Coating structure and method for applying same

Abstract

The application discloses a coating structure and a construction method thereof. The coating structure comprises a base layer, a release layer, a three-dimensional modeling layer and a metal foil layer which are sequentially arranged on the base layer, the three-dimensional modeling layer is patterned on the release layer, the metal foil layer is attached to the surface of the three-dimensional modeling layer, and the edge of the metal foil layer does not extend to the release layer area outside the three-dimensional modeling layer. The pattern boundary of the coating structure is clear and regular, the visual three-dimensional sense is strong, and the visual performance and the decorative beauty of product packaging can be significantly improved.

Description

Technical Field

[0001] This application relates to the field of cosmetic packaging technology, and in particular to a coating structure and its application method. Background Technology

[0002] The appearance and texture of cosmetic packaging are core elements in enhancing a product's market competitiveness. To cater to consumers' aesthetic demand for three-dimensionality, high-relief three-dimensional shapes are often used as packaging decoration to strengthen the visual depth and tactile texture of the product packaging. Building upon this, a hot stamping process is used to transfer metallic foil onto the surface of the three-dimensional shape (i.e., hot stamping), creating decorative patterns with a metallic sheen and further elevating the packaging's overall quality.

[0003] However, the three-dimensional shape of high relief often affects the transfer and forming of metal foil, which can easily lead to defects such as uneven adhesion between the metal foil and the three-dimensional shape, foil misalignment, and gold foil overflow, resulting in packaging decoration effect that is not as expected. Summary of the Invention

[0004] In view of the problems of the prior art, this application provides a coating structure that can improve the effect of three-dimensional hot stamping.

[0005] A coating structure includes a base layer, and a release layer, a three-dimensional shaping layer, and a metal foil layer sequentially stacked on the base layer, wherein the three-dimensional shaping layer is patterned on the release layer; the metal foil layer is adhered to the surface of the three-dimensional shaping layer, and the edge of the metal foil layer does not extend beyond the release layer area outside the three-dimensional shaping layer.

[0006] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0007] Optionally, the thickness of the three-dimensional shaping layer is 0.1 mm to 2.0 mm.

[0008] Optionally, the metal foil layer is connected to the three-dimensional molding layer via an adhesive layer.

[0009] Optionally, the metal foil layer completely covers the three-dimensional molding layer.

[0010] Optionally, the release layer is made of rubber paint.

[0011] Optionally, the material of the three-dimensional shaping layer is a photocurable resin.

[0012] Optionally, the Shore D hardness of the three-dimensional shaping layer is 60~90.

[0013] Optionally, the thickness of the release layer is 20 μm to 50 μm.

[0014] Optionally, the coating structure may further include a coloring layer disposed on the outer surface of the metal foil layer.

[0015] This application also provides a method for constructing the coating structure, including the following steps: (1) Provide a substrate, coat the surface of the substrate with rubber paint, and form a release layer after heating and curing; (2) On the surface of the release layer, a preset three-dimensional pattern is formed by photocuring resin through three-dimensional printing, and then photocured to form a three-dimensional model layer; (3) Perform a metal foil hot-press transfer process on the surface of the three-dimensional modeling layer to form a metal foil layer; (4) A printing coloring layer is superimposed on the metal foil layer.

[0016] Compared with existing technologies, this application adds a release layer, which on the one hand provides a flat reference surface for 3D printing of the three-dimensional model layer, ensuring the precise forming of the three-dimensional model layer; on the other hand, it can form an isolation and protection for the base layer in the hot stamping process, preventing the metal foil layer from adhering to non-decorative model areas, so that the pattern boundary is clear and regular, the visual three-dimensionality is strong, and the overall decorative visual effect is good. Attached Figure Description

[0017] Figure 1 This is a partial schematic diagram of the coating structure in this application; Figure 2 This is a partial schematic diagram of another coating structure in this application; Figure 3 A partial schematic diagram of the coating structure with a coloring layer in this application; Figure 4 This is a partial schematic diagram of the uneven coating structure in this application; Figure 5 This is an appearance drawing of the sample from Test Example 1 of this application.

[0018] The annotations in the figure are explained as follows: 10. Base layer; 20. Release layer; 30. 3D shaping layer; 40. Adhesive layer; 50. Metal foil layer; 60. Coloring layer. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that when a component is said to be "connected" to another component, it can be directly connected to the other component or it can be connected to a component in between. When a component is said to be "set on" another component, it can be directly set on the other component or it may be set to a component in between.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] See Figure 1 This application provides a coating structure, including a base layer 10, and a release layer 20, a three-dimensional shaping layer 30 and a metal foil layer 50 sequentially stacked on the base layer 10. The functional layers cooperate with each other to form a three-dimensional embossed pattern with a metallic luster on the packaging surface, thereby significantly enhancing the visual three-dimensionality and tactile texture of the packaging.

[0023] The base layer 10 of this application is a packaging substrate, which possesses at least structural rigidity and resistance to deformation, providing a basic load-bearing capacity for subsequent layered decoration. Specifically, the base layer 10 can be made of plastic or metal. The plastic material is selected from plastic raw materials suitable for injection molding of cosmetic packaging, including acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate (PET), polyethylene terephthalate-1,4-cyclohexanediol (PETG), and polymethyl methacrylate (PMMA). The metal material is selected from lightweight aluminum alloys, which can balance structural strength and processing performance, making it suitable for the preparation of packaging such as lipstick tubes and makeup boxes.

[0024] The core function of the release layer 20 in this application is to block the base layer 10 and the three-dimensional modeling layer 30, realize physical isolation of the interface, provide boundary constraints for the subsequent metal foil transfer process, ensure that the metal foil is only precisely attached to the surface of the three-dimensional modeling layer 30, prevent the metal foil layer 50 from overflowing, ensure that the product pattern boundary is clear and regular, and thus improve the visual effect.

[0025] Specifically, the release layer 20 is divided into two main areas: (1) the attachment area, which is covered by the three-dimensional shape and the two are closely attached; (2) the blank area, which is not covered by the three-dimensional shape layer 30 and is directly exposed. It is also the area where the metal foil layer 50 needs to avoid attachment. It relies on its own low adhesion characteristics to block the adhesion of the metal foil layer.

[0026] The release layer 20 in this application is made of rubber paint. Rubber paint possesses both excellent flexibility and low interfacial adhesion (ASTM D903 standard test method). On one hand, its high elasticity and cushioning properties can absorb and dissipate interlayer stress generated by the molding or thermal deformation of the base layer 10 and the 3D modeling layer 30, weakening interfacial tensile forces and effectively suppressing interfacial warping, delamination, and cracking defects. On the other hand, rubber paint has excellent surface printability and moderate surface tension (using the contact angle method), serving as a stable substrate for 3D modeling and improving the flatness and adhesion of the 3D modeling layer 30. Simultaneously, the rubber paint has low interfacial adhesion to the metal foil, preventing the metal foil from adhering to the blank areas of the release layer 20 during the transfer process, completely eliminating metal contamination problems in non-patterned areas.

[0027] Furthermore, thermosetting rubber paint is selected, which can be cured and molded through hot pressing, making the operation simple and convenient. In terms of specific composition, the rubber paint can be polyurethane-based or acrylic-based. Among them, polyurethane-based rubber paint has better elasticity and temperature buffering performance, making it suitable for high and low temperature molding conditions; acrylic-based rubber paint has good printability and lower cost, and can be flexibly selected according to product process requirements.

[0028] The rubber coating used meets the following physical parameters: elongation at break ≥300%, peel force at 180°C ≤1.0N / 25mm, water contact angle 35°~65°, Shore A hardness 20~40. These parameters balance the elastic buffering capacity of the adhesive layer, the 3D printing spreading effect, and the low adhesion characteristics to metal foil, ensuring the stable performance of all functions of the release layer 20. Further optimization resulted in the selection of thermosetting rubber coating C-QL-KS-2031 (Zhejiang Youqian Special Materials Co., Ltd.).

[0029] The thickness of the release layer 20 in this application is controlled between 20μm and 50μm, preferably between 30μm and 40μm. This thickness range can meet the requirements of interlayer isolation and stress buffering, while avoiding the defects of insufficient protection due to excessive thinness and deformation and increased cost due to excessive thickness.

[0030] The three-dimensional modeling layer 30 of this application is the core functional layer for achieving exterior decoration. It is formed only on a partial surface of the release layer 20, constructing pre-set three-dimensional patterns, text, or textures. Its shape and thickness directly determine the visual three-dimensionality and aesthetic appeal of the finished decorative product. The three-dimensional modeling layer 30 is directly formed on the attachment area of ​​the release layer 20 using 3D printing technology, allowing for flexible printing of different configurations, such as undulating configurations.

[0031] The thickness of the three-dimensional shaping layer 30 in this application is controlled between 0.1 mm and 2.0 mm, preferably between 0.1 mm and 0.12 mm, which can stably produce the expected three-dimensional visual effect. If the thickness is less than 0.1 mm, the height of the three-dimensional protrusion is insufficient, the visual sense of layering is weak, and the thin-walled structure is prone to breakage under pressure and damage from bumps and knocks; if the thickness is greater than 2.0 mm, the accumulation of internal stress is prone to shrinkage and warping, as well as deformation of the overall decoration.

[0032] The three-dimensional modeling layer 30 of this application is made of a UV-curable resin. After curing, the Shore D hardness of the resin matrix is ​​controlled at 60-90; preferably, the Shore D hardness is 70-80, which can balance the rigidity of the resin structure, its scratch and wear resistance, and its moderate toughness. This ensures that the three-dimensional model remains sturdy and undeformed for a long time, while also buffering minor external impacts and reducing the risk of breakage. Preferably, the UV-curable resin is a UV-curable ink.

[0033] See Figure 4 In some embodiments, the three-dimensional modeling layer 30 has an inclined surface or sidewall structure, with an angle greater than 90° between it and the normal to the flat surface of the release layer 20; wherein the normal to the surface of the release layer 20 is a perpendicular line to the flat base surface of the release layer 20. This design enables layered light reflection, enhances the light and shadow levels and three-dimensional metallic texture of the metal foil layer 50, and improves the problem of the thinness of the planar metallic structure. At the same time, relying on the printing support performance of the bottom release layer 20, 3D printing can stably form the above-mentioned inclined surface or sidewall structure with an angle greater than 90°, and it is not easy for suspended structures to collapse or fall off, resulting in a complete and clear outline.

[0034] The metal foil layer 50 of this application covers the surface of the three-dimensional modeling layer 30, and relies on the unique mirror-reflective properties of metal to give the relief structure a strong metallic luster, greatly enhancing the high-end visual texture and three-dimensional relief expression of the decorative part. The metal foil layer 50 only needs to cover the three-dimensional modeling layer 30 and does not come into contact with the blank areas, avoiding contamination of the blank areas by the metal foil, thereby ensuring the clear boundary of the pattern of the coating structure.

[0035] The metal foil layer 50 can be made of aluminum foil, copper foil, or gold foil, etc. The thickness of the metal foil layer 50 is controlled between 12μm and 18μm, preferably between 12μm and 16μm. The covering can be applied by bonding it to the surface of the three-dimensional molding layer 30 with an adhesive layer 40, see [reference needed]. Figure 2 .

[0036] See Figure 3 The coating structure of this application also includes a coloring layer 60, which is stacked on the surface of the metal foil layer 50. It can not only play a role in isolating and protecting the coating structure, but also adjust the visual effect of the metallic texture to achieve different styles such as matte metal, glossy metal, and colored metal, thus enriching the diversity of decoration.

[0037] Specifically, the material of the coloring layer 60 can be selected from a transparent light-cured coating, a colored polyurethane coating, or an acrylic coating, giving the surface of the coating structure high transparency, water resistance, weather resistance, and scratch resistance. Furthermore, the thickness of the coloring layer 60 is controlled between 15μm and 30μm, preferably between 20μm and 25μm.

[0038] This application also provides a method for constructing a coated structure, including the following steps: (1) Provide a substrate, coat the surface of the substrate with rubber paint, and form a release layer 20 after heating and curing; (2) On the surface of the release layer 20, a preset three-dimensional pattern is formed by using a light-curing resin through a three-dimensional printing method, and then light-cured to form a three-dimensional modeling layer 30; (3) Perform a metal foil hot-press transfer process on the surface of the three-dimensional modeling layer 30 to form a metal foil layer 50; (4) A printing coloring layer 60 is superimposed on the metal foil layer 50.

[0039] Specifically, the heating and curing temperature in step (1) is 75℃~100℃.

[0040] In step (2), the photocuring process uses ultraviolet light irradiation with a power of 5W.

[0041] In step (3), the metal foil is hot-pressed onto the three-dimensional modeling layer 30 using a rubber roller. The temperature of the rubber roller is set to 75℃~120℃, and the pressing and holding time is 1s~3s.

[0042] The following specific test examples further illustrate the technical solution of this application.

[0043] Experimental Example 1 1.1 Preparation process (1) In this test example, aluminum or plastic parts were used as substrates. Thermosetting rubber paint C-QL-KS-2031 (Zhejiang Youqian Special Materials Co., Ltd.) was sprayed onto the entire surface of the substrate, and the dry film thickness was controlled to be 30μm~40μm. After spraying, the coating was baked and cured on a production line. The baking temperature was controlled to be 75℃~100℃ and the production line speed was 18HZ to ensure that the rubber paint coating was fully cured and formed a flexible, low-adhesion, and highly adaptable release layer 20 for printing.

[0044] (2) Place the baked and cured sprayed finished products neatly on the digital printing platform, and use the 4K visual imaging system to complete the product positioning and precise alignment of the artwork; use Japanese Mimaki-LH-100CL hot stamping three-dimensional glossy ink to print an embossed three-dimensional pattern on the release layer 20 attachment area, and control the three-dimensional printing height to 0.1mm~0.12mm; after printing, use a 5W power LED lamp for ultraviolet curing to quickly set and cure the three-dimensional varnish layer, forming a three-dimensional model layer 30 with complete structure and clear outline.

[0045] (3) Subsequently, a hot stamping machine with a rubber wheel is used to hot press the cured three-dimensional model layer 30 with metal foil (aluminum foil). The temperature of the rubber wheel is set to 75℃~120℃, and the hot pressing and holding time is 1s~3s.

[0046] (4) After the hot stamping is completed, the sample is transferred to the digital printing platform again and accurately aligned by 4K visual image. A color layer 60 is printed on the surface of the metal hot stamping layer (presenting a raster effect at different angles); the coating structure test sample of this application is obtained for subsequent performance tests.

[0047] 1.2 Test Methods Water resistance test method: Immerse the test sample completely in room temperature water for 24 hours. During the immersion process, the sample must be completely submerged with no exposed areas. After the immersion is completed, remove the sample and allow it to air dry at room temperature.

[0048] 3M 616 tape peel adhesion test: Cut a piece of 3M 616 Magic Tape of sufficient length to ensure that the tape can completely cover the sample test area and leave a small section for holding; flatly stick the tape to the decorative surface area of ​​the sample, press the tape evenly to completely remove air bubbles between the tape and the surface, and ensure that the tape and the surface are fully adhered; after standing for 1 minute, quickly peel off the tape with a uniform and continuous motion, and observe the coating condition of the test area.

[0049] 3M 616 tape cross-cut adhesion test: Select a flat test area (1 square inch) of the sample, and use a sharp special cross-cut blade to make parallel cuts 1 foot long horizontally and vertically at 2 mm intervals to form a regular 2 mm × 2 mm grid. The cut depth penetrates the surface coating structure and reaches the underlying coating. Firmly adhere 3M 616 Magic Tape to the cross-cut test area, press to release air, and then slowly peel off the tape at a uniform speed. Observe the coating peeling off in the grid area.

[0050] 300g weight manual rubbing test: Take two sets of the same test samples, fix one sample with the test area facing upward, and place a 300g standard weight above the test area; align the test surface of the other sample with the test area on the weight side, and manually control the uniform speed to rub back and forth 10 times, ensuring that the force is uniform and there is no deviation during the rubbing process.

[0051] Fingertip artificial friction test: The tester cleans his hands and ensures that his fingertips are free of impurities and grease. He then places his fingertips against the core decorative test area of ​​the sample and rubs them back and forth at a uniform speed 10 times.

[0052] Roller abrasion and vibration test: A counterweight material, including 364g of coins, 6 key rings, 181g of loose screws and 1 metal lipstick, is placed inside the standard test roller; 10 assembled test samples are placed inside at the same time, the roller equipment is turned off, and the motor is started to continuously roll for 10 minutes; after the test, the samples are removed, surface impurities are cleaned, and the appearance and structural condition of the samples are observed.

[0053] LED light aging test: A 5000K LED light-white 950 lumen test device was used. The test samples were placed in the effective irradiation area of ​​the light source, with no contact, no obstruction, and no mutual shading between the samples, and were continuously exposed to light for 24 hours. After the test, the samples were taken out and compared with the initial state to check the changes in appearance, gloss, and color.

[0054] The test results for Example 1 are as follows: (1) Appearance evaluation: There is no metal foil adhesion or overflow contamination in the blank area of ​​the centrifugal layer, and the pattern boundary is sharp and regular. See Figure 5 .

[0055] (2) After 24 hours of water immersion, the surface colored coating, metal hot stamping layer, three-dimensional shape layer and release layer of the sample in Test Example 1 were all intact and undamaged, without defects such as whitening, bubbling, peeling, or watermarks. The interlayer bonding was tight and there was no warping or delamination, indicating excellent waterproof performance.

[0056] (3) After the sample of Test Example 1 was tested by 3M 616 tape peeling test, the surface color layer, metal foil layer and three-dimensional varnish layer did not peel off, break or fade. The pattern boundary was clear and complete, and there was basically no interlayer peeling problem, indicating that the adhesion of each coating interface was excellent.

[0057] (4) After the cross-cut test of the sample in Example 1, the coating in all grid areas was firmly bonded, with no peeling, curling, chipping or powdering. The interlayer bonding strength was high and the cross-cut adhesion reached the optimal level.

[0058] (5) After the sample in Test Example 1 was subjected to a 300g weight for abrasion test, the surface was smooth and intact, with no visible scratches, abrasions, or discoloration. The metallic luster and colored texture were clear as before, and the three-dimensional relief structure was free from wear and collapse, indicating excellent wear resistance.

[0059] (6) After the fingertip rubbing test, the sample of Test Example 1 showed no color fading or delamination, no fingerprint residue, no change in color texture and metallic luster, and no impact on pattern clarity. It also showed good wear resistance and stain resistance during daily contact.

[0060] (7) After the 10-minute roller bump abrasion test, all samples of Test Example 1 showed no scratches, bumps, or coating peeling on their surfaces. The three-dimensional relief structure was free from deformation and collapse. The metal hot stamping layer and the colored decorative layer were intact and had clear boundaries, indicating excellent anti-bump, anti-friction, and anti-bump performance.

[0061] (8) After 24 hours of high-intensity LED light aging test, the color saturation and metallic luster of the sample in Test Example 1 were consistent with the initial state. There were no aging defects such as fading, yellowing, loss of gloss, or cracking. The three-dimensional light and shadow and grating-like dynamic effects were not attenuated, indicating that the light aging resistance performance was excellent.

[0062] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification. When technical features of different embodiments are embodied in the same drawing, it can be regarded as the drawing also disclosing examples of combinations of the various embodiments involved.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A coating structure, comprising a base layer, and a release layer, a three-dimensional shaping layer, and a metal foil layer sequentially stacked on the base layer, characterized in that: The three-dimensional modeling layer is patterned on the release layer; The metal foil layer is attached to the surface of the three-dimensional shaping layer, and the edge of the metal foil layer does not extend into the release layer area outside the three-dimensional shaping layer.

2. The coating structure according to claim 1, characterized in that, The thickness of the three-dimensional shaping layer is 0.1 mm to 2.0 mm.

3. The coating structure according to claim 1, characterized in that, The metal foil layer is connected to the three-dimensional modeling layer through an adhesive layer.

4. The coating structure according to claim 1, characterized in that, The metal foil layer completely covers the three-dimensional shape layer.

5. The coating structure according to claim 1, characterized in that, The release layer is made of rubber paint.

6. The coating structure according to claim 1, characterized in that, The material of the three-dimensional shaping layer is a light-cured resin.

7. The coating structure according to claim 1, characterized in that, The Shore D hardness of the three-dimensional shaping layer is 60~90.

8. The coating structure according to claim 1, characterized in that, The thickness of the release layer is 20 μm to 50 μm.

9. The coating structure according to claim 1, characterized in that, It also includes a coloring layer disposed on the outer surface of the metal foil layer.

10. The construction method of the coating structure according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Provide a substrate, coat the surface of the substrate with rubber paint, and form a release layer after heating and curing; (2) On the surface of the release layer, a preset three-dimensional pattern is formed by photocuring resin through three-dimensional printing, and then photocured to form a three-dimensional model layer; (3) Perform a metal foil hot-press transfer process on the surface of the three-dimensional modeling layer to form a metal foil layer; (4) A printing coloring layer is superimposed on the metal foil layer.

Images