JPH09157080A - Gas generating agent for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generating agent for an air bag having the same combustion velocity, combustion temp. and concns. of the toxic components such as CO and NOx in the gas as the conventional azide and non-azide gas generating agent, extremely low in impact ignitability, detonability and toxicity and excellent in thermal stability. SOLUTION: This gas generating agent for an air bag includes at least one kind selected from a group consisting of a gas generating agent for an air bag with biscarbamoylhydrazine and a nitrate as the effective components, a gas generating agent for an air bag with biscarbamoylhydrazine, a nitrate and a oxohalogenate as the effective components and a gas generating agent for an air bag with biscarbamoylhydrazine and an oxohalogenate as the effective components and further consisting of a combustion catalyst, a combustion control agent and a slag forming agent.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a gas generating agent for an air bag.

The gas generating agent for an air bag of the present invention has appropriate combustion performance, has a low combustion temperature, and has a low concentration of toxic components such as CO and NOx in the gas produced by the combustion, and is released. It has favorable characteristics that the concentration of suspended particulate matter is low, the thermal stability is good, and the safety is remarkably higher than that of conventional azide-based and non-azide-based gas generating agents.

[0003]

With the increasing demand for vehicle safety, the demand for airbag systems is increasing exponentially. In an airbag system, when a car crashes at high speed, the nylon bag (airbag) mounted inside the steering wheel, dashboard, etc. is inflated, causing the occupant to crash into various parts of the vehicle and die or be injured. The gas generated by burning the gas generating agent loaded in the inflator (gas generating container) in the system is used for inflating the bag.

Various properties are required for the gas generating agent for an air bag, and the following six requirements are particularly important.

The first requirement is "to show an appropriate burning rate in the inflator". In an air bag system, a sensor detects the impact on the vehicle, determines if it is a true collision, and if it is a true collision, it ignites the gas generating agent in the inflator and releases the gas. Inflate the airbag to protect the occupant's body, especially the head. That is, when an automobile collides, the occupant's head begins to move after a certain period of time, and the airbag needs to be deployed in accordance with the movement of the head. Therefore, it is unsuitable if the burning rate of the gas generating agent is too fast or too slow.

The second requirement is "low combustion temperature". If the combustion temperature of the gas generating agent is high, the temperature of the gas released into the bag becomes high, damaging the bag, and further, the gas leaked to the outside due to the damage of the bag may injure an occupant. Further, normally, solid matter is by-produced during combustion, but it is removed by a filter provided between the inflator and the bag, and is not contained in the released gas. However, when the combustion temperature is high, the solid matter is vaporized and discharged together with the gas into the bag, where it is condensed into suspended particulate matter, which may damage the bag.

The third requirement is "the concentration of toxic components such as CO and NOx in the gas produced by combustion is low".
In an airbag system, in order to cushion the impact of the occupant colliding with the inflated bag, the bag releases some of the gas into the vehicle immediately after inflation and contracts somewhat, but if the concentration of toxic components is high, the occupant will be poisoned. May occur.

The fourth requirement is "good thermal stability". The gas generant must normally have a long life of over ten years. It is an essential condition that the gas generating agent does not decompose at a temperature to which an automobile is exposed, particularly at a high temperature in summer.

The fifth requirement is "high safety of raw materials, intermediates and products". Among safety, it is important that impact ignitability (ignition sensitivity to impact) is low. If the impact ignition property is high, the handling risk is high, and a detonation is likely to occur in the manufacturing process such as mixing and molding, which may damage the surrounding equipment and environment, and even cause fatal injury to the human body. is there.

The sixth requirement is "low toxicity".
The high toxicity of gas generant raw materials, intermediates and products can cause problems during manufacturing and disposal.

The azide-based gas-generating agents having sodium azide as the gas-generating base, which are widely used at present, are the first to the above-mentioned ones.
Although it is an excellent gas generating agent that satisfies the fourth requirement, it has the drawbacks of high impact ignitability and the toxicity of the base sodium azide being extremely high. Therefore, strict protective measures are required to protect workers in each process of manufacturing, transporting, and storing an azide-based gas generating agent. in addition,
When an airbag-equipped vehicle loaded with an azide-based gas generating agent falls into a river or the sea or encounters water damage, or when the airbag-equipped vehicle is scrapped by a cutter,
Sodium azide can leak and cause serious environmental pollution.

As a substitute for the azide-based gas generating agent, for example, azodicarbonamide (hereinafter referred to as "ADCA")
A non-azide gas generating agent containing a nitrogen-containing organic compound and an oxidizing agent is known (JP-A-6-32689).
JP-A-6-32690, JP-A-6-22
7884, etc.). The gas generating agent has an appropriate burning rate comparable to that of a conventional azide-based gas generating agent, has low impact ignitability, and has extremely low detonation and toxicity. Further, the combustion temperature and the concentration of toxic components such as CO and NOx in the gas are low enough to be put to practical use, but further reduction is desired. In addition, the non-azide gas generating agent is required to be further improved in terms of thermal stability.

Further, in JP-A-7-300383, a composition containing biscarbamoylhydrazine (hydrazodicarbonamide) and an oxohalogenate as active ingredients is used as a non-azide gas generating agent having excellent thermal stability. The thing is disclosed. However, the gas generant exhibits high detonation properties and is dangerous. In addition to the high combustion temperature, it also has a drawback that a large amount of potassium chloride, which is liable to become suspended particulate matter, is by-produced during the combustion.

