Ink, cover plate assembly, preparation method thereof and electronic device

Abstract

This application provides an ink, a cover plate assembly, a method for preparing the same, and an electronic device. The ink comprises a first component and a second component. Based on the first component, the first component comprises 26 wt%–30 wt% epoxy resin, 6 wt%–10 wt% urea resin, a first additive, and a solvent. The second component comprises a curing agent and a second additive, wherein the mass ratio of the curing agent to the first component is 10%–20%. This ink can form an ink layer with excellent surface properties and bonding performance, which is beneficial for its use in cover plate assemblies and electronic devices.

Description

Technical Field

[0001] This application belongs to the field of electronic equipment technology, specifically relating to inks, cover plate assemblies and their preparation methods, and electronic equipment. Background Technology

[0002] In related technologies, ink is often coated onto the surface of electronic device covers to achieve decorative or masking effects. However, the adhesion between existing inks and covers is generally weak, and problems such as ink peeling off may occur after prolonged use, affecting the use of electronic devices. Summary of the Invention

[0003] In view of this, this application provides an ink, a cover plate assembly, a method for preparing the same, and an electronic device.

[0004] In a first aspect, this application provides an ink comprising a first component and a second component. Based on the first component, the first component comprises 26wt%-30wt% epoxy resin, 6wt%-10wt% urea resin, a first additive, and a solvent. The second component comprises a curing agent and a second additive, wherein the mass ratio of the curing agent to the first component is 10%-20%.

[0005] Secondly, this application provides a cover plate assembly, including a cover plate and an ink layer disposed on the surface of the cover plate, wherein the raw material of the ink layer includes the ink described in the first aspect.

[0006] Thirdly, this application provides a method for preparing a cover plate assembly, comprising: applying ink to the surface of a cover plate, curing it to form an ink layer, and obtaining a cover plate assembly, wherein the ink comprises a first component and a second component, and based on the first component, the first component comprises 26wt%-30wt% epoxy resin, 6wt%-10wt% urea resin, a first additive, and a solvent, and the second component comprises a curing agent and a second additive, wherein the mass ratio of the curing agent to the first component is 10%-20%.

[0007] Fourthly, this application provides an electronic device, including the cover plate assembly described in the second aspect or the cover plate assembly prepared by the preparation method described in the third aspect.

[0008] The epoxy resin and urea resin in the ink provided in this application can cross-link under the action of a curing agent to form an ink layer with excellent surface energy and adhesion. This is beneficial for the use of the ink layer in cover plate assemblies, improving the reliability, stability, and service life of the cover plate assemblies, and enhancing the product competitiveness of electronic devices. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0010] Figure 1 A flowchart illustrating the preparation method of the cover plate assembly provided in one embodiment of this application.

[0011] Figure 2 This is a cross-sectional schematic diagram of a pad printing component provided in one embodiment of this application.

[0012] Figure 3 This is a top view of a pad printing component provided according to one embodiment of this application.

[0013] Figure 4 for Figure 3 Cross-sectional view along the AA direction.

[0014] Figure 5 for Figure 4 Enlarged view of the area within the middle circular dashed line.

[0015] Figure 6 for Figure 4 Enlarged view of the area within the square dashed line.

[0016] Figure 7 This is a cross-sectional schematic diagram of the transfer piece and ink provided in one embodiment of this application.

[0017] Figure 8 As described in one embodiment of this application Figure 7 Enlarged view of the area indicated by the circular dashed line.

[0018] Figure 9 In another embodiment of this application Figure 7 Enlarged view of the area indicated by the circular dashed line.

[0019] Figure 10 This is a cross-sectional schematic diagram of the ink and cover plate provided in one embodiment of this application.

[0020] Figure 11 for Figure 10 Enlarged view of the area indicated by the circular dashed line.

[0021] Figure 12 This is a cross-sectional schematic diagram of a cover plate assembly provided in one embodiment of this application.

[0022] Figure 13 A cross-sectional schematic diagram of a cover plate assembly provided for another embodiment of this application.

[0023] Figure 14 This is a cross-sectional schematic diagram of the ink layer provided in one embodiment of this application.

[0024] Figure 15 A schematic diagram of an electronic device provided according to one embodiment of this application. Detailed Implementation

[0025] The following are exemplary embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0026] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0027] This application provides an ink comprising a first component and a second component. Based on the first component, the first component includes 26wt%-30wt% epoxy resin, 6wt%-10wt% urea resin, a first additive, and a solvent. The second component includes a curing agent and a second additive. The mass ratio of the curing agent to the first component is 10%-20%. In the ink provided by this application, the epoxy resin and urea resin can crosslink under the action of the curing agent to form an ink layer. This ink layer has good surface energy, excellent bonding performance, and good reliability, which is beneficial to the use of the ink.

[0028] The ink of this application contains epoxy resin and urea resin. Under the action of the curing agent, the epoxy groups in the epoxy resin and the amino groups in the urea resin can react to achieve cross-linking. The high degree of cross-linking increases the surface energy of the formed ink layer, allowing it to better wet the cover plate and other attachments, improving the interfacial properties between the ink layer and the attachments. Simultaneously, the cross-linked polymer contains numerous active groups, enabling strong intermolecular forces and chemical bonds with the attachments, thereby enhancing the adhesion between the ink layer and the attachments, resulting in excellent adhesion performance. Understandably, the ink can be used by simply mixing the first and second components.

[0029] In this application, based on the first component, the epoxy resin content is 26wt%-30wt%; that is, the mass ratio of epoxy resin to the first component is 26%-30%. If the epoxy resin content in the ink is too low, the number of epoxy groups during the crosslinking process decreases, which is detrimental to the crosslinking between urea resin and epoxy resin, affecting the degree of crosslinking and the content of active groups in the formed ink layer, thereby reducing its surface energy and adhesion. If the epoxy resin content in the ink is too high, the degree of crosslinking is too high, the flexibility of the resin molecular chain segments in the ink layer is poor, and the ink layer is prone to cracking, affecting its surface energy and adhesion. The epoxy resin content mentioned above ensures a suitable content of active groups and a suitable degree of crosslinking, thus facilitating the acquisition of an ink layer with good surface energy and excellent adhesion. Specifically, based on the first component, the epoxy resin content can be, but is not limited to, 26wt%, 27wt%, 28wt%, 29wt%, or 30wt%, etc. In one embodiment of this application, based on the first component, the content of epoxy resin can be 26wt%-28wt%, which is beneficial to further improve the flexibility of the ink layer and expand the application scenarios of the ink.

[0030] In one embodiment of this application, the epoxy equivalent of the epoxy resin is 500 g / eq to 900 g / eq. Here, epoxy equivalent refers to the number of grams of epoxy resin containing one equivalent of epoxy groups. When the epoxy equivalent of the epoxy resin is 500 g / eq to 900 g / eq, the ink has more resin chains with epoxy end groups, making it easier to crosslink with the curing agent and urea resin, forming more crosslinking points, further improving the adhesion and surface energy of the formed ink layer, while not excessively increasing the brittleness of the ink layer, ensuring its reliability in use. Specifically, the epoxy equivalent of the epoxy resin can be, but is not limited to, 500 g / eq, 550 g / eq, 580 g / eq, 600 g / eq, 630 g / eq, 690 g / eq, 700 g / eq, 710 g / eq, 750 g / eq, 770 g / eq, 800 g / eq, 870 g / eq, or 900 g / eq, etc. In one embodiment of this application, the epoxy equivalent of the epoxy resin can be 600g / eq-750g / eq, which is beneficial for obtaining an ink layer with good surface energy, high adhesion, excellent strength and good flexibility.

[0031] In one embodiment of this application, the solid content of the epoxy resin is 45%-50%, which is beneficial for further improving the adhesion, surface energy, hardness, and strength of the ink layer, thereby obtaining an ink layer with excellent overall performance. Specifically, the solid content of the epoxy resin can be, but is not limited to, 45%, 45.5%, 46%, 46.4%, 47%, 47.5%, 48%, 48.7%, 49%, 49.3%, or 50%, etc.

[0032] In one embodiment of this application, the density of the epoxy resin is 1.05 g / cm³. 3-1.1g / cm 3 This is beneficial for further improving the strength and hardness of the ink layer, thereby enhancing the overall performance of the ink layer. Specifically, the density of the epoxy resin can be, but is not limited to, 1.05 g / cm³. 3 1.06 g / cm 3 1.07g / cm 3 1.08g / cm 3 1.09 g / cm 3 Or 1.1g / cm 3 wait.

[0033] In one embodiment of this application, the epoxy resin is a thermosetting resin, capable of curing under conditions of a curing agent and heat treatment to form an ink layer. Specifically, the epoxy resin may be, but is not limited to, at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester type epoxy resin, and glycidyl amine type epoxy resin.

[0034] In this application, based on the first component, the content of urea resin is 6wt%-10wt%; that is, the mass ratio of urea resin to the first component is 6%-10%. If the urea resin content in the ink is too low, the number of active groups during the crosslinking process decreases, which is detrimental to the crosslinking between urea resin and epoxy resin, affecting the degree of crosslinking and the content of active groups in the formed ink layer, thereby reducing its surface energy and adhesion. If the urea resin content in the ink is too high, the degree of crosslinking is too high, the flexibility of the resin molecular chain segments in the ink layer is poor, and the ink layer is prone to cracking, affecting its surface energy and adhesion. The aforementioned content of urea resin ensures a suitable content of active groups and a suitable degree of crosslinking, thus facilitating the acquisition of an ink layer with good surface energy and excellent adhesion performance. Specifically, based on the first component, the content of urea resin can be, but is not limited to, 6wt%, 7wt%, 7.5wt%, 8wt%, 8.3wt%, 9wt%, 9.5wt%, 9.8wt%, or 10wt%, etc. In one embodiment of this application, the content of urea resin, based on the first component, can be 6 wt%-8 wt%. In another embodiment of this application, the content of urea resin, based on the first component, can be 7 wt%-10 wt%.

