US3407731A - Flexible detonating fuse - Google Patents

Flexible detonating fuse Download PDF

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US3407731A
US3407731A US651061A US65106167A US3407731A US 3407731 A US3407731 A US 3407731A US 651061 A US651061 A US 651061A US 65106167 A US65106167 A US 65106167A US 3407731 A US3407731 A US 3407731A
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explosive
weight
percent
copolymer
compositions
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US651061A
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William L Evans
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EIDP Inc
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EI Du Pont de Nemours and Co
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Priority claimed from US481150A external-priority patent/US3338764A/en
Priority to GB36195/66A priority Critical patent/GB1106396A/en
Priority to CH1178266A priority patent/CH498789A/de
Priority to DE19661571277 priority patent/DE1571277A1/de
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Priority to US651062A priority patent/US3401215A/en
Priority to US651061A priority patent/US3407731A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B33/00—Manufacture of ammunition; Dismantling of ammunition; Apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • 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
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
    • C06C5/00—Fuses, e.g. fuse cords
    • C06C5/04—Detonating fuses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion

Definitions

  • a detonating fuse comprising a cap-sensitive particulate high explosive, a polymeric metallocarboxylate elastomer and a plasticizer, preferably containing a polyurethane elastomer and, more preferably, a reinforcing element.
  • This invention relates to novel explosive compositions, to flexible, shaped, detonating articles made from said compositions, and to methods for manufacturing such compositions and articles.
  • This fuse was relatively low in tensile strength, especially in small diameters; was easily deformed or fractured by mild impacts and by bends because of its low order of resilience, toughness and tensile strength; was relatively heavy per unit of length; was relatively low in initiating power because of the metal sheath surrounding the explosive core; could not be used above about 175 F. because the explosive core melted and became less sensitive; and was expensive to manufacture.
  • m1 effective successor to Cordeau is a detonating fuse which consists of an explosive core of PETN (pentaerythritol tetranitrate) contained within a waterproofed textile covering or a textile and plastic covering, these assemblies for a given length of detonating fuse being only about one-fifth as heavy as the same length of Cordeau.
  • PETN penentaerythritol tetranitrate
  • Commercially available forms of this deto nating fuse are well known. They have much greater tensile strength than Cordeau fuse, better resistance to deformation, are relatively easy to handle and use, and
  • detonating fuse having even higher tensile strength can be obtained by applying metal wire wrapping over the fabric covering.
  • the flexibility of the fabric-covered cord is inadequate for satisfactory use at temperatures below about 40. F., and the flexibility is even further impaired by the presence of reinforcing wire coverings.
  • PETN the explosive core
  • the above described fabriccovered, PETN-containing, detonating fuse is not completely waterproof; for example, wet ends may lead to priming failures, and failure of propagation of detonation to branch lines may occur if water penetrates at knotted connections where the water proofing cover is broken.
  • knotted connections may cause failures of propagation unless the branch line is at an angle greater than about 30 from the main line in the direction of detonation.
  • These detonating compositions generally comprise a cap-sensitive explosive held in a matrix of one of several polymeric binders, incorporation of which requires exothermic fluid polymerization, relatively high temperature curing, or incorporation in volatile, toxic or flammable solvents which subsequently are removed; all processes which are unattractive from the standpoint of safety in manufacture, and generally give products which lack flexibilityv at low or subzero temperatures, or have limited toughness at ordinary temperatures, said toughness being further reduced at elevated temperature.
  • These deficiencies in physical properties are especially apparent, for example, in the case with which the compositions are cut through by reinforcing members under tension, in the significant loss of tensile strength as temperatures of the compositions increase from room temperature to 140 F.
  • An object of this invention is to provide novel explosive compositions.
  • a further object of the invention is to provide explosive compositions that are flexible.
  • Another object of the invention is to provide a novel detonating fuse that has superior properties of flexibility and tensile strength over a wide temperature range.
  • Another object of the invention is to provide a commercially feasible and economical method for making explosive compositions and also for fabricating the compositions into various shapes for subsequent use.
  • novel explosive compositions are obtained by intimately mixing a polymeric carboxylic elastomer that is a copolymer of from about 50 to percent by weight of a butadiene, from about 10 to 45 percent by weight of an acrylonitrile and a suflicient amount of an acrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per parts by weight of said copolymer; a source of polyvalent metal ions in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of the copolymer; from about 1 to 20 percent by weight of a plasticizer; and from about 40 to 80 percent by weight of a particulate capsensitive high explosive.
  • a liquid polyurethane elastomer is added to the explosive composition in order to obtain optimum physical properties in relation to flexibility.
  • polymeric metallocarboxylate elastomer is the reaction product of a polyvalent metal ion, which acts as a curing agent for the elastomer, with a copolymer of from about 50 to 80 percent by weight of a 'butadiene, from about 10 to 45 percent by Weight of an acrylonitrile and a suflicient amount of an acrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per 100 parts of said copolymer, the polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times ,the carboxyl content of said copolymer.
  • the explosive composition contains up to about 25 percent by weight of a polyurethane elastomer. However, the amount of polyurethane, if used, should generally not exceed about the amount of metallocarboxylate elastomer.
  • the resultant explosive composition is flexible and can be for-med into a variety of shapes that retain substantially the dimensions and form into which the compositions are fabricated.
  • the explosive compositions can be shaped by pressing into blocks, slabs or sheets, by rolling into sheets and films, and by extruding into rods, cords, tubes or sheets.
  • the shaped articles are flexible, yet have a desirable high tensile strength.
  • These explosive compositions have been found to be particularly useful and supply a long sought after need in the explosive industry, especially when formed into tubes, tapes and cords which can be produced by, for example, continuous rolling or extrusion operations.
  • detonating fuse fabricated from the novel explosive compositions, and preferably, but not necessarily, containing a reinforcing element and a polyurethane elastomer, greatly increases the uses and conditions under which detonating fuse operates effectively. For example, flexibility and strength of the detonating fuse of this invention are retained to such an extent that the compositions and articles of the invention are useful over a temperature range of from about -50 F. to 180 F.
  • any reinforcing element that is compatible with the explosive composition can be used.
  • Optimum physical properties as to flexibility and tensile strength are obtained when the explosive composition is formed into an elongated or cord-shaped fuse, and yarn, particularly nylon yarn, is employed as the reinforcing element which is substantially centrally positioned within the fuse and along its longitudinal axis.
  • the drawing illustrates a cross sectional view of an apparatus for extruding the explosive composition around a central reinforcing member in order to make a reinforced detonating fuse, which is a preferred embodiment of the invention.
  • the apparatus comprises a ram type extruder 10 and a barrel 12, a ram 11 at one end of extruder 10 and a forming means comprising a die 15 at the other end of the extruder.
  • the carboxylate elastomer-containing explosive 18 is added to barrel 12 of extruder 10.
  • Reinforcing means 17, e.g., nylon yarn is fed from a source, not shown, into a channel in guide member 13, through guide insert 14 into the explosive composition.
  • detonating fuse In operation, when pressure is applied to the ram 11, provided with type sealing rings 16, it thus forces the explosive composition through die 15 while the reinforcing element is simultaneously fed through guide 13 and guide insert 14 at a predetermined synchronized rate into the explosive composition thus forming detonating fuse 19.
  • the detonating fuse may be wound on a spool, or other suitable means, for storage.
  • the detonating fuse After the detonating fuse has been formed, e.g., extruded, it is cured. Curing is merely the completion of the reaction between the polyvalent metal ion and the carboxylic elastomer and can take place at room temperature during storage. However, heating the detonating fuse at temperatures below the decomposition temperature of the particulate cap-sensitive high explosive greatly reduces the curing time. A convenient curing temperature being of the order of 160 to 225 F. and from about 8 to 24 hours. 7
  • High explosives suitable for'u'se in the present invention include particulate cap-sensitive materials-which are stable under the processing conditions, which are compatible with other ingredients of the compositions, and which are not dissolved by other components of the mixtures.
  • the cap-sensitive particulate high explosive constitutes 40 to percent by weight of the explosive composition.
  • cap-sensitive high explosives that can be used are trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), trinitrophenyl methylnitra-mine (tetryl), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitramine (HMX), mannitol hexanitrate, tetranitrodibenzo 1,3a,4,6a-tetraazapeutalene, diazidodinitrophenol, hexamethylene triperoxydiamine, picry-lsulfone, potassium dinitroacetonitrile, and lead azide.
  • TNT trinitrotoluene
  • PETN pentaerythritol tetranitrate
  • tetryl trinitrophenyl methylnitra-mine
  • RDX cyclotrimethylenetrinitramine
  • HMX cyclotetramethylene
  • PETN, tetryl, and RDX are the preferred cap-sensitive explosives of the composition, and especially preferred for general use is PETN.
  • the particle size of the high explosive is not critical to the success of the invention, although particles all of which pass an 80-mesh U.S. standard sieve are preferred, and especially preferred are particles whose major dimension on the average does not exceed microns. The latter are designated herein as superfine explosives.
  • the compositions are more sensitive to initation if they contain a very fine crystalline cap-sensitive explosive.
  • the particulate, capsensitive high explosive may be dry when added for incorporation into the mixture or it may be wet with water, since water is a major component in the latex of the reaction mixture.
  • plasticizers for the carboxylic copolymer of the explosive composition can be used. Incorporating from about 1 to 20 percent plasticizer by weight assists in providing low temperature flexibility for the explosive composition.
  • Plasticizers which are particularly suitable for use either alone or in combination in said compositions are esters and include, for example, triethyleneglycol-di- 2-ethylhexoate, di-n-butyl phthalate, tricresyl phosphate, acetyl tributyl citrate, isodecyloctylphthalate, d-isodecyl adipatc, di-isooctyl adipate, dioctyl adipate, dioctyl sebacate.
  • plasticizers are di-n-butyl phthalate and triethyleneglycol di-2-ethylhexoate which may be used either alone or in combination.
  • Other plasticizers which may be used include, for example, di(butoxyethoxyethyl)formal, tris( 8 chloroethyl)-phosphate, and highly aromatic oils such as Mobilsol N, Picco 25, and Dutrex 1739. Preferably these will be used in combination with one of the organic ester type plasticizers named above.
  • Carboxylic elastomers which are suitable for manufacture of compositions and articles of this invention and constitute the major portion of the binding matrix thereof are copolymers formed from a butadiene-1,3-hydrocarbon, an acrylic nitrile, and an acrylic acid.
  • Typical butadiene-1,3-hydrocarbons used in preparing said copolymers are, for example, butadiene-1,3 and the 5 to 9 carbon atom homologues thereof such as isoprene, 2,3-
  • acrylic nitriles are acrylonitrile, methacrylonitrile, ethacrylonitrile, alpha-butylacrylonitrile, alphaphenyl acrylonitrile, alpha-chloroacrylonitrile and alphamethoxymethyl acrylonitrile and mixtures thereof.
  • Carboxyl groups are introduced into the copolymers by copolymerizing the aforementioned butadiene-1,3-hydrocarbons and acrylic nitriles with at least one acrylic acid.
  • Copolymers containing about from 0.001 to 0.3, and preferably 0.02 to 0.15, carboxyl equivalent of at least one acrylic acid per 100 parts by weight of copolymer are preferred.
  • carboxyl equivalent of an acrylic acid refers to the amount of the chemically combined acrylic acid which contains one equivalent weight, that is, 45 parts by weight of free carboxyl groups.
  • the amount of free carboxyl groups in a given copolymer can be determined by titrating a solution of the carboxylic-modified copolymer with alcoholic potassium hydroxide to a phenolphthalein end-point.
  • acrylic acid refers to acrylic acid and alpha-substituted acrylic acids, that is, compounds having the structural formula:
  • Acrylic acids which are copolymerized with butadiene- 1,3-hydrocarbons and acrylic nitriles thereby introducing free carboxyl groups into the copolymers are, for example, acrylic acid, methacrylic acid, ethacrylic acid and alpha-chloro acrylic acid.
  • Copolyrners of from 50 to 80% by weight of a butadiene and from about to by weight of an acrylonitrile containing from about 0.001 to 0.3, and especially 0.02 to 0.15, carboxyl equivalent of an acrylic acid per 100 parts by weight of copolymer are preferred.
  • Especially preferred carboxylic copolymers for use in making articles of the present invention are made from butadiene-l,3, acrylonitrile, and methacrylic acid.
  • copolymers may be incorporated into the explosive composition by first dispersing them in volatile organic solvents such as aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, toluene, or methyl ethyl ketone
  • the preferred form of the copolymers is a latex containing from about 35-60% of solids dispersed in an aqueous medium.
  • latices present several advantages since latices are the form in which said copolymers are made and, therefore, represent the lowest cost form of the copolymers; no costly and hazardous organic solvents are required to fabricate the articles of this invention; and finally the presence of water in the latex greatly increases the safety of mixing operations wherein a cap-sensitive particulate high explosive is incorporated with the copolymer, the plasticizer, and the source of polyvalent metallic ion. During the reaction mixture may be heated to slowly remove the water or solvent.
  • butadiene-1,3, acrylonitrile, methacrylic acid copolymers may be made, depending upon the ratios of the monomeric molecules which are incorporated in the copolymer. Generally these are described as high, medium, or low acrylonitrile copolymers depending on the proportion of acrylonitrile incorporated in the copolymer, e.g., -35%, 35-17%, and 17- 1%, respectively for high, medium, and low; and are further characterized by the carboxyl content of the copolymer, as indicated above.
  • latices of copolymers of intermediate acrylonitrile content, and carboxyl (COOH) content of 0.02 to 0.15 parts by weight per 100 parts of copolymer are preferred.
  • Such latices are commercially available as, for example, Hycar 1570x20, 1570x36, 1571 and 1572 (made by the B. F. Goodrich Chemical Co.), of which Hycar 1572 is especially suitable.
  • Such commercially available copolymer latices may be used alone, or in combination with one another or in combination with polyurethane elastomers in order to obtain the physical properties desired in the finished compositions. Adjustments of compositions, curing agents and processing conditions to obtain desired physical properties is well known in elastomer technology and is regularly practiced by those familiar with elastomer art.
  • Any source of polyvalent metal ions can be used as a curing agent for the carboxylic copolymer.
  • Polyvalent metal oxides, hydroxides and other sources of polyvalent metal ions such as salts of an acid weaker than acetic acid, and salts of an acid readily eliminated from the crosslinking site, and even finely divided metals, are compounded with, and are used to cure, said carboxylic copolymers by forming corresponding metallocarboxylate.
  • metal oxides and other sources of polyvalent metal ions are, for example, zinc oxide, calcium oxide, magnesium oxide, dibutyltin oxide, lead oxide, barium oxide, cobalt oxide, tin oxide, zinc carbonate, calcium silicate, zinc acetate, sodium aluminate, sodium phosphomolybdate, and mixtures thereof.
