US4362854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Poly(p-methylstyrene) with broad molecular weight distribution and process for preparation
Assignee: Mobil Oil AS
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Filing: 1981-12-30
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Granted: 1982-12-07
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Expires: 2001-12-30
Abstract
Abstract Poly(p-methylstyrene) with a broad molecular weight distribution and having a melt index suitable for injection molding is prepared by polymerizing p-methylstyrene monomer with a low temperature initiator and a high temperature initiator added with all the monomer at the start of the reaction.
Inventors
- 👤 Aristotle G. Prapas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:33
CPC Classifications
C; C08; C08F; C08F12/00; C08F12/02; C08F12/04; C08F12/06; C08F12/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
51 words
Poly(methylstyrene) having a molecular weight distribution (MWD) of at least about 4.0 and a melt index of at least 5.0, said polymethylstyrene comprising the polymerization product of methylstyrene isomers in the following proportions: p-methylstyrene at least 90 weight percent; m-methylstyrene 0 to 10 weight percent; o-methylstyrene less than 0.1 weight percent.
Claim 2
Dependent Claim
51 words
Poly(methylstyrene) having a molecular weight distribution (MWD) of at least about 4.0 and a melt index of at least 5.0, said polymethylstyrene comprising the polymerization product of methylstyrene isomers in the following proportions: p-methylstyrene at least 90 weight percent; m-methylstyrene 0 to 10 weight percent; o-methylstyrene less than 0.1 weight percent.
Claim 3
Dependent Claim
11 words
Poly(methylstyrene) of claim 1 having a MWD of at least 6.0.
Claim 4
Dependent Claim
26 words
Poly(methylstyrene) of claim 1 in which the methylstyrene monomers are present in the following proportions: p-methylstyrene at least 95 weight percent; m-methylstyrene 0 to 5 percent.
Claim 5
Dependent Claim
71 words
A process for polymerizing a methylstyrene isomer mixture which is predominantly the para-isomer comprising the steps of mixing substantially all of the methylstyrene isomer mixture to be polymerized with polymerization initiators including a high temperature initiator and a low temperature initiator and reacting the mixture at a temperature sufficient to effect polymerization to obtain a product having a MWD of at least 4.0 and a melt index of at least 5.0.
Claim 6
Dependent Claim
71 words
A process for polymerizing a methylstyrene isomer mixture which is predominantly the para-isomer comprising the steps of mixing substantially all of the methylstyrene isomer mixture to be polymerized with polymerization initiators including a high temperature initiator and a low temperature initiator and reacting the mixture at a temperature sufficient to effect polymerization to obtain a product having a MWD of at least 4.0 and a melt index of at least 5.0.
Claim 7
Dependent Claim
26 words
The process of claim 4 in which the weight ratio of said low temperature initiator to said high temperature initiator is from about 1:1 to 5:1.
Claim 8
Dependent Claim
25 words
The process of claims 4 or 5 in which said low temperature initiator is benzoyl peroxide, and said high temperature peroxide is t-butyl peroxy (2-methylbenzoate).
Claim 9
Dependent Claim
21 words
The process of claim 4 in which the polymerization reaction is conducted at a temperature from about 80° C. to 150°.
Claim 10
Dependent Claim
42 words
The process of claim 1 in which said methylstyrene isomer mixture comprises at least about 90 weight percent of the para isomer, 0 to 10 weight percent of the meta isomer and less than about 0.1 weight percent of the ortho isomer.
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) | 1985-12-06 | 1986-06-07 | 1986-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-06 | 1990-06-07 | 1990-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-06 | 1994-06-07 | 1994-12-07 | $7700.00 | Window Closed / Lapsed |