[0014]

As a result of intensive studies to solve the above problems, the present inventor succeeded in improving the conventional non-azide gas generating agent, and completed the present invention. It was

That is, the present invention relates to (1) a gas generating agent for an air bag containing biscarbamoylhydrazine as a gas generating base and nitrate as an oxidizing agent as active ingredients, and (2) biscarbamoyl as a gas generating base. A gas generating agent for an air bag, which contains hydrazine and an oxidizing agent, nitrate and oxohalogenate as active ingredients, and (3) an active ingredient, biscarbamoylhydrazine which is a gas generating base and oxohalogenate which is an oxidizing agent. And a gas generating agent for an air bag, which further comprises at least one selected from the group consisting of a combustion catalyst, a combustion control agent and a slag forming agent.

According to the present invention, there is provided a gas generating agent for an air bag, which satisfies all the above first to sixth requirements. That is, according to the present invention, the burning rate, the burning temperature, and the C in the gas equivalent to those of the conventional azide-based and non-azide-based gas generating agents are used.
Oxygen, NOx and other toxic components, impact ignitability, detonation and toxicity are extremely low, airborne particulate matter concentration is low, and thermal stability is also outstanding. A gas generant is provided.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Biscarbamoylhydrazine (also known as biurea or hydrazodicarbonamide), which is a gas generating base for a gas generating agent for an airbag of the present invention, is mainly
It is a compound that has been used as a raw material for ADCA. In addition to the above, biscarbamoylhydrazine is a synthetic resin with high chemical resistance and heat resistance such as vinyl chloride resin, which is used for ADC.
It is only used as a cell nucleating agent for adjusting the shape of foam cells when foaming with A.

Biscarbamoylhydrazine is ADCA
Since it has a higher thermal stability than the above, and has a significantly higher stability against alkali, it has an advantage that the selection range of the oxidant, the combustion catalyst, etc. is widened, and it significantly improves the thermal stability of the gas generating agent of the present invention. Also contributed. In addition, biscarbamoylhydrazine has very low toxicity and no danger of explosion, and in that respect, it contributes to the improvement of the safety of the gas generating agent of the present invention.

In the present invention, biscarbamoylhydrazine may be a commercially available product as it is. Further, the particle size thereof is not particularly limited, and may be appropriately selected from a wide range according to various conditions such as the blending amount thereof, the types and blending ratios of other components used in combination, the capacity of the airbag and the like.

As the oxidizing agent which is another active ingredient of the gas generating agent of the present invention, a nitrate is used alone, an oxohalogenate is used alone, or a nitrate and an oxohalogenate are used in combination. To do. When the oxohalic acid salt is used alone, at least one selected from the group consisting of a combustion catalyst, a combustion control agent and a slag forming agent described later is used in combination.

Examples of the nitrate include lithium nitrate,
Examples thereof include alkali metal salts such as sodium nitrate and potassium nitrate; alkaline earth metal salts such as magnesium nitrate, barium nitrate and strontium nitrate; and ammonium salts such as ammonium nitrate. Among them, alkali metal salts and alkaline earth metal salts are preferred, and potassium nitrate and strontium nitrate are particularly preferred.

Known oxohalogenates can be used, and examples thereof include perhalogenates and halogenates. Specific examples of perhalates include:
For example, lithium perchlorate, potassium perchlorate, sodium perchlorate, lithium perbromate, potassium perbromate,
Alkali metal salts such as sodium perbromate, alkaline earth metal salts such as magnesium perchlorate, barium perchlorate, calcium perchlorate, magnesium perbromate, barium perbromate, calcium perbromate, perchloric acid And ammonium salts such as ammonium and ammonium perbromate. Specific examples of the halogenate include, for example, lithium chlorate, potassium chlorate, sodium chlorate, lithium bromate, potassium bromate, alkali metal salts such as sodium bromate, magnesium chlorate, barium chlorate,
Examples include alkaline earth metal salts such as calcium chlorate, magnesium bromate, barium bromate and calcium bromate, and ammonium salts such as ammonium chlorate and ammonium bromate. Among these, alkali metal salts of halogen acids and perhalogen acids are preferable, and potassium perchlorate and potassium chlorate are particularly preferable.

Commercially available nitrates and oxohalogenates can be used as they are, and their shape, particle size, etc. are not particularly limited. For example, the blending amount, the blending ratio with each component, the airbag capacity, etc. It may be appropriately selected and used according to various conditions.

Further, both when the nitrate is used alone, when the oxohalogenate is used alone, and when the nitrate and the oxohalogenate are used in combination,
The mixing amount of these oxidizing agents may be a stoichiometric amount that can completely oxidize and burn biscarbamoylhydrazine based on the amount of oxygen, but by appropriately changing the mixing ratio of the gas generating base and the oxidizing agent. , The burning rate, the burning temperature (gas temperature), the burning gas composition, etc. can be arbitrarily adjusted, so that it can be appropriately selected from a wide range, for example, nitrate, oxohalogenate or 100 parts by weight of biscarbamoylhydrazine. About 10 to 400 parts by weight of nitrate and oxohalogenate, preferably 100 to 24
You may mix | blend about 0 weight part. When nitrate and oxohalogenate are used in combination, the mixing ratio of these is not particularly limited and may be appropriately selected. When the compounding ratio of potassium perchlorate is higher than the above amount, the combustion temperature becomes high, the possibility of detonation occurs, and a large amount of potassium chloride as suspended particulate matter is generated, which is not preferable.

Further, in the present invention, at least one known oxidant other than nitrates and oxohalogenates can be used in combination within a range that does not impair the preferable characteristics of the gas generating agent of the present invention. The oxidizing agent is not particularly limited and may be appropriately selected from those conventionally used in the art, but those capable of generating and / or supplying oxygen at high temperature are preferable, and examples thereof include nitrite and metal peroxide. Oxides, superoxides,
Examples thereof include ozone compounds. As the nitrite, for example, lithium nitrite, sodium nitrite, alkali metal salts such as potassium nitrite, magnesium nitrite,
Examples thereof include alkaline earth metal salts such as barium nitrite and calcium nitrite. As the metal peroxide,
Examples thereof include alkali metal salts such as lithium peroxide, sodium peroxide and potassium peroxide, alkaline earth metal salts such as magnesium peroxide, calcium peroxide and barium peroxide. Examples of the superoxide include alkali metal compounds such as sodium superoxide and potassium superoxide, calcium superoxide, strontium superoxide, alkaline earth metal compounds such as barium superoxide, rubidium superoxide, and cesium superoxide. You can Examples of the ozone compound include the general formula MO ₃ (wherein M is Na,
Group Ia elements such as K, Rb and Cs are shown. ). In the present invention, metal sulfides such as molybdenum disulfide, bismuth-containing compounds, lead-containing compounds and the like can also be used as oxidizing agents. Commercially available products can be used as these oxidizing agents as they are, and their shape, particle size, etc. are not particularly limited. For example, various amounts such as the blending amount, the type and blending ratio of each component used in combination, the capacity of the airbag, etc. It may be appropriately selected and used according to.

In the gas generating agent of the present invention, in addition to the above two components, at least one selected from combustion catalysts, combustion control agents, slag forming agents and the like can be added.

It is considered that the combustion catalyst mainly has the effect of lowering the combustion temperature and reducing the concentration of CO and / or NOx in the gas. As a combustion catalyst, Periodic Table No. 4
An oxide of a metal having up to 6 cycles, an oxygen-containing metal compound capable of generating the metal oxide by heating, a heteropolyacid, and the like are used.

Specific examples of the metal oxides of the 4th to 6th periods of the periodic table include copper oxide, nickel oxide, cobalt oxide, iron oxide, chromium oxide, manganese oxide, zinc oxide, calcium oxide and titanium oxide. , Vanadium oxide, cerium oxide, holmium oxide, ytterbium oxide, molybdenum oxide, tungsten oxide, antimony oxide, titanium oxide, tin oxide and the like. Among them, copper oxide, nickel oxide, cobalt oxide, molybdenum oxide, tungsten oxide, iron oxide, tin oxide, zinc oxide, chromium oxide and the like are particularly preferable, and CuO, CoO, N
iO, Ni ₂ O ₃ , MoO ₃ , WO ₃ , Cr ₂ O ₃ , Ti
O ₂ , SnO, ZnO, Fe ₂ O _{3 and the} like are more preferable. These metal oxides also include hydrates thereof. An example of a hydrate of tungsten oxide is WO ₃ .H ₂ O. As these metal oxides, BE is preferable.
T specific surface area of 5 m ² / g or more, more preferably 10 m ² /
It is preferable to use those having a weight of at least g, more preferably at least 40 m ² / g. Among the above metal oxides, MoO ₃ ,
WO _{3 and the} like have preferable characteristics that CO concentration and NOx concentration can be simultaneously reduced.

The oxygen-containing metal compound capable of forming a metal oxide having a period of 4 to 6 in the periodic table by heating is not particularly limited, and known compounds can be used. MoO ₃ by heating
Examples of the oxygen-containing molybdenum compound that produces a compound include a group VIII metal salt of molybdic acid such as cobalt molybdate and nickel molybdate, molybdic acid, and molybdenum hydroxide. The oxygen-containing tungsten compound that generates WO ₃ by heating is, for example, tungstic acid and a metal salt thereof. Examples of the metal salt of tungstic acid include lithium tungstate, potassium tungstate, calcium tungstate, sodium tungstate, magnesium tungstate, cobalt tungstate, nickel tungstate, iron tungstate, and the like.
Copper tungstate etc. can be mentioned.

Specific examples of the heteropolyacid include, for example,
Examples thereof include phosphomolybdic acid, phosphotungstic acid, and metal salts thereof. The metal salt of heteropolyacid is not particularly limited, and examples thereof include Co salt, Mg salt, N
Examples thereof include i salt, Sr salt, Pb salt, Bi salt, Fe salt and the like, and among these, Co salt and the like are preferable.

Among these combustion catalysts, CuO, Co
O, NiO, Ni ₂ O ₃ , MoO ₃ , WO ₃ , M
Oxygen-containing molybdenum compound that generates oO ₃ , oxygen-containing tungsten compound that generates WO ₃ by heating, cobalt phosphomolybdate, Cr ₂ O ₃ , TiO ₂ , SnO, Zn
O, Fe ₂ O _{3 and the} like are particularly preferable, and CuO, CoO, Ni
O, Ni ₂ O ₃ , MoO ₃ , WO ₃ , VIII of molybdic acid
Group metal salts, cobalt phosphomolybdate and the like are even more preferred.

The above combustion catalysts may be used alone or in combination of two or more.

The particle size of the combustion catalyst is not particularly limited and may be appropriately selected from a wide range according to various conditions such as the blending amount thereof, the blending ratio with other components, and the capacity of the airbag. When blending the combustion catalyst with the gas generating agent of the present invention, the blending amount is not particularly limited, and is appropriately selected from a wide range according to various conditions such as the type and blending ratio of other components used in combination, the capacity of the airbag, and the like. it can.

For example, when the combustion catalyst is added to the mixed system of biscarbamoylhydrazine and the oxidizing agent in a large excess compared to the additives other than the combustion catalyst, both CO and NOx can be reduced. From such a viewpoint, the combustion catalyst is usually used in an amount of about 0.1 to 150 parts by weight based on 100 parts by weight of the total amount of biscarbamoylhydrazine and the oxidizing agent,
Preferably about 10 to 120 parts by weight, more preferably 3
The amount may be about 0 to 80 parts by weight.

