EP0404651A1 - Solid gas-generating composition and its application in gas generators for inflatable safety bags in motor vehicles - Google Patents

Solid gas-generating composition and its application in gas generators for inflatable safety bags in motor vehicles Download PDF

Info

Publication number
EP0404651A1
EP0404651A1 EP90401697A EP90401697A EP0404651A1 EP 0404651 A1 EP0404651 A1 EP 0404651A1 EP 90401697 A EP90401697 A EP 90401697A EP 90401697 A EP90401697 A EP 90401697A EP 0404651 A1 EP0404651 A1 EP 0404651A1
Authority
EP
European Patent Office
Prior art keywords
weight
azide
composition
composition according
relative
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
EP90401697A
Other languages
German (de)
French (fr)
Other versions
EP0404651B1 (en
Inventor
Christian Perotto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Livbag SAS
Original Assignee
Livbag SAS
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Livbag SAS filed Critical Livbag SAS
Publication of EP0404651A1 publication Critical patent/EP0404651A1/en
Application granted granted Critical
Publication of EP0404651B1 publication Critical patent/EP0404651B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B35/00—Compositions containing a metal azide
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06D—MEANS FOR GENERATING SMOKE OR MIST; GAS-ATTACK COMPOSITIONS; GENERATION OF GAS FOR BLASTING OR PROPULSION (CHEMICAL PART)
    • C06D5/00—Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets
    • C06D5/06—Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets by reaction of two or more solids

Definitions

  • the present invention relates to the field of protection in the event of an impact on the passengers of a motor vehicle by an airbag by means of a pyrotechnic generator of non-toxic cold gases. More specifically, the invention relates to a new solid gas-generating composition based on molybdenum sulfide and alkali or alkaline earth azide and its use in such a gas generator.
  • nitrogen-generating compositions are particularly sought after.
  • the solid compositions based on alkali or alkaline earth azide and on molybdenum sulfide, optionally in the presence of sulfur have been found to satisfy the first two requirements, namely the high combustion rate, particularly well. and a moderate combustion temperature.
  • Such compositions are for example described in US Patents 3,741,585, 4,203,787 and 4,547,235. These compositions are entirely satisfactory in terms of the generation of cold gases which are non-toxic for motor vehicle safety, but have certain disadvantages of use. and storage associated with the presence of metal azides which are explosive and moisture sensitive bodies, the hydrolysis products of which are themselves dangerous explosives.
  • the azide functional group can be introduced into a composition by certain polymers carrying this group such as, for example, glycidyl polyazide.
  • the object of the present invention is precisely to propose such a composition.
  • the object of the invention relates to a solid composition generating non-toxic cold gases comprising molybdenum sulfide, an alkali or alkaline earth azide, characterized in that it contains between 3% and 6% by weight relative to the weight total of said composition of a binder consisting of the reaction product of a glycidyl polyazide with hydroxyl endings with at least one polyisocyanate chosen from the group consisting of diisocyanates and triisocyanates.
  • the said azide is sodium azide.
  • part of the molybdenum sulphide is replaced by sulfur.
  • the invention also relates to the use of such a composition in a gas generator for an airbag intended for motor vehicles.
  • compositions according to the invention are thus particularly suitable for pyrotechnic gas generators intended to inflate the airbags of motor vehicles.
  • the invention relates to compositions based on molybdenum sulfide and alkali or alkaline earth azide such as for example sodium azide, lithium azide, strontium azide, calcium azide.
  • sodium azide will be used.
  • compositions according to the invention contain between 3% and 6% by weight relative to the total weight of said composition of a binder consisting of the reaction product of a glycidyl polyazide with OH hydroxyl endings with at least a polyisocyanate chosen from the group consisting of diisocyanates and triisocyanates.
  • the glycidyl polyazides with OH hydroxyl endings which can be used in the context of the present invention are polyethers of general formula: in which C, H, O, N represent carbon, hydrogen, oxygen and nitrogen respectively and where n represents an integer between 5 and 100.
  • polymers are generally obtained by reaction of sodium azide on a polyepichlorohydrin as described for example in US Patents 4,268,460, 4,379,894 or 4,486,351.
  • glycidyl polyazides with a molecular weight will be used between 600 and 7000 and we prefer those whose molecular mass is between 1500 and 2500.
  • polyisocyanate it is possible to use the usual aliphatic, cycloaliphatic or aromatic diisocyanates and triisocyanates such as, for example, methyl-1 cyclohexane-2,4 diisocyanate, methyl-1 cyclohexane-2,6 diisocyanate, dicyclohexylmethane-4,4′diisocyanate, l isophorone diisocyanate, methylene diisocyanate, hexane-1,6 diisocyanate, trimethyl-2,2,4 hexane-1,6 diisocyanate, toluene diisocyanate, biuret trimer of hexamethylene diisocyanate, polymethylene polyphenyl isocyanate.
  • trimer biuret of hexamethylene diisocyanate of formula: polyisocyanate is preferred: and polymethylene polyphenylisocyanates of formula: in which x represents an integer or zero and which have an average functionality in group NCO of 2.7.
  • the NCO: OH ratio is close to 1: 1.
  • the weight content of the binder composition is within a very precise range, between 3% and 6% relative to the total weight of the composition. , so that the composition retains the advantages of traditional compositions based on molybdenum sulfide and sodium azide in terms of the non-toxicity of the gases while being easier to use and store thanks to the fact that the azide grains are, at least partially, coated with a binder.
  • the weight content of the binder composition is between 4% and 5% relative to the total weight of the composition.
  • the weight content of the azide composition is advantageously between 55% and 71% relative to the total weight of the composition and the weight content of molybdenum sulfide is advantageously between 25% and 40% relative to the total weight. of the composition.
  • part of the molybdenum sulphide can be replaced by sulfur.
  • the weight content of the sulfur composition must be less than 8% relative to the total weight of the composition, the content overall composition of sulfur and molybdenum sulphide being between 25% and 40% relative to the total weight of the composition.
  • compositions according to the invention are advantageously carried out in the following manner.
  • the solid constituents namely the azide, the molybdenum sulphide and optionally the sulfur, are mixed.
  • a liquid mixer a solution of glycidyl polyazide and isocyanate in a non-reactive volatile anhydrous solvent such as methylene chloride is prepared.
  • a 50:50 volume solution is produced between the solvent on the one hand and the constituents of the binder on the other hand.
  • the mixture of solid constituents and said solution is then introduced into a kneader, catalysts intended to promote the reaction of the isocyanate on the glycidyl polyazide, such as dibutyltin dilaurate or acetylacetonate, are optionally added and kneaded under vacuum to remove the solvent.
  • a powder is then obtained which can be shaped by tableting or compression.
  • the pellets or blocks thus obtained are then baked in an oven heated to a temperature between 60 ° C and 100 ° C to complete the crosslinking of the binder.
  • pellets or blocks thus obtained burn at a moderate temperature with high combustion rates, releasing a large volume of non-toxic gases within the meaning of the standards imposed by the manufacturers of motor vehicles, these gases being essentially constituted by nitrogen. Furthermore, it has been found that the pellets or blocks of compositions according to the invention are much less sensitive to external aggressions, in particular humidity, than the pellets or blocks of traditional compositions based on alkali or alkaline earth azide and molybdenum sulfide.
  • compositions according to the invention can thus advantageously be used to constitute the pyrotechnic charge of non-toxic cold gas generators intended to inflate the airbags of motor vehicles.
  • the binder was obtained by reaction of a glycidyl polyazide with OH hydroxyl endings of average molecular weight 2000 on the trimer biuret of hexamethylene diisocyanate.
  • Dibutyltin dilaurate was used as the catalyst.
  • the pellets obtained burn with a speed of 7 mm / s at 7 MPa in a pressure bomb.
  • the combustion temperature is 867 ° K or 594 ° C.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Air Bags (AREA)

Abstract

La présente invention concerne de nouvelles compositions pyrotechni­ ques génératrices de gaz froids non toxiques. Les compositions selon l'invention contiennent entre 55% et 71% en poids d'azoture alcalin ou alcalino-terreux, entre 25% et 40% en poids de sulfure de molybdène et entre 3% et 6% en poids d'un liant constitué par le produit de réaction d'un polyazoture de glycidyle à terminaisons hydroxyles avec au moins un polyisocyanate. Une com­ position préférée comprend 35% en poids de sulfure de molybdène, 60% en poids d'azoture de sodium et 5% en poids d'un liant obtenu par réaction d'un polyazoture de glycidyle à terminaisons hydroxy­ les OH de masse 2 000 sur le biruet trimère de l'hexaméthylène dii­ socyanate. Les compositions selon l'invention sont beaucoup moins sensibles aux agressions extérieures, et notamment à l'humidité, que les com­ positions traditionelles à base d'azoture et de sulfure de molybdè­ ne. Elles conviennent particulièrement bien aux générateurs de gaz froids non toxiques destinés à gonfler les coussins de sécurité des véhicules automobiles.The present invention relates to novel pyrotechnic compositions generating cold non-toxic gases. The compositions according to the invention contain between 55% and 71% by weight of alkaline or alkaline earth azide, between 25% and 40% by weight of molybdenum sulfide and between 3% and 6% by weight of a binder consisting by the reaction product of a hydroxyl terminated glycidyl polyazide with at least one polyisocyanate. A preferred composition comprises 35% by weight of molybdenum sulphide, 60% by weight of sodium azide and 5% by weight of a binder obtained by reaction of a polyhydroxy-terminated glycidyl azide with the OH having a mass of 2000. on the trimer biruet of hexamethylene dii socyanate. The compositions according to the invention are much less sensitive to external attacks, and in particular to humidity, than traditional compositions based on azide and molybdenum sulphide. They are particularly suitable for cold non-toxic gas generators intended to inflate the safety bags of motor vehicles.

Description

La présente invention se rapporte au domaine de la protection en cas de choc des passagers d'un véhicule automobile par un coussin gonflable au moyen d'un générateur pyrotechnique de gaz froids non toxiques. Plus précisément l'invention concerne une nouvelle compo­sition solide génératrice de gaz à base de sulfure de molybdène et d'azoture alcalin ou alcalino-terreux et son utilisation dans un tel générateur de gaz.The present invention relates to the field of protection in the event of an impact on the passengers of a motor vehicle by an airbag by means of a pyrotechnic generator of non-toxic cold gases. More specifically, the invention relates to a new solid gas-generating composition based on molybdenum sulfide and alkali or alkaline earth azide and its use in such a gas generator.

