To obtain a radical hardenable resin composition causing a low volume shrinkage at pressure molding, and capable of providing a mold product excellent in surface properties such as surface smoothness and luster.
This radical hardenable resin composition comprises a radical hardenable resin comprising a polymer and a vinyl monomer, and a shrinkage diminishing agent comprising a cross-linked polymer particles. The degree of swelling of the cross-linked particle by the vinyl monomer at 120°C under 75 kgf/cm2 is larger than the degree of swelling of the cross-linked particle by the vinyl monomer at 25°C under a normal pressure. Further, the average particle diameter of the cross-linked polymer particles is preferably within a range of 5-100 μm. Moreover, the glass transition temperature of the cross-linked polymer particle is within a range of 110-190°C.
MIZUTA KEIICHIRO
SASABE MASAZUMI
TORIBUCHI HIRONOBU
