Composite resin, composite cover plate, preparation method of composite cover plate and electronic equipment

Abstract

The invention relates to the technical field of electronic equipment cover plates, and provides composite resin, a composite cover plate, a preparation method of the composite cover plate and electronic equipment. The composite resin is prepared from the following raw materials in parts by weight: 70 to 110 parts of urethane acrylate; 0.2 to 10 parts of a photoinitiator; 0.2 to 2 parts of a thermal initiator; 1 to 10 parts of a coloring agent; 10 to 30 parts of a diluent; and 0.1 to 10 parts of an auxiliary agent. The polyurethane acrylate and the coloring agent are mixed, and light / heat dual curing is combined, so that the leather texture layer prepared from the composite resin has the leather texture appearance effect of leather.

Description

Technical Field

[0001] This application relates to the field of electronic device cover technology, and in particular to a composite resin, a composite cover, a method for preparing the same, and an electronic device. Background Technology

[0002] PU (polyurethane) artificial leather is made by mixing color powder or pigment into resin and then curing it through heat. Its color and appearance closely resemble genuine leather, and electronic device casings are often manufactured by laminating / pressing PU artificial leather. To achieve efficient and low-cost manufacturing of electronic device casings, some technologies on the market involve screen printing color layers onto PC (polycarbonate) sheets, PC / PMMA (polymethyl methacrylate) composite sheets, fiberglass sheets, or PET (polyethylene terephthalate) sheets, and then UV transferring a transparent or semi-transparent leather-textured adhesive layer to achieve the appearance and feel of imitating PU synthetic leather. While a transparent or semi-transparent leather-textured adhesive layer improves curing efficiency during UV curing, a certain thickness of this layer can create a certain degree of translucency, resulting in a shiny appearance under light, making the overall look less realistic than traditional heat-cured PU leather. Adding colorants directly to the leather texture adhesive can affect the penetration of ultraviolet light into dark corners. Using only UV curing may result in incomplete curing, ultimately affecting the performance of the leather texture adhesive layer. Summary of the Invention

[0003] Based on this, a composite resin with a PU-like artificial leather feel and effect, a composite cover plate, a method for preparing the same, and an electronic device are provided.

[0004] In a first aspect, this application provides a composite resin, wherein the raw materials of the composite resin, by weight parts, include:

[0005] 70 to 110 parts of polyurethane acrylate;

[0006] Photoinitiator 0.2 to 10 parts;

[0007] 0.2 to 2 parts of thermal initiator;

[0008] Colorant: 1 to 10 parts;

[0009] 10 to 30 parts of diluent; and,

[0010] Additives: 0.1 to 10 parts.

[0011] In some embodiments, the polyurethane acrylate includes at least one of aromatic polyurethane acrylate, aliphatic polyurethane acrylate, and alicyclic polyurethane acrylate.

[0012] And / or, the number average molecular weight of polyurethane acrylates is 1000~10000.

[0013] And / or, the polyurethane acrylate is further grafted with modifying groups, including at least one of isocyanate groups, hydroxyl groups, carboxyl groups, epoxy groups, siloxane groups, polyester groups and polyether groups.

[0014] In some embodiments, the photoinitiator includes a radical photoinitiator, which includes at least one selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methylphenylpropanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, and 1-hydroxycyclohexylphenyl methyl ketone.

[0015] And / or, the thermal initiator includes a peroxide, which includes at least one of benzoyl peroxide, tert-butyl peroxide, tert-butyl peroxide, and tert-amyl peroxide.

[0016] And / or, the diluent includes at least one of tripropylene glycol diacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and dipropylene glycol diacrylate.

[0017] And / or, colorants include color pastes or color powders.

[0018] In some embodiments, the additives include at least one of leveling agents and abrasion resistant agents.

[0019] In some embodiments, the leveling agent includes at least one of silicone leveling agents, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0020] And / or, the abrasion-resistant agent includes sericite and polyethylene wax; the mass ratio of the sericite to the polyethylene wax is (2~3):1.

[0021] Secondly, this application provides a composite cover plate, comprising:

[0022] substrate;

[0023] The texture layer is disposed on the substrate and is prepared from the composite resin of the first aspect.

[0024] In some embodiments, the substrate includes a cover ink layer, a substrate layer and a base layer stacked sequentially, with the base layer located between the substrate layer and the texture layer.

[0025] In some embodiments, the substrate layer includes at least one of polycarbonate, polycarbonate / polymethyl methacrylate, polyethylene terephthalate, thermoset glass fiber composite and thermoplastic glass fiber composite.

[0026] And / or, the underlayer comprises at least one of acrylic resin and polyurethane resin.

[0027] In some embodiments, the composite cover plate further includes a patterned layer disposed on the side of the textured layer opposite to the substrate.

[0028] Thirdly, this application provides a method for preparing a composite cover plate, the method comprising:

[0029] A transparent textured release film is used to apply the composite resin of the first aspect to the surface of the substrate;

[0030] The composite resin is subjected to photocuring and thermocuring treatments.

[0031] In some embodiments, the photocuring process includes: performing a first photocuring treatment on the composite resin using a UV LED lamp, removing the transparent leather texture release film, and then performing a second photocuring treatment on the composite resin after the first photocuring treatment using a UV mercury lamp.

[0032] In some embodiments, the UV LED lamp in the first photocuring process has a light source wavelength of 360nm~410nm and a light-emitting surface power of 16W / cm². 2 ~25W / cm 2 The energy is 3000 mJ / cm³. 2 ~4000mJ / cm 2 The duration is 5s to 15s.

[0033] And / or, in the second photocuring process, the UV mercury lamp has a light source wavelength of 300nm~400nm and a light intensity of 80W / cm². 2 ~220W / cm 2 The energy is 1200 mJ / cm². 2 ~1800mJ / cm 2 The duration is 10s to 60s.

[0034] In some embodiments, the temperature for thermosetting is 80°C to 100°C, and the time is 0.5 to 1.5 hours.

[0035] Fourthly, this application also provides an electronic device, which includes the composite cover as described in the second aspect.

[0036] Compared with traditional technologies, this application has at least the following beneficial effects:

[0037] This application uses a mixture of polyurethane acrylate and colorant, combined with photoinitiators and thermal initiators for dual light / heat curing. On one hand, it can quickly achieve a leather-textured appearance using UV transfer printing. On the other hand, the colorant is fixed and dispersed in the composite resin as the polyurethane acrylate cures. At this point, light diffuses through the dispersed colorant in the composite resin, eliminating the reflective effect on the resin surface and making the leather-textured appearance more realistic. Furthermore, this application achieves the desired color effect without the need for a separate color effect layer, saving on screen printing color effect layers and reducing processing steps. With the synergy of diluents and additives, the composite resin of this application exhibits excellent flowability and coatability, making it suitable for complex molding processes. The composite resin of this application, through the synergy of the raw materials in each weight proportion and the dual light / heat curing, achieves a leather-textured appearance and feel similar to PU artificial leather, realizing an integrated design of the leather-like adhesive layer and the color effect layer. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the composite cover plate provided in one embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the appearance of the composite cover plate obtained in Embodiment 1 of this application.

[0041] Among them, 100-composite cover plate; 110-substrate; 111-cover ink layer; 112-substrate layer; 113-undercoat layer; 120-textured layer; 200-electronic device body. Detailed Implementation

[0042] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0043] 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 be limiting of the application.

[0044] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0045] In this application, the terms "first aspect," "second aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first aspect," "second aspect," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0046] In traditional techniques, to achieve a leather-like effect on a cover plate, a color layer with a leather texture is first applied to the material to create a leather-like appearance. Then, a leather-like adhesive layer is applied over the color layer to achieve a leather-like feel. The combination of these two techniques creates a cover plate with a leather-like effect. However, the surface of the transparent or semi-transparent leather-like adhesive layer becomes shiny, resulting in an unrealistic leather-like appearance and a difference from the actual effect of leather.

[0047] The first aspect of this embodiment provides a composite resin, wherein the raw materials of the composite resin, by weight parts, include:

[0048] 70 to 110 parts of polyurethane acrylate;

[0049] Photoinitiator 0.2 to 10 parts;

[0050] 0.2 to 2 parts of thermal initiator;

[0051] Colorant: 1 to 10 parts;

[0052] 10 to 30 parts of diluent; and,

[0053] Additives: 0.1 to 10 parts.

[0054] The mass fractions of polyurethane acrylate include, but are not limited to, 70, 74, 78, 82, 86, 90, 94, 98, 102, 106, or 110 parts. The mass fractions of photoinitiator include, but are not limited to, 0.2, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts. The mass fractions of thermal initiator include, but are not limited to, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, or 2.0 parts. The mass fractions of colorant include, but are not limited to, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts. The mass fractions of the diluent include, but are not limited to, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30 parts. The mass fractions of the additives include, but are not limited to, 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts.

[0055] This embodiment uses a mixture of polyurethane acrylate and colorant, combined with photoinitiator and thermal initiator for dual light / heat curing, giving the composite resin a leather-like effect. On one hand, the colorant is fixed and dispersed in the composite resin as the polyurethane acrylate cures. At this point, light diffuses across the dispersed colorant, eliminating surface reflection and making the leather texture more realistic. On the other hand, no additional color effect layer is needed to achieve the desired color effect, saving on screen printing and reducing processing steps. Furthermore, with the synergistic effect of diluent and additives, the composite resin of this application exhibits excellent flowability and coatability, making it suitable for complex molding processes. In this embodiment, the composite resin, through the synergistic effect of its various weight proportions of raw materials and dual light / heat curing, achieves a leather-like appearance and effect similar to PU artificial leather, realizing an integrated design of the leather-like adhesive layer and color effect layer.

[0056] In one example, the polyurethane acrylate includes at least one of aromatic polyurethane acrylate, aliphatic polyurethane acrylate, and alicyclic polyurethane acrylate. The number-average molecular weight of the polyurethane acrylate is 1000 to 10000, for example, it can be 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, or 10000. The selection of the polyurethane acrylate resin and its number-average molecular weight in this embodiment can improve the curing process, optimize the photocurable crosslinking and thermocurable crosslinking composite structure, and further enhance the leather-like feel and appearance of the composite resin.

[0057] Furthermore, the polyurethane acrylate is grafted with modifying groups, including at least one of isocyanate groups, hydroxyl groups, carboxyl groups, epoxy groups, siloxane groups, polyester groups, and polyether groups. In this embodiment, by grafting modifying groups onto the polyurethane acrylate resin, both photocuring and thermocuring crosslinking can be performed simultaneously, further improving the photo / thermocuring crosslinking effect and optimizing the crosslinking structure, thereby enhancing the leather-like feel and appearance of the composite resin.

[0058] In one example, the photoinitiator may be a radical photoinitiator, including at least one selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methylphenylacetone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, and 1-hydroxycyclohexylphenyl ketone. The thermal initiator includes a peroxide, including at least one selected from benzoyl peroxide, tert-butyl peroxide, tert-butyl peroxide, and tert-amyl peroxide. The diluent includes at least one of tripropylene glycol diacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and dipropylene glycol diacrylate. The colorant includes a color paste or color powder, which is understood to be adjusted according to the desired color.

[0059] This embodiment, by selecting photoinitiator, thermal initiator, diluent, and colorant as described above, can further improve the photo / thermal curing process and enhance the overall performance of the composite resin.

[0060] In one example, different additives can be added according to the specific needs of the composite resin. For example, the additives include at least one of leveling agents and abrasion resistant agents. Optionally, the leveling agent includes at least one of silicone leveling agents, anionic surfactants, cationic surfactants, and amphoteric surfactants. The abrasion resistant agent includes at least one of sericite and polyethylene wax. More optionally, the abrasion resistant agent includes sericite and polyethylene wax in a mass ratio of (2~3):1. This embodiment, by adding leveling agents and abrasion resistant agents, enables the composite resin surface to be smooth and have a skin-like feel, further improving the corrugated effect and stability of the composite resin.

[0061] Please see Figure 1 The second aspect of this embodiment provides a composite cover plate 100, including a substrate 110 and a textured layer 120. The textured layer 120 is disposed on the substrate 110 and is prepared from the composite resin of the first aspect.

[0062] The surface of the composite cover plate 100 provided in this embodiment is made of a composite resin material formed by light / heat dual curing of polyurethane acrylate and colorant, which makes the leather texture layer 120 have the feel of leather and a realistic leather texture appearance effect, realizing the design of the leather adhesive layer and the color effect layer as one.

[0063] In one example, the thickness of the dermal layer 120 can be 80 μm to 200 μm.

[0064] Please refer to the following: Figure 1 In one example, the substrate 110 includes a cover ink layer 111, a substrate layer 112 and a base layer 113 stacked sequentially, with the base layer 113 located between the substrate layer 112 and the texture layer 120.

