| 摘要 |
PURPOSE:To produce a diaphragm for speakers which is light in weight, is highly rigid and is superior in moldability by firing the base material composed of fabrics of phenolic fibers impregnated with phenolic resins in an inert atmosphere thereby carbonizing the same. CONSTITUTION:The fabrics (non-woven fabrics) 1 of the phenolic fibers formed by the novolak resin obtained through condensation polymerization of modified phenols such as phenols, cresols, fluorophenols or other and aldehydes are used as a base material and are then impregnated wth phenolic resins 2 composed of modified phenols such as phenols, cresols, fluorophenols, etc. After the fabrics are thermoformed to a diaphragm shape, they are fired at temperature above 700 deg.C in an inert atmosphere to be thereby carbonized. Further a layer of boron or beryllium is laminated on the surface of the diaphragm for speakers produced in this way, whereby the rigidity of the diaphragm may be enhanced. |
