Gas generating agent composition

Abstract

A gas-generating agent composition containing guanidine nitrate, basic copper nitrate, and potassium perchlorate, the gas-generating agent composition having a potassium perchlorate content of 12 parts by weight or more when the total content of guanidine nitrate, basic copper nitrate, and potassium perchlorate is 100 parts by weight, and the gas-generating agent composition containing guanidine nitrate, basic copper nitrate, and potassium perchlorate. The gas-generating agent composition further contains an amorphous oxide.

Description

Technical Field

[0001] The present disclosure relates to a gas generant composition. Background Art

[0002] In vehicle safety devices such as airbag devices mounted on vehicles, inflators using gas generant compositions are used, and various attempts have been made to ensure product reliability. The composition of gas generant compositions is being developed extensively, but from the viewpoint of less generation of toxic gas and excellent combustion speed, guanidine nitrate and basic copper nitrate type gas generant compositions using guanidine nitrate as a fuel component and basic copper nitrate as an oxidant have attracted attention.

[0003] For example, Patent Document 1 discloses a technique for providing a gas generant composition as a guanidine nitrate and basic copper nitrate type gas generant composition, wherein the gas generant composition contains a specific reducing agent and an oxidizing agent and is subjected to a specific roller pressing process in the manufacturing stage, thereby achieving an excellent combustion rate.

[0004] In addition, Patent Document 2 discloses a technology for providing a gas generant composition as a guanidine nitrate and basic copper nitrate type gas generant composition, wherein the gas generant composition contains potassium perchlorate, and the contents of guanidine nitrate, basic copper nitrate and potassium perchlorate are each set within a specific range, thereby improving combustion characteristics and heat resistance.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application No. 2009-511411

[0008] Patent Document 2: Japanese Patent Application Publication No. 2018-154539 Summary of the invention

[0009] Problems to be solved by the invention

[0010] Conventionally, gas generant compositions of guanidine nitrate and basic copper nitrate type have been studied with a focus on combustion rate, and potassium perchlorate has been added in an attempt to further increase the combustion rate.

[0011] The inventors of the present invention have further studied a system in which potassium perchlorate is added to a guanidine nitrate and basic copper nitrate type gas generant composition, and found that as the proportion of potassium perchlorate increases, the ignition time becomes shorter. On the other hand, it is known that in a low-pressure environment, if the proportion of potassium perchlorate exceeds a certain level, the combustion may sometimes become unstable and interrupted. In the case where a gas generant composition whose combustion is interrupted in a low-pressure environment is used in an inflator, etc., there is a risk that the gas generant composition will go out during the combustion process when the pressure inside the inflator is low, such as at the beginning or end of the operation of the inflator. In such a case, the amount of gas used to inflate the airbag is insufficient, and it may be impossible to meet the requirements for restraining passengers.

[0012] Therefore, the present disclosure sets as a technical problem to provide a gas generant composition having a short ignition time and being less likely to suffer from combustion interruption in a low-pressure environment.

[0013] Solutions for solving problems

[0014] The present inventors have conducted intensive studies and have found that the above-mentioned technical problems can be solved by adding a specific amount of potassium perchlorate or more to a gas generating agent composition of guanidine nitrate and basic copper nitrate and containing an amorphous oxide, thereby completing the present disclosure.

[0015] [1] A gas generant composition comprising guanidine nitrate, basic copper nitrate and potassium perchlorate, wherein the content of potassium perchlorate is 12 parts by weight or more, when the total content of the guanidine nitrate, the basic copper nitrate and the potassium perchlorate is 100 parts by weight, and the gas generant composition further comprises an amorphous oxide.

[0016] [2] The gas generant composition according to [1], wherein the amorphous oxide is one or more selected from the group consisting of silica gel, silicate glass, borosilicate glass, borate glass, aluminosilicate glass, aluminophosphate glass and aluminoborosilicate glass.

[0017] [3] The gas generant composition according to [2], wherein the silica gel has an average specific surface area of ​​300 m 2 / g or more silica gel

[0018] [4] The gas generant composition according to any one of [1] to [3], wherein the total content of the amorphous oxide in the gas generant composition is 0.1% by weight or more and 10% by weight or less.

[0019] [5] The gas generant composition according to any one of [1] to [4], wherein the average aspect ratio of the amorphous oxide is 8 or less.

[0020] [6] The gas generant composition according to any one of [1] to [5], wherein the average particle size of the amorphous oxide is 1 μm or more and 100 μm or less.

[0021] [7] The gas generant composition according to any one of [1] to [6], which does not contain a binder.

[0022] [8] The gas generant composition according to [7], wherein the content of guanidine nitrate is 30 mass % or more and 70 mass % or less.

[0023] [9] The gas generant composition according to any one of [1] to [8], wherein the oxygen balance calculated based on the following components (A) to (D) is greater than -0.05 g / g and less than 0.05 g / g.

[0024] (A) Guanidine nitrate, nitroguanidine, melamine, melamine cyanurate, 5-aminotetrazole, 5,5'-ditetrazole diammonium salt, guanyl urea dinitramide, dicyanodicarbonamide, cyanuric acid, tartaric acid, sodium tartrate, succinic acid, 3-nitro-1,2,4-triazol-5-one, 2-nitroimino-5-nitrohexahydro-1,3,5-triazine and carbonaceous substances.

[0025] (B) Basic copper nitrate, strontium nitrate, basic copper carbonate, 5-AT-BCN complex, copper oxide, potassium perchlorate, potassium chlorate, potassium nitrate, sodium nitrate, ammonium nitrate, ammonium perchlorate, sodium perchlorate, copper (II) oxide, copper (I) oxide, phase-stabilized ammonium nitrate (AN / KN=90 / 10) and phase-stabilized ammonium nitrate (AN / KN=85 / 15).

[0026] (C) sodium carboxymethyl cellulose, guar gum, polyacrylamide, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, ethyl cellulose, polyvinyl pyrrolidone, starch and silicone.

[0027] (D) Calcium stearate and magnesium stearate.

[0028]

[10] The gas generant composition according to any one of [1] to [9], further comprising aluminum hydroxide.

[0029]

[11] A gas generant molded body obtained by molding the gas generant composition according to any one of [1] to

[10] into a granular shape, a single-hole cylindrical shape, or a multi-hole cylindrical shape.

[0030]

[12] An inflator for a side airbag, comprising the gas generant composition according to any one of [1] to

[10] .

[0031]

[13] An inflator for a side airbag, comprising the gas generating agent molded body as described in

[11] .

[0032] Beneficial Effects

[0033] According to the present disclosure, it is possible to provide a gas generating agent composition that has a short ignition time and is less likely to suffer from combustion interruption in a low-pressure environment. DETAILED DESCRIPTION

[0034] The following is a detailed description of the embodiments of the present disclosure, but each configuration and combination thereof in each embodiment is an example, and addition, omission, substitution and other changes of the configuration may be appropriately made within the scope of the present disclosure. The present disclosure is not limited to the embodiments but only to the claims.

[0035] In the present disclosure, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit, and "A to B" means A or more and B or less.

[0036] In addition, the expression of "A or B" in the present disclosure may be replaced by "at least one selected from the group consisting of A and B".

[0037] Furthermore, in the present disclosure, “plurality” means “two or more”.

[0038] <Gas Generant Composition>

[0039] A gas generant composition (also referred to as a "gas generant composition") as an embodiment of the present disclosure is a gas generant composition comprising guanidine nitrate, basic copper nitrate and potassium perchlorate, wherein the content of the potassium perchlorate is 12 parts by weight or more when the total content of the guanidine nitrate, the basic copper nitrate and the potassium perchlorate is 100 parts by weight, and the gas generant composition further comprises an amorphous oxide.

[0040] The present inventors have found that in a system in which potassium perchlorate is added to a conventional gas generant composition of guanidine nitrate and basic copper nitrate, the time until ignition is shortened by increasing the mixing ratio of potassium perchlorate. On the other hand, it is known that in a low-pressure environment, if the mixing ratio of potassium perchlorate exceeds a certain level, the problem of combustion becoming unstable and interrupted occurs.

[0041] Therefore, the present inventors conducted intensive research and found that, by including an amorphous oxide, a gas generating agent composition in which combustion is not easily interrupted in a low-pressure environment can be obtained even when the mixing ratio of potassium perchlorate is high. The present inventors speculate that under low pressure, the residue of the burned part is easily dispersed, and the transfer of heat to the unburned part is stagnant, and the combustion is interrupted, but by including an amorphous oxide, the residue is not easily dispersed, and heat is easily transferred, so that the combustion is not easily interrupted in a low-pressure environment.

[0042] It should be noted that, in the present disclosure, a low-pressure environment refers to an environment of 1 MPa or less.

[0043] [Guanidine nitrate]

[0044] The gas generating agent composition contains guanidine nitrate as a combustion component. Guanidine nitrate produced by a known method may be used, or a commercially available product may be used.

[0045] The content of guanidine nitrate in the gas generant composition is not particularly limited, but is preferably 30% by weight or more and 70% by weight or less, more preferably 40% by weight or more and 60% by weight or less, particularly when the composition is manufactured by a wet process (when the composition contains a binder), it is further preferably 40% by weight or more and 50% by weight or less, and when the composition is manufactured by a dry process (when the composition does not contain a binder), it is further preferably 50% by weight or more and 60% by weight or less.

[0046] By setting the content to be below the upper limit of the above range, a large amount of harmful carbon monoxide can be prevented from being generated due to insufficient oxidant components, and the load resistance strength can be improved. In addition, by setting the content to be above the lower limit of the above range, the amount of gas generated is reduced, and an increase in nitrogen oxides due to excess oxygen can be prevented.

[0047] In particular, when the composition is manufactured in a dry manner (when the composition does not contain a binder), if the content of guanidine nitrate in the composition is less than 30% by mass, it is difficult to mold. In addition, if it exceeds 70% by mass, although molding is possible, the strength is insufficient.

[0048] [Basic copper nitrate]

[0049] The gas generating agent composition contains basic copper nitrate as the first oxidant. Basic copper nitrate may be produced by a known method or a commercially available product.

[0050] The content of basic copper nitrate in the gas generant composition is not particularly limited, but is usually 10% by weight or more and 60% by weight or less, preferably 10% by weight or more and 50% by weight or less, more preferably 10% by weight or more and 40% by weight or less, and further preferably 15% by weight or more and 40% by weight or less.

[0051] By setting the content below the upper limit of the range, the amount of gas generated is reduced, and it is easy to prevent the increase of nitrogen oxides due to excess oxygen. In addition, by setting the content above the lower limit of the range, the combustion temperature can be lowered while maintaining the oxygen balance.

[0052] [Potassium perchlorate]

[0053] The gas generant composition contains potassium perchlorate as the second oxidant. Potassium perchlorate produced by a known method may be used, or a commercially available product may be used.

[0054] In the gas generant composition, when the total content of guanidine nitrate, basic copper nitrate and potassium perchlorate is set to 100 parts by weight, the content of potassium perchlorate is not particularly limited as long as it is 12 parts by weight or more, and is preferably 12 parts by weight or more and 35 parts by weight or less, more preferably 12.5 parts by weight or more and 30 parts by weight or less, and further preferably 12 parts by weight or more and 25 parts by weight or less.

[0055] By setting the content to be below the upper limit of the above range, it is easy to prevent the airbag from being damaged due to excessive combustion temperature. In addition, by setting the content to be above the lower limit of the above range, the ignition time of the gas generant composition can be improved.

[0056] The total content of guanidine nitrate, basic copper nitrate and potassium perchlorate in the gas generant composition is not particularly limited, and is generally 85% by weight or more and less than 100% by weight, preferably 90% by weight or more and 99.9% by weight or less, more preferably 90% by weight or more and 99.5% by weight or less, and further preferably 93% by weight or less and 99.5% by weight or less.

[0057] By setting the content to be less than the upper limit of the above range, the effect of the amorphous oxide can be exerted. In addition, by setting the content to be more than the lower limit of the above range, the ignition time of the gas generating agent composition can be improved.

[0058] In the gas generant composition, the ratio of the content (weight) of potassium perchlorate × 100 to the content (weight) of guanidine nitrate (content (weight) of potassium perchlorate × 100 / content (weight) of guanidine nitrate) is not particularly limited, and is generally greater than 10 and less than 70, preferably greater than 10 and less than 60, more preferably greater than 10 and less than 55, further preferably greater than 15 and less than 55, and particularly preferably greater than 18 and less than 50.

[0059] By setting the ratio below the upper limit of the range, the amount of fine-particle residue that cannot be captured even by the inflator components can be prevented from increasing excessively. In addition, by setting the ratio above the lower limit of the range, the ignition timing of the gas generant composition can be improved.

[0060] The oxygen balance calculated based on the (A) and (B) components described later in the gas generant composition is not particularly limited, and is usually greater than -0.05 g / g and less than 0.05 g / g, preferably greater than -0.05 g / g and less than 0.04 g / g, more preferably greater than -0.05 g / g and less than 0.04 g / g, further preferably greater than -0.04 g / g and less than 0.03 g / g, and particularly preferably greater than -0.03 g / g and less than 0.03 g / g. The oxygen balance refers to the excess or deficiency of oxygen required to completely oxidize the gas generant composition, and is a positive value when there is excess oxygen and a negative value when there is a deficiency of oxygen.

[0061] The oxygen balance is preferably satisfied as a parameter calculated based on the components (A) to (D) described later, or may be satisfied as a parameter of the oxygen balance of the gas generating composition (the entire gas generating composition).

[0062] By setting the oxygen balance to be below the upper limit of the above range, it is easy to prevent the increase of nitrogen oxides due to excess oxygen. In addition, by setting the oxygen balance to be above the lower limit of the above range, it is easy to prevent the increase of carbon monoxide due to insufficient oxygen.

[0063] It is preferred that the oxygen balance calculated based on the following components (A) to (D) satisfy the above-mentioned oxygen balance range. The components listed below do not indicate components that must be included in the composition, but indicate components that become the objects of calculation of oxygen balance when included. It should be noted that component (A) is a component equivalent to fuel, component (B) is a component equivalent to oxidant, component (C) is a component equivalent to adhesive, and component (D) is a component equivalent to lubricant. It should be noted that, in addition to these components, the gas generating composition may also contain components that affect oxygen balance.

[0064] (A) Guanidine nitrate, nitroguanidine, melamine, melamine cyanurate, 5-aminotetrazole, 5,5'-ditetrazole diammonium salt, guanyl urea dinitramide, dicyanodicarbonamide, cyanuric acid, tartaric acid, sodium tartrate, succinic acid, 3-nitro-1,2,4-triazol-5-one, 2-nitroimino-5-nitrohexahydro-1,3,5-triazine and carbonaceous materials (such as activated carbon).

[0065] (B) Basic copper nitrate, strontium nitrate, basic copper carbonate, 5-AT-BCN complex, copper oxide, potassium perchlorate, potassium chlorate, potassium nitrate, sodium nitrate, ammonium nitrate, ammonium perchlorate, sodium perchlorate, copper (II) oxide, copper (I) oxide, phase-stabilized ammonium nitrate (AN / KN=90 / 10) and phase-stabilized ammonium nitrate (AN / KN=85 / 15).

[0066] (C) sodium carboxymethyl cellulose, guar gum, polyacrylamide, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, ethyl cellulose, polyvinyl pyrrolidone, starch and silicone.

[0067] (D) Calcium stearate and magnesium stearate.

[0068] It should be noted that, in the present disclosure, an expression such as “phase-stabilized ammonium nitrate (AN / KN=90 / 10)” means “ammonium nitrate (AN) phase-stabilized with potassium nitrate (KN) (AN / KN=90 / 10 in terms of weight ratio)”.

[0069] Specific examples of the carbonaceous material in the component (A) include activated carbon, coal, purified carbon, carbon black, carbon products, solid crude oil, coal tar pitch, carbon fiber, tar, carbon, coke, and graphite.

[0070] The following describes a method for calculating the oxygen balance.

[0071] For example, guanidine nitrate is oxidized by the following reaction.

[0072] CH6N4O3+O2→2N2+CO2+3H2O

[0073] Therefore, the oxygen balance of guanidine nitrate is -0.262 g / g according to the following formula (1). If the oxygen balance of basic copper nitrate and potassium perchlorate is calculated similarly according to the oxidation reaction, the oxygen balance of basic copper nitrate is

[0074] 0.300g / g, the oxygen balance of potassium perchlorate is 0.462g / g.

[0075] [Formula 1]

[0076]

[0077] Therefore, for example, in the case where the gas generating agent composition contains only guanidine nitrate, basic copper nitrate and potassium perchlorate as components (A) to (D), if the content of guanidine nitrate is set to a (weight %), the content of basic copper nitrate is set to b (weight %), and the content of potassium perchlorate is set to c (weight %), the oxygen balance calculated based on the components (A) to (C) is expressed by the following formula.

[0078] The oxygen balance of the gas generating agent composition (g / g) = {a×(-0.262)+b×0.300+c×0.462} / 100 preferably satisfies the above-mentioned oxygen balance numerical range in the form of a parameter calculated based on the components (A) to (D), or can satisfy the above-mentioned oxygen balance numerical range in the form of a parameter of the oxygen balance of the gas generating composition (the gas generating composition as a whole).

[0079] When considering the oxygen balance (of the entire gas generating composition), it can be calculated from the oxygen balances of all components contributing to the oxygen balance in the composition.

[0080] The oxygen balance of each component (A) to (D) is shown in the following Table 1.

[0081] 1, Al(OH) 3 and basic magnesium carbonate are described as the additive substance, i.e., component (E), but these substances do not contribute to the oxygen balance (i.e., the oxygen balance is 0 g / g).

[0082] [Table 1]

[0083] Table 1

[0084]

[0085]

[0086] [Amorphous oxide]

[0087] The gas generant composition contains an amorphous oxide in addition to the above-mentioned components. By containing the amorphous oxide in the gas generant composition, a short ignition time can be ensured, and a sufficient combustion amount of the gas generant composition can be ensured.

[0088] The type of amorphous oxide is not particularly limited, and for example, one or more substances selected from the group consisting of silica gel, silicate glass, borosilicate glass, borate glass, aluminosilicate glass, aluminophosphate glass and aluminoborosilicate glass can be listed, preferably one or more substances selected from the group consisting of silica gel, aluminophosphate glass and aluminoborosilicate glass, more preferably one or more substances selected from the group consisting of silica gel and aluminoborosilicate glass, and silica gel is further preferred from the viewpoint of short combustion time under low pressure environment. It should be noted that the oxygen balance of the amorphous oxide specifically listed here is 0g / g.

[0089] The amorphous oxide may be produced by a known method or a commercially available product.

[0090] The total content of amorphous oxides in the gas generant composition is not particularly limited, but is preferably 0.1 wt% to 10 wt%, more preferably 0.5 wt% to 10 wt%, further preferably 0.5 wt% to 5 wt%, and particularly preferably 0.5 wt% to 3 wt%.

[0091] By setting the content to be below the upper limit of the above range, the time until ignition of the gas generating agent composition can be prevented from increasing. In addition, by setting the content to be above the lower limit of the above range, the phenomenon of combustion interruption in a low-pressure environment can be improved.

[0092] The shape of the amorphous oxide is not particularly limited, and may be, for example, particulate or non-fibrous, but is preferably particulate from the viewpoint of the density of the gas generant composition. In the present disclosure, particulate means an average aspect ratio of 8 or less.

[0093] The average aspect ratio of the amorphous oxide is not particularly limited, but is usually 8 or less, preferably 7.5 or less, and more preferably 7 or less. The lower limit is not particularly limited as long as it is 1 or more.

[0094] By setting the average aspect ratio to be equal to or less than the upper limit of the above range, the density of the gas generant composition can be increased, thereby contributing to weight reduction of the inflator.

[0095] The average aspect ratio of the amorphous oxide can be calculated as follows: (1) When the amorphous oxide can be collected from the gas generant composition, a plurality of amorphous oxides (at least ten particles of amorphous oxide) are collected, and each amorphous oxide is observed using a scanning electron microscope (SEM), and the ratio of the major axis to the minor axis (major axis / minor axis) of each amorphous oxide is obtained, and the average value of these ratios is calculated; and (2) when the amorphous oxide cannot be collected from the gas generant composition, a cross-section of the gas generant composition is observed using an SEM, and the ratio of the major axis to the minor axis (major axis / minor axis) of each amorphous oxide observed on the cross-section is obtained, and the average value of these ratios is calculated.

[0096] When the amorphous oxide is in the form of particles, the average particle size is not particularly limited and is usually greater than 0.1 μm and less than 100 μm, preferably greater than 0.5 μm and less than 100 μm, more preferably greater than 1 μm and less than 100 μm, further preferably greater than 2 μm and less than 90 μm, and particularly preferably greater than 2 μm and less than 80 μm.

[0097] By setting the average particle size in the above range, it is possible to achieve an effect of improving combustion interruption in a low-pressure environment.

[0098] The average particle size of the amorphous oxide can be calculated as follows: (1) When the amorphous oxide can be collected from the gas generant composition, multiple amorphous oxides (at least ten amorphous oxides) are collected, and each amorphous oxide is observed using a scanning electron microscope (SEM), and the particle size of each amorphous oxide is determined, and the average value of these particle sizes is calculated; in addition, (2) when the amorphous oxide cannot be collected from the gas generant composition, the cross-section of the gas generant composition is observed using an SEM, and the particle size of each amorphous oxide observed in the cross-section is determined, and the average value of these particle sizes is calculated.

[0099] When porous silica gel is used as the amorphous oxide, the average specific surface area is not particularly limited, but is preferably 250 m 2 / g or more, more preferably 300m 2 / g or more, preferably 900 m 2 / g or less, more preferably 700m 2 / g or less, more preferably 500m 2 For amorphous oxides other than porous bodies such as silica gel, it is preferred to set the average particle size rather than the average specific surface area to a preferred range.

[0100] By setting the average specific surface area to be less than the upper limit of the above range, it is easy to prevent the hygroscopicity of the gas generant composition from increasing. In addition, by setting the average specific surface area to be more than the lower limit of the above range, it is easy to prevent the combustibility from decreasing.

[0101] The above average specific surface area can be measured by a gas adsorption method.

[0102] [Other ingredients]

[0103] The gas generant composition may also contain components other than the above-mentioned guanidine nitrate, basic copper nitrate, potassium perchlorate and amorphous oxide (hereinafter also referred to as "other components"), for example, the following may include: fuel components other than guanidine nitrate; oxidants other than basic copper nitrate and potassium perchlorate; adhesives; lubricants; neutralizers; other well-known additives, etc.

[0104] As the fuel component other than guanidine nitrate, for example, one or more selected from the following substances can be cited: tetrazole compounds including 5-aminotetrazole and ditetrazole ammonium salt; guanidine compounds including guanidine nitrate and dicyandiamide (excluding nitroguanidine); triazine compounds including melamine, trimethylol melamine, alkylated methylol melamine, ammeline, ammeline, nitrate of melamine, perchlorate of melamine, trihydrazinotriazine and nitrated compound of melamine, etc. In addition, in the above-mentioned component (A), components other than these fuel components can also be used as fuel components.

[0105] As the oxidizing agent other than basic copper nitrate and potassium perchlorate, for example, one or more selected from the following substances can be mentioned: basic cobalt nitrate, basic zinc nitrate, basic manganese nitrate, metal nitrate, ammonium nitrate, metal perchlorate, ammonium perchlorate, metal chlorate, metal nitrite, etc. In addition, in the above-mentioned (B) component, components other than these oxidizing agents can also be used as the oxidizing agent.

[0106] As the binder, one or more selected from the following substances can be listed: carboxymethyl cellulose (CMC), sodium carboxymethyl cellulose (CMCNa), potassium carboxymethyl cellulose, ammonium carboxymethyl cellulose, cellulose acetate, cellulose acetate butyrate (CAB), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), microcrystalline cellulose, polyacrylhydrazide, acrylamide / acrylic acid metal salt copolymer, copolymer of polyacrylamide / polyacrylate compound, acrylic rubber and silicone, etc. In addition, in the above-mentioned (C) component, components other than these binders can also be used as binders. The gas generating composition may contain a binder or may not contain a binder.

[0107] Examples of the lubricant include one or more selected from calcium stearate, magnesium stearate, and the like.

[0108] As the neutralizing agent, there can be mentioned compounds containing one or more cations selected from alkali metals and alkaline earth metals. Such compounds can be listed as carbonates, silicates, nitrates, oxalates, peroxides or oxides of alkali metals and alkaline earth metals, such as sodium carbonate, sodium silicate, sodium nitrate, sodium oxalate, strontium peroxide, calcium peroxide, magnesium oxide, strontium oxide or calcium oxide.

[0109] As other well-known additives, one or more selected from the following substances can be listed: metal oxides such as copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, silicon dioxide, and aluminum oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, cobalt hydroxide, and iron hydroxide; cobalt carbonate and calcium carbonate; composite compounds of metal oxides or hydroxides such as acid clay, kaolin, talc, bentonite, and diatomaceous earth; metal acid salts such as sodium silicate, mica molybdate, cobalt molybdate, and ammonium molybdate; molybdenum disulfide, calcium stearate, silicon nitride, silicon carbide, metaboric acid, boric acid, boric anhydride, glass, etc.

[0110] In addition to the above-mentioned components, the gas generant composition may also contain Al(OH)3 (aluminum hydroxide) as another component. When aminophosphate glass is used as the amorphous oxide, this additive is advantageous from the perspective of being able to lower the combustion temperature of the gas generant composition.

