Manufacturing method for oriented film, polarizing film, polarizing plate, and visual display

摘要

An oriented film with a high degree of orientation may be manufactured even a width of master roll film is wider width, by a manufacturing method for an oriented film, comprising steps of stretching an un-oriented polyvinyl alcohol derived film in dry and in longitudinal uniaxial direction by applying tension produced by peripheral velocity difference between rolls, wherein a value of L/W is not more than 0.6 when a distance between rolls defined as L and a width of the un-oriented polyvinyl alcohol derived film is defined as W; and further heating at 60 to 160° C. after the stretching step.