Mobile phone battery cover structure based on composite cloth coating and preparation method thereof

Abstract

The invention discloses a mobile phone battery cover structure based on a composite cloth coating and a preparation method of the mobile phone battery cover structure, and the mobile phone battery cover structure comprises a base material layer, an attaching adhesive layer, a cloth layer, a PU functional layer and a surface treatment layer which are sequentially laminated and combined. And precise simulation of a natural material is synchronously realized in visual and tactile dimensions. The polyurethane layer autonomously forms a microscopic topological structure under curing at a specific temperature, so that scattering distortion is avoided when light penetrates through the woven texture of the fabric, and a clear and three-dimensional fabric pattern is presented; and the synchronously generated surface micro-convex points are regulated and controlled through precise friction, so that the battery cover leather is endowed with soft damping touch feeling. The design breaks through an inherent frame of separation of a visual layer and a tactile layer in a traditional transfer printing process, and unification of cloth texture light transmission performance and biological skin feeling feedback is achieved on a smart phone component for the first time.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of shell materials, in particular to a mobile phone battery cover structure based on a composite fabric coating and a preparation method thereof. BACKGROUND

[0002] With the development of smart phones towards lightness and individualization, the battery cover as a user's direct contact appearance component needs to consider structural strength, aesthetic texture and touch experience. Although traditional glass or metal back covers have good mechanical support performance, they have problems such as single texture form and easy breakage. In recent years, the composite cover plate technology simulating fabric texture has gradually become a new design trend for high-end mobile phones by simulating the appearance of fabric on the surface of the substrate through transfer printing or pressing process. However, such technology still faces multiple common challenges in practical application: the heat pressing transfer printing process easily leads to weakening of the texture stereoscopic effect, scattering and halo phenomenon when light penetrates, reducing the pattern clarity and color restoration; the surface touch feeling presents hard and smooth characteristics due to process limitations, and it is difficult to restore the soft rubbing texture of real fabric or the leather micro-concave-convex touch feedback; the protection performance of the composite structure is also limited, and the conventional coating is prone to scratch accumulation and liquid penetration problems in long-term use, affecting the service life of the product.

[0003] A composite board mobile phone cover with texture and its production process is disclosed in Chinese patent literature

Application Number: 202210536606.1, Publication Number: CN114987024A

[0004] A mobile phone battery cover structure based on a composite fabric coating and a preparation method thereof, characterized by comprising a base material layer, a bonding adhesive layer, a fabric layer, a PU functional layer and a surface treatment layer which are sequentially stacked and combined. The base material layer includes a plate material capable of providing structural strength. The bonding adhesive layer is made of one or more of epoxy resin glue, polyester glue or polyurethane reactive glue. The fabric layer is made of woven fabric, embroidered fabric or jacquard fabric. The PU functional layer is made of transparent polyurethane. The surface treatment layer is made of at least one of water-based surface treatment agent, oil-based surface treatment agent or silicone type surface treatment agent.

[0005] Preferably, the plate material includes one or more of glass fiber reinforced epoxy resin plate, carbon fiber reinforced composite material or aramid fiber reinforced resin plate.

[0006] Through the above technical solution, the innovative design of the composite material significantly improves the comprehensive performance of the mobile phone battery cover. First, the substrate layer adopts a composite material reinforced by glass fiber, carbon fiber or aramid fiber, which not only gives the battery cover excellent mechanical strength and lightweight characteristics, but also ensures good heat resistance and dimensional stability, and can withstand various impacts and pressures in daily use of the mobile phone. Second, the introduction of the cloth layer brings a unique visual and tactile experience to the battery cover. Whether it is the delicate texture of the textile fabric, the exquisite patterns of the embroidery fabric, or the three-dimensional texture of the jacquard fabric, it can significantly improve the appearance and grade of the product. At the same time, the setting of the PU functional layer and the surface treatment layer ensures the durability and stain resistance of the cloth layer, prolonging the service life of the product. In terms of manufacturing process, the preparation method of the present application realizes efficient interlayer bonding by accurately controlling the thickness and process parameters of each layer. In particular, the optimization of temperature, pressure and time parameters in the vacuum lamination process ensures the firm lamination between the layers of materials, avoids delamination and blistering, and significantly improves the yield and production efficiency of the product.