[0065] In one example, the substrate layer 112 includes at least one of polycarbonate, polycarbonate (PC) / polymethyl methacrylate (PMMA), polyethylene terephthalate, thermoset glass fiber composite, and thermoplastic glass fiber composite. Optionally, the thickness of the substrate layer 112 can be 0.3 mm to 0.6 mm. When the substrate layer 112 is a PC board or a PC / PMMA composite board, the cover can be directly made into a two-dimensional structure. Alternatively, the two-dimensional structure cover can be pressure-formed to obtain the desired three-dimensional composite cover 100. When the substrate layer 112 is a thermoset glass fiber composite board (e.g., a material that can be a composite of glass fiber and epoxy resin), after forming a textured layer of composite resin material, it is not hot-bent and is CNC (computer numerical control) machined to become a 2D composite cover 100. When the substrate layer 112 is a thermoplastic glass fiber composite board (e.g., a material that can be a composite of glass fiber and polycarbonate), after forming a textured layer of composite resin material, it can be placed in a mold for hot bending to form the desired three-dimensional composite cover 100.

[0066] It is understood that the substrate layer 112 in this application can be a transparent or translucent board, or it can be a colored board, so a cover ink layer 111 can be set on the substrate layer 112 according to actual needs. For example, when the substrate layer 112 has the same color as the texture layer 120, the cover ink layer 111 may not be set on the substrate layer 112. The cover ink layer 111 can be selected according to the requirements in terms of color, function and number of layers. The cover ink layer 111 may include flame-retardant ink or colored ink. Optionally, the cover ink layer 111 is formed by multiple screen printing processes, and the thickness of each cover ink layer 111 can be 7μm~12μm, and the total thickness of the cover ink layer 111 can be 20μm~50μm. In this embodiment, by setting the cover ink layer 111, the opacity can be improved, the color saturation can be enhanced, the printed color can be more vivid and bright, and the overall visual effect can be improved. In addition, the bottom ink layer 111 can also protect the printed area, improve flame retardant performance, and increase the adhesion between the composite cover plate 100 and auxiliary materials such as foam.

[0067] The textured layer 120 of this application can be directly transferred or coated onto the surface of the substrate layer 112. Furthermore, to improve the adhesion between the substrate layer 112 and the textured layer 120, a primer layer 113 can be provided on the surface of the substrate layer 112. The primer layer 113 includes at least one of acrylic resin and polyurethane resin. The primer layer 113 can be formed by methods such as screen printing. Optionally, the thickness of the primer layer 113 can be 20µm to 50µm. In this embodiment, the primer layer 113 effectively enhances the adhesion between the textured layer 120 and the substrate layer 112, effectively improving the structural stability of the composite cover plate 100.

[0068] In one example, the composite cover 100 also includes a pattern layer (not shown) disposed on the side of the texture layer 120 facing away from the substrate 110. The pattern layer can be formed on at least a portion of the surface of the texture layer 120 by means of screen printing, embossing, lamination, inlay, etc. Alternatively, a groove with the same shape as the pattern layer can be formed on the texture layer 120, and then the pattern layer can be screen printed or embossed into the groove. The pattern of the pattern layer includes, but is not limited to, fonts or logos. The groove can be formed by CNC machining, and the shape of the groove can be the same as the shape of the pattern layer, that is, a groove with the same shape as the pattern layer is formed only in the area covered by the pattern layer. In this embodiment, a groove is formed on the surface of the texture layer, so that the pattern layer is disposed in the groove. When the depth of the groove is the same as the thickness of the texture layer 120, the pattern layer can be attached to the rigid substrate layer, improving the adhesion effect. In addition, the exposed surfaces of the texture layer 120 and the pattern layer can be flush to ensure the flatness of the surface of the composite cover 100; the exposed surface of the texture layer 120 can also be lower or higher than the surface of the pattern layer to form a concave or convex effect.

[0069] The third aspect of this embodiment provides a method for preparing a composite cover plate, the method comprising:

[0070] The first aspect of the composite resin is applied to the surface of the substrate using a transparent leather-textured release film;

[0071] The composite resin is subjected to photocuring and thermocuring treatments.

[0072] In this embodiment, a transparent leather-textured release film is used to mold the mixture during the preparation of the composite resin, creating a leather-textured pattern on the surface of the composite resin. The composite resin is then rapidly cured using a photocuring process to achieve transfer and shaping. Because the composite resin contains colorants, some areas are masked by the colorants, resulting in the formation of photocurable cross-linked structures in certain areas. Subsequently, a thermocuring process is used to fully cure the composite resin, ensuring that the leather-textured layer possesses both photocurable and thermocurable cross-linked structures. These structures work synergistically to improve the overall performance of the composite resin, achieving a leather-textured appearance and effect similar to PU artificial leather.

[0073] Specifically, during the photocuring process, the colorant blocks the light, causing rapid curing of the surface and un-blocked areas of the composite resin. This allows some of the polyurethane acrylate in the composite resin to undergo photocuring. Furthermore, by combining this with thermocuring, the polyurethane acrylate within the composite resin is fully cured. The composite resin possesses both photocurable and thermocurable crosslinking structures. The synergistic effect of these two crosslinking structures gives the composite resin a leather-like texture and feel similar to PU artificial leather. This application overcomes the prejudice that non-transparent polyurethane acrylate containing pigments cannot undergo sufficient photocuring. The composite resin of this application can be used in ultra-thick coatings and colored coatings, broadening the applications of UV curing systems.

[0074] Understandably, during the photocuring process, polyurethane acrylic resin relies on rapid cross-linking via carbon-carbon double bonds. Multiple acrylate groups connect polyurethane acrylic resin molecules through addition polymerization of carbon-carbon double bonds, forming a three-dimensional network structure and achieving rapid curing of the composite resin. During the thermocuring process, the active groups of polyurethane undergo a "thermally accelerated addition reaction," relying on the active groups to form covalent cross-linking. Polyurethane segments are connected through urethane bonds, urea bonds, etc., forming a three-dimensional network. Therefore, this application, by adding colorants to polyurethane acrylic resin and utilizing the masking effect of the colorants combined with photo / thermal dual curing, presents multiple cross-linking structures in the resin, giving the composite resin a leather-textured appearance and effect similar to PU artificial leather.

[0075] Understandably, the transparent leather-textured release film can maintain the shape of the composite resin and create a textured structure on its surface; furthermore, it can be peeled off from the partially cured composite resin and has a certain degree of light transmittance, and it can be recycled. For example, the transparent leather-textured release film can be PET (polyethylene terephthalate). Furthermore, the transparent leather-textured release film is removed after the composite resin undergoes photocuring to prevent it from adhering to the surface of the leather-textured layer during the heat-curing process, thus affecting the appearance of the leather-textured layer.

[0076] In one example, the photocuring process includes: firstly curing the composite resin with a UV LED (ultraviolet light-emitting diode) lamp, then removing the transparent leather-textured release film, and finally performing a second photocuring process on the composite resin after the first photocuring process using a UV mercury lamp. This application combines the first and second photocuring processes. The first photocuring process using a UV LED has higher light intensity density and directional energy transfer, resulting in a significantly faster curing speed than the second photocuring process using a UV mercury lamp. This effectively ensures the separation of the composite resin from the transparent leather-textured release film and the curing effect of the composite resin, further improving the overall performance of the composite resin.

[0077] In one example, the UV LED lamp in the first photocuring process has a light source wavelength of 360nm~410nm, for example, it can be 360nm, 370nm, 380nm, 390nm, 400nm or 410nm; the power of the light source's emitting surface is 16W / cm². 2 ~25W / cm 2 For example, it could be 16W / cm 2 17W / cm 2 18W / cm 2 19W / cm 2 20W / cm 2 21W / cm 2 22W / cm 2 23W / cm 2 24W / cm 2 Or 25W / cm 2 The energy is 3000 mJ / cm³. 2 ~4000mJ / cm 2 For example, it could be 3000mJ / cm 2 3100mJ / cm 2 3200mJ / cm 2 3300mJ / cm 2 3400mJ / cm 2 3500mJ / cm 2 3600mJ / cm 23700mJ / cm 2 3800mJ / cm 2 3900mJ / cm 2 Or 4000mJ / cm 2 The curing time is 5s to 15s, for example, 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, or 15s. Optionally, the curing rate of the composite resin is less than 80%, for example, it can be 60% to 80%. The parameters for the first photocuring treatment selected above in this application promote the photocuring process, further improve the rapid curing effect of the photocuring treatment, ensure the resin crosslinking density, improve the overall performance of the composite resin, and avoid textural deformation and excessive material hardness.

[0078] In one example, the UV mercury lamp in the second photocuring process has a light source wavelength of 300nm~400nm, for example, it can be 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm or 400nm; the light intensity is 80W / cm². 2 ~220W / cm 2 For example, it could be 80W / cm 2 100W / cm 2 120W / cm 2 140W / cm 2 160W / cm 2 180W / cm 2 200W / cm 2 Or 220W / cm 2 The energy is 1200 mJ / cm³. 2 ~1800mJ / cm 2 For example, it could be 1200mJ / cm 2 1300mJ / cm 2 1400mJ / cm 2 1500mJ / cm 2 1600mJ / cm 2 1700mJ / cm 2 Or 1800mJ / cm 2 The time is 10s to 60s, for example, 10s, 20s, 30s, 40s, 50s, or 60s. This application selects the parameters for the second photocuring treatment as described above, which work synergistically with the first photocuring treatment to further optimize the photocuring crosslinking effect of the resin and effectively improve the overall performance of the composite resin.

[0079] In one example, the thermosetting temperature is 80℃~100℃, for example, 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, 96℃, 98℃, or 100℃; the time is 0.5~1.5h, for example, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, or 1.5h. The curing rate of the composite resin after thermosetting is 95%~100%. This application selects the above-mentioned thermosetting parameters, which, in conjunction with photocuring, ensure sufficient thermosetting and cross-linking of the resin, thereby improving the overall performance of the composite resin.

[0080] By way of example, a method for preparing the above-mentioned composite cover plate 100 is provided, comprising the following steps:

[0081] S1. A cover ink layer 111 is screen-printed on one side of the substrate layer 112, and a base layer 113 is screen-printed on the other side to form a substrate 110.

[0082] S2. Apply the composite resin of the first aspect to the surface of the substrate using a transparent textured release film.

[0083] S3. The composite resin is subjected to a first photocuring treatment using a UV LED lamp. The wavelength of the UV LED lamp is 360nm~410nm, and the power of the light-emitting surface is 16W / cm². 2 ~25W / cm 2 The energy is 3000 mJ / cm³. 2 ~4000mJ / cm 2 The curing time is 5s~15s. After light curing, the transparent leather texture release film is removed.

[0084] S4. The composite resin is subjected to a second photocuring treatment using a UV mercury lamp. The wavelength of the UV mercury lamp is 300nm~400nm, and the light intensity is 80W / cm². 2 ~220W / cm 2 The energy is 1200 mJ / cm². 2 ~1800mJ / cm 2 The duration is 10s to 60s.

[0085] S5. The composite resin is heated at 80℃~100℃ for 0.5h~1.5h to obtain a textured layer 120 on the surface of the substrate 110.

[0086] The fourth aspect of this embodiment also provides an electronic device, which includes a composite cover plate 100 as described in the third aspect.

[0087] Understandably, the electronic device of this application has all the advantages of the composite cover 100 described above, so it will not be repeated here.

[0088] See also Figure 2 For example, an electronic device includes a composite cover plate 100 and an electronic device body 200. The electronic device body 200 is bonded to the side of the composite cover plate 100 having a cover ink layer 111. For example, the electronic device includes, but is not limited to, a mobile phone, tablet, computer, television, printer, copier, or electronic watch. For example, the composite cover plate 100 may be the rear cover of the electronic device.

[0089] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0090] In the following examples, the polyurethane acrylate is brand EBECRYL 265, purchased from Cytec Chemicals.

[0091] Example 1

[0092] S1. A 30μm thick cover ink layer 111 is screen-printed on one side of a substrate layer 112 with a thickness of 0.5mm and made of thermosetting glass fiber (glass fiber + epoxy resin), and a 30μm thick underlayer 113 made of polyurethane resin is screen-printed on the other side to form a substrate 110.

[0093] S2. Weigh out 90 parts of polyurethane acrylate, 5 parts of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 1 part of BPO (benzoyl peroxide), 6 parts of color powder purchased from DIC Corporation, 20 parts of TPGDA (tripropylene glycol diacrylate), and 5 parts of silicone leveling agent according to the following mass ratios, and mix them to obtain a composite resin.

[0094] A transparent leather-textured release film made of PET material is used to apply composite resin to one side surface of substrate 110 with a base layer 113.

[0095] S3. The composite resin is subjected to a first photocuring treatment using a UV LED. The UV LED light source wavelength is 380nm, and the power of the light-emitting surface is 20W / cm². 2 The energy is 3500 mJ / cm³. 2 The time is 10 seconds. After the first light curing treatment, the transparent leather texture release film is removed.

[0096] S4. The composite resin is subjected to a second photocuring treatment using a UV mercury lamp. The wavelength of the UV mercury lamp is 350nm, and the light intensity is 150W / cm². 2 The energy is 1500 mJ / cm². 2 The time is 30 seconds.

[0097] S5. The composite resin is heat-cured at 90°C for 1 hour to form a textured layer 120 with a thickness of 150 μm on the surface of the substrate 110. For example... Figure 3 As shown, the black area is the substrate 110, and the remaining area is the texture layer 120.

[0098] Example 2

[0099] S1. A 50μm thick cover ink layer 111 is screen-printed on one side of a 0.3mm thick PC / PMMA substrate layer 112, and a 20μm thick underlayer 113 made of polyurethane resin is screen-printed on the other side to form a substrate 110.

