| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a thermoplastic resin composition containing an ultraviolet absorber, comprising: a step of melt-kneading a thermoplastic resin and an ultraviolet absorber by means of an extruder; and a step of filtering a thermoplastic resin composition formed by the melt-kneading by introducing the same into a polymer filter, which enables suppression of brown discoloration of the resin composition during startup of the extruder and speedy startup of production of the resin composition.SOLUTION: Provided is a method for producing a thermoplastic resin composition containing an ultraviolet absorber in a percentage content of X mass%. From the time introduction of the composition into a polymer filter is started until a path of the composition inside the polymer filter is filled with the composition, an amount of the composition introduced into the polymer filter is maintained less than a steady state and, at the same time, the percentage content of the ultraviolet absorber is set to Y mass% (where 0≤Y≤1.5×X). Thereafter, the amount of introduction of the composition is increased to a steady state and the percentage content of the ultraviolet absorber is changed to X mass% to obtain a desired thermoplastic resin composition. |
