| 摘要 |
PURPOSE:To obtain a film having expanded layer suitable for protecting containers by such a simple system wherein an expanded substance is coated on a thermoplastic film and the expanded material is caused to expand during the process of drawing of said film. CONSTITUTION:On a thermoplastic film (A), a expanded material (B) (e.g.: particles of thermoplastic resin obtained by polymerizing stylene, etc. are impregnated with butane, etc. and then they are processed into microcapsules, etc.) is coated and ingredient (B) is caused to expand during the process of drawing of the film and the desired film is thus obtained. It is preferable that ingredient (B) is caused to expand in such a stage immediately before or after the drawing of the film at a desired magnification is completed to obtain uniform foams. |
