US4737549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Terpolymers of maleic acid anhydride, (meth)acrylic acid, and (meth)acrylonitrile
Assignee: Bayer AG
•
Filing: 1986-08-01
•
Granted: 1988-04-12
•
Expires: 2006-08-01
Abstract
Abstract Terpolymers of 30 to 75% by weight of maleic acid (anhydride), 5 to 60% by weight of (meth)acrylic acid and 5 to 40% by weight of (meth)acrylonitrile are suitable as retanning agents for mineral-tanned leather.
Inventors
- 👤 Bruno Bomer
- 👤 Franz Schade
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:36
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/28; C08; C08F; C08F222/00; C08F222/04; C08F222/06; C08F8/00; C08F8/30; C08F8/32; C14C3/08; C14C3/22; C08F2800/00; C08F2800/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
33 words
A terpolymer consisting essentially of 30 to 75% by weight of maleic acid or maleic acid anhydride, 5 to 60% by weight of (meth)acrylic acid and 5 to 40% by weight of (meth)acrylonitrile.
Claim 2
Dependent Claim
33 words
A terpolymer consisting essentially of 30 to 75% by weight of maleic acid or maleic acid anhydride, 5 to 60% by weight of (meth)acrylic acid and 5 to 40% by weight of (meth)acrylonitrile.
Claim 3
Dependent Claim
31 words
A terpolymer according to claim 1 of 45 to 65% by weight of maleic acid, 15 to 40% by weight of acrylic acid and 15 to 35% by weight of acrylonitrile.
Claim 4
Dependent Claim
23 words
A terpolymer according to claim 1 wherein the terpolymer is in the form of a completely or partly neutralized aqueous solution or suspension.
Claim 5
Dependent Claim
72 words
A terpolymer according to claim 3, wherein the terpolymer is completely or partially neutralized with an alkali metal hydroxide, ammonia or an amine of the formula ##STR2## wherein R 1 , R 2 and R 3 deonote C 1 -C 6 -alkyl or C 2 -C 6 -alkyl which is substituted by OH, NH 2 or mono- or di-C 1 -C 4 alkylamino and R 1 and R 2 also denote hydrogen.
Claim 6
Dependent Claim
23 words
A terpolymer according to claim 3, wherein the aqueous solution or suspension has a pH, established with ammonia, of between 3.5 and 7.0.
Claim 7
Dependent Claim
47 words
A process for the preparation of the terpolymers according to claim 1, comprising polymerization of a monomer mixture comprising 30 to 75% by weight of maleic acid or maleic acid anhydride, 5 to 60% by weight of (meth)acrylic acid and 5 to 40% by weight of (meth)acrylonitrile.
Claim 8
Dependent Claim
22 words
A process according to claim 6, wherein the free radical polymerization is carried out in an aqueous medium by a feed process.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |