High-gloss scratch-resistant heat-resistant grade PMMA composite material and preparation method thereof

Abstract

The present application relates to a kind of high-gloss scratch-resistant heat-resistant grade PMMA composite material and its preparation method, by weight fraction, high-gloss scratch-resistant heat-resistant grade PMMA composite material includes PMMA, toughening agent, compatibilizer, heat-resistant agent, brightener and auxiliary agent;Toughening agent has core-shell structure, outer shell is the copolymer of styrene and acrylonitrile, inner core is organosiloxane and acrylic rubber;The particle size of toughening agent is 80-120nm;Compatibilizer is MABS;Heat-resistant agent is the copolymer of alpha-methylstyrene and acrylonitrile;Brightener is EBS;Its preparation method is: after being mixed uniformly according to weight ratio, high-gloss scratch-resistant heat-resistant grade PMMA composite material is prepared by twin-screw extruder extrusion granulation.The preparation method of the present application is simple, and the prepared PMMA composite material has the characteristics of high gloss, scratch resistance, high heat-resistant temperature.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-gloss, scratch-resistant, and heat-resistant PMMA composite material and its preparation method. Background Technology

[0002] Due to environmental regulations and cost requirements, automotive interior parts are increasingly trending towards paint-free leather-textured and paint-free high-gloss finishes. Leather-textured finishes improve scratch resistance; however, high-gloss finishes, due to their surface characteristics and lack of high-gloss paint protection, are more prone to scratches. Traditional high-gloss interior trim materials such as PC / ABS (polycarbonate / acrylonitrile-butadiene-styrene copolymer) alloys and ABS (acrylonitrile-butadiene-styrene copolymer) have limited the development and application of paint-free high-gloss interior trim parts due to their poor scratch resistance.

[0003] Polymethyl methacrylate (PMMA) is widely used in the automotive and lighting industries due to its excellent optical properties. PMMA not only boasts high transparency but also high gloss and high surface hardness; its pencil hardness can reach over 3H, making it the engineering plastic with the highest surface hardness. These excellent surface properties meet the high gloss and scratch resistance requirements of automotive interior trim parts. PMMA also possesses high strength and high modulus. Its drawbacks include relative brittleness and low impact strength.

[0004] Patent CN111592730A proposes using ASA (acrylonitrile-styrene-acrylic rubber copolymer) and MBS (methyl methacrylate-butadiene-styrene copolymer) as toughening agents to improve the toughness of PMMA. The notched impact resistance can reach around 10, which basically meets the toughness requirements of automotive interior parts. However, the toughening effect of ASA is limited, and ASA will affect the gloss of the material and its heat resistance, thus failing to meet the high heat resistance requirements of interior parts.

[0005] Patent CN106751099A improves the toughness of PMMA by adding high-impact powder and AS (i.e., ABS). Due to the high proportion of added materials, it has a significant impact on the heat resistance of the final product. Therefore, patent CN106751099A increases the heat distortion temperature by adding N-phenylmaleimide copolymer. However, the glass transition temperature of this heat resistant agent is too high, and its dispersion in PMMA is poor, which reduces the gloss of the PMMA composite material.

[0006] In summary, existing PMMA composite materials cannot simultaneously possess the characteristics of high gloss, scratch resistance, and high heat resistance. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art and provide a high-gloss, scratch-resistant, and heat-resistant PMMA composite material and its preparation method.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A high-gloss, scratch-resistant, and heat-resistant PMMA composite material, by weight, comprises 40-60 parts PMMA, 20-40 parts toughening agent, 2-4 parts compatibilizer, 10-30 parts heat resistant agent, 0.2-0.4 parts gloss agent, 0-0.4 parts UV resistant agent, and 0-0.4 parts antioxidant.

[0010] The toughening agent has a core-shell structure, with the outer shell being a copolymer of styrene and acrylonitrile, and the core being an organosiloxane and acrylic rubber; the particle size of the toughening agent is 80-120 nm;

[0011] The compatibilizer is MABS (a copolymer of methyl methacrylate, styrene, acrylonitrile, and butadiene);

[0012] The heat resistant agent is a copolymer of α-methylstyrene and acrylonitrile;

[0013] The brightener is EBS (ethylene bis-stearamide).

[0014] As a preferred technical solution:

[0015] The high-gloss, scratch-resistant, and heat-resistant PMMA composite material described above has a melt flow index of 2-5 g / 10 min at 250°C and 2.16 kg.

[0016] As described above, in a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, the toughening agent has a particle size between 80-120 nm. The toughening agent and the base material have an island structure. The toughening agent particles, acting as islands, have good compatibility with the base material, but they cannot be further sheared and dispersed by a twin-screw extruder to become smaller. If the particle size is too large, it will form a microscopic uneven surface on the product surface, resulting in a decrease in the surface gloss of the product. If the particle size is too small, the toughening effect will be poor.

[0017] As described above, for a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, the glass transition temperature of the heat resistant agent is between 120-140℃. If the glass transition temperature is too high, it will affect the dispersion of the heat resistant agent in the substrate; if the glass transition temperature is too low, the heat resistance will be poor.

[0018] The high-gloss, scratch-resistant, and heat-resistant PMMA composite material described above has a tensile strength of 47.6-55.1 MPa, a flexural strength of 68.2-76.1 MPa, a flexural modulus of 2175-2390 MPa, and a notched impact strength of 6.5-13.6 KJ / m. 2 The Vicat temperature is 99.8-106.2℃, the pencil hardness is 2-3H, and the gloss is 107-112.

[0019] The present invention also provides a method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material as described in any of the preceding claims, wherein the components are mixed according to the weight ratio and then extruded and granulated by a twin-screw extruder to obtain the high-gloss, scratch-resistant, and heat-resistant PMMA composite material.

[0020] As a preferred technical solution:

[0021] As described above, the extrusion temperature of the twin-screw extruder is 220-230℃, and the rotation speed is 350-400 rpm.

[0022] Beneficial effects

[0023] (1) The present invention selects a copolymer as a toughening agent, which presents a core-shell structure, wherein the organosiloxane and acrylic rubber are the core of the toughening agent, which is used to improve the toughness and low temperature resistance of the composite material; the glass transition temperature of the organosiloxane can reach -120℃, which can provide the composite material with excellent impact resistance and cold resistance; the copolymer of styrene and acrylonitrile is the shell of the toughening agent, which is used to provide compatibility with PMMA. The acrylonitrile segments of the shell are similar in structure to PMMA and have good compatibility.

[0024] (2) The present invention controls the particle size of the toughening agent to be between 80-120nm, which will not affect the gloss of PMMA.

[0025] (3) In this invention, MABS is selected as a compatibilizer. The MMA segment of MABS has similar compatibility with PMMA; the AS segment of MABS also has good compatibility with the shell of the toughening agent and the heat resistant agent.

[0026] (4) Existing technologies often use N-phenylmaleimide copolymers as heat resistant agents because they have high heat resistance efficiency and glass transition temperature generally above 170°C. This is significantly different from the glass transition temperature of PMMA. Such heat resistant agents are poorly dispersed in PMMA, and the heat resistant agent particles exposed on the product surface make the product surface microscopically uneven, affecting the gloss. In this invention, a copolymer of α-methylstyrene and acrylonitrile is selected as the heat resistant agent. The side methyl groups on the main chain of the heat resistant agent can inhibit the movement of chain segments, which can increase the glass transition temperature of PMMA. Furthermore, the heat resistant agent and PMMA have good compatibility and dispersibility, and do not affect the gloss of PMMA.

[0027] (5) In this invention, EBS is selected as a brightener. During the processing of the finished composite material, EBS is precipitated onto the surface of the product, filling the tiny gaps between the resin, toughening agent and heat resistant agent to improve the gloss of the product surface.

[0028] (6) The high-gloss, scratch-resistant, and heat-resistant PMMA composite material of the present invention is suitable for high-gloss, paint-free interior parts, such as decorative strips and control panels. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0030] The following are the testing methods for the relevant properties of the high-gloss, scratch-resistant, and heat-resistant PMMA composite materials prepared in the various embodiments and comparative examples:

[0031] The prepared composite material was dried in a forced-air oven at 90°C for more than 4 hours, and then injection molded into standard specimens. After the injection-molded standard specimens were placed at 50% relative humidity and 23°C for at least 24 hours, the following tests were performed:

[0032] The tensile strength test method is as follows: The test is carried out in accordance with ISO 527-2:2012, wherein the test sample is type 1A and the tensile speed is 50 mm / min.

[0033] The testing methods for bending strength and bending modulus are as follows: The tests shall be conducted in accordance with ISO 178:2019, with a test speed of 2 mm / min.

[0034] The method for testing notched impact strength is as follows: The test is conducted in accordance with the method of ISO 179-1 / 1eA-2010, wherein the notch type is type A and the pendulum energy is 2J.

[0035] The Vicat temperature test method is as follows: The test is conducted in accordance with ISO 306:2013, where the load is 50 N and the heating rate is 50 °C / h.

[0036] Pencil hardness testing method: The test shall be conducted in accordance with the method of ISO 15184:2012;

[0037] Gloss testing method: The test shall be conducted in accordance with ASTM D523-2014, with a test angle of 60°.

[0038] Example 1

[0039] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0040] (1) Preparation of raw materials;

[0041] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0042] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0043] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0044] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0045] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0046] Antioxidant: Brand is BASF (Germany), grade is B215;

[0047] UV protectant: Brand is BASF (Germany), product name is UV-234;

[0048] (2) By weight, 50 parts PMMA, 30 parts toughening agent, 2 parts compatibilizer, 20 parts heat resistant agent, 0.2 parts brightener, 0.3 parts UV agent and 0.4 parts antioxidant are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first to tenth zones are 220℃, 225℃, 230℃, 230℃, 230℃, 230℃, 230℃, 230℃, 225℃ and 225℃ respectively.

[0049] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 55.1 MPa, a flexural strength of 68.8 MPa, a flexural modulus of 2175 MPa, and a notched impact strength of 7.2 KJ / m. 2 The Vicat temperature is 103.2℃, the pencil hardness is 2H, and the gloss is 110.

[0050] Comparative Example 1

[0051] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material is basically the same as in Example 1, except that the toughening agent in step (1) is manufactured by LG Chem and its brand name is EM500.

[0052] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 53.7 MPa, a flexural strength of 67.1 MPa, a flexural modulus of 2130 MPa, and a notched impact strength of 8.6 KJ / m. 2 The Vicat temperature is 102.5℃, the pencil hardness is 1H, and the gloss is 96.

[0053] Comparing Comparative Example 1 and Example 1, it can be seen that the core and shell material of the toughening agent used in Comparative Example 1 is methyl methacrylate-butadiene-styrene copolymer (styrene-butadiene rubber as the core, and styrene and methyl methacrylate as the shell), with a particle size of about 300 nm. This will lead to a decrease in the gloss of the obtained PMMA composite material. This is because the toughening agent has a large particle size, which will form an obvious uneven interface on the surface of the composite material, resulting in a lower gloss.

[0054] Comparative Example 2

[0055] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material is basically the same as in Example 1, except that: no compatibilizer is prepared in step (1) and no compatibilizer is added in step (2).

[0056] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 54.9 MPa, a flexural strength of 68.2 MPa, a flexural modulus of 2150 MPa, and a notched impact strength of 6.2 KJ / m. 2 The Vicat temperature is 103.3℃, ​​the pencil hardness is 2H, and the gloss is 110.

[0057] Comparing Comparative Example 2 with Example 1, it can be seen that the absence of compatibilizer in Comparative Example 2 leads to a certain degree of reduction in the overall performance of the high-gloss, scratch-resistant, and heat-resistant PMMA composite material.

[0058] Comparative Example 3

[0059] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material is basically the same as in Example 1, except that the heat resistant agent in step (1) is of the brand name Denki Chemical of Japan, and the grade name is MS-NB.

[0060] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 53.4 MPa, a flexural strength of 66.7 MPa, a flexural modulus of 2125 MPa, and a notched impact strength of 6.5 KJ / m. 2 The Vicat temperature is 108.1℃, the pencil hardness is 1H, and the gloss is 93.4.

[0061] Comparing Comparative Example 3 and Example 1, it can be seen that the heat resistant agent used in Comparative Example 3 is an N-phenylmaleimide-styrene-maleic anhydride copolymer. This heat resistant agent has a glass transition temperature of over 190°C, which significantly improves the heat resistance. However, it also leads to a significant decrease in gloss and a certain decrease in pencil hardness. This is because the glass transition temperature of this heat resistant agent is too different from that of the PMMA substrate, making it difficult to completely disperse the heat resistant agent into the PMMA through a twin-screw extruder. The unmelted heat resistant agent aggregates form micro-pits on the surface of the composite material, resulting in lower gloss and reduced scratch resistance of the obtained PMMA composite material.

[0062] Example 2

[0063] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0064] (1) Preparation of raw materials;

[0065] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0066] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0067] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0068] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0069] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0070] Antioxidant: Brand is BASF (Germany), grade is B215;

[0071] (2) By weight, 70 parts PMMA, 20 parts toughening agent, 4 parts compatibilizer, 10 parts heat resistant agent, 0.3 parts brightener and 0.2 parts antioxidant are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 350 rpm, and the extrusion temperatures of the first to tenth zones are 230℃, 223℃, 220℃, 220℃, 220℃, 220℃, 220℃, 220℃, 225℃ and 225℃ respectively.

[0072] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 53.3 MPa, a flexural strength of 76.1 MPa, a flexural modulus of 2380 MPa, and a notched impact strength of 6.5 KJ / m. 2 The Vicat temperature is 100℃, the pencil hardness is 3H, and the gloss is 112.

[0073] Example 3

[0074] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0075] (1) Preparation of raw materials;

[0076] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0077] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0078] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0079] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0080] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0081] UV protectant: Brand is BASF (Germany), product name is UV-234;

[0082] (2) By weight, 60 parts PMMA, 25 parts toughening agent, 3 parts compatibilizer, 15 parts heat resistant agent, 0.2 parts brightener and 0.4 parts UV agent are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 360 rpm, and the extrusion temperatures of the first to tenth zones are 225℃, 220℃, 225℃, 225℃, 225℃, 225℃, 225℃, 230℃ and 230℃ respectively.

[0083] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 54.2 MPa, a flexural strength of 75.9 MPa, a flexural modulus of 2390 MPa, and a notched impact strength of 6.8 KJ / m. 2 The Vicat temperature is 99.8℃, the pencil hardness is 2H, and the gloss is 112.

[0084] Example 4

[0085] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0086] (1) Preparation of raw materials;

[0087] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0088] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0089] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0090] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0091] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0092] Antioxidant: Brand is BASF (Germany), grade is B215;

[0093] UV protectant: Brand is BASF (Germany), product name is UV-234;

[0094] (2) By weight, 55 parts PMMA, 30 parts toughening agent, 2 parts compatibilizer, 25 parts heat resistant agent, 0.4 parts brightener, 0.2 parts UV agent and 0.2 parts antioxidant are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 390 rpm, and the extrusion temperatures of the first to tenth zones are 228℃, 230℃, 224℃, 224℃, 224℃, 224℃, 224℃, 224℃, 220℃ and 220℃ respectively.

[0095] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 53.2 MPa, a flexural strength of 74.5 MPa, a flexural modulus of 2340 MPa, and a notched impact strength of 8.9 KJ / m. 2 The Vicat temperature is 100.1℃, the pencil hardness is 2H, and the gloss is 110.

[0096] Example 5

[0097] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0098] (1) Preparation of raw materials;

[0099] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0100] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0101] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0102] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0103] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0104] Antioxidant: Brand is BASF (Germany), grade is B215;

[0105] UV protectant: Brand is BASF (Germany), product name is UV-234;

[0106] (2) By weight, 40 parts PMMA, 35 parts toughening agent, 3 parts compatibilizer, 30 parts heat resistant agent, 0.3 parts brightener, 0.2 parts UV agent and 0.3 parts antioxidant are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 355 rpm, and the extrusion temperatures of the first to tenth zones are 230℃, 227℃, 228℃, 228℃, 228℃, 228℃, 228℃, 228℃, 223℃ and 223℃ respectively.

