Liquid, radiation-curable composition, especially for producing flexible cured articles by stereolithography

The present invention relates to a liquid, radiation-curable composition which is particularly suitable for the production of three-dimensional shaped articles by means of stereolithography, to a process for the production of a cured product and, in particular, for the stereolithographic production of a three-dimensional shaped article from this composition. The present invention relates to stereolithographic compositions containing an actinic radiation-curable and cationically polymerizable organic substance, a cationic initiator, a radical photoinitiator, and at least one cationic reactive modifier containing at least two reactive groups per molecule or at least one polyether polyol or mixtures thereof. The cationic reactive modifier has at least one chain extension segment with a molecular weight of at least about 100 and not more than about 2,000. The polyether polyol has a molecular weight greater than or equal to about 4,000. The use of the cationically reactive modifiers and polyether polyol modifiers substantially increases the flexibility and toughness of the cured articles without compromising photospeed, accuracy and wetting-recoatability of the compositions. The present invention further relates to a method of producing a cured product, particularly three-dimensional shaped articles by treating the composition described above with actinic radiation.