| 摘要 |
PURPOSE:To prevent a molded product from changing its color, appearance and the like when the same is emission treated by ultraviolet rays by heat treating the molded product composed of crystalline propylene resin to which a phosphorus oxidation inhibitor is added in the range of specified treating temperature and treating time and ultraviolet emission treating after a short time. CONSTITUTION:Heat treatment depends on the treating temperature and treating time. The treating temperature (A: unit deg.C) is in the range of 80-450 deg.C preferably 100-350 deg.C. At the temperature lower than 80 deg.C, color change prevention effect is almost none, while at the temperature beyong 450 deg.C, deformation, change of properties and the like of a PP molded product are generated. Further, the treating time (B: unit second) depends on the relation with the temperature, and when the treating time (B) is less than 100/A<1/2> seconds, curing for color change prevention is not generated, while when the treating time (B) is beyong 300/A<1/2> seconds, deformation and change of properties are generated in the molded product. |
