A basalt fiber reinforced anti-fall mobile phone case and preparation method thereof

Abstract

The present invention proposes a basalt fiber reinforced anti-fall mobile phone case and a preparation method thereof, comprising: immersing basalt fiber fabric in a silane coupling agent solution containing isocyanate, taking it out and drying it to obtain an isocyanate grafted basalt fiber fabric; immersing the isocyanate grafted modified basalt fiber fabric in an aminobenzimidazole solution, heating it for reaction and taking it out to obtain a benzimidazole grafted modified basalt fiber fabric; coating the surface of the benzimidazole grafted modified basalt fiber fabric with epoxy resin glue, and curing it to obtain the anti-fall mobile phone case. The present invention proposes a method for preparing a basalt fiber reinforced anti-fall mobile phone case, wherein the mobile phone case is obtained by curing and molding the basalt fiber fabric after surface treatment and coating it with epoxy resin glue, which effectively improves the strength and impact resistance of the mobile phone case, thereby enhancing the anti-fall performance of the mobile phone case.

Description

Technical Field

[0001] The invention relates to the technical field of mobile phone cases, and in particular to a basalt fiber reinforced anti-fall mobile phone case and a preparation method thereof. Background Art

[0002] With the rapid development of society, consumers have put forward new requirements for the functions and appearance of electronic products such as mobile phones. With the development of thinner and lighter electronic products, how to use high-strength and lightweight materials such as glass fiber and carbon fiber to make mobile phone cases has become an existing research hotspot.

[0003] There is a problem of affecting the reception of mobile phone signals when making mobile phone cases with carbon fiber as raw material. Although glass fiber will not affect the reception of signals, the glass fiber cloth in mobile phone cases in the existing market is mostly single-layered, which has problems with puncture resistance and poor heat dissipation. Usually, a large amount of inorganic fillers are filled to improve the heat dissipation of the mobile phone case, but at the same time it also causes its impact resistance to decrease.

[0004] In order to overcome the above-mentioned defects in the use of fiber, people have proposed to use basalt fiber to make mobile phone cases. As for basalt fiber, we know that it is made of natural volcanic extrusive rock as raw material. After melting at a high temperature of 1450-1500℃, it is made into continuous fiber through platinum-germanium alloy drawing plate. It has many excellent properties such as high strength, high modulus, high temperature resistance, oxidation resistance, acid and alkali resistance, radiation resistance, electrical insulation, thermal insulation and sound insulation, good filtration, high compressive strength, shock absorption and high shear strength. It is also a new type of environmentally friendly fiber. However, the mobile phone cases made of basalt fiber still need to be strengthened in mechanical properties such as impact resistance. Summary of the invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a basalt fiber reinforced anti-fall mobile phone case and a preparation method thereof. The mobile phone case is obtained by curing and molding basalt fiber fabric after surface treatment and coating with epoxy resin glue, which effectively improves the strength and impact resistance of the mobile phone case, thereby enhancing the anti-fall performance of the mobile phone case.

[0006] The present invention provides a method for preparing a basalt fiber reinforced anti-fall mobile phone case, comprising the following steps:

[0007] S1, immersing the basalt fiber fabric in a silane coupling agent solution containing isocyanate, taking it out and drying it to obtain the isocyanate grafted modified basalt fiber fabric;

[0008] S2, immersing the isocyanate grafted modified basalt fiber fabric in an aminobenzimidazole solution, heating the solution and then taking it out to obtain a benzimidazole grafted modified basalt fiber fabric;

[0009] S3, coating the surface of the benzimidazole-grafted modified basalt fiber fabric with epoxy resin glue, and curing and forming it to obtain the drop-proof mobile phone case.

[0010] Preferably, in step S1, the surface density of the basalt fiber fabric is 200-600 g / m 2 .

[0011] Preferably, in step S1, the isocyanate-containing silane coupling agent is at least one of isocyanate propyl trimethoxy silane, isocyanate propyl triethoxy silane, isocyanate methyl trimethoxy silane or isocyanate methyl triethoxy silane;

[0012] Preferably, the isocyanate-containing silane coupling agent solution is an ethanol-water solution with a concentration of 1-10 wt%.

[0013] Preferably, in step S1, the immersion time is 1-3 hours; the drying comprises: first vacuum drying at 75-95°C for 0.5-1 hour, and then vacuum drying at 100-120°C for 1-2 hours.

[0014] Preferably, in step S2, the aminobenzimidazole is at least one of 4-aminobenzimidazole, 5-aminobenzimidazole, 2-(3-aminophenyl)-5-aminobenzimidazole or 2-(4-aminophenyl)-5-aminobenzimidazole;

[0015] Preferably, the aminobenzimidazole solution is an acetone solution with a concentration of 1-10 wt%.

[0016] Preferably, in step S2, the heating reaction temperature is 60-80°C and the time is 5-8h.

[0017] Preferably, in step S3, the epoxy resin glue comprises a base epoxy resin and a curing agent;

[0018] Preferably, the weight ratio of the base epoxy resin to the curing agent is 100:5-25.

[0019] Preferably, the base epoxy resin is bisphenol A epoxy resin or bisphenol F epoxy resin; the curing agent is an amine curing agent or an acid anhydride curing agent, preferably at least one of dicyandiamide, boron trifluoride monoethylamine, m-phenylenediamine, diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, methyl nadic anhydride or dodecylsuccinic anhydride.

[0020] Preferably, in step S3, the curing molding temperature is 110-150° C., the time is 1-3 h, and the pressure is 1-3 MPa.

[0021] The present invention also provides a basalt fiber reinforced anti-fall mobile phone case, which is prepared by the above preparation method.

[0022] Beneficial effects of the present invention:

[0023] In the present invention, the basalt fiber fabric is pretreated first, and isocyanate groups are grafted onto the surface of the basalt fiber fabric by immersing it in a silane coupling agent solution containing isocyanate. The isocyanate is then reacted with aminobenzimidazole to graft benzimidazole groups onto the surface of the basalt fiber fabric. After that, the benzimidazole groups are used as accelerators to not only promote the effective curing of epoxy resin glue on the surface of the basalt fiber fabric, but also improve the bonding strength between the subsequently formed resin glue layer and the basalt fiber fabric, thereby enhancing the strength and mechanical properties of the obtained mobile phone shell, such as impact resistance, to obtain a basalt fiber-reinforced anti-fall mobile phone shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the basalt fiber fabric modified by benzimidazole grafting described in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0026] Example 1

[0027] A method for preparing a basalt fiber reinforced anti-fall mobile phone case comprises the following steps:

[0028] (1) Basalt fiber plain weave cloth (surface density 225g / m 2 ) was added into an ethanol-water solution (ethanol-water volume ratio is 1:1) containing 4 wt% 3-isocyanatepropyltriethoxysilane, immersed for 2 h, taken out, put into a vacuum drying oven, first vacuum dried at 85° C. for 1 h, and then vacuum dried at 100° C. for 1 h, to obtain an isocyanate-grafted basalt fiber plain weave fabric;

[0029] (2) The above-mentioned isocyanate grafted modified basalt fiber plain weave fabric is added into an acetone solution containing 2 wt% 4-aminobenzimidazole, and the temperature is raised to 70° C. and maintained for 7 h. After being taken out, it is dried to obtain a benzimidazole grafted modified basalt fiber plain weave fabric, as shown in FIG. Figure 1 As shown;

[0030] (3) Epoxy resin E-51, epoxy resin E-44 and dicyandiamide were stirred and mixed in a mass ratio of 80:20:20 to obtain epoxy resin glue, and the epoxy resin glue was evenly coated on the surface of the above-mentioned benzimidazole grafted modified basalt fiber plain weave cloth using a brush tool (the amount of epoxy resin glue was 35wt% of the mass of the basalt fiber plain weave cloth), placed in a vacuum drying oven, and dried at 60°C for 1h to obtain a prepreg; the prepreg was cut into a size of 10cm×10cm, stacked into 8 layers, and placed in a homemade mold on a flat vulcanizer for compression molding, pressurized to 2MPa, and then heated to 120°C at a heating rate of 10°C / min and cured for 1h, and then continued to heat to 150°C and cured for 1h. After cutting and shaping, the basalt fiber reinforced anti-fall mobile phone case was obtained.

[0031] Example 2

[0032] A method for preparing a basalt fiber reinforced anti-fall mobile phone case comprises the following steps:

[0033] (1) Basalt fiber plain weave cloth (surface density 225g / m 2 ) was added into an ethanol-water solution (ethanol-water volume ratio is 1:1) containing 6 wt % 3-isocyanatepropyltrimethoxysilane, immersed for 3 h, taken out, put into a vacuum drying oven, first vacuum dried at 75° C. for 1 h, and then vacuum dried at 120° C. for 1 h, to obtain an isocyanate-grafted basalt fiber plain weave fabric;

[0034] (2) adding the above-mentioned isocyanate grafted modified basalt fiber plain weave cloth into an acetone solution containing 3 wt% 5-aminobenzimidazole, heating it to 60° C. and maintaining it for 8 h, taking it out and drying it to obtain a benzimidazole grafted modified basalt fiber plain weave cloth;

[0035] (3) After the epoxy resin E-51 and dicyandiamide are stirred and mixed in a mass ratio of 100:15, an epoxy resin glue is obtained, and the epoxy resin glue is evenly coated on the surface of the above-mentioned benzimidazole grafted modified basalt fiber plain weave cloth using a brush tool (the amount of epoxy resin glue is 35wt% of the mass of the basalt fiber plain weave cloth), placed in a vacuum drying oven, and dried at 60°C for 1h to obtain a prepreg; the prepreg is cut into a size of 10cm×10cm, stacked into 8 layers, and placed in a homemade mold on a flat vulcanizer for compression molding, pressurized to 1MPa, and then heated to 110°C at a heating rate of 10°C / min and cured for 0.5h, and then continued to heat to 150°C and cured for 2.5h. After cutting and shaping, the basalt fiber reinforced anti-fall mobile phone case is obtained.

[0036] Example 3

[0037] A method for preparing a basalt fiber reinforced anti-fall mobile phone case comprises the following steps:

[0038] (1) Basalt fiber plain weave cloth (surface density 225g / m 2 ) was added into an ethanol-water solution (ethanol-water volume ratio is 1:1) containing 2 wt% 3-isocyanatepropyltriethoxysilane, immersed for 1 hour, taken out, put into a vacuum drying oven, first vacuum dried at 95° C. for 0.5 hour, and then vacuum dried at 100° C. for 2 hours to obtain an isocyanate-grafted basalt fiber plain weave fabric;

[0039] (2) adding the above-mentioned isocyanate grafted modified basalt fiber plain weave cloth into an acetone solution containing 1 wt% 2-(3-aminophenyl)-5-aminobenzimidazole, heating it to 80° C. and maintaining it for 5 h, taking it out and drying it to obtain a benzimidazole grafted modified basalt fiber plain weave cloth;

[0040] (3) Epoxy resin E-51, epoxy resin E-44 and dicyandiamide were stirred and mixed in a mass ratio of 80:20:15 to obtain epoxy resin glue, and the epoxy resin glue was evenly coated on the surface of the above-mentioned benzimidazole grafted modified basalt fiber plain weave cloth using a brush tool (the amount of epoxy resin glue was 35wt% of the mass of the basalt fiber plain weave cloth), placed in a vacuum drying oven, and dried at 60°C for 1h to obtain a prepreg; the prepreg was cut into a size of 10cm×10cm, stacked into 8 layers, and placed in a homemade mold on a flat vulcanizer for compression molding, pressurized to 3MPa, and then heated to 150°C at a heating rate of 10°C / min and cured for 1h. After cutting and shaping, the basalt fiber reinforced anti-fall mobile phone case was obtained.

[0041] Comparative Example 1

[0042] A method for preparing a basalt fiber reinforced anti-fall mobile phone case, comprising:

[0043] Epoxy resin E-51, epoxy resin E-44 and dicyandiamide were stirred and mixed in a mass ratio of 80:20:20 to obtain epoxy resin glue, which was evenly coated on a basalt fiber plain weave cloth (surface density 225 g / m 2) surface (the amount of epoxy resin glue is 35wt% of the mass of basalt fiber plain weave cloth), put it into a vacuum drying oven, and dry it at 60°C for 1h to obtain a prepreg; after cutting the prepreg into a size of 10cm×10cm, stack it into 8 layers, place it in a homemade mold on a flat vulcanizer for compression molding, pressurize it to 2MPa, and then heat it to 120°C at a heating rate of 10°C / min and then cure it for 1h, continue to heat it to 160°C and then cure it for 1h, and after cutting and shaping, the basalt fiber reinforced anti-fall mobile phone case is obtained.

[0044] Comparative Example 2

[0045] A method for preparing a basalt fiber reinforced anti-fall mobile phone case comprises the following steps:

[0046] (1) Basalt fiber plain weave cloth (surface density 225g / m 2 ) was added into an ethanol-water solution (ethanol-water volume ratio is 1:1) containing 4 wt% 3-isocyanatepropyltriethoxysilane, immersed for 2 h, taken out, put into a vacuum drying oven, first vacuum dried at 85° C. for 1 h, and then vacuum dried at 100° C. for 1 h, to obtain an isocyanate-grafted basalt fiber plain weave fabric;

[0047] (2) Epoxy resin E-51, epoxy resin E-44 and dicyandiamide were stirred and mixed in a mass ratio of 80:20:20 to obtain epoxy resin glue, and the epoxy resin glue was evenly coated on the surface of the above-mentioned isocyanate grafted basalt fiber plain cloth using a brush tool (the amount of epoxy resin glue was 35wt% of the mass of the basalt fiber plain cloth), placed in a vacuum drying oven, and dried at 60°C for 1h to obtain a prepreg; the prepreg was cut into a size of 10cm×10cm, stacked into 8 layers, and placed in a homemade mold on a flat vulcanizer for compression molding, pressurized to 2MPa, and then heated to 120°C at a heating rate of 10°C / min and cured for 1h, and then continued to heat to 160°C and cured for 1h. After cutting and shaping, the basalt fiber reinforced anti-fall mobile phone case was obtained.

[0048] The basalt fiber reinforced anti-fall mobile phone case described in the embodiment and the comparative example was tested for tensile strength, impact toughness and bending strength according to GB / T1447, GB / T1451 and GB / T1449 standards. The results are shown in Table 1 below.

[0049] Table 1 Performance test results of the mobile phone shells described in the embodiments and comparative examples

[0050] Tensile strength / MPa Bending strength / MPa <![CDATA[Impact toughness / kj / m 2 > Example 1 389 461 477 Example 2 372 453 469 Example 3 356 438 431 Comparative Example 1 261 287 256 Comparative Example 2 303 328 346

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a basalt fiber reinforced anti-fall mobile phone case, characterized in that: The steps include: S1, immersing the basalt fiber fabric in a silane coupling agent solution containing isocyanate, taking it out and drying it to obtain the isocyanate-grafted modified basalt fiber fabric; S2, immersing the isocyanate grafted modified basalt fiber fabric in an aminobenzimidazole solution, heating the solution and then taking it out to obtain a benzimidazole grafted modified basalt fiber fabric; S3, coating the surface of the benzimidazole-grafted modified basalt fiber fabric with epoxy resin glue, and curing and forming it to obtain the drop-proof mobile phone case.

2. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to claim 1, characterized in that: In step S1, the surface density of the basalt fiber fabric is 200-600g / m 2 .

3. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to claim 1 or 2, characterized in that: In step S1, the isocyanate-containing silane coupling agent is at least one of isocyanate propyl trimethoxy silane, isocyanate propyl triethoxy silane, isocyanate methyl trimethoxy silane or isocyanate methyl triethoxy silane; Preferably, the isocyanate-containing silane coupling agent solution is an ethanol-water solution with a concentration of 1-10 wt%.

4. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to any one of claims 1 to 3, characterized in that: In step S1, the immersion time is 1-3 hours; the drying includes: first vacuum drying at 75-95°C for 0.5-1 hour, and then vacuum drying at 100-120°C for 1-2 hours.

5. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to any one of claims 1 to 4, characterized in that: In step S2, the aminobenzimidazole is at least one of 4-aminobenzimidazole, 5-aminobenzimidazole, 2-(3-aminophenyl)-5-aminobenzimidazole or 2-(4-aminophenyl)-5-aminobenzimidazole; Preferably, the aminobenzimidazole solution is an acetone solution with a concentration of 1-10 wt%.

6. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to any one of claims 1 to 5, characterized in that: In step S2, the heating reaction temperature is 60-80°C and the time is 5-8h.

7. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to any one of claims 1 to 6, characterized in that: In step S3, the epoxy resin glue includes a base epoxy resin and a curing agent; Preferably, the weight ratio of the base epoxy resin to the curing agent is 100:5-25.

8. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to claim 7, characterized in that: The base epoxy resin is bisphenol A epoxy resin or bisphenol F epoxy resin; the curing agent is an amine curing agent or an acid anhydride curing agent, preferably at least one of dicyandiamide, boron trifluoride monoethylamine, m-phenylenediamine, diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, methyl nadic anhydride or dodecyl succinic anhydride.

9. The method for preparing the basalt fiber reinforced anti-fall mobile phone case according to any one of claims 1 to 8, characterized in that: In step S3, the curing temperature is 110-150°C, the time is 1-3h, and the pressure is 1-3MPa.

10. A basalt fiber reinforced anti-fall mobile phone case, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9.

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