When a combustion catalyst and a combustion control agent which will be described later are used in combination, biscarbamoylhydrazine and an oxidizing agent are used from the viewpoint of stabilizing the gas generation amount and combustion performance and reducing both CO and NOx. 0.1 to 30 parts by weight of the combustion catalyst per 100 parts by weight of the total amount of
It is preferable to add about 0.5 to 25 parts by weight.

When an oxygen-containing metal compound which produces a metal oxide by heating is used, the amount of the produced metal oxide may be set within the range specified above.

[0037] Combustion regulators generally lower the combustion temperature, regulate the combustion rate, produce, transport,
In a process such as preservation, it is used to prevent the gas generating agent from being caught in a fire or the like or detonated by a strong impact.

Examples of the combustion regulator include the following (A)
(C) and the like can be mentioned.

(A) Metal simple substance such as B, Al, Mg, Ti, Zr, Mo, etc. (b) Oxide, hydroxide, etc. of the 2nd to 3rd periodic elements of the periodic table such as Al, Mg, Si, B, etc. Carbonates, bicarbonates (preferably B ₂ O ₃ , aluminum hydroxide, bentonite, alumina, diatomaceous earth, silicon dioxide, etc.) (C) Alkali metal carbonates, bicarbonates such as Na and K,
Oxides (d) Carbonates and bicarbonates of alkaline earth metals such as Ca, Mg, Ba and Sr (e) 4th to 6th periodic tables other than (b) to (c) above
Periodic elements (for example, Zn, Cu, Fe, Pb, Ti,
V, Ce, Ho, Ca, Yb, etc.), carbonates, sulfates (f) Carboxymethyl cellulose, hydroxymethyl cellulose, ethers thereof, cellulose compounds such as microcrystalline cellulose powder (g) Soluble starch, polyvinyl Organic polymer compounds such as alcohols and partially saponified products thereof. (H) Amino acids such as glycine, organic acids such as organic carboxylic acids such as ascorbic acid and citric acid.

Among the above-mentioned combustion regulators, for example, (a)
To (d) and (h) compounds are preferable, and B, Al, T
i, metal such as Zr, metal oxide such as B ₂ O ₃ , Al ₂ O ₃ , alkali metal and alkaline earth metal carbonate such as lithium carbonate, magnesium carbonate and calcium carbonate, metal such as aluminum hydroxide Amino acids such as hydroxide and glycine are particularly preferable.

One of the combustion regulators can be used alone, or two or more can be used in combination. A commercially available product may be used as it is as the combustion control agent. The particle size is not particularly limited, and may be appropriately selected from a wide range according to various conditions such as, for example, the blending amount, the blending ratio with other components, and the capacity of the airbag.

When a combustion control agent is added to the gas generating agent of the present invention, the amount thereof is not particularly limited, and the mixing ratio of biscarbamoylhydrazine and the oxidizing agent, the type of combustion control agent,
It can be appropriately selected from a wide range according to various conditions such as the type of other components used in combination and the capacity of the airbag, but is usually 0.5 to 50 per 100 parts by weight of the total amount of biscarbamoylhydrazine and the oxidizing agent. Parts by weight, preferably 5 to 3
It may be about 0 parts by weight. When boron is used as the combustion control agent, the amount used is 0.5 to 5 with respect to 100 parts by weight of the total amount of biscarbamoylhydrazine and the oxidizing agent, from the viewpoint of obtaining a low combustion temperature and an appropriate combustion rate.
The amount is preferably about 1 part by weight, preferably about 1 to 3 parts by weight.

The slag forming agent is an additive for solidifying the residue generated after the combustion of the gas generating agent and making it easy to remove by a filter in an airbag inflator. As the slag forming agent, known ones can be used, for example, silicon dioxide, alumina, etc., which have already been exemplified as the combustion controlling agent, can be used, and one kind thereof can be used alone or two or more kinds can be used in combination. When the slag generating agent is blended with the gas generating agent of the present invention, the amount thereof is not particularly limited and may be appropriately selected from a wide range depending on the composition of the gas generating agent and the like. For example, when silicon dioxide is used as a slag forming agent, the addition amount thereof is 1 mol of potassium nitrate in a molar ratio.
Around / 2 is appropriate. An oxide containing an alkaline earth metal and an alkaline earth metal compound that reacts to form an oxide, such as strontium oxide or strontium nitrate, can also be used as the slag forming agent.

Further, various additives conventionally used for this purpose may be blended within a range that does not impair the preferable properties of the gas generating agent of the present invention.

In the present invention, in order to further improve the thermal stability of the gas generating agent of the present invention, at least one of the gas generating base and / or the component other than the gas generating base,
You may perform surface treatment using a coupling agent or a chelating agent. The coupling agent is not particularly limited and known ones can be used, for example, γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, silane coupling agents such as methyltrimethoxysilane, isopropyltriisosilane, etc. Examples thereof include titanate coupling agents such as stearoyl titanate, and aluminum coupling agents such as acetoalkoxyaluminum diisopropylate. Known chelating agents can also be used, such as ethylenediaminetetraacetic acid (EDTA) and its metal salts (EDTA).
・ 2Na salt, EDTA ・ 2K salt, EDTA ・ 2Li salt,
EDTA.2 ammonium salt), sodium diethyldithiocarbamate and the like. The surface treatment is carried out by mixing a component to be treated with a coupling agent or a chelating agent in a suitable solvent or without a solvent according to a usual method.

