A recycled transparent polycarbonate material and a method for producing the same

Abstract

The present application belongs to the technical field of polycarbonate recycling, and relates to a regenerated transparent polycarbonate material and a preparation method thereof. The material comprises the following components in parts by weight: 95.5-99.87 parts of waste polycarbonate chips, 0.1-0.5 parts of an antioxidant compound, 0.01-3.0 parts of a chain extender, and 0.01-0.5 parts of a lubricant. The preparation method comprises the following steps: (1) drying; (2) mixing; and (3) melt granulation. The regenerated transparent polycarbonate material obtained by the present application has excellent mechanical properties and color stability, and is more likely to replace the application of virgin polycarbonate materials, thereby achieving effective recycling and utilization of waste transparent polycarbonate products.

Description

Technical Field

[0001] This invention belongs to the field of polycarbonate recycling technology, and relates to a recycled transparent polycarbonate material and its preparation method. Background Technology

[0002] Polycarbonate (PC) is the only one of the five major engineering plastics with good transparency. It boasts excellent light transmittance, high impact resistance, heat resistance, V2 flame retardancy, and dimensional stability, making it widely used in electronics, automotive, aerospace, medical devices, and optical lenses. In 2022, my country's polycarbonate production capacity reached 3.2 million tons, a 29.6% increase compared to 2021. This rapid expansion of polycarbonate production capacity inevitably leads to an increase in waste polycarbonate. Recycling recycled polycarbonate can effectively reduce the continuous increase in waste. However, current technologies primarily focus on chemical recycling, modified functionalization recycling, and physical and mechanical property restoration recycling for waste polycarbonate.

[0003] Chinese patent CN107345060A discloses a formulation and preparation method for recycled white non-magnetic reinforced plastic based on white polycarbonate recycled plastic. The formulation comprises the following components by weight percentage: pulverized white polycarbonate recycled material; toughening agent MBS; titanium dioxide R103; dispersant EB-FF; whitening agent; light stabilizer 791; ultraviolet absorber UV531; antioxidant 1010; antioxidant 168; the total of the above components is 100%. The advantage of this invention is that after processing the recycled white polycarbonate material using the above preparation method, discoloration, impurities, and magnetic substances present in the material are removed. The yellowish or blackish material is adjusted to be more white and bluish, meeting the strict color requirements of the product. This method only provides a physical recycling method for non-transparent polycarbonate materials and cannot be applied to the recycling of transparent polycarbonate materials.

[0004] Chinese patent CN108864676A discloses a weather-resistant matte polycarbonate recycled material and its preparation method. This invention improves the weather resistance and processing performance of polycarbonate by adding a matting agent, antioxidant, light stabilizer, and UV absorber, resulting in a modified material with a relatively stable melt flow index, whose performance is not significantly different from virgin material. However, this physically recycled material is a matte polycarbonate, which has lost its light transmittance and can no longer replace virgin polycarbonate materials in transparent applications.

[0005] Chinese patent CN102911397A discloses a recycling process for waste polycarbonate (PC) materials. The process includes crushing the waste PC material and dissolving it in an organic solvent to form a homogeneous solution; adding an adsorbent to the homogeneous solution for decolorization and removal of insoluble substances; and then filtering and crystallizing to obtain the desired crystalline polycarbonate material. This invention solves the problems of controlling the intrinsic viscosity, crystallization, and impurity removal in recycled polycarbonate. The entire process does not involve adding water, reducing environmental pollution. The intrinsic viscosity of the recycled PC product reaches 0.77 dL / g, and the purity reaches 99.5%, achieving a level comparable to virgin material. However, this invention requires a large amount of dissolving solvent and has high purity requirements for the waste raw materials, making industrialization difficult.

[0006] Chinese Patent CN113214629A discloses a transparent, highly wear-resistant, and stain-resistant recycled polycarbonate material and its preparation method. The material includes a recycled polycarbonate substrate and a hardening coating applied to the recycled polycarbonate substrate. The recycled polycarbonate substrate contains the following components by mass percentage: 20-70% recycled polycarbonate, 5-10% polystyrene, 3-10% compatibilizer, 0.3-0.6% antioxidant, and 0.2-0.8% ultraviolet absorber; the balance is virgin polycarbonate. The advantage of this invention is that the resulting transparent, highly wear-resistant, and stain-resistant recycled polycarbonate material has excellent mechanical properties and good heat resistance, realizing the high-value application of waste polycarbonate plastics. However, the preparation method of the recycled polycarbonate in this invention requires the addition of polystyrene and virgin polycarbonate, and the hardening coating is required to enhance transparency, making the process complex. The preparation of recycled transparent polycarbonate materials still needs further research and development.

[0007] Chinese patent CN111073245A discloses a recycled polycarbonate composite material and its preparation method. This invention uses a highly reactive graft polymer containing oxazoline groups as a chain extender in PC, introduces modified nano-silica to increase crosslinking density, and adds appropriate amounts of antioxidants and lubricants to increase the molecular weight and melt viscosity of the recycled PC, ultimately obtaining a recycled polycarbonate composite material with good impact resistance. However, the technical solution of this patent achieves recycled polycarbonate material through chain extension repair, primarily aiming to restore the physical and mechanical properties of the recycled polycarbonate material, rather than focusing on its transparency.

[0008] In summary, existing polycarbonate recycling technologies suffer from problems such as solvent pollution and difficulties in industrialization through chemical recycling. Modified functional recycling and physical and mechanical property restoration recycling mainly aim to improve the physical properties of waste polycarbonate materials, but they damage the transparency of polycarbonate materials and cannot completely replace virgin polycarbonate. Therefore, it is essential to invent a transparent recycled polycarbonate material that can replace virgin polycarbonate and its preparation method. This would reduce environmental pollution, save resources, and contribute to the sustainable development of society and the economy. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing a recycled transparent polycarbonate material with good transparency and physical, thermal, and aging properties close to those of virgin polycarbonate material, as well as a method for its preparation.

[0010] One objective of this invention is achieved through the following technical solution:

[0011] A recycled transparent polycarbonate material, comprising the following components in parts by weight:

[0012]

[0013] Preferably, the waste polycarbonate chips are prepared from waste transparent polycarbonate products through processes including collection, sorting, crushing, washing, impurity removal, and drying.

[0014] Preferably, waste transparent polycarbonate products can be listed as transparent products such as polycarbonate sheets, polycarbonate water bottles or cups, car lights, discs, hollow boards, telecommunications equipment, and textile accessories.

[0015] Preferably, the pH value of the waste polycarbonate chips is 6.5 to 8.5.

[0016] Preferably, the chain extender is a copolymer containing epoxy functional groups, each copolymer molecule containing 2 to 10 active epoxy groups, such as at least one of BASF ADR-4400 and BASF ADR-4468.

[0017] The lubricant is not particularly limited and can be any component that can be used in plastic products to reduce frictional resistance during processing, such as one or more of pentaerythritol stearate, ethylene bis-stearamide, and ethylene bis-stearamide.

[0018] Preferably, the antioxidant complex comprises the following components by mass fraction:

[0019] Main antioxidant 40-80%,

[0020] 15-40% auxiliary antioxidants

[0021] Free radical scavenger 5-20%.

[0022] Preferably, the primary antioxidant is a hindered phenolic antioxidant. More preferably, the hindered phenolic antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionate], octadecyl β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate, and 2,6-di-tert-butyl-4-methylphenol.

[0023] Preferably, the auxiliary antioxidant is a phosphite antioxidant. More preferably, the phosphite antioxidant includes one or more of tris(2,4-di-tert-butyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and bisoctadecylpentaerythritol diphosphite.

[0024] Preferably, the free radical scavenger is one or more of the following: di(hydrogenated tallow alkyl)amine oxide, 2-acrylate-2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-tolyl ester, 2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate, and 2-(2-hydroxy-3-tert-butyl-5-methylbenzyl)-4-methyl-6-tert-butylphenyl acrylate.

