The vitreous carbon disclosed herein is prepared from intimate uniform mixtures of powder or otherwise blendable form of 20-80% by weight of a solid phenolic-aldehyde Novolak resin and of 20-80% by weight of a solid phenolic-aldehyde resol resin, the percentages being based on the combined weight of the Novolak and resol resins, and the aldehyde in said Novolak resin comprising at least 50 molar percent, preferably substantially 100 percent, furfuraldehyde, together with a carbonaceous filler, preferably graphite, in a proportion as high as 76% by weight based on the total composition. Generally the graphite may comprise 30-70%, advantageously 35-65% and preferably 40-60% of the molding composition. The vitreous carbon is improved in electrical properties and in the capability of being shaped into large thin plates which are much more stress-free than otherwise produced. The intimate mixture of the resins used for this preparation is advantageously made by blending resin components having a particle size of less than 40 mesh, preferably less than 100 mesh.
本文所披露的
玻璃炭是由20-80%重量的固态
酚醛Novolak
树脂和20-80%重量的固态
酚醛Resol
树脂的粉末或可混合形式的密切均匀混合物制备而成,所述百分比基于Novolak和Resol
树脂的组合重量,且Novolak
树脂中的醛至少包含50摩尔百分比,优选基本上为100%的
呋喃醛,以及一种碳质填料,优选为石墨,其比例可高达总成分的76%重量。通常,石墨可以占成型组合物的30-70%,有利的是35-65%,优选为40-60%。该
玻璃炭在电学性能和成型成大型薄板的能力方面得到改善,这些薄板比其他生产的薄板更无应力。用于此制备的
树脂的密切混合物通常是通过混合粒径小于40目,优选小于100目的
树脂组分制成的。