The preferred embodiments of the gas generating agent of the present invention will be described below.

(1) A gas generating agent containing biscarbamoylhydrazine, nitrate and a combustion catalyst as main components.

As the combustion catalyst, CuO, CoO, Ni
O, MoO ₃ , Group VIII metal salts of molybdic acid, cobalt phosphomolybdate, etc. are particularly preferable, and CuO, MoO
₃ , CoMoO _{4 and the} like are even more preferable.

As the nitrate, an alkali metal salt and an alkaline earth metal salt are particularly preferable, and potassium nitrate is even more preferable. The preferred nitrate is the same in the following embodiments.

(1) -1 In the gas generating agent according to the above (1), the compounding ratio of biscarbamoylhydrazine and nitrate is usually 10 to 400 nitrate per 100 parts by weight of biscarbamoylhydrazine.
It is about 100 parts by weight, preferably about 100 to 240 parts by weight.

The blending amount of the combustion catalyst is usually about 0.1 to 30 parts by weight, preferably 0.5 to 2 parts, based on 100 parts by weight of the total amount of biscarbamoylhydrazine and nitrate.
It is about 5 parts by weight.

(2) A gas generating agent containing biscarbamoylhydrazine, nitrate and a combustion control agent as main components.

As the combustion control agent, B, Al, Ti, Z
A simple metal such as r and a metal oxide such as B ₂ O ₃ and Al ₂ O ₃ are particularly preferable.

(2) -1 In the gas generating agent of the above (2), when the burner modifier is used, the amount of biscarbamoylhydrazine and nitrate is usually 100 parts by weight based on the total amount. The amount is about 0.5 to 5 parts by weight, preferably about 0.5 to 3 parts by weight.

When a metal oxide is used, it is about 0.5 to 50 parts by weight, preferably about 5 to 30 parts by weight, based on 100 parts by weight of the total amount of biscarbamoylhydrazine and nitrate.

(3) A gas generating agent containing biscarbamoylhydrazine, a nitrate, a combustion catalyst and a combustion control agent as main components. The combustion control agent is the same as that exemplified in (2) above.

The blending amount of each component may be the same as the above (1) -1 and (2) -1.

(4) A gas generating agent containing biscarbamoylhydrazine, a nitrate, an oxohalogenate and a combustion catalyst as main components.

As the oxohalogenate, potassium perchlorate, potassium chlorate and the like are particularly preferable. The same applies to the following embodiments.

As the combustion catalyst, CuO, CoO, Ni
O, MoO ₃ , Group VIII metal salts of molybdic acid, cobalt phosphomolybdate, etc. are particularly preferable, and CuO, MoO
₃ , CoMoO _{4 and the} like are even more preferable, and CuO is most preferable.

(4) -1 In the gas generating agent of the above (4), the compounding ratio of biscarbamoylhydrazine, nitrate and oxohalogenate is such that nitrate and oxohalogenate are mixed with 100 parts by weight of biscarbamoylhydrazine. The gas generating agent is usually about 10 to 400 parts by weight, preferably about 100 to 240 parts by weight.

(4) -2 In the gas generating agent according to the above (4) -1, the compounding amount of the oxohalogenate is less than 40% by weight, preferably 30% by weight of the total amount of itself and biscarbamoylhydrazine.
Gas generating agent to be less than. Thereby, the combustion temperature and the detonation property can be further reduced.

(4) -3 In the gas generating agent according to the above (4), the amount of the combustion catalyst used is the total amount of biscarbamoylhydrazine and the oxidizing agent of 1
It is usually 0.1 to 150 parts by weight, preferably 10 to 120 parts by weight, and more preferably 30 parts by weight with respect to 00 parts by weight.
A gas generating agent of about 80 parts by weight. As a result, CO
Further significant reductions of both NOx and NOx can be achieved.

(4) -4 A gas generating agent satisfying both the above conditions (4) -1 and (4) -3 or (4) -2 and (4) -3.

(5) A gas generating agent containing biscarbamoylhydrazine, nitrates, oxohalogenates, combustion catalysts and combustion regulators as main components.

Examples of the combustion control agent include metal oxides such as B ₂ O ₃ and Al ₂ O ₃ , alkaline earth metals such as magnesium carbonate, calcium carbonate and lithium carbonate, carbonates of alkali metals, and aluminum hydroxide. Metal hydroxide and the like are particularly preferable.

(5) -1 In the gas generating agent of the above (5), the compounding ratio of biscarbamoylhydrazine, nitrate and oxohalogenate is such that the nitrate and oxohalogenate are 100 parts by weight of biscarbamoylhydrazine. The gas generating agent is usually about 10 to 400 parts by weight, preferably about 100 to 240 parts by weight.

(5) -2 In the gas generating agent according to the above (5) -1, the compounding amount of the oxohalic acid salt is less than 40% by weight, preferably 30% by weight of the total amount of itself and biscarbamoylhydrazine.
Gas generating agent to be less than. Thereby, the combustion temperature and the detonation property can be further reduced.

(5) -3 In the gas generating agent of the above (5), the blending amount of the combustion catalyst is set to a total amount of biscarbamoylhydrazine and the oxidizing agent of 1
The gas generating agent is usually 0.1 to 30 parts by weight, preferably 0.5 to 25 parts by weight, relative to 00 parts by weight. As a result, it is possible to improve the combustion performance such as the combustion speed and the combustion temperature and further reduce both CO and NOx.

Further, in the above-mentioned gas generating agent (5),
The blending amount of the combustion control agent is usually 0.5 to 5 with respect to 100 parts by weight of the total amount of biscarbamoylhydrazine and the oxidizing agent.
It is about 0 parts by weight, preferably about 5 to 30 parts by weight.

(5) -4 A gas generating agent satisfying both the conditions (5) -1 and (5) -3 or (5) -2 and (5) -3.

(6) A gas generating agent containing biscarbamoylhydrazine, a nitrate, an oxohalogenate and a combustion control agent as main components. B, Al, Ti, Z as combustion control agents
A simple metal such as r is particularly preferable.

(6) -1 In the gas generating agent according to the above (6), biscarbamoylhydrazine is 10 to 35% by weight (preferably 15 to 30% by weight) and nitrate is 20 to 70% by weight (preferably 30 to 65% by weight).
%), Less than 5% by weight of boron (preferably 1-3% by weight) and less than 40% by weight of potassium perchlorate (preferably less than 30% by weight).

(7) A gas generating agent containing biscarbamoylhydrazine, an oxohalogenate and a combustion catalyst as main components. As the combustion catalyst, CuO, CoO, NiO, Mo
O ₃ , a Group VIII metal salt of molybdic acid, cobalt phosphomolybdate, etc. are particularly preferable, and CuO, MoO ₃ , Co
MoO _{4 and the} like are even more preferable, and CuO is most preferable. Further, the gas generating agent may contain a combustion control agent.

(7) -1 In the gas generating agent according to the above (7), the compounding ratio of biscarbamoylhydrazine and oxohalogenate is 10 to 400 parts by weight of oxohalogenate based on 100 parts by weight of biscarbamoylhydrazine. Part, preferably 100
A gas generating agent of about 240 parts by weight.

(7) -2 In the gas generating agent of (7) above, the amount of the combustion catalyst used is usually 0.1 to 150 parts by weight based on 100 parts by weight of the total amount of biscarbamoylhydrazine and oxohalogenate. Parts, preferably about 10 to 120 parts by weight, more preferably about 30 to 80 parts by weight. This makes it possible to achieve an even greater reduction in both CO and NOx.

(7) -3 A gas generating agent satisfying both the conditions (7) -1 and (7) -2.

The preferred embodiment of the gas generating agent of the present invention may include a slag forming agent and other known additives.

The gas generating agent of the present invention is produced by mixing biscarbamoylhydrazine, an oxidizing agent and, if necessary, other components.

The gas generant of the present invention can be formulated into a suitable shape. For example, an appropriate amount of a binder may be mixed with the gas generating agent of the present invention and compressed or compressed and dried.
At that time, it is particularly preferable for safety to add an appropriate amount of water or warm water. As the binder, a binder commonly used for such a purpose may be used. There is no particular limitation on the form of the preparation, and examples thereof include pellets, discs, spheres, rods, hollow cylinders, sugary sugars, tetrapots, and the like. (For example, briquettes). Further, in the case of pellets or disks, one to several projections may be provided on one side or both sides. The shape of the protrusion is not particularly limited, and for example, a columnar shape,
Examples thereof include a conical shape, a polygonal pyramid shape, and a polygonal columnar shape.
Further, the size of the preparation of the gas generating agent of the present invention is not particularly limited and can be appropriately selected from a wide range, but in order to further lower the combustion temperature and obtain a more appropriate combustion rate, the particle size is 0.3 to It is preferable to formulate into granules having a particle size of about 1.5 mm, preferably the above-mentioned particle size.

Alternatively, each component of the gas generating agent of the present invention may be formulated alone and used by mixing them.

The formulation of the gas generating agent of the present invention can be safely stored and transported by filling it in a container made of synthetic resin such as polyethylene or metal.

The gas generating agent of the present invention is not limited to automobiles, and can be suitably used as a gas generating source for an air bag system mounted on various transportation equipment.

[0084]

The present invention will be specifically described below with reference to Examples, Comparative Examples and Test Examples. The manufacturing companies of the raw materials used below are as follows unless otherwise specified.

Biscarbamoylhydrazine (BCH):
Otsuka Chemical Co., Ltd. Azodicarbonamide (ADCA): Otsuka Chemical Co., Ltd. Potassium nitrate: Otsuka Chemical Co., Ltd. Potassium perchlorate: Nippon Carlit Co., Ltd. Silicon dioxide: Product name Nipseal NPS, Nippon Silica Industry ( Soluble starch (starch): first-grade reagent, Wako Pure Chemical Industries, Ltd. CuO: specific surface area 48 m ² / g and average particle size about 7.4.
μm, JGC Chemical Co., Ltd. MoO ₃ : manufactured by Nippon Inorganic Chemical Industry Co., Ltd. Also, “part” and “%” in the following represent “part by weight” and “% by weight” respectively, unless otherwise specified. .

Example 1 45 parts by weight of biscarbamoylhydrazine, 72.1 parts by weight of potassium perchlorate, 10 parts by weight of potassium nitrate, MoO.
₃ : 5 parts by weight of each powder and 1 part by weight of silicon dioxide were thoroughly mixed, and a 20% by weight aqueous solution of soluble starch was added to the mixture so that the starch content became 3.5 parts by weight, and further mixed to obtain a wet powder. Manufactured body. The wet powder is granulated by a granulator, the obtained wet granules are dried, and further pressed by a hydraulic tablet molding machine, and pellets of a gas generating agent (diameter 6 mm, thickness 3 mm, weight 0. 15 g) was produced.

Example 2 The amount of potassium perchlorate was changed to 67.7 parts by weight,
Moreover, pellets of the gas generating agent of the present invention were produced in the same manner as in Example 1 except that 10 parts by weight of CuO was used instead of MoO ₃ .

