Stretch method of polymer film and manufacturing method of polymer film

Abstract

An off-line stretching device is provided with an accepting chamber and a stretching frame. The accepting chamber accepts an advanced film roller and a subsequent film roller. The width of the advanced film roller is expanded while the stretching machine maintains the maintenance area of the advanced film roller sent out from the advanced film roller. After all advanced films are sent out, subsequent films are sent out to the stretching machine from the subsequent roller. In the jointing part installed in front of the stretching machine, the rear end of the advanced film is overlapped with the front end of the subsequent film so as to form an overlapped part. A deposition area is installed at the part of the overlapped part depart from the central part of the maintenance are in B direction. The jointing part is jointed and processed in the deposition area. After jointing and processing, the jointed film is sent to the stretching machine and stretched towards both sides in B direction at the state of maintaining the maintenance area.

Description

technical field [0001] The present invention relates to a method for stretching a polymer film (polymer web, polymer web) and a method for producing a polymer film. Background technique [0002] Polymer films (hereinafter referred to as films) have the characteristics of excellent light transmittance, flexibility, light weight and thin films. Therefore, the film is utilized in various ways as an optical film. Among them, the TAC film formed from cellulose acylate, especially cellulose triacetate (hereinafter referred to as TAC) with an average degree of acetylation of 57.5% to 62.5%, is used as a protective film for a polarizing plate of a liquid crystal display device, an optical compensation film, etc. Optical films such as thin films. As an optical compensation film, for example, there is a viewing angle expansion film. [0003] A solution film forming method is known as a main method for producing a thin film. In the solution film forming method, a polymer solution (...

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Problems solved by technology

[0007] However, as described in Japanese Patent Application Laid-Open No. 2008-238682, in the case where the bonding process is uniformly performed over the entire area of ​​the overlapped portion, it is difficult to compare the portion of the film that constitutes the overlapped portion with the portion that does not constitute the overlapped portion of the film. elongation

Therefore, when stretching is performed on the joined film, the film breaks due to the difference in the amount of deformation in the vicinity of the boundary between the two parts, and failures frequently occur.

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