Plastic composite material, preparation method and application thereof, and plastic spliced sound box

Abstract

The invention relates to a plastic composite material, a preparation method and application thereof, and a plastic spliced sound box, and relates to the technical field of plastic materials, the plastic composite material comprises the following raw materials by weight: 55-70 parts of a polypropylene resin base material, 20-35 parts of a filler, 0.1-1 part of an antioxidant, 0.1-0.5 part of an antistatic agent, and 0.5-2 parts of a lubricant; the polypropylene resin base material is prepared by taking first homo-polypropylene resin and second homo-polypropylene resin as raw materials and then carrying out alternate circulation treatment through a microwave plasma process and a freezing process. The plastic composite material provided by the invention has the advantages of excellent mechanical properties such as impact strength, good stability and the like, can significantly improve the overall stability, safety, service life and the like of products when being applied to preparation of spliced plates and electronic product shells, meets the use requirements of consumers for DIY (do it yourself), and has wide practical application.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation materials, and in particular to a plastic composite material, a preparation method and application thereof, and a plastic spliced ​​speaker. Background Art

[0002] In the field of modern materials science, plastic composites have become one of the preferred materials in many industrial applications due to their strong plasticity, convenient processing and high cost-effectiveness. In particular, the demand for plastic composites is growing in the preparation of spliced ​​panels, electronic product housings, and audio equipment such as plastic spliced ​​speakers. However, as the market's requirements for product performance continue to increase, traditional plastic composites have gradually shown limitations in terms of mechanical strength, stability, safety and service life.

[0003] Traditional plastic composite materials often use a single polypropylene resin as the base material. Although the cost is low, it has deficiencies in impact strength, heat resistance, antistatic properties, etc., and it is difficult to meet the needs of high-end applications. Especially when preparing products that need to withstand certain external impacts or long-term use, such as the shell of a spliced ​​speaker, the performance bottleneck of traditional materials is particularly obvious.

[0004] In addition, traditional preparation processes often lack the step of deep processing of raw materials, resulting in uneven microstructure inside the material, affecting the overall performance of the material. For example, polypropylene resin that has not been specially treated is prone to photothermal degradation or photothermal aging during processing, resulting in reduced product performance, which further limits the widespread application of plastic composite materials.

[0005] Therefore, in order to break through the performance bottleneck of traditional plastic composite materials, develop new composite materials and their efficient preparation processes to meet the market's urgent demand for high-performance and high-stability materials, which has become a hot topic in current material research. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a plastic composite material and a preparation method and application thereof, and a plastic spliced ​​speaker.

[0007] In a first aspect, the present invention provides a plastic composite material, which comprises the following raw materials in parts by weight:

[0008] 55-70 parts of polypropylene resin base material, 20-35 parts of filler, 0.1-1 parts of antioxidant, 0.1-0.5 parts of antistatic agent and 0.5-2 parts of lubricant;

[0009] The polypropylene resin base material is obtained by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then undergoing alternating cycles of microwave plasma processing and freezing processing;

[0010] The melt index of the first homopolymer polypropylene resin is 4 to 11 g / 10 min;

[0011] The melt index of the second homopolymer polypropylene resin is 30 to 40 g / 10 min.

[0012] Furthermore, the plastic composite material comprises the following raw materials in parts by weight:

[0013] 63 parts of polypropylene resin base material, 30 parts of filler, 0.4 parts of antioxidant, 0.2 parts of antistatic agent and 1 part of lubricant.

[0014] Furthermore, the preparation method of the polypropylene resin base material comprises the following process:

[0015] Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin to obtain a first mixture;

[0016] Step (2): subjecting the first mixed material to microwave plasma treatment to obtain a second mixed material;

[0017] Step (3): freezing the second mixed material to obtain a third mixed material;

[0018] Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 3 to 6 times, to obtain the polypropylene resin base material;

[0019] Wherein, the weight ratio of the first homopolymer polypropylene resin to the second homopolymer polypropylene resin is (3-7):(1-2);

[0020] The working condition parameters of the microwave plasma treatment include: microwave power of 450-760W, time of 90-180 seconds, working mode of atmospheric pressure open, and working medium of air;

[0021] The working condition parameters of the freezing treatment include: a freezing temperature of -25 to -15°C and a freezing time of 30 to 60 minutes.

[0022] Furthermore, the weight ratio of the first homopolypropylene resin to the second homopolypropylene resin is 5:1.5; the working condition parameters of the microwave plasma treatment include: microwave power of 550 W, time of 140 seconds, working mode of atmospheric pressure open, and working medium of air; the working condition parameters of the freezing treatment include: freezing temperature of -20°C and time of 45 minutes.

[0023] Furthermore, the preparation method of the filler comprises the following process:

[0024] Potassium feldspar powder, hydrotalcite powder and silane coupling agent in a weight ratio of (1-2):(5-8):(0.01-0.05) are added to an ethanol aqueous solution with a volume percentage of 75-85%, and ground and mixed to obtain a mixed slurry with a solid content of 50-60wt%;

[0025] The mixed slurry is spray-dried to obtain a modified powder;

[0026] The modified powder and glass fiber are mixed in a weight ratio of (3-5):(1-2) to obtain the filler.

[0027] Further, the antioxidant includes at least one of antioxidant 245, antioxidant 626 and antioxidant 1098; the antistatic agent includes at least one of dodecyl dihydroxyethyl methyl ammonium bromide, octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine; the lubricant includes at least one of N,N'-ethylene bisstearamide, polyethylene wax, oxidized polyethylene wax, calcium stearate and zinc stearate.

[0028] In a second aspect, the present invention provides a method for preparing the plastic composite material according to any one of the first aspects, the method for preparing the plastic composite material comprising the following steps:

[0029] Mixing a polypropylene resin base material, an antioxidant, an antistatic agent and a lubricant to obtain a mixed raw material;

[0030] The mixed raw material and the inorganic filler are added into a twin-screw extruder for melt extrusion, and then granulated and dried to obtain the plastic composite material.

[0031] In a third aspect, the present invention provides the use of the plastic composite material described in any one of the first aspect and / or the plastic composite material obtained by the preparation method described in any one of the second aspect in the preparation of spliced ​​plates and electronic product housings.

[0032] In a fourth aspect, the present invention provides a plastic splicing speaker, the shell of which is formed by connecting and fixing splicing plates, and the material of the splicing plates is the plastic composite material described in any one of the first aspect and / or the plastic composite material obtained by the preparation method described in any one of the second aspect.

[0033] Furthermore, the thickness H of the spliced ​​plate is in mm, the length C of the plate is in mm, the width K of the plate is in mm, and the Izod notched impact strength Q of the plastic composite material is in KJ / cm 2 The values ​​satisfy formula 1: (4H+Q) / (C / K)≥4.

[0034] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0035] The embodiments of the present invention provide a plastic composite material, a preparation method and application thereof, and a plastic splicing speaker. The plastic composite material provided by the present invention has the advantages of excellent mechanical properties such as impact strength and good stability. When used to prepare splicing plates and electronic product shells, it can significantly improve the overall stability, safety and service life of the product, meet the DIY needs of consumers, and has a wide range of practical uses. Specifically:

[0036] 1. Resin raw material selection and performance complementarity:

[0037] The present invention uses a first homopolymer polypropylene resin (hereinafter referred to as "low MI resin") and a second homopolymer polypropylene resin (hereinafter referred to as "high MI resin") as resin raw materials. The low MI resin has a higher molecular weight and better mechanical properties, such as high strength and toughness, but relatively poor processing fluidity, while the high MI resin has a lower molecular weight and excellent processing properties, is easy to melt and flow, but has slightly inferior mechanical properties. The two resins are mixed in a certain proportion to combine the advantages of the two, thereby ensuring the mechanical properties of the material and improving processing efficiency.

[0038] 2. Alternating cycle treatment of microwave plasma process and freezing process:

[0039] Microwave plasma process: Use microwaves to excite gas to generate plasma, and perform high-energy radiation and surface modification on the resin. This process can break some chemical bonds between resin molecules, promote mutual penetration and cross-linking between low MI resin and high MI resin molecules, and form a more compact network structure. At the same time, plasma treatment can also improve the activity and compatibility of the resin surface, which is conducive to the subsequent combination with other components.

[0040] Freezing process: After microwave plasma treatment, the resin is quickly cooled to a low temperature state. This rapid cooling process helps to fix the configuration of the resin molecules in a high energy state, which is beneficial to promote the modification of the resin raw materials by microwave plasma.

[0041] Alternating cycle treatment: Through multiple microwave plasma-freezing cycle treatments, the degree of cross-linking between resin molecules gradually deepens, forming a more uniform and dense microstructure. This structure not only improves the impact strength and mechanical properties of the material, but also enhances its thermal and chemical stability.

[0042] 3. Achieve high performance and application advantages:

[0043] The polypropylene resin base material that has undergone the above special treatment can fully exert its high performance characteristics and has good compatibility with other components such as fillers when mixed with other fillers and additives to form plastic composite materials. The mechanical properties of the composite material such as impact strength, tensile strength, and flexural strength are significantly improved, while maintaining good processability and formability.

[0044] When used in areas such as splicing panels and electronic product housings, this high-performance plastic composite material can significantly improve the overall stability, safety and service life of the product. For example, in splicing panels, it can effectively resist external impact and deformation, maintaining the flatness and structural integrity of the panels; in electronic product housings, it can provide excellent protection to prevent internal components from being damaged by the external environment.

[0045] In addition, the excellent performance of the composite material also meets the needs of consumers for DIY products. Whether it is the installation of splicing panels in home decoration or the personalized customization of electronic product shells, consumers can easily operate and enjoy the fun and sense of accomplishment of DIY (self-assembly).

[0046] In summary, the present invention achieves high performance of polypropylene resin base material through carefully designed raw material ratio and innovative processing technology. This high-performance plastic composite material not only has excellent mechanical properties and stability, but is also widely used in the fields of splicing panels and electronic product housings, significantly improving the overall quality and service life of the product and meeting the diversified DIY needs of consumers. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0049] Figure 1 A schematic flow chart of a method for preparing a plastic composite material provided by an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram of the exploded structure of the plastic splicing speaker;

[0051] Figure 3 It is a structural schematic diagram of the splicing of the speaker mounting plate and the sound guide plate in the plastic splicing speaker box;

[0052] Figure 4 It is a schematic diagram of the structure of the speaker mounting plate in the plastic splicing speaker box;

[0053] Figure 5 This is a schematic diagram of the structure of the reinforced stabilizing frame in the plastic spliced ​​speaker;

[0054] Figure 6 This is a schematic diagram of the structure of the bottom splicing plate of the plastic splicing speaker;

[0055] Figure 7 This is a schematic diagram of the structure of the connection between the shell and the speaker in a plastic spliced ​​speaker.

[0056] Figure 2-7 Middle: 10, left splicing plate; 11, right splicing plate; 12, rear splicing plate; 13, bottom splicing plate; 14, sound guide plate; 140, step surface; 15, speaker mounting plate; 151, speaker mounting port; 1510, speaker; 16, top splicing plate; 20, convex strip; 21, groove strip; 22, limit groove; 30, reinforced stabilizing frame; 301, tripod A; 302, tripod B; 40, connecting angle code; 50, mesh plate. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0059] In a first aspect, the present invention provides a plastic composite material, which comprises the following raw materials in parts by weight:

[0060] 55-70 parts of polypropylene resin base material, 20-35 parts of filler, 0.1-1 parts of antioxidant, 0.1-0.5 parts of antistatic agent and 0.5-2 parts of lubricant;

[0061] The polypropylene resin base material is obtained by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then undergoing alternating cycles of microwave plasma processing and freezing processing;

[0062] The melt index of the first homopolymer polypropylene resin is 4 to 11 g / 10 min;

[0063] The melt index of the second homopolymer polypropylene resin is 30 to 40 g / 10 min.

[0064] An embodiment of the present invention provides a plastic composite material, which has the advantages of excellent mechanical properties such as impact strength and good stability. When used in the preparation of spliced ​​panels and electronic product housings, it can significantly improve the overall stability, safety and service life of the product, meet the DIY needs of consumers, and has a wide range of practical uses.

[0065] In some specific embodiments, the first homopolymer polypropylene resin and the second homopolymer polypropylene resin can be prepared in accordance with the technical content disclosed in the prior art or directly adopt a commercially available homopolymer polypropylene resin that meets the requirements of the melt index (or melt flow rate, tested according to the ASTM D1238 test standard); specifically, in the embodiment of the present invention, the first homopolymer polypropylene resin can be ExxonMobil Corporation's product model ExxonMobil TM PP1304E5 (melt index is 11g / 10min), ExxonMobil's product model is ExxonMobil TM PP2822E2 (melt index is 4g / 10min), the product model of SK Company of South Korea is H390F (melt index is 8g / 10min), the product model of SK Company of South Korea is H150F (melt index is 7.5g / 10min), the product model of SK Company of South Korea is H350F (melt index is 7g / 10min) and other commercially available products; and the second homopolymer polypropylene resin can be used, for example, the product model of ExxonMobil TM PP3155E3 (melt index is 36g / 10min), the product model of SK Company of South Korea is H390F (melt index is 40g / 10min), the product model is PP T30S (melt index is 30g / 10min) and other commercial products; in the comparative example, the first homopolymer polypropylene resin can be directly used, such as the product model of ExxonMobil Company is ExxonMobil TM The commercially available products such as PP5262 (melt index is 2g / 10min) and the second homopolymer polypropylene resin can be commercially available products such as the product model BX3910 (melt index is 80g / 10min) of SK Company of South Korea. Preferably, the melt index of the first homopolymer polypropylene resin is 7.5g / 10min, and the melt index of the second homopolymer polypropylene resin is 36g / 10min.

[0066] In some specific embodiments, the plastic composite material includes the following raw materials in parts by weight:

[0067] 63 parts of polypropylene resin base material, 30 parts of filler, 0.4 parts of antioxidant, 0.2 parts of antistatic agent and 1 part of lubricant.

[0068] In some specific embodiments, the method for preparing the polypropylene resin base material comprises the following process:

[0069] Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin to obtain a first mixture;

[0070] Step (2): subjecting the first mixed material to microwave plasma treatment to obtain a second mixed material;

[0071] Step (3): freezing the second mixed material to obtain a third mixed material;

[0072] Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 3 to 6 times, to obtain the polypropylene resin base material;

[0073] Wherein, the weight ratio of the first homopolymer polypropylene resin to the second homopolymer polypropylene resin is (3-7):(1-2);

[0074] The working condition parameters of the microwave plasma treatment include: microwave power of 450-760W, time of 90-180 seconds, working mode of atmospheric pressure open, and working medium of air;

[0075] The working condition parameters of the freezing treatment include: a freezing temperature of -25 to -15°C and a freezing time of 30 to 60 minutes.

[0076] In some specific embodiments, the weight ratio of the first homopolymer polypropylene resin to the second homopolymer polypropylene resin is 5:1.5; the working condition parameters of the microwave plasma treatment include: microwave power of 550 W, time of 140 seconds, working mode of atmospheric pressure open, and working medium of air; the working condition parameters of the freezing treatment include: freezing temperature of -20°C, time of 45 minutes.

[0077] In some specific embodiments, the method for preparing the filler comprises the following process:

[0078] Potassium feldspar powder, hydrotalcite powder and silane coupling agent in a weight ratio of (1-2):(5-8):(0.01-0.05) are added to an ethanol aqueous solution with a volume percentage of 75-85%, and ground and mixed to obtain a mixed slurry with a solid content of 50-60wt%;

[0079] The mixed slurry is spray-dried to obtain a modified powder;

[0080] The modified powder and glass fiber are mixed in a weight ratio of (3-5):(1-2) to obtain the filler.

[0081] In some specific embodiments, the silane coupling agent can be directly used, such as commercially available products such as silane coupling agent KH-550 (γ-aminopropyltriethoxysilane), KH-560 (γ-(2,3-epoxypropyloxy)propyltrimethoxysilane), KH-570 (γ-methacryloxypropyltrimethoxysilane), KH-792 (N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane), A-1100 (aminosilane coupling agent); the diameter of the glass fiber is 3-13 microns and the length is 1-2 mm; potassium feldspar powder is a powder made from potassium feldspar after fine grinding, and the chemical formula is KAlSi3O8; hydrotalcite powder can be directly used, such as commercially available magnesium aluminum carbonate type hydrotalcite powder.

[0082] In some specific embodiments, the antioxidant includes at least one of antioxidant 245, antioxidant 626 and antioxidant 1098; the antistatic agent includes at least one of dodecyl dihydroxyethyl methyl ammonium bromide, octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine; the lubricant includes at least one of N,N'-ethylene bisstearamide, polyethylene wax, oxidized polyethylene wax, calcium stearate and zinc stearate.

[0083] In a second aspect, based on the same inventive concept, the present invention provides a method for preparing the plastic composite material as described in any one of the first aspects, such as Figure 1 As shown, the preparation method of the plastic composite material comprises the following steps:

[0084] Mixing a polypropylene resin base material, an antioxidant, an antistatic agent and a lubricant to obtain a mixed raw material;

[0085] The mixed raw material and the inorganic filler are added into a twin-screw extruder for melt extrusion, and then granulated and dried to obtain the plastic composite material.

[0086] The plastic composite material provided by the present invention is easy to operate, does not require additional special equipment, and is suitable for industrial batch production. In some specific embodiments, when the mixed raw materials and inorganic fillers are added to a twin-screw extruder for melt extrusion, the mixed raw materials can be added to the main feeding bin of the twin-screw extruder, the inorganic fillers are added to the side feeding bin, and the components of the main feeding bin and the side feeding bin are added to the twin-screw extruder according to a proportion, and the temperature of the melting section is controlled to be 190-210°C, the temperature of the mixing section is 220-240°C, and the temperature of the extrusion section is 200-210°C.

[0087] In a third aspect, based on the same inventive concept, the present invention provides the use of the plastic composite material described in any one of the first aspect and / or the plastic composite material obtained by the preparation method described in any one of the second aspect in the preparation of spliced ​​plates and electronic product housings.

[0088] The plastic composite material provided by the present invention has the advantages of excellent mechanical properties such as impact strength, good stability, etc., and the filler contains antibacterial mineral components, which give the plastic composite material good antibacterial properties. It can be used to prepare splicing plates and electronic product shells such as audio equipment, early education machines, children's toys, etc., and has a wide range of uses.

[0089] In a fourth aspect, based on the same inventive concept, the present invention provides a plastic spliced ​​speaker, the shell of which is formed by connecting and fixing spliced ​​plates, and the material of the spliced ​​plates is the plastic composite material described in any one of the first aspect and / or the plastic composite material obtained by the preparation method described in any one of the second aspect.

[0090] In some specific embodiments, the structural unit of the spliced ​​plate materials described in the present invention can be designed according to the methods disclosed in the prior art such as Chinese patent CN114377412A, specifically, including two plastic plates spliced ​​together by a plug unit and a jack unit, the two plastic plates are locked by a fastening screw, the plug unit includes a pair of plugs and a reserved groove located between the two plugs; the jack unit includes jacks corresponding to the two plugs and reserved holes corresponding to the reserved groove; a single jack is a strip hole structure, the reserved hole is a square hole or a round hole, the outer diameter of the fastening screw is respectively larger than the slot width of the reserved groove and the inner diameter of the reserved hole, and the fastening screw is screwed into the reserved hole and the reserved groove in turn to lock the two plastic plates spliced ​​together. At the same time, the material of the splicing plate in the present invention is the plastic composite material described in any one of the first aspects and / or the plastic composite material obtained by the preparation method described in any one of the second aspects, which has the advantages of excellent mechanical properties and good stability, so it is not necessary to be subject to the constraints of thickness and U-shaped tensile strength in CN 114377412 A, the reserved groove depth of the plug unit, the weak edge thickness and hole length of the jack unit hole, and the length of the fastening screw.

[0091] In some specific embodiments, the thickness H of the spliced ​​plate is in mm, the length C of the plate is in mm, the width K of the plate is in mm, and the Izod notched impact strength Q of the plastic composite material is in KJ / cm 2 The values ​​satisfy formula 1: (4H+Q) / (C / K)≥4.

[0092] In order to enable consumers or producers to better and more conveniently use the high-performance plastic composite material provided by the present invention in the fields of splicing plates and electronic product housings, the present invention has found through further experiments that the thickness H of the splicing plate is designed to be mm, the length C of the plate is designed to be mm, the width K of the plate is designed to be mm, and the Izod notched impact strength Q of the plastic composite material is designed to be KJ / cm 2 When the values ​​of satisfy Formula 1: (4H+Q) / (C / K)≥4 (hereinafter referred to as "(4H+Q) / (C / K)" as the stability index S), the resulting product has better stability and reliability.

[0093] In some specific embodiments, the plastic splicing speaker provided by the present invention may adopt conventional design methods in the prior art, such as including a speaker and a plurality of splicing panels, wherein the plurality of splicing panels are at least partially made of the plastic composite material described in any one of the first aspects and / or the plastic composite material obtained by the preparation method described in any one of the second aspects, and the plurality of splicing panels are respectively a bottom splicing panel, a left splicing panel, a right splicing panel, a top splicing panel, a rear splicing panel and a front splicing panel, the left splicing panel and the right splicing panel are respectively connected and fixed to the opposite ends of the bottom splicing panel, the rear splicing panel is connected and fixed to the rear end of the bottom splicing panel, the top splicing panel is connected and fixed to the upper end of the bottom splicing panel, and the front splicing panel is connected and fixed to the front end of the bottom splicing panel, so that the enclosure between the bottom splicing panel, the left splicing panel, the right splicing panel, the top splicing panel, the rear splicing panel and the front splicing panel forms the shell of the speaker, etc. Specifically, the design structure as in CN 220234869 U may be adopted, such as Figure 2-7 As shown, Figure 2-7 Middle: 10, left splicing plate; 11, right splicing plate; 12, rear splicing plate; 13, bottom splicing plate; 14, sound guide plate; 140, step surface; 15, speaker mounting plate; 151, speaker mounting port; 1510, speaker; 16, top splicing plate; 20, convex strip; 21, groove strip; 22, limit groove; 30, reinforced stabilizing frame; 301, tripod A; 302, tripod B; 40, connecting angle code; 50, mesh plate; the specific connection method refers to the prior art, and the present invention will not repeat it.

[0094] It should be noted that the plastic composite material provided by the embodiments of the present invention, its preparation method and application, and the component raw materials involved in the plastic spliced ​​speaker, unless otherwise specified or specified, can directly adopt commercially available products or be homemade using existing public preparation methods; at the same time, the steps and parameters involved, unless otherwise specified or specified, can be carried out according to existing processing technology or directly using existing equipment, and the present invention document will not describe them one by one.

[0095] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0096] Example 1

[0097] This example provides a plastic composite material, which includes the following raw materials in parts by weight: 63 parts of polypropylene resin base material, 30 parts of filler, 0.4 parts of antioxidant, 0.2 parts of antistatic agent and 1 part of lubricant;

[0098] The polypropylene resin base material is prepared by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then subjected to alternating cycles of microwave plasma process and freezing process; the melt index of the first homopolymer polypropylene resin is 7.5 g / 10 min; the melt index of the second homopolymer polypropylene resin is 36 g / 10 min; the antioxidant is antioxidant 245, the antistatic agent is composed of octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine in a weight ratio of 1:1, and the lubricant is calcium stearate;

[0099] The preparation method of the polypropylene resin base material comprises the following process:

[0100] Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin in a weight ratio of 5:1.5 to obtain a first mixture;

[0101] Step (2): subjecting the first mixed material to microwave plasma treatment, with a microwave power of 550 W, a time of 140 seconds, an atmospheric pressure open working mode, and air as a working medium, to obtain a second mixed material;

[0102] Step (3): freezing the second mixed material at a temperature of -20°C for 45 minutes to obtain a third mixed material;

[0103] Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 4 times, to obtain the polypropylene resin base material;

[0104] The preparation method of the filler comprises the following steps:

[0105] Step (1): adding potassium feldspar powder, magnesium aluminum carbonate type hydrotalcite powder and γ-aminopropyltriethoxysilane in a weight ratio of 1.5:6:0.03 to an ethanol aqueous solution with a volume percentage of 80%, grinding and mixing, the grinding speed is 300 rpm, and the grinding time is 45 minutes to obtain a mixed slurry with a solid content of 55wt%;

[0106] Step (2): spray drying the mixed slurry to obtain a modified powder;

[0107] Step (3): Mixing the modified powder and glass fiber in a weight ratio of 4:1 to obtain the filler.

[0108] The method for preparing the above-mentioned plastic composite material comprises the following steps:

[0109] Mixing a polypropylene resin base material, an antioxidant, an antistatic agent and a lubricant to obtain a mixed raw material;

[0110] The mixed raw materials and inorganic fillers are added into a twin-screw extruder for melt extrusion, with the melting section temperature being 200° C., the mixing section temperature being 230° C., and the extrusion section temperature being 205° C., followed by granulation and drying to obtain the plastic composite material.

[0111] Example 2

[0112] This example provides a plastic composite material, which includes the following raw materials in parts by weight: 55 parts of a polypropylene resin base material, 20 parts of a filler, 0.1 parts of an antioxidant, 0.1 parts of an antistatic agent, and 0.5 parts of a lubricant;

[0113] The polypropylene resin base material is prepared by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then subjected to alternating cycles of microwave plasma process and freezing process; the melt index of the first homopolymer polypropylene resin is 4g / 10min; the melt index of the second homopolymer polypropylene resin is 30g / 10min; the antioxidant is antioxidant 245, the antistatic agent is composed of octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine in a weight ratio of 1:1, and the lubricant is calcium stearate;

[0114] The preparation method of the polypropylene resin base material comprises the following process:

[0115] Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin in a weight ratio of 3:1 to obtain a first mixture;

[0116] Step (2): subjecting the first mixed material to microwave plasma treatment, with a microwave power of 450 W, a time of 180 seconds, an atmospheric pressure open working mode, and air as a working medium, to obtain a second mixed material;

[0117] Step (3): freezing the second mixed material at a temperature of -15°C for 60 minutes to obtain a third mixed material;

[0118] Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 4 times, to obtain the polypropylene resin base material;

[0119] The preparation method of the filler comprises the following steps:

[0120] Step (1): adding potassium feldspar powder, magnesium aluminum carbonate type hydrotalcite powder and γ-aminopropyltriethoxysilane in a weight ratio of 1:5:0.01 to an ethanol aqueous solution with a volume percentage of 80%, grinding and mixing, the grinding speed is 300 rpm, and the grinding time is 45 minutes to obtain a mixed slurry with a solid content of 55wt%;

[0121] Step (2): spray drying the mixed slurry to obtain a modified powder;

[0122] Step (3): Mixing the modified powder and glass fiber in a weight ratio of 4:1 to obtain the filler.

[0123] The preparation method of the above plastic composite material is the same as that of Example 1.

[0124] Example 3

[0125] This example provides a plastic composite material, which includes the following raw materials in parts by weight: 70 parts of a polypropylene resin base material, 35 parts of a filler, 1 part of an antioxidant, 0.5 parts of an antistatic agent, and 2 parts of a lubricant;

[0126] The polypropylene resin base material is prepared by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then subjected to alternating cycles of microwave plasma process and freezing process; the melt index of the first homopolymer polypropylene resin is 11 g / 10 min; the melt index of the second homopolymer polypropylene resin is 40 g / 10 min; the antioxidant is antioxidant 245, the antistatic agent is composed of octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine in a weight ratio of 1:1, and the lubricant is calcium stearate;

[0127] The preparation method of the polypropylene resin base material comprises the following process:

[0128] Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin in a weight ratio of 7:2 to obtain a first mixture;

[0129] Step (2): subjecting the first mixed material to microwave plasma treatment, with a microwave power of 760 W, a time of 90 seconds, an atmospheric pressure open working mode, and air as a working medium, to obtain a second mixed material;

[0130] Step (3): freezing the second mixed material at a temperature of -25°C for 30 minutes to obtain a third mixed material;

[0131] Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 4 times, to obtain the polypropylene resin base material;

[0132] The preparation method of the filler comprises the following steps:

[0133] Step (1): adding potassium feldspar powder, magnesium aluminum carbonate type hydrotalcite powder and γ-aminopropyltriethoxysilane in a weight ratio of 2:8:0.05 to an ethanol aqueous solution with a volume percentage of 80%, grinding and mixing, the grinding speed is 300 rpm, and the grinding time is 45 minutes to obtain a mixed slurry with a solid content of 55wt%;

[0134] Step (2): spray drying the mixed slurry to obtain a modified powder;

[0135] Step (3): Mixing the modified powder and glass fiber in a weight ratio of 4:1 to obtain the filler.

[0136] The preparation method of the above plastic composite material is the same as that of Example 1.

[0137] Comparative Example 1

[0138] This example provides a plastic composite material and a preparation method thereof. The only difference from Example 1 is that the polypropylene resin base material is obtained by directly mixing a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials (i.e., no microwave plasma process and freezing process are performed for alternating cycles); the remaining steps and parameters are the same.

[0139] Comparative Example 2

[0140] This example provides a plastic composite material and a preparation method thereof, which differs from Example 1 only in that: the polypropylene resin base material is prepared by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then subjected to alternating cycles of microwave processing and freezing processing (i.e., adjusting the microwave plasma process to a microwave process). Specifically, the preparation method of the polypropylene resin base material is adjusted as follows: step (1): mixing the first homopolymer polypropylene resin and the second homopolymer polypropylene resin in a weight ratio of 5:1.5 to obtain a first mixture; step (2): subjecting the first mixture to microwave processing at a microwave power of 550 W for 140 seconds to obtain a second mixture; step (3): subjecting the second mixture to freezing processing at a freezing temperature of -20°C for 45 minutes to obtain a third mixture; step (4): subjecting the third mixture to a cyclic processing of the microwave processing in step (2) and the freezing processing in step (3) in sequence for 4 times to obtain the polypropylene resin base material; and the remaining steps and parameters are the same.

[0141] Comparative Example 3

[0142] This example provides a plastic composite material and a preparation method thereof. The difference from Example 1 is that the polypropylene resin base material is obtained by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials and then subjected to a microwave plasma process (i.e., without freezing treatment). Specifically, the preparation method of the polypropylene resin base material is adjusted as follows: Step (1): mixing the first homopolymer polypropylene resin and the second homopolymer polypropylene resin in a weight ratio of 5:1.5 to obtain a first mixture; Step (2): subjecting the first mixture to a microwave plasma treatment with a microwave power of 550 W, a time of 560 seconds, an atmospheric pressure open working mode, and an air working medium to obtain the polypropylene resin base material; the remaining steps and parameters are the same.

[0143] Comparative Example 4

[0144] This example provides a plastic composite material and a preparation method thereof, which is different from Example 1 only in that a first homopolymer polypropylene resin with a melt index of 2.0 g / 10 min and a second homopolymer polypropylene resin with a melt index of 80 g / 10 min are used as resin raw materials; the remaining steps and parameters are the same.

[0145] Test Case

[0146] In this example, the performance of the plastic composite materials obtained in the above Examples 1 to 3 and Comparative Examples 1 to 4 was tested according to the test method disclosed in the prior art. The tensile strength was tested according to ISO527 standard, the flexural modulus was tested according to ISO178 standard, and the Izod notched impact strength was tested according to ISO179 standard. The test results are shown in Table 1.

[0147] Table 1

[0148]

[0149] It can be seen from Table 1 that, compared with Comparative Examples 1 to 3, the plastic composite material provided in the embodiment of the present invention adopts the first homopolymer polypropylene resin and the second homopolymer polypropylene resin as raw materials, and the polypropylene resin base material obtained by alternating and cyclically treating the microwave plasma process and the freezing process significantly improves the mechanical properties and stability of the material, especially the improvement of the cantilever beam notched impact strength is the most significant.

[0150] In addition, the present invention designs and splices the plastic composite material obtained in Example 1 according to the content disclosed in CN 114377412 A, and splices multiple plastic plates to obtain a closed box sample, and performs a drop stability test on it. The test results show that when the stability index S ((4H+Q) / (C / K)) of the closed box sample is 6, the closed box sample is intact and does not loosen after falling 20 times; when the stability index S ((4H+Q) / (C / K)) of the closed box sample is 1, the closed box sample loosens after falling 20 times.

[0151] In summary, the embodiments of the present invention provide a plastic composite material, a preparation method and application thereof, and a plastic spliced ​​speaker. The plastic composite material has the advantages of excellent mechanical properties such as impact strength and good stability. When used to prepare spliced ​​panels and electronic product casings, it can significantly improve the overall stability, safety and service life of the product, meet the DIY needs of consumers, and has a wide range of practical uses.

[0152] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0153] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A plastic composite material, characterized in that: The plastic composite material comprises the following raw materials in parts by weight: 55-70 parts of polypropylene resin base material, 20-35 parts of filler, 0.1-1 parts of antioxidant, 0.1-0.5 parts of antistatic agent and 0.5-2 parts of lubricant; The polypropylene resin base material is obtained by using a first homopolymer polypropylene resin and a second homopolymer polypropylene resin as raw materials, and then undergoing alternating cycles of microwave plasma processing and freezing processing; The melt index of the first homopolymer polypropylene resin is 4 to 11 g / 10 min; The melt index of the second homopolymer polypropylene resin is 30 to 40 g / 10 min.

2. The plastic composite material according to claim 1, characterized in that: The plastic composite material comprises the following raw materials in parts by weight: 63 parts of polypropylene resin base material, 30 parts of filler, 0.4 parts of antioxidant, 0.2 parts of antistatic agent and 1 part of lubricant.

3. The plastic composite material according to claim 1, characterized in that: The preparation method of the polypropylene resin base material comprises the following process: Step (1): mixing the first homopolypropylene resin and the second homopolypropylene resin to obtain a first mixture; Step (2): subjecting the first mixed material to microwave plasma treatment to obtain a second mixed material; Step (3): freezing the second mixed material to obtain a third mixed material; Step (4): subjecting the third mixed material to a cyclic treatment in sequence according to the microwave plasma treatment in step (2) and the freezing treatment in step (3), the cyclic treatment number of times being 3 to 6 times, to obtain the polypropylene resin base material; Wherein, the weight ratio of the first homopolymer polypropylene resin to the second homopolymer polypropylene resin is (3-7):(1-2); The working condition parameters of the microwave plasma treatment include: microwave power of 450-760W, time of 90-180 seconds, working mode of atmospheric pressure open, and working medium of air; The working condition parameters of the freezing treatment include: a freezing temperature of -25 to -15°C and a freezing time of 30 to 60 minutes.

4. The plastic composite material according to claim 3, characterized in that: The weight ratio of the first homopolymer polypropylene resin to the second homopolymer polypropylene resin is 5:1.5; the working condition parameters of the microwave plasma treatment include: microwave power is 550W, time is 140 seconds, working mode is atmospheric pressure open, and working medium is air; the working condition parameters of the freezing treatment include: freezing temperature is -20°C, time is 45 minutes.

5. The plastic composite material according to claim 1, characterized in that: Preparation method of the filler The process includes: Potassium feldspar powder, hydrotalcite powder and silane coupling agent in a weight ratio of (1-2):(5-8):(0.01-0.05) are added to an ethanol aqueous solution with a volume percentage of 75-85%, and ground and mixed to obtain a mixed slurry with a solid content of 50-60wt%; The mixed slurry is spray-dried to obtain a modified powder; The modified powder and glass fiber are mixed in a weight ratio of (3-5):(1-2) to obtain the filler.

6. The plastic composite material according to claim 1, characterized in that: The antioxidant includes at least one of antioxidant 245, antioxidant 626 and antioxidant 1098; the antistatic agent includes at least one of dodecyl dihydroxyethyl methyl ammonium bromide, octadecyl dihydroxyethyl methyl ammonium bromide and N-trimethylglycine; the lubricant includes at least one of N,N'-ethylene bisstearamide, polyethylene wax, oxidized polyethylene wax, calcium stearate and zinc stearate.

7. A method for preparing the plastic composite material according to any one of claims 1 to 6, characterized in that: The method for preparing the plastic composite material comprises the following steps: Mixing a polypropylene resin base material, an antioxidant, an antistatic agent and a lubricant to obtain a mixed raw material; The mixed raw material and the inorganic filler are added into a twin-screw extruder for melt extrusion, and then granulated and dried to obtain the plastic composite material.

8. Use of the plastic composite material according to any one of claims 1 to 6 and / or the plastic composite material obtained by the preparation method according to claim 7 in the preparation of spliced ​​plates and electronic product casings.

9. A plastic splicing speaker, characterized in that: The shell of the plastic spliced ​​speaker is formed by connecting and fixing spliced ​​plates, and the material of the spliced ​​plates is the plastic composite material described in any one of claims 1 to 6 and / or the plastic composite material obtained by the preparation method described in claim 7.

10. The plastic splicing speaker box according to claim 9, characterized in that: The thickness H of the spliced ​​plate is in mm, the length C of the plate is in mm, the width K of the plate is in mm and the Izod notched impact strength Q of the plastic composite material is in KJ / cm 2 The values ​​satisfy formula 1: (4H+Q) / (C / K)≥4.

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