A method for depositing a coating on a substrate that at least partially covers visible light.

Abstract

To provide a method for depositing a coating with at least locally high light absorption on a substrate while avoiding the use of carbon nanotubes and / or graphene particles.SOLUTION: There is provided a method for depositing a coating 20 on a substrate 1, the method comprising: a first step of supplying a substrate; a second step of depositing a first layer 21 formed by depositing a first liquid mixture comprising a binder, a solvent and pigments with a d90 value of nanometric dimension to cover at least a portion of the substrate through evaporation of the solvent; a third step of depositing a second layer 22 formed by depositing a second liquid mixture comprising pigments with a d90 value greater than that of the pigments in the first layer to cover a first portion of the first layer; a fourth step of depositing a third layer 23 formed by depositing a third liquid mixture comprising pigments with a d90 value greater than that of the pigments in the second layer to cover a second portion of the first layer.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 particularly relates to a method of depositing a decorative coating having optical properties that absorb visible light.

[0003] The present invention further relates to an article coated with a decorative coating that absorbs visible light as described above, such as a component of a timepiece.

[0004] 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, gear trains, screws, pendulums, dials, indexes, decorations, aperture disks, hands, or any other arbitrary components of the movement and outer components of a timepiece.

Background Art

[0005] There are coatings that absorb visible light and have a light absorption rate exceeding 99.8%.

[0006] Particularly, a carbon nanotube-based Vantablack (registered trademark) coating that is oriented perpendicular to the surface of a substrate and pressed against each other is known. Such a coating gives a black color having an absorption coefficient of 99.965% in visible light.

[0007] 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.

[0008] Musou® acrylic paint, known for its ease of use and application, boasts a maximum absorption rate of 99.4% for visible light and a luminance component L* close to 10. However, this coating is extremely fragile; even a light touch can easily cause it to peel or reduce its absorption rate. For example, if dust or fibers accumulate, it is very difficult to clean this type of coating without compromising its aesthetic appearance. Such paints are not readily available in industries such as the portable watch industry.

[0009] As a result, there is a need to improve such visible light-absorbing coatings so that they can be used on items, such as components of timekeeping devices, without health risks and without the risk of the coating being damaged by simple contact or handling of the item. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] In view of these circumstances, the present invention aims to provide an article comprising a coating having a high light absorption rate at least locally, while avoiding the use of carbon nanotubes and / or graphene particles. [Means for solving the problem]

[0011] For this purpose, the present invention relates to a method for depositing a coating on a substrate that at least partially absorbs visible light in order to form an article such as a component of a timekeeping device, the method being The first step is to prepare the base material, A second step involves depositing a first liquid mixture comprising a binder, a solvent, and a pigment having a d90 value at the nanometer level, thereby depositing a first layer that covers at least a portion of the substrate and is formed by the evaporation of the solvent. A third step involves depositing a second liquid mixture comprising a binder, a solvent, and a pigment whose d90 value is greater than the d90 value of the pigment in the first layer, thereby depositing a second layer that covers a first portion of the first layer and is formed by the evaporation of the solvent. The process includes a fourth step of depositing a third liquid mixture comprising a binder, a solvent, and a pigment whose d90 value is greater than the d90 value of the pigment in the second layer, thereby covering a second portion of the first layer and depositing a third layer formed by the evaporation of the solvent.

[0012] One object of the present invention is to provide a method for depositing decorative coatings having different levels of visible light absorption, which is easy to implement, and which can be used to create decorative coatings with a luminance component L* of less than 20 using various substrates.

[0013] Preferably, the second step of depositing a second layer and / or the third step of depositing a third layer include a substep of placing a selectivity mask on the first layer to select at least a portion of the first layer to be covered, before depositing the corresponding liquid mixture.

[0014] Preferably, the first liquid mixture forming the first layer of the coating contains 5 to 10% by weight of pigment.

[0015] Preferably, the second liquid mixture forming the second layer and the third liquid mixture forming the third layer each contain 4 to 10% by weight, preferably 4 to 8% by weight, of a pigment and 1 to 5% by weight, preferably 1 to 4% by weight, of a pigment.

[0016] Preferably, the deposition method further includes a fifth step of deposition of a fourth liquid mixture comprising a binder, a solvent, and a pigment whose d90 value is greater than the d90 value of the pigment in the third layer, thereby depositing a fourth layer which covers a third portion of the first layer that is different from the first portion covered by the second layer and different from the second portion covered by the third layer, and which is formed by the evaporation of the solvent.

[0017] Preferably, the fourth liquid mixture forming the fourth layer contains 0.5 to 5% by weight, preferably 0.5 to 4% by weight, and more preferably 0.5 to 1% by weight of pigment.

[0018] Preferably, some of the layers of the coating are deposited by sputtering, spraying, dipping, screen printing, printing, or pad printing.

[0019] Preferably, some of the liquid mixtures deposited to form some of the layers of the coating include a binder, a solvent, a pigment, and optionally a matting agent, a glass coating, etc. beads , and / or a dispersant.

[0020] Preferably, the binder is a polymer.

[0021] Preferably, the binder is made of acrylic, epoxy polymer, or polyurethane.

[0022] Preferably, some of the liquid mixtures deposited to form some of the layers of the coating are colored inks.

[0023] The present invention further relates to an article comprising a substrate and a coating deposited by a method according to the present invention.

[0024] Therefore, such articles include light-absorbing surface coatings in which the luminance component L* is less than 20.

[0025] Preferably, the article is a component of a timepiece.

[0026] The present invention further relates to a timepiece including such a component of a timepiece.

[0027] 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

[0028] [Figure 1] A cross-sectional view of an article such as a component of a timepiece is schematically shown, including a substrate and a coating that at least partially absorbs visible light according to the present invention. [Figure 2] Some of the main sequential steps of an implementation example of a method for making an article such as a component of a timepiece by depositing a coating that at least partially absorbs visible light on a substrate according to the present invention are shown. [Figure 3] One exemplary embodiment of an article according to the present invention is shown.

Modes for Carrying Out the Invention

[0029] 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 a 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 a diameter of 4 mm.

[0030] 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 a material, which is luminance, and in addition, there are an a* component that is a green / red component and a b* component that is a blue / yellow component.

[0031] In this application, particle and pigment sizes 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 their d90 value.

[0032] Figure 1 schematically shows a cross-sectional view of an article 10, such as a component of a timekeeping device, which includes a base material 1 and a decorative coating 20 having the property of absorbing visible light.

[0033] The coating 20 covers at least a portion of the substrate 1. Such a coating 20 according to the present invention forms a non-homogeneous structure composed of multiple regions of varying roughness, where different regions of the coating contain pigments of different particle sizes.

[0034] Preferably, the density of the pigment between different regions of the coating 20 also changes, preferably decreasing as the size of the pigment increases.

[0035] For example, article 10 is a component of a timepiece that does not reflect light, has a luminance component L* of less than 20, and is intended to give the impression of a deep, high-intensity color, such as a timepiece movement or an external component of a timepiece, such as a plate, cock, bridge, wheel, screw, oscillating weight, dial, index, decoration, aperture disc, hands, or any other component or member.

[0036] Figure 3 shows a timer 200 including article 10 according to the present invention. In this exemplary embodiment, article 10 according to the present invention is a display panel.

[0037] The base material 1 can have any properties and can be made of, for example, metal, polymer, ceramic, or composite material.

[0038] The method according to the present invention can be used to obtain an article 10 containing a coating 20 having a luminance component L* of less than 20 using various substrates. In comparison, coating methods using physical vapor deposition (PVD) cannot be used to produce a coating with 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.

[0039] Thanks to the specific multi-region structure of the coating 20 according to the present invention, it becomes possible to create patterns by changing different levels of visible light absorption. Preferably, thanks to the multi-region structure of the coating 20 according to the present invention, it becomes possible to create monochrome patterns having different levels of visible light absorption.

[0040] The coating 20 includes a first layer 21 that forms a base layer, configured to cover at least a portion of the substrate 1.

[0041] Preferably, the first layer 21 completely covers at least one surface of the substrate 1.

[0042] The first layer 21 has sufficient thickness to ensure that the underlying layer 21 is homogeneous and opaque and that optical disturbances from the substrate 1 are not active. For example, the first layer 21 has a thickness of 1 μm or more and less than 20 μm, and more preferably 5 μm to 10 μm.

[0043] Preferably, the first layer 21 is formed by depositing a first liquid mixture containing a binder, a pigment, and a solvent onto the substrate 1.

[0044] For example, this underlayer is formed by depositing a first liquid mixture containing 30-40% by weight of a binder, 50-60% by weight of a solvent, and 5-10% by weight of a pigment.

[0045] For example, this underlayer is formed by depositing a first liquid mixture containing 30% by weight of an acrylic binder, 60% by weight of a solvent, and 10% by weight of Emperor® 1600 carbon black pigment.

[0046] Optionally, the first liquid mixture may further contain a matting agent, such as nanosilica, to make the strength of the coating 20 more noticeable.

[0047] Optionally, the first liquid mixture may further include a dispersant that contributes to suspending the pigment in the liquid mixture.

[0048] Preferably, the binder in the first liquid mixture forming the first layer 21 is made of a polymer, such as an acrylic, epoxy polymer, or polyurethane.

[0049] For example, the first liquid mixture is colored ink.

[0050] For example, the first liquid mixture is a black ink containing carbon black pigment.

[0051] The first liquid mixture is applied to the substrate 1 by, for example, sputtering, spraying, dipping, screen printing, printing, or pad printing.

[0052] When the liquid mixture is applied to the substrate 1, the solvent evaporates and the binder shrinks around the pigment, thereby forming the first layer 21 of the coating 20.

[0053] Preferably, the pigment in the first layer 21 has a d90 value at the nanometer level, for example, 20 to 120 nm, and preferably less than 100 nm. In this way, the base layer 21 is a homogeneous layer with low roughness.

[0054] The multi-region structure of the coating 20 is formed by a plurality of adjacent layers, each covering a predetermined portion of the first layer 21.

[0055] As shown in Figure 1, the first layer 21 is covered by the second layer 22 in a predetermined portion of the first layer 21. The pigment contained in the second layer has a d90 value greater than the d90 value of the pigment in the first layer 21.

[0056] The first layer 21 is further covered by a third layer 23 in a predetermined second portion of the first layer 21, and this second portion is different from the first portion covered by the second layer 22. This second portion may be arranged alongside the first portion, or it may not be arranged alongside it.

[0057] The pigment in the third layer 23 has a d90 value greater than the d90 value of the pigment in the second layer 22.

[0058] The first layer 21 can also be covered by other layers in various specific parts of the first layer 21, thereby creating a specific pattern with certain optical characteristics in which the level of light absorption changes depending on the size of the pigment used.

[0059] For illustrative purposes, the exemplary embodiment shown in Figure 1 includes a fourth layer 24 locally deposited on the first layer 21 in a predetermined third portion. This third portion differs from the first portion covered by the second layer 22, and also differs from the second portion covered by the third layer 23. This third portion can be positioned adjacent to the first and / or second portions. These various layers deposited on the first layer 21 do not overlap each other.

[0060] The pigment in the fourth layer 24 has a d90 value greater than the d90 value of the pigment in the third layer 23.

[0061] For example, the pigments in layers 22, 23, and 24 covering the first layer 21 have dimensions on the micrometer level.

[0062] For example, the pigments contained in the second layer 22 have a d90 value that is on the micrometer level, less than 20 μm, and on the order of, for example, 15 μm.

[0063] For example, the pigment contained in the third layer 23 has a d90 value of 20 to 100 μm, preferably on the order of 80 μm.

[0064] For example, the pigment contained in the fourth layer 24 has a d90 value of 100 to 300 μm, preferably on the order of 250 μm.

[0065] Each of the layers 22, 23, and 24 that partially cover the first layer 21 is formed by depositing a liquid mixture through one or more masks deposited on the first layer 21, thereby masking a specific area and exposing other areas intended to receive a layer having a predetermined particle size.

[0066] Each of the layers 22, 23, and 24 that partially cover the first layer 21 is formed by depositing a liquid mixture containing a binder, a solvent, and a pigment, and the d90 value of the pigment in these different liquid mixtures varies between the different layers.

[0067] Each of the layers 22, 23, and 24 that partially cover the first layer 21 is formed by depositing a liquid mixture by sputtering, spraying, dipping, screen printing, printing, or pad printing.

[0068] After each mixture is deposited on the first layer 21, the solvent evaporates, allowing the binder to polymerize and shrink around the pigment, thereby forming various layers with different particle sizes.

[0069] Preferably, the binder, pigment, and solvent used to form the liquid mixture for depositing the various layers 22, 23, and 24 have the same properties.

[0070] Optionally, the liquid mixture for forming various layers of coating 20 may include a matting agent, such as nanosilica, to further enhance the strength of coating 20.

[0071] Optionally, the liquid mixture used to form various layers of coating 20 may include a dispersant that contributes to suspending the pigment in the first liquid mixture.

[0072] Optionally, the liquid mixture used to form the laminate 25 may be glass to further increase the roughness of the laminate. beads It can include...

[0073] Preferably, the binder in the liquid mixture forming the various layers of the coating 20 is made of a polymer, such as acrylic, epoxy polymer, or polyurethane.

[0074] For example, the liquid mixture that forms the various layers of the coating 20 is a colored ink, such as black ink containing carbon black as a pigment.

[0075] Preferably, the properties of the binder, pigment, and solvent used to form the various layers of the coating 20 are the same.

[0076] However, the pigments used to form the various layers of the coating 20 may have different properties between the different layers and compared to the pigment used to form the first layer 21.

[0077] Preferably, the pigment content in the liquid mixture forming the various layers 22, 23, and 24 deposited on the first layer 21 is 5 to 10% by weight. Preferably, the pigment content in the liquid mixture is higher as the d90 value of the pigment decreases.

[0078] For example, the second layer 22 is made from a liquid mixture containing 4-10% by weight, preferably 4-8% by weight, of pigment.

[0079] For example, the third layer 23 is made from a liquid mixture containing 1 to 5% by weight, preferably 1 to 4% by weight, of pigment.

[0080] For example, the fourth layer 24 is made from a liquid mixture containing 0.5 to 4% by weight, preferably 0.5 to 1% by weight, of pigment.

[0081] Figure 2 shows some of the main steps in a method 100 for depositing a coating 20 that at least partially absorbs visible light on a substrate 1 according to the present invention.

[0082] The deposition method 100 according to the present invention includes a first step 110 of preparing a substrate 1.

[0083] The deposition method 100 according to the present invention includes a second step 120 of depositing a first layer 21 called a base layer that covers at least a portion of a substrate 1. This second deposition step 120 is carried out by sputtering, spraying, dipping, screen printing, printing or pad printing of a first liquid mixture comprising a binder, a solvent, and 5 to 10% by weight of a pigment having a d90 value at the nanometer level, for example, less than 100 nm.

[0084] Step 120 for depositing this first layer 21 includes a substep of evaporating the solvent from the liquid mixture applied to the substrate 1 to shrink the binder around the pigment and form the first layer 21 of the coating 20.

[0085] The deposition method 100 further includes a third step 130 of depositing a second layer 22 that covers a first portion of the previously deposited first layer 21. The particle size of this second layer 22 is different from that of the first layer 21. In particular, the pigments contained in this second layer have a d90 value greater than the d90 value of the pigments in the first layer 21.

[0086] This second layer 22 is deposited by sputtering, spraying, dipping, screen printing, printing, or pad printing of a second liquid mixture containing a binder, a solvent, and 4-10% by weight of pigment.

[0087] Preferably, the second liquid mixture for depositing the second layer 22 contains 4-8% by weight of pigment.

[0088] This third step 130 includes a first substep of placing a mask on the first layer 21 so as to select an area of ​​the first layer 21 that will be covered by the second layer 22.

[0089] This third step 130 includes a second substep of selectively evaporating the solvent from the second liquid mixture applied to the first layer 21 to shrink the binder around the pigment and form the second layer 21 of the coating 20 on top of the first layer 21.

[0090] The deposition method 100 further includes a fourth step 140 of depositing a third layer 23 covering a second portion of the first layer 21, which is a different portion from the first portion selected to receive the second layer 22. The particle size of this third layer 23 is different from that of the second layer 22. In particular, the pigments contained in this third layer 23 have a d90 value greater than the d90 value of the pigments in the second layer 22.

[0091] Furthermore, this third layer 23 is deposited by sputtering, spraying, dipping, screen printing, printing, or pad printing of a third liquid mixture containing a binder, a solvent, and 1-5% by weight of pigment.

[0092] Preferably, the third liquid mixture for depositing the third layer 23 contains 1 to 4% by weight of pigment.

[0093] This fourth step 140 includes a first substep of placing a mask on the first layer 21 so as to select an area of ​​the first layer 21 that will be covered by the third layer 23.

[0094] This fourth step 140 includes a second substep of selectively evaporating the solvent from the third liquid mixture applied to the first layer 21 to shrink the binder around the pigment and form a third layer 23 of the coating 20 on the first layer 21.

[0095] As illustrated as an example, the deposition method 100 further includes a fifth step 140 of depositing a fourth layer 24 that covers a third portion of the first layer 21, which is a different portion from the first portion previously selected to receive the second layer 22 and the third layer 23. The particle size of this fourth layer 24 is different from that of the third layer 23. In particular, the pigments contained in this fourth layer 24 have a d90 value greater than the d90 value of the pigments in the third layer 22.

[0096] Furthermore, this fourth layer 24 is deposited by sputtering, spraying, dipping, screen printing, printing, or pad printing of a fourth liquid mixture containing a binder, a solvent, and 0.5 to 5% by weight of pigment.

[0097] Preferably, the fourth liquid mixture for depositing the fourth layer 24 contains 0.5 to 4% by weight of pigment.

[0098] This fifth step 150 includes a first substep of placing a mask on the first layer 21 so as to select an area of ​​the first layer 21 that will be covered by the fourth layer 24.

[0099] This fifth step 150 includes a second substep in which the solvent is selectively evaporated from the fourth liquid mixture applied to the first layer 21 to shrink the binder around the pigment and form a fourth layer 24 of the coating 20 on the first layer 21.

[0100] Naturally, this deposition method 100 may include other steps of depositing additional layers depending on the desired pattern and properties of the coating 20.

[0101] According to a first exemplary embodiment of the present invention, a brass substrate is used, for example, to form a surface plate, and a light-absorbing coating according to the present invention is applied thereto.

[0102] The thickness of this brass base material is, for example, 0.27 mm.

[0103] A first layer 21 is applied to a brass substrate by immersion 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.

[0104] The second layer 22 is applied to the first layer 21 through a first selective mask by immersion in a second liquid mixture consisting of 2 g of polyurethane resin (Berlacryl), 0.3 g of Emperor 1600 carbon black pigment, and 3.5 g of Berlaflex diluent. The layer is allowed to dry for 20 minutes to evaporate the diluent.

[0105] The third layer 23 is applied to the first layer 21 through a second selective mask by immersion 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 allowed to dry for 20 minutes to evaporate the diluent.

[0106] 2g polyurethane resin (Berlacryl), 0.2g Norit SX super E153 pigment, 1.5g 90-150μm glass beads The fourth layer 24 is applied to the first layer 21 through a third selective mask by immersion in a fourth liquid mixture consisting of 4 g of Berlaflex diluent. The layer is allowed to dry for 20 minutes to evaporate the diluent.

[0107] This coating provides a brass surface plate with a black surface coating and a luminance component L* of 16. [Explanation of Symbols]

[0108] 1 Base material 10 Goods 20 Covering 21. The first layer 22. Second Layer 23. The third layer 24. The fourth layer 200 clock

Claims

1. A method (100) for depositing a coating (20) that at least partially absorbs visible light onto a substrate (1) in order to form an article (10) such as a component of a timer, wherein the method (100) The first step (110) is to prepare the base material (1), A second step (120) involves depositing a first liquid mixture comprising a binder, a solvent, and a pigment having a particle size distribution d90 value of 20 to 120 nm, thereby depositing a first layer (21) that covers at least a portion of the substrate (1) and is formed by the evaporation of the solvent. A third step (130) involves depositing a second liquid mixture comprising a binder, a solvent, and a pigment whose particle size distribution d90 value is greater than that of the pigment in the first layer (21), thereby depositing a second layer (22) that covers a first portion of the first layer (21) and is formed by the evaporation of the solvent. The fourth step (140) includes depositing a third liquid mixture comprising a binder, a solvent, and a pigment whose d90 particle size distribution value is greater than the d90 particle size distribution value of the pigment in the second layer (22), thereby depositing a third layer (23) formed by evaporation of the solvent, which covers a second portion of the first layer (21) that is different from the first portion covered by the second layer (22), The pigment in the first layer (21) is a carbon black pigment. A method characterized by (100).

2. A third step (130) for depositing a second layer (22) and / or a fourth step (140) for depositing a third layer (23) includes a substep of placing a selectivity mask on the first layer (21) to select at least a portion of the first layer (21) to be covered, before depositing the corresponding liquid mixture. The method according to claim 1 (100).

3. The first liquid mixture forming the first layer (21) of the coating (20) contains 5 to 10% by weight of pigment. The method according to claim 1 (100).

4. The second liquid mixture forming the second layer (22) contains 4 to 10% by weight of pigment. The method according to claim 1 (100).

5. The third liquid mixture forming the third layer (23) contains 1 to 5% by weight of pigment. The method according to claim 1 (100).

6. Furthermore, the fifth step (150) includes depositing a fourth liquid mixture comprising a binder, a solvent, and a pigment whose d90 particle size distribution is greater than the d90 particle size distribution of the pigment in the third layer (23), thereby depositing a fourth layer (24) which covers the third portion of the first layer (21) that is different from the first portion covered by the second layer (22) and the second portion covered by the third layer (23), and which is formed by the evaporation of the solvent. The method according to claim 1 (100).

7. The fourth liquid mixture forming the fourth layer (24) contains 0.5 to 5% by weight of pigment. The method according to 6 (100), characterized by the features of 6.

8. Each of the layers (21, 22, 23, 24) of the coating (20) is deposited by sputtering, spraying, dipping, screen printing, printing, or pad printing. The method according to claim 1 (100).

9. Each of the liquid mixtures deposited to form each of the layers (21, 22, 23, 24) of the coating (20) comprises a binder, a solvent, a pigment, and optionally a matting agent, glass beads, and / or a dispersant. The method according to claim 1 (100).

10. The binder is a polymer. The method according to 9 (100), characterized by the features of 9.

11. The binder is acrylic, epoxy polymer, or polyurethane. The method according to 10, characterized by (100).

12. Each of the liquid mixtures deposited to form each of the layers (21, 22, 23, 24) of the coating (20) is a colored ink. The method according to claim 1 (100).

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