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US 6,270,863 B1Granted
Process and apparatus for forming plastic sheet
AssigneeRohm and Haas Company
InventorsJeffrey Lawrence Daecher, Steven David Fields, Toshiaki Yatabe, Kazuo Yahata
Life of this patent
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Abstract
Disclosed is a process and apparatus for formation of high quality plastic sheet in a continuous fashion, wherein the plastic sheet produced is capable of use in a variety of optical and electronic display applications.
Claims9
A substrate for a liquid crystal display comprising a) a high quality plastic sheet produced by the method comprising the steps:
- a) providing molten plastic resin;
- b) directing the molten plastic resin to an overflow die having an inlet and an outlet;
- c) shaping the molten plastic resin into a molten web using said overflow die;
- d) guiding said molten web away from said overflow die;
- and
- e) cooling said molten web to form a solid sheet;
- wherein the molten plastic resin is a polycarbonate containing as bisphenol components:
- (1) 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane;
- (2) a mixture of 2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane;
- a blend of (1) and (2);
- or a blend of (1) or (2) with a second polycarbonate containing as a bisphenol component 2,2-bis(4-hydrozyphenyl)propane;
- and b) a conductive layer disposed on at least one side of the sheet, wherein the high quality plastic sheet has a sheet waviness value of less than or equal to 2.0 μ, a birefringence of less than or equal to 0.0002, a thickness variation of 10% or less and a surface roughness of less than or equal to 50 nm over a 0.4 mm length.
9 more elements
A substrate for a liquid crystal display comprising a) a high quality plastic sheet produced by the method comprising the steps:
- a) providing molten plastic resin;
- b) directing the molten plastic resin to an overflow die having an inlet and an outlet;
- c) shaping the molten plastic resin into a molten web using said overflow die;
- d) guiding said molten web away from said overflow die;
- and
- e) cooling said molten web to form a solid sheet;
- wherein the molten plastic resin is a polycarbonate containing as bisphenol components:
- (1) 1,1-bis(4-hydroxyphenyl)-3,3,5 -trimethylcyclohexane;
- (2) a mixture of 2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane;
- a blend of (1) and (2);
- or a blend of (1) or (2) with a second polycarbonate containing as a bisphenol component 2,2-bis(4-hydrozyphenyl)propane;
- and b) a layer of active electronic devices disposed on at least one side of the sheet, wherein the high quality plastic sheet has a sheet waviness value of less than or equal to 2.0 μ, a birefringence of less than or equal to 0.0002, a thickness variation of 10% or less and a surface roughness of less than or equal to 50 nm over a 0.4 mm length.
9 more elements
Dependencies are inferred from the claim text.