Protective film specially used for ASA coextrusion profile and preparation method thereof

The invention provides a protective film specially used for an ASA coextrusion profile and a preparation method thereof. Compared with the prior art, a key technology of the protective film specially used for the ASA coextrusion profile is adoption of an oxidation-reduction polymerization technology and an internal-external crosslinking method, the molecular weight and crosslinking degree of resin are appropriately improved, the production and migration of a lower molecular compound are reduced, phantoms after pasting and covering are reduced, a reactive emulsifier is adopted for replacing a common emulsifier, and the emulsifier participates in macromolecular polymerization reaction, is grafted on a macromolecular polymer and can not migrate, so that pollution of the emulsifier on the profile is reduced. 本发明提供了种ASA共挤型材专用保护膜及制备方法，与现有技术相比，本发明提供的ASA共挤型材专用保护膜关键技术是通过采用氧化-还原聚合工艺和内外交联的方法，适度提高树脂的分子量和交联程度，减少低分子化合物的产生和迁移，降低贴覆后幻影的产生，采用反应型乳化剂替代普通乳化剂，乳化剂参与高分子聚合反应，接枝在高分子聚合物上，不会迁移，减少乳化剂对型材的污染。