Plastic and nonmetallic article shaping or treating: processes – Optical article shaping or treating – Light polarizing article or holographic article
Reexamination Certificate
2005-07-05
2005-07-05
Vargot, Mathieu D. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Optical article shaping or treating
Light polarizing article or holographic article
C264S040100, C264S210200, C264S211120
Reexamination Certificate
active
06913714
ABSTRACT:
A method of preparing a thermoplastic polycarbonate film having an optical retardation value of less than or equal to 20 nm, is described. The method includes: (a) forming a molten extrudate (20) of a thermoplastic polycarbonate polymer in an extruder (11) having a terminal die (17) through which the molten extrudate is passed, the molten extrudate having a temperature of 150° C. to 400° C. upon emerging from terminal die (17); and (b) passing molten extrudate (20), from die (17), between two counter-rotating rolls (23and26) each having an elastomeric polymer surface (35and38), the counter-rotating rolls having a roll speed ratio and a nip (41), the distance between the terminal die (17) and the nip (41) being a die-nip distance (47). The extrudate temperature, the roll speed ratio and the die-nip distance (47) are each selected such that a thermoplastic polycarbonate film (32) having an optical retardation value of less than or equal to 20 nm is formed.
REFERENCES:
patent: 4368240 (1983-01-01), Nauta et al.
patent: 4859392 (1989-08-01), Vetter
patent: 5076987 (1991-12-01), Wank et al.
patent: 5244713 (1993-09-01), Nakamura et al.
patent: 5286436 (1994-02-01), Funk et al.
patent: 5561180 (1996-10-01), Taketani et al.
patent: 5779962 (1998-07-01), Andraschko
patent: 5914150 (1999-06-01), Porter et al.
patent: 6201045 (2001-03-01), Koike
patent: 6280808 (2001-08-01), Fields et al.
patent: 6682805 (2004-01-01), Lilly
patent: 6773649 (2004-08-01), Bourne et al.
patent: 2003/0099808 (2003-05-01), Coyle et al.
patent: 0 380 028 (1990-08-01), None
patent: 0 916 474 (1999-05-01), None
patent: 0 916 475 (1999-05-01), None
patent: 0 999 031 (2000-05-01), None
patent: 02/066234 (2002-08-01), None
Colon Luis A.
Liu Shu
Bayer MaterialScience LLC
Franks James R.
Gil Joseph C.
Vargot Mathieu D.
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