US4539371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High impact poly(p-methylstyrene) polymers
Assignee: Mobil Oil AS
•
Filing: 1983-12-30
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Granted: 1985-09-03
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Expires: 2003-12-30
Abstract
Abstract The present invention provides a method for improving the environmental stress crack resistance of high impact poly(p-methylstyrene) by blending high impact poly(p-methylstyrene) with an additive copolymer having a higher environmental stress crack resistance. The invention further provides a shaped container resistant to fats.
Inventors
- 👤 Binnur Z. Gunesin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:33
CPC Classifications
C; C08; C08L; C08L25/00; C08L25/02; C08L25/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
A method of improving the environmental stress crack resistance of high impact poly(p-methylstyrene), comprising (a) melting said high impact poly(p-methylstyrene) at a temperature between 150° and 250° C.; (b) blending an additive copolymer with said melted high impact poly(p-methylstyrene) capable of imparting a higher environmental stress crack resistance to the final blend of said high impact poly(p-methylstyrene) and said additive copolymer, said additive copolymer being selected from the group comprising linear low density polyethylene, polypropylene, polycarbonate, ethylene methylacrylate acrylic acid terpolymer, polyethylene teraphalate glycol, polystyrene-polybutadiene diblock, and budadiene-paramethylstyrene diblock, said blending occurring at a temperature between 150° and 250° C.
Claim 2
Independent Claim
100 words
A method of improving the environmental stress crack resistance of high impact poly(p-methylstyrene), comprising (a) melting said high impact poly(p-methylstyrene) at a temperature between 150° and 250° C.; (b) blending an additive copolymer with said melted high impact poly(p-methylstyrene) capable of imparting a higher environmental stress crack resistance to the final blend of said high impact poly(p-methylstyrene) and said additive copolymer, said additive copolymer being selected from the group comprising linear low density polyethylene, polypropylene, polycarbonate, ethylene methylacrylate acrylic acid terpolymer, polyethylene teraphalate glycol, polystyrene-polybutadiene diblock, and budadiene-paramethylstyrene diblock, said blending occurring at a temperature between 150° and 250° C.
Claim 3
Dependent Claim
20 words
The method according to claim 1, wherein said blending continues for ten minutes after said additive copolymer is completely added.
Claim 4
Dependent Claim
18 words
The method according to claim 1, wherein said additive copolymer is trickle-fed into said melted high impact poly(p-methylstyrene).
Claim 5
Dependent Claim
19 words
The method according to claim 2, further comprising cooling to room temperature and pelletizing the product of step (b).
Claim 6
Dependent Claim
25 words
The method according to claim 1, wherein said additive copolymer is blended in an amount no more than 10 weight % of the entire blend.
Claim 7
Dependent Claim
25 words
The method according to claim 1, wherein said additive copolymer is blended in an amount no more than 5 weight % of the entire blend.
References Cited (Backward Citations)
US4205114A
Cited
CA1132746A
Cited
US4275179A
Cited
US4260694A
Cited
US4351889A
Cited
US4335181A
Cited
US4352908A
Cited
US4397988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |