Airbag explosive composition and process for producing said composition

• US 6,033,500 A
• Filed: 01/27/1998
• Issued: 03/07/2000
• Est. Priority Date: 07/27/1995
• Status: Expired due to Term

• Current Assignee: Nippon Kayaku Company Limited
• Original Assignee: Nippon Kayaku Company Limited, Sentech Co., Ltd. (Omron Corporation)
• Inventors: Oishi, Eri, Ito, Yuji, Yoshikawa, Eiichiro, Iwasaki, Makoto, Tanaka, Akihiko, Minoguchi, Ryo, Ikeda, Kenjiro, Sato, Eishi, Kuroiwa, Akihiko
• Primary Examiner(s): Miller, Edward A.
• Application Number:
  US08/983,507
• Time in Patent Office: 770 Days
• Field of Search: 149/36, 149/46, 149/61, 149/109.6, 149/109.4, 149/77, 149/17, 264/3.1
• US Class Current: 149/36
• CPC Class Codes: C06B 45/04 comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

The present invention is directed to an airbag explosive composition comprising a fuel ingredient, an oxidizing agent and a binder for binding them, said binder being hydrotalcite group expressed by the following general formula (1), and a producing method therefor:

[M.sup.2+.sub.1-x M.sup.3+.sub.x (OH).sub.2 ].sup.x+ [A.sup.n-.sub.x/n.

mH₂ O]^x- (1)

where

M²⁺ represents a bivalent metal such as Mg²⁺, Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺ ;

M³⁺ represents a trivalent metal such as Al³⁺, Fe³⁺, Cr³⁺, Co³⁺ and In³⁺ ;

A^n- represents an n-valence anion such as OH^-, F^-, Cl^-, NO₃^-, C0₃^2-, SO₄^2-, Fe(CN)₆^3-, CH₃ COO^-, oxalate ion and salicylate ion; and

0<x≦0.33.

Claims

1. An airbag explosive composition, comprising:

(a) a fuel selected from the group consisting of (i) 5-aminotetrazole, (ii) an alkali metal salt of 5-aminotetrazole and (iii) an alkaline earth metal salt of 5-aminotetrazole;

(b) an oxidizing agent for the combustion of said fuel; and

(c) a hydrotalcite binder for ingredients (a) and (b) having the formula;

space="preserve" listing-type="equation">[M.sup.2+.sub.1-x M.sup.3+.sub.x (OH).sub.2 ].sup.x+ [A.sup.n-.sub.x/n.mH.sub.2 O].sup.x-

wherein

M²⁺ is a bivalent metal ion;

M³⁺ is a trivalent metal ion;

A^n- is an n-valent anion; and

<

x≦

0.33 and m is a positive integer.

2. The composition as set forth in claim 1, wherein said bivalent metal ion M²⁺ is selected from the group consisting of Mg²⁺, Mn^2-, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺, said trivalent metal ion M³⁺ is selected from the group consisting of Al³⁺, Fe³⁺, Cr²⁺, Co³⁺ and In³⁺ and said n-valent anion is a member selected from the group consisting of OH^-, F^-, Cl^-, NO^3-, CO₃^2-, SO₄^2-, Fe(CN)₆^3-, CH₃ COO^-, oxalate ion and salicylate ion.

3. The composition as set forth in claim 1, wherein said hydrotalcite is a hydrotalcite of the formula:

Mg₆ Al₂ (OH)₁₆ CO₃.4H₂ O or pyroaurite of the formula;

Mg₆ Fe₂ (OH)₁₆ CO₃.4H₂ O.

4. The composition as set forth in claim 3, wherein the amount of said hydrotalcite in the composition is 2-30% by weight.

5. The composition as set forth in claim 4, wherein the amount of said hydrotalcite in the composition is 3-10% by weight.

6. The composition as set forth in claim 3, wherein the 50% average particle diameter of a reference number of particles of said hydrotalcite is 30 μ

m or less.

7. The composition as set forth in claim 1, wherein the 50% average particle diameter of a reference number of said fuel is 5-80 μ

m.

8. The composition as set forth in claim 1, wherein said oxidizing agent is at least one nitrate or nitrite of an alkali metal ion, an alkaline earth metal ion or ammonium ion.

9. The composition as set forth in claim 1, wherein said oxidizing agent is a mixture of an oxohalogen acid salt and at least one nitrate or nitrite of an alkali metal ion, an alkaline earth metal ion or an ammonium ion.

10. The composition as set forth in claim 1, wherein said oxidizing agent is strontium nitrate.

11. The composition as set forth in claim 8, wherein the 50% average particle diameter of a reference number of particles of said oxidizing agent is 5-80 μ

m.

12. The composition as set forth in claim 1, wherein said explosive composition comprises at least one combustion catalyst selected from the group consisting of components (d) and (e), wherein:

(d) is at least one metal selected from the group consisting of zirconium, hafnium, molybdenum, tungsten, manganese, nickel or iron or an oxide or sulfide thereof; and

(e) is at least one member selected from the group consisting of carbon, sulfur and phosphorus.

13. The composition as set forth in claim 12, wherein the amount of said combustion catalyst is 10% by weight or less.

14. The composition as set forth in claim 13, wherein the amount of said combustion catalyst is 2-8% by weight.

15. The composition as set forth in claim 12, wherein the 50% average particle diameter of a reference number of particles of said combustion catalyst is 10 μ

m or less.

16. The composition as set forth in claim 1, wherein a water-soluble polymer as a formability modifier is added to the composition.

17. The composition as set forth in claim 16, wherein said water-soluble polymer is at least one member selected from the group consisting of polyethylene glycol, polypropylene glycol, polyvinyl ether, polymaleic copolymer, polyethyleneimide, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, sodium polyacrylate and ammonium polyacrylate.

18. The composition as set forth in claim 17, wherein said water-soluble polymer is polyvinyl alcohol which is present in the composition in an amount of 0.01-0.5% by weight.

19. The composition as set forth in claim 1, wherein a lubricant is added to the composition and then the composition is shaped.

20. The composition as set forth in claim 19, wherein said lubricant is at least one material selected from the group consisting of stearic acid, zinc stearate, magnesium stearate, calcium stearate, aluminum stearate, molybdenum disulfide, graphite, atomized silica and boron nitride.

21. The composition as set forth in claim 1, wherein the explosive composition is shaped into tablets or disk-like objects.

22. The composition as set forth in claim 1, wherein said composition is an enhancer for an airbag.

23. The composition as set forth in claim 22, wherein said explosive composition is shaped into granules of a diameter of 1.0 mm or less.

24. The composition as set forth in claim 23, wherein said explosive composition is heat-treated at 100-120°

C. for 2-24 hours after being shaped into a granular shape.

25. A method of preparing an airbag explosive composition, comprising:

mixing (a) a fuel selected from the group consisting of (i) 5-aminotetrazole, (ii) an alkali metal salt of 5-aminotetrazole and (iii) an alkaline earth metal salt of 5-aminotetrazole;

(b) an oxidizing agent for the combustion of said fuel; and

(c) a hydrotalcite binder for ingredients (a) and (b) having the formula;

space="preserve" listing-type="equation">[M.sup.2+.sub.1-x M.sup.3+.sub.x (OH).sub.2 ].sup.x+ [A.sup.n-.sub.x/n.mH.sub.2 O].sup.x-

wherein

M²⁺ is a bivalent metal ion;

M³⁺ is a trivalent metal ion;

A^n- is an n-valent anion; and

0<

x≦

0.33 and m is a positive integer;

shaping the mixture into a given shape; and

thereafter

heat-treating the shaped mixture at 100-120°

C. for 2-24 hours.

26. The composition as set forth in claim 25, wherein said bivalent metal ion M²⁺ is selected from the group consisting of Mg²⁺, Mn^2-, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺, said trivalent metal ion M³⁺ is selected from the group consisting of Al³⁺, Fe³⁺, Cr²⁺, Co³⁺ and In³⁺ and said n-valent anion is a member selected from the group consisting of OH^-, F^-, Cl^-, NO^3-, CO₃^2-, SO₄^2-, Fe(CN)₆^3-, CH₃ COO^-, oxalate ion and salicylate ion.

