BASIC METAL NITRATE, PROCESS FOR PRODUCING THE SAME AND GAS GENERATING AGENT COMPOSITION

• US 20100326574A1
• Filed: 09/08/2010
• Published: 12/30/2010
• Est. Priority Date: 09/27/1999
• Status: Active Grant

• Current Assignee: Jianzhou Wu, Kaoru Yamazaki, Kazuyuki Matsuoka, Takeshi Takahori, Xingxi Zhou, Yo Yamato
• Original Assignee: Jianzhou Wu, Kaoru Yamazaki, Kazuyuki Matsuoka, Takeshi Takahori, Xingxi Zhou, Yo Yamato
• Inventors: Wu, Jianzhou, Yamato, Yo, Zhou, Xingxi, Takahori, Takeshi, Matsuoka, Kazuyuki, Yamazaki, Kaoru
• Granted Patent: US 8,613,821 B2
• Time in Patent Office: Days
• US Class Current: 149/17
• CPC Class Codes: C01B 21/48 Methods for the preparation of nitrates in general particular individual nitrates, see the relevant groups of subclasses C01B - C01G, according to the cation
• CPC Class Codes: C01G 1/08 Nitrates
• CPC Class Codes: C01G 3/08 Nitrates
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C06B 31/00 Compositions containing an inorganic nitrogen-oxygen salt
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

Provided is a basic metal nitrate suitable as an oxidizing agent for a gas generating agent, which is a basic metal nitrate having a good thermal stability and meeting at least one requirement of the following (a) to (d):

• • (a) a particle diameter of 0.5 to 40 μm; (b) a degree of crystallinity having 0.4 deg or less of a half band width of the peak in the X-ray analysis; (c) an initiation temperature of weight loss being 220° C. or higher according to TG-DTA analysis; and (d) an impurity content of 1,000 ppm or less based on Na atom. Further provided is a gas generating composition which has a low toxicity, a high burning rate and a low combustion temperature and which is used in a gas generator for an air bag. The gas generating composition comprises (a) tetrazole derivatives, guanidine derivatives or a mixture thereof, (b) a basic metal nitrate and (c) a binder and/or a slag-forming agent.

Claims

1. A gas generating composition comprising:

(a) a tetrazole derivative selected from the group consisting of tetrazole, 5-aminotetrazole, 5,5′

-bi-1H-tetrazole, 5-nitroaminotetrazole, 5-aminotetrazole zinc salt, 5-aminotetrazole copper salt, bitetrazole, bitetrazole potassium salt, bitetrazole sodium salt, bitetrazole magnesium salt, bitetrazole calcium salt, bitetrazole diammonium salt, bitetrazole copper salt, and bitetrazole melamine salt, or

a guanidine derivative selected from the group consisting of guanidine, mono-aminoguanidine nitrate, di-aminoguanidine nitrate, tri-aminoguanidine nitrate, guanidine nitrate, guanidine carbonate, nitroguanidine, dicyandiamide, and nitroaminoguanidine nitrate,

as a fuel; and

(b) a basic metal nitrate having a particle diameter of 0.5 to 40 μ

m, wherein the basic metal nitrate is at least one member selected from the group consisting of a basic copper nitrate, a basic cobalt nitrate, a basic zinc nitrate, a basic manganese nitrate, a basic iron nitrate, a basic molybdenum nitrate, and a basic bismuth nitrate

as an oxidizing agent,

wherein said gas generating composition comprises 40 to 90 weight-% of oxidizing component (b).

2. The gas generating composition of claim 1, comprising 10 to 60 weight-% of fuel component (a).

3. The gas generating composition of claim 1, further comprising (c) a binder and/or slag-forming agent.

4. The gas generating composition of claim 1 or 2, wherein oxidizing component (b) is a basic copper nitrate.

5. The gas generating composition of claim 1, wherein oxidizing component (b) is a mixture of a basic metal nitrate and at least one other oxidizing agent.

6. The gas generating composition of claim 1, wherein, when oxidizing component (b) is a mixture, the content of the basic metal nitrate in the mixture is 55 to 99.9% by weight of component (b).

7. The gas generating composition of claim 3, wherein component (c) comprises a binder which is not crosslinkable.

8. The gas generating composition of claim 3, wherein the binder and/or the slag-forming agent as component (c) is not crosslinkable and is at least one member selected from the group consisting of carboxymethylcellulose, sodium carboxymethylcellulose, potassium carboxymethylcellulose, ammonium carboxymethylcellulose, cellulose acetate, cellulose acetatebutylate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylethyl cellulose, fine crystalline cellulose, polyacrylic amide, aminated compounds of polyacrylic amide, polyacrylic hydrazide, a copolymer of an acrylic amide and a metal salt of acrylic acid, a copolymer of polyacrylic amide and polyacrylic ester, polyvinyl alcohol, acrylic rubber, guar gum, starch, polysaccharides including starch, silicone, molybdenum disulfide, Japanese acid clay, talc, bentonite, diatomaceous earth, kaolin, calcium stearate, silica, alumina, sodium silicate, silicon nitrate, silicon carbide, hydrotalcite, mica, a metal oxide, a metal hydroxide, a metal carbonate, a basic metal carbonate, and a molybdate.

9. The gas generating composition of claim 8, wherein

when the metal oxide is selected as component (c), it is at least one member selected from the group consisting of copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, and bismuth oxide,

when the metal hydroxide is selected as component (c), it is at least one member selected from the group consisting of cobalt hydroxide and aluminum hydroxide,

when the metal carbonate or basic metal carbonate is selected as component (c), it is at least one member selected from the group consisting of calcium carbonate, cobalt carbonate, a basic zinc carbonate, and a basic copper carbonate, and

when the molybdate is selected as component (c), it is at least one member selected from the group consisting of cobalt molybdate and ammonium molybdate.

10. The gas generating composition of claim 1, which comprises (a) nitroguanidine and (b) a basic copper nitrate.

11. The gas generating composition of claim 10, which comprises 40 to 60% by weight of (a) nitroguanidine and 40 to 60% by weight of (b) a basic copper nitrate.

12. The gas generating composition of claim 3, which comprises (a) nitroguanidine, (b) a basic copper nitrate, and (c) sodium carboxymethylcellulose.

13. The gas generating composition of claim 12, which comprises 15 to 55% by weight of (a) nitroguanidine, 45 to 70% by weight of (b) a basic copper nitrate, and 0.1 to 15% by weight of (c) sodium carboxymethylcellulose.

14. The gas generating composition of claim 8 or 9, which comprises (a) nitroguanidine, (b) a basic copper nitrate, (c-1) sodium carboxymethylcellulose, and (c-2) a component (c) as recited in one of claim 10 or 11 in addition to sodium carboxymethylcellulose.

15. The gas generating composition of claim 3, which comprises (a) nitroguanidine, (b) a basic copper nitrate, and (c) guar gum.

16. The gas generating composition of claim 15, which comprises 30 to 50% by weight of (a) nitroguanidine, 40 to 65% by weight of (b) a basic copper nitrate, and 0.7 to 8% by weight of guar gum.

17. The gas generating composition of claim 8 or claim 9, which comprises (a) nitroguanidine, (b) a basic copper nitrate, (c-1) guar gum, and (c-2) a component as recited in one of claim 10 or 11 in addition to guar gum.

18. An inflator for an air bag using the gas generating composition as claimed in any one of claim 1, 2, 3, 8, or 9.

19. A molded article in the form of a single-perforated cylinder, a perforated (porous) cylinder, or pellets, wherein said molded article is obtained from the gas generating composition as claimed in any one of claim 1, 2, 3, 8, or 9.

20. An inflator for an air bag using the molded article as claimed in claim 19.