[0025] The antioxidant complex used in this invention is a ternary complex, wherein the primary antioxidant mainly inhibits the formation of peroxide free radicals ROO· in polycarbonate, the secondary antioxidant mainly inhibits the formation of peroxide ROOH, and the free radical scavenger mainly inhibits the formation of free radical R·. The three synergistic effects can effectively prevent the generation of free radicals, peroxide free radicals, and peroxides in waste polycarbonate melt, thereby protecting the physical properties of polycarbonate and improving the yellowness and transparency of recycled polycarbonate materials.

[0026] Another objective of this invention is achieved through the following technical solution:

[0027] A method for preparing a recycled transparent polycarbonate material includes the following steps:

[0028] (1) Dry the waste polycarbonate chips at 90-150°C for 1-4 hours;

[0029] Drying the raw materials to remove moisture can effectively reduce the hydrolysis of waste polycarbonate in the main screw. Compared with water molecule traps, direct drying without adding other substances can ensure the removal of moisture while also maintaining the transparency and physical properties of polycarbonate.

[0030] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant from (1) into a mixer and mix for 5 to 20 minutes to obtain the mixture.

[0031] (3) The mixture from (2) above is fed into a two-stage screw extruder, which includes a main screw and a sub-screw. The mixture is fed into the feed port of the main screw and the chain extender is fed into the feed port of the sub-screw. Transparent polycarbonate recycled material is obtained by melt extrusion and granulation.

[0032] The mixture of waste polycarbonate chips, antioxidant compound, and lubricant is fed into the feed port of the main screw, while the chain extender is fed into the feed port of the daughter screw. The purpose is to allow the antioxidant compound to first form a protective layer on the waste polycarbonate melt in the main screw, inhibiting the generation of free radicals, peroxides, and peroxides in the melt. This avoids excessive free radicals and peroxides affecting the chain extender, effectively improving the chain extender's ability to repair polycarbonate molecular chains in the daughter screw.

[0033] Preferably, the screw speed of the main screw compressor is controlled at 10-100 rpm, and the temperature of each zone is set at 180-280℃; the screw speed of the daughter screw compressor is controlled at 200-500 rpm, and the temperature of each zone is set at 230-280℃.

[0034] Preferably, the main screw compressor is a single screw, and the sub-screw compressor is a twin screw. The single screw of the main screw compressor improves the feeding capacity, avoids jamming caused by unevenly shaped fragments of recycled material, and at the same time, the single screw has low shearing force. When used with the lubricant in the formula, the molecular damage caused by screw shearing can be minimized.

[0035] Preferably, both the main screw compressor and the slave screw compressor are equipped with vacuum systems, and both operate under vacuum. This dual vacuum system effectively removes and isolates water, oxygen, and small molecules from the entire processing system. The vacuum system of the main screw compressor removes water molecules and decomposed small molecules from the waste polycarbonate melt through vacuum adsorption, while maintaining the main screw compressor system under vacuum to prevent the hot water oxygen decomposition reaction of the polycarbonate by oxygen and water molecules. The vacuum system of the slave screw compressor further enhances the devolatilization and isolation effects, significantly improving the effectiveness of additives and the purity of the materials.

[0036] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0037] 1. Beneficial effects of the antioxidant complex of the present invention: The antioxidant complex used in the present invention is a ternary complex, which can effectively inhibit peroxide free radicals ROO·, peroxide ROOH, and free radicals R·. The three synergistic effects can effectively prevent the generation of peroxide free radicals, peroxides and free radicals in waste polycarbonate melt, thereby protecting the performance and color stability of polycarbonate.

[0038] 2. Beneficial effects of the equipment and process of the present invention:

[0039] ① Drying the raw materials effectively reduces the hydrolysis of waste polycarbonate in the main screw. Compared to water molecule traps, direct drying does not require the addition of other substances, ensuring the removal of moisture while maintaining the transparency and physical properties of the polycarbonate. ② The single screw of the main screw compressor improves the feeding capacity, avoiding jamming caused by unevenly shaped fragments of recycled material. At the same time, the single screw has low shearing force, which, when used in conjunction with the lubricant in the formula, minimizes molecular damage caused by screw shearing. ③ The adoption of a dual vacuum system greatly improves the effectiveness of additives and the purity of materials.

