| 摘要 |
PROBLEM TO BE SOLVED: To improve the erasing propery, and also, increase the strength by producing an eraser containing at least an ethylene-vinyl acetate copolymer, a polyolefinic elastomer, a filler and a plasticizer. SOLUTION: Thirty wt.% of EVA and 25 wt.% of TPE are kneaded at 160 deg.C for one hour by a press-kneader. Then, to the mixture, 26 wt.% of calcium carbonate, 12 wt.% of quartzite, and 7 wt.% of paraffin oil are added, and the mixture is kneaded for another one hour. The obtained mixture is pelletized, and is extrusion-molded by an extruder into a shape having a diameter of 3.8 mmϕ. Then, the molded article is cut into a proper length, and an eraser which is fitted in a knocking type eraser holder for the usage, is obtained. The obtained eraser has a hardness (JIS:A) of 80. When used while being fitted in the holder, the slivering of waste in erasing is good, the erasing property is good, and the erasing factor (by a test specified based on JIS:S-6004) is 85%.
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