JP2005314669A5

JP2005314669A5 -

Info

Publication number: JP2005314669A5
Application number: JP2005088334A
Authority: JP
Filing date: 2005-03-25
Publication date: 2007-09-20

Description

上記支持体から剥離されたゲルフィルムは、通常回転ロールにより走行速度を規制しながら走行方向に延伸される。機械搬送方向への延伸倍率（ＭＤＸ）は、１４０℃以下の温度で１．０１〜１．９倍、好ましくは１．０５〜１．６倍、さらに好ましくは１．０５〜１．４倍で実施される。搬送方向に延伸されたゲルフィルムは、テンター装置に導入され、テンタークリップに幅方向両端部を把持されて、テンタークリップと共に走行しながら、幅方法へ延伸される。この時フィルムの機械搬送方向（ＭＤ）の延伸倍率に比べ幅方向（ＴＤ）の延伸倍率を高く設定すること、具体的には幅方向の延伸倍率を機械搬送方向の延伸倍率の１．１〜１．５倍に設定することによってフィルムＴＤに配向勝ったフィルムすなわちフィルムＭＤには金属に近似した熱膨張係数を保持しつつ、フィルムＴＤの熱膨張係数を低く抑えたフィルムを得ることができる。これら範囲内にて両者の延伸倍率の調整を行い、フィルムのＴＤの熱膨張係数α_ＴＤが３〜１０ｐｐｍ／℃、フィルムのＭＤの熱膨張係数α_ＭＤが１０〜２０ｐｐｍ／℃の範囲にするのが好ましく、α_ＴＤが３〜７ｐｐｍ／℃、α_ＭＤが１４〜１８ｐｐｍ／℃の範囲がより好ましい。 The gel film peeled off from the support is usually stretched in the running direction while regulating the running speed with a rotating roll. The draw ratio (MDX) in the machine conveying direction is 1.01 to 1.9 times, preferably 1.05 to 1.6 times, more preferably 1.05 to 1.4 times at a temperature of 140 ° C. or less. To be implemented. The gel film stretched in the transport direction is introduced into a tenter device, and both ends in the width direction are gripped by the tenter clip and stretched in the width method while running with the tenter clip. At this time, the stretch ratio in the width direction (TD) is set higher than the stretch ratio in the machine transport direction (MD) of the film, specifically, the stretch ratio in the width direction is 1.1 to 1.1 of the stretch ratio in the machine transport direction. By setting the film to 1.5 times, it is possible to obtain a film in which the thermal expansion coefficient of the film TD is kept low while maintaining the thermal expansion coefficient close to that of the metal in the film MD that is well aligned with the film TD. To adjust the draw ratio of the two in within these ranges, the thermal expansion coefficient alpha _TD in the TD of the film is 3~10ppm / ℃, the thermal expansion coefficient alpha _MD in the MD of the film to within the range of 10 to 20 ppm / ° C. The α _TD is preferably 3 to 7 ppm / ° C., and the α _MD is more preferably 14 to 18 ppm / ° C.