Patent US5183871A successfully refreshed from Google Patents.
US5183871A
Expired / Lapsed
US
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Styrene polymer molding material and process for preparing same
Assignee: Dow Chemical Co
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Filing: 1990-05-14
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Granted: 1993-02-02
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Expires: 2010-05-14
Abstract
Abstract Disclosed are a styrene polymer molding material which has a high degree of syndiotacticity, a weight average molecular weight of 50,000 or more, and at least one melting points of 285° C. or higher, and a process for producing the same by melting a styrene polymer having a high degree of syndioacticity and then molding it under a stress of 1×10 6 dyne/cm 2 or higher. The styrene polymer molding material of the present invention has excellent heat resistance. In addition, according to the process of the present invention, the above polymer molding material having excellent heat resistance can be prepared by a simple operation, and thus has marked advantages for practical use.
Inventors
- 👤 Komei Yamasaki
- 👤 Funaki Keisuke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:32
CPC Classifications
C; C08; C08L; C08L25/00; C08L25/02; C08L25/04; C08L25/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
82 words
A molding material of styrene polymer having a high degree of syndiotacticity, a weight average molecular weight of 50,000 or more, and at least one melting point in the surface layer or subsurface parts thereof of the molding material in the range of 285° C. to 300° C. and, if present, an inner portion having a conventional syndiotactic configuration and a melting point no higher than 275° C., as measured by differential scanning calorimeter with a temperature rising rate of 20° C./min.
Claim 2
Dependent Claim
82 words
A molding material of styrene polymer having a high degree of syndiotacticity, a weight average molecular weight of 50,000 or more, and at least one melting point in the surface layer or subsurface parts thereof of the molding material in the range of 285° C. to 300° C. and, if present, an inner portion having a conventional syndiotactic configuration and a melting point no higher than 275° C., as measured by differential scanning calorimeter with a temperature rising rate of 20° C./min.
Claim 3
Dependent Claim
32 words
The molding material according to claim 1, wherein the said syndiotacticity measured by a nuclear magnetic resonance method using a carbon isotope is a stereoregularity having 30% or more of racemic pentad.
Claim 4
Dependent Claim
21 words
The molding material according to claim 2, wherein the said syndiotacticity is a stereoregularity having 50% or more of racemic pentad.
Claim 5
Dependent Claim
29 words
The molding material according to claim 1, wherein the said styrene polymer is a styrene homopolymer or a styrene copolymer containing 50 mole % or more of styrene unit.
Claim 6
Dependent Claim
16 words
The molding material according to claim 4, wherein the said styrene polymer is a styrene homopolymer.
Claim 7
Dependent Claim
25 words
The molding material according to claim 4, wherein the said styrene polymer is a styrene copolymer containing 70 mole % or more of styrene unit.
Claim 8
Dependent Claim
22 words
The molding material according to claim 1, wherein the said styrene polymer has a weight average molecular weight of 100,000 or more.
Claim 9
Dependent Claim
42 words
A process for producing a molding material of styrene polymer according to claim 1, which comprises melting a styrene polymer having a high degree of syndiotacticity and thereafter molding the styrene polymer under a stress of 1×10 6 dyne/cm 2 or higher.
Claim 10
Dependent Claim
52 words
The process according to claim 8, wherein the said molding material is composed of a styrene polymer having a high degree of syndiotacticity and at least one of a thermoplastic resin, a rubber, an inorganic filler, an antioxidant, a nucleating agent, a plasticizer, a solubilizing agent, a colorant and an antistatic agent.
Claim 11
Dependent Claim
24 words
The process according to claim 8, wherein the said styrene polymer having a high degree of syndiotacticity is melted at 260° to 340° C.
Claim 12
Dependent Claim
23 words
The process according to claim 8, wherein the said molding is carried out under a stress of 1×10 7 dyne/cm 2 or higher.
Claim 13
Dependent Claim
30 words
The process according to claim 8, wherein the said molding is carried out by melt spinning under a stress of 1×10 7 dyne/cm 2 or higher in the stretching direction.
Claim 14
Dependent Claim
30 words
The process according to claim 8, wherein said molding is carried out by an injection molding under a shear stress in a cavity of 5×10 6 dyne/cm 2 or higher.
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) | 1996-02-02 | 1996-08-03 | 1997-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-02 | 2000-08-03 | 2001-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-02 | 2004-08-03 | 2005-02-02 | $7700.00 | Window Closed / Lapsed |