A transparent abs resin and a method for producing the same

Abstract

This invention provides a transparent ABS resin and its preparation method, belonging to the technical field of styrene-based resin materials. Existing transparent ABS preparation methods suffer from high cost, complex processes, and unstable product quality, making industrialization difficult. Therefore, a new method for preparing transparent ABS resin is needed. The transparent ABS resin prepared by this invention has a low-styrene rubber core and a special three-layer core-shell structure, achieving good transparency and high impact resistance. It is low-cost, has a simple and efficient process, stable product quality, and is easily industrially achievable.

Description

Technical Field

[0001] This invention belongs to the technical field of styrene-based resin materials, specifically relating to a transparent ABS resin and its preparation method. Background Technology

[0002] The market demand for transparent polymer materials exceeds 100,000 tons per year. Existing transparent polymer materials mainly include polystyrene (MBS), acrylic glass (PMMA), and polycarbonate (PC). Among these, polystyrene and acrylic glass are brittle and not scratch-resistant, while polycarbonate is expensive and prone to stress cracking. Acrylonitrile-butadiene-styrene terpolymer resin (ABS) has good light transmittance, high impact toughness, and a relatively low price. Its overall performance is superior to other common transparent acrylic glass materials, including methyl methacrylate, butadiene-styrene terpolymer resin (MBS), and styrene-butadiene transparent impact-resistant resin (K resin). Current research on transparent ABS production methods has not yet achieved industrial-scale production due to the complexity of the methods. Therefore, there is an urgent need for a transparent ABS resin preparation technology that is easy to industrially produce and has excellent performance.

[0003] The basic principle for achieving transparency in ABS resin is to reduce the refractive index difference between the rubber and plastic phases and eliminate light scattering effects. However, the specific methods used to achieve this principle vary in different preparation processes. Patent application CN117986800A describes the synthesis of star-shaped low-cis polybutadiene rubber through anionic polymerization, and the use of this structure to synthesize transparent ABS resin. The methyl acrylate content is 20%-40%, and the impact strength is 10-12 kJ / m². 2 The light transmittance is 85%-90%. Star-shaped low-cis polybutadiene rubber requires separate production, resulting in higher costs. Patent application CN116162204A employs the addition of a second monomer with a methyl / cyclic structure during the preparation of small-particle-size polybutadiene latex. Due to the greater steric hindrance of its methyl / cyclic structure, the prepared transparent ABS exhibits better optical properties over a wider operating temperature range. The transparency of the ABS resin is achieved by utilizing the principle of light transmission from small-particle-size latex, with an impact strength of approximately 17 kJ / m². 2The light transmittance is approximately 90%. Patent application CN114230740A successfully improved the polarity of styrene-butadiene resin by adjusting the content of side chains in the molecular chain segments and introducing polar groups into the molecular chain, thereby enabling it to have good compatibility with polar materials and ultimately obtaining a transparent material with excellent impact resistance. Styrene-butadiene rubber contains 40%-75% styrene and has a light transmittance of 88-89%. Other methods for preparing transparent materials from non-ABS resins include patent application CN106589690A, which uses a blending method to add various agents to prepare transparent alloy materials; patent applications CN109929076A and CN109971086A, which use transparent PVC as a matrix and modify it with MBS resin to improve the impact resistance of PVC, but the transparency of the material is somewhat affected; and patent application CN111763396A, which uses a controlled casting process with MBS resin to improve the impact resistance of acrylic glass and ensure its transparency.

[0004] Existing methods for preparing transparent ABS resin suffer from high costs, complex processes, and unstable product quality, making industrialization difficult. Therefore, there is a need for a new method for preparing transparent ABS resin to achieve good transparency and high impact resistance. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a transparent ABS resin and its preparation method. The transparent ABS resin comprises a MABS resin with a three-layer core-shell structure, wherein the three-layer core-shell structure is as follows: a styrene-butadiene latex rubber core is the innermost layer, a styrene-acrylonitrile copolymer graft layer is surrounding the styrene-butadiene latex rubber core, and a methyl methacrylate copolymer graft layer is the outermost layer. Specifically, this is achieved through the following technical solution:

[0006] Step 1: Prepare styrene-butadiene latex with large particle size and low styrene content;

