Dow Global Technolgoies LLC

Dow Brasil Sudeste Industrial Ltda

Nhi Dang

Otto J Berbee

Cornelis J F Hosman

Joaquin Flores

Cornelis F J Den Doelder

Stefan Hinrichs

Sergio E Goncalves

Juergen Siebdrat

Cornelis FJ Den Doelder

Cornelis Jf Hosman

A process is provided to form an ethylene-based polymer, in the presence of at least one free-radical, said process comprises at least the following: polymerizing a mixture comprising ethylene, in a reactor configuration comprising at least three reaction zones, and comprising two ethylene feed streams, and wherein the ratio (R), in percent, of the 'LCB content of the first 40 wt % of the total polymer formed' to 'the total LCB content in the final polymer' is &#x2264;22.5%; and wherein the amount of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the first reaction zone, is from 40 mole % to 80 mole %, based on the total moles of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the polymerization.

High pressure free radical polymerizations

A process to form an ethylene-based polymer, in the presence of at least one free-radical, said process comprises at least the following: polymerizing a mixture comprising ethylene in a reactor configuration comprising at least four reaction zones, and comprising at least three ethylene feed streams; and wherein the ratio of (R), in percent, of the LCB content of the 'first 40 wt % of the total polymer formed' to the 'total LCB content in the final polymer' is &#x2264;29%; and wherein the amount of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the first reaction zone, is from 20 mole % to 70 mole %, based on the total moles of ethylene, and optionally one or more comonomers, and optionally one or more CTAs, fed to the polymerization.

Ethylene-based polymers formed by high pressure free radical polymerizations

Ethylene-based polymer is made by a process comprising polymerizing a reaction mixture comprising ethylene and at least one chain transfer agent system; wherein the polymerization takes place in the presence of at least one free-radical initiator; and wherein the polymerization takes place in a reactor configuration comprising at least one tubular reactor with at least three reaction zones; and wherein at least two reaction zones receive an ethylene feed; and wherein the degree of polymerization in the first reaction zone is less than, or equal to, (5/LCBf)*3150; and wherein the ethylene-based polymer formed by the process comprises the following properties: (A) LCBf&#x2265;(4.7+0.5*log(I2)); and (B) I2 from 0.2 to 25 dg/min.

Process for producing ethylene-based polymers with reduced gel counts and low reactor fouling

The invention provides a process to prepare an ethylene-based polymer, said process comprising polymerizing ethylene in the presence of at least one initiator system selected from the following: a) class 1 initiator system, b) class 2 initiator system, c) class 3 initiator system, or d) a combination thereof; and at a inlet pressure (P) greater than, or equal to, 1000 Bar (100 MPa); and in a reactor system comprising at least one hyper compressor and a reactor configuration comprising at least one reactor, which comprises at least one reaction zone; and wherein the inlet pressure (P) is reduced by at least 200 Bar, as compared to a similar polymerization, in the same reactor system, except it is operated at a higher inlet pressure (P), and at a different hyper compressor throughput, and at a different maximum temperature for at least one reaction zone, and optionally, at a different amount of CTA system fed to the reactor configuration; and wherein, for the process, the 'Ratio of total reactor consumption of the highest temperature class initiator system(s) (Y)' meets the following Equation D: 0.95*x^((P&#x2212;P)/10 MPa)&#x3c;Y&#x3c;1.04*z^((P&#x2212;P)/10 MPa) (Eqn. D), wherein x is greater than, or equal to, 0.97; and wherein z is less than, or equal to, 1.03. The invention also provides a process to prepare an ethylene-based polymer, said process comprising polymerizing ethylene in the presence of at least one initiator system selected from the following: a) a class 1 initiator system, b) a class 2 initiator system, c) a class 3 initiator system, or d) a combination thereof; and at an inlet pressure (P) greater than, or equal to, 1000 Bar (100 MPa); and in a reactor system comprising a reactor configuration comprising at least one reactor, which comprises at least one reaction zone; and wherein the inlet pressure (P) is reduced by at least 200 Bar, as compared to a similar polymerization, in the same reactor configuration, except it is operated at a higher inlet pressure (P), and at a different maximum temperature for at least one reaction zone, and optionally, at a different amount of CTA system fed to the reactor configuration; and wherein, for the process, the 'Ratio of total reactor consumption of the highest temperature class initiator system(s) (Y)' meets the following Equation D: 0.95*x^((P&#x2212;P)/10 MPa)&#x3c;Y&#x3c;1.04*z^((P&#x2212;P)/10 MPa) (Eqn. D), wherein x is greater than, or equal to, 0.97; and wherein z is less than, or equal to, 1.03.

Process to control output and quality of ethylene-based polymer formed by high pressure free radical polymerization

Growing community of inventors

Terneuzen, Netherlands

Nhi Dang