Manufacturing method of specialty paper capable of generating different colors at different visual angles

Abstract

The invention discloses a manufacturing method of specialty paper capable of generating different colors at different visual angles, the specialty paper is coated with a substrate coating layer, the substrate coating layer is coated with a second coating layer after being cured and dried, the substrate coating layer comprises granular substrate pearl powder dyed and printed with a first color, and the second coating layer comprises granular second pearl powder dyed and printed with a second color. The diameter of the base pearl powder particles is smaller than that of the second pearl powder, and the spectral wavelength of the first-color reflection light is larger than that of the second-color reflection light. According to the technical scheme of multi-layer printing, the effects of different visual angles and different colors can be presented on a rough paper surface according to different particle diameters and concentrations of the pearl powder in the ink.

Description

Technical Field

[0001] This invention relates to a method for manufacturing specialty paper, and particularly to a method for manufacturing specialty paper that produces different colors from different viewing angles. Background Technology

[0002] Currently, the main technical solution for producing different colors from different angles on sheet-like paper materials, plastics, or metal films is to coat the surface with a coating that produces different refractive indices at different angles, thereby achieving the purpose of color change.

[0003] The technical solution is achieved by coating the outer surface of mica sheets with different oxides, thereby generating different refractive indices and achieving the technical objective. For example, existing patents from the applicant, Flex Products Inc. (USA): CN1688659A and CN1186467A; existing patents from applicant Fu Jiansheng (CN1323117C); and existing patents from Hebei Ouke Chemical Co., Ltd. (CN101200605A) all involve coating the outer layer of mica particles, then integrating them into a relevant chemical solution to form a colored coating. This coating is then applied to a carrier to create an effect where different colors appear depending on the angle.

[0004] While the above techniques produce good results, because this approach involves coating a layer of fine mica flakes, it places strict requirements on the smoothness of the carrier surface. If the carrier surface is not smooth enough, the mica particles will not be on a single plane, resulting in disordered patterns and refraction. Therefore, in practical applications, either this coating is typically applied to a smooth carrier, or a base coat is applied to the substrate being printed on (for substrates with poor smoothness) to ensure a smooth and flat surface. Printing is then performed on the base coat to achieve the desired different refractive colors.

[0005] Meanwhile, this technical solution utilizes the refractive effect of mica particles, so the coating printed on the carrier surface must be very thin; otherwise, the refractive effect will also be affected. Furthermore, since the refractive effect is produced by mica particles, external friction can cause the particles to detach or the coating to be damaged, also affecting the refractive effect. Therefore, it is generally printed on small areas (in large-area printing, when the paper is bent, cracks and mica particles will appear at the mica printing area). A protective film is usually printed on the coating surface afterwards to protect the refractive coating. This results in this technical solution not producing a thick, substantial feel, having poor abrasion resistance, and a small printing area.

[0006] Furthermore, because this type of coating refracts across the multispectral spectrum, it refracts multiple colors, resulting in a single color appearing at minute angles and creating a dazzling effect. This effect is not suitable for some products (such as high-value packaging boxes).

[0007] For the reasons mentioned above, this type of coating has never been suitable for products such as specialty papers and packaging boxes with rough surfaces.

[0008] Therefore, a new technical solution is needed to solve the above problems. By adopting the new solution on special paper with a rough surface, the entire paper surface can present different colors from different viewing angles. Summary of the Invention

[0009] The purpose of this invention is to overcome the above-mentioned defects and provide a method for manufacturing special paper that produces different colors from different viewing angles. By using a multi-layer printing technology, the method achieves different color effects on a rough paper surface by varying the particle diameter and concentration of pearlescent powder in the ink.

[0010] The objective of this invention is achieved through the following means: A method for manufacturing a specialty paper that produces different colors from different viewing angles involves coating a base coating layer onto the specialty paper, and after the base coating layer has cured and dried, coating a second coating layer. The base coating includes granular base pearlescent powder dyed and printed with a first color, and the second coating includes granular second pearlescent powder dyed and printed with a second color. The diameter of the base pearlescent powder particles is smaller than the diameter of the second pearlescent powder, and the spectral wavelength of the light reflected by the first color is greater than the spectral wavelength of the light reflected by the second color.