Comparative Example 1 45 parts by weight of azodicarbonamide, 5 parts of potassium perchlorate
6.3 parts by weight, potassium nitrate 10 parts by weight, silicon dioxide 1
1 part by weight and molybdenum (VI) oxide powder are mixed well, and a 10% by weight aqueous solution of soluble starch is added to the mixture so that the starch content is 1.5 parts by weight, and further mixed to produce a wet powder. did. The wet powder is granulated by a granulator and dried, and then pressed by a tablet molding machine to form pellets of a gas generating agent (diameter 6 mm, thickness 3 mm, weight 0.1
5 g) was produced.

Test Example 1 The gas generating agent obtained in Examples 1 and 2 and Comparative Example 3 was placed in the combustion chamber of an inflator equipped with gas ejection holes having a diameter of 7 mm and charged with 0.8 g of boron / potassium nitrate as a transfer charge. An aluminum cup having a plate thickness of 0.3 mm filled with the above pellets was loaded. This inflator was installed in a 60 liter tank, and was operated by passing an electric current to burn the pellets of the gas generating agent, and the pressure and temperature in the inflator and in the 60 liter tank were measured. The gas in the 60 liter tank after combustion was sampled from a sampling hole into a 1 liter Tedlar bag, and the CO concentration and NOx concentration in the gas were measured using a detector tube. Table 1 shows the results.

The English symbols in Table 1 have the following meanings.

CPmax: Maximum pressure (kgf / cm ² ) in the combustion chamber of the inflator.

TPmax: Maximum pressure in a 60 liter tank (kgf / cm ² ). It is a parameter indicating the gas generating ability of the gas generating agent.

TTPmax: Time required until the pressure in the 60 liter tank reaches its maximum (msec). A parameter that simulates the deployment speed when the airbag is deployed.

TTP90: Time required for the pressure in the 60-liter tank to reach 90% of the maximum value (msec).
A parameter that simulates the deployment speed when the airbag is deployed.

[0095]

[Table 1]

From Table 1, the gas generating agent of the present invention is
It can be seen that A has a burning rate equivalent to that of the gas generating base material, and the concentration of toxic components such as CO and NOx in the after gas is also low to the same extent.

Comparative Example 2 A gas generating agent pellet was produced in the same manner as in Example 2 except that ADCA was used instead of biscarbamoylhydrazine.

Test Example 2 The pellets of the gas generant obtained in Example 2 were heated to 107 ° C.
Was stored in a thermostat for 400 hours to calculate the residual weight ratio (%), and the degree of decomposition of the gas generating base was examined. Example 2
Has a residual weight ratio of 99.5% or more,
It was confirmed that biscarbamoylhydrazine was not substantially decomposed.

On the other hand, the gas generating agent of Comparative Example 2 also
The residual weight ratio (%) was examined in the same manner as described above except that the storage time was changed to 190 hours. The residual weight ratio was 75%. Storage time 1 of pellets of the gas generant of the present invention
It can be seen that the degradation of ADCA has progressed considerably, even though it is less than / 2.

From the above results, the gas generating agent of the present invention is
It is clear that the thermal stability is much higher than that of the gas generating agent using ADCA as the gas generating base.

Test Example 3 The combustion temperature of the gas generants of Example 2 and Comparative Example 2 was changed to NA.
SA thermal equilibrium calculation program (B.McBride, “CET89-Chem
ical Equilibrium with Transport Properties, 1989 "C
A simulation calculation was performed based on OSMIC Program # LEW-15113 (1989), NASA, hereafter referred to as "CET89"), and the gas generating agent of Example 2 was about 21.
The gas generating agent of Comparative Example 2 was about 2300K.

As described above, the gas generating agent of the present invention is AD
It can be seen that the combustion temperature is about 200 K lower than that of the gas generating agent using CA as the gas generating base.

Example 3 Pellets of the gas generant of the present invention were produced in the same manner as in Example 1, except that the components were used in the amounts (parts) shown in Table 2 below.

[0104]

[Table 2]

Test Example 4 Using the pellets of the gas generant of the present invention obtained in Example 3, the same operation as in Test Example 1 was carried out to determine the combustion performance of the gas generant and the CO concentration and NOx concentration in the post gas. Examined.

Table 3 shows the results.

[0107]

[Table 3]

From Table 3, it can be seen that the gas generating agent of the present invention has excellent combustion performance and low CO concentration and NOx concentration in the post gas.

Example 4 The gas generant pellets of the present invention were produced in the same manner as in Example 1, except that the components were used in the amounts (parts) shown in Table 4 below.

[0110]

[Table 4]

Test Example 5 Using the pellets of the gas generating agent of the present invention obtained in Example 4 and operating in the same manner as in Test Example 1, the combustion performance of the gas generating agent and the CO concentration and NOx concentration in the gas were examined. It was Table 5 shows the results.

[0112]

[Table 5]

Example 5 and Comparative Example 3 Pellets of the gas generant of the present invention (Example 5) were used in the same manner as in Example 1 except that the components were used in the amounts (parts) shown in Table 6 below. And pellets of the gas generating agent described in JP-A-7-300383 (Comparative Example 3) were produced. The following tests were conducted on these gas generating agents. The results are also shown in Table 6.

1) Thermochemical calculation temperature (referred to as "Tc") Based on the NASA thermal equilibrium calculation program (CET89), the thermochemical calculation temperature (adiabatic flame temperature) of the gas generating agent is calculated, and is a standard for knowing the combustion temperature. And

2) DSC exothermic decomposition onset temperature ("TDSC")
Exothermic decomposition start temperature (TDS) of DSC (Differential Scanning Calorimetry)
C) was measured to examine the thermal stability of the gas generant.

