| 摘要 |
PROBLEM TO BE SOLVED: To provide an eraser using polyurethane as the base material and capable of erasing letters well by lightly rubbing handwriting on paper, which means by light touch. SOLUTION: The present invention provides the eraser using the polyurethane as the base material which can be obtained by reacting at least one kind of polyols chosen from castor oil and hardened castor oil with organic diisocyanate. The base material contains a plasticizer, an abrasive, and a filler to compose the eraser. Aromatic diisocyanate is preferably used as organic diisocyanate. COPYRIGHT: (C)2011,JPO&INPIT
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