Preparation method of weather-resistant MS (Murashige-Skoog) resin, MS resin obtained by preparation method and application of MS resin

Abstract

The invention discloses a preparation method of weather-resistant MS (Murashige-Skoog) resin, the MS resin obtained by the preparation method and application of the MS resin. In the preparation method, MS resin is produced by copolymerization of methyl methacrylate and styrene, the production process comprises a batching process, a polymerization process, a devolatilization process, a granulation process and an optional mixing process, and the preparation method is characterized in that an antioxidant compound A is added in at least one of the batching process, the polymerization process and the devolatilization process; the antioxidant compound A comprises a phosphorus-based antioxidant and an optional hindered phenol antioxidant; an antioxidant compound B is added in at least one of a granulation process and an optional mixing process; and the antioxidant compound B comprises a hindered phenol antioxidant and an optional phosphorus-based antioxidant. The invention provides a method for preparing the MS resin by adding antioxidants with different compounding proportions in different working procedures and multiple stages, and the excellent weather resistance of the MS resin can be ensured while the yellowness value of the MS resin is greatly reduced.

Description

Technical Field

[0001] The invention relates to a methyl methacrylate copolymer, in particular to a method for preparing a weather-resistant MS resin, the MS resin obtained thereby and applications thereof. Background Art

[0002] Methyl methacrylate-styrene copolymer resin (MS resin) is a transparent plastic with excellent light transmittance, which is mainly prepared by free radical polymerization of two monomers, methyl methacrylate and styrene. Due to its good processability, low moisture absorption rate, excellent solvent resistance and lower cost, it is often used as an alternative to polymethyl methacrylate (PMMA resin), such as in automotive light guide plates, cosmetic packaging, etc.

[0003] However, since methyl methacrylate-styrene copolymer resin contains more benzene vinyl units, the MS resin pellets and the molded bodies formed by extrusion, injection molding and other processing methods have poor hue (yellowish); the introduction of styrene structural units will also lead to a decrease in the yellowing resistance of the polymer resin. MS resin is often exposed to light during use, especially in outdoor use scenarios, and may also face the test of high temperature conditions. These factors will accelerate the aging of MS resin, thereby shortening its service life.

[0004] From the published patents, the use of antioxidants within a limited dosage range can improve the shortcomings of MS resins, such as high yellowness and poor weather resistance, to a certain extent. Relevant patent reports include CN103987780, CN104245823, CN102257021, and CN115397913. However, the technical solutions proposed in these patents are to add the antioxidants at one time in one of the batching process, polymerization process, devolatilization process, granulation process, and mixing process, without considering the consumption of different types of antioxidants in the resin production process, and the influence of antioxidant consumption on the color tone and weather resistance of the polymer resin. Therefore, the prior art cannot simultaneously improve the problems of high yellowness and poor weather resistance of the resin by adding hindered phenol antioxidants and phosphorus-based antioxidants at one time in the MS resin production process. Summary of the invention

[0005] The present inventors have continuously studied and found that if antioxidants are added in the front-end processes such as the batching process, the polymerization process, and the devolatilization process, the antioxidants, especially the hindered phenol antioxidants, are easily modified into coloring substances under the high temperature conditions in the production process, thereby deteriorating the color tone of the resin, and the modification and degradation of these antioxidants leads to a decrease in the antioxidant content in the produced MS resin particles, thereby reducing the weather resistance of the MS resin; if antioxidants are added in the rear-end processes such as the granulation process and the mixing process, the MS resin contains more styrene copolymer units, and its yellowness value is already high under the high temperature conditions of the front-end processes, especially the devolatilization process. Antioxidants without color adjustment function cannot improve this and can only improve the weather resistance of the MS resin.

[0006] In addition, it is well known in the industry that hindered phenol antioxidants and phosphorus antioxidants have a synergistic effect when used together, and the effect is better than using either alone. However, after in-depth research by the inventors, hindered phenol antioxidants are more likely to become coloring substances after high-temperature modification and degradation compared to phosphorus antioxidants; and phosphorus antioxidants are more likely to be modified and degraded than hindered phenol antioxidants.

[0007] In order to solve the above technical problems, the present invention provides a method for preparing a weather-resistant MS resin, the MS resin obtained thereby, and applications thereof.

[0008] According to the first aspect of the present invention, a method for preparing a weather-resistant MS resin is provided. The MS resin is produced by copolymerization of methyl methacrylate and styrene. The production process includes a batching step, a polymerization step, a devolatilization step, a granulation step and an optional mixing step. The method is characterized in that an antioxidant complex A is added in at least one of the batching step, the polymerization step and the devolatilization step; the antioxidant complex A includes a phosphorus antioxidant and an optional hindered phenol antioxidant;

[0009] The antioxidant complex B is added in at least one of the granulation process and the optional kneading process; the antioxidant complex B comprises a hindered phenol antioxidant and optionally a phosphorus-based antioxidant.

[0010] During the research process, it was found that excessive use of antioxidants will damage the hue and light transmittance of MS resin, while too little use of antioxidants will have little effect on improving the hue and weather resistance of MS resin. Therefore, it is necessary to limit the dosage range of antioxidants to maximize the improvement of the hue and weather resistance of MS resin. Preferably, the total content of the hindered phenol antioxidant is 0.01-0.15% of the total mass of methyl methacrylate and styrene, such as 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, 0.12%, 0.13%, 0.14%, 0.15%, etc., preferably 0.02-0.10%; the total content of the phosphorus antioxidant is 0.01-0.2% of the total mass of methyl methacrylate and styrene, such as 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, 0.12%, 0.14%, 0.15%, 0.16%, 0.18%, etc., preferably 0.02-0.15%.

[0011] MS resin will go through a high-temperature pipeline transportation and devolatilization process between the completion of polymerization and the granulation process. During this process, the styrene copolymer units in the resin slurry are easily affected by high temperature and oxidized to generate coloring substances, making the yellowness value of the final produced resin higher. Therefore, it is necessary to add a certain amount of antioxidants in the batching process, polymerization process, and devolatilization process, which are relatively front-end processes, to reduce or avoid this situation. However, although hindered phenol antioxidants and phosphorus-based antioxidants have a synergistic effect when used together, hindered phenol antioxidants are prone to become coloring substances after high-temperature modification and degradation. Therefore, when adding antioxidants in these relatively front-end processes, it is necessary to reduce the amount of hindered phenol antioxidants and increase the amount of phosphorus-based antioxidants accordingly. In some preferred embodiments, in the antioxidant complex A, the amount of hindered phenol antioxidants is 0-50% of the mass of all hindered phenol antioxidants, the amount of phosphorus-based antioxidants is 30-100% of the mass of all phosphorus-based antioxidants, and the amount of hindered phenol antioxidants is not more than the amount of phosphorus-based antioxidants;

[0012] Since part of the antioxidant added in the front-end processes such as the batching process, polymerization process, and devolatilization process will be consumed, this can better reduce the yellowness value of the resin and improve the hue of the resin, but at the same time, the content of antioxidant in the final produced resin particles is significantly less than the added amount, which weakens the improvement effect on the weather resistance of the resin. Therefore, it is necessary to add additional antioxidants after the devolatilization process (no long-term high-temperature production process) to further improve the weather resistance of the resin. In addition, hindered phenol antioxidants are often used as primary antioxidants, while phosphorus-based antioxidants are often used as auxiliary antioxidants. Therefore, when adding antioxidants in these later processes, in order to ensure effective resin weather resistance, it is necessary to increase the amount of hindered phenol antioxidants and correspondingly reduce the amount of phosphorus-based antioxidants that are more easily degraded. Preferably, in the antioxidant complex B, the amount of hindered phenol antioxidant is 50-100% of the total mass of hindered phenol antioxidants; the amount of phosphorus antioxidant is 0-70% of the total mass of phosphorus antioxidants, and the amount of hindered phenol antioxidant is not less than that of phosphorus antioxidant.

[0013] In some preferred embodiments, the mass ratio of the hindered phenol antioxidant to the phosphorus antioxidant in the antioxidant complex A is 1:(1-3);

[0014] Preferably, the mass ratio of the hindered phenol antioxidant to the phosphorus antioxidant in the antioxidant complex B is (1-3):1.

[0015] In some preferred embodiments, the hindered phenol antioxidant includes but is not limited to one or more of antioxidant 1010, antioxidant 1076, antioxidant 330, antioxidant 3114, antioxidant 1098, antioxidant 245, antioxidant 1790, antioxidant 1035, antioxidant 1135, and antioxidant 565; in addition, at least a portion of the hindered phenol antioxidants can also be replaced by a phosphorus-based antioxidant containing phenolic hydroxyl groups.

[0016] Preferably, the phosphorus-based antioxidant is a phosphite antioxidant, including but not limited to one or more of antioxidant 168, antioxidant 626, antioxidant 636, antioxidant 686, antioxidant TNPP, antioxidant 618, and di[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl phosphite.

[0017] In some preferred embodiments, in the batching process, theoretical amounts of methyl methacrylate and styrene monomers are added to the batching tank, and preferably nitrogen is used to deoxygenate the materials in the batching tank. Based on the total mass of methyl methacrylate and styrene as 100%, the mass ratio of the two is in the range of 15 / 85-85 / 15, preferably adjusted in the range of 20 / 80-70 / 30.

[0018] According to the reaction conditions and product quality requirements, an initiator and a chain transfer agent can be optionally used; the initiator is preferably selected from organic peroxide initiators and / or azo initiators, and more preferably the initiator is used in an amount of 50-300 ppm based on the total mass of methyl methacrylate and styrene; the chain transfer agent is preferably selected from C4-C18 aliphatic thiols and / or C6-C11 aromatic thiols, and more preferably the chain transfer agent is used in an amount of 200-2000 ppm based on the total mass of methyl methacrylate and styrene.

[0019] Further preferably, the initiator is preferably selected from one or more of tert-butyl diisopropylbenzene peroxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, tert-butyl hydroperoxide, tert-butyl peroxybenzoate, 1,1-bis-(tert-butyl peroxy)cyclohexane, 1,1-bis-(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, and peroxy-3,5,5-trimethyl tert-butyl hexanoate;

[0020] Further preferably, the chain transfer agent is preferably selected from one or more of n-butyl mercaptan, tert-butyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, n-dodecyl mercaptan, and tert-dodecyl mercaptan.

[0021] In addition, without damaging the hue, transparency and weather resistance of the MS resin, the present invention can also use auxiliary agents such as ultraviolet absorbers, colorants, and release agents. The above auxiliary agents can refer to the conventional selection and dosage in the field, and will not be repeated here.

[0022] In some preferred embodiments, from the aspects of product quality and production efficiency, the polymerization process can adopt any one of the known general processes such as bulk polymerization and solution polymerization. Considering production safety, a continuous bulk polymerization process in the presence of a small amount of solvent is more preferred; preferably, the solvent can be one or more of toluene, ethylbenzene, xylene, acetone, butanone, ethyl acetate, butyl acetate, tetrahydrofuran, and N,N-dimethylformamide; the amount of the solvent used is, for example, 0-30% of the total mass of methyl methacrylate and styrene.

[0023] In some more preferred embodiments, for bulk polymerization and solution polymerization, the polymerization process can refer to known literature records such as CN114891147B, CN101338001B, CN102336864B, etc.

[0024] In some preferred embodiments, in the devolatilization process, the devolatilizer used is one of a flash tank, a strip devolatilizer, a venting extruder, or any combination thereof; since unreacted monomers and solvents are more easily oxidized than polymers, they will not only reduce the weather resistance of the resin, but also produce odor during processing and practical application. The devolatilizer is used to remove the unreacted monomers and solvents, but too high a devolatilization temperature will deteriorate the hue of the resin and increase the yellowness value, so the devolatilizer needs to be set with a suitable vacuum degree and temperature. Preferably, the vacuum degree of the devolatilizer is 0Mpa to -0.099MPa, preferably -0.030MPa to -0.099MPa, and the operating temperature is 150-260°C, preferably 190-250°C;

[0025] Preferably, the total amount of residual monomers and solvents in the MS resin is controlled to be below 5000 ppm, preferably below 2000 ppm, and more preferably below 1500 ppm in the devolatilization process. The total amount of residual monomers and solvents within this range has little effect on the weather resistance of the MS resin.

[0026] In some preferred embodiments, the granulation equipment used is one of a strand granulator, a spray granulator, a water ring granulator, an underwater granulator, an underwater granulator, or any combination thereof;

[0027] Preferably, in the granulation process, the copolymer is melt-extruded and then pelletized to obtain plastic pellets with a particle size of 1-3 mm.

[0028] In some preferred embodiments, in the optional mixing process, the equipment used is a single screw extruder, a twin screw extruder, a heating roller, a drum mixer, an internal mixer or any combination thereof, preferably a twin screw extruder, more preferably a barrel temperature of 200-250°C, and a screw speed of 200-500rpm. The mixing process is generally used for functional modification of resins, for example, downstream customers may further blend and extrude it with the resin pellets obtained in the granulation process by adding functional additives to obtain functional modified products.

[0029] In some embodiments of the present invention, the hindered phenol antioxidant and the phosphorus antioxidant can be added in the form of a monomer or solvent solution, a molten state, or a solid state. According to the process conditions of different steps, the appropriate addition method is preferred. In the batching step, the monomer or solvent solution is preferably added; in the polymerization step, the monomer or solvent solution or molten state is preferably added; in the devolatilization step, the molten state is preferably added; in the granulation step, the molten state is preferably added; in the mixing step, the solid state is preferably added as a masterbatch. According to the addition methods in different states and the needs of different processes, a suitable mixing method is preferably selected. In the batching process, mixing is preferably performed by a stirrer equipped in the batching tank; in the polymerization process, if a full mixed flow reactor with a stirrer is selected, mixing is preferably performed by a stirrer, and if a reactor without a stirrer (such as a plug flow reactor) is selected, mixing is preferably performed by a static mixer before entering the process; in the devolatilization process, if a devolatilizer without mixing ability such as a falling strip devolatilizer is selected, mixing is preferably performed by a static mixer before entering the process, and if a devolatilizer in the form of an extruder is selected, mixing is preferably performed by an extruder; in the granulation process and the mixing process, mixing can be performed directly by an extruder.

[0030] According to the second aspect of the present invention, there is also provided a weather-resistant MS resin prepared by the method described above, wherein the MS resin has a YI value ≤ 1, a b value ≤ 0.7, and after 14 days of UV aging, ΔYI ≤ 2.4, and ΔE ≤ 1.4.

[0031] Based on the third aspect of the present invention, there is also provided an application of the weather-resistant MS resin prepared by the method described above in transparent materials in the fields of automobiles, electrical appliances, daily chemicals, medical supplies, and optical lenses.

[0032] The invention provides a method for preparing MS resin by adding antioxidants in different compounding ratios in different processes and stages, which can significantly reduce the yellowness value of the MS resin and ensure that the MS resin has excellent weather resistance. DETAILED DESCRIPTION

[0033] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0034] Unless otherwise specified, all raw materials used in the following examples and comparative examples of the present invention can be obtained through commercial channels.

[0035] The following embodiments and comparative examples of the present invention are uniformly operated using the following equipment:

[0036] Batching tank: used for batching process, effective volume 15L;

[0037] Fully mixed flow reactor: used for polymerization process, effective volume 30L;

[0038] Falling strip devolatilizer: used for the devolatilization process;

[0039] Strand granulator: used for granulation process;

[0040] The test method used in the following embodiments of the present invention is as follows:

[0041] (1) Light transmittance: The total light transmittance of a 3 mm sheet was tested according to the method in ASTM D1003_13.

[0042] (2) Hue L, a, b, YI test: refer to the method in standard ASTM E313-15e1, use the American Hunterlab VIS instrument, and evaluate the initial hue of the sample with b value and YI value. The higher the b value and YI value, the worse the initial hue.

[0043] (3) Weather resistance: at "irradiance 0.63W / m 2 After aging for 14 days under the conditions of ", wavelength 340nm, light cycle (60℃, 4h), condensation (50℃, 4h)", the transmittance and hue were tested, and the overall color difference ΔE and yellowness change ΔYI before and after aging were calculated. The weather resistance of the sample was evaluated with the values ​​of ΔE and ΔYI. The higher the values ​​of ΔE and ΔYI, the worse the weather resistance.

