Inorganic UV ink, color coated metal plate and preparation method of color coated metal plate

Abstract

The invention discloses UV ink, a color coated metal plate and a preparation method of the color coated metal plate, and the inorganic UV ink comprises the following raw materials: an inorganic pigment, an active diluent, an active oligomer, a dispersant, a photoinitiator and an auxiliary agent. The inorganic UV ink has excellent weather resistance when being applied to a colored coated metal plate, and can meet the weather resistance requirement of the plate.

Description

Technical Field

[0001] This invention belongs to the field of sheet metal technology, and specifically relates to inorganic UV ink, color-coated metal sheets and their preparation methods. Background Technology

[0002] Currently, color-coated metal sheets refer to composite metal materials made by surface processing of pure metal or alloy substrates processed from metal materials such as aluminum, steel, and zinc, coating them with paint and decorative paint, and then shaping them through processes such as baking and cutting. The coating process involves first uniformly applying a primer using rollers, followed by a topcoat and a backcoat. After coating comes the baking process, where the primer, topcoat, and backcoat are baked and cured in a specific temperature environment to ensure the coating's smoothness, hardness, gloss, and adhesion meet application requirements. The entire coating process is lengthy, time-consuming, energy-intensive, and land-intensive.

[0003] To address the problem of excessively long existing coating process paths, UV ink printing has begun to replace traditional paint spraying for color-coated metal sheets, thereby shortening the production process, reducing time and energy consumption, and also reducing equipment footprint. However, most of the existing UV inks used for color-coated metal sheets are organic pigment UV inks, which cannot meet the weather resistance requirements of the sheets. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an inorganic UV ink, a color-coated metal plate, and a method for preparing the same. The inorganic UV ink exhibits excellent weather resistance when applied to the color-coated metal plate, meeting the weather resistance requirements of the plate.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: Inorganic UV inks include the following raw materials: inorganic pigments, reactive diluents, reactive oligomers, dispersants, photoinitiators, and additives.

[0006] In some embodiments of the present invention, the inorganic UV ink comprises the following raw materials in parts by weight: inorganic pigment: 10-25 parts; reactive diluent: 50-80 parts; reactive oligomer: 2-5 parts; dispersant: 2-5 parts; photoinitiator: 3-10 parts; and additives: 0.5-2 parts.

[0007] In some embodiments of the present invention, the inorganic pigment is at least one selected from red inorganic pigment, yellow inorganic pigment, blue inorganic pigment, black inorganic pigment, and white inorganic pigment.

[0008] In some embodiments of the present invention, the red inorganic pigment is selected from one of iron oxide red, cadmium red and cerium sulfide red inorganic pigments; the yellow inorganic pigment is selected from one of bismuth yellow, zirconium praseodymium yellow and vanadium zirconium yellow inorganic pigments; the blue inorganic pigment is selected from one of cobalt blue and vanadium zirconium blue inorganic pigments; the black inorganic pigment is selected from one of carbon black, copper chromium black and cobalt black; and the white inorganic pigment is selected from titanium dioxide inorganic pigment.

[0009] In some embodiments of the present invention, the reactive diluent includes at least one of monofunctional acrylates, difunctional acrylates, and polyfunctional acrylates.

[0010] In some embodiments of the present invention, the active oligomer includes at least one of polyester acrylate, polyether acrylate, polyurethane acrylate, epoxy acrylate, polyamide acrylate and polyamine acrylate.

[0011] In some embodiments of the present invention, the dispersant includes at least one of DisperBYK-9130, DisperBYK-9151, Lubrizol Solsperse 24000, Lubrizol Solsperse 35000, Evka EFKA4310, Evka EFKA4701, and Evka EFKA4703.

[0012] In some embodiments of the present invention, the photoinitiator includes at least one of photoinitiator 184, photoinitiator 819, photoinitiator ITX, photoinitiator TPO, photoinitiator 907, photoinitiator 1173, and photoinitiator Detx.

[0013] In some embodiments of the present invention, the additives include at least one of leveling agents and stabilizers.

