Patent US4888141A successfully refreshed from Google Patents.
US4888141A
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Process for producing polyethylene articles having a high tensile strength and modulus
Assignee: DSM BV
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Filing: 1987-10-09
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Granted: 1989-12-19
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Expires: 2007-10-09
Abstract
Abstract High strength and modulus articles, such as filaments, fibers, tapes, films, tubes, bars or profiles, are prepared by irradiating a solid, particular, lamellar, disentangled polyethylene with a Mw>4×10 5 , transforming this polyethylene above the melt temperature into an article, cooling said article to below the melting point and stretching it in several steps at rising temperature but below the melting point of the article. Advantages are i.a. the lower costs compared with the known processes, such as solid state extrusion or thermoreversible gelation.
Inventors
- 👤 Cornelis W. M. Bastiaansen
- 👤 Pieter J. Lemstra
- 👤 Lambert H. T. van Unen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:31
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/28; B; B29; B29C; B29C69/00; B29B; B29B13/00; B29B13/08; B29B9/00; B29B9/16; B29C55/00; B29C55/005; B29C55/02; B29C55/04; B29C55/06; B29C55/065; B29C67/00; B29C67/24; C08J5/00; C08J5/18; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; D; D01; D01F; D01F6/00; D01F6/02; D01F6/04; B29C35/00; B29C35/02; B29C35/08; B29C35/0866; B29C2035/0877; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0658; B29K2023/0683; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A process for producing polyethylene articles having a high tensile strength and a high modulus, comprising: irradiating a solid, particle-shaped, linear polyethylene having a lamellar structure, a low degree of entanglement and a weight-average molecular weight of at least 4×10 5 ; transforming the irradiated polyethylene into an article at a temperature above the melting point of the polyethylene; cooling the article to a temperature below the melting point of the polyethylene; and stretching the article, in a plurality of steps, with an increasing temperature, which is below the melting point of the polyethylene article, to form a polyethylene article having a high tensile strength and a high modulus.
Claim 2
Dependent Claim
109 words
A process for producing polyethylene articles having a high tensile strength and a high modulus, comprising: irradiating a solid, particle-shaped, linear polyethylene having a lamellar structure, a low degree of entanglement and a weight-average molecular weight of at least 4×10 5 ; transforming the irradiated polyethylene into an article at a temperature above the melting point of the polyethylene; cooling the article to a temperature below the melting point of the polyethylene; and stretching the article, in a plurality of steps, with an increasing temperature, which is below the melting point of the polyethylene article, to form a polyethylene article having a high tensile strength and a high modulus.
Claim 3
Dependent Claim
15 words
The process according to claim 1, wherein irradiating the polyethylene is accomplished with electron irradiation.
Claim 4
Dependent Claim
13 words
The process according to claim 1, wherein the irradiation is about 1-20 Mrad.
Claim 5
Dependent Claim
13 words
The process according to claim 3, wherein the irradiation is about 2-6 Mrad.
Claim 6
Dependent Claim
21 words
The process of claim 1, wherein transforming the irradiated polyethylene occurs at a temperature between about 135° C. and 155° C.
Claim 7
Dependent Claim
29 words
The process of claim 1, wherein the particle-shaped polyethylene is in a mixture containing at least one plasticizer in an equal amount, based upon the weight of the polyethylene.
Claim 8
Dependent Claim
15 words
The process of claim 6, wherein the plasticizer is a paraffinic, hydroaromatic or aromatic hydrocarbon.
Claim 9
Dependent Claim
36 words
The process according to claim 6, wherein the transforming of the mixture of irradiated polyethylene and plasticizer occurs at a temperature above the melting point of the mixture but below the decomposition temperature of the polyethylene.
Claim 10
Dependent Claim
26 words
The process according to claim 1, wherein the stretching, in a plurality of steps, occurs at a temperature between about 90° C. and about 155° C.
Claim 11
Dependent Claim
21 words
The process according to claim 1, wherein the product article is one comprising a filament, tape, film, tube, bar or profile.
References Cited (Backward Citations)
US3886056A
Cited
US3887319A
Cited
US4422993A
Cited
US4430383A
Cited
EP0055001A1
Cited
US4411854A
Cited
US4436689A
Cited
JPS58217322A
Cited
US4617233A
Cited
EP0139141A2
Cited
JPS59216913A
Cited
JPS59216914A
Cited
US4643865A
Cited
JPS60132744A
Cited
US4600633A
Cited
US4600631A
Cited
JPS60236716A
Cited
US4616059A
Cited
US4655769A
Cited
EP0531685A1
Cited
JPH0659172A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |