US4786656A
Expired / Lapsed
US
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Polyhydroxyalkane/aromatic diamine chain extenders
Assignee: Albemarle Corp
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Filing: 1988-02-22
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Granted: 1988-11-22
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Expires: 2008-02-22
Abstract
Abstract Blends of 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3 are useful as chain extenders for polyurethanes derived from diphenylmethanediisocyanate (MDI) prepolymers. Their use overcomes the sensitivity to stoichiometry common to MDI prepolymer/polyhydroxyalkane systems and leads to the formation of cast elastomers having better green strength and a shorter demold time. The preferred blends are blends of 1,4-butanediol and di(alkylthio)toluenediamines.
Inventors
- 👤 J. Kenneth Presswood
- 👤 James H. Simon
- 👤 Christopher J. Nalepa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:31
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/32; C08G18/08; C08G18/10; C08G18/38
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
31 words
A blend of 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3.
Claim 2
Dependent Claim
31 words
A blend of 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3.
Claim 3
Dependent Claim
10 words
The blend of claim 1 wherein the polyhydroxyalkane is 1,4-butanediol.
Claim 4
Dependent Claim
31 words
The blend of claim 1 wherein the aromatic diamine is a poly(alkylthio)aromatic diamine having at least two alkylthio substituents on the same ring as at least one of the amino substituents.
Claim 5
Dependent Claim
12 words
The blend of claim 3 wherein the aromatic diamine is a di(alkylthio)toluenediamine.
Claim 6
Dependent Claim
10 words
The blend of claim 4 wherein the di(alkylthio)toluenediamine is 3,5-di(methylthio)-2,4-diaminotoluene.
Claim 7
Dependent Claim
10 words
The blend of claim 4 wherein the di(alkylthio)toluenediamine is 3,5-di(methylthio)-2,6-diaminotoluene.
Claim 8
Dependent Claim
15 words
The blend of claim 4 wherein the di(alkylthio)toluenediamine is a mixture of 3,5-di(methylthio)-2,4-diaminotoluene and 3,5-di(methylthio)-2,6-diaminotoluene.
Claim 9
Dependent Claim
13 words
The blend of claim 1 containing 5-10 mol % of the aromatic diamine.
Claim 10
Dependent Claim
22 words
The blend of claim 1 containing 90-95 mol % of 1,4-butanediol and 5-10 mol % of a mixture of 3,5-di(methylthio)-2,4-diaminotoluene and 3,5-di(methylthio)-2,6-diaminotoluene.
Claim 11
Dependent Claim
43 words
A polyurethane prepared by reacting (A) a chain extender comprising 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3 with (B) a diphenylmethanediisocyanate prepolymer.
Claim 12
Dependent Claim
43 words
A polyurethane prepared by reacting (A) a chain extender comprising 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3 with (B) a diphenylmethanediisocyanate prepolymer.
Claim 13
Dependent Claim
10 words
The polyurethane of claim 10 wherein the polyhydroxyalkane is 1,4-butanediol.
Claim 14
Dependent Claim
16 words
The polyurethane of claim 10 wherein the aromatic diamine is a mixture of 3,5-di(methylthio)-2,4-diaminotoluene and 3,5-di(methylthio)-2,6-diaminotoluene.
Claim 15
Dependent Claim
14 words
The polyurethane of claim 10 wherein the diphenylmethanediisocyanate component of the prepolymer is 4,4'-diphenylmethanediisocyanate.
Claim 16
Dependent Claim
19 words
The polyurethane of claim 10 wherein the diphenylmethanediisocyanate component of the prepolymer is a mixture of 4,4'-diphenylmethanediisocyanate and 2,4'-diphenylmethanediisocyanate.
Claim 17
Dependent Claim
14 words
The polyurethane of claim 10 wherein the prepolymer is a diphenylmethanediisocyanate/polyether polyol reaction product.
Claim 18
Dependent Claim
14 words
The polyurethane of claim 15 wherein the polyether polyol is a polytetramethylene ether glycol.
Claim 19
Dependent Claim
16 words
The polyurethane of claim 10 wherein the prepolymer has a free --NCO content of about 4-12%.
Claim 20
Dependent Claim
27 words
The polyurethane of claim 10 wherein the chain extender is employed in an amount such as to provide 0.8-1.2 equivalents of chain extender per free --NCO group.
Claim 21
Dependent Claim
27 words
The polyurethane of claim 18 wherein the chain extender is employed in an amount such as to provide 0.95-1.05 equivalents of chain extender per free --NCO group.
Claim 22
Dependent Claim
23 words
The polyurethane of claim 10 wherein the polyhydroxyalkane and the aromatic diamine are blended with one another before being mixed with the prepolymer.
Claim 23
Dependent Claim
67 words
The polyurethane of claim 10 which is prepared by reacting (A) 0.95-1.05 equivalent proportions of a chain extender blend of 90-95 mol % of 1,4-butanediol and 5-10 mol % of a mixture of 3,5-di(methylthio)-2,4-diaminotoluene and 3,5-di(methylthio)-2,6-diaminotoluene with (B) one equivalent proportion of a diphenylmethanediisocyanate prepolymer having a free --NCO content of about 4-12% by weight and obtained by reacting a diphenylmethanediisocyanate component with a polytetramethylene ether glycol.
Claim 24
Dependent Claim
76 words
A process which comprises (A) casting into a mold a reaction mixture of a diphenylmethanediisocyanate prepolymer and a chain extender comprising 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3, (B) curing the reaction mixture in the mold at a temperature of about 90°-110° C. to form a polyurethane, and (C) removing the polyurethane from the mold.
Claim 25
Dependent Claim
76 words
A process which comprises (A) casting into a mold a reaction mixture of a diphenylmethanediisocyanate prepolymer and a chain extender comprising 90-99 mol % of a polyhydroxyalkane containing 2-6 carbons and 2-3 hydroxyl groups and 1-10 mol % of an aromatic diamine having a pKb value greater than 11.3, (B) curing the reaction mixture in the mold at a temperature of about 90°-110° C. to form a polyurethane, and (C) removing the polyurethane from the mold.
Claim 26
Dependent Claim
63 words
The process of claim 22 wherein the reaction mixture comprises 0.8-1.2 equivalent proportions of a blend of 90-95 mol % of 1,4-butanediol and 5-10 mol % of a mixture of 3,5-di(methylthio)-2,4-diaminotoluene and 3,5-di(methylthio)-2,6-diaminotoluene and one equivalent proportion of a diphenylmethanediisocyanate prepolymer having a free --NCO content of about 4-12% by weight and obtained by reacting a diphenylmethanediisocyanate component with a polytetramethylene ether glycol.
Claim 27
Dependent Claim
23 words
The process of claim 23 wherein the reaction mixture comprises 0.95-1.05 equivalent proportions of the blend and one equivalent proportion of the prepolymer.
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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) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |