WEATHER-RESISTANT RETICULATED SPLIT FILM-ITS NONWOVEN FABRIC AND MANUFACTURE THEREOF

摘要

PURPOSE:To enhance stretching effect and to keep mechanical characteristics and adhesiveness over a long period of time by containing a light-resistant agent only in the surface layer of at least a two-layered structure formed by extrusion molding. CONSTITUTION:A resin forming a thermoplastic resin layer II pref. has an m.p. different by at least 5 deg.C or higher, further, 10 - 50 deg.C or higher from that of a resin forming a thermoplastic resin layer I from a manufacturing aspect. The compounding amount of a light-resistant agent is different according to environment and a purpose and may be contained in an effective amount but said light-resistant agent is desirably contained in the resin forming the thermoplastic resin layer in an amount 300ppm or more in general. A film composed of at least a two-layered structure is prepared by an extrusion molding method such as a multilayer inflation method or a multilayer T-die method and rolled and/or stretched in the longitudinal direction of the film to be primarily oriented in a draw ratio of 1.1 - 8 times at first and further secondarily stretched in a draw ratio of 5 - 15 times and subsequently split to prepare a split film.