Vinylidene chloride-based resin composition, manufacturing method thereof, and vinylidene chloride-based resin molded product

A method for manufacturing a vinylidene chloride-based resin composition, the method comprising the step of:

• blending a paste-like additive, which is obtained by preparing particles (A) which are solid at room temperature in the presence of a plasticizer (B) which is liquid at room temperature and comprises 30% by weight or more and 60% by weight or less of the particles (A), with a vinylidene chloride-based copolymer,
• wherein, in an area of 0.4 cm2 of the particles (A) observed with a transmission optical microscope, a ratio of the particles (A) which have a projected area of 1000 μm2 or more and 3000 μm2 or less to the particles (A) which have a projected area of 10 μm2 or more and 3000 μm2 or less is 20% or less;
• and a ratio of the particles (A) which have a projected area of 10 μm2 or more and less than 100 μm2 to the particles (A) which have a projected area of 10 μm2 or more and 3000 μm2 or less is 40% or more.