FR2876097A1 - AGENT GENERATING GAS. - Google Patents

Abstract

There is provided a highly heat resistant gas generating agent. This gas generating agent is used for a gas generator for an air bag system which is installed at least outside the passenger compartment of a vehicle and which protects an individual impacted by the vehicle, and a mass loss rate of not more than 1% after holding for 400 hours at 130 ° C in a sealed system. The gas generating agent preferably comprises a fuel and an oxidizing agent, the melting point of the fuel preferably being at least 250 ° C.

Description

Technical area

  The invention relates to a gas generating agent for a gas generating composition which is used in an airbag system for protecting an individual subjected to impact by a vehicle. Hereinafter, the gas generating composition will be more simply referred to as a gas generator.

  Background technology In addition to airbag (airbag) systems for the protection of passengers in a car, it has recently been desired to develop airbag systems for the protection of individuals (pedestrians and the like) to an impact by a car.

  Since the gas generator of an airbag system for the protection of a pedestrian is installed outside the passenger compartment ie (inside the car where the passengers are installed), this generator of gas is easily subjected to the influences of the external environment and in particular to the heat especially from the engine of the car, which requires the implementation of countermeasures to overcome these influences.

  The claims of WO-A No. 96/27574 disclose a gas generating composition comprising a combination of nitroguanidine and phase stabilized ammonium nitrate; this gas-generating composition is heat-stable and has a melting point of not less than 100 ° C. In addition, in the examples, the ammonium nitrate exhibits phase transitions at 120 ° C. and 130 ° C. and volumetric changes occur. as a result, they are produced at such high temperatures, which prevents the gas-generating composition from maintaining its shape.

  The claims of WO-A No. 98/04507 disclose a heat-stable, nonacidic gas generating agent comprising a combination of nitroguanidine, tetrazoles and triazoles as a fuel with ammonium nitrate or perchlorate. phase stabilized ammonium as an oxidizing agent. When phase-stabilized ammonium nitrate is added, however, the ammonium nitrate undergoes phase transitions at 120 ° C and 130 ° C, and therefore significant volumetric changes occur when left at these temperatures. high, which prevents the gas generating composition from maintaining its shape. In addition, the tetrazoles and triazoles react at 100 C with phase stabilized ammonium nitrate and decompose, generating ammonia gas. Ammonium perchlorate is not suitable for use in air bag systems because it produces large quantities of gases, such as hydrogen chloride and chlorine, during combustion.

  The claims of WO-A No. 03/011798 disclose a heat stable and cohesive gas generating agent which comprises a cationic polymer and an anionic polymer, with further a binder.

  However, in detail, the operating temperature range for the gas generating agent is limited to -40 ° C to 120 ° C and only a 400-hour high temperature storage test of 107 ° C and a thermal shock test 200 cycles at a temperature of -40 C to 100 C are performed in the examples.

  The heat resistance of the gas generating agents according to the inventions of the aforesaid WO-A No. 96/27574, WO-A No. 98/04507 and WO-A No. 03/011798 is inadequate when the gas generator is installed in a a place that can easily be subjected to the thermal effects induced by the car, for example, close to the engine compartment.

Description of the invention

  The invention provides a gas generating agent adapted for the gas generator of an airbag system for protecting an impacted individual by a vehicle, said gas generating agent having in particular an excellent resistance to pressure. heat.

  More specifically, the invention provides a gas generating agent for a gas generator for an airbag system that is installed at least outside the passenger compartment of the vehicle and that protects an individual subjected to impact by the vehicle. where the gas generating agent has a mass loss rate of not more than 1% after holding for 400 hours at 130 ° C in a sealed system.

  The invention also relates to the gas generating agent as mentioned above, housed in a gas generator of an airbag system, which is installed at least outside the passenger compartment of a vehicle. In this context, the subject of the invention is also the gas generator, as well as the airbag system which is installed at least outside the passenger compartment of the vehicle and which contains the above-mentioned gas generating object. in its gas generator.

  The invention also relates to the use of the gas generating agent presented above for a gas generator of an airbag system, which is installed at least outside the passenger compartment of a vehicle.

  In general, the gas generating agent of the present invention comprises a fuel (fuel) and an oxidizing agent, and the melting point or the decomposition point of the fuel is preferably at least 250 ° C.

  The oxidizing agent of the gas generating agent according to the present invention is advantageously at least one agent selected from the group consisting of basic copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, perchlorate of sodium, potassium perchlorate and strontium perchlorate.

  The gas generating agent of the present invention is suitable for use in a pyrotechnic inflation system which uses only flue gas as a means of inflating an airbag, but it can also be when the airbag inflating means is used, both the combustion gas and an additional compressed gas (gas in which argon, helium, nitrogen gas is present at high pressure). ), or when compressed gas is used (in this case, only the gas generating agent can be used to break the rupture plate that is used to form a sealed system to maintain the interior of the high pressure inflator ).

  Because of its very high heat resistance, the gas generating agent of the present invention is resistant to the thermal influences of the external environment and can, therefore, maintain the gas generating performance of the original model over a period of time. at least 10 years, which generally corresponds to the life of the vehicle.

  The gas generating agent of the present invention can, therefore, be used for gas generators used in airbag systems for the protection of individuals (pedestrians and the like) subjected to impact by a vehicle.

  Embodiments of the Invention Mass Loss Rate The gas generating agent according to the present invention has a mass loss rate of not more than 1%, preferably not more than 0.8%, more preferably not more than 0, 6%, in each case after holding for 400 hours at 130 C in a sealed system. This rate of mass loss can be determined by the test method described in the examples. The individual components of the gas generating agents that have the specified mass loss rate are described below.

  Components of the gas generating agent The gas generating agent according to the invention generally comprises (a) fuel and (b) an oxidizing agent and, if necessary, it may optionally contain (c) a binder and / or (d) an additive.

  The fuel (fuel) of component (a) preferably has a melting point or a decomposition point of at least 250 ° C. By way of example of such a fuel, mention may be made of at least one fuel chosen from components of Tables I to V, as well as the plastic materials and rubber-like materials listed below.

  In the tables, the fuel substances are accompanied by their melting point (PF).

Table I

  n Compound name PF (C) 1 Aurine 292 2 Akuammine 255 3 Acridone 354 4 8-azaguanine> 300 m, p-Acetamidobenzoic acid 248-257 6 Acenaphthoquinone 260-261 7 2,2'- acid, 3,3'- , 4,4'-240-320 azoxybenzoic acid 8 Azodibenzoic acid 330 9 Adenine trihydrate 360-365 Adamantane 268-270 11 Afatoxin B1 268 12 Amaric acid 246 13 1-, 2-aminoanthraquinone 252-302 14 2-Amino acid 2-methylbutyric 317-318 () -2-Aminobutyric acid 307 16 L-2-aminobutyric acid 270-280 17 Alloxantine dihydrate 253-255 18 Alloxane 256 19 Sodium benzoate monohydrate 410-430 Anthraquinone 287 21 Acid 1-, 2- 292-293,5 anthraquinone carboxylic acid 2,2-anthracenecarboxylic acid 246-286 23 1,5-, 2,6-anthracenediol 265-295 24 2-anthrol 255 Isonicotinic acid 317 26 Isovanillic acid 251 27 Isophthalic acid 349 28 Indigo 390-392 29 Urazole 249-250 Uramil 310-320

Table II

  n Compound name PF (C) 31 Urusolic acid 283-285 32 Eosin 295-296 33 Equilenin 254-256 34 Estrone 254-256 Oxindigo 276-278 36 4-Oxo-4H-pyran-2-carboxylic acid 37 Acid 4 -oxo-4H-pyran-2,6- 262 dicarboxylic acid 38 Kainic acid 251 39 Kainin 266-267 Gamabufogenin 260-269 41 Camptothecin 264-267 42 M-tannic acid 268 43 Sodium formate 253 44 Gitogenin 264-267 Acid 3- , 4-, 5- 253-342 quinolinecarbolic 46 p-quinquephenyl 395 47 p-quaterphenyl 320 48 Guanidinobutyric acid 280-284 49 Guanine> 360 Glycyrrhetinic acid 292-294 51 Chrysene 255-256 52 Potassium acetate 292 53 Coronene 442 54 Acetate anhydrous sodium 320-321 Thalidomide 269-273 56 4,4'-diaminobenzene 250-251 57 1,2-diaminoanthraquinone 303-304 58 1,4-diaminoanthraquinone 268 59 1,5-diaminoanthraquinone 319 1,8-diaminoanthraquinone 262

