EP0234138A1 - Protective varnish for preventing thermal ignition of ammunition without a cartridge case or with a combustible cartridge case - Google Patents

Protective varnish for preventing thermal ignition of ammunition without a cartridge case or with a combustible cartridge case Download PDF

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Publication number
EP0234138A1
EP0234138A1 EP86402381A EP86402381A EP0234138A1 EP 0234138 A1 EP0234138 A1 EP 0234138A1 EP 86402381 A EP86402381 A EP 86402381A EP 86402381 A EP86402381 A EP 86402381A EP 0234138 A1 EP0234138 A1 EP 0234138A1
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EP
European Patent Office
Prior art keywords
layer
ammunition
resin
varnish
insulating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86402381A
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German (de)
French (fr)
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EP0234138B1 (en
Inventor
Gérard Sauvestre
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Giat Industries SA
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Direction General pour lArmement DGA
Etat Francais
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
    • F42B5/02—Cartridges, i.e. cases with charge and missile
    • F42B5/18—Caseless ammunition; Cartridges having combustible cases
    • F42B5/192—Cartridge cases characterised by the material of the casing wall
    • F42B5/196—Coatings

Definitions

  • the technical sector of the present invention is that of protective varnishes against thermoinitiation or any other thermal attack.
  • Ammunition without a cartridge case or with a combustible case must be protected against thermoinitiation due to the high temperatures reached in the weapon. Without protection, and for relatively low temperatures of 350 to 400 ° C, the propellants of ammunition may ignite spontaneously upon introduction into the weapon, which can cause very serious accidents.
  • thermal protection - or to create an insulating shield thanks to the introduction of expanded materials (microballoons, glass microspheres).
  • patent FR-A-2 294 421 describes the production of a combustible case made of polyurethane foam, loaded with explosive or oxidizing mineral agents.
  • the implementation process is expensive due to its complicated technology. In addition, it most often leads to unburnt due in particular to the minimum thickness (1 to 2 mm) compatible with the manufacturing process. It is indeed an envelope and not a varnish.
  • Patent FR-A-2 444 251 describes a protective varnish made of a resin loaded with phenolic microbeads having a few tenths of a mm of thickness. In this case, it is a non-combustible varnish which inevitably produces unburned combustion as soon as it becomes necessary to increase the thickness of the layer as is the case for protection at higher high temperatures. at 500 ° C reached in medium and small caliber weapons.
  • the coating in one or more homogeneous thin layers of this material is not possible due to the low rate of binder indicated (less than 40%).
  • the necessary presence of explosives has the following two drawbacks: an increase in sensitivity and a low decomposition temperature. This material cannot therefore be applied to ammunition as a protective varnish.
  • the object of the invention is to propose a new protective varnish ensuring thermal protection up to a temperature of 750 ° C. while being entirely combustible.
  • the subject of the invention is therefore a protective varnish against thermoinitiation of ammunition without a casing or with a combustible casing, characterized in that it comprises at least one reactive layer applied to the ammunition comprising a synthetic resin and an oxidant whose temperature decomposition is greater than 350 ° C and at least one insulating layer applied to the reactive layer comprising a synthetic resin and a thermal insulating compound.
  • the resins can be of the polyurethane, alkyd or oleophenolic type.
  • the oxidant can be chosen from the group consisting of potassium perchlorate, lead or barium chromate in a proportion of 1 to 20% by mass of the total composition of the layer.
  • the insulating compound can be represented by organic or mineral microballoons.
  • the varnish may comprise an internal layer of resin interposed between the munition and the reactive layer and an external layer of resin applied to the insulating layer.
  • the internal resin layer may be of the oleophenolic type, the reactive layer a polyurethane resin loaded with 10% by mass of potassium perchlorate, the insulating layer a polyurethane resin loaded with phenolic microballoons, and the outer layer a polyurethane resin.
  • the varnish can include two insulating layers.
  • the total thickness of the coating can be between 0.15 and 0.25 mm.
  • a result of the present invention lies in the causes the varnish to provide thermal protection for the propellant charge to which it is applied while leaving no solid residue of combustion in the weapon.