[0007] 80-100 parts butadiene, 1-5 parts styrene, 100-150 parts demineralized water, 1-10 parts emulsifier, 1-5 parts stabilizer, 1-2 parts pH adjuster, 1-5 parts catalyst, and 0.1-1 parts molecular weight adjuster are added to a reaction vessel. Under the protection of nitrogen or inert gas, the reaction process involves three aging processes: the first aging at 55-65℃, the second aging at 55-65℃, and the third aging at 70-80℃, to obtain a styrene-butadiene latex with low styrene content. The styrene content in this styrene-butadiene latex is about 1%-6%, which is much lower than the styrene content in commonly used styrene-butadiene latex.

[0008] The particle size of the styrene-butadiene latex is made to 180-220 nm by chemical agglomeration, which serves as the grafting base latex, i.e. the rubber core phase. Latex with this particle size range can reduce the impact of particle size growth on light transmittance while ensuring a certain impact strength.

[0009] Step 2: Graft the large-particle-size, low-styrene-content styrene-butadiene latex prepared in Step 1 using the emulsion grafting method. Styrene is grafted into the rubber core, a layer of styrene-acrylonitrile polymer is grafted into the rubber core, and a layer of methyl methacrylate polymer is coated on the outermost layer to form a three-layer core-shell structure of MABS rubber phase.

[0010] Grafting a layer of polystyrene into the rubber core phase: 55-70 parts of the large-particle-size, low-styrene-content styrene-butadiene latex prepared in the first step, 0.1-1 parts of emulsifier, 1-5 parts of styrene, 0.1-1 parts of molecular weight regulator, and 0.1-1 parts of initiator are heated to 65-75℃ and reacted for 20-50 minutes. By adding pre-swelled monomers, a honeycomb-like internal support structure is formed inside the rubber core phase particles to obtain a styrene-butadiene latex rubber core with polymerized styrene.

[0011] A second styrene-acrylonitrile polymer shell and a third polymethyl methacrylate polymer shell are grafted onto the outside of the polystyrene-butadiene latex rubber core: 5-20 parts of second-stage styrene, 1-10 parts of acrylonitrile, and 0.1-1 parts of crosslinking agent are added to 56-75 parts of the polystyrene-butadiene latex rubber core. The temperature is raised to 70-80℃, an initiator is added, and 10-30 parts of second-stage monomer methyl methacrylate and 0.1-1 parts of molecular weight regulator, pre-emulsified with sodium dodecyl sulfate for 1-3 hours, are added dropwise. The initiator is then replenished, with a total of 0.1-1 parts of initiator added in the two reactions. After the dropwise addition is completed, the temperature is raised to 75-85℃, and the reaction is carried out for 1-2 hours. The material is then discharged to obtain a three-layer core-shell structured MABS rubber phase.

[0012] Step 3: Mass polymerization of MSN (also known as MAS) is carried out. Based on the synthesis of SAN resin by polymerization of styrene and acrylonitrile, 40-50 parts of methyl methacrylate (MMA) are added to synthesize a special MSAN resin. The amount of methyl methacrylate added is less than 50 wt.%, and the ratio of styrene:acrylonitrile:methyl methacrylate by mass is 2-4:1-2:3-9.

[0013] Step 4: Mix the three-layer core-shell structured MABS rubber phase prepared in Step 2 and the MSAN resin prepared in Step 3 at a mass ratio of 15-25:75-85, add lubricant and antioxidant, and granulate to obtain transparent ABS resin.

[0014] Specifically, the emulsifier is selected from at least one of potassium oleate, potassium disproportionated rosinate, sodium salt of naphthalenesulfonic acid formaldehyde condensate, potassium salt of naphthalenesulfonic acid formaldehyde condensate, potassium stearate, sodium dodecylbenzene sulfonate, or sodium dodecyl sulfonate.

[0015] Specifically, the stabilizer is at least one of potassium carbonate, potassium chloride, potassium sulfate, potassium carbonate, calcium chloride, calcium sulfate, calcium nitrate, calcium carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, or magnesium carbonate.

[0016] Specifically, the pH adjuster is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, or potassium silicate;

[0017] Specifically, the catalyst is selected from at least one of potassium persulfate, ammonium persulfate, or sodium persulfate;

[0018] Specifically, the molecular weight regulators used in all the above reaction steps are selected from at least one of tert-dodecyl mercaptan, mercaptoacrylate, or n-dodecyl mercaptan;

[0019] Specifically, the initiator used in all the above reaction steps is selected from at least one of cumene hydroperoxide, sodium persulfate, potassium persulfate, ammonium persulfate, or azobisisobutyl nitrile;

[0020] Specifically, the crosslinking agent is selected from at least one of diallyl phthalate, diallyl cyanoethyl acetate, polyethylene glycol diacrylate, ethylene glycol diacrylate, glycerol diacrylate, or pentaerythritol diacrylate.

[0021] Specifically, the lubricant is selected from at least one of vinyl bis-stearamide, oxidized polyethylene wax, magnesium stearate, or white oil;

[0022] Specifically, the antioxidant is selected from at least one of hindered phenols and their derivatives or phosphites and their derivatives.

[0023] The transparent ABS resin prepared by the above method has an impact strength of 15 kJ / m. 2 Above, the light transmittance reaches 89%, and the haze is reduced to below 5%. For example... Figure 1 As shown, traditional ABS grafted core-shell polymers have poor light transmittance due to light scattering when light passes through the large-particle-size rubber core phase. However, multilayer ABS grafted core-shell polymers, when matched with specialized SAN resins, exhibit less light scattering and better light transmittance.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] ① The transparent ABS resin prepared by this invention has a special grafted three-layer core-shell structure, which significantly improves the light transmittance of the ABS resin. The principle of ABS resin light transmission is to match the refractive index difference between the rubber phase and the resin phase by adjusting the difference between the two, thus achieving transparency. The polystyrene core in the three-layer core-shell structure increases the overall refractive index of the rubber phase, and the small amount of methyl methacrylate grafted on the outermost layer increases the refractive index of the material and also improves the compatibility of the prepared MABS with MSAN.

[0026] ②This invention achieves good transparency and high impact resistance with relatively low amounts of styrene and methyl methacrylate, and has low preparation cost and is easy to implement in industrial production. Attached Figure Description

[0027] Figure 1 A comparison diagram showing the light transmittance principle of traditional ABS grafted core-shell structure polymer and multilayer ABS grafted core-shell structure polymer;

[0028] Figure 2 Photograph of the transparent ABS resin prepared in Example 1. Detailed Implementation

[0029] Examples 1-4:

[0030] Preparation of grafted base latex: 80 parts butadiene, 1 part styrene, 100 parts demineralized water, 1 part potassium oleate emulsifier, 1 part potassium carbonate stabilizer, 1 part sodium hydroxide pH adjuster, 1 part potassium persulfate catalyst, and 0.1 part tert-dodecyl mercaptan molecular weight regulator are mixed and aged under nitrogen protection. The mixture is then aged at 55°C for the first time, 65°C for the second time, and 70°C for the third time. Through chemical agglomeration, styrene-butadiene latex with a particle size of 180 nm is obtained, which is the grafted base latex.

[0031] Polystyrene-butadiene latex rubber core: 55 parts of the prepared grafted base latex, 0.1 parts of potassium oleate emulsifier, 2 parts of styrene-1, 0.1 parts of tert-dodecyl mercaptan molecular weight regulator, and 0.1 parts of cumene hydroperoxide initiator are mixed and reacted at 65°C for 20 min to obtain a styrene-butadiene latex rubber core for polystyrene-butadiene latex.

[0032] External grafting of rubber core to prepare grafted powder: According to the formulations in Examples 1-4 of Table 1, add basic latex to the grafting reactor, add potassium oleate as an emulsifier for protection, and heat to 65°C. Add 0.5 parts of styrene-2, acrylonitrile-2, and diallyl phthalate as a crosslinking agent to the reactor, and add 0.5 parts of cumene hydroperoxide as an initiator. React for 30 minutes, then heat to 70°C, add more initiator, and begin dripping pre-emulsified methyl methacrylate and tert-dodecyl mercaptan as a molecular weight regulator for 2 hours. After dripping, heat to 75°C and react for 1 hour before unloading. Coagulate and dry the grafted latex to prepare grafted powder.

[0033] Preparation of MSAN resin: According to the formulation in Table 1, styrene and acrylonitrile in SAN are mixed and methyl methacrylate is introduced for bulk polymerization to prepare MSAN resin.

[0034] Preparation of transparent ABS resin: By weight, 15 parts of grafting powder, 85 parts of MSAN resin, antioxidant 1010, and lubricant vinyl bis-stearamide were mixed and added to a twin-screw extruder. The extruded strip was cooled in a water bath and then pelletized to obtain transparent ABS resin. A photograph of the transparent ABS resin prepared in Example 1 is shown below. Figure 2 As shown.

[0035] Table 1. Formulation composition of Implementation 1-4 (parts by weight)

[0036]

[0037] Example 5

[0038] Preparation of grafted base latex: 100 parts butadiene, 5 parts styrene, 150 parts deionized water, 10 parts potassium disproportionated rosinate emulsifier, 5 parts magnesium carbonate stabilizer, 2 parts sodium silicate pH adjuster, 5 parts ammonium persulfate catalyst, and 1 part mercaptoacrylate molecular weight adjuster are mixed and aged at 65°C for the first time, 65°C for the second time, and 80°C for the third time under nitrogen protection. Through chemical agglomeration, styrene-butadiene latex with a particle size of 220nm is obtained, which is the grafted base latex.

[0039] Polystyrene-butadiene latex rubber core: 70 parts of the prepared grafted base latex, 1 part of the emulsifier potassium disproportionate, 5 parts of styrene-butadiene, 1 part of the molecular weight regulator mercaptoacrylate, and 1 part of the initiator sodium persulfate are mixed and reacted at 75°C for 50 min to obtain the polystyrene-butadiene latex rubber core.

[0040] External grafting of rubber core to prepare grafted powder: According to the formulations in Examples 1-4 of Table 1, 56 parts of base latex were added to the grafting vessel, with emulsifier added for protection. The temperature was raised to 65°C, and 5 parts of distyrene, 1 part of acrylonitrile, and 0.1 parts of diallyl phthalate (crosslinking agent) were added to the vessel. 0.1 parts of sodium persulfate (initiator) were added, and the reaction was carried out for 30 minutes. The temperature was raised to 70°C, the initiator was added again, and 10 parts of methyl methacrylate (pre-emulsified with sodium dodecyl sulfate) and 0.1 parts of mercaptoacrylate (molecular weight adjuster) (pre-emulsified with sodium dodecyl sulfate) were added dropwise for 2 hours. After the dropwise addition was completed, the temperature was raised to 75°C, and the reaction was carried out for 1 hour before unloading. The grafted latex was coagulated and dried to prepare grafted powder.

[0041] Preparation of MSAN resin: By mass, styrene: acrylonitrile: methyl methacrylate is 2:1:3, and MSAN resin is obtained by polymerization.

[0042] Preparation of transparent ABS resin: By weight, 20 parts of grafting powder, 80 parts of MSAN resin, antioxidant 2,6-di-tert-butyl-4-methylphenol, and lubricant oxidized polyethylene wax are mixed and added to a twin-screw extruder. The extruded strip is cooled in a water tank and then granulated to obtain transparent ABS resin.

[0043] Example 6

[0044] Preparation of grafted base latex: 90 parts butadiene, 3 parts styrene, 120 parts demineralized water, 5 parts naphthalenesulfonic acid formaldehyde condensate potassium salt emulsifier, 3 parts potassium chloride stabilizer, 1 part potassium carbonate pH adjuster, 3 parts sodium persulfate catalyst, and 0.5 parts n-dodecyl mercaptan molecular weight adjuster are mixed and aged at 60°C for the first time, 60°C for the second time, and 75°C for the third time under nitrogen protection. Through chemical agglomeration, styrene-butadiene latex with a particle size of 200nm is obtained, which is the grafted base latex.

[0045] Polystyrene-butadiene latex rubber core: 60 parts of the prepared grafted base latex, 0.5 parts of the emulsifier naphthalenesulfonic acid formaldehyde condensate potassium salt, 1 part of a styrene stage, 0.5 parts of the molecular weight regulator n-dodecyl mercaptan, and 0.5 parts of the initiator potassium persulfate are mixed and reacted at 65℃ for 20 min to obtain a styrene-butadiene latex rubber core for polystyrene.

[0046] External grafting of rubber core to prepare grafted powder: According to the formulations in Examples 1-4 of Table 1, 75 parts of base latex were added to the grafting vessel, with emulsifier added for protection. The temperature was raised to 65°C, and 20 parts of di-styrene, 10 parts of di-acrylonitrile, and 1 part of crosslinking agent diallyl cyanoethyl acetate were added to the vessel. 1 part of initiator potassium persulfate was added, and the reaction was carried out for 30 minutes. The temperature was raised to 80°C, and more initiator was added. Then, 30 parts of di-monomer methyl methacrylate pre-emulsified with sodium dodecyl sulfate and 1 part of molecular weight regulator n-dodecyl mercaptan were added dropwise for 2 hours. After the dropwise addition was completed, the temperature was raised to 85°C, and the reaction was carried out for 1 hour before unloading. The grafted latex was coagulated and dried to prepare grafted powder.

[0047] Preparation of MSAN resin: By mass, styrene: acrylonitrile: methyl methacrylate is 2:1:9, and MSAN resin is obtained by polymerization.

[0048] Preparation of transparent ABS resin: By weight, 25 parts of grafting powder, 85 parts of MSAN resin, antioxidant 168 and lubricant magnesium stearate are mixed and added to a twin-screw extruder. The extruded strip is cooled in a water tank and then granulated to obtain transparent ABS resin.

[0049] Example 7

[0050] Preparation of grafted base latex: 85 parts butadiene, 2 parts styrene, 110 parts demineralized water, 3 parts sodium dodecyl sulfonate emulsifier, 4 parts magnesium sulfate stabilizer, 2 parts potassium hydroxide pH adjuster, 5 parts potassium persulfate catalyst, and 0.8 parts n-dodecyl mercaptan molecular weight adjuster are mixed and aged at 55°C for the first time, 65°C for the second time, and 70°C for the third time under nitrogen protection. Through chemical agglomeration, styrene-butadiene latex with a particle size of 210 nm is obtained, which is the grafted base latex.

[0051] Polystyrene-butadiene latex rubber core: 65 parts of the prepared grafted base latex, 0.8 parts of sodium dodecyl sulfonate emulsifier, 4 parts of styrene-1 stage, 0.8 parts of n-dodecyl mercaptan molecular weight regulator and 0.3 parts of azobisisobutyl nitrile initiator are mixed and reacted at 70℃ for 45 min to obtain a styrene-butadiene latex rubber core with polystyrene.

[0052] External grafting of rubber core to prepare grafted powder: According to the formulations in Examples 1-4 of Table 1, 65 parts of base latex were added to the grafting vessel, with emulsifier added for protection. The temperature was raised to 65°C, and 15 parts of distyrene, 5 parts of diacrylonitrile, and 0.5 parts of pentaerythritol diacrylate (crosslinking agent) were added to the vessel. 0.5 parts of azobisisobutyl nitrile (initiator) were added, and the reaction was carried out for 30 minutes. The temperature was raised to 75°C, the initiator was added again, and 20 parts of methyl methacrylate (pre-emulsified with sodium dodecyl sulfate) and 0.5 parts of n-dodecyl mercaptan (molecular weight adjuster) were added dropwise for 2 hours. After the dropwise addition was completed, the temperature was raised to 80°C, and the reaction was carried out for 1 hour before unloading. The grafted latex was coagulated and dried to prepare grafted powder.

[0053] Preparation of MSAN resin: By mass, styrene: acrylonitrile: methyl methacrylate is 4:1:3, and MSAN resin is obtained by polymerization.

[0054] Preparation of transparent ABS resin: By weight, 15 parts of grafting powder, 75 parts of MSAN resin, antioxidant 1010 and lubricant white oil are mixed and added to a twin-screw extruder. The extruded strip is cooled in a water tank and then granulated to obtain transparent ABS resin.

[0055] Comparative Example 1:

[0056] The styrene-butadiene latex used was synthesized using a conventional method. 250 parts butadiene, 83 parts styrene, 518 parts demineralized water, 18 parts potassium oleate (emulsifier), 2.5 parts potassium carbonate (stabilizer), 1.2 parts potassium persulfate (catalyst), and 1 part tert-dodecyl mercaptan (molecular weight regulator) were mixed and emulsion polymerized in a 68°C water bath for 14 hours, resulting in large-particle-size styrene-butadiene latex through chemical agglomeration. The styrene content was 25%, and styrene was not grafted into the rubber core. All other conditions were the same as in Example 1.

[0057] Comparative Example 2:

[0058] The styrene-butadiene latex used was synthesized using a conventional method. 250 parts butadiene, 83 parts styrene, 518 parts demineralized water, 18 parts potassium oleate (emulsifier), 2.5 parts potassium carbonate (stabilizer), 1.2 parts potassium persulfate (catalyst), and 1 part tert-dodecyl mercaptan (molecular weight regulator) were mixed and emulsion polymerized in a 68°C water bath for 14 hours, resulting in large-particle-size styrene-butadiene latex through chemical agglomeration. The styrene content was 25%. All other conditions were the same as in Example 1.

[0059] Comparative Example 3:

[0060] Styrene was not grafted into the rubber core. All other conditions were the same as in Example 1.

[0061] Experimental Example 1

[0062] The transparent ABS resins prepared in Examples 1-4 and Comparative Examples 1-3 were dried in a forced-air oven at 70-90°C for 4 hours, and then injection molded into standard strips and 80mm*10mm*4mm templates using a plastic injection molding machine at an injection temperature of 200-240°C. The injection-molded strips and templates were then placed at 50% relative humidity and 23°C for at least 24 hours before performance testing.

[0063] The performance of Examples 1-4 and Comparative Examples 1-3 is shown in Table 2:

[0064] Table 2 shows the performance of the ABS transparent resin prepared in Examples 1-4 and Comparative Examples 1-3.

[0065]

[0066]

[0067] The transparent ABS resins prepared in Examples 1-4 all have impact strengths higher than 15 kJ / m. 2 Example 1 shows a light transmittance of up to 90.55% and a haze as low as 3.57%.

[0068] Traditional ABS grafted core-shell polymers have poor light transmittance due to light scattering when light passes through the large-particle-size rubber core phase. Multilayer ABS grafted core-shell polymers, when matched with specialized SAN resins, exhibit less light scattering and better light transmittance.

[0069] Comparing Comparative Example 1 and Example 1, it can be found that in the traditional styrene-butadiene latex grafting system, the traditional ABS grafted core-shell structure produces transparent ABS resin with poor light transmittance and high haze.

[0070] Comparing Comparative Example 2 and Example 1, it can be found that under the traditional styrene-butadiene latex grafting system, the transparent ABS resin prepared by constructing the three-layer core-shell structure of the present invention has a certain improvement in light transmittance compared with Comparative Example 1, but is still worse than Example 1.

[0071] Comparing Comparative Example 3 and Example 1, it can be found that the transparent ABS resin prepared by using the large-particle-size, low-styrene-content styrene-butadiene latex of the present invention to construct a traditional ABS grafted core-shell has a certain improvement in light transmittance compared with Comparative Example 1.

[0072] By comparing Example 1 and Comparative Examples 1-3, it was found that the light transmittance of Comparative Examples 2 and 3 was increased by 10.21% and 5.52% respectively compared with Comparative Example 1, and the light transmittance of Example 1 was increased by 30.20% compared with Comparative Example 1. Since 10.21% + 5.52% < 30.20%, it can be shown that the three-layer core-shell structure and the use of styrene-butadiene latex with low styrene content of the present invention have a synergistic effect on improving the transparency of ABS resin, and the effect is obvious.

Claims

1. A transparent ABS resin having a three-layer core-shell structure, characterized by, The three-layer core-shell structure consists of: a styrene-butadiene latex rubber core as the innermost layer, a styrene-acrylonitrile copolymer grafted layer outside the styrene-butadiene latex rubber core, and a methyl methacrylate copolymer grafted layer as the outermost layer.

2. The method for preparing transparent ABS resin as described in claim 1, characterized in that, Includes the following steps: Preparation of styrene-butadiene latex: Butadiene, styrene, demineralized water, emulsifier, stabilizer, pH adjuster, catalyst, and molecular weight adjuster are mixed and aged under nitrogen or inert gas protection to chemically agglomerate and obtain styrene-butadiene latex. Preparation of styrene-butadiene latex rubber core for polystyrene: The styrene-butadiene latex is mixed and reacted with styrene, emulsifier, molecular weight regulator and initiator to obtain styrene-butadiene latex rubber core for polystyrene; Preparation of a polymer with a three-layer core-shell structure: Styrene, acrylonitrile, a crosslinking agent, and an initiator are added to the styrene-butadiene latex rubber core of the polymerized styrene and reacted to polymerize a styrene-acrylonitrile copolymer graft layer. Then, methyl methacrylate, a molecular weight regulator, and an initiator are added to react and obtain a methyl methacrylate copolymer graft layer, forming a polymer with a three-layer core-shell structure. Preparation of MSAN resin: MSAN resin is obtained by polymerizing styrene with acrylonitrile and methyl methacrylate; Preparation of transparent ABS resin: The polymer with the three-layer core-shell structure and the MSAN resin are mixed, lubricant and antioxidant are added, and granulation is performed to obtain transparent ABS resin.

3. The preparation method according to claim 2, characterized in that, The preparation of styrene-butadiene latex comprises, by weight, 80-100 parts butadiene, 1-5 parts styrene, 100-150 parts demineralized water, 1-10 parts emulsifier, 1-5 parts stabilizer, 1-2 parts pH adjuster, 1-5 parts catalyst, and 0.1-1 parts molecular weight adjuster.

4. The preparation method according to claim 2, characterized in that, The emulsifier is selected from at least one of potassium oleate, potassium disproportionated rosinate, sodium salt of naphthalenesulfonic acid formaldehyde condensate, potassium salt of naphthalenesulfonic acid formaldehyde condensate, potassium stearate, sodium dodecylbenzene sulfonate, or sodium dodecyl sulfonate.

5. The preparation method according to claim 2, characterized in that, The stabilizer is selected from at least one of potassium carbonate, potassium chloride, potassium sulfate, potassium carbonate, calcium chloride, calcium sulfate, calcium nitrate, calcium carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, or magnesium carbonate.

6. The method of claim 2, wherein, The pH adjuster is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, or potassium silicate.

7. The preparation method according to claim 2, characterized in that, The catalyst is selected from at least one of potassium persulfate, ammonium persulfate, or sodium persulfate.

8. The preparation method according to claim 2, characterized in that, The molecular weight regulator is selected from at least one of tert-dodecyl mercaptan, mercaptoacrylate, or n-dodecyl mercaptan.

9. The preparation method according to claim 2, characterized in that, The preparation of the styrene-butadiene latex rubber core for polymerizing styrene comprises, by weight, 55-70 parts of styrene-butadiene latex, 0.1-1 parts of emulsifier, 1-5 parts of styrene, 0.1-1 parts of molecular weight regulator, and 0.1-1 parts of initiator.

10. The method of claim 2, wherein, The initiator is selected from at least one of cumene hydroperoxide, sodium persulfate, potassium persulfate, ammonium persulfate, or azobisisobutyl nitrile.

11. The method of claim 2, wherein, The preparation of the polymer with a three-layer core-shell structure comprises, by mass, 56-75 parts of styrene-butadiene latex rubber core, 5-20 parts of styrene, 1-10 parts of acrylonitrile, 10-30 parts of methyl methacrylate, 0.1-1 parts of crosslinking agent, 0.1-1 parts of initiator, and 0.1-1 parts of molecular weight regulator.

12. The method of claim 2, wherein, The crosslinking agent is selected from at least one of diallyl phthalate, diallyl cyanoethyl acetate, polyethylene glycol diacrylate, ethylene glycol diacrylate, glycerol diacrylate, or pentaerythritol diacrylate.

13. The preparation method according to claim 2, characterized in that, The MSAN resin, by mass, has a styrene:acrylonitrile:methyl methacrylate ratio of 2-4:1-2:3-9.

14. The method of claim 2, wherein, The transparent ABS resin is prepared in a ratio of 15-25:75-85 by mass of polymer with a three-layer core-shell structure and MSAN.

15. The preparation method according to claim 2, characterized in that, The lubricant is selected from at least one of vinyl bis-stearamide, oxidized polyethylene wax, magnesium stearate, or white oil.

16. The method of claim 2, wherein, The antioxidant is selected from at least one of hindered phenols and their derivatives or phosphites and their derivatives.

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