[0100] S2. Weigh out 70 parts by weight of polyurethane acrylate, 0.2 parts by weight of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 0.2 parts by weight of BPO (benzoyl peroxide), 1 part by weight of color paste purchased from Guangdong Kedi New Material Technology Co., Ltd., 10 parts by weight of TPGDA (tripropylene glycol diacrylate), and 0.1 parts by weight of silicone leveling agent, and mix them to obtain composite resin;

[0101] A transparent leather-textured release film made of PET material is used to apply composite resin to one side surface of substrate 110 with a base layer 113.

[0102] S3. The composite resin is subjected to a first photocuring treatment using a UV LED. The UV LED light source wavelength is 360nm, and the power of the light-emitting surface is 16W / cm². 2 The energy is 3000 mJ / cm³. 2 The time is 15 seconds. After the first light curing treatment, the transparent leather texture release film is removed.

[0103] S4. The composite resin is subjected to a second photocuring treatment using a UV mercury lamp. The UV mercury lamp has a light source wavelength of 400nm and a light intensity of 220W / cm². 2 The energy is 1800 mJ / cm². 2 The time is 60 seconds.

[0104] S5. The composite resin is heated at 80°C for 1.5 hours to perform heat curing treatment, and a textured layer 120 with a thickness of 200 μm is formed on the surface of the substrate 110.

[0105] Example 3

[0106] S1. A 20μm thick cover ink layer 111 is screen-printed on one side of a substrate layer 112 with a thickness of 0.6mm and a material of thermosetting glass fiber (glass fiber + epoxy resin), and a 50μm thick underlayer layer 113 with a material of polyurethane resin is screen-printed on the other side to form a substrate 110.

[0107] S2. Weigh out 110 parts of polyurethane acrylate, 10 parts of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 2 parts of BPO (benzoyl peroxide), 10 parts of color powder purchased from DIC Corporation, 30 parts of TPGDA (tripropylene glycol diacrylate), and 10 parts of silicone leveling agent according to the following mass ratios, and mix them to obtain a composite resin.

[0108] A transparent leather-textured release film made of PET material is used to apply composite resin to one side surface of substrate 110 with a base layer 113.

[0109] S3. The composite resin is subjected to a first photocuring treatment using a UV LED. The UV LED light source wavelength is 410nm, and the power of the light-emitting surface is 25W / cm². 2 The energy is 4000 mJ / cm². 2 The time is 5 seconds. After the first light curing treatment, the transparent leather texture release film is removed.

[0110] S4. The composite resin is subjected to a second photocuring treatment using a UV mercury lamp. The UV mercury lamp has a light source wavelength of 300nm and a light intensity of 80W / cm². 2 The energy is 1200 mJ / cm². 2 The time is 10 seconds.

[0111] S5. The composite resin is heated at 100°C for 0.5 hours to perform a thermosetting treatment, thereby obtaining a textured layer 120 with a thickness of 20 μm on the surface of the substrate 110.

[0112] Comparative Example 1

[0113] The texture layer was prepared according to the method of Example 1, except that the thermal initiator TPO was not added to the composite resin in step S2, and the thermal curing treatment in step S5 was not performed; only the composite resin was photocured.

[0114] Because the raw materials contain colorants, the composite resin has poor light transmittance, making it difficult to initiate curing inside the composite resin during the photocuring process. This results in the composite resin not being fully cross-linked, and the material lacks a thermosetting cross-linking structure. The resulting skin texture layer has an adhesion of 1B according to ASTM D3359-23 standard, which cannot meet the requirements of the cover plate.

[0115] The composite cover plate 100 prepared in Examples 1-3 meets the relevant mobile phone tests. Adhesion, according to the standard test method of ASTM D3359-23 for assessing adhesion using adhesive tape, yielded a result of 5B. The boiling water resistance test met the requirements of 80 degrees Celsius for 30 minutes. The high temperature and high humidity test met the requirements of 65±1℃, humidity: 90%RH, and time: 48 hours. The RCA test, according to the ASTM F2357 RCA paper tape friction test method, met the requirement of 175g / 200 cycles without leakage.

[0116] In summary, this application employs a mixture of polyurethane acrylate and colorant, combined with photoinitiator and thermal initiator for dual light / heat curing, resulting in a composite resin with a leather-like simulation effect. On one hand, the colorant is fixed and dispersed in the composite resin as the polyurethane acrylate cures. At this point, light diffuses across the dispersed colorant, eliminating surface reflection and enhancing the realistic leather texture. On the other hand, the desired color effect can be achieved without a separate color effect layer, saving on screen printing and reducing processing steps. Furthermore, with the synergistic effect of diluents and additives, the composite resin exhibits excellent flowability and coatability, making it suitable for complex molding processes. The composite resin of this application, with the synergistic effect of each part by weight of raw materials, possesses the feel of leather and a realistic leather texture appearance, achieving an integrated design of the leather-like adhesive layer and color effect layer.