[0040] 3. The beneficial effects of adding chain extender and the addition process of the present invention: The chain extender is fed between the main screw and the daughter screw. The antioxidant complex can first form a protection for the waste polycarbonate melt in the main screw, inhibit the generation of free radicals, peroxide free radicals and peroxides in the melt, and avoid the influence of excessive free radicals and peroxides on the chain extender. This can effectively improve the chain extender's ability to repair polycarbonate molecular chains in the daughter screw. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the two-stage screw extruder of the present invention. Detailed Implementation

[0042] The technical solution of the present invention will be further described and illustrated below with reference to specific embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of helping to understand the present invention and are not intended to limit the specific scope of the present invention. Furthermore, the accompanying drawings used herein are merely for better illustrating the content disclosed in the present invention and do not limit the scope of protection. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used in the art, and the methods used in the embodiments are all conventional methods in the art.

[0043] Figure 1This is a schematic diagram of the structure of the two-stage screw extruder of the present invention. The two-stage screw extruder includes a main screw and a daughter screw. The main screw is a single screw, and the daughter screw is a twin screw. Both the main screw and the daughter screw are equipped with a vacuum system, and the main screw and the daughter screw operate under vacuum. A mixture of waste polycarbonate chips, antioxidant compound, and lubricant is fed into the feed port of the main screw, melt-extruded through the main screw, and then fed into the feed port of the daughter screw. At the same time, a chain extender is fed into the feed port of the daughter screw. After melt extrusion and granulation, a transparent recycled polycarbonate material is obtained.

[0044] Example 1

[0045] The recycled transparent polycarbonate material of this embodiment comprises the following components in parts by weight:

[0046] Waste polycarbonate chips: 95.5 parts, antioxidant compound: 0.5 parts, chain extender: 3.0 parts, lubricant: 0.5 parts.

[0047] The waste polycarbonate chips are transparent polycarbonate sheet chips with a pH of 7.5. The antioxidant complex consists of the following components by weight percentage: 60.00% primary antioxidant (pentaerythritol tetrakis[β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionate]), 27.50% secondary antioxidant (tris(2,4-di-tert-butyl)phosphite), 12.5% ​​free radical scavenger (2-acrylate-2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-tolyl ester), chain extender is BASF ADR-4400, and lubricant is pentaerythritol stearate.

[0048] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0049] (1) Dry the waste polycarbonate chips at 100℃ for 2 hours;

[0050] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant in a mixer and mix for 15 minutes to obtain the mixture.

[0051] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with vacuum systems, and both are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 100 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and zone 6 are 180°C, 200°C, 240°C, 250°C, 260°C, and 250°C, respectively. The screw speed of the slave screw is controlled at 400 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and die head are 260°C.

[0052] The physical property test results of the recycled transparent polycarbonate material prepared in Example 1 are shown in Table 1.

[0053] Example 2

[0054] The recycled transparent polycarbonate material of this embodiment comprises the following components in parts by weight:

[0055] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0056] The waste polycarbonate chips were automotive headlight chips with a pH of 7.5. The antioxidant complex consisted of the following components by weight percentage: 60.00% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 27.50% secondary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), 12.5% ​​free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), chain extender BASF ADR-4468, and lubricant ethylene bis-stearamide.

[0057] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0058] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0059] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0060] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0061] The physical property test results of the recycled transparent polycarbonate material prepared in Example 2 are shown in Table 1.

[0062] Example 3

[0063] The recycled transparent polycarbonate material of this embodiment comprises the following components in parts by weight:

[0064] Waste polycarbonate chips: 99.87 parts, antioxidant compound: 0.1 parts, chain extender: 0.01 parts, lubricant: 0.01 parts.

