Regenerated ABS material and preparation method thereof

Abstract

The invention relates to a regenerated ABS (acrylonitrile butadiene styrene) material and a preparation method thereof, and belongs to the technical field of ABS materials, the regenerated ABS material is prepared from the following raw material components by taking the total mass of the regenerated ABS material as 100%: 60-70% of an ABS recycled material, 15-25% of first ABS plastic, 9-12% of second ABS plastic, 5-10% of modified rubber powder and 0.1-2% of an antioxidant, and the melt flow index of the first ABS plastic under the condition of 220 DEG C / 10 kg is greater than that of the ABS recycled material under the condition of 220 DEG C / 10 kg; the preparation method comprises the following steps: swelling rubber powder with ethanol, reacting the swelled rubber powder with water glass under an alkaline condition to obtain a pretreated product, carrying out graft copolymerization and reaction on the pretreated product and gamma-urea propyl trimethoxy silane in an ethanol system, and carrying out suction filtration and vacuum drying to obtain the modified rubber powder. The regenerated ABS material prepared by the invention meets excellent melt flowability and anti-static capability, and secondary processing is not influenced.

Description

Technical Field

[0001] This application relates to the field of ABS material technology, and in particular to a recycled ABS material and its preparation method. Background Technology

[0002] Recycled ABS, due to its repeated thermo-mechanical processes, generally suffers from problems such as molecular chain degradation, high impurity levels, uneven color, and poor melt flowability, limiting its application in high-end products. To improve the melt flowability of recycled ABS, lubricants are typically added. However, these lubricants tend to migrate to the surface under high shear or high temperature conditions, causing "blooming" and affecting secondary processing (such as spraying and bonding). Furthermore, ordinary recycled ABS materials usually lack antistatic properties, making them unsuitable for direct use in electronic components. Existing methods to improve this include adding antistatic agents or conductive fillers. However, these agents and fillers have poor compatibility with recycled ABS and are prone to agglomeration or migration, leading to a deterioration in the overall performance of the recycled plastic. Summary of the Invention

[0003] The purpose of this application is to address the shortcomings of existing recycled ABS materials in that they cannot simultaneously satisfy excellent melt flowability and antistatic ability without affecting secondary processing, and thus proposes a recycled ABS material and its preparation method.

[0004] In the first aspect, the recycled ABS material provided in this application adopts the following technical solution: based on the total mass of the raw material components of the recycled ABS material as 100%, it includes: 60~70% recycled ABS material, 15~25% first ABS plastic, 9~12% second ABS plastic, 5~10% modified rubber powder and 0.1~2% antioxidant, wherein the melt flow index of the first ABS plastic at 220 ℃ / 10 kg is greater than that of the recycled ABS material at 220 ℃ / 10 kg; the modified rubber powder is prepared by: swelling the rubber powder with ethanol and reacting it with water glass under alkaline conditions to obtain a pretreated product, grafting and copolymerizing the pretreated product with γ-ureapropyltrimethoxysilane in an ethanol system, and obtaining the modified rubber powder after filtration and vacuum drying.

[0005] Through the above technical solution, the Si-O-Si network formed by water glass permeates the adhesive powder to form a hybrid adhesive powder. The γ-ureapropyltrimethoxysilane grafted onto the surface of the hybrid adhesive powder hydrolyzes to form urea groups. The nitrogen atom and carbonyl oxygen in the urea group have strong polarity and can adsorb environmental water molecules to form a hydrogen bond network. The adsorbed water dissociates in the hydrogen bond network to produce H₂. + and OH -Driven by an electric field, the urea groups migrate in a directional manner, reducing surface resistance. Simultaneously, the Si-O-Si network acts as a rigid framework, supporting the uniform distribution of urea groups and preventing the breakage of conductive pathways caused by agglomeration, thus improving charge mobility and enhancing antistatic capabilities. Furthermore, γ-ureapropyltrimethoxysilane forms an organic modification layer on the surface of the ABS powder, improving the interfacial compatibility between the modified ABS powder and the ABS matrix, reducing interfacial frictional resistance, and facilitating the flow of ABS segments during melt processing, thereby improving melt fluidity. The synergistic addition of antioxidants can prevent yellowing and embrittlement of the prepared recycled ABS material.

[0006] Optionally, based on the total mass of the raw material components of the recycled ABS material as 100%, the raw material components of the recycled ABS material include: 63~66% recycled ABS material, 18~22% first ABS plastic, 9.5~11% second ABS plastic, 5~8% modified rubber powder and 0.1~0.5% antioxidant.

[0007] Optionally, the preparation method of the modified adhesive powder includes the following steps: S1. Immerse the adhesive powder in an ethanol solution for the first mixing, and drain the ethanol solution in the system after the first mixing. Then add water glass to the drained system for the second mixing, and adjust the pH value of the system after the second mixing to 9-11. Finally, let the system after adjusting the pH value stand and filter it. The solid product obtained is the pretreated product. S2. The pretreated product is dispersed in an ethanol solution to form a swelling system, and γ-ureapropyltrimethoxysilane is added to the swelling system for a third mixing. The pH value of the system after the third mixing is adjusted to 6-7, and the third mixing system after pH adjustment is filtered. The solid product obtained by filtration is then vacuum dried at 55-65 °C to obtain modified adhesive powder.

[0008] Using the above technical solution, Si-O-Si interpenetrating network structured adhesive powder is prepared by sol-gel method, and γ-ureapropyltrimethoxysilane is grafted by hydrolysis and condensation of silanol groups in Si-O-Si interpenetrating network structured adhesive powder.

[0009] Optionally, in step S1, the ratio of the amount of adhesive powder, ethanol solution and water glass is 100 g: 300~500 mL: 10~20 mL. Specifically, for example, it can be 100 g: 300 mL: 10 mL, 100 g: 300 mL: 15 mL, 100 g: 300 mL: 20 mL, 100 g: 400 mL: 10 mL, 100 g: 400 mL: 15 mL, 100 g: 400 mL: 20 mL, 100 g: 500 mL: 10 mL, 100 g: 500 mL: 15 mL or 100 g: 500 mL: 20 mL.

[0010] By using the above technical solutions, limiting the ratio of adhesive powder to ethanol solution to greater than 100 g: 300 mL ensures that the adhesive powder is fully wetted and swollen, thereby opening the surface pore structure and facilitating subsequent water glass penetration. Limiting the ratio of adhesive powder to ethanol solution to less than 100 g: 500 mL avoids excessive dilution that could lead to excessively low system viscosity, affecting subsequent solid-liquid separation efficiency. Limiting the ratio of adhesive powder to water glass to greater than 100 g: 10 mL activates the hydroxyl groups on the adhesive powder surface, forming a Si-O-Si interpenetrating network structure within the adhesive powder. Limiting the ratio of adhesive powder to water glass to less than 100 g: 20 mL prevents excessive sodium silicate residue, thereby avoiding subsequent γ-ureapropyltrimethoxysilane hydrolysis failure.

[0011] In a specific embodiment, the volume fraction of the ethanol solution is 92-98%, and the mass fraction of the water glass is 35-40%.

[0012] Optionally, in step S2, the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane is 6 to 8:1, specifically, for example, it can be 6:1, 6.5:1, 7:1, 7.5:1 or 8:1.

[0013] By using the above technical solution, when the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane is greater than 6:1, it can avoid the self-condensation caused by excessive γ-ureapropyltrimethoxysilane, which would affect the grafting efficiency of γ-ureapropyltrimethoxysilane. When the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane is less than 8:1, it can ensure that γ-ureapropyltrimethoxysilane fully covers the activated hydroxyl groups on the surface of the pretreated product, thereby improving the grafting efficiency.

[0014] Optionally, the particle size of the adhesive powder is 20 to 60 mesh, specifically, for example, 20 mesh, 25 mesh, 30 mesh, 35 mesh, 40 mesh, 45 mesh, 50 mesh, 55 mesh or 60 mesh.

[0015] By limiting the particle size of the adhesive powder to 20-60 mesh using the above technical solution, it can be ensured that the ethanol solution and water glass can fully wet the surface of the adhesive powder, thus optimizing the surface modification efficiency of the adhesive powder. When the particle size of the adhesive powder is less than 20 mesh, the specific surface area is insufficient, resulting in a decrease in the grafting rate of γ-ureapropyltrimethoxysilane. When the particle size of the adhesive powder is greater than 60 mesh, the particles are prone to agglomeration, which hinders the etching of surface micropores by water glass and reduces the Si-O-Si network interpenetration structure formed in the adhesive powder, thereby affecting the melt flowability and antistatic efficiency of recycled ABS materials.

[0016] Optionally, the ABS recycled material has a melt flow index of 27~31 mL / 10 min at 220 ℃ / 10 kg, and the test standard is ISO 1133-1-2011; the first ABS plastic has a melt flow index of 36~39 mL / 10 min at 220 ℃ / 10 kg, and the test standard is ISO 1133-1-2011; the second ABS plastic has a melt flow index of 18~21 g / 10 min at 200 ℃ / 21.6 kg, and the test standard is ASTM D 1238.

[0017] Optionally, the ABS recycled material has an impact strength of 8~10 KJ / m² under the test standard ISO 179-2. 2 The first ABS plastic has an impact strength of 20~25 KJ / m² under the test standard ISO 179-2. 2 The second ABS plastic has a cantilever beam notched impact strength of 26~34 kg·cm / cm under the test standard ASTM D256.

[0018] Optionally, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168; preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0019] Secondly, this application provides a method for preparing the above-mentioned recycled ABS material. The method includes: melting and mixing the recycled ABS material, a first ABS plastic, an antioxidant, and 40-60 wt% modified rubber powder in the premixing zone of a twin-screw extruder; blending the resulting mixture with the second ABS plastic and the remaining modified rubber powder in the reaction zone of the twin-screw extruder; and then vacuuming, extruding, pelletizing, cooling, and drying to obtain the recycled ABS material. The temperature of the premixing zone is 160-180 °C, and the temperature of the reaction zone is 190-210 °C.

