| 摘要 |
PURPOSE:To obtain a pulp-based friction material having excellent durability, by carrying out the heat-treatment in at least three different heating atmospheres, in the production of a pulp-based friction material. CONSTITUTION:In the production of a pulp-based friction material using, as a binder, a thermosetting resin such as a phenol resin, the heat-treatment of the friction material is carried out in at least three heating atmospheres each having a different temperature range. As compared with the conventional heat-treatment processes in which heat-treatment is conducted each once (twice in total) before and after a pressure/heat molding step, the present process requires more heating steps. Use of too many heating steps markedly increases the treating time and equipment cost. This results in high cost of production. Accordingly, use of 3-7 steps is total, each having a different temperature range, before and after the pressure/heat molding step is preferred. |
