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公开(公告)号:DE69713131T2
公开(公告)日:2002-10-31
申请号:DE69713131
申请日:1997-11-13
Applicant: DOW CHEMICAL CO
Abstract: This invention relates to an improved shrink film obtained by selectively controlling and optimizing the melt index and density differential between at least two polyolefin polymer components to provide narrow density splits. One aspect of this invention relates to a biaxially oriented polyolefin shrink film having balanced properties and another aspect of this invention relates to an oriented shrink film having improved toughness. This invention also relates to a biaxial orientation method of making an improved shrink film using elaborate shrink orientation techniques such as tenter framing, double-bubble, trapped bubble, tape orientation or combination thereof. Most preferably, the first polyolefin polymer component is a lower density, substantially linear ethylene/alpha-olefin interpolymer and the second polyolefin polymer component is a higher density, heterogeneously branched ethylene/alpha-olefin interpolymer.
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公开(公告)号:DE69715818T2
公开(公告)日:2003-06-18
申请号:DE69715818
申请日:1997-01-22
Applicant: DOW CHEMICAL CO
Inventor: PARIKH R , CHUM S , JAIN PRADEEP , PATEL M , CLAYFIELD E , MCKEAND J , KUMMER G , KHAN AHMED , MARKOVICH P
Abstract: Polymer mixtures are disclosed which comprise at least one homogeneously branched ethylene polymer (A) and at least one ethylene polymer (B) having a crystallinity which is at least 7% greater than the crystallinity of polymer (A) with certain provisos. A process for making a molded article using the disclosed polymer mixtures is disclosed as well as films, film layers, coatings and molded articles formed from those mixtures. These mixtures have several advantages over polymer compositions of the prior art, including improved properties at elevated temperatures such as improved softening point under load, improved hardness, improved toughness, improved 100% modulus of elasticity, improved compression set, improved ability to prevent oil bleed out at lower temperatures when the mixture contains oil and reduced injection molding cycle time. The mixtures retain their performance advantages even when substantial amounts of additives such as oil and filler are incorporated into the mixture. The mixtures may also be crosslinked after they are formed into the shape of an article to form vulcanized elastomeric products. The polymer mixtures have utility in a variety of applications.
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公开(公告)号:DE69715818D1
公开(公告)日:2002-10-31
申请号:DE69715818
申请日:1997-01-22
Applicant: DOW CHEMICAL CO
Inventor: PARIKH R , CHUM S , JAIN PRADEEP , PATEL M , CLAYFIELD E , MCKEAND J , KUMMER G , KHAN AHMED , MARKOVICH P
Abstract: Polymer mixtures are disclosed which comprise at least one homogeneously branched ethylene polymer (A) and at least one ethylene polymer (B) having a crystallinity which is at least 7% greater than the crystallinity of polymer (A) with certain provisos. A process for making a molded article using the disclosed polymer mixtures is disclosed as well as films, film layers, coatings and molded articles formed from those mixtures. These mixtures have several advantages over polymer compositions of the prior art, including improved properties at elevated temperatures such as improved softening point under load, improved hardness, improved toughness, improved 100% modulus of elasticity, improved compression set, improved ability to prevent oil bleed out at lower temperatures when the mixture contains oil and reduced injection molding cycle time. The mixtures retain their performance advantages even when substantial amounts of additives such as oil and filler are incorporated into the mixture. The mixtures may also be crosslinked after they are formed into the shape of an article to form vulcanized elastomeric products. The polymer mixtures have utility in a variety of applications.
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公开(公告)号:DE69713131D1
公开(公告)日:2002-07-11
申请号:DE69713131
申请日:1997-11-13
Applicant: DOW CHEMICAL CO
Abstract: This invention relates to an improved shrink film obtained by selectively controlling and optimizing the melt index and density differential between at least two polyolefin polymer components to provide narrow density splits. One aspect of this invention relates to a biaxially oriented polyolefin shrink film having balanced properties and another aspect of this invention relates to an oriented shrink film having improved toughness. This invention also relates to a biaxial orientation method of making an improved shrink film using elaborate shrink orientation techniques such as tenter framing, double-bubble, trapped bubble, tape orientation or combination thereof. Most preferably, the first polyolefin polymer component is a lower density, substantially linear ethylene/alpha-olefin interpolymer and the second polyolefin polymer component is a higher density, heterogeneously branched ethylene/alpha-olefin interpolymer.
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