Item, such as timepiece component, comprising substrate and visible light-absorbing coating

Abstract

To provide an item comprising a coating with very high light absorption, while avoiding the use of carbon nanotubes and / or graphene particles.SOLUTION: One aspect of the present invention relates to an item (10) including a substrate (1) and a multilayer coating (20) deposited on the substrate (1). The multilayer coating (20) being formed by combining a plurality of layers (21, 22, 23, 24) including a binder and pigments, the coating (20) including pigments of different particle sizes.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of surface treatment of articles such as components of ornaments and timepieces.

[0002] The present invention further relates to an article coated with a coating that absorbs visible light as described above, such as a component of a timepiece.

[0003] The present invention has particularly interesting applications in the field of portable timepieces for the decoration of components used in articles and timepieces. Such articles and components include, for example, plates, cocks, bridges, gear trains, screws, balance weights, dials, indices, decorations, aperture disks, hands, or any other arbitrary components of the movement and outer components of a timepiece.

Background Art

[0004] There are coatings that absorb visible light and have a light absorption rate exceeding 99.8%.

[0005] In particular, a carbon nanotube-based Vantablack® coating that is oriented perpendicular to the surface of the substrate and pressed against each other is known. Such a coating gives a black color with an absorption coefficient of 99.965% in visible light.

[0006] However, carbon nanotube-based coatings are very expensive and pose health risks. This is because such particles are known to have carcinogenic, mutagenic, or reproductive toxicity.

[0007] The easy-to-use and easy-to-apply Musou (registered trademark) acrylic paint has a maximum absorption rate of 99.4% for visible light and a luminance component L* close to 10. However, this coating has the characteristic of being very fragile, and just lightly touching this coating can easily cause the coating to peel off or the absorption rate to decrease. For example, when dust or fibers are deposited, it is very difficult to clean this type of coating without damaging the aesthetic appearance. Such paints are not easily available in the portable watch industry, etc.

[0008] As a result, it is necessary to improve such visible light absorbing coatings so that they can be handled without risk to health and without the risk of damage to the coating due to simple contact or handling of the article, for use on articles such as components of timepieces.

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of such a situation, an object of the present invention is to provide an article including a coating having a very high light absorption rate while avoiding the use of particles of carbon nanotubes and / or graphene.

Means for Solving the Problems

[0010] For this purpose, the present invention relates to an article including a substrate and a multilayer coating deposited on the substrate, the multilayer coating being formed by combining a plurality of layers including a binder and a pigment, and the multilayer coating including pigments having different particle sizes.

[0011] According to the present invention, an article coated with the visible light absorbing coating according to the present invention can provide a luminance component L* of less than 20 using various types of substrates.

[0012] In addition to the features described in the above paragraph, the article according to the present invention can have one or more of the following complementary features, considered individually or in any technically possible combination. - The multi-layer coating includes pigments at the nanometer level and pigments at the micrometer level. - The multi-layer coating includes glass beads. - The multi-layer coating includes a base layer that covers at least a part of the substrate, and the base layer includes a pigment with a d90 value being a dimension at the nanometer level. - The multi-layer coating includes a laminate of a plurality of overlapping sequential layers that cover at least a part of the base layer, and each of the sequential layers of the laminate includes a pigment having a d90 value different from the d90 value of the pigment in the lower layer. - Each of the sequential layers of the laminate includes a pigment having a d90 value larger than the d90 value of the pigment in the lower layer. - Each layer of the laminate includes a pigment with a d90 value of n·k / 10 μm, where k is a similarity coefficient between the d90 values of the pigments in two consecutive layers of the laminate. - The multi-layer coating includes a plurality of layers with different particle sizes, and these layers are arranged side by side, with each layer covering a predetermined part of the base layer. - The pigments in the plurality of layers covering the base layer are at the micrometer level in size. - The multi-layer coating includes a first layer that at least partially covers a first part of the base layer and a second layer that is arranged side by side with the first layer and at least partially covers a second part of the base layer different from the first part, and the pigment included in the second layer has a d90 value larger than the d90 value of the pigment in the first layer. - The multi-layer coating includes a first layer that covers at least a part of the base layer, and the first layer includes pigment aggregates composed of a mixture of pigments with different particle sizes. - The first layer includes pigment aggregates composed of a mixture of a pigment with a d90 value being a dimension at the nanometer level and a pigment with a d90 value being a dimension at the micrometer level. - The pigment aggregates in the first layer are composed of a central pigment with dimensions at the micrometer level and a plurality of pigments with dimensions at the nanometer level chemically grafted around the central pigment. - The binders in the plurality of layers of the multilayer coating are made of a polymer. - The binders in the plurality of layers of the multilayer coating are made of acrylic, epoxy polymer, or polyurethane. - The pigments in the plurality of layers of the multilayer coating are carbon black. - The multilayer coating has a luminance component L* of less than 20. - The article is a component of a timepiece.

[0013] The present invention further relates to a timepiece including such a component of a timepiece.

[0014] The objects, advantages, and features of the present invention can be further understood by reading the following detailed description while referring to the drawings.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0016] In this specification, the colorimetric properties of the light-absorbing coating obtained according to the method of depositing the coating according to the present invention are represented using the CIE L*a*b* color space, and for the polished sample, using a KONICA MINOLTA CM-3610-A spectrophotometer, the following parameters are used and measured according to the CIE 1976 standard. That is, the illumination source is CIE D65 (daylight 6500K), 10° inclination, SCI measurement (including specular reflection), and the measurement area is 4 mm in diameter.

[0017] The CIELAB color space (conforming to CIE standard No. 15, ISO 7724 / 1, DIN 5033 Teil 7, ASTM E-1164) has a luminance component L* representing the light reflectivity of the material, which is luminance, and in addition, there are an a* component that is a green / red component and an ab* component that is a blue / yellow component.

[0018] In the present application, the sizes of the particles and pigments are characterized in relation to the d90 value of the particle size distribution. In the particle size distribution, the use of the d90 value means that at least 90% of the particles or pigments in the total particles used are smaller than that d90 value.

[0019] First exemplary embodiment FIG. 1 shows a cross-sectional view of a first exemplary embodiment of an article 10 such as a component of a timepiece, including a substrate 1 and a visible light-absorbing coating 20 that covers at least a part of the substrate 1 using the deposition method 100 according to the present invention. Such a light-absorbing coating 20 according to the present invention preferably forms a multilayer structure including pigments with different particle sizes between the layers such that the particle size increases as the number of layers increases.

[0020] Preferably, the density of the pigments between the various layers of the coating 20 also varies such that it preferably decreases as the number of layers increases.

[0021] As an example, the article 10 is a component of a timepiece, such as a component of a movement for a timepiece or a component outside the timepiece, such as a plate, cock, wheel, screw, pendulum, dial, index, decoration, aperture disk, hand, or any other component or member, that does not reflect light and has a luminance component L* of less than 20 and is intended to give an impression of a deep and intense color.

[0022] FIG. 3 shows a timepiece 200 including the article 10 according to the present invention. In this exemplary embodiment, the article 10 according to the present invention is a dial.

[0023] The substrate 1 can have any property and can be made of, for example, metal, polymer, ceramics, or composite material.

[0024] The article 10 includes a heterogeneous coating 20 having a luminance component L* of less than 20 using various substrates. In comparison, a coating method using physical vapor deposition (PVD) of a homogeneous thin film cannot be used to create a coating having a luminance component L* of less than 20 due to the topology of the deposited layer. In the case of PVD, the luminance component L* of a matte coating is 25 to 30.

[0025] Thanks to the specific multilayer structure of the light-absorbing coating 20 according to the present invention, it is possible to avoid the reflection phenomenon on the visible surface of this coating. Also, thanks to this coating 20, it is possible to scatter light until it is trapped in the structure formed by the difference in the particle size of the pigments constituting this coating 20, maximizing light absorption.

[0026] The coating 20 includes an underlayer 21 that forms a base layer configured to cover the substrate 1 over at least a part of the substrate 1.

[0027] Preferably, the underlayer 21 completely covers at least one surface of the substrate 1.

[0028] This underlayer 21 has a thickness sufficient to ensure that the underlayer 21 is homogeneous and opaque and that optical disturbances from the substrate 1 are inactive. For example, the underlayer 21 has a thickness of 1 μm or more and less than 20 μm, more preferably 5 μm to 10 μm.

[0029] Preferably, the underlayer 21 is formed by depositing a first liquid mixture containing a binder, a pigment, and a solvent on the substrate 1. This solvent evaporates as the first liquid mixture dries, and the binder shrinks around the pigment to form the underlayer 21 of the coating 20.

[0030] For example, the underlayer is formed by depositing a first liquid mixture containing 30 to 40 wt% binder, 50 to 60 wt% solvent, and 5 to 10 wt% pigment.

[0031] For example, the underlayer is formed by depositing a first liquid mixture containing 30 wt% acrylic binder, 60 wt% solvent, and 10 wt% Emperor® 1600 carbon black pigment.

[0032] Optionally, the underlayer 21 can further contain a matting agent, such as nanosilica, to further enhance the strength of the coating 20.

[0033] Optionally, the underlayer 21 can further contain a dispersant to contribute to suspending the pigment in the liquid mixture.

[0034] Preferably, the binder of the underlayer 21 is a polymer, such as acrylic, epoxy polymer or polyurethane.

[0035] For example, the underlayer 21 is formed by applying a colored ink.

[0036] For example, the underlayer 21 is formed by applying a black ink containing a carbon black pigment.

[0037] The underlayer 21 is formed on the substrate 1 by performing sputtering, spraying, dipping, screen printing, printing, or pad printing of a first liquid mixture.

[0038] Preferably, the pigment in the underlayer 21 has a d90 value that is at the nanometer level of dimension, for example, 20 to 120 nm, and preferably less than 100 nm. Thus, the underlayer 21 is a homogeneous layer with low roughness.

[0039] The underlayer 21 is covered with a laminate 25 of a plurality of layers 22, 23, 24 that overlap each other, and the pigment contained in each layer of this laminate 25 has a d90 value different from the particle size of the pigment in the layer below it.

[0040] Preferably, the pigments contained in the laminate 25 are distributed such that the d90 value increases as it moves from the substrate side to the surface side of the coating 20. In this way, the pigment contained in each layer of the laminate 25 has a d90 value greater than the d90 value of the pigment in the layer below it.

[0041] Preferably, the pigment contained in each layer n of the laminate 25 has a d90 value of n·k / 10 μm. Here, k is the similarity coefficient between the d90 value of the pigment in the previously deposited layer n - 1 and the d90 value of the pigment in the layer n to be deposited, that is, between two consecutive layers of the laminate 25.

[0042] Preferably, the similarity coefficient is 5 to 1000.

[0043] In the exemplary embodiment shown in FIG. 1, the laminate 25 includes three sequentially deposited layers 22, 23, 24. Of course, the laminate 25 can include at least two sequential layers to form a specific structure of the laminate 25 that covers the underlayer 21, and can also include more than three sequential layers.

[0044] The pigment contained in the first layer 22 of the laminate 25 has a d90 value that is larger than the d90 value of the pigment in the base layer 21, for example, on the order of micrometers, less than 20 μm, and preferably 15 μm or less.

[0045] The second layer 23 of the laminate 25 that at least partially covers the first layer 22 of the laminate 25 contains a pigment having a d90 value on the order of, for example, 80 μm.

[0046] The third layer 24 of the laminate 25 that at least partially covers the second layer 23 of the laminate 25 contains a pigment having a d90 value on the order of, for example, 250 μm.

[0047] Each of the layers 22, 23, 24 is formed by sequential deposition of a liquid mixture containing a binder, a solvent, and a pigment, and the d90 values of the pigments in the different liquid mixtures vary according to the ratio so as to form various layers having a particle size distribution in which the particle size increases so that the roughness of the coating increases.

[0048] After applying each mixture by sputtering, spraying, dipping, screen printing, printing, or pad printing, the solvent evaporates, enabling polymerization and shrinkage of the binder around the pigment, thereby forming a solid layer that at least partially covers the underlying layer or base layer 21, and the new layer is rougher than the underlying layer.

[0049] Preferably, the properties of the binder and pigment in the various layers 22, 23, 24 of the laminate 25 are the same.

[0050] Optionally, the layers 22, 23, 24 of the laminate 25 can contain a matting agent, such as nanosilica, to further enhance the strength of the laminate 25, and more generally, the coating 20.

[0051] Optionally, the layers 22, 23, 24 of the laminate 25 can contain glass beads to further increase the roughness of the laminate 25. Preferably, the glass beads are used in the last layer of the laminate 25.

[0052] Optionally, the layers 22, 23, 24 of the laminate 25 can contain a dispersant to contribute to suspending the pigment in the first liquid mixture.

[0053] Preferably, the binder in the layers 22, 23, 24 forming the laminate 25 is made of a polymer, such as acrylic, epoxy polymer or polyurethane.

[0054] For example, the layers 22, 23, 24 forming the laminate 25 are formed by applying a colored ink.

[0055] Preferably, the nature of the binder, pigment and solvent used to form the layers of the laminate 25 is the same as that used to make the underlayer 21.

[0056] The nature of the pigment used to form the layers of the laminate 25 may be different from the nature of the pigment used to make the underlayer 21.

[0057] Preferably, the density of the pigment in the various layers 22, 23, 24 is different.

[0058] Preferably, the density of the pigment in the layers 22, 23, 24 of the laminate 25 decreases as the d90 value of the pigment increases in the layers 22, 23, 24.

[0059] For example, the first layer 22 of the laminate 25 is made from a liquid mixture containing 4 to 10% by weight, preferably 4 to 8% by weight, of pigment.

[0060] For example, the first layer 23 of the laminate 25 is made from a liquid mixture containing 4 to 10% by weight, preferably 4 to 8% by weight, of pigment.

[0061] For example, the third layer 24 of the laminate 25 is made from a liquid mixture containing 0.5 to 4% by weight, preferably 0.5 to 1% by weight, of pigment.

[0062] As an example, the base material is made of brass, forms, for example, a watch face, and the light-absorbing coating according to the present invention is applied thereto. The thickness of this brass base material is, for example, 0.27 mm.

[0063] The underlayer 21 is applied onto the brass base material by immersing it in a first liquid mixture containing 2 g of polyurethane resin (Berlacryl), 0.5 g of Emperor 1600 carbon black pigment, and 2.8 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0064] The first layer 22 of the laminate 25 is applied onto the underlayer 21 by immersing it in a second liquid mixture containing 2 g of polyurethane resin (Berlacryl), 0.3 g of Living Ink pigment, and 3.5 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0065] The second layer 23 of the laminate 25 is applied onto the first layer 22 by immersing it in a third liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.2 g of Norit A ultra E153 pigment, and 4 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0066] The third layer 24 of the laminate 25 is applied onto the second layer 23 by immersing it in a fourth liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.2 g of Norit SX super E153 carbon pigment, and 4 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0067] Such a coating 10 provides a brass watch face with a black surface coating and a luminance component L* of 15.9.

[0068] Second exemplary embodiment FIG. 2 schematically shows a cross-sectional view of a second exemplary embodiment of an article 10', such as a component of a timepiece, including a substrate 1 and a decorative coating 20 having the property of absorbing visible light.

[0069] Coating 20' covers at least a portion of substrate 1. In this second exemplary embodiment, the coating 20' according to the present invention forms a non-uniform structure composed of a plurality of regions with varying roughness, and different regions of this coating contain pigments with different particle sizes.

[0070] Preferably, the density of the pigment between the various regions of the coating 20' also varies, preferably decreasing as the size of the pigment increases.

[0071] As an example, the article 10' is, for example, a component of a timepiece such as a movement for a timepiece or an outer component of a timepiece, which does not reflect light, has a luminance component L* of less than 20, and is intended to give an impression of a deep and intense color, such as a plate, cock, wheel, screw, pendulum, dial, index, decoration, aperture disk, hand, or any other component or member.

[0072] Thanks to the specific multi-region structure of the coating 20' according to the present invention, it is possible to create patterns by varying different levels of absorption of visible light. Preferably, thanks to the specific multi-region structure of the coating 20' according to the present invention, it is possible to create a monochromatic pattern having different levels of absorption of visible light.

[0073] Coating 20' includes an underlayer 21 that forms a base layer configured to cover substrate 1 over at least a portion of substrate 1. This underlayer 21 is the same as the underlayer described above with reference to FIG. 1.

[0074] The multi-region structure of the coating 20' is formed by a plurality of juxtaposed layers that each cover a predetermined portion of the underlayer 21.

[0075] The underlayer 21 is covered by a first layer 22' in a first predetermined portion of the underlayer 21. The pigment contained in the first layer 22' has a d90 value greater than the d90 value of the pigment in the underlayer 21.

[0076] The underlayer 21 is further covered by a second layer 23' in a predetermined second portion of the underlayer 21, and this second portion is different from the first portion covered by the first layer 22'. This second portion may be arranged side by side with the first portion, or may not be arranged side by side.

[0077] The pigment contained in the second layer 23' has a d90 value greater than the d90 value of the pigment in the first layer 22.

[0078] The underlayer 21 can further be covered by other layers in various specific portions of the underlayer 21, thereby creating a specific pattern in which the level of light absorption varies according to the size of the pigment having specific optical characteristics and being used.

[0079] For the sake of explanation, in the exemplary embodiment shown in FIG. 2, there is a third layer 24' locally deposited on the underlayer 21 in a predetermined third portion. This third layer is different from the first portion covered by the first layer 22', and is also different from the second portion covered by the second layer 23'. This third portion can be arranged to be aligned with the first portion and / or the second portion. These various layers deposited on the underlayer 21 do not overlap with each other.

[0080] The pigment contained in the third layer 24' has a d90 value greater than the d90 value of the pigment in the second layer 23'.

[0081] As an example, the pigments in the layers 22', 23', 24' covering the underlayer 21 have dimensions at the micrometer level.

[0082] As an example, the pigment contained in the first layer 22’ has a d90 value that is on the order of micrometers, less than 20 μm, for example on the order of 15 μm.

[0083] As an example, the pigment contained in the second layer 23’ has a d90 value that is between 20 and 100 μm, preferably on the order of 80 μm.

[0084] As an example, the pigment contained in the third layer 24’ has a d90 value that is between 100 and 300 μm, preferably on the order of 250 μm.

[0085] Each of the layers 22’, 23’, 24’ that partially covers the underlying layer 21 is formed by depositing a liquid mixture through one or more masks deposited on the underlying layer 21 to mask specific regions and expose other regions intended to receive a layer having a predetermined particle size.

[0086] Each of the layers 22’, 23’, 24’ is formed by depositing a liquid mixture containing a binder, a solvent, and a pigment, and the d90 values of the pigments in those different liquid mixtures vary between the various layers.

[0087] Each of the layers 22’, 23’, 24’ that partially covers the underlying layer 21 is formed by depositing the liquid mixture by sputtering, spraying, dipping, screen printing, printing, or pad printing.

[0088] After each mixture is deposited on the underlying layer 21, the solvent evaporates, enabling the binder to polymerize and shrink around the pigment, thereby forming various layers having different particle sizes.

[0089] Preferably, the properties of the binder and pigment in the various layers 22’, 23’, 24’ are the same.

[0090] Optionally, the various layers of the coating 20 can include a matting agent, such as nanosilica, to further enhance the strength of the coating 20.

[0091] Optionally, the various layers of the coating 20 can include glass beads to further increase the roughness of the laminate.

[0092] Preferably, the binder in the various layers of the coating 20' is made of a polymer, such as acrylic, epoxy polymer or polyurethane.

[0093] For example, the various layers of the coating 20 are formed by applying a colored ink, such as a black ink containing carbon black.

[0094] Preferably, the properties of the binder and pigment in the various layers of the coating 20' are the same.

[0095] However, the pigments in the various layers of the coating 20' can have different properties between the various layers and compared to the pigments in the underlayer 21.

[0096] The density of the pigment between the various layers 22', 23', 24' preferably varies such that it decreases as the size of the pigment increases.

[0097] For example, the first layer 22' is made from a liquid mixture containing 4 - 10 wt%, preferably 4 - 8 wt%, of pigment.

[0098] For example, the second layer 23' is made from a liquid mixture containing 1 - 5 wt%, preferably 1 - 4 wt%, of pigment.

[0099] For example, the third layer 24' is made from a liquid mixture containing 0.5 - 4 wt%, preferably 0.5 - 1 wt%, of pigment.

[0100] As an example, the base material 1 is made of brass, forms, for example, a watch face, and the light-absorbing coating according to the present invention is applied thereto. The thickness of this brass base material 1 is, for example, 0.27 mm.

[0101] The underlayer 21 is applied onto the brass base material by immersing it in a first liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.5 g of Emperor 1600 carbon black pigment, and 2.8 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0102] The first layer 22’ is applied onto the underlayer 21 through a first selective mask by immersing it in a second liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.3 g of Living Ink pigment, and 3.5 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0103] The second layer 23’ is applied onto the underlayer 21 through a second selective mask by immersing it in a third liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.2 g of Norit A ultra E153 pigment, and 4 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0104] The third layer 24’ is applied onto the underlayer 21 through a third selective mask by immersing it in a fourth liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.2 g of Norit SX super E153 carbon pigment, 1.5 g of 90 - 150 μm glass melting spheres, and 4 g of Berlaflex diluent. This layer is dried for 20 minutes to evaporate the diluent.

[0105] Such a coating 10’ gives a brass watch face with a black surface coating and 16 luminance components L*.

[0106] Third exemplary embodiment FIG. 3 schematically shows a cross-sectional view of a third exemplary embodiment of an article 10", such as a component of a timepiece, including a substrate 1 and a decorative coating 20" having the property of absorbing visible light.

[0107] The coating 20" covers at least a part of the substrate 1. Such a coating 20" according to the present invention forms a non-uniform structure including pigment aggregates having different particle sizes. The coating 20" can include a plurality of stacked layers including such pigment aggregates.

[0108] Preferably, the density of the pigment aggregates between the various layers of the coating 20" also varies, preferably decreasing as the number of layers increases.

[0109] This third exemplary structure of the coating 20" is substantially the same as the structure of the coating 20 described with reference to FIG. 1, except that the layer includes an aggregate composed of a plurality of pigments having different particle sizes.

[0110] Due to the non-uniform structure of the coating 20", the reflection phenomenon on the visible surface of this coating is prevented. Also, due to this coating 20", it is possible to scatter light within a non-uniform structure created by separate pigment aggregates having different particle sizes and, optionally, by the change in the density of the aggregates between the various overlapping layers. As a result, as much light as possible is captured and the light absorption rate is increased.

[0111] The coating 20" includes an underlayer 21 that forms a base layer configured to cover the substrate 1 over at least a part of the substrate 1. This underlayer 21 is the same as the underlayer described above with reference to FIG. 1.

[0112] The underlayer 21 is at least partially covered by a first layer 22". This first layer 22" can form a part of a laminate 25 of a plurality of layers overlapping each other, and this laminate 25 at least partially covers the underlayer 21.

[0113] The first layer 22 is formed by depositing a formulation on the underlying layer 21, the formulation comprising a binder, pigment aggregates dispersed in the binder, a solvent, and a coupling agent.

[0114] After this formulation has been deposited on the underlying layer 21, the solvent evaporates and the binder shrinks around the pigment aggregates to create the first layer 22” of the coating 20”.

[0115] The first layer 22” is made up of a plurality of pigment aggregates constituted by a mixture of pigments with different particle sizes.

[0116] Preferably, the first layer 22” consists of pigment aggregates constituted by a mixture of a pigment with a d90 value in the nanometer range and a pigment with a d90 value in the micrometer range.

[0117] Preferably, the pigment aggregates of the first layer 22” are constituted by a central pigment with a dimension in the micrometer range and a plurality of pigments with dimensions in the nanometer range chemically grafted to this central pigment (by the coupling agent of the formulation), and these pigments in the nanometer range are bonded around the central pigment.

[0118] Thanks to the coupling agent, it becomes possible to generate strong chemical interactions between different pigments.

[0119] Optionally, the first layer 22” can include a matting agent, for example, nanosilica, to further enhance the strength of the coating 20”.

[0120] Preferably, the formulation for forming the first layer 22 contains 4 to 8 wt% pigment aggregates with respect to this formulation.

[0121] Preferably, the binder of the first layer 22” is made of a polymer, such as acrylic, epoxy polymer or polyurethane. For example, this binder is the same as the binder in the underlying layer 21.

[0122] For example, the first layer 22” is formed by applying a colored ink.

[0123] For example, the first layer 22” is formed by applying a black ink containing a carbon black pigment.

[0124] For example, the coupling agent for the formation of pigment aggregates in the formulation is a silane.

[0125] The first layer 22” is formed on the base layer 21 by performing sputtering, spraying, dipping, screen printing, printing, or pad printing of the formulation.

[0126] As shown in FIG. 3 as an example, the coating 20 can include a second layer 23” that at least partially covers the first layer 22”. The second layer 23” forms the second layer of the laminate 25, and this laminate 25 can include a plurality of layers.

[0127] Also, this second layer 23” is composed of a plurality of pigment aggregates constituted by a mixture of pigments having different particle sizes.

[0128] Preferably, the second layer 23” is composed of pigment aggregates constituted by a mixture of a pigment having a d90 value in the nanometer level dimension and a pigment having a d90 value in the micrometer level dimension.

[0129] Preferably, the pigment aggregates of the second layer 23” are composed of a central pigment having a dimension in the micrometer level and a plurality of pigments having a dimension in the nanometer level chemically grafted to this central pigment, and these pigments at the nanometer level are bonded around the central pigment.

[0130] Preferably, the d90 value of the pigment in the aggregates of the second layer 23” is the same as the d90 value of the pigment constituting the aggregates of the first layer 22”.

[0131] Optionally, the second layer 22” can include a matting agent, such as nanosilica, to further enhance the strength of the coating 20”.

[0132] Preferably, the formulation for forming the second layer 23” contains 1 - 4 wt% pigment based on this formulation.

[0133] Preferably, the weight percentage of aggregates in the second layer 23” is lower than that in the first layer 22”.

[0134] Preferably, the binder of the second layer 23” is made of a polymer, such as acrylic, epoxy polymer or polyurethane. Preferably, the binders in the various layers of the laminate 25 are of the same type.

[0135] For example, the second layer 23” is formed by applying a colored ink.

[0136] For example, the second layer 23” is formed by applying a black ink containing a carbon black pigment.

[0137] The second layer 23” is formed on the first layer 22” by performing sputtering, spraying, dipping, screen printing, printing or pad printing of the formulation.

[0138] As an example, the substrate 1 is made of brass and forms, for example, a watch face, onto which the light - absorbing coating 10” according to the present invention is applied. The thickness of this brass substrate is, for example, 0.27 mm.

[0139] The underlayer 21 is applied onto the brass substrate by dipping it into a first formulation consisting of 2 g of polyurethane resin (Berlacryl), 0.5 g of Emperor 1600 carbon black pigment, and 2.8 g of Berlaflex diluent. This first layer 21 is dried for 20 minutes to evaporate the diluent.

[0140] The pigment aggregates constituting the second solution are prepared in advance from an isopropyl alcohol solution containing 5% organosilane (e.g., methoxysilane) in which pigments of micrometer size and pigments of nanometer size are suspended. This solution is dried and the aggregates are recovered.

[0141] By immersing in a second formulation consisting of 2 g of polyurethane resin (Berlacryl), 0.3 g of aggregate powder, and 2.8 g of Berlaflex diluent, a first layer 22” of coating 20” is applied onto the base layer 21. This second layer 22 is dried for 20 minutes to evaporate the diluent.

[0142] Such a coating 20” results in a brass watch face with a black surface coating and 16 luminance components L*.

Explanation of Reference Numerals

[0143] 1 Substrate 10, 10’, 10” Articles 20, 20’, 20” Coatings 21 Base layer 22, 23, 24 Layers 25 Laminate 200 Timepiece

Claims

1. An article (10, 10', 10") comprising a substrate (1) and a multilayer coating (20, 20', 20") deposited on the substrate (1), said multilayer coating (20, 20', 20") is formed by combining a plurality of layers (21, 22, 22', 22", 23, 23', 23", 24, 24') containing a binder and a pigment; The multilayer coating (20, 20', 20") comprises pigments with different particle sizes and glass beads; the pigment in the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is carbon black; 1. An article (10, 10', 10") characterized by:

2. An article (10, 10', 10") comprising a substrate (1) and a multilayer coating (20, 20', 20") deposited on the substrate (1), said multilayer coating (20, 20', 20") is formed by combining a plurality of layers (21, 22, 22', 22", 23, 23', 23", 24, 24') containing a binder and a pigment; The multilayer coating (20, 20', 20") comprises pigments with different particle sizes, The multilayer coating (20, 20', 20") includes a base layer (21) covering at least a portion of the substrate (1), The multilayer coating (20) comprises a stack (25) of a plurality of overlapping, sequential layers (22, 23, 24) covering at least a portion of the base layer (21), each of the sequential layers (22, 23, 24) of the stack (25) comprising a pigment having a particle size distribution d90 value greater than the particle size distribution d90 value of the pigment in the layer below; the pigment in the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is carbon black; 1. An article (10, 10', 10") characterized by:

3. The multilayer coating (20, 20', 20") comprises pigments with a particle size distribution having a d90 value of 20 to 120 nanometers and pigments with a particle size distribution having a d90 value of less than 20 micrometers.

3. An article (10, 10', 10") according to claim 1 or 2.

4. The multilayer coating (20, 20', 20") includes a base layer (21) covering at least a portion of the substrate (1), The undercoat layer (21) contains a pigment having a particle size distribution d90 value of 20 to 120 nanometers.

3. An article (10, 10', 10") according to claim 1 or 2.

5. An article (10, 10', 10") comprising a substrate (1) and a multilayer coating (20, 20', 20") deposited on the substrate (1), said multilayer coating (20, 20', 20") is formed by combining a plurality of layers (21, 22, 22', 22", 23, 23', 23", 24, 24') containing a binder and a pigment; The multilayer coating (20, 20', 20") comprises pigments with different particle sizes, The multilayer coating (20, 20', 20") includes a base layer (21) covering at least a portion of the substrate (1), The multilayer coating (20') includes a plurality of layers (22', 23', 24') having different particle sizes; These layers are arranged side by side, each layer covering a predetermined portion of the base layer (21); the pigment in the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is carbon black; 1. An article (10, 10', 10") characterized by:

6. The pigments in the layers (22', 23', 24') covering the base layer (21) have particle size distributions with d90 values ​​of less than 20 micrometers, 20 to 100 micrometers, and 100 to 300 micrometers, respectively.

6. An article (10') according to claim 5.

7. The multilayer coating (20') includes a first layer (22') that at least partially covers a first portion of the base layer (21), and second layers (23', 24') that are arranged next to the first layer (22') and at least partially cover a second portion of the base layer (21) that is different from the first portion, The pigment contained in the second layer (23', 24') has a particle size distribution d90 value greater than the particle size distribution d90 value of the pigment in the first layer (22').

6. An article (10') according to claim 5.

8. The multilayer coating (20, 20', 20") includes a base layer (21) covering at least a portion of the substrate (1), The multilayer coating (20") includes a first layer (22") covering at least a portion of the base layer (21), The first layer (22") comprises pigment agglomerates made up of a mixture of pigments with different particle sizes.

6. An article (10") according to any one of claims 1, 2 and 5.

9. The pigment aggregate of the first layer (22") is composed of a central pigment and a plurality of pigments chemically grafted around the central pigment.

9. The article (10") of claim 8.

10. The binder of the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is a polymer.

10. An article (10, 10', 10") according to any one of claims 1, 2 and 5.

11. The binder of the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is made of acrylic, epoxy polymer or polyurethane.

11. An article (10, 10', 10") according to claim 10.

12. The multilayer coating (20, 20', 20") has a luminance component L* of less than 20.

10. An article (10, 10', 10") according to any one of claims 1, 2 and 5.

13. A component of a timepiece comprising a substrate (1) and a multilayer coating (20, 20', 20") deposited on the substrate (1), said multilayer coating (20, 20', 20") is formed by combining a plurality of layers (21, 22, 22', 22", 23, 23', 23", 24, 24') containing a binder and a pigment; The multilayer coating (20, 20', 20") comprises pigments with different particle sizes, the pigment in the layers (21, 22, 22', 22", 23, 23', 23", 24, 24') of the multilayer coating (20, 20', 20") is carbon black; 1. A timepiece component comprising:

14. 14. A timepiece comprising a component according to claim 13. A timer (200) characterized by:

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