  • each layer, applied to the propellant charge, has a very specific role and the order of application must be respected. A minimum of two coats can be used. The order in which these layers are to be applied must be scrupulously observed.
  • the insulating layer acting as the main heat shield It consists of a thermostable resin, loaded with an insulating material such as phenolic microballoons.
  • the role of the inner reactive layer is to eliminate any residues generated by the insulating layer and is applied to the load. Also, the resin is charged with oxidizing products which contribute to improving the combustibility of the varnish. These materials must have high decomposition temperatures in order not to degrade the thermal resistance of the assembly.
  • first resin layer or internal layer and / or an external layer can be applied to the load on the insulating layer.
  • This first layer is a primer layer and has the function of eliminating surface irregularities and improving the adhesion of the reactive layer.
  • it is essential to ensure that the chemical nature of the resin used is compatible with that of the propellant charge of the ammunition.
  • the outer layer is a topcoat applied to the insulating layer which also eliminates any irregularities which generate hot spots.
  • Polyurethane resin is perfectly suited to this requirement.
  • the resins used in the insulating and reactive layers and the outer layer are preferably those having good thermal stability. They must also have a low viscosity compatible with the charge rates used, generally from 1 to 20% by mass, so as to obtain homogeneous layers of low thickness, because the residue rate generally increases with the thickness. some nail polish. A total thickness of 0.2 mm gives good results, each layer then having a thickness of between 0.02 and 0.08 mm.
  • the resins used for the different layers can be identical or different and each layer can be produced in several sublayers.
  • the compounds used in the invention are those of the trade but it is preferable that their purity is the best possible.
  • the average particle size of the oxidant and of the thermal insulating compound can advantageously be of the order of 50 to 80 ⁇ m.
  • the thermal stability was assessed on a hot plate.
  • the test consists in determining the reaction time necessary for the appearance of a pyrotechnic event (smoke, flames, ...) when a test piece of combustible propellant material coated with varnish is brought into contact with a hot worn plate at a specific temperature.
  • layer 1 Oleophenolic resin layer 2 Polyurethane resin loaded with 10% by mass of potassium perchlorate.
  • layer 3 Polyurethane resin loaded with 10% by mass of phenolic microballoons layer 4 Polyurethane resin.
  • Oleophenolic resin layer 2 Polyurethane resin loaded with 10% by mass of KCl04 layer 3
  • Polyurethane resin loaded with 5% by mass of phenolic microballoons layer 5 Polyurethane resin.
  • Oleophenolic resin layer 1 Oleophenolic resin layer 2 Polyurethane resin loaded with 10% lead chromate layer 3 Polyurethane resin loaded with 5% phenolic microballoons layer 4 Polyurethane resin loaded with 5% phenolic microballoons layer 5 Polyurethane resin.
  • the combustible product test piece of the following dimensions: height 15 mm, diameter 42 mm, consists of known simple tubular base powders agglomerated by means of a binder under low pressure.
  • the increase in mass of a treated propellant block is of the order of 3.5 to 4.5 g.
  • the multilayer varnishes according to the invention therefore offer excellent results in terms of temperature resistance and the residue rate.
  • the thermoinitiation times obtained of the order of 2 s at 600 ° C and 1.2 s at 750 ° C, show good efficiency against the short-term thermal effect (time between the placement of the munition in the chamber of the weapon and the closing of the breech) mainly in the case of automatic weapons.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Paints Or Removers (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Laminated Bodies (AREA)

Abstract

1. A varnish protecting a caseless or combustible case of ammunition against thermoinitiation comprising an insulating layer consisting of a synthetic resin and a heat insulating compound, characterized by the fact that it includes a reactive layer applied to the ammunition consisting of a synthetic resine and an oxidizer with a decomposition temperature above 350 degrees C, the insulated layer being applied to the reactive layer.

Description

Le secteur technique de la présente invention est celui des vernis protecteurs contre la thermoinitiation ou toute autre agression thermique.The technical sector of the present invention is that of protective varnishes against thermoinitiation or any other thermal attack.

Les munitions sans douille ou a douille combustible doivent être protégées contre la thermoinitiation consécutive aux températures élevées atteintes dans l'arme. Sans protec­tion, et pour des températures relativement basses de 350 à 400°C, les blocs propulsifs des munitions risquent ainsi de s'enflammer spontanément dès leur introduction dans l'arme, ce qui peut provoquer des accidents très graves.Ammunition without a cartridge case or with a combustible case must be protected against thermoinitiation due to the high temperatures reached in the weapon. Without protection, and for relatively low temperatures of 350 to 400 ° C, the propellants of ammunition may ignite spontaneously upon introduction into the weapon, which can cause very serious accidents.

Les deux grands principes utilisés en matière de protection thermique visent:
- soit à créer un bouclier isolant grâce à l'introduction de matières expansées (microballons, microsphè­res de verre).
- soit à créer un bouclier thermoconducteur sous l'effet de poudres métalliques (cuivre, aluminium)The two main principles used in thermal protection are:
- or to create an insulating shield thanks to the introduction of expanded materials (microballoons, glass microspheres).
- or to create a heat-conducting shield under the effect of metallic powders (copper, aluminum)

Ainsi, le brevet FR-A-2 294 421 décrit la réalisa­tion d'un étui combustible en mousse de polyuréthane, chargé d'explosif ou d'agents minéraux oxydants. Le procédé de mise en oeuvre est onéreux en raison de sa technologie compliquée. En outre, il conduit le plus souvent à des imbrûlés en raison notamment de l'épaisseur minimale (de 1 à 2 mm) compatible avec le procédé de fabrication. Il s'agit en effet d'une enve­loppe et non d'un vernis.Thus, patent FR-A-2 294 421 describes the production of a combustible case made of polyurethane foam, loaded with explosive or oxidizing mineral agents. The implementation process is expensive due to its complicated technology. In addition, it most often leads to unburnt due in particular to the minimum thickness (1 to 2 mm) compatible with the manufacturing process. It is indeed an envelope and not a varnish.

Le brevet FR-A-2 444 251 fait état d'un vernis pro­tecteur constitué d'une résine chargée de microbilles phéno­liques ayant quelques dixièmes de mm d'épaisseur. Dans ce cas, il s'agit d'un vernis non combustible produisant inévitable­ment des imbrûlés de combustion dès qu'il s'avère nécessaire d'accroître l'épaisseur de la couche comme c'est le cas pour la protection aux températures élevées supérieures à 500°C at­teintes dans les armes de moyens et petits calibres.Patent FR-A-2 444 251 describes a protective varnish made of a resin loaded with phenolic microbeads having a few tenths of a mm of thickness. In this case, it is a non-combustible varnish which inevitably produces unburned combustion as soon as it becomes necessary to increase the thickness of the layer as is the case for protection at higher high temperatures. at 500 ° C reached in medium and small caliber weapons.

On connaît également un matériau alvéolaire agglo­méré selon le brevet FR-A-2 508 896 qui est constitué d'un oxydant minéral, d'un explosif, de microballons phénoliques et d'un liant durcissable. Ce produit de par sa conception est mis en oeuvre par moulage ou extrusion. Il en résulte que son application principale concerne la réalisation d'objets com­bustibles tels que des étuis et conteneurs rigides.Also known is an agglomerated cellular material according to patent FR-A-2 508 896 which consists of an inorganic oxidant, an explosive, phenolic microballoons and a curable binder. This product by design is implemented by molding or extrusion. As a result, its main application relates to the production of combustible objects such as cases and rigid containers.

L'enduction en une ou plusieurs couches minces homogènes de ce matériau n'est pas envisageable en raison du faible taux de liant indiqué (inférieur à 40%). En outre, la présence néces­saire d'explosifs présente les deux inconvénients suivants: une augmentation de la sensibilité et une faible température de décomposition. Ce matériau ne peut donc pas être appliqué sur des munitions comme vernis protecteur.The coating in one or more homogeneous thin layers of this material is not possible due to the low rate of binder indicated (less than 40%). In addition, the necessary presence of explosives has the following two drawbacks: an increase in sensitivity and a low decomposition temperature. This material cannot therefore be applied to ammunition as a protective varnish.

