US3773701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polyurethanes
Assignee: BASF Corp
•
Filing: 1972-03-02
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Granted: 1973-11-20
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Expires: 1992-03-02
Abstract
Abstract High molecular weight linear thermoplastic elastomeric polyurethanes of I.V. 0.9-2 are prepared by reaction in solution. A hydroxyl-terminated prepolymer and a diol chain extender are reacted, in the solvent, with a small excess of diisocyanate, until the -NCO content becomes constant, then a diol chain extender in amount equivalent to the remaining -NCO; reaction is continued, and then terminated after the high I.V. is attained.
Inventors
- 👤 F Loew
- 👤 E Stone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:24
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/65; C08G18/66; C08G18/6603; C08G18/6607; C08G18/08; C08G18/10; C08G18/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
14 words
Process as in claim 1 in which said added difunctional reagent is a glycol.
Claim 2
Dependent Claim
14 words
Process as in claim 1 in which said reaction is carried out in dimethylformamide.
Claim 3
Dependent Claim
14 words
Process as in claim 1 in which said reaction is carried out in tetrahydrofuran.
Claim 4
Dependent Claim
17 words
Process as in claim 1 in which said diisocyanate consists of a hydrocarbon having two -NCO substituents.
Claim 5
Dependent Claim
23 words
Process as in claim 1 in which said reaction is carried out in dimethylformamide, and said concentration is about 30 to 35 percent.
Claim 6
Dependent Claim
23 words
Process as in claim 1 in which said reaction is carried out in tetrahydrofuran and said concentration is about 15 to 25 percent.
Claim 7
Dependent Claim
34 words
Process as in claim 1 in which said added difunctional reagent is a glycol, said diisocyanate is aromatic, and said proportion of isocyanate group per active hydrogen containing isocyanate-reactive group is 1.05 to 1.15.
Claim 8
Dependent Claim
69 words
Process as in claim 8 in which the proportion of said hydroxyl-terminated prepolymer is about 50 percent of the total weight of the polyurethane and the proportion of diisocyanate is about 40 percent of the total weight of the polyurethane, said prepolymer is polycaprolactone or butanediol adipate, and said reaction is carried out in an amount of dimethylformamide such that the polyurethane concentration is about 30 to 35 percent.
Claim 9
Dependent Claim
29 words
Process as in claim 9 in which said added difunctional reagent is selected from the group consisting of ethylene glycol, tetramethylene glycol, diethylene glycol, hexamethylene glycol and octamethylene glycol.
Claim 10
Dependent Claim
72 words
Process as in claim 9 in which the proportion of said hydroxyl-terminated prepolymer is about 45 to 55 percent of the total weight of the polyurethane, the proportion of diisocyanate is about 30 to 45 percent of the total weight of the polyurethane, said prepolymer is polycaprolactone or butanediol adipate, and said reaction is carried out in an amount of tetrahydrofuran such that the polyurethane concentration is about 15 to 25 percent.
Claim 11
Dependent Claim
12 words
Process as in claim 10 in which the diisocyanate is diphenylmethane -p,p''-diisocyanate.
Claim 12
Dependent Claim
11 words
Process as in claim 11 in which the diisocyanate is diphenylmethane-p,p''-diisocyanate.
Claim 13
Dependent Claim
31 words
Process as in claim 9 ) which said added difunctional reagent is a glycol selected from the group consisting of ethylene glycol, tetramethylene glyCol, diethylene glycol, hexamethylene glycol and octamethylene glycol.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |