KR20010041919A - Propellants for gas generator - Google Patents

Abstract

The present invention relates to solid propellants for gas generators (gas-generating mixtures), wherein said propellants are mainly intended for use in propelling charges for gas generators used in airbags or seat-belt pre-tensioning devices. The solid propellants for gas generators further include an essentially chemically-inert slag trap which has a high fusion point and a good dispersion, wherein said slag trap acts as an inner filter and globally prevents the formation of powder particles as well as their exit from the housing of the gas generator. A portion of the slag trap having a good dispersion may be used as a carrier substance for catalyst metals.

Description

Propellant for gas generators {PROPELLANTS FOR GAS GENERATOR}

The airbag consists essentially of a housing of the gas generator (typically in the form of a tablet) filled with a propulsion charge for the gas generator, an initial primer for exploding the propulsion charge for the gas generator (a primer), and also a gas bag. Suitable primers are described, for example, in US Pat. No. 4,931,111. The gas bag, which was initially folded into a small bag, is filled with the gas produced by the combustion of the propulsion charge for the gas generator after the initial explosion and reaches its total volume in about 10 to 50 ms. The release of hot sparks, molten material and solids from the gas generator into the gas bag should be largely prevented, as this could result in the destruction of the gas bag or injury to the passengers of the car. This is accomplished by bonding and filtration of the slag formed by burning the propulsion charge for the gas generator.

Propellant charges for gas generators used in airbags based on sodium azide are well known. However, the use of very toxic sodium azide is labor intensive and requires a costly process for the production of propulsion charges for gas generators. Moreover, the increasing number of non-combustion propulsion charges for gas generators used in automobiles worldwide so far leads to processing and safety issues.

Therefore, efforts have recently been made to find suitable substitutes for sodium azide.

DE-A-44 35 790 describes propellants for gas generators based on suitable carrier based guanidine compounds which inherently exhibit improved combustion characteristics and improved building of slag. DE-A-44 35 790 gives no indication of the use of a highly dispersed, inherently chemically inert slag trap with a high melting point and of the catalyst in the propulsion charge for the gas generator.

From EP-B-0 482 852 and the prior art mentioned herein, azide-free propulsion charges for gas generators, in particular for use in airbags, are known. The gas-generating mixtures described in EP-B-0 482 852 include: a) a fuel selected from aminotetrazole, tetrazole, bitetrazole and its metal salts and triazole compounds and their metal salts; b) oxygen-containing oxidants selected from nitrates and perchlorates of alkali metals, alkaline earth metals, lanthanoids and ammonium, and chlorates and peroxides of alkali metals and alkaline earth metals, and c) oxides, hydroxides, carbonates, hydroxides, peroxides of alkaline earth metals. And high temperature slag forming materials selected from alkaline earth metal salts of nitrates, chlorates and perchlorates, and tetrazole, bitetrazol and triazoles, and d) silicon dioxide, boron oxide, vanadium pentoxide, natural clays and talc, silicates of alkali metals Or a low temperature slag forming material selected from borates, carbonates, nitrates, perchlorates and chlorates and alkali metal salts of tetrazole, bitetrazole and triazole, or e) oxides, hydroxides, carbonates, oxalates, peroxides of transition metals. Slag type selected from nitrates, chlorates and perchlorates And one containing a material and f) a low-temperature silicon dioxide material forming the tagger, wherein d) or f) is the amount sufficient to form a coherent chunks or slag of low viscosity is not enough to make the liquid. It is clear that a single material can be used in more than one category.

An essential advantage of the propellant charge for this kind of gas generator is the advantageous formation of slag which can be easily filtered out of the gaseous combustion products formed. Another advantage is high gas yield.

However, the disadvantages of the propulsion charge for this kind of gas generator are as follows.

With regard to the preparation of the propulsion charges for gas generators with the most favorable slag formation, in terms of combustion properties (combustion rate), gas formation, properties for the production of pellets and other process factors, in particular with regard to the quality of the gas For example, a compromise must be made regarding the share of toxic gaseous combustion products. Moreover, the number of suitable fuels is relatively limited.

EP-B-0 482 852 gives no hint as to how these problems can be solved by changing the composition of the propulsion charge for the gas generator.

In US Pat. No. 4,948,439, the same inventors are toxic when using azide-substituents, such as, for example, tetrazole compounds (e.g., aminotetrazole and metal salts thereof) and mixtures thereof in a propulsion charge for a gas generator. Reference is made to the problem of the formation of gaseous combustion products.

However, the contents of US Pat. No. 4,948,439 relate to how it can reduce the share of toxic gas combustion products generated during the combustion of propellant charges for gas generators containing tetrazole or triazole compounds, metal salts or mixtures thereof as fuel. No suggestions are provided. In contrast, a method of inflation of an air bag is described, in which the primary gas mixture is initially obtained by ignition of a propellant for gas generator containing at least one tetrazole or triazole compound as fuel. The primary gas mixture is then mixed with the surrounding atmosphere so as to dilute the content of toxic gas combustion products from the primary gas mixture to a toxicologically acceptable amount.

However, mixing with the ambient atmosphere results in a more complex overall airbag system (size, structure, etc.). The problem is the rate at which the airbag should be inflated (10-50 ms) if additional ambient air needs to be absorbed.

DE-C-44 01 213 is a fuel, oxidant, " catalyst " characterized in that the oxidant is Cu (NO ₃ ) ₂ .3Cu (OH) ₂ and the catalyst is a metal oxide, or a mixture or mixture of metal oxides. , And a gas-generating mixture consisting of a coolant.

In addition, DE-C-44 01 214 describes gas-generating mixtures having a similar composition, wherein the catalyst is a metal or metal alloy on a carrier, preferably a pyrophoric metal or a metal alloy. The carrier is a silicate, preferably layered silicate or structural silicate. As the metal, Ag is particularly useful. Among the known fuels used are triaminoguanidine (TAGN), nitroguanidine (NIGU, NQ), 3-nitro-1,2,3-triazol-5-one and, in particular, diguanidine-5,5'- Azotetrazolate (GZT).

The most important advantages of the gas-generating mixtures described in the two German patents are, according to the content of these patents, a decrease in combustion temperature and an increase in combustion rate.

The gas-generating mixtures described in DE-C-44 01 213 and DE-C-44, 01 214 do not contain the cold melt and hot melt slag formers and slag traps according to the invention. In contrast, the patent states that no slag forming agent is required.

Contrary to this claim, the inventors have found that the use of cold melting and hot melting slag formers, in particular the use of slag traps according to the invention, results in a significant reduction in toxic gas combustion products. Part of the hot molten slag trap can be used as a carrier of the platinum metal and the metal alloy containing the platinum metal, and thus can serve as part of the catalyst.

In the two German patents, the term "catalyst" is used broadly and as the active part of the reaction, the "catalyst" can be reacted and acts to steer and / or promote the reaction.

Therefore, since the catalyst is not a component to be reacted in the reaction, the catalyst of the German patent is not a catalyst in the strict sense. The catalyst in the strict sense is not consumed during the reaction, ie it does not react.

The definition of catalyst also includes that the catalyst is added only to very low concentrations in the reaction mixture. However, in this German patent, the proportion of catalyst in the gas-generating mixture is at most 30% by weight, and therefore is a substantial part of the gas generating mixture and is also considered part of it in the mixture.

Therefore, in summary, the term "catalyst" is used in DE-C-44 01 213 and DE-C-44 01 214, but the meaning of this term also corresponds to the general definition of catalyst as also indicated in the above two patents themselves. Do not.

FIELD OF THE INVENTION The present invention relates to solid propellants (gas generating mixtures) for gas generators, wherein the solid propellants are mainly used in airbags or seatbelt pre-tentioning equipment based on nitrogen-rich fuels with as low carbon content as possible. It is intended for use in propulsion charges for gas generators used. In addition, solid propellants for gas generators include chemically inert slag traps in a highly dispersed form having essentially high melting points, where the slag traps act as internal filters and substantially the housing of the gas generator. It prevents the release of powder from the as well as the formation of powder (dust-type) particles.

The present invention therefore relates to a method for trapping liquid and solid combustion products and dust-type slag particles in the propulsion charge for a gas generator directly during formation, respectively. Therefore, it is possible to use a filter package of simple structure in the housing of the gas generator.

The invention also relates to the use of catalysts based on platinum-based metals (Ru, Os, Rh, Ir, Pd, Pt) or platinum-based metals or metal alloys of copper on slag traps as carriers in solid propellants for gas generators. will be. In particular, the present invention relates to the use in solid propellant charges for gas generators used in airbags.

Compared with the prior art, a fundamental technical problem of the present invention is for gas generators, in which the combustion characteristics of the propellant are adjusted as desired, which in particular reduces the formation of toxic gases and powder (dust form) components that can exit the housing of the gas generator and enter the lungs. To provide improved propellants, particularly for airbags.

Propellant charges for gas generators made from gas generator propellants are aimed at having thermally stable, easily ignited, fast burning (even at low temperatures), well stored and ensuring high gas yields. In addition, the above propellant for gas generators aims to reduce the size and number of components of the housing of the gas generator, simplify the housing of the gas generator and consequently reduce its weight in comparison with known generators.

According to the invention, these objects are achieved by a propellant for a gas generator consisting of:

(A) Guanine nitrate (GUNI; GuNO ₃ ), dicyanamide, ammonium dicyanamide, sodium dicyanamide (Na-DCA), copper dicyanamide, tin dicyanamide, calcium dicyanamide (Ca-DCA) , Guanidine dicyanamid (GDCA), aminoguanidine bicarbonate (AGB), aminoguanidine nitrate (AGN), triaminoguanidine nitrate (TAGN), nitroguanidine (NIGU), dicyandiamide (DCD), azodicarbon From the group consisting of tetrazol (HTZ), 5-aminotetrazole (ATZ), 5-nitro-1,2,4-triazol-3-one (NTO), as well as salts and mixtures thereof, as well as amides (ADCA) At least one fuel selected,

(B) at least one alkali metal nitrate, or alkaline earth metal nitrate or ammonium nitrate, ammonium chlorate, or ammonium perchlorate,

(C) at least one highly inert, essentially chemically inert slag trap having a high melting point selected from the group consisting of Al ₂ O ₃ , TiO ₂ , and ZrO ₂ and mixtures thereof, and

Optionally (D) carbonates and oxides of alkali and alkaline earth metals, silicates, aluminates and aluminum silicates, iron (III) as well as silicon nitride (Si ₃ N ₄ ), and during combustion, nitrogen (N) ₂ ) and at least one slag former that forms silicon dioxide (SiO ₂ ) and

Optionally, (E) a binder that is water soluble at least one room temperature.

Preferred fuels, component (A) are nitroguanidine (NIGU), 5-aminotetrazole (ATZ), dicyanidiamide (DCD), dicyanamide, salts thereof, in particular sodium- and calcium dicyanamide and guanidine nitrate, And mixtures thereof. They are substantially non-toxic, non-hygroscopic, poorly water soluble, heat stable, burn at low temperatures and have low impact and frictional sensitivity. The gas yield during combustion is high, where a large share of nitrogen gas is generated.

Alkali metal salts (Li, Na, K) and alkaline earth metal salts (Mg, Ca, Sr, Ba) are examples of suitable salts of 5-aminotetrazol.

As the oxidizing agent, component (B) is an alkylate metal- or alkaline earth metal nitrate (e.g. lithium nitrate, sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, strontium nitrate or barium nitrate), ammonium nitrate, alkali metal- Or chlorates or perchlorates of alkaline earth metals (e.g. lithium chlorate, sodium chlorate, potassium chlorate, magnesium chlorate, calcium chlorate, strontium or barium chlorate and lithium perchlorate, sodium perchlorate, potassium perchlorate, magnesium perchlorate, calcium perchlorate, perchlorate) Strontium or barium perchlorate) as well as ammonium perchlorate and mixtures thereof can be used. Potassium nitrate and strontium nitrate are preferred. Strontium nitrate is nonhygroscopic, nontoxic and allows high gas yields during combustion. In addition, potassium nitrate has a low combustion temperature.

As an example of an essentially chemically inert slag trap having a high melting point, component (C) is Al ₂ O ₃ , TiO ₂ and ZrO ₂ or mixtures thereof in a highly dispersed form. Al ₂ O ₃ with a BET-surface (according to DIN 66131) of 100 ± 15 m ² / g (melting point about 2,050 ° C), TiO ₂ , with a BET-surface of 50 ± 15 m ² / g (melting point about 1,850 ° C), Particular preference is given to ZrO ₂ with a BET-surface of 40 ± 10 m ² / g (melting point about 2,700 ° C.). These highly dispersed oxides are commercially available, for example, under the trade names Aluminiumoxid C, Titanoxid P25 and VP Zirkonoxid under the name Degussa AG.

Such exothermic oxides are obtained by the reaction of H ₂ and O ₂ with respective metal chlorides in corresponding molar ratios by gas phase reaction (flame hydrolysis). These oxides generally do not have pores and distinct lumps as they are produced by wet processes.

The term "slag-trap" according to the invention, component (C) refers to an essentially chemically inert metal oxide having a high melting point, which is, for example, in a highly dispersed form, such oxides are much larger than conventional oxides. Has a surface.

For example, a conventional Al ₂ O ₃ such as α-oxide has a BET-surface of only 5-10 m ² / g, and a conventional pigment-TiO ₂ has a BET-surface of only 5-10 m ² / g. And conventional ZrO ₂ has a BET-surface of only 3-8 m ² / g (for refractory products), whereas the metal oxides used in the propulsion charge for gas generators according to the invention have a BET-surface of about 40-. 100 m ² / g, more preferably about 50 to 100 m ² / g, particularly preferably about 100 m ² / g.

Moreover, the slag traps according to the invention are characterized by high melting points of about 1,850-2,700 ° C. As a result of this high melting point, slag traps do not melt during the reaction and therefore act as solids.

Moreover, the slag traps of the present invention are substantially chemically inert compounds. That is, the slag trap of the present invention does not participate in chemical reactions during the combustion reaction of the propellant charge for the gas generator or only participates to a small extent on the surface of the metal oxide used as the slag trap. Highly decomposed lattice, ie large internal surfaces (for example highly dispersed forms) of Al ₂ O ₃ , TiO ₂ or ZrO ₂ , on the one hand cause cooling of the combustion products due to their inertness and on the other hand combustion Each of which results in absorption of some of the liquid and / or solid slag and particles. Therefore, the purified form of the propellant charge for the gas generator remains during and after combustion, and the formed pieces and pieces can be easily filtered out. This means that there is little formation of dust coming out of the propulsion charge for the gas generator during combustion and consequently coming out of the housing for the gas generator. Therefore, the slag trap acts as an internal filter in the propulsion charge of the gas generator itself, substantially preventing the formation and release of dust-like slag portions from the housing of the gas generator. Thus, a significant simplification of the filter of the gas generator's housing is obtained, in which no additional (mechanical) fine filter is required in the housing of the gas generator. This also leads to an advantageous reduction in the weight of the airbag gas generator.

At the same time, the formation of dust-like particles that can exit the gas generator of the airbag and enter the lungs is minimized by the formation of slugs. Dust-like particles that can enter the lungs have a diameter of about 6 μm or less.

Optionally, the slag forming agent, component (D) may comprise carbonates of alkali metals and alkaline earth metals (e.g. sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate and barium carbonate), oxides of alkali metals and alkaline earth metals ( For example, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, strontium oxide, and barium oxide), silicates (eg hectorite), aluminates (eg sodium-beta-aluminate (Na ₂ O ₁₁ Al ₂ O ₃ ) or tricalcium aluminate (Ca ₃ Al ₂ O ₆ )) or aluminum silicate (eg bentonite or zeolite) or iron (III) oxide or mixtures thereof may be used.

The function of component (D) is to form slag that is easily filtered during combustion of the propellant for the gas generator.

In addition, the slag forming agent and component (D) can act as a coolant. Silicates, aluminates and aluminum silicates react with oxides of alkali metals and alkaline earth metals formed during combustion.

The invention also relates to platinum metals (Ru, Os, Rh, Ir, Pd, Pt) on highly dispersed slag traps as carriers for use in the solid propellant for gas generators of the present invention, in particular in solid propellant charges for gas generators for airbags. Or a catalyst based on a metal alloy of platinum metal or copper.

Part of the slag trap, component (C), acts as a carrier of the platinum metal or metal alloy of platinum metal or copper in a catalytically effective thickness.

Platinum metals are ruthenium (Ru), osmium (Os), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt). The catalyst used in the present invention is based on Ru, Pd or Pt, particularly based on Pt.

Examples of metal alloys of platinum metals are all catalytically effective metal alloys of the platinum metals, preferably Pt / Pd and Pt / Rh alloys.

The metal or metal alloy of the platinum metal is on the carrier in a catalytically effective layer thickness, preferably a single layer.

The catalyst is contained only in catalytic amounts in the propulsion charge for the gas generator. The weight ratio to component (C) is 0.1 to 5% by weight, preferably 0.2 to 1.2% by weight of component (C).

Preferred catalysts have Al ₂ O ₃ as a highly dispersed carrier and Pt, Pd or Cu as metal, in particular Pt.

Suitable catalysts can be obtained from Degussa AG, for example, γ-Al ₂ O ₃ substrate 1% Pt-Al ₂ O ₃ substrate or γ 1% Pd + Pt.

Catalysts are useful to control the reaction, where little toxic gas combustion products such as carbon monoxide (CO), nitrogen oxides (NOx) and ammonia (NH ₃ ) are formed.

The catalyst is particularly useful for use in propulsion charges for gas generators in airbags.

Besides the benefits of the use of highly dispersed metal oxides (reduction of particles in the form of solid dust, ie coarse and fine dust), the low share of toxic gases is somehow further reduced.

The catalyst can be recycled not only from the ones released by known methods, i.e. from the air bags used, but also from the non-emissions, i. This reduces waste that may contaminate the environment and allows reuse of catalytic metals. The catalytic metal and metal alloy are not oxidized during combustion, respectively.

The catalyst should not be added as an additional part of the propulsion charge for the gas generator and is part of the component (component (C)) no matter how present in the gas generator propulsion charge.

Component (A) is present in an amount of about 20-60% by weight, preferably about 28-52% by weight, in particular about 45-51% by weight; Component (B) is present in an amount of about 38 to 63 weight percent, preferably about 38 to 55 weight percent, especially about 39 to 45 weight percent; Component (C) is present in an amount of about 5 to 22% by weight, preferably about 8 to 20% by weight, in particular about 9 to 11% by weight; Finally, component (D), if any present, is present in an amount of about 2 to 12% by weight, preferably about 4 to 10% by weight. All given weight percentages refer to the total composition of the propellant charge for the gas generator.

Optionally, the propellant for the gas generator may also contain a binder that is water soluble at room temperature as component (E). Preferred binders are polymers of cellulose compounds or polymerizable one or more olefinically unsaturated monomers. Cellulose compounds are, for example, carboxymethylcellulose, methylcellulose ethers, in particular cellulose ethers such as methylhydroxyethylcellulose. Methylhydroxyethylcellulose which can be used satisfactorily is CULMINAL supplied by Aqualon MHEC 30000 PR. Suitable polymers with binding action are polyvinylpyrrolidone, polyvinylacetate, polyvinylalcohol and polyvinylbutyral, for example Pioloform supplied by Wacker Chemie (Burghausen, Germany) B is.

In addition, metal salts of stearic acid which are insoluble in water at room temperature, such as aluminum stearate, magnesium stearate, potassium stearate or zinc stearate, may be used as the binder (component (E)).

Moreover, graphite is suitable as binder.

Component (E) is present at 0-2 wt% and preferably 0.3-0.8 wt%.

The binder, component (E), serves as a process aid to produce granular material or tablets (pellets) from sensitizers and propellants for gas generators. This also serves to reduce the hydrophilic properties of the propulsion charges for the gas generator and to stabilize them.

Preparation of the gas generator propellant (Examples 1 to 57 of Table I) and the propellant charge for the gas generator was carried out as follows.

Roughly premixed raw materials (components (A), (B), (C) and optionally (D) and (E)) were each ground using a ball mill to increase the density in advance.

Granulation of the propellant mixture for the gas generator was performed with a vertical mixer, where about 20% of water was added at a high temperature of about 40 ° C. during operation. After short evacuation, the resulting mixed mass was pulverized at room temperature through a grinder having a 1 mm sieve. The granules thus obtained were dried in a drying oven at 80 ° C. for 2 hours. The prepared granules (granule- (particle size) distribution 0-1 mm) of the propellant for the gas generator were compressed into tablets (pellets) using a rotary granulator. The pellets of the propellant charge for the gas generator were dried again at 80 ° C. in a drying oven.

Tablets and pellets, each used in a gas generator and made from a propellant for the gas generator, can be produced by known techniques such as hot pressing, extrusion, for example in a rotary-assembly or compactor. The size of the pellets and tablets depends on the desired combustion time in each individual case.

The propellants for gas generators of the present invention are made of nontoxic, inexpensive components, which can be easily produced, and their treatment is without problems. More expensive components, such as catalytic metals, can be recycled by known processes. Because of the thermal safety of the components, good storage is obtained. The mixture is easily burned. They ensure fast combustion and high gas yields with proportions of CO, NOx and NH ₃ below the acceptable upper limit. Therefore, the mixtures of the present invention are particularly suitable as gas generating agents, as extinguishing agents or propellants in various airbag systems.

The following Examples 1 to 57 will be described without restricting the invention. Examples 15, 18 and 21 are comparative examples using conventional ZrO ₂ , TiO ₂ and Al ₂ O ₃ .

Table I:

The superscripts in the table have the following meanings.

1. Titandioxid P25, manufactured by Degussa AG.

2. Zirkonoxid VP, product of Degussa AG.

3. Aluminiumoxid C, manufactured by Degussa AG.

4. Titandioxid Kronos 3025, manufactured by Kronos Titan-GmbH.

5. Zirkonoxid, Merck.

6.Aluminiumoxid NO 615-30 II 24, manufactured by Nabaltec.

7. Oxidation catalyst 1% Pt on Gamma-Aluminiumoxid, manufactured by Degussa AG.

8. Oxidation catalyst 1% Pd + Pt on Gamma-Aluminiumoxid, manufactured by Degussa AG.

9. Ironoxide, Bayoxide E8710, from Bayer AG.

10. Benton EW, Rheox, Inc. products.

11. CULMINAL MHEC 30000 PR, manufactured by Aqualon.

Example number One 2 3 4 5 6 A = ATZ [%] 30.2 32.8 29.75 29.7 29.75 29.7 NIGU [%] - - - - - - Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - - - B = KNO ₃ [%] 49.8 - 50.25 - 50.25 - Sr (NO ₃ ) ₂ [%] - 57.2 - 54.8 - 54.8 NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - 20.0 15.0 - - ZrO ₂ ² [%] - - - - 20.0 15.0 Al ₂ O ₃ ³ [%] 10.0 10.0 - - - - Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] 10.0 - - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - - - - - - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] - - - 0.5 - 0.5 Theory Gas output (V = constant) [Mol / kg] 17.8 19.3 17.6 21.7 17.6 18.0 Temperature (p = 135 × 10 ⁵ Pa) [K] 1780 2420 1780 2370 1780 2520 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 4000 2800 3000 3300 3000 3300 Nitric oxide [ppm] 150 300 200 350 200 250 ammonia [ppm] 150 0 0 0 100 100 Rough dust in the can [g] 1.2 0.6 1.2 1.0 1.1 1.2 Fine dust in cans [g] 0.2 0.1 0.3 0.3 0.3 0.3

Example number 7 8 9 10 11 12 A = ATZ [%] 29.75 32.8 29.75 32.8 21.5 25.6 NIGU [%] - - - - - - Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - - - B = KNO ₃ [%] 50.25 - 50.25 - 58.0 - Sr (NO ₃ ) ₂ [%] - 57.2 - 57.2 - 54.1 NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - - - - - ZrO ₂ ² [%] - - - - - - Al ₂ O ₃ ³ [%] 10.0 - 10.0 - 10.0 10.0 Al ₂ O3 + 1% Pt ⁷ [%] 10.0 10.0 - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - 10.0 10.0 - - D = iron oxide (III) ⁹ [%] - - - - - 5.0 Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - 10.0 5.0 E = graphite [%] - - - - 0.5 - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] [%] - - - - - 0.3 Theory Gas output (V = constant) [Mol / kg] 17.6 19.3 17.6 19.3 16.8 16.8 Temperature (p = 135 × 10 ⁵ Pa) [K] 1780 2420 1780 2420 2120 2420 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 2500 2300 2300 2100 4500 4000 Nitric oxide [ppm] 200 250 200 250 400 250 ammonia [ppm] 0 0 0 0 200 150 Rough dust in the can [g] 0.7 0.6 0.7 0.7 0.9 1.3 Fine dust in cans [g] 0.2 0.2 0.2 0.1 0.3 0.5

Example number 13 14 15 16 17 18 A = ATZ [%] - - - - - - NIGU [%] 48.2 47.0 47.0 48.5 47.0 47.0 Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - - - B = KNO ₃ [%] 41.3 - - 41.0 - - Sr (NO ₃ ) ₂ [%] - 42.5 42.5 - 42.5 42.5 NaNO ₃ [%] - - - - - - C = TiO ₂ ^{1 or 4} [%] 10.0 ¹ 10.0 ¹ 10.0 ⁴ - - ZrO ₂ ^{2 or 5} [%] - - - 10.0 ² 10.0 ² 10.0 ⁵ Al ₂ O ₃ ³ [%] - - - - - - Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] - - - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - 0.5 0.5 - 0.5 0.5 Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] [%] 0.5 - - 0.5 - - Theory Gas output (V = constant) [Mol / kg] 23.8 23.1 23.1 23.9 23.1 23.1 Temperature (p = 135 × 10 ⁵ Pa) [K] 2030 2490 2490 2080 2550 2550 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 8000 6500 8000 6500 6500 8000 Nitric oxide [ppm] 600 450 450 800 700 800 ammonia [ppm] 100 0 0 150 0 0 Rough dust in the can [g] 1.4 0.3 0.7 1.0 0.1 0.3 Fine dust in cans [g] 0.6 0.4 0.3 0.3 0.3 0.3

Example number 19 20 21 22 23 24 A = ATZ [%] - - - - - - NIGU [%] 50.6 46.0 46.0 46.5 50.6 46.5 Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - - - B = KNO ₃ [%] 39.4 - - - 39.4 - Sr (NO ₃ ) ₂ [%] - 43.5 43.5 38.5 - 38.5 NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - - - - - ZrO ₂ ² [%] - - - - - - Al ₂ O ₃ ^{3 or 6} [%] 10.0 ³ 10.0 ³ 10.0 ⁶ 15.0 ³ - - Al ₂ O3 + 1% Pt ⁷ [%] - - - - 10.0 15.0 Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] - - - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - 0.5 0.5 - - - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] [%] - - - - - - Theory Gas output (V = constant) [Mol / kg] 24.3 22.8 22.8 22.4 24.3 22.4 Temperature (p = 135 × 10 ⁵ Pa) [K] 2050 2380 2380 2330 2430 2330 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 5700 6000 8000 5000 4600 4200 Nitric oxide [ppm] 300 450 600 300 200 250 ammonia [ppm] 0 0 0 0 0 0 Rough dust in the can [g] 1.0 0.7 0.8 0.3 1.2 0.5 Fine dust in cans [g] 0.4 0.1 0.3 0.3 0.3 0.3

Example number 25 26 27 28 29 30 A = ATZ [%] - - - - - - NIGU [%] 50.6 46.5 43.5 37.4 48.0 - Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - - 51.7 B = KNO ₃ [%] 39.4 - 45.9 - 41.4 - Sr (NO ₃ ) ₂ [%] - 38.5 - 52.1 - 37.8 NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - - - - - ZrO ₂ ² [%] - - - - - - Al ₂ O ₃ ³ [%] - - - - 5.0 5.0 Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] 10.0 15.0 - - - - D = iron oxide (III) ⁹ [%] - - 5.0 - 5.0 5.0 Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - 5.0 10.0 - - E = graphite [%] - - 0.6 0.5 0.6 - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] - - - - - 0.5 Theory Gas output (V = constant) [Mol / kg] 24.3 22.4 23.3 19.8 23.6 26.0 Temperature (p = 135 × 10 ⁵ Pa) [K] 2430 2330 2130 2820 1970 2100 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 4500 4000 6300 6700 8000 5500 Nitric oxide [ppm] 250 250 400 450 150 900 ammonia [ppm] 0 0 0 0 250 10 Rough dust in the can [g] 1.1 0.4 1.3 1.3 1.5 0.6 Fine dust in cans [g] 0.2 0.3 0.4 0.5 0.3 0.4

Example number 31 32 33 34 35 36 A = ATZ [%] - - - - - - NIGU [%] - 43.0 17.7 9.0 18.1 16.0 Ca-DCA [%] 27.8 3.0 17.7 23.8 - - Na-DCA [%] - - - - 18.1 16.0 TAGN [%] - - - - - - GuNO ₃ [%] - - - - - - B = KNO ₃ [%] - - - 57.2 58.0 Sr (NO ₃ ) ₂ [%] 62.2 45.5 54.6 - 53.8 - NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - - - - - ZrO ₂ ² [%] - - - - - - Al ₂ O ₃ ³ [%] 10.0 8.0 10.0 10.0 10.0 10.0 Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] - - - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - - - - - - Methyl hydroxyethyl cellulose ¹¹ [%] - 0.5 - - - - Polyvinyl Butyral [%] [%] - - - - - - Theory Gas output (V = constant) [Mol / kg] 11.4 22.5 15.8 14.0 17.4 14.7 Temperature (p = 135 × 10 ⁵ Pa) [K] 2440 2470 2420 1780 2230 1780 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 2800 8000 3600 8000 10000 450 Nitric oxide [ppm] 700 1000 800 500 800 100 ammonia [ppm] 0 0 0 50 3 2 Rough dust in the can [g] 2.2 0.6 1.2 3.2 1.3 1.5 Fine dust in cans [g] 0.5 0.3 0.4 0.4 0.2 0.3

Example number 37 38 39 40 41 42 A = ATZ [%] - - - - - - NIGU [%] - - - - - - Ca-DCA [%] 26.0 28.7 - - - - Na-DCA [%] - - 28.5 28.5 - - TAG [%] - - - - 48.6 22.7 GuNO ₃ [%] - - - - - 22.7 B = KNO ₃ [%] - 61.3 - 61.0 41.4 34.6 Sr (NO ₃ ) ₂ [%] 59.6 - 61.5 - - - NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] 14.0 10.0 10.0 10.0 - - ZrO ₂ ² [%] - - - - - - Al ₂ O ₃ ³ [[%]%] - - - - 10.0 20.0 Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] - - - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - - - - - - Methyl hydroxyethyl cellulose ¹¹ [%] 0.4 - - - - - Polyvinyl Butyral [%] - - - 0.5 - - Theory Gas output (V = constant) [Mol / kg] 10.9 11.7 9.7 10.7 26.2 23.4 Temperature (p = 135 × 10 ⁵ Pa) [K] 2400 1780 2240 1780 2140 1800 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 1500 1800 2000 2500 3000 2700 Nitric oxide [ppm] 300 800 500 1000 150 350 ammonia [ppm] 10 5 15 3 160 24 Rough dust in the can [g] 1.0 1.7 1.1 1.5 1.4 0.8 Fine dust in cans [g] 0.4 0.5 0.3 0.4 0.3 0.2

Example number 43 44 45 46 47 48 A = ATZ [%] 17.7 - - - - - NIGU [%] - - - - - - Ca-DCA [%] - - 18.8 - - - Na-DCA [%] - - - - - - TAGN [%] 17.7 - - - - - GuNO ₃ [%] - 54.2 18.8 50.0 50.0 51.5 B = KNO ₃ [%] 44.6 35.8 52.4 - - - Sr (NO ₃ ) ₂ [%] - - - 39.4 39.4 38.0 NaNO ₃ [%] - - - - - - C = TiO ₂ ¹ [%] - - - - 10.0 - ZrO ₂ ² [%] - - - - - 10.0 Al ₂ O ₃ ³ [%] 20.0 5.0 10.0 10.0 - - Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - - - - D = iron oxide (III) ⁹ [%] - 5.0 - - - - Aluminum Silicate ¹⁰ [%] - - - - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - - - 0.6 0.6 - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - 0.5 Polyvinyl Butyral [%] [%] - - - - - - Theory Gas output (V = constant) [Mol / kg] 20.0 26.6 16.9 25.1 25.1 25.7 Temperature (p = 135 × 10 ⁵ Pa) [K] 1810 1780 1780 2120 2130 2170 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 1000 5000 7000 6000 4000 3500 Nitric oxide [ppm] 150 400 150 800 100 500 ammonia [ppm] 50 100 150 5 0 10 Rough dust in the can [g] 1.0 2.0 1.8 1.5 1.0 0.5 Fine dust in cans [g] 0.4 0.5 0.6 0.4 0.5 0.3

Example number 49 50 51 52 53 54 A = ATZ [%] 29.75 30.2 30.2 26.5 26.8 33.7 NIGU [%] - - - 8.0 - - Ca-DCA [%] - - - - - - Na-DCA [%] - - - - - - TAGN [%] - - - - - - GuNO ₃ [%] - - - - 8.0 - B = KNO ₃ [%] 50.25 49.8 49.8 32.5 32.2 56.3 Sr (NO ₃ ) ₂ [%] - - - - - - NaNO ₃ [%] - - - 15.0 15.0 - C = TiO ₂ ¹ [%] - - - - - 10.0 ZrO ₂ ² [%] 3.0 10.0 - - - - Al ₂ O ₃ ³ [%] 14.0 10.0 10.0 18.0 18.0 - Al ₂ O3 + 1% Pt ⁷ [%] - - - - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] 3.0 - - - - - D = iron oxide (III) ⁹ [%] - - - - - - Aluminum Silicate ¹⁰ [%] - - 10.0 - - - Silicon Nitride Si ₃ N ₄ [%] - - - - - - E = graphite [%] - - - - - - Methyl hydroxyethyl cellulose ¹¹ [%] - - - - - - Polyvinyl Butyral [%] [%] - - - - - - Theory Gas output (V = constant) [Mol / kg] 17.6 17.8 19.3 19.4 19.7 19.8 Temperature (p = 135 × 10 ⁵ Pa) [K] 1780 1780 1920 1800 1780 1820 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 2600 3000 4500 3500 6500 8000 Nitric oxide [ppm] 300 200 300 800 500 250 ammonia [ppm] 23 50 50 0 5 300 Rough dust in the can [g] 1.0 1.1 1.2 0.8 1.0 0.8 Fine dust in cans [g] 0.2 0.4 0.5 0.2 0.2 0.3

Example number 55 56 57 A = ATZ [%] 30.35 31.66 29.75 NIGU [%] - - - Ca-DCA [%] - - - Na-DCA [%] - - - TAGN [%] - - - GuNO ₃ [%] - - - B = KNO ₃ [%] 49.65 - 50.25 Sr (NO ₃ ) ₂ [%] - 56.34 - NaNO ₃ [%] - - - C = TiO ₂ ¹ [%] - - - ZrO ₂ ² [%] - - - Al ₂ O ₃ ³ [%] 10.0 9.0 20.0 Al ₂ O3 + 1% Pt ⁷ [%] - - - Al ₂ O ₃ + 1% (Pd + Pt) ⁸ [%] - - - D = iron oxide (III) ⁹ [%] 6.0 - - Aluminum Silicate ¹⁰ [%] 4.0 3.0 - Silicon Nitride Si ₃ N ₄ [%] - - - E = graphite [%] - - - Methyl hydroxyethyl cellulose ¹¹ [%] - - - Polyvinyl Butyral [%] [%] - - - Theory Gas output (V = constant) [Mol / kg] 18.2 18.8 17.6 Temperature (p = 135 × 10 ⁵ Pa) [K] 1780 2390 1780 Measured value (in 60 dm ³ cans) carbon monoxide [ppm] 6000 7500 3500 Nitric oxide [ppm] 100 250 400 ammonia [ppm] 150 0 0 Rough dust in the can [g] 1.5 0.7 0.7 Fine dust in cans [g] 0.4 0.3 0.3

Combustion tests were performed in a practice-placed housing of a gas generator for a 60 liter operator-airbag with an original size, igniter and steel filter package.

The weight of the propellant charge for the gas generator is 50-55 g, which depends on the gas output of the individual composition of the propellant for the gas generator.

Depending on the combustion characteristics, the pellets have a diameter of 4-6 mm and a height of 1.5 and 2.1 mm, respectively.

Gas output and temperature are within a range advantageous for propellants for gas generators for airbags.

The terms "rough dust" and "fine dust" in the table refer to dust in the can after combustion.

The measurements for CO, NOx and NH ₃ given in the table are for 60 liter cans. It is good to consider that the values obtained are those using a non-optimal test gas generator.

From the comparison of Examples 14 and 15, 17 and 18, and 20 and 21, the effect obtained using highly dispersed oxides compared to conventional oxides was explained. The reduction of particle release (rough and fine dust) for the nitroguanidine / strontium nitrate system is a highly dispersed specific slag trap (C) used by the present invention, compared to conventional oxides having the same chemical structure but low surface area. Due to it is about 20 to 40%. In addition, the reduction of about 10-25% of toxic gases is due to the improvement of combustion by the use of the specific slag traps (C) used in the present invention, the characteristics of which are obvious.

In addition, a further beneficial effect on the formation of toxic gases of highly dispersed slag traps C having a catalyst on the surface can be seen by comparison of the propellant for gas generators according to Examples 2-8 and 10.

The share of CO and NOx is according to Examples 8 and 10 (with a catalyst), and is less than or equal to that of Example 2 (without catalyst, having the same composition is a separate matter).

Particularly preferred compositions are the compositions of Examples 14, 17 and 20.

Thermodynamic data of the various compositions were calculated for excess oxygen balance, where the minimum possible amount of toxic gases during combustion is expected.

Claims (18)

(A) Guanine nitrate (GUNI; GuNO ₃ ), dicyanamide, ammonium dicyanamide, sodium dicyanamide (Na-DCA), copper dicyanamide, tin dicyanamide, calcium dicyanamide (Ca-DCA) , Guanidine dicyanamid (GDCA), aminoguanidine bicarbonate (AGB), aminoguanidine nitrate (AGN), triaminoguanidine nitrate (TAGN), nitroguanidine (NIGU), dicyandiamide (DCD), azodicarbon Tetrazol (HTZ), 5-aminotetrazole (ATZ), 5-nitro-1,2,4-triazol-3-one (NTO), as well as amides (ADCA), as well as salts and mixtures thereof At least one fuel selected, (B) at least one alkali metal nitrate, or alkaline earth metal nitrate or ammonium nitrate, ammonium chlorate, or ammonium perchlorate, (C) Propellants for gas generators consisting essentially of chemically inert slag traps having a high melting point selected from the group consisting of at least one, highly dispersed form of Al ₂ O ₃ , TiO ₂ , and ZrO ₂ and mixtures thereof. . The composition according to claim 1, wherein component (A) is present in an amount of about 20 to 60% by weight, preferably about 28 to 52% by weight, in particular about 45 to 51% by weight; Component (B) is present in an amount of about 38 to 63 weight percent, preferably about 38 to 55 weight percent, especially about 39 to 45 weight percent; Propellant for gas generator, wherein component (C) is present in an amount of about 5 to 22% by weight, preferably about 8 to 20% by weight, in particular about 9 to 11% by weight. The method of claim 1 or 2, wherein component (A) is selected from the group consisting of nitroguanidine, 5-aminotetrazole, dicyandiamide, dicyanamid, sodium and calcium dicyanamid and guanine nitrate, and mixtures thereof. Propellant for the selected gas generator. The gas generator propellant according to any one of claims 1 to 3, wherein the component (B) is selected from the group consisting of sodium nitrate, potassium nitrate and strontium nitrate. 5. The propellant of claim 1, wherein component (C) is selected from the group consisting of highly dispersed Al ₂ O ₃ , highly dispersed TiO ₂ and highly dispersed ZrO _{2. 6} . The method of claim 5, wherein the component (C) is non-surface is 100 ± 15 m ² / g of the dispersed Al ₂ O highly _3, the specific surface area is 50 ± 15 m ² / g is dispersed TiO _highly-2, specific surface A propellant for a gas generator selected from the group consisting of highly dispersed ZrO ₂ which is 40 ± 10 m ² / g. The propellant for gas generators according to claim 5, wherein a part of component (C) is a carrier of a platinum metal or a metal alloy of platinum metal or copper in a catalytically effective layer thickness. 8. The propellant of claim 7, wherein the platinum metal is selected from ruthenium (Ru), osmium (Os), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt). 8. The propellant of claim 7, wherein the metal alloy of platinum metal is selected from Pt / Pd and Pt / Rh alloys. Propellant for gas generator according to claim 7, wherein the weight ratio of catalyst to component (C) is from 0.1 to 5% by weight, preferably from 0.2 to 1.2% by weight. The composition according to any one of claims 1 to 10, wherein component (A) is nitroguanidine, component (B) is strontium nitrate, and component (C) is highly dispersed Al ₂ O ₃ , TiO ₂ or Propellant for gas generators with ZrO ₂ . 12. Component (A) is present in an amount of 45-51% by weight, component (B) is present in an amount of 39-45% by weight, and component (C) is 9-9 with respect to the total composition Propellant for gas generator present in an amount of 11% by weight. 12. The compound according to any one of claims 1 to 11, wherein carbonates of one alkali metal and alkaline earth metal, oxides of alkali metal and alkaline earth metal, silicates, aluminates, aluminum silicates, silicon nitride (Si ₃ N _4). And (D) consisting of at least one slag forming agent selected from iron oxide (III). 14. The gas generator propellant according to claim 13, wherein component (D) is present in an amount of 2 to 12% by weight, preferably in an amount of 4 to 10% by weight. The gas generator propellant according to any one of claims 1 to 14, further comprising component (E) consisting of at least one binder which is water soluble at room temperature. 16. The propellant of claim 15, wherein said binder is selected from the group consisting of a cellulose compound, a polymer of at least one polymerizable olefinically unsaturated monomer, a metal salt of stearic acid and graphite insoluble in water at room temperature. 17. The propellant for gas generators according to claim 15 or 16, wherein the binder is present in an amount of 0 to 2% by weight, preferably 0.3 to 0.8% by weight. Propellant for a gas generator according to any one of claims 1 to 17, used as a gas-generating agent, fire extinguishing agent or propellant of an airbag.