Method of forming gas generant fuel mixture

Abstract

According to various implementations, there is provided a method of forming a fuel mixture for a gas generating composition, comprising the steps of providing a mixture of melamine and water, adding nitric acid to the mixture to form melamine nitrate, mixing guanidine carbonate therein to form guanidine nitrate. The guanidine carbonate mixing step may be performed at room temperature for at least 10 minutes. Melamine nitrate and guanidine nitrate form a solid precipitated fuel mixture, which is filtered and flushed with water, and then the flushed fuel mixture is dried. The drying step may be performed at a temperature in the range of 100 DEG C to 110 DEG C. The nitric acid may be added in the form of an aqueous solution having a molar concentration of 0.1 to 0.25. Also disclosed is a gas generating composition for an airbag gas generator comprising a melamine nitrate and guanidine nitrate fuel mixture.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 387,551, filed December 15, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to safety devices for passenger vehicles. In particular, the present disclosure relates to a method for forming a gas generant fuel mixture for an airbag inflator. For example, passenger vehicles may include automobiles, ships, trains, airplanes, and spacecraft. Background Art

[0004] Airbag systems have been widely adopted to improve the safety of passengers in traffic vehicles such as automobiles. In these systems, a gas generator is operated by an ignition signal from a collision sensor that detects a collision, and an airbag between a passenger and a part of the automobile is inflated. The gas generator needs to produce a sufficient amount of gas to inflate the airbag in a very short time. The typical gas generating composition for producing gas in current gas generators comprises at least an oxidant and a fuel. The specific ingredients used in a given composition and the content of these ingredients greatly affect the performance (for example, ignition rate, burning rate, heat, sensitivity, etc.), cost, and applicability of the composition for inflating the airbag.

[0005] An example of a gas generating composition for an air bag can be found in U.S. Patent No. 10,358,393, issued to the applicant of the present application. Example fuels for such a gas generating composition include melamine nitrate and guanidine nitrate. Melamine nitrate and guanidine nitrate can be mixed with at least one oxidizing agent and optionally additives to form the gas generating composition. However, each fuel is typically manufactured separately before being added to the gas generating composition, which results in higher costs and complexity. In addition, the production of melamine nitrate produces a large amount of waste acid, which is difficult to properly manage from a safety and environmental perspective. Therefore, an improved process for producing a fuel mixture of melamine nitrate and guanidine nitrate would be cost-effective and safer in many respects. Accordingly, a gas generating composition using such a fuel mixture would also be more cost-effective and more beneficial. Summary of the Invention

[0006] Various implementations include a method for forming a fuel mixture for a gas generating composition. The method comprises the following steps: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, nitric acid, and melamine nitrate to form guanidine nitrate; (d) filtering the melamine nitrate and guanidine nitrate; (e) rinsing the melamine nitrate and guanidine nitrate filtered in step (d) with water; and (f) drying the melamine nitrate and guanidine nitrate rinsed in step (e). The mixing in step (c) is performed at room temperature for at least 10 minutes, and the drying in step (f) is performed at a temperature in the range of 100° C. to 110° C. The nitric acid can be added as an aqueous solution having a molar concentration of 0.1 to 0.25. In some implementations, the molar ratio of melamine to guanidine carbonate is about 1:1. In some implementations, 2-4 molar equivalents of nitric acid are added. In some implementations, 3 molar equivalents of nitric acid are added. In some implementations, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3. In other implementations, the fuel mixture is prepared by the method disclosed above. In other implementations, a gas generator comprises a gas generating composition comprising the fuel mixture prepared by the method disclosed above.

[0007] In other embodiments, a method of forming a gas generating composition includes the following steps: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, nitric acid, and melamine nitrate to form guanidine nitrate; (d) filtering the melamine nitrate and guanidine nitrate; (e) rinsing the filtered melamine nitrate and guanidine nitrate in step (d) with water; (f) drying the rinsed melamine nitrate and guanidine nitrate in step (e); and (g) mixing the dried melamine nitrate and guanidine nitrate of step (f) with an oxidant. The mixing in step (c) is carried out at room temperature for at least 10 minutes, and the drying in step (f) is carried out at a temperature in the range of 100° C. to 110° C. The nitric acid can be added as an aqueous solution having a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is about 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3. In some embodiments, the oxidant is basic copper nitrate. In other embodiments, the gas generating composition is prepared by the method disclosed above. In other embodiments, a gas generator comprises the gas generating composition prepared by the method disclosed above.

