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:
May. 09, 2006
Filed:
Nov. 05, 2002
Li-min Tau, Lake Jackson, TX (US);
Pak-wing S. Chum, Lake Jackson, TX (US);
Seema Karande, Pearland, TX (US);
Clive Bosnyak, Missouri City, TX (US);
Li-Min Tau, Lake Jackson, TX (US);
Pak-Wing S. Chum, Lake Jackson, TX (US);
Seema Karande, Pearland, TX (US);
Clive Bosnyak, Missouri City, TX (US);
Dow Global Technologies Inc., Midland, MI (US);
Abstract
Films with excellent machine direction (MD) tear properties comprise at least one layer made from a polymer comprising: (A) at least 50 weight percent (wt%) propylene; and (B) at least 5 wt % ethylene and/or one or more unsaturated comonomers. Representative of component (B) unsatuarated comonomers are the Cα-olefins, Cdienes, styrenic compounds, and the like. Preferably, the film has at least one of a (i) haze value of less than about 10, (ii) 45 degree gloss of greater than about 65, and (iii) dart value of greater than about 100 g/mil. In one preferred embodiment, the layer comprises a compolymer characterized as having at least one of the following properties: (i)C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt %, (iii) a skewness index, S, greater than about −1.20, (iv) a DSC curve with a Tthat remains essentially the same and a Tthat decreases as the amount of comonomer, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-forn crystals than a comparable copolymer prepared with a Ziegler-Natta (Z-N) catalyst.