US4990204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved spunbonding of linear polyethylenes
Assignee: Dow Chemical Co
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Filing: 1989-04-17
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Granted: 1991-02-05
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Expires: 2009-04-17
Abstract
Abstract Blends of high molecular weight linear polyethylene and low molecular weight linear polyethylene provide improved fiber-forming capabilities over that found with either polymer taken alone. Preferably at least one of the polymers used in the blend is a linear low density polyethylene, LLDPE, which is a linear polyethylene comprising ethylene copolymerized with an amount of a higher alpha-olefin which causes the density of the copolymer to be less than that of a homopolymer made using the same process and catalyst. The higher alpha-olefin can be at least one in the C3-C12 range, preferably in the C4-C8 range.
Inventors
- 👤 Stephen P. Krupp
- 👤 Edward N. Knickerbocker
- 👤 John O. Bieser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:01
CPC Classifications
D; D04; D04H; D04H3/00; D04H3/08; D04H3/16; B; B01; B01F; B01F33/00; B01F33/30; C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; D01; D01F; D01F6/00; D01F6/02; D01F6/04; C08L2203/00; C08L2203/12; C08L2205/00; C08L2205/02; C08L2205/025
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
140 words
A method for improving the spunbonding capability of a high molecular weight linear polyethylene in a spunbonded process, said method comprising (A) blending with the high molecular weight linear polyethylene a sufficient amount of low molecular weight linear polyethylene to produce a blend which is spunbondable at a throughput rate and a linear spinning velocity suitable to produce a fiber size of smaller than 3 denier/filament in commercial operations, said high molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes, and said low molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) greater than 25 g/10 minutes, and (B) spunbonding said blend to a fiber size of smaller than 3 denier/filament.
Claim 2
Independent Claim
140 words
A method for improving the spunbonding capability of a high molecular weight linear polyethylene in a spunbonded process, said method comprising (A) blending with the high molecular weight linear polyethylene a sufficient amount of low molecular weight linear polyethylene to produce a blend which is spunbondable at a throughput rate and a linear spinning velocity suitable to produce a fiber size of smaller than 3 denier/filament in commercial operations, said high molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes, and said low molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) greater than 25 g/10 minutes, and (B) spunbonding said blend to a fiber size of smaller than 3 denier/filament.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene with at least one C 3 to C 12 olefin.
Claim 4
Dependent Claim
30 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene with at least one C 4 to C 8 olefin.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and octene-1.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and butene.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein each of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and octene.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene, butene, and octene.
Claim 9
Dependent Claim
23 words
The method of claim 1 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene, hexene, and octene.
Claim 10
Dependent Claim
54 words
The method of claim 1 wherein the high molecular weight linear polyethylene is LLDPE having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes and a density in the range of about 0.91 to about 0.96 g/cm 3 .
Claim 11
Dependent Claim
53 words
The method of claim 1 wherein the low molecular weight linear polyethylene is LLDPE having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between 25 to about 300 g/10 minutes and a density in the range of about 0.91 to about 0.96 g/cm 3 .
Claim 12
Dependent Claim
87 words
The method of claim 1 wherein the high molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes and a density above about 0.91 g/cm 3 , and wherein the low molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between 25 to about 300 g/10 minutes and a density above about 0.91 g/cm 3 .
Claim 13
Dependent Claim
20 words
The method of claim 1 wherein said throughput rate is a commercial rate of about 1.0 to about 1.2 grams/minute/hole.
Claim 14
Dependent Claim
18 words
The method of claim 1 wherein said linear spinning velocity is at least about 3500 meters per minute.
Claim 15
Dependent Claim
37 words
The method of claim 1 wherein said high molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 20 g/10 minutes.
Claim 16
Dependent Claim
37 words
The method of claim 1 wherein said high molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 5 g/10 minutes.
Claim 17
Dependent Claim
40 words
The method of claim 1 wherein said low molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range of from about 25 g/10 minutes to about 40 g/10 minutes.
Claim 18
Dependent Claim
31 words
The method of claim 1 wherein said low molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) above about 40 g/10 minutes.
Claim 19
Dependent Claim
16 words
The method of claim 1 wherein at least one of the linear polyethylenes contains no comonomer.
Claim 20
Independent Claim
140 words
A method for improving the strength of spunbonded webs and fabrics of linear polyethylene in a spunbonded process, said method comprising (A) blending a high molecular weight linear polyethylene with a sufficient amount of low molecular weight linear polyethylene to produce a blend which is spunbondable at a throughput rate and a linear spinning velocity suitable to produce a fiber size of smaller than 3 denier/filament in commercial operations, said high molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes, and said low molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) greater than 25 g/10 minutes, and (B) spunbonding said blend to a fiber size of smaller than 3 denier/filament.
Claim 21
Independent Claim
140 words
A method for improving the strength of spunbonded webs and fabrics of linear polyethylene in a spunbonded process, said method comprising (A) blending a high molecular weight linear polyethylene with a sufficient amount of low molecular weight linear polyethylene to produce a blend which is spunbondable at a throughput rate and a linear spinning velocity suitable to produce a fiber size of smaller than 3 denier/filament in commercial operations, said high molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes, and said low molecular weight linear polyethylene having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) greater than 25 g/10 minutes, and (B) spunbonding said blend to a fiber size of smaller than 3 denier/filament.
Claim 22
Dependent Claim
30 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene with at least one C 3 to C 12 alpha-olefin.
Claim 23
Dependent Claim
30 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene with at least one C 4 to C 8 alpha-olefin.
Claim 24
Dependent Claim
22 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and octene-1.
Claim 25
Dependent Claim
22 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and butene-1.
Claim 26
Dependent Claim
20 words
The method of claim 19 wherein each of the linear polyethylenes is LLDPE comprising a copolymer of ethylene and octene-1.
Claim 27
Dependent Claim
23 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene, butene-1, and octene-1.
Claim 28
Dependent Claim
23 words
The method of claim 19 wherein at least one of the linear polyethylenes is LLDPE comprising a copolymer of ethylene, hexene-1, and octene-1.
Claim 29
Dependent Claim
16 words
The method of claim 19 wherein at least one of the linear polyethylenes contains no comonomer.
Claim 30
Dependent Claim
54 words
The method of claim 19 wherein the high molecular weight linear polyethylene is LLDPE having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between about 0.5 to about 25 g/10 minutes and a density in the range of about 0.91 to about 0.96 g/cm 3 .
Claim 31
Dependent Claim
53 words
The method of claim 19 wherein the low molecular weight linear polyethylene is LLDPE having a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between 25 to about 300 g/10 minutes and a density in the range of about 0.91 to about 0.96 g/cm 3 .
Claim 32
Dependent Claim
87 words
The method of claim 19 wherein the high molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./21.6) within the range between about 0.5 to about 25 g/10 minutes and a density above about 0.91 g/cm 3 , and wherein the low molecular weight linear polyethylene has a melt index measured in accordance with ASTM D-1238, Condition E (190° C./2.16) within the range between 25 to about 300 g/10 minutes and a density above about 0.91 g/cm 3 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |