JP5022157B2 - Gas generant composition - Google Patents

Description

  The present invention relates to a gas generant composition that can be used in an inflator for a vehicle airbag device.

  Among inflators for vehicle airbag devices, those that use a gas generating agent as a gas generation source include a coolant filter for cooling the combustion gas. A coolant filter made of a metal wire is widely used, but it is the largest cause of the increase in mass of the inflator, and from the viewpoint of weight reduction, the coolant filter is required to be reduced.

  As a method for reducing the amount of the coolant filter, it is known to reduce the combustion temperature of the gas generating agent. Patent Document 1 discloses an invention for reducing the combustion temperature of the gas generating agent by adding glass powder. Are listed. However, glass powder is not satisfactory because it is expensive and increases the mass of the gas generant.

Patent Document 2 describes a gas generating agent in which aluminum hydroxide or the like and a phosphate are blended together with a fuel and an oxidizing agent as means for solving the problems in the case of using gas powder.
Japanese National Patent Publication No. 10-502610 JP 2006-76824 A

  The present invention provides a gas generant composition that can be used in an inflator for a vehicle airbag device and the like that can lower the combustion temperature and can also suppress the generation of harmful gases due to the contained components. Let it be an issue.

The invention of claim 1 includes (A) fuel, (B) an oxidant, and (C) a binder as means for solving the problem, and (D) phosphoric acid for lowering the combustion temperature. It contains basic magnesium carbonate and / or magnesium oxide as a component to form a reaction product with the salt and (E) the phosphorus oxide generated from the phosphate of component (D) by combustion. ,
Gas generator composition in which the number of phosphorus atoms (P) and the number of magnesium atoms (Mg) in the total amount of component (E) and component (D) are Mg number / P number ≧ 1.5 I will provide a.

  As a means for solving the problem, the invention according to claim 2 is characterized in that the phosphate for lowering the combustion temperature of component (D) is potassium dihydrogen phosphate, potassium monohydrogen phosphate, potassium triphosphate Sodium dihydrogen phosphate, sodium monohydrogen phosphate, tribasic sodium phosphate, calcium dihydrogen phosphate, calcium monohydrogen phosphate, tricalcium phosphate, magnesium dihydrogen phosphate, magnesium monohydrogen phosphate, tertiary phosphorus The gas generant composition according to claim 1, which is one or more selected from magnesium oxide, ammonium dihydrogen phosphate, ammonium monohydrogen phosphate, and ammonium magnesium phosphate.

  Invention of Claim 3 provides the gas generating composition of Claim 1 or 2 whose said Mg number / P number is 1.5-3.0 as a means for solving a subject.

  The invention according to claim 4 provides the gas generant composition according to claim 1 or 2, wherein the Mg number / P number is 1.5 to 2.0 as means for solving the problem.

  The gas generant composition of the present invention can reduce the combustion temperature, and can suppress the content of phosphorus oxide derived from phosphate, which is a component contained during combustion, in the combustion gas.

<(A) component>
Examples of the component (A) fuel used in the present invention include at least one nitrogen-containing organic compound selected from tetrazole compounds, guanidine compounds, triazine compounds, and nitroamine compounds.

  The tetrazole compound is preferably 5-aminotetrazole, bitetrazole ammonium salt or the like. The guanidine compound is preferably guanidine nitrate (guanidine nitrate), aminoguanidine nitrate, nitroguanidine, triaminoguanidine nitrate or the like. The triazine compound is preferably melamine, cyanuric acid, ammelin, ammelide, ammeland and the like. The nitroamine compound is preferably cyclo-1,3,5-trimethylene-2,4,6-trinitramine.

  10-70 mass% is preferable and, as for content of (A) component in a composition, 30-50 mass% is more preferable.

<(B) component>
The oxidizing agent of the component (B) used in the present invention can include at least one selected from basic metal nitrates, nitrates, ammonium nitrates, perchlorates and chlorates.

  The basic metal nitrate is at least selected from basic copper nitrate, basic cobalt nitrate, basic zinc nitrate, basic manganese nitrate, basic iron nitrate, basic molybdenum nitrate, basic bismuth nitrate, and basic cerium nitrate. One type can be mentioned.

  Examples of the nitrate include alkaline metal nitrates such as potassium nitrate and sodium nitrate, and alkaline earth metal nitrates such as strontium nitrate.

  Examples of the perchlorate and the chlorate include at least one selected from ammonium perchlorate, potassium perchlorate, sodium perchlorate, potassium chlorate, and sodium chlorate.

  The content of the component (B) in the composition is preferably 25 to 85% by mass, and more preferably 40 to 60% by mass.

<(C) component>
As the binder of component (C) used in the present invention, 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 product, poly Acrylic hydrazide, acrylamide / metal acrylate copolymer, polyacrylamide / polyacryl Copolymers of an ester compound, polyvinyl alcohol, acrylic rubber, may be mentioned guar gum, starch, one or more selected from silicone.

  0.1-15 mass% is preferable and, as for content of the binder which is (C) component in a composition, 1-10 mass% is more preferable.

<(D) component>
The component (D) used in the present invention is a component that acts to lower the combustion temperature of the gas generant composition.

(D) As a phosphate of a component,
Potassium dihydrogen phosphate, potassium monohydrogen phosphate, tribasic potassium phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, sodium triphosphate, calcium dihydrogen phosphate, calcium monohydrogen phosphate, third One or more selected from calcium phosphate, magnesium dihydrogen phosphate, magnesium monohydrogen phosphate, tertiary magnesium phosphate, ammonium dihydrogen phosphate, ammonium monohydrogen phosphate, ammonium magnesium phosphate are preferred, but others It is also possible to use one or two or more selected from these phosphates.

Other phosphates include
Sodium phosphite, hypophosphorous acid;
Sodium pyrophosphate, sodium acid pyrophosphate; calcium pyrophosphate, calcium acid pyrophosphate; potassium pyrophosphate, calcium pyrophosphate, magnesium pyrophosphate;
Sodium metaphosphate, potassium metaphosphate, magnesium metaphosphate, aluminum metaphosphate;
Sodium tripolyphosphate, sodium tetrapolyphosphate, sodium pentapolyphosphate, potassium tripolyphosphate, calcium dihydrogen pyrophosphate, calcium pyrophosphate;
Sodium ultraphosphate;
Can be mentioned.

  1-30 mass% is preferable, as for content of the phosphate which is (D) component in a composition, 5-20 mass% is more preferable, and 5-15 mass% is still more preferable.

<(E) component>
The basic magnesium carbonate and / or magnesium oxide of the component (E) used in the present invention is the phosphorus oxide and reaction product generated by the combustion of the gas generant composition and derived from the phosphate salt of the component (D). Is a component for reducing the amount of phosphorus oxide in the combustion gas.

  As the component (E), basic magnesium carbonate and magnesium oxide may be used alone or in combination. Further, if the proportion of basic magnesium carbonate and / or magnesium oxide in component (E) exceeds 50% by mass (preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass). As described above, other magnesium compounds may be used in combination, but the higher the proportion of basic magnesium carbonate and / or magnesium oxide, the better from the viewpoint of obtaining the effects of the present invention.

  1-30 mass% is preferable, as for content of the basic magnesium carbonate and / or magnesium oxide which are (E) components in a composition, 5-20 mass% is more preferable, and 5-15 mass% is still more preferable.

  Component (D) and component (E) are such that the number of phosphorus atoms (P) and the number of magnesium atoms (Mg) in the total amount of components (D) and (E) are Mg number / P number ≧ 1.5. The Mg number / P number is preferably 1.5 to 3.0, more preferably 1.5 to 2.0.

  The number of Mg in the total amount of the component (D) and the component (E) is the sum of Mg in the component (D) and the component (E) when the component containing Mg is used as the component (D). When the component (D) that does not contain Mg is used, the number of Mg in the component (E).

  In addition to the components (A) to (E), the composition of the present invention can contain various known additives as long as the effects of the present invention can be obtained.

  Known 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, calcium carbonate, base Metal carbonates such as basic zinc carbonate and basic copper carbonate or basic metal carbonates; complex compounds of metal oxides or hydroxides such as acid clay, kaolin, talc, bentonite, diatomaceous earth, hydrotalcite; silicic acid Examples thereof include metal salts such as sodium, mica molybdate, cobalt molybdate, and ammonium molybdate, molybdenum disulfide, calcium stearate, silicon nitride, and silicon carbide.

  The 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 composition of the present invention or a molded product obtained from the same is, for example, an airbag inflator for a driver seat of various vehicles, an airbag inflator for a passenger seat, an inflator for a side airbag, an inflator for an inflatable curtain, an inflator for a knee bolster, It can be applied to inflators for inflatable seat belts, inflators for tubular systems, and gas generators for pretensioners.

  The inflator using the composition of the present invention or a molded product obtained from the composition is either a pyro type that supplies gas only from a gas generating agent or a hybrid type that uses both a compressed gas such as argon and a gas generating agent. But you can.

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

Examples and Comparative Examples Each component of Examples and Comparative Examples shown in Table 1 and water of 16% by weight of the outer split were mixed using a kneader. Next, the obtained mixture (bulky gas generant composition) was extruded using a drawing machine at a pressure of 80 kg / cm ² , and what was successfully extruded was further cut and dried. A gas generant composition having an outer diameter of 6.5 mm and a length of 10 mm (pellet shape without an inner diameter hole) was obtained. The combustion temperature of each composition and the amount of phosphorus oxide in the gas were determined by simulation using a thermochemical equilibrium calculation program.

(A) component: GN (guanidine nitrate)
: Mel (melamine)
(B) component: SrN (strontium nitrate)
: BCN (basic copper nitrate)
(C) Component: CMCNa (Carboxymethylcellulose sodium salt)
Component (D): ADP (ammonium dihydrogen phosphate)
: MAP (ammonium magnesium phosphate monohydrate)
(E) component: BMC (basic magnesium carbonate tetrahydrate)

Claims (4)

(A) Fuel, (B) Oxidizing agent, (C) Binder, (D) Phosphate for lowering combustion temperature, (E) Phosphoric acid as component (D) by combustion Contains basic magnesium carbonate and / or magnesium oxide as a component to form reaction products with phosphorus oxide generated from the salt,
Gas generator composition in which the number of phosphorus atoms (P) and the number of magnesium atoms (Mg) in the total amount of component (E) and component (D) are Mg number / P number ≧ 1.5 .   (D) Phosphate for reducing the combustion temperature of the component is potassium dihydrogen phosphate, potassium monohydrogen phosphate, tribasic potassium phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate, tertiary phosphorus Sodium phosphate, calcium dihydrogen phosphate, calcium hydrogen phosphate, tertiary calcium phosphate, magnesium dihydrogen phosphate, magnesium monohydrogen phosphate, magnesium tertiary phosphate, ammonium dihydrogen phosphate, ammonium monohydrogen phosphate, phosphorus The gas generant composition according to claim 1, which is one or more selected from ammonium magnesium oxide.   The gas generating composition according to claim 1 or 2, wherein the Mg number / P number is 1.5 to 3.0.   The gas generating composition according to claim 1 or 2, wherein the Mg number / P number is 1.5 to 2.0.