A pmma-asa reinforced thermoplastic vulcanizate and method of making same

Abstract

The application discloses a PMMA-ASA reinforced thermoplastic vulcanized rubber and a manufacturing method thereof, and belongs to the technical field of high polymer materials. The thermoplastic vulcanized rubber comprises, by weight, 40-80 parts of a rubber phase, 20-60 parts of a thermoplastic resin continuous phase and 0.5-5 parts of a vulcanizing agent, and is manufactured by dynamic vulcanization of a mixture of the above components; the thermoplastic resin continuous phase is a blended resin composed of polymethyl methacrylate and acrylonitrile-styrene-acrylate copolymer, and the weight ratio of the two is 1:9 to 9:1. The manufacturing method comprises the following steps: after melt blending of the rubber phase, the resin phase and the like, the vulcanizing agent is added and dynamic vulcanization is carried out at 170-210 DEG C. Through the synergistic compounding of PMMA and ASA, the performance defects of single material are overcome, the material has excellent weather resistance, high surface gloss and hardness, good mechanical strength, toughness and processing performance, and is significantly superior to traditional polypropylene-based thermoplastic vulcanized rubber.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically, it relates to a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method. Background Technology

[0002] Thermoplastic vulcanizate (TPV) is a special type of thermoplastic elastomer prepared through a dynamic vulcanization process. Its microstructure consists of cross-linked rubber particles dispersed within a continuous thermoplastic resin phase. This structure gives TPV the elasticity and compression set resistance of traditional vulcanized rubber, as well as the easy processing and recyclability of thermoplastics. It has been widely used in the automotive, construction, electronics, and consumer goods industries.

[0003] Currently, most commercially available TPVs use polypropylene as the continuous phase and ethylene propylene diene monomer (EPDM) as the dispersed phase. These TPVs offer good overall performance, but their weather resistance, surface gloss, and hardness are primarily limited by the PP matrix itself. PP has weak resistance to UV aging, and long-term outdoor use can easily lead to color changes, surface chalking, and degradation of mechanical properties. Furthermore, the surface gloss and hardness of PP often fail to meet the aesthetic requirements of high-end decorative components. This limits the use of traditional PP-based TPVs in applications requiring long-term outdoor use and stringent surface quality standards.

[0004] To improve the weather resistance of TPV, the industry has attempted to introduce resins with superior weather resistance as the continuous phase. For example, using acrylonitrile-styrene-acrylate copolymer (ASA) can significantly improve the material's resistance to UV aging. However, the introduction of ASA resin brings new challenges to the overall performance of TPV: on the one hand, the modulus and tensile strength of ASA are generally lower than those of some engineering plastics, which may affect the application of TPV in applications requiring high rigidity and dimensional stability; on the other hand, the compatibility of ASA with certain rubbers (such as EPDM) and the fine-tuning of its phase structure during dynamic vulcanization still need further optimization to ensure a balance between the elasticity and strength of the final product.

[0005] Polymethyl methacrylate (PMMA) possesses excellent weather resistance, high gloss, high hardness, and good rigidity, making it a potential candidate material for high-performance continuous phase in TPV (Total Volatile Physical) production. However, if PMMA is used alone in a TPV system, its high melt viscosity during melt blending and dynamic vulcanization, its compatibility with the rubber phase, and the toughness requirements of the final product are all challenges that need to be overcome in practical preparation.

[0006] Therefore, in pursuing the superior weather resistance and high surface quality of TPV, existing technologies face a significant contradiction: using high-gloss, high-hardness PMMA sacrifices processability and toughness; while using easily processable, tough ASA makes it difficult to simultaneously achieve extremely high surface hardness and gloss. Simply using PMMA or ASA makes it difficult to simultaneously achieve a balance between excellent weather resistance, high surface gloss / hardness, and good toughness while ensuring good processing flowability and efficient dynamic vulcanization.

[0007] Based on this, the present invention aims to provide a novel thermoplastic vulcanizate and its manufacturing method to synergistically resolve the above-mentioned contradictions and obtain a composite material with excellent weather resistance, high surface quality, high rigidity, good toughness and excellent processing performance. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0009] To achieve the above objectives, the technical solution provided by the present invention is as follows: A PMMA-ASA reinforced thermoplastic vulcanizate, comprising the following components by weight: Rubber phase: 40-80 parts; Thermoplastic resin continuous phase: 20-60 parts; Vulcanizing agent: 0.5-5 parts; The continuous phase of the thermoplastic resin is a blend of PMMA and ASA, wherein the weight ratio of PMMA to ASA is 1:9 to 9:1. The thermoplastic vulcanizate is made by dynamic vulcanization of a mixture containing the components.

[0010] This invention resolves the performance contradictions of using a single material as the continuous phase in TPV by blending PMMA and ASA in a specific ratio as the continuous phase of the thermoplastic resin. PMMA contributes extremely high surface hardness, gloss, and weather resistance, while ASA provides good toughness, processing fluidity, and impact resistance. The synergistic effect of both materials allows the final TPV material to achieve high gloss, high hardness, and superior weather resistance—qualities not found in traditional PP-based TPVs—without sacrificing processing performance and toughness. Simultaneously, it provides a stable and well-balanced melting environment for the dynamic vulcanization of the rubber phase.

[0011] Furthermore, the weight ratio of PMMA to ASA is 3:7 to 7:3. By further limiting the weight ratio of PMMA to ASA within a preferred range, this invention enables a better synergistic balance in the properties of the two resins. At this ratio, the core properties of the material, such as processing fluidity, melt strength, rigidity, toughness, and surface gloss, are optimally matched, thereby producing a thermoplastic vulcanizate with superior and stable overall performance, particularly suitable for high-end applications with stringent requirements for appearance and mechanical properties.

[0012] Furthermore, the rubber phase is selected from at least one of EPDM rubber, nitrile rubber, silicone rubber, or acrylate rubber. The rubber phases selected in this invention all exhibit good synergistic potential with the PMMA-ASA continuous phase. After dynamic vulcanization, these rubbers can form a stable cross-linked rubber particle phase, providing the material with durable elasticity, sealing properties, and resistance to compression set. This selection range covers various performance requirements such as weather resistance, oil resistance, and high / low temperature resistance, allowing the TPV of this invention to flexibly adjust its basic elastic properties according to the target application.

[0013] Furthermore, the rubber phase consists of cross-linked rubber particles formed after dynamic vulcanization and dispersed within the continuous thermoplastic resin phase. This invention clarifies the core microstructural feature of the product: the cross-linked rubber particles formed by dynamic vulcanization are uniformly dispersed within the PMMA-ASA continuous phase. This structure ensures that the material possesses excellent elasticity and resilience similar to vulcanized rubber, while also guaranteeing the reprocessability of thermoplastics. This island-island structure is fundamental to the high performance of TPV, particularly its resistance to permanent compression set and high-temperature performance, and is the structural guarantee for the successful achievement of the performance targets of this solution.

[0014] Furthermore, the invention includes 0.1 to 5 parts of a compatibilizer, wherein the compatibilizer is at least one selected from maleic anhydride-grafted polyolefin, ethylene-acrylate-glycidyl methacrylate copolymer, or styrene-maleic anhydride copolymer. In this invention, the addition of a specific type of compatibilizer effectively improves the interfacial compatibility and adhesion between the PMMA-ASA blend resin phase and the rubber phase. This facilitates the formation of finer, more uniformly dispersed vulcanized rubber particles during dynamic vulcanization and enhances stress transfer between the two phases. The result is a significant improvement in the tensile strength, tear strength, and impact toughness of the final TPV material, while reducing internal losses under repeated deformation.

[0015] Furthermore, it also includes at least one of the following: 0.5-10 parts of plasticizer, 0.1-3 parts of antioxidant and light stabilizer, and 0.1-5 parts of lubricant. In this invention, the addition of plasticizer helps improve the processing fluidity of the blend system, reduces melt viscosity, facilitates dynamic vulcanization, and ultimately enhances the flexibility of the product; the combination of antioxidant and light stabilizer specifically strengthens the material's resistance to thermal oxidation and UV aging during long-term outdoor use, forming a double protection with the inherent weather resistance of PMMA-ASA, greatly extending the service life of the product; the addition of lubricant not only improves the material's processing and demolding properties but also enhances the surface smoothness of the product, synergistically improving the final product's appearance quality in conjunction with the high-gloss PMMA-ASA.

[0016] The present invention also provides a method for manufacturing the PMMA-ASA reinforced thermoplastic vulcanizate, comprising the following steps: S1 The rubber phase, the thermoplastic resin continuous phase, and optional compatibilizers and plasticizers are melt-blended in an internal mixer or screw extruder at 160~200°C to obtain an initial blend. S2. Add the vulcanizing agent to the initial blend and carry out a dynamic vulcanization reaction in the internal mixer or screw extruder at 170~210℃ and 50~300 rpm for 3~15 minutes to obtain a dynamic vulcanized product. S3 extrudes, cools, and granulates the dynamic vulcanization product to obtain the PMMA-ASA reinforced thermoplastic vulcanized granules.

[0017] The above method provides a clear and reliable process route for preparing high-performance TPVs. By employing a "melt blending followed by dynamic vulcanization" step, it ensures that the components are first thoroughly mixed to form a homogeneous continuous phase, in which the rubber phase is then vulcanized in situ. This scientifically designed process, with parameter ranges precisely matched to the melting characteristics and vulcanization kinetics of the PMMA-ASA blend system, enables the efficient and stable preparation of TPV materials with an ideal "sea-island" microstructure.

[0018] Further, in step S1, the continuous thermoplastic resin phase is added in the form of a premix of PMMA and ASA. This premix is ​​obtained by pre-dry mixing PMMA and ASA particles or by melt blending and granulation using a twin-screw extruder. This method, by adding PMMA and ASA in the form of a premix, ensures that the two are initially and uniformly mixed at the molecular level before entering the main mixing process. This avoids the problem of uneven dispersion that may result from the large differences in melting point and viscosity between PMMA and ASA, and is beneficial for obtaining a continuous phase with uniform and stable properties in the final product, thereby ensuring the consistency of product quality between batches.

[0019] Further, in step S2, the vulcanizing agent is at least one of peroxide, phenolic resin, or sulfur donor; the dynamic vulcanization reaction is carried out under inert gas protection or vacuum conditions. The above method matches the appropriate vulcanization system according to the selected rubber type, achieving efficient and complete cross-linking of the rubber phase and ensuring the elastomer properties of TPV. In addition, dynamic vulcanization under inert gas protection or vacuum conditions effectively prevents thermo-oxidative degradation of polymers such as PMMA and ASA under high temperature and high shear, avoiding yellowing and performance degradation of the material, and ensuring the color stability and mechanical property integrity of the final product, especially light-colored or high-transparency products.

[0020] Furthermore, in step S2, the dynamic vulcanization reaction is carried out continuously in a twin-screw extruder, and the vulcanizing agent is injected through the side injection port of the twin-screw extruder. The above method utilizes a twin-screw extruder for continuous production and precisely injects the vulcanizing agent through the side injection port, greatly improving production efficiency and process controllability. This method enables the vulcanizing agent to be instantly and uniformly dispersed in the melt, ensuring a rapid and uniform vulcanization reaction, making it suitable for large-scale industrial production, and resulting in stable and reliable product quality.

[0021] Compared with the prior art, the present invention has the following beneficial effects: I. This invention creatively employs a blend of PMMA and ASA resins as the thermoplastic continuous phase, leveraging the complementary advantages of PMMA's high hardness and high gloss with ASA's excellent toughness and processability. This approach fundamentally overcomes the inherent contradictions encountered when using PMMA or ASA alone, resulting in a novel TPV matrix material that combines excellent surface finish, superior weather resistance, good toughness, and processing fluidity.

[0022] Second, compared with traditional TPV using polypropylene as the continuous phase, the material produced by this invention achieves a qualitative leap in resistance to ultraviolet aging, thermal oxidation, gloss, and hardness, while maintaining the elasticity and processability inherent in TPV. This makes it suitable for applications such as high-end automotive exteriors and outdoor electronic appliance housings, which have stringent requirements for long-term weather resistance and appearance, filling a market gap.

[0023] Third, the manufacturing method designed in this invention precisely matches the process parameters with the characteristics and dynamic vulcanization requirements of the PMMA-ASA blend system. By optimizing the feeding method, reaction conditions, and equipment configuration, efficient and uniform vulcanization of the rubber phase is ensured, forming a stable "sea-island" structure. This method has good repeatability and high efficiency, providing a reliable guarantee for the stable and large-scale production of the high-performance TPV. Detailed Implementation

[0024] The specific embodiments are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the examples are commercially available.

[0025] The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the invention without departing from the spirit and scope of the invention, and all such modifications and substitutions should be covered within the scope of the claims of the invention.

[0026] Example 1 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0027] The formula is as follows, by weight: EPDM rubber: 50.0 kg; Polymethyl methacrylate: 15.0 kg; Acrylonitrile-styrene-acrylate copolymer: 15.0 kg; Peroxide vulcanizing agent: 1.5 kg; Compatibilizer: 1.0 kg; Plasticizer: 3.0 kg; Antioxidant: 0.3 kg; Light stabilizer: 0.3 kg; Lubricant: 0.5 kg.

[0028] The Mooney viscosity [ML(1+4) 125℃] of the EPDM rubber is 50. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 1:1. The peroxide vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. The compatibilizer is maleic anhydride-grafted polyethylene. The plasticizer is dioctyl phthalate. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate. The lubricant is zinc stearate.

[0029] Its manufacturing method includes the following steps: S1 Premix: 15.0 kg of polymethyl methacrylate granules and 15.0 kg of acrylonitrile-styrene-acrylate copolymer granules are put into a high-speed mixer and dry-mixed at room temperature for 5 minutes to obtain polymethyl methacrylate / acrylonitrile-styrene-acrylate copolymer premix.

[0030] S2 Melt Blending: 50.0 kg of EPDM rubber, all of the polymethyl methacrylate / acrylonitrile-styrene-acrylate copolymer premix obtained in step S1, 1.0 kg of maleic anhydride-grafted polyethylene, 3.0 kg of dioctyl phthalate, 0.3 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.3 kg of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 0.5 kg of zinc stearate were added to a mixer. The mixture was melt-blended for 8 minutes at 185°C and a rotor speed of 80 rpm to obtain a homogeneous initial blend.

[0031] S3 Dynamic Vulcanization: With the internal mixer sealed, add 1.5 kg of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane to the initial blend. Under nitrogen protection, conduct the dynamic vulcanization reaction at 190°C and a rotor speed of 100 rpm for 8 minutes. Once the internal mixer torque curve reaches equilibrium or the reaction is complete according to the predetermined time, the dynamically vulcanized product is obtained.

[0032] S4 Granulation: The dynamic vulcanization product is discharged from the internal mixer, immediately pressed and cooled to room temperature through a two-roll mill, and then fed into a pelletizer for granulation to obtain PMMA-ASA reinforced thermoplastic vulcanizate granules.

[0033] Example 2 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0034] The formula is as follows, by weight: Nitrile rubber: 40.0 kg; Polymethyl methacrylate: 6.0 kg; Acrylonitrile-styrene-acrylate copolymer: 54.0 kg; Phenolic resin vulcanizing agent: 2.0 kg; Vulcanization activator: 1.0 kg; Compatibilizer: 2.0 kg; Plasticizer: 8.0 kg; Antioxidant: 0.5 kg; Light stabilizer: 0.5 kg; Lubricant: 1.0 kg.

[0035] The acrylonitrile content of the nitrile rubber is 33%, and the Mooney viscosity [ML(1+4)100℃] is 50. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 1:9. The phenolic resin vulcanizing agent is bromomethylalkylphenolic resin. The vulcanization activator is active zinc oxide. The compatibilizer is ethylene-acrylate-glycidyl methacrylate copolymer. The plasticizer is dioctyl adipate. The antioxidant is tris[2,4-di-tert-butylphenyl]phosphite. The light stabilizer is poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidinyl)imino}]. The lubricant is N,N'-ethylene bis-stearamide.

[0036] Its manufacturing method includes the following steps: S1 Premix: 6.0 kg of polymethyl methacrylate granules and 54.0 kg of acrylonitrile-styrene-acrylate copolymer granules are melt-blended, extruded, water-cooled, and pelletized using a co-rotating twin-screw extruder at 200°C to obtain polymethyl methacrylate / acrylonitrile-styrene-acrylate copolymer premix granules.

[0037] S2 Melt Blending: A co-rotating twin-screw extruder was used. 40.0 kg of nitrile rubber and all the polymethyl methacrylate / acrylonitrile-styrene-acrylate copolymer premix granules obtained in step S1 were added to the main feed port. 2.0 kg of ethylene-acrylate-glycidyl methacrylate copolymer, 8.0 kg of dioctyl adipate, 1.0 kg of active zinc oxide, 0.5 kg of tris[2,4-di-tert-butylphenyl] phosphite, 0.5 kg of poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidinyl)imino}] and 1.0 kg of N,N'-ethylene bis-stearamide were added to the side feed port. The materials are melt-blended in the front section of the extruder (temperature 170-190℃) to obtain the initial blend.

[0038] S3 Dynamic Vulcanization: 2.0 kg of bromomethylalkylphenol resin powder is precisely injected into the initial blend through the side injection port. The material undergoes dynamic vulcanization reaction in the rear section of the extruder (temperature 195-205℃), with a total residence time of 4 minutes, yielding the dynamically vulcanized product.

[0039] S4 Granulation: The dynamic vulcanization product is extruded through a die, cooled in water, and granulated to obtain PMMA-ASA reinforced thermoplastic vulcanized granules.

[0040] Example 3 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0041] The formula is as follows, by weight: Acrylic rubber: 70.0 kg; Polymethyl methacrylate: 27.0 kg; Acrylonitrile-styrene-acrylate copolymer: 3.0 kg; Peroxide vulcanizing agent: 3.5 kg; Compatibilizer: 3.5 kg; Plasticizer: 1.0 kg; Antioxidant: 0.8 kg; Light stabilizer: 0.8 kg; Lubricant: 2.0 kg.

[0042] The acrylate rubber is an ethylene-methyl acrylate copolymer. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 9:1. The peroxide vulcanizing agent is dicumyl peroxide. The compatibilizer is styrene-maleic anhydride copolymer. The plasticizer is trioctyl trimellitate. The antioxidant is octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. The light stabilizer is poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester. The lubricant is polyethylene wax.

[0043] Its manufacturing method includes the following steps: S1 Melt Blending: 70.0 kg of acrylate rubber, 27.0 kg of polymethyl methacrylate granules, 3.0 kg of acrylonitrile-styrene-acrylate copolymer granules, 3.5 kg of styrene-maleic anhydride copolymer, 1.0 kg of trioctyl trimellitate, 0.8 kg of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (octadecyl alcohol), 0.8 kg of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol), and 2.0 kg of polyethylene wax were added to a mixer. The mixture was melt-blended for 10 minutes at 175°C and a rotor speed of 60 rpm to obtain the initial blend.

[0044] S2 Dynamic Vulcanization: Start the vacuum system of the internal mixer and add 3.5 kg of dicumyl peroxide to the initial blend. Perform the dynamic vulcanization reaction at 180℃ and a rotor speed of 80 rpm for 12 minutes. Once the internal mixer torque curve reaches equilibrium or the reaction is complete according to the predetermined time, the dynamically vulcanized product is obtained.

[0045] S3 Granulation: The dynamic vulcanization product is discharged from the internal mixer, immediately pressed and cooled to room temperature through a two-roll mill, and then fed into a pelletizer for granulation to obtain PMMA-ASA reinforced thermoplastic vulcanizate granules.

[0046] Example 4 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0047] The formula is as follows, by weight: Silicone rubber: 60.0 kg; Polymethyl methacrylate: 12.0 kg; Acrylonitrile-styrene-acrylate copolymer: 28.0 kg; Peroxide vulcanizing agent: 4.0 kg; Compatibilizer: 0.5 kg; Plasticizer: 5.0 kg; Antioxidant: 0.1 kg; Light stabilizer: 0.1 kg; Lubricant: 0.1 kg.

[0048] The silicone rubber is methyl vinyl silicone rubber. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 3:7. The peroxide vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. The compatibilizer is maleic anhydride-grafted polypropylene. The plasticizer is epoxidized soybean oil. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate. The lubricant is calcium stearate.

[0049] Its manufacturing method includes the following steps: S1 Melt Blending: 60.0 kg of silicone rubber, 12.0 kg of polymethyl methacrylate granules, 28.0 kg of acrylonitrile-styrene-acrylate copolymer granules, 0.5 kg of maleic anhydride-grafted polypropylene, 5.0 kg of epoxidized soybean oil, 0.1 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.1 kg of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 0.1 kg of calcium stearate were added to an internal mixer. The mixture was melt-blended for 6 minutes at 165°C and a rotor speed of 70 rpm to obtain the initial blend.

[0050] S2 Dynamic Vulcanization: 4.0 kg of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane was added to the initial blend. The dynamic vulcanization reaction was carried out at 175°C and a rotor speed of 90 rpm for 10 minutes. The dynamically vulcanized product was obtained after the internal mixer torque curve reached equilibrium or the reaction was completed according to the predetermined time.

[0051] S3 Granulation: The dynamic vulcanization product is discharged from the internal mixer, immediately pressed and cooled to room temperature through a two-roll mill, and then fed into a pelletizer for granulation to obtain PMMA-ASA reinforced thermoplastic vulcanizate granules.

[0052] Example 5 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0053] The formula is as follows, by weight: EPDM rubber: 80.0 kg; Polymethyl methacrylate: 10.0 kg; Acrylonitrile-styrene-acrylate copolymer: 10.0 kg; Peroxide vulcanizing agent: 0.5 kg; Compatibilizer: 0.0 kg; Plasticizer: 0.0 kg; Antioxidant: 0.05 kg; Light stabilizer: 0.05 kg; Lubricant: 0.05 kg.

[0054] The Mooney viscosity [ML(1+4) 125℃] of the EPDM rubber is 70. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 1:1. The peroxide vulcanizing agent is dicumyl peroxide. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate. The lubricant is zinc stearate.

[0055] Its manufacturing method includes the following steps: S1 Melt Blending: 80.0 kg of EPDM rubber, 10.0 kg of polymethyl methacrylate granules, 10.0 kg of acrylonitrile-styrene-acrylate copolymer granules, 0.05 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.05 kg of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 0.05 kg of zinc stearate were added to an internal mixer. The mixture was melt-blended for 5 minutes at 160°C and a rotor speed of 50 rpm to obtain the initial blend.

[0056] S2 Dynamic Vulcanization: 0.5 kg of dicumyl peroxide is added to the initial blend. The dynamic vulcanization reaction is carried out at 170℃ and a rotor speed of 50 rpm for 15 minutes. The dynamic vulcanized product is obtained after the internal mixer torque curve reaches equilibrium or the reaction is completed according to the predetermined time.

[0057] S3 Granulation: The dynamic vulcanization product is discharged from the internal mixer, immediately pressed and cooled to room temperature through a two-roll mill, and then fed into a pelletizer for granulation to obtain PMMA-ASA reinforced thermoplastic vulcanizate granules.

[0058] Example 6 This embodiment provides a PMMA-ASA reinforced thermoplastic vulcanizate and its manufacturing method.

[0059] The formula is as follows, by weight: Nitrile rubber: 40.0 kg; Polymethyl methacrylate: 30.0 kg; Acrylonitrile-styrene-acrylate copolymer: 30.0 kg; Peroxide vulcanizing agent: 5.0 kg; Compatibilizer: 5.0 kg; Plasticizer: 10.0 kg; Antioxidant: 1.5 kg; Light stabilizer: 1.5 kg; Lubricant: 5.0 kg.

[0060] The acrylonitrile content of the nitrile rubber is 41%, and its Mooney viscosity [ML(1+4) 100℃] is 80. The weight ratio of polymethyl methacrylate to acrylonitrile-styrene-acrylate copolymer is 1:1. The peroxide vulcanizing agent is 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The compatibilizer is maleic anhydride-grafted polyethylene. The plasticizer is dioctyl phthalate. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate. The lubricant is zinc stearate.

[0061] Its manufacturing method includes the following steps: S1 Melt Blending: 40.0 kg of nitrile rubber, 30.0 kg of polymethyl methacrylate granules, 30.0 kg of acrylonitrile-styrene-acrylate copolymer granules, 5.0 kg of maleic anhydride-grafted polyethylene, 10.0 kg of dioctyl phthalate, 1.5 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1.5 kg of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 5.0 kg of zinc stearate were added to an internal mixer. The mixture was melt-blended for 10 minutes at 200°C and a rotor speed of 150 rpm to obtain the initial blend.

[0062] S2 Dynamic Vulcanization: 5.0 kg of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane was added to the initial blend. The dynamic vulcanization reaction was carried out at 205℃ and a rotor speed of 200 rpm for 5 minutes. After the internal mixer torque curve reached equilibrium or the reaction was completed according to the predetermined time, the dynamic vulcanized product was obtained.

[0063] S3 Granulation: The dynamic vulcanization product is discharged from the internal mixer, immediately pressed and cooled to room temperature through a two-roll mill, and then fed into a pelletizer for granulation to obtain PMMA-ASA reinforced thermoplastic vulcanizate granules.

[0064] Comparative Example 1 This comparative example provides a conventional polypropylene-based thermoplastic vulcanizate for comparison with the PMMA-ASA-based TPV of the present invention.

[0065] The formula is as follows, by weight: EPDM rubber: 50.0 kg; Polypropylene: 30.0 kg; Peroxide vulcanizing agent: 1.5 kg; Compatibilizer (maleic anhydride-grafted polypropylene): 1.0 kg; The types and amounts of other additives (antioxidants, lubricants, etc.) are exactly the same as in Example 1.

[0066] The manufacturing method is the same as in Example 1, except that the PMMA-ASA premix is ​​replaced with an equal amount of polypropylene granules.

[0067] Comparative Example 2 This comparative example provides a thermoplastic vulcanizate with pure ASA as the continuous phase, used to compare the PMMA-ASA blend system.

[0068] The formula is as follows, by weight: EPDM rubber: 50.0 kg; Acrylonitrile-styrene-acrylate copolymer: 30.0 kg; Peroxide vulcanizing agent: 1.5 kg; Compatibilizer (maleic anhydride-grafted polyethylene): 1.0 kg; The types and dosages of other adjuvants are exactly the same as in Example 1.

[0069] The manufacturing method is the same as in Example 1, except that the PMMA-ASA premix is ​​replaced with an equal amount of pure ASA granules.

[0070] Comparative Example 3 This comparative example provides a thermoplastic vulcanizate with pure PMMA as the continuous phase, used to compare the PMMA-ASA blend system.

[0071] The formula is as follows, by weight: EPDM rubber: 50.0 kg; Polymethyl methacrylate: 30.0 kg; Peroxide vulcanizing agent: 1.5 kg; Compatibilizer (styrene-maleic anhydride copolymer): 3.5 kg; Plasticizer (dioctyl phthalate): 5.0 kg; The types and dosages of other adjuvants are similar to those in Example 1.

[0072] The manufacturing method is the same as in Example 1, but due to the high melt viscosity, the processing temperature is increased to 195°C, and the mixing and vulcanization time is extended.

[0073] Comparative Example 4 This comparative example provides a thermoplastic vulcanizate without compatibilizer to verify the key role of compatibilizer in the system of the present invention.

[0074] Its formulation and manufacturing method are exactly the same as those in Example 1, but without the addition of 1.0 kg of maleic anhydride-grafted polyethylene compatibilizer.

[0075] Comparative Example 5 This comparative example uses mismatched process conditions to prepare the formulation of Example 1, in order to verify the necessity of the manufacturing method of the present invention.

[0076] Its formula is exactly the same as that of Example 1.

[0077] The manufacturing method has been modified as follows: In the S2 dynamic vulcanization step, the reaction is carried out in an air environment at 150°C for 20 minutes. If this temperature is too low, the vulcanizing agent may not decompose sufficiently, resulting in incomplete vulcanization.

[0078] The performance of Examples 1-6 was compared with that of Comparative Examples 1-5 using the following test methods: All tests were conducted in a standard laboratory environment (temperature 23±2℃, relative humidity 50±10%). Before testing, the granules obtained from the examples and comparative examples were prepared into corresponding standard test specimens under the same injection molding conditions (injection temperature: 200-220℃, mold temperature: 40℃), and conditioned in a standard environment for at least 24 hours before testing.

[0079] I. Rockwell Hardness (R Scale) Test standards: Refer to ASTM D785 or GB / T 3398.2.

[0080] Testing instrument: Rockwell hardness tester.

[0081] Test Procedure: Use an R-grid (indenter is a 12.7 mm diameter steel ball, initial test force is 98 N, total test force is 588 N). Place the sample stably on the worktable, apply the initial test force, adjust the dial to zero, and then steadily apply the total test force over 2-4 seconds and hold for 15 seconds. Remove the main test force, maintain the initial test force, and read the hardness value 15 seconds after removing the main test force. Perform at least 5 tests at different locations on the same sample, take the arithmetic mean, and round the result to the nearest integer.

[0082] II. Gloss (60° Gloss) Test standards: Refer to ASTM D523 or GB / T 8807.

[0083] Testing instrument: 60° gloss meter.

[0084] Test Procedure: Calibrate the instrument to the high-gloss and low-gloss reference values ​​of the standard plate. Place the injection-molded flat sample surface (typically a 60mm × 40mm × 3mm plate) firmly against the test hole. Measure the specular reflected luminous flux of the spot area at a 60° incident angle. Measure at least three times at different locations on the sample surface, and take the arithmetic mean. The result is expressed in gloss units (GU) and rounded to the nearest integer.

[0085] III. Tensile Strength & Elongation at Break Test standard: Refer to ASTM D412 (Die C) or GB / T 1040.2.

[0086] Testing instrument: Universal testing machine.

[0087] Sample specifications: Use standard dumbbell-shaped samples (such as Type IV or 1BA).

[0088] Test Procedure: Clamp the specimen symmetrically in the fixture and set the gauge length. Tensile the specimen at a constant speed of 500 ± 50 mm / min until fracture. The testing machine automatically records the maximum tensile force (tensile strength) and the elongation of the gauge length at fracture (elongation at break). At least 5 valid specimens should be tested in each group, and the results should be the arithmetic mean. Tensile strength is expressed in MPa, rounded to one decimal place; elongation at break is expressed as a percentage, rounded to the nearest integer.

[0089] IV. Melt Flow Rate (MFR) Test standards: Refer to ASTM D1238 or GB / T 3682.1.

[0090] Testing instrument: Melt flow rate meter.

[0091] Test conditions: Select condition T (220℃, 10.00 kg). This is a commonly used test condition for high melt viscosity engineering plastics and TPV.

[0092] Test Procedure: Add approximately 5g of granules to a barrel preheated to 220°C and preheat for 4 minutes. Add a 10.00 kg weight to the top of the piston, cut and discard the initially extruded strip. Then cut the strip at specified time intervals (e.g., every 30 seconds) and weigh it. Calculate the number of grams of polymer extruded per 10 minutes, which is the melt flow rate (MFR), expressed in g / 10min, rounded to one decimal place.

[0093] V. Compression Set Test standards: Refer to ASTM D395 (Method B) or GB / T 7759.1.

[0094] Testing instruments: compression clamp, constant temperature oven, thickness gauge.

[0095] Sample specifications: Cylindrical sample, diameter 29.0±0.5 mm, thickness 12.5±0.5 mm.

[0096] Test Procedure: Measure the original thickness (h0) of the specimen. Stack the specimens in the fixture and compress them to 75% of their original thickness (i.e., a compression rate of 25%). Place the fixture containing the specimens in an oven at 70±1℃ for 22±0.25 hours. After removal, quickly release the fixture and allow the specimens to recover at room temperature for 30 minutes. Measure the thickness (h0) of the recovered specimens. r The compression set C is calculated using the formula: C (%) = [(h0 - h)] r ) / (h0 - h s )] × 100, where h sThe thickness is the limiter thickness (i.e., the thickness under compression). Each test group should include at least 3 specimens, and the results should be the arithmetic mean, rounded to the nearest integer.

[0097] VI. Color Difference after Xenon Arc Aging Test standards: Refer to ASTM D4459 or GB / T 16422.2 (Xenon lamp aging) and ASTM D2244 or GB / T 7921 (color difference calculation).

[0098] Testing instruments: Xenon lamp weathering test chamber, colorimeter.

[0099] Sample specifications: flat plate with a thickness ≥ 2 mm.

[0100] Test steps: Initial measurement: The CIE L*a*b* color space values ​​of the sample before aging were measured using a colorimeter under D65 standard light source and 10° field of view conditions.

[0101] Aging conditions: The samples were placed in a xenon lamp test chamber. The black panel temperature was set to 70±3℃, the chamber temperature to 50±3℃, and the relative humidity to 50±10%. Waterless illumination cycling was used, with the irradiance controlled at 0.51 W / m². 2 @ 340 nm. Continuous exposure for 1000 hours.

[0102] Final measurement: Remove the sample, wipe it clean, and after 24 hours of conditioning under standard conditions, measure its L*a*b* value again.

[0103] Color difference calculation: Calculate the total color difference ΔE according to the CIE 1976 formula: ΔE = √[(ΔL*)] 2 +(Δa*) 2 +(Δb*) 2 The smaller the ΔE value, the less the color change and the better the weather resistance. The result is rounded to one decimal place.

[0104] The test results are shown in the table below: Test Project Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Surface Rockwell hardness 112 98 118 95 105 110 75 85 120 108 100 gloss 92 85 94 82 88 90 65 78 95 89 85 Tensile strength 24.5 20.1 26.8 18.5 15.0 22.0 16.0 18.5 8.5 18.0 20.5 Elongation at break 380 420 280 450 500 350 450 400 50 350 370 Melt Flow Index 8.5 15.2 4.0 12.8 6.5 9.0 12.0 18.0 0.8 8.0 8.2 Compression permanent deformation 35 38 40 42 32 45 38 36 55 48 58 Color difference ΔE after xenon lamp aging for 1000 hours 1.8 2.0 1.5 2.2 2.5 1.9 15.5 2.5 1.7 2.0 3.5 Analysis of the table data yields the following: This invention resolves the technical contradiction between traditional materials and single-component formulations through a core PMMA-ASA compound system. Compared to Comparative Example 1, which is closest to the prior art, this invention achieves significant improvements in weather resistance and surface properties. More importantly, the compound design proves to be crucial; the single ASA in Comparative Example 2 results in insufficient hardness and gloss, while the single PMMA in Comparative Example 3 severely sacrifices toughness, processability, and elasticity. In particular, the data from Comparative Example 4 confirms the indispensable role of the compatibilizer, whose tensile strength and compressive set are significantly inferior to those of the preferred embodiment 1. This directly demonstrates the necessity of the compatibilizer in the claims for strengthening the two-phase interface and improving the overall mechanical properties of the material.

[0105] The specialized dynamic vulcanization process described in this invention is an integral technical guarantee for achieving superior performance. Data from Comparative Example 5 provides direct evidence: due to its excessively low vulcanization temperature, the crosslinking reaction of the rubber phase was insufficient, resulting in a compression set as high as 58%, far exceeding that of Example 1. This comparison demonstrates that the process temperature range defined in the claims is the critical condition for achieving high elastic recovery performance of TPV, and is by no means a conventional or arbitrary choice in the art. The optimized process ensures sufficient vulcanization of the rubber phase, which is key to forming a stable "sea-island" structure and obtaining excellent end-use performance.

[0106] In summary, this invention provides a complete technical solution, from innovative material formulation to specialized preparation processes. The solution systematically overcomes all the major shortcomings of existing technologies: it not only circumvents the weather resistance and appearance bottlenecks of traditional TPV, but also resolves the performance contradictions of single materials through synergistic compounding, and rigorously verifies the indispensability of specific additives and core process parameters through experimental data. Therefore, compared to all the prior art or non-preferred solutions represented by the comparative examples, this invention exhibits comprehensive, significant, and unpredictable technological advancements, possessing outstanding substantive features and significant industrial application value.

[0107] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A PMMA-ASA reinforced thermoplastic vulcanizate, characterized in that, By weight, it includes the following components: Rubber phase: 40-80 parts; Thermoplastic resin continuous phase: 20~60 parts; Vulcanizing agent: 0.5~5 parts; The continuous phase of the thermoplastic resin is a blend of PMMA and ASA, wherein the weight ratio of PMMA to ASA is 1:9 to 9:

1. The thermoplastic vulcanizate is made by dynamic vulcanization of a mixture containing the components.

2. The thermoplastic vulcanizate according to claim 1, characterized in that: The weight ratio of PMMA to ASA is 3:7 to 7:

3.

3. The thermoplastic vulcanizate according to claim 1, characterized in that: The rubber phase is selected from at least one of EPDM rubber, nitrile rubber, silicone rubber, or acrylate rubber.

4. The thermoplastic vulcanizate according to claim 1, characterized in that: The rubber phase consists of cross-linked rubber particles formed after dynamic vulcanization and dispersed in the continuous phase of the thermoplastic resin.

5. The thermoplastic vulcanizate according to claim 1, characterized in that: It also includes 0.1 to 5 parts of a compatibilizer, wherein the compatibilizer is at least one of maleic anhydride-grafted polyolefin, ethylene-acrylate-glycidyl methacrylate copolymer or styrene-maleic anhydride copolymer.

6. The thermoplastic vulcanizate according to claim 1, characterized in that: It also includes at least one of the following: 0.5 to 10 parts of plasticizer, 0.1 to 3 parts of antioxidant and light stabilizer, and 0.1 to 5 parts of lubricant.

7. A method for manufacturing a PMMA-ASA reinforced thermoplastic vulcanizate as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1 The rubber phase, the thermoplastic resin continuous phase, and optional compatibilizers and plasticizers are melt-blended in an internal mixer or screw extruder at 160~200°C to obtain an initial blend. S2. Add the vulcanizing agent to the initial blend and carry out a dynamic vulcanization reaction in the internal mixer or screw extruder at 170~210℃ and 50~300 rpm for 3~15 minutes to obtain a dynamic vulcanized product. S3 extrudes, cools, and granulates the dynamic vulcanization product to obtain the PMMA-ASA reinforced thermoplastic vulcanized granules.

8. The manufacturing method according to claim 7, characterized in that: In step S1, the continuous phase of thermoplastic resin is added in the form of a premix of PMMA and ASA, which is obtained by pre-dry mixing PMMA and ASA particles or by melt blending and granulation using a twin-screw extruder.

9. The manufacturing method according to claim 7, characterized in that: In step S2, the vulcanizing agent is at least one of peroxide, phenolic resin, or sulfur donor; the dynamic vulcanization reaction is carried out under inert gas protection or vacuum conditions.

10. The manufacturing method according to claim 7, characterized in that: In step S2, the dynamic vulcanization reaction is carried out continuously in a twin-screw extruder, and the vulcanizing agent is injected through the side injection port of the twin-screw extruder.