JP4294331B2 - Production method of gas generant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a gas generating agent suitable for a gas generator for an air bag.
[0002]
[Prior art]
A gas generating agent used in a gas generator for an air bag is generally manufactured by wet mixing using a fuel, an oxidant, and various additives from the viewpoint of preventing ignition of the fuel. When the wet mixing method is applied, it is important to volatilize and remove the used solvent and to uniformly disperse each component. The following are known as prior arts for the method for producing a gas generating agent.
[0003]
[Patent Document 1]
USP 4,997,497
[Patent Document 2]
USP 6,110,308
[0004]
US Pat. No. 4,997,497 discloses a method for producing a composition that produces colored smoke, in which a component containing a curing agent is mixed under vacuum and then cured at 160 ° F. overnight. However, there is no disclosure about the significance of mixing under vacuum, and there is no suggestion about volatilization removal of the solvent.
[0005]
USP 6,110,308 describes a process in which the solvent is recovered under a weak vacuum after the explosive component mixing is complete.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a gas generating agent that efficiently mixes and recovers a solvent in a short time.
[0007]
[Means for Solving the Problems]
As a means for solving the problems, the present invention provides a method for producing a gas generating agent characterized by mixing a fuel, an oxidant and, if necessary, an additive and a solvent under reduced pressure.
[0008]
As another means for solving the problems, the present invention provides a method for producing a gas generating agent characterized by mixing a fuel, an oxidant and, if necessary, an additive and a solvent under reduced pressure and heating. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the production method of the present invention, the fuel, the oxidant and, if necessary, the additive and the solvent are mixed under reduced pressure, or are mixed under reduced pressure and warming.
[0010]
The degree of reduced pressure during mixing is preferably 13.3 kPa or less, more preferably 9.3 kPa or less, and still more preferably 5.3 kPa or less.
[0011]
The heating temperature during mixing is preferably 40 ° C to 90 ° C, more preferably 60 to 85 ° C, and still more preferably 70 to 80 ° C.
[0012]
Thus, by mixing under reduced pressure, or mixing under reduced pressure and warming, while ensuring safety, the solvent volatilization time can be shortened and the dispersibility of each component can be increased. .
[0013]
The production method of the present invention can be applied as a production method of a gas generating agent using a known fuel, an oxidant, and, if necessary, an additive.
[0014]
Examples of the gas generating agent include smokeless explosives, explosives mainly composed of nitrates, and explosives mainly composed of perchlorates, as well as the following fuels, oxidizing agents, and additives as required. Things can be mentioned.
[0015]
Nitrogen-containing compounds include tetrazole derivatives such as 5-aminotetrazole and 5,5′-bitetrazole diammonium salts, bitetrazole derivatives such as bitetrazole diammonium salts, triazole derivatives such as 4-aminotriazole, dicyandiamide, nitroguanidine , Guanidine derivatives such as guanidine nitrate, triazine derivatives such as trihydrazinotriazine, oxamide, ammonium oxalate, azodicarbonamide, hydrazodicarbonamide, melamine, melamine cyanurate, cobalt (III) hexaammine nitrate, RDX, nitrified cotton 1 or 2 or more selected from the above.
[0016]
Examples of the guanidine derivative include one or more selected from guanidine, mono-, di- or triaminoguanidine nitrate, guanidine nitrate, guanidine carbonate, nitroguanidine (NQ), dicyandiamide (DCDA), and nitroaminoguanidine nitrate, and among these, nitroguanidine Dicyandiamide is preferred.
[0017]
Oxidizing agents include nitrates such as basic metal nitrates, alkali metal nitrates and alkaline earth metal nitrates such as strontium nitrate, oxyacid salts, metal oxides, metal double oxides, metal hydroxides and metal peroxides. One or more selected may be mentioned.
[0018]
Basic metal nitrates are a series of compounds generally represented by the following formula. Further, there may be a compound further containing water of hydration. Where M is the metal, x ′ is the number of metals, y, y ′ is the number of NO ₃ ions, z ′ is the number of OH ions, and n is the M (OH) _z part relative to the M (NO ₃ ) _y part. The ratio is shown.
[0019]
M (NO ₃ ) _y · nM (OH) _z or M _{x ′} (NO ₃ ) _{y ′} (OH) _{z ′}
Examples of those corresponding to the above formula include basic copper nitrate [(BCN) Cu ₂ (NO ₃ ) (OH) ₃ , which contains copper, cobalt, zinc, manganese, iron, molybdenum, bismuth, cerium as the metal M, _{Cu 3 (NO 3) (OH} ) 5 · 2H 2 O ], basic cobalt nitrate _{[Co 2 (NO 3) (OH} ) 3 ], basic zinc nitrate _{[Zn 2 (NO 3) (OH} ) 3 ], basic manganese nitrate _{[Mn (NO 3) (OH)} 2 ], basic iron nitrate _{[Fe 4 (NO 3) (OH} ) 11 · 2H 2 O ], basic molybdenum nitrate, basic bismuth nitrate [Bi (NO ₃ ) (OH) ₂ ] and one or more selected from basic cerium nitrate [Ce (NO ₃ ) ₃ (OH) · 3H ₂ O]. Among these, basic copper nitrate is preferred.
[0020]
Basic copper nitrate is superior in thermal stability because it has no phase transition in the operating temperature range and has a high melting point as compared with ammonium nitrate as an oxidizing agent. Furthermore, since basic copper nitrate acts to lower the combustion temperature of the gas generating agent, the amount of nitrogen oxide produced can be reduced.
[0021]
Oxygenates include ammonium, alkali metal, alkaline earth metal, alkaline earth metal complex, transition metal and transition metal nitrates (ammonium nitrate, sodium nitrate, potassium nitrate, strontium nitrate), nitrite, chlorate or peroxy Chlorates (potassium perchlorate, ammonium perchlorate, etc.) can be mentioned.
[0022]
Metal oxide, metal double oxide and metal hydroxide include copper [copper oxide (I) and copper oxide (II)], cobalt, iron, manganese, nickel, zinc, molybdenum and bismuth oxide, double oxide Or a hydroxide.
[0023]
Examples of metal peroxides include magnesium, calcium, and strontium peroxides, such as MgO2, CaO2, and SrO2.
[0024]
As the oxidizing agent, among them, potassium perchlorate, ammonium perchlorate, ammonium nitrate, sodium nitrate, potassium nitrate, strontium nitrate, basic copper nitrate, copper oxide (I), copper oxide (II) or A combination of two or more is more desirable.
[0025]
When the gas generating agent contains a fuel and an oxidizing agent, the content of the fuel is preferably 5 to 60% by weight, and more preferably 15 to 55% by weight. The content of the oxidizing agent is preferably 40 to 95% by weight, and more preferably 45 to 85% by weight.
[0026]
As additives, carboxymethylcellulose (CMC), carboxymethylcellulose sodium salt (CMCNa), carboxymethylcellulose potassium salt, carboxymethylcellulose ammonium salt, cellulose acetate, cellulose acetate butyrate (CAB), methylcellulose (MC), ethylcellulose (EC), Hydroxyethylcellulose (HEC), Ethylhydroxyethylcellulose (EHEC), Hydroxypropylcellulose (HPC), Carboxymethylethylcellulose (CMEC), Microcrystalline cellulose, Polyacrylamide, Polyacrylamide amination, Polyacrylhydrazide, Acrylamide metal acrylate Salt copolymers, copolymers of polyacrylamide / polyacrylate compounds, Livinyl alcohol, acrylic rubber, guar gum, starch, silicone, molybdenum disulfide, acid clay, talc, bentonite, diatomaceous earth, kaolin, calcium stearate, silica, alumina, sodium silicate, silicon nitride, silicon carbide, hydrotalcite, One or more kinds selected from mica, nitrates (KNO ₃ , NaNO ₃ etc.), perchlorates (KClO ₄ etc.), metal oxides, metal hydroxides, metal carbonates, basic metal carbonates and molybdates Is mentioned.
[0027]
Examples of the metal oxide include one or more selected from copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, and bismuth oxide. Examples of the metal hydroxide include cobalt hydroxide, 1 or more types chosen from aluminum hydroxide are mentioned, As metal carbonate and basic metal carbonate, calcium carbonate, cobalt carbonate, basic zinc carbonate, basic copper carbonate, basic cobalt carbonate, basic iron carbonate 1 or more types chosen from basic bismuth carbonate and basic magnesium carbonate are mentioned, As a molybdate, 1 or more types chosen from cobalt molybdate and ammonium molybdate are mentioned. These compounds can act as slag formers and / or binders. The binder preferably has a 1% by weight aqueous solution having a viscosity of 100 to 10,000 mPas.
[0028]
As the binder, a water-soluble cellulose compound is desirable, and among them, carboxymethylcellulose sodium salt and guar gum are preferable.
[0029]
Aluminum hydroxide is desirable because it has the effect of lowering the generated gas and reducing toxic components while maintaining the combustion reaction.
[0030]
In order to enhance the ignitability of the gas generating agent, carboxymethyl cellulose sodium salt and potassium salt are preferable, and among these, sodium salt is more preferable.
[0031]
When the gas generating agent contains a fuel, an oxidant, and an additive, the content of the fuel is preferably 5 to 60% by weight, and more preferably 15 to 55% by weight. The content of the oxidizing agent is preferably 40 to 95% by weight, and more preferably 45 to 85% by weight. The content of the additive is preferably 0.1 to 25% by weight, more preferably 0.1 to 15% by weight, and further preferably 0.1 to 10% by weight.
[0032]
In the production method of the present invention, a combustion regulator (combustion improver) can be further blended. The combustion improver is a component that acts to improve the combustibility such as the combustion rate, the sustainability of combustion, and the ignitability of the gas generating agent as a whole.
[0033]
Combustion improvers include silicon nitride, alkali metal or alkaline earth metal nitrites, nitrates, chlorates or perchlorates (KNO ₃ , NaNO ₃ , KClO ₄ etc.), iron oxide hydroxide (III) [ FeO (OH)], copper oxide, iron oxide, zinc oxide, cobalt oxide, or manganese oxide can be mentioned. Among these, when iron oxide hydroxide (III) [FeO (OH)] is used, the binder has an excellent combustion promoting effect when a binder having a large number of carbons is blended, and the combustion of the entire gas generant is promoted. Can contribute.
[0034]
1-10 mass parts is preferable with respect to 100 mass parts of fuel and an oxidizing agent or the total amount of a fuel, an oxidizing agent, and an additive, and, as for the compounding quantity of a combustion improving agent, 1-5 mass parts is more preferable.
[0035]
As the solvent, one or more selected from water, acetone, ethyl acetate, diethyl ether, methanol, ethanol and isopropanol can be used.
[0036]
The solvent added in the initial stage is preferably 5 to 100 parts by mass, more preferably 40 to 60 parts by mass with respect to 100 parts by mass of the fuel, the oxidant, and the additives blended as necessary.
[0037]
If the amount of the solvent added is too large, the dissolved components contained in the raw material components will dissolve too much, and the resulting gas generant may not exhibit the prescribed performance, or it may take too much time to volatilize by the amount of the amount. is there.
[0038]
If the concentration of the solvent is too low, some of the dissolved components that act as binders are not sufficiently dissolved and dispersed, which may impair the mixing properties. As the solvent, it is desirable to select and use a solvent in which a part of the soluble component serving as a binder in the raw material component is dissolved.
[0039]
The gas generating agent obtained by the present invention includes, for example, an airbag inflator for driver seats of various vehicles, an airbag inflator for passenger seats, an inflator for side airbags, an inflator for inflatable curtains, an inflator for knee bolsters, and an inflatable seat. It can be applied to inflators for belts, inflators for tubular systems, and gas generators for pretensioners.
[0040]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited by these.
[0041]
Example 1
Warm water at 80 ° C. was passed through the jacket to adjust the temperature of the mixer of the Werner type kneader (Werner type kneader 10L type with fishtail stirring blades manufactured by Satake Chemical Machinery Industry).
[0042]
Next, after adding 45 parts by mass of ion-exchanged water to a total of 100 parts by mass of 49.5% by mass of nitroguanidine, 55.5% by mass of basic copper nitrate, and 5% by mass of guar gum in the mixer, While stirring the stirring blades and stirring the high speed side at 20 rpm and the low speed side at 9 rpm, the mixing was performed for 30 minutes in the normal rotation direction, that is, the direction in which the stirring blades rotated outward.
[0043]
Next, the temperature of the hot water was lowered to 40 ° C., the vacuum line was adjusted so that the degree of vacuum inside the mixer was 5.2 kPa, and stirring was performed for 2 hours.
[0044]
Next, it was drawn and drawn using a mold having an outer diameter of 3.2 mm, an inner diameter of 0.7 mm, and a length of 4 mm, and further cut, and then dried at 110 ° C. for 120 hours to obtain a gas generating agent.
[0045]
An inflator combustion evaluation test (60 L tank combustion test) was performed using the obtained gas generating agent. As a result, the tank curve [(pressure / time) curve] shown in FIG. 1 was obtained, and it was confirmed that the necessary performance as an inflator could be exhibited.
[0046]
Example 2
A gas generating agent was produced in the same manner as in Example 1. However, the mixing agent was obtained after 1 hour at 70 ° C. in the mixer jacket temperature in the vacuum evaporation stage. When this was molded and dried by the same method as in Example 1 and then the inflation combustion was evaluated, the same results as in Example 1 were obtained.
