US3711344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processing of crosslinked nitrocellulose propellants
Assignee: United States Department of the Army
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Filing: 1970-09-23
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Granted: 1973-01-16
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Expires: 1990-09-23
Abstract
Abstract This invention relates to an improved process for crosslinking of nitrocellulose with an isocyanate to form a polymeric binder for a solid propellant grain. Gassing of the propellant grain is prevented, and reproducible propellant grains, with substantially void free properties, and having improved mechanical properties, are prepared.
Inventors
- 👤 E Pierce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:20
CPC Classifications
C; C06; C06B; C06B45/00; C06B45/04; C06B45/06; C06B45/10; C06B21/00; C06B21/0033; C06B21/0058; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/64; C08G18/6484
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
167 words
The process of claim 1 wherein said predetermined amount of plasticizer is from about 20 to about 60 percent by weight; said predetermined amount of stabilizer is from about 1 to about 2 percent by weight; said predetermined amount of a first portion of a diisocyanate crosslinker is from about 0.1 to about 0.2 percent by weight; said predetermined amount of a first and minor portion of a nitrocellulose source ingredient is from about 3 to about 10 percent by weight, said percent by weight being based on the total weight of the propellant composition; a second and major portion of a nitrocellulose source ingredient is the ingredient selected for combining with said first homogeneous blend, said second and major portion of nitrocellulose being used in an amount to provide up to about 25 percent by weight of the propellant grain; and said second portion of a diisocyanate crosslinker being selected in an amount from about 0.3 to about 3 percent by weight of said propellant grain.
Claim 2
Dependent Claim
75 words
The process of claim 2 wherein said plasticizer is selected from the plasticizers consisting of nitroglycerin, butane trioltrinitrate, diethylene glycol dinitrate, trimethylol ethane trinitrate, tetraethylene glycol dinitrate, triacetin, diethyl phthalate, propyl adipate, and dibutyl sebacate; said first portion of a diisocyanate crosslinker and said second portion of a diisocyanate crosslinker is selected from the diisocyanates consisting of toluene diisocyanate and hexamethylene diisocyanate; and said stabilizer is selected from the stabilizers consisting of resorcinol and 2-nitrodiphenylamine.
Claim 3
Dependent Claim
21 words
The process of claim 3 wherein said heating is accomplished within a range of temperature from about 85*F to about 140*F.
Claim 4
Dependent Claim
80 words
The process of claim 4 wherein said selected propellant ingredients for preparing said first homogeneous blend additionally includes a metal fuel selected from the metal fuels consisting of aluminum, zirconium, boron, beryllium, and magnesium in amounts up to about 30 percent by weight of said propellant grain; and an oxidizer selected from the oxidizers consisting oF ammonium perchlorate, ammonium nitrate, potassium perchlorate, nitronium perchlorate, cyclotetramethylenetetranitramine, and cyclotrimethylenetrinitramine in amounts up to about 70 percent by weight of said propellant grain.
Claim 5
Dependent Claim
172 words
The process of claim 1 wherein said predetermined amount of plasticizer is from about 20 to about 60 percent by weight; said predetermined amount of stabilizer is from about 1 to about 2 percent by weight; said predetermined amount of a first portion of an isocyanate crosslinker is from about 0.1 to about 0.2 percent by weight; said predetermined amount of a first and major portion of a nitrocellulose source ingredient is from about 3 to about 10 percent by weight, said percent by weight being based on the total weight of the propellant composition; said ingredient selected for combining with said first homogeneous blend is a prepolymer ingredient which is used in amounts up to about 22 percent by weight of the propellant grain, said prepolymer ingredient being polyglycol adipate having a suitable amount of a diisocyanate crosslinker mixed therein, said suitable amount of a diisocyanate crosslinker being a second portion of a diisocyanate crosslinker sufficient to provide from about 0.5 to about 3 percent diisocyanate crosslinker in said propellant grain.
Claim 6
Dependent Claim
75 words
The process of claim 6 wherein said plasticizer is selected from the plasticizers consisting of nitroglycerin, butane trioltrinitrate, diethylene glycol dinitrate, trimethylol ethane trinitrate, tetraethylene glycol dinitrate, triacetin, diethyl phthalate, propyl adipate, and dibutyl sebacate; said first portion of a diisocyanate crosslinker and said second portion of a diisocyanate crosslinker is selected from the diisocyanates consisting of toluene diisocyanate and hexamethylene diisocyanate; and said stabilizer is selected from the stabilizers consisting of resorcinol and 2-nitrodiphenylamine.
Claim 7
Dependent Claim
21 words
The process of claim 7 wherein said heating is accomplished within a range of temperature from about 85*F to about 140*F.
Claim 8
Dependent Claim
80 words
The process of claim 8 wherein said selected propellant ingredients for preparing said first homogeneous blend additionally includes a metal fuel selected from the metal fuels consisting of aluminum, zirconium, boron, beryllium, and magnesium in amounts up to about 30 percent by weight of said propellant grain; and an oxidizer selected from the oxidizers consisting of ammonium perchlorate, ammonium nitrate, potassium perchlorate, nitronium perchlorate, cyclotetramethylenetetranitramine, and cyclotrimethylenetrinitramine in amounts up to about 70 percent by weight of said propellant grain.
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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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |