| 摘要 |
<p>A liquid or pasty pencil is produced by (a) very finely dry-grinding pencil quality graphite or graphite mixts. of (un) calcined pencil lead compsns., (b) grinding or dispersing the compsns., wet or dry, with addn. of water, glycols, or plant or synthetic mucilages, and (c) bringing the compsn. to a writing consistency by addn. of more or less viscous mucilages. The pencil does not have to be sharpened, does not become blunt after prolonged use, writes immediately after being dropped, is ready for use for a long time, gives lines of uniform thickness, and is not appreciably more expensive than conventional pencils.</p> |
