Impact-resistant composite material and application thereof in mobile phone backboard

Abstract

The invention relates to an impact-resistant composite material and application thereof in a mobile phone backboard, and belongs to the technical field of mobile phone backboard materials, the composite material comprises the following raw materials: a base material, a compatibilizer, hydroquinone bis (diphenyl phosphate), talcum powder, calcium carbonate, sodium sulfate, sulfur, an ester exchange inhibitor, a chain extender, a heat stabilizer and an antioxidant; wherein the base material comprises PC, PET, HDPE and CPE. The PC, the PET, the HDPE and the CPE are matched and blended, so that the excellent properties of the PC, the PET, the HDPE and the CPE can be integrated, and the prepared composite material has high impact resistance and tensile property; the added talcum powder, hydroquinone bis (diphenyl phosphate) and sulfur are matched for use, so that a material with more perfect crystallization can be obtained, and the high impact resistance of the prepared composite material is enhanced; in addition, the talcum powder, the calcium carbonate and the modified sodium sulfate can synergistically improve the tensile strength of the prepared composite material.

Description

Technical Field

[0001] The present invention belongs to the technical field of mobile phone backplane materials, and specifically relates to an impact-resistant composite material and its application in mobile phone backplanes. Background Art

[0002] With the popularization and continuous upgrading of functions of smart phones, the performance requirements for mobile phone backplane materials are getting higher and higher. Traditional mobile phone backplane materials mainly include metals, glasses, ceramics, and plastics. However, these materials have certain limitations in practical applications. For example, metal backplanes will shield signals to a certain extent, which is not conducive to the application of 5G communication and wireless charging technologies; although glass backplanes have high transparency and are easy to color, their hardness is low and they are prone to breakage; although ceramic backplanes have high hardness and good luster, their cost is high and their toughness is insufficient; single polymer material backplanes have low cost but poor strength and impact resistance.

[0003] In recent years, novel composite materials prepared by blending or grafting, block copolymerization, etc. of two or more resin materials with different properties can integrate the advantages of each component and overcome the performance defects of single materials. Therefore, they have attracted much attention in the field of mobile phone backplanes. However, at present, the performance of mobile phone backplane materials that can simultaneously meet the requirements of high impact resistance and high tensile strength is still lacking. Therefore, providing a novel mobile phone backplane material with both high impact resistance and high tensile strength has become an urgent technical problem to be solved in the mobile phone manufacturing field. Summary of the Invention

[0004] The purpose of the present invention is to provide an impact-resistant composite material and its application in mobile phone backplanes, which solves the problem of poor impact resistance and tensile strength in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An impact-resistant composite material, the composite material comprising the following raw materials:

[0007] Base material, compatibilizer, hydroquinone bis(diphenyl phosphate), talcum powder, calcium carbonate, sodium sulfate, sulfur, transesterification inhibitor, chain extender, heat stabilizer, antioxidant.

[0008] As a preferred technical solution of the present invention, the base material comprises PC, PET, HDPE, and CPE;

[0009] PC (polycarbonate) is an engineering plastic with excellent toughness, good mechanical properties, heat resistance, and electrical properties. However, polycarbonate also has disadvantages such as poor processing fluidity, poor stress cracking resistance, and poor solvent resistance;

[0010] PET (Polyethylene Terephthalate) has good abrasion resistance, heat resistance, and solvent resistance, and has a certain crystallization ability. However, the crystallization rate of the PET molecular chain is slow, and it has relatively high rigidity, making injection molding relatively difficult.

[0011] HDPE (High-Density Polyethylene) has a regular molecular chain and is a thermoplastic resin with a high degree of crystallinity and a simple and symmetric molecular chain structure. The hardness, tensile strength, and creep resistance of HDPE are superior to those of low-density polyethylene, and it has good abrasion resistance, electrical insulation, toughness, and cold resistance. However, the anti-aging performance of HDPE is not as good as that of LDPE.

[0012] CPE (Chlorinated Polyethylene) has high elasticity, flexibility, anti-aging property, and flame retardancy, and is an excellent toughening material with good compatibility with other polymer materials.

[0013] As a preferred technical solution of the present invention, the compatibilizer includes ethylene-butyl acrylate-glycidyl methacrylate copolymer and HDPE-G-MAH.

[0014] As a preferred technical solution of the present invention, the particle size of the talc powder is 6 - 6.5 μm, the particle size of the calcium carbonate is 8.5 - 9 μm, and the particle size of the sodium sulfate is 10 - 12 μm.

[0015] As a preferred technical solution of the present invention, the transesterification inhibitor includes anhydrous sodium dihydrogen phosphate.

[0016] As a preferred technical solution of the present invention, the chain extender includes chain extender cxp5045.

[0017] As a preferred technical solution of the present invention, the heat stabilizer includes barium stearate.

[0018] As a preferred technical solution of the present invention, the antioxidant includes antioxidant 1010.

[0019] As a preferred technical solution of the present invention, the PC is 30 - 35 parts by weight, the PET is 25 - 30 parts by weight, the HDPE is 25 - 30 parts by weight, the CPE is 15 - 20 parts by weight, the ethylene-butyl acrylate-glycidyl methacrylate copolymer is 3 - 3.5 parts by weight, the HDPE-G-MAH is 15 - 18 parts by weight, the hydroquinone bis(diphenyl phosphate) is 1 - 1.5 parts by weight, the talc powder is 10 - 14 parts by weight, the calcium carbonate is 10 - 12 parts by weight, the sodium sulfate is 6 - 8 parts by weight, the sulfur is 0.1 - 0.12 parts by weight, the transesterification inhibitor is 0.4 - 0.5 parts by weight, the chain extender is 0.2 - 0.25 parts by weight, the heat stabilizer is 5 - 6 parts by weight, and the antioxidant is 10 - 12 parts by weight.

[0020] A preparation method of an impact-resistant composite material, comprising the following steps:

[0021] S1. Dry PC, PET, HDPE, and CPE respectively, and modify sodium sulfate.

[0022] S2. Mix the dried PC, PET, HDPE, CPE, and the remaining raw materials evenly and then use a twin-screw extruder to granulate. After drying the extruded granules, inject them into standard specimens to obtain the finished composite material.

[0023] As a preferred technical solution of the present invention, in step S1, the drying temperature of PC and PET is 115 - 120 °C and the time is 4 - 5 h; the drying temperature of HDPE and CPE is 80 - 85 °C and the time is 4 - 5 h.

[0024] As a preferred technical solution of the present invention, the steps for modifying sodium sulfate in step S1 include:

[0025] Dry sodium sulfate, mix KH-570 and absolute ethanol evenly and then add the dried sodium sulfate for ultrasonic dispersion, wash with absolute ethanol and dry to obtain modified sodium sulfate.

[0026] Furthermore, the mass ratio of KH-570, absolute ethanol, and the dried sodium sulfate is 1:95 - 100:2 - 2.2; the time for ultrasonic dispersion is 25 - 30 min.

[0027] As a preferred technical solution of the present invention, the conditions for extrusion granulation in step S2 are 230 - 250 °C and the screw speed is 250 - 270 r / min; the drying temperature is 100 - 110 °C and the time is 4 - 5 h; the injection molding temperature is 220 - 240 °C and the injection molding pressure is 55 - 60 MPa.

[0028] As another preferred technical solution of the present invention, a mobile phone back panel is provided, which contains the above-mentioned impact-resistant composite material.

[0029] The beneficial effects of the present invention:

[0030] (1) In the present invention, PC provides toughness, PET provides wear resistance, HDPE provides tensile strength, and CPE provides elasticity. Innovatively, the combination and blending of PC, PET, HDPE, and CPE can integrate the excellent properties of the four, complement each other in performance, and make the prepared composite material have high impact resistance and tensile properties.

[0031] Meanwhile, the present invention adds talcum powder for induced nucleation, adds hydroquinone bis(diphenyl phosphate) to accelerate the crystallization rate, and also uses sulfur to increase the grain size of the formed crystals. In this way, the combined use of talcum powder, hydroquinone bis(diphenyl phosphate) and sulfur can obtain a material with more perfect crystallization. Moreover, when the material is subjected to external forces, it can well absorb the external forces, thereby strengthening the high impact resistance of the prepared composite material.

[0032] (2) The molecular chains in the system material take the talcum powder added in the present invention as crystal nuclei, increasing the orderliness of the molecular chain arrangement and, to a certain extent, increasing the mechanical properties of the material. At the same time, the present invention also adds calcium carbonate and modified sodium sulfate to assist the talcum powder and enhance the interaction binding force with the resin, further improving the tensile strength of the prepared composite material. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0034] The PC (polycarbonate), brand: Sabic, grade: 141R-111, used in the examples, comparative examples and test examples of the present invention was purchased from Dongguan Fangheng Plastic Co., Ltd.; the PET (polyethylene terephthalate), brand: DuPont of the United States, grade: 543-LBK, was purchased from Dongguan Baojia Plastic Co., Ltd.; the HDPE (high density polyethylene), brand: Huajin Chemical Industry, grade: TR571-H, was purchased from Shanghai Qiao Wei Chemical Technology Co., Ltd.; the CPE (chlorinated polyethylene), brand: Yuquan New Materials, grade: 135A, was purchased from Shandong Yuquan New Material Technology Co., Ltd.; the ethylene-butyl acrylate-glycidyl methacrylate copolymer, brand: Arkema of France, grade: PTW-1, was purchased from Dongguan Dingxin Plastic Raw Materials Co., Ltd.; HDPE-G-MAH, brand: Dow of the United States, grade: TY1352, was purchased from Wuxi Weixinlong Plastic Import and Export Co., Ltd.; the chain extender cxp5045, brand: brand, grade: CXP5045, was purchased from Qingdao Linke Industry and Trade Co., Ltd.; the remaining raw materials are also commercially available; the above will not be elaborated hereinafter.

[0035] Example 1

[0036] An impact-resistant composite material, the composite material comprising the following raw materials:

[0037] 30 parts by weight of PC, 30 parts by weight of PET, 30 parts by weight of HDPE, 15 parts by weight of CPE, 3 parts by weight of ethylene-butyl acrylate-glycidyl methacrylate copolymer, 18 parts by weight of HDPE-G-MAH, 1.2 parts by weight of hydroquinone bis(diphenyl phosphate), 10 parts by weight of talc powder, 12 parts by weight of calcium carbonate, 6 parts by weight of sodium sulfate, 0.1 part by weight of sulfur, 0.4 part by weight of anhydrous sodium dihydrogen phosphate, 0.25 part by weight of chain extender cxp5045, 5 parts by weight of barium stearate, 10 parts by weight of antioxidant 1010;

[0038] The particle size of the talc powder is 6 μm, the particle size of the calcium carbonate is 8.5 μm, and the particle size of the sodium sulfate is 12 μm;

[0039] The preparation method of the impact-resistant composite material includes the following steps:

[0040] S1. Control the temperature of PC and PET at 115°C and dry for 5 h respectively, and control the temperature of HDPE and CPE at 80°C and dry for 4.5 h respectively; Dry the sodium sulfate, mix KH-570 and absolute ethanol evenly, add the dried sodium sulfate and ultrasonically disperse for 25 min, wash with absolute ethanol and dry to obtain modified sodium sulfate;

[0041] The mass ratio of KH-570, absolute ethanol and the dried sodium sulfate is 1:100:2;

[0042] S2. Mix the dried PC, PET, HDPE, CPE and the remaining raw materials evenly, and then extrude and pelletize them at 230°C and a screw speed of 270 r / min using a twin-screw extruder. Dry the extruded and pelletized particles at 105°C for 4 h, and then injection mold them into standard specimens at 220°C and an injection pressure of 60 MPa to obtain the finished composite material.

[0043] Example 2

[0044] An impact-resistant composite material, the composite material includes the following raw materials:

[0045] 35 parts by weight of PC, 25 parts by weight of PET, 27.5 parts by weight of HDPE, 20 parts by weight of CPE, 3.2 parts by weight of ethylene-butyl acrylate-glycidyl methacrylate copolymer, 16.5 parts by weight of HDPE-G-MAH, 1 part by weight of hydroquinone bis(diphenyl phosphate), 12 parts by weight of talc powder, 10 parts by weight of calcium carbonate, 7 parts by weight of sodium sulfate, 0.12 part by weight of sulfur, 0.45 part by weight of anhydrous sodium dihydrogen phosphate, 0.2 part by weight of chain extender cxp5045, 5.5 parts by weight of barium stearate, 12 parts by weight of antioxidant 1010;

[0046] The particle size of the talcum powder is 6.2 μm, the particle size of the calcium carbonate is 9 μm, and the particle size of the sodium sulfate is 10 μm;

[0047] The preparation method of the impact-resistant composite material comprises the following steps:

[0048] S1. Control the temperature of PC and PET at 117.5 °C and dry for 4 h, and control the temperature of HDPE and CPE at 82.5 °C and dry for 4 h; Dry the sodium sulfate, mix KH-570 and absolute ethanol evenly, add the mixture to the dried sodium sulfate, ultrasonically disperse for 30 min, wash with absolute ethanol and dry to obtain modified sodium sulfate;

[0049] The mass ratio of KH-570, absolute ethanol and the dried sodium sulfate is 1:97.5:2.1;

[0050] S2. Mix the dried PC, PET, HDPE, CPE and the remaining raw materials evenly, and extrude and pelletize them at 240 °C and a screw speed of 250 r / min using a twin-screw extruder. Dry the extruded and pelletized particles at 100 °C for 4.5 h, and then injection mold them into standard specimens at 240 °C and an injection pressure of 55 MPa to obtain the finished composite material.

[0051] Example 3

[0052] An impact-resistant composite material, the composite material comprising the following raw materials:

[0053] 32.5 parts by weight of PC, 27.5 parts by weight of PET, 25 parts by weight of HDPE, 17.5 parts by weight of CPE, 3.5 parts by weight of ethylene-butyl acrylate-glycidyl methacrylate copolymer, 15 parts by weight of HDPE-G-MAH, 1.5 parts by weight of hydroquinone bis(diphenyl phosphate), 14 parts by weight of talcum powder, 11 parts by weight of calcium carbonate, 8 parts by weight of sodium sulfate, 0.11 parts by weight of sulfur, 0.5 parts by weight of anhydrous sodium dihydrogen phosphate, 0.23 parts by weight of chain extender cxp5045, 6 parts by weight of barium stearate, 11 parts by weight of antioxidant 1010;

[0054] The particle size of the talcum powder is 6.5 μm, the particle size of the calcium carbonate is 8.7 μm, and the particle size of the sodium sulfate is 11 μm;

[0055] The preparation method of the impact-resistant composite material comprises the following steps:

[0056] S1. Control the temperature of PC and PET at 120 °C and dry for 4.5 h, and control the temperature of HDPE and CPE at 85 °C and dry for 5 h; Dry the sodium sulfate, mix KH-570 and absolute ethanol evenly, add the mixture to the dried sodium sulfate, ultrasonically disperse for 27 min, wash with absolute ethanol and dry to obtain modified sodium sulfate;

[0057] The mass ratio of KH-570, absolute ethanol and dried sodium sulfate is 1:95:2.2;

[0058] S2. After mixing the baked PC, PET, HDPE, CPE and the remaining raw materials evenly, extrude and pelletize them using a twin-screw extruder under the conditions of 250°C and a screw speed of 260 r / min. Dry the extruded and pelletized particles at 110°C for 5 h, and then injection-mold them into standard specimens at 230°C and an injection pressure of 57 MPa to obtain the finished composite material.

[0059] Comparative Examples 1-4

[0060] Compared with Example 1, the difference is that the weight parts of PC, PET, HDPE and CPE in Comparative Examples 1-4 are shown in Table 1, and the remaining operation steps and parameters remain unchanged.

[0061] Table 1

[0062] PC (parts by weight) PET (parts by weight) HDPE (parts by weight) CPE (parts by weight) Comparative Example 1 0 40 40 25 Comparative Example 2 40 0 40 25 Comparative Example 3 40 40 0 25 Comparative Example 4 35 35 35 0

[0063] Comparative Example 5

[0064] Compared with Example 1, the difference is that talcum powder is not added in Comparative Example 5, and the remaining operation steps and parameters remain unchanged.

[0065] Comparative Example 6

[0066] Compared with Example 1, the difference is that hydroquinone bis(diphenyl phosphate) is not added in Comparative Example 6, and the remaining operation steps and parameters remain unchanged.

[0067] Comparative Example 7

[0068] Compared with Example 1, the difference is that sulfur is not added in Comparative Example 7, and the remaining operation steps and parameters remain unchanged.

[0069] Comparative Example 8

[0070] Compared with Example 1, the difference is that talcum powder is not added in Comparative Example 8, while the calcium carbonate is 17 weight parts and the modified sodium sulfate is 11 weight parts, and the remaining operation steps and parameters remain unchanged.

[0071] Comparative Example 9

[0072] Compared with Example 1, the difference is that calcium carbonate is not added in Comparative Example 9, while the talcum powder is 16 weight parts and the modified sodium sulfate is 12 weight parts, and the remaining operation steps and parameters remain unchanged.

[0073] Comparative Example 10

[0074] Compared with Example 1, the difference is that in Comparative Example 10, modified sodium sulfate is not added, while the talcum powder is 13 parts by weight and the calcium carbonate is 15 parts by weight, and the rest of the operation steps and parameters remain unchanged.

[0075] Test Example

[0076] (1) Tensile strength: The tensile strength of the composite material products prepared in Examples 1-3, Comparative Examples 1-4 and Comparative Examples 8-10 was tested according to GB / T 1040-1992, and the tensile speed was 50 mm / min. The results are shown in Table 2;

[0077] (2) Izod notched impact strength: The Izod notched impact strength of the composite material products prepared in Examples 1-3 and Comparative Examples 1-7 was tested according to GB / T 1843-1996, and the pendulum energy was 2.75 J. The results are shown in Table 2;

[0078] Table 2

[0079]

[0080]

[0081] It can be seen from Examples 1-3 and Comparative Examples 1-4 in Table 2 that by blending PC, PET, HDPE and CPE in the present invention, the excellent properties of the four can be integrated, making up for each other's strengths and weaknesses in performance, so that the prepared composite material has high impact resistance and tensile properties; and it is not difficult to see from Examples 1-3 and Comparative Examples 5-7 that the talcum powder, hydroquinone bis(diphenyl phosphate) and sulfur added in the present invention can be used in combination to obtain a material with more perfect crystallization, strengthening the high impact resistance of the prepared composite material; it is easy to obtain from Examples 1-3 and Comparative Examples 8-10 that the talcum powder, calcium carbonate and modified sodium sulfate in the present invention can synergistically improve the tensile strength of the prepared composite material.

[0082] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0083] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology make various modifications or supplements to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the claims of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An impact-resistant composite material, characterized in that: The composite material comprises the following raw materials: base material, compatibilizer, hydroquinone bis(diphenyl phosphate), talcum powder, calcium carbonate, sodium sulfate, sulfur, ester exchange inhibitor, chain extender, heat stabilizer, antioxidant; Wherein, the base material includes PC, PET, HDPE and CPE.

2. The impact-resistant composite material according to claim 1, characterized in that: The compatibilizer includes ethylene-butyl acrylate-glycidyl methacrylate copolymer and HDPE-G-MAH.

3. The impact-resistant composite material according to claim 1, characterized in that: The particle size of the talc powder is 6-6.5 μm, the particle size of the calcium carbonate is 8.5-9 μm, and the particle size of the sodium sulfate is 10-12 μm.

4. The impact-resistant composite material according to claim 1, characterized in that: The transesterification inhibitor includes anhydrous sodium dihydrogen phosphate; the chain extender includes chain extender cxp5045; and the antioxidant includes antioxidant 1010.

5. The impact-resistant composite material according to claim 2, characterized in that: The PC comprises 30-35 parts by weight, PET 25-30 parts by weight, HDPE 25-30 parts by weight, CPE 15-20 parts by weight, ethylene-butyl acrylate-glycidyl methacrylate copolymer 3-3.5 parts by weight, HDPE-G-MAH 15-18 parts by weight, hydroquinone bis(diphenyl phosphate) 1-1.5 parts by weight, talc 10-14 parts by weight, calcium carbonate 10-12 parts by weight, sodium sulfate 6-8 parts by weight, sulfur 0.1-0.12 parts by weight, ester exchange inhibitor 0.4-0.5 parts by weight, chain extender 0.2-0.25 parts by weight, heat stabilizer 5-6 parts by weight, and antioxidant 10-12 parts by weight.

6. A method for preparing the impact-resistant composite material according to any one of claims 1 to 5, characterized in that: The steps include: S1. Dry PC, PET, HDPE and CPE separately and modify the sodium sulfate; S2. The baked PC, PET, HDPE, CPE and the remaining raw materials are mixed evenly and then granulated by twin-screw extrusion. The granules after extrusion granulation are dried and then injection molded into standard specimens to obtain a finished composite material.

7. The method for preparing the impact-resistant composite material according to claim 6, characterized in that: Step S1: the PC and PET are dried at 115-120°C for 4-5 hours; the HDPE and CPE are dried at 80-85°C for 4-5 hours; The step of modifying the sodium sulfate comprises: drying the sodium sulfate, uniformly mixing KH-570 and anhydrous ethanol, adding the dried sodium sulfate for ultrasonic dispersion, washing with anhydrous ethanol, and drying to obtain modified sodium sulfate.

8. The method for preparing the impact-resistant composite material according to claim 7, characterized in that: The mass ratio of KH-570, anhydrous ethanol and dried sodium sulfate is 1:95-100:2-2.2; and the ultrasonic dispersion time is 25-30 minutes.

9. The method for preparing the impact-resistant composite material according to claim 6, characterized in that: The conditions of the extrusion granulation in step S2 are 230-250°C and a screw speed of 250-270 r / min; the drying temperature is 100-110°C and the time is 4-5h; the injection temperature is 220-240°C and the injection pressure is 55-60MPa.

10. A mobile phone back panel, characterized in that: A composite material comprising the impact-resistant material described in any one of claims 6 to 9.

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