[0065] The waste polycarbonate chips are transparent polycarbonate water bottle and cup chips. The pH value of the waste polycarbonate chips is 7.5. The antioxidant complex consists of the following components by weight percentage: 60.00% primary antioxidant (2,6-di-tert-butyl-4-methylphenol), 27.50% secondary antioxidant (dioctadecyl pentaerythritol diphosphite), 12.50% free radical scavenger (di(hydrogenated tallow alkyl)amine), chain extender is BASF ADR-4400, and lubricant is ethylene bis-stearamide.

[0066] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0067] (1) Dry the waste polycarbonate chips at 140℃ for 4 hours;

[0068] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 9 minutes to obtain the mixture.

[0069] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with vacuum systems, and both are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 10 rpm, the temperature of zone 1 is 190℃, zone 2 is 220℃, zone 3 is 260℃, zone 4 is 270℃, zone 5 is 280℃, and zone 6 is 270℃; the screw speed of the slave screw is controlled at 200 rpm, the temperature of zone 1 is 250℃, zone 2 is 260℃, zone 3 is 270℃, zone 4 is 260℃, zone 5 is 260℃, and the die head temperature is 280℃.

[0070] The physical property test results of the recycled transparent polycarbonate material prepared in Example 3 are shown in Table 1.

[0071] Example 4

[0072] The recycled transparent polycarbonate material of this embodiment comprises the following components in parts by weight:

[0073] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0074] The waste polycarbonate chips are transparent product chips of discs and hollow boards. The pH value of the waste polycarbonate chips is 7.5. The antioxidant complex consists of the following components by weight percentage: 80.00% primary antioxidant (tetra-[β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionic acid] pentaerythritol), 15.00% secondary antioxidant (bis(octadecyl) pentaerythritol diphosphite), 5.00% free radical scavenger (2-(2-hydroxy-3-tert-butyl-5-methylbenzyl)-4-methyl-6-tert-butylphenyl acrylate), chain extender is BASF ADR-4468, and lubricant is ethylene bis-stearamide.

[0075] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0076] (1) Dry the waste polycarbonate chips at 150°C for 2 hours;

[0077] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 6 minutes to obtain the mixture;

[0078] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent recycled polycarbonate material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with vacuum systems, and both are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 80 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and zone 6 are 190°C, 230°C, 260°C, 270°C, 280°C, and 270°C, respectively. The screw speed of the slave screw is controlled at 500 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and die head are 280°C.

[0079] The physical property test results of the recycled transparent polycarbonate material prepared in Example 4 are shown in Table 1.

[0080] Example 5

[0081] The recycled transparent polycarbonate material of this embodiment comprises the following components in parts by weight:

[0082] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0083] The waste polycarbonate chips are transparent polycarbonate sheet chips with a pH of 7.5. The antioxidant complex consists of the following components by weight percentage: 40.00% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 40.00% secondary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), 20.00% free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), chain extender is BASF ADR-4468, and lubricant is ethylene bis-stearamide.

[0084] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0085] (1) Dry the waste polycarbonate chips at 90°C for 3 hours;

[0086] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 5 minutes to obtain the mixture.

[0087] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent recycled polycarbonate material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with vacuum systems, and both are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 30 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0088] The physical property test results of the recycled transparent polycarbonate material prepared in Example 5 are shown in Table 1.

[0089] Comparative Example 1

[0090] The recycled transparent polycarbonate material of Comparative Example 1 comprises the following components in parts by weight:

[0091] Waste polycarbonate chips: 97.7 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0092] The waste polycarbonate chips were automotive headlight chips with a pH of 7.5. The chain extender was BASF ADR-4468, and the lubricant was ethylene bis-stearamide.

[0093] The recycled polycarbonate material of Comparative Example 1 was prepared by the following steps:

[0094] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0095] (2) Place the dried waste polycarbonate chips and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0096] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0097] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 1 are shown in Table 1.

[0098] Comparative Example 2

[0099] The recycled transparent polycarbonate material of Comparative Example 2 comprises the following components in parts by weight:

[0100] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0101] The waste polycarbonate chips were automotive headlight chips with a pH of 7.5. The antioxidant complex consisted of the following components by weight percentage: 87.50% auxiliary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), 12.5% ​​free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), chain extender BASF ADR-4468, and lubricant ethylene bis-stearamide.

