Resin composition of layered silicate

A resin composition containing:

• 100 parts by weight of a thermosetting resin being at least one selected from the group consisting of an epoxy resin, a thermosetting modified polyphenylene ether resin, a thermosetting polyimide resin, a silicone resin, a benzoxazine resin, and a melamine resin;
• 0.1-65 parts by weight of an inorganic compound;
• and
• one or more curing agents, catalysts or initiators, as required to increase the molecular weight of the thermosetting resin and finally form a cured product of the resin composition having a three-dimensional network structure,
• wherein said inorganic compound comprises a layered silicate being dispersed in the thermosetting resin such that stacks of the layered silicate have a mean interlayer spacing of between 3 to 5 nm along (001) plane within said cured product;
• and
• wherein said cured product has a mean linear expansion coefficient (α2) of up to 17×10−5(° C.−1) over a temperature range of from 10° C. higher than a glass transition temperature of said cured product to a temperature 50° C. higher than the glass transition temperature of said cured product.