Process for minimizing haze of extruded clear blends containing styrene/butadiene polymer and product thereof
AssigneePhillips Petroleum Company
InventorsMark D. Hanes, Lee A. Carvell
Life of this patent
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Abstract
A process for reducing the haze of extrusions of clear polymeric blends containing styrene-butadiene copolymer and a polymer immiscible therewith. An assembly of extrusion layers in which a layer of clear polymeric blends containing styrene/butadiene copolymer and a polymer immiscible therewith is overlayered with layers of clear material that provides a smooth extruded surface.
Claims22
A process for reducing the haze of sheet-like extrusions of clear polymeric blends attributable to rough surface of the extrudate comprising:
- (A) coextruding
- (1) at least one core layer of a blend of (a) a first polymer and (b) a second polymer immiscible therewith,
- (2) a first outer layer of a polymer that extrudes with a smooth surface and
- (3) a second outer layer of a polymer that extrudes with a smooth surface and thereafter
- (B) assembling, while the layers are molten, the first outer layer to a first surface of the at least one core layer and the second outer layer to a second surface of the at least one core layer and
- (C) cooling the assembled layers to a temperature below molten temperature.
An assembly of sheet-like extrusions of clear polymeric blends containing (a) a first polymer and (b) a polymer immiscible therewith comprising a coextruded and assembled multilayer structure of at least one core layer sandwiched between an outer layer at each of its sides wherein the layers comprise:
- (1) at least one extruded core layer of a blend of (a) the first polymer and (b) a polymer immiscible therewith with the core layer subject to having a rough surface,
- (2) a first extruded layer of a polymer that extrudes with a smooth surface co-extruded with the core layer and assembled, while the layers are molten, to a first surface of the core layer thereby providing a smooth surface and
- (3) a second extruded layer of a polymer that extrudes with a smooth surface co-extruded with the core layer and assembled, while the layers are molten, to a second surface of the core layer thereby providing a smooth surface.
Dependencies are inferred from the claim text.