A gradient color plate and its preparation process

Abstract

The present application relates to the field of metal sheets, and in particular to a gradient color plate and its process, which mainly includes a substrate, a topcoat, a microcrystalline coating, a gradient color transfer ink layer and a high-viscosity non-adhesive PE protective film arranged in sequence; wherein the content of pigment fillers in the surface microcrystalline coating is less than 15%; the high-viscosity non-adhesive PE protective film has a peeling resistance of not less than 350g / 25mm and a tensile strength of not less than 140MPa. The present application has the effect that the gradient color can be adjusted at any time, and the gradient effect can be observed on the plane, and the cost is relatively low compared with the cost of coating the pearlescent gradient color plate.

Description

Technical Field

[0001] The present application relates to the field of metal plates, and in particular to a gradient color plate and a preparation process thereof. Background Art

[0002] Color steel refers to color-coated steel plate. Color-coated steel plate is a steel plate with an organic coating. It has the advantages of good corrosion resistance, bright colors, beautiful appearance, easy processing and molding, and the original strength of the steel plate, and low cost. With the continuous changes of the times and the continuous evolution of technological development, the public's cognition and preference for colors are also constantly changing. They are no longer satisfied with color steel plates of a single color. In this process, gradient colors are gradually entering the public's eyes. Gradient colors use two or more different colors to form a pattern effect, and these colors fade in or out. Gradient colors have a magical feature: it does not feel like any color, it looks a bit unique and fashionable, and full of freshness. Therefore, color steel plates with gradient effects also provide a new direction for the development of home appliance appearance.

[0003] At present, the main method for realizing gradient color plates is to apply color-changing pearlescent powder, that is, to apply color-changing pearlescent powder topcoat on the substrate to make the color plate have a gradient effect. However, this method of applying color-changing pearlescent powder has the following problems:

[0004] 1. Color changes are fixed;

[0005] 2. The color change can only be observed when the angle changes;

[0006] 3. The cost of color-changing pearlescent paint is relatively high, about 400 yuan / kg;

[0007] 4. The stability of batch production is poor. During the production process, the color-changing pearlescent powder particles float up, which can easily lead to differences in the appearance of the same batch of products before and after. Summary of the invention

[0008] In order to solve the problems existing in the existing gradient color plates coated with pearlescent powder, the present application provides a gradient color plate and a preparation process thereof.

[0009] The first aspect of the present application provides a gradient color palette, which adopts the following technical solution:

[0010] A gradient color plate, comprising a substrate, a topcoat, a microcrystalline coating, a gradient color transfer ink layer and a high-viscosity non-adhesive PE protective film arranged in sequence;

[0011] Among them, the content of pigments and fillers in the surface microcrystalline coating is less than 15%;

[0012] The peeling resistance of the high-viscosity glue-free PE protective film is not less than 350g / 25mm, and the tensile strength is not less than 140MPa.

[0013] By adopting the above technical scheme, the gradient color ink is infiltrated into the surface of the microcrystalline coating by thermal transfer, so that a color steel plate with a gradient color effect is formed. The gradient color can be adjusted at any time, and the gradient effect can be observed on the plane. The cost is relatively low compared to the cost of coating pearlescent gradient color plates. After adding the microcrystalline coating, the surface microcrystalline coating pigment content is less than 15%, which can ensure the ink transfer effect and color saturation. The added high-viscosity glue-free PE protective film solves the problem that the surface of the microcrystalline coating feels different from the previous smooth surface. It meets the requirements of the unwinding force of the protective film and the non-slip requirements of the glue and the protective film substrate during processing, and solves the problem of easy removal of the high-viscosity protective film. The overall transfer color has high firmness and strong stability, which better solves the problems existing in the existing gradient color plates.

[0014] Optionally, the microcrystalline coating mainly comprises: a sealed catalyst, a diluent and acrylic particles;

[0015] The particle size of the acrylic acid particles is 10-15 μm.

[0016] By adopting the above technical solution, the forming of the microcrystalline coating can be ensured, the fineness of the microcrystalline coating can be ensured, and the microcrystalline coating can have a good touch.

[0017] Optionally, the microcrystalline coating has a thickness of not less than 15 μm.

[0018] By adopting the above technical solution, the thickness of the microcrystalline coating is set to be no less than 15μm, which can enable the gradient color transfer ink to fully sublimate and penetrate into the microcrystalline coating. The ink is more fully distributed on the entire microcrystalline coating surface, with higher color saturation and better color fastness.

[0019] Optionally, the microcrystalline coating has a microcrystalline wrinkle line width range of 3-15 μm, and a wrinkle line spacing range of 10-30 μm; the surface roughness Ra of the microcrystalline coating is ≤3.2 μm; and the surface glossiness of the microcrystalline coating is ≤5%.

[0020] By adopting the above technical solution, the surface of the microcrystalline coating can have a skin-feeling effect and ensure a good transfer effect.

[0021] Optionally, the topcoat includes aluminum powder paint or plain paint.

[0022] By adopting the above technical solution, the topcoat uses aluminum powder paint or solid color paint to make the product more colorful and have a metallic texture.

[0023] Optionally, a primer is provided between the substrate and the topcoat, a backcoat is provided on a side of the substrate away from the primer, and a chemical treatment layer is provided between the primer and the backcoat on the substrate.

[0024] By adopting the above technical solution, the chemical treatment layer can effectively improve the anti-oxidation and corrosion performance of the substrate.

[0025] The second aspect of the present application provides a process for preparing a gradient color plate, which adopts the following technical solution:

[0026] A process for preparing a gradient color plate comprises the following steps:

[0027] S1, topcoat coating: coating the topcoat on the pretreated substrate surface and curing the topcoat;

[0028] S2, microcrystalline coating application: applying the microcrystalline coating on the cured topcoat layer, and curing the microcrystalline coating;

[0029] S3, transfer: the transfer paper pre-coated with gradient ink is subjected to thermal transfer, and the gradient ink of the transfer paper is sublimated and penetrated into the microcrystalline coating. After penetration, the content of pigment and filler in the microcrystalline coating on the surface is less than 15%;

[0030] S4, lamination: compound a high-viscosity glue-free PE protective film on the upper side of the transferred microcrystalline coating to ensure that the peeling resistance of the high-viscosity glue-free PE protective film is not less than 350g / 25mm and the tensile strength is not less than 140MPa.

[0031] By adopting the above technical solution: adding a microcrystalline coating on the topcoat can effectively improve the color fastness of the transferred product, and the surface of the microcrystalline coating has a better skin feel, giving people a soft sensory effect. The surface microcrystalline coating has a pigment content of less than 15%, and the ink transfer effect and color saturation are better; multi-color and flat gradient effects can be achieved; the product surface has excellent tactile effects while also having excellent pollution resistance and fingerprint resistance; the original surface pits, orange peel and other appearance defects that appeared when transferring on VCM products are solved.

[0032] Optional, microcrystalline coating with microcrystalline wrinkle line width ranging from 3-15μm;

[0033] The fold line spacing of the microcrystalline coating ranges from 10 to 30 μm;

[0034] The surface roughness of microcrystalline coating is Ra≤3.2μm;

[0035] The glossiness of microcrystalline coating is ≤5%.

[0036] Optionally, the transfer comprises the following steps:

[0037] Design of gradient color pattern: Use Ai software to make gradient effect, add multiple gradient sliders in the middle of the gradient color, adjust the CMYK value of each segment respectively, and refine the color change trend of the whole pattern;

[0038] Transfer, use a printer to print the thermal transfer ink onto the transfer paper, and use the thermal transfer machine to sublimate the ink on the transfer paper and penetrate into the microcrystalline coating. The heating temperature of the thermal transfer machine is 160-200°C, the pressure is 0.3-0.6MPa, and the duration is 60-100s.

[0039] By adopting the above technical solution: the color change trend of the entire pattern is refined, making the transferred gradient effect softer, smoother and more natural as a whole, avoiding the abruptness of color changes.

[0040] In summary, the present application includes at least one of the following beneficial technical effects:

[0041] The color steel plate with gradient color effect is produced by thermal transfer on the gradient color transfer ink layer on the surface of the microcrystalline coating. The gradient color can be adjusted at any time, and the gradient effect can be observed on the plane. The cost is relatively low. After adding the microcrystalline coating, the transfer color has high fastness and stability, which better solves the problems existing in the existing gradient color plates.

[0042] The thickness of the microcrystalline coating is set to be no less than 15 μm, which enables the gradient color transfer ink to fully sublimate and penetrate into the microcrystalline coating. The ink is more fully distributed on the entire microcrystalline coating surface, with higher color saturation and better color fastness. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the structure of a gradient color palette in one embodiment of the present application;

[0044] Figure 2 is a schematic structural diagram of a gradient color palette according to another embodiment of the present application;

[0045] Figure 3 is a schematic structural diagram of a chemical treatment layer of a gradient color plate according to another embodiment of the present application;

[0046] Figure 4 is a schematic diagram of a process for preparing a gradient color plate according to another embodiment of the present application;

[0047] Figure 5 It is a schematic flow chart of another transfer method of a gradient color plate preparation process according to another embodiment of the present application.

[0048] Explanation of the accompanying reference numerals: 1. substrate; 2. topcoat; 3. microcrystalline coating; 4. gradient color transfer ink layer; 5. high-viscosity glue-free PE protective film; 6. primer; 7. back paint; 8. chemical treatment layer. DETAILED DESCRIPTION

[0049] The following is combined with Figure 1-5 This application is described in further detail.

[0050] The embodiment of the present application discloses a gradient color plate, which is used for household appliances including but not limited to refrigerator door panels, panels, air conditioner panels, etc. The main purpose is to solve the problems of the existing gradient color plates made by coating color-changing pearlescent powder, such as fixed colors, poor color rendering effect, high cost and poor production stability.

[0051] The main ideas of this application are:

[0052] Reference Figure 1 A color plate with a gradient effect comprises a substrate 1, a topcoat 2, a microcrystalline coating 3 and a gradient color transfer ink layer 4 which are arranged in sequence.

[0053] By adopting the thermal transfer method, a color steel plate with a gradient color effect is produced on the surface of the microcrystalline coating 3 with a gradient color transfer ink layer 4. The gradient color can be adjusted at any time, and the gradient effect can be observed on the plane. The cost is relatively low. After adding the microcrystalline coating 3, the transfer color has high fastness and strong stability, which better solves the problems existing in the existing gradient color plates.

[0054] In another embodiment of the present application, the microcrystalline coating 3 is further described in detail:

[0055] The microcrystalline coating 3 is a coating material that can form a microcrystalline effect on the surface of the substrate 1 after high-temperature curing. Adding a microcrystalline coating 3 on the topcoat 2 can effectively improve the color fastness of the transfer product.

[0056] The thickness of the microcrystalline coating 3 is not less than 15 μm, and the content of pigments and fillers in the microcrystalline coating 3 is less than 15% to ensure that the transfer ink can fully sublimate and penetrate into the microcrystalline coating 3, so that the ink is more fully distributed on the entire surface, the color saturation is higher, and the color fastness is better.

[0057] The microcrystalline fold line width of the microcrystalline coating 3 is in the range of 3-15μm; the fold line spacing is in the range of 10-30μm; the surface roughness Ra of the microcrystalline coating 3 is ≤3.2μm; and the glossiness of the surface of the microcrystalline coating 3 is ≤5%, so that the skin feel of the surface of the microcrystalline coating 3 is better and gives people a soft sensory effect.

[0058] Reference Figure 2 The surface of the microcrystalline coating 3 can also be compounded with a microcrystalline protective film, but because the touch of the surface of the microcrystalline coating 3 is different from the smooth surface in the past, a high-viscosity glue-free PE protective film 5 must be used to avoid the glue layer being too thick and easy to slip with the PE substrate. The protective film peeling force of the high-viscosity glue-free PE protective film 5 should be ≥350g / 25mm and the tensile strength should be ≥140MPa. In order to meet the requirements of the unwinding force of the protective film and the non-slipping of the glue and the protective film substrate during processing, the problem of easy removal of the high-viscosity protective film is solved, so that the product surface has both tactile effects and excellent pollution resistance and fingerprint resistance.

[0059] In addition, in order to improve the color rendering effect of the color plate, the topcoat 2 can be aluminum paint or solid color paint to make the product more colorful and have a more metallic texture.

[0060] In another embodiment of the present application, a primer 6, a back paint 7 and a chemical treatment layer 8 may be further added, more specifically:

[0061] Reference Figure 3 A gradient color plate comprises a back paint 7, a chemical treatment layer 8, a substrate 1, a chemical treatment layer 8, a primer 6, a topcoat 2, a microcrystalline coating 3 and a gradient color transfer ink layer 4 which are sequentially arranged. By adding the back paint 7, the primer 6 and the chemical treatment layer 8, the anti-oxidation and corrosion performance of the substrate 1 can be effectively improved, and the color rendering effect and service life of the color plate can be improved.

[0062] Another embodiment of the present application also provides a process for preparing a gradient color plate.

[0063] Reference Figure 4 , a gradient color plate preparation process, mainly comprising the following steps:

[0064] S1, substrate pretreatment: chemical treatment is performed on both surfaces of the metal substrate, and a primer and a back paint are coated on the chemical treatment layer, and then cured respectively;

[0065] S2, topcoat coating: select aluminum paint or plain paint as the topcoat, apply the topcoat on the varnish surface of the substrate, and cure the topcoat;

[0066] S3, microcrystalline coating application: applying the microcrystalline coating on the cured topcoat layer, and curing the microcrystalline coating;

[0067] The microcrystalline coating includes: a closed catalyst, a diluent and a microcrystalline component. The diluent may be triethylamine, and the microcrystalline component may be acrylic particles. The acrylic particles are 10-15 μm, and the film thickness of the microcrystalline coating is not less than 15 μm.

[0068] The pigment and filler content in the microcrystalline coating is less than 15%; the microcrystalline fold line width of the microcrystalline coating is in the range of 3-15μm; the fold line spacing range is 10-30μm; the surface roughness of the microcrystalline coating Ra≤3.2μm; the glossiness of the microcrystalline coating is ≤5%.

[0069] S4, transfer: Use thermal transfer to transfer paper pre-coated with gradient ink, and sublimate the gradient ink of the transfer paper into the microcrystalline coating. To test the color fastness of the microcrystalline coating after the ink is penetrated, wipe it with alcohol to ensure that it still has good color fastness after being wiped for no less than 100 times;

[0070] S4, Lamination: Since the surface touch of the microcrystalline coating is different from the previous smooth surface, a high-viscosity glue-free PE protective film needs to be compounded on the upper side of the transferred microcrystalline coating to ensure that the peeling resistance of the high-viscosity glue-free PE protective film is not less than 350g / 25mm and the tensile strength is not less than 140Mpa. This can meet the requirements of the unwinding force of the protective film and the non-slip requirements of the glue and the protective film substrate during processing, while solving the problem of easy removal of the high-viscosity protective film.

[0071] Through the above settings, the gradient color plate preparation process of the present application mainly has the following effects:

[0072] Adding a microcrystalline coating on the topcoat can effectively improve the color fastness of the transferred product, and the surface of the microcrystalline coating has a better skin feel, giving people a soft sensory effect. The pigment content of the surface microcrystalline coating is less than 15%, and the ink transfer effect and color saturation are better; the film thickness of the surface microcrystalline coating is not less than 15μm, and the transfer ink fully sublimates and penetrates into the coating. The ink is more fully distributed on the entire surface, the color saturation is higher, and the color fastness is better; the use of aluminum powder paint or solid color paint for the topcoat makes the product color richer and has a metallic texture; the gradient color transition is more natural; multi-color and flat gradient effects can be achieved; the product surface has excellent tactile effects while also having excellent pollution resistance and fingerprint resistance; it solves the problems of surface pits, orange peel and other appearance defects that occur when transferring on VCM products.

[0073] In addition, due to the problem that the color transition of the gradient effect is not smooth when observed by naked eyes after transfer, the color has a discontinuous change, and the crossing is more obvious, in order to overcome the above problems, the present application further describes the transfer method in detail in another embodiment:

[0074] Reference Figure 4 , the transfer includes the following steps:

[0075] Design of gradient color pattern: Use Ai software to make gradient effect, add 3-6 gradient sliders in the middle of the gradient color, adjust the CMYK value of each segment respectively, refine the color change trend of the whole pattern, make the gradient effect of the transfer more soft, smooth and natural, and avoid the abruptness of color change;

[0076] Transfer pattern: Use a printer to print the thermal transfer ink onto the transfer paper, and use a thermal transfer machine to sublimate the ink on the transfer paper and penetrate into the microcrystalline coating. The heating temperature of the thermal transfer machine is 160-200°C, the pressure is 0.3-0.6MPa, and the duration is 60-100s.

[0077] In addition, after the metal sheet is printed, it is necessary to be bent to meet the processing and forming of the product. For the metal printed plate with ordinary pattern or solid color pattern, the pattern change is not obvious after the bending process. However, after the metal plate with gradient color effect is bent, due to the reduction of the thickness of the ink layer and the stretching, the gradient effect of the bent part will be stretched after the plate is bent. There will be a more obvious discontinuous area between the coating color value and the gradient pattern on both sides of the bent part, resulting in poor gradient color effect of the bent part of the metal bent plate. In order to solve this problem, in another embodiment of the present application, the transfer step can be modified as follows:

[0078] Reference Figure 5 , the transfer includes the following steps:

[0079] S1, trial production of microcrystalline coating sample: using a substrate sample coated with microcrystalline coating, thermal transfer penetrating pure color ink, recording the thickness of the microcrystalline coating to be bent, the thickness of the ink penetration layer of the microcrystalline coating to be bent, the length of the microcrystalline coating to be bent, and the original color value of the ink on the surface of the microcrystalline coating;

[0080] S2, sample bending data recording: bend the substrate in order from large to small bending angles, and record the thickness of the bending portion of the microcrystalline coating, the thickness of the ink penetration layer of the bending portion of the microcrystalline coating, the length of the bending portion of the microcrystalline coating, and the color value of the ink on the surface of the microcrystalline coating after each bending process;

[0081] S3, data fitting relationship: the original thickness, original length, original penetration ink thickness and original ink color value of the microcrystalline coating to be bent are calculated.

[0082] The bending angle of each bending part of the microcrystalline coating, the thickness after bending, length, penetration ink thickness and surface color value of the microcrystalline coating are imported into the computer system and fitted through the machine learning algorithm to form a relationship formula;

[0083] S4, Gradient effect pattern production: Use Ai software to make the gradient effect, add 3-6 gradient sliders in the middle of the gradient color, adjust the CMYK value of each segment respectively, and refine the color change trend of the entire pattern;

[0084] S5, pattern selection: mark the bending area of ​​the plate in the prepared gradient color pattern, and select the pattern in the area;

[0085] S6, preset color extraction: extract the color value of the selected pattern through computer software, and import them into the pre-fitted relationship formula as the color value after bending, and input the original thickness of the bending part of the microcrystalline coating, the original length of the bending part of the microcrystalline coating and the bending angle into the relationship formula to derive the actual preset color value and the actual ink penetration thickness;

[0086] S7, generating the actual transfer pattern: refitting the calculated actual preset color values ​​of each point and importing them into the transfer pattern to obtain the actual pattern style to be transferred;

[0087] S8, pattern transfer: print the thermal transfer ink of the actual pattern to be transferred onto the transfer paper, sublimate the ink on the transfer paper into the microcrystalline coating through the thermal transfer machine, and make the ink penetration depth of the bent part of the plate reach the actual ink penetration thickness calculated.

[0088] Through the above-mentioned transfer method, according to the predetermined effect to be achieved, the actual parameters before processing are obtained, and the gradient color pattern effect obtained by transfer can ensure a better color rendering effect after the plate is bent.

[0089] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A process for preparing a gradient color plate, characterized in that: The following steps are involved: S1, topcoat coating: coating the topcoat on the pretreated substrate surface and curing the topcoat; S2, microcrystalline coating application: applying the microcrystalline coating on the cured topcoat layer, and curing the microcrystalline coating; S3, transfer: the transfer paper pre-coated with gradient ink is subjected to thermal transfer, and the gradient ink of the transfer paper is sublimated and penetrated into the microcrystalline coating. After penetration, the pigment content of the microcrystalline coating on the surface is less than 15%. In order to test the color fastness of the microcrystalline coating after the ink is penetrated, it is wiped with alcohol to ensure that it still has good color fastness after wiping for no less than 100 times; S4, laminating: compounding a high-viscosity non-adhesive PE protective film on the upper side of the transferred microcrystalline coating to ensure that the peeling resistance of the high-viscosity non-adhesive PE protective film is not less than 350g / 25mm and the tensile strength is not less than 140Mpa; wherein the transfer includes the following steps: 1) Trial production of microcrystalline coating samples: using substrate samples coated with microcrystalline coating, thermal transfer penetrating pure color ink, and recording the original pure color ink color data; 2) Sample bending data recording: bend the substrate from large to small bending angles in sequence, and record the thickness of the microcrystalline coating, the thickness of the ink penetration layer, the length of the microcrystalline coating, and the ink color value on the surface of the microcrystalline coating after each bending process; 3) Data fitting relationship: The original thickness, original length, original ink penetration thickness and original ink color value of the part to be bent of the microcrystalline coating, and the bending angle of each bending part of the microcrystalline coating, the thickness, length, ink penetration thickness after bending and the surface color value of the microcrystalline coating are imported into the computer system, and the relationship formula is formed through the machine learning algorithm; 4) Gradient effect pattern production: Use Ai software to make the gradient effect, add 3-6 gradient sliders in the middle of the gradient color, adjust the CMYK value of each segment respectively, and refine the color change trend of the entire pattern; 5) Pattern selection: mark the bending area of ​​the sheet in the prepared gradient pattern and select the pattern in the area; 6) Preset color extraction: The selected pattern is extracted by computer software, and the color value after bending is imported into the pre-fitted relationship formula respectively, and the original thickness, original length and bending angle of the bending part of the microcrystalline coating are input into the relationship formula to derive the actual preset color value and actual ink penetration thickness; 7) Actual transfer pattern generation: The calculated actual preset color values ​​of each point are re-fitted and imported into the transfer pattern to obtain the actual pattern style to be transferred; 8) Pattern transfer: Print the thermal transfer ink of the actual pattern to be transferred onto the transfer paper, and use the thermal transfer machine to sublimate the ink on the transfer paper and penetrate into the microcrystalline coating, so that the ink penetration depth of the bent part of the plate reaches the actual ink penetration thickness calculated; Among them, the microcrystalline wrinkle line width of the microcrystalline coating ranges from 3 to 15 μm; The fold line spacing of the microcrystalline coating ranges from 10 to 30 μm; The surface roughness of microcrystalline coating is Ra≤3.2μm; Glossiness of microcrystalline coating ≤5%; The microcrystalline coating comprises: a closed catalyst, a diluent and acrylic particles; The particle size of the acrylic acid particles is 10-15 μm.

2. A process for preparing a gradient color plate according to claim 1, characterized in that: The transfer process includes the following steps: Design of gradient color pattern: Use Ai software to make gradient effect, add multiple gradient sliders in the middle of the gradient color, adjust the CMYK value of each segment respectively, and refine the color change trend of the whole pattern; Transfer, use a printer to print the thermal transfer ink onto the transfer paper, and use the thermal transfer machine to sublimate the ink on the transfer paper and penetrate into the microcrystalline coating. The heating temperature of the thermal transfer machine is 160-200°C, the pressure is 0.3-0.6MPa, and the duration is 60-100s.

3. A gradient color plate prepared by the gradient color plate preparation process according to claim 1, characterized in that: It includes a substrate, a topcoat, a microcrystalline coating, a gradient color transfer penetrating ink layer and a high-viscosity glue-free PE protective film which are arranged in sequence; Among them, the ink pigment and filler content of the microcrystalline coating on the surface after penetration is less than 15%; The peeling resistance of the high-viscosity glue-free PE protective film is not less than 350g / 25mm, and the tensile strength is not less than 140MPa.

4. A gradient color plate according to claim 3, characterized in that: The thickness of the microcrystalline coating is not less than 15 μm.

5. The gradient color plate according to claim 3, characterized in that: The topcoat includes aluminum powder paint or plain paint.

6. The gradient color plate according to claim 3, characterized in that: A primer is arranged between the substrate and the topcoat, a backcoat is arranged on the side of the substrate away from the primer, and a chemical treatment layer is arranged between the primer and the backcoat of the substrate.

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