| 摘要 |
PURPOSE:To prevent the deterioration of processed articles due to plasticizer, and lessen heat deterioration thereof by applying and infiltrating an organic solvent having a specific temperature in its boiling point into polyvinylidene chloride copolymer and extruding it by means of a screw extruder. CONSTITUTION:Polyvinylidene chloride copolymer is applied and infiltrated with an organic solvent of 50 deg.C - 150 deg.C in its boiling point and extruded by means of a screw extruder and then subjected to a process. The copolymer is used in the form of powders, flakes, pellets and the like suitable for a screw extruding process. Small ball-shaped powders obtained by suspension polymerization are the most suitable therefore because of the easy infiltration of an organic solvent or the excellent fluidity of powders. As an organic solvent, hydrocarbon, halogenated hydrocarbon, alcohol, ether, ketone, ester or the like are employed, and the solvent having a boiling point of at most 50 deg.C are difficult to be treated upon blending and infiltration and, after extrusion, bubbles are liable to be created in the copolymer. And the solvent having a boiling point of at least 150 deg.C are apt to reside in the copolymer after extrusion process, thereby deteriorating properties thereof. |
