Patent Description:
The present invention relates to a gas generant composition, a preparation method therefor, and use thereof and pertains to the technical field of gas generators for vehicle airbags.

A gas generant for a vehicle airbag is loaded into a gas generator as a gas generating agent and is triggered when necessary to generate a lot of gas. An airbag consists of a gas generator and an inflatable bag. Generally, when a collision exceeds the preset intensity, the gas generator is activated and triggered to start combusting the internal gas generant to generate a gas to inflate the inflatable bag, so that a cushioning air cushion is formed between the interior trim and a human body to protect the human body from injury.

At the early stage, the gas generant is mainly formulated as a sodium azide type of gas generant. This formulation has many advantages such as allowing stable combustion, a low combustion temperature, easy ignition, low internal pressure, high gas production rate, and less residues. However, it is now rarely used in vehicle airbags due to environmental protection and human health and safety issues.

Currently, the prevailing gas generants in the world are guanidine nitrate and basic copper nitrate based gas generants, in which guanidine nitrate is used as a main fuel and basic copper nitrate is used as a main oxidizer. This type of gas generants generally has a high combustion temperature. Molten copper metal is mainly generated from the basic copper nitrate after combustion and usually should be filtered and cooled by a multilayered metal filter so as to be left inside the generator. On the one hand, the increase in the weight of the metal filter leads to an increase in the cost and in the weight of the generator. On the other hand, even if a multilayered filter is used, not all the residues can be filtered, and a few residues may pass through the filter and burn the inflatable bag and may burn a human body in a more severe case.

Therefore, this problem is generally solved by means of: (<NUM>) reducing the amount of basic copper nitrate used, thereby reducing molten copper residues formed after combustion of the gas generant composition; and (<NUM>) adding a form-retaining agent to the composition formulation. The form-retaining agent is generally a high-melting substance, which serves to increase the viscosity of the molten residues and to maintain its own shape as a tablet matrix.

Strontium titanate is a high-melting metal compound. It has also been used previously in the field of gas generants for airbags. For example, Patent <CIT> is directed to a gas generant formulation mainly containing guanidine nitrate, basic copper nitrate, and a titanate. However, the titanate used as a form-retaining agent in this patent does not have a remarkable form-retaining effect and fails to achieve a good form-retaining effect in combustion and cannot achieve a good form-retaining effect in combustion especially for a gas generant comprising more than <NUM>% of basic copper nitrate and more than <NUM>% of guanidine nitrate. Moreover, this gas generant formulation is less easily ignited.

For example, Patent <CIT> discloses a gas generating composition, comprising guanidine nitrate, basic copper nitrate, auxiliary oxidizers (sodium nitrate, copper oxide, and iron oxide), and ignition improvers (aluminum oxide, copper chloride, copper chromate, and potassium chromate). The use of ignition improvers allows easier ignition of the gas generating composition with a short ignition delay period. However, aluminum oxide is generally used for agglomeration of residues and has little effect on ignition improvement; copper chloride is a weak oxidizer and has a little effect on ignition improvement; copper chromate and potassium chromate are both strong copper-containing oxidizers, can play a certain role in ignition improvement, but will increase the residue content. Copper chromate increases the content of insoluble residues. Potassium chromate increases the content of soluble residues, and soluble aerosol particles will be formed by combustion of substances containing alkali metal potassium, which are unfavorable for agglomeration of residues.

For another example, Patent <CIT> discloses a gas generating agent for an air bag, comprising an azole or its metal salt as a fuel, an oxidizing agent, a burning catalyst, a burning control agent, and a slagging agent, wherein an azole and a metal salt are used as the fuel, and the slagging agent is an additive which solidifies the residue of the combustion of the gas generating agent, and thereby facilitates the removal of the residue by the filter in the air bag. However, this patent is applicable to formulations using azoles as fuels. This type of formulations has a much higher combustion temperature than that of the formulations of the type comprising guanidine nitrate and basic copper nitrate and cannot be retained in a good tablet form even if slagging agents are added.

In addition, Patent <CIT> discloses a method for making a gas generant, by adding guanidine nitrate, basic copper nitrate, an auxiliary oxidizer (e.g., potassium nitrate, strontium nitrate, and sodium nitrate), a burning rate regulator (potassium perchlorate), a slag promoting agent (silicon dioxide, zinc oxide, ammonium oxide, aluminum oxide), and a tableting demolding adjuvant used also as a form-retaining synergistic adjuvant B (graphite, molybdenum disulfide, tungsten disulfide, boron nitride). The granulation method used in this patent is spray granulation, which requires higher energy consumption than wet granulation. Furthermore, the slag promoting agent used in this patent is mainly selected from metal oxides, such as silicon dioxide, aluminum oxide, zinc oxide, and cerium oxide. Metal oxides can play a certain role in promoting slag agglomeration as slag promoting agents, but are not remarkably effective in retaining the forms of tablets.

A prior patent application with patent <CIT> discloses a gas generant consisting of guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, strontium titanate, and talc. Strontium titanate added in this patent application has a slag-forming effect, but does not show a significant slag-forming effect in a BCN/GN-based formulation. In practical use, its slag-forming effect is found to fail to meet the requirements. Moreover, a large number of tests have shown that such tablets, after being combusted, have poor density, are easily broken when touched by hand, and will tend to fly out of the generator filter and fall into the airbag and may burn through the inflatable bag and cause potential danger to a human body. <CIT> discloses a gas generating agent for an automobile safety airbag comprising <NUM>-<NUM> wt. % of guanidinium nitrate, <NUM>-<NUM> wt. % of basic copper nitrate, <NUM>-<NUM> wt. % of strontium nitrate, <NUM>-<NUM> wt. % of ammonium perchlorate and <NUM>-<NUM> wt. % of kaolin.

The present invention concerns a gas generant composition according to claim <NUM>, a method for preparing said gas generant composition according to claim <NUM>, the use of said gas generant composition for a vehicle airbag according to claim <NUM> and a gas generator using said gas generant composition according to claim <NUM>.

An object of the present disclosure is to overcome the above-mentioned shortcomings of the prior art and provide a gas generant composition, in which zirconate, silicate, or a mixture of zirconate and silicate is used as a slag-forming agent in combination with other components, so that the tablets, after being combusted, can coagulate and agglomerate in a filter and retain their pre-combustion form very well, thereby completely avoiding burning of the inflatable bag due to melting and splashing of the combusted tablets. In this way, slag formation during combustion of the gas generant composition is increased by at least <NUM>%.

Another object of the present disclosure is to provide a method for improving the slag-forming ability of a gas generant composition. The method includes introducing, as slagging agent components, zirconate and silicate which are high-melting substances into a gas generant composition comprising basic copper nitrate, guanidine nitrate, strontium nitrate, and AP.

A further object of the present disclosure is to provide a method for preparing a gas generant composition and its use.

The above-mentioned objects of the present disclosure are mainly achieved by the following technical solutions.

A gas generant composition comprises guanidine nitrate, basic copper nitrate, strontium nitrate, and ammonium perchlorate and is characterized by further comprising a slag-forming agent and a lubricant, wherein the slag-forming agent is at least one zirconate, or at least one silicate, or a mixture of at least one zirconate and at least one silicate.

The contents, in percent by mass, of the respective components are as follows:.

In the gas generant composition described above, the zirconate is one or a combination of strontium zirconate, barium zirconate, or calcium zirconate.

In the gas generant composition described above, the silicate is one or a combination of zirconium silicate or calcium silicate.

In the gas generant composition described above, the slag-forming agent is a mixture of at least one zirconate and at least one silicate, in which the mass ratio of zirconate to silicate is <NUM>:<NUM>-<NUM>, preferably <NUM>:<NUM>-<NUM>.

In the gas generant composition described above, the slag-forming agent is a mixture of strontium zirconate, zirconium silicate, and calcium silicate in a mass ratio of <NUM>:<NUM>-<NUM>:<NUM>-<NUM>, preferably <NUM>:<NUM>-<NUM>:<NUM>-<NUM>.

In the gas generant composition described above, the slag-forming agent is a mixture of strontium zirconate and barium zirconate in a mass ratio of <NUM>:<NUM>-<NUM>, preferably <NUM>: <NUM>-<NUM>.