[0008] In other embodiments, a method of forming a fuel mixture for a gas generant composition includes the following steps: (a) mixing melamine, guanidine carbonate, and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering the melamine nitrate and guanidine nitrate formed in step (a); (c) rinsing the filtered melamine nitrate and guanidine nitrate in step (b) with water; and (d) drying the melamine nitrate and guanidine nitrate from step (c). The mixing in step (a) is performed at room temperature for at least 10 minutes, and the drying in step (d) is performed at a temperature in the range of 100°C to 110°C. The nitric acid can be added as an aqueous solution having a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is approximately 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3. In other implementations, the fuel mixture is prepared by the methods disclosed above. In other implementations, a gas generator comprises a gas generant composition comprising the fuel mixture prepared by the methods disclosed above.

[0009] In other embodiments, a method of forming a gas generating composition includes the following steps: (a) mixing melamine, guanidine carbonate, and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering the melamine nitrate and guanidine nitrate formed in step (a); (c) rinsing the filtered melamine nitrate and guanidine nitrate in step (b) with water; (d) drying the melamine nitrate and guanidine nitrate of step (c); and (e) mixing the dried melamine nitrate and guanidine nitrate of step (d) with an oxidizing agent. The mixing in step (a) is carried out at room temperature for at least 10 minutes, and the drying in step (d) is carried out at a temperature in the range of 100° C. to 110° C. The nitric acid can be added as an aqueous solution with a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is about 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some implementations, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3. In some implementations, the oxidizing agent is basic copper nitrate. In other implementations, the gas generating composition is prepared by the method disclosed above. In other implementations, a gas generator comprises the gas generating composition prepared by the method disclosed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are merely exemplary and are used to illustrate steps, structures, and certain features that may be used alone or in combination with other features. The present disclosure should not be limited to the implementations shown.

[0011] Figure 1 is a cross-sectional view of an air bag inflator for use with a gas generant composition formed by the methods disclosed herein.

[0012] Figure 2 is a block diagram of method steps for forming a fuel mixture for a gas generant composition, according to one implementation.

[0013] Figure 3 Is used to use Figure 2 A block diagram of the method steps for forming a fuel mixture to form a gas generating composition.

[0014] Figure 4 is a block diagram of method steps for forming a fuel mixture for a gas generant composition according to another implementation.

[0015] Figure 5 Is used to use Figure 4 A block diagram of the method steps for forming a fuel mixture to form a gas generating composition.

[0016] Figure 6 is through Figure 2 FTIR spectra of fuel mixtures formed by the method steps and comparative fuel mixtures. DETAILED DESCRIPTION

[0017] Gas generator

[0018] like Figure 1 As shown, the exemplary inflator 10 includes a single ignition chamber containing a primary gas generant 14. The inflator 10 also includes a boost chamber containing a pressurized gas generant 12. When the inflator 10 deploys, the boost gas generant 12 is ignited, thereby causing the primary gas generant 14 to ignite, thereby providing inflation gas for the attached airbag. The fuel mixtures and gas generant compositions described herein may be used with the boost gas generant 12, the primary gas generant 14, or both. Preferably, the fuel mixtures and gas generant compositions described herein are used with the primary gas generant 14.

[0019] fuel mixture

[0020] According to one implementation, the fuel mixture for the gas generating composition may be prepared by Figure 2 The method 200 shown is for production. In a first step 201, a mixture of melamine and water is provided. In step 202, an excess of two molar equivalents of nitric acid relative to the melamine is added to the water to form melamine nitrate. In step 203, guanidine carbonate is mixed into the mixture of water, nitric acid, and melamine nitrate, allowing the remaining nitric acid to react with the guanidine carbonate to form guanidine nitrate and carbon dioxide. The guanidine carbonate mixing step is carried out at room temperature for at least 10 minutes. As used herein, room temperature is used to describe a temperature in the range of 15°C to 25°C, inclusive. The nitric acid can be added as an aqueous solution with a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is approximately 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3.

