Hee Ju Yoo

US Patent:

20090017710, Jan 15, 2009

Filed:

Feb 2, 2007

Appl. No.:

12/223414

Inventors:

Daniele Bugada - Newark DE, US
Hee Ju Yoo - Wilmington DE, US

Assignee:

Basell Polyolefine GmbH - Wesseling

International Classification:

C08F 4/642
C08F 110/06
D04H 5/00

US Classification:

442327, 526351, 526159

Abstract:

A polypropylene homopolymer melt blown resin comprising a melt flow rate of about 300 to about 2500 g/10 min. at 230 C., a polydispersion index of about 1.3 to about 2.9, and a melting point of at least 160 C.

US Patent:

58209816, Oct 13, 1998

Filed:

Apr 2, 1996

Appl. No.:

8/626412

Inventors:

Stephen D. Williams - Newark DE
Hee Ju Yoo - Wilmington DE
Miriam R. Drickman - Boulder CO

Assignee:

Montell North America Inc. - Wilmington DE

International Classification:

D02G 300
C08F11006
C08F21002
C08F21006

US Classification:

428364

Abstract:

A propylene homopolymer having a stick-point of 30 cm or less during melt spinning, an oligomer content of less than 1500 ppm without postpolymerization treatment to remove oligomers, and a melt flow rate greater than 300 dg/min is prepared by radiation visbreaking in a multistage fluidized bed reactor. The polymer is subjected to irradiation in the substantial absence of oxygen, followed by a multistage treatment in the presence of a controlled amount of oxygen. The radiation visbreaking process can also be applied to other propylene polymer materials. The propylene polymer materials produced by this radiation visbreaking process can be used, for example, for extrusion coating, film production, and injection molding.

US Patent:

58043047, Sep 8, 1998

Filed:

Aug 8, 1997

Appl. No.:

8/908761

Inventors:

Stephen D. Williams - Newark DE
Hee Ju Yoo - Wilmington DE

Assignee:

Montell North America Inc. - Wilmington DE

International Classification:

D02G 300
C08F 600

US Classification:

428364

Abstract:

A propylene homopolymer having a stick-point of 30 cm or less during melt spinning, an oligomer content of less than 1500 ppm without postpolymerization treatment to remove oligomers, and a melt flow rate greater than 300 dg/min is prepared by radiation visbreaking in a multistage fluidized bed reactor. The polymer is subjected to irradiation in the substantial absence of oxygen, followed by a multistage treatment in the presence of a controlled amount of oxygen. The radiation visbreaking process can also be applied to other propylene polymer materials. The propylene polymer materials produced by this radiation visbreaking process can be used, for example, for extrusion coating, film production, and injection molding.