[0014] In some embodiments of the present invention, the leveling agent includes at least one of BYK-377, TEGOFLOW370, TEGOFLOW425 and TEGOFLOW432.

[0015] In some embodiments of the present invention, the stabilizer includes GENORAD16.

[0016] In some embodiments of the present invention, the inorganic UV ink satisfies onepass 5-color channel continuous printing and high-speed jet printing, with a printhead-to-media distance of 5-20mm.

[0017] A method for preparing an inorganic UV ink as described above includes the following steps: mixing and grinding inorganic pigments, reactive diluents, reactive oligomers, dispersants, photoinitiators and additives.

[0018] In some embodiments of the present invention, the grinding is performed by a sand mill, and the D50 of the material obtained after grinding is 0.2-0.3 μm.

[0019] A color-coated metal sheet comprises, from bottom to top, a metal sheet layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer, wherein the inorganic UV ink printing layer is obtained by printing with the inorganic UV ink as described above.

[0020] In some embodiments of the present invention, the metal sheet in the metal sheet layer includes one of stainless steel sheet, galvanized sheet and aluminum sheet.

[0021] In some embodiments of the present invention, the primer in the primer layer includes an epoxy zinc-rich primer, and the surface of the epoxy zinc-rich primer is coated with a polyurethane acrylate coating or a water-based hydroxyl polyurethane baking varnish.

[0022] In some embodiments of the present invention, the thickness of the primer layer is 10-20 μm.

[0023] In some embodiments of the present invention, the thickness of the inorganic UV ink printing layer is 5-10 μm.

[0024] In some embodiments of the present invention, the thickness of the varnish protective layer is 5-30 μm.

[0025] In some embodiments of the present invention, the varnish in the varnish protective layer includes polyurethane acrylate varnish.

[0026] A method for preparing a color-coated metal plate as described above includes the following steps: selecting a metal plate, performing a surface cleaning treatment, applying a primer to obtain a primer layer, then printing inorganic UV ink on the primer layer to obtain an inorganic UV ink printing layer to form a decorative pattern, and finally applying a varnish on the inorganic UV ink printing layer to obtain a varnish protective layer, thereby obtaining a color-coated metal plate.

[0027] The beneficial effects of this invention are: (1) The inorganic UV ink of the present invention can withstand high temperature baking at 250°C for 1 hour after drying without yellowing or cracking; (2) The colored coated metal plate prepared by the inorganic UV ink of the present invention was tested for weather resistance, and the color difference ΔE < 3, and the weather resistance level can reach level 5. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the color-coated metal plate of Embodiment 1 of the present invention.

[0029] Figure label: 100. Metal sheet layer; 200. Primer layer; 300. Inorganic UV ink printing layer; 400. Glossy protective layer. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments.

[0031] Example 1: An inorganic UV ink comprises the following raw materials in parts by weight: iron oxide red inorganic pigment: 10 parts; monofunctional acrylate: 50 parts; polyester acrylate: 2 parts; DisperBYK-9130: 2 parts; photoinitiator 184: 3 parts; BYK-377: 0.3 parts; GENORAD16: 0.2 parts.

[0032] A method for preparing an inorganic UV ink as described above includes the following steps: mixing the raw materials and grinding them through a sand mill until the D50 of the material is 0.2 μm.

[0033] A type of color-coated metal sheet, such as Figure 1 As shown, from bottom to top, it includes a metal plate layer 100, a primer layer 200, an inorganic UV ink printing layer 300, and a varnish protective layer 400. The inorganic UV ink printing layer 300 is obtained by printing with the inorganic UV ink as described above. The metal plate layer 100 is a stainless steel plate. The primer of the primer layer 200 is an epoxy zinc-rich primer. A water-based hydroxyl polyurethane baking varnish is coated on the epoxy zinc-rich primer. The thickness of the primer layer 200 is 20 μm. The thickness of the inorganic UV ink printing layer 300 is 5 μm. The thickness of the varnish protective layer 400 is 20 μm. The varnish in the varnish protective layer 400 is a polyurethane acrylate varnish.

[0034] A method for preparing a color-coated metal sheet as described above includes the following steps: selecting a stainless steel sheet, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer 200 by roller coating; then printing an inorganic UV ink layer 300 on the primer layer 200 using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish layer 400 to the inorganic UV ink varnish layer 300 by roller coating, thus obtaining the color-coated metal sheet.

[0035] Example 2: An inorganic UV ink comprises the following raw materials in parts by weight: bismuth yellow inorganic pigment: 25 parts; bifunctional acrylate: 80 parts; polyether acrylate: 5 parts; DisperBYK-9151: 5 parts; photoinitiator 819: 10 parts; TEGOFLOW370: 1 part; GENORAD16: 1 part.

[0036] A method for preparing an inorganic UV ink as described above includes the following steps: mixing the raw materials and grinding them through a sand mill until the D50 of the material is 0.3 μm.

[0037] A color-coated metal plate comprises, from bottom to top, a metal plate layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer. The inorganic UV ink printing layer is obtained by printing with the inorganic UV ink as described above. The metal plate layer is a galvanized plate. The primer of the primer layer is an epoxy zinc-rich primer. A water-based hydroxyl polyurethane baking varnish is coated on the epoxy zinc-rich primer. The thickness of the primer layer is 20 μm. The thickness of the inorganic UV ink printing layer is 5 μm. The thickness of the varnish protective layer is 20 μm. The varnish in the varnish protective layer is a polyurethane acrylate varnish.

[0038] A method for preparing a color-coated metal sheet as described above includes the following steps: selecting a galvanized sheet, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer by roller coating; then printing an inorganic UV ink layer on the primer layer using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish layer to the entire sheet by roller coating to obtain a varnish protective layer, thus obtaining the color-coated metal sheet.

[0039] Example 3: An inorganic UV ink comprises the following raw materials in parts by weight: cobalt blue inorganic pigment: 20 parts; bifunctional acrylate: 60 parts; polyurethane acrylate: 3 parts; Lubrizol Solsperse 24000: 3 parts; photoinitiator ITX: 6 parts; TEGOFLOW 425: 0.5 parts; GENORAD 16: 0.5 parts.

[0040] A method for preparing an inorganic UV ink as described above includes the following steps: mixing the raw materials and grinding them through a sand mill until the D50 of the material is 0.25 μm.

[0041] A color-coated metal plate comprises, from bottom to top, a metal plate layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer. The inorganic UV ink printing layer is obtained by printing with the inorganic UV ink as described above. The metal plate layer is an aluminum plate. The primer of the primer layer is an epoxy zinc-rich primer. A polyurethane acrylate coating (cured by UV) is applied to the epoxy zinc-rich primer. The thickness of the primer layer is 20 μm. The thickness of the inorganic UV ink printing layer is 8 μm. The thickness of the varnish protective layer is 20 μm. The varnish in the varnish protective layer is a polyurethane acrylate varnish.

[0042] A method for preparing a color-coated metal plate as described above includes the following steps: selecting an aluminum plate, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer by roller coating; then printing an inorganic UV ink layer on the primer layer using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish layer to the entire plate by roller coating to obtain a varnish protective layer, thus obtaining the color-coated metal plate.

[0043] Example 4: An inorganic UV ink comprises the following raw materials in parts by weight: inorganic pigment: 20 parts; bifunctional acrylate: 60 parts; epoxy acrylate: 3 parts; Efka EFKA4310: 3 parts; photoinitiator TPO: 6 parts; TEGOFLOW432: 0.5 parts; GENORAD16: 0.5 parts.

[0044] A method for preparing an inorganic UV ink as described above includes the following steps: mixing the raw materials and grinding them through a sand mill until the D50 of the material is 0.25 μm.

[0045] Red inorganic UV ink, yellow inorganic UV ink, blue inorganic UV ink, and black inorganic UV ink were prepared by replacing the aforementioned inorganic pigments with cadmium red inorganic pigment, zirconium praseodymium yellow inorganic pigment, vanadium zirconium blue inorganic pigment, and carbon black inorganic pigment, respectively.

[0046] A color-coated metal plate comprises, from bottom to top, a metal plate layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer. The inorganic UV ink printing layer is obtained by printing with four kinds of inorganic UV inks as described above. The metal plate layer is an aluminum plate. The primer of the primer layer is an epoxy zinc-rich primer. A water-based hydroxyl polyurethane baking varnish is coated on the epoxy zinc-rich primer. The thickness of the primer layer is 20 μm. The thickness of the inorganic UV ink printing layer is 10 μm. The thickness of the varnish protective layer is 20 μm. The varnish in the varnish protective layer is a polyurethane acrylate varnish.

[0047] A method for preparing a color-coated metal plate as described above includes the following steps: selecting an aluminum plate, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer by roller coating; then printing an inorganic UV ink layer on the primer layer using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish layer to the entire plate by roller coating to obtain a varnish protective layer, thus obtaining the color-coated metal plate.

[0048] Example 5: An inorganic UV ink comprises the following raw materials in parts by weight: inorganic pigment: 20 parts; monofunctional acrylate: 60 parts; polyamide acrylate: 3 parts; Efka EFKA4703: 3 parts; photoinitiator 907: 6 parts; TEGOFLOW425: 0.5 parts; GENORAD16: 0.5 parts.

[0049] A method for preparing an inorganic UV ink as described above includes the following steps: mixing the raw materials and grinding them through a sand mill until the D50 of the material is 0.25 μm.

[0050] Red inorganic UV ink, yellow inorganic UV ink, blue inorganic UV ink, black inorganic UV ink, and white inorganic UV ink were prepared by replacing the aforementioned inorganic pigments with cadmium red inorganic pigment, zirconium praseodymium yellow inorganic pigment, vanadium zirconium blue inorganic pigment, copper chromium black inorganic pigment, and titanium dioxide inorganic pigment, respectively.

[0051] A color-coated metal plate comprises, from bottom to top, a metal plate layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer. The inorganic UV ink printing layer is obtained by printing with the five inorganic UV inks mentioned above. The metal plate layer is an aluminum plate. The primer of the primer layer is an epoxy zinc-rich primer. A water-based hydroxyl polyurethane baking primer layer with a thickness of 10 μm is coated on the epoxy zinc-rich primer. The inorganic UV ink printing layer has a thickness of 10 μm. The varnish protective layer has a thickness of 20 μm. The varnish in the varnish protective layer is a polyurethane acrylate varnish.

[0052] A method for preparing a color-coated metal plate as described above includes the following steps: selecting an aluminum plate, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer by roller coating; then printing an inorganic UV ink layer on the primer layer using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish layer to the entire plate by roller coating to obtain a varnish protective layer, thus obtaining the color-coated metal plate.

[0053] Comparative Example 1: (The only difference from Example 3 is that an organic UV ink printing layer was obtained by printing with organic UV ink) A color-coated metal sheet comprises, from bottom to top, a metal sheet layer, a primer layer, an organic UV ink printing layer, and a varnish protective layer. The organic UV ink printing layer is obtained by printing with organic UV ink, which is S3200 label blue UV ink produced by Zhilai (Guangdong) New Materials Co., Ltd., with phthalocyanine blue pigment and a solid content of 2.5%.

[0054] The metal sheet layer is an aluminum plate, the primer layer is an epoxy zinc-rich primer, and a polyurethane acrylate coating (cured by UV) is applied on the epoxy zinc-rich primer. The thickness of the primer layer is 20μm, the thickness of the organic UV ink printing layer is 8μm, and the thickness of the varnish protective layer is 20μm. The varnish in the varnish protective layer is a polyurethane acrylate varnish.

[0055] A method for preparing a color-coated metal plate as described above includes the following steps: selecting an aluminum plate, treating its surface to remove impurities and oil stains to improve adhesion; after surface treatment, applying a primer layer by roller coating; then printing an organic UV ink layer on the primer layer using onepass 5-color channels (10mm distance from printhead to medium) to form a decorative pattern; and finally applying a varnish protective layer to the organic UV ink printing layer by roller coating, thus obtaining a color-coated metal plate.

[0056] Experimental example: 1. The inorganic UV inks prepared in Examples 1-5 were printed on stainless steel plates to form inorganic UV ink printing layers. After drying, the stainless steel plates were placed in an oven and baked at 250°C for 1 hour. The plates were then removed and the presence of yellowing and cracking of the paint film was observed. The results are shown in Table 1 below.

[0057] Table 1. Test Results

[0058] As shown in Table 1, the inorganic UV ink of the present invention can withstand high temperature baking at 250°C for 1 hour after drying without yellowing or cracking.

[0059] 2. The weather resistance of the colored coated metal plates prepared in Examples 1-5 and Comparative Example 1 was tested according to GB / T 1865-2009 "Pigments - Weather resistance - Latent discoloration method". The test results are shown in Table 2 below.

[0060] Table 2. Test Results

[0061] As shown in Table 2, the colored coated metal plate prepared using the inorganic UV ink of the present invention has a color difference ΔE < 3 and a weather resistance level of 5 after weather resistance testing. Comparing Example 3 and Comparative Example 1, it can be seen that when the inorganic UV ink of the present invention is replaced with the existing organic UV ink, the color difference ΔE of the prepared colored coated metal plate will increase significantly and the weather resistance will deteriorate.

[0062] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An inorganic UV ink, characterized in that: It includes the following raw materials: inorganic pigments, reactive diluents, reactive oligomers, dispersants, photoinitiators, and additives.

2. The inorganic UV ink according to claim 1, characterized in that: The raw materials include the following parts by weight: inorganic pigments: 10-25 parts; reactive diluents: 50-80 parts; reactive oligomers: 2-5 parts; dispersants: 2-5 parts; Photoinitiator: 3-10 parts; Additives: 0.5-2 parts.

3. The inorganic UV ink according to claim 1, characterized in that: The reactive diluent includes at least one of monofunctional acrylates, difunctional acrylates, and polyfunctional acrylates.

4. The inorganic UV ink according to claim 1, characterized in that: The active oligomers include at least one of polyester acrylate, polyether acrylate, polyurethane acrylate, epoxy acrylate, polyamide acrylate, and polyamine acrylate.

5. The inorganic UV ink according to claim 1, characterized in that: The additives include at least one of leveling agents and stabilizers.

6. A method for preparing an inorganic UV ink as described in any one of claims 1-5, characterized in that: The process includes the following steps: mixing and grinding inorganic pigments, reactive diluents, reactive oligomers, dispersants, photoinitiators, and additives.

7. A color-coated metal sheet, characterized in that: From bottom to top, it includes a metal sheet layer, a primer layer, an inorganic UV ink printing layer, and a varnish protective layer, wherein the inorganic UV ink printing layer is obtained by printing with the inorganic UV ink as described in any one of claims 1-5.

8. The color-coated metal sheet according to claim 7, characterized in that: The primer layer includes an epoxy zinc-rich primer, and the surface of the epoxy zinc-rich primer is coated with a polyurethane acrylate coating or a water-based hydroxyl polyurethane baking varnish.

9. The color-coated metal sheet according to claim 7, characterized in that: The varnish in the protective varnish layer includes polyurethane acrylate varnish.

10. A method for preparing a color-coated metal plate as described in any one of claims 7 to 9, characterized in that: Includes the following steps: Select a metal sheet, clean its surface, apply a primer to obtain a primer layer, then print inorganic UV ink on the primer layer to obtain an inorganic UV ink printing layer, forming a decorative pattern. Finally, apply varnish on the inorganic UV ink printing layer to obtain a varnish protective layer, thus obtaining a color-coated metal sheet.

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