TW201420792A - Fully dry wire drawing method for plastic base material - Google Patents

Abstract

The invention discloses a fully dry wire drawing method for plastic base material, which relates to a plastic surface treatment method. The invention provides a fully dry wire drawing method for plastic base material, which can realize coating and wire drawing treatment on the plastic material, avoids wastewater discharge and is wide in applicability. The method comprises the following steps: (1) manually wiping off the oil on the plastic base material; (2) executing physical vapor deposition plasma modification on the plastic base material treated in step (1), then, carrying out high-power sputtering to deposit a metal layer; (3) executing wire drawing treatment on the plastic base material treated in step (2); (4) manually wiping off dust and oil on the plastic base material treated in step (3); (5) executing physical vapor deposition plasma glow cleaning on the plastic base material treated in step (4), and then, carrying out high-power sputtering to deposit the metal layer; (6) spraying a primer layer and a finish layer or spraying powder coating on the plastic base material treated in step (5), and realizing the fully dry wire drawing method for the plastic base material.

Description

Method for fully dry drawing process of plastic substrate

The invention relates to a plastic surface treatment method, in particular to a method for full dry wire drawing treatment of a plastic substrate. Suitable for green surface treatment of sanitary ware, home appliances, automobiles and other parts.

The conventional plastic electroplating drawing process is: degreasing, waxing, roughening, activation, sensitization, reduction, chemical nickel, electroplating of copper, electroplating acid copper, electroplating nickel, and then drawing, degreasing, activating, electroplating The disadvantage of chromium or the final PVD is that it produces large amounts of wastewater and heavy metal contaminants.

Chinese patent 200910135647.4 discloses a copper-like drawing process of metal surface with good effect of copper-like effect, strong copper metal texture, long gloss and color retention time and easy scale production. 1) Conventional chemical pretreatment of the surface of the metal to make the metal surface clean and smooth; 2) Electrostatic spraying of pigmented transparent red outdoor powder coating or pure transparent outdoor powder coating; 3) Dark blue or black with imitation copper background The straight-line thermal transfer paper is subjected to thermal transfer to obtain a copper-like brushed effect.

Chinese Patent No. 201110080260.0 discloses a method for performing imitation metal wire drawing on the surface of engineering plastics, the steps comprising: adding pigment to the plastic masterbatch for dyeing treatment; dry cleaning and activating the plastic blank; spraying the plastic blank with colored Coating; drawing the workpiece to obtain the surface of the wire drawing; dry cleaning and activating the workpiece; spraying the workpiece with the brushed pattern to the topcoat, ie Finished the imitation metal wire drawing on the engineering plastic surface.

Chinese patent 201010183049.5 discloses a manufacturer of a housing The method comprises the steps of: providing a male mold and a female mold; performing a biting treatment on the surface of the female mold by using a chemical agent to form a bite structure on the surface of the female mold; and drawing the surface of the female mold The surface of the master mold is formed into a brushed texture; and the outer mold and the master mold are used to produce an outer shell having a biting and drawing effect. In the manufacturing method of the casing of the invention, the outer casing having the effect of biting and drawing can be produced, the production process is simple, and the pattern on the produced outer casing is not easily peeled off.

The object of the present invention is to provide a method for the full dry-drawing treatment of a plastic substrate, which can realize the coating and drawing process of the plastic material by the prior art plastic plating drawing process, without the waste water discharge and wide adaptability.

The invention comprises the following steps: 1) manual wiping and degreasing treatment of the plastic substrate; 2) performing physical vapor deposition plasma modification on the plastic substrate treated in the step 1), and then performing high-power sputtering deposition of the metal 3) drawing the plastic substrate treated by the step 2); 4) manually wiping the dust removal and degreasing treatment of the plastic substrate treated by the step 3); 5) treating the plastic substrate subjected to the step 4) After performing physical vapor deposition plasma glow cleaning, high-power sputtering deposition of the metal layer is performed; 6) spraying the primer layer and the topcoat layer or spraying the powder coating on the plastic substrate treated in the step 5) to realize the plastic base The full dry drawing method of the material.

In step 2), the physical vapor deposition plasma modified The process conditions can be ion source current 0.3~0.6A, bias voltage 20~80V, duty cycle 40%~80%, argon flow rate 10~100SCCM, oxygen flow rate 0~150SCCM, acetylene flow rate 0~150SCCM, time 3~5min In order to achieve the purpose of cleaning and chemically activating the surface of the substrate; the high-power sputter deposition metal layer can be processed by using a high-power IF pulse or a high-power DC power source, a power supply current of 50 to 200 A, a voltage of 400 to 600 V, and deposition. Time 5~15min, bias voltage 20~80V, duty ratio 40%~80%, argon flow rate 60~200SCCM; the metal layer can be aluminum metal, copper metal, nickel-chromium alloy, chromium metal, zirconium metal, titanium At least one of metal and the like; in the step 3), the wire drawing process may be performed by an automatic or manual method, the rotation speed of the wire drawing machine is 200-800 r/min, and the wire drawing wheel may be a nylon wheel or a flying wing wheel. At least one of a melon cloth wheel and the like.

In step 5), the physical vapor deposition plasma glow clear The washing process conditions can be ion source current 0.3~0.6A, bias voltage 20~80V, duty cycle 40%~80%, argon flow rate 100~300SCCM, time 3~5min, to achieve the purpose of cleaning the surface of the substrate; The process conditions for high-power sputter deposition metal layer can be high-power IF pulse or high-power DC power supply, power supply current 50~200A, voltage 400~600V, deposition time 2~10min, bias voltage 20~80V, duty The ratio of 40% to 80%, the flow rate of argon gas is 60 to 200 SCCM, and the flow rate of nitrogen gas is 0 to 200 SCCM; and the metal layer may be at least one of aluminum metal, nickel-chromium alloy, chromium metal, zirconium metal, titanium metal, and the like.

In step 6), the spray primer layer and the topcoat layer may be purple At least one of an external light curing (UV) lacquer and a polyurethane lacquer (PU) lacquer; the spraying method is a method known to those skilled in the art, the primer layer may have a thickness of 10 to 30 μm; and the topcoat layer may have a thickness of 10 ~30 μm; the spraying method of the sprayed powder coating is a method known to those skilled in the art, the thickness of the powder coating layer It can be 20~50μm, and can be processed in the topcoat according to need, and the required color can be debugged. The full dry drawing effect can be selected from: brushed nickel (BN) color: L*=72.7 ~75.7, A*=0.2~0.8, B*=6.2~8.0; brushed stainless steel (SS) color: L*=72~76, A*=0.2~0.8, B*=4.2~6; brushed deep nickel color ( SL) Color: L*=72~76, A*=0.2~0.8, B*=8.5~11; Brushed Nickel Paint (BNP) Color: L*=70~78, A*=-0.5~1.5, B* =6~10; where L* means black and white, 0 is black, 100 is white, black is between 0 and 100; A*: positive value indicates red, negative value indicates green; B*: positive value indicates yellow, negative The value indicates blue.

Compared with the existing plastic substrate electroplating drawing, the invention has the following advantages:

1) Manually wiping and degreasing the plastic substrate to replace the existing ultrasonic degreasing, etc., can reduce the discharge of wastewater.

2) Physical vapor deposition (PVD) high-power sputtering technology is adopted, and PVD plasma modification and sputtering of metal layers are sequentially performed; instead of conventional electroplating, high concentration of chromic acid is coarsened, neutralized, sensitized and reduced. Processes such as chemical nickel, electroplating copper and electroplating nickel can meet the requirements of no waste water discharge and the environmental and human hazards of these harmful substances.

3) The vacuum coating layer can be used for the final color toning, which is more stable than the coloring in the paint, and the production process is more stable, and the yield is higher.

4) The drawing effect processed by the full-drying drawing process can completely achieve the drawing effect of the current metal plating of water plating, and can fully satisfy the high-end wei Bath customer needs.

The full dry draw effect of the present invention is comparable to the wire drawing effect of a thick metal layer plated with water.

Example 1 Modified PP plastic substrate coating film drawing treatment

(1) Manually wiping and degreasing the modified PP plastic substrate.

(2) High-power sputter deposition metal layer: physical vapor deposition (PVD) metal layer on the plastic substrate treated by step (1), followed by physical vapor deposition plasma modification, high-power sputter deposition Metal layer; physical vapor deposition plasma modification process conditions are ion source current 0.3A, bias voltage 20V, duty cycle 80%, argon flow rate 10SCCM, acetylene flow rate 150SCCM; time 3min to achieve cleaning and chemical activation of the matrix The purpose of the surface; high-power sputter deposition metal layer process conditions can be high-power DC power supply, power supply current is 200A, voltage is 600V, deposition time is 5min, bias voltage is 20V, duty cycle is 40%, argon flow rate is 60SCCM The deposited metal layer is aluminum.

(3) Wire drawing treatment: The plastic substrate treated by the step (2) is subjected to wire drawing treatment, and the drawing is performed by an artificial method, the rotation speed of the wire drawing machine is 200 r/min; the wire drawing wheel is a vegetable melon cloth wheel.

(4) Manually wiping, dusting and degreasing the plastic substrate treated in the step (3).

(5) High-power sputter deposition metal layer: physical vapor deposition plasma glow cleaning of the plastic substrate treated in step (4), followed by high-power sputtering deposition of metal layer; physical vapor deposition plasma The process conditions of the glow cleaning may be an ion source current of 0.3, a bias voltage of 20 V, a duty ratio of 80%, an argon gas flow rate of 100 SCCM, and a time of 3 min to achieve the purpose of cleaning the surface of the substrate; the process conditions for high-power sputter deposition of the metal layer may be High-power IF pulse, power supply current 200A, voltage 600V, deposition time 2min, bias voltage 20V, duty cycle 80%, argon flow rate 60SCCM, nitrogen flow rate 60SCCM; deposited metal layer zirconium nitride metal layer.

(6) Spraying primer and topcoat: spraying the UV-based primer (UV) primer and UV topcoat on the plastic substrate treated in step 5), using an automatic spray gun for spraying, the specific method of primer spraying may be After spraying a layer of UV paint (paint layer thickness 10μm), it is sent into the infrared drying section, leveling and drying (70°C×5min), leveling, drying and then feeding into the UV curing section for UV irradiation curing. Cross-linking (time 10s), UV irradiation curing energy is 1000mJ/cm2, and a high corrosion inhibitor is added to the primer to improve the corrosion resistance of the PVD metal layer. The specific method of top coat spraying can be: after spraying a layer of UV paint (paint layer thickness 30μm), feeding into the infrared drying section, leveling and drying (70°C×8min), leveling, drying and feeding The ultraviolet light curing section was subjected to UV irradiation curing crosslinking (time 10 s), and the energy of UV irradiation curing was 1500 mJ/cm 2 . A brushed nickel (BN) color is obtained.

According to the standard of sanitary ware, the following test standards are applied to the coated wire drawing products: 1. CASS (anti-corrosion test ASTM B368-09)-----8h; 2. AASS (salt spray test ASTM G85-9)--- -----48h; 3. Hot and cold loop test (ASME A112.18.1-2005/CSA B125.1-05)---4cycles; 4. Falling sand test (ASTM D968-09, Method A)-----12liter; 5. Water immersion test (ASTM D870-02)------- -38±2°C×24h; 6. Chemical resistance test (ASTM D1308-02)--------Na OH 6mol/L; 7. Pencil hardness (ASTM D3363-05)----Chinese pencil 2H; 8. Hundred cut test (ASTM D3359-09) ------ 3B or more.

The results are as follows: 1. CASS 8hOK; 2. AASS 48h OK; 3. Hot and cold loop test OK; 4. Falling sand test OK; 5. Water immersion test OK, no color change; 6. Chemical resistance test OK; Pencil hardness Chinese pencil 3H; 8. Hundred cut test 5B.

The color of the product is measured by the Minolta Spectrophotometer | Color Difference Meter CM-2600d to measure the LAB value. The measurement results are as follows: L*=74.2, A*=0.35, B*=7.2.

Example 2 ABS plastic substrate coating wire drawing treatment

(1) ABS plastic substrate is manually wiped and degreased.

(2) High-power sputter deposition metal layer: physical vapor deposition (PVD) metal layer on the plastic substrate treated by step (1), followed by physical vapor deposition plasma modification, high-power sputter deposition Metal layer; physical vapor deposition plasma modification process conditions are ion source current 0.6A, bias voltage 80V, duty cycle 40%, argon flow rate 10SCCM, oxygen flow rate 150SCCM; time 5min to achieve cleaning and chemical activation of the matrix The purpose of the surface; high-power sputter deposition metal layer process conditions can be high-power IF pulse power supply, power supply current is 50A, voltage is 400V, deposition time is 15min, bias voltage is 80V, duty cycle is 80%, argon The flow rate is 200 SCCM and the deposited metal layer is a nickel-chromium alloy.

(3) Wire drawing treatment: the plastic substrate treated by the step (2) is subjected to wire drawing treatment, and the drawing is performed by an artificial method, the rotation speed of the wire drawing machine is 800 r/min; the wire drawing wheel is a flying wing wheel.

(4) Manually wiping, dusting and degreasing the plastic substrate treated in the step (3).

(5) High-power sputter deposition metal layer: physical vapor deposition plasma glow cleaning of the plastic substrate treated in step (4), followed by high-power sputtering deposition of metal layer; physical vapor deposition plasma The process conditions of the glow cleaning may be an ion source current of 0.6, a bias voltage of 80 V, a duty ratio of 40%, an argon gas flow rate of 300 SCCM, and a time of 5 min to achieve the purpose of cleaning the surface of the substrate; the process conditions for high-power sputter deposition of the metal layer may be Using high-power DC power supply, power supply current 200A, voltage 400V, deposition time 10min, bias voltage 80V, duty cycle 40%, argon flow rate 200SCCM, deposited metal layer nickel-chromium alloy metal layer.

(6) Spraying primer and topcoat: spraying the polyurethane substrate (PU) primer and polyurethane lacquer (PU) topcoat on the plastic substrate treated in step 5), spraying with automatic spray gun, and spraying the primer The method can be: spraying a layer of polyurethane paint (PU) paint (paint layer thickness 30 μm), feeding into the infrared drying section, leveling and drying (60 ° C × 120 min), and adding a high corrosion inhibitor to the primer To improve the corrosion resistance of the PVD metal layer. The specific method for spraying the topcoat can be: after spraying a layer of polyurethane paint (PU) paint (paint layer thickness 10 μm), feeding into the infrared drying section, leveling and drying (60 ° C × 60 min). Obtained brushed stainless steel (SS) color.

According to the standard of sanitary ware, the following test standards are tested for coated wire drawing products: 1. CASS (anti-corrosion test ASTM B368-09)-----8h; 2. AASS (salt spray test ASTM G85-9) --- 48h; 3. hot and cold loop test (ASME A112 .18.1-2005/CSA B125.1-05)---4cycles; 4. Falling sand test (ASTM D968-09, Method A)-----12liter; 5. Water immersion test (ASTM D870-02)- -------38±2°C×24h; 6. Chemical resistance test (ASTM D1308-02)--------NaOH 6mol/L; 7. Pencil hardness (ASTM D3363-05)-- -- Chinese pencil 2H; 8. Hundred cut test (ASTM D3359-09) ------ 3B or more.

The results are as follows: 1. CASS 8hOK; 2. AASS 48h OK; 3. Hot and cold loop test OK; 4. Falling sand test OK; 5. Water immersion test OK, no color change; 6. Chemical resistance test OK; Pencil hardness Chinese pencil 3H; 8. Hundred cut test 5B.

The color of the product is measured by the Minolta Spectrophotometer | Color Difference Meter CM-2600d to measure the LAB value. The measurement results are as follows: L*=75.6, A*=0.25, B*=5.3.

Example 3 Modified nylon plastic substrate coating wire drawing treatment

(1) Modified nylon plastic substrate is manually wiped and degreased.

(2) High-power sputter deposition metal layer: physical vapor deposition (PVD) metal layer on the plastic substrate treated by step (1), followed by physical vapor deposition plasma modification, high-power sputter deposition Metal layer; physical vapor deposition plasma modification process conditions are ion source current 0.4A, bias voltage 60V, duty cycle 60%, argon flow rate 50SCCM, oxygen flow rate 50SCCM; time 5min to achieve cleaning and chemical activation of the matrix The purpose of the surface; the process conditions for high-power sputter deposition of the metal layer can be adopted High-power IF pulse power supply, power supply current is 100A, voltage is 500V, deposition time is 10min, bias voltage is 40V, duty cycle is 60%, argon flow rate is 100SCCM, and the deposited metal layer is copper.

(3) Wire drawing treatment: the plastic substrate treated by the step (2) is subjected to wire drawing treatment, and the drawing is performed by an artificial method, the rotation speed of the wire drawing machine is 600 r/min; the wire drawing wheel is a flying wing wheel.

(4) Manually wiping, dusting and degreasing the plastic substrate treated in the step (3).

(5) High-power sputter deposition metal layer: physical vapor deposition plasma glow cleaning of the plastic substrate treated in step (4), followed by high-power sputtering deposition of metal layer; physical vapor deposition plasma The process conditions of the glow cleaning may be an ion source current of 0.4, a bias voltage of 20 V, a duty ratio of 80%, an argon gas flow rate of 100 SCCM, and a time of 3 min to achieve the purpose of cleaning the surface of the substrate; the process conditions for high-power sputter deposition of the metal layer may be High-power IF pulse, power supply current 70A, voltage 480V, deposition time 5min, bias voltage 50V, duty cycle 50%, argon flow rate 100SCCM, nitrogen flow rate 60SCCM; deposited metal layer is chrome metal layer.

(6) Spraying primer and topcoat: spraying the polyurethane substrate (PU) primer and UV topcoat on the plastic substrate treated by the step (5), using an automatic spray gun for spraying, the specific method of the primer spraying may be : After spraying a layer of polyurethane paint (PU) paint (paint layer thickness 20μm), send it into the infrared drying section, leveling and drying (70°C×90min), and adding high corrosion inhibitor to the primer to enhance PVD Corrosion resistance of the metal layer. The specific method of top coat spraying can be: after spraying a layer of UV paint (paint layer thickness 20μm), feeding into infrared drying section, leveling and drying (70°C×8min), leveling and drying The ultraviolet light curing section was fed to perform UV irradiation curing crosslinking (time 10 s), and the energy of UV irradiation curing was 1200 mJ/cm 2 . The color is applied in the topcoat to adjust the color of the brushed nickel paint (BNP).

According to the standard of sanitary ware, the following test standards are applied to the coated wire drawing products: 1. CASS (anti-corrosion test ASTM B368-09)-----8h; 2. AASS (salt spray test ASTM G85-9)--- -----48h; 3. Hot and cold loop test (ASME A112.18.1-2005/CSA B125.1-05)---4cycles; 4. Falling sand test (ASTM D968-09, MethodA)---- -12liter; 5. Water immersion test (ASTM D870-02) -------- 38 ± 2 ° C × 24h; 6. Chemical resistance test (ASTM D1308-02) -------- Na OH 6mol/L; 7. Pencil hardness (ASTM D3363-05)---Chinese pencil 2H; 8. Hundred cut test (ASTM D3359-09) ------ 3B or more.

The results are as follows: 1. CASS 8hOK; 2. AASS 48h OK; 3. Hot and cold loop test OK; 4. Falling sand test OK; 5. Water immersion test OK, no color change; 6. Chemical resistance test OK; Pencil hardness Chinese pencil 3H; 8. Hundred cut test 5B.

The color of the product is measured by the Minolta Spectrophotometer | Color Difference Meter CM-2600d to measure the LAB value. The measurement results are as follows: L*=74.6, A*=0.45, B*=9.8.

Example 4 Modified nylon plastic (adding 40% by weight of glass fiber, high temperature resistant to 180 ° C), substrate coating, wire drawing treatment, processing method, the first 5 steps are the same as in the case of the second embodiment, except that the powder coating is sprayed in the sixth step. The spray was sprayed with an automatic spray gun and then baked at 170 ° C for 50 min.

According to the standard of sanitary ware, the following test standards are applied to the coated wire drawing products: 1. CASS (anti-corrosion test ASTM B368-09)-----8h; 2. AASS (salt spray test ASTM G85-9)--- -----48h; 3. Hot and cold loop test (ASMEA112.18.1-2005/CSA B125.1-05)---4cycles; 4. Falling sand test (ASTM D968-09, Method A)---- -12liter; 5. Water immersion test (ASTM D870-02) -------- 38 ± 2 ° C × 24h; 6. Chemical resistance test (ASTM D1308-02) -------- NaOH 6mol/L; 7. Pencil hardness (ASTM D3363-05)---Chinese pencil 2H; 8. Hundred cut test (ASTM D3359-09) ------ 3B or more.

The results are as follows: 1. CASS 8hOK; 2. AASS 48h OK; 3. Hot and cold loop test OK; 4. Falling sand test OK; 5. Water immersion test OK, no color change; 6. Chemical resistance test OK; Pencil hardness Chinese pencil 3H; 8. Hundred cut test 5B.

The color of the product is measured by the Minolta Spectrophotometer | Color Difference Meter CM-2600d to measure the LAB value. The measurement results are as follows: L*=74.2, A*=0.45, B*=5.9.

Claims (10)

A method for fully dry-drawing the plastic substrate, comprising the steps of: 1) manually wiping and degreasing the plastic substrate; 2) performing physical vapor deposition plasma modification on the plastic substrate treated by the step 1) After that, high-power sputtering deposition of the metal layer is performed; 3) the plastic substrate treated by the step 2) is subjected to wire drawing treatment; 4) the plastic substrate treated by the step 3) is subjected to manual wiping, dust removal and degreasing treatment; 5) After the physical vapor deposition plasma glow cleaning of the plastic substrate processed in the step 4), high-power sputtering deposition of the metal layer is performed; 6) the plastic substrate treated by the step 5) is sprayed with the primer layer and the surface. The paint layer or spray powder coating is used to realize the full dry drawing method of the plastic substrate. The method for all-dry wire drawing treatment of a plastic substrate according to claim 1, wherein in the step 2), the process condition of the physical vapor deposition plasma modification is an ion source current of 0.3 to 0.6 A. , bias voltage 20~80V, duty cycle 40%~80%, argon flow rate 10~100SCCM, oxygen flow rate 0~150SCCM, acetylene flow rate 0~150SCCM, time 3~5min. The method for all-dry-drawing treatment of a plastic substrate according to claim 1, wherein in the step 2), the high-power sputter deposition metal layer is subjected to a high-power IF pulse or a large Power DC power supply, power supply current 50~200A, voltage 400~600V, deposition time 5~15min, bias voltage 20~80V, duty cycle 40%~80%, argon flow rate 60~200SCCM. The method for all-dry-drawing treatment of a plastic substrate according to claim 1, wherein in the step 2), the metal layer is made of aluminum metal, copper metal, nickel-chromium alloy, chromium metal, zirconium metal, At least one of titanium metals. The method for all-dry drawing processing of a plastic substrate according to the first aspect of the invention, wherein in the step 3), the drawing process is performed by an automatic or manual method, and the rotation speed of the wire drawing machine is 200~ 800r/min, the wire drawing wheel is at least one of a nylon wheel, a flying wing wheel and a melon cloth wheel. The method for all-dry wire drawing treatment of a plastic substrate according to claim 1, wherein in the step 5), the process condition of the physical vapor deposition plasma glow cleaning is an ion source current of 0.3 to 0.6 A. The bias voltage is 20~80V, the duty ratio is 40%~80%, the argon flow rate is 100~300SCCM, and the time is 3~5min. The method for all-dry-drawing treatment of a plastic substrate according to claim 1, wherein in the step 5), the high-power sputter deposition metal layer is subjected to a high-power IF pulse or a large Power DC power supply, power supply current 50~200A, voltage 400~600V, deposition time 2~10min, bias voltage 20~80V, duty cycle 40%~80%, argon flow rate 60~200SCCM, nitrogen flow rate 0~200SCCM. The method for all-dry-drawing treatment of a plastic substrate according to claim 1, wherein in the step 5), the metal layer is made of aluminum metal, nickel-chromium alloy, chromium metal, zirconium metal or titanium metal. At least one of them. The method of claim 1, wherein the spraying primer layer and the topcoat layer are in step 6) UV-curable lacquer or polyurethane lacquer; the thickness of the primer layer is 10~30μm; the thickness of the topcoat layer is 10~30μm. The method for all-dry wire drawing treatment of a plastic substrate according to claim 1, wherein in the step 6), the spraying method of the powder coating material is: the thickness of the powder coating layer is 20~ 50μm, if necessary, can also be toned in the topcoat to debug the desired color, and the full dry drawing effect can be selected from: brushed nickel (BN) color: L*=72.7~75.7, A *=0.2~0.8, B*=6.2~8.0; brushed stainless steel (SS) color: L*=72~76, A*=0.2~0.8, B*=4.2~6; brushed deep nickel (SL) color: L*=72~76, A*=0.2~0.8, B*=8.5~11; brushed nickel spray paint (BNP) color: L*=70~78, A*=-0.5~1.5, B*=6~10 ; L* means black and white, 0 is black, 100 is white, black is between 0 and 100; A*: positive value indicates red, negative value indicates green; B*: positive value indicates yellow, negative value indicates blue .