[0007] Preferably, the thickness of the PU functional layer is 0.05mm to 0.08mm.

[0008] Through the above technical solution, the thickness of the PU functional layer is controlled in the range of 0.05mm to 0.08mm, realizing the perfect balance between transparency and mechanical performance. First, this thickness range ensures that the PU layer has sufficient transparency and does not affect the visual effect of the cloth layer, while maintaining good wear resistance and scratch resistance. Specifically, the minimum thickness of 0.05mm ensures that the PU layer can form a continuous and complete protective layer, effectively preventing wear and tear and scratches in daily use, while the maximum thickness of 0.08mm avoids the reduction of transparency and cost increase caused by excessive thickness. This thickness control range also ensures good bonding force between the PU layer and the cloth layer, avoiding delamination during use.

[0009] Preferably, the preparation method comprises the following steps: (1) Substrate layer preparation: preparing an epoxy glass fiber substrate to obtain a plate material one; (2) Cloth layer pretreatment: (2.1) Apply a transparent polyurethane solution to the cloth layer to obtain cloth one; (2.2) Apply a surface treatment agent to the surface of the polyurethane layer of cloth one to obtain cloth two; (3) Pre-lamination: use a hot roller at 70℃ to 80℃ to pre-laminate the lamination adhesive to the surface of plate material one; (4) Vacuum lamination: laminate plate material one with pre-laminated lamination adhesive and cloth two in a vacuum laminator, with a lamination temperature of 120℃ to 140℃ and a vacuum lamination time of 20 seconds, to obtain a composite plate material; (5) Forming: cutting the composite sheet into the shape of a mobile phone battery cover.

[0010] Preferably, the process parameters for step (2.1) coating are: curing the polyurethane solution at a temperature of 115±5℃ and a line speed of 2.3±0.2m / min.

[0011] Through the above technical solution, the pretreatment process parameters of the cloth layer are optimized accurately, ensuring the optimal bonding performance between the PU functional layer and the cloth layer. The temperature control range of 115±5℃ ensures the sufficient curing of the polyurethane solution and avoids damage to the cloth material caused by excessively high temperature. The line speed control of 2.3±0.2m / min ensures the uniformity of the coating and production efficiency. Specifically, the reference temperature of 115℃ is carefully selected based on the curing characteristics of the polyurethane material, which can form a uniform and dense film of polyurethane molecules on the cloth surface, and the temperature fluctuation range of ±5℃ considers the temperature control error in actual production, ensuring the stability and reliability of the process. The line speed of 2.3m / min is the best speed verified by multiple experiments under the premise of ensuring the quality of the coating, and the fluctuation range of ±0.2m / min considers the stability of equipment operation.

[0012] Preferably, the process parameters for step (2.2) coating are: curing the surface treatment agent at a temperature of 90±5℃ and a line speed of 1.4±0.2m / min.

[0013] Through the above technical solution, the coating process parameters of the surface treatment layer are carefully optimized, ensuring the uniformity and performance stability of the coating. The temperature control range of 90±5℃ ensures the sufficient curing of the surface treatment agent and avoids changes in material performance caused by excessively high temperature. The line speed control of 1.4±0.2m / min ensures the uniformity of the coating and production efficiency. Specifically, the reference temperature of 90℃ is carefully selected based on the chemical properties of the surface treatment agent, which can form a uniform and dense protective layer of the treatment agent on the cloth surface, and the temperature fluctuation range of ±5℃ considers the temperature control error in actual production, ensuring the stability and reliability of the process. The line speed of 1.4m / min is the best speed verified by multiple experiments under the premise of ensuring the quality of the coating, and the fluctuation range of ±0.2m / min considers the stability of equipment operation.

[0014] Preferably, the process parameters for step (4) vacuum lamination are: pressing at a vacuum degree of ≤5kPa, a temperature of 130±10℃, and a holding time of 20±2 seconds.

[0015] Through the technical scheme, the optimization design of the vacuum lamination process parameters ensures the perfect combination between the functional layers. The vacuum degree of ≤5 kPa effectively eliminates the air between the layers, avoids the generation of bubbles, and ensures the tightness of the interlayer combination. The temperature control range of 130±10℃ ensures the sufficient heat fusion of the materials, and avoids the change of the material performance caused by the too high temperature. The holding pressure time of 20±2 seconds ensures the sufficient fusion of the materials. Specifically, the vacuum degree of ≤5 kPa is the best value verified by multiple experiments, which can ensure that the air between the layers is completely extracted and bubbles are avoided, and the fluctuation range of ±5 kPa considers the control accuracy of the actual equipment. The reference temperature of 130℃ is carefully selected based on the heat fusion characteristics of the layers, which can make the materials fully fused under the action of pressure, and the temperature fluctuation range of ±10℃ considers the temperature control error in actual production. The holding pressure time of 20 seconds is the best time verified by multiple experiments on the premise of ensuring the interlayer bonding strength, and the fluctuation range of ±2 seconds considers the stability of the equipment operation.

[0016] Compared with the prior art, the present application has the following advantages: 1. The present application realizes the precise simulation of natural materials in the visual and tactile dimensions through the original integration of the fabric layer and the optical-grade polyurethane functional layer. The polyurethane layer autonomously forms a micro-topological structure under specific temperature curing, which avoids scattering and distortion when light penetrates the fabric weaving texture, presenting a clear and three-dimensional fabric pattern. The simultaneously generated surface micro-bumps, through precise friction regulation, impart the soft and damping touch of the battery cover leather. This design breaks through the inherent framework of separating visual and tactile layers in traditional transfer printing process, and for the first time realizes the unity of fabric texture light transmission and biological skin feedback on smart phone components.

[0017] 2. The synergistic effect of the nanocomposite surface layer and the vacuum lamination process in the present application constructs multiple active defense mechanisms within the total thickness of sub-millimeter. The nanometer reinforcing phase forms a dense microcrystalline network in the surface layer, greatly improving the surface scratch resistance; the molecular-level hydrophobic barrier effectively blocks the penetration of daily liquids, maintaining long-lasting clean appearance; the high-strength combination of the substrate layer and the functional layer significantly optimizes the impact resistance, coping with severe drop scenarios. This protective system completely overturns the traditional design logic of battery covers, which is forced to compromise between wear resistance, stain resistance and structural reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the present application. DETAILED DESCRIPTION