[0035] In this application, the first additive can improve the performance of the first component, which is beneficial to the formation and storage of the first component, and can also improve the performance of the ink and enhance the performance of the ink layer. In one embodiment of this application, the first additive includes at least one of a filler, a matting agent, and a pigment. The filler can improve the physical properties of the first component and the ink, such as mechanical properties and surface properties, and can also reduce the preparation cost of the ink. In one embodiment of this application, based on the first component, the content of the filler is 5wt%-10wt%; that is, the mass ratio of the filler to the first component is 5%-10%, which is beneficial to improving the physical properties of the first component and the ink and enhancing the performance of the ink layer. Specifically, based on the first component, the content of the filler can be, but is not limited to, 5wt%, 6wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%. Specifically, the filler can be, but is not limited to, barium sulfate. In one embodiment of this application, the particle size D50 of the filler is less than or equal to 7 μm, which is beneficial for improving the uniform dispersion of the filler and the encapsulation of the filler by the resin, while also avoiding any impact on the surface properties of the ink layer and improving the overall performance of the formed ink layer. Specifically, the particle size D50 of the filler can be, but is not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, or 7 μm. Matting powder can reduce the reflectivity of the formed ink layer, which is beneficial for the use of the ink layer. In one embodiment of this application, based on the first component, the content of matting powder is 2 wt%-5 wt%; that is, the mass ratio of matting powder to the first component is 2%-5%, which is beneficial for improving the reflectivity of the ink layer without affecting its performance. Specifically, based on the first component, the content of matting powder can be, but is not limited to, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%. Specifically, the matting powder can be, but is not limited to, silicon dioxide. In one embodiment of this application, the particle size D50 of the matting powder is less than or equal to 7 μm, which is beneficial for improving the uniform dispersion of the matting powder and the resin's encapsulation of the matting powder, while also avoiding any impact on the surface properties of the ink layer, thus improving the overall performance of the formed ink layer. Specifically, the particle size D50 of the matting powder can be, but is not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, or 7 μm. Pigments can change the appearance color of the ink layer, making the ink layer suitable for different scenarios and expanding its application range. In one embodiment of this application, based on the first component, the pigment content is 12wt%-18wt%; that is, the mass ratio of pigment to the first component is 5%-10%, which is beneficial for improving the appearance color of the ink layer, enhancing the resin's encapsulation of the pigment, and without affecting the performance of the ink layer.Specifically, based on the first component, the pigment content can be, but is not limited to, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, or 18wt%. The pigment color can be selected as needed, and the pigment can include, but is not limited to, carbon black, titanium dioxide, etc. For example, the pigment can be carbon black, thereby obtaining an ink layer with good hiding properties. In one embodiment of this application, the pigment particle size D50 is less than or equal to 7μm, which is beneficial to the uniform dispersion of the pigment, can also avoid affecting the surface properties of the ink layer, and can also improve the appearance and visual effect of the ink layer, which is beneficial to the use of the ink layer. Specifically, the pigment particle size D50 can be, but is not limited to, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, or 7μm.

[0036] In this application, the solvent can adjust the viscosity of the first component and the ink, improve the dispersion performance of each component in the first component and the ink, enhance the leveling properties of the ink, and facilitate the obtaining of an ink layer with excellent surface properties; the remaining components in the first component are all solvents. In one embodiment of this application, based on the first component, the solvent content is 30wt%-35wt%; that is, the mass ratio of solvent to the first component is 30%-35%, which is beneficial to improving the viscosity of the ink, further enhancing the leveling properties of the ink, and improving the surface properties of the ink layer. Specifically, based on the first component, the solvent content can be, but is not limited to, 30wt%, 31wt%, 32wt%, 32.5wt%, 33wt%, 33.5wt%, 34wt%, or 35wt%, etc. In one embodiment of this application, the solvent includes at least one of isophorone and naphtha. Isophorone and naphtha have stable properties and can better disperse the components in the first component and the ink, which is beneficial to the coating of the ink.

[0037] In this application, the curing agent is used to promote the crosslinking of epoxy resin and urea resin, ensuring the formation of the ink layer. The mass ratio of the curing agent to the first component is 10%-20%; that is, based on the first component, the content of the curing agent is 10wt%-20wt%. If the curing agent content in the ink is too low, the degree of crosslinking of the epoxy resin and urea resin is low, failing to guarantee the surface energy and bonding performance of the ink layer. If the curing agent content in the ink is too high, the degree of crosslinking of the epoxy resin and urea resin is too high, resulting in poor flexibility and increased brittleness of the formed ink layer, affecting reliability. The above-mentioned curing agent content ensures appropriate crosslinking between the epoxy resin and urea resin, which can improve both the surface energy and adhesion of the formed ink layer, and also improve the reliability of the ink layer. Specifically, the mass ratio of the curing agent to the first component can be, but is not limited to, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, etc. In one embodiment of this application, the mass ratio of the curing agent to the first component can be 10%-15%. In another embodiment of this application, the mass ratio of the curing agent to the first component can be 15%-20%. In one embodiment of this application, the curing agent includes an isocyanate curing agent, which can be matched with epoxy resin and urea resin to further improve the surface energy and flexibility of the formed ink. In one embodiment of this application, the mass content of isocyanate groups in the isocyanate curing agent is 10%-30%, which is beneficial to further improve the degree of crosslinking and improve the surface energy of the ink layer. Specifically, the mass content of isocyanate groups in the isocyanate curing agent can be, but is not limited to, 10%, 13%, 15%, 17%, 20%, 23%, 25%, 28%, or 30%. In one embodiment of this application, the mass content of isocyanate groups in the isocyanate curing agent can be 10%-20%. In another embodiment of this application, the mass content of isocyanate groups in the isocyanate curing agent can be 20%-30%.

[0038] In this application, the second additive can improve the performance of the second component, which is beneficial to the formation and storage of the second component, and can also improve the performance of the ink and enhance the performance of the ink layer. In one embodiment of this application, the second additive includes at least one of a coupling agent and a diluent. The coupling agent can improve the surface properties of the ink layer, enhance the bonding performance of the ink layer, and also help to increase the crosslinking density. In one embodiment of this application, based on the first component, the content of the coupling agent is 3wt%-6wt%; that is, the mass ratio of the coupling agent to the first component is 3%-6%, which is beneficial to further improve the performance of the ink layer. Specifically, based on the first component, the content of the coupling agent can be, but is not limited to, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, or 6wt%, etc. The coupling agent can be, but is not limited to, a urea-based coupling agent or a silane coupling agent, such as a urea-silane coupling agent. The diluent can improve the dispersion performance of the second component and the ink, and enhance the performance of the ink layer. In one embodiment of this application, the content of the diluent is 10wt%-15wt% based on the first component; that is, the mass ratio of the diluent to the first component is 10%-15%, which is beneficial for further improving the performance of the ink layer. Specifically, based on the first component, the content of the diluent can be, but is not limited to, 10wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 14wt%, or 15wt%. The diluent can be, but is not limited to, alcohol-based diluents, ester-based diluents, ketone-based diluents, etc. In one embodiment of this application, the diluent includes at least one of cyclohexanone and isophorone. Cyclohexanone can improve the curing and drying speed of the ink, thereby improving preparation efficiency.

[0039] In one embodiment of this application, the viscosity of the ink is 2000 cps-2800 cps, which is beneficial for ink leveling, avoids defects such as bubbles during leveling, and also increases the surface energy of the formed ink layer, which is conducive to the bonding of the ink layer with other layer structures and improves the overall performance of the ink layer; furthermore, it is more conducive to the formation of a stepped ink layer during use. Specifically, the viscosity of the ink can be, but is not limited to, 2000 cps, 2100 cps, 2200 cps, 2250 cps, 2300 cps, 2350 cps, 2400 cps, 2500 cps, 2600 cps, 2700 cps, or 2800 cps, etc.

[0040] This application provides a method for preparing ink, comprising mixing epoxy resin, urea resin, a first additive and a solvent to form a first component, and mixing a curing agent and a second additive to form a second component, thereby obtaining ink.

[0041] This application provides a method for preparing an ink layer, comprising mixing a first component and a second component, coating the mixture, and then curing it to form an ink layer.

[0042] This application provides a method for preparing a cover plate assembly, comprising: applying the ink as described in any of the above embodiments to the surface of a cover plate, and curing it to form an ink layer, thereby obtaining the cover plate assembly. The ink layer exhibits high adhesion to the cover plate, excellent surface energy, and a high dyne value, which facilitates the connection of the cover plate assembly with other structures and improves the reliability of the cover plate assembly.

[0043] Please see Figure 1 The flowchart illustrates a method for preparing a cover plate assembly according to an embodiment of this application, including:

[0044] S101: Provides a pad printing part, the surface of which has stepped grooves, into which ink is filled.

[0045] S102: Transfer the ink in the stepped grooves to the transfer piece.

[0046] S103: Transfer the ink-containing transfer piece to the cover plate surface and set the ink on the cover plate surface.

[0047] S104: After curing, an ink layer is formed. The ink layer is stepped, and a cover plate assembly is obtained.

[0048] In related technologies, multiple pad printing processes are required to form a stepped ink layer, resulting in a lengthy process, low efficiency, and high cost. In contrast, this application fills the stepped grooves with ink and transfers it to a transfer piece, allowing the transfer piece to carry the stepped ink. This ink is then transferred to the cover plate surface and cured to directly form a stepped ink layer. This single pad printing process directly forms the stepped ink layer, reducing the number of steps, increasing efficiency, and lowering costs. Furthermore, the ink layer exhibits excellent adhesion and reliability to the cover plate, which is beneficial for the application of both the ink layer and the cover plate assembly. Specifically, compared to the process of forming a stepped ink layer through multiple pad printing processes, the method provided in this application increases efficiency by 40%-50%, reduces wear on the pad printing and transfer pieces by 30%-50%, and lowers the production cost of the cover plate assembly.