Table III

  n Compound name PF (C) 61 1,8-diaminoanthraquinone 310-320 62 a-, 3-cyclodextrin 278, 298-300 63 Trans-312-313 cyclohexanedicarboxylic acid 64 Cytosine 320-325 1,5-dinitroanthraquinone 384-385 66 1,8-dinitroanthraquinone 311-312 67 2,7-dinitroanthraquinone 290-291 68 1,2-dihydroxyanthraquinone 292 69 1,3-dihydroxyanthraquinone 262 1,5-dihydroxyanthraquinone 280 71 1,6-dihydroxyanthraquinone 270-273 72 1, 7-dihydroxyanthraquinone> 293 73 2,3-dihydroxyanthraquinone> 260,74 2,6-dihydroxyanthraquinone> 365 2,7-dihydroxyanthraquinone 350-355 76 6,7-dihydroxycoumarin 272 77 7,8-dihydroxycoumarin 261-263 78 Dibenz [a, h] anthracene 266-267 79 Calcium oxalate 250 Potassium tartrate hemihydrate 260 81 Cinchonine 265 82 Succinamide 268-270 83 Potassium stearate 353 84 Sodium stearate 288 Solanine 285 86 Daidzein 315-320 87 Tetracyanobenzene 270-272 88 1.2, 5,6-tetrahydroxyanthraquinone> 300 89 1,2,5,8-tetrahydroxyanthraquinone 313-316 1,3,5,7-tetrahydroxyanthraqui none> 360

Table IV

  n Compound name PF (C) 91 3,3 ', 4', 7-tetrahydroxyflavone 330 92 3,4 ', 5,7-tetrahydroxyflavone 276-278 93 3,4', 5,7-tetrahydroxyflavone 329-330 94 Tetrahydroxy-p-benzoquinone> 320 Tetraphenylmethane 284-285 96 Terephthalaldehyde acid 256 97 1,2,3-trihydroxyanthracene 313-314 98 1,2,4-trihydroxyanthracene 263 99 1,2,5-trihydroxyanthracene 278 1,2,6 3-Trihydroxyanthracene 360 101 1,2,7-trihydroxyanthracene 369 102 4 ', 5,7-trihydroxyflavone 345-350 103 4,5,7-trihydroxy-2-259-260 methylanthraquinone 104 2,4,5-triphenylimidazole 275 Triptycene 251 -253 106 Uric acid> 400 107 Sodium palmitate 292-297 108 Potassium palmitate 375 109 Harmine 261 110,10'-bianthrone> 300 111 Violanthrone 490-495 112 3, 3'-biquinolyl 271 113 Potassium picrate 250.1 114 Picene 367-369 2-, 4-, 5-hydroxyisophthalic acid 250-310 116 2-Hydroxyterephthalic acid 320-325 117 7-Hydroxy-1-naphthoic acid 257 118 4,4'-bi-1-naphthol 300 119 Acid 3,3'-Biphenyldicarboxylic 357-358 A 2,5-piperazinecarboxylic acid 262

Table V

  n Name of the compound PF (C) 121 2,4- 248-250 pyridinedicarboxylic acid 122 2,5-254 pyridinedicarboxylic acid 123 3,4- 266-268 pyridinedicarboxylic acid 124 3,5-323 pyridinedicarboxylic acid 3,4,5-Acid - 261 pyridinetricarboxylic 126 Fumaric acid 300-302 127 Friedelin 267-269 128 Betaine 293-294 129 Bétuline 259 Hématéine 250 131 Perylène 279 132 Heroin (diacetylmorphine) 272-274 133 Acid 2,2 '-, 3,3'265-275 benzidine carboxylic acid 134 1,2,3,5- 252 benzenetetracarboxylic acid 1,2,4,5- 279 benzenetetracarboxylic acid 136 1,2,3,5-Dichloro-benzenetetracarboxylic anhydride 137 Benzene hexacarboxylic acid 285-287 138 Trianhydride 320 benzene hexacarboxylic acid 139 Benzimidazolone 310 Acid 4,4'-360-365 benzophenonedicarboxylic acid 141 Pentacene 270-271 142 2 ', 3,4', 5,7-290 pentahydroxyflavone 143 2 ', 3,4', 4 ', 6- 314 pentahydroxyflavone 144 Acid monohydrate 258-265 5-methylisophthalic acid 292-293 146 7-methyluric acid 370-decomp.

  147 6-Methoxy-4- 280 quinolinecarboxylic acid 148 Melamine <250 149 Lycorine 275-280 Rubicene 306 151 Luminol 332-333 152 Reserpine 264-265 153 Rosolic acid> 270 Plastic materials Phenol-formaldehyde resins, urea-formaldehyde resins, melamine resins formaldehyde, unsaturated polyesters, poly (diallyl phthalates), epoxy resins, polyurethanes, polyimides, polyethylenes, polypropylenes, polystyrenes, acrylonitrile / butadiene / styrene copolymers, polyamides, poly (methyl methacrylates), polyoxymethylenes, polycarbonates, poly ( ethylene terephthalates), silicone resins, diallyl phthalate resins, dicyclopentadiene resins, polyphenylene ethers, liquid crystal polymers, polyarylates, polyetherketones, polyamideimides, polyetherimides or the like.

  Rubber-type materials Natural rubber, isoprene rubbers, butadiene rubbers, butyl rubbers, styrene-butadiene rubbers, nitrile rubbers, urethane rubbers, ethylenepropylene rubbers, acrylic rubbers, silicone rubbers or the like.

  By way of example of an oxidizing agent of component (b), mention may be made of at least one oxidizing agent chosen from the group consisting of basic copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate and perchlorate. of sodium, potassium perchlorate and strontium perchlorate. Potassium perchlorate, basic copper nitrate, sodium nitrate and potassium nitrate are preferred among the aforementioned oxidizing agents from the point of view of achieving the object of the invention.

  The gas generating agent according to the present invention can use, as needed, a binder as component (c) within a range in which the object of the invention can be achieved.

  As useful binders, mention may be made of at least one binder selected from carboxymethylcellulose (CMC), sodium carboxymethylcellulose (CMCNa), potassium carboxymethylcellulose, ammonium carboxymethylcellulose, cellulose acetate, acetate-butyrate and cellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, carboxymethylethylcellulose, microcrystalline cellulose, polyacrylamides, polyacrylamide amines, polyacrylhydrazides, acrylamide-polyacrylate ester copolymer, polyvinyl alcohol, acrylic rubber, guar gum, starch, silicone or the like.

  The gas generating agent according to the present invention can use, as needed, various additives, as component (d), within a range in which the object of the invention can be achieved.

  By way of example of such additives, mention may be made of at least one additive chosen from copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, gallium oxide, silica, alumina, or the like; metal carbonates or alkali metal carbonates, such as cobalt carbonate, calcium carbonate, magnesium carbonate, basic zinc carbonate, basic copper carbonate, or the like; composite compounds of methane oxides or hydroxides, such as Japanese acid clay, kaolin, talc, bentonite, diatomaceous earth, hydrotalcite or the like; salts of acidic metals, such as sodium silicate, mica molybdate, cobalt molybdate, ammonium molybdate or the like; molybdenum disulfide, calcium stearate, silicon nitride and silicon carbide.

  Grade Reports in the Gas Generating Agent In the case where the gas generating agent of the present invention contains two components, (a) fuel (fuel) and (b) an oxidizing agent, the following ratios of the contents are Preferred for achieving the object of the invention: the ratio of the contents of (a) the fuel is preferably from 5 to 65% by weight, more preferably from 8 to 60% by weight, more preferably from 10 to 50% by weight; mass; and the ratio of the contents of (b) the oxidizing agent is preferably from 35 to 95% by weight, preferably from 40 to 92% by weight, more preferably from 50 to 90% by weight.

  In the case where the gas generating agent of the present invention contains three components, (a) fuel, (b) an oxidizing agent and (c) a binder, the following ratios of contents are preferred to achieve the object of the invention: the ratio of the contents of (a) the fuel is preferably from 5 to 60% by weight, preferably from 8 to 55% by weight, more preferably from 10 to 50% by weight; the ratio of the contents of (b) is preferably 95% by weight, preferably 40 to 92% by weight, more preferably 50 to 90% by weight of oxidizing agent (b); and the ratio of the contents of (c) the binder is preferably from 0.1 to 15% by weight, more preferably from 1 to 12% by weight, and more preferably from 2 to 10% by weight.

  In the case where the gas generating agent of the present invention contains four components, (a) the fuel, (b) an oxidizing agent, (c) a binder and (d) an additive, the following ratios of the contents are preferred to achieve the object of the invention: the ratio of the contents of (a) fuel is preferably from 5 to 60% by weight, more preferably from 8 to 55% by weight, more preferably from 10 to 50% by weight ; the ratio of the contents of (b) the oxidizing agent is preferably from 35 to 95% by weight, more preferably from 40 to 92% by weight, more preferably from 50 to 90% by weight; the ratio of the contents of (c) the binder is preferably from 0.1 to 15% by weight, more preferably from 1 to 12% by weight, more preferably from 2 to 10% by weight; and the ratio of the contents of (d) the additive is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 7% by weight, and more preferably from 1 to 5% by weight.

  The gas generating agent according to the invention may be molded into the desired shape and may be shaped into a molded article of a shape such as a single perforation cylinder, a porous cylinder or a pellet. These molded articles may be produced by mixing water or an organic solvent with the gas generating agent and then extrusion molding (in the case of molded articles having the shape of a single perforation cylinder and a porous cylinder) or by compression using a pelletizer or the like (in the case of a molded article in the form of a pellet).

  The gas generating agent of the present invention (and in particular the molded articles obtained therefrom) can be used as a gas generating agent for a gas generator used in an airbag system for the protection of gas. individuals impacted by a vehicle, but it can also be used with more commonly known inflators, in particular for airbags on the driver's side, the passenger side, side airbags, curtain airbags, knee pads, inflatable seat belts and tubular systems and gas generators for pretensioners.

  On the other hand, the gas generating agent of the present invention (or the molded articles obtained therefrom) can also be used as an ignition agent, known as an enhancer, to transfer the energy of a detonator or an initiator to an agent. gas generator.

EXAMPLES

  Mass Loss Rate Immediately following the introduction of 40.0 0, 1 g of accurately weighed gas generator (powder) into a vessel (118 mL internal volume) equipped with a SUS rupture plate (0.2 mm aluminum plate, the rupture pressure being approximately 12 kg / cm 2), the container is sealed. The inside of the container is isolated from the outside atmosphere. The container is placed in a thermostat at 130 C and is removed after remaining there for 400 hours. The gas generating agent is then accurately weighed and the mass loss rate is calculated using the following formula.

  mass loss rate (%) = (initial mass - mass after test) x 100 / initial mass (The terms initial mass and mass after-test refer to the mass of the gas generating agent).

  Combustion Rate A gas generating composition is prepared and molded into a strand with a diameter of about 9.6 mm and a height of about 12.7 mm. The rate of combustion is measured under a nitrogen atmosphere at a pressure of 6860 kPa.

EXAMPLE 1

  A gas generating agent having a composition comprising a melamine-formaldehyde resin, potassium perchlorate and sodium carboxymethylcellulose (CMCNa) is prepared in the ratio 24.1 / 70.9 / 5 (% by weight). The mass loss rate and the rate of combustion are measured on this gas generating agent. The result is a mass loss rate of 0.3%, which indicates excellent heat resistance. The burning rate is 14 mm / s, which indicates combustion performance useful in practice.

EXAMPLE 2

  Gold. Prepares a molded article of gas generating agent having a composition comprising polyamide-6 and potassium perchlorate in the ratio 16.4 / 83.6 (% by weight). The mass loss rate and the rate of combustion are measured using the molded article of gas generating agent. The result is a mass loss rate of 0.4%, which indicates excellent heat resistance. The burning rate is 7.5 mm / s, which indicates useful combustion performance in practice.

EXAMPLE 3

  Or, prepare a molded article of gas generating agent having a composition comprising methylvinylsilicone rubber and potassium perchlorate in the ratio 21.2 / 78.8 (% by weight). The mass loss rate and the rate of combustion are measured using the molded article of gas generating agent. The result is a mass loss rate of 0.6%, which indicates excellent heat resistance. The burning rate is 18 mm / s, which indicates useful combustion performance in practice.

Claims (6)

  A gas generating agent for a gas generator for an airbag system which is installed at least outside the passenger compartment of a vehicle and which protects an individual subjected to impact by the vehicle, said generating agent of gas comprising a fuel and an oxidizing agent, wherein the melting point or the decomposition point of the fuel is at least 250 C, and wherein said gas generating agent has a mass loss rate of not more than 1% after hold for 400 hours at 130 C in a sealed system.   The gas generating agent according to claim 1, wherein the oxidizing agent is at least one agent selected from the group consisting of basic copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, sodium perchlorate, potassium perchlorate and strontium perchlorate.   3. Gas generating agent according to claim 1 or 2, housed in a gas generator of an airbag system which is installed at least outside the passenger compartment of a vehicle.   4. Use of a gas generating agent according to claim 1 or 2 for a gas generator of an airbag system which is installed at least outside the passenger compartment of a vehicle.   A gas generator adapted for an air bag system installed at least outside the passenger compartment of a vehicle, comprising a gas generating agent according to claim 1 or 2.   An airbag system installed at least outside the passenger compartment of a vehicle, comprising a gas generator according to claim 5.