27. The method of claim 25, wherein said hydrotalcite binder consists of hydrotalcite having the formula:

Mg₆ Al₂ (OH)₁₆ CO₃.4H₂ O or pyroaurite having the formula;

Mg₆ Fe₂ (OH)₁₆ CO₃.4H₂ O.

31. The method of claim 25, wherein the 50% average particle diameter of a reference number of particles of said fuel is 5-80 μ

m;

the 50% average particle diameter of a reference number of particles of said oxidizing agent is 5-80 μ

m; and

a 50% the average particle diameter of a reference number of particles of said binder is 30 μ

m or less.

28. A method of preparing an airbag explosive composition, comprising:

mixing the following ingredients (a)-(d);

(a) a fuel selected from the group consisting of (1) 5-aminotetrazole, (2) an alkali metal salt of 5-aminotetrazole and (3) an alkaline earth metal salt of 5-aminotetrazole;

(b) an oxidizing agent for the combustion of said fuel; and

(d) at least one combustion catalyst selected from the group consisting of (i) and (ii) which regulate the oxidation reaction;

(i) is at least one metal selected from the group consisting of zirconium, hafnium, molybdenum, tungsten, manganese, nickel or iron or an oxide or sulfide thereof; and

(ii) at least one of carbon, sulfur or phosphorus, and

(c) a hydrotalcite binder for ingredients (a), (b) and (d) having the formula;

space="preserve" listing-type="equation">[M.sup.2+.sub.1-x M.sup.3+.sub.x (OH).sub.2 ].sup.x+ [A.sup.n-.sub.x/n.mH.sub.2 O].sup.x-

wherein

M²⁺ is a bivalent metal ion;

M³⁺ is a trivalent metal ion;

A^n- is an n-valent anion; and

<

x≦

0.33 and m is a positive integer;

shaping the mixture into a given shape; and

thereafter

heat-treating the shaped mixture at 100-120°

C. for 2-24 hours.

29. The composition as set forth in claim 28, wherein said bivalent metal ion M²⁺ is selected from the group consisting of Mg²⁺, Mn^2-, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺, said trivalent metal ion M³⁺ is selected from the group consisting of Al³⁺, Fe³⁺, Cr²⁺, Co³⁺ and In³⁺ and said n-valent anion is a member selected from the group consisting of OH^-, F^-, Cl^-, NO^3-, CO₃^2-, SO₄^2-, Fe(CN)₆^3-, CH₃ COO^-, oxalate ion and salicylate ion.

30. The method of claim 28, wherein said hydrotalcite binder consists of hydrotalcite having the formula:

Mg₆ Al₂ (OH)₁₆ CO₃.4H₂ O or pyroaurite having the formula;

Mg₆ Fe₂ (OH)₁₆ CO₃.4H₂ O.

32. The method of claim 28, wherein the 50% average particle diameter of a reference number of particles of said fuel is 5-80 μ

m;

the 50% average particle diameter of a reference number of particles of said oxidizing agent is 5-80 μ

m;

the 50% average particle diameter of a reference number of particles of said combustion catalyst is 10 μ

m or less; and

the average particle diameter of 50% of the particles of said binder is 30 μ

m or less.

33. An airbag explosive composition, comprising:

(a) a fuel which is an organic compound containing a plurality of nitrogen atoms;

(b) an oxidizing agent for the combustion of said nitrogen containing fuel; and

(c) a hydrotalcite binder for ingredients (a) and (b) having the formula;

space="preserve" listing-type="equation">[M.sup.2+.sub.1-x M.sup.3+.sub.x (OH).sub.2 ].sup.x+ [A.sup.n-.sub.x/n.mH.sub.2 O].sup.x-

wherein

M²⁺ is a bivalent metal ion;

M³⁺ is a trivalent metal ion;

A^n- is an n-valent anion; and

0<

x≦

0.33 and m is a positive integer.