60.42 Paraffin oil2.2 1.6 - 2.3 2O5 Fuel oil No. 2 - - - - - 1~66 Paraffin wax1.5 1.5 2,7 2.0 1.01.19 20 ~-propyl nitrate - - 6.0 Glass microspheres 2,3 2,0 2.0 0.5 Dop~s Ammonium nitrate prills - - - 25,0 25.0 25.56 TWT prills - - - - 15.0 Properties at 5C in 25 mm Oxygen balance (%) -~1.4 -0.4 -1.9 -3.9 0.0 -8.1 Density (g/cc) 1.15 1.17 1.18 1.32 1.31 1,47 Cartridge diameter (mm) 25 25 25 75 75 75 Minimum initiator5 F/C 6 F/C 8 F/C
Booster (g pentolite) - - - 160 160 160 Velocity of detonation 4.8 4,9 4.4 4.3 4.8 4.0 (km/sec) ~ _ , 1 - Block copolymer comprising 30% of component B (residue of a polyalkylene glycol of MW 1500) 2 - Contains whipped-in air bu~bles s As can be seen from the results of Tab1e VIII a variety ) of cap or booster sensitive compositions may be prepared over a broad range of densities (i e at various levels o~ occluded gas bubbles) by using various self-explosive ingredients such as TNT or water-soluble and/or hydrocarbon-soluble organic sensitizers such as ethylene glycol mononitrate, methylamine nitrate, n-propyl nitra-te, ethanolamine nitrate and the like.
The versatility of the emulsifier combinations of this lQ invention towards producing stable microemulsions in the pre-sence of a broad range of usually hostile organic nitrate sensitizers is clearly evident in Examples 53-5~3. Further, this versatility provides the formulator with a most useful tool in defining a complete, tailor made range of products //
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, ~ _. _ e ~
11~0'~65 SUPPLEME~TAR~ DISCLOSURE
It has now been found that an additional type of amphiphatic, synthetic pol~meric emulsi~ier possesses parti-lar utility, when combined ;~ith a conventional water-in-oil emulsifier, in the production oftime-stable, emulsion explosive compositions This type of polymeric emulsifier is com~only designated an alkyd resin and is the condensation product of (a) a polybasic acid or anhydride alone or in combina-tion lO with a monobasic acid, and (b) a polyhydric alcohol of mole-cular weight at least 500. More particularly, the polybasic acid component of the alkyd resin may be saturated, or un-saturated either by olefinic or aromatic unsaturation Com-monly used acids arealiphatic or aromat.ic dibasic acids con-15 taining up to 20 carbon atoms, preferably up to 10 carbonatoms such as, for example, orthQ-, iso- or terephthalic acid, maleic acid and fumaric acid. The polybasic acid may also be tri- or tetra-basic, suitably an aromatic acid con-taining up to 20, preferably up to 10 carbon atoms such as, 20 for e~ample, trimellitic acid or pyromellitic acid The optional monobasic acid component of the alkyd resin, which runctior.s as a monofunctional chain terminator, may be derived from a rr2e acid or Erom an ester of the acid, par-ticularly a gl-yceride The acid is preferably an aliphatic 25 saturated or e hylenically unsaturated acid containing up to 30 carbon atoms, ~referably 6 to 22 carbon atoms Mixtures of acids or their esters may also be used to derive the mono-basic acid component, partlcularly naturally-occurring mix-tures such as tall oil acids, or acids derived from linseed 30 oil, soyabean oil, castor oil, cottonseed oil and the like Other monobasic acid chain terminators known to those expert in the field may also be used as may monohydricalcohol chain terminators which are also known for this purpose, for example, Cl to C20 alkanols The polyhydric alcohol is a water-soluble polyalkylene ~14(~7~6~
glycol which has a molecular weight in the range of 500 to 10,000, preferably 500 to 5,000. The water-soluble poly-alkylene glycol is preferably polyethylene glycol, bu-t poly-propylene glycol or polyalkylene glycols containiny a majorproportion of ethyleneoxy groups together with minor pro-portions of randomly distributed propyleneoxy and/or butylene-oxy groups may also be used. One of the terminal hydroxyl groups of the polyalkylene glycol may, if desired, be~etheri-10 fied, for examplej with a lower Cl to C6 alcohol.
The alkyd resins so obtained contain at least 10% byweight of residues of the polyalkylene glycol, and pre~erably from 25% to 50%.
To demonstrate the effectiveness o~ a blend of a poly-meric alkyd resin emulsifier and a conventional emulsifier in producing a time-stable microemulsion explosive composition, a composition was prepared from the ingredients shown in Table IX, below. From an examination of Table IX, it will be 20 seen that the composition produced compares favourably wi-th other previously demonstrated compositions made in accordance with the invention - /
~ . . _ . _ _ , _, . . .
1l4(d7~6s TABLE IX
Ammonium nitrate 61 8 Sodium nitrate 16.6 Water 12.6 Alkyd resin emulsifier - Tall oil fatty acid/trimellitic an-hydride alkyl resin containing 30% of a polyalkylene ~lycol of MW 1500 0,3 Sorbitan sesqui-oleate 0.7 Lecithin 0.7 Paraffin oii 2,8 Paraffin wax 2,0 Glass microspheres 2,5 Density tg/cc) 1.15 Oxygen balance (5) -0.6 Cartridge diameter (mm) 25 Temperature (C) 5 Minimum initiator 7 F/C
Claims (44)
l. A water-in-oil microemulsion explosive composition comprising from 3% to 30% by weight of the total composition of an aqueous solution of one or more oxygen-supplying salts as a discontinuous phase, from 0.1% to 20% by weight of the total composition of an insoluble liquid or liquefiable carbonaceous fuel selected from the group consisting of paraffinic, olefinic, naphthenic, aromatic, elastomeric, saturated or unsaturated hydrocarbons as a continuous phase, at least one sensitizing component distributed substantially homogeneously throughout the composition as a further discontinuous phase and from 0.4% to 4.0% by weight of an emulsifying agent, characterized in that the emulsifying agent comprises a combination of at least one conven-tional water-in-oil emulsifier, and at least one amphiphatic graft, block or branch polymeric emulsifier of the general formula (A-COO)2-B wherein each polymeric component A has a molecular weight of at least 500 and is the residue of an oil-soluble complex monocarboxylic acid and wherein each polymeric component B has a molecular weight of at least 500 and is the divalent residue of a water-soluble polyalkylene glycol, the ratio of said polymeric emulsifier to said conventional emulsifier being in the range of
1:25 to 3:1.
2. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the amphiphatic polymeric emulsifier comprises a polyester which is the product of condensation of a compound of the formula 1) wherein R is a saturated or unsaturated hydrocarbon substituent derived from a polymer of a mono-olefin, the said polymer chain containing from 40-500 carbon atoms, and 2) a polyalkylene gylcol which has a molecular weight of 500 to 20,000.
3. A water-in-oil microemulsion explosive composition as claimed in Claim 2 wherein the polyalkylene glycol moiety of compound B is replaced by a polyethyleneimine chain.
4. A water-in-oil microemulsion explosive composition as claimed in Claim 3 wherein the polyalkylene glycol component is replaced by a polyethyleneimine component.
5. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the conventional water-in-oil emulsifier used in combinations with the amphiphatic polymeric emulsifier is selected from the group consisting of sorbitan fatty acid esters, glycerides of fat-forming fatty acids, polyoxyethylene sorbitol esters, substituted imidazolines, aliphatic amido-amines, glycerol esters, fatty acid amines or ammonium salts, hydrocarbon sulfonate salts and alkali metal or ammonium stearates alone or in combination with stearic acid or combinations of all of these.
6. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein from 0.05% to 5.0% by weight of a phos-phatide emulsion stabilizer is admixed with the polymeric emulsifier and the conventional water-in-oil emulsifier.
7. A water-in-oil microemulsion explosive composition as claimed in Claim 6 wherein the phosphatide emulsion stabilizer is soybean lecithin.
8. A water-in-oil microemulsion explosive composition as claimed in Claim 1 containing from 0.1% to 2.0% by weight of an emulsion promotion agent.
9. A water-in-oil microemulsion explosive composition as claimed in Claim 8 wherein the said emulsion promotion agent is a highly chlorinated paraffinic hydrocarbon.
10. A water-in-oil microemulsion explosive composition as claimed in Claim 6 wherein the ratio of the total mixed emulsifiers to the optional phosphatide stabilizer is in the range of 1:10 to 100:1.
11. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the oxygen-supplying salt of the said aqueous solution comprises ammonium nitrate.
12. A water-in-oil microemulsion explosive composition as claimed in Claim 11 wherein said aqueous salt solution also contains up to 40% by weight of a further oxygen-supplying salt selected from the group consisting of alkali metal and alkaline earth metal nitrates, chlorates and perchlorates or mixtures thereof.
13. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the said sensitizing component dis-tributed substantially homogeneously throughout said composition comprises gas bubbles.
14. A water-in-oil microemulsion explosive composition as claimed in Claim 13 wherein the said gas bubble sensitizing component comprises up to 50% of the volume of the total composition.
15. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the said sensitizing component dis-tributed substantially homogeneously throughout said composition comprises a water-soluble or an hydrocarbon-soluble organic nitrate sensitizer.
16. A water-in-oil microemulsion explosive composition as claimed in Claim 1 wherein the said sensitizing component dis-tributed substantially homogeneously throughout said composition comprises a particulate solid self-explosive.
17. A water-in-oil microemulsion explosive composition as claimed in Claim 15 or 16 wherein the said sensitizing component comprises up to 40% by weight of said composition.
18. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing up to 50% by weight of un-dissolved particulate solid oxygen-supplying salts homogeneously dispersed therein.
19. A water-in-oil microemulsion explosive composition as claimed in Claim 18 wherein said undissolved particulate solid oxygen-supplying salts are selected from the group consisting of ammonium nitrate, sodium nitrate, and calcium nitrate.
20. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing up to 50% by weight of pre-blended ammonium nitrate/fuel oil mixture homogeneously dispersed therein.
21. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing up to 15% by weight of a particulate metal fuel selected from the group consisting of aluminum, aliminum alloys, silicon and ferro-silicon homogeneously dispersed therein.
22. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing up to 10% by weight of a particulate solid fuel homogeneously dispersed therein.
23. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing up to 40% by weight of a particulate solid inert material homogeneously dispersed therein.
24. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing a water phase or hydrocarbon phase thickening agent.
25. A water-in-oil microemulsion explosive composition as claimed in Claim 24 also containing a crosslinking agent.
26. A water in-oil microemulsion explosive composition as claimed in Claim 1 also containing a liquid phase extender.
27. A water-in-oil microemulsion explosive composition as claimed in Claim 1 also containing a crystal habit modifier.
28. A water-in-oil microemulsion explosive composition consisting essentially of:
1) from 4% to 20% by weight of water;
2) from 30% to 85% by weight of dissolved oxygen-supplying salts;
3) from 1% to 8% by weight of an insoluble liquid or liquefiable carbonaceous fuel;
4) from 0.5% to 1.2% by weight of an emulsifying agent comprising a combination of at least one conventional water-in-oil emulsifier and at least one synthetic polymeric emulsifier selected from amphiphatic graft, block or branch polymeric emulsifiers; and 5) a sensitizing amount of at least one sensitizing component selected from dispersed gas bubbles, water-soluble explosives, hydrocarbon-soluble explosives, and insoluble particulate explosives.
1) from 4% to 20% by weight of water;
2) from 30% to 85% by weight of dissolved oxygen-supplying salts;
3) from 1% to 8% by weight of an insoluble liquid or liquefiable carbonaceous fuel;
4) from 0.5% to 1.2% by weight of an emulsifying agent comprising a combination of at least one conventional water-in-oil emulsifier and at least one synthetic polymeric emulsifier selected from amphiphatic graft, block or branch polymeric emulsifiers; and 5) a sensitizing amount of at least one sensitizing component selected from dispersed gas bubbles, water-soluble explosives, hydrocarbon-soluble explosives, and insoluble particulate explosives.
29. A water-in-oil microemulsion explosive composition as claimed in Claim 28 also containing from 0.1% to 1% by weight of a phosphatide stabilizer.
30. A water-in-oil microemulsion explosive composition as claimed in Claim 28 also containing up to 50% by weight of undissolved particulate oxygen-supplying salt.
31. A water-in-oil microemulsion explosive composition as claimed in Claim 28 also containing up to 15% by weight of an auxiliary fuel ingredient.
32. A water-in-oil microemulsion explosive composition as claimed in Claim 28 wherein the conventional water-in-oil emulsifier is selected from the group consisting of sorbitan fatty acid esters, glycerides of fat-forming fatty acids, substituted imidazolines, aliphatic amidoamines, fatty acid amines or ammonium salts and alkali metal or ammonium stearates.
33. A water-in-oil microemulsion explosive composition as claimed in Claim 28 wherein the said dispersed gas bubble sensitizing component comprises:
occluded air or gas;
glass or resin microspheres;
in-situ generated gas bubbles or mixtures of these.
occluded air or gas;
glass or resin microspheres;
in-situ generated gas bubbles or mixtures of these.
34. The water-in-oil microemulsion explosive composition as claimed in Claim 31 wherein the said auxiliary fuel is aluminum.
35. A process for producing a microemulsion explosive composition comprising the steps of :
1) forming an aqueous solution of at least one oxygen-supplying salt and heating said solution to above the temperature of crys-tallization of the said salts;
2) forming a fuel solution of at least one liquid or liquefiable hydrocarbon fuel and from 0.4%
to 4% by weight of the total composition of an emulsifying agent comprising a combination of at least one conventional water-in-oil emulsifier and at least one synthetic emulsifier selected from amphiphatic graft, block or branch polymeric emulsifiers, and heating said solution to a temperature approximately equivalent to the temperature of said oxygen-supplying salt;
3) blending said oxygen-supplying salt solution and said fuel/emulsifiers solution to form a water-in-oil microemulsion; and 4) incorporating into the said microemulsion a predetermined quantity of gas in an amount sufficient to cause a lowering of the density of said composition and thereby regulate its sensitivity.
1) forming an aqueous solution of at least one oxygen-supplying salt and heating said solution to above the temperature of crys-tallization of the said salts;
2) forming a fuel solution of at least one liquid or liquefiable hydrocarbon fuel and from 0.4%
to 4% by weight of the total composition of an emulsifying agent comprising a combination of at least one conventional water-in-oil emulsifier and at least one synthetic emulsifier selected from amphiphatic graft, block or branch polymeric emulsifiers, and heating said solution to a temperature approximately equivalent to the temperature of said oxygen-supplying salt;
3) blending said oxygen-supplying salt solution and said fuel/emulsifiers solution to form a water-in-oil microemulsion; and 4) incorporating into the said microemulsion a predetermined quantity of gas in an amount sufficient to cause a lowering of the density of said composition and thereby regulate its sensitivity.
36. A process for producing a microemulsion explosive composition as claimed in Claim 35 wherein the quantity of gas incorporated is sufficient to provide a composition density of from 0.8 to 1.4 g/cc.
37. A process for producing a microemulsion explosive composition as claimed in Claim 35 wherein the said gas incorpora-tion is by means of direct air injection and occlusion.
38. A process for producing a microemulsion explosive composition as claimed in Claim 35 wherein the said gas incor-poration is by means of the addition of a gas-generating material.
39. A process for producing a microemulsion explosive composition as claimed in Claim 35 wherein the said gas incor-poration is by means of the addition of a void-containing material.
40. A process for producing a microemulsion explosive composition as claimed in Claim 35 wherein the said fuel component and said emulsifying component are heated separately and blended with the said heated salt solution.
41. A process for producing a water-in-oil microemulsion explosive composition as claimed in Claim 35 comprising the further step of adding to the said microemulsion undissolved solid ingredients selected from particulate oxygen-supplying salts, particulate ammonium nitrate/fuel oil mixtures, particulate self-explosives, particulate metals, particulate fuels and particulate inert materials.
CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE
CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE
42. A water-in-oil microemulsion explosive composition comprising an aqueous solution of one or more oxygen-supplying salts as a discontinuous phase, an insoluble liquid or liquefiable carbonaceous fuel as a continuous phase, at least one sensitizing component distributed substantially homogeneously throughout the composition as a further discontinuous phase and from 0.4 to 4.0 by weight of an emulsifying agent as claimed in Claim 1 charac-terized in that the emulsifying agent comprises a combination of at least one conventional water-in-oil emulsifier, and at least one amphiphatic polymeric emulsifier comprising an alkyd resin which is the product of condensation of (a) a polybasic acid or anhydride alone or in combination with a monobasic acid, and (b) a polyhydric alcohol which has a molecular weight of at least 500.
43. A water-in-oil microemulsion explosive composition as claimed in Claim 42 wherein the said polybasic acid is selected from an aliphatic or aromatic dibasic acid containing up to 20 carbon atoms.
44. A water-in-oil microemulsion explosive composition as claimed in Claim 42 wherein the said polyhydric alcohol is a polyalkylene glycol.
Priority Applications (16)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000342098A CA1140765A (en) | 1979-12-14 | 1979-12-14 | Explosive compositions based on time-stable colloidal dispersions |
| NZ192888A NZ192888A (en) | 1979-04-02 | 1980-02-15 | Water-in-oil microemulsion explosive compositions |
| IE422/80A IE49645B1 (en) | 1979-04-02 | 1980-03-03 | Explosive compostions based on time-stable colloidal dispersions and process for the preparation thereof |
| IN153/DEL/80A IN153804B (en) | 1979-04-02 | 1980-03-04 | |
| AU56243/80A AU528656B2 (en) | 1979-04-02 | 1980-03-07 | Water-in-oil explosive |
| EP80300814A EP0018085B1 (en) | 1979-04-02 | 1980-03-18 | Explosive compositions based on time-stable colloidal dispersions and a process for the preparation thereof |
| GB8009093A GB2050340B (en) | 1979-04-02 | 1980-03-18 | Rsions and process for the preparation thereof explosive compositions based on timestable colloidal dispe |
| DE8080300814T DE3061476D1 (en) | 1979-04-02 | 1980-03-18 | Explosive compositions based on time-stable colloidal dispersions and a process for the preparation thereof |
| PH23794A PH15721A (en) | 1979-12-14 | 1980-03-21 | Explosive compositions based time-stable colloidal dispersions |
| BR8001981A BR8001981A (en) | 1979-04-02 | 1980-03-31 | EXPLOSIVE COMPOSITION IN WATER MYCOEMULSION IN OIL AND PROCESS TO PRODUCE AN EXPLOSIVE COMPOSITION IN MICROEMULATION |
| NO800929A NO149205C (en) | 1979-04-02 | 1980-03-31 | EXPLOSIVE MIXTURE IN THE FORM OF A WATER-IN-OIL MICROEMULUM |
| ZW76/80A ZW7680A1 (en) | 1979-04-02 | 1980-03-31 | Explosive compositions based on sub-micron colloidal dispersions |
| ES490126A ES490126A0 (en) | 1979-04-02 | 1980-03-31 | PROCEDURE TO PREPARE AN EXPLOSIVE COMPOSITION IN MY-CROEMULSION OF WATER IN OIL |
| OA57072A OA06502A (en) | 1979-04-02 | 1980-04-01 | Explosive compositions based on colloidal dispersions which are stable over time. |
| US06/210,300 US4357184A (en) | 1979-04-02 | 1980-11-25 | Explosive compositions based on time-stable colloidal dispersions |
| MY362/87A MY8700362A (en) | 1979-04-02 | 1987-12-30 | Explosing compositions based on time-stable colloidal dispersions and process for the preparation thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000342098A CA1140765A (en) | 1979-12-14 | 1979-12-14 | Explosive compositions based on time-stable colloidal dispersions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1140765A true CA1140765A (en) | 1983-02-08 |
Family
ID=4115848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000342098A Expired CA1140765A (en) | 1979-04-02 | 1979-12-14 | Explosive compositions based on time-stable colloidal dispersions |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1140765A (en) |
| PH (1) | PH15721A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114316309A (en) * | 2021-12-28 | 2022-04-12 | 上海瑞凝生物科技有限公司 | Polyethylene glycol-polylysine hydrogel microspheres and preparation method thereof |
-
1979
- 1979-12-14 CA CA000342098A patent/CA1140765A/en not_active Expired
-
1980
- 1980-03-21 PH PH23794A patent/PH15721A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114316309A (en) * | 2021-12-28 | 2022-04-12 | 上海瑞凝生物科技有限公司 | Polyethylene glycol-polylysine hydrogel microspheres and preparation method thereof |
| CN114316309B (en) * | 2021-12-28 | 2023-12-05 | 上海瑞凝生物科技有限公司 | Polyethylene glycol-polylysine hydrogel microsphere and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| PH15721A (en) | 1983-03-18 |
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