| 摘要 |
<p>A pencil lead, as in the parent patent, in which the resin part of the mixture comprises (A) a (plasticised) hard resin such as PVC, ABS, MBS or polymethyl methacrylate, and (B) 10-50 wt.%, based on (A), of a compatible soft resin such as EVA copolymers, poly-propylene or Neoprene (RTM). Lead has good writability and durability.</p> |
