Patent US5034070A successfully refreshed from Google Patents.
US5034070A
Expired / Lapsed
US
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Gas generating material
Assignee: ZF Passive Safety Systems US Inc
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Filing: 1990-06-28
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Granted: 1991-07-23
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Expires: 2010-06-28
Abstract
Abstract A gas generating grain has a water-based particulate booster coating thereon. The coating comprises an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a nucleating amount of a small particle size metal oxide, preferably selected from the group consisting of iron oxide, nickel oxide and aluminum oxide. The coating is applied to said grain from a water slurry and dried, and when dried has an average particle size of less than about 50 microns.
Inventors
- 👤 George W. Goetz
- 👤 Thomas H. Vos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:28
CPC Classifications
C; C06; C06D; C06D5/00; C06D5/06; C06B; C06B45/00; C06B45/12; C06B45/14; C06B45/16; Y; Y10; Y10S; Y10S149/00; Y10S149/11
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
48 words
A gas generating grain having a particulate booster coating thereon, said coating comprising an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a water-insoluble metal oxide, said coating being applied to said grain as a water slurry and dried.
Claim 2
Dependent Claim
48 words
A gas generating grain having a particulate booster coating thereon, said coating comprising an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a water-insoluble metal oxide, said coating being applied to said grain as a water slurry and dried.
Claim 3
Dependent Claim
21 words
The grain of claim 1 wherein said coating when dried has an average particle size of about 50 microns or less.
Claim 4
Dependent Claim
15 words
The grain of claim 2 wherein said metal oxide is present in a nucleating amount.
Claim 5
Dependent Claim
19 words
The grain of claim 3 wherein said metal oxide has an average particle size less than about 0.5 micron.
Claim 6
Dependent Claim
23 words
The grain of claim 4 wherein said metal oxide is selected from the group consisting of iron oxide, nickel oxide, and aluminum oxide.
Claim 7
Dependent Claim
21 words
The grain of claim 4 wherein said metal oxide is iron oxide having an average particle size of about 0.2 micron.
Claim 8
Dependent Claim
18 words
The grain of claim 1 comprising about 5-6% by weight coating, based on the weight of the grain.
Claim 9
Dependent Claim
11 words
The grain of claim 1 wherein said oxidizer is a nitrate.
Claim 10
Dependent Claim
47 words
The grain of claim 8 wherein said nitrate is an alkali metal nitrate and the coating is applied to said grain from a water-based slurry, the proportion of nitrate to alkali metal azide in said slurry being about 107% of the stoichiometric proportion of nitrate to azide.
Claim 11
Dependent Claim
13 words
The grain of claim 1 wherein said coating comprises about 3-6% metal fuel.
Claim 12
Dependent Claim
21 words
The grain of claim 10 wherein said metal fuel is selected from the group consisting of boron, titanium, zirconium and silicon.
Claim 13
Dependent Claim
11 words
The grain of claim 10 wherein said metal fuel is boron.
Claim 14
Dependent Claim
26 words
The grain of claim 1 comprising boron and a nucleating amount of a water-insoluble metal oxide having an average particle size less than about 0.5 micron.
Claim 15
Dependent Claim
13 words
The grain of claim 13 wherein said boron is a pyrotechnic grade boron.
Claim 16
Dependent Claim
21 words
The grain of claim 13 wherein said metal oxide is iron oxide having an average particle size of about 0.2 micron.
Claim 17
Dependent Claim
29 words
The grain of claim 1 wherein said coating comprises on a weight basis; about 34-37% inorganic oxidizer; about 54-58% alkali metal azide; about 3-6% boron; about 1-3% iron oxide.
Claim 18
Dependent Claim
20 words
The grain of claim 16 wherein said alkali metal azide is sodium azide and said inorganic oxidizer is sodium nitrate.
Claim 19
Dependent Claim
18 words
The grain of claim 16 having a grain composition comprising sodium azide, sodium nitrate, iron oxide and bentonite.
Claim 20
Dependent Claim
15 words
The grain of claim 18 having a moisture content of about 1.4% prior to coating.
Claim 21
Dependent Claim
13 words
The grain of claim 16 wherein said slurry comprises a 60/40 solids/water mixture.
Claim 22
Dependent Claim
18 words
The grain of claim 16 oven dried following coating at a temperature of at least about 260° F.
Claim 23
Dependent Claim
36 words
The grain of claim 1 coated from a water slurry comprising: ______________________________________
Ingredient Weight Percentage
______________________________________
Sodium Nitrate
36.59 ± 1.0%
Sodium Azide 56.82 ± 1.5%
Boron 4.51 ± 0.1%
Iron Oxide 2.08 ± 0.1%
______________________________________
Claim 24
Dependent Claim
66 words
A gas generating grain having a particulate booster coating thereon, said coating comprising an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a nucleating amount of a water-insoluble metal oxide, said coating being applied to said grain as a water slurry and dried and when dried having an average particle size of about 50 microns or less.
Claim 25
Dependent Claim
66 words
A gas generating grain having a particulate booster coating thereon, said coating comprising an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a nucleating amount of a water-insoluble metal oxide, said coating being applied to said grain as a water slurry and dried and when dried having an average particle size of about 50 microns or less.
Claim 26
Independent Claim
66 words
A method for making a gas generating grain having a booster coating thereon, comprising the steps of: (a) preparing said grain; (b) preparing a coating slurry comprising water, an alkali metal azide, a water soluble inorganic oxidizer, and a water-insoluble metal oxide; (c) immersing said grain in said coating slurry; (d) removing said grain from said coating slurry and drying said grain and the coating thereon.
Claim 27
Independent Claim
66 words
A method for making a gas generating grain having a booster coating thereon, comprising the steps of: (a) preparing said grain; (b) preparing a coating slurry comprising water, an alkali metal azide, a water soluble inorganic oxidizer, and a water-insoluble metal oxide; (c) immersing said grain in said coating slurry; (d) removing said grain from said coating slurry and drying said grain and the coating thereon.
Claim 28
Dependent Claim
14 words
The method of claim 24 wherein said grain and coating thereon are rapidly dried.
Claim 29
Dependent Claim
21 words
The method of claim 25 wherein said grain and coating thereon are dried at a temperature in excess of 260° F.
Claim 30
Dependent Claim
20 words
The method of claim 24 wherein said metal oxide is a small particle size oxide present in a nucleating amount.
Claim 31
Dependent Claim
20 words
The method of claim 27 wherein said metal oxide is iron oxide having a particle size of about 0.2 micron.
Claim 32
Dependent Claim
24 words
The method of claim 24 wherein the ratio of inorganic oxidizer to azide is in excess of a stoichiometric proportion of oxidizer to azide.
Claim 33
Dependent Claim
26 words
The method of claim 29 wherein said inorganic oxide is sodium nitrate and said ratio is about 107% of the stoichiometric proportion of oxidizer to azide.
Claim 34
Dependent Claim
12 words
The method of claim 24 wherein said slurry contains a metal fuel.
Claim 35
Dependent Claim
18 words
The method of claim 24 wherein said grain has a moisture content prior to coating of about 1.4%.
Claim 36
Dependent Claim
16 words
The method of claim 24 wherein the weight ratio of solids to water is about 60/40.
Claim 37
Dependent Claim
21 words
The method of claim 24 wherein said slurry is comminuted prior to coating to reduce the particle size of the azide.
Claim 38
Dependent Claim
21 words
The method of claim 34 wherein said azide has an average particle size prior to coating less than about 20 microns.
Claim 39
Dependent Claim
10 words
A coated grain made by the method of claim 24.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |