Dual Cure Isocyanate Inkjet Composition

A process for printing a three dimensional object comprising:

• jetting an inkjet composition by means of a printing machine to form a layer in a configured pattern corresponding to the shape of the object,
• irradiating the formed layer to form a photo-cured layer,
• sequentially repeating the jetting and the irradiating to form a plurality of photo-cured layers in order to prepare a green body of the three dimensional object, and
• heating the green body to post cure the three-dimensional object,
• the inkjet composition having 1.8-3.3 mol/kg acryloyl groups and comprising:
• photo polymerization reactive compound (M) containing exactly one acryloyl group,
• photo polymerization reactive compound (N) containing at least two acryloyl groups,
• radical photoinitiator (R),
• isocyanate compound (D) containing at least two isocyanate groups, and
• compound (H) containing at least one hydroxyl group,
• wherein
• (M) is different from (D) with the proviso that isocyanate compound containing exactly one acryloyl group and additionally containing at least two isocyanate groups is subsumed to (D);
• (N) is different from (D) with the proviso that isocyanate compound containing at least two acryloyl groups and additionally containing at least two isocyanate groups is subsumed to (D);
• (H) is different from (D), (M) and (N);
• 10-28 mol % of acryloyl groups in the composition are provided by reactive compound (N);
• and
• a molar ratio of acryloyl groups in the composition to isocyanate groups in the composition and provided by compound (D) is 0.9 to 3.3.

A three-dimensional object made using an inkjet composition having 1.8-3.3 mol/kg acryloyl groups and comprising:

• photo polymerization reactive compound (M) containing exactly one acryloyl group,
• photo polymerization reactive compound (N) containing at least two acryloyl groups,
• radical photoinitiator (R),
• isocyanate compound (D) containing at least two isocyanate groups, and
• compound (H) containing at least one hydroxyl group,
• wherein
• (M) is different from (D) with the proviso that isocyanate compound containing exactly one acryloyl group and additionally containing at least two isocyanate groups is subsumed to (D);
• (N) is different from (D) with the proviso that isocyanate compound containing at least two acryloyl groups and additionally containing at least two isocyanate groups is subsumed to (D);
• (H) is different from (D), (M) and (N);
• 10-28 mol % of acryloyl groups in the composition are provided by reactive compound (N);
• and
• a molar ratio of acryloyl groups in the composition to isocyanate groups in the composition and provided by compound (D) is 0.9 to 3.3.