Improved multi-layer coextruded blow-molded objects (such as fuel containers) having at least a barrier layer and a support layer are disclosed together with improved methods for preparing such objects. The barrier layer includes an amount of modified polyolefin having approximately the same density as the support layer, wherein the modified polyolefin is prepared by grafting an unsaturated carboxylic acid or a derivative thereof to the polyolefin, the modified polyolefin being added in an amount such that the gas-barrier layer sufficiently adheres to the adjacent layer and such that the gas barrier properties of the fabricated article are still adequate. The present invention also relates to modification of the rheology of base resins, such as PET (a preferred material for the barrier layer), so that they more closely match the rheology of high density polyethylene (a preferred material for the support layer).

Title
Polyester compositions for multilayer extrusion and barrier performance
Application Number
10/275135
Publication Number
20030215655
Application Date
November 1, 2002
Publication Date
November 20, 2003
Inventor
Kalyan Sehanobish
Lake Jackson
TX, US
Chuiwah A Cheung
Lake Jackson
TX, US
Malcolm F Finlayson
Houston
TX, US
Ravi Ramanathan
Midland
MI, US
Joseph A Schomaker
Mt Pleasant
MI, US
Mark A Barger
Midland
MI, US
Agent
The Dow Chemical Company
MI, US
IPC
B32B 27/06
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