Additive manufacturing processes, such as powder bed fusion of thermoplastic particulates, may be employed to form printed objects in a range of shapes. Formation of printed objects having various colors may sometimes be desirable. Thermoplastic particulates incorporating a color-changing material capable of forming different colors under specified activation conditions may impart different colors to a printed object. Such particulate compositions may comprise a plurality of thermoplastic particulates comprising a thermoplastic polymer and a color-changing material associated with the thermoplastic particulates, wherein the color-changing material is photochromic and thermochromic. Conjugated diynes, such as 10,12-pentacosadiynoic acid or a derivative thereof, may be particularly suitable color-changing materials having photochromic and thermochromic properties for forming a range of colors upon a printed object. Nanoparticles, particularly silica nanoparticles, associated with an outer surface of the thermoplastic particulates may enhance the brightness of the color obtained under various activation conditions and afford coloration permanence.

Additive manufacturing processes, such as powder bed fusion of thermoplastic particulates, may be employed to form printed objects in a range of shapes. Formation of printed objects having various colors may sometimes be desirable. Thermoplastic particulates incorporating a color-changing material capable of forming different colors under specified activation conditions may impart different colors to a printed object. Such particulate compositions may comprise a plurality of thermoplastic particulates comprising a thermoplastic polymer and a color-changing material associated with the thermoplastic particulates, wherein the color-changing material is photochromic and thermochromic. Conjugated diynes, such as 10,12-pentacosadiynoic acid or a derivative thereof, may be particularly suitable color-changing materials having photochromic and thermochromic properties for forming a range of colors upon a printed object. Nanoparticles, particularly silica nanoparticles, associated with an outer surface of the thermoplastic particulates may enhance the brightness of the color obtained under various activation conditions and afford coloration permanence.

An ink jet method records a radiation-curable ink composition containing a polymerizable compound. The radiation-curable ink composition includes a first ink composition and a second ink composition. The ink jet method includes a first discharging step of discharging the first ink composition with an ink jet head to adhere the composition to a recording medium, a first curing step of irradiating the first ink composition adhered to the recording medium with radioactive rays, a cooling step of cooling the recording medium, a second discharging step of discharging the second ink composition with the ink jet head to adhere the composition to the cooled recording medium at least in a part of the region where the first ink composition adhered; and a second curing step of irradiating the second ink composition adhered to the recording medium with radioactive rays.

In one aspect, inks for use with a three-dimensional printing system are described herein. In some embodiments, an ink described herein comprises up to about 90 wt. % monofunctional curable material, up to about 10 wt. % difunctional curable material, and up to about 10 wt. % liquid rubber, based on the total weight of the ink, wherein the liquid rubber comprises one or more curable moieties. In some cases, the liquid rubber comprises one or more ethylenically unsaturated moieties. For example, in some instances, the liquid rubber comprises a butadiene acrylonitrile copolymer.

In one aspect, inks for use with a three-dimensional printing system are described herein. In some embodiments, an ink described herein comprises up to about 90 wt. % monofunctional curable material, up to about 10 wt. % difunctional curable material, and up to about 10 wt. % liquid rubber, based on the total weight of the ink, wherein the liquid rubber comprises one or more curable moieties. In some cases, the liquid rubber comprises one or more ethylenically unsaturated moieties. For example, in some instances, the liquid rubber comprises a butadiene acrylonitrile copolymer.

Provided herein are methods of obtaining good photocured-ink adhesion to low surface energy materials. The methods have greatly improved adhesion of photocured ink on low surface energy materials, including those that are subjected to high humidity or wet environments. The methods take into account the glass transition temperature (T.sub.g) of the materials and the onset for the glass transition temperature, including ink applied to an exposed surface of the material at an elevated temperature that is close to the T.sub.g of the material. The ink is allowed to sit briefly or soak, such as for more than 1 second, before the ink is cured. The ink may be photocured. Furthermore, the methods do not require solvents or surface treatment, including plasma or corona treatments, to obtain good ink adhesion.

Provided herein are methods of obtaining good photocured-ink adhesion to low surface energy materials. The methods have greatly improved adhesion of photocured ink on low surface energy materials, including those that are subjected to high humidity or wet environments. The methods take into account the glass transition temperature (T.sub.g) of the materials and the onset for the glass transition temperature, including ink applied to an exposed surface of the material at an elevated temperature that is close to the T.sub.g of the material. The ink is allowed to sit briefly or soak, such as for more than 1 second, before the ink is cured. The ink may be photocured. Furthermore, the methods do not require solvents or surface treatment, including plasma or corona treatments, to obtain good ink adhesion.

Thermoset compositions and methods for forming three-dimensional articles via an additive fabrication process, and articles made therefrom are disclosed herein. In an embodiment, a composition comprises a first network-forming component comprising a first oligomer comprising a backbone and having at least 2 polymerizable groups, one or more first network monomers, and a first network initiator. The backbone of the first oligomer comprises a polyepoxide based on Bisphenol A, F, or S, a polyepoxide based on hydrogenated Bisphenol A, F, or S, a polycarbonate, or a polyimide. The composition may further comprise a second network-forming component.

Thermoset compositions and methods for forming three-dimensional articles via an additive fabrication process, and articles made therefrom are disclosed herein. In an embodiment, a composition comprises a first network-forming component comprising a first oligomer comprising a backbone and having at least 2 polymerizable groups, one or more first network monomers, and a first network initiator. The backbone of the first oligomer comprises a polyepoxide based on Bisphenol A, F, or S, a polyepoxide based on hydrogenated Bisphenol A, F, or S, a polycarbonate, or a polyimide. The composition may further comprise a second network-forming component.

A print material includes a vinylic molecule, a vinylic cross-linker molecule having a plurality of vinyl groups, a quantum dot, a light-scattering particle having a surface composition, and a dispersant having a chemical affinity matched to the surface composition. Methods of making and using such print materials are also described.