| 摘要 |
PROBLEM TO BE SOLVED: To provide a game board of a pinball game machine excellent in nail holdability, dimension stability (the sink of a molded article) and an appearance (surface roughness). SOLUTION: The game board of the pinball game machine is provided with a game plate molded by a counter pressure method of injecting and filling a thermoplastic resin mixed with a foaming agent inside a die and discharging a gas inside the die in the state of enclosing the gas such as air or nitrogen inside the die by a prescribed pressure. The average density of the game plate is 0.5-1.0 g/cm<SP>3</SP>, the non-foamed layer of 0.5-3.0 mm is provided on both front and rear surface sides, and the distal end side of a game nail driven from the front surface side to the game plate reaches the non-foamed layer on the rear surface side. COPYRIGHT: (C)2006,JPO&NCIPI
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