[0111] When using Al(OH)3, the content of Al(OH)3 in the gas generant composition is not particularly limited. From the viewpoint of being able to lower the combustion temperature of the gas generant composition, it is preferably from 0.5 wt% to 10 wt%, more preferably from 1 wt% to 10 wt%, and further preferably from 1 wt% to 8 wt%.

[0112] The content of each component in the gas generant composition can be analyzed by conventional qualitative and quantitative analysis methods, for example, by combining the measurement results of ion chromatography, FT-IR, ICP-AES, XRD, etc. In addition, it can also be calculated based on the amount of raw materials used in the gas generant composition.

[0113] The gas generant composition can be molded into a desired shape for use, and can be made into a granular, disc-shaped, spherical, rod-shaped, cylindrical, single-hole cylindrical or porous cylindrical shaped molded body (gas generant molded body), and granular, single-hole cylindrical or porous cylindrical shapes are particularly preferred. These molded bodies can be manufactured by adding water or an organic solvent to the gas generant composition and performing an extrusion molding method or a compression molding method using a tablet press or the like.

[0114] The gas generant composition according to the embodiment of the present disclosure has a high combustion rate, and therefore, there is no need to reduce the size of the molded body, and the production process is not complicated.

[0115] The gas generant composition of the embodiment of the present disclosure or the molded article obtained therefrom (hereinafter also referred to as the gas generant composition, etc.) can be applied to, for example, the inflator for the driver's seat airbag, the inflator for the passenger seat airbag, the inflator for the side airbag, the inflator for the inflatable curtain, the inflator for the knee bolster, the inflator for the inflatable seat belt, the inflator for the tubular system, or the inflator for the pretensioner of various vehicles. Among them, it can be preferably applied to the inflator for the side airbag that requires early deployment, particularly short ignition time and sufficient combustion amount.

[0116] The inflator including the gas generant composition or the molded body obtained therefrom may be either a pyrotechnic type in which the gas supply source is only the gas generant or a mixed type in which the gas supply source is a compressed gas such as argon and the gas generant.

[0117] The gas generant composition or a molded article obtained therefrom can also be used as an ignition agent called an enhancer (or booster) or the like for transferring energy from a detonator or a squib to the gas generant.

[0118] <Method for producing gas generant composition>

[0119] The method for producing the gas generant composition is not particularly limited, and the gas generant composition can be produced by a known method or a combination of known methods. For example, the gas generant composition can be produced by preparing desired raw materials and mixing them. Specifically, the gas generant composition can be produced by a dry method in which the raw materials are mixed in powder form, or by a wet method in which the raw materials are mixed in the presence of water, an organic solvent, or the like.

[0120] In addition, when the gas generant composition is used as a molded body, the mixture obtained by the above-mentioned dry method can be compression-molded using a tablet press to obtain a molded body, or the mixture obtained by the above-mentioned wet method can be extruded by an extruder and then cut and dried to obtain a molded body. The manufacturing conditions in the manufacturing method of these molded bodies are not particularly limited and can be appropriately set according to the purpose. For example, when the extrusion molding method is applied, it is easier to mold a product with a thin mesh than the compression molding method, so even a composition with a slow combustion rate can obtain a molded product. Moreover, the extrusion molding method is suitable for mass production because the molding is completed in a shorter time. In addition, when the extrusion molding method is applied, since molded products with complex shapes such as non-porous, single-porous, and porous can be manufactured, various combustion characteristics can be imparted.

[0121] In the manufacture of the gas generant composition, when the tablet press is used for molding, a lubricant is preferably used. The type of lubricant is not particularly limited, and examples thereof include calcium stearate, magnesium stearate, sucrose fatty acid ester, talc, etc. The content of the lubricant in the gas generant composition can be set to 0.1% by mass or more and 1% by mass or less, or can be set to 0.15% by mass or more and 0.6% by mass or less.

[0122] In the measurement of each characteristic in the present disclosure, unless otherwise specified, the measurement sample is kept in the same environment as the measurement environment for more than 2 hours before the measurement. In addition, regarding the measurement temperature, measurement humidity and measurement pressure, unless otherwise specified, it is set to normal temperature (26±2°C), normal humidity (59±5%RH) and normal pressure (atmospheric pressure).

[0123] Example

[0124] Hereinafter, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not to be construed as being limited to the following examples.

[0125] <Experiment 1>

[0126] [Manufacturing of Gas Generant Composition]

[0127] (Comparative Example 1)

[0128] Prepare the raw materials in the ratio shown in Table 2, mix the raw materials with water in an amount of 0.16 times the total weight of the raw materials, and extrude the mixture using an extruder with a 3.4 mm die at a shear rate of 200 to 1000 / sec so that the diameter after shrinkage after drying becomes 3.2 mm. Cut the sample obtained by the extrusion into a length of 2.6 to 2.9 mm and make it into cylindrical pellets. In order to remove water, let it stand at room temperature for more than 48 hours as pre-drying, and then use a dryer to dry it at 110°C for more than 72 hours to produce a gas generating agent composition (oxygen balance: -0.01 g / g). The oxygen balance is the oxygen balance calculated based on the above-mentioned (A) to (D) components, which is the same in other embodiments and comparative examples.