[0049] In S101, the pad printing part has stepped grooves, which facilitates ink filling and the formation of stepped ink. See also... Figure 2 This is a cross-sectional schematic diagram of a pad printing component provided in one embodiment of this application. The pad printing component 10 has a stepped groove, which includes a first recess 11 and a second recess 12 connected together. The depth of the first recess 11 is greater than the depth of the second recess 12. By providing a first recess with a greater depth and a second recess with a smaller depth, the pad printing component achieves a stepped groove. Please refer to... Figure 3 This is a top view of a pad printing component provided in one embodiment of this application. Figure 4 for Figure 3 Cross-sectional view along the AA direction. Figure 5 for Figure 4 Enlarged view of the area within the middle circular dashed line. Figure 6 for Figure 4 An enlarged view of the square dotted line area shows that the first recess 11 and the second recess 12 are arranged in a ring shape, which is beneficial for the formation of the ring-shaped ink layer. The shape and arrangement of the pad printing element and the stepped groove in this application are merely examples; specific arrangements can be made according to application needs. When filling the stepped groove with ink, the ink may or may not completely fill the groove, depending on the preset ink layer thickness. In this application, the material of the pad printing element can be selected as needed, for example, it can be steel.

[0050] In this application, the stepped groove includes recesses of at least two depth dimensions, and the connection method between the recesses and the cross-sectional shape of the stepped groove are not limited. It is understood that the pad printing component has a first surface and a second surface disposed opposite to the first surface. The direction from the first surface to the second surface is the thickness direction of the pad printing component. The first surface has a stepped groove, and the depth of the first recess is the maximum dimension of the first recess in the thickness direction of the pad printing component. Figure 2 In h1, the depth of the second recess is the maximum dimension of the second recess in the thickness direction of the pad printing part, that is... Figure 2 h2; the lengths of the first and second recesses are the maximum dimensions of the first and second recesses in their extending directions; the width of the first recess is the maximum dimension of the first recess perpendicular to both the thickness and extending directions, i.e. Figure 2 In w1, the width of the second recess is the maximum dimension of the second recess perpendicular to both the thickness direction and the extension direction, i.e. Figure 2The depth and width of the first and second recesses in this application can be selected according to application needs. In one embodiment of this application, the depth of the first recess is 17μm-25μm, and the depth of the second recess is 9μm-15μm, which is beneficial for forming a thinner ink layer and further beneficial for the use of the cover plate assembly in electronic devices. Specifically, the depth of the first recess can be, but is not limited to, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, or 25μm, and the depth of the second recess can be, but is not limited to, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm. In one embodiment of this application, the width of the first recess is 0.5mm-1.2mm, and the width of the second recess is 0.2mm-0.6mm, which is beneficial for the ink layer on the surface of the cover plate to play decorative and masking effects, and also beneficial for the bonding between the ink layer and other structures. Specifically, the width of the first recess may be, but is not limited to, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm or 1.2mm, etc., and the width of the second recess may be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.5mm or 0.6mm, etc.

[0051] In step S102, ink is transferred onto a transfer element, the material and shape of which are selected according to the transfer requirements. For example, the transfer element can be, but is not limited to, a silicone pad, which has better flexibility and deformability, facilitating ink transfer. In one embodiment of this application, the transfer element is pressed against the surface of the printing pad having stepped grooves, and the orthographic projection of the transfer element onto the surface of the printing pad at least covers the surface of the stepped grooves, that is, the orthographic projection of the transfer element onto the surface of the printing pad at least covers the ink, thereby ensuring that the ink can be completely transferred to the surface of the transfer element. By pressing the transfer element against the ink surface, the ink adheres to the surface of the transfer element and then leaves the printing pad.

[0052] In step S103, the transfer piece is moved to the cover plate surface, and the ink is applied to the cover plate surface. Initially, the ink transferred to the transfer piece still appears stepped. During the movement of the transfer piece, ink in different thickness areas flows to some extent, resulting in ink on the transfer piece still having different thickness areas, but the transition between these areas is smoother. (See also...) Figure 7 This is a cross-sectional schematic diagram of the transfer piece and ink provided in one embodiment of this application. Figure 8 As described in one embodiment of this application Figure 7 An enlarged view of the circular dashed area, in which the shape of the ink 20 on the transfer piece 30 is almost identical to the shape of the stepped groove; Figure 9 In another embodiment of this application Figure 7An enlarged view of the circular dashed area shows that the shape of the ink 20 on the transfer piece 30 changes from the shape of the stepped grooves, and ink flows between areas of different thicknesses, making the transition between these areas smoother. It is understood that the ink transfer time on the transfer piece is extremely short, and the ink on the transfer piece still maintains its stepped shape, ensuring the formation of the stepped ink layer. In one embodiment of this application, during the process of the transfer piece moving to the cover plate surface, hot air at 70℃-90℃ is blown for 3s-10s, thereby avoiding significant changes in the shape of the ink on the transfer piece surface and ensuring the shape of the ink layer. After the transfer piece moves to the cover plate surface, it is pressed against the cover plate surface to transfer the ink to the cover plate surface, while maintaining the stepped shape of the ink under pressure. Please refer to [link to relevant documentation]. Figure 10 This is a cross-sectional schematic diagram of the ink and cover plate provided in one embodiment of this application. Figure 11 for Figure 10 An enlarged view of the area indicated by the circular dashed line, where the ink 20 on the surface of the cover plate 100 is stepped.

