Patent US4755576A successfully refreshed from Google Patents.
US4755576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copolymers of alpha-methyl styrene and acrylonitrile
Assignee: Bayer AG
•
Filing: 1985-08-14
•
Granted: 1988-07-05
•
Expires: 2005-08-14
Abstract
Abstract Copolymers of from 65 to 75%, by weight, of α-methyl styrene and from 35 to 25%, by weight, of α-methyl styrene and from 35 to 25%, by weight, of acrylonitrile, obtainable by radical emulsion polymerization, the monomers being metered in during the course of the polymerization, wherein the molar ratio: ##EQU1## of the unreacted monomers in the reaction mixture is maintained during the metering phase between 0.7 and 1.25.
Inventors
- 👤 Karl Zabrocki
- 👤 Rainer Fritz
- 👤 Alfred Pischtschan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:12
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
60 words
Copolymers of from 65 to 75% by weight, of α-methyl styrene and from 35 to 25%, by weight, of acrylonitrile, obtained by radical emulsion polymerisation, in which the monomers are metered in during polymerisation, wherein the ratio (mol α-methyl styrene)(mol acrylonitrile) of the unreacted monomers found in the reaction mixture is maintained during the metering phase between 0.7 and 1.25.
Claim 2
Dependent Claim
60 words
Copolymers of from 65 to 75% by weight, of α-methyl styrene and from 35 to 25%, by weight, of acrylonitrile, obtained by radical emulsion polymerisation, in which the monomers are metered in during polymerisation, wherein the ratio (mol α-methyl styrene)(mol acrylonitrile) of the unreacted monomers found in the reaction mixture is maintained during the metering phase between 0.7 and 1.25.
Claim 3
Dependent Claim
25 words
Copolymers according to claim 1, which contain polymerised from 71 to 73%, by weight, of α-methyl styrene and from 29 to 27%, by weight, acrylonitrile.
Claim 4
Dependent Claim
56 words
A process for producing copolymers containing from 65 to 75% by weight of copolymerized alpha-methylstyrene units and from 35 to 25% by weight of copolymerized acrylonitrile units which comprises copolymerizing alpha-methylstyrene and acrylonitrile in aqueous emulsion with a radical catalyst wherein during the polymerization a molar ratio of unreacted alpha-methylstyrene:acrylonitrile is maintained between 0.7 and 1.25.
Claim 5
Dependent Claim
56 words
A process for producing copolymers containing from 65 to 75% by weight of copolymerized alpha-methylstyrene units and from 35 to 25% by weight of copolymerized acrylonitrile units which comprises copolymerizing alpha-methylstyrene and acrylonitrile in aqueous emulsion with a radical catalyst wherein during the polymerization a molar ratio of unreacted alpha-methylstyrene:acrylonitrile is maintained between 0.7 and 1.25.
Claim 6
Dependent Claim
26 words
A process according to claim 3 wherein from 75 to 73% by weight of alpha-methylstyrene and from 29 to 27% by weight of acrylonitrile are copolymerized.
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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |