US3745078A - Dispersion of fine ammonium perchlorate,aluminum or ferric oxide particles in propellants - Google Patents
Dispersion of fine ammonium perchlorate,aluminum or ferric oxide particles in propellants Download PDFInfo
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- US3745078A US3745078A US00677846A US3745078DA US3745078A US 3745078 A US3745078 A US 3745078A US 00677846 A US00677846 A US 00677846A US 3745078D A US3745078D A US 3745078DA US 3745078 A US3745078 A US 3745078A
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- aluminum
- ferric oxide
- surfactant
- ammonium perchlorate
- oxide particles
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- GDDNTTHUKVNJRA-UHFFFAOYSA-N 3-bromo-3,3-difluoroprop-1-ene Chemical compound FC(F)(Br)C=C GDDNTTHUKVNJRA-UHFFFAOYSA-N 0.000 title claims abstract description 42
- 239000002245 particle Substances 0.000 title claims abstract description 34
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 25
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 24
- 239000003380 propellant Substances 0.000 title description 30
- 239000006185 dispersion Substances 0.000 title description 19
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 title description 15
- 239000007788 liquid Substances 0.000 claims abstract description 42
- 239000004094 surface-active agent Substances 0.000 claims abstract description 40
- 238000000034 method Methods 0.000 claims abstract description 24
- 239000002002 slurry Substances 0.000 claims abstract description 23
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000007787 solid Substances 0.000 claims abstract description 15
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims abstract description 12
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims abstract description 12
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 claims abstract description 11
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000002480 mineral oil Substances 0.000 claims abstract description 9
- 235000010446 mineral oil Nutrition 0.000 claims abstract description 9
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims abstract description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000011734 sodium Substances 0.000 claims abstract description 8
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 8
- IIZPXYDJLKNOIY-JXPKJXOSSA-N 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCC\C=C/C\C=C/C\C=C/C\C=C/CCCCC IIZPXYDJLKNOIY-JXPKJXOSSA-N 0.000 claims abstract description 7
- 239000000787 lecithin Substances 0.000 claims abstract description 7
- 229940067606 lecithin Drugs 0.000 claims abstract description 7
- 235000010445 lecithin Nutrition 0.000 claims abstract description 7
- 239000000203 mixture Substances 0.000 claims abstract description 7
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 6
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 claims abstract description 6
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims abstract description 5
- SWXVUIWOUIDPGS-UHFFFAOYSA-N diacetone alcohol Natural products CC(=O)CC(C)(C)O SWXVUIWOUIDPGS-UHFFFAOYSA-N 0.000 claims abstract description 4
- 235000019441 ethanol Nutrition 0.000 claims abstract description 4
- 150000002169 ethanolamines Chemical class 0.000 claims abstract description 4
- 150000004001 inositols Chemical class 0.000 claims abstract description 4
- AJDIZQLSFPQPEY-UHFFFAOYSA-N 1,1,2-Trichlorotrifluoroethane Chemical compound FC(F)(Cl)C(F)(Cl)Cl AJDIZQLSFPQPEY-UHFFFAOYSA-N 0.000 claims abstract description 3
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims abstract 10
- VLTRZXGMWDSKGL-UHFFFAOYSA-M perchlorate Inorganic materials [O-]Cl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-M 0.000 claims abstract 4
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims abstract 4
- JLPULHDHAOZNQI-JLOPVYAASA-N [(2r)-3-hexadecanoyloxy-2-[(9e,12e)-octadeca-9,12-dienoyl]oxypropyl] 2-(trimethylazaniumyl)ethyl phosphate Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCCCCCC\C=C\C\C=C\CCCCC JLPULHDHAOZNQI-JLOPVYAASA-N 0.000 claims abstract 2
- YXFVVABEGXRONW-CNRUNOGKSA-N tritiomethylbenzene Chemical compound [3H]CC1=CC=CC=C1 YXFVVABEGXRONW-CNRUNOGKSA-N 0.000 claims abstract 2
- 239000004615 ingredient Substances 0.000 description 8
- 239000011230 binding agent Substances 0.000 description 7
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000010297 mechanical methods and process Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 3
- UGCSPKPEHQEOSR-UHFFFAOYSA-N 1,1,2,2-tetrachloro-1,2-difluoroethane Chemical compound FC(Cl)(Cl)C(F)(Cl)Cl UGCSPKPEHQEOSR-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 229910001651 emery Inorganic materials 0.000 description 2
- CDAISMWEOUEBRE-GPIVLXJGSA-N inositol Chemical compound O[C@H]1[C@H](O)[C@@H](O)[C@H](O)[C@H](O)[C@@H]1O CDAISMWEOUEBRE-GPIVLXJGSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003472 neutralizing effect Effects 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 150000008105 phosphatidylcholines Chemical class 0.000 description 2
- -1 sodium sulfonates Chemical class 0.000 description 2
- 239000004449 solid propellant Substances 0.000 description 2
- 235000010469 Glycine max Nutrition 0.000 description 1
- 244000068988 Glycine max Species 0.000 description 1
- SQUHHTBVTRBESD-UHFFFAOYSA-N Hexa-Ac-myo-Inositol Natural products CC(=O)OC1C(OC(C)=O)C(OC(C)=O)C(OC(C)=O)C(OC(C)=O)C1OC(C)=O SQUHHTBVTRBESD-UHFFFAOYSA-N 0.000 description 1
- 239000005062 Polybutadiene Substances 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011436 cob Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 229960000367 inositol Drugs 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000002075 main ingredient Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000005226 mechanical processes and functions Effects 0.000 description 1
- 229930014626 natural product Natural products 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 235000019198 oils Nutrition 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920002857 polybutadiene Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- CDAISMWEOUEBRE-UHFFFAOYSA-N scyllo-inosotol Natural products OC1C(O)C(O)C(O)C(O)C1O CDAISMWEOUEBRE-UHFFFAOYSA-N 0.000 description 1
- 239000011949 solid catalyst Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 235000012424 soybean oil Nutrition 0.000 description 1
- 239000003549 soybean oil Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B23/00—Compositions characterised by non-explosive or non-thermic constituents
- C06B23/009—Wetting agents, hydrophobing agents, dehydrating agents, antistatic additives, viscosity improvers, antiagglomerating agents, grinding agents and other additives for working up
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
- C06B21/0008—Compounding the ingredient
- C06B21/0025—Compounding the ingredient the ingredient being a polymer bonded explosive or thermic component
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
- C09K23/14—Derivatives of phosphoric acid
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S149/00—Explosive and thermic compositions or charges
- Y10S149/11—Particle size of a component
- Y10S149/113—Inorganic oxygen-halogen salt
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S149/00—Explosive and thermic compositions or charges
- Y10S149/11—Particle size of a component
- Y10S149/114—Inorganic fuel
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S516/00—Colloid systems and wetting agents; subcombinations thereof; processes of
- Y10S516/01—Wetting, emulsifying, dispersing, or stabilizing agents
Definitions
- Fine ammonium perchlorate (or aluminum or ferric oxide) particles can be completely dispersed in propellants by first preparing a slurry of fine ammonium perchlorate particles (and other propellant solid or liquid ingredients, if desired) with a suitable surfactant and an organic liquid. This is normally done by conventional mixing. The slurry is then allowed to stand, until the surfactant reacts with the ammonium perchlorate surface and establishes equilibrium at the ammonium perchlorate-liquid interface. The surfactant reaction produces complete dispersion of the ammonium perchlorate, ferric oxide or aluminum particles in the slurry by effectively neutralizing the charges and reducing the cohesive forces between the particles.
- Preferred organic liquids are normal-hexane, normal-heptane, l,1,2-trichloro-l,2,2-trifluoroethane and l,l,2,2-tetrachloro 1,2 difluoroethane.
- the type and amount of surfactant are critical. Sodium sulfonate of mineral oil has been found satisfactory as a surfactant. Preferably 0.1 to 0.5 weight percent (on a total solids basis) should be used. Examples of other suitable surfactants are lecithin and Asolectin.
- the propellant binder is mixed in, and the organic liquid is then removed. If desired, the binder can be added after the organic liquid is removed.
- Fine ammonium perchlorate (or aluminum or ferric oxide) particles can be completely dispersed in propellants by means of a chemical method of dispersion.
- the method involves preparing a slurry of fine ammonium perchlorate particles (together with other propellant solid or liquid ingredients, if desired) with a suitable surfactant and an organic liquid. This is done by conventional mixing.
- These other propellant solids include (usually) fine aluminum powder and any solid catalyst such as ferric oxide.
- the propellant binder is mixed in, and the organic liquid is then removed. If desired, the binder can be added after removal of the organic liquid.
- the curing agent is generally added and mixed in after the removal of the organic liquid, but can instead be added before removal of the organic liquid.
- the slurry must be allowed to stand until equilibrium is established at the solid(s)- liquid interface, before the propellant binder and other propellant ingredients are mixed in.
- This allows the surfactant to react with the ammonium perchlorate or other solid surface.
- the surfactant reaction produces complete dispersion of the ammonium perchlorate in the slurry by elfectively neutralizing the charges and reducing the cohesive forces between the particles.
- the surfactant reduces the interfacial surface tension.
- the use of a surfactant and an organic liquid enables the surfactant to more readily establish equilibrium at the bindersolid interface as the organic liquid is removed.
- the specific organic liquid employed in the tests referred to hereinafter is normal-heptane.
- Equivalent organic liquids other than normal-heptane can also be employed. Examples are: normal-hexane,
- organic liquids which can also be employed are ethyl acetate, tetrahydrofuran, benzene, toluene, hexane, acetone and ethyl alcohol.
- the liquid boiling point and vapor pressure should be low enough so that it can be readily removed during subsequent propellant processing, but not so low that it will readily evaporate during slurry preparation and standing.
- the ammonium perchlorate must be insoluble in the organic liquid and the surfactant must be soluble in the organic liquid.
- the type of surfactant used is critical.
- a surfactant which will work is Twitchell Base -8240, a trademark of Emery Industries, Cincinnati, Ohio. This surfactant is sodium sulfonate of mineral oil.
- the amount of surfactant used is also important, because it affects the final propellant properties.
- the amount of Twitchell Base -8240 used is preferably from about 0.1 to about 0.5 percent by weight (on a total solids basis). Amounts of surfactant less than about 0.1% may not be completely effective while amounts in excess of 0.5% may have detrimental effects on final propellant properties. If the organic liquid is used without the surfactant, the desired ammonium perchlorate dispersion is not achieved.
- the method of this invention is concerned with dispersing fine ammonium perchlorate, aluminum or ferric oxide particles having less than 50g weight-median diameter.
- the particles to be dispersed must be in the organic liquid-surfactant slurry.
- surfactants are sodium sulfonates of mineral oil.
- mineral oil is meant that portion of petroleum which distills at '626734 F is purified and redistilled (boiling at 680 F.).
- Mineral oil is a mixture of long-chain aliphatic hydrocarbons.
- Surfactants other than sodium sulfonates of miner oil can also be employed to achieve the solids dispersion.
- the following surfactants have also been demonstrated to be effective:
- Asolectin (marketed by Associated Concentrates, Inc., Long Island, N.Y.). This material from soybeans is a mixture consisting essentially of approximately equal parts (by weight) of phosphatidyl cholines (lecithin), ethanolamines, and inositols. This is a qualitative estimate. Numerous unknown liquids are also present as well as antioxidant pigments.
- the structures of the main ingredients are:
- the method of this invention eliminates most of the disadvantages of the prior art mechanical methods of dispersion.
- the advantages of this invention are:
- the method of this invention is beneficial for any propellant which contains ammonium perchlorate, aluminum or ferric oxide that is difficult to disperse, but is especially applicable to high burning rate propellants that contain high percentages of fine ammonium perchlorate and aluminum and/or ferric oxide.
- a method for dispersing fine ammonium perchlorate, aluminum or ferric oxide particles of less than 50g weight median diameter comprising the steps of mixing a slurry of said fine ammonium perchlorate, aluminum or ferric oxide particles, an organic liquid and a surfactant, said surfactant being of about 0.1 to about 0.5 percent by weight on a total solids basis, which lowers the interfacial surface tension between said fine ammonium perchlorate, aluminum or ferric oxide particles and said organic liquid, and allowing said slurry to stand until said surfactant reacts with said ammonium perchlorate, aluminum or ferric oxide particles to effectively disperse said ammonium perchlorate, aluminum or ferric oxide particles in said slurry, said surfactant being selected from the group consisting of sodium sulfonate of mineral oil, lecithin, and a mixture consisting essentially of approximately equal parts by weight of phosphatidyl cholines, ethanolamines and inositols, and said organic liquid being selected
- organic liquid is normal-heptane, normal-hexane, 1,1,2-trichloro-1,2,2- trifiuoroethane or 1,1,2,2-tetrachloro-1,2-difluoroethane.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Colloid Chemistry (AREA)
- Cosmetics (AREA)
Abstract
1. A METHOD FOR DISPERSING FINE ANMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES OF LESS THAN 50U WEIGHT MEDIAN DIAMETER COMPRISING THE STEPS OF MIXING A SLURRY OF SAID FINE AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES, AN ORGANIC LIQUID AND A SURFACTANT, SAID SURFACTANT BEING OF ABOUT 0.1 TO ABOUT 0.5 PERCENT BY WEIGHT ON A TOTAL SOLIDS BASIS, WHICH LOWERS THE INTERFACIAL SURFACE TENSION BETWEEN SAID FINE ANMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES AND SAID ORGANIC LIQUID, AND ALLOWING SAID SLURRY TO STAND UNTIL SAID SURFACTANT REACTS WITH SAID AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLEES TO EFFECTIVELY DISPERSE SAID AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES IN SAID SLURRY SAID SURFACTANT BEING SELECTED FROM THE GROUP CONSISTING OF SODIUM SULFONATE OF MINERAL OIL, LECITHIN, AND A MIXTURE CONSISTING ESSENTIALLY OF APPROXIMATELY EQUAL PARTS BY WEIGHT OF PHOSPHATIDYL CHOLINES, ETHANOLAMINES AND INOSITOLS, AND SAID ORGANIC LIQUID BEING SELECTED FROM THE GROUP CONSISTING OF NORMAL-HEPTANE, NORMAL-HEXANE, 1,1,2-TRICHLORO-1,2,2-TRIFLUOROETHANE, 1,1,2,2-TETRACHLORO-1,2,-DIFLUOROETHANE, ETHYL ACETATE, TETRAHYDROFURAN, BENZENE, TOLUENE, HEXANE, ACETONE, AND ETHYL ALCOHOL.
Description
United States Patent lint. Cl. C06b 11/00 U5. Cl. 149-76 8 Claims Mechanical methods of dispersion other than those employing conventional mixers have also been developed to disperse fine ammonium perchlorate particles in propellants. One such method involves the mechanical incorporation of fine ammonium perchlorate particles, such as by the use of a roll mill, in a carboxyl-terminated polybutadiene polymer to form a paste. The paste is subsequently added to the propellant mix. However, this method has several disadvantages. Only a portion of the total propellant oxidizer can be added in the paste form because of the limitation of the amount of ammonium perchlorate which can be held in the paste. The remainder must be added in the dry nondispersed state. Furthermore, a solvent must be added to the paste during dispersion to facilitate processing. Additionally, complete dispersion is usually not achieved by this mechanical process, and a portion of the ammonium perchlorate is ground. This affects the repeatability of the finished propellant properties.
Logically, chemical dispersion methods have been investigated as a means of improving the dispersion of the ammonium perchlorate, aluminum or ferric oxide particles in the propellant.
Accordingly, it is the principal object of this invention to provide an improved method for dispersing fine ammonium perchlorate, aluminum or ferric oxide particles in a propellant.
It is a particular object of this invention to provide such a method which involves chemical dispersion.
SUMMARY OF THE INVENTION Fine ammonium perchlorate (or aluminum or ferric oxide) particles can be completely dispersed in propellants by first preparing a slurry of fine ammonium perchlorate particles (and other propellant solid or liquid ingredients, if desired) with a suitable surfactant and an organic liquid. This is normally done by conventional mixing. The slurry is then allowed to stand, until the surfactant reacts with the ammonium perchlorate surface and establishes equilibrium at the ammonium perchlorate-liquid interface. The surfactant reaction produces complete dispersion of the ammonium perchlorate, ferric oxide or aluminum particles in the slurry by effectively neutralizing the charges and reducing the cohesive forces between the particles. Preferred organic liquids are normal-hexane, normal-heptane, l,1,2-trichloro-l,2,2-trifluoroethane and l,l,2,2-tetrachloro 1,2 difluoroethane. The type and amount of surfactant are critical. Sodium sulfonate of mineral oil has been found satisfactory as a surfactant. Preferably 0.1 to 0.5 weight percent (on a total solids basis) should be used. Examples of other suitable surfactants are lecithin and Asolectin.
After the ammonium perchlorate (and other propellant solid ingredients, if desired) is dispersed, the propellant binder is mixed in, and the organic liquid is then removed. If desired, the binder can be added after the organic liquid is removed.
DESCRIPTION OF THE PREFERRED EMBODIMENT Fine ammonium perchlorate (or aluminum or ferric oxide) particles can be completely dispersed in propellants by means of a chemical method of dispersion. The method involves preparing a slurry of fine ammonium perchlorate particles (together with other propellant solid or liquid ingredients, if desired) with a suitable surfactant and an organic liquid. This is done by conventional mixing. These other propellant solids include (usually) fine aluminum powder and any solid catalyst such as ferric oxide. After the solids are dispersed by allowing equilibrium to be established at the ammonium perchlorate-liquid interface or other solid-liquid interface, the propellant binder is mixed in, and the organic liquid is then removed. If desired, the binder can be added after removal of the organic liquid. The curing agent is generally added and mixed in after the removal of the organic liquid, but can instead be added before removal of the organic liquid.
It must be emphasized that the slurry must be allowed to stand until equilibrium is established at the solid(s)- liquid interface, before the propellant binder and other propellant ingredients are mixed in. This allows the surfactant to react with the ammonium perchlorate or other solid surface. The surfactant reaction produces complete dispersion of the ammonium perchlorate in the slurry by elfectively neutralizing the charges and reducing the cohesive forces between the particles. The surfactant reduces the interfacial surface tension. Furthermore, the use of a surfactant and an organic liquid enables the surfactant to more readily establish equilibrium at the bindersolid interface as the organic liquid is removed.
The specific organic liquid employed in the tests referred to hereinafter is normal-heptane. Equivalent organic liquids other than normal-heptane can also be employed. Examples are: normal-hexane,
Other organic liquids which can also be employed are ethyl acetate, tetrahydrofuran, benzene, toluene, hexane, acetone and ethyl alcohol. Although still other organic liquids can also be employed, the liquid boiling point and vapor pressure should be low enough so that it can be readily removed during subsequent propellant processing, but not so low that it will readily evaporate during slurry preparation and standing. The ammonium perchlorate must be insoluble in the organic liquid and the surfactant must be soluble in the organic liquid.
The type of surfactant used is critical. A surfactant which will work is Twitchell Base -8240, a trademark of Emery Industries, Cincinnati, Ohio. This surfactant is sodium sulfonate of mineral oil. The amount of surfactant used is also important, because it affects the final propellant properties. The amount of Twitchell Base -8240 used is preferably from about 0.1 to about 0.5 percent by weight (on a total solids basis). Amounts of surfactant less than about 0.1% may not be completely effective while amounts in excess of 0.5% may have detrimental effects on final propellant properties. If the organic liquid is used without the surfactant, the desired ammonium perchlorate dispersion is not achieved.
Generally speaking, the method of this invention is concerned with dispersing fine ammonium perchlorate, aluminum or ferric oxide particles having less than 50g weight-median diameter. The particles to be dispersed must be in the organic liquid-surfactant slurry.
The foregoing procedure has been tested and has resulted in complete dispersion of the fine ammonium perchlorate particles in the normal-heptane slurry (as established by using an accepted packing fraction measurement procedure). Using a nominal 4p. weight-median diameter ammonium perchlorate particle size (which size is normally very diflicult to disperse), the dispersion analysis for a normal-heptane slurry without the surfactant showed a measured packing fraction (6) of 0.34. The same analysis for a normal-heptane slurry with 02% of Twitchell Base -8240 showed e to be 0.77. The much larger e for the slurry with the surfactant added shows that the 4p. ammonium perchlorate was completely dispersed.
Certain other equivalent proprietary surfactants (both of Emery Industries and other companies) can also be employed. In general, these surfactants are sodium sulfonates of mineral oil. By mineral oil is meant that portion of petroleum which distills at '626734 F is purified and redistilled (boiling at 680 F.). Mineral oil is a mixture of long-chain aliphatic hydrocarbons.
Surfactants other than sodium sulfonates of miner oil can also be employed to achieve the solids dispersion. In particular, the following surfactants have also been demonstrated to be effective:
(1) Asolectin (marketed by Associated Concentrates, Inc., Long Island, N.Y.). This material from soybeans is a mixture consisting essentially of approximately equal parts (by weight) of phosphatidyl cholines (lecithin), ethanolamines, and inositols. This is a qualitative estimate. Numerous unknown liquids are also present as well as antioxidant pigments. The structures of the main ingredients are:
R-Pl-O-CH;
Phosphatldyl ethanolamlne R-ii-O-CH;
| om-o-i -o-Qon K HO 0H Phosphatldyl inositol (2) Lecithin (marketed by Central Soya Co., 1825 N. Laramie Avenue, Chicago, 111.). This is a fluid natural product from soybean oil. The structure is given above.
The method of this invention eliminates most of the disadvantages of the prior art mechanical methods of dispersion. The advantages of this invention are:
(1) The procedure is safer than mechanical methods of dispersion, because little work is required and the slurry is less sensitive than the dry ammonium perchlorate.
(2) All of the ammonium perchlorate in the final propellant formulation can be added using the chemical dispersion method of this invention.
(3) The particle size of the ammonium perchlorate is not altered.
(4) Better dispersion of the ammonium perchlorate is achieved, which results in better propellant mechanical properties and easier propellant processing.
(5) Higher solid loadings for high density impulse propellants can be obtained by optimum combinations of fine ammonium perchlorate sizes with larger ammonium perchlorate sizes.
(6) High burning rates can be obtained by high solidloading of fine ammonium perchlorate sizes.
The method of this invention is beneficial for any propellant which contains ammonium perchlorate, aluminum or ferric oxide that is difficult to disperse, but is especially applicable to high burning rate propellants that contain high percentages of fine ammonium perchlorate and aluminum and/or ferric oxide.
Various other modifications and variations of this invention will readily suggest themselves to those skilled in the art in the light of the above teachings, which modifications and variations are within the spirit and scope of this invention.
We claim:
1. A method for dispersing fine ammonium perchlorate, aluminum or ferric oxide particles of less than 50g weight median diameter comprising the steps of mixing a slurry of said fine ammonium perchlorate, aluminum or ferric oxide particles, an organic liquid and a surfactant, said surfactant being of about 0.1 to about 0.5 percent by weight on a total solids basis, which lowers the interfacial surface tension between said fine ammonium perchlorate, aluminum or ferric oxide particles and said organic liquid, and allowing said slurry to stand until said surfactant reacts with said ammonium perchlorate, aluminum or ferric oxide particles to effectively disperse said ammonium perchlorate, aluminum or ferric oxide particles in said slurry, said surfactant being selected from the group consisting of sodium sulfonate of mineral oil, lecithin, and a mixture consisting essentially of approximately equal parts by weight of phosphatidyl cholines, ethanolamines and inositols, and said organic liquid being selected from the group consisting of normal-heptane, normal-hexane, 1,1,2-trichloro 1,2,2 trifluoroethane, 1,1,2,2-tetrachloro-1,2-difluoroethane, ethyl acetate, tetrahydrofuran, benzene, toluene, hexane, acetone, and ethyl alcohol.
2. The method of claim 1 wherein said particles are solid propellant ingredients, wherein a propellant binder and other propellant ingredients that are liquid are added to said slurry after dispersion, and wherein said organic liquid is thereafter removed.
3. The method of claim 2 wherein said organic liquid is normal-heptane, normal-hexane, 1,1,2-trichloro-1,2,2- trifiuoroethane or 1,1,2,2-tetrachloro-1,2-difluoroethane.
4. The method of claim 1 wherein said organic liquid is normal-heptane.
5. The method of claim 4 wherein said surfactant is said lecithin in an amount of about 0.2 percent by weight on a total solids basis.
6. The method of claim 4 wherein said surfactant is sodium sulfonate of mineral oil.
7. The method of claim 1 wherein said particles are solid propellant ingredients, wherein said organic liquid is removed from said particles and thereafter a propellant binder and other propellant ingredients that are liquid are added to said dispersed particles.
8. The method of claim 1 wherein said organic liquid is tetrahydrofuran.
References Cited UNITED STATES PATENTS 2,938,780 5/1960 Proell et al 149-19 2,942,964 6/ 1960 Burgwalcl et a1. 149-19 2,946,671 7/1960 Marti 149-19 2,946,672 7/1960 Marti 149-19 2,967,098 1/ 1961 Weil 149-76 X 2,970,046 1/ 1961 Cutforth 149-19 2,974,026 3/1961 Batchelder 149-19 2,991,167 7/1961 Burton 149-19 3,027,283 3/1962 Bice 149-76 X 3,109,761 11/1963 Cobb et a1 149-76 X STEPHEN J. LECHERT, JR., Primary Examiner US. Cl. X.R.
Claims (1)
1. A METHOD FOR DISPERSING FINE ANMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES OF LESS THAN 50U WEIGHT MEDIAN DIAMETER COMPRISING THE STEPS OF MIXING A SLURRY OF SAID FINE AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES, AN ORGANIC LIQUID AND A SURFACTANT, SAID SURFACTANT BEING OF ABOUT 0.1 TO ABOUT 0.5 PERCENT BY WEIGHT ON A TOTAL SOLIDS BASIS, WHICH LOWERS THE INTERFACIAL SURFACE TENSION BETWEEN SAID FINE ANMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES AND SAID ORGANIC LIQUID, AND ALLOWING SAID SLURRY TO STAND UNTIL SAID SURFACTANT REACTS WITH SAID AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLEES TO EFFECTIVELY DISPERSE SAID AMMONIUM PERCHLORATE, ALUMINUM OR FERRIC OXIDE PARTICLES IN SAID SLURRY SAID SURFACTANT BEING SELECTED FROM THE GROUP CONSISTING OF SODIUM SULFONATE OF MINERAL OIL, LECITHIN, AND A MIXTURE CONSISTING ESSENTIALLY OF APPROXIMATELY EQUAL PARTS BY WEIGHT OF PHOSPHATIDYL CHOLINES, ETHANOLAMINES AND INOSITOLS, AND SAID ORGANIC LIQUID BEING SELECTED FROM THE GROUP CONSISTING OF NORMAL-HEPTANE, NORMAL-HEXANE, 1,1,2-TRICHLORO-1,2,2-TRIFLUOROETHANE, 1,1,2,2-TETRACHLORO-1,2,-DIFLUOROETHANE, ETHYL ACETATE, TETRAHYDROFURAN, BENZENE, TOLUENE, HEXANE, ACETONE, AND ETHYL ALCOHOL.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US67784667A | 1967-10-19 | 1967-10-19 |
Publications (1)
Publication Number | Publication Date |
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US3745078A true US3745078A (en) | 1973-07-10 |
Family
ID=24720343
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Application Number | Title | Priority Date | Filing Date |
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US00677846A Expired - Lifetime US3745078A (en) | 1967-10-19 | 1967-10-19 | Dispersion of fine ammonium perchlorate,aluminum or ferric oxide particles in propellants |
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Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4244699A (en) * | 1979-01-15 | 1981-01-13 | Otisca Industries, Ltd. | Treating and cleaning coal methods |
US4392895A (en) * | 1981-11-09 | 1983-07-12 | The United States Of America As Represented By The Secretary Of The Navy | Ramjet fuel |
USH273H (en) | 1986-12-01 | 1987-05-05 | Processing of high solids propellant | |
EP0245871A2 (en) * | 1986-05-16 | 1987-11-19 | Asahi Denka Kogyo Kabushiki Kaisha | Surfactant composition having improved functions |
US5007973A (en) * | 1989-10-12 | 1991-04-16 | Atlas Powder Company | Multicomponent explosives |
EP0487246A1 (en) * | 1990-11-19 | 1992-05-27 | Dyno Nobel Inc. | Stabilized emulsion explosive |
-
1967
- 1967-10-19 US US00677846A patent/US3745078A/en not_active Expired - Lifetime
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4244699A (en) * | 1979-01-15 | 1981-01-13 | Otisca Industries, Ltd. | Treating and cleaning coal methods |
US4392895A (en) * | 1981-11-09 | 1983-07-12 | The United States Of America As Represented By The Secretary Of The Navy | Ramjet fuel |
EP0245871A2 (en) * | 1986-05-16 | 1987-11-19 | Asahi Denka Kogyo Kabushiki Kaisha | Surfactant composition having improved functions |
EP0245871B1 (en) * | 1986-05-16 | 1991-08-07 | Asahi Denka Kogyo Kabushiki Kaisha | Surfactant composition having improved functions |
USH273H (en) | 1986-12-01 | 1987-05-05 | Processing of high solids propellant | |
US5007973A (en) * | 1989-10-12 | 1991-04-16 | Atlas Powder Company | Multicomponent explosives |
EP0487246A1 (en) * | 1990-11-19 | 1992-05-27 | Dyno Nobel Inc. | Stabilized emulsion explosive |
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