Il est connu d'assurer la protection contre les chocs des passa­gers d'un véhicule automobile grâce à des coussins qui se gonflent au moment du choc sous l'effet de gaz provenant d'un générateur py­rotechnique de gaz initié par un détecteur de choc. La génération des gaz se fait par combustion dans le dit générateur d'une composi­tion solide génératrice de gaz qui sont refroidis et filtrés avant de pénétrer dans le dit coussin.It is known to provide protection against shocks to passengers of a motor vehicle by means of cushions which inflate at the time of impact under the effect of gas from a pyrotechnic gas generator initiated by a shock detector. The generation of the gases is done by combustion in the said generator of a solid composition which generates gases which are cooled and filtered before entering the said cushion.

Pour assurer un fonctionnement satisfaisant du générateur de gaz, la composition solide qui se présente en général sous forme de pas­tilles ou de petits blocs, doit satisfaire à plusieurs impératifs :

  • a) elle doit avoir une vitesse de combustion très élevée de maniè­re à assurer le gonflement du coussin dans des durées de quel­ques dizaines de millisecondes, sans pour cela être explosive,
  • b) elle doit générer des gaz dits "froids" de manière à ce que, après passage rapide dans le dispositif de refroidissement du gé­nérateur, ces gaz refroidis entrent dans le coussin à une tempé­rature supportable par l'organisme du passager. On admet en géné­ral que ces gaz "froids" doivent avoir une température de combus­tion qui ne doit pas être supérieure à 500°C-600°C,
  • c) elle doit générer des gaz non toxiques pour les passagers,
  • d) enfin pour éviter tout risque inutile d'incendie, elle doit géné­rer des gaz inertes.
To ensure satisfactory operation of the gas generator, the solid composition, which is generally in the form of pellets or small blocks, must satisfy several imperatives:
  • a) it must have a very high combustion speed so as to ensure the inflation of the cushion over periods of a few tens of milliseconds, without being explosive,
  • b) it must generate so-called "cold" gases so that, after rapid passage through the cooling device of the generator, these cooled gases enter the cushion at a temperature tolerable by the body of the passenger. It is generally accepted that these "cold" gases must have a combustion temperature which must not be higher than 500 ° C-600 ° C,
  • c) it must generate gases which are non-toxic to passengers,
  • d) finally to avoid any unnecessary risk of fire, it must generate inert gases.

Pour ces deux dernières raisons les compositions génératrices d'azo­te sont particulièrement recherchées. Parmi les compositions généra­trices d'azote, les compositions solides à base d'azoture alcalin ou alcalino-terreux et de sulfure de molybdène, éventuellement en présence de soufre, se sont avérées satisfaire particulièrement bien aux deux premières exigences à savoir la vitesse de combus­tion élevée et une température de combustion modérée. De telles com­positions sont par exemple décrites dans les brevets US 3 741 585, 4 203 787 et 4 547 235. Ces compositions donnent parfaitement satis­faction au niveau de la génération de gaz froids non toxiques pour la sécurité automobile mais présentent certains inconvénients de mise en oeuvre et de stockage liés à la présence d'azotures métalli­ques qui sont des corps explosifs et sensibles à l'humidité, dont les produits d'hydrolyse sont eux-mêmes des explosifs dangereux.For these last two reasons, nitrogen-generating compositions are particularly sought after. Among the nitrogen-generating compositions, the solid compositions based on alkali or alkaline earth azide and on molybdenum sulfide, optionally in the presence of sulfur, have been found to satisfy the first two requirements, namely the high combustion rate, particularly well. and a moderate combustion temperature. Such compositions are for example described in US Patents 3,741,585, 4,203,787 and 4,547,235. These compositions are entirely satisfactory in terms of the generation of cold gases which are non-toxic for motor vehicle safety, but have certain disadvantages of use. and storage associated with the presence of metal azides which are explosive and moisture sensitive bodies, the hydrolysis products of which are themselves dangerous explosives.

Ces inconvénients de mise en oeuvre qui sont exposés par exemple dans le brevet US 4 370 181, ont incité l'homme de métier à rechercher des compositions à base de sulfure de molybdène mais sans azoture. Le brevet US 4 370 181 sus-mentionné propose ainsi des compositions génératrices de gaz froids non toxiques à base de sulfure de molybdène et d'un composé non hydrogéné du tétrazole. De telles compositions présentent cependant l'inconvénient de faire ap­pel à un produit peu disponible sur le marché, les composés non hy­drogénés du tétrazole comme le bitétrazole ne sont en effet pas des produits de grande diffusion industrielle, et par ailleurs ces com­positions ne sont pas faciles à pastiller.These disadvantages of implementation which are set out, for example, in US Pat. No. 4,370,181, prompted those skilled in the art to search for compositions based on molybdenum sulfide but without azide. The aforementioned US Pat. No. 4,370,181 thus proposes compositions which generate non-toxic cold gases based on molybdenum sulfide and a non-hydrogenated tetrazole compound. However, such compositions have the drawback of using a product which is not very available on the market, the non-hydrogenated tetrazole compounds such as bitetrazole are not in fact products of wide industrial distribution, and moreover these compositions are not easy. to pellet.

Il est connu par ailleurs que le groupe fonctionnel azoture peut être introduit dans une composition par certains polymères por­teurs de ce groupe comme par exemple le polyazoture de glycidyle.It is also known that the azide functional group can be introduced into a composition by certain polymers carrying this group such as, for example, glycidyl polyazide.

Le brevet US 4 601 344 décrit par exemple des compositions généra­trices de gaz pour extincteurs qui sont constituées d'une part par des composés du tétrazole et d'autre part par un liant à base de po­lyazoture de glycidyle. De telles compositions présentent cepen­dant l'inconvénient de générer des gaz toxiques à des teneurs incom­patibles avec les exigences de la sécurité automobile.US Pat. No. 4,601,344 describes, for example, gas-generating compositions for extinguishers which consist, on the one hand, of tetrazole compounds and, on the other hand, of a binder based on poly (glycidyl azide). However, such compositions have the drawback of generating toxic gases at contents incompatible with the requirements of motor vehicle safety.

Dans le domaine de la protection des passagers d'un véhicule automo­bile par coussin gonflable, l'homme de métier est donc toujours à la recherche d'une composition génératrice de gaz qui présente tous les avantages des compositions à base de sulfure de molybdène et d'azotures alcalins ou alcalino-terreux sans présenter leurs incon­vénients de mise en oeuvre et de stockage.In the field of the protection of the passengers of a motor vehicle by an airbag, the skilled person is always looking for a gas generating composition which has all the advantages of compositions based on molybdenum sulfide and d alkali or alkaline earth azides without having their disadvantages of implementation and storage.

Le but de la présente invention est précisément de proposer une tel­le composition. L'objet de l'invention concerne une composition so­lide génératrice de gaz froids non toxiques comprenant du sulfure de molybdène, un azoture alcalin ou alcalino-terreux, caractérisée en ce qu'elle contient entre 3% et 6% en poids par rapport au poids total de la dite composition d'un liant constitué par le produit de réaction d'un polyazoture de glycidyle à terminaisons hydroxyles avec au moins un polyisocyanate choisi dans le groupe constitué par les diisocyanates et les triisocyanates.The object of the present invention is precisely to propose such a composition. The object of the invention relates to a solid composition generating non-toxic cold gases comprising molybdenum sulfide, an alkali or alkaline earth azide, characterized in that it contains between 3% and 6% by weight relative to the weight total of said composition of a binder consisting of the reaction product of a glycidyl polyazide with hydroxyl endings with at least one polyisocyanate chosen from the group consisting of diisocyanates and triisocyanates.

Selon une première réalisation préférée de l'invention le dit azotu­re est l'azoture de sodium.According to a first preferred embodiment of the invention, the said azide is sodium azide.

Selon une seconde réalisation préférée de l'invention une partie du sulfure de molybdène est remplacée par du soufre.According to a second preferred embodiment of the invention, part of the molybdenum sulphide is replaced by sulfur.

L'invention concerne également l'utilisation d'une telle composi­tion dans un générateur de gaz pour coussin gonflable de sécurité destiné aux véhicules automobiles.The invention also relates to the use of such a composition in a gas generator for an airbag intended for motor vehicles.

Il a été en effet constaté, de manière surprenante, par la demande­ resse que lorsque l'on remplace dans une composition traditionnel­le à base de sulfure de molybdène et d'azoture alcalin ou alcalino-­terreux, une faible proportion -entre 3% et 6% en poids par rap­port au poids total de la composition- des azotures métalliques par un liant polyuréthanne à base de polyazoture de glycidyle, on ob­tient une composition génératrice de gaz froids, non toxiques, à grande vitesse de combustion qui ne présente plus les inconvé­nients de mise en oeuvre et de stockage des dites compositions tra­ditionnelles.It was indeed found, surprisingly, by the request resse that when replacing in a traditional composition based on molybdenum sulfide and alkali or alkaline earth azide, a small proportion - between 3% and 6% by weight relative to the total weight of the composition - azides metal by a polyurethane binder based on glycidyl polyazide, there is obtained a composition generating cold gases, non-toxic, high combustion speed which no longer has the disadvantages of implementation and storage of said traditional compositions.

Les compositions selon l'invention conviennent ainsi particulière­ment bien pour les générateurs pyrotechniques de gaz destinés à gon­fler les coussins de sécurité des véhicules automobiles.The compositions according to the invention are thus particularly suitable for pyrotechnic gas generators intended to inflate the airbags of motor vehicles.

On donne ci-après une description détaillée de l'invention.A detailed description of the invention is given below.

L'invention concerne des compositions à base de sulfure de molybdè­ne et d'azoture alcalin ou alcalino-terreux comme par exemple l'azo­ture de sodium, l'azoture de lithium, l'azoture de strontium, l'azo­ture de calcium.The invention relates to compositions based on molybdenum sulfide and alkali or alkaline earth azide such as for example sodium azide, lithium azide, strontium azide, calcium azide.

Selon une première réalisation préférée de l'invention on utilise­ra de l'azoture de sodium.According to a first preferred embodiment of the invention, sodium azide will be used.

De manière caractéristique les compositions selon l'invention con­tiennent entre 3% et 6% en poids par rapport au poids total de la dite composition d'un liant constitué par le produit de réaction d'un polyazoture de glycidyle à terminaisons hydroxyles OH avec au moins un polyisocyanate choisi dans le groupe constitué par les dii­socyanates et les triisocyanates.Typically, the compositions according to the invention contain between 3% and 6% by weight relative to the total weight of said composition of a binder consisting of the reaction product of a glycidyl polyazide with OH hydroxyl endings with at least a polyisocyanate chosen from the group consisting of diisocyanates and triisocyanates.

Les polyazotures de glycidyle à terminaisons hydroxyles OH utilisa­bles dans le cadre de la présente invention sont des polyéthers de formule générale:

Figure imgb0001
dans laquelle C, H, O, N représentent respectivement le carbone, l'hydrogène, l'oxygène et l'azote et où n représente un nombre entier compris entre 5 et 100.The glycidyl polyazides with OH hydroxyl endings which can be used in the context of the present invention are polyethers of general formula:
Figure imgb0001
 in which C, H, O, N represent carbon, hydrogen, oxygen and nitrogen respectively and where n represents an integer between 5 and 100.

Ces polymères sont en général obtenus par réaction de l'azoture de sodium sur une polyépichlorhydrine comme décrit par exemple dans les brevets US 4 268 460, 4 379 894 ou 4 486 351. On utilisera en général des polyazotures de glycidyle dont la masse moléculaire est comprise entre 600 et 7000 et on préfèrera ceux dont la masse molé­culaire est comprise entre 1500 et 2500.These polymers are generally obtained by reaction of sodium azide on a polyepichlorohydrin as described for example in US Patents 4,268,460, 4,379,894 or 4,486,351. In general, glycidyl polyazides with a molecular weight will be used between 600 and 7000 and we prefer those whose molecular mass is between 1500 and 2500.

Comme polyisocyanate on peut utiliser les diisocyanates et triiso­cyanates aliphatiques, cycloaliphatiques ou aromatiques usuels com­me par exemple le méthyl-1 cyclohexane-2,4 diisocyanate, le méthyl-­1 cyclohexane-2,6 diisocyanate, le dicyclohexylméthane-4,4′diisocya­nate, l'isophorone diisocyanate, le méthylène diisocyanate, l'hexa­ne-1,6 diisocyanate, le triméthyl-2,2,4 hexane-1,6 diisocyanate, le toluène diisocyanate, le biuret trimère de l'hexaméthylène diisocya­nate, le polyméthylène polyphényl isocyanate.As polyisocyanate, it is possible to use the usual aliphatic, cycloaliphatic or aromatic diisocyanates and triisocyanates such as, for example, methyl-1 cyclohexane-2,4 diisocyanate, methyl-1 cyclohexane-2,6 diisocyanate, dicyclohexylmethane-4,4′diisocyanate, l isophorone diisocyanate, methylene diisocyanate, hexane-1,6 diisocyanate, trimethyl-2,2,4 hexane-1,6 diisocyanate, toluene diisocyanate, biuret trimer of hexamethylene diisocyanate, polymethylene polyphenyl isocyanate.

Cependant on préfèrera comme polyisocyanate le biuret trimère de l'hexaméthylène diisocyanate de formule :

Figure imgb0002
et les polyméthylène polyphénylisocyanates de formule :
Figure imgb0003
 dans laquelle x représente un nombre entier ou nul et qui ont une fonctionnalité moyenne en groupe NCO de 2,7.However, the trimer biuret of hexamethylene diisocyanate of formula: polyisocyanate is preferred:
Figure imgb0002
 and polymethylene polyphenylisocyanates of formula:
Figure imgb0003
 in which x represents an integer or zero and which have an average functionality in group NCO of 2.7.

Dans la formulation du liant selon l'invention le rapport NCO : OH est voisin de 1 : 1.In the formulation of the binder according to the invention, the NCO: OH ratio is close to 1: 1.

Comme il a été dit plus haut, une caractéristique de l'invention ré­side dans le fait que la teneur pondérale de la composition en liant se situe dans une fourchette très précise, comprise entre 3% et 6% par rapport au poids total de la composition, de manière à ce que la composition conserve les avantages des compositions tradi­tionnelles à base de sulfure de molybdène et d'azoture de sodium au plan de la non toxicité des gaz tout en étant d'une mise en oeuvre et d'un stockage plus aisés grâce au fait que les grains d'azoture sont, au moins partiellement,enrobés par un liant. Selon une réali­sation préférée de l'invention la teneur pondérale de la composi­tion en liant est comprise entre 4% et 5% par rapport au poids to­tal de la composition.As mentioned above, a characteristic of the invention resides in the fact that the weight content of the binder composition is within a very precise range, between 3% and 6% relative to the total weight of the composition. , so that the composition retains the advantages of traditional compositions based on molybdenum sulfide and sodium azide in terms of the non-toxicity of the gases while being easier to use and store thanks to the fact that the azide grains are, at least partially, coated with a binder. According to a preferred embodiment of the invention the weight content of the binder composition is between 4% and 5% relative to the total weight of the composition.

Dans ces conditions la teneur pondérale de la composition en azotu­re est avantageusement comprise entre 55% et 71% par rapport au poids total de la composition et la teneur pondérale en sulfure de molybdène est avantageusement comprise entre 25% et 40% par rap­port au poids total de la composition.Under these conditions, the weight content of the azide composition is advantageously between 55% and 71% relative to the total weight of the composition and the weight content of molybdenum sulfide is advantageously between 25% and 40% relative to the total weight. of the composition.

Selon une dernière variante préférée de l'invention une partie du sulfure de molybdène peut être remplacée par du soufre. Dans ce cas la teneur pondérale de la composition en soufre doit être inférieu­re à 8% par rapport au poids total de la oomposition, la teneur globale de la composition en soufre et en sulfure de molybdène étant comprise entre 25% et 40% par rapport au poids total de la composition.According to a last preferred variant of the invention, part of the molybdenum sulphide can be replaced by sulfur. In this case the weight content of the sulfur composition must be less than 8% relative to the total weight of the composition, the content overall composition of sulfur and molybdenum sulphide being between 25% and 40% relative to the total weight of the composition.

La formulation des compositions selon l'invention est avantageuse­ment effectuée de la manière suivante.The formulation of the compositions according to the invention is advantageously carried out in the following manner.

Dans un mélangeur à poudres on mélange les constituants solides, à savoir l'azoture, le sulfure de molybdène et éventuellement le sou­fre. Dans un mélangeur à liquide on prépare une solution de polyazo­ture de glycidyle et d'isocyanate dans un solvant anhydre volatil non réactif comme par exemple le chlorure de méthylène. Avantageuse­ment on réalise une solution 50:50 en volumes entre le solvant d'u­ne part et les constituants du liant d'autre part. On introduit alors dans un malaxeur le mélange des constituants solides et la di­te solution, on rajoute éventuellement des catalyseurs destinés à favoriser la réaction de l'isocyanate sur le polyazoture de glycidy­le comme le dilaurate de dibutyl étain ou l'acétyl acétonate de fer et on malaxe sous vide pour chasser le solvant. On obtient alors une poudre qui peut être mise en forme par pastillage ou com­pression. Les pastilles ou blocs ainsi obtenus sont alors mis en cuisson dans une étuve chauffée à une température comprise entre 60°C et 100°C pour achever la réticulation du liant.In a powder mixer, the solid constituents, namely the azide, the molybdenum sulphide and optionally the sulfur, are mixed. In a liquid mixer a solution of glycidyl polyazide and isocyanate in a non-reactive volatile anhydrous solvent such as methylene chloride is prepared. Advantageously, a 50:50 volume solution is produced between the solvent on the one hand and the constituents of the binder on the other hand. The mixture of solid constituents and said solution is then introduced into a kneader, catalysts intended to promote the reaction of the isocyanate on the glycidyl polyazide, such as dibutyltin dilaurate or acetylacetonate, are optionally added and kneaded under vacuum to remove the solvent. A powder is then obtained which can be shaped by tableting or compression. The pellets or blocks thus obtained are then baked in an oven heated to a temperature between 60 ° C and 100 ° C to complete the crosslinking of the binder.

Les pastilles ou blocs ainsi obtenus brûlent à une température modérée avec de grandes vitesses de combustion en dégageant un im­portant volume de gaz non toxiques au sens des normes imposées par les constructeurs de véhicules automobiles, ces gaz étant essentiel­lement constitués par de l'azote. Par ailleurs il a été constaté que les pastilles ou blocs de compositions selon l'invention sont beaucoup moins sensibles aux agressions extérieures, notamment à l'humidité, que les pastilles ou blocs de compositions traditionnel­les à base d'azoture alcalin ou alcalino-terreux et de sulfure de molybdène.The pellets or blocks thus obtained burn at a moderate temperature with high combustion rates, releasing a large volume of non-toxic gases within the meaning of the standards imposed by the manufacturers of motor vehicles, these gases being essentially constituted by nitrogen. Furthermore, it has been found that the pellets or blocks of compositions according to the invention are much less sensitive to external aggressions, in particular humidity, than the pellets or blocks of traditional compositions based on alkali or alkaline earth azide and molybdenum sulfide.

Les compositions selon l'invention peuvent ainsi avantageusement être utilisées pour constituer le chargement pyrotechnique des géné­rateurs de gaz froids non toxiques destinés à gonfler les coussins de sécurité des véhicules automobiles.The compositions according to the invention can thus advantageously be used to constitute the pyrotechnic charge of non-toxic cold gas generators intended to inflate the airbags of motor vehicles.

ExempleExample

On a fabriqué des pastilles répondant à la composition suivante :
. sulfure de molybdène : 36 % en poids
. azoture de sodium : 60 % en poids
. liant : 5 % en poidsWe made pellets with the following composition:
. molybdenum sulfide: 36% by weight
. sodium azide: 60% by weight
. binder: 5% by weight

Le liant a été obtenu par réaction d'un polyazoture de glycidyle à terminaisons hydroxyles OH de masse molaire moyenne 2000 sur le biu­ret trimère de l'hexaméthylène diisocyanate. On a utilisé du dilau­rate de dibutyl étain comme catalyseur.The binder was obtained by reaction of a glycidyl polyazide with OH hydroxyl endings of average molecular weight 2000 on the trimer biuret of hexamethylene diisocyanate. Dibutyltin dilaurate was used as the catalyst.

Les pastilles obtenues brûlent avec une vitesse de 7 mm/s sous 7 MPa en bombe manométrique. La température de combustion est de 867°K soit 594°C.The pellets obtained burn with a speed of 7 mm / s at 7 MPa in a pressure bomb. The combustion temperature is 867 ° K or 594 ° C.

L'analyse des gaz de combustion non filtrés donne un pourcentage d'azote supérieur à 99%, un taux de monoxyde de carbone CO infé­rieur à 120 ppm et un taux d'oxydes d'azote (NO + NO₂) inférieur à 0,5 ppm.Analysis of unfiltered combustion gases gives a percentage of nitrogen greater than 99%, a rate of carbon monoxide CO less than 120 ppm and a rate of nitrogen oxides (NO + NO₂) less than 0.5 ppm.

