Exxonmobil Chemical Patents Inc.

Caitlin A Spofford

George James Pehlert

Anthony Poloso

Sasha P Schmitt

John M Donahue

Adrian G Barry

The present disclosure provides polypropylene compositions that have a high gloss and minimum or no haze while also having a high melt strength (e.g., high temperature resistance) and a relative high stiffness. Polypropylene compositions contain one or more base polypropylenes (e.g., trimmed polypropylenes (tPPs)) and one or more clarifying agents. The base or trimmed polypropylene contains at least 50 mol % of propylene and has a molecular weight distribution (Mw/Mn) in a range from 7 to 22, a z-average molecular weight of less than 2,500,000 g/mol, a branching index (g') of at least 0.95, and a melt strength of less than 20 cN determined using an extensional rheometer at 190° C. The base or trimmed polypropylene can be produced from one or more high melt strength polypropylenes (HMS PPs).

Polypropylene for films

A polypropylene comprising within a range from 0.1 wt % to 4 wt % ethylene and/or C4 to C12 &#x3b1;-olefin derived units, one or more clarifiers, or both; wherein the polypropylene has a flexural modulus of at least 200 kpsi (0.05 in/min ASTM D790(A)) and an Mz/Mw of at least 4. The polypropylenes may be made by combining propylene and a comonomer with a Ziegler-Natta catalyst and at least two external electron donors, wherein the concentration of the electron donors is within a range from 1 to 100 ppm. The concentration of electron donors may be decreased to control the haze level of the polypropylene, and/or the level of comonomer derived units may be controlled to reduce the haze level of the polypropylene.

Growing community of inventors

Houston, TX, United States of America

Caitlin A Spofford