| 摘要 |
PROBLEM TO BE SOLVED: To accelerate the discharge of a residual resin which adheres to the metal surface in the resin channel of a melt molding machine by a method in which a purging agent is composed of a hydrophobic thermoplastic resin, a hydrophilic thermoplastic resin, and water and the mixing weight ratio is specified. SOLUTION: A purging agent is composed of a hydrophobic thermoplastic resin A, a hydrophilic thermoplastic resin B, and water C, its mixing weight ratio A/B is 99/1-30/70, and the agent contains 0.1-20 pts.wt. of C to 100 pts.wt. of (A+B). Linear low density polyethylene, low density polyethylene, and polypropylene are used preferably as the resin A, and the preferable melt indices (measured at 190 deg.C under a load of 2160g) of them are 0.1-80g/10min. The saponification product (EVOH) of an ethylene-vinyl acetate copolymer, a polyvinyl acetate type resin, a polyamide resin are preferable as the resin B. The ethylene content of EVOH is preferably 15-70% and the degree of saponification of EVOH is preferably 90% or more. |
