| abstract |
In an eraser composed of a plurality of layers, an improvement in durability is achieved while securing the function as an eraser. In the rubber (E1) formed by laminating a plurality of layers (S1 to S4, H1 to H3) formed of a first material and a second material having different formulations, the rubber (E1) is configured such that the adjacent layers (S1 to S4) , H1 to H3), when a crack occurs in one of the layers (S1 to S4, H1 to H3), the propagation of the crack is suppressed in the vicinity of the boundary surface (B) of the layers (S1 to S4, H1 to H3). In the vicinity of the boundary surface (B), the materials forming the adjacent layers (S1 to S4, H1 to H3) are fused to each other so that the layers (S1 to S4, H1 to H3) do not peel off along the boundary surface (B). |