[0044] [Example S1]

[0045] The MS resin is produced according to the following process:

[0046] (1) Ingredients: Add 15 parts by mass of methyl methacrylate, 85 parts by mass of styrene, 30 parts by mass of ethylbenzene, 0.005 parts by mass of tert-butyl diisopropylbenzene peroxide, and 0.15 parts by mass of tert-dodecyl mercaptan into a batching tank, and then mix 0.01 parts by mass of antioxidant 1076 and 0.03 parts by mass of antioxidant 636 with the materials in the batching tank; introduce nitrogen to fully remove oxygen in the tank;

[0047] (2) Polymerization: The reaction liquid was continuously added into a fully mixed flow reactor at a flow rate of 10 kg / h, the temperature in the reactor was controlled at 145°C, the average residence time was 4 hours, and the outlet conversion rate was 70%;

[0048] (3) Devolatilization: The polymerization reaction slurry is continuously fed into a strip-type devolatilizer to remove unreacted monomers, solvents and other light components under the conditions of a devolatilization vacuum of -0.98 MPa, a devolatilization temperature of 240°C and a residence time of 15 min;

[0049] (4) Granulation: The devolatilized polymer, 0.04 parts by mass of antioxidant 1076 and 0.02 parts by mass of antioxidant 168 were mixed in a static mixer, and then extruded and granulated by a strand pelletizer to obtain MS resin with a particle size of 1-3 mm.

[0050] [Examples S2-S6]

[0051] MS resin was prepared according to the different conditions in Table 1, and others were referred to Example S1.

[0052] Table 1. Timing and amount of material addition in different embodiments (unit: mass parts)

[0053]

[0054] [Comparative Example D1]

[0055] MS resin was produced by referring to the method basically the same as Example S1, except that the antioxidant 1076 and the antioxidant 636 added in the batching process were both 0.05 parts by weight, and no antioxidant was added in the granulation process.

[0056] [Comparative Example D2]

[0057] The MS resin was produced by referring to the method basically the same as Example S1, except that no antioxidant was added in the batching process, and the added antioxidant 1076 and antioxidant 168 were both changed to 0.05 parts by mass in the granulation process.

[0058] [Comparative Example D3]

[0059] MS resin was produced by referring to the method basically the same as Example S1, except that the antioxidant 1076 and the antioxidant 636 added in the batching process were both 0.12 parts by weight, and no antioxidant was added in the granulation process.

[0060] [Comparative Example D4]

[0061] MS resin was produced by referring to the method basically the same as Example S1, except that antioxidant 1076 and antioxidant 168 were not added in the batching process and the granulation process.

[0062] The performance of the MS resin prepared in each embodiment and comparative example was evaluated, and the results are shown in Table 2. It can be seen from the test results in Table 2 that compared with the methyl methacrylate-styrene copolymer resin prepared without adding an antioxidant and adding an antioxidant at one time, the methyl methacrylate-styrene copolymer resin prepared by the method of adding a specific ratio of antioxidants in multiple stages proposed by the present invention has lower initial b value and YI value, indicating that the initial hue is better; and the values ​​of ΔE and ΔYI before and after aging are lower, indicating that the weather resistance is better. In addition, it can be seen from the comparison results of Comparative Example D3 and Example S1 that although the use of more antioxidants in the front-end process can also improve the weather resistance of the resin, it seriously damages the initial hue and light transmittance of the resin.

[0063] Table 2. Performance evaluation results

[0064]

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a weather-resistant MS resin, wherein the MS resin is produced by copolymerization of methyl methacrylate and styrene, and the production process includes a batching step, a polymerization step, a devolatilization step, a granulation step and an optional mixing step, characterized in that: Adding an antioxidant complex A in at least one of the batching process, the polymerization process and the devolatilization process; the antioxidant complex A comprises a phosphorus antioxidant and optionally a hindered phenol antioxidant; The antioxidant complex B is added in at least one of the granulation process and the optional kneading process; the antioxidant complex B comprises a hindered phenol antioxidant and optionally a phosphorus-based antioxidant.

2. The method for preparing weather-resistant MS resin according to claim 1, characterized in that: The total content of the hindered phenol antioxidant is 0.01-0.15% of the total mass of methyl methacrylate and styrene, preferably 0.02-0.10%; Preferably, the total content of the phosphorus antioxidant is 0.01-0.2%, preferably 0.02-0.15%, of the total mass of methyl methacrylate and styrene.

3. The method for preparing the weather-resistant MS resin according to claim 2, characterized in that: In the antioxidant complex A, the amount of the hindered phenol antioxidant is 0-50% of the total mass of the hindered phenol antioxidant, the amount of the phosphorus antioxidant is 30-100% of the total mass of the phosphorus antioxidant, and the amount of the hindered phenol antioxidant is no more than the amount of the phosphorus antioxidant; Preferably, in the antioxidant complex B, the amount of hindered phenol antioxidant is 50-100% of the total mass of hindered phenol antioxidants; the amount of phosphorus antioxidant is 0-70% of the total mass of phosphorus antioxidants, and the amount of hindered phenol antioxidant is not less than that of phosphorus antioxidant.

4. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 3, characterized in that: The mass ratio of the hindered phenol antioxidant to the phosphorus antioxidant in the antioxidant complex A is 1:(1-3); Preferably, the mass ratio of the hindered phenol antioxidant to the phosphorus antioxidant in the antioxidant complex B is (1-3):

1.

5. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 4, characterized in that: The hindered phenol antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant 330, antioxidant 3114, antioxidant 1098, antioxidant 245, antioxidant 1790, antioxidant 1035, antioxidant 1135, and antioxidant 565; Preferably, the phosphorus-based antioxidant is a phosphite antioxidant, preferably selected from one or more of antioxidant 168, antioxidant 626, antioxidant 636, antioxidant 686, antioxidant TNPP, antioxidant 618, and di[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl phosphite.

6. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 5, characterized in that: In the batching process, based on the total mass of methyl methacrylate and styrene being 100%, the mass ratio of the two is in the range of 15 / 85-85 / 15, preferably in the range of 20 / 80-70 / 30; Preferably, the copolymerization raw materials further optionally include an initiator and a chain transfer agent; the initiator is preferably selected from organic peroxide initiators and / or azo initiators, and more preferably the initiator is used in an amount of 50-300 ppm based on the total mass of methyl methacrylate and styrene; the chain transfer agent is preferably selected from C4-C18 aliphatic thiols and / or C6-C11 aromatic thiols, and more preferably the chain transfer agent is used in an amount of 200-2000 ppm based on the total mass of methyl methacrylate and styrene.

7. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 6, characterized in that: The polymerization process adopts any one of bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization processes, preferably bulk polymerization or solution polymerization, and more preferably continuous bulk polymerization process in the presence of a small amount of solvent.

8. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 7, characterized in that: In the devolatilization process, the devolatilizer used is one of a flash tank, a falling strip devolatilizer, a venting extruder, or any combination thereof; Preferably, the vacuum degree of the devolatilizer is 0 MPa to -0.099 MPa, preferably -0.030 MPa to -0.099 MPa, and the operating temperature is 150-260°C, preferably 190-250°C; Preferably, the total amount of residual monomers and solvents in the MS resin is controlled to be 5000 ppm or less, preferably 2000 ppm or less, and more preferably 1500 ppm or less in the devolatilization step.

9. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 8, characterized in that: In the granulation process, the granulation equipment used is one of a strand granulator, a spray granulator, a water ring granulator, an underwater granulator, an underwater granulator or any combination thereof; Preferably, in the granulation process, the copolymer is melt-extruded and then pelletized to obtain plastic pellets with a particle size of 1-3 mm.

10. The method for preparing the weather-resistant MS resin according to any one of claims 1 to 9, characterized in that: In the optional mixing process, the equipment used is one of a single-screw extruder, a twin-screw extruder, a heating roll, a drum mixer, an internal mixer, or any combination thereof.

11. A weather-resistant MS resin prepared by the method according to any one of claims 1 to 10.

12. Application of the weather-resistant MS resin prepared by the method according to any one of claims 1 to 10 in transparent materials in the fields of automobiles, electrical appliances, daily chemicals, medical supplies, and optical lenses.

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