[0053] In S104, the ink is cured to form an ink layer, thus obtaining a cover plate assembly. The ink layer formed by the ink provided in this application exhibits excellent bonding performance with the cover plate, and its high surface energy is beneficial for the use of the cover plate assembly. In one embodiment of this application, curing includes holding at 140℃-160℃ for 20min-45min. Specifically, the curing temperature can be, but is not limited to, 140℃, 142℃, 145℃, 148℃, 150℃, 155℃, 157℃, or 160℃, and the curing time can be, but is not limited to, 20min, 23min, 25min, 27min, 30min, 33min, 35min, 36min, 40min, or 43min. In one embodiment of this application, curing includes pre-curing at 140℃-160℃ for 3min-5min, followed by final curing at 140℃-160℃ for 20min-40min, which is beneficial for improving the bonding performance between the ink layer and the cover plate. In one embodiment of this application, the pre-curing temperature is lower than the final curing temperature, which is beneficial to improving the performance of the cured ink layer.

[0054] In one embodiment of this application, the preparation method further includes: pre-treating the substrate to obtain a cover plate, applying ink to the surface of the cover plate, and curing it to form an ink layer, thereby obtaining a cover plate assembly. The pre-treatment may include, but is not limited to, cutting, processing, cleaning, hot bending, scanning probe microscope engraving, polishing (such as convex surface polishing, concave surface polishing, etc.), and strengthening. The order and number of pre-treatment processes are not limited and can be selected as needed.

[0055] In one embodiment of this application, the preparation method further includes: applying ink to the surface of the cover plate, curing it to form an ink layer, and then applying a decorative layer to obtain the cover plate assembly. The decorative layers, such as pattern layers, color layers, texture layers, and coating layers, can be formed through methods including, but are not limited to, screen printing, coating curing, embossing curing, and film coating; the specific method can be selected as needed.

[0056] This application provides a cover plate assembly, including a cover plate and an ink layer disposed on the surface of the cover plate. The raw material of the ink layer includes the inks described in any of the above embodiments. The cover plate assembly can be manufactured by the preparation methods described in any of the above embodiments.

[0057] The material, shape, and thickness of the cover plate in this application can be selected according to application needs. Specifically, the material of the cover plate can be, but is not limited to, at least one of glass, ceramic, metal, and plastic. In one embodiment of this application, the cover plate is made of glass, which provides excellent bonding performance between the glass and the ink layer, resulting in high structural reliability of the cover plate assembly. The cover plate can be planar or curved; for example, it can be a 3D curved surface, which helps improve the appearance of the cover plate assembly. In one embodiment of this application, the thickness of the cover plate can be 0.5mm-7mm. Specifically, the thickness of the cover plate can be, but is not limited to, 1mm, 3mm, 4mm, 5mm, 6mm, or 7mm. In one embodiment of this application, the thickness of the cover plate can be 3mm-6mm.

[0058] In this application, the ink layer can completely cover the surface of the cover plate, or it can cover only a portion of the cover plate's surface; the ink layer can be applied to one surface of the cover plate, or it can be applied to multiple surfaces of the cover plate, depending on the application requirements. Please refer to [link / reference]. Figure 12 This is a cross-sectional schematic diagram of a cover plate assembly provided in one embodiment of this application. The cover plate assembly 300 includes a cover plate 100 and an ink layer 200 disposed on the surface of the cover plate 100, the ink layer 200 completely covering the surface of the cover plate 100. Please refer to... Figure 13 This is a cross-sectional schematic diagram of a cover plate assembly provided in another embodiment of this application. The cover plate assembly 300 includes a cover plate 100 and an ink layer 200 disposed on the surface of the cover plate 100. The ink layer 200 covers a portion of the surface of the cover plate 100 and is stepped.

[0059] In one embodiment of this application, the thickness of the ink layer is 9μm-15μm, thus not excessively increasing the thickness of the cover plate assembly. Specifically, the thickness of the ink layer can be, but is not limited to, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm, etc. Please refer to [link / reference]. Figure 14This is a cross-sectional schematic diagram of an ink layer provided in one embodiment of this application. The ink layer 200 includes a first sub-ink layer 201 and a second sub-ink layer 202. The second sub-ink layer 202 is disposed on the surface of the first sub-ink layer 201 facing away from the cover plate 100. The orthographic projection of the second sub-ink layer 202 onto the surface of the first sub-ink layer 201 covers a portion of the first sub-ink layer 201, thus making the ink layer 200 stepped. In one embodiment of this application, the thickness of the first sub-ink layer is 4μm-10μm. Specifically, the thickness of the first sub-ink layer can be, but is not limited to, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm. In one embodiment of this application, the thickness of the second sub-ink layer is 5μm-8μm. Specifically, the thickness of the second sub-ink layer can be, but is not limited to, 5μm, 6μm, 7μm, or 8μm. In one embodiment of this application, the ratio of the orthographic projection area of ​​the second ink layer on the surface of the first ink layer to the surface area of ​​the first ink layer can be 25%-75%. Specifically, the ratio of the projected area of ​​the second ink layer on the surface of the first ink layer to the surface area of ​​the first ink layer can be, but is not limited to, 27%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70%. In one embodiment of this application, the width of the first sub-ink layer can be 0.7mm-1.8mm, and the width of the second ink layer can be 0.5mm-1.2mm. Specifically, the width of the first sub-ink layer can be, but is not limited to, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.6mm, or 1.7mm, and the width of the second ink layer can be, but is not limited to, 0.5mm, 0.7mm, 0.8mm, 1mm, 1.1mm, or 1.2mm.

[0060] In one embodiment of this application, the adhesion between the ink layer and the cover plate is greater than or equal to 4B. The adhesion between the ink layer and the cover plate is tested using the cross-cut adhesion test. The cover plate assembly provided in this application exhibits high adhesion between the ink layer and the cover plate, resulting in good adhesion stability and improved reliability and service life of the cover plate assembly.

[0061] In one embodiment of this application, the dyne value of the ink layer is greater than or equal to 36 Dyne, and the surface energy of the ink layer surface is excellent, which is beneficial to the connection between the ink layer and other structures, thereby improving the reliability of the cover plate assembly in use.

[0062] In a first specific embodiment, a first component and a second component are prepared, wherein the first component comprises 26 wt% epoxy resin, 10 wt% urea resin, 8 wt% barium sulfate, 5 wt% silica, 16 wt% carbon black, and 35 wt% solvent. The epoxy resin has an epoxy equivalent of 550 g / eq, a solid content of 46%, and a density of 1.05 g / cm³. 3The solvents are isophorone and naphtha. The second component includes an isocyanate curing agent, a diluent, and a urea-silane coupling agent. The diluents are cyclohexanone and isophorone. Based on the first component, the content of the isocyanate curing agent is 10 wt%, the content of the diluent is 11 wt%, and the content of the urea-silane coupling agent is 3 wt%. The first and second components are mixed to obtain an ink with a viscosity of 2100 cps. The ink is then filled into... Figure 4 In the groove of the pad printing part shown, ink is transferred to the surface of the glass cover plate after being transferred by the transfer part, and then cured to form a stepped black ink layer, thus obtaining the cover plate assembly.

[0063] In the second specific embodiment, a first component and a second component are prepared, wherein the first component comprises 30 wt% epoxy resin, 6 wt% urea resin, 10 wt% barium sulfate, 4 wt% silica, 16 wt% carbon black, and 34 wt% solvent. The epoxy resin has an epoxy equivalent of 600 g / eq, a solid content of 47%, and a density of 1.06 g / cm³. 3 The solvents are isophorone and naphtha. The second component includes an isocyanate curing agent, a diluent, and a urea-silane coupling agent. The diluents are cyclohexanone and isophorone. Based on the first component, the content of the isocyanate curing agent is 14 wt%, the content of the diluent is 12 wt%, and the content of the urea-silane coupling agent is 4 wt%. The first and second components are mixed to obtain an ink with a viscosity of 2500 cps. The ink is then filled into... Figure 4 In the groove of the pad printing part shown, ink is transferred to the surface of the glass cover plate after being transferred by the transfer part, and then cured to form a stepped black ink layer, thus obtaining the cover plate assembly.

[0064] In the third specific embodiment, a first component and a second component are prepared, wherein the first component comprises 28 wt% epoxy resin, 9 wt% urea resin, 9 wt% barium sulfate, 5 wt% silica, 14 wt% carbon black, and 35 wt% solvent. The epoxy resin has an epoxy equivalent of 800 g / eq, a solid content of 48%, and a density of 1.09 g / cm³. 3 The solvents are isophorone and naphtha. The second component includes an isocyanate curing agent, a diluent, and a urea-silane coupling agent. The diluents are cyclohexanone and isophorone. Based on the first component, the content of the isocyanate curing agent is 20 wt%, the content of the diluent is 15 wt%, and the content of the urea-silane coupling agent is 5 wt%. The first and second components are mixed to obtain an ink with a viscosity of 2750 cps. The ink is then filled into... Figure 4 In the groove of the pad printing part shown, ink is transferred to the surface of the glass cover plate after being transferred by the transfer part, and then cured to form a stepped black ink layer, thus obtaining the cover plate assembly.

[0065] The adhesion between the ink layer and the cover plate in the above embodiments was tested using the cross-cut adhesion test. All results showed an adhesion strength of 4B or higher, and the surface dyne value of the ink layer was 36 Dyne or higher. Simultaneously, an adhesive was applied to the surface of the ink layer away from the cover plate assembly using either Wilbond 7025BH adhesive or Fuller EH9652BH adhesive. After curing, the pull-out force between the adhesive and the ink layer was tested, and the results showed that the pull-out force was consistently above 13 N / mm. 2 The above indicates that the ink layer surface has a high dyne value, resulting in stable bonding with other structural components, which is beneficial for the use of the cover plate assembly.

[0066] In the first comparative example, it was substantially the same as the first specific embodiment, except that the first component did not contain urea resin and was 36 wt% epoxy resin. In the second comparative example, it was substantially the same as the first specific embodiment, except that the first component did not contain epoxy resin and was 36 wt% urea resin. In the third comparative example, it was substantially the same as the first specific embodiment, except that the first component contained 35 wt% epoxy resin and 1 wt% urea resin. In the fourth comparative example, it was substantially the same as the first specific embodiment, except that the first component contained 21 wt% epoxy resin and 15 wt% urea resin. Similarly, through cross-cut adhesion testing, surface dyne value testing, and pull-out force testing with the adhesive, the adhesion between the ink layer and the cover plate in the comparative examples was all below 3B, the ink layer dyne value was all below 36 Dyne, and the pull-out force was all below 13 N / mm. 2 The performance of the ink layer in the comparative example is significantly lower than that of the ink layer in this application.

