Classifications

• • 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 an acid-free, gas-generating Composition, in particular for use in security devices for motor vehicles, with one of at least two components existing fuel mixture in a proportion of 20 to 60 wt .-% and an oxidizer mixture consisting of at least three components in a proportion of 40 to 80 wt .-%, each based on the total composition.
• Gas generating compositions used in safety devices used for motor vehicles mostly consist of a fuel based on sodium azide and an oxidizing agent. However, due to the toxicity of sodium azide, it was premature started looking for alternatives to the azide-containing gas generators To look for mixtures.
• US-A-5 608 183 describes a gas generating mixture containing between about 30 and 85 percent by weight of a fuel and between about 15 and about 70 percent by weight of an oxidizing agent.
• At least 60% by weight of the fuel consists of the nitrate of an acidic polyamine or a C 2 -C 3 -alkyldiamine, such as, for example, the nitrates of urea, guanidine, aminoguanidine, diaminoguanidine, semicarbazide, ethylenediamine, 1,3-propanediamine or 1, 2-propanediamine, or mixtures thereof.
• the oxidizing agent comprises at least 60% by weight of basic copper nitrate and / or cobalt triamine trinitrate. The mixture is processed in a wet process.
• the gas generating mixture known from US-A-5 608 183 has however, an insufficient willingness to ignite and a too low Burn-up speed. Because the combustion temperature of the mixture is above 1700 Kelvin, there is also an increased proportion toxic gases can be detected in the released gas mixture. The processing of the mixture in a wet process requires additional Drying levels and is therefore expensive.
• the present invention provides such a composition ready, the fuel mixture consisting of at least two components in a proportion of 20 to 60 wt .-% and on at least three components existing oxidizer mixture in one Proportion of 40 to 80% by weight, in each case based on the overall composition, includes.
• the composition is characterized in that the fuel mixture is composed of 5 to 95 wt .-% one Guanidine compound, 5 to 95% by weight of a heterocyclic, organic acid and 0 to 20 wt .-% other fuels, each based on the fuel mixture.
• the oxidizer mixture is according to the invention composed of 20 to 70% by weight of one or more transition metal oxides, 10 to 50 wt .-% basic copper nitrate and 2 to 30% by weight metal chlorate, metal perchlorate, ammonium perchlorate, alkali nitrate, Alkaline earth nitrate or mixtures thereof, each based on the Oxidizer mixture.
• the guanidine compound is preferably made of guanidine carbonate, Guanidine nitrate, guanidine perchlorate, aminoguanidine nitrate, diaminoguanidine nitrate, Triaminoguanidine nitrate, nitroguanidine or their Blends existing group selected.
• the heterocyclic organic acid is preferably a cyclic organic compound with the general empirical formula C a H b N c O d , where a is an integer between 1 and 5, b and c are each an integer between 1 and 6 and d is an integer between Is 0 and 6.
• the salts and derivatives of the cyclic organic compound can also be used.
• heterocyclic organic acid from cyanuric acid, isocyanuric acid, cyamelid, urazole, uracil, uramine, urazin, alloxan alloxanic acid, alloxantin, xanthine, allantoin, barbituric acid, orotic acid, dilituric acid, triazolone, violuric acid, succinimide, dialuric acid is particularly preferred.
• the use of an at least two-component fuel mixture from a guanidine compound and a heterocyclic Organic acid has been found to be beneficial for production if possible lower harmful gas values in the released gas mixture.
• the compounds mentioned usually have an above 200 ° C melting point and are therefore thermally extreme stable. They therefore meet the requirements for gas generator fuels Requirements for high long-term and temperature stability.
• the Compounds mentioned also generally have high negative Standard enthalpies of formation ⁇ Hf, resulting in the combustion of the mixture released energy and thus also the combustion temperature of the mixture remains low.
• heterocyclic organic acid In addition, too high a proportion of carbon in the heterocyclic organic acid is undesirable since in this case an increased proportion of oxidizing agent is required and the combustion temperature of the mixture also increases undesirably as a result of the highly exothermic formation of CO 2 .
• Compounds having 5 or 6 ring atoms are therefore particularly suitable as the heterocyclic organic acid.
• the number of carbon atoms per molecule of the organic heterocyclic acid should preferably not be greater than 4.
• Compounds which contain at most 3 carbon atoms per molecule are particularly preferred. In individual cases, for example in compounds with fused ring systems, up to 5 carbon atoms can also be present. Examples include guanine, C 5 H 4 N 5 O, or uric acid, C 5 H 4 N 3 O 3 .
• the retention capacity solid combustion residues by controlling the combustion temperature and in particular the relationship between influences metallic and non-metallic residues.
• the formation is favorable both firmly adhering to each other and yet sufficient porous residues to escape the combustion gases to allow.
• the setting of low combustion temperatures of below 1700 Kelvin is desirable for many reasons, in itself, however, not sufficient to provide the necessary restraint to ensure the solid combustion residues. So will for example in Comparative Example 1 described below a burning temperature of 1708 Kelvin and a metallic part a 37% incineration residue that is difficult to filter Residue generated, which is atomized under the burning conditions.
• the exemplary embodiment according to the invention is used in a comparable Burning temperature of 1680 Kelvin, but with a metallic content of 69% in the combustion residues a solid Clinker formed, which is still in tablet form after burning and can therefore be removed from the gas stream very easily.
• the in State of the art regarded as cheap education of exclusively Metallic combustion residues result from the slight Atomization and the formation of droplets from molten metal poor retention of combustion residues.
• the metal content in the solid combustion residues of the invention Compositions are preferably about 50 to 90% by weight.
• compositions according to the invention additionally contain the oxidizers metal oxide and basic copper nitrate Proportion of conventional oxidizers based on chlorates, Perchlorates and / or nitrates.
• This conventional The burn-up rates of the invention can be oxidized Control mixtures in a wide range.
• the share of this conventional oxidizers according to the invention is at most 30% by weight, based on the oxidizer mixture, and preferably at most 20 wt .-%, um the combustion temperatures and the proportion of gravely condensable Keep combustion residues as low as possible.
• a high proportion of potassium perchlorate the combustion temperatures greatly increased and large amounts of potassium chloride releases which is gaseous under the combustion conditions. This gaseous potassium chloride can come from the combustion gases cannot be removed by filters and will result after condensing undesirable smoke formation in the vehicle interior.
• compositions according to the invention can be processed dry, which is why additional cost-intensive drying steps can be dispensed with in the preparation of the compositions.
• the calculated burning temperature of the mixture was 1683 Kelvin.
• the combustion residues had a metallic content of 69.5 % By weight and were in the form of a solid clinker while maintaining the original tablet form.
• the proportion of carbon monoxide in the combustion gas was 110 ppm and the proportion of nitrous gases was 30 ppm
• the mixture showed good ignitability and a sufficiently high burning rate, but atomization of the solid combustion residues occurred.
• the metallic proportion of the solid combustion residues was 36.8% by weight.
• the CO concentration in the combustion gas was 190 ppm, the NO x concentration was 20 ppm.
• Example 1 43.7 parts micronized guanidine nitrate, 48.3 parts finely ground Copper oxide and 8.0 parts of potassium perchlorate were as in Example 1 described processed into fuel tablets. The so Fuel tablets obtained were put into a conventional one Gas generator filled and ignited in a test can.
• the calculated combustion temperature of the mixture was 1792 Kelvin.
• the solid combustion residues were in fragments, the metallic portion of the combustion residues was 51.5% by weight.
• the mixture was easy to ignite and burned quickly.
• an undesirably high proportion of toxic gases was measured in the combustion gases with a CO concentration of 255 ppm and a NO x concentration of 48 ppm.
• the mixture was filled into a conventional gas generator and ignited in a test can.
• the mixture showed one poor willingness to ignite and only a slow burning rate.
• the can pressure reached was insufficient.
• the metal part of the solid combustion residue was 100%, the formation of melted droplets could be observed.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Organic Chemistry (AREA)
• Air Bags (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)

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• 1998
  • 1998-04-08 DE DE29806504U patent/DE29806504U1/de not_active Expired - Lifetime
• 1999
  • 1999-03-31 DE DE59903442T patent/DE59903442D1/de not_active Expired - Lifetime
  • 1999-03-31 EP EP99105181A patent/EP0949225B1/fr not_active Expired - Lifetime
  • 1999-04-07 US US09/287,800 patent/US6132537A/en not_active Expired - Lifetime
  • 1999-04-08 JP JP11101118A patent/JPH11343192A/ja active Pending

Patent Citations (7)

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