JP2005145718A - Gas generating agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generating agent composition capable of preventing the formation of mist. <P>SOLUTION: The gas generating composition contains (a) glass powder, (b) aluminum hydroxide and/or magnesium hydroxide, (c) an organic compound as fuel and (d) an oxygen-containing oxidizing agent. By the action of the component (a), combustion residues can be solidified to form slag, thus preventing the formation of the mist. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas generant composition suitable for an air bag restraining system such as an automobile, a molded body thereof, and an inflator for an air bag using the same.

Conventionally, a composition using sodium azide has been frequently used as a gas generating agent for an air bag as an occupant protection device in an automobile. However, the toxicity of sodium azide to the human body [LD ₅₀ (oral-rat) = 27 mg / kg] and the danger during handling are regarded as problems, and as a safer so-called non-azide gas generant composition, there are various Gas generant compositions containing these nitrogen-containing organic compounds have been developed.

  Patent Document 1 discloses a composition of a tetrazole or triazole compound containing hydrogen and an oxygen-containing oxidizing agent. Patent Document 2 discloses a gas generant composition comprising a metal salt of bitetrazole containing no hydrogen and an oxidizing agent containing no oxygen. Patent Document 3 discloses a gas generant composition comprising a metal salt of bitetrazole containing no hydrogen and an alkali metal nitrate, an alkali metal nitrite, an alkaline earth metal nitrate, an alkaline earth metal nitrite, and a mixture thereof. Has been. Patent Document 4 discloses a gas generating agent comprising a fuel such as GZT, TAGN (triaminoguanidine nitrate), NG (nitroguanidine), NTO, etc., basic copper nitrate, a catalyst for reducing toxic gas, and a coolant agent. Yes. Patent Document 5 discloses a gas generant composition comprising a fuel such as guanidine nitrate, basic copper nitrate and guar gum.

  However, since the non-azide gas generant composition generates a residue (mist) after combustion, it is necessary to use a filter in order to prevent the residue from flowing into the airbag. At that time, there is a method of making the composition easy to form a slag having a shape easily collected by a filter after the gas generating agent composition is burned.

Patent Document 6 discloses that silica is added as a slag forming agent to a composition composed of a fuel such as guanidine nitrate, a metal oxide such as basic copper nitrate, alumina, etc. to produce a good slag (clinker). Has been. Patent Document 7 discloses that a glass powder is added to a fuel such as a tetrazole compound and strontium nitrate to lower the combustion temperature, and as a result, NOx and CO are reduced, and solid slag is formed. Has been. Patent Document 8 discloses that mist is reduced by mixing and using alkali metal azide, pellets made of an oxidizing agent, and particles made of a silica-containing substance.
US Pat. No. 4,909,549 U.S. Pat. No. 4,370,181 US Pat. No. 4,369,079 US Pat. No. 5,542,999 US Pat. No. 5,608,183 US Pat. No. 6,143,102 Special table hei 10-502610 US Pat. No. 5,104,466 (Japanese Patent Laid-Open No. 5-70109)

  It is an object of the present invention to provide a novel gas generant composition that can form slag more easily than the above-described prior art composition.

  As a means for solving the problems, the present invention provides a gas generant composition comprising (a) glass powder and (b) aluminum hydroxide and / or magnesium hydroxide.

  Furthermore, this invention provides the gas generating composition characterized by containing the following (a)-(d) component as another solution means of a subject.

(A) Glass powder (b) Aluminum hydroxide and / or magnesium hydroxide (c) Organic compound as fuel (d) Oxygen-containing oxidizer The present invention provides the above gas generating agent as another means for solving the problems. A single-hole cylindrical or porous cylindrical molded body obtained from the composition is provided. The single hole or porous molded body may be a through hole or a non-through hole.

  Furthermore, the present invention provides an inflator for an air bag using the gas generating composition and the molded body as a means for solving other problems.

  Since the gas generating composition of the present invention and the molded body thereof contain glass powder, the combustion residue is solidified to form slag, so that the combustion residue becomes mist and is released outside the inflator. Is prevented. This effect is further enhanced by the combined use of glass powder and aluminum hydroxide and / or magnesium hydroxide.

  The glass powder of component (a) used in the present invention is in a molten state at the time of combustion of the gas generant composition, and instantly solidifies as the temperature decreases after combustion. In this process, combustion residues derived from other components are melted and solidified to trap and form slag. For this reason, it can prevent that a combustion residue turns into mist, is discharge | released outside the inflator, and flows in into an airbag.

  The glass powder is preferably an amorphous material composed of a mixture of a metal oxide and / or a nonmetal oxide. The metal oxide is preferably selected from silicon dioxide, sodium oxide, potassium oxide, calcium oxide, magnesium oxide, barium oxide, lead oxide, boron oxide, aluminum oxide and the like. The non-metal oxide is preferably selected from phosphorus oxide, tellurium oxide, and bismuth oxide.

  Glass powders include quartz glass, 96% quartz glass, soda lime glass (window glass, plate glass, bottle glass, light bulbs, etc.), lead glass (electrical, optical, industrial use, etc.), aluminoborosilicate glass, borosilicate Those selected from acid glass (low expansion, low loss, tungsten sealing, etc.), aluminosilicate glass, phosphate glass, chalcogenide glass and the like are preferable.

  In particular, since these various glass powders have different softening points depending on their compositions, the softening point is optimal in accordance with the combustion temperature of the composition in combination with an organic compound as a fuel, an oxygen-containing oxidant, and other additives. It is desirable to select a glass powder that falls within the range. In the present invention, it is preferable to use a glass powder having a particularly low softening point, preferably a softening point of 1000 ° C. or lower, more preferably 590 ° C. or lower, and even more preferably 550 ° C. or lower. When glass powder having a low softening point is used, the slag forming effect is enhanced, so that it is difficult to generate mist.

As such a glass having a low softening point, phosphate glass (including P ₂ O ₅ , CaO, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , MgO, Na ₂ O, which include those selected from K 2 _O, etc.) can be used those represented by the following general formula (I).

_{xMnO-ySiO 2 -zAl 2 O 3} (I)
[Wherein, x, y and z represent the number of moles of each. ]
The ratio of x, y and z in the general formula (I) is such that x is 35 to 50 mol%, y is 30 to 60 mol%, z is preferably 5 to 20 mol%, x is 40 to 45 mol%, More preferably, y is 40 to 50 mol% and z is 10 to 15 mol%.

  The particle size of the glass powder is preferably 10 to 300 μm, more preferably 10 to 100 μm, and still more preferably 10 to 50 μm as a 50% particle size.

  The content of the glass powder in the gas generant composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 5% by mass. When the content of the glass powder is within the above range, the slag forming action as described above is suitably exhibited without significantly reducing the gas generation efficiency of the composition.

  The component (b) aluminum hydroxide and magnesium hydroxide used in the present invention can be used alone or in combination. As the component (b), magnesium hydroxide is preferable.

  The components (b), aluminum hydroxide and magnesium hydroxide, have low toxicity, high decomposition start temperature, and when thermally decomposed, they absorb a large amount of heat and produce aluminum oxide or magnesium oxide and water. For this reason, the inclusion of aluminum hydroxide and / or magnesium hydroxide lowers the combustion temperature of the gas generant composition and reduces the amount of toxic nitrogen oxides and carbon monoxide produced after combustion. In addition, aluminum oxide or magnesium oxide produced by the decomposition of aluminum hydroxide or magnesium hydroxide has a slag forming action together with the glass powder of component (a).

The content of aluminum hydroxide and / or magnesium hydroxide in the gas generant composition is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass. When the content of aluminum hydroxide and / or magnesium hydroxide is within the above range, the production of toxic nitrogen oxides and carbon monoxide can be reduced as the combustion temperature decreases, and it can be applied to inflators for airbags. In this case, it is possible to secure the combustion speed necessary for inflating and deploying the airbag within the required time.

  The gas generant composition of the present invention is a four-component system comprising (a) glass powder, (b) aluminum hydroxide and / or magnesium hydroxide, (c) an organic compound as fuel, and (d) an oxygen-containing oxidant. Can be.

  Examples of the organic compound as the component (c) fuel include one or more selected from tetrazole compounds, guanidine compounds, triazine compounds, and nitroamine compounds.

  Examples of the tetrazole compounds include 5-aminotetrazole and bitetrazole ammonium salt. Examples of the guanidine compounds include guanidine nitrate, mono-, di- or triaminoguanidine nitrate, nitroguanidine and the like. Examples of the triazine compound include melamine, cyanuric acid, ammelin, ammelide, ammeland and the like.

   Examples of the oxygen-containing oxidizing agent (d) include one or more selected from nitrates, perchlorates, chloric acids, basic metal nitrates, and ammonium nitrates.

  Examples of the nitrate include alkali metal nitrates such as potassium nitrate and sodium nitrate, and alkaline earth metal nitrates such as strontium nitrate. Examples of perchlorates include potassium perchlorate, sodium perchlorate, magnesium perchlorate, and ammonium perchlorate. Examples of the basic metal nitrate include basic copper nitrate.

  When the gas generant composition of the present invention is a four-component system of the components (a) to (d), the content of the component (a) is preferably 0.1 to 20% by mass, more preferably 1 to 10%. The content of component (b) is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass; the content of component (c) is preferably 30 to 60% by mass, and more preferably. 35 to 50 mass%; The content of the component (d) is preferably 30 to 60 mass%, more preferably 40 to 55 mass%.

  As a preferred embodiment of the quaternary gas generant composition, (a) glass powder, (b) aluminum hydroxide and / or magnesium hydroxide, (c) guanidine nitrate, and (d) basic copper nitrate are used. The thing to contain is mentioned. The content in this case is (a) 2-6% by mass of glass powder, (b) 1-10% by mass of aluminum hydroxide and / or magnesium hydroxide, (c) 30-60% by mass of guanidine nitrate, (d) 30-60 mass% of basic copper nitrate is preferable.

  Other preferred embodiments of the quaternary gas generant composition include (a) glass powder, (b) aluminum hydroxide and / or magnesium hydroxide, (c) nitroguanidine, and (d) basic copper nitrate. The thing containing is mentioned. The content in this case is (a) 1-5% by mass of glass powder, (b) 1-15% by mass of aluminum hydroxide and / or magnesium hydroxide, (c) 25-60% by mass of nitroguanidine, (d) 30-60 mass% of basic copper nitrate is preferable.

  The gas generating composition of the present invention includes the components (a) and (b) but no binder, the four-component system (a) to (d), or the components (a) to (d), ( If the molding strength of the molded product is not strong when it is made of the additive of component f) and the component (g) silicon dioxide, and the molded product is not strong, the molded product will collapse and burn out of control. There is a risk that combustion cannot be controlled. Therefore, it is preferable to add a binder of component (e).

  As the binder of component (e), carboxymethyl cellulose (CMC), carboxymethyl cellulose sodium salt (CMCNa), carboxymethyl cellulose potassium salt, carboxymethyl cellulose ammonium salt, cellulose acetate, cellulose acetate butyrate (CAB), methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), ethyl hydroxyethyl cellulose (EHEC), hydroxypropyl cellulose (HPC), carboxymethyl ethyl cellulose (CMEC), microcrystalline cellulose, polyacrylamide, polyacrylamide amination, polyacryl hydrazide, acrylamide・ Acrylic acid metal salt copolymer, polyacrylamide ・ polyacrylic acid ester compound Copolymers, polyvinyl alcohol, acrylic rubber, guar gum, starch, one or more selected from silicone. Among these, carboxymethylcellulose sodium salt (CMCNa) and guar gum are preferable in view of the adhesive performance, price, ignitability, and the like of the binder.

