CA2736014C

Dual metallocene catalyst for producing film resins with good machine direction (md) elmendorf tear strength

Abstract

This invention relates to catalyst compositions comprising a first metallocene compound, a second metallocene compound, at least one chemically-treated solid oxide, and at least one organoaluminum compound. This invention also relates to methods to prepare and use the catalyst compositions and new polyolefins. The compositions and methods disclosed herein provide ethylene polymers and copolymers with lower MI, increased melt strength, and good MD tear properties.

CA2736014C, drawing sheet 1
Sheet 1 of 24

Term

Term ended

Expired 20 January 2025, 1.7 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

21 claims: 2 independent, 19 dependent

  1. 1
    CA 02736014 2011-03-28 What is claimed is:1. A homopolymer or copolymer of ethylene having a melt index (MI) from about 0.3 to about 2.0 dg/min, a high load melt index (HLMI) to melt index ratio (HLMI/MI) from about 16.5 to about 25, a polydispersity index (Mm,/M„) from about 2 to about 6, a CY-a parameter from about 0.45 to about 0.70, a MD Elmendorf tear resistance greater than about 150 g for a 1 mil blown film, a TD Elmendorf tear resistance greater than about 350 g for a 1 mil blown film, and a Dart impact strength greater than about 800 g for a 1 mil blown film.
  2. 12
    A homopolymer or copolymer of ethylene having a melt index (MI) from about 0.3 to about 2.0 dg/min, a high load melt index (HLMI) to melt index ratio (HLMI/MI) from about 16.5 to about 25, a polydispersity index (Μ»/Μ„) from about 2.6 to about 4, a CY-a parameter from about 0.45 to about 0.70, a MD Elmendorf tear resistance greater than about 150 g for a 1 mil blown film, a TD Elmendorf tear resistance greater than about 350 g for a 1 mil blown film, and a Dart impact strength greater than about 600 g for a 1 mil blown film.