High-temperature-resistant and low-warp PMMA alloy resin material and preparation method thereof

Abstract

The application relates to a high-temperature-resistant and low-warp PMMA alloy resin material and a preparation method thereof, and comprises the following components and weight parts: PMMA resin: 40-60, toughening agent: 20-35, carbon tube functional master batch: 10-30, weather-resistant agent: 0.1-1.5, antioxidant: 0.1-1, black color powder: 0.3-1, and the preparation method of the high-temperature-resistant and low-warp PMMA alloy resin material comprises the following steps: (a) adding PMMA resin, a toughening agent, a carbon tube functional master batch, a weather-resistant agent and an antioxidant into a mixing stirrer to carry out mixing; (b) carrying out blending granulation, melt extrusion and granulation of the mixture obtained in step a through a double-screw extruder to obtain a PMMA alloy material. Compared with the prior art, the PMMA alloy material prepared by the application has good high-temperature resistance and low-warp performance, and can be applied to the situation of local uneven heating and warp deformation of products.

Description

Technical Field

[0001] This invention relates to the field of polymer material processing technology, and in particular to a high-temperature resistant and low-warpage PMMA alloy resin material and its preparation method. Background Technology

[0002] Due to its good weather resistance, chemical resistance, appearance, and toughness, methyl methacrylate (PMMA) alloy has become the preferred material for paint-free automotive exterior trim in recent years, and is currently widely used in automotive exterior grilles, pillars, and other components.

[0003] However, with the diversification of automotive design and the excellent plasticity of paint-free applications, people are pursuing more visual effects, such as carbon fiber textures, ultra-matte textures, and various technological textures, which have special requirements for the matte blackness of materials; for example, styling designs such as integrated streamlined bodies, with more complex part structures or higher requirements for part dimensional accuracy. For these types of parts, PMMA alloy materials have relatively low heat resistance and a low glass transition temperature. If the parts are exposed to direct sunlight or high temperatures outdoors for a long time, uneven heating and insufficient rigidity can easily cause local shrinkage or warping deformation. Therefore, the uniform heating and warping deformation of the material are of high importance. There are requirements, but there is currently little research on PMMA alloy products in this regard. Moreover, most previous patents have adopted glass fiber reinforced systems to improve the problem of material warping deformation. CN104927193A discloses glass fiber reinforced polypropylene with good mechanical properties and long-term heat aging resistance. CN102719071A discloses that shaped glass fiber reinforced polycarbonate resin can improve the problem of conventional glass fiber warping. However, due to the aspect ratio characteristics of glass fiber, there is still a problem of large differences in anisotropic orientation, which makes it difficult to completely solve the problem of warping shrinkage. In particular, due to uneven heating of the resin material, the material shrinkage is inconsistent, resulting in warping shrinkage deformation and other problems.

[0004] Carbon nanotubes possess high modulus and tensile strength, with Young's modulus reaching 500-1000 GPa, significantly contributing to improved material rigidity. Secondly, carbon nanotubes exhibit excellent thermal conductivity, with an axial thermal conductivity as high as 2000-3000 W / mK, approximately 10 times that of copper. This effectively improves heat transfer in plastic products, promoting uniform heating and preventing defects such as shrinkage, warping, or deformation caused by localized overheating. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a high-temperature resistant and low-warpage PMMA alloy resin material and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] This invention provides a high-temperature resistant and low-warpage PMMA alloy resin material, comprising the following components in parts by weight:

[0008]

[0009] Preferably, the PMMA resin has a light transmittance of ≥90% and a melt flow rate of 10-35 g / 10 min at 220°C and 10 kg.

[0010] Preferably, the toughening agent includes one or more of ASA, ACR, and EMA resins.

[0011] Preferably, the carbon nanotube functional masterbatch comprises the following components in parts by weight: 80-90 parts AS resin, 10-15 parts carbon nanotubes, 5-10 parts compatibilizer, and 1-2 parts dispersant.

[0012] The AS resin is a copolymer of styrene and acrylonitrile. This resin is compatible with PMMA and helps to disperse functional masterbatch. The relative molecular weight of the resin is 80,000-160,000, the acrylonitrile content is 25-32%, and the light transmittance is ≥85%.

[0013] The carbon nanotubes mentioned are multi-walled carbon nanotubes that have undergone oxidation pretreatment, with a diameter of 10-20 nm, a length of 4-6 μm, a purity >97%, an ash content ≤3 wt%, and a specific surface area of ​​100-160 m². 2 / g. To improve the inertness of carbon nanotube surface and the poor wettability of substrate, this invention performs an oxidation treatment. The oxidation pretreatment method is as follows: the carbon nanotubes are subjected to oxidation pretreatment in an acid solution, preferably a mixture of sulfuric acid and hydrochloric acid in a volume ratio of 7:3. This mixed acid oxidation pretreatment before use allows hydrophilic groups such as -OH and -CO to be grafted onto the surface of the carbon nanotubes, resulting in better wettability with the PMMA substrate.

[0014] The compatibilizer includes one or more of styrene-maleic anhydride and styrene-methacrylate-maleic anhydride resin, wherein the maleic anhydride content is 10-25%.

[0015] The dispersant includes one or more of the following: polar polyolefin wax, catalyst ester wax, amide wax, silicone powder, stearic acid, and butyl stearate.

[0016] Preferably, the carbon nanotube functional masterbatch is prepared by the following method:

[0017] A1. Carbon nanotubes are pretreated by oxidation in an acid solution;

[0018] A2. Weigh the obtained carbon nanotubes, AS resin, compatibilizer, and dispersant according to the proportions and premix them to obtain a premix.

[0019] A3. Add the premixed material to a twin-screw extruder, and after extrusion and granulation, obtain carbon nanotube functional masterbatch.

[0020] Preferably, the weathering agent includes one or more of benzophenone, benzotriazole, benzotriazine UV absorbers, and hindered amine free radical scavengers (hindered amine weathering agents).

[0021] Preferably, the antioxidant comprises one or more of 2,6-di-tert-butyl-p-cresol, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, tris(2,4-di-tert-butyl)phosphite, or tetrakis(2,4-di-tert-butylphenyl)4,4'-biphenylene diphosphate.

[0022] Preferably, the black pigment is dye black, and more preferably dye black is a mixture of the three primary color pigments in a 1:1:1 ratio.

[0023] This invention also provides a method for preparing a high-temperature resistant and low-warpage PMMA alloy resin material, comprising the following steps:

[0024] S1. Weigh 40-60 parts of PMMA resin, 20-35 parts of toughening agent, 10-30 parts of carbon nanotube functional masterbatch, 0.1-1.5 parts of weathering agent, 0.1-1 parts of antioxidant, and 0.3-1 parts of black pigment according to the following weight proportions, and premix evenly to obtain a premix.

[0025] S2. Add the premixed material to a twin-screw extruder, melt and plasticize it, then extrude it, cool and extrude it to obtain PMMA alloy resin material.

[0026] Preferably, in step S1, the premixing is performed using a high-speed mixer with a rotation speed of 100-300 r / min and a mixing time of 10-20 min.

[0027] Preferably, in step S2, the melt extrusion temperature is 180-240℃ and the screw speed is 200-500 rpm.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The present invention uses a pre-made carbon nanotube masterbatch method to add to PMMA alloy material to prepare a material that can meet the outdoor light aging and sun exposure performance. At the same time, it can solve the problems of insufficient heat resistance or rigidity of conventional PMMA alloy, as well as the warping and shrinkage deformation that are easy to occur when encountering uneven heating. If carbon nanotubes are not prepared as masterbatch, they are very easy to generate agglomeration and uneven dispersion.

[0030] (2) The present invention provides a preparation method for the material, which has a simple process and stable product performance. Detailed Implementation

[0031] The present invention will be described in detail below with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and alterations without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] Example 1

[0033] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material, and the preparation method is as follows:

[0034] Weigh out the following raw materials: 50 parts PMMA resin, 30 parts toughening agent, 20 parts carbon nanotube functional masterbatch, 0.8 parts weathering agent, 0.3 parts antioxidant, and 0.5 parts black pigment. Premix them evenly using a high-speed mixer at 200 rpm for 15 minutes to obtain the premix. Add the premix to a twin-screw extruder at a melt extrusion temperature of 180-240℃ and a screw speed of 300 rpm. After melting and plasticizing, extrude, cool, and granulate to obtain the target product.

[0035] The PMMA resin is commercially available from Chi Mei Pharmaceutical, with a light transmittance ≥90% and a melt flow rate of 17g / 10min at 220℃ and 10kg. The toughening agent is ASA (Kumho XC500A). The weathering agent is hindered amine weathering agent (BASF Tinuvin 770). The antioxidant is phosphite antioxidant (tris(2,4-di-tert-butyl)phosphite). The black pigment is dye black pigment (a 1:1:1 blend of three primary color pigments).

[0036] The carbon nanotube functional masterbatch was prepared by the following method: 15 parts of carbon nanotubes (diameter 15nm, length 5μm) were oxidized and pretreated in a mixture of sulfuric acid and hydrochloric acid (7:3); then, 85 parts of AS resin (relative molecular weight 120000, acrylonitrile content 27%, light transmittance 86%), 8 parts of compatibilizer (SMMA), and 1 part of dispersant (catalyst ester wax) were weighed in proportion and premixed for 20 minutes to obtain a premix; the premix was added to a twin-screw extruder, extruded and granulated to obtain the carbon nanotube functional masterbatch.

[0037] Example 2

[0038] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material. The preparation method is basically the same as that in Example 1, except that the component content is different. The weight parts of each component are shown in Table 1.

[0039] Table 1

[0040]

[0041] Example 3

[0042] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material. The preparation method is basically the same as that in Example 1, except that the component content is different. The weight parts of each component are shown in Table 1.

[0043] Comparative Example 1

[0044] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material. The preparation method is basically the same as that in Example 1, except that the amount of carbon nanotube functional masterbatch is less. The weight parts of each component are shown in Table 1.

[0045] Comparative Example 2

[0046] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material. The preparation method is basically the same as that in Example 1, except that the amount of carbon nanotube functional masterbatch is larger. The weight parts of each component are shown in Table 1.

[0047] Comparative Example 3

[0048] This comparative example provides a high-temperature resistant and low-warpage PMMA alloy resin material, whose raw material composition is basically the same as that of Example 1. The only difference is that the carbon nanotubes used in the carbon nanotube functional masterbatch used in this comparative example are not pre-oxidized.

[0049] Comparative Example 4

[0050] This embodiment provides a high-temperature resistant and low-warpage PMMA alloy resin material. The preparation method is basically the same as that in Example 1, except that carbon nanotubes are used to replace carbon nanotube functional masterbatch. The weight parts of each component are shown in Table 1.

[0051] Performance evaluation methods and their implementation standards

[0052] Mechanical property testing: The high-gloss black ultra-tough ASA materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to mechanical property testing. The testing methods are as follows:

[0053] Notched impact strength of simply supported beam: tested according to ISO 179-1:2010(E) standard, the impact energy is 4J, and the test temperature is 23℃ and -30℃;

[0054] Flexural modulus: Tested according to ISO 178:2010(E) standard, at a test speed of 2 mm / min;

[0055] Vicat softening point: Tested according to ISO 306:2013 standard, test condition B50;

[0056] Appearance: The surface to be observed is smooth. Visually evaluate for any appearance defects.

[0057] Warpage Verification: A rectangular sample was selected for high-temperature warpage verification. The sample used was an internal part of Kumho Sunrise, with dimensions of 355*100*3.0mm. Infrared lamps were used for heating during the high-temperature warpage test, illuminating only one side of the sample to further verify the warpage of the material under localized uneven heating. The temperature in the test area reached 90℃*249. After the test, the sample was removed, cooled to room temperature, and its appearance was observed.

[0058] The mechanical properties of the resins prepared in each embodiment and comparative example were tested according to the ISO standard by injection molding into standard mechanical property test strips, while the appearance and warpage tests were conducted using internal samples from Kumho Sunrise.

[0059] Table 2 Performance tests of each embodiment and comparative example

[0060]

[0061] As can be seen from the comparative examples of the present invention, compared with Example 1, