EP0080198A2
Expired / Lapsed
EP
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Polymeric films having one-sided cling and compositions useful in their preparation
Assignee: Dow Chemical Co
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Filing: 1982-11-22
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Granted: —
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Expires: 2002-11-22
Abstract
Abstract A polymeric film prepared from a relatively crystalline polymer such as a copolymer of ethylene and an a-olefin having at least 3 carbon atoms, e.g.,1-octene (linear low density polyethylene); a relatively amorphous polymer such as low density polyethylene and a tackifying polymer such as a low molecular weight polybutene exhibits a substantially higher cling on one side than the other. A film of a low density polyethylene, linear low density polyethylene and a low molecular weight polybutene also exhibits excellent film strengths and has unexpectedly high resistance to tear, particularly in the cross-direction.
Inventors
- 👤 Lambertus P. P. M. Van Der Heijden
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 17:41
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; C08L23/08; C08L23/0807; C08L23/0815; C08J2323/00; C08J2323/02; C08J2323/04; C08L2205/00; C08L2205/03; C08L23/18; C08L23/20; C08L23/22
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
111 words
A polymeric blend comprising from 45 to 90 weight percent of a first polymer, from 10 to 45 weight percent of a second polymer and from 1 to 10 weight percent of a tackifying agent, said weight percentages being based on the total weight of the first and second polymers and the tackifying agent, wherein the tackifying agent is employed in amounts sufficient to impart an increased cling to at least one surface of a film prepared therefrom and the second polymer is employed in an amount and has sufficiently different crystallinity properties from the first polymer such that a film having preferential one-sided cling can be prepared from the blend.
Claim 2
Dependent Claim
111 words
A polymeric blend comprising from 45 to 90 weight percent of a first polymer, from 10 to 45 weight percent of a second polymer and from 1 to 10 weight percent of a tackifying agent, said weight percentages being based on the total weight of the first and second polymers and the tackifying agent, wherein the tackifying agent is employed in amounts sufficient to impart an increased cling to at least one surface of a film prepared therefrom and the second polymer is employed in an amount and has sufficiently different crystallinity properties from the first polymer such that a film having preferential one-sided cling can be prepared from the blend.
Claim 3
Dependent Claim
60 words
The polymeric blend of Claim 1 wherein the blend comprises from 65 to 80 weight percent of the first polymer, from 35 to 20 weight percent on the second polymer and from 3 to 8 weight percent of the tackifying agent, said weight percentages being based on the total weight of the first and second polymers and the tackifying agent.
Claim 4
Dependent Claim
25 words
The polymeric blend of Claim 1 or 2 wherein the tackifying agent is atactic polypropylene having a number average molecular weight from 2000 to 4000.
Claim 5
Dependent Claim
27 words
The polymeric blend of Claim 1 or 2 wherein the tackifying agent is a polymer of isobutylene having a number average molecular weight from 600 to 1500.
Claim 6
Dependent Claim
56 words
The polymeric blend of any one of the preceding claims wherein the first polymer has a degree of crystallinity from 20 to 40 percent, the second polymer has a degree of crystallinity from 35 to 80 percent and the second polymer has a degree of crystallinity at least about 5 percent higher than the first polymer.
Claim 7
Dependent Claim
53 words
The polymeric blend of Claim 5 wherein the first polymer is a homopolymer of ethylene having a degree of crystallinity from 20 to 35 percent, the second polymer is a copolymer of ethylene with an a-olefin having 3 or more carbon atoms and has a degree of crystallinity from 35 to 70 percent.
Claim 8
Dependent Claim
38 words
The polymeric blend of Claim 5 wherein the second polymer is a copolymer of from 85 to 99 mole percent polymerized ethylene and from 15 to 1 mole percent of polymerized a-olefin having 3 or more carbon atoms.
Claim 9
Dependent Claim
62 words
The polymeric blend of Claim 7 wherein the first polymer has a degree of crystallinity from 20 to 30 percent, the second polymer is a copolymer of ethylene with 1-butene or 1-octene and has a degree of crystallinity from 40 to 50 percent and the tackifying agent is a polymer of isobutylene having a number average molecular weight from 800 to 1200.
Claim 10
Dependent Claim
127 words
A film having preferential one-sided cling prepared from a polymeric blend comprising from 45 to 90 weight percent of a homopolymer of ethylene having a density from 0.91 to 0.94 g/cc at 20°C and a degree of crystallinity from 20 to 40 percent, from 45 to 10 weight percent of a copolymer of from 85 to 99 mole percent polymerized ethylene with from 15 to 1 mole percent polymerized a-olefin having 3 or more carbon.atoms and having a degree of crystallinity from 35 to 80 percent and from 1 to 10 weight percent of a tackifying agent selected from a polymer of atactic polypropylene or a polymer of isobutylene, said weight percentages being based on the total weight of the first and second polymers and tackifying agent.
Claim 11
Dependent Claim
127 words
A film having preferential one-sided cling prepared from a polymeric blend comprising from 45 to 90 weight percent of a homopolymer of ethylene having a density from 0.91 to 0.94 g/cc at 20°C and a degree of crystallinity from 20 to 40 percent, from 45 to 10 weight percent of a copolymer of from 85 to 99 mole percent polymerized ethylene with from 15 to 1 mole percent polymerized a-olefin having 3 or more carbon.atoms and having a degree of crystallinity from 35 to 80 percent and from 1 to 10 weight percent of a tackifying agent selected from a polymer of atactic polypropylene or a polymer of isobutylene, said weight percentages being based on the total weight of the first and second polymers and tackifying agent.
Claim 12
Dependent Claim
106 words
The film of Claim 9 wherein the polymeric blend comprises from 65 to 80 weight percent of the first polymer, from 35 to 20 weight percent of the second polymer and from 3 to 8 weight percent of the tackifying agent, said weight percentages being based on the total weight of the first and second polymers and the-tackifying agent and wherein the first polymer has a degree of crystallinity from 20 to 40 percent, the second polymer has a degree of crystallinity from 35 to 80 percent and the second polymer has a degree of crystallinity at least about 5 percent higher than the first polymer.
Claim 13
Dependent Claim
52 words
The film of Claim 10, wherein the first polymer is a homopolymer of ethylene having a degree of crystallinity from 20 to 35 percent, the second polymer is a copolymer of ethylene with an a-olefin having 3 or more carbon atoms and has a degree of crystallinity from 35 to 70 percent.
Claim 14
Dependent Claim
39 words
. 12. The film of Claim 11 wherein the second polymer is a copolymer of from 85 to 99 mole percent polymerized ethylene and from 15 to 1 mole percent of polymerized a-olefin having 3 or more carbon atoms.
Claim 15
Dependent Claim
61 words
The film of Claim 12 wherein the first polymer has a degree of crystallinity from 20 to 30 percent, the second polymer is a copolymer of ethylene with 1-butene or 1-octene and has a degree of crystallinity from 40 to 50 percent and the tackifying agent is a polymer of isobutylene having a number average molecular weight from 800 to 1200.
Claim 16
Independent Claim
102 words
A method for preparing a film having preferential one-sided cling, said method comprising: (a) blending a first polymer, a second polymer and sufficient amounts of a tackifying agent to impart increased cling to at least one surface of the resulting film; the second polymer having crystallinity properties sufficiently different from the first polymer and being employed in an amount such that the resulting film exhibits preferential one-sided cling, (b) extruding the blend as a film at temperatures sufficient to maintain the blend as a liquid, and (c) cooling the extruded blend at rates sufficient to prepare a film having preferential one-sided cling.
Claim 17
Independent Claim
102 words
A method for preparing a film having preferential one-sided cling, said method comprising: (a) blending a first polymer, a second polymer and sufficient amounts of a tackifying agent to impart increased cling to at least one surface of the resulting film; the second polymer having crystallinity properties sufficiently different from the first polymer and being employed in an amount such that the resulting film exhibits preferential one-sided cling, (b) extruding the blend as a film at temperatures sufficient to maintain the blend as a liquid, and (c) cooling the extruded blend at rates sufficient to prepare a film having preferential one-sided cling.
Claim 18
Dependent Claim
77 words
The method of Claim 14 wherein the first polymer is a homopolymer of ethylene, the second polymer is a copolymer of ethylene with one or more a-olefins having 3 or more carbon atoms, the tackifying agent is atactic polypropylene or a polymer of isobutylene and the film is prepared by extruding a melt of the blend to form a tubular film, and cooling one surface of the tubular film at a higher rate than the opposite surface.
Claim 19
Dependent Claim
40 words
The method of Claim 15 wherein the tubular film is cooled by passing air or other suitable gas over the exterior surface of the tubular film while applying no direct, external cooling to the interior surface of the tubular film.
Claim 20
Dependent Claim
16 words
The method of Claim 16 wherein the frost line height is from 2 to 15 cm.
References Cited (Backward Citations)
No citation records indexed.
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