A method for preparing a black decorative film layer applied on plastic

Abstract

The present invention discloses a method for preparing a black decorative film for application on plastics, comprising electroplating, cleaning, baking, glow cleaning, and physical vapor deposition (PVD) steps. The PVD process deposits a chromium-tungsten alloy layer on a plastic substrate using medium-frequency magnetron sputtering. Acetylene reaction gas is then introduced and doped with the carbon element in the acetylene reaction gas using medium-frequency magnetron sputtering, thereby forming a CrWC black film. The present invention utilizes a novel alloy target material and medium-frequency magnetron sputtering to deposit the CrWC film on the surface of the plastic substrate. This method eliminates the need for workpiece heating and utilizes a staged sputtering process to deposit the alloy target, resulting in a more stable black decorative film.

Description

Technical Field

[0001] The invention relates to a method for preparing a black decorative film layer applied on plastic. Background Art

[0002] In the early 1980s, imitation gold decorative coatings such as TiN and TiNC were introduced to the market and gradually became commercialized. Over time, driven by the pursuit of diverse decorative colors, TiC gun black coatings were developed, gaining a wider market and contributing to the increasing maturity of black coating technology. However, black coatings place higher demands on equipment and technology, and also present challenges such as poor color stability and internal stress in the film. The industry often uses high-temperature heating to eliminate internal stress in the production of black coatings, such as in various tool plating and DLC coatings, but this heating method is not suitable for plastic materials. Summary of the Invention

[0003] In order to solve the above technical problems, the object of the present invention is to provide a method for preparing a black decorative film layer applied on plastic.

[0004] The present invention is achieved through the following technical solution: A method for preparing a black decorative film layer applied on plastic, characterized by comprising the following steps:

[0005] 1) Electroplating:

[0006] The plastic substrate is electroplated, and the film structure after the electroplating treatment is a copper layer, a nickel layer and a chromium layer in sequence;

[0007] 2) Cleaning:

[0008] Cleaning the electroplated plastic substrate in step 1);

[0009] 3) Baking:

[0010] The plastic substrate cleaned in step 2) is baked at a temperature of 50-70° C.;

[0011] 4) Glow cleaning:

[0012] The furnace body is evacuated to vacuum, and argon gas is introduced to perform bias glow cleaning on the baked plastic substrate;

[0013] 5) Physical vapor deposition:

[0014] The first stage of deposition process: 100-300 sccm of inert gas is introduced, and a chromium-tungsten alloy layer is deposited on the plastic substrate using medium-frequency magnetron sputtering;

[0015] The second stage deposition process: 100-300 sccm of inert gas and 50-200 sccm of acetylene reaction gas are introduced, and the C element in the acetylene reaction gas is doped into the chromium-tungsten alloy layer using medium-frequency magnetron sputtering, thereby forming a CrWC black film layer.

[0016] Preferably, during the first stage deposition process of step 5), the output current is 10-15 A and the sputtering time is 2-3 min.

[0017] Preferably, in the second stage deposition process of step 5), the output current is 10-15 A, the coating bias is 100-150 V, and the sputtering time is 30-60 min.

[0018] Preferably, the acetylene reaction gas in step 5) is added in batches during the sputtering time.

[0019] Preferably, in step 5), a CrW target is used to deposit the chromium-tungsten alloy layer, wherein the mass fraction of the Cr element in the CrW target is 30% to 50%, and the mass fraction of the W element is 50% to 70%.

[0020] Preferably, in step 4), the furnace body is evacuated to 0.006 Pa, and 1000 sccm of argon gas is introduced to perform bias glow.

[0021] Preferably, in step 4), the bias voltage of the glow cleaning step is controlled to be 350V, the duty cycle is 50%, and the glow time is 3 to 5 minutes.

[0022] Preferably, the color Lab value of the CrWC black film layer is L: 33 to 46, a: -1 to 0.7, and b: -1 to 2.

[0023] Preferably, the thickness of the CrWC black film layer is 0.3-1 μm.

[0024] The present invention adopts a new alloy target material and uses medium-frequency magnetron sputtering to deposit a CrWC film layer on the surface of a plastic substrate. There is no need to heat the workpiece, and a staged sputtering method is used to deposit the alloy target to obtain a more stable black decorative film layer. The black decorative film layer has strong adhesion to the plastic substrate and can meet the requirements of the black film layer on the market, with better color stability and controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] Reference Manual Figure 1 A method for preparing a black decorative film layer applied on plastic comprises the following steps:

[0029] 1) Electroplating:

[0030] The plastic substrate is electroplated, and the film structure after the electroplating treatment is a copper layer, a nickel layer and a chromium layer in sequence;

[0031] 2) Cleaning:

[0032] Cleaning the electroplated plastic substrate in step 1), and sequentially performing degreasing, neutralization, and ultrapure water washing treatments on the electroplated plastic substrate;

[0033] 3) Baking:

[0034] Baking the plastic substrate cleaned in step 2) at a temperature of 50-70° C.;

[0035] 4) Glow cleaning:

[0036] When the furnace body is evacuated to 0.006 Pa, 1000 sccm of argon gas is introduced for bias glow, wherein the bias voltage is controlled to 350 V, the duty cycle is 50%, and the glow time is 3 to 5 minutes;

[0037] 5) Physical vapor deposition:

[0038] After the glow cleaning is completed, physical vapor deposition is carried out. Physical vapor deposition includes two stages of deposition process. The first stage of deposition process is:

[0039] 100 to 300 sccm of inert gas, such as argon, is introduced, and a chromium-tungsten alloy layer is deposited using a medium-frequency magnetron sputtering method. The deposition is performed using a chromium-tungsten alloy target as a target material, with an output current of 10 to 15 A and a sputtering time of 2 to 3 minutes.

[0040] The second stage of deposition process is:

[0041] 100-300 sccm of inert gas, such as argon, and 50-200 sccm of acetylene reaction gas are introduced. Medium-frequency magnetron sputtering is used to dope the carbon element in the acetylene gas into the chromium-tungsten alloy layer, thereby forming a CrWC black film. During the deposition process, the output current is 10-15A, the coating bias voltage is controlled at 100-150V, and the sputtering time is 30-60 minutes. The inert gas is then introduced to passivate the film surface before breaking the vacuum. The above steps can form a black decorative film on a plastic substrate, and a stable black film can be obtained without heating the plastic substrate. The color Lab values ​​of the black decorative film are measured to be L: 33-46, a: -1-0.7, and b: -1-2. The film thickness of the prepared black decorative film is 0.3-1 μm.

[0042] In the above-mentioned method for preparing the black decorative film layer, the black decorative film layer is highly controllable. In step 5), the Lab value is adjusted to meet product requirements by controlling the sputtering time of the second-stage CrWC black film layer deposition and the amount of acetylene used.

[0043] In one embodiment, various plastic substrates were subjected to electroplating, cleaning, baking, and glow cleaning before physical vapor deposition. The medium-frequency magnetron sputtering current for the second stage of physical vapor deposition was set to 13A, and the coating bias voltage was controlled to 120V. Under this condition, the acetylene gas used at different times was controlled as shown in the following table:

[0044] Sputtering time Acetylene dosage Lab value First embodiment 30min 110 sccm L: 44~46a:0.7b:2 Second embodiment 40min 180sccm L: 40~42a: 0.5b: 0.8 Third embodiment 50min 230sccm L: 34~36a:-0.5b:0..3

[0045] Among them, the plastic substrate with a black decorative film layer in the above embodiment was subjected to a high temperature and high humidity test, and its Lab values ​​after the test all fell within the measured Lab value range (L: 33 to 46, a: -1 to 0.7, b: -1 to 2), meeting product requirements. Taking the plastic substrate with a black decorative film layer obtained in the third embodiment as an example, it was subjected to a high temperature and high humidity test. Its Lab values ​​after the test were L: 35 to 37, a: 0, b: 0.6, indicating good film stability.

[0046] The present invention uses a medium-frequency magnetron sputtering method, and at the same time, acetylene reaction gas is added in batches during the sputtering time in step 5). That is, the amount of acetylene needs to be added in batches one by one during the sputtering time to eliminate the internal stress between the layers of the film, and avoid the disappearance of the anode and target poisoning caused by excessive carbon content in the reaction gas, thereby ensuring the stability of the film layer.

[0047] Preferably, the different mass ratios of Cr and W elements in the chromium-tungsten alloy target (CrW target) in step 5) can be adjusted to obtain CrWC film layers with different hardnesses; preferably, the mass fraction of Cr in the CrW target is adjusted to 30% to 50%, and the mass fraction of W is adjusted to 50% to 70%, so that a more stable CrWC film layer can be obtained.

[0048] The present invention adopts a new alloy target material and uses medium-frequency magnetron sputtering to deposit a CrWC film layer on the surface of a plastic substrate. There is no need to heat the workpiece, and a staged sputtering method is used to deposit the alloy target to obtain a more stable black decorative film layer. The black decorative film layer has strong adhesion to the plastic substrate and can meet the requirements of the black film layer on the market, with better color stability and controllability.

[0049] The foregoing description shows and describes preferred embodiments of the present invention. As previously mentioned, it should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the inventive concept described herein by the teachings above or by techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art without departing from the spirit and scope of the present invention are intended to be within the scope of the appended claims.

Claims

1. A method for preparing a black decorative film layer applied on plastic, characterized in that: The steps are as follows: 1) Electroplating: The plastic substrate is electroplated, and the film structure after the electroplating treatment is a copper layer, a nickel layer and a chromium layer in sequence; 2) Cleaning: Cleaning the plastic substrate after electroplating in step 1); 3) Baking: The plastic substrate cleaned in step 2) is baked at a temperature of 50-70°C; 4) Glow Cleaning: The furnace body is evacuated to vacuum, and argon gas is introduced to perform bias glow cleaning on the baked plastic substrate; 5) Physical vapor deposition: The first stage of deposition process: 100-300 sccm of inert gas is introduced, and a chromium-tungsten alloy layer is deposited on the plastic substrate using medium-frequency magnetron sputtering. The second stage of deposition process: 100-300 sccm of inert gas and 50-200 sccm of acetylene reaction gas are introduced, and medium-frequency magnetron sputtering is used to dope the carbon element in the acetylene reaction gas into the chromium-tungsten alloy layer, thereby forming a CrWC black film layer; In the second stage deposition process of step 5), the output current is 10-15A, the coating bias voltage is 100-150V, and the sputtering time is 30-60min; The acetylene reaction gas in step 5) is added in batches during the sputtering time.

2. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: During the first stage of deposition in step 5), the output current is 10-15 A and the sputtering time is 2-3 min.

3. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: In step 5), a CrW target is used to deposit a chromium-tungsten alloy layer, wherein the mass fraction of the Cr element in the CrW target is 30% to 50%, and the mass fraction of the W element is 50% to 70%.

4. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: In step 4), the furnace body is evacuated to 0.006 Pa, and 1000 sccm of argon gas is introduced to perform bias glow.

5. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: In step 4), the bias voltage of the glow cleaning step is controlled to 350 V, the duty cycle is 50%, and the glow time is 3 to 5 minutes.

6. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: The color Lab value of the CrWC black film layer is L: 33~46, a: -1~0.7, and b: -1~2.

7. The method for preparing a black decorative film layer applied on plastic according to claim 1, characterized in that: The thickness of the CrWC black film layer is 0.3-1 μm.

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