Method For Manufacturing Retardation Film By Using Dual-Axial Stretching Process And A Retardation Film

A method for manufacturing a retardation film by using a dual-axial stretching process, comprising the steps of:

• Step (A):
• providing a cast film;
• Step (B):
• in a preheating process, at a predetermined preheating temperature, preheating the cast film;
• Step (C):
• in a stretching process, at a predetermined stretching temperature, performing simultaneously dual-axial stretching upon the cast film;
• wherein, in this stretching process, the cast film is stretched by a vertical stretching magnification factor (MD) and a horizontal stretching magnification factor (TD), and both the MD and the TD are within 1.0˜5.0 times;
• Step (D):
• in an annealing process, at a predetermined annealing temperature, annealing the cast film so as to shrink the cast film simultaneously in both a vertical direction and a horizontal direction;
• and
• Step (E):
• in a cooling process, at a predetermined cooling temperature, cooling the cast film, and then outputting an output retardation film.