US4948545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion process for preparing orientated polyolefins
Assignee: DSM BV
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Filing: 1989-10-06
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Granted: 1990-08-14
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Expires: 2009-10-06
Abstract
Abstract An orientated polyolefin composition comprising an olefin (co)polymer having a weight average molecular weight (Mw) from 30,000 to 1,000,000 and a high molecular weight tail extending to molelcular weights above 1,000,000, and has a microstructure which is substantially parallel chain extended cores of the component polymer(s) and associated lamellar overgrowths extending in planes normal to the cores in which the lamellar overgrowths on adjacent cores intermesh and are capable of sustaining a haul off tension of at least 10 MPa without breaking during its extrusion, is produced by extruding an olefin copolymer through a die under a pressure of about 5-10 MPa, at a temperature above the self-blocking temperature thereof and by hauling off the extrudate at a tension of at least 10 MPa without breaking. The extrudates so produced have a high modulus.
Inventors
- 👤 Zahir Bashir
- 👤 Andrew Keller
- 👤 Jeffrey A. Odell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:12
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/04; B; B29; B29C; B29C55/00; B29K; B29K2023/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
151 words
In an extrusion process for preparing a polyolefin composition having an orientated microstructure which comprises substantially parallel chain extended cores of the component polymer(s) and associated lamellar overgrowths extending in planes normal to the cores and in which the lamellar overgrowths on adjacent cores intermesh, the improvement comprising: (a) using as starting material a polyolefin comprising an olefin (co)polymer having a weight average molecular weight (Mw) above 30,000 and not greater 1,000,000 and a high molecular weight tail extending to molecular weights greater than 1,000,000; (b) performing the extrusion through a die under pressure and at a temperature above, but not more than 5° C. above, the self blocking temperature; (c) cooling the extrudate at the die exit while maintaining the die temperature conditions set forth in (b) above; and (d) continuously hauling off the extrudate at a haul-off stress of at least 10 MPa so as to avoid die swell.
Claim 2
Dependent Claim
151 words
In an extrusion process for preparing a polyolefin composition having an orientated microstructure which comprises substantially parallel chain extended cores of the component polymer(s) and associated lamellar overgrowths extending in planes normal to the cores and in which the lamellar overgrowths on adjacent cores intermesh, the improvement comprising: (a) using as starting material a polyolefin comprising an olefin (co)polymer having a weight average molecular weight (Mw) above 30,000 and not greater 1,000,000 and a high molecular weight tail extending to molecular weights greater than 1,000,000; (b) performing the extrusion through a die under pressure and at a temperature above, but not more than 5° C. above, the self blocking temperature; (c) cooling the extrudate at the die exit while maintaining the die temperature conditions set forth in (b) above; and (d) continuously hauling off the extrudate at a haul-off stress of at least 10 MPa so as to avoid die swell.
Claim 3
Dependent Claim
24 words
A process according to claim 1 wherein the extrusion takes place at a temperature not more than 2° C. above the self blocking temperature.
Claim 4
Dependent Claim
26 words
A process according to claim 1 wherein the olefin (co) polymer starting material has a low molecular weight tail in the range of 500 to 10,000.
Claim 5
Dependent Claim
24 words
A process according to claim 1, wherein the olefin (co)polymer starting material includes substantially no molecular weight tail below a molecular weight of 500.
Claim 6
Dependent Claim
23 words
A process according to claim 1, wherein the olefin (co)polymer starting material contains at least 0.5% w/w of high molecular weight tail component.
Claim 7
Dependent Claim
15 words
A process according to claim 1 wherein the olefin (co)polymer is dried prior to extrusion.
Claim 8
Dependent Claim
24 words
A process according to claim 1 or 6 wherein the extruded product is a fiber and has a modulus of at least 3 GPa.
Claim 9
Dependent Claim
44 words
A process according to claim 1, wherein the olefin (co)polymer starting material is polyethylene having a weight average molecular weight (Mw) from 30,000 to 1,000,000 and the molecular weight of the high molecular weight tail component in the (co)polymer is from 1,000,000 to 5,000,000.
Claim 10
Dependent Claim
25 words
A process according to claim 1 wherein the olefin (co)polymer starting material is an unblended homo - or (co)polymer as obtained from a polymerization reactor.
Claim 11
Dependent Claim
23 words
A process according to claim 1, wherein the olefin (co)polymer starting material has a density which is at least 910 kg/m 3 .
Claim 12
Dependent Claim
21 words
A process according to claim 1 wherein the distance between adjacent cores in the extruded composition is less than 5000 angstroms.
References Cited (Backward Citations)
US3112160A
Cited
US3214503A
Cited
FR2330716A1
Cited
US4053270A
Cited
FR2385823A1
Cited
GB2056996A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |