Gas generant and synthesis

• US 7,667,045 B2
• Filed: 06/01/2005
• Issued: 02/23/2010
• Est. Priority Date: 06/02/2004
• Status: Expired due to Fees

• Current Assignee: Joyson Safety Systems Acquisition, LLC
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Williams, Graylon K., Miller, Cory G.
• Primary Examiner(s): Shameem; Golam M. M.
• Assistant Examiner(s): CHUNG, SUSANNAH LEE
• Application Number:
  US11/143,198
• Publication Number:
  US 20050272873A1
• Time in Patent Office: 1,728 Days
• Field of Search: 548/250
• US Class Current: 548/250
• CPC Class Codes: C08F 8/30 Introducing nitrogen atoms or nitrogen-containing groups

Abstract

A vinylated tetrazole substituted at the 5-position of the tetrazole ring is formed by a water-based method. A gas generating composition 12 containing the vinylated tetrazole is contained within an exemplary gas generator 10. A gas generating system 200 incorporates the vinylated tetrazole therein. A vehicle occupant protection system 180 incorporates the gas generating system 200.

Claims

1. A method of forming a poly (5-vinyl)tetrazole, the method including the steps of:

providing a reaction vessel;

adding water to the reaction vessel;

adding at least one aide salt to the reaction vessel;

adding at least one surfactant to the reaction vessel;

adding a polyacrylonitrile polymer to the reaction vessel, wherein the order of adding the water, azide salt, surfactant and the polyacrylonitrile polymer to the reactant vessel may be varied;

mixing the contents of the reaction vessel into a liquid aqueous mixture void of organic solvent;

heating the contents of the reaction vessel consisting of the liquid aqueous mixture, thereby reacting the contents of the reaction vessel;

cooling the contents of the reaction vessel;

filtering the contents of the reaction vessel to produce a filtrate;

washing the filtrate with water to produce a filtrate/water mixture;

acidifying the filtrate/water mixture to a pH of about 1-3 and stirring the same, to form an acidified filtrate/water mixture;

filtering the acidified filtrate/water mixture to separate a solid from the acidified filtrate/water mixture;

suspending the solid in water and adding an excess amount of a base to the suspension while stirring the same;

dissolving the solid in the base/water mixture to form a slurry; and

pouring the slurry into a container and drying the slurry to form the poly(5-vinyltetrazole).

2. The method of claim 1 wherein the step of heating the contents of the reaction vessel includes heating the slurry to a temperature ranging from about 100-200C.

3. The method of claim 2 wherein the slurry is heated to about 170C.

4. The method of claim 1 wherein the water is added at about 0.5 to about 5 molar equivalents, the azide salt is added at about 0.5 to 1.5 molar equivalents, the surfactant is added in a catalytic amount, the catalytic reagent is added at about 0.5 to 1.5 molar equivalents, and the polyacrylonitrile is added at about 0.5 to 1.5 molar equivalents.

5. The method of claim 1 wherein dissolving the solid within the base includes heating the water and the suspended solid to form a slurry, the slurry heated to about 25 to 100C.

6. The method of claim 1 further containing the step of grinding the poly(5-vinyltetrazole) to a fine powder.

7. The method of claim 1 wherein the contents of the reaction vessel are permitted to react for about 12 to 48 hours prior to cooling.

8. The method of claim 1 wherein the azide salt is selected from organic and inorganic azide salts.

9. The method of claim 8 wherein the azide salt is selected from ammonium azide, potassium azide, and trimethylsilyl azide.

10. The method of claim 1 wherein the surfactant is selected from quaternary ammonium salts, lauryl sulfates, hand soaps, dish soaps, and mixtures thereof.

11. The method of claim 1 wherein the azide salt is about 1.1 molar equivalents of sodium azide, the surfactant is about 0.0025 molar equivalents of sodium lauryl sulfate, the polyacrylonitrile polymer is provided at about 1.0 molar equivalents and the catalytic reagent is about 0.5 molar equivalents of zinc bromide dihydrate.

12. A method of forming a vinylated tetrazole substituted at the 5-position, the method including the steps of:

providing a reaction vessel;

adding water, at least one azide salt, at least one surfactant, at least one zinc-containing compound, and at least one polymer containing cyano or nitrile functionality to the reaction vessel, wherein the order of adding the water, the azide salt, the surfactant, the zinc-containing compound, and the polymer to the reactant vessel may be varied;

mixing the contents of the reaction vessel into a liquid mixture to react the mixture;

washing and filtering the contents of the reaction vessel to produce a filtrate/water mixture;

acidifying the filtrate/water mixture to a pH of about 1-3 and stirring the same;

filtering the acidified filtrate/water mixture to separate a solid from the acidified filtrate/water mixture;

suspending the solid in water and adding an excess amount of a base to the suspension while stirring the same;

dissolving the solid in the base/water mixture to form a slurry; and

pouring the slurry into a container and drying the slurry to form the poly(5-vinyltetrazole).

13. The method of claim 12 wherein the base is ammonium hydroxide.

14. A method of forming a poly(5-vinyl)tetrazole, the method including the steps of:

providing a reaction vessel;

adding water to the reaction vessel;

adding at least one azide salt to the reaction vessel;

adding at least one surfactant to the reaction vessel;

adding polyacrylonitrile to the reaction vessel, wherein the order of adding the water, azide salt, surfactant, and polyacrylonitrile to the reactant vessel may be varied;

mixing the contents of the reaction vessel into a liquid aqueous mixture void of organic solvent;

heating the contents of the reaction vessel consisting of the aqueous mixture, thereby reacting the contents of the reaction vessel;

cooling the contents of the reaction vessel;

filtering the contents of the reaction vessel to produce a filtrate;

washing the filtrate with water to produce a filtrate/water mixture;

dispersing the filtrate/water mixture into cold water and stirring the same;

acidifying the filtrate/water mixture to a pH of about 1-3 and stirring the same;

filtering the acidified filtrate/water mixture to separate a solid from the acidified filtrate/water mixture;

suspending the solid in water and adding an excess amount of ammonium hydroxide to the suspension while stirring the same, thereby forming a base/water mixture;

dissolving the solid in the base/water mixture to form a slurry; and

pouring the slurry into a container and drying the slurry to form the poly(5-vinyltetrazole.