Le but de l'invention est de proposer un nouveau vernis protecteur assurant une protection thermique jusqu'à une température de 750°C tout en étant entièrement combustible.The object of the invention is to propose a new protective varnish ensuring thermal protection up to a temperature of 750 ° C. while being entirely combustible.

L'invention a donc pour objet un vernis protecteur contre la thermoinitiation d'une munition sans douille ou à douille combustible, caractérisé en ce qu'il comprend au moins une couche réactive appliquée sur la munition comprenant une résine synthétique et un oxydant dont la température de décom­position est supérieure à 350°C et au moins une couche isolan­te appliquée sur la couche réactive comprenant une résine synthétique et un composé isolant thermique.The subject of the invention is therefore a protective varnish against thermoinitiation of ammunition without a casing or with a combustible casing, characterized in that it comprises at least one reactive layer applied to the ammunition comprising a synthetic resin and an oxidant whose temperature decomposition is greater than 350 ° C and at least one insulating layer applied to the reactive layer comprising a synthetic resin and a thermal insulating compound.

Les résines peuvent être du type polyuréthanes, al­kydes ou oléophénoliques.The resins can be of the polyurethane, alkyd or oleophenolic type.

L'oxydant peut être choisi dans le groupe constitué par le perchlorate de potassium, le chromate de plomb ou de baryum à raison de 1 à 20% en masse de la composition totale de la couche.The oxidant can be chosen from the group consisting of potassium perchlorate, lead or barium chromate in a proportion of 1 to 20% by mass of the total composition of the layer.

Le composé isolant peut être représenté par des mi­croballons organiques ou minéraux.The insulating compound can be represented by organic or mineral microballoons.

Le vernis peut comprendre une couche interne de ré­sine interposée entre la munition et la couche réactive et une couche externe de résine appliquée sur la couche isolante.The varnish may comprise an internal layer of resin interposed between the munition and the reactive layer and an external layer of resin applied to the insulating layer.

La couche interne de résine peut être du type oléo­phénolique, la couche réactive une résine polyuréthane chargée à 10% en masse de perchlorate de potassium, la couche isolante une résine polyuréthane chargée en microballons phénoliques, et la couche externe une résine polyuréthane.The internal resin layer may be of the oleophenolic type, the reactive layer a polyurethane resin loaded with 10% by mass of potassium perchlorate, the insulating layer a polyurethane resin loaded with phenolic microballoons, and the outer layer a polyurethane resin.

Le vernis peut comprendre deux couches isolantes.The varnish can include two insulating layers.

L'épaisseur totale du revêtement peut être comprise entre 0,15 et 0,25 mm.The total thickness of the coating can be between 0.15 and 0.25 mm.

Un résultat de la présente invention réside dans le fait que le vernis assure la protection thermique du charge­ment propulsif sur lequel il est appliqué tout en ne laissant aucun résidu solide de combustion dans l'arme.A result of the present invention lies in the causes the varnish to provide thermal protection for the propellant charge to which it is applied while leaving no solid residue of combustion in the weapon.

Un autre résultat réside dans le fait que ce vernis est appliqué sur la munition en couche mince, ce qui a peu d'influence sur la balistique intérieure du bloc par rapport à un bloc nu.Another result lies in the fact that this varnish is applied to the ammunition in a thin layer, which has little influence on the interior ballistics of the block compared to a bare block.

Chaque couche, appliquée sur le chargement propulsif, a un rôle bien particulier et l'ordre d'appliction doit être respecté. On peut utiliser au minimum deux couches. L'ordre dans lequel ces couches doivent être appliquées, doit être scrupuleusement respecté. En se plaçant au plus près de la source de chaleur, par exemple dans la chambre de l'arme, on trouve la couche isolante agissant comme écran thermique prin­cipal. Elle est constituée d'une résine thermostable, chargée d'un matériau isolant tel que des microballons phénoliques.Each layer, applied to the propellant charge, has a very specific role and the order of application must be respected. A minimum of two coats can be used. The order in which these layers are to be applied must be scrupulously observed. By being placed as close as possible to the heat source, for example in the gun chamber, we find the insulating layer acting as the main heat shield. It consists of a thermostable resin, loaded with an insulating material such as phenolic microballoons.

