JP2004163981A5

JP2004163981A5 -

Info

Publication number: JP2004163981A5
Application number: JP2004030367A
Authority: JP
Filing date: 2004-02-06
Publication date: 2007-02-08
Anticipated expiration: 2017-07-03

Claims

(1) After casting a 10-30 wt% polycarbonate solution consisting of polycarbonate and methylene chloride on a support, (2) peeling off the formed solvent-containing film from the support, and (3) drying (4) In the method for producing a retardation film made of polycarbonate by uniaxial stretching, the uniaxial stretching step (4) is performed by first-stage stretching and second-stage stretching, and the second-stage stretching is performed. A method for producing a retardation film comprising a polycarbonate, characterized in that the temperature is 1 to 20 ° C. higher than the temperature of stretching in the first stage,
The uniaxial stretching step (4) is performed under the conditions of a temperature (Tg ₁ +10) to (Tg ₁ +35) ° C. and a stretching ratio of 1.1 to 3.2 times, and the second stage stretching is performed at the first stage stretching temperature. At a temperature 5 to 10 ° C. higher and a draw ratio of 1.01 to 1.20 times (Tg ₁ (° C.) is a glass transition temperature of a film comprising a polycarbonate containing a solvent, and this temperature Increases with decreasing residual solvent content as drying proceeds).
The drying step (3) includes (3-1) a step of drying while gripping the film with a pin tenter, and (3-2) a step of drying using a roll suspension type drying apparatus,
In the drying step (3-1), with respect to the film peeled off from the support, the temperature (Tg) while holding the film with a pin tenter so that the shrinkage rate of the film in the direction orthogonal to the running direction is 2 to 5%. ₂ +10) to (Tg ₂ +90) ° C., wherein drying is performed (Tg ₂ (° C.) is a glass transition temperature of a film made of polycarbonate containing a solvent, and this temperature is a residual solvent as the drying proceeds. Increases with decreasing content).
The characteristic value of the film after drying in the drying step (3-1) is a residual solvent amount of 3.5 to 4.5 wt. %, A retardation value of 10 to 15 nm, and a slow axis angle of −10 to +10 degrees,
The film was dried in the drying step (3-1), while applying a tension of 1~2.5Kg / cm ² in the film running direction using a roll suspension type drying apparatus, further temperature (Tg ₃ -20) ~ (Tg ₃ +10) ° C. for drying,
(Tg ₃ (° C.) is the glass transition temperature of the polymer film containing the solvent, and this temperature increases with decreasing residual solvent content as drying proceeds.)
The characteristic value of the film subjected to the uniaxial stretching step has a solvent content of 0.5 to 2.0 wt. %, A retardation value of 10 to 20 nm, and a slow axis angle of −7 to +7 degrees,
The first stage of stretching is performed under the condition that the length between the stretching rolls is 1.5 times to 4.0 times the film width before stretching,
A method for producing a retardation film, wherein the film heating method in the first stage stretching comprises an air jet heating method.

(1) A polymer solution is cast on a support, (2) the formed solvent-containing film is peeled off from the support, (3) dried, and (4) uniaxially stretched to form a retardation film. A production apparatus for a retardation film to be produced, which is a cast film forming apparatus (A), a film peeling apparatus (B), a pin tenter drying apparatus (C), a roll suspension drying apparatus (D), a first stage stretching apparatus ( E), a first cooling chamber (F), a second stage stretching device (G), and a second cooling chamber (H), and these devices and chambers are arranged in this order, and the second stage The apparatus for producing a retardation film according to claim 1, wherein the temperature condition of the stretching apparatus is 1 to 20 ° C. higher than the temperature condition of the first stage stretching apparatus.