  • Zinc oxide is preferred.
  • the metallocarboxylate is the reaction product, formed in situ between a polyvalent metal ion and a carboxylic copolymer of a butadiene, an acrylonitrile, and an acrylic acid, said copolymer containing from 0.001 to 0.3 carboxyl equivalents of an acrylic acid for each parts by weight of copolymer, and constitutes 15 to 50% by weight of the explosive composition.
  • At least about 15% of the polymeric metallocarboxylate is required to give the desired flexibility, abrasion resistance, and tensile strength to the compositions, but if more than about 50% of said metallocanboxylate is present, the sensitivity of the explosive composition may be less than is desired for effective initiation and propagation of detonation, especially in articles of small cross section or diameter, or across joints between articles.
  • the ca rboxylic copolymers which are used in the compositions, and their methods of preparation are described in detail, for example, in U.S. Patents Nos.
  • a polyurethane elastomer either a polyether or linear polyester type
  • a polyurethane elastomer is especially desirable in explosive compositions which are to be shaped into detonating fuse.
  • Liquid polyurethane elastomers which are characterized by having reactive isocyanate groups by which said liquid polymers can be cured to form solid elastomers, as is well known in the art pertaining to synthetic elastomers, are particularly suitable and are comvrnercially available as, for example, Adiprenes 11-100, L-167, L-315, and L-420 which are manufactured by E. I. du Pont de Nemours & Co.
  • Adiprene L-100 is a liquid polyether urethane elastomer which is made by reacting 1 mol. of polytetramethylene ether glycol (PTMEG) of number average molecular weight about 1000 with about 1.6 mols. of mixed tolylene diisocyanates, as disclosed, for example, in U.S. Patent Nos. 2,929,800 or 2,948,691.
  • PTMEG polytetramethylene ether glycol
  • Adiprene L-315 also is a liquid polyether urethane elastomer and is made by reacting 1 mol. of PTMEG of number average molecular weight about 1000, 1 mol. of butanediol-l,3 and about 7 4 mols.
  • liquid polyether urethane elastomers sometimes are designated as prepolymers of intermediate polymers because on reaction with curing agents they are cured or vulcanized to form solid elastomers.
  • Liquid polyurethane elastomers even when incorporated into composition of the invention without added curing agents, do cure to some extent and enhance the toughness of the final explosive composition.
  • curing agents for the liquid polyurethane elastomers also are included in the formulation, as exemplified hereinafter.
  • Said curing agents include diamines, polyols, titanatc esters, and others well known in the art. Diamines are the best general purpose curing agents, and 4,4-methylenebis- (2-chloroaniline), commonly designated MOCA, is preferred.
  • MOCA 4,4-methylenebis- (2-chloroaniline
  • the designated carboxylic elastomers and polyurethane elastomers are especially suitable for the preparation of shaped articles, e.g., detonating fuse, of the present invention because these polymers can be crosslinked, i.e., vulcanized or cured, at temperatures much lower than those employed with other elastomers. Curing may be achieved even at room temperature, but preferably is accomplished in a shorter time at elevated temperatures.
  • the temperature chosen will be regulated by the thermal stability of the explosive-containing mixture which is being cured, and, of course, curing temperatures are less than the thermal decomposition temperature of the cap-sensitive explosive. Thus, for example, a temperature of ZOO-225 F. is convenient for curing PETN-containing compositions.
  • a further advantage associated with use of said elastomers in the products and process of the present invention is that the commonly used sulfur and sulfur-bearing accelenators are not required to cure the initially plastic rubbery mixture.
  • Sulfur and sulfur-bearing vulcanization ac celerators are incompatible with many cap-sensitive explosives, i.e., degradative chemical reactions may take place at elevated temperatures of processing and storage.
  • the advantages of good cure at relatively low temperatures, freedom from the requirernct of milling which is standard practice with conventional curable elastomeric materials, and elimination of sulfur and sulfur-bearing curing agents are highly desirable for high explosivescontaining compositions, as in the present invention, and are characteristic of elastomers employed in the practice of this invention.
  • Useful shaped articles may be formed from the explosive compositions of this invention as hereinbefore described, without incorporating reinforcing means, and the scope of the invention should be understood to include such articles.
  • the explosive compositions in an uncured or partially cured state may be shaped into blocks, slabs, tubes, sheets, cords, strips or trains and other forms and finished-cured at room or elevated temperatures.
  • Such explosive articles are elastically extensible and find many uses in the explosive field, but their utility is greatly increased by including in the article a reinforcing means bound to the explosive composition in such manner as to provide an article having great flexibility, even at subzero temperatures, little extensibility, and much greater tensile strength than in the absence of such reinforcing means.
  • compositions and articles of the present invention are provided.
  • any reinforcing element can be used in the detonating fuse but yarns and threads are preferred.
  • Yarns which are suitable for use as reinforcing means in the detonating fuse will be selected in accordance with the strength and performance requirements of the fuse.
  • Such yarns may be made of cotton, linen, jute, silk, wool, rayonespecially high tenacity rayon, cellulose esters, nylon, poly (ethylene terephthalate), polyacrylonitrile, glass or other fibers.
  • Spun fiber yarn construction usually is preferred to simple monofilament threads since a better bond is established between the spun yarn and the explosive composition of the invention.
  • Especially preferred reinforcing means are textured and multiplex yarns more specifically described below. It is believed that the strength of the bond between the explosive composition and the reinforcing means represents a combination of adhesive and mechanical interlocking forces.
  • Textured and multiplex yarns are preferred for use as reinforcing means because of the high inherent tensile strength of said yarns and the firm bond which is produced between the yarn and the surrounding sheath of cap-sensitive high explosive composition.
  • Textured yarn is defined as a bulky yarn comprising a plurality of subtantially continuous filaments which are individually convoluted into coils, loops, and whorls at random intervals along their lengths, and characterized by the presence of ring-like loops irregularly spaced along the yarn surface.
  • 'A multiplex yarn is defined as a wrapped yarn comprising a core composed of at least two continuous integral core elements of textile fibers and surface wrappings composed of discontinuous textile fibers, the surface fibers being tightly twisted about the core with portions of fibers locked into'place in the core, and the core fibers being relatively straight and held together as a compact bundle by the surface wrappings.
  • a multiplex yarn in which the continuous core elements are nylon is especially preferred for use as the reinforcing means in articles of the present invention.
  • the gross tensile strength of said multiplex yarn is conveyed to the shaped articles of this invention because of the strength of binding which is established between said strand of multiplex yarn and the surrounding detonating explosive composition described herein.
  • individual fibers may be dispersed in the plastic rubbery explosive mixture before sheeting out, as by calendering, and curing, or yarns may extend linearly parallel to the long dimension of the sheet.
  • the sheeted explosive composition may be calendered onto one or both sides of a latex-impregnated woven fabric or mesh and cured, said woven fabric or mesh constituting the reinforcing means.
  • Another alternate permits wrapping reinforcing yarns or threads around an extruded cord of said explosive composition, preferably the surface of said cord is coated with the aforementioned latex or liquid urethane polymers, and curing the shaped article.
  • the thread or yarn wrap may be applied as a braided structure over the extruded explosive cord which has been precoated with the aforementioned latex or liquid urethane polymer, and the whole assemly cured by mild heating, Said woven, wrapped, or braided structure in itself provides the necessary tensile strength for the article, but the bonding of external reinforcing member to explosive core is desirable to prevent the covering from unraveling when the article, a detonating fuse for example, is cut and to prevent the core form slipping out of the external reinforcing means if tension is applied separately to core and cover.
  • wire especially galvanized wire
  • the aforementioned, elastomeric carboxylic copolymers are strongly adherent to metal and that they can be cured by reaction with free metals, especially metals which provide a polyvalent ion. Prominent among these is zinc.
  • free carboxyl groups are available in the copolymer-bound explosive composition, or the galvanized wire is precoated with said carboxylic elastomer before being covered by said explosive composition, said composition simultaneously cures and adheres to the galvanized iron wire reinforcing member by reaction between the zinc coating on said wire and carboxyl groups of said carboxylic elastomer.
  • urethane polymers are good adhesives between wire and explosive composition even in the absence of specific salt-like chemical bonds.
  • the reinforcing means is impregnated with a carboxylic elastomer, for example a latex of the kind used in making the explosive composition, or a liquid polyether urethane such as, for instance, Adiprene L-l00.
  • a carboxylic elastomer for example a latex of the kind used in making the explosive composition
  • a liquid polyether urethane such as, for instance, Adiprene L-l00
  • the elastomer with which yarns, for example, are impregnated may contain plasticizer and curing agents. These promote adhesion between said reinforcing means and the surrounding composition. A firm bond then is established between the reinforcing means and the explosive composion with which it is in contact during the curing period which .follows the forming or shaping of said articles.
  • the final step in their manufacture is that of curing the elastomeric binder matrix and simultaneously binding the explosive composition to the reinforcing means.
  • curing at room temperature is known, effective cure can be achieved in shorter times by raising the temperature of the article. Curing at elevated temperatures is preferred because much less time is required and because abrasion resistance, toughness, and adhesion to the reinforcing means are all increased.
  • the upper temperature limit for processing, and thereby simultaneously curing the carboxylic copolymer generally is determined by the thermal stability of the cap-sensitive explosive ingredient in the explosive mixture and thus cu ring temperatures do not exceed the temperature at which decomposition of the explosive occurs. For example, temperatures of 160-250 F. for 8 to 24 hours are preferred for curing articles containing PETN, but higher temperatures for shorter times, for example 8 minutes at 300 F., may be employed with explosives of greater thermal stability.
  • Example 1 Into a jacketed, kneading-type mixer fitted with a vacuum-tight cover are charged 55 parts of dry superfine PETN (i.e., average particle size of PETN is less than 10 microns in maximum dimension), or water-wet PETN containing 55 parts net of PETN; 59 parts of a carboxylic copolymer latex (Hycar 1572) containing about 50% solids prepared by aqueous copolymerization of about 71.4% of butadiene-l,3, about 28.5% of acrylonitrile, and 0.07% of methacrylic acid; 8 parts of plasticizer, triethyleneglycoldi-2-ethyl-hexoate; 0.5 part of Agerite White, i.e., di-beta-nap'hthyl-p-phenylenediamine (an antioxidant); 1.0 part of stearic acid; and 6 parts of ZnO.
  • dry superfine PETN i.e., average particle size
  • the order of adding the ingredients is not critical; however, addition of the particulate high explosive last is preferred as a somewhat safer procedure.
  • the cover is placed in position on the mixer, water at about 160 F. is circulated through the mixer jacket, and the agitator is put in motion. After the mixer has operated for about 5 minutes, vacuum gradually is applied, with the agitator in motion, until a vacuum of about 29 inches or more of mercury is achieved, and this is maintained until substantially all water is removed from the charge in the mixer.
  • the use of vacuum is not necessary to complete removal of water or solvent, but its use is preferred because it speeds up processing of the composition.
  • the dried explosive composition is transferred from the mixer to the barrel or charging hopper of a ram-type or screw-type extruder fitted with a crosshead type, circular-orifice die which permits extrusion of the plastic rubbery explosive composition around a multiplex nylon yarn having a gross tensile strength of about pounds as it is drawn through the die.
  • the barrel and die-head of the extruder are held at from about to F. while said composition is being extruded.
  • the multiplex nylon yarn may contain, for example, 8 ends, each of 840 denier, as hereinbefore described, and be preimpregnated with a carboxylic elastomer.
  • T-he shaped article thereby produced is a partially cured detonating fuse having a central reinforcing means surrounded by a cap-sensitive detonating composition.
  • the detonating fuse as it is continuously extruded may 'be taken up on a reel, spool, or other storage means.
  • the partially cured fuse is stored at a temperature of from about 200 to 225 F. for about 8 hours when the cure is substantially complete.
  • the fuse has a diameter of about 9.180 inch, is totally unaffected by exposure to water, has a gross tensile strength of about 125 pounds, is easily primed by a commercial blasting cap, and detonates at a velocity of about 6568 meters/sec. (m./s.).
  • the end of a length of primed detonating fuse was attached to and initiated a block of pressed TNT.
  • the flexibility of said detonating fuse was demonstrated by holding the fuse at -50 F. for about one hour and then wrapping said cord around a A1 in. diameter mandrel without fracturing or cracking the detonating cord.
  • the reinforcing yarn is not stripped from the surrounding detonating composition, even under tension up to rupture, nor does the yarn cut through the explosive composition.
  • percentages represent the composition on a dry basis, as mixture of from about 40 to 80 percent by Weight of a charged to the mixer.
  • cap sensitive particulate high explosive from about to Example Explosive PETN PETN PE'IN Tetryl RDX Explosive, percent 55 55 55 80 75.
  • Example 7 20 50 percent by weight of a polymeric metallocarboxylate elastomer which is the reaction product of a polyvalent metal ion with a copolymer of from about 50 to 80 percent by weight of a butadiene, from about 10 to 45 percent by weight of an acrylonitrile and a sufficient amount of an acrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per 100 parts of said copolymer, said polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of said copolymer; and from about 1 to 20 percent by An explosive composition is prepared as in Example 1 and extruded Without a central reinforcing means.
  • a polymeric metallocarboxylate elastomer which is the reaction product of a polyvalent metal ion with a copolymer of from about 50 to 80 percent by weight of a butadiene, from about 10 to 45 percent by weight of an acrylonitrile and a sufficient amount of an acrylic
  • the extruded fuse after curing has a diameter of about 0.19 inch and has similar properties to the cord of Example 1 except that it is elastically extensible at room temperature and has a gross tensile strength at 68 F. of about 15 pounds at rupture.
  • the unreinforced fuse of this example is flexible at 50 F. when tested as in Example 1.
  • the detonatrng fuse of claim 1 containing up to 25
  • a detonating fuse comprising an intimate uniform composition is particularly well suited for mixture of from about to 80 percent by weight of a fabrication into detonating fuse which is to be knotted, as 35 cap-sensitive particulate high explosive; from about 15 to in joining one piece of detonating fuse to another or to 50 percent by weight of a polymeric metallocarboxylate a high explosive primer, and then subjected to a tensile elastomer which is the reaction product of a polyvalent stress, for example, as in lowering an explosive charge metal ion with a copolymer of from about 50 to 80 perinto a borehole.
  • cent by weight of a butadiene from about 10 to per-
  • the procedure employed is substantially the same as 40 cent by weight of an acrylonitrile and a sufiicient amount that described in Example 1, and the ingredients for the of an acrylic acid to provide from about 0.001 to 0.3 composition are: carboxyl equivalents per 100 parts of said copolymer, said polyvalent metal ion being present in an amount 58 Parts of Superfine PETN chemically equivalent to about 0.5 to 2 times the carboxyl parts of Hycar 1572 sohds) content of said copolymer; from about 1 to 20 percent by parts of Ethylene glycol dlz'ethylhexoate weight plasticizer; and a reinforcing element bonded to Parts Zno said explosive composition.
  • antioxidant (Agerite White) 3.0 parts of liquid urethane polymers, i.e., -1.0 part Adiprene L-lOO; 2.0 parts Adiprene L-3l5-polyurethane 50 0.7 part methylene-bis(o-chloroaniline) (MOCA) dissolved in about 7 parts of trichloroethylene 0.5 part dyestuif 4.
  • MOCA methylene-bis(o-chloroaniline)
  • a detonating fuse comprising an intimate uniform mixture of from about 40 to 80 percent by weight of a cap-sensitive particulate high explosive; from about 15 to 50 percent by weight of a polymeric metallocarboxylate elastomer which is the reaction product of a polyvalent metal ion with a copolymer of from about 50 to 80 percent by weight of a butadiene, from about 10 to 45 percent by weight of an acrylonitrile and a sufficient amount of an acrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per 100 parts of said copolymer, said polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of said copolymer; from about 1 to 20 percent by weight of a plasticizer; up to 25 percent by weight of a polyurethane elastomer; and a reinforcing element substantially centrally positioned along the longitudinal axis Extrusion and curing of the mixed explosive composi- 55 tion in the form of deton
  • a novel explosive composition is obtained that is flexible and exhibits excellent tensile strength over a wide temperature range of the order of -50 F. to 180 F.
  • the explosive composition can be formed into a variety of shapes which retain their dimensions under conditions of the of use; for example, flexible, extensible detonating fuse 5 5.
  • An elongated detonating fuse comprising an intimate may be made, with or without a reinforcing means, that uniform mixture of from about 40 to 80 percent by is insensitive to impact and elfective after exposure to weight of a cap-sensitive particulate high explosive; from water for an extended period.
  • the reinforcabout 15 to 50 percent by weight of a polymeric metaling means of the detonating fuse remains integrally locarboxylate elastomer which is the reaction product of a bound to the explosive composition to prevent any detripolyvalent metal ion with a copolymer of from about 50 to mental slippage between said explosive and reinforcing percent by weight of a butadiene, from about 10 to 45 means under differential stress up to the rupture stress percent by weight of an acrylonitrile and a sufficient of the reinforcing means.
  • amount of an acrylic acid to provide from about 0.001 to I claim: 0.3 carboxyl equivalents per parts of said copolymer,
  • a detonating fuse comprising an intimate uniform 75 said polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of said copolymer; from about 1 to 20 percent by weight of a plasticizer; up to 25 percent by weight of a polyurethane elastomer; and a reinforcing element bonded to said explosive composition and substantially centrally positioned along the longitudinal axis of the fuse.
  • An elongated detonating fuse comprising an intimate uniform mixture of from about 40 to 80 percent by weight of a cap-sensitive particulate high explosive; from about 15 to 50 percent by weight of a polymeric metallocarboxylate elastorner which is the reaction product of a polyvalent metal ion with a copolymer of from about 50 to 80 percent by weight butadiene, from about 10 to 45 percent by weight acrylonitrile and a suflicient amount of methacrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per 100 parts of said copolyrner, said polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of said copolymer; from about 1 to percent by weight of a plasticizer; up to about percent by Weight of a polyurethane elastomer; and a reinforcing element bonded to said explosive composition and substantially centrally positioned along the longitudinal axis of the fuse.
  • An elongated detonating fuse comprising an intimate uniform mixture of from about to 80 percent by weight of the cap-sensitive particulate high explosive pentaerythritol tetranitrate; from about 15 to percent by weight of a polymeric metallocarboxylate elastomer which is the reaction product of a polyvalent metal ion with a copolymer of from 50 to percent by Weight butadiene, from about 10 to 45 percent by weight acrylonitrile and a sufficient amount of methacrylic acid to provide from about 0.001 to 0.3 carboxyl equivalents per parts of said copolymer, said polyvalent metal ion being present in an amount chemically equivalent to about 0.5 to 2 times the carboxyl content of said copolymer; from about 1 to 20 percent by weight of a plasticizer; up to about 25 percent by weight of a polyether urethane elastomer; and a nylon yarn reinforcing element substantially centrally positioned along the longitudinal axis of the fuse.

