The present invention refers to a printed three-dimensional optical component built up from layers of printing ink characterized in that the three-dimensional optical component comprises at least one foil between two consecutive layers. The present invention further relates to a corresponding manufacturing method.

The present invention relates to multifunctional bisacylphosphine oxides, which are useful as photoinitiators, and to compositions comprising said photoinitiators. The invention also relates to a process for photocuring and to articles of manufacture prepared by said process.

The present invention relates to multifunctional bisacylphosphine oxides, which are useful as photoinitiators, and to compositions comprising said photoinitiators. The invention also relates to a process for photocuring and to articles of manufacture prepared by said process.

Some variations provide a composition for additive manufacturing (3D printing) of metals, comprising: from 10 vol % to 70 vol % of a photocurable liquid resin; from 10 vol % to 70 vol % of metal or metal alloy particles, optionally configured with a photoreflective surface; and from 0.01 vol % to 10 vol % of a photoinitiator. Other variations provide a composition for additive manufacturing of metals, comprising: from 1 vol % to 70 vol % of a photocurable liquid resin; from 0.1 vol % to 98 vol % of an organometallic compound containing a first metal; from 1 vol % to 70 vol % of metal or metal alloy particles containing a second metal (which may be the same as or different than the first metal); and from 0.01 vol % to 10 vol % of a photoinitiator. Many examples of metals, photocurable resins, organometallic compounds, photoinitiators, and optional additives are disclosed, and methods of making and using the composition are described.

Some variations provide a composition for additive manufacturing (3D printing) of metals, comprising: from 10 vol % to 70 vol % of a photocurable liquid resin; from 10 vol % to 70 vol % of metal or metal alloy particles, optionally configured with a photoreflective surface; and from 0.01 vol % to 10 vol % of a photoinitiator. Other variations provide a composition for additive manufacturing of metals, comprising: from 1 vol % to 70 vol % of a photocurable liquid resin; from 0.1 vol % to 98 vol % of an organometallic compound containing a first metal; from 1 vol % to 70 vol % of metal or metal alloy particles containing a second metal (which may be the same as or different than the first metal); and from 0.01 vol % to 10 vol % of a photoinitiator. Many examples of metals, photocurable resins, organometallic compounds, photoinitiators, and optional additives are disclosed, and methods of making and using the composition are described.

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent colour change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent colour change (flip/flop effect), different colours in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent colour change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent colour change (flip/flop effect), different colours in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

Provided in one example herein is a liquid electrophotographic ink composition. The composition comprises a charge director; a non-polar carrier fluid comprising a polymer; and ink particles each comprising a polymeric resin mixture comprising a first polymeric resin having a first melting temperature and a second polymeric resin having a second melting temperature. The second polymeric resin may be a UV-curable polymer that is solid at room temperature, and the second melting temperature is lower than the first melting temperature.

Provided in one example herein is a liquid electrophotographic ink composition. The composition comprises a charge director; a non-polar carrier fluid comprising a polymer; and ink particles each comprising a polymeric resin mixture comprising a first polymeric resin having a first melting temperature and a second polymeric resin having a second melting temperature. The second polymeric resin may be a UV-curable polymer that is solid at room temperature, and the second melting temperature is lower than the first melting temperature.

The present invention provides a method of multi-pass inkjet printing comprising: (i) providing an inkjet ink comprising a radiation-curable monomer and a photoinitiator; (ii) jetting the ink via a printhead on to a substrate, wherein the ink is applied in multiple passes of the printhead with respect to the substrate, with each pass jetting a portion of ink in a layer on the substrate, with a first layer being jetted directly on to the substrate and subsequent layers being jetted onto the preceding layer, to build an image formed of the multiple layers; and (iii) exposing all of the layers of ink to actinic radiation to cure the ink, wherein the order of jetting the layers and curing is that pairs of layers are applied to the substrate without exposing the first layer of the pair to actinic radiation prior to the second layer of the pair of layers being applied, curing the pair of layers simultaneously by exposing the pair of layers to actinic radiation, and repeating until the image is formed.