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Document Type and Number:
Japanese Patent JP3816137
Kind Code:

PROBLEM TO BE SOLVED: To solve technical problems such as impact resistance, solvent resistance, low double refractive index and separation mark by molding polycarbonate resin at specified surface temperatures for a sheet on the roll side in a specular shaping process and a specified ratio between the velocities of a final shaping specular roll and a take-up roll.
SOLUTION: When rolling polycarbonate resin into a sheet with the help of plural specular rolls 3, 4, 5, the surface temperatures of the sheet on the roll side immediately after the sheet separated from a final specular roll 5 runs over the radial length of the final specular roll 5 are set to the glass transition temperatures of the resin of -10-+30°C. The resin is also molded within the range of a velocity ratio between the final specular roll 5 and the take-up roll 8 of 1:0.95-1.05. The surface of the specular rolls 3, 4, 5 is important as a determining factor for the appearance of the sheet, and the required surface roughness for smoothness is generally 0.1-0.005μm. The interior of the roll is structurally designed so that a heat medium such as water or oil can be internally circulated, and therefore, the temperatures of the roll can be adjusted.

Yu Tsukada
Yokoyama Masahiko
Application Number:
Publication Date:
August 30, 2006
Filing Date:
February 06, 1996
Export Citation:
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Asahi Kasei Chemicals Corporation
International Classes:
B29C43/22; B29D7/01; B29C43/52; B29C43/58; B29C71/00; C08G64/00; B29K69/00; (IPC1-7): B29D7/01; B29C43/22; B29C43/52; B29C43/58; C08G64/00; //B29K69:00
Domestic Patent References: