Univation Technologies, LLC

Exxonmobil Chemical Patents Inc.

Daniel P Zilker

Bruce Jon Savatsky

James McLeod Farley

Timothy R Lynn

Fathi David Hussein

Robert Olds Hagerty

Mark Gregory Goode

Pradeep P Shirodkar

Michael E Muhle

Kevin Joseph Cann

Roger L Kuhlman

John Francis Szul

Francis Charles Rix

Ching-Tai Lue

Rainer Kolb

John H Moorhouse

Chi-I Kuo

Dongming Li

Richard B Pannell

C Jeff Harlan

Eric John Markel

Wesley R Mariott

F David Hussein

Timothy Marlow Boller

Michael D Awe

Porter Clarke Shannon

Mark Bradley Davis

Phuong Anh Cao

Lixin Sun

Fred David Ehrman

Ronald Steven Eisinger

Steven A Best

Tae Hoon Kwalk

R Eric Pequeno

John Henry Oskam

Haiqing Peng

Kersten Anne Terry

Maria A Apecetche

Jose Fernando Cevallos-Candau

Natarajan Anand Muruganandam

Timothy M Boller

Cliff Robert Mure

Marc L DeChellis

Brandon C Locklear

Daniel D Vanderlende

Minghui Zhang

Charles W Lipp

C Dale Lester

Ian D Burdett

Abarajith S Hari

Mahsa McDougal

Mark K Davis

Douglas H Jackson

Mark W Blood

Kersten A Terry

Mark B Davis

John H Oskam

Fathi D Hussein

James Leland Swecker

Mahsa Mcdougal

Jeff C Harlan

Methods for reducing gels and/or dome sheeting in gas phase polymerization processes and their resulting products are provided. The polymerization processes include polymerizing ethylene and one or more optional comonomers in a fluidized bed reactor in the presence of a metallocene catalyst, hydrogen, and at least one condensing agent.

Methods for making polyethylene polymers

A method for increasing the melt strength of a polyolefin polymer composition is provided. The method includes mixing a first polyolefin composition derived from at least one olefin polymerization catalyst (a) and at least one olefin polymerization catalyst (b) with a second polyolefin composition derived from the at least one olefin polymerization catalyst (b) or from at least one olefin polymerization catalyst (c), and obtaining the polyolefin polymer composition.

Methods for making polyolefin polymer compositions

Embodiments of the present disclosure directed towards polymerization catalysts having improved ethylene enchainment. As an example, the present disclosure provides a polymerization catalyst having improved ethylene enchainment, the polymerization catalyst comprising a zirconocene catalyst of Formula (I) where Ris a Cto Calkyl, aryl or aralkyl group, wherein Ris an Cto Calkyl, aryl or aralkyl group, and where Ris a Cto Calkyl or a hydrogen, and where each X is independently a halide, Cto Calkyl, aralkyl group or hydrogen. 

Polymerization catalysts with improved ethylene enchainment

The use of induced condensing agent (ICA) in fluidized bed gas phase reactor systems enables higher production rates but can affect the resulting polyolefins melt index. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, by altering the concentration of olefin monomer within the reactor system.

Methods of controlling polyolefin melt index

The catalyst productivity of a polyolefin catalyst in the methods disclosed herein may be increased by increasing the concentration of an induced condensing agent (ICA) in the reactor system. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, in various ways.

Methods of controlling polyolefin melt index while increasing catalyst productivity

The number of small gels that form in polyolefin thin films may be reduced by altering certain production parameters of the polyolefin. In some instances, the number of small gels may be influenced by the melt index of the polyolefin. However, in many instances, melt index is a critical part of the polyolefin product specification and, therefore, is not manipulated. Two parameters that may be manipulated to mitigate small gel count while maintaining the melt index are polyolefin residence time in the reactor and ICA concentration in the reactor.

Methods of changing polyolefin production conditions to mitigate small gels in a polyolefin article

Generally, a method of monitoring a polymerization reaction in a fluid bed reactor to generate, in on-line fashion, data indicative of the imminent occurrence of a discontinuity event (for example, sheeting) and optionally also control the reaction to prevent the occurrence of the discontinuity event is provided. Typical embodiments include the steps of generating in on-line fashion at least one of bed static data indicative of static charge in the fluidized bed and carryover static data indicative of carryover static; and generating at least one of temperature data (in on-line fashion using at least one monitored reaction parameter) indicative of a first temperature and acoustic emission data indicative of resin stickiness in the reactor, where the first temperature is indicative of at least one of degree of resin stickiness in the reactor and a characteristic of melting behavior of polymer resin in the reactor in the presence of at least one diluent.

Method for on-line monitoring and control of polymerization processes and reactors to prevent discontinuity events

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Easton, PA, United States of America

Daniel P Zilker