Colored photocurable composition

Abstract

The present invention relates to a colored photocurable composition, its manufacturing process, and its uses. In particular, the present invention relates to a colored photocurable composition characterized in that it comprises at least one pigment exhibiting a thermo-photo-induced non-equilibrium phase transition mechanism.

Description

Description Title of the invention: Colored photocrosslinkable composition Technical field

[0001] — The present invention relates to the technical field of photoretic compositions- culables. The invention relates in particular to a specific composition, its preparation process and its uses. State of the art

[0002] = Photocrosslinking is a technique that exposes a material to a light source (UV or LED) to start a chemical and irreversible transformation. This trans- formation induces hardening of the starting material.

[0003] …— Photocrosslinkable compositions generally consist of a resin and of a photoinitiator. Thus, the resins which were initially liquid become solids and resins that were solid, fusible and soluble become infusible and in- soluble.

[0004] — The first uses of this technology date back to the 1970s in the field of graphic arts. Since then, applications have multiplied, particularly in electronics (fiber optic sheathing), in automobiles (bodywork), in cosmetics (varnishes), in inks, coatings and more recently in three-step printing dimensions.

[0005] — Photocrosslinking is a growing technique offering rapid drying with many advantages.

[0006] — In addition to being a clean technique without the use of solvent, photocrosslinking allows for quick drying at low energy cost. In fact, it is possible to dry thin layers of material in less than one second.

[0007] This ultra-fast drying makes it possible to treat heat-sensitive supports such as wood or plastic.

[0008] — These advantages make photocrosslinkable compositions a popular material for in- industrialists who are always looking for alternative photocrosslinkable compositions presenting improvements that can extend its use.

[0009] = Today, one of the big challenges is to succeed in creating a composition colored photocrosslinkable allowing to obtain a thickness of dry matter su- superior to Imm.

[0010] = Although there are now colored photocrosslinkable compositions, none existing composition does not allow to obtain such a thickness. Indeed, the pigments prevent waves from reaching the core of the material exposed to a light source. This problem is accentuated when the coloring of the photoreactive composition- crosslinkable is dark. Thus, there is a need for a colored photocrosslinkable composition capable of being photocrosslinked so as to obtain a dry material with a thickness greater than 1 mm. Summary of the invention To meet this need, the invention proposes a new colored photocrosslinkable composition capable of crosslinking over a thickness of at least 1 mm. This colored photocrosslinkable composition includes: -at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism; and - at least one photocrosslinkable matrix Particularly advantageously, said pigment can be activated so as to enter a non-equilibrium transparent transient state before crosslinking of the composition according to the invention. Thus, during photocrosslinking, after activation of the transparent transient state of said pigment, the composition is transparent for a sufficient period of time to allow the waves to penetrate a significant thickness, in particular a thickness greater than 1 mm. Exposure to UV and / or heat released by photocrosslinking allows said pigment to return to its initial colored energy state. Advantageously, the invention makes it possible to obtain a thickness of colored dry matter of at least 1 m in a single application. According to a preferred object of the invention, the composition is in photocrosslinked, solid form, and it has: - a clarity defined by an L* parameter less than 60, and - a thickness of at least 1 mm. Preferably, the composition according to the invention has at least one color chosen from black, blue, red, green and brown. Advantageously, the photocrosslinked composition according to the invention can have a dark color. Such a composition is particularly useful in the context of the invention, thus making it possible to provide a colored photocrosslinkable composition which can be photocrosslinked to a thickness of at least 1 mm in a single application. Preferably, the composition according to the invention comprises at least one pigment chosen from the family of spin transition or phase change pigments. According to another aspect, the invention relates to a method for manufacturing a photocrosslinkable composition according to the invention comprising a step of preparing a liquid varnish, a step of mixing with at least one pigment according to the invention, and a grinding step. Finally, the invention also relates to the use of the composition according to the invention in and / or as photocrosslinkable product(s) such as inks, paints, plastics and coatings. Other characteristics and advantages will emerge from the detailed description of the invention and from the examples which are purely illustrative and in no way limitative of the scope of the invention. Brief description of the Figures [Fig.1] Photograph of a measuring device calculating the thickness obtained from a composition according to the invention comprising [Fe(R-Trz)3]X2 with R-Trz=aminotriazole and X=Br / [Fig.2] Photograph of a measuring device calculating the thickness obtained from a composition according to the invention comprising Methyl hexadecanoate. Detailed description of the invention Defined For the purposes of the invention, the term “light source” means at least one light source chosen from all natural or artificial light sources. For the purposes of the invention, the term “photocrosslinkable” means any composition whose crosslinking is activated when exposed to a wavelength, in particular a wavelength between 254 and 500 nm. For the purposes of the invention, the term “photocrosslinked” means any composition which has undergone crosslinking following exposure to at least one wavelength, in particular at least one wavelength between 254 and 500nm. By "a thermo-photo-induced non-equilibrium phase transition mechanism" within the meaning of the invention, we mean a mechanism generating a change in phase and concomitantly in absorption spectrum generated by a thermo- and / or photo-assisted stimulus. By "spin transition pigment" within the meaning of the invention is meant at least one compound selected from coordination compounds, species in which various anions or neutral molecules bind to an atom or, to an ion of a transition metal, have a defined spin state. In the case of 3d4 to 3d7 ions, in an octahedral or slightly distorted geometric configuration, the spin transition phenomenon can be observed. This transition is encountered when the strength of the ligand field is in a certain range, for which a thermal conversion becomes possible between the ions in the Low Spin (LS) state, at low temperature, and in the High Spin (HS) state at high temperature. For the purposes of the invention, the term “dark color” means at least one color chosen from among the colors having a lightness defined by a parameter L* less than 60. By "lightness" within the meaning of the invention, we mean a parameter on the whiteness of the color studied. The darker / darker the color, the lower the lightness. To measure the lightness, it is necessary to deposit the composition, colored and photocrosslinked according to the invention on black background contrast cards by forming a film of uniform thickness. The measurement is obtained using a spectrocolorimeter equipped with an integrating sphere and a D65 illuminant. The closer the parameter L* is to 0, the darker the composition. For the purposes of the invention, “photoinitiator” means a molecule which creates reactive species when exposed to radiation (UV or visible). Composition The present invention therefore relates to a colored photocrosslinkable composition comprising: - at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism; and - at least one photocrosslinkable matrix. Advantageously, the pigment having a thermophoto-induced non-equilibrium phase transition mechanism can pass into a transparent transient state making the composition according to the invention transparent and thus making it possible to be photocrosslinked over a significant thickness, in particular over a thickness of at least 1 mm. In a preferred embodiment, the composition according to the invention comprises at least one photocrosslinkable matrix itself comprising: -at least one resin and; -at least one crosslinking initiator, preferably at least one photoinitiator. When the composition according to the invention comprises at least one photocrosslinkable matrix comprising a resin, the resin may be chosen from the family of unsaturated polyester-styrene, thiol-polyenes, acrylates, methacrylates and epoxy. Preferably, the composition according to the invention comprises at least one photocrosslinkable matrix comprising an acrylic resin and / or an epoxy resin. According to one embodiment of the invention, the photocrosslinkable matrix comprises a polyurethane-based resin. When the composition according to the invention comprises at least one photocrosslinkable matrix comprising a photoinitiator, the photoinitiator may be chosen from the class of Acyloins also called α-hydroxyketones, phenylglyoxylate, Benzyldimethylketal, the class of α-Aminoketone, organometallic complexes such as metallocenes, Bis Acyl Phosphine and their mixture. Advantageously, the composition according to the invention is suitable for any type of matrix. photocrosslinkable. According to a particular embodiment of the invention, the photocrosslinkable matrix comprises at least 2 different resins and / or at least 2 different photoinitiators. The photocrosslinking of the composition according to the invention can be activated or activated by exposing the composition to a wavelength between 254 and 500nm. Preferably, the composition according to the invention can be activated by any continuous and / or discontinuous light source emitting between 254 and 500nm. Advantageously, the photocrosslinking can be carried out when the pigment having a thermophoto-induced non-equilibrium phase transition mechanism is in a transparent transient state in order to obtain a composition in solid form, colored and having a thickness of at least 1 mm. Said pigment in a transparent transient state returns to its initial state following exposure to UV and / or temperature generated by excitation between 254nm and 500nm. The composition according to the invention can be presented: - in photocrosslinkable and colored but not photocrosslinked liquid form, or - in photocrosslinked and colored solid form, after photocrosslinking of the composition in liquid form, According to one embodiment, the composition is in solid, colored, photo-crosslinked form and has a thickness of at least 1 mm and can be obtained by the photocrosslinking of a composition in photocrosslinkable liquid form according to the invention. According to one embodiment, the composition according to the invention is in non-photocrosslinked liquid form, preferably in the form of a dispersion. Preferably, the composition in liquid form according to the invention is photocrosslinkable over a thickness of at least 1 mm, preferably at least 2 mm, in particular at least 3 mm, even more preferably at least 4 mm. Advantageously, the composition according to the invention makes it possible to effectively photocrosslink deposits with a thickness of at least 1 mm. According to another embodiment of the invention, the composition according to the invention is in solid, colored, photocrosslinked form and it has a thickness of at least 1 mm. Preferably, the photocrosslinked composition according to the invention has a clarity defined by a parameter L* of less than 60, preferably less than 50, in particular less than 40. Advantageously, the photocrosslinked composition according to the invention is dark in color. According to a particular embodiment of the invention, the composition is in the form solid, photocrosslinked, having a clarity defined by an L* parameter of less than 60 and a thickness of at least 1 mm capable of being obtained by the photocrosslinking of a colored photocrosslinkable composition comprising: - at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism; and - at least one photocrosslinkable matrix. Preferably, the composition according to the invention is in solid, photo-crosslinked form and has a thickness of at least 1 mm, preferably at least 2 mm, in particular at least 3 mm, even more preferably at least 4 mm. The composition according to the invention is colored. Preferably it is dark in color. Preferably it has at least one color chosen from black, blue, green, brown, red and mixtures thereof. According to a preferred embodiment, the composition according to the invention comprises at least one pigment having a thermophoto-induced non-equilibrium phase transition mechanism chosen from: -spin transition pigments and; - phase change pigments. In one embodiment, the pigment having a thermo-photo-induced non-equilibrium phase transition mechanism is a phase change pigment. More particularly, it may be an organic derivative of the diyn type, electron and / or proton transfer, in a micellar environment or not, and / or a metal oxide of formula AMoO, in which A is a metal preferably chosen from copper, zinc, iron, nickel and cobalt. According to a preferred embodiment, the pigment having a thermo-photo-induced non-equilibrium phase transition mechanism is a phase change pigment chosen from: - a tungsten-doped pigment of formula CuMo,,W,04 with x a real number between 0 inclusive and 1 inclusive, preferably between 0.07 inclusive and 0.1 inclusive - a magnesium-doped pigment of formula Co,,Mg,MoO, with x a real number between 0 inclusive and 1 inclusive. In another embodiment, the pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism is a spin transition pigment, i.e., a coordination complex comprising at least one metal center exhibiting one of the 3d4, 3d6, or 3d7 electronic configurations, at least one nitrogen ligand, and at least one anion, said pigment exhibiting at least two spin states stable at ambient pressure and temperatures. Preferably, the pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism is a spin transition pigment comprising: - a metal center comprising a ferrous ion Fe(ID), at least two triazole ligands, and at least one anion among BF,, CIO,, CO-*, Br, CI, NO,*, PF2. Preferably, the pigment exhibiting a thermo-photo-induced non-equilibrium phase transition mechanism is a spin transition pigment exhibiting the following formula Fe,,M,(R-Trz) 3 (X2x) 2-2 (Y35-)Z in which: - R-Trz is a 1,2,4-triazole ligand bearing an R substituent on the nitrogen in position 4; - R is an alkyl group or a RIR2N- group in which R1 and R2 each independently represent H or an alkyl radical - X is an anion having valence x whose | < x < 2; - Y is an anion different from X having the valence x' of which | < x < 2; - M is a metal other than Iron, having a configuration 3d4, 3d5, 3d6 or 3d7; - y having a value between 0 inclusive and 1 inclusive; and - z having a value between Ô inclusive and 2 inclusive. Thus, according to a particularly preferred embodiment, the composition according to the invention comprises at least one pigment having a thermophoto-induced non-equilibrium phase transition mechanism chosen from: -- a tungsten-doped pigment of formula CuMo,,W,04 with x a real number between 0 inclusive and 1 inclusive, preferably between 0.07 inclusive and 0.1 inclusive; - a magnesium-doped pigment of formula Co,,.Mg.MoO4 with x a real number between 0 inclusive and 1 inclusive; -- a pigment comprising: -a metallic center comprising a ferrous ion Fe(ll) -at least two triazole ligands; and -at least one anion among BF,, CIO,, CO4*, Br, CH, NO47, PF& According to another embodiment, the composition according to the invention comprises: - at least one pigment having a thermophoto-induced non-equilibrium phase transition mechanism chosen from 10,12-Pentacodiynoic acid, a pigment having the formula [Fe(R-Trz)3]X2 with R-Trz=aminotriazole and X=Br; phenyldecan-1-one, methyl hexadecanoate and their mixture; and - at least one photocrosslinkable matrix chosen from a varnish, an acrylic ink, an epoxy ink, an aqueous polyurethane-based ink. According to a preferred embodiment, the composition according to the invention may also comprise at least one other compound chosen from an organic pigment, an inorganic pigment, a chromophore or a color activator and their combination. Advantageously, the organic or inorganic pigment present in addition to the pigment exhibiting a thermo-photo-induced non-equilibrium phase transition mechanism makes it possible to optimize the final color without preventing the photocrosslinking of the com- position according to the invention. According to one embodiment of the invention, the composition comprises: - a pigment exhibiting a thermophoto-induced phase change non-equilibrium phase transition mechanism preferentially phenyldecan-1-one or methyl hexadecanoate - a chromophore, preferably 7-Anilino-3-diethylamino-6-methyl fluoran; - a color activator, preferably 4,4”-Isopropylidenedi-o-cresol; and - a photocrosslinkable matrix According to one embodiment, the composition according to the invention comprises at least one pigment having a thermophoto-induced non-equilibrium phase transition mechanism, at least one resin and at least one photoinitiator. Preferably, the composition according to the invention comprises between 1 and 50% of pigment having a thermophoto-induced non-equilibrium phase transition mechanism. According to another embodiment, the composition according to the invention comprises at least one pigment having a thermophoto-induced non-equilibrium phase transition mechanism and at least one varnish. Preferably, the composition according to the invention comprises: - between 1 and 50% photocrosslinkable matrix - between 1 and 50% of pigment presenting a thermophoto-induced non-equilibrium phase transition mechanism. According to another aspect, the composition according to the invention is capable of being obtained by a manufacturing process comprising the following steps: a) Preparation of a photocrosslinkable matrix; b) Mixture of at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism in the photocrosslinkable matrix obtained in step a); and c) Grinding the mixture obtained in step b) to obtain a particle size less than Sum. According to one embodiment, the composition according to the invention is capable of being obtained by a manufacturing process according to the invention as described in the present application. Process Also, the invention also relates to a method for manufacturing a composition according to the invention comprising at least the implementation of the following steps: a) Preparation of a photocrosslinkable matrix; b) Mixture of at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism in the photocrosslinkable matrix obtained in step a); and c) Grinding the mixture obtained in step b) to obtain a particle size less than Sum. Preferably, the photocrosslinkable matrix of step a) is chosen from a liquid varnish, a paint, an ink, a plastic, a coating. According to a preferred embodiment, the photocrosslinkable matrix of step a) comprises at least one resin and at least one photoinitiator. More particularly, the photocrosslinkable resin can be chosen from the family of unsaturated polyesters-styrene, thiol-polyenes, acrylates, methacrylates and epoxies. According to a particularly preferred embodiment, the photocrosslinkable matrix of step a) comprises an epoxy resin and / or an acrylic resin. The mixture of step b) is preferably carried out with a pigment having a thermophoto-induced non-equilibrium phase transition mechanism chosen from: -spin transition pigments and; - phase change pigments. According to a preferred embodiment, at least one pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism of step b) is chosen from: -- a tungsten-doped pigment of formula CuMo,,W,04 with x a real number between 0 inclusive and 1 inclusive, preferably between 0.07 inclusive and 0.1 inclusive; - a magnesium-doped pigment of formula Co,,Mg,MoO, with x a real number between 0 inclusive and 1 inclusive; -- a pigment comprising: a metal center comprising a ferrous ion Fe(IT) at least two triazole ligands; and at least one anion from BF,, CIO;,, CO7, Br, CI, NO;%, PF67 Step b) of mixing is preferably carried out by mechanical dispersion. Particularly preferably, the mixing of step b) is carried out in a paddle mixer at a speed of between 1 and 20 rpm, preferably between 1 and 10 rpm, even more preferably at 10 rpm. Advantageously, the speed of the mixing in step b) makes it possible to obtain a homogeneous mixture. Preferably, the mixing of step b) is carried out for a period of between 1 and 10 hours, preferably 1 to 5 hours, even more preferably 2 hours. According to a particularly preferred embodiment, the mixing of step b) is carried out using a paddle mixer at a speed of 10 rpm for 2 hours. Advantageously, the mixture of step b) makes it possible to obtain a composition homogeneous. According to another embodiment, grinding step c) is carried out using a ball mill or tri-cylinder. Preferably, the grinding of step c) is carried out for a period of between 20 min and 5 hours, in particular between 1 hour and 3 hours. The particle size of the composition according to the invention resulting from step c) can be measured by methods well known to those skilled in the art, such as dynamic diffusion and / or laser diffraction. Preferably, the size of the particles of the composition according to the invention at the end of step c) is less than Sum. Advantageously, such a granulometry makes it possible to obtain a homogeneous suspension and good transparency during activation of the composition, thus allowing good crosslinking. Thus, the method according to the invention makes it possible to obtain a colored photocrosslinkable composition capable of crosslinking over a thickness of at least 1 mm. Uses According to a final aspect, the invention relates to the use of a composition according to the invention in inks, paints, plastics, protective films and surface coatings. Preferably, the composition according to the invention is particularly suitable for use as an ink, paint, plastic, coating, photocrosslinkable protective film (in liquid form before application) or photocrosslinked (in solid form in a layer after application). According to a particularly preferred embodiment, the composition can be used as printing materials for 3D printers, preferably as a plastic material suitable for 3D printing. Preferably, the composition according to the invention is used in a solid layer with a thickness of at least 1 mm. Advantageously, the composition according to the invention makes it possible to produce solid layers of at least 1 mm and colored, preferably having a clarity defined by a parameter L* of less than 60. According to a final aspect, the invention relates to inks, paints, plastics, coatings, photocrosslinkable protective films (in liquid form before application) or photocrosslinked (in solid form in a layer after application) comprising the composition according to the invention. Examples Exempl ition according to the inn * Example | : The composition of Example 1 is obtained by implementing the manufacturing process according to the invention. The composition according to example 1 comprises: -60% aqueous polyurethane ink containing a photoinitiator; and - 40% of 10,12-Pentacosadiynoic acid 10,12-Pentacosadiynoic acid is a pigment exhibiting a blue, diyne-like, thermophoto-induced non-equilibrium phase transition mechanism. The ink and pigment are ground together using a three-roll mill. The particle size is measured at the end of grinding to ensure that the particle size is less than 5 µm. The mixture is then deposited on a glass surface and crosslinked using a UV lamp. After crosslinking, the entire deposit is dry and has a blue color and a thickness greater than 1 mm. [Tables 1] type of |Pigment type of matrix photocrosslinkable pigment has Color |Color coordinates- Thickness | r metric r «eh [Blue [52.6 |-1.59|-42.2 [2 mm Changeme |Acid Aqueous ink with 10,12-Pentacod |poly-phase urethane base Example 2: The composition of Example 2 is obtained by implementing the manufacturing process according to the invention. The composition according to example 2 comprises: -60% epoxy ink containing a photoinitiator; and -40% of a pigment having the formula [Fe(R-Trz):]X2 with R-Trz=aminotriazole and X=Br. The pigment of Example 2 is a pigment exhibiting a thermophoto-induced non-equilibrium phase transition mechanism of red color. The ink and pigment are ground together using a three-roll mill. The particle size is measured at the end of grinding to check that the size of particles is less than 5 um. The mixture is then deposited on a glass surface and crosslinked using a UV lamp. After crosslinking, the entire deposit is dry and has a blue color and a thickness greater than 1 mm ([Fig.1]) [Tables 2] |Pi gment pigment type |Epoxy ink throw type Coordinates co [re photoreticulabl metric r qe ep [Epoxy ink [Red [27.22 [0.01 |-0.83|1 mm Transition |[Fe(R-Trz)3]X2 | of spin with R- Trz=aminotriazol | e and X=Br Example 3: The composition of Example 3 is obtained by implementing the manufacturing process according to the invention. The composition according to example 3 comprises: -60% acrylic ink containing a photoinitiator; and -40% of a mixture of Phenyldecan-1-one, 7-Anilino-3-diethylamino-6-methyl fluoran and 4,4"-Isopropylidenedi-o-cresol in a mass ratio of 3:1:18. Phenyldecan-1-one is a pigment with a thermophoto-induced non-equilibrium phase transition mechanism of black color. The ink and pigment mixture are ground together using a three-roll mill. The particle size is measured at the end of grinding to ensure that the particle size is less than 5 µm. The mixture is then deposited on a glass surface and crosslinked using a UV lamp. After crosslinking, the entire deposit is dry and has a blue color and a thickness greater than 1 mm. [Tables 3] |Pigment pigment type matrix type |Color|Color coordinates |Thick | photocurable metric ur ê |" |a pp [acrylic ink [Black [52.09 52.9 |38.4 Jas mm | 3 Changeme |Phenyldecan-1-0 [acrylic ink [Black nt of ne phase Example 4: The composition of Example 4 is obtained by implementing the manufacturing process according to the invention. The composition according to example 4 comprises: -95% acrylic ink containing a photoinitiator; and 5% of a mixture of Methyl hexadecanoate, 7-Anilino-3-diethylamino-6-methyl fluoran and 4,4"-Isopropylidenedi-o-cresol in a mass ratio of 3:1:18. Methyl hexadecanoate is a pigment with a thermophoto-induced non-equilibrium phase transition mechanism of black color. The ink and pigment mixture are ground together using a three-roll mill. The particle size is measured at the end of grinding to ensure that the particle size is less than 5 µm. The mixture is then deposited on a glass surface and crosslinked using a UV lamp. After crosslinking, the entire deposit is dry and has a blue color and a thickness greater than 1 mm ([Fig.2]). [Tables 4] |Pigment pigment type [acrylic ink [Black Matrix type |Color|Color coordinates |Thick photocurable metric ur € [= a bb [acrylic ink [Black [2029 [-0.15 [0.82 [8 mm Changeme |Methyl hexa- phase decanoate

Claims

Claims

1. Photocrosslinkable, colored composition, characterized in that it understand : -at least one pigment exhibiting a phase transition mechanism out of thermo-photo-induced equilibrium; and -at least one photocrosslinkable matrix.

2. Composition according to the preceding claim, characterized in that it is in non-photocrosslinked liquid form.

3. Composition according to claim 2, characterized in that it is pho- crosslinkable to a thickness of at least 1 mm.

4. Composition, in solid, colored, photocrosslinked form having a thickness of at least 11 mm capable of being obtained by photoreti- culation of a composition according to claim 1.

5. Composition according to the preceding claim, characterized in that the composition has a clarity defined by a parameter L* less than 60.

6. Composition according to one of the preceding claims, characterized in that the composition presents at least one color chosen from the black, blue, red, green, brown.

7. Composition according to one of the preceding claims, characterized in that the photocrosslinking of the composition is activatable or activated in exposing the composition to a wavelength between 254 and 500nm.

8. Composition according to one of the preceding claims, characterized in that said at least one pigment having a transition mechanism of thermo-photo-induced non-equilibrium phase is chosen from the family spin transition or phase change pigments.

9. Composition according to one of the preceding claims, characterized in that the composition also includes at least one other compound chosen from at least one organic pigment, one inorganic pigment, a chromophore, a color activator or their combination.

10. Use of a composition according to one of claims 1 to 9, as photocurable ink or paint.

11. Use of the composition according to one of claims 1 to 9, in solid, colored layer, at least 1 mm thick and having a clarity defined by an L* parameter less than 60.

12. Use of a composition according to one of claims 1 to 8 in protective films, plastics, coatings.

13. Use of a composition according to one of claims 1 to 8 in as a plastic material suitable for 3D printers.

14. Method of manufacturing a composition according to one of the claims 1 to 9, characterized in that it comprises the following steps: a) Preparation of a photocrosslinkable matrix b) Mixture of at least one pigment having a mechanism of thermophoto-induced non-equilibrium phase transition with the matrix photocrosslinkable obtained in step a) c) Grinding the mixture obtained in step b) to obtain a granulation lometry less than Sum.

15. A method of manufacturing a composition according to claim 14, ca- characterized in that the mixture of step b) is carried out by dispersion mechanical.

16. Method of manufacturing a composition according to one of the claims 14 and 15, characterized in that the grinding is carried out using a grinder ball or three-cylinder.

17. Method of manufacturing a composition according to one of the claims 14 to 16, characterized in that the mixing of step b) is carried out for a period of between | and 10 hours.