PURPOSE: The titled material having high denseness and improved mold release characteristics free from deterioration of material, obtained by blending an unsaturated polyester resin with a hydrous silicate being basic by magnesium and aluminum, followed by forming it into powder or pellets.

CONSTITUTION: 30W50wt% based on the total wt. of an unsaturated polyester resin having a softing poing not lower than 40°C, preferably one having a degree of unsaturation 0.3W0.5, is blended with 5W150pts.wt. based on 100pts.wt. of the unsaturated polyester resin of a hydrous silicate being basic by magnesium and aluminum and formed into powder, granules, pellets, bulks, etc. A filler, reinforcing material, and release agent are added to the blend.

USE: Parts of switch, e.g., rotary switch, slide switch, pull switch, etc., relay parts, variable condenser parts, etc. of electric and electronic devices.