[0021] Both melamine nitrate and guanidine nitrate will form a solid precipitated fuel mixture, which can be filtered out in step 204. Filtration can be carried out with a standard laboratory or production-scale filtration system, such as filter paper or fine mesh screen used in a vibrating screen machine. In step 205, the filtered melamine nitrate and guanidine nitrate fuel mixture is rinsed with water. Finally, in step 206, the rinsed melamine nitrate and guanidine nitrate fuel mixture is dried at a temperature within the range of 100° C. to 110° C. (including the end values of this range). This method produces a fuel mixture of melamine nitrate and guanidine nitrate, which can be used for gas generating compositions of air bag inflators. This method significantly reduces costs and eliminates harmful acid waste byproducts. As a non-limiting example, the reaction can be represented by the following chemical equation:

[0022]

[0023] According to another implementation, the fuel mixture for the gas generating composition can be prepared by Figure 4 The method 400 shown is produced. In a first step 401, melamine, guanidine carbonate and nitric acid are mixed in water so that the melamine and guanidine carbonate react with the nitric acid to form melamine nitrate and guanidine nitrate, respectively. The mixing is carried out at room temperature for at least 10 minutes. As used herein, room temperature is used to describe a temperature in the range of 15°C to 25°C, including the end values of the range. Nitric acid can be added as an aqueous solution with a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is about 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3.

[0024] Both the melamine nitrate and the guanidine nitrate will form a solid precipitated fuel mixture, which can be filtered out in step 402. Filtration can be performed using a standard laboratory or production-scale filtration system, such as filter paper or a fine mesh screen used in a vibrating screen machine. In step 403, the filtered melamine nitrate and guanidine nitrate fuel mixture is rinsed with water. Finally, in step 404, the rinsed melamine nitrate and guanidine nitrate fuel mixture is dried at a temperature in the range of 100° C. to 110° C. (including the end values of this range). The method produces a fuel mixture of melamine nitrate and guanidine nitrate, which can be used in a gas generating composition for air bag inflators. This method significantly reduces costs and eliminates harmful acid waste byproducts. As a non-limiting example, the reaction can be represented by the following chemical equation:

[0025]

[0026] Gas generating composition

[0027] According to another implementation, Figure 3 The illustrated method 300 produces a gas generating composition. In a first step 301, a mixture of melamine and water is provided. In step 302, an excess of two molar equivalents of nitric acid relative to the melamine is added to the water to form melamine nitrate. In step 303, guanidine carbonate is mixed into the mixture of water, nitric acid, and melamine nitrate, and the remaining nitric acid reacts with the guanidine carbonate to form guanidine nitrate and carbon dioxide. The mixing is performed at room temperature for at least 10 minutes. As used herein, room temperature is used to describe a temperature in the range of 15°C to 25°C, inclusive. The nitric acid can be added as an aqueous solution having a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is approximately 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3.

[0028] Both the melamine nitrate and the guanidine nitrate will form a solid precipitated fuel mixture, which can be filtered out in step 304. Filtration can be performed using a standard laboratory or production-scale filtration system, such as filter paper or fine mesh screens used in vibrating screen machines. In step 305, the filtered melamine nitrate and guanidine nitrate fuel mixture is rinsed with water. In step 306, the rinsed melamine nitrate and guanidine nitrate fuel mixture is dried at a temperature in the range of 100° C. to 110° C. (inclusive). Then, in step 307, the resulting melamine nitrate and guanidine nitrate fuel mixture is mixed with an oxidant to form a gas generating composition. The gas generating composition at this point is typically in the form of a powder mixture. Then, in step 308, this powder can be pressed into tablet or wafer form, as required by the needs of the specific gas generator.