[0129] (Comparative Example 2)

[0130] The raw materials were prepared at the ratios shown in Table 2, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0131] (Comparative Example 3)

[0132] The raw materials are prepared in the ratio shown in Table 2, mixed and granulated, 0.15 wt % of calcium stearate relative to their total weight is added as a lubricant, and then compression molding is performed using a tablet molding machine under conditions of 19 to 22 kN to produce a gas generating agent composition having cylindrical particles with a bottom diameter of 3.2 mm and a height of 2.6 to 2.9 mm (oxygen balance: -0.01 g / g).

[0133] (Comparative Example 4)

[0134] The raw materials were prepared at the ratios shown in Table 2, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0135] (Comparative Example 5)

[0136] The raw materials were prepared at the ratios shown in Table 2, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0137] (Comparative Example 6)

[0138] The raw materials were prepared at the ratios shown in Table 2, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0139] (Example 1)

[0140] The raw materials were prepared at the ratios shown in Table 2, mixed, and then a gas generating agent composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 3. Aluminoborosilicate glass having an average particle size of 11 μm and an average length of 75 μm (average aspect ratio 6.82) was used.

[0141] (Example 2)

[0142] The raw materials were prepared in the ratios shown in Table 2, and the raw materials were mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generating agent composition (oxygen balance: -0.01 g / g) was prepared in the same manner as in Comparative Example 1. Silica gel was used with an average particle size of 3 to 5 μm, an average aspect ratio of 1 to 1.2, and an average specific surface area of ​​300 m 2 / g of silica gel.

[0143] (Example 3)

[0144] The raw materials were prepared at the ratios shown in Table 2, and the raw materials were mixed with water in an amount 0.16 times the total weight of the raw materials, and then a gas generant composition (oxygen balance: -0.01 g / g) was prepared in the same manner as in Comparative Example 1. Aluminoborosilicate glass having an average particle size of 11 μm, an average length of 75 μm, and an average aspect ratio of 6.82 was used.

[0145] [Combustion test under atmospheric pressure]

[0146] 100 g of each of the above-mentioned gas generating agent compositions was placed on a SUS plate, and a nickel-chromium alloy wire was brought into contact with a portion of the gas generating agent composition in a test field under atmospheric pressure. A specified current was passed through the nickel-chromium alloy wire, and the melting energy thereof was used to ignite the 100 g of the gas generating agent composition to burn, and it was confirmed whether a portion of the unburned gas generating agent composition remained (whether the combustion was interrupted), or whether the entire gas generating agent composition was completely burned out. The confirmation results are shown in Table 2. In Table 2, A means complete combustion, and B means interrupted combustion.

[0147] The meanings of the abbreviations in Table 2 are as follows. The same applies to other tables.

[0148] GN: Guanidine nitrate.

[0149] ·BCN: Basic copper nitrate.

[0150] KClO4: Potassium perchlorate.

[0151] ·Al(OH)3: Aluminum hydroxide.

[0152] · CMCNa: carboxymethyl cellulose sodium salt.

[0153] It should be noted that the mixing ratios in Table 2 can be regarded as the content ratios of the respective components in the gas generating agent composition.

[0154] [5cc pump 10% ignition time]

[0155] 0.7 g of each of the above-mentioned gas generant compositions was placed in a 5 cc pump test jig in a prescribed amount and ignited in a low temperature environment (-40°C) using an explosive containing ZPP (Zinc Protoporphyrin). The time to reach 10% of the maximum pressure was defined as the ignition time.

[0156] [Table 2]

[0157]

[0158] As can be seen from Table 2, the ignition time becomes shorter as the mixing ratio of potassium perchlorate in the gas generant composition increases. On the other hand, it can be seen that in the case where no amorphous oxide is added, combustion is interrupted when the mixing amount of potassium perchlorate is 11% by weight or more, while in the case where the amorphous oxide is added, the ignition time is short and complete combustion is achieved even when the mixing amount of potassium perchlorate is 11% by weight or more.

[0159] (Comparative Example 7)

[0160] The raw materials were prepared at the ratios shown in Table 3, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0161] (Comparative Example 8)

[0162] The raw materials were prepared at the ratios shown in Table 3, and mixed with water in an amount 0.16 times the total weight of the raw materials. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 1.

[0163] (Comparative Example 9)

[0164] The raw materials were prepared at the ratios shown in Table 3, and these were mixed. Then, a gas generant composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 3.

[0165] (Example 4)

[0166] The raw materials were prepared at the ratios shown in Table 3, mixed, and then a gas generating composition (oxygen balance: -0.01 g / g) was produced in the same manner as in Comparative Example 3. Aluminophosphate glass having an average particle size of 30 to 65 μm and an average aspect ratio of 1 to 2 was used.

[0167] Using 100 g of each of the gas generant compositions, the properties of each of the gas generant compositions were evaluated by the same tests as the atmospheric pressure combustion test and the 5cc pump 10% ignition time evaluation test.

[0168] [Table 3]

[0169]

[0170] As can be seen from Table 3, the ignition time becomes shorter as the mixing ratio of potassium perchlorate in the gas generant composition increases. On the other hand, it can be seen that in the case where no amorphous oxide is added, combustion is interrupted when the mixing amount of potassium perchlorate is 11% by weight or more, while in the case where the amorphous oxide is added, the ignition time is short and complete combustion is achieved even when the mixing amount of potassium perchlorate is 11% by weight or more.