[0047]
Example 3
A gas generating agent was produced in the same manner as in Example 1. However, the mixing agent was obtained after 45 minutes at 90 ° C. in the mixer jacket temperature in the vacuum evaporation stage. When this was molded and dried by the same method as in Example 1 and then the inflation combustion was evaluated, the same results as in Example 1 were obtained.
[0048]
Example 4
A gas generating agent was produced in the same manner as in Example 1. However, a mixed drug was obtained after 1 hour and 20 minutes at a mixer jacket temperature of 70 ° C. and a vacuum of 13.3 kPa at the vacuum evaporation stage. When this was molded and dried by the same method as in Example 1 and then the inflation combustion was evaluated, the same results as in Example 1 were obtained.
[0049]
Example 5
A gas generating agent was produced in the same manner as in Example 1. However, the mixture jacket was obtained after 1 hour at 90 ° C. and 13.3 kPa at the mixer jacket temperature in the vacuum volatilization stage. When this was molded and dried by the same method as in Example 1 and then the inflation combustion was evaluated, the same results as in Example 1 were obtained.
[0050]
Comparative Example 1
A gas generating agent was produced in the same manner as in Example 1. However, in the volatilization stage, it was carried out under normal pressure conditions by simply opening the lid instead of the vacuum type. At this time, the mixer jacket temperature was 40 ° C., but even after 3 hours, the water content did not reach the predetermined level, and the nitroguanidine was still present in a white mass with a diameter of several millimeters. It was confirmed by visual observation that the dispersibility was not sufficient.
[0051]
Comparative Example 2
A gas generating agent was produced in the same manner as in Example 1. However, in the volatilization stage, it was carried out under normal pressure conditions by simply opening the lid instead of the vacuum type. At this time, the mixer jacket temperature was 70 ° C., but even after 2 hours had passed, the water content did not reach a predetermined level, and a mixed drug was finally obtained after 3 hours. When this was molded and dried by the same method as in Example 1 and then the inflation combustion was evaluated, the same results as in Example 1 were obtained.
[0052]
【The invention's effect】
According to the production method of the present invention, the gas generating agent can be industrially produced under mixing conditions that do not require special reaction equipment and can be easily controlled. Furthermore, when the gas generating agent obtained by the production method of the present invention is used for an inflator, it can obtain a predetermined performance with good reproducibility.
[Brief description of the drawings]
1 is a pressure / time curve obtained by a 60 L tank combustion test in Examples 1 to 5 and Comparative Example 2. FIG.

Claims (9)

And wherein the fuel, those containing 5-100 parts by weight of water relative to the oxidant及beauty added pressure agent 100 parts by weight, the mixing with heating under the following reduced pressure and 40 ° C. to 90 ° C. 13.3 kPa A method for producing a gas generating agent , wherein the additive is a water-soluble cellulose compound serving as a binder . Fuel, relative to 100 parts by weight of oxidizing agent及beauty added pressure agent, method for producing the gas generating agent according to claim 1, wherein the mixing those containing solvent 40-60 parts by weight.   The method for producing a gas generating agent according to claim 1 or 2, wherein the gas generating agent is a smokeless explosive, an explosive mainly composed of nitrate, or an explosive mainly composed of perchlorate.   One or more fuels selected from nitroguanidine, guanidine nitrate, dicyandiamide, 5 aminotetrazole, melamine, melamine cyanurate, cobalt (III) hexaammine nitrate, 5,5'-bitetrazole diammonium salt, RDX and nitrified cotton The method for producing a gas generating agent according to any one of claims 1 to 3.   The oxidizing agent is one or more selected from potassium perchlorate, ammonium perchlorate, ammonium nitrate, sodium nitrate, potassium nitrate, strontium nitrate, basic copper nitrate, copper oxide (I) and copper oxide (II). The manufacturing method of the gas generating agent of any one of 1-4. Gas generating agent is gunpowder which mainly nitrate, preparation of the gas generating agent according to claim 1 or 2. Fuel nitroguanidine, the oxidizing agent is strontium nitrate, the additive is carboxymethyl cellulose sodium salt and acidic white soil, method of producing the gas generating composition according to claim 1 or 2. Fuel nitroguanidine, the oxidizing agent is a basic copper nitrate, the additive is Guaga beam method for producing a gas generating agent according to claim 1 or 2. Fuel guanidine nitrate, basic copper nitrate is an oxidizing agent, the additive is sodium carboxymethyl cellulose and hydroxide aluminum, the preparation of the gas generating agent according to claim 1 or 2.

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