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US4959434A
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Modified impact-resistant vinylaromatic copolymers
Assignee: Montedison SpA
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Filing: 1989-12-28
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Granted: 1990-09-25
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Expires: 2009-12-28
Abstract
Abstract Modified impact-resistant vinylaromatic copolymers containing from 2 to 10% by weight of an ethylenically unsaturated nutrile and from 0 to 30% by weight of alpha-methyl-styrene and having a gel content higher than 23%, a cracking resistance, in an olive oil/oleic acid mixture under a load of 10 MPa, higher than 100 min., and a melt index below 1.5 g/10 minutes.
Inventors
- 👤 Gianfranco Biglione
- 👤 Savino Matarrese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:33
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08F212/10; C08L; C08L25/00; C08L25/02; C08L25/04; C08L25/08; C08L25/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
81 words
An impact-resistant styrene copolymer containing from 2 to 8% by weight of an ethylenically unsaturated nitrile and from 8 to 30% by weight of alphamethylstyrene and having a gel content higher than 23%, a cracking resistance, in an oil/oleic acid mixture in a 50/50 ratio by weight and under a load of 10 MPa higher than 100 minutes, a melt index (200° C./5 kg) lower than 1.5 g/10 minutes and obtained by polymerization carried out in the absence of lubricating oils.
Claim 2
Dependent Claim
81 words
An impact-resistant styrene copolymer containing from 2 to 8% by weight of an ethylenically unsaturated nitrile and from 8 to 30% by weight of alphamethylstyrene and having a gel content higher than 23%, a cracking resistance, in an oil/oleic acid mixture in a 50/50 ratio by weight and under a load of 10 MPa higher than 100 minutes, a melt index (200° C./5 kg) lower than 1.5 g/10 minutes and obtained by polymerization carried out in the absence of lubricating oils.
Claim 3
Dependent Claim
17 words
An modified impact-resistant vinylaromatic copolymer according to claim 1, in which the ethylenically unsaturated nitrile is acrylonitrile.
References Cited (Backward Citations)
US2384547A
Cited
US2459126A
Cited
US2450028A
Cited
GB621703A
Cited
US2713566A
Cited
GB751497A
Cited
US2713562A
Cited
US2854439A
Cited
US3118854A
Cited
US3956246A
Cited
NL7504486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |