The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 2003
Filed:
Oct. 18, 2000
Shih-Yaw Lai, Sugar Land, TX (US);
John R. Wilson, Baton Rouge, LA (US);
George W. Knight, Lake Jackson, TX (US);
James C. Stevens, Richmond, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Elastic ethylene polymers are disclosed which have processability similar to highly branched low density polyethylene (LDPE), but the strength and toughness of linear low density polyethylene (LLDPE). The polymers have processing indices (PI's) less than or equal to 70 percent of those of a comparative linear ethylene polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear ethylene polymer at about the same I and M /M . The novel polymers can also have from about 0.01 to about 3 long chain branches/1000 total carbons and have higher low/zero shear viscosity and lower high shear viscosity than comparative linear ethylene polymers. The novel polymers can also be characterized as having a melt flow ratio, I /I , ≧5.63, a molecular weight distribution, M /M , defined by the equation: M /M ≦(I /I )−4.63, a critical shear stress at onset of gross melt fracture greater than about 4×10 dyne/cm , and a single DSC melt peak between −30 C. and 150 C.