La couche réactive intérieure a pour rôle d'éliminer les résidus éventuellement générés par la couche isolante et est appliquée sur le chargement. Aussi, la résine est-elle chargée de produits oxydants qui contribuent à améliorer la combustibilité du vernis. Ces matériaux doivent posséder des températures de décomposition élevées afin de ne pas dégrader la tenue thermique de l'ensemble.The role of the inner reactive layer is to eliminate any residues generated by the insulating layer and is applied to the load. Also, the resin is charged with oxidizing products which contribute to improving the combustibility of the varnish. These materials must have high decomposition temperatures in order not to degrade the thermal resistance of the assembly.

Des produits comme le perchlorate de potassium (TD 630°C) et le chromate de plomb (TD = 1200°C) répondent parfai­tement à cet objectif.Products such as potassium perchlorate (T D 630 ° C) and lead chromate (T D = 1200 ° C) meet this objective perfectly.

Bien entendu, ces deux couches peuvent être utili­sées en combinaison avec des couches de résine seule. Ainsi, on peut appliquer sur le chargement une première couche de ré­sine ou couche interne et/ou une couche externe sur la couche isolante.Of course, these two layers can be used in combination with layers of resin alone. Thus, a first resin layer or internal layer and / or an external layer can be applied to the load on the insulating layer.

Cette première couche est une couche d'apprêt et a pour fonction d'éliminer les irrégularités de surface et d'améliorer l'adhérence de la couche réactive. Bien entendu, il est essentiel de s'assurer que la nature chimique de la ré­sine utilisée est compatible avec celle du chargement propul­sif de la munition. En particulier, on doit éviter la présence de réactions chimiques qui, certes améliorent l'adhérence de la couche, mais conduisent le plus souvent à une augmentation du taux de résidus ou d'imbrûlés. On a constaté qu'une résine oléophénolique répondait parfaitement à ces impératifs lorsqu'on utilise un chargement à base de nitrocellulose.This first layer is a primer layer and has the function of eliminating surface irregularities and improving the adhesion of the reactive layer. Of course, it is essential to ensure that the chemical nature of the resin used is compatible with that of the propellant charge of the ammunition. In particular, it is necessary to avoid the presence of chemical reactions which, certainly improve the adhesion of the layer, but most often lead to an increase in the rate of residues or unburnt. It was found that a resin oleophenolic met these requirements perfectly when using a nitrocellulose-based load.

La couche externe est une couche de finition appli­quée sur la couche isolante qui élimine également toute irré­gularité génératrice de points chauds. Une résine polyuréthane convient parfaitement à cet impératif.The outer layer is a topcoat applied to the insulating layer which also eliminates any irregularities which generate hot spots. Polyurethane resin is perfectly suited to this requirement.

Les résines utilisées dans les couches isolantes et réactives et la couche externe sont de préférence celles ayant une bonne stabilité thermique. Elles devront également possé­der une faible viscosité compatible avec les taux de charge utilisés, généralement de 1 à 20% en masse, de façon à obtenir des couches homogènes de faible épaisseur, car le taux de ré­sidus augmente d'une manière générale avec l'épaisseur du ver­nis. Une épaisseur totale de 0,2 mm donne de bons résultats, chaque couche ayant alors un épaisseur comprise entre 0,02 et 0,08 mm.The resins used in the insulating and reactive layers and the outer layer are preferably those having good thermal stability. They must also have a low viscosity compatible with the charge rates used, generally from 1 to 20% by mass, so as to obtain homogeneous layers of low thickness, because the residue rate generally increases with the thickness. some nail polish. A total thickness of 0.2 mm gives good results, each layer then having a thickness of between 0.02 and 0.08 mm.

Bien entendu, les résines utilisées pour les diffé­rentes couches peuvent être identiques ou différentes et cha­que couche peut être réalisée en plusieurs sous-couches.Of course, the resins used for the different layers can be identical or different and each layer can be produced in several sublayers.

Les composés utilisés dans l'invention sont ceux du commerce mais il est préférable que leur pureté soit la meil­leure possible. La granulométrie moyenne de l'oxydant et du composé isolant thermique peut avantageusement être de l'ordre de 50 à 80 µm.The compounds used in the invention are those of the trade but it is preferable that their purity is the best possible. The average particle size of the oxidant and of the thermal insulating compound can advantageously be of the order of 50 to 80 μm.

Les exemples suivants illustrent l'invention.The following examples illustrate the invention.

Pour chacune des compositions testées, on a évalué la stabilité thermique sur plaque chaude. L'essai consiste à déterminer le temps de réaction nécessaire à l'apparition d'un évènement pyrotechnique (fumée, flammes,...) lorsqu'une éprou­vette en matériau propulsif combustible enduite de vernis est mise au contact d'une plaque chaude portée à une température déterminée.For each of the compositions tested, the thermal stability was assessed on a hot plate. The test consists in determining the reaction time necessary for the appearance of a pyrotechnic event (smoke, flames, ...) when a test piece of combustible propellant material coated with varnish is brought into contact with a hot worn plate at a specific temperature.

Des essais de compatibilité et de sensibilité à la friction ont également été effectués. Pour étudier la compati­bilité, on a déterminé la stabilité thermique des vernis par les techniques suivantes:
- l'analyse thermique différentielle et thermogravimétrique,
- la stabilité sous vide (100°C pendant 200h).Compatibility and sensitivity to friction tests were also carried out. To study compatibility, the thermal stability of varnishes was determined by the following techniques:
- differential thermal and thermogravimetric analysis,
- stability under vacuum (100 ° C for 200h).

On ne note aucune incompatibilité chimique.No chemical incompatibility is noted.

Quant à la sensibilité à la friction, aucune diffé­ rence n'a été décelée entre un bloc nu et un bloc traité par le vernis selon l'invention.As for sensitivity to friction, no difference Rence was not detected between a bare block and a block treated with the varnish according to the invention.

EXEMPLE 1EXAMPLE 1

couche 1 Résine oléophénolique
couche 2 Résine polyuréthane chargée à 10% en masse de perchlorate de potassium.
couche 3 Résine polyuréthane chargée à 10% en masse de microballons phénoliques
couche 4 Résine polyuréthane.layer 1 Oleophenolic resin
layer 2 Polyurethane resin loaded with 10% by mass of potassium perchlorate.
layer 3 Polyurethane resin loaded with 10% by mass of phenolic microballoons
layer 4 Polyurethane resin.

EXEMPLE 2EXAMPLE 2

couche 1 Résine oléophénolique
couche 2 Résine polyuréthane chargée à 10% en masse de KCl0₄
couche 3 Résine polyuréthane chargée à 5% en masse de microballons phénoliques
couche 4 Résine polyuréthane chargée à 5% en masse de microballons phénoliques
couche 5 Résine polyuréthane.layer 1 Oleophenolic resin
layer 2 Polyurethane resin loaded with 10% by mass of KCl0₄
layer 3 Polyurethane resin loaded with 5% by mass of phenolic microballoons
layer 4 Polyurethane resin loaded with 5% by mass of phenolic microballoons
layer 5 Polyurethane resin.

EXEMPLE 3EXAMPLE 3

couche 1 Résine oléophénolique
couche 2 Résine polyuréthane chargée à 10% de chromate de plomb
couche 3 Résine polyuréthane chargée à 5% de microballons phénoliques
couche 4 Résine polyuréthane chargée à 5% de microballons phénoliques
couche 5 Résine polyuréthane.layer 1 Oleophenolic resin
layer 2 Polyurethane resin loaded with 10% lead chromate
layer 3 Polyurethane resin loaded with 5% phenolic microballoons
layer 4 Polyurethane resin loaded with 5% phenolic microballoons
layer 5 Polyurethane resin.

On a rassemblé dans le tableau suivant les principa­les caractéristiques de ces vernis protecteurs. Dans le cas présent, l'éprouvette de produit combustible de dimensions suivantes: hauteur 15 mm, diamètre 42 mm, est constituée de poudres simple base tubulaires connues agglomérées au moyen d'un liant sous faible pression.The main characteristics of these protective varnishes have been collected in the following table. In the present case, the combustible product test piece of the following dimensions: height 15 mm, diameter 42 mm, consists of known simple tubular base powders agglomerated by means of a binder under low pressure.

Les résultats obtenus sont équivalents en remplaçant la résine polyuréthane par une résine alkyde ou oléophénoli­que.The results obtained are equivalent by replacing the polyurethane resin with an alkyd or oleophenolic resin.

L'augmentation de masse d'un bloc propulsif traité est de l'ordre de 3,5 à 4,5g.

Figure imgb0001
The increase in mass of a treated propellant block is of the order of 3.5 to 4.5 g.
Figure imgb0001

Les vernis multicouches selon l'invention offrent donc d'excellents résultats sur les plans de la tenue à la température et du taux de résidus. Les temps de thermoinitia­tion obtenus, de l'ordre de 2s à 600°C et 1,2 s à 750°C, mon­trent une bonne efficacité contre l'effet thermique à court terme (temps entre la mise à poste de la munition dans la chambre de l'arme et la fermeture de la culasse) principale­ment dans le cas des armes automatiques.The multilayer varnishes according to the invention therefore offer excellent results in terms of temperature resistance and the residue rate. The thermoinitiation times obtained, of the order of 2 s at 600 ° C and 1.2 s at 750 ° C, show good efficiency against the short-term thermal effect (time between the placement of the munition in the chamber of the weapon and the closing of the breech) mainly in the case of automatic weapons.

On ne note pas grâce à l'action conjuguée des agents oxydants et de la faible épaisseur de vernis, la présence d'imbrûlés ni au cours des essais laboratoires d'inflammation sur plaque chaude, ni au tir canon. En effet, les taux d'im­purétés de 7°/oo sont équivalents à ceux obtenus avec des échantillons non traités.We do not note, thanks to the combined action of oxidizing agents and the low thickness of varnish, the presence of unburnt materials, neither during hot-plate ignition laboratory tests, nor with cannon fire. Indeed, the impurity rates of 7 ° / oo are equivalent to those obtained with untreated samples.

Claims (8)

1 - Vernis protecteur contre la thermoinitiation d'une muni­tion sans douille ou à douille combustible, caractérisé en ce qu'il comprend au moins une couche réactive appliquée sur la munition comprenant une résine synthétique et un oxydant dont la température de décomposition est supérieure à 350 °C, et au moins une couche isolante appliquée sur la couche réactive comprenant une résine synthétique et un composé isolant ther­mique.1 - Protective varnish against thermoinitiation of ammunition without a casing or a combustible casing, characterized in that it comprises at least one reactive layer applied to the ammunition comprising a synthetic resin and an oxidant whose decomposition temperature is greater than 350 ° C, and at least one insulating layer applied to the reactive layer comprising a synthetic resin and a thermal insulating compound. 2 - Vernis selon la revendication 1, caractérisé en ce que les résines sont du type polyuréthanes, alkydes ou oléophénoli­ques.2 - Varnish according to claim 1, characterized in that the resins are of the polyurethane, alkyd or oleophenolic type. 3 - Vernis selon la revendication 1 ou 2, caractérisé en ce que l'oxydant est choisi dans le groupe constitué par le per­chlorate de potassium, le chromate de plomb ou de baryum se­lon un pourcentage en masse compris entre 1 et 20%3 - Varnish according to claim 1 or 2, characterized in that the oxidant is chosen from the group consisting of potassium perchlorate, lead or barium chromate according to a percentage by mass of between 1 and 20% 4 - Vernis selon l'une quelconque des revendications 1 à 3, caractérisé en ce que le composé isolant est représenté par des microballons organiques ou minéraux.4 - Varnish according to any one of claims 1 to 3, characterized in that the insulating compound is represented by organic or mineral microballoons. 5 - Vernis selon l'une quelconque des revendications 1 à 4, caractérisé en ce qu'il comprend une couche interne de résine interposée entre la munition et la couche réactive et une cou­che externe de résine appliquée sur la couche isolante.5 - Varnish according to any one of claims 1 to 4, characterized in that it comprises an internal layer of resin interposed between the ammunition and the reactive layer and an external layer of resin applied to the insulating layer. 6 - Vernis selon la revendication 5, caractérisé en ce que la couche interne de résine est du type oléophénolique, la couche réactive est une résine polyuréthane chargée à 10% en masse de perchlorate de potassium, la couche isolante est une résine polyuréthane chargée en microballons phénoliques, et la couche externe est une résine polyuréthane.6 - Varnish according to claim 5, characterized in that the internal resin layer is of the oleophenolic type, the reactive layer is a polyurethane resin loaded with 10% by mass of potassium perchlorate, the insulating layer is a polyurethane resin loaded with microballoons phenolic, and the outer layer is a polyurethane resin. 7 - Vernis selon la revendication 6, caractérisé en ce qu'il comprend deux couches isolantes.7 - Varnish according to claim 6, characterized in that it comprises two insulating layers. 8 - Vernis selon l'une quelconque des revendications 1 à 7, caractérisé en ce que l'épaisseur totale du revêtement est comprise entre 0,10 à 0,25 mm.8 - Varnish according to any one of claims 1 to 7, characterized in that the total thickness of the coating is between 0.10 to 0.25 mm.
EP86402381A 1985-11-12 1986-10-24 Protective varnish for preventing thermal ignition of ammunition without a cartridge case or with a combustible cartridge case Expired EP0234138B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8516640 1985-11-12
FR8516640A FR2590013B1 (en) 1985-11-12 1985-11-12 PROTECTIVE VARNISH AGAINST THERMO-INITIATION OF AMMUNITION WITHOUT SOCKET OR FUEL SOCKET

Publications (2)

Publication Number Publication Date
EP0234138A1 true EP0234138A1 (en) 1987-09-02
EP0234138B1 EP0234138B1 (en) 1989-04-19

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EP86402381A Expired EP0234138B1 (en) 1985-11-12 1986-10-24 Protective varnish for preventing thermal ignition of ammunition without a cartridge case or with a combustible cartridge case

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EP (1) EP0234138B1 (en)
DE (1) DE3662944D1 (en)
FR (1) FR2590013B1 (en)
NO (1) NO163651C (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3630019A1 (en) * 1986-09-03 1988-03-17 Dynamit Nobel Ag COMBUSTIBLE DRIVE CHARGE TANK WITH IMPROVED TEMPERATURE RESISTANCE
US5237927A (en) * 1991-10-21 1993-08-24 Olin Corporation Energetic consumable cartridge case
FR2849179B1 (en) * 2002-12-18 2006-06-30 Giat Ind Sa MUNITION WITHOUT SLEEVE AND METHOD FOR MOUNTING SUCH AMMUNITION

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2294421A1 (en) * 1974-12-12 1976-07-09 Saint Louis Inst Thermal effects resisting combustible envelope for propellant charge - consists of plastics foam with secondary explosives
EP0012690A1 (en) * 1978-12-15 1980-06-25 Societe Nationale Des Poudres Et Explosifs Combustible objects, in particular heat-resistant combustible cartridge cases
FR2508896A1 (en) * 1981-07-02 1983-01-07 France Etat Cellular pyrotechnic material with controlled porosity - comprising binder, oxidn.-redn. couple and micro-cavities, useful smoke producing, incendiary, heat vaporising or fuel compsns.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2294421A1 (en) * 1974-12-12 1976-07-09 Saint Louis Inst Thermal effects resisting combustible envelope for propellant charge - consists of plastics foam with secondary explosives
EP0012690A1 (en) * 1978-12-15 1980-06-25 Societe Nationale Des Poudres Et Explosifs Combustible objects, in particular heat-resistant combustible cartridge cases
FR2508896A1 (en) * 1981-07-02 1983-01-07 France Etat Cellular pyrotechnic material with controlled porosity - comprising binder, oxidn.-redn. couple and micro-cavities, useful smoke producing, incendiary, heat vaporising or fuel compsns.

Also Published As

Publication number Publication date
DE3662944D1 (en) 1989-05-24
NO864484D0 (en) 1986-11-11
NO864484L (en) 1987-05-13
FR2590013B1 (en) 1989-07-13
NO163651C (en) 1990-06-27
FR2590013A1 (en) 1987-05-15
EP0234138B1 (en) 1989-04-19
NO163651B (en) 1990-03-19

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