[0020] The above technical solution involves first mixing the recycled ABS material, the first ABS plastic, antioxidant, and 40-60 wt% modified rubber powder in a low-temperature premixing zone at 160-180 ℃ to form a continuous phase skeleton. The first ABS plastic has a high melt index, which ensures processing fluidity. Then, the mixture with the continuous phase skeleton is reacted with the second ABS plastic and the remaining modified rubber powder in a high-temperature reaction zone at 190-210 ℃ to induce the modified rubber powder to react with the ABS. Finally, the second ABS plastic, which has a low melt index, migrates to the interface to anchor the rubber powder under high shear, preventing the conductive network from being encapsulated and failing.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. This application uses recycled ABS material in combination with two types of ABS plastics, and controls the flowability and strength balance of the recycled ABS material by adjusting the melt rheological gradient. At the same time, a hybrid rubber powder with a Si-O-Si interpenetrating network structure is prepared by sol-gel method, and γ-ureapropyltrimethoxysilane is grafted by hydrolysis and condensation of silanol groups in the hybrid rubber powder to obtain modified rubber powder. The modified rubber powder is then used in combination with recycled ABS material and ABS plastic with a specific melt flow index relationship. This can effectively improve the melt flowability and antistatic ability of the final recycled ABS material, and also improve its strength to a certain extent. No lubricant is added to the raw material components of the recycled ABS material described in this application, so it will not cause blooming and will not affect the secondary processing of the recycled ABS material. 2. In the modified rubber powder described in this application, water glass generates an in-situ Si-O-Si inorganic network inside the rubber powder through a sol-gel process. This network forms an interpenetrating structure with the rubber network of the rubber powder, providing abundant and uniformly distributed silanol active sites for subsequent grafting of γ-ureapropyltrimethoxysilane. Compared with directly grafting silane coupling agents onto the surface of the rubber powder, the two-step modification strategy of this application significantly improves the grafting density and uniformity, thereby making the improvement of antistatic properties and melt flowability more significant. 3. In a preferred embodiment, limiting the particle size of the adhesive powder to 20-60 mesh can further improve the melt flowability and antistatic properties of the recycled ABS material; 4. In the preparation of recycled ABS material, recycled ABS material, first ABS plastic, antioxidant and 40-60 wt% modified rubber powder are first mixed in a low-temperature premixing zone to form a mixed product with a continuous phase skeleton. The first ABS plastic has a high melt index, which can ensure processing fluidity. Then, the mixed product is reacted with the second ABS plastic and the remaining modified rubber powder in a high-temperature reaction zone to induce the modified rubber powder to react with ABS. The second ABS plastic added last has a low melt index and migrates to the interface to anchor the rubber powder under high shear, avoiding the failure of the conductive network due to encapsulation. This allows the prepared recycled ABS material to simultaneously meet the requirements of excellent melt flowability and antistatic ability. Detailed Implementation

[0022] The present application will be further described in detail below with reference to specific embodiments.

[0023] The following examples further illustrate the recycled ABS material and its preparation method described in this application. These examples are implemented based on the technical solution of this application, providing detailed implementation methods and specific operating procedures; however, the scope of protection of this application is not limited to the following examples.

[0024] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0025] Rubber Powder-1: Purchased from China Rubber Resources Recycling (Suzhou) Co., Ltd., with a particle size of 25 mesh; Rubber Powder-2: Purchased from China Rubber Resources Recycling (Suzhou) Co., Ltd., with a particle size of 40 mesh; Rubber Powder-3: Purchased from China Rubber Resources Recycling (Suzhou) Co., Ltd., with a particle size of 60 mesh; Rubber Powder-4: Purchased from China Rubber Resources Recycling (Suzhou) Co., Ltd., with a particle size of 10 mesh; Rubber Powder-5: Purchased from China Rubber Resources Recycling (Suzhou) Co., Ltd., with a particle size of 80 mesh; Water glass: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number S598453, mass fraction 35%; ABS Recycled Material: This recycled material is ABS granules recycled by Chi Mei Industrial Co., Ltd. of Taiwan, model ABS018512. Its melt flow index (test method: ISO 1133-1-2011, test conditions: 220 ℃ / 10 kg) is 29.04 mL / 10 min, and its impact strength (test method: ISO 179-2) is 9.79 KJ / m². 2The tensile strength (test method ISO 527) is 43.28 MPa, the tensile breaking rate (test method ISO 527) is 34.89%, the flexural strength (test method ISO 178) is 73.55 MPa, and the flexural modulus (test method ISO 178) is 2633.68 MPa. Firstly, the ABS plastic was purchased from Chi Mei Industrial Co., Ltd. in Taiwan, model ABSPA737. Its melt flow index (test method: ISO 1133-1-2011, test conditions: 220 ℃ / 10 kg) is 37.15 mL / 10 min, and its impact strength (test method: ISO 179-2) is 21.5 KJ / m². 2 The tensile strength (test method ISO 527) is 37.75 MPa, the tensile breaking strength (test method ISO 527) is 30.8 MPa, and the elongation at break (test method ISO 527) is 17.5%. The second type of ABS plastic was purchased from Chi Mei Industrial Co., Ltd. in Taiwan. The model is ABSHR181. Its melt flow index (test method: ASTM D 1238, test conditions: 200 ℃ / 21.6 kg) is 19.9 g / 10 min, cantilever beam notched impact strength (test method: ASTM D256) is 31.1 kg·cm / cm, rubber content (test method: Fourier transform infrared analysis) is 58.1%, and tensile strength (test method: ASTM D638) is 466.2 kgf / m². 2 ; Antioxidant 1010: Chemical name is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], purchased from BASF (China) Co., Ltd.; Antioxidant 168: Chemical name is tris[2,4-di-tert-butylphenyl]phosphite, purchased from BASF (China) Co., Ltd.

[0026] Preparation Examples 1-9 and Comparative Example 1 are preparations of modified adhesive powder.

[0027] Preparation Example 1 The preparation method of modified adhesive powder includes the following steps: S1. Immerse the adhesive powder-1 in a 95% ethanol solution and stir continuously at 500 r / min for 3 h for the first mixing. Drain the ethanol solution in the first mixing system, then add water glass to the drained system and stir continuously at 600 r / min for 2 h for the second mixing. The ratio of adhesive powder-1, ethanol solution and water glass is 100 g: 300 mL: 10 mL. Adjust the pH value of the second mixing system to 10 using 1 mol / L NaOH solution. Finally, let the pH-adjusted system stand for 16 h, then repeatedly wash and filter with distilled water. The resulting solid product is the pretreated product. S2. The pretreated product is dispersed in a 95% (v / v) ethanol solution to form a swelling system. γ-Ureapropyltrimethoxysilane is added to the swelling system, and the mixture is stirred for 3 h at a stirring rate of 300 r / min for a third mixing. The mass ratio of the pretreated product to γ-Ureapropyltrimethoxysilane is 6:1. The pH of the third mixing system is then adjusted to 6 using a 1 mol / L acetic acid solution. The pH-adjusted third mixing system is then filtered using anhydrous ethanol. Finally, the solid product obtained by filtration is vacuum dried at 55 °C for 2 h to obtain modified adhesive powder.

[0028] Preparation Example 2 The preparation method was carried out as in Example 1, except that all of the adhesive powder-1 was replaced with adhesive powder-2.

[0029] Preparation Example 3 The preparation method was carried out as in Example 1, except that all of the adhesive powder-1 was replaced with adhesive powder-3.

[0030] Preparation Example 4 The preparation method was carried out as in Example 1, except that all of the adhesive powder-1 was replaced with adhesive powder-4.

[0031] Preparation Example 5 The preparation method was carried out as in Example 1, except that all of the adhesive powder-1 was replaced with adhesive powder-5.

[0032] Preparation Example 6 The preparation method was carried out in accordance with Example 2, except that the ratio of the amount of adhesive powder-2, ethanol solution and water glass was 100 g: 400 mL: 15 mL.

[0033] Preparation Example 7 The preparation method was carried out in accordance with Example 2, except that the ratio of the amount of adhesive powder-2, ethanol solution and water glass was 100 g: 500 mL: 20 mL.

[0034] Preparation Example 8 The preparation was carried out in accordance with Preparation Example 6, except that the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane was 7:1.

[0035] Preparation Example 9 The preparation was carried out in accordance with Preparation Example 6, except that the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane was 8:1.

[0036] Preparation of Comparative Example 1 The preparation method was carried out as in Example 9, except that all of the γ-ureapropyltrimethoxysilane was replaced with KH-550.

[0037] Example 1 The recycled ABS material, based on the total mass of the raw material components of the recycled ABS material as 100%, comprises: 65% recycled ABS material, 20% first ABS plastic, 9.8% second ABS plastic, 5% modified rubber powder prepared in Preparation Example 1, and 0.2% antioxidant, wherein the antioxidant is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0038] A method for preparing recycled ABS material, the method comprising: melting and mixing the recycled ABS material, a first ABS plastic, an antioxidant, and 50 wt% modified rubber powder in the premixing zone of a twin-screw extruder; blending the resulting mixture with a second ABS plastic and the remaining modified rubber powder in the reaction zone of the twin-screw extruder; and then vacuuming, extruding, pelletizing, cooling, and drying to obtain the recycled ABS material, wherein the temperature of the premixing zone is 160 ℃ and the temperature of the reaction zone is 190 ℃.

[0039] Examples 2-8 The method was implemented in accordance with Example 1, except that the modified adhesive powder prepared in Preparation Example 1 was replaced with the modified adhesive powder prepared in Preparation Examples 2 to 8.

[0040] Example 9 The recycled ABS material, based on the total mass of the raw material components of the recycled ABS material as 100%, comprises: 65% recycled ABS material, 20% first ABS plastic, 9.8% second ABS plastic, 5% modified rubber powder prepared in Preparation Example 9, and 0.2% antioxidant, wherein the antioxidant is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0041] A method for preparing recycled ABS material, the method comprising: melting and mixing the recycled ABS material, a first ABS plastic, an antioxidant, and 50 wt% modified rubber powder in the premixing zone of a twin-screw extruder; blending the resulting mixture with a second ABS plastic and the remaining modified rubber powder in the reaction zone of the twin-screw extruder; and then vacuuming, extruding, pelletizing, cooling, and drying to obtain the recycled ABS material, wherein the temperature of the premixing zone is 160 ℃ and the temperature of the reaction zone is 190 ℃.

[0042] Example 10 The method of Example 1 is followed, except that, based on the total mass of the raw material components of the recycled ABS material as 100%, the raw material components of the recycled ABS material include: 70% recycled ABS material, 15% first ABS plastic, 9% second ABS plastic, 5% modified rubber powder prepared in Preparation Example 1, and 1% antioxidant.

[0043] Example 11 The method of Example 1 is followed, except that, based on the total mass of the raw material components of the recycled ABS material being 100%, the raw material components of the recycled ABS material include: 60% recycled ABS material, 20% first ABS plastic, 9% second ABS plastic, 10% modified rubber powder prepared in Preparation Example 1, and 1% antioxidant.

[0044] Comparative Example 1 The procedure was carried out in accordance with Example 1, except that all the modified rubber powder prepared in Preparation Example 1 was replaced with the modified rubber powder prepared in Comparative Example 1.

[0045] Comparative Example 2 The method of Example 1 is followed, except that the second ABS plastic is completely replaced with the first ABS plastic. Specifically, the raw material components of the recycled ABS material are: 65% recycled ABS material, 29.8% first ABS plastic, 5% modified rubber powder prepared in Preparation Example 1, and 0.2% antioxidant, based on the total mass of the raw material components of the recycled ABS material as 100%.

[0046] Comparative Example 3 The method of Example 1 is followed, except that the raw material composition of the recycled ABS material includes: 50% recycled ABS material, 22.3% first ABS plastic, 22.3% second ABS plastic, 5% modified rubber powder prepared in Example 1, and 0.2% antioxidant.

[0047] Comparative Example 4 The process was carried out in accordance with Example 1, except that in the preparation of the recycled ABS material, the recycled ABS material, the first ABS plastic, the second ABS plastic, the antioxidant and the modified rubber powder were melt-mixed in a twin-screw extruder at a temperature of 190 °C. Then, the mixture was vacuumed, extruded, pelletized, cooled and dried to obtain the recycled ABS material.

[0048] Comparative Example 5 The method of Example 1 is followed, except that no modified adhesive powder is added. Specifically, the raw material components of the recycled ABS material are: 68% recycled ABS, 21% first ABS plastic, 10.8% second ABS plastic and 0.2% antioxidant, based on the total mass of the raw material components of the recycled ABS material as 100%.

[0049] Comparative Example 6 The procedure was carried out as described in Example 1, except that the modified rubber powder prepared in Preparation Example 1 was replaced with unmodified raw rubber powder-1 (25 mesh).

[0050] Comparative Example 7 The procedure was carried out in accordance with Example 1, except that the modified adhesive powder prepared in Preparation Example 1 was replaced with adhesive powder that was only treated with water glass but not grafted with γ-ureapropyltrimethoxysilane (i.e., the pretreated product obtained in step S1 of Preparation Example 1).

[0051] Test case Melt flow index: conducted according to ISO 1133-1-2011, under test conditions of 220 ℃ and 10 kg; Volume resistivity: Tested according to GB / T 15662-1995; Charpy impact strength: Tested according to ISO 179, under test conditions of 4 mmt.

[0052] The melt flow index and Charpy impact strength of the recycled ABS materials prepared in Examples 1-11 and Comparative Examples 1-7 were measured respectively. The recycled ABS materials prepared in Examples 1-11 and Comparative Examples 1-7 were molded into ABS plastic sheets with the same shape and size and a thickness of 0.3 mm. The volume resistivity of the ABS plastic sheets prepared in Examples 1-11 and Comparative Examples 1-7 was measured respectively. The test results are shown in Table 1. Table 1

[0053] As can be seen from Table 1, this application uses recycled ABS material with a certain melt flow index relationship to combine with two types of ABS plastics, which can improve the fluidity and strength of the prepared recycled ABS material and achieve a balance. Furthermore, a hybrid rubber powder with a Si-O-Si interpenetrating network structure is prepared by sol-gel method. γ-Ureapropyltrimethoxysilane is grafted onto the silanol groups in the hybrid rubber powder through hydrolysis and condensation to obtain a modified rubber powder. This modified rubber powder is then combined with recycled ABS material and ABS plastic with a specific melt flow index relationship, which can effectively improve the melt flowability and antistatic properties of the final prepared recycled ABS material. In Comparative Example 1, KH-550 was grafted onto the hybrid rubber powder during the preparation of the modified rubber powder. Since KH-550 does not have urea groups, the melt flow, antistatic ability and Charpy impact strength of the recycled ABS material prepared by Comparative Example 1 are all low. Comparative Example 2 did not add a second ABS plastic with a lower melt flow index when preparing recycled ABS material, and the prepared recycled ABS material had lower melt flow and Charpy impact strength. In Comparative Example 3, when preparing recycled ABS material, the content of recycled ABS was reduced while keeping the content of the two types of ABS plastics consistent. The resulting recycled ABS material had lower melt flowability and Charpy impact strength.

[0054] In Comparative Example 4, when preparing recycled ABS material, all raw materials were mixed and melted together. The resulting recycled ABS material had low melt flowability and low antistatic properties.

[0055] Comparative Example 5 did not add modified rubber powder when preparing recycled ABS material. The prepared recycled ABS material had low melt flowability and Charpy impact strength, and did not have antistatic properties. In Comparative Example 6, unmodified virgin rubber powder was used instead of modified rubber powder when preparing recycled ABS material. Although the addition of rubber powder improved the impact strength to a certain extent, the melt flow was limited due to the poor interfacial compatibility between the virgin rubber powder and the ABS matrix, and the antistatic ability was not significantly improved. Comparative Example 7 used a rubber powder that was only treated with water glass but not grafted with γ-ureapropyltrimethoxysilane when preparing recycled ABS material. Although the Si-O-Si network interpenetrating structure formed by water glass in the rubber powder improved the impact strength and melt flow to a certain extent, the improvement in antistatic ability was limited due to the lack of urea group introduction, and the interfacial compatibility was not as good as that of the fully modified rubber powder.

[0056] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application.

Claims

1. A recycled ABS material, characterized in that, The recycled ABS material comprises, by weight (100%): 60-70% recycled ABS, 15-25% first ABS plastic, 9-12% second ABS plastic, 5-10% modified rubber powder, and 0.1-2% antioxidant. The first ABS plastic has a higher melt flow index at 220°C / 10 kg than the recycled ABS at the same temperature. The modified rubber powder is prepared by: swelling the rubber powder with ethanol and reacting it with water glass under alkaline conditions to obtain a pretreated product; grafting and copolymerizing the pretreated product with γ-ureapropyltrimethoxysilane in an ethanol system; and obtaining the modified rubber powder after filtration and vacuum drying.

2. The recycled ABS material according to claim 1, characterized in that, Based on the total mass of the raw material components of the recycled ABS material as 100%, the raw material components of the recycled ABS material include: 63~66% recycled ABS material, 18~22% first ABS plastic, 9.5~11% second ABS plastic, 5~8% modified rubber powder and 0.1~0.5% antioxidant.

3. The recycled ABS material according to claim 1, characterized in that, The preparation method of the modified adhesive powder includes the following steps: S1. Immerse the adhesive powder in an ethanol solution for the first mixing, and drain the ethanol solution in the system after the first mixing. Then add water glass to the drained system for the second mixing, and adjust the pH value of the system after the second mixing to 9-11. Finally, let the system after adjusting the pH value stand and filter it. The solid product obtained is the pretreated product. S2. The pretreated product is dispersed in an ethanol solution to form a swelling system, and γ-ureapropyltrimethoxysilane is added to the swelling system for a third mixing. The pH value of the system after the third mixing is adjusted to 6-7, and the third mixing system after pH adjustment is filtered. The solid product obtained by filtration is then vacuum dried at 55-65 °C to obtain modified adhesive powder.

4. The recycled ABS material according to claim 3, characterized in that, In step S1, the ratio of the amount of adhesive powder, ethanol solution and water glass is 100 g: 300~500 mL: 10~20 mL.

5. The recycled ABS material according to claim 3 or 4, characterized in that, In step S2, the mass ratio of the pretreated product to γ-ureapropyltrimethoxysilane is 6~8:

1.

6. The recycled ABS material according to claim 3 or 4, characterized in that, The particle size of the adhesive powder is 20-60 mesh.

7. The recycled ABS material according to claim 1 or 2, characterized in that, The ABS recycled material has a melt flow index of 27~31 mL / 10 min at 220 ℃ / 10 kg, and the test standard is ISO 1133-1-2011; the first ABS plastic has a melt flow index of 36~39 mL / 10 min at 220 ℃ / 10 kg, and the test standard is ISO 1133-1-2011; the second ABS plastic has a melt flow index of 18~21 g / 10 min at 200 ℃ / 21.6 kg, and the test standard is ASTM D1238.

8. The recycled ABS material according to claim 7, characterized in that, The impact strength of the recycled ABS material under the test standard ISO179-2 is 8~10 KJ / m. 2 The first ABS plastic has an impact strength of 20~25 KJ / m² under the test standard ISO 179-2. 2 The second ABS plastic has a cantilever beam notched impact strength of 26~34 kg·cm / cm under the test standard ASTM D256.

9. The recycled ABS material according to claim 1 or 2, characterized in that, The antioxidant is a mixture of antioxidant 1010 and antioxidant 168, wherein the mass ratio of antioxidant 1010 to antioxidant 168 is 1:

1.

10. A method for preparing the recycled ABS material according to any one of claims 1 to 9, characterized in that, The preparation method includes: melting and mixing the recycled ABS material, the first ABS plastic, the antioxidant, and 40-60 wt% modified rubber powder in the premixing zone of a twin-screw extruder; blending the resulting mixture with the second ABS plastic and the remaining modified rubber powder in the reaction zone of the twin-screw extruder; then vacuuming, extruding, pelletizing, cooling, and drying to obtain recycled ABS material. The temperature of the premixing zone is 160-180 ℃, and the temperature of the reaction zone is 190-210 ℃.

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