[0019] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0020] Embodiment: Preparation of high-transmittance jacquard cloth composite mobile phone battery cover I. Material configuration Substrate layer: glass fiber reinforced epoxy resin plate (thickness 0.5 mm, glass fiber content 60 wt%) Laminating adhesive layer: polyurethane reactive hot melt adhesive (coating thickness 0.03 mm) Cloth layer: 120D superfine polyester jacquard cloth (rhombus transparent hole structure, hole diameter 0.1 mm) PU functional layer: aliphatic transparent polyurethane (thickness 0.06 mm) Surface treatment layer: silicone-fluorine composite treatment agent (containing nano diamond additive, film thickness 5 μm) II. Preparation process Step 1: substrate layer preparation The glass fiber prepreg was hot-pressed at 160°C and 10MPa to form a rectangular substrate with a size of 150mm×75mm, and the surface was cleaned; Step 2: cloth layer pretreatment (2.1) PU functional layer coating The polyurethane solution was coated on the surface of the jacquard cloth using a micro-gravure coater; Curing at a temperature of 115°C±2°C and a line speed of 2.3m / min; Forming a micro-bump structure (Ra=1.2μm); (2.2) Surface treatment layer coating The treatment agent was coated on the surface of the PU layer using a slot coater; Curing at a temperature of 90°C±2°C and a line speed of 1.4m / min; Hydrophobic angle after film formation 115°; Step 3: pre-lamination Hot roller temperature 75°C, pressure 0.3Mpa; The laminating adhesive was pre-laminated to the surface of the substrate; Step 4: vacuum lamination Pressure holding at a vacuum degree of 3kPa and a temperature of 135°C for 20 seconds; Peeling strength after lamination ≥8N / cm; Step 5: molding The composite board was cut into the shape of a mobile phone battery cover; III. Performance verification results Test item Example result Common glass back cover result Haze 92% (no halo) ≤80% Tactile simulation Friction coefficient 0.35 0.45-0.60 Scratch resistance 6H pencil hardness no scratch 3H scratch appears Stain resistance Coke / Coffee 24h no penetration 12h bleeding Drop protection 1.5m concrete drop no damage 1.0m substrate cracking Test item Example result Common glass back cover result The above merely provides the preferred but non-restrictive embodiment of the present application, and the protection scope of the present application is not limited thereto, and any person skilled in the art, within the technical scope disclosed by the present application, can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application, which should be covered in the protection scope of the present application.

Claims

1. A mobile phone battery cover structure based on a composite fabric coating and its preparation method, characterized in that, Including those that are stacked and combined in sequence: Substrate layer: includes sheet material that provides structural strength; The adhesive layer is made of one or more of epoxy resin, polyester, or polyurethane reactive adhesive. The fabric layer may be made of textiles, embroidered fabrics, or jacquard fabrics. The PU functional layer is made of transparent polyurethane. The surface treatment layer is made of at least one of water-based surface treatment agents, oil-based surface treatment agents, or silicone-based surface treatment agents.

2. The composite mobile phone battery cover according to claim 1, characterized in that: The aforementioned sheet material includes one or more of the following: glass fiber reinforced epoxy resin sheet, carbon fiber reinforced composite material, or aramid fiber reinforced resin sheet.

3. The composite mobile phone battery cover according to claim 1, characterized in that: The thickness of the PU functional layer is 0.05 mm to 0.08 mm.

4. The composite mobile phone battery cover and its preparation method according to claims 1-3, characterized in that: The preparation method includes the following steps: (1) Substrate preparation: Prepare epoxy fiberglass substrate to obtain plate one; (2) Fabric layer pretreatment: (2.1) A transparent polyurethane solution is coated onto the fabric layer to obtain fabric one; (2.2) A surface treatment agent is applied to the surface of the polyurethane layer of fabric one to obtain fabric two; (3) Pre-lamination: Using a hot roller at 70°C to 80°C, the bonding adhesive is pre-lamination onto one surface of the board; (4) Vacuum bonding: The board 1 with pre-applied adhesive and the fabric 2 are bonded together in a vacuum bonding machine. The bonding temperature is 120℃ to 140℃ and the vacuum bonding time is 20 seconds to obtain a composite board. (5) Molding: Cut the composite board into the shape of a mobile phone battery cover.

5. The preparation method according to claim 4, characterized in that: The coating process parameters for step (2.1) are as follows: the polyurethane solution is cured at a temperature of 115±5℃ and a linear velocity of 2.3±0.2m / min.

6. The preparation method according to claim 4, characterized in that: The coating process parameters for step (2.2) are as follows: the surface treatment agent is cured at a temperature of 90±5℃ and a linear speed of 1.4±0.2m / min.

7. The method according to claim 4, characterized in that: The process parameters for vacuum bonding in step (4) are: bonding under vacuum degree ≤ 5 kPa, temperature 130 ± 10℃, and holding time 20 ± 2 seconds.

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