[0029] According to another implementation, Figure 5The method 500 shown produces a gas generating composition. In a first step 501, melamine, guanidine carbonate and nitric acid are mixed in water so that the melamine and guanidine carbonate react with the nitric acid to form melamine nitrate and guanidine nitrate, respectively. The mixing is carried out at room temperature for at least 10 minutes. As used herein, room temperature is used to describe a temperature in the range of 15°C to 25°C, inclusive. The nitric acid can be added as an aqueous solution having a molar concentration of 0.1 to 0.25. In some embodiments, the molar ratio of melamine to guanidine carbonate is about 1:1. In some embodiments, 2-4 molar equivalents of nitric acid are added. In some embodiments, 3 molar equivalents of nitric acid are added. In some embodiments, the molar ratio of melamine:guanidine carbonate:nitric acid is 1:1:3.

[0030] Both the melamine nitrate and the guanidine nitrate will form a solid precipitated fuel mixture, which can be filtered out in step 502. Filtration can be performed using a standard laboratory or production-scale filtration system, such as filter paper or fine mesh screens used in a vibrating screen machine. In step 503, the filtered melamine nitrate and guanidine nitrate fuel mixture is rinsed with water. In step 504, the rinsed melamine nitrate and guanidine nitrate fuel mixture is dried at a temperature in the range of 100° C. to 110° C. (inclusive). Then, in step 505, the resulting melamine nitrate and guanidine nitrate fuel mixture is mixed with an oxidant to form a gas generating composition. The gas generating composition at this point is typically in the form of a powder mixture. Then, in step 506, this powder can be pressed into tablet or disc form, as required by the needs of the specific gas generator.

[0031] In some embodiments of the disclosed gas generating composition, the oxidizer is selected from the group consisting of metal perchlorates, non-metal perchlorates, metal nitrates, basic metal nitrates, non-metal nitrates, and combinations thereof. In some embodiments, the metal nitrate is potassium nitrate. In other embodiments, the metal nitrate is a basic metal nitrate. Suitable basic metal nitrates can be selected from the group consisting of 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. Specific examples of these suitable metal nitrates are Cu2(NO3)(OH)3, Cu3(NO3)(OH)5.2H2O, Co2(NO3)(OH)3, Zn2(NO3)(OH)3, Mn(NO3)(OH)2, Fe4(NO3)(OH) 11 .2H2O, MoO2(NO3)2, Bi(NO3)(OH)2 and Ce(NO3)3(OH).3H2O. Among them, basic copper nitrate is preferred.

[0032] Example

[0033] Example 1: According to this article about Figure 2 The disclosed method 200 produces a fuel mixture with a yield of >90% by mass. Thereafter, the fuel mixture is analyzed using an FTIR instrument and compared with a comparative fuel mixture that is also analyzed using an FTIR instrument. The comparative fuel mixture is prepared by mixing separately produced melamine nitrate and guanidine nitrate in water and then drying the mixture overnight. Figure 6 As shown, the FTIR absorbance curve of the fuel mixture prepared according to method 200 indicates the formation of melamine nitrate and guanidine nitrate, thereby confirming the feasibility of method 200 to produce a high-quality fuel mixture of melamine nitrate and guanidine nitrate at low cost and with limited acid waste byproducts.

[0034] A variety of implementations have been described. The descriptions in this disclosure are presented for illustrative purposes and are not intended to be exhaustive or limited to the disclosed implementations. It will be understood that various modifications and variations will be apparent to one of ordinary skill in the art and may be made without departing from the spirit and scope of the claims. Therefore, other implementations are within the scope of the appended claims. The described implementations were selected in order to best explain the principles of the fuel mixtures and gas generating compositions and their practical applications, and to enable one of ordinary skill in the art to understand the fuel mixtures and gas generating compositions for various implementations with various modifications suitable for the specific use contemplated.

[0035] The terms used herein are only used to describe specific implementations and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" used herein also include the plural forms. It should be further understood that when used in this specification, the terms "comprise" and / or "include" specify the presence of stated steps, features, operations, elements and / or components, but do not exclude the presence or addition of one or more other steps, features, operations, elements, components and / or combinations thereof.

Claims

1. A method of forming a fuel mixture for a gas generating composition comprising the steps of: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, nitric acid and melamine nitrate to form guanidine nitrate; (d) filtering out the melamine nitrate and guanidine nitrate; (e) washing the melamine nitrate and guanidine nitrate filtered in step (d) with water; and (f) drying the melamine nitrate and guanidine nitrate washed in step (e).

2. The method of claim 1, wherein the mixing of step (c) is performed at room temperature for at least 10 minutes.

3. The method according to claim 1, wherein the drying of step (f) is performed at a temperature in the range of 100°C to 110°C.

4. The method according to claim 1, wherein the nitric acid is added as an aqueous solution having a molar concentration of 0.1 to 0.

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5. A method of forming a gas generating composition comprising the steps of: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, nitric acid and melamine nitrate to form guanidine nitrate; (d) filtering out the melamine nitrate and guanidine nitrate; (e) washing the filtered melamine nitrate and guanidine nitrate in step (d) with water; (f) drying the melamine nitrate and guanidine nitrate washed in step (e); and (g) mixing the dried melamine nitrate and guanidine nitrate of step (f) with an oxidizing agent.

6. The method of claim 5, wherein the mixing of step (c) is performed at room temperature for at least 10 minutes.

7. The method according to claim 5, wherein the drying of step (f) is performed at a temperature in the range of 100°C to 110°C.

8. The method of claim 5, wherein the nitric acid is added as an aqueous solution having a molar concentration of 0.1 to 0.

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9. The method of claim 5, wherein the oxidizing agent is selected from the group consisting of metal perchlorates, non-metal perchlorates, metal nitrates, basic metal nitrates, non-metal nitrates, and combinations thereof.

10. The method of claim 9, wherein the oxidizing agent is basic copper nitrate.

11. The method of claim 5, further comprising the step of compressing the gas generating composition into tablets or wafers.

12. A gas generator for use with an air bag, comprising the tablet or wafer according to claim 11.

13. A fuel mixture for a gas generating composition, prepared by a method comprising the steps of: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, nitric acid and melamine nitrate to form guanidine nitrate; (d) filtering out the melamine nitrate and guanidine nitrate; (e) washing the melamine nitrate and guanidine nitrate filtered in step (d) with water; and (f) drying the melamine nitrate and guanidine nitrate washed in step (e).

14. The fuel mixture of claim 13, wherein the mixing of step (c) is performed at room temperature for at least 10 minutes.

15. The fuel mixture according to claim 13, wherein the drying of step (f) is performed at a temperature in the range of 100°C to 110°C.

16. The fuel mixture of claim 13, wherein the nitric acid is added as an aqueous solution having a molar concentration of 0.1 to 0.

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17. A gas generating composition prepared by a method comprising the steps of: (a) providing a mixture of melamine and water; (b) adding nitric acid in an amount exceeding two molar equivalents relative to the melamine to the mixture to form melamine nitrate; (c) mixing guanidine carbonate into the mixture of water, excess nitric acid and melamine nitrate to form guanidine nitrate; (d) filtering out the melamine nitrate and guanidine nitrate; (e) washing the filtered melamine nitrate and guanidine nitrate in step (d) with water; (f) drying the melamine nitrate and guanidine nitrate washed in step (e); and (g) mixing the dried melamine nitrate and guanidine nitrate of step (f) with an oxidizing agent.

18. The gas generant composition of claim 17, wherein the mixing of step (c) is performed at room temperature for at least 10 minutes.

19. The gas generant composition of claim 17, wherein the drying of step (f) is performed at a temperature in the range of 100°C to 110°C.

20. The gas generant composition of claim 17, wherein the nitric acid is added in the form of an aqueous solution having a molar concentration of 0.1 to 0.

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21. The gas generant composition of claim 17, wherein the oxidant is selected from the group consisting of metal perchlorates, non-metal perchlorates, metal nitrates, basic metal nitrates, non-metal nitrates, and combinations thereof.

22. The gas generant composition of claim 21, wherein the oxidizing agent is basic copper nitrate.

23. The gas generant composition of claim 17, further comprising the step of compressing the gas generant composition into tablets or wafers.