[0011] In the above description, as a preferred embodiment, the diameter ratio of the base pearlescent powder and the second pearlescent powder is 1:1.5-1:3.

[0012] In the above description, as a preferred embodiment, the diameter of the substrate pearlescent powder is 10-60 μm.

[0013] In the above description, as a preferred option, the second pearlescent powder is 20-100um.

[0014] In the above description, as a preferred embodiment, the base coating also includes a first color water-based ink, ink thinner, anhydrous ethanol, leveling agent, defoamer, wetting agent, and adhesion promoter.

[0015] In the above description, as a preferred embodiment, the materials of the base coating are as follows by mass ratio: 20-28 for base pearlescent powder, 4-6 for the first color water-based ink, 40-60 for ink thinner, 17-21 for anhydrous ethanol, 0.15-0.25 for leveling agent, 0.1-0.18 for defoamer, 0.17-0.32 for wetting agent, and 0.3-0.4 for adhesion promoter.

[0016] In the above description, as a preferred embodiment, the second coating also includes a second color water-based ink, ink thinner, anhydrous ethanol, leveling agent, defoamer, wetting agent, and adhesion promoter.

[0017] In the above description, as a preferred embodiment, the materials of the second coating are as follows by mass ratio: second pearlescent powder 13-18, second color ink 4-6, ink thinner 45-55, anhydrous ethanol 28-32, leveling agent 0.15-0.25, defoamer 0.1-0.18, wetting agent 0.17-0.32, and adhesion promoter 0.3-0.4.

[0018] In the above description, as a preferred embodiment, a third coating layer is applied after the second coating layer has cured and dried. The third coating layer includes granular pearlescent powder dyed with a third color. The diameter of the third pearlescent powder particles is larger than the diameter of the second pearlescent powder, and the spectral wavelength of the reflected light of the third color is smaller than the spectral wavelength of the reflected light of the second color. The ratio of the diameters of the second pearlescent powder and the third pearlescent powder is 1:2 to 1:3.

[0019] In the above description, as a preferred embodiment, the third coating comprises the following materials in the following mass ratios: 6-10 parts third pearlescent powder, 0.9-1.1 parts third color water-based ink, 50-60 parts ink thinner, 32-37 parts anhydrous ethanol, 0.15-0.25 parts leveling agent, 0.1-0.18 parts defoamer, 0.19-0.21 parts wetting agent, and 0.4-0.5 parts anti-abrasion agent.

[0020] In the above description, as a preferred embodiment, the first color is red, the second color is purple, and the third color is blue.

[0021] The beneficial effects of this invention are: by using a multi-layer printing technology, different colors can be produced on a rough paper surface by varying the particle diameter and concentration of pearlescent powder in the ink, depending on the viewing angle. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a single-sided coating in this embodiment; Figure 2 This is a side view schematic diagram of the arrangement of pearlescent powder particles in a single-sided coating according to this embodiment; Figure 3 This is a top view schematic diagram of the arrangement of pearlescent powder particles in the single-sided coating of this embodiment; 1. Specialty paper; 2. Base coating layer, 201, base pearlescent powder particles; 3. Second coating layer, 301, second pearlescent powder particles; 4. Third coating layer, 401, third pearlescent powder particles. Detailed Implementation The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] The objective of this invention is achieved through the following means: The formulation and manufacturing process of the base coating layer are as follows: The base coating formulation for Example 1 is as follows, with proportions calculated by mass: 215 interference red pearlescent powder (this pearlescent powder is an existing product, available in major markets and e-commerce platforms, such as the website: https: / / cn.diytrade.com / china / pd / 13075866 / %E8%99%B9%E5%BD%A9%E7%B3%BB%E5%88%97%E9%87%91%E7%BA%A2%E7%9F% B3XL215%E7%8F%8D%E7%8F%A0%E7%BA%A2%E7%8F%A0%E5%85%89%E7%B2%89.html (and website: http: / / china.makepolo.com / product-picture / 100249391783_0.html), particle size: 25-35um (using grinding and mesh screening processes, so it is generally a range value, that is, the diameter of the ground powder particles within the range is selected. The relevant grinding and screening processes are detailed in the following existing public documents CN201822209894.1, CN115382646A, CN111388508A, CN107913846A), content: 25%, water-based rose red paste: 5%, ink oil: 50%, anhydrous ethanol: 19%, leveling agent: 0.2%, defoamer: 0.15%, wetting agent: 0.3%, adhesion promoter: 0.35%. The water-based rose red paste, anhydrous ethanol, and ink oil mentioned above are all standard names and products in the chemical industry, and are sold by various chemical companies and e-commerce sales platforms. They will not be described one by one here. The proportions of the above materials are based on an error of less than 2%.

[0024] The manufacturing process of the base coating in Example 1 is as follows: 1. First, add 50kg of ink-mixing oil to the disperser's hopper and run the machine at 150 rpm for 5 minutes.

[0025] 2. Add 0.2 kg of leveling agent to the disperser hopper and run the machine at 1500 rpm for 5 minutes.

[0026] 3. Add 0.3 kg of wetting agent into the material hopper and run the machine at 1500 rpm for 10 minutes.

[0027] 4. Add 0.35 kg of adhesion promoter to the material bucket and stir for 3 minutes at 1200 rpm.

[0028] 5. Add 0.15 kg of defoamer to the material tank and stir for 10 minutes at 800 rpm.

[0029] 6. Add 19 kg of anhydrous ethanol to the material tank and start the machine at 600 rpm for 10 minutes to thoroughly mix all the added materials.

[0030] 7. Finally, add 25kg of pearlescent powder and 5kg of rose red paste into the mixing tank and start the machine at 1800 rpm for 20 minutes.

[0031] 8. Viscosity test: Use a Forte 4 cup to measure the viscosity in 20 to 22 seconds.

[0032] 9. Surface effect inspection: When scraping a 15mm thread stick onto 120g black cardstock, there should be no pinholes, bubbles, pits, or other defects.

[0033] 10. Adhesion test: Stick 3M tape to the surface of the paper, smooth it with a ruler, pull the paper with a force of 20kg for 1 second, and test with a No. 42 dyne pen to ensure there is no shrinkage.

[0034] The base coating was tested using the LAB color system (also known as the X-Rite color difference test method), and its color values ​​are: L: 56.11, a: +48.52, b: +1.80.

[0035] The qualified base coating is prepared and placed in the coating tank. White specialty paper 1 passes through the tank, so that both sides are evenly coated with the coating. Then, using a cashmere scraper and roller (the paper passes through the roller and the scraper treats the coating on the paper surface), the excess coating on the surface is removed, so that the coating is evenly applied to the specialty paper to form the base coating layer 2. The paper is then dried to facilitate the second coating.

[0036] The base pearlescent powder particles 201 have a relatively fine particle size and a high pigment content. At the bottom layer, they act as a masking agent for the surface color and fibers of the base specialty paper 1, preventing the color and paper fibers from showing through. Simultaneously, they ensure a smooth, even, and opaque paper surface. No anti-abrasion agents should be added during this step, as this facilitates the recoating of the second coating layer and enhances the adhesion between the base coating layer 2 and the second coating layer 3.

[0037] The second coating formulation is as follows, with proportions calculated by mass: 6583 Crystal Violet Pearl Powder, particle size: 55-65µm, content 15%; Qinglian paste ink: 3%; ink thinner: 50%; anhydrous ethanol: 30%; leveling agent: 0.2%; wetting agent: 0.3%; adhesion promoter: 0.35%; defoamer: 0.15%. The proportions of the above materials should be within a 2% tolerance. The manufacturing process of the second coating in Example 1 is as follows: 1. Add 50kg of ink-mixing oil to the disperser's hopper and run the machine at 150 rpm for 5 minutes.

[0038] 2. Add 15 kg of anhydrous ethanol to the disperser's hopper and run the machine at 300 rpm for 15 minutes. (Run the machine slowly to avoid excessive overflow, which could damage the material's properties.) 3. Add 0.2 kg of leveling agent to the disperser hopper and run the machine at 1500 rpm for 5 minutes.

[0039] 4. Add 0.3 kg of wetting agent to the disperser hopper and start the machine at 1500 rpm for 10 minutes.

[0040] 5. Add 0.35 kg of adhesion promoter to the disperser hopper and run the machine at 1200 rpm for 3 minutes.

[0041] 6. Add 0.15 kg of defoamer to the disperser hopper, run the machine at 800 rpm, and stir for 10 minutes.

[0042] 7. Add 15 kg of anhydrous ethanol to the disperser hopper and run the machine at 600 rpm for 10 minutes.

[0043] 8. Add 15kg of No. 6583 crystal shimmering purple pearl powder and 3kg of Qinglian paste ink to the material bucket, and stir quickly at 1800 rpm for 20 minutes.

[0044] 9. Viscosity test: Use a 4-cup to measure the viscosity in 15 to 18 seconds.

[0045] 10. Surface effect inspection: When scraping a 15mm thread stick onto 120g black cardstock, there should be no pinholes, lines, bubbles, pits, or other defects.

[0046] 11. Adhesion test: Stick 3M tape to the surface of the paper, smooth it with a ruler, pull it with 20kg force for 1 second until it tears, and test with a No. 42 dyne pen to ensure there is no shrinkage.

[0047] The color displayed by the second coating, as measured by the LAB color system (also known as the X-Rite color difference test method), has the following color values: L: 38.43, a: +24.54, b: -25.99.

[0048] A qualified second coating is prepared and placed in a coating tank. Special paper 1, which is coated with the base coating layer 2, passes through the tank, so that both sides are evenly coated with the second coating. Then, using a cashmere scraper and a roller (the paper passes through the roller and the scraper treats the coating on the paper surface), the remaining coating on the surface is treated, so that the coating is evenly coated on the special paper 1 to form the second coating layer 3. The paper is then dried to facilitate a third coating.

[0049] Compared to the base pearlescent particles in the base coating layer, the second pearlescent particles 301 of the second coating layer 3 have a larger diameter. The content of the second pearlescent particles 301 and the pigment is reduced, and the viscosity is also reduced. The spacing between the second pearlescent particles 301 is also larger, which reduces the hiding power and allows the base material to show through. Because it is made in the middle layer, it is easy to make the base material show through with different effects when viewed from different angles, so that two colors refract when the second coating layer 3 and the base coating layer 2 are superimposed.

[0050] The second coating layer 2 plays a crucial and prominent role, serving as a bridge between the previous and subsequent layers. It lacks anti-wear agents, facilitating recoating of the third coating layer 4. It exhibits good adhesion. The content and concentration of the second pearlescent powder particles 301 and colorant are reduced. Furthermore, the second pearlescent powder particles 301 utilize crystal iridescent pearlescent material with a particle size of 55-65µm, and their content is appropriately reduced to lower hiding power. Due to the larger interparticle gaps, the base coating layer is appropriately revealed. The use of crystal iridescent pearlescent material creates a significant difference in color development from the base coating layer, resulting in better color rendering and a lower color intensity.

[0051] The third coating formulation is as follows, with proportions calculated by mass: 6550 crystal blue pearl powder (particle size: 110-120µm, content: 8%), pure blue ink paste: 1% content, ink thinner: 55%, anhydrous ethanol: 35%, leveling agent: 0.2%, wetting agent: 0.2%, adhesion promoter: 0.35% content, defoamer: 0.15%, anti-abrasion agent: 0.45%. The proportions of the above materials should be within a 2% tolerance. The manufacturing process of the third coating in Example 1 is as follows: 1. Add 55kg of ink-mixing oil to the disperser's hopper and run the machine at 150 rpm for 5 minutes.

[0052] 2. Add 15 kg of anhydrous ethanol to the disperser hopper and run the machine at 300 rpm for 15 minutes.

[0053] 3. Add 0.2 kg of leveling agent to the disperser hopper and run the machine at 1500 rpm for 5 minutes.

[0054] 4. Add 0.2 kg of wetting agent to the disperser hopper and run the machine at 1500 rpm for 10 minutes.

[0055] 5. Add 0.45 kg of anti-wear agent to the disperser hopper and run the machine at 1800 rpm for 8 minutes.

[0056] 6. Add 0.15 kg of defoamer to the disperser hopper, run the machine at 800 rpm, and stir for 10 minutes.

[0057] 7. Add 20 kg of anhydrous ethanol to the disperser hopper and run the machine at 600 rpm for 10 minutes.

[0058] 8. Add 8kg of 6550 crystal blue pearl powder and 1kg of pure blue paste to the disperser hopper, set the machine speed to 1800 rpm, and stir rapidly for 20 minutes.

[0059] 9. Viscosity test: Use a 4-cup to measure the viscosity in 12 to 15 seconds.

[0060] 10. Surface effect inspection: When scraping a 15mm thread stick onto 120g black cardstock, there should be no pinholes, lines, bubbles, pits, or other defects.

[0061] 11. Adhesion test: Stick 3M tape to the surface of the paper, smooth it with a ruler, pull it with 20kg force for 1 second without tearing the paper, and the surface should not be damaged. Also, test with a No. 38 dyne pen and there should be no shrinkage.

[0062] The color displayed by the third coating, measured using the LAB color system (also known as the X-Rite color difference test), has the following color values: L: 38.43, a: +24.54, b: -25.99. A qualified third coating is prepared and placed in a coating tank. Special paper 1, which is coated with the base coating layer 2 and the second coating layer 3, passes through the tank, so that both sides are evenly coated with the coating. Then, using a cashmere scraper and a roller (the paper passes through the roller and the scraper treats the coating on the paper surface), the remaining coating on the surface is treated, so that the coating is evenly coated on the special paper to form the third coating layer 4. The paper is then dried.

[0063] The particle size of the third pearlescent powder particles 401 in the third coating layer 4 is further coarsened, and the ratio of the third pearlescent powder particles 401 to the color paste is lower than that of the base coating and the second coating, resulting in a lower viscosity. Simultaneously, the gaps between the third pearlescent powder particles 401 are further increased. This facilitates the transmission of the colors from the base coating layer 2 and the second coating layer 3, allowing them to refract different colors at different angles, achieving a refractive effect of three different colors after the three coatings are layered.

[0064] The third coating layer 4 allows the colors of the base coating layer 2 and the second coating layer 4 to show through, and the surface is protected by an anti-abrasion agent, playing a crucial role in highlighting the color. Adding 4.5% anti-abrasion agent makes the paper surface scratch-resistant, waterproof, and anti-sticking. The 6550 crystal blue pearl powder has a particle size of 110-120um and a lower concentration, significantly reducing the hiding power of the third coating layer 4, allowing both the base coating layer 2 and the second coating layer 3 to show through. Furthermore, during overlapping, it refracts different visual colors at different angles. This results in a more vibrant and stable color effect, without any flickering of multiple colors.

[0065] Example 1: Refraction at different angles produces different colors, and the color detection results are as follows: 1. Sample for testing: Example 1 2. Testing tool: X-Rite colorimeter 3. Testing method: X-Rite color difference testing method 4. Testing environment: Indoor light intensity 300-500 lux, color temperature 5000K Implementation 2 By adjusting the formula, and modifying the formulas of various coatings based on Example 1, it was determined whether the special paper 1 could still achieve a good color change effect under the minimum value, thus forming Example 2. The specific formula of Example 2 is as follows: Implementation 3 By adjusting the formula, and modifying the formulas of various coatings based on Example 1, it was determined whether the special paper 1 could still achieve a good color change effect under the maximum value, thus forming Example 3. The specific formula of Example 3 is as follows: Under the same detection methods and conditions as in Example 1, color difference detection was performed on the samples from Examples 2 and 3, and the following detection results were obtained: The data from the above embodiments demonstrate that this technical solution is effective, successfully achieving the goal of displaying different colors on the surface of specialty paper from different viewing angles. Furthermore, actual testing shows that the optimal effect of this technical solution is achieved when the wavelength of the base coating's color spectrum is greater than the wavelength of the second coating's color spectrum, which is then greater than the wavelength of the third coating's color spectrum. Applying a coating with a longer wavelength over a coating with a shorter wavelength results in poor color transmission, thus negating the color-changing effect.

[0066] The embodiments of this technical solution are mainly tests conducted on specialty papers. The same effect can be achieved using this technical solution on materials such as cartoon paper and rough plastic sheets.

[0067] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method of manufacturing a special paper which produces different colors at different viewing angles, characterized by: A base coating layer is applied to a special paper. After the base coating layer has cured and dried, a second coating layer is applied. The base coating includes granular pearlescent powder dyed with the first color, and the second coating includes granular pearlescent powder dyed with the second color. The diameter of the base pearlescent powder particles is smaller than the diameter of the second pearlescent powder particles, and the spectral wavelength of the light reflected by the first color is greater than the spectral wavelength of the light reflected by the second color.

2. The method of claim 1, wherein the special paper is characterized in that: The ratio of the diameter of the base pearlescent powder particles to the diameter of the second pearlescent powder particles is 1:1.5-1:

3.

3. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 2, characterized in that: The diameter of the pearlescent powder particles in the substrate is 10-60 μm.

4. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 2, characterized in that: The diameter of the second pearlescent powder particles is 20-100um.

5. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 1, characterized in that: The base coating also includes a first color water-based ink, ink thinner, anhydrous ethanol, leveling agent, defoamer, wetting agent, and adhesion promoter.

6. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 5, characterized in that: The base coating materials are as follows by mass ratio: 20-28 for base pearlescent powder, 4-6 for first color water-based ink, 40-60 for ink thinner, 17-21 for anhydrous ethanol, 0.15-0.25 for leveling agent, 0.1-0.18 for defoamer, 0.17-0.32 for wetting agent, and 0.3-0.4 for adhesion promoter.

7. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 1, characterized in that: The second coating also includes a second color water-based ink, ink thinner, anhydrous ethanol, leveling agent, defoamer, wetting agent, and adhesion promoter.

8. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 7, characterized in that: The materials of the second coating are as follows by mass ratio: second pearlescent powder 13-18, second color water-based ink 2-4, ink thinner 45-55, anhydrous ethanol 28-32, leveling agent 0.15-0.25, defoamer 0.1-0.18, wetting agent 0.17-0.32, and adhesion promoter 0.3-0.

4.

9. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 1, characterized in that: After the second coating layer has cured and dried, a third coating layer is applied. The third coating includes granular pearlescent powder dyed with a third color. The diameter of the third pearlescent powder particles is larger than that of the second pearlescent powder particles, and the spectral wavelength of the reflected light of the third color is smaller than that of the reflected light of the second color. The ratio of the diameters of the second pearlescent powder to the third pearlescent powder is 1:2 to 1:

3.

10. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 8, characterized in that: The third coating comprises the following materials in the following mass ratios: 6-10 parts third pearlescent powder, 0.9-1.1 parts third color water-based ink, 50-60 parts ink thinner, 32-37 parts anhydrous ethanol, 0.15-0.25 parts leveling agent, 0.1-0.18 parts defoamer, 0.19-0.21 parts wetting agent, and 0.4-0.5 parts anti-abrasion agent.

11. The method for manufacturing special paper that produces different colors from different viewing angles according to claim 9, characterized in that: The first color is red, the second color is purple, and the third color is blue.

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