  When the binder of the component (e) is combined with the component (b), particularly aluminum hydroxide, the content of the binder of the component (e) is preferably 1.0 to 5.0 mass in the gas generant composition. %, More preferably 1.5 to 3.5% by mass, since the combustion gas can be cleaned without impairing moldability.

  The gas generating composition of the present invention includes (a) and (b) components but no additives, (a) to (d) four-component systems, or (a) to (d) components, When a 6-component system containing (e) component binder and (g) component silicon dioxide is used, the additive of (f) component may be added for the purpose of assisting the action of components (a) and (b). preferable.

  (F) Component additives include metal oxides such as copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, gallium oxide, silica, and alumina; cobalt carbonate, carbonic acid Metal carbonate or basic metal carbonate such as calcium, magnesium carbonate, basic zinc carbonate, basic copper carbonate; metal oxide or hydroxide such as acid clay, kaolin, talc, bentonite, diatomaceous earth, hydrotalcite 1 or 2 or more selected from metal acid salts such as sodium silicate, mica molybdate, cobalt molybdate, and ammonium molybdate, molybdenum disulfide, calcium stearate, silicon nitride, and silicon carbide. These additives can lower the combustion temperature of the gas generating agent, adjust the combustion rate, and reduce the amount of toxic nitrogen oxides and carbon monoxide produced after combustion.

  The gas generant composition of the present invention is a four-component system comprising the components (a) to (d), or six components including the components (a) to (d), the binder (e), and the additive (f). In order to improve the ignitability of the component (c), it is preferable to add silicon dioxide as the component (g). In particular, when a guanidine compound is used as the component (c), the effect of improving ignitability is high.

Component (g) of silicon dioxide has a specific surface area of 100 to 500 m ² / g, preferably from 150 to 300 m ² / g. The specific surface area is measured by the BET method.

  When the gas generant composition of the present invention is made from 5 to 7 component systems (a) to (g), the content of the component (a) is preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass; the content of component (b) is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass; and the content of component (c) is preferably 5 to 60% by mass. %, More preferably 10-55% by mass; (d) component content is preferably 10-85% by mass, more preferably 20-75% by mass; (e) component content is preferably 20% by mass The content of the component (f) is preferably 20% by mass or less; the content of the component (g) is 5% by weight or less.

  Preferred embodiments of the five-component gas generant composition include (a) glass powder as component, (b) aluminum hydroxide and / or magnesium hydroxide as component, (c) nitroguanidine as component (d) ) Strontium nitrate as the component, and (e) those containing carboxymethylcellulose sodium salt or guar gum as the component.

  Other preferred embodiments of the five-component gas generant composition include (a) glass powder as component, (b) aluminum hydroxide and / or magnesium hydroxide as component, (c) nitroguanidine as component, (D) What contains basic copper nitrate as a component and (e) a component containing guar gum as a component.

  Other preferred embodiments of the five-component gas generant composition include (a) glass powder as component, (b) aluminum hydroxide and / or magnesium hydroxide as component, (c) melamine as component, Examples include d) basic copper nitrate as component, and (e) component containing carboxymethylcellulose sodium salt or guar gum.

  Other preferred embodiments of the five-component gas generant composition include (a) glass powder as component, (b) aluminum hydroxide and / or magnesium hydroxide as component, (c) guanidine nitrate as component, (D) What contains basic copper nitrate as a component, and what contains carboxymethylcellulose sodium salt or guar gum as (e) component.

  Preferred embodiments of a gas generant composition of 5 or more components include (a) glass powder as component, (b) aluminum hydroxide and / or magnesium hydroxide as component, (c) guanidine nitrate as component, Two or three component fuels selected from nitroguanidine and melamine, (d) basic copper nitrate as component, and (e) containing carboxymethylcellulose sodium salt or guar gum.

  As another preferred embodiment, in addition to the gas generant composition containing the above (a) to (e), one containing silicon dioxide as the component (g) can be mentioned.

  The gas generant composition of the present invention can be molded into a desired shape, and can be formed into a single-hole cylindrical, porous cylindrical, or pellet-shaped molded body. These molded products are prepared by adding water or an organic solvent to the gas generating composition, mixing and extruding (single-hole cylindrical or porous cylindrical molded body) or compression molding using a tableting machine or the like. It can be manufactured by (pellet-shaped molded body).

  The gas generant composition of the present invention or a molded product obtained therefrom includes, for example, an air bag inflator for various vehicles, an air bag inflator for a passenger seat, a side air bag inflator, an inflatable curtain inflator, and a knee bolster. It can be applied to an inflator for an inflator, an inflator for an inflatable seat belt, an inflator for a tubular system, and a gas generator for a pretensioner.

  The inflator using the gas generant composition of the present invention or a molded product obtained therefrom is a hybrid in which the gas supply is a pyrotype only from the gas generant, and a compressed gas such as argon and the gas generant. Any type.

  Furthermore, the gas generant composition of the present invention or a molded product obtained therefrom can be used as an igniting agent called an enhancer (or booster) for transmitting the energy of the detonator or squib to the gas generant.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited by these.

Examples 1-6, Comparative Example 1
Gas generant compositions having the compositions shown in Table 1 were prepared, and these compositions were molded into 2 g strands. The strand was attached to a sealed bomb with an internal volume of 1 liter, and the inside of the bomb was replaced with nitrogen. Then, the strand was further pressurized to 6860 kPa with nitrogen, and the strand was ignited by energization with a nichrome wire and completely burned. After combustion, the combustion residue was taken out from the bomb, and the state thereof was visually observed.

  In Table 1, GN is guanidine nitrate, BCN is basic copper nitrate, CMCNa is carboxymethylcellulose sodium salt, and # 1723 and # 7056 are glass powders having the following composition.

# 1723 (aluminosilicate glass; softening point 908 ° C.) (mass%): SiO ₂ (57) / Al ₂ O ₃ (16) / B ₂ O ₃ (4) / MgO (7) / CaO (10) / BaO (6) (softening point 908 ° C)
# 7056 (borosilicate glass; softening point 718 ° C.) (mass%): SiO ₂ (68) / Al ₂ O ₃ (3) / B ₂ O ₃ (18) / LiO ₂ (1) / Na ₂ O (1 ) / K ₂ O (9) (softening point 718 ° C.)
# C-490P (phosphate glass; softening point about 400 ° C.) (mass%): P ₂ O ₅ (54-56) / Al ₂ O ₃ (9-11) / Na ₂ O (19-21) / K ₂ O (14-16)
# C-700P (phosphate glass; softening point about 640 ° C.) (mass%): P ₂ O ₅ (50.5) / Al ₂ O ₃ (14.5) / Na ₂ O (20) / K ₂ O (15)

In Examples 1-6, the strand after combustion maintained the same shape as before combustion, but in Comparative Example 1, it was broken finely after combustion.

Claims (20)

  A gas generating composition comprising (a) glass powder and (b) aluminum hydroxide and / or magnesium hydroxide. A gas generant composition comprising the following components (a) to (d):
(A) glass powder (b) aluminum hydroxide and / or magnesium hydroxide (c) organic compound as fuel (d) oxygen-containing oxidant Furthermore, the gas generating composition of Claim 1 or 2 containing 1 or 2 or more chosen from the group which consists of the following (e) component, (f) component, and (g) component as needed.
(E) Binder (f) Additive selected from metal oxide and metal carbonate (g) Silicon dioxide having a specific surface area of 100 to 500 m ² / g   (A) Component content is 0.1-20% by mass, (b) component content is 0.1-20% by mass, (c) component content is 30-60% by mass, (d) component The content of (e) is 10% by mass or less, the content of (f) component is 10% by mass or less, and the content of (g) component is 5% by mass or less. Item 4. The gas generant composition according to Item 2 or 3.   The gas generant composition according to any one of claims 1 to 4, wherein the glass powder of component (a) is an amorphous material composed of a mixture of a metal oxide and / or a nonmetal oxide.   The gas generant composition according to claim 5, wherein the metal oxide is selected from silicon dioxide, sodium oxide, potassium oxide, calcium oxide, magnesium oxide, barium oxide, lead oxide, boron oxide, and aluminum oxide.   (A) The glass powder of the component is selected from quartz glass, 96% quartz glass, soda lime glass, lead glass, aluminoborosilicate glass, borosilicate glass, aluminosilicate glass, phosphate glass, chalcogenide glass The gas generant composition according to any one of claims 1 to 6. The gas generating composition according to any one of claims 1 to 6, wherein the glass powder of component (a) is represented by the following general formula (I).
_{xMnO-ySiO 2 -zAl 2 O 3} (I)
[Wherein, x, y and z represent the number of moles of each. ]   The gas generating composition according to claim 8, wherein the ratio of x, y, and z in the general formula (I) is such that x is 35 to 50 mol%, y is 30 to 60 mol%, and z is 5 to 20 mol%. Stuff.   The gas generant composition according to any one of claims 2 to 9, wherein the fuel of component (c) is one or more selected from tetrazole compounds, guanidine compounds, triazine compounds, and nitroamine compounds.   The gas generating agent according to any one of claims 2 to 10, wherein the oxygen-containing oxidant as component (d) is one or more selected from nitrate, perchlorate, chloric acid, basic metal nitrate, and ammonium nitrate. Composition.   (E) Component binder is carboxymethyl cellulose, carboxymethyl cellulose sodium salt, carboxymethyl cellulose potassium salt, carboxymethyl cellulose ammonium salt, cellulose acetate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, carboxy Methyl ethyl cellulose, microcrystalline cellulose, polyacrylamide, polyacrylamide amination, polyacryl hydrazide, acrylamide / metal acrylate copolymer, polyacrylamide / polyacrylate copolymer, polyvinyl alcohol, acrylic rubber, 1 or 2 selected from guar gum, starch and silicone The gas generating composition according to any one of claims 3 to 11 is a top.   (F) Component additive is cupric oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, gallium oxide, silica, metal oxide containing alumina, cobalt hydroxide Metal hydroxide containing iron hydroxide; metal carbonate or basic metal carbonate containing cobalt carbonate, calcium carbonate, magnesium carbonate, basic zinc carbonate, basic copper carbonate; acid clay, kaolin, talc, bentonite, Metal oxides or hydroxide complex compounds including diatomaceous earth, hydrotalcite; metal acid salts such as sodium silicate, mica molybdate, cobalt molybdate, ammonium molybdate; silicone, molybdenum disulfide, calcium stearate, It is 1 or 2 or more chosen from silicon nitride and silicon carbide. The gas generating composition according to any Re.   The gas generation according to any one of claims 1 to 13, wherein the component (b) is aluminum hydroxide, and the content of the binder of the component (e) in the gas generant is 1.0 to 5.0% by mass. Agent composition.   A gas generating composition containing glass powder, guanidine nitrate and basic copper nitrate.   A gas generating composition containing glass powder, a mixed fuel containing guanidine nitrate, and basic copper nitrate.   The gas generation according to claim 16, wherein the mixed fuel containing guanidine nitrate is a mixed fuel of guanidine nitrate and one or more selected from nitroguanidine, melamine, monoaminoguanidine nitrate, diaminoguanidine nitrate, and triaminoguanidine nitrate. Agent composition.   Furthermore, the gas generating composition in any one of Claims 15-17 containing aluminum hydroxide and / or magnesium hydroxide.   A single-hole cylindrical or porous cylindrical gas generant composition molded body obtained by extrusion molding the gas generant composition according to any one of claims 1 to 18. An inflator for an air bag using the gas generant composition according to any one of claims 1 to 18 or the gas generant molded article according to claim 19.