US4576993A
Expired / Lapsed
US
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Low density polyethylene polymeric compositions
Assignee: Raychem Ltd
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Filing: 1984-01-30
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Granted: 1986-03-18
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Expires: 2004-01-30
Abstract
Abstract A cross-linked polymeric composition comprises a linear, low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25 DEG C. of 0.940 gm/cm3 or less (b) a linearity expressed in terms of pendant methyl groups per 103 carbon atoms of the polymeric chain of less than 30 with a substantial absence of long chain branches, and preferably (c) no more than 5 branches greater in length than C8. The cross-linked polymeric composition is particularly suitable for the production of dimensionally recoverable articles, for the production of insulation material, for the production of semi-conductive or conductive polymers for use in electrical heating materials, and for the production of semi-permeable membranes.
Inventors
- 👤 Paul Tamplin
- 👤 Malcolm D. Heaven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:50
CPC Classifications
H; H02; H02G; H02G15/00; H02G15/08; H02G15/18; B; B01; B01D; B01D71/00; B01D71/06; B01D71/26; B01D71/261; B01D71/76; C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; H01; H01B; H01B1/00; H01B1/20; H01B1/24; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/441; H01M; H01M50/00; H01M50/40; H01M50/489; H01M50/494; B01D2323/00; B01D2323/30; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
115 words
A substantially cross-linked polymeric composition comprising a first linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 30, (c) no more than 5 branches greater in length than C 8 , and (d) a stress exponent in the range of from 1.2 to 1.4, wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 2
Dependent Claim
115 words
A substantially cross-linked polymeric composition comprising a first linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 30, (c) no more than 5 branches greater in length than C 8 , and (d) a stress exponent in the range of from 1.2 to 1.4, wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 3
Dependent Claim
27 words
A composition according to claim 1 wherein the degree of cross-linking of the composition expressed in terms of gel content (ANSI/ASTM D 2765-68) is at least 40%.
Claim 4
Dependent Claim
30 words
A composition according to claim 1 wherein the first ethylene homo- or copolymer prior to cross-linking is characterised by a ΔT value as hereinbefore defined of greater than 15° C.
Claim 5
Dependent Claim
28 words
A composition according to claim 1 wherein the first ethylene homo- or copolymer prior to cross-linking is characterised by a molecular weight distribution index of less than 8.
Claim 6
Dependent Claim
25 words
A composition according to claim 1 wherein the first ethylene homo- or copolymer has substantially no chain branches greater in length than C 6 .
Claim 7
Dependent Claim
21 words
A composition according to claim 5 wherein substantially all chain branches of the first ethylene homo- or copolymer are ethyl branches.
Claim 8
Dependent Claim
29 words
A composition according to claim 6 wherein the first ethylene homo- or copolymer has from 15 to 30 ethyl branches per 10 3 carbon atoms of the polymer chain.
Claim 9
Dependent Claim
29 words
A composition according to claim 6 wherein the first ethylene homo- or copolymer has no more than 10 ethyl branches per 10 3 carbon atoms of the polymer chain.
Claim 10
Dependent Claim
43 words
A composition according to claim 1 wherein the first ethylene homo- or copolymer is, prior to cross-linking, characterised by a degree of unsaturation expressed in terms of terminal vinyl groups per 10 3 carbon atoms of the polymer chain of at least 0.2.
Claim 11
Dependent Claim
21 words
A composition according to claim 1 wherein the first ethylene polymer is a copolymer of ethylene with an olefinically unsaturated monomer.
Claim 12
Dependent Claim
19 words
A composition according to claim 10 wherein the olefinically unsaturated monomer is a C 3 to C 8 α-olefin.
Claim 13
Dependent Claim
11 words
A composition according to claim 11 wherein the α-olefin is n-but-1-ene.
Claim 14
Dependent Claim
15 words
A composition according to claim 1 wherein the first ethylene copolymer is a random copolymer.
Claim 15
Dependent Claim
22 words
A composition according to claim 1 wherein the blendable polymer is a branched low density polyethylene or a linear high density polyethylene.
Claim 16
Dependent Claim
16 words
A composition according to claim 1 wherein the blendable polymer is an ethylene/unsaturated aliphatic ester copolymer.
Claim 17
Dependent Claim
17 words
A composition according to claim 15 wherein the ethylene/unsaturated aliphatic ester copolymer is an ethylene/vinyl acetate copolymer.
Claim 18
Dependent Claim
15 words
A composition according to claim 1 including at least 10 weight percent of a filler.
Claim 19
Dependent Claim
13 words
A composition according to claim 17 wherein the filler is a non-reinforcing filler.
Claim 20
Dependent Claim
19 words
A composition according to claim 18 wherein the filler has a particle size of from 1 to 120 microns.
Claim 21
Dependent Claim
13 words
A composition according to claim 17 wherein the filler is a reinforcing filler.
Claim 22
Dependent Claim
19 words
A composition according to claim 20 wherein the filler has a particle size of from 0.01 to 1 microns.
Claim 23
Dependent Claim
28 words
A cross-linkable composition comprising a linear low density ethylene homo- or copolymer as defined in claim 1 incorporating an effective amount of a cross-linking agent or a prorad.
Claim 24
Dependent Claim
11 words
A dimensionally recoverable article comprising a composition according to claim 1.
Claim 25
Dependent Claim
10 words
An article according to claim 23 which is heat shrinkable.
Claim 26
Dependent Claim
9 words
An article according to claim 24 which is hollow.
Claim 27
Dependent Claim
18 words
An article according to claim 25 of monolithic construction consisting wholly of the composition defined in claim 1.
Claim 28
Dependent Claim
12 words
An article according to claim 26 in the form of a sleeve.
Claim 29
Dependent Claim
14 words
Electrical insulation for a wire or cable comprising a composition according to claim 1.
Claim 30
Dependent Claim
29 words
Electrical insulation which comprises a composition according to claim 1 incorporating an anti-tracking filler and having an initial tracking voltage according to ASTM D2303 of greater than 2.5 kV.
Claim 31
Dependent Claim
23 words
A semi-conductive or conductive polymeric composition comprising a composition according to claim 1 having incorporated therein an effective amount of a conductive filler.
Claim 32
Dependent Claim
24 words
A stress grading tube for the electrical stress grading of the termination of high voltage cables comprising a semi-conductive composition according to claim 29.
Claim 33
Dependent Claim
18 words
An electrical screen for wire or cable which comprises a semi-conductive or conductive composition according to claim 29.
Claim 34
Dependent Claim
14 words
A semi-permeable membrane comprising a composition according to claim 1 in semi-permeable film form.
Claim 35
Dependent Claim
18 words
A membrane according to claim 33 wherein the film has a thickness of between 0.001 and 0.5 mm.
Claim 36
Dependent Claim
22 words
A membrane according to claim 33 wherein the film has been grafted with monomers to modify the selectivity thereof to ionic species.
Claim 37
Dependent Claim
13 words
An electrolytic cell or battery separator comprising a membrane according to claim 33.
Claim 38
Dependent Claim
18 words
A composition according to claim 1 having been quenched across the crystalline melting point thereof prior to cross-linking.
Claim 39
Dependent Claim
111 words
A substantially cross-linked polymeric composition comprising a first linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 30, (c) no more than 5 branches greater in length than C 8 , and (d) a molecular weight distribution less than 8, wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 40
Dependent Claim
111 words
A substantially cross-linked polymeric composition comprising a first linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 30, (c) no more than 5 branches greater in length than C 8 , and (d) a molecular weight distribution less than 8, wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 41
Dependent Claim
103 words
A substantially cross-linked polymeric composition comprising a first linear low density ehtylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 10, and (c) no more than 5 branches greater in length than C 8 , wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 42
Dependent Claim
103 words
A substantially cross-linked polymeric composition comprising a first linear low density ehtylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of less than 10, and (c) no more than 5 branches greater in length than C 8 , wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 43
Dependent Claim
103 words
A substantially cross-linked polymeric composition comprising a linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of from 15 to 30, and (c) no more than 5 branches greater in length than C 8 , wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
Claim 44
Dependent Claim
103 words
A substantially cross-linked polymeric composition comprising a linear low density ethylene homo- or copolymer which, prior to cross-linking is characterized by (a) a density at 25° C. of less than 0.930 gm/cm 3 , (b) a linearity expressed in terms of pendant methyl groups per 10 3 carbon atoms of the polymer chain of from 15 to 30, and (c) no more than 5 branches greater in length than C 8 , wherein the first ethylene homo- or copolymer is present in the form of a blend with a blendable branched, ethylene homo- or copolymer, the polymers having been blended prior to cross-linking.
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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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |