Laminated mobile phone shell and preparation method thereof

Abstract

The invention provides a veneered mobile phone shell which comprises a supporting layer, a bonding layer and a veneer which are tightly attached in sequence, the veneer comprises a base cloth layer, a polyolefin base material layer and a surface coating, and the polyolefin base material layer is prepared from, by weight, 15-40 parts of ethylene copolymer elastomer, 15-40 parts of ethylene propylene diene monomer and 20-70 parts of filler. The sum of the weight parts of the ethylene copolymer elastomer, the ethylene propylene diene monomer and the filler is 100. The veneered mobile phone shell provided by the invention has good mechanical performance, wear resistance, heat resistance, water resistance, shock resistance, style diversity and the like, and is simple in process and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile phone accessories, and particularly relates to a leather-covered mobile phone case and a preparation method thereof. Background Art

[0002] A mobile phone case is an ornament for protecting or decorating the appearance of a mobile phone. At present, mobile phone cases mainly include plastic types, plastic cases with leather covers, metal types, wood, etc. Among them, plastic mobile phone cases are the most commonly used in the market because of their simple technology, low price, and high fitting degree. However, plastic mobile phone cases lack attraction for high-end mobile phones and high-end users. Wood and metal mobile phone cases often have poor hand feeling, poor fitting degree, are bulky, and provide poor protection when dropped, so there are fewer users. Covering a leather layer on the outside of a plastic mobile phone case can make the mobile phone case more beautiful, generous and increase a good touch feeling.

[0003] A mobile phone protective case not only makes your mobile phone a scenery as an ornament, but also can protect the mobile phone, preventing it from being dropped, scratched, watered and shocked. At present, the surface of common mobile phone cases on the market is easy to wear after long-term use, making the whole mobile phone case look very shabby, and people have to buy new mobile phone protective cases, thus wasting more costs; in addition, during the production process of mobile phone protective case manufacturers, one type of mobile phone protective case requires one type of mold. If you want to produce more types of protective cases, you need to prepare more molds for production, increasing the overall production cost.

[0004] Therefore, it is necessary to develop a leather-covered mobile phone case with good mechanical properties, wear resistance, heat resistance, water resistance, shock resistance, diverse styles, easy to process and low cost. Summary of the Invention

[0005] The present invention provides a leather-covered mobile phone case, which includes a support layer, an adhesive layer and a leather cover that are closely attached in sequence. The leather cover includes a base cloth layer, a polyolefin base material layer and a surface coating. The polyolefin base material layer includes: 15-40 parts by weight of an ethylene copolymer elastomer, 15-40 parts by weight of ethylene propylene diene monomer rubber and 20-70 parts by weight of a filler. The sum of the weight parts of the ethylene copolymer elastomer, ethylene propylene diene monomer rubber and the filler is 100 parts.

[0006] Preferably, the ethylene copolymer elastomer is copolymerized from ethylene and a monomer, and the monomer is selected from one of α-olefins with a carbon chain length of C4-C8 or vinyl acetate.

[0007] Preferably, the monomer is vinyl acetate, and the content of vinyl acetate in the ethylene copolymer elastomer is greater than 10wt% and less than 40wt%.

[0008] Preferably, the ethylene propylene diene monomer rubber is a copolymer of ethylene, propylene and a small amount of non-conjugated diene, and the content of the non-conjugated diene in the ethylene propylene diene monomer rubber is not less than 5wt%.

[0009] Preferably, the non-conjugated diene is selected from one of ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene.

[0010] Preferably, the filler is one or more of talc powder, ultrafine calcium carbonate, magnesium hydroxide, aluminum hydroxide, mica powder, barium sulfate and feldspar powder.

[0011] Preferably, the base fabric layer, the polyolefin substrate layer and the surface coating layer are closely attached together in sequence.

[0012] Preferably, the support layer and the base fabric layer are bonded via an adhesive layer.

[0013] Preferably, the adhesive layer is one of a pressure-sensitive adhesive and a heat-sensitive adhesive.

[0014] Preferably, the support layer is a PC board or a glass fiber board.

[0015] Preferably, the polyolefin substrate layer further contains a phosphonate or hindered phenol antioxidant.

[0016] Preferably, the polyolefin substrate layer further contains an inorganic metal oxide, preferably zinc oxide.

[0017] Preferably, the polyolefin substrate layer further contains a coupling agent.

[0018] Preferably, a plurality of pre-reserved holes or pre-reserved holes are arranged on the support layer, the adhesive layer, the base fabric layer, the polyolefin substrate layer and the surface coating.

[0019] Preferably, the surface coating is one or more of a polyurethane layer, an acrylic resin layer and a silicone coating.

[0020] Preferably, the polyolefin substrate layer has a cross-linking degree of at least 40%, and the cross-linking method is electron beam irradiation cross-linking.

[0021] Preferably, the polyolefin substrate layer has a cross-linking degree of not less than 70%.

[0022] The present invention also proposes a method for preparing a laminated mobile phone case, comprising the following steps:

[0023] (1) fully mixing EPDM rubber and ethylene copolymer elastomer, and granulating the mixture at a granulation temperature of 160 to 180° C. to obtain mixture particles A;

[0024] (2) fully mixing the mixture particles A, filler, antioxidant, inorganic metal oxide and coupling agent to obtain a mixture B;

[0025] (3) Extruding and casting the mixture B onto a base fabric at an extrusion temperature of 70 to 130° C. to obtain a composite layer;

[0026] (4) Coat a coating on the surface of the composite layer;

[0027] (5) Dry the coating to obtain a surface coating;

[0028] (6) Emboss the surface coating to obtain the film material C;

[0029] (7) Irradiate the film material C with β-rays, and the irradiation dose is 5 - 200 KGY to obtain the skin;

[0030] (8) Bond the skin to the surface of the support layer through pressure-sensitive adhesive or heat-sensitive adhesive.

[0031] This application includes at least one of the following beneficial technical effects:

[0032] 1. For the polyolefin base material layer of the skin mobile phone case provided by the present invention, a three-dimensional network structure is formed after irradiation cross-linking, improving the mechanical strength, shock resistance and heat resistance of the skin mobile phone case.

[0033] 2. For the skin mobile phone case provided by the present invention, the surface coating coated on the polyolefin base material layer improves the wear resistance and drop resistance of the skin mobile phone case. The surface coating can be embossed into various patterns, making the styles of the mobile phone case diverse.

[0034] 3. The present invention can emboss after the film material is formed. The film material before cross-linking is a linear structure, which is easy to emboss and form. After embossing and then irradiation cross-linking, the film material forms a three-dimensional structure, improving the embossing retention.

[0035] 4. The present invention uses a blend of ethylene copolymer elastomer and uncrosslinked ethylene-propylene-diene monomer rubber for molding. Both are thermoplastic polyolefin elastomers with a linear structure, which are easy to process. The extrusion or casting molding temperature is 70 - 130 °C, with a lower processing temperature and a wider processing window.

[0036] 5. The skin mobile phone case provided by the present invention has good mechanical properties, wear resistance, heat resistance, waterproofness, shock resistance, and diverse styles, and has a simple process and low cost. Specific Embodiments

[0037] In order to make the invention purpose, technical solution and beneficial technical effects of the present invention clearer, the present invention will be described in detail below with specific embodiments. It should be understood that the embodiments described in this specification are only for explaining the present invention and not for limiting the present invention.

[0038] For simplicity, only some numerical ranges are explicitly disclosed in this document. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, although not explicitly recited, each point or single numerical value between the range endpoints is included in the range. Thus, each point or single numerical value can be used as its own lower or upper limit and combined with any other point or single numerical value or combined with other lower or upper limits to form a range not explicitly recited.

[0039] In the description of this document, it should be noted that unless otherwise specified, "above" and "below" include the recited number, and in "one or more", the meaning of "more" is two or more.

[0040] The above summary of the invention does not intend to describe every disclosed embodiment or every implementation of the invention. The following description more specifically illustrates exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments, which can be used in various combinations. In each embodiment, the listings are only representative groups and should not be construed as exhaustive.

[0041] The present invention provides a leather - pasted mobile phone case, which includes a support layer, an adhesive layer, and a leather paste that are closely attached in sequence. The leather paste includes a base cloth layer, a polyolefin substrate layer, and a surface coating. The polyolefin substrate layer includes: 15 - 40 parts by weight of an ethylene copolymer elastomer, 15 - 40 parts by weight of ethylene - propylene - diene monomer rubber, and 20 - 70 parts by weight of a filler, and the sum of the weight parts of the ethylene copolymer elastomer, ethylene - propylene - diene monomer rubber, and filler is 100 parts.

[0042] In the leather - pasted mobile phone case provided by the present invention, the surface coating can adopt coating materials known in the art for leather, including one or more of polyurethane - based coatings, acrylate - based coatings, or silicone coatings. The surface coating usually has suitable abrasion resistance, brightness, adhesion, etc., and those skilled in the art can select according to actual needs.

[0043] The leather - pasted mobile phone case provided by the present invention uses polyolefin as the substrate. Using polyolefin as the substrate, the amount of odor - volatile substances generated by polyolefin is very small, it has a lower odor, and the production process has better environmental protection performance, so as to meet the occasions with higher requirements for odor and environmental protection.

[0044] The ethylene copolymer elastomer of the polyolefin substrate layer is copolymerized from ethylene and a monomer, and the monomer is selected from one of α - olefins with a carbon chain length of C4 - C8 or vinyl acetate.

[0045] Based on the influence of the carbon chain length on the processing conditions and mechanical properties of the polymer, an α-olefin with a carbon chain length between C4-C8 is selected as one monomer of the ethylene copolymer elastomer. In the copolymer formed with ethylene, the longer the carbon chain length of the α-olefin, the better the softness of the polymer, while the mechanical strengths such as folding resistance, tear strength, and tensile strength will decrease accordingly. Based on the balance of the above properties, an α-olefin with C4-C8 is selected as one monomer of the ethylene copolymer elastomer.

[0046] Vinyl acetate can also be selected as one monomer of the ethylene copolymer elastomer. The higher the content of vinyl acetate in the ethylene copolymer elastomer, the better the fluidity and softness of the polymer, and the ester group unit in the vinyl acetate structure can serve as a crosslinking point during the radiation crosslinking process to form a three-dimensional structure. According to the performance requirements of the leather-covered mobile phone case product, the content of vinyl acetate monomer in the ethylene copolymer elastomer is selected within the range of 10-40% by mass.

[0047] The composition of the polyolefin base layer contains ethylene-propylene-diene monomer (EPDM), which can improve the processing performance and film-forming performance of the polyolefin base material. EPDM is a copolymer of ethylene, propylene, and a third monomer. The third monomer has a non-conjugated diene structure, and there are carbon-carbon double bonds that can participate in the polymerization reaction in EPDM, providing crosslinking active points for the radiation crosslinking reaction. The non-conjugated diene is selected from one of ethylidene norbornene, dicyclopentadiene, and 1,4-hexadiene, preferably ethylidene norbornene; using EPDM with an appropriate content of non-conjugated diene helps to improve the crosslinking density and crosslinking speed of the polyolefin base material. When the content of non-conjugated diene in EPDM is greater than 5 wt%, it can provide sufficient crosslinking density and crosslinking speed for the polyolefin base layer.

[0048] In the leather-covered mobile phone case provided by the present invention, a number of reserved holes or reserved cavities are provided on the support layer, adhesive layer, base cloth layer, polyolefin base layer, and surface coating. Holes or cavities for the camera, charging port, speaker, etc. can be reserved on the back panel and around the mobile phone case to improve the convenience of use.

[0049] The filler in the polyolefin base layer is one or more of talc, ultrafine calcium carbonate, magnesium hydroxide, aluminum hydroxide, mica powder, barium sulfate, and feldspar powder. The addition of the filler can significantly improve the heat resistance performance of the leather-covered mobile phone case.

[0050] In the leather-covered mobile phone case provided by the present invention, the base cloth layer, polyolefin base layer, and surface coating are closely adhered together in sequence.

[0051] In the leather-covered mobile phone case provided by the present invention, the support layer and the base cloth layer are adhered through the adhesive layer.

[0052] The adhesive layer is one of a pressure-sensitive adhesive and a heat-sensitive adhesive. The heat-sensitive adhesive can be divided into a water-soluble adhesive, a hot-melt adhesive, a solvent-based adhesive, an emulsion adhesive, and a solvent-free liquid adhesive. In some embodiments, the heat-sensitive adhesive used is preferably a hot-melt adhesive. The pressure-sensitive adhesive can be divided into a rubber-based pressure-sensitive adhesive, an acrylate-based pressure-sensitive adhesive, and a silicone rubber-based pressure-sensitive adhesive. In some embodiments, the pressure-sensitive adhesive used is preferably an acrylate-based pressure-sensitive adhesive.

[0053] The supporting layer is PC board or fiberglass board.

[0054] The production process of the polyolefin substrate layer is extrusion molding or casting, and its processing technology is related to the melting point of the polymer.

[0055] The polyolefin substrate layer has a cross-linking degree of at least 40%, and the cross-linking method is electron beam irradiation cross-linking.

[0056] The polyolefin base material layer has a cross-linking degree of not less than 70%.

[0057] The side of the polyolefin substrate layer facing away from the coating layer can be attached to the base fabric.

[0058] In some embodiments, the polyolefin substrate layer may further selectively contain other additives, such as colorants.

[0059] In some embodiments, the polyolefin substrate layer further contains a phosphonate or hindered phenol antioxidant.

[0060] In some embodiments, the polyolefin substrate layer further contains an inorganic metal oxide, preferably zinc oxide.

[0061] In some embodiments, the polyolefin substrate layer further contains a coupling agent.

[0062] The present invention also proposes a method for preparing a laminated mobile phone case, comprising the following steps:

[0063] (1) fully mixing EPDM rubber and ethylene copolymer elastomer, and granulating the mixture at a granulation temperature of 160 to 180° C. to obtain mixture particles A;

[0064] (2) fully mixing the mixture particles A, filler, antioxidant, inorganic metal oxide and coupling agent to obtain a mixture B;

[0065] (3) Extruding and casting the mixture B onto a base fabric at an extrusion temperature of 70 to 130° C. to obtain a composite layer;

[0066] (4) applying a coating to the surface of the composite layer;

[0067] (5) drying the coating to obtain a surface coating;

[0068] (6) embossing the surface coating to obtain film material C;

[0069] (7) irradiating the film material C with β rays at a dose of 5 to 200 kGY to obtain a laminated film;

[0070] (8) The skin is bonded to the surface of the support layer by pressure-sensitive adhesive or heat-sensitive adhesive.

[0071] In some embodiments, the composite layer includes a base fabric layer and a polyolefin substrate layer.

[0072] In some embodiments, EPDM rubber and ethylene copolymer elastomer are fully mixed and granulated in a granulator at a granulation temperature of 160-180°C to obtain mixture particles A; the mixture particles A, filler, antioxidant, inorganic metal oxide and coupling agent are fully mixed; the mixture is added to an extruder at an extrusion temperature of 70-130°C, extruded through a T-shaped flat die to be cast onto a fabric base cloth, and rolled up to obtain a film material.

[0073] In some embodiments, the skin can be cross-linked by radiation. This allows the polyolefin substrate layer to have the desired degree of cross-linking, i.e., the polyolefin substrate layer is a radiation-cross-linked polyolefin substrate layer. Alpha rays, beta rays, gamma rays, X-rays, or neutron rays can be used for radiation cross-linking. It is easier to control the degree of cross-linking using electron beam radiation cross-linking, and the cross-linking process is more environmentally friendly. During radiation cross-linking, the film structure itself has no physical contact with the radiation generating device, and the shape of the film structure does not change before and after the reaction, but a cross-linking reaction has occurred inside it. As an example, beta rays (i.e., high-energy electron beams) can be used for radiation cross-linking. The irradiation dose can be selected from 5KGy to 200KGy, 10KGy to 100KGy, 20KGy to 80KGy, or 50KGy to 150KGy, etc.

[0074] In some embodiments, a surface texture treatment step may be included before the cross-linking step. In the surface texture treatment step, the polyolefin substrate layer may be subjected to surface texture treatment to form the desired texture. Then, a cross-linking step is performed to obtain a polyolefin substrate layer with surface texture. The substrate layer is then bonded to the surface of the support layer, thereby obtaining a three-dimensional style leather mobile phone case product with texture.

[0075] In some embodiments, the surface texture treatment step may include: vacuum forming, hot roller hot pressing or cold roller cold pressing to transfer the texture of the mold to the surface coating. The aforementioned forming may be performed using a vacuum forming machine; the aforementioned hot pressing or cold pressing may be performed using an embossing machine. In the hot roller hot pressing method, the temperature of the hot roller may be equal to or slightly lower than the melting temperature of the polyolefin substrate layer resin. Furthermore, after the polyolefin substrate layer with surface texture treatment undergoes a subsequent cross-linking step, good pattern retention can be obtained.

[0076] Example

[0077] The following examples more specifically describe the disclosure of the present invention. These examples are for illustrative purposes only, as various modifications and variations within the scope of the present invention are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and the reagents and instruments used in the examples are commercially available.

[0078] The raw materials for the polyolefin substrate layer used in the following examples are selected from Table 1:

[0079] Table 1 Raw material grades and related properties used in the examples

[0080] Type Grade Vinyl acetate content (%) Ethylene-vinyl acetate copolymer EV40LX 40 Ethylene-vinyl acetate copolymer EV270 28 Ethylene-vinyl acetate copolymer P1007 10 Ethylene-vinyl acetate copolymer EV45LX 45 Ethylene-vinyl acetate copolymer UE508 8 Type Grade Non-conjugated diene content (%) Ethylene propylene diene monomer rubber Mitsui 3092PM 4.2 Ethylene propylene diene monomer rubber Sabic 756 5.0 Ethylene propylene diene monomer rubber Mitsui 9720 10 Type Grade Ethylene-butene copolymer LF675 / Ethylene-octene copolymer XUS38680 / Ethylene-octene copolymer DF940 / Ethylene-octene copolymer DF110 / Ethylene-propylene copolymer VERSIFY2300 / Type Specification Aluminum hydroxide 1250 mesh /

[0081] In addition to the above raw materials, the polyolefin substrate layer also contains 0.2 parts of a hindered phenol antioxidant, 2 parts of zinc oxide, and 0.2 parts of a titanate coupling agent.

[0082] The leather samples prepared in the examples were tested for performance according to the following methods:

[0083] Heat aging: Take a 100*100 mm specimen, place it in an aging test chamber, keep it at the specified temperature for 168 h, then take it out and cool it at room temperature for 30 min, and evaluate the appearance.

[0084] Crosslinking degree: Detected by the xylene extraction method in GB / T 29848-2018 "Ethylene-vinyl acetate copolymer (EVA) film for encapsulation of photovoltaic modules";

[0085] Temperature resistance: No change in appearance after being placed at high temperature for 7 days

[0086] Roughness: GB / T 3505-2000 "Geometrical Product Specifications - Surface Texture: Profile Method - Terms, Definitions and Parameters for Surface Texture", which defines some parameters for characterizing surface roughness.

[0087] Example 1

[0088] A leather mobile phone case includes a support layer, an adhesive layer, and a leather cover that are closely attached in sequence. The leather cover includes a base fabric layer, a polyolefin substrate layer, and a surface coating. The polyolefin substrate layer includes: 25 parts of POE resin of DF940, 25 parts of ethylene propylene diene monomer rubber of Sabic 756, and 50 parts of filler aluminum hydroxide.

[0089] The preparation method of the leather mobile phone case in this example includes the following steps:

[0090] (1) EPDM rubber and POE resin are fully mixed and granulated at a granulation temperature of 170° C. to obtain mixture particles A;

[0091] (2) fully mixing the mixture particles A, filler, antioxidant, inorganic metal oxide and coupling agent to obtain a mixture B;

[0092] (3) Extruding and casting the mixture B onto a base fabric at an extrusion temperature of 100° C. to obtain a composite layer;

[0093] (4) applying a polyurethane coating to the surface of the composite layer;

[0094] (5) drying the polyurethane coating to obtain a surface coating;

[0095] (6) embossing the surface coating to obtain film material C;

[0096] (7) β-ray irradiation is performed on the film material C, and the irradiation dose is 150 KGY to obtain a laminated film;

[0097] (8) The skin is bonded to the surface of the supporting layer PC board by hot melt adhesive.

[0098] Example 2

[0099] The difference between Example 2 and Example 1 is that the EPDM rubber is 25 parts of Mitsui 9720.

[0100] Example 3

[0101] The difference between Example 3 and Example 1 is that the EPDM rubber is 50 parts of Sabic 756 and the filler aluminum hydroxide is 25 parts.

[0102] Embodiments 4 to 7

[0103] The difference between Examples 4 to 7 and Example 2 is that different irradiation doses are used in the preparation process. Examples 5 to 8 use irradiation doses of 5 KGY, 50 KGY, 100 KGY, and 200 KGY, respectively.

[0104] Example 8

[0105] The difference between Example 8 and Example 2 is that the POE resin is 25 parts of LF675.

[0106] Example 9

[0107] The difference between Example 9 and Example 2 is that the POE resin is 25 parts of XUS38680.

[0108] Example 10

[0109] The difference between Example 10 and Example 2 is that the POE resin is 25 parts of DF110.

[0110] Embodiment 11

[0111] A laminated mobile phone case comprises a supporting layer, an adhesive layer and a laminated skin which are closely fitted in sequence. The laminated skin comprises a base fabric layer, a polyolefin substrate layer and a surface coating. The polyolefin substrate layer comprises: 25 parts of EV40LX EVA resin, 25 parts of Mitsui 9720 EPDM rubber, and 50 parts of filler aluminum hydroxide.

[0112] The method for preparing the laminated mobile phone case of this embodiment comprises the following steps:

[0113] (1) EPDM rubber and EVA resin are fully mixed and granulated at a granulation temperature of 170° C. to obtain mixture particles A;

[0114] (2) fully mixing the mixture particles A, filler, antioxidant, inorganic metal oxide and coupling agent to obtain a mixture B;

[0115] (3) Extruding and casting the mixture B onto a base fabric at an extrusion temperature of 100° C. to obtain a composite layer;

[0116] (4) applying a polyurethane coating to the surface of the composite layer;

[0117] (5) drying the polyurethane coating to obtain a surface coating;

[0118] (6) embossing the surface coating to obtain film material C;

[0119] (7) β-ray irradiation is performed on the film material C, and the irradiation dose is 150 KGY to obtain a laminated film;

[0120] (8) The skin is bonded to the surface of the supporting layer PC board by using an acrylic ester-based pressure-sensitive adhesive.

[0121] Example 12

[0122] The difference between Example 12 and Example 11 is that the EVA resin is 25 parts of EV270.

[0123] Embodiment 13

[0124] The difference between Example 13 and Example 11 is that the EVA resin is 25 parts of P1007.

[0125] Embodiment 14

[0126] The difference between Example 14 and Example 12 is that the EVA resin is 15 parts of EV270, the EPDM rubber is 40 parts of Mitsui 9720, and the filler is 45 parts of aluminum hydroxide.

[0127] Embodiment 15

[0128] Example 15 is different from Example 12 in that: the EVA resin is 40 parts of EV270, the ethylene-propylene-diene rubber is 15 parts of Mitsui 9720, and the filler is 45 parts of aluminum hydroxide.

[0129] Examples 16 to 19

[0130] Examples 16 to 19 are different from Example 12 in that different irradiation doses are used in the preparation process. Examples 16 to 19 respectively adopt irradiation doses of 5 KGY, 50 KGY, 100 KGY, and 200 KGY.

[0131] Comparative Example 1

[0132] Comparative Example 1 is different from Example 2 in that: the POE resin is 25 parts of VERSIFY2300.

[0133] Comparative Example 2

[0134] Comparative Example 2 is different from Example 2 in that: the ethylene-propylene-diene rubber is 25 parts of Mitsui 3092PM.

[0135] Comparative Example 3

[0136] Comparative Example 3 is different from Example 2 in that: the ethylene-propylene-diene rubber is 14 parts of Mitsui 9720, the POE resin is 41 parts of DF940, and the filler is 45 parts of aluminum hydroxide.

[0137] Comparative Example 4

[0138] Comparative Example 4 is different from Example 2 in that: the ethylene-propylene-diene rubber is 41 parts of Mitsui 9720, the POE resin is 14 parts of DF940, and the filler is 45 parts of aluminum hydroxide.

[0139] Comparative Examples 5 to 6

[0140] Comparative Examples 5 to 6 are different from Example 2 in that irradiation doses of 3 KGY and 210 KGY are respectively adopted in the preparation process.

[0141] Comparative Example 7

[0142] Comparative Example 7 is different from Example 12 in that: the EVA resin is 25 parts of EV45LX.

[0143] Comparative Example 8

[0144] Comparative Example 8 is different from Example 12 in that: the EVA resin is 25 parts of UE508.

[0145] Comparative Example 9

[0146] Comparative Example 9 is different from Example 12 in that: the ethylene-propylene-diene rubber is 14 parts of Mitsui 9720, the EVA resin is 41 parts of EV270, and the filler is 45 parts of aluminum hydroxide.

[0147] Comparative Example 10

[0148] The difference between Comparative Example 10 and Example 12 is that the ethylene propylene diene rubber is 41 parts of Mitsui 9720, the EVA resin is 14 parts of EV270, and the filler is 45 parts of aluminum hydroxide.

[0149] Comparative Examples 11 - 12

[0150] The differences between Comparative Examples 11 - 12 and Example 12 are that irradiation doses of 3 KGY and 210 KGY are used respectively during the preparation process.

[0151] Comparative Examples 13 - 14

[0152] For Comparative Examples 13 - 14, commercially available mobile phone cases made of common PVC and TPU materials are respectively selected as comparative samples for performance comparison.

[0153] The performance test results are shown in Table 2

[0154]

Claims

1. A leather - pasted mobile phone case, comprising a support layer, an adhesive layer and a leather paste that are closely attached in sequence, characterized in that, The skin comprises a base fabric layer, a polyolefin substrate layer and a surface coating, wherein the polyolefin substrate layer comprises: The invention comprises 15 to 40 parts by weight of an ethylene copolymer elastomer, 15 to 40 parts by weight of an ethylene propylene diene monomer rubber and 20 to 70 parts by weight of a filler, wherein the sum of the weight parts of the ethylene copolymer elastomer, the ethylene propylene diene monomer rubber and the filler is 100 parts.

2. The leather-covered mobile phone case according to claim 1, wherein The ethylene copolymer elastomer is copolymerized by ethylene and a monomer, and the monomer is selected from one of alpha olefins with a carbon chain length of C4-C8 or vinyl acetate.

3. The leather-covered mobile phone case according to claim 2, characterized in that, The monomer is vinyl acetate, and the content of the vinyl acetate in the ethylene copolymer elastomer is greater than 10 wt % and less than 40 wt %.

4. A leather - pasted mobile phone case according to claim 1, characterized in that, The EPDM rubber is a copolymer of ethylene, propylene and a small amount of non-conjugated diene, and the content of the non-conjugated diene in the EPDM rubber is not less than 5wt%.

5. The leather pasted mobile phone case according to claim 4, characterized in that The non-conjugated diene is selected from one of ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene.

6. The leather-covered mobile phone case according to claim 1, characterized in that, The filler is one or more of talc powder, ultrafine calcium carbonate, magnesium hydroxide, aluminum hydroxide, mica powder, barium sulfate and feldspar powder.

7. The leather-covered mobile phone case according to claim 1, wherein, The base fabric layer, the polyolefin substrate layer and the surface coating layer are tightly adhered together in sequence.

8. The leather-covered mobile phone case according to claim 1, characterized in that, The support layer and the base fabric layer are bonded via the bonding layer.

9. The leather-covered mobile phone case according to claim 1 or 8, characterized in that The supporting layer is a PC board or a glass fiber board.

10. A leather - covered mobile phone case according to claim 1, characterized in that, The polyolefin substrate layer further contains a phosphonate or hindered phenol antioxidant.

11. A leather - pasted mobile phone case according to claim 1, characterized in that, The polyolefin substrate layer further contains an inorganic metal oxide.

12. A leather - covered mobile phone case according to claim 1, wherein, The polyolefin substrate layer further contains a coupling agent.

13. A leather - pasted mobile phone case according to claim 1, characterized in that, A plurality of reserved holes or reserved holes are arranged on the support layer, the adhesive layer, the base fabric layer, the polyolefin substrate layer and the surface coating layer.

14. The leather - pasted mobile phone case according to claim 1, wherein, The surface coating is one or more of a polyurethane layer, an acrylic resin layer and a silicone coating.

15. A leather - pasted mobile phone case according to claim 1, characterized in that, The polyolefin substrate layer has a cross-linking degree of at least 40%, and the cross-linking method is electron beam irradiation cross-linking.

16. A leather - pasted mobile phone case according to claim 15, characterized in that, The polyolefin substrate layer has a cross-linking degree of not less than 70%.

17. A method for preparing the veneered mobile phone case according to any one of claims 1-16, characterized in that, The following steps are involved: (1) fully mixing the EPDM rubber and the ethylene copolymer elastomer, and granulating the mixture at a granulation temperature of 160 to 180° C. to obtain mixture particles A; (2) fully mixing the mixture particles A, the filler, the antioxidant, the inorganic metal oxide and the coupling agent to obtain a mixture B; (3) Extruding and casting the mixture B onto a base fabric at an extrusion temperature of 70 to 130° C. to obtain a composite layer; (4) applying a coating to the surface of the composite layer; (5) drying the coating to obtain the surface coating; (6) embossing the surface coating to obtain a film material C; (7) irradiating the film material C with beta rays at a dose of 5 to 200 kGY to obtain the laminated skin; (8) The skin is bonded to the surface of the support layer by a pressure-sensitive adhesive or a heat-sensitive adhesive.

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