Stabilized matrix-filled liquid radiation curable resin compositions for additive fabrication

A liquid radiation curable composition for additive fabrication comprising:

• (a) a cationically polymerizable aliphatic epoxide;
• (b) a multifunctional (meth)acrylate component;
• (c) a cationic photoinitiator;
• (d) a free-radical photoinitiator;
• and
• (e) a filled matrix comprising
• a nanoparticle constituent comprising a plurality of inorganic nanoparticles, and
• a microparticle constituent comprising a plurality of inorganic microparticles;
• wherein the ratio by weight of the microparticle constituent to the nanoparticle constituent is from about 1:1 to about 12:1;
• and
• wherein the ratio of the average particle size of the inorganic microparticles in the microparticle constituent to the average particle size of the inorganic nanoparticles in the nanoparticle constituent is from about 2.41:1 to about 200:1.