Gas generating material

• US 4,696,705 A
• Filed: 12/24/1986
• Issued: 09/29/1987
• Est. Priority Date: 12/24/1986
• Status: Expired due to Term

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive Products, Inc. (Northrop Grumman Corporation)
• Inventors: Hamilton, Brian K.
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Application Number:
  US06/946,376
• Time in Patent Office: 279 Days
• Field of Search: 149/2, 149/40, 149/21, 149/41, 149/35, 149/110, 149/114, 102/530, 102/289, 102/292
• US Class Current: 149/21
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06B 35/00 Compositions containing a metal azide
• CPC Class Codes: C06D 5/06 by reaction of two or more solids
• CPC Class Codes: Y10S 149/11 Particle size of a component
• CPC Class Codes: Y10S 149/114 Inorganic fuel

Abstract

Structure for generating nitrogen gas for inflating an air bag vehicle occupant restraint comprises a grain made of an azide based material which generates gas upon combustion. The grain is made of a gas generating material which includes 61-68% by weight of sodium azide, 0-5% by weight of sodium nitrate, 0-5% by weight of bentonite, 23-28% by weight of iron oxide, 1-2% by weight of fumed silica, and from about 2 to about 6% by weight of graphite fibers having a diameter of 3-15 microns and an average length of 40 to 125 thousandths of an inch.

Claims

1. A structure for generating gas, said structure comprising:

a grain made of an azide based material which generates gas and forms a sinter upon combustion;

said gas generating material including from about 2 to about 6% by weight of graphite fibers,

said graphite fibers having a diameter of 3-15 microns and an average length of 40 to 125 thousandths of an inch to reinforce the sinter which remains after combustion of the gas generating material.

2. The structure defined in claim 1 wherein, said grain has opposite ends and passages which extend through the grain and intersect said opposite ends.

3. The structure defined in claim 1 wherein said material comprises:

61-68% by weight of sodium azide,

0-5% by weight of sodium nitrate,

0-5% by weight of bentonite,

23-28% by weight of iron oxide, and

1-2% by weight of fumed silicon dioxide.

4. A structure for generating gas, said structure comprising:

a grain which generates gas and forms a sinter upon combustion;

said grain being made of an alkali metal azide based material and having 2-6% fibers therein which have a melting temperature above the combustion temperature of the grain and a thermal conductivity above about 200 watts per meter per degree kelvin.

5. A structure as defined in claim 4 wherein said fibers are graphite fibers having a diameter of 3-15 microns and an average length of 40 to 125 thousandths of an inch.

6. A structure as defined in claim 4 wherein said grain further has an ignition enhancing coating thereon.

7. A structure as defined in claim 5 wherein said material comprises:

61-68% by weight of sodium azide,

0-5% by weight of sodium nitrate,

0-5% by weight of bentonite,

23-28% by weight of iron oxide, and

1-2% by weight of fumed silicon dioxide.