[0107] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 50.4 MPa, a flexural strength of 73.2 MPa, a flexural modulus of 2280 MPa, and a notched impact strength of 9.1 KJ / m. 2 The Vicat temperature is 106.2℃, the pencil hardness is 2H, and the gloss is 108.

[0108] Example 6

[0109] A method for preparing a high-gloss, scratch-resistant, and heat-resistant PMMA composite material, comprising the following steps:

[0110] (1) Preparation of raw materials;

[0111] PMMA: Manufacturer is Mitsubishi Rayon Co., Ltd. of Japan, grade VH001, melt index is 2g / 10min at 250℃ and 2.16kg;

[0112] Toughening agent: Manufacturer is Mitsubishi Chemical Co., Ltd., Japan; brand name is SX-006.

[0113] Compatibilizer: MABS, brand name: Chi Mei Industrial Co., Ltd. (Taiwan), brand name: PA-758;

[0114] Heat resistant agent: a copolymer of α-methylstyrene and acrylonitrile, brand name BASF Germany, grade HH-120;

[0115] Brightener: EBS (ethylene bis-stearamide), brand name Kao Corporation of Japan, grade EB-G;

[0116] Antioxidant: Brand is BASF (Germany), grade is B215;

[0117] UV protectant: Brand is BASF (Germany), product name is UV-234;

[0118] (2) By weight, 40 parts PMMA, 40 parts toughening agent, 4 parts compatibilizer, 20 parts heat resistant agent, 0.2 parts brightener, 0.4 parts UV agent and 0.4 parts antioxidant are mixed evenly and then extruded and granulated by a twin-screw extruder to obtain a high-gloss, scratch-resistant and heat-resistant PMMA composite material; wherein, the rotation speed of the twin-screw extruder is 370 rpm, and the extrusion temperatures of the first to tenth zones are 224℃, 230℃, 223℃, 223℃, 223℃, 223℃, 223℃, 223℃, 228℃ and 228℃ respectively.

[0119] The final high-gloss, scratch-resistant, and heat-resistant PMMA composite material exhibits a tensile strength of 47.6 MPa, a flexural strength of 68.2 MPa, a flexural modulus of 2180 MPa, and a notched impact strength of 13.6 KJ / m. 2 The Vicat temperature is 102.3℃, the pencil hardness is 2H, and the gloss is 107.

Claims

1. A high gloss, scratch resistant, heat resistant grade PMMA composite material, characterized in that, The high-gloss scratch-resistant heat-resistant PMMA composite material is prepared by mixing the components in proportion by weight and then extruding and granulating by a double-screw extruder. The toughening agent has a core-shell structure, the outer shell is a copolymer of styrene and acrylonitrile, and the inner core is an organosiloxane and an acrylic rubber; the particle size of the toughening agent is 80-120 nm; The compatibilizer is MABS; The heat-resistant agent is a copolymer of alpha-methylstyrene and acrylonitrile; the glass transition temperature of the heat-resistant agent is between 120-140℃; The brightener is EBS; The tensile strength of the high-gloss scratch-resistant heat-resistant grade PMMA composite material is 47.6-55.1 MPa, the bending strength is 68.2-76.1 MPa, the bending modulus is 2175-2390 MPa, the notched impact strength is 6.5-13.6 KJ / m 2 , the Vicat temperature is 99.8-106.2℃, the pencil hardness is 2-3H, and the gloss is 107-112.

2. A high gloss, scratch resistant, heat resistant grade PMMA composite material as claimed in claim 1, wherein, The melt index of PMMA at 250℃ under a load of 2.16kg is 2-5g / 10min.

3. A process for the preparation of a high gloss, scratch resistant, heat resistant grade PMMA composite material as claimed in any one of claims 1 to 2, characterized in that, The high-gloss scratch-resistant heat-resistant PMMA composite material is prepared by mixing the components in proportion by weight and then extruding and granulating by a double-screw extruder.

4. The method of claim 3, wherein, The extrusion temperature of the double-screw extruder is 220-230℃, and the rotation speed is 350-400rpm.