Catalyst compositions comprising support materials having an improved particle-size distribution

Abstract

A catalyst composition that includes a support material having an improved particle-size distribution is provided. Processes for producing polyolefin composition also are provided. Polymers and films also are provided. An example of a catalyst composition is a supported multi-transition-metal catalyst composition that includes: (a) at least two catalyst components selected from the group consisting of: a nonmetallocene catalyst component and a metallocene catalyst component; (b) a support material that has a D50 of less than about 30 microns and a particle size distribution having a D90 / D10 ratio of less than about 6; and (c) an activator.

Description

FIELD OF INVENTION [0001] The present invention relates to catalysts for polyolefin production, and more particularly, to supported catalysts for use in making polyolefins that may be used in producing polymer products, wherein the supported catalyst comprises a support material having an improved particle-size distribution, and wherein, in a desirable embodiment, the supported catalyst is used to produce the polyolefin in a single reactor. BACKGROUND [0002] Advances in polymerization and catalysis have resulted in the ability to produce many new polymers having improved physical and chemical properties useful in a wide variety of superior products and applications. With the development of new catalysts, the choice of polymerization techniques (solution, slurry, high pressure or gas phase) for producing a particular polymer have been greatly expanded. Also, advances in polymerization technology have provided more efficient, highly productive and economically enhanced processes. [000...

AI Technical Summary

Benefits of technology

[0228] The use of the support materials of the present invention, having an improved particle size distribution, in the supported, multitransition metal catalysts of the present invention is believed to provide a number of benefits, including, inter alia, enhancing the productivity of the multitransition metal catalyst in polymerization processes that produce polymer products such as polyolefins. Moreover, the use of the supports of the present invention in the catalysts of the present invention also is believed to favorably impact the film appearance rating and gel count of such polymer products. Though not wishing to be limited by theory, it is believed that the improved particle size distribution of the supports of the present invention may improve the absorption of activators (e.g., trimethylaluminum, and the like) onto the multitransition metal catalyst, particularly as such absorption is thought to be surface-area-dependent. Additionally, because the catalysts of the present invention comprise multiple transition metal catalyst components, the improved particle size distribution of the supports of the present invention may improve the distribution of each component (e.g., one or more metallocene catalyst components and one or more nonmetallocene catalyst components) on the catalyst.

Problems solved by technology

Polymer products, especially films, that are produced with a high gel concentration may have limited or no commercial value due to, inter alia, poor aesthetics, bubble stability, or continuity.

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