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EP0170255A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Impact-resistant polypropylene compositions having an improved whitening resistance

Assignee: Himont Inc
•
Filing: 1985-07-30
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Granted: —
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Expires: 2005-07-30
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Abstract

Abstract Polypropylene compositions having a high impact resistance at low temperatures and an improved whitening resistance, comprising : A) 60-90 parts by weight of polypropylene with an isotacticity index > 90; B) 10-40 parts by weight of an ethylene/butene-1 polymeric mixture containing 50-95% by weight of ethylene consisting of: - 20-95% parts by weight of a crystalline fraction (I) with crystallinity of the polyethylene type, insoluble in xylene at room temperature; - 5-80% parts by weight of an ethylene/butene-1 amorphous copolymeric fraction (II), soluble in xylene at 23 DEG C, containing 40-70% by weight of ethylene; and in which the weight ratio between the total polymerized ethylene and the amorphous fraction (II) ranges from 0.6 to 8. <??>Such compositions are obtained through polymerization processes comprising at least a step for homopolymerizing propylene to stereoregular polymer and a subsequent step for copolymerizing ethylene/butene-1 mixtures in the presence of Ziegler-Natta stereospecific catalysts, which include a titanium compound carried on a magnesium halide in the active form.

Inventors

  • 👤 Guiliano Cecchin
  • 👤 Floriano Guglielmi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-03 17:05
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/06; C08F297/08; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/12; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; C08L2314/00; C08L2314/02

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 112 words
Polypropylene compositions having a high impact resistance at low temperatures and an improved whitening resistance, comprising, as essential components . - 60-90 parts by weight of polypropylene having an isotacticity index > 90, preferably 95; - 10-40 parts by weight of an ethylene/butene-1 polymeric fraction containing 50-95% by weight of ethylene and consisting for 20-95% by weight of a crystalline fraction (I), with a polyethylene- type crystallinity, insoluble in xylene at room temperature, and for 5-80% by weight of an amorphous fraction (II), soluble in xylene at 23°C, containing 40-70% by weight of ethylene, and in which the weight ratio between total polymerized ethylene and fraction II ranges from 0.6 to 8.
Claim 2
Dependent Claim 112 words
Polypropylene compositions having a high impact resistance at low temperatures and an improved whitening resistance, comprising, as essential components . - 60-90 parts by weight of polypropylene having an isotacticity index > 90, preferably 95; - 10-40 parts by weight of an ethylene/butene-1 polymeric fraction containing 50-95% by weight of ethylene and consisting for 20-95% by weight of a crystalline fraction (I), with a polyethylene- type crystallinity, insoluble in xylene at room temperature, and for 5-80% by weight of an amorphous fraction (II), soluble in xylene at 23°C, containing 40-70% by weight of ethylene, and in which the weight ratio between total polymerized ethylene and fraction II ranges from 0.6 to 8.
Claim 3
Dependent Claim 185 words
A process for preparing the compositions according to claim 1, by polymerization of propylene and of ethylene/butene-1 mixtures accomplished for in subsequent steps comprising at least a step for the stereoregular homopolymerization of propylene and a step for the copolymerization of mixtures of ethylene and of butene-1, characterized in that the polymerization is carried out in the presence of stereospecitic coordination catalysts comprising a titanium compound carried on a magnesium halide in the active form having a surface area greater than 3 m 2/b and/or having a X-ray spectrum in which the line of higher intensity appearing in the spectrum of the non-activated magnesium halide is broadened or replaced by a halo. by operating in such conditions as to permit the formation, in the homopolymerization step,of polypropylene with an isotacticity index higher than 90, in an amount by weight ranging from 60 to 90 of the final product, and the formation, in the copolymerization step, of an amorphous ethylene/butene-1 copolymer extractable with xylene at 23°C, in such amounts that the weight ratio between total polymerized ethylene and amorphous copolymer may range from 0.6 to 8.
Claim 4
Dependent Claim 27 words
The process according to claim 1, in which the propylene homopolymerization is accomplished in liquid monomer and the ethylene/butene-1 copolymerization is effected in the gas phase. Milan,

References Cited (Backward Citations)

US4415718A Cited
US4454306A Cited

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