[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] 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 the 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 modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A composite resin, characterized in that, The raw materials of the composite resin, by weight, include: 70 to 110 parts of polyurethane acrylate; Photoinitiator 0.2 to 10 parts; 0.2 to 2 parts of thermal initiator; Colorant: 1 to 10 parts; 10 to 30 parts of diluent; and, Additives: 0.1 to 10 parts.

2. The composite resin as described in claim 1, characterized in that, The polyurethane acrylate includes at least one of aromatic polyurethane acrylate, aliphatic polyurethane acrylate and alicyclic polyurethane acrylate; And / or, the number average molecular weight of the polyurethane acrylate is 1000~10000; And / or, the polyurethane acrylate is further grafted with modifying groups, the modifying groups including at least one of isocyanate groups, hydroxyl groups, carboxyl groups, epoxy groups, siloxane groups, polyester groups and polyether groups.

3. The composite resin as described in claim 1, characterized in that, The photoinitiator includes a radical photoinitiator, which includes at least one selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methylphenylpropanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, and 1-hydroxycyclohexylphenyl methyl ketone. And / or, the thermal initiator includes a peroxide, which includes at least one of benzoyl peroxide, tert-butyl peroxide, tert-butyl peroxide, and tert-amyl peroxide. And / or, the diluent comprises at least one of the following: tripropylene glycol diacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and dipropylene glycol diacrylate. And / or, the colorant includes a color paste or color powder.

4. The composite resin according to any one of claims 1-3, characterized in that, The additives include at least one of leveling agents and abrasion-resistant agents.

5. The composite resin as described in claim 4, characterized in that, The leveling agent includes at least one of silicone leveling agents, anionic surfactants, cationic surfactants, and amphoteric surfactants; And / or, the wear-resistant agent comprises sericite and polyethylene wax; the mass ratio of the sericite to the polyethylene wax is (2~3):

1.

6. A composite cover plate, characterized in that, include: substrate; A textured layer is disposed on the substrate, and the textured layer is prepared from the composite resin according to any one of claims 1-5.

7. The composite cover plate as described in claim 6, characterized in that, The substrate includes a cover ink layer, a substrate layer and a base layer stacked sequentially, wherein the base layer is located between the substrate layer and the texture layer.

8. The composite cover plate as described in claim 7, characterized in that, The substrate layer includes at least one of polycarbonate, polycarbonate / polymethyl methacrylate, polyethylene terephthalate, thermoset glass fiber composite material, and thermoplastic glass fiber composite material; And / or, the underlayer comprises at least one of acrylic resin and polyurethane resin.

9. The composite cover plate according to any one of claims 6-8, characterized in that, The composite cover plate also includes a pattern layer disposed on the side of the textured layer opposite to the substrate.

10. A method for preparing a composite cover plate, characterized in that, The preparation method includes: The composite resin described in any one of claims 1-5 is applied to the surface of the substrate using a transparent leather-textured release film; The composite resin is subjected to photocuring and thermocuring treatments.

11. The method for preparing the composite cover plate as described in claim 10, characterized in that, The photocuring process includes: performing a first photocuring treatment on the composite resin using a UV LED lamp, removing the transparent leather texture release film, and then performing a second photocuring treatment on the composite resin after the first photocuring treatment using a UV mercury lamp.

12. The method for preparing the composite cover plate as described in claim 11, characterized in that, In the first photocuring process, the UV LED lamp has a light source wavelength of 360nm~410nm and a light-emitting surface power of 16W / cm². 2 ~25W / cm 2 The energy is 3000 mJ / cm³. 2 ~4000mJ / cm 2 The duration is 5s to 15s; And / or, in the second photocuring process, the UV mercury lamp has a light source wavelength of 300nm~400nm and a light intensity of 80W / cm². 2 ~220W / cm 2 The energy is 1200 mJ / cm 2 ~1800mJ / cm 2 The duration is 10s to 60s.

13. The method for preparing the composite cover plate according to any one of claims 10-12, characterized in that, The temperature for the thermosetting treatment is 80℃~100℃, and the time is 0.5~1.5h.

14. An electronic device, characterized in that, The electronic device includes the composite cover plate according to any one of claims 6-9.

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