The thermal stability of the gas generating agent for an air bag was determined by using an inflator loaded with the gas generating agent at 4 ° C at 107 ° C.
It is evaluated by the fact that the gas generation performance is the same as that before heating after being operated after being held for 00 hours. According to this method, as already shown in Test Example 2, the canister is filled with the gas generating agent, and the canister is held at 107 ° C. for 400 hours to measure the weight loss of the gas generating agent and evaluate the thermal stability. (Heating loss test).

The present inventor conducted the results of the heat weight loss test and DSC.
By studying the correlation between the exothermic decomposition initiation temperature (TDSC) of (Differential Scanning Calorimetry), we found that if TDSC was 200 ° C or higher, the heating loss test passed, and based on this finding, the gas generant Was evaluated for thermal stability.

3) Strand burning rate test (referred to as "r") A gas generating agent was molded into a rectangular rod-shaped strand having a length and width of 7 mm and a length of 30 mm, and a restrictor was applied to the sample with the upper end left to prepare a sample body. did. This sample was burned under pressure of nitrogen (70 kg / cm 2) in a pressure vessel having an internal volume of about 1 liter, a time-pressure curve was recorded, and a linear burning rate (mm /
sec) was calculated. The higher the linear burning rate, the greater the detonation tendency.

4) Detonation Test The detonation transmissibility of the gas generant was examined by the UN-recommended gap test. A sample (gas generant) was filled in a drawn steel pipe with an inner diameter of 40 mm and an outer diameter of 48 mm, 160 g of pentolite (PETN / TNT = 50/50) explosive and No. 6 detonator were attached to the lower end, and 100 mm x 100 mm at the upper end. × 3
A mm (thickness) mild steel plate was placed as a proof plate. The No. 6 detonator was energized to detonate the detonator and the transfer charge. The propagation of detonation by the sample was judged by the fact that the steel pipe became fragments. The non-explosion was judged by the fact that the steel pipe did not become fragments and the unreacted sample remained.

[0120]

[Table 6]

From Table 6, it is clear that the gas generating agent of the present invention has a preferable characteristic that the combustion temperature is low, the thermal stability is good, there is no detonation property, and the combustion can be continued. On the other hand, the gas generating agent described in JP-A-7-300383 has an appropriate burning rate and good thermal stability, but has a problem that the burning temperature is high and there is detonation.

Example 6 Pellets of the gas generating agent of the present invention were produced in the same manner as in Example 1 except that each component was used in the compounding amounts (parts) shown in Table 7 below, and these gas generating agents were prepared. For the NASA thermal equilibrium calculation program (CET89) in the same manner as in Example 5.
Of the thermochemical calculation temperature (Tc) of the gas generant based on
A DSC exothermic decomposition onset temperature (TDSC) was measured and a strand burn rate test ("r") was performed. The results are also shown in Table 7.

[0123]

[Table 7]

Example 7 29 parts of hydrazodicarbonamide, 44 potassium nitrate
Of DSC exothermic decomposition start temperature (TDSC) in the same manner as in Example 5 for the gas generant consisting of 10 parts, silicon dioxide 13 parts, potassium perchlorate 12 parts, combustion catalyst 5 parts and starch 2 parts shown in Table 8. And a strand test was performed. The results are also shown in Table 8.

[0125]

[Table 8]

From Table 8 it is seen that combustion catalysts, especially MoO3 and C
It is clear that the burning rate is increased by the addition of uO.

Example 8 A gas generating agent comprising hydrazodicarbonamide having the composition (parts by weight) shown in Table 9, potassium nitrate, potassium perchlorate, silicon dioxide, starch and a combustion control agent was prepared in the same manner as in Example 5. A thermochemical calculation temperature (Tc) was calculated based on the NASA thermal equilibrium calculation program (CET89) and a strand test was performed. The results are also shown in Table 9.

[0128]

[Table 9]

From Table 9, combustion modifiers, especially Zr, Al,
It is clear that the burning rate is improved by adding Ti or the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C06B 43/00 C06B 43/00 (72) Inventor Kazuo Hara 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture Otsuka Kagaku Co., Ltd.In the Tokushima Plant (72) Inventor Shiro Chikazu 463 Kagasuno, Kawauchi-cho, Tokushima City, Tokushima Prefecture Otsuka Chemical Co., Ltd. In Tokushima Plant (72) Inoue Junichi 463, Kagasuno, Kawauchi-cho, Tokushima Prefecture Otsuka Chemical Tokushima Factory Co., Ltd.

Claims (6)

[Claims] 1. A gas generating agent for an air bag, which comprises biscarbamoylhydrazine as a gas generating base and nitrate as an oxidizing agent as active ingredients. 2. A gas generating agent for an air bag, which comprises biscarbamoylhydrazine as a gas generating base and nitrates and oxohalogenates as oxidizing agents as active ingredients. 3. The third component other than the gas generating base and the oxidizer, containing at least one selected from the group consisting of a combustion catalyst, a combustion control agent and a slag forming agent. Gas generating agent for airbags. 4. A gas generating base, biscarbamoylhydrazine, and an oxidant, oxohalogenate, are used as active ingredients, and at least one selected from the group consisting of combustion catalysts, combustion control agents, and slag forming agents. Gas generating agent for airbags. 5. The gas generating agent for an air bag according to claim 4, wherein biscarbamoylhydrazine which is a gas generating base and oxohalogenate which is an oxidizing agent are used as active ingredients, and a combustion catalyst is further contained. 6. The gas generating agent for an air bag according to claim 1, 2 or 4, which is formed into particles having a particle diameter of 0.3 to 1.5 mm.