In the gas generant composition described above, the lubricant is one or a combination of talc, graphite, calcium stearate, magnesium stearate, molybdenum disulfide, or boron nitride.

In the gas generant composition described above, the ammonium perchlorate has a particle size D90 not greater than <NUM>; and the slag-forming agent has a particle size D90 not greater than <NUM>.

In the gas generant composition described above, the basic copper nitrate and the lubricant each have a particle size D90 not greater than <NUM>.

In the gas generant composition described above, a sum of water contents in the respective components of the gas generant composition is not more than <NUM>% of the total mass of the respective components.

In the gas generant composition described above, the gas generant composition is molded as a circular or elliptical sheet structure, a circular or elliptical columnar structure, a special-shaped sheet or columnar structure, a circular or elliptical monoporous structure, a circular or elliptical porous structure, or a special-shaped monoporous or porous structure.

In the gas generant composition described above, the circular sheet structure has a diameter of <NUM> to <NUM> and a height of <NUM> to <NUM>; the circular columnar structure has a diameter of <NUM> to <NUM> and a height of <NUM> to <NUM>; the circular monoporous structure has an inner diameter of <NUM> to <NUM>, an outer diameter of <NUM> to <NUM>, and a height of <NUM> to <NUM>; and the elliptical monoporous structure has an inner diameter of <NUM> to <NUM>, a major diameter of <NUM> to <NUM>, a minor diameter of <NUM> to <NUM>, and a height of <NUM> to <NUM>.

In a method for preparing the gas generant composition described above, the gas generant composition is prepared by wet granulation, spray granulation, or dry granulation. A specific preparation method for the wet granulation comprises the steps of:.

In the method for preparing the gas generant composition described above, in the step (<NUM>), the first material is obtained by mixing guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, and a slag-forming agent in a mixing device for a mixing duration larger than or equal to <NUM>.

In the method for preparing the gas generant composition described above, the wet mixing in the step (<NUM>) is performed for a duration of <NUM> to <NUM>; and the wet mixing is performed by a device selected from a kneader or a mixer.

In a method for preparing the gas generant composition described above, the gas generant composition is prepared by wet granulation, and the specific preparation method comprises the steps of:.

In the method for preparing the gas generant composition described above, in the step (<NUM>), the first material is obtained by mixing guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, a slag-forming agent, and a lubricant in a mixing device for a mixing duration larger than or equal to <NUM>.

In use of the gas generant composition described above, the gas generant composition is used in a gas generator for a vehicle airbag.

A gas generator uses the gas generant composition described above.

Compared with the prior art, the present disclosure has the following advantageous effects.

The present disclosure will be described in further detail below with reference to the accompanying drawings and specific examples.

The present disclosure discloses a gas generant composition, comprising guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, a slag-forming agent, and a lubricant, wherein the slag-forming agent is at least one zirconate, or at least one silicate, or a mixture of at least one zirconate and at least one silicate, and the lubricant is selected from at least one of talc, graphite, calcium stearate, magnesium stearate, molybdenum disulfide, or boron nitride.

The above-mentioned zirconate is one or a combination of strontium zirconate, barium zirconate, or calcium zirconate.

The above-mentioned silicate is one or a combination of zirconium silicate or calcium silicate.

The above-mentioned slag-forming agent is a mixture of at least one zirconate and at least one silicate, in which the mass ratio of zirconate to silicate is <NUM>:<NUM>-<NUM>.

In an optional embodiment of the present disclosure, the slag-forming agent is a mixture of strontium zirconate, zirconium silicate, and calcium silicate in a mass ratio of <NUM>:<NUM>-<NUM>:<NUM>-<NUM>.

In an optional embodiment of the present disclosure, the slag-forming agent is a mixture of strontium zirconate and barium zirconate in a mass ratio of <NUM>:<NUM>-<NUM>.

The above-mentioned ammonium perchlorate has a particle size D90 not greater than <NUM>.

The above-mentioned slag-forming agent has a particle size D90 not greater than <NUM>.

The above-mentioned basic copper nitrate and the lubricant/release agent each have a particle size D90 not greater than <NUM>.

A sum of water contents in the respective components of the gas generant composition described above is not more than <NUM>% of the total mass of the respective components.

In an optional embodiment of the present disclosure, the gas generant composition is molded as a circular or elliptical sheet structure, a circular or elliptical columnar (or cylindrical) structure, a special-shaped sheet or columnar structure, a circular or elliptical monoporous structure, a circular or elliptical porous structure, or a special-shaped monoporous or porous structure. Here, the circular sheet structure has a diameter of <NUM> to <NUM> and a height of <NUM> to <NUM>; the circular columnar structure has a diameter of <NUM> to <NUM> and a height of <NUM> to <NUM>; the circular monoporous structure has an inner diameter of <NUM> to <NUM>, an outer diameter of <NUM> to <NUM>, and a height of <NUM> to <NUM>; and the elliptical monoporous structure has an inner diameter of <NUM> to <NUM>, a major diameter of <NUM> to <NUM>, a minor diameter of <NUM> to <NUM>, and a height of <NUM> to <NUM>.

A method for preparing a gas generant composition according to the present disclosure may be carried out by a method comprising wet granulation, spray granulation, or dry granulation. Here, spray granulation or dry granulation may be carried out by using a traditional granulation process method.

Here, a specific preparation method for wet granulation includes the following steps.

Another specific preparation method for wet granulation includes the following steps.

The above-mentioned gas generant composition of the present disclosure is used in a gas generator of a vehicle airbag.

In the gas generant formulation based on basic copper nitrate and guanidine nitrate according to the present disclosure, zirconate, silicate, or a mixture of zirconate and silicate is added for the first time as a slag-forming agent of the gas generant, so that molten copper metal can be coagulated and agglomerated into lumps. The slag-forming agent has a melting point about <NUM>,<NUM>, which is much higher than the melting point of metallic copper. A large number of tests have shown that the slag-forming agent is less combustible and can gather all the solid combustion products and agglomerates together during combustion of the gas generant composition, so that the gas generant retains its original shape after being combusted. Zirconate, silicate, or a mixture thereof used in the present disclosure can create a good effect of coagulating a metallic copper melt formed after the decomposition of basic copper nitrate, to further reduce molten copper residues, and can serve to increase the viscosity of the molten residues and to maintain its own shape as a tablet matrix, thereby obtaining significant agglomeration and slagging effects.

In the following examples, the mixing device used is a three-dimensional multi-directional motion mixer (or an ultra-efficient mixer), the kneader used is a horizontal kneader, the drying device used is a vacuum oven, and the molding device used is a rotary tablet press.

A gas generant composition comprised components having the following contents, in percent by mass:.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, and strontium titanate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

The prepared round tablets were loaded into a test generator and subjected to an ignition and combustion test. After the test, the generator was dissected to observe the form of the combusted tablets.

<FIG> was a picture showing the morphology of residues obtained after combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure. Table <NUM> below showed statistics of the weights of soluble residues and insoluble residues discharged after the combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure and their low-temperature ignition delay time. It could be seen from <FIG> and Table <NUM> that the tablets were in the form of sheets, were tightly attached to the inner wall of the filter, had poor density, were easily broken when touched by hand, and would tend to fly out of the generator filter and fall into the airbag and might burn through the inflatable bag and cause potential danger to a human body. Their low-temperature ignition time met the requirement of being less than <NUM>.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, and barium zirconate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

<FIG> was a picture showing the morphology of residues obtained after combustion of the gas generant composition tablets in Example <NUM> of the present disclosure. Table <NUM> below showed statistics of the weights of soluble residues and insoluble residues discharged after the combustion of the gas generant composition tablets in Example <NUM> of the present disclosure and their low-temperature ignition delay time. It could be seen from <FIG> and Table <NUM> that after combusted at high temperature, the tablets were in the form of the original tablet, were tightly attached to the inner wall of the filter, and had larger density. The tablets had retained a very good original appearance and had higher strength and higher density to support the maintaining of their original appearance. Their low-temperature ignition time met the requirement of being less than <NUM>.

In this example, barium zirconate was added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and talc was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, and strontium titanate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; and talc was added to the fourth material, and the material was molded (shaped) by a rotary tablet press.

<FIG> was a picture showing the morphology of residues obtained after combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure. Table <NUM> below showed statistics of the weights of soluble residues and insoluble residues discharged after the combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure and their low-temperature ignition delay time. It could be seen from <FIG> and Table <NUM> that the tablets were in the form of sheets and partially in powder form, were tightly attached to the inner wall of the filter, had poor density, and would tend to fly out of the generator filter and fall into the airbag and might burn through the inflatable bag and cause potential danger to a human body. Their low-temperature ignition time did not meet the requirement of being less than <NUM>.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, strontium zirconate, and talc were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

<FIG> was a picture showing the morphology of residues obtained after combustion of the gas generant composition tablets in Example <NUM> of the present disclosure. Table <NUM> below showed statistics of the weights of soluble residues and insoluble residues discharged after the combustion of the gas generant composition tablets in Example <NUM> of the present disclosure and their low-temperature ignition delay time. It could be seen from <FIG> and Table <NUM> that after combusted at high temperature, the tablets were in the form of the original tablet and exhibited a significant coagulation effect. The residues were tightly attached to the inner wall of the filter and had larger density. The tablets had retained a very good original appearance and had higher strength and higher density to support the maintaining of their original appearance. Their low-temperature ignition time met the requirement of being less than <NUM>.

In this example, strontium zirconate was added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and talc was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, copper oxide, potassium perchlorate, silicon dioxide, and calcium stearate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

<FIG> was a picture showing the morphology of residues obtained after combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure. Table <NUM> below showed statistics of the weights of soluble residues and insoluble residues discharged after the combustion of the gas generant composition tablets in Comparative Example <NUM> of the present disclosure and their low-temperature ignition delay time. It could be seen from <FIG> and Table <NUM> that the tablets were agglomerated after combustion, and a large amount of metallic copper was separated out and attached to the inner wall of the filter but was not agglomerated into a desired sheet shape. As a result, the residue would tend to fly out of the generator filter and fall into the airbag and might burn through the inflatable bag and cause potential danger to a human body. Their low-temperature ignition time met the requirement of being less than <NUM>.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, calcium zirconate, and calcium stearate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

In this example, calcium zirconate was added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and calcium stearate was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, strontium zirconate, barium zirconate, and magnesium stearate were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

In this example, strontium zirconate and barium zirconate were added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and magnesium stearate was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, zirconium silicate, and talc were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

In this example, zirconium silicate was added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and talc was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

These components were weighed and then were pressed into round tablets with a diameter of <NUM> and a thickness of <NUM> by wet granulation and by a rotary tablet press. The specific preparation method was carried out as follows. Guanidine nitrate, basic copper nitrate, strontium nitrate, ammonium perchlorate, strontium zirconate, zirconium silicate, and talc were mixed by a mixing device to obtain a first material; <NUM>% of distilled water was added to the first material and the first material was subjected to wet kneading for <NUM> to obtain a second material, and the second material was caused to pass through a <NUM>-mesh sieve to obtain a third material; the third material was dried to a water content less than <NUM>% of the total mass of the third material and was caused to pass through the <NUM>-mesh sieve again to obtain a fourth material; talc was added to the fourth material, and the material was molded by a rotary tablet press.

In this example, strontium zirconate and zirconium silicate were added as a slag-forming agent, basic copper nitrate was used as a primary oxidizer, guanidine nitrate was used as a fuel, AP and strontium nitrate were used as auxiliary oxidizers, and talc was used as a lubricant and a release agent. The tablets retained a very good original appearance after being tested in a generator for an airbag. After a TANKWASH test was conducted, the weight of the water-soluble matter and the weight of the insoluble matter were decreased significantly. Moreover, the composition was combusted at an increased speed and had an ignition delay that met the strict requirements of USCAR.

Claim 1:
A gas generant composition, comprising guanidine nitrate, basic copper nitrate, strontium nitrate and ammonium perchlorate, characterized by further comprising a slag-forming agent and a lubricant, wherein the slag-forming agent is at least one zirconate, at least one silicate or a mixture of at least one zirconate and at least one silicate,
wherein contents, in percent by mass, of respective components are as follows:

<TAB>