[0102] The recycled transparent polycarbonate material in this embodiment is prepared by the following steps:

[0103] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0104] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0105] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0106] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 2 are shown in Table 1.

[0107] Comparative Example 3

[0108] Comparative Example 3, a recycled transparent polycarbonate material, comprises the following components in parts by weight:

[0109] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0110] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The antioxidant complex consists of the following components by weight percentage: 87.50% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 12.5% ​​free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), chain extender is BASF ADR-4468, and lubricant is ethylene bis-stearamide.

[0111] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0112] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0113] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0114] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0115] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 3 are shown in Table 1.

[0116] Comparative Example 4

[0117] Comparative Example 4: The recycled transparent polycarbonate material comprises the following components in parts by weight:

[0118] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0119] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The antioxidant complex consists of the following components by weight percentage: 72.50% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 27.50% secondary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), chain extender BASF ADR-4468, and lubricant ethylene bis-stearamide.

[0120] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0121] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0122] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0123] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0124] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 4 are shown in Table 1.

[0125] Comparative Example 5

[0126] Comparative Example 5: The recycled transparent polycarbonate material comprises the following components in parts by weight:

[0127] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0128] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The main antioxidant is an antioxidant complex (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), the chain extender is BASF ADR-4468, and the lubricant is ethylene bis-stearamide.

[0129] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0130] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0131] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0132] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0133] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 5 are shown in Table 1.

[0134] Comparative Example 6

[0135] The recycled transparent polycarbonate material of Comparative Example 6 comprises the following components in parts by weight:

[0136] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0137] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The antioxidant complex is an auxiliary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), the chain extender is BASF ADR-4468, and the lubricant is ethylene bis-stearamide.

[0138] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0139] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0140] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0141] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0142] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 6 are shown in Table 1.

[0143] Comparative Example 7

[0144] Comparative Example 7, a recycled transparent polycarbonate material, comprises the following components in parts by weight:

[0145] Waste polycarbonate chips: 97.4 parts, antioxidant compound: 0.3 parts, chain extender: 2.0 parts, lubricant: 0.3 parts.

[0146] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The antioxidant complex is a free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), the chain extender is BASF ADR-4468, and the lubricant is ethylene bis-stearamide.

[0147] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0148] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0149] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0150] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0151] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 7 are shown in Table 1.

[0152] Comparative Example 8

[0153] Comparative Example 8, a recycled transparent polycarbonate material, comprises the following components in parts by weight:

[0154] Waste polycarbonate chips: 99.4 parts, antioxidant compound: 0.3 parts, lubricant: 0.3 parts.

[0155] The waste polycarbonate chips are automotive headlight chips with a pH of 7.5. The antioxidant complex consists of the following components by weight percentage: 60.00% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 27.50% secondary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), 12.5% ​​free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-bis(2-methylbut-2-yl)phenyl acrylate), and the lubricant is ethylene bis-stearamide.

[0156] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0157] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0158] (2) Place the dried waste polycarbonate chips, antioxidant complex and lubricant into a mixer and mix for 12 minutes to obtain the mixture.

[0159] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. Transparent recycled polycarbonate material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with vacuum systems, and both are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and zone 6 are 185°C, 210°C, 250°C, 260°C, 270°C, and 260°C, respectively. The screw speed of the slave screw is controlled at 300 rpm, and the temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, and die head are 270°C.

[0160] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 8 are shown in Table 1.

[0161] Comparative Example 9

[0162] Comparative Example 9, a recycled transparent polycarbonate material, comprises the following components in parts by weight:

[0163] Waste polycarbonate chips: 97.7 parts, antioxidant complex: 0.3 parts, chain extender: 2.0 parts.

[0164] The waste polycarbonate chips were automotive headlight chips with a pH of 7.5. The antioxidant complex consisted of the following components by weight percentage: 60.00% primary antioxidant (β-(4-hydroxyphenyl-3,5-di-tert-butyl)propionate octadecyl alcohol ester), 27.50% secondary antioxidant (bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite), 12.5% ​​free radical scavenger (2-{1-[2-hydroxy-3,5-bis(2-methylbut-2-yl)phenyl]ethyl}-4,6-di(2-methylbut-2-yl)phenyl acrylate), and the chain extender was BASF ADR-4468.

[0165] The recycled transparent polycarbonate material in this comparative example was prepared by the following steps:

[0166] (1) Dry the waste polycarbonate chips at 120°C for 3 hours;

[0167] (2) Place the dried waste polycarbonate chips and antioxidant complex into a mixer and mix for 12 minutes to obtain the mixture.

[0168] (3) The mixture from (2) is fed into the feed port of the main screw of a two-stage screw extruder. After melt extrusion by the main screw, it is fed into the feed port of the slave screw. At the same time, a chain extender is fed into the feed port of the slave screw. Transparent polycarbonate recycled material is obtained through melt extrusion and granulation. Both the main screw and the slave screw are equipped with a vacuum system, and both the main screw and the slave screw are under vacuum during the melt extrusion process. The screw speed of the main screw is controlled at 50 rpm, the temperature of zone 1 is 185℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 250℃, the temperature of zone 4 is 260℃, the temperature of zone 5 is 270℃, and the temperature of zone 6 is 260℃; the screw speed of the slave screw is controlled at 300 rpm, the temperature of zone 1 is 240℃, the temperature of zone 2 is 250℃, the temperature of zone 3 is 260℃, the temperature of zone 4 is 250℃, the temperature of zone 5 is 250℃, and the die head temperature is 270℃.

[0169] The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 9 are shown in Table 1.

[0170] Comparative Example 10

[0171] The only difference between Comparative Example 10 and Example 2 is that the chain extender is fed into the main feed port. The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 10 are shown in Table 1.

[0172] Comparative Example 11

[0173] The only difference between Comparative Example 11 and Example 2 is that the host machine does not use a vacuum system. The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 11 are shown in Table 1.

[0174] Comparative Example 12

[0175] The only difference between Comparative Example 12 and Example 2 is that the sub-machine does not use a vacuum system. The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 12 are shown in Table 1.

[0176] Comparative Example 13

[0177] The only difference between Comparative Example 13 and Example 2 is that a dual vacuum system was not used. The physical property test results of the recycled transparent polycarbonate material prepared in Comparative Example 13 are shown in Table 1.

[0178] The physical property test results of the materials prepared in the examples and comparative examples are as follows:

[0179] Table 1. Test results of materials from the examples and comparative examples.

[0180]

[0181]

[0182] As can be seen from the mechanical and optical properties data of the recycled transparent polycarbonate material in Table 1, the recycled transparent polycarbonate material of the present invention has good optical transparency (visible light transmittance is above 85%), yellowness is below 5.2, excellent impact resistance, and good physical and mechanical properties. All values ​​are close to those of virgin polycarbonate material. Comparative Example 1, without the addition of an antioxidant complex, and Comparative Examples 2, 3, and 4, respectively, without the addition of a primary antioxidant, a secondary antioxidant, and a free radical scavenger, all resulted in recycled polycarbonate materials with low IZOD notched impact strength, low tensile strength, and low elongation at break, along with high yellowness and low light transmittance. Comparative Examples 5, 6, and 7, respectively, using only a primary antioxidant, a secondary antioxidant, and a free radical scavenger, also resulted in recycled polycarbonate materials with low IZOD notched impact strength, low tensile strength, and low elongation at break, along with high yellowness and low light transmittance. Comparative Example 8, without the addition of a chain extender, and Comparative Example 10, with the chain extender added from the main machine's feed port, all resulted in recycled polycarbonate materials with low IZOD notched impact strength, high yellowness, and low light transmittance. Comparative Examples 11, 12, and 13, respectively, with the main machine and the slave machine not in vacuum, and with both the main machine and the slave machine not in vacuum, all resulted in recycled polycarbonate materials with low IZOD notched impact strength, high yellowness, and low light transmittance. Therefore, the antioxidant complex of this invention can effectively prevent the generation of free radicals, peroxide free radicals, and peroxides in waste polycarbonate melt, thereby protecting the physical properties and transparency stability of polycarbonate. The chain extender, fed through the feed port of the sub-machine, effectively enhances its ability to repair polycarbonate molecular chains in the sub-machine. The use of a dual vacuum system greatly improves the effectiveness of the additives and the purity of the resulting material, thus obtaining a recycled transparent polycarbonate material with high toughness and light transmittance. Compared to recycled polycarbonate materials prepared by existing technologies, the transparent recycled polycarbonate of this invention has mechanical and optical properties closer to virgin polycarbonate materials, making it easier to replace virgin polycarbonate materials in applications, thereby achieving effective recycling of waste transparent polycarbonate products.

[0183] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for the preparation of a recycled transparent polycarbonate material, characterized in that, The method comprises the following steps: (1) drying the waste polycarbonate chips at 90-150℃ for 1-4h; (2) mixing the dried waste polycarbonate chips, antioxidant compound and lubricant to obtain a mixture; (3) feeding the mixture into a double-stage screw extruder, wherein the double-stage screw extruder comprises a main screw machine and a sub-screw machine, the main screw machine is a single screw, and the sub-screw machine is a double screw, the mixture is fed into the feeding port of the main screw machine, and the chain extender is fed through the feeding port of the sub-screw machine, and then transparent polycarbonate recycled material is obtained through melt extrusion and granulation; The recycled transparent polycarbonate material comprises the following components by weight: waste polycarbonate chips 95.5-99.87 parts, antioxidant compound 0.1-0.5 parts, chain extender 0.01-3.0 parts, lubricant 0.01-0.5 parts; The antioxidant compound is composed of the following components by mass fraction: primary antioxidant 40-80%, auxiliary antioxidant 15-40%, radical scavenger 5-20%; The primary antioxidant is a hindered phenolic antioxidant, the auxiliary antioxidant is a phosphite antioxidant, and the radical scavenger is one or more of oxidized di(hydrogenated tallow alkyl)amine, 2-propenoic acid-2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenyl ester, 2-{1-[2-hydroxy-3,5-bis(2-methylbutan-2-yl)phenyl]ethyl}-4,6-di(2-methylbutan-2-yl)phenyl acrylate, and 2-(2-hydroxy-3-tert-butyl-5-methylbenzyl)-4-methyl-6-tert-butylphenyl acrylate.

2. The production method according to claim 1, characterized by, The waste polycarbonate chips are prepared from waste transparent polycarbonate products through processes including collection, classification, crushing, cleaning, impurity removal and drying, and the pH value of the waste polycarbonate chips is 6.5-8.

5.

3. The preparation method according to claim 1, characterized in that, The hindered phenolic antioxidant comprises one or more of tetra[β-(3,5-di-tert-butyl, 4-hydroxyphenyl) propionic acid] pentaerythritol ester, β-(4-hydroxyphenyl-3,5-di-tert-butyl) propionic acid octadecyl ester, and 2,6-di-tert-butyl-4-methylphenol.

4. The preparation method according to claim 1, characterized in that, The auxiliary antioxidant is a phosphite antioxidant, and the phosphite antioxidant comprises one or more of tris(2,4-di-tert-butyl) phenyl phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, and dioctadecyl pentaerythritol bisphosphite.

5. The preparation method according to claim 1, characterized in that, The chain extender is a copolymer containing an epoxy functional group.

6. The production method according to claim 5, wherein Each copolymer molecule contains 2-10 active epoxy groups.

7. The preparation method according to claim 1, characterized in that, The screw rotation speed of the main screw machine is 10-100 rpm, and the temperature of each zone is 180-280℃, and the screw rotation speed of the sub-screw machine is 200-500 rpm, and the temperature of each zone is 230-280℃.

8. The method of claim 1, wherein, The main screw machine and the sub-screw machine work in a vacuum state.

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