Patent EP0445083A1 successfully refreshed from Google Patents.
Patent EP0341091A2 successfully refreshed from Google Patents.
EP0341091A2
Expired / Lapsed
EP
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Linear low density polyethylene of ultra low density
Assignee: Dow Chemical Co
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Filing: 1989-05-08
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Granted: —
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Expires: 2009-05-08
Abstract
Abstract A heat-sealable LLDPE for packaging is prepared by employing conditions, catalyts, and an amount of C₅-C₁₂ aliphatic alpha-olefin comonomer(s) sufficient to produce a density in the range of 0.87 to 0.918 g/cc whereby a narrow molecular weight copolymer is produced which has a low I₁₀/I₂ ratio and a z₁/z₀ value which is in the range of 3.5 to 7, along with a numerical value which is not greater than the sum of (62.4 - 63.7·density), and also exhibiting good heat-seal strength and low concentrations of hexane-extractables. Preferably, the comonomer is at least one straight chain C₅-C₈, most preferably octene-1. The density is preferably not more than 0.915 g/cc. Due to its strength, good heat-sealability, and low levels of n-hexane extractables, the material is ideally suitable for packaging food, but also has other utility.
Inventors
- 👤 Kathryn K. Dohrer
- 👤 Lonnie G. Hazlitt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 02:12
CPC Classifications
C; C08; C08F; C08F210/00; C08F210/16
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
111 words
A linear low density polyethylene (LLDPE) which comprises a copolymer of ethylene and at least one straight chain aliphatic alpha-olefin comonomer of C₅ to C₁₂ carbon atoms, said comonomer being present in the copolymer in an amount effective to provide a copolymer density in the range of 0.87 to 0.918 g/cc, wherein said copolymer has a z₁/z₀ ratio which is (a) in the range of 3.5 to 7, and (b) a numerical value which is not greater than the numerical value of (62.4-63.7·density) where density is expressed in g/cc; and said copolymer has an I₂ value in the range of 0.1 to 30 gm/10 min. as measured by ASTM D-1238 (190/2.16).
Claim 2
Dependent Claim
111 words
A linear low density polyethylene (LLDPE) which comprises a copolymer of ethylene and at least one straight chain aliphatic alpha-olefin comonomer of C₅ to C₁₂ carbon atoms, said comonomer being present in the copolymer in an amount effective to provide a copolymer density in the range of 0.87 to 0.918 g/cc, wherein said copolymer has a z₁/z₀ ratio which is (a) in the range of 3.5 to 7, and (b) a numerical value which is not greater than the numerical value of (62.4-63.7·density) where density is expressed in g/cc; and said copolymer has an I₂ value in the range of 0.1 to 30 gm/10 min. as measured by ASTM D-1238 (190/2.16).
Claim 3
Dependent Claim
11 words
The LLDPE of Claim 1 wherein the alpha-olefin comonomer is octene-1.
Claim 4
Dependent Claim
17 words
The LLDPE of Claim 1 or claim 2, having a density of from 0.87 to 0.915 g/cc.
Claim 5
Dependent Claim
20 words
The LLDPE of any one of the preceding Claims wherein the I₂ value is from 0.2 to 10 gm/10 min.
Claim 6
Dependent Claim
20 words
The LLDPE of any one of the preceding Claims wherein the LLDPE has an I₁₀/I₂ ratio of less than 8.5.
Claim 7
Dependent Claim
16 words
The LLDPE of Claim 5 wherein the LLDPE has an I₁₀/I₂ ratio of less than 8.0.
Claim 8
Dependent Claim
39 words
The LLDPE of any one of the preceding Claims wherein the LLDPE has been prepared by employing in the polymerization a catalyst which produces a molecular weight distribution having a M W /M N ratio of less than 8.8.
Claim 9
Dependent Claim
23 words
The LLDPE of any one of the preceding Claims wherein the LLDPE has a M W /M N ratio of less than 7.
Claim 10
Dependent Claim
27 words
The LLDPE of Claim 8 wherein the LLDPE has an I₂ value of from 0.2 to 10 gm/10 min., and an I₁₀/I₂ ratio of less than 8.
Claim 11
Dependent Claim
35 words
The LLDPE of any one of the preceding Claims wherein the LLDPE has a plurality of melting points in the range of 75° to 140°C and less than 5.5 weight percent n-hexane extractables at 50°C.
Claim 12
Dependent Claim
15 words
A packaging material comprising an LLDPE as claimed in any one of the preceding Claims.
Claim 13
Dependent Claim
15 words
A material as claimed in Claim 11, in the form of a heat sealable film.
Claim 14
Dependent Claim
18 words
The use of a material as claimed in Claim 11 or Claim 12 in the packaging of food.
Claim 15
Independent Claim
92 words
A method of preparing an LLDPE having less than 5.5. weight percent n-hexane extractables at 50°C, which method comprises copolymerising ethylene and at least one straight chain alpha-olefin comonomer, under conditions such as to obtain a copolymer having a density of from 0.87 to 0.918g/cc, a ratio of Z₁/Z₀ which is:- (a) from 3.5 to 7, and (b) not greater than the numerical value of 62.4 - 63.7.density, where density is expressed in g/cc, and an I₂ value of from 0.1 to 30 gm/10 min., as measured by ASTMD - 1238 (190/2.16).
Claim 16
Independent Claim
92 words
A method of preparing an LLDPE having less than 5.5. weight percent n-hexane extractables at 50°C, which method comprises copolymerising ethylene and at least one straight chain alpha-olefin comonomer, under conditions such as to obtain a copolymer having a density of from 0.87 to 0.918g/cc, a ratio of Z₁/Z₀ which is:- (a) from 3.5 to 7, and (b) not greater than the numerical value of 62.4 - 63.7.density, where density is expressed in g/cc, and an I₂ value of from 0.1 to 30 gm/10 min., as measured by ASTMD - 1238 (190/2.16).
References Cited (Backward Citations)
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