Classifications

• • 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
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
  • C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
  • C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
  • C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin

Definitions

• the present invention relates to a propellant for gas generators of the "base-bleed" type, that is to say for generators comprising a gas-generating charge to increase the range of the projectiles which are equipped with it and containing one or more granular or pulverulent solid bodies, at least one of which is an oxidant, and a binder, as well as a propellant of this kind.
• gas generators of the base-bleed type means gas-producing motor devices intended to increase the range of the projectiles which are equipped with it, and this without this effect being obtained by active acceleration of the projectile.
• base-bleed gas generators are used exclusively in the form of solid molded blocks ready for use, most often without the compositions from which they are produced being produced. lend themselves to storage. Base-bleed gas generators are described in Belgian Patent No. 834,903.
• the manufacture of propellant masses or charges for "base-bleed” gas generators is carried out by known methods as follows.
• An oxidant such as ammonium perchlorate, and possibly other solid bodies, such as aluminum as fuel or the like, are mixed with a binder in the liquid state, such as for example butadiene, so as to form a very viscous mass or paste, which is then optionally, after addition of a hardener, molded and left to harden for 4-7 days at a temperature of 50-80 ° C.
• a disadvantage of this known process is that the composition from which the manufacture is carried out, that is to say the mixture of oxidant and binder, does not keep and therefore cannot be put into use. reserve due to the spontaneous segregation of the mixture, on the one hand, and the risk of hardening, on the other hand.
• Another disadvantage consists in that the filling of the molds with the viscous composition for the formation of propellant charges of reduced dimensions proves to be rather laborious and is therefore not very economical, so that the molding of the composition in the form is preferred. large blocks, which are then cut into smaller blocks, worked in turn to give them the final shape, which, after all, is also very laborious and very uneconomical.
• the present invention proposes to remedy the aforementioned drawbacks of the known processes for the manufacture of propellant charges of the genre concerned and aims for this purpose the development and development of a new process which lends itself to the production of compositions intended for the manufacture of propellant charges, compositions whose conservation does not present any problems and which can thus be easily stored either with a view to their sale as intermediate products, or pending their further processing.
• the method according to the invention for the manufacture of propellants is characterized in that the binder is an elastomer with thermoplastic deformation and in that this elastomer is added with solvents, then intimately mixed with the solid ingredients and finally deposited on the latter by elimination of solvents, so as to form a granular product.
• Another object of the invention is to make available to the interested parties a propellant of the kind concerned, which is free from the abovementioned drawbacks and can easily be kept for later use as a propellant charge in "base” gas generators. -bleed “shots.
• composition according to the invention is, with a view to achieving the above-mentioned objectives, characterized in that its binder is an elastomer with thermoplastic deformation, in that it is in the granular state and in that its grains are coated by this thermoplastic deformation elastomer.
• the invention also relates to a process for the manufacture of propellant charges for "base-bleed" gas generators, that is to say generators provided with a gas-generating charge for increasing the scope of projectiles concerned, containing one or more granular or powdery solid ingredients, at least one of which is an oxidant and another of which is a binder, characterized in that the mixture of said granulated solid ingredients and of said binder in the form of a thermoplastic deformation elastomer is molded at high temperature and the body thus obtained is provided with an insulating envelope.
• the solvents used in the implementation of the process according to the invention are trichloroethane and trichlorethene.
• the oxidant is, for example, ammonium perchlorate, ammonium nitrate or another analogous compound.
• the essence of the invention therefore consists in that the solid components of the propellants in question are incorporated therein by coating by means of an elastomer with thermoplastic deformation, which allows the composition obtained to be preserved with a view to placing it subsequent work for the manufacture of bodies of any suitable shape at high temperature and under high pressure, which is made possible by the presence of this elastomer with thermoplastic deformation.
• the advantages of the solution according to the invention are as follows.
• the propellant can easily be produced in the form of granules for storage for later use.
• the grainy ingredients are easily mixed and their dispersion in a solvent does not present any problems. It is also a question of the subsequent transformation of the composition thus prepared into bodies of suitable shape, which also presents no difficulties.
• any risk of separation of the solid components is excluded thanks to the fact that the transformation of the granular composition into propellant charge by compression excludes any risk of sedimenta tion, and this contrary to the usual process based on the use of liquid binders, where phenomena of segregation by sedimentation are always to be feared.
• the elastomer with elastic deformation is, according to a preferred embodiment of the invention, a triple block polymer, such as in particular a copolymer of butadiene and styrene or isoprene and styrene with regularly ordered groups .
• a triple block polymer such as in particular a copolymer of butadiene and styrene or isoprene and styrene with regularly ordered groups .
• Another preferred embodiment of the invention provides that the removal of the solvent is carried out by evaporation.
• the elimination of the solvent results in the deposition of the thermoplastic-deforming elastomer on the grains of the solid components, such as in particular the grains of the oxidant so that, according to this embodiment, the elimination of the solvent and the deposition of the elastomer takes place simultaneously.
• these two processes namely the deposition of the elastomer and the elimination of the solvent, take place successively, the elastomer being precipitated on the particles of the solid components by addition of a non-dissolving liquid and the mixture of the dissolving agent and of non-dissolving liquid then being removed by aspiration.
• This embodiment is therefore characterized in that the elastomer is first precipitated in the suspension so as to deposit on the grains of the solid bodies and the mixture of the liquid bodies present in the composition is then removed by suction, for example by means of a suction filter.
• the non-dissolving liquid is for example acetone.
• the mixture of solid bodies in the composition according to the invention contains, in addition to the oxidant, also other bodies rich in energy. to regulate the rate of combustion of the propellant charges produced from the composition.
• They are, for example, nitroguanidine, guanidine nitrate, hexogen, octogen or pentaerythritis tetranitrate.
• composition according to the invention may, alongside combustion moderators and stabilizers added at one or the other stage of its preparation, also contain a plasticizer for the binder, such as trioctylphosphate.
• a plasticizer for the binder such as trioctylphosphate.
• the mixing of all the components of the composition according to the invention is preferably carried out at high temperature, the final homogeneous kneading at the last stage must in any case be carried out at a temperature of approximately 80 ° C.
• 550 g of granular ammonium perchlorate (oxidizing agent) and 250 g of granular nitroguanidine (auxiliary fuel) are intimately mixed in a horizontal duplex mixer.
• a 10% solution of butadiene and styrene copolymer in trichloroethane is added to the mixture thus obtained, the total amount of butadiene and styrene copolymer thus added being equal to approximately 180 g.
• the mixture of granular solids and the 10% solution of butadiene and styrene copolymer in the trichloroethane thus obtained is then ren homogeneous by thorough mixing.
• the suspension thus obtained is, after the addition of 20 g of trioctylphosphate as plasticizer, again kneaded at a temperature of about 80 ° C, after which the solvent is removed by evaporation under vacuum.
• Another method of removing the solvent, different from removing it by evaporation consists in adding a sufficient amount of a non-dissolving liquid, such as acetone, to cause precipitation of the butadiene copolymer and of dissolved styrene and its deposition on the grains of the solid components of the dispersion, after which the mixture of trichloroethane and acetone is separated from the solid components by suction filtration.
• a non-dissolving liquid such as acetone
• a granular composition is obtained, the grains of which are coated with a layer of binder, that is to say with a layer of copolymer of butadiene and styrene.
• the last remnants of solvent still present in the granular mass with grains wrapped in copolymer are eliminated by drying continued for at least 12 hours at a temperature of approximately 50 ° C., which, in this case, that is to say to say in the presence of the relatively small quantities obtained in the implementation example described here, is carried out for example in a lacquer dryer. After this drying, the content of volatile matter in the composition is less than 0.1%.
• the granular composition according to a particular embodiment of the invention consists of solid ingredients, such as ammonium perchlorate as an oxidant and nitroguanidine as an auxiliary fuel and speed regulator combustion, the grains of which are coated with a layer of butadiene and styrene copolymer as a binder with a low trioctylphosphate content as a plasticizer.
• the percentages of the different components of the preparation are as follows: 55% of ammonium perchlorate, 25% of nitroguanidine, 2% of trioctylphosphate and 18% of copolymer of butadiene and styrene or isoprene and styrene.
• composition according to the invention intended for the manufacture of propellant charges lends itself to practically unlimited conservation without risk of alteration of its properties. It is recommended to homogenize it by mixing before its subsequent use. According to the invention, it lends itself to the manufacture of propellant charges for gas generators of the "base-bleed" type by compression in a mold and coating of an insulating envelope, applied thereto either by compression in the mold, or by subsequent application after leaving the mold.
• the bodies thus obtained have, for example, a length of 130 mm and a diameter of 120 mm and are provided with an axial channel with a diameter of 43.5 mm, intended for the evacuation by regular jet of the gases formed by the combustion of the propellant charge during the flight of the projectile which is equipped with it.
• the propellant charge may consist of two semi-cylindrical bodies, each provided with a longitudinal groove of semi-circular section, and this so that the two grooves of the two semi-cylindrical bodies united in the gas generator form the aforementioned channel gas evacuation.
• gas flow pressure approximately 0.11 MPa at a combustion speed of 1.11 mm / second; 0.89 MPa at a combustion speed of 3.0 mm / second; 1.37 MPa at a combustion speed of 3.4 mm / second, etc.
• the maximum tensile strength of the product according to the invention is, at 20 ° C and an elongation speed of 50 m / second, equal to 0.51 N / mm2 with a corresponding elongation which is greater than 150%.
• Specific weight at 100-140 ° C under a pressure of 20-50 MPa about 1.52 g / cm3.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Dispersion Chemistry (AREA)
• Molecular Biology (AREA)
• Health & Medical Sciences (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Glanulating (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Cosmetics (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Glass Compositions (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Air Bags (AREA)
• Medicinal Preparation (AREA)
• Catalysts (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

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Publications (4)

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Family Applications (1)

Country Status (14)

Cited By (3)

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• 1980
  • 1980-02-21 DE DE3006475A patent/DE3006475C2/de not_active Expired
• 1981
  • 1981-02-06 AT AT81200144T patent/ATE7687T1/de active
  • 1981-02-06 EP EP81200144A patent/EP0034849B2/de not_active Expired
  • 1981-02-11 IN IN154/CAL/81A patent/IN154057B/en unknown
  • 1981-02-12 IL IL62123A patent/IL62123A/xx not_active IP Right Cessation
  • 1981-02-17 GR GR64164A patent/GR71625B/el unknown
  • 1981-02-17 US US06/234,603 patent/US4452145A/en not_active Expired - Lifetime
  • 1981-02-19 TR TR21297A patent/TR21297A/xx unknown
  • 1981-02-19 NO NO810563A patent/NO150678C/no unknown
  • 1981-02-20 CA CA000371396A patent/CA1173653A/fr not_active Expired
  • 1981-02-20 PT PT72555A patent/PT72555B/pt unknown
  • 1981-02-20 BR BR8101052A patent/BR8101052A/pt unknown
  • 1981-02-20 ES ES499651A patent/ES499651A0/es active Granted
• 1986
  • 1986-10-14 SG SG831/86A patent/SG83186G/en unknown

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