Polyolefin film containing cycloolefin polymer, process for the production thereof, and the use thereof
First Claim
1. A film structure comprising a major amount of olefinic polymer which includes at least one mixed-polymer layer containing a non-cyclic polyolefin, hereafter referred to as a polyolefin, and a cycloolefin polymer, hereafter referred to as a COP, the polymer composition of said mixed-polymer layer being essentially homogeneous and comprising, based on the weight of said layer:
- at least 50% by weight of polyolefin, anda polyolefin-compatible amount, which is less than 50% by weight, of COP,wherein said COP is essentially amorphous and has a mean molecular weight, Mw, in the range from 200 to 100,000, and the Mw of the COP ranges from 0.05 to at most 50% of the Mw of said polyolef in, said COP containing up to 20% by weight of comonomer.
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Abstract
A polyolefin film which includes at least one layer containing polyolefin and cycloolefin polymer (COP), where the cycloolefin polymer is amorphous and has a mean molecular weight Mw in the range from 200 to 100,000, and this mean molecular weight Mw of the cycloolefin polymer is at most 50% of the mean molecular weight Mw of the polyolefin, and the cycloolefin polymer is a homopolymer or a copolymer containing at most 20% by weight of comonomer.
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Citations
20 Claims
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1. A film structure comprising a major amount of olefinic polymer which includes at least one mixed-polymer layer containing a non-cyclic polyolefin, hereafter referred to as a polyolefin, and a cycloolefin polymer, hereafter referred to as a COP, the polymer composition of said mixed-polymer layer being essentially homogeneous and comprising, based on the weight of said layer:
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at least 50% by weight of polyolefin, and a polyolefin-compatible amount, which is less than 50% by weight, of COP, wherein said COP is essentially amorphous and has a mean molecular weight, Mw, in the range from 200 to 100,000, and the Mw of the COP ranges from 0.05 to at most 50% of the Mw of said polyolef in, said COP containing up to 20% by weight of comonomer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A process for the production of a film structure, comprising
preparing at least one polymeric mixture comprising, for each 100 parts by weight of polymer, at least 50 parts by weight of polyolefin, and a polyolefin-compatible amount, not exceeding 50 parts by weight, of cycloolefin polymer, hereafter COP, wherein said COP is essentially amorphous and has a mean molecular weight, Mw, in the range from 200 to 100,000, and the Mw of the COP ranges from 0.05 to at most 50% of the Mw of said polyolefin, said COP containing up to 20% by weight of comonomer, and wherein the resulting polymeric mixture is essentially homogeneous, compressing and warming the resulting polymeric mixture in an extruder to form a melt, extruding said melt through a flat-film die, alone or in combination with at least one additional melt, to obtain a film structure, wherein said extruding step is carried out at a temperature above the glass transition temperature of the COP, taking off the resulting film structure over at least one roll, said film structure being essentially free of optical flaws caused by incompatibility, optionally orienting said resulting film structure, and optionally heat-setting and surface-treating said resulting film structure.
Specification