Composition to replace titanium dioxide

Abstract

The present invention relates to a composition intended to replace TiO2, its manufacturing process and its uses. In particular, the present invention relates to a white-colored composition, having a clarity defined by an L* parameter greater than 85, comprising the mixture of at least two different white-colored compounds, at least one of the two compounds being chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile.

Description

Title of the invention: Composition for replacing titanium dioxide Technical field

[0001] The present invention relates to the technical field of pigments. The invention relates in particular to a particular composition, its preparation process and its uses. State of the art

[0002] A pigment is an insoluble colored substance that can be of animal, vegetable, inorganic, organic or synthetic origin.

[0003] Pigments are commonly used to impart color to a medium such as paints, inks, or clothing.

[0004] Nowadays, the most widely used pigments in industry are those of inorganic origin. Indeed, their resistance to light and their low cost make them highly sought-after materials. They are made of dry ground minerals, generally metals or metal salts. Due to their composition, inorganic pigments are generally more opaque and more insoluble than organic pigments.

[0005] TiO2 is an inorganic pigment used in powder form in many applications, particularly for its numerous properties such as the absorption of ultraviolet rays, its white coloring character, its opacifying properties, its resistance to chemicals, its thermal stability and its photocatalyst potential.

[0006] Thanks to its remarkable properties, TiO2 is used in the composition of a wide variety of finished products such as paints, inks, but also medicines, toothpastes, construction products (building and public works).

[0007] With the evolution of regulations, more and more studies are focusing on the safety of pigments on humans and the environment. Some studies have been able to show the carcinogenic potential of TiO2 by inhalation and the authorities have thus reclassified TiO2 as a category 2 carcinogen by inhalation.

[0008] Therefore, since January 1, 2020, the use of TiO2 has been banned in Europe in any food product. In a report by the European Food Safety Authority (EFSA) in 2021, EFSA confirms that TiO2 can no longer be considered safe as a food additive, in particular because genotoxic effects cannot be excluded.

[0009] Faced with the ubiquitous use of TiO2, the authorities recommend limiting the exposure of workers, consumers and the environment, by promoting safe and equivalent alternatives in terms of effectiveness. Summary of the invention

[0010] To meet this need, the invention proposes a new composition intended to be an alternative to TiO2.

[0011] This composition comprises the mixture of at least two different white-colored compounds, at least one of which is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile. It has properties equivalent to those of TiO2, namely a clarity defined by an L* parameter greater than 85.

[0012] Advantageously, the combination of the compounds according to the invention makes it possible to generate a synergistic effect on the clarity of the composition which is greater than the combination of the clarity of each of the compounds taken individually.

[0013] The composition according to the invention has a clarity allowing it to be particularly suitable for use in particular in inks and paints as a substitute for TiO2.

[0014] According to a particularly suitable embodiment, the composition according to the invention comprises the mixture of at least 3 white-colored compounds.

[0015] Preferably, the composition according to the invention also comprises, in addition to the compound chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile, at least one other different compound chosen from calcium carbonate, quartz, zirconia, calcium silicate, barium sulfate, zinc oxide, zinc sulfide, mullite, clay, aluminum, starch, bromazolon, boron nitride, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, hydrochloride arbidol, bismuth oxychloride, arginine, antimony trioxide, tourmaline, nitrile.

[0016] According to a preferred subject of the invention, the composition according to the invention comprises the mixture of two white-colored compounds chosen from: - a Cl compound having a particle size range comprising a peak centered on a PI value corresponding to a diameter Dl, -a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml released by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles correspond to each end of a square.

[0017] Preferably, the composition according to the invention also comprises a compound C3 having a particle size range comprising a peak centered on a value P3 corresponding to a diameter D3, such that D3 is equal to the maximum diameter of a particle in the inter-particle space M2 released by the presence of 2 particles of diameter DI and one particle of diameter D2, juxtaposed so that the center of the 3 particles corresponds to each end of a triangle.

[0018] Such a composition is particularly useful in the context of the invention, thus providing an alternative to the use of TiO2.

[0019] According to another aspect, the invention relates to a method for manufacturing a composition according to the invention comprising in particular a step of selecting the compounds, mixing and recovering the composition according to the invention.

[0020] Finally, the invention also relates to the use of the composition according to the invention in inks or paints.

[0021] 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

[0022] [Fig.l] Explanatory diagram of the measurement of the particle size of the compounds according to the invention

[0023] [Fig.2] Comparison of the clarity of a solvent-based ink with TiO2 or with a composition according to the invention

[0024] [Fig.3] Comparison of the clarity of a UV ink with TiO2 or with a composition according to the invention

[0025] [Fig.4] Comparison of the clarity of a solvent-based paint with TiO2 or with a composition according to the invention

[0026] [Fig.5] Comparison of the clarity of an aqueous paint with TiO2 or with a composition according to the invention

[0027] [Fig.6] Comparison of the clarity of a commercial luminescent paint with TiO2 or with a composition according to the invention

[0028] [Fig.7] Comparison of the luminescence after 10 minutes of decline of a commercial luminescent paint with TiO2 or with the composition according to the invention Detailed description of the invention

[0029] Definition

[0030] By "clarity" within the meaning of the invention, we mean an indication of the whiteness of the color studied. The darker the color, the lower the clarity. To measure the clarity, it is necessary to deposit the composition according to the invention on cards of black background contrast 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 L* parameter is to 100, the whiter the composition.

[0031] For the purposes of the invention, the term "coverage" means the capacity of a composition to cover a substrate for a given thickness. Thus, the greater the coverage of a composition, the more the film applied to the substrate, at a given thickness, will have the capacity to mask it.

[0032] Composition

[0033] The present invention therefore relates to a white-colored composition, having a clarity defined by a parameter L* greater than 85, comprising the mixture of at least two different white-colored compounds, of which at least one of the two compounds is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile.

[0034] Advantageously, the composition according to the invention has a clarity equivalent to that of TiO2.

[0035] The clarity of the composition according to the invention is evaluated by measuring the chromatic coordinate L* from the CIELAB chromatic space, generally called CIE 1976, using an integrating sphere spectrocolorimeter under D65 illumination.

[0036] Preferably, the composition according to the invention has a clarity greater than 85, in particular greater than 87, preferably greater than 90, even more preferably greater than 92.

[0037] Advantageously, the higher the clarity of the composition according to the invention, the whiter the composition.

[0038] According to another preferred embodiment, the composition according to the invention has a clarity greater than that of each of the compounds constituting the composition.

[0039] Advantageously, the selected compounds exhibit a synergistic effect on the parameter L* measured on a dark background, which is linked to the coverage.

[0040] The composition according to the invention advantageously retains its characteristics, in particular its clarity and its coverage, even after drying. After application, the composition according to the invention can form a dry film retaining its structural organization, in particular its coverage and its clarity.

[0041] The composition according to the invention preferably comprises a mixture of at least three white-colored compounds.

[0042] Advantageously, the composition according to the invention comprising 3 compounds has an improved L* clarity on a black background.

[0043] Preferably, the composition according to the invention also comprises, in addition to the compound selected from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile, at least one other different compound selected from calcium carbonate, quartz, zirconia, calcium silicate, barium sulfate, zinc oxide, zinc sulfide, mullite, clay, aluminum, starch, bromazolon, boron nitride, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, bismuth oxychloride, arginine, trioxide antimony, tourmaline, nitrile.

[0044] According to another embodiment, the composition according to the invention comprises the mixture of two white-colored compounds chosen from: - a Cl compound having a particle size range comprising a peak centered on a PI value corresponding to a DI diameter; and - a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml released by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles corresponds to each end of a square.

[0045] Preferably, the composition according to the invention comprises the mixture of three white-colored compounds chosen from: - a Cl compound having a particle size range comprising a peak centered on a PI value corresponding to a diameter Dl; - a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml freed by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles corresponds to each end of a square; and - a compound C3 having a particle size range comprising a peak centered on a value P3 corresponding to a diameter D3, such that D3 is equal to the maximum diameter of a particle in the inter-particle space M2 released by the presence of 2 particles of diameter D1 and one particle of diameter D2, juxtaposed so that the center of the 3 particles corresponds to each end of a triangle.

[0046] [Fig. 1] shows schematically all the components for precisely measuring the size of the particles relative to each other. The shape of the particles chosen in [Fig. 1] is for purely illustrative purposes and is in no way limiting of the scope of the invention.

[0047] Said particles may have a spherical, substantially spherical, elongated or fibrous shape, preferably the particles have a sens- possibly spherical.

[0048] The shape of the particles can be analyzed using a microscope, preferably using an electron microscope.

[0049] When several particle conformations are possible due to their particular shape, the shape allowing the smallest particle diameter to be obtained is chosen.

[0050] The size of the particles according to the invention is between 200nm and 15pm, preferably between 500nm and 8pm, even more preferably between 1 and 15pm.

[0051] The size of the particles according to the invention can be measured by different techniques such as sieving, micro-sieving, by light diffraction, by optical or electron microscopy, preferably the size of the particles is measured by electron microscopy.

[0052] The ratio of each of the compounds in the composition according to the invention, whatever its embodiment, is variable and adapted to obtain the characteristics of the composition.

[0053] According to another subject, the invention relates to a composition comprising the mixture of two white-colored compounds chosen from: - a Cl compound having a particle size range comprising a peak centered on a PI value corresponding to a DI diameter; and - a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml released by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles corresponds to each end of a square.

[0054] At least one of the compounds Cl or C2 is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile.

[0055] Preferably, in an alternative embodiment, the invention relates to a composition comprising the mixture of three white-colored compounds chosen from: - a Cl compound having a particle size range comprising a peak centered on a PI value corresponding to a diameter Dl; - a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml freed by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles corresponds to each end of a square; and - a compound C3 having a particle size range comprising a peak centered on a value P3 corresponding to a diameter D3, such that D3 is equal to the maximum diameter of a particle in the inter-particle space M2 released by the presence of 2 particles of diameter DI and one particle of diameter D2, juxtaposed so that the center of the 3 particles corresponds to each end of a triangle.

[0056] At least one of the compounds C1 to C3 is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile.

[0057] Preferably, in these embodiments, the composition has a clarity defined by a parameter L* greater than 85.

[0058] In these embodiments, the particles may have a spherical, substantially spherical, elongated or fibrous shape, preferably the particles have a substantially spherical shape.

[0059] When several particle conformations are possible due to their particular shape, the shape allowing the smallest particle diameter to be obtained is chosen.

[0060] The size of the particles according to the invention is between 200nm and 15pm, preferably between 500nm and 8pm, even more preferably between 1 and 15pm.

[0061] The size of the particles according to the invention can be analyzed by different techniques such as sieving, micro-sieving, by light diffraction, by optical or electronic microscopy.

[0062] In another alternative embodiment, the invention relates to a white-colored composition, having a clarity greater than that of each of the compounds constituting it, comprising the mixture of at least two different white-colored compounds, of which at least one of the two compounds is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile.

[0063] Method

[0064] Also, according to another aspect, the invention relates to a method for manufacturing a composition according to the invention comprising at least the implementation of the following steps: a. Selection of at least two compounds, b. Mixing of the compounds selected in step a) by successive addition c. Recovery of a white color composition, presenting a clarity defined by an L* parameter greater than 85.

[0065] The compounds of step a) are different compounds of white color: - of which at least one of the two compounds is chosen from calcium carbonate, quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline, nitrile, and / or, - the compounds of which are chosen from: * a Cl compound having a particle size range including a peak centered on a PI value corresponding to a DI diameter; and * a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space Ml freed by the presence of 4 particles of diameter Dl, juxtaposed so that the center of the 4 particles corresponds to each end of a square, and * possibly a compound C3 having a particle size range comprising a peak centered on a value P3 corresponding to a diameter D3, such that D3 is equal to the maximum diameter of a particle in the inter-particle space M2 freed by the presence of 2 particles of diameter D1 and one particle of diameter D2, juxtaposed so that the center of the 3 particles corresponds to each end of a triangle.

[0066] The mixing of step b) is carried out by convection, diffusion or mechanical dispersion, preferably the mixing of step b) is carried out using a powder mixer.

[0067] Advantageously, the powder mixer makes it possible to mix the composition according to the invention without causing the composition to crush on the walls.

[0068] Preferably, the mixing of step b) is carried out in a powder mixer at a speed of between 1 and 20 rpm, preferably between 1 and 10 rpm, even more preferably at 10 rpm.

[0069] Advantageously, the speed of the mixing in step b) makes it possible to obtain a homogeneous mixture.

[0070] 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.

[0071] According to a particularly preferred embodiment, the mixing of step b) is carried out using a powder mixer at a speed of 5 rpm for 2 hours.

[0072] Advantageously, the mixing of step b) makes it possible to obtain a homogeneous composition.

[0073] Thus, the method according to the invention makes it possible to obtain a color composition white, with a clarity defined by an L* parameter greater than 85.

[0074] Use

[0075] According to a final aspect, the invention relates to the use of a composition according to the invention in inks or paints.

[0076] Preferably, the composition according to the invention is particularly suitable for use in solvent-based paints or inks.

[0077] The composition according to the invention can be used in a paint chosen from the polyurethane, acrylic or epoxy family.

[0078] The composition according to the invention can also be used in an ink chosen from the family of epoxy, acrylic, solvent naphtha, nitrocellulose, alkyds, polyurethanes, polyamides, ketones or polyesters.

[0079] Advantageously, the composition according to the invention makes it possible to replace TiO2 while having a clarity parameter equivalent to that of TiO2. Examples

[0080] Example of composition according to the invention:

[0081] Example 1:

[0082] The composition of example 1 is obtained by implementing the manufacturing method according to the invention.

[0083] Composition 1 comprises a mixture of three compounds: - Zinc sulfide: 90g - Barium sulfate: 0.5g - Aluminum: 0.5g

[0084] The clarity L* of each compound and of the mixture of the three compounds is measured using an integrating sphere spectrocolorimeter under D65 illumination for a deposit made on a black background.

[0085] [Tables 1] Clarity L* Zinc sulfide 89.33 Barium sulfate 87.62 Aluminum 85.87 Mixture (90g / 9.5g / 0.5g) 92.6

[0086] It is noted that the combination of the three compounds generates a synergistic effect on the clarity of the composition according to the invention.

[0087] Example 2:

[0088] The composition of example 2 is obtained by implementing the manufacturing method according to the invention.

[0089]

[0090]

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[0098]

[0099] Composition 2 comprises a mixture of three compounds: - Zirconia: 1g - Bismuth oxychloride: 10g - Zinc sulfide: 89g The clarity L* of each compound and of the mixture of the three compounds is measured using an integrating sphere spectrocolorimeter under D65 illumination for a deposit made on a dark background. [Tables 2] Clarity L* Zirconia 78.37 Bismuth Oxychloride 85.42 Zinc Sulfide 89.33 Mixture (lg / 10g / 89g) 92.17 It is observed that the combination of the three compounds generates a synergistic effect on the clarity of the composition according to the invention. Example 3: The composition of example 3 is obtained by implementing the manufacturing method according to the invention. Composition 3 comprises a mixture of three compounds: - Zirconia: 0.5g - Barium sulfate: 0.5g - Zinc sulfide: 99g The clarity L* of each compound and of the mixture of the three compounds is measured using an integrating sphere spectrocolorimeter under D65 illumination for a deposit made on a dark background. [Tables 3] Clarity L* Zirconia 78.37 Barium sulfate 87.62 Zinc sulfide 89.33 Mixture (0.5g / 0.5g / 99g) 93.75 It is observed that the combination of the three compounds generates a synergistic effect on the clarity of the composition according to the invention. Examples of comparative tests: compositions including TIOrct compositions according to the invention

[0100] Example 4: Solvent-based ink composition

[0101] For this example, the solvent-based ink composition comprises either 20% TiO2 or 20% of the composition according to the invention from example 3.

[0102] After applying a 35pm film to application cards, the clarity is then measured on a black background and on a white background using an integrating sphere spectrocolorimeter under D65 illumination.

[0103] It is observed in [Fig.2] that the results are similar between the solvent-based ink composition comprising TiO2 and the solvent-based ink compositions comprising composition 3 (substitute 3) according to the invention.

[0104] Therefore, a composition according to the invention can effectively replace TiO2 in solvent-based inks.

[0105] Example 5: UV Ink Composition

[0106] For this example, the UV ink composition comprises either 20% TiO2 or 20% of the composition according to the invention from example 1

[0107] After applying a 35pm film to application cards, the clarity is then measured on a black background and on a white background using an integrating sphere spectrocolorimeter under D65 illumination.

[0108] It is observed in [Fig.3] that the results are similar between the UV ink composition comprising TiO2 and the UV ink composition comprising composition 1 (substitute 1) according to the invention.

[0109] Therefore, a composition according to the invention can effectively replace TiO2 in UV inks.

[0110] Example 6: Solvent-based paint composition

[0111] For this example, the solvent-based paint composition comprises either 20% TiO2 or 20% of the composition according to the invention from example 2.

[0112] After applying a 35pm film to application cards, the clarity is then measured on a black background and on a white background using an integrating sphere spectrocolorimeter under D65 illumination.

[0113] It is observed in [Fig.4] that the results are similar between the solvent-based paint composition comprising TiO2 and the solvent-based paint composition comprising composition 2 (substitute 2) according to the invention.

[0114] Therefore, the composition according to the invention can effectively replace TiO2 in solvent-based paints.

[0115] Example 7: Water-based paint composition

[0116] For this example, an aqueous paint composition comprises either 20% TiO2 or 20% of the composition according to the invention from Example 1.

[0117] After applying a 35pm film to application cards, clarity is then measured on a black background and on a white background using an integrating sphere spectrocolorimeter under D65 illumination.

[0118] It is observed in [Fig.5] that the results are similar between the aqueous paint composition comprising TiO2 and the aqueous paint composition comprising composition 1 (substitute 1) according to the invention.

[0119] Therefore, the composition according to the invention can effectively replace TiO2 in aqueous paints.

[0120] Example 8: Composition of commercial luminescent paint

[0121] For this example, a commercial luminescent paint composition (LuminoKrom®) comprises either 5% TiO2 or 5% of the composition according to the invention from example 3.

[0122] After applying a 500pm film to application cards, the clarity is then measured on a dark background using an integrating sphere spectrocolorimeter under D65 illumination.

[0123] It is observed in [Fig.6] that the results are similar between the commercial luminescent paint composition LuminoKrom® comprising TiO2 and the paint composition comprising composition 3 (substitute 3) according to the invention: the color measured using a spectrocolorimeter via the L*a*b* parameters is similar,

[0124] Furthermore, the use of a composition according to the invention has no significant impact on the parameters cited in standard EN1436 “Road marking products - Performance of markings applied to the road”, namely:

[0125] - Chromatic range to be respected

[0126] - SRT parameter which defines the adhesion value of a road marking on a roadway. This value is measured with an SRT pendulum and the minimum threshold defined by the standard is 0.45

[0127] - Luminance coefficient under diffuse lighting QD which defines daytime visibility of a marking as perceived by a user at a distance of 30 meters. This coefficient is measured with a reflectometer and the minimum threshold defined by the standard is 130.

[0128] It was also verified that the luminescence properties were not affected by the addition of the composition according to the invention in the luminescent paint.

[0129] The luminescence is measured using a luminance meter after excitation of the sample for 15 minutes under a D65 light cabin simulating the solar spectrum. A first measurement is taken after extinction of the excitation source (y0) and a second is taken after 10 minutes of decline (y600).

[0130] It is observed in [Fig.7] that the luminescence after 10 minutes of decline is not affected by the addition of composition 3 according to the invention in the luminous paint- nescent.

[0131] Therefore, the composition according to the invention can effectively replace TiO2 in luminescent paints.

[0132] Example of a method for manufacturing a composition according to the invention:

[0133] Example 9:

[0134] The manufacturing process comprises the implementation of the following steps: a. Selection of each compound, namely: - Zinc sulfide - Barium sulfate - Aluminum b. Mixing of the compounds selected in step a) by successive addition using a powder mixer at a speed of 5 rpm for 2 hours c. Recovery of a white color composition, presenting a clarity defined by an L* parameter greater than 85.

Claims

Claims

1. A white-colored composition having a clarity defined by an L* parameter measured on a black background using a spectrocolorimeter greater than 85, comprising a mixture of at least two different white-colored compounds, at least one of the two compounds being chosen from quartz, zirconia, calcium silicate, mullite, clay, aluminum, starch, bromazolon, cerium oxide, mica, lauroyl lysine, glucoraphanin, arbidol hydrochloride, arginine, antimony trioxide, tourmaline and nitrile, said composition not comprising titanium dioxide.

2. Composition according to one of the preceding claims, characterized in that it has a clarity defined by a parameter L* measured on a black background using a spectrocolorimeter greater than 87.

3. Composition according to one of the preceding claims, characterized in that it comprises the mixture of at least three white-colored compounds.

4. Composition according to one of the preceding claims, characterized in that it comprises at least one other compound chosen from calcium carbonate, quartz, zirconia, calcium silicate, barium sulfate, zinc oxide, zinc sulfide, mullite, clay, aluminum, starch, bromazolon, boron nitride, cerium oxide, mica, lauroyl lysine, alumina, glucoraphanin, arbidol hydrochloride, bismuth oxychloride, arginine, antimony trioxide, tourmaline, nitrile.

5. Composition according to claim 1 comprising the mixture of two white-colored compounds chosen from: - a compound C1 having a particle size range comprising a peak centered on a value P1 corresponding to a diameter D1, - a compound C2 having a particle size range comprising a peak centered on a value P2 corresponding to a diameter D2, such that D2 is equal to the maximum diameter of a particle in the inter-particle space M1 released by the presence of 4 particles of diameter D1, juxtaposed so that the center of the 4 particles corresponds to each end of a square.

6. Composition according to claim 5, comprising a white compound C3 having a particle size range comprising a peak centered on a value P3 corresponding to a diameter D3, such that so that D3 is equal to the maximum diameter of a particle in the inter-particle space M2 freed by the presence of 2 particles of diameter DI and one particle of diameter D2, juxtaposed so that the center of the 3 particles corresponds to each end of a triangle.

7. Use of a composition according to one of the preceding claims, in inks or paints.

8. Process for manufacturing a composition according to one of claims 1 to 7, characterized in that it comprises the following steps: a. Selection of each compound according to one of claims 1 to 7 b. Mixing of the compounds selected in step a) by successive addition c. Recovery of a white-colored composition having a clarity defined by a parameter L* greater than 85

9. Process for manufacturing a composition according to claim 9, characterized in that the mixing of step b) is carried out by mechanical dispersion.

10. Method of manufacturing a composition according to one of claims 9 and 10, characterized in that the mixing is carried out using a powder mixer at a speed of 10 rpm.

11. Process for manufacturing a composition according to one of claims 9 to 11, characterized in that the mixing of step b) is carried out for 1 to 10 hours.

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