Exxonmobil Chemical Patents Inc.

Jan Cyriel Donck

Stefan B Ohlsson

Bart Lauwers

Jef Vaes

Henri Aime Lammens

Tubular reactor apparatus and processes are provided for improved polymerization including using chain transfer agents and multiple monomer feeds spaced lengthwise along the tubular reactor providing high conversions of monomer into polymer. The invention also relates to polymers made from such a tubular reactor apparatus and processes including those polymers having a low haze value, a density over 0.92 g/cmand/or having terminal carbonyl groups. The apparatus and methods uncouple or reduce the dependency between the monomer concentration and transfer agent concentration. The uncoupling in other embodiments may also be varied leading to multiple desirable effects.

Tubular polymerization reactors and polymers made therein

The invention relates to a polymer comprising units derived from ethylene having: a) a Melt Index of from 0.05 to 20 g/10 min; b) at least 10 per 1000 C-atoms of short chain branches, containing five carbon atoms or less, and less than 3.5 mol %, of units derived from a copolymerizable ethylenically unsaturated ester, c) a density of from 0.90 to 0.94 g/cm, preferably 0.91 to 0.935 g/cm, especially 0.92 to 0.93 g/cm, and d) a relaxation time as described herein of at least 10 s. The polymer may be used for stretch hood film, preferably as a blown film coextruded tube comprising: a) a core of the above polymer; and b) a skin layer, on each side of the core which may be of the same or different composition, comprising at least 60 wt % of an LLDPE having density of 0.91 to 0.94 g/cm.

Polymers of ethylene and, optionally, copolymerizable esters, films using such polymers and stretch hood packaging processes using such films

Polymers comprising units derived from ethylene, said polymer having: a) a Melt Index of from 0.05 to 20 g/10 min. as determined by ASTM-1238 Condition E; b) at least 10 per 1000 C-atoms of short chain branches, containing five carbon atoms or less, as determined by C13 NMR, and less than 3.5 mol %, of units derived from a copolymerizable ethylenically unsaturated ester; c) a density of from 0.90 to 0.94 g/cm, preferably 0.91 to 0.935 g/cm, especially 0.92 to 0.93 g/cmas determined by ASTM D1505; and d) a relaxation time as described herein of at least 10 s. Such polymers can be obtained by free radical polymerization using a chain transfer agent that incorporates into the polymer chain such as an alpha-olefin, preferably propylene, as a chain transfer agent, preferably in a tubular reactor under circumstances to favor LCB formation in a down stream part of the tubular reactor.

Tubular reactor apparatus and processes are provided for improved polymerization including using chain transfer agents and multiple monomer feeds spaced lengthwise along the tubular reactor providing high conversions of monomer into polymer. The invention also relates to polymers made from such a tubular reactor apparatus and processes including those polymers having a low haze value, a density over 0.92 g/cm and/or having terminal carbonyl groups. The apparatus and methods uncouple or reduce the dependency between the monomer concentration and transfer agent concentration. The uncoupling in other embodiments may also be varied leading to multiple desirable effects.

Growing community of inventors

Holsbeek, Belgium

Jan Cyriel Donck