Composite cloth, mobile phone shell and preparation method thereof

Abstract

This invention discloses a composite fabric, a mobile phone case, and their preparation method, belonging to the field of functional composite material technology. The preparation method of the composite fabric includes: pretreating Kevlar woven fabric; preparing an aqueous polyurethane foaming slurry; coating the foaming slurry onto the surface of the pretreated Kevlar woven fabric and forming a three-dimensional embossed pattern through an embossing process; and drying and curing the above product to obtain a soft composite fabric with a three-dimensional embossed pattern. The beneficial effects of this invention are that the composite fabric and mobile phone case obtained by the preparation method can achieve both high strength and a soft, three-dimensional feel.

Description

Technical Field

[0001] This invention relates to the field of functional composite materials technology, and in particular to a composite fabric, a mobile phone case, and a method for preparing the same. Background Technology

[0002] Kevlar fiber has been widely used in bulletproof protection, aerospace and consumer electronics due to its excellent properties such as high strength, high modulus, impact resistance and flame retardancy.

[0003] Currently, the mainstream processes for using Kevlar materials in mobile phone cases include thermoforming and vacuum forming. For example, existing technology discloses a Kevlar mobile phone case that obtains a hard shell by laminating layers of Kevlar-impregnated fabric and then molding it under high temperature and pressure in a vacuum heating tank. In addition, there are also ultra-thin mobile phone case solutions that use a composite of a Kevlar woven inner shell layer and an outer shell layer. The common characteristic of these processes is that the final product is a fixed-shape, hard protective case. Although the Kevlar fabric is impregnated with resin before molding, it does not form a soft, three-dimensional patterned fabric with independent usability.

[0004] On the other hand, in the field of waterborne polyurethane coating, there exists a process for preparing waterborne embossed garment leather. This process first foams a waterborne polyurethane slurry and then coats it onto a base fabric to form a base layer. Next, it undergoes dry lamination and embossing with embossing rollers, and finally, the texture is rubbed to obtain a soft synthetic leather with a three-dimensional pattern. However, this technology is geared towards the garment fabric sector, using ordinary textile fabric as the base fabric, without involving Kevlar fibers, and does not consider subsequent integration with mobile phone case injection molding processes.

[0005] Therefore, developing a composite fabric that retains the high strength of Kevlar, has a soft feel and durable three-dimensional texture, and can be well integrated with injection molding processes, as well as its preparation method, has significant market value. Summary of the Invention

[0006] To address the aforementioned problems, the primary objective of this invention is to provide a composite fabric that combines high strength with a soft, three-dimensional feel.

[0007] Another objective of this invention is to provide a phone case that combines high strength with a soft, three-dimensional feel.

[0008] Another objective of this invention is to provide a method for preparing a composite fabric that combines high strength with a soft, three-dimensional feel.

[0009] Another objective of this invention is to provide a method for preparing a mobile phone case, which results in a mobile phone case that combines high strength with a soft, three-dimensional feel.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows: This invention provides a composite fabric, characterized in that it comprises: a Kevlar base fabric and a waterborne polyurethane layer, wherein the waterborne polyurethane layer coats the Kevlar base fabric and has an uneven structure to form a three-dimensional uneven layer. The Kevlar base fabric has high strength, and the waterborne polyurethane layer has softness; the three-dimensional uneven layer on the waterborne polyurethane layer gives the composite fabric a three-dimensional soft effect.

[0011] Furthermore, the Kevlar base fabric is a Kevlar woven fabric, and the water-based polyurethane layer is coated on the Kevlar woven fabric. The formation of the three-dimensional uneven layer can be achieved by the water-based polyurethane layer partially penetrating into the pores of the Kevlar woven fabric after coating, creating an uneven surface; or by creating grooves in the water-based polyurethane layer after coating it onto the Kevlar woven fabric, thereby forming the three-dimensional uneven layer.

[0012] This invention also provides a mobile phone case, characterized in that it includes a main body with a mobile phone receiving space, and a composite fabric on the back of the main body away from the receiving space. The composite fabric includes a Kevlar base fabric and a water-based polyurethane layer, wherein the water-based polyurethane layer covers the Kevlar base fabric and has an uneven structure to form a three-dimensional uneven layer. This structure allows the mobile phone case to achieve both high strength and a soft, three-dimensional feel.

[0013] Furthermore, the main body of the phone case and the composite fabric are integrally connected by injection molding.

[0014] This invention also provides a method for preparing a composite fabric, characterized by comprising: Pre-treat the Kevlar woven fabric; Preparation of water-based polyurethane foam slurry; The foaming slurry is coated onto the surface of the pretreated Kevlar woven fabric, and a three-dimensional embossed pattern is formed by embossing. The above product is dried and cured to obtain a composite fabric with a soft overall texture and a three-dimensional embossed pattern.

[0015] Furthermore, the pretreatment includes plasma treatment or water-based polyurethane sizing agent impregnation treatment.

[0016] Furthermore, the expansion ratio of the waterborne polyurethane foam slurry is 1.8-2.0 times.

[0017] Furthermore, the embossing process employs hot pressing with an embossing roller having a predetermined pattern, or uses release paper with a pattern for transfer printing. Specifically, it can be: Method A (embossing roller method): After the coated semi-finished product is heated, it is embossed by an embossing roller with a predetermined pattern to obtain a composite fabric with a three-dimensional raised and recessed pattern.

[0018] Method B (release paper method): Water-based polyurethane slurry is coated onto patterned release paper, dried to form a patterned surface layer, and then laminated with Kevlar base fabric.

[0019] This invention also provides a method for preparing a mobile phone case, characterized in that the aforementioned composite fabric is cut into pieces and used as an insert, which is then integrally molded with the mobile phone case material through an injection molding process. The mobile phone case material can be thermoplastic polyurethane.

[0020] The beneficial effects of this invention are: compared to the prior art: 1. This invention uses water-based polyurethane resin, avoiding the use of toxic solvents such as DMF in traditional solvent-based resins, making it environmentally friendly and safe.

[0021] 2. By combining foam coating with embossing or release paper transfer processes, a durable, three-dimensional raised pattern is formed on the Kevlar high-strength fabric, which has both decorative and functional properties.

[0022] 3. The prepared composite fabric remains soft, overcoming the shortcomings of traditional Kevlar mobile phone case materials, which are hard and have a monotonous feel, and providing a flexible insert for subsequent injection molding.

[0023] 4. By using the soft patterned composite fabric of the present invention as an insert for secondary injection molding, the Kevlar three-dimensional pattern on the back of the phone case and the TPU soft rubber on the frame can be integrated. The process is simple and the bond is strong. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the exploded structure of the mobile phone case of the present invention.

[0025] In the image: 1. Kevlar base fabric; 2. Waterborne polyurethane layer; 3. Textured structure; 4. Main body of the phone case. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] To achieve the above objectives, the technical solution of the present invention is as follows: This embodiment provides a composite fabric, characterized in that it comprises: a Kevlar base fabric 1 and a waterborne polyurethane layer 2, wherein the waterborne polyurethane layer 2 covers the Kevlar base fabric 1, and the waterborne polyurethane layer 2 is provided with a textured structure 3 to form a three-dimensional textured layer. The Kevlar base fabric has high strength, and the waterborne polyurethane layer has softness; the three-dimensional textured layer on the waterborne polyurethane layer gives the composite fabric a three-dimensional soft effect.

[0028] In this embodiment, the Kevlar base fabric is a Kevlar woven fabric, and the waterborne polyurethane layer 2 is coated on the Kevlar woven fabric. The formation of the three-dimensional uneven layer can be achieved by the waterborne polyurethane layer partially penetrating into the pores of the Kevlar woven fabric after coating, creating an uneven surface; or by creating grooves in the waterborne polyurethane layer after coating it onto the Kevlar woven fabric, thereby forming the three-dimensional uneven layer.

[0029] This invention also provides a mobile phone case, characterized in that it includes a main body 4, a mobile phone housing space provided on the main body 4, and a composite fabric provided on the back of the main body away from the mobile phone housing space. The composite fabric includes a Kevlar base fabric 1 and a water-based polyurethane layer 2, the water-based polyurethane layer 2 covering the Kevlar base fabric 1, and the water-based polyurethane layer 2 having a concave-convex structure 3 to form a three-dimensional concave-convex layer. The above structure allows the mobile phone case to achieve both high strength and a soft, three-dimensional feel.

[0030] In this embodiment, the main body of the phone case and the composite fabric are integrally connected by injection molding.

[0031] This invention also provides a method for preparing a composite fabric, characterized by comprising: Pre-treat the Kevlar woven fabric; Preparation of water-based polyurethane foam slurry; Foaming slurry is coated onto the surface of pretreated Kevlar woven fabric, and a three-dimensional embossed pattern is formed by embossing. The above product is dried and cured to obtain a composite fabric with a soft overall texture and a three-dimensional embossed pattern.

[0032] In this embodiment, the pretreatment includes plasma treatment or water-based polyurethane sizing agent impregnation treatment.

[0033] In this embodiment, the expansion ratio of the waterborne polyurethane foam slurry is 1.8-2.0 times.

[0034] In this embodiment, the embossing process uses an embossing roller with a predetermined pattern for hot pressing, or uses release paper with a pattern for transfer printing. Specifically, it can be: Method A (embossing roller method): After the coated semi-finished product is heated, it is embossed by an embossing roller with a predetermined pattern to obtain a composite fabric with a three-dimensional raised and recessed pattern.

[0035] Method B (release paper method): Water-based polyurethane slurry is coated onto patterned release paper, dried to form a patterned surface layer, and then laminated with Kevlar base fabric.

[0036] This invention also provides a method for preparing a mobile phone case, characterized in that the composite fabric is cut into pieces and used as an insert, which is then integrally molded with the mobile phone case material through an injection molding process. See the following two embodiments for details: 1. Select plain weave Kevlar fabric with a thickness of 0.4mm and perform plasma surface treatment.

[0037] 2. Take 100 parts by weight of waterborne polyurethane resin (commercially available WPU dispersions, such as Bayhydrol® series), add 0.5 parts by weight of dispersant, 5 parts by weight of foaming agent, 3 parts by weight of waterborne pigment, and 1.5 parts by weight of thickener, stir evenly, and foam to 1.8 times the original volume using a foaming machine.

[0038] 3. Apply the foaming slurry to the surface of Kevlar fabric to a thickness of about 0.5 mm.

[0039] 4. Heat the coated composite fabric to 80-100℃ and emboss it through an embossing roller with a diamond pattern, with a pressure of 0.5-1.0MPa.

[0040] 5. Dry and cure the embossed composite fabric in a 120℃ oven for 10 minutes to obtain a soft composite fabric with a three-dimensional diamond pattern.

[0041] 6. Cut the composite fabric into the shape of a mobile phone back panel, place it into an injection mold, inject TPU material for secondary injection molding, and obtain a Kevlar 3D patterned mobile phone protective case. Example 2

[0042] 1. Select Kevlar woven fabric, impregnate it with a water-based polyurethane sizing agent with a concentration of 0.8wt%, and then dry it to enhance the interfacial bonding strength.

[0043] 2. Prepare an aqueous polyurethane foam slurry similar to that in Example 1.

[0044] 3. Apply the slurry to the release paper with teardrop-shaped grooves, dry it to form a patterned film, and then heat-press the Kevlar fabric and the patterned film together.

[0045] 4. Peel off the release paper to obtain a composite fabric with a teardrop-shaped embossed pattern on the surface.

[0046] 5. The subsequent injection molding process is the same as in Example 1.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite fabric, characterized in that, include: The Kevlar base fabric and the waterborne polyurethane layer are provided, wherein the waterborne polyurethane layer is coated on the Kevlar base fabric and has a textured structure to form a three-dimensional textured layer.

2. The composite fabric as described in claim 1, characterized in that, The Kevlar base fabric is a Kevlar woven fabric, and the water-based polyurethane layer is coated on the Kevlar woven fabric.

3. A mobile phone case, characterized in that, The device includes a main body for a phone case, which has a space for holding the phone. A composite fabric is provided on the back of the main body of the phone case away from the space for holding the phone. The composite fabric includes a Kevlar base fabric and a water-based polyurethane layer. The water-based polyurethane layer is wrapped on the Kevlar base fabric and has a textured structure to form a three-dimensional textured layer.

4. A mobile phone case as described in claim 3, characterized in that, The main body of the phone case and the composite fabric are integrally connected by injection molding.

5. A method for preparing a composite fabric, used to prepare the composite fabric according to any one of claims 1-2, characterized in that, include: Pre-treat the Kevlar woven fabric; Preparation of water-based polyurethane foam slurry; The foaming slurry is coated onto the surface of the pretreated Kevlar woven fabric, and a three-dimensional embossed pattern is formed by embossing. The above product is dried and cured to obtain a composite fabric with a soft overall texture and a three-dimensional embossed pattern.

6. The method for preparing a composite fabric as described in claim 5, characterized in that, The pretreatment includes plasma treatment or water-based polyurethane sizing agent impregnation treatment.

7. The method for preparing a composite fabric as described in claim 5, characterized in that, The expansion ratio of the waterborne polyurethane foam slurry is 1.8-2.0 times.

8. The method for preparing a composite fabric as described in claim 5, characterized in that, The embossing process uses an embossing roller with a predetermined pattern for hot pressing, or uses release paper with a pattern for transfer printing.

9. A method for preparing a mobile phone case, used to prepare the mobile phone case according to any one of claims 3-4, characterized in that, The composite fabric is cut into pieces and used as an insert, which is then integrally molded with the phone case material using an injection molding process.

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