US4328281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dimer isocyanate liner compositions
Assignee: Aerojet Rocketdyne Inc
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Filing: 1979-08-24
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Granted: 1982-05-04
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Expires: 1999-08-24
Abstract
Abstract A composition is disclosed in which a solid isocyanate compound such as toluene-diisocyanate dimer is dispersed within a polyurethane based on a hydroxy-terminated organic compound, preferably polybutadiene. The composition can be fully cured on a surface and yet provides an excess of stable material, i.e. dormant isocyanate containing groups, which are reactive on demand to strengthen interfaces with adjacent layers containing available hydroxyl groups, such as a layer of solid polyurethane-based propellant, without the need for intermediate reactive coatings.
Inventors
- 👤 John M. Wrightson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:07
CPC Classifications
F; F02; F02K; F02K9/00; F02K9/08; F02K9/32; F02K9/34; F02K9/346; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/131; Y10T428/1314; Y10T428/1352; Y10T428/1355; Y10T428/1359; Y10T428/31504; Y10T428/31536; Y10T428/31551; Y10T428/31554; Y10T428/31598; Y10T428/31601; Y10T428/31605
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
88 words
A composite article comprising a rocket motor casing and a fully cured polyurethane liner, in which is dispersed a stable, solid organic polyisocyanate precursor which does not migrate, in excess of the stoichiometric amount of isocyanate necessary to form said polyurethane, and which is reactive after cure of the liner with organic active-hydrogen containing compounds in a curable propellant composition, said precursor being present in an effective amount for forming interfacial bonds between said liner and said curable propellant composition upon curing thereof in contact with said liner.
Claim 2
Dependent Claim
88 words
A composite article comprising a rocket motor casing and a fully cured polyurethane liner, in which is dispersed a stable, solid organic polyisocyanate precursor which does not migrate, in excess of the stoichiometric amount of isocyanate necessary to form said polyurethane, and which is reactive after cure of the liner with organic active-hydrogen containing compounds in a curable propellant composition, said precursor being present in an effective amount for forming interfacial bonds between said liner and said curable propellant composition upon curing thereof in contact with said liner.
Claim 3
Dependent Claim
22 words
A composite article according to claim 1 in which the precursor is a solid up to a temperature of about 150° F.
Claim 4
Dependent Claim
23 words
A composite article according to claim 1 in which the precursor is present in an amount from 2-10% by weight of the liner.
Claim 5
Dependent Claim
42 words
A composite article according to claim 3 in which the precursor is selected from compounds of the formula: ##STR4## where R is an aliphatic or aromatic group containing at least one --NCO group and n is an integer from 0 to 1.
Claim 6
Dependent Claim
31 words
A composite article according to claim 4 in which the precursor is a dimer selected from those of the formula: ##STR5## where R 2 is arylene, alkyl arylene or aryl alkylene.
Claim 7
Dependent Claim
30 words
A composite article according to claim 5 in which the precursor is a dimer of a diisocyanate selected from the group consisting of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate and bis-phenyl diisocyanate.
Claim 8
Dependent Claim
17 words
A composite article according to claim 6 in which the precursor is a dimer of toluene diisocyanate.
Claim 9
Dependent Claim
51 words
A composite article according to claim 1 in which the polyurethane liner is the cured product of a mixture including at least one polyol, a stoichiometric amount of organic polyisocyanate sufficient to react with said polyol, and said precursor in an amount over the stoichiometric amount of isocyanate necessary for cure.
Claim 10
Dependent Claim
15 words
A composite article according to claim 8 in which the organic polyisocyanate is toluene diisocyanate.
Claim 11
Dependent Claim
31 words
A composite article according to claim 8 in which the polyol is present in an amount of 20-65 parts by weight of the composition and comprises a liquid hydroxyl containing prepolymer.
Claim 12
Dependent Claim
30 words
A composite article according to claim 10 in which the prepolymer is a conjugated diene polymer having an equivalent weight from 1000-5000 and a functionality from about 1.7 to 3.0.
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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) | 1985-05-03 | 1985-11-02 | 1986-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-03 | 1989-11-02 | 1990-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-03 | 1993-11-02 | 1994-05-04 | $7700.00 | Window Closed / Lapsed |