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US651061A 1965-08-19 1967-05-02 Flexible detonating fuse Expired - Lifetime US3407731A (en)

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Application Number Priority Date Filing Date Title
GB36195/66A GB1106396A (en) 1965-08-19 1966-08-12 Explosive composition
CH1178266A CH498789A (de) 1965-08-19 1966-08-16 Sprengmasse
DE19661571277 DE1571277A1 (de) 1965-08-19 1966-08-19 Sprengmittel
US651062A US3401215A (en) 1965-08-19 1967-05-02 Making flexible detonating fuse
US651061A US3407731A (en) 1965-08-19 1967-05-02 Flexible detonating fuse

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US481150A US3338764A (en) 1965-08-19 1965-08-19 Flexible detonating compositions containing high explosives and polymeric metallocarboxylates
US651061A US3407731A (en) 1965-08-19 1967-05-02 Flexible detonating fuse

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3867884A (en) * 1973-02-19 1975-02-25 Ici Ltd Explosive fuse-cord
US3968723A (en) * 1975-03-03 1976-07-13 The United States Of America As Represented By The Secretary Of The Navy Method for reclaiming and recycling plastic bonded energetic material
US4178016A (en) * 1976-07-10 1979-12-11 Daimler-Benz Aktiengesellschaft Triggering installation for a passenger protection device in a vehicle
US4230041A (en) * 1977-08-01 1980-10-28 Ici Australia Limited Explosive fuze cord
US5187320A (en) * 1991-12-06 1993-02-16 E. I. Du Pont De Nemours And Company Fibrillatable PTFE in plastic-bonded explosives
US6170399B1 (en) 1997-08-30 2001-01-09 Cordant Technologies Inc. Flares having igniters formed from extrudable igniter compositions
US6224099B1 (en) 1997-07-22 2001-05-01 Cordant Technologies Inc. Supplemental-restraint-system gas generating device with water-soluble polymeric binder
RU2227132C2 (ru) * 2002-06-05 2004-04-20 Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Краснознаменец" Эластичный взрывчатый состав
RU2435751C1 (ru) * 2010-04-09 2011-12-10 Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Краснознаменец" Способ получения эластичного взрывчатого состава

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE428057B (sv) * 1973-07-10 1983-05-30 Giampiero Ferri Ammunition for leksaksvapen och sett for framstellning av densamma
DE2529432C2 (de) * 1975-07-02 1985-10-17 Dynamit Nobel Ag, 5210 Troisdorf Verfahren zur Herstellung von flexiblen Sprengstoff-Formkörpern
GB2384207B (en) * 1989-04-18 2003-10-29 Royal Ordnance Plc Production of energetic materials
CN111960906B (zh) * 2020-07-29 2021-12-21 西安近代化学研究所 一种钝感太安及其制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2363569A (en) * 1940-07-01 1944-11-28 Ici Ltd Manufacture of nondetonating fuses for blasting and similar purposes
US2999743A (en) * 1960-08-17 1961-09-12 Du Pont Deformable self-supporting explosive composition
US3102833A (en) * 1961-03-07 1963-09-03 Du Pont Process for producing a fibrous explosive having variable density
US3227588A (en) * 1963-03-14 1966-01-04 Jones Walter Thomas Crystalline explosives in a viscoelastic binder of sheet form
US3269880A (en) * 1965-01-13 1966-08-30 Visnov Martin Heat resistant butadiene-acrylonitrile propellants
US3296041A (en) * 1964-07-08 1967-01-03 Eastman Kodak Co Granulated crystalline plastic bonded explosives

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2363569A (en) * 1940-07-01 1944-11-28 Ici Ltd Manufacture of nondetonating fuses for blasting and similar purposes
US2999743A (en) * 1960-08-17 1961-09-12 Du Pont Deformable self-supporting explosive composition
US3102833A (en) * 1961-03-07 1963-09-03 Du Pont Process for producing a fibrous explosive having variable density
US3227588A (en) * 1963-03-14 1966-01-04 Jones Walter Thomas Crystalline explosives in a viscoelastic binder of sheet form
US3296041A (en) * 1964-07-08 1967-01-03 Eastman Kodak Co Granulated crystalline plastic bonded explosives
US3269880A (en) * 1965-01-13 1966-08-30 Visnov Martin Heat resistant butadiene-acrylonitrile propellants

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3867884A (en) * 1973-02-19 1975-02-25 Ici Ltd Explosive fuse-cord
US3968723A (en) * 1975-03-03 1976-07-13 The United States Of America As Represented By The Secretary Of The Navy Method for reclaiming and recycling plastic bonded energetic material
US4178016A (en) * 1976-07-10 1979-12-11 Daimler-Benz Aktiengesellschaft Triggering installation for a passenger protection device in a vehicle
US4230041A (en) * 1977-08-01 1980-10-28 Ici Australia Limited Explosive fuze cord
US5187320A (en) * 1991-12-06 1993-02-16 E. I. Du Pont De Nemours And Company Fibrillatable PTFE in plastic-bonded explosives
US6224099B1 (en) 1997-07-22 2001-05-01 Cordant Technologies Inc. Supplemental-restraint-system gas generating device with water-soluble polymeric binder
US6170399B1 (en) 1997-08-30 2001-01-09 Cordant Technologies Inc. Flares having igniters formed from extrudable igniter compositions
RU2227132C2 (ru) * 2002-06-05 2004-04-20 Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Краснознаменец" Эластичный взрывчатый состав
RU2435751C1 (ru) * 2010-04-09 2011-12-10 Федеральное государственное унитарное предприятие "Научно-производственное предприятие "Краснознаменец" Способ получения эластичного взрывчатого состава

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Publication number Publication date
GB1106396A (en) 1968-03-13
DE1571277A1 (de) 1970-12-10
CH498789A (de) 1970-11-15

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