24. A gas generator for use with an air bag, comprising the tablet or wafer according to claim 23.

25. A method of forming a fuel mixture for a gas generant composition comprising the steps of: (a) mixing melamine, guanidine carbonate and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering out the melamine nitrate and guanidine nitrate formed in step (a); (c) washing the melamine nitrate and guanidine nitrate filtered in step (b) with water; and (d) drying the melamine nitrate and guanidine nitrate of step (c).

26. The method of claim 25, wherein the mixing of step (a) is performed at room temperature for at least 10 minutes.

27. The method of claim 25, wherein the drying of step (d) is performed at a temperature in the range of 100°C to 110°C.

28. The method of claim 25, wherein the nitric acid is mixed as an aqueous solution having a molar concentration of 0.1 to 0.

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29. A method of forming a gas generating composition comprising the steps of: (a) mixing melamine, guanidine carbonate and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering out the melamine nitrate and guanidine nitrate formed in step (a); (c) washing the melamine nitrate and guanidine nitrate filtered in step (b) with water; and (d) drying the melamine nitrate and guanidine nitrate of step (c); and (e) mixing the dried melamine nitrate and guanidine nitrate of step (d) with an oxidizing agent.

30. The method of claim 29, wherein the mixing of step (a) is performed at room temperature for at least 10 minutes.

31. The method of claim 29, wherein the drying of step (d) is performed at a temperature in the range of 100°C to 110°C.

32. The method of claim 29, wherein the nitric acid is mixed as an aqueous solution having a molar concentration of 0.1 to 0.

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33. The method of claim 29, wherein the oxidizing agent is selected from the group consisting of metal perchlorates, non-metal perchlorates, metal nitrates, basic metal nitrates, non-metal nitrates, and combinations thereof.

34. The method of claim 33, wherein the oxidizing agent is basic copper nitrate.

35. The method of claim 29, further comprising the step of compressing the gas generant composition into tablets or wafers.

36. A gas generator for use with an air bag, comprising the tablet or wafer according to claim 35.

37. A fuel mixture for a gas generant composition prepared by a process comprising the steps of: (a) mixing melamine, guanidine carbonate and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering out the melamine nitrate and guanidine nitrate formed in step (a); (c) washing the melamine nitrate and guanidine nitrate filtered in step (b) with water; and (d) drying the melamine nitrate and guanidine nitrate of step (c).

38. The fuel mixture of claim 37, wherein the mixing of step (a) is performed at room temperature for at least 10 minutes.

39. The fuel mixture of claim 37, wherein the drying of step (d) is performed at a temperature in the range of 100°C to 110°C.

40. The fuel mixture of claim 37, wherein the nitric acid is mixed as an aqueous solution having a molar concentration of 0.1 to 0.

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41. A gas generating composition prepared by a method comprising the steps of: (a) mixing melamine, guanidine carbonate and nitric acid in water to form melamine nitrate and guanidine nitrate; (b) filtering out the melamine nitrate and guanidine nitrate formed in step (a); (c) washing the melamine nitrate and guanidine nitrate filtered in step (b) with water; and (d) drying the melamine nitrate and guanidine nitrate of step (c); and (e) mixing the dried melamine nitrate and guanidine nitrate of step (d) with an oxidizing agent.

42. The gas generant composition of claim 41, wherein the mixing of step (a) is performed at room temperature for at least 10 minutes.

43. The gas generant composition of claim 41, wherein the drying of step (d) is performed at a temperature in the range of 100°C to 110°C.

44. The gas generant composition of claim 41, wherein the nitric acid is mixed as an aqueous solution having a molar concentration of 0.1 to 0.

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45. The gas generant composition of claim 41, wherein the oxidant is selected from the group consisting of metal perchlorates, non-metal perchlorates, metal nitrates, basic metal nitrates, non-metal nitrates, and combinations thereof.

46. The gas generant composition of claim 45, wherein the oxidant is basic copper nitrate.

47. The gas generant composition of claim 41, further comprising the step of compressing the gas generant composition into tablets or wafers.

48. A gas generator for use with an air bag, comprising the tablet or wafer according to claim 47.

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