Claims (12)

1. Composition solide génératrice de gaz non toxiques comprenant du sulfure de molybdène, un azoture alcalin ou alcalino-terreux, carac­térisée en ce qu'elle contient entre 3% et 6% en poids par rapport au poids total de la dite composition d'un liant constitué par le produit de réaction d'un polyazoture de glycidyle à terminaisons hy­droxyles avec un moins un polyisocyanate choisi dans le groupe cons­titué par les diisocyanates et les triisocyanates.1. Solid composition generating non-toxic gases comprising molybdenum sulfide, an alkali or alkaline earth azide, characterized in that it contains between 3% and 6% by weight relative to the total weight of said composition of a binder consisting of the reaction product of a glycidyl polyazide with hydroxyl endings with at least one polyisocyanate chosen from the group consisting of diisocyanates and triisocyanates. 2. Composition selon la revendication 1 caractérisée en ce que le dit azoture est choisi dans le groupe constitué par l'azoture de so­dium, l'azoture de lithium, l'azoture de strontium, l'azoture de calcium.2. Composition according to claim 1 characterized in that said azide is chosen from the group consisting of sodium azide, lithium azide, strontium azide, calcium azide. 3. Composition selon la revendication 2 caractérisée en ce que le dit azoture est l'azoture de sodium.3. Composition according to claim 2 characterized in that said azide is sodium azide. 4. Composition selon l'une quelconque des revendications 1 à 3 ca­ractérisée en ce que la teneur pondérale en azoture est comprise en­tre 55% et 71% par rapport au poids total de la dite composition.4. Composition according to any one of claims 1 to 3 characterized in that the weight content of azide is between 55% and 71% relative to the total weight of said composition. 5. Composition selon l'une quelconque des revendications 1 à 4 ca­ractérisée en ce que le dit polyazoture de glycidyle à terminai­sons hydroxyles a une masse moléculaire moyenne comprise entre 1000 et 7000.5. Composition according to any one of claims 1 to 4 characterized in that the said glycidyl polyazide with hydroxyl endings has an average molecular weight of between 1000 and 7000. 6. Composition selon la revendication 6 caractérisée en ce que le dit polyazoture de glycidyle à terminaisons hydroxyles a une masse moléculaire moyenne comprise entre 1500 et 2500.6. Composition according to claim 6 characterized in that said glycidyl polyazide with hydroxyl endings has an average molecular weight of between 1500 and 2500. 7. Composition selon l'une quelconque des revendications 1 à 6 ca­ractérisée en ce que le dit polyisocyanate est choisi dans le grou­pe constitué par le biuret trimère de l'hexamèthylène diisocyanate et le polyméthylène polyphényl isocyanate.7. Composition according to any one of claims 1 to 6 characterized in that said polyisocyanate is chosen from the group consisting of the trimer biuret of hexamethylene diisocyanate and polymethylene polyphenyl isocyanate. 8. Composition selon l'une quelconque des revendications 1 à 7 ca­ractérisée en ce que la teneur pondérale en liant est comprise en­tre 4% et 5% par rapport au poids total de la dite composition.8. Composition according to any one of claims 1 to 7 characterized in that the weight content of binder is between 4% and 5% relative to the total weight of said composition. 9. Composition selon l'une quelconque des revendications 1 à 8 ca­ractérisée en ce que la teneur pondérale en sulfure de molybdène est comprise entre 25% et 40% par rapport au poids total de la di­te composition.9. Composition according to any one of claims 1 to 8 characterized in that the weight content of molybdenum sulfide is between 25% and 40% relative to the total weight of said composition. 10. Composition selon l'une quelconque des revendications 1 à 9 ca­ractérisée en ce qu'une partie du sulfure de molybdène est rempla­cée par du soufre.10. Composition according to any one of claims 1 to 9 characterized in that part of the molybdenum sulfide is replaced by sulfur. 11. Composition selon la revendication 10 caractérisée en ce que la teneur pondérale en soufre est inférieure à 8% par rapport au poids total de la dite composition.11. Composition according to claim 10 characterized in that the sulfur content by weight is less than 8% relative to the total weight of said composition. 12. Utilisation d'une composition selon l'une quelconque des reven­dications 1 à 11 dans un générateur de gaz pour coussin gonflable de sécurité destiné aux véhicules automobiles.12. Use of a composition according to any one of claims 1 to 11 in a gas generator for an airbag intended for motor vehicles.
EP90401697A 1989-06-21 1990-06-18 Solid gas-generating composition and its application in gas generators for inflatable safety bags in motor vehicles Expired - Lifetime EP0404651B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8908224A FR2648809B1 (en) 1989-06-21 1989-06-21 SOLID GAS GENERATOR COMPOSITION AND ITS USE IN GAS GENERATORS FOR AIR BAGS FOR PROTECTING PASSENGERS OF A MOTOR VEHICLE
FR8908224 1989-06-21

Publications (2)

Publication Number Publication Date
EP0404651A1 true EP0404651A1 (en) 1990-12-27
EP0404651B1 EP0404651B1 (en) 1994-05-18

Family

ID=9382955

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90401697A Expired - Lifetime EP0404651B1 (en) 1989-06-21 1990-06-18 Solid gas-generating composition and its application in gas generators for inflatable safety bags in motor vehicles

Country Status (5)

Country Link
US (1) US4976795A (en)
EP (1) EP0404651B1 (en)
JP (1) JPH0725633B2 (en)
DE (1) DE69008934T2 (en)
FR (1) FR2648809B1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19821010C1 (en) * 1998-05-11 1999-10-28 Bayern Chemie Gmbh Flugchemie Gas generator solid propellant for submarine emergency surfacing system
FR3027597A1 (en) * 2014-10-28 2016-04-29 Herakles PERFORMANT COMPOSITE PYROTECHNIC PRODUCT WITHOUT PB IN ITS COMPOSITION AND PREPARATION
KR20170101898A (en) * 2014-10-28 2017-09-06 에어버스 사프란 론처스 에스아에스 Composite pyrotechnic product with adn and rdx charges in a gap binder and preparation of same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5743557A (en) * 1996-05-07 1998-04-28 Amphenol-Tuchel Electronics Gmbh Hybrid inflator
KR100849750B1 (en) * 2002-02-28 2008-07-31 솔루티아인코포레이티드 Embossed reflective laminates
US6824868B2 (en) * 2002-04-30 2004-11-30 Solutia, Inc. Digital color-design composite for use in laminated glass

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3779823A (en) * 1971-11-18 1973-12-18 R Price Abrasion resistant gas generating compositions for use in inflating safety crash bags
US4268450A (en) * 1977-08-08 1981-05-19 Rockwell International Corporation Energetic hydroxy-terminated azido polymer
US4601344A (en) * 1983-09-29 1986-07-22 The United States Of America As Represented By The Secretary Of The Navy Pyrotechnic fire extinguishing method

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4405392A (en) * 1975-09-11 1983-09-20 Imperial Metal Industries (Kynoch) Limited Method of making priming composition
US4288262A (en) * 1978-03-30 1981-09-08 Rockwell International Corporation Gun propellants containing polyglycidyl azide polymer
CA1087851A (en) * 1978-07-17 1980-10-21 Lechoslaw A.M. Utracki Gas generating composition
US4919737A (en) * 1988-08-05 1990-04-24 Morton Thiokol Inc. Thermoplastic elastomer-based low vulnerability ammunition gun propellants

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3779823A (en) * 1971-11-18 1973-12-18 R Price Abrasion resistant gas generating compositions for use in inflating safety crash bags
US4268450A (en) * 1977-08-08 1981-05-19 Rockwell International Corporation Energetic hydroxy-terminated azido polymer
US4601344A (en) * 1983-09-29 1986-07-22 The United States Of America As Represented By The Secretary Of The Navy Pyrotechnic fire extinguishing method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19821010C1 (en) * 1998-05-11 1999-10-28 Bayern Chemie Gmbh Flugchemie Gas generator solid propellant for submarine emergency surfacing system
FR3027597A1 (en) * 2014-10-28 2016-04-29 Herakles PERFORMANT COMPOSITE PYROTECHNIC PRODUCT WITHOUT PB IN ITS COMPOSITION AND PREPARATION
WO2016066945A1 (en) * 2014-10-28 2016-05-06 Herakles Efficient composite pyrotechnic product with no pb in the composition thereof and preparation of same
KR20170101898A (en) * 2014-10-28 2017-09-06 에어버스 사프란 론처스 에스아에스 Composite pyrotechnic product with adn and rdx charges in a gap binder and preparation of same
KR20170101897A (en) * 2014-10-28 2017-09-06 에어버스 사프란 론처스 에스아에스 EFFICIENT COMPOSITE PYROTECHNIC PRODUCT WITH NO Pb IN THE COMPOSITION AND PREPARATION THEREOF

Also Published As

Publication number Publication date
DE69008934D1 (en) 1994-06-23
DE69008934T2 (en) 1994-09-22
US4976795A (en) 1990-12-11
JPH0725633B2 (en) 1995-03-22
EP0404651B1 (en) 1994-05-18
FR2648809B1 (en) 1991-09-13
JPH03141185A (en) 1991-06-17
FR2648809A1 (en) 1990-12-28

Similar Documents

Publication Publication Date Title
EP0576326B1 (en) Pyrotechnic composition, which generates a hot non-toxic gas and use thereof in a protection system for motor vehicle occupants
EP1216977B1 (en) Hydrocarbon binder containing pyrotechnic gas-generating compositions and method for continuous manufacturing
US5989367A (en) Particle-free, gas-producing mixture
EP1790626B1 (en) Semicontiunuous process for making an explosive composite charge having a polyurethane matrix by using two components
CA2418319C (en) Semi-continuous bicomposite process for obtaining a composite explosive charge with a polyurethane matrix
EP1713745A2 (en) Gas-generating pyrotechnical compositions and pyrotechnical compounds for automotive safety
EP0404651B1 (en) Solid gas-generating composition and its application in gas generators for inflatable safety bags in motor vehicles
EP2231556A2 (en) Composition for generating nitrogenous gas and including azodicarbonamide, and method for generating nitrogen gas by decomposition of said composition
EP0467731B1 (en) Pyrotechnic composition containing an inorganic binder, which generates à non-toxic gas and its method of manufacture
EP0816307B1 (en) Clean-gas generating pyrotechnic compositions and use thereof in a gas generator employed in a protection system in motor vehicles
EP0218511B1 (en) Binder-charge bonding agent and propellant composition containing it
WO2008001005A2 (en) Pyrotechnic compositions initiable by heat, and their use
EP3687962B1 (en) Gas-generating composition
EP3753916B1 (en) Composite pyrotechnical product
US20230250038A1 (en) Removing dissolved gasses from propellant compositions
WO2024062190A1 (en) Composite propellant with reduced combustion rate
NO803572L (en) SUSPENSION FURNISHED DOUBLE BASE DRIVES.
FR3005657A1 (en) NON-SMOKE PROPELLANT COMPOSITION CONTAINING A BISMUTH COMPOUND AND PROCESS FOR PREPARING THE SAME
EP1346970A2 (en) Energetic materials containing an antioxidant
EP0930284A1 (en) Ablative solid material for hybrid gas generator
FR2697833A1 (en) Binding agent for propellant charge.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE

17P Request for examination filed

Effective date: 19910525

17Q First examination report despatched

Effective date: 19930505

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE

REF Corresponds to:

Ref document number: 69008934

Country of ref document: DE

Date of ref document: 19940623

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19940831

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19960301