[0171] <Experiment 2>

[0172] [Manufacturing of Gas Generant Composition]

[0173] (Reference Example 1)

[0174] The raw materials were prepared in the ratios shown in Table 4, and these were mixed. Then, a gas generating agent composition was produced in the same manner as in Comparative Example 3.

[0175] (Reference Example 2)

[0176] The raw materials were prepared in the ratios shown in Table 4, and these were mixed. Then, a gas generating agent composition was produced in the same manner as in Comparative Example 3.

[0177] (Reference Example 3)

[0178] The raw materials were prepared in the ratios shown in Table 4, and these were mixed. Then, a gas generating agent composition was produced in the same manner as in Comparative Example 3.

[0179] (Reference Example 4)

[0180] The raw materials were prepared in the ratios shown in Table 4, and these were mixed. Then, a gas generating agent composition was produced in the same manner as in Comparative Example 3.

[0181] [Load resistance strength test]

[0182] A flat metal jig was used to clamp one gas generant particle in a manner that it was compressed in the radial direction, and a load was applied using a compression test. The point at which the particle cracked and broke was measured as the load resistance strength. The evaluation results are shown in Table 4.

[0183] [Table 4]

[0184]

[0185] As can be seen from Table 4, by setting the amount of GN in the gas generant composition to a specific range, a gas generant composition having excellent load resistance strength can be obtained. In the system of the present embodiment having GN and BCN as main components, the content ratio of GN is important and is not easily affected by other substances such as BCN, KClO4 and amorphous oxides, so it is considered that the same tendency is shown even if substances such as KClO4 and amorphous oxides are included.

[0186] Industrial Applicability

[0187] The gas generant composition disclosed in the present invention has a short ignition time and is not prone to combustion interruption in a low-pressure environment. Therefore, even when the pressure inside the inflator is low, such as at the beginning or end of the inflator operation, the gas generant composition can be completely burned with a short ignition time. When the gas generant composition is used in an airbag, the amount of gas used to inflate the airbag can be fully ensured, and the requirements for restraining passengers can be easily met.

Claims

1. A gas generant composition, comprising guanidine nitrate, basic copper nitrate and potassium perchlorate, In the gas generant composition, when the total content of the guanidine nitrate, the basic copper nitrate and the potassium perchlorate is 100 parts by weight, the content of the potassium perchlorate is 12 parts by weight or more. The gas generant composition further includes an amorphous oxide.

2. The gas generant composition according to claim 1, wherein The amorphous oxide is at least one selected from the group consisting of silica gel, silicate glass, borosilicate glass, borate glass, aluminosilicate glass, aluminophosphate glass, and aluminoborosilicate glass.

3. The gas generant composition according to claim 2, wherein: The silica gel has an average specific surface area of ​​300m 2 / g or more silica gel 4. The gas generating agent composition according to any one of claims 1 to 3, wherein The total content of the amorphous oxides in the gas generating agent composition is 0.1% by weight or more and 10% by weight or less.

5. The gas generating agent composition according to any one of claims 1 to 4, wherein The average aspect ratio of the amorphous oxide is 8 or less.

6. The gas generating agent composition according to any one of claims 1 to 5, wherein The average particle size of the amorphous oxide is 1 μm or more and 100 μm or less.

7. The gas generating agent composition according to any one of claims 1 to 6, wherein Does not contain adhesive.

8. The gas generant composition according to claim 7, wherein The content of guanidine nitrate is 30% by mass or more and 70% by mass or less.

9. The gas generating agent composition according to any one of claims 1 to 8, wherein The oxygen balance calculated based on the following components (A) to (D) is -0.05 g / g or more and 0.05 g / g or less, (A) guanidine nitrate, nitroguanidine, melamine, melamine cyanurate, 5-aminotetrazole, 5,5'-di-tetrazole diammonium salt, guanyl urea dinitramide, dicyanodicarbonamide, cyanuric acid, tartaric acid, sodium tartrate, succinic acid, 3-nitro-1,2,4-triazol-5-one, 2-nitroimino-5-nitrohexahydro-1,3,5-triazine and carbonaceous substances; (B) basic copper nitrate, strontium nitrate, basic copper carbonate, 5-AT-BCN complex, copper oxide, potassium perchlorate, potassium chlorate, potassium nitrate, sodium nitrate, ammonium nitrate, ammonium perchlorate, sodium perchlorate, copper (II) oxide, copper (I) oxide, phase-stabilized ammonium nitrate with AN / KN=90 / 10, and phase-stabilized ammonium nitrate with AN / KN=85 / 15; (C) sodium carboxymethyl cellulose, guar gum, polyacrylamide, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, ethyl cellulose, polyvinyl pyrrolidone, starch and silicone; (D) Calcium stearate and magnesium stearate.

10. The gas generant composition according to any one of claims 1 to 9, wherein The gas generant composition further comprises aluminum hydroxide. 11 . A gas generant molded body, the gas generant molded body being obtained by molding the gas generant composition according to claim 1 into a pellet shape, a single-hole cylindrical shape, or a multi-hole cylindrical shape. 12 . An inflator for a side airbag, comprising the gas generant composition according to claim 1 . 13 . An inflator for a side airbag, comprising the gas generating agent molded article according to claim 11 .

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