CN113549872B

CN113549872B - black coating

Info

Publication number: CN113549872B
Application number: CN202110370178.5A
Authority: CN
Inventors: 唐智
Original assignee: Nafeng Vacuum Coating Shanghai Co ltd
Current assignee: Nafeng Vacuum Coating Shanghai Co ltd
Priority date: 2020-04-07
Filing date: 2021-04-06
Publication date: 2023-11-17
Anticipated expiration: 2041-04-06
Also published as: CN113549872A

Abstract

The present invention provides a substrate having a very dark or black coating comprising a substrate having a coating applied thereto, said coating comprising in order the following parallel layers: a first functional layer adjacent to the substrate, and a second functional layer, wherein the first functional layer has a dark appearance, and wherein the second functional layer has a thickness less than the wavelength of visible light. The invention also provides a method of preparing the coated substrate and a product comprising the coated substrate.

Description

Black coating

Technical Field

The present invention relates to very dark or black coatings on substrates, to methods of making the coatings, and methods of use.

Background

A number of deposition techniques are used to coat the substrate. Vapor deposition techniques are commonly used to form thin film deposited layers in a variety of applications, including microelectronics and high frequency of use product applications. Such deposition techniques can be divided into two broad categories, the first category being known as Chemical Vapor Deposition (CVD), which generally refers to deposition processes that occur as a result of chemical reactions. Common CVD processes include semiconductor silicon layer deposition, epitaxy, and thermal oxidation.

The second type of deposition technique is commonly referred to as Physical Vapor Deposition (PVD). PVD generally refers to the deposition of solid matter due to a physical reaction. The main concept of PVD processes is that the deposited material is transferred to the substrate surface by direct physical means. Typically, no chemical reaction occurs during this process, and the deposited layer thickness is independent of the kinetics of the chemical reaction.

Sputtering is a known PVD technique that deposits elements or compounds onto a substrate, wherein atoms, ions or molecules are sputtered from a target material (also referred to as a sputter target) by particle bombardment, such that the sputtered atoms or molecules deposit as a thin film on the substrate surface.

Many consumer products require very dark or black coatings. Such coatings are known to contain carbon, for example, some metal carbides, however, carbon-containing coatings may not be used for all materials. If some metals, including zinc, magnesium, aluminum and alloys thereof, are combined with carbon, a battery effect can occur, resulting in accelerated corrosion of the metal substrate. Thus, these materials cannot be coated with carbon-containing coatings on their surfaces, even though these materials are very dark colors that are commonly used, or even preferred, in certain manufacturing industries.

However, the aesthetic need for very dark or black coatings remains great in the industry.

It is therefore an object of the present invention to provide very dark or black coatings, especially some consumer products that have the appearance of very dark or black coatings. It is another object of particular examples to provide such coatings that are optimized to address and/or overcome one or more of the problems described above. The object of a particular example is to provide a very dark or black interference coating.

Disclosure of Invention

Accordingly, the present invention provides a coated substrate comprising a substrate to which a coating is applied, the coating comprising, in order, the following basic coatings: a first functional layer adjacent to the substrate, and a second functional layer, wherein the first functional layer has a very dark appearance, and wherein the second functional layer has a thickness that is less than the wavelength of visible light.

Advantageously, the addition of the second functional layer makes the coating appear darker (darker) than the first functional layer. Optionally, a third transparent functional layer is provided to protect the coating.

The invention also provides a method of providing a very dark or black coating on a substrate comprising the successive deposition of a first functional layer and a second functional layer of the coating according to the invention and, in the present case, a third layer and any further functional layers. Further functional layers may be located between the second and third functional layers. Further functional layers may be located in a third functional layer, such as a scratch resistant layer and/or a non-reflective layer.

In addition, products comprising the coatings of the present invention are provided. Examples of products include, in particular, moulded products, but also products made of materials which have not been able to be easily coated with carbon-containing coatings to date, such as zinc, magnesium, aluminium and alloys thereof. Further provided are specific products, such as consumer medical devices, e.g., shavers, and portions thereof that include the coatings of the present invention. In one particular product, the razor handle is die cast from zinc and coated with the black coating of the present invention.

Detailed Description

The preferred first functional layer of the present invention is visually very dark or black. The first functional layer has specific L, a and b values to provide a very dark or black base color to the coating.

Suitably, the first functional layer has an L value of 55 or less, preferably 50 or less, most preferably 48 or less.

Suitably, the values of a and b of the first functional layer are in the range 10 to-10, preferably 5 to-5, most preferably 2 to-2, respectively.

CIE Lab is a well-known chromaticity space defined by the International Commission on illumination (CIE) and the corresponding standard ISO/CIE 11664-4:2019. The color was measured using a UV/Vis spectrophotometer according to the CIE Lab system. The L, a and b values are typically measured according to the CIE L x a x b (or CIE Lab) color space. For simplicity, throughout the application, the values of L, a, and b are referred to as L, a and b. The value of L is typically between 0 and 100, where l=0 represents completely black and l=100 represents diffusely reflective white.

The "a" value indicates a green red portion, the "a" value is more negative indicates a larger green portion, and the "a" value is more positive indicates a larger red portion. The "b" value indicates a blue yellow portion, the "b" value is more negative indicates a larger blue portion, and the correction indicates a larger yellow portion.

Spectrophotometers measure color under standard light sources, most commonly D65 daylight. D65 is defined by standard ISO 11664-2:2007 (the present standard is identical throughout the world and is independent of the local environment).

The first functional layer is typically black or visually black. According to the invention, the viewer's perception of the layer is affected by the second functional layer, making the overall combination appear darker. This usually requires, i.e. a second functional layer, because the first functional layer itself is not sufficiently black.

The thickness of the first functional layer is generally not critical, as the inherent properties of the layer are not significantly affected by its thickness. Optionally, the substrate is made entirely of the material of the first functional layer. However, it is typically deposited on the substrate and preferably does not significantly alter the shape or size of the substrate, and may be an expensive or deposition costly material, which is typically relatively thin, e.g., 5 μm or less; the thickness thereof may suitably be in the range 0.2 μm to 1.8 μm, preferably 0.4 μm to 1.5 μm, most preferably 0.6 μm to 1.0 μm.

Suitable materials for the first functional layer are compounds of metals or metal nitrides, such as silicon, aluminum or nitrides of some transition metals, such as titanium, zirconium, chromium, aluminum, niobium, hafnium and mixtures thereof. For example, the first functional layer may include or consist of Ti, zr, zrN, tiZrNx, crSiNx, tiAlN, crAlN, linbn, tiCN, crN, tiN, hfN, etc., where x is a variable. Preferably, x is between 1 and 5, and most preferably x has a value of about 2.

Specifically, preferred embodiments of the present invention are described below, having a first functional layer that is or includes TiZrNx. Where x is an integer value, and the value of x may be different in different embodiments of the invention. However, in any given embodiment, the value of x in TiZrNx remains substantially constant. When the first functional layer comprises TiZrN _X When x is preferably 2. The preferred value of x for the first functional layer is 2.

In other examples, the first functional layer is or includes CrN, tiN, zrN, crSiN. Thus, the first functional layer is a dark base layer of the coating.

The first functional layer may also serve as a primer layer to improve the bonding between the substrate and other layers of the invention, particularly the second functional layer.

The refractive index of the first functional layer may be between 1.1 and 3.0, preferably between 1.2 and 2.8, most preferably between 1.3 and 2.6.

The second functional layer is relatively thin to create the effect of deepening the first functional layer, which is already dark. The thickness of the second functional layer is thus chosen in order to further deepen the overall appearance of the coating by interference.

The thickness of the second functional layer may be up to about 100nm. Suitable thicknesses are from 30nm to 100nm, for example from 40nm to 60nm, preferably from 50nm to 60nm, most preferably from 15nm to 58nm.

Thus, according to the present invention, a second functional layer that is relatively thin and has a different refractive index from the first functional layer is used, whereby the phase difference between the light reflected from the upper surface of the first functional layer and the light reflected at the upper surface of the second functional layer is about pi, resulting in destructive interference over a wide range or all wavelengths of light, the net effect being visual color darkening. Thus, very dark and black coatings can be obtained, as in the specific example below.

Preferably, the second functional layer is SiNx, zrOx or TiOj, where x and j are variables. The preferred value of x for the second functional layer is typically between 1 and 2, e.g. 4/3. The preferred value of j for the second functional layer is typically between 1.5 and 2.5, preferably 2.

Preferably, the second functional layer is SiNx, where x is a variable. The preferred value of x for the second functional layer is typically between 1 and 2, e.g. 4/3.

A particularly preferred example of the present invention shown below includes a first functional layer of or including TiZrNx and a second functional layer of SiNx. x is defined in each case as described above.

In the examples of the invention described in more detail below, the first functional layer has a higher refractive index than the second functional layer. When an optional transition layer or protective layer is present, the second functional layer preferably has a lower refractive index than these transition/protective layers. Without being limited by theory, light reflected from the upper (outermost) surface of the first functional layer interferes with and cancels light reflected from the upper surface of the second functional layer; when light propagates from a medium with a lower refractive index to a medium with a higher refractive index, light reflected from an interface between the two mediums undergoes pi phase difference; in the present invention, pi phase difference occurs in light reflected from the interface between the first functional layer and the second functional layer into the coating layer; in contrast, light reflected from the interface between the protective/transition layer and the second functional layer into the coating does not undergo a phase difference.

The refractive index of the second functional layer may be between 1.0 and 3.0, preferably between 1.2 and 2.8, most preferably between 1.4 and 2.0.

The refractive index of the second functional layer may be between 1.5 and 3.0, preferably between 1.8 and 2.8, most preferably between 1.9 and 2.7.

Specific preferred examples of the present invention shown below include protective layers.

The protective layer is preferably relatively transparent. The transparency of the layer is generally greater than 40%, preferably greater than 50%. One possible method of measuring transparency is described in ASTM D-1000.

The protective layer preferably has a low refractive index. The refractive index of this layer is preferably higher than the refractive index of the second functional layer and than the refractive index of the optional transition layer (if present).

Preferred materials for the protective layer include SiO ₂ 、TiO ₂ SiNx, and other materials having similar properties, wherein the preferred value of x for the second functional layer is typically between 1 and 2, e.g. 4/3.

Preferred materials for the protective layer include SiO ₂ 、TiO ₂ And other materials having similar properties.

The refractive index of the protective layer is preferably between 1.3 and 3.0, preferably between 1.4 and 2.8, and most preferably between 1.4 and 2.7.

The protective layer may have a thickness of 1.0 μm to 2.5 μm, preferably 1.3 μm to 2.2 μm, most preferably 1.5 μm to 2.0 μm.

The coating may optionally include a transition layer. The transition layer may have a thickness of 0.5 μm to 2.0 μm, preferably 1.0 μm to 2.0 μm, most preferably 1.2 μm to 1.8 μm. This layer may also be used as a transition layer between the second functional layer and the protective layer (when present) to improve the bond between the second functional layer and the protective layer. In the deposition of the layers, the layers may also represent a convenient transition using the respective reactant gases (oxygen, nitrogen) used in the other different layers.

Preferably, the optional transition layer is SiOyNz, wherein y and z are independently varying integers. In a specific example, siOγNz can be amorphous or crystalline and can have a y value and a z value such that the composition is at the SiO ₂ And Si (Si) ₃ N ₄ And changes between. The value of y is suitably between 0.1 and 3, preferably between 0.1 and 2. The value of z is suitably between 0.1 and 2, preferably between 0.1 and 4/3. The optimum y value is 0.5 and the optimum z value is 1. Alternatively, the ratio of z to y (i.e., z/y) is 0.5 to 5, preferably 1 to 3, and most preferably 2.

Products containing such coatings are often used in large quantities and abused and must therefore meet certain manufacturer standards. These prices tend to increase as the life of the product increases. The coating may further comprise one or more additional layers. These may be one or more PVD or CVD layers. These may include chemical layers such as the outermost layer of AFP. One known example is a fluorine-containing organic layer applied by evaporation. Typically, the additional layer has a thickness of 5nm to 500nm, preferably 5nm to 100nm, most preferably 5nm to 20 nm.

Further specific preferred embodiments of the present invention include or are described herein as substrates comprising

Transparent silicon dioxide protective layer

Transition layer of SiOyNz

Si ₃ N ₄ Is a functional layer of (2)

Functional layer of TiZrNx

Substrate material

A transparent silicon dioxide protective layer with a thickness of 1.0 μm-2.5 μm

SiOyNz transition layer with thickness of 0.5 μm-2.0 μm

Si with thickness of 40nm-60nm ₃ N ₄ Functional layer

TiZrNx functional layer with thickness of 0.2-1.8 mu m

Substrate material

The substrate to be coated may be a metal, preferably the substrate is zinc, zinc alloy, aluminum alloy, magnesium alloy. The most preferred substrates are zinc and zinc alloys. Typical products to be coated include products made of materials such as zinc, magnesium, aluminum and alloys thereof which heretofore have not been readily coated with carbon-containing coatings. Further provided are consumer care devices such as shavers and the like and coated components thereof comprising the present invention.

As shown above, a particularly preferred example of the present invention includes first and second functional layers, a transition layer, and a protective layer, which are all made by sputtering. The coating is deposited in two steps. The first functional layer is deposited in a single chamber, for example, with Ti and Zr containing targets and nitrogen as the reactant gases. The second functional layer, the transition layer and the protective layer may all be deposited by separate chambers with adjustable reactive gases (e.g. nitrogen and oxygen) and with e.g. Si targets. This can be accomplished in multiple chambers with adjacent seals, or in a single chamber with multiple sputtering stations.

The coatings of the present invention can be formed by varying the reactant gases (e.g., nitrogen, oxygen), the target materials (e.g., silicon, titanium, and zirconium), and the layer thickness.

The invention also describes a method of making the coated substrate of the invention, comprising depositing a coating on the substrate,

wherein the coating comprises, in order, substantially parallel coatings:

a first functional layer adjacent to the substrate, and

the second functional layer is provided with a second layer,

wherein the first functional layer has a dark appearance and

wherein the second functional layer has a thickness smaller than the wavelength of visible light.

Examples

The invention will now be illustrated in the following examples.

The test pieces of zinc alloy substrate were coated using a sputtering apparatus with different targets (silicon, titanium and zirconium) and nitrogen and oxygen reactive gases.

The test strip is rinsed in deionized water outside the chamber and then enters the chamber where air is pumped to the working pressure. The test strip is then ion beam cleaned. The cleaned surface was coated with the following materials and thicknesses of coating. In these examples, both matte and polished surface zinc alloys were used as the substrate. The color values L, a and b of the coatings were tested using conventional equipment and the results are shown in the following table.

TABLE 1

The coating thickness represents the desired thickness programmed in the sputter coating apparatus. In practice, the actual thickness may vary within a tolerance of +/-about 1nm-2 nm.

Uncoated zinc alloys failed the salt spray test within 10 minutes, whereas coated matt and polished zinc alloy substrates passed the test even after 4 hours.

In the visual inspection, both coatings appeared very black and also passed the test of the brine corrosion resistance of the internal TP-42; the coated matte and polished zinc alloy substrates passed the 20 cycles test.

Color values L, a and b of the coated substrate are recorded as follows:

TABLE 2

These values correspond to the visual appearance of a very dark substrate observed by the naked eye, both of which are substantially black in daylight.

Thus, the present invention provides very dark and black coatings that are carbon free.

Claims

1. A coated substrate comprising a substrate coated with a coating comprising, in order, substantially parallel layers:

a first functional layer adjacent to the substrate, and

the second functional layer is provided with a second layer,

wherein the first functional layer has a dark appearance,

wherein the second functional layer has a thickness thinner than a wavelength of visible light;

wherein the first functional layer comprises Ti, zr, zrN, tiZrNx, crSiNx, tiAlN, crAlN, tiNbN, crN, tiN, or HfN, wherein x is between 1 and 5,

the first functional layer has a thickness of 0.2 μm to 1.8 μm;

the second functional layer has a thickness of 40nm-60 nm;

the first functional layer has a higher refractive index than the second functional layer;

the second functional layer is SiN _x ，ZrO _x Or TiO _j Where x and j are variables.

2. The coated substrate according to claim 1, wherein the first functional layer L value is 55 or less.

3. The coated substrate of any preceding claim, wherein the first functional layer has a and b values of from 10 to-10.

4. The coated substrate of any preceding claim, wherein the second functional layer comprises Si ₃ N ₄ 。

5. The coated substrate of any preceding claim, wherein there is an outermost protective layer, wherein the protective layer optionally has a thickness of 1.0 μιη -2.5 μιη.

6. The coated substrate of claim 5, wherein a transition layer is present between the second functional layer and the protective layer, and optionally wherein the transition layer has a thickness of 0.5 μιη -2.0 μιη.

7. A coated substrate according to any preceding claim comprising a substrate coated with a coating comprising, in order, substantially parallel layers:

a TiZrNx functional layer adjacent to the substrate, wherein x is 1 to 5,

Si ₃ N ₄ the functional layer is arranged on the surface of the functional layer,

an SiOyNz transition layer, wherein y is 0 to 3, z is 0 to 2, and

SiO ₂ and (3) a protective layer.

8. A coated substrate according to any preceding claim comprising a substrate coated with a coating comprising, in order, substantially parallel layers:

a TiZrNx functional layer adjacent to the substrate and having a thickness of 0.2 μm to 1.8 μm, wherein x is 1 to 5,

Si ₃ N ₄ a functional layer with a thickness of 40nm-60nm,

an SiOyNz transition layer having a thickness of 0.5 μm to 2.0 μm, wherein y is 0 to 3, z is 0 to 2, and

SiO with thickness of 1.0 μm-2.5 μm ₂ And (3) a protective layer.

9. The coated substrate of any preceding claim, wherein the substrate is zinc, zinc alloy, aluminum alloy, magnesium or magnesium alloy.

10. The coated substrate of any preceding claim, wherein the substrate is zinc or a zinc alloy.

11. A process for preparing a coated substrate according to any one of claims 1 to 10, comprising depositing a coating onto the substrate,

wherein the coating comprises, in order, substantially parallel layers:

a first functional layer adjacent to the substrate, and

the second functional layer is provided with a second layer,

wherein the first functional layer has a dark appearance and

wherein the second functional layer has a thickness thinner than a wavelength of visible light.