Composite graphite sheets

A composite sheet for gaskets, prepared by the steps of mixing expanded graphite having a c direction expansion of 10-300 times the c direction dimension of the original graphite particles with oxidized graphite as a binder in an amount of 3-40 wt.%, inserting a hooked metallic sheet into said mixture as a core, said metallic sheet having a plurality of protrusions extending from the general plane of the metallic sheet, and compression molding the mixture at a pressure of 50-200 kg/cm.sup.2 and a temperature of at least 500.degree. C. to form a composite gasket sheet in which the metallic sheet is embedded within the gasket sheet and secured by said protrusions.

A method of making a composite gasket sheet comprising the steps of mixing expanded graphite having a c direction expansion of 10-300 times the c direction dimension of the original graphite particles with oxidized graphite as a binder in an amount of 3 to 40 wt.%, inserting a hooked metallic sheet into said mixture as a core, said metallic sheet having a plurality of protrusions extending from the general plane of the metallic sheet, and compression molding the mixture at a pressure of 500-200 kg/cm.sup.2 and a temperature of at least 500.degree. C. to form a composite gasket sheet in which the metallic sheet is embedded within the gasket sheet and secured by said protrusions.

A method of making a composite gasket sheet comprising the steps of mixing expanded graphite having a c direction expansion of 10-300 times the c direction dimension of the original graphite particles with an inorganic binder selected from the group consisting of Al.sub.2 O.sub.3.3P.sub.2 O.sub.5.6H.sub.2 O and Al.sub.2 O.sub.3.0.25Cr.sub.2 O.sub.3.3P.sub.2 O.sub.5.nH.sub.2 O, each in an amount of 0.1 to 30 wt.%, inserting a hooked metallic sheet into said mixture as a core, said metallic sheet having a plurality of protrusions extending from the general plane of the metallic sheet, and compression molding the mixture at pressure of 50-200 kg/cm.sup.2 and a temperture of at least 500.degree. C. to form a composite gasket sheet in which the metallic sheet is embedded within the gasket sheet and secured by said protrusions.