[0067] This application also provides an electronic device including the cover assembly from any of the above embodiments. The electronic device in this application may be, but is not limited to, a mobile phone, tablet computer, laptop computer, watch, wristband, navigator, digital camera, etc., and the cover assembly may be, but is not limited to, the front cover, back cover, or mid-frame of the electronic device. Please refer to [link / reference]. Figure 15 This is a schematic diagram of an electronic device provided according to one embodiment of this application. The electronic device 400 includes a cover plate assembly 300 and a display assembly. The display assembly is not shown in the figure. The cover plate assembly can protect the display assembly. In one embodiment of this application, the ink layer is disposed on the edge of the cover plate to avoid affecting the display effect of the display assembly. The ink layer may be stepped and connected to the display assembly by an adhesive or the like. The high surface dynamism of the ink layer improves the bonding reliability between the cover plate assembly and the display assembly, which is beneficial to the use of the electronic device. In another embodiment of this application, the cover plate assembly is the back cover of the electronic device. By changing the color and placement of the ink layer, the appearance of the electronic device is improved, which is beneficial to its use.

[0068] The above provides a detailed description of the embodiments provided in this application. This document elucidates and explains the principles and implementation methods of this application. The above description is only intended to help understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An ink, characterized in that, The ink comprises a first component and a second component. Based on the first component, the first component includes 26wt%-30wt% epoxy resin, 6wt%-10wt% urea resin, a first additive, and a solvent. The second component includes a curing agent and a second additive. The mass ratio of the curing agent to the first component is 10%-20%. The resin in the ink is the epoxy resin and the urea resin. The epoxy equivalent of the epoxy resin is 500g / eq-900g / eq, and the solid content of the epoxy resin is 45%-50%.

2. The ink as described in claim 1, characterized in that, The first auxiliary agent includes at least one of filler, matting agent and pigment, and the second auxiliary agent includes at least one of coupling agent and diluent; Based on the first component, the content of the filler is 5wt%-10wt%, the content of the matting agent is 2wt%-5wt%, the content of the pigment is 12wt%-18wt%, the content of the coupling agent is 3wt%-6wt%, the content of the diluent is 10wt%-15wt%, and the content of the solvent is 30wt%-35wt%. The viscosity of the ink is 2000cps-2800cps.

3. A cover plate assembly, characterized in that, The invention includes a cover plate and an ink layer disposed on the surface of the cover plate, wherein the raw material of the ink layer includes the ink according to any one of claims 1-2, and the dyne value of the ink layer is greater than or equal to 36 Dyne.

4. The cover plate assembly as claimed in claim 3, characterized in that, The ink layer includes a first sub-ink layer and a second sub-ink layer. The second sub-ink layer is disposed on the surface of the first sub-ink layer opposite to the cover plate. The orthographic projection of the second sub-ink layer on the surface of the first sub-ink layer covers a portion of the first sub-ink layer. The thickness of the ink layer is 9μm-15μm; The thickness of the first sub-ink layer is 4μm-10μm; The thickness of the second sub-ink layer is 5μm-8μm.

5. The cover plate assembly as claimed in claim 3, characterized in that, The bonding force between the ink layer and the cover plate is greater than or equal to 4B.

6. A method for preparing a cover plate assembly, characterized in that, include: An ink is applied to the surface of a cover plate and cured to form an ink layer, thereby obtaining a cover plate assembly. The ink comprises a first component and a second component. Based on the first component, the first component comprises 26wt%-30wt% epoxy resin, 6wt%-10wt% urea resin, a first additive, and a solvent. The second component comprises a curing agent and a second additive. The mass ratio of the curing agent to the first component is 10%-20%. The resin in the ink is the epoxy resin and the urea resin. The epoxy equivalent of the epoxy resin is 500g / eq-900g / eq, and the solid content of the epoxy resin is 45%-50%. The dyne value of the ink layer is greater than or equal to 36 Dyne.

7. The preparation method according to claim 6, characterized in that, Also includes: A pad printing component is provided, the surface of which has stepped grooves, and the ink is filled into the stepped grooves; The ink in the stepped grooves is transferred onto the transfer piece; The transfer piece containing the ink is moved to the surface of the cover plate, and the ink is disposed on the surface of the cover plate; The ink layer is formed after curing, and the ink layer is stepped.

8. The preparation method according to claim 7, characterized in that, The stepped groove includes a first recess and a second recess connected together; The depth of the first recess is 17μm-25μm; The width of the first recess is 0.5mm-1.2mm; The depth of the second recess is 9μm-15μm; The width of the second recess is 0.2mm-0.6mm.

9. An electronic device, characterized in that, Includes the cover plate assembly according to any one of claims 3-5 or the cover plate assembly prepared by the preparation method according to any one of claims 6-8.

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