Abstract: A photoacid generator which can generate an acid efficiently when energy was absorbed, is excellent in the developing property and can form fine patterns, and a cationic polymerization initiator excellent in curability are provided; and a resist composition and a cationically polymerizable composition using them are provided. An aromatic sulfonium salt compound represented by the General Formula (I) below: (wherein each of E1 to E4 independently represents a substituent represented by the General Formula (II) below or the General Formula (III) below). Preferably, in the General Formula (I), r and s are 0; m and n are 0; or n and r are 0, and more preferably, one of m and s in the General Formula (I) is 1.

Abstract: Novel aromatic sulfonium salt compounds of general formula (I), photo-acid generators comprising the same, and photo-polymerizable compositions containing the same, capable of providing stereolithographic resin compositions which do not suffer from the hindrance to curing by oxygen, can easily give shaped articles having desired sizes by virtue of the high accuracy thereof in curing, can attain a satisfactory curing depth owing to the high sensitivity thereof for radiant energy and can be employed for wide usage, such as photoresist and ink for foods-packing medium, since the release of benzene is suppressed; and a stereolithographic process, using said stereolithographic resin composition.

Abstract: Novel aromatic sulfonium salt compounds of general formula (I), photo-acid generators comprising the same, and photo-polymerizable compositions containing the same, capable of providing stereolithographic resin compositions which do not suffer from the hindrance to curing by oxygen, can easily give shaped articles having desired sizes by virtue of the high accuracy thereof in curing, can attain a satisfactory curing depth owing to the high sensitivity thereof for radiant energy and can be employed for wide usage, such as photoresist and ink for foods-packing medium, since the release of benzene is suppressed; and a stereolithographic process, using said stereolithographic resin composition.

Abstract: The energy beam curable epoxy resin composition comprising as essential components, (1) specific cationically polymerizing organic substance,(2) energybeam sensitive cation polymerization initiator, (3) cationically polymerizing organic substance except for the specific cationically polymerizing organic substance, described above, (4) radically polymerizing organic compound, and (5) energy beam sensitive radical polymerization initiator. The cured articles resulted from said resin composition, have superior properties and particularlly superior dimensional stability on humidity absorption. Therefore, a stereolithographic resin composition and a stereolithographic method are also provided.

Abstract: The energy beam curable epoxy resin composition comprising as essential components, (1) specific cationically polymerizing organic substance, (2) energybeam sensitive cation polimerization initiator, (3) cationically polymerizing organic substance except for the specific cationically polymerizing organic substance, described above, (4) radically polymerizing organic compound, and (5) energy beam sensitive radical polymerization initiator. The cured articles resulted from said resin composition, have superior properties and particularlly superior dimensional stability on humidity absorption. Therefore, a stereolithographic resin composition and a stereolithographic method are also provided.