To keep the excellent antibacterial effect and transparency of a vessel wall by distributing germless antibacterial particles whose mean grain size is below the prescribed value at the concentration of not less than the prescribed ratio in the thermoplastic resin matrix in the surface layer within the prescribed ratio to the thickness of the vessel wall from the outer surface of the vessel wall.
Germless antibacterial particles which is little in toxicity, excellent in thermal stability, and easy in dispersion in the resin, and whose mean grain size is below 10μm, are used as the antibacterial agent. The germless antibacterial particles are distributed in the surface layer within 1/3 of the thickness of the vessel wall from the outer surface of a vessel wall so as to be present in the thermoplastic resin matrix by ≥0.5wt.% and in the surface layer by ≥50wt.%. The inorganic antibacterial particles in the resin are effectively utilized in the antibacterial effect of a packaged body, and the mold-preventive effect is also improved. An intermediate layer of the vessel wall is made of the thermoplastic resin substantially containing no inorganic antibacterial particles by concentrating the inorganic antibacterial particles in the surface layer, and the transparency of the vessel wall of the packaging body is remarkably improved.
MARUHASHI KICHIJI
GORYODA TOSHIO
TAKAHATA ENSHIYUU
SAKO KAZUTADA
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