Amoco Corporation

Standard Oil Company (indiana)

Philip Jacoby

Charles W Bauer

William T Tapp

Scott R Clingman

James H Fisher

Willilam T Tapp

Mark Heiden

Jesse Wu

Polyolefin resin compositions and oriented microporous films prepared from same comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %, a propylene homopolymer or random propylene copolymer having up to about 10 wt % of a comonomer of ethylene or an .alpha.-olefin of 4 to 8 carbon atoms, and components selected from a low molecular weight polypropylene, a beta-spherulite nucleating agent and an inorganic filler, and to processes for forming such films wherein the microporous films have improved breathability, strength, toughness and break elongation.

Oriented polymeric microporous films

Polyolefin resin compositions and oriented microporous films prepared from same comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %, a propylene homopolymer or random propylene copolymer having up to about 10 wt % of a comonomer of ethylene or an .alpha.-olefin of 4 to 8 carbon atoms, a low molecular weight polypropylene, a beta-spherulite nucleating agent and an inorganic filler. The microporous films have improved breathability, strength, toughness and break elongation.

The invention provides a thermoformable sheet comprising a resinous polymer of propylene and an effective amount of a beta-spherulite nucleating agent, a process for making the sheet and articles thermoformed from the sheet.

Thermoformable polypropylene-based sheet

This invention relates to polymeric compositions capable of being converted into oriented microporous films having microvoid cells, interconnecting pores between the cells, and improved elongation, softness and tear strength, comprising an ethylene-propylene block copolymer having an ethylene content of about 10 to about 50 wt %, a low flexural modulus propylene-based polymer, a propylene homopolymer or copolymer having up to about 10 wt % of a comonomer of ethylene or an .alpha.-olefin of 4 to 8 carbon atoms, an inorganic filler such as calcium carbonate, a beta-spherulite nucleating agent, and optionally, a low molecular weight polypropylene and to microporous films formed from such compositions.

This invention relates to oriented porous films having cells with polygonal cross sections and average pore diameters of about 5 to about 30 microns and interconnecting pores between the cells which have a diameter of about 0.2 to about 20 microns which are formed from a polypropylene-based resin and a process for forming the film which comprises the steps of forming a film containing beta-spherulites, selectively extracting a portion of the beta-spherulites to form a porous film and stretching the porous film in at least one direction to form the oriented polymeric porous film.

Oriented porous polypropylene films

A method and device are disclosed for the determination of the environmental stress crack resistance (ESCR) of polymer articles made from polymers such as acrylonitrile-butadiene-styrene copolymers, polycarbonate, polystyrene and blends thereof. The method and device involve the external application of stress to an unstressed test article which has been exposed to a stress cracking agent. The stress is induced by means of a weight located below the horizontal plane of the plastic article. The time between the application of stress and the cracking of the test article is measured to compute a characteristic ESCR parameter and thereby evaluate the environmental stress crack resistance of the article.

Method for determining the environmental stress cracking resistance of

Method and device for determining the environmental stress cracking

This invention relates to porous films having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns and the method for preparing these films. More particularly this invention relates to a porous film having pores with polygonal cross sections and average pore diameters of about 3 to about 100 microns formed from a resinous polymer of propylene and the process for forming the film which comprises the steps of (a) forming a film containing beta-spherulites and (b) selectively extracting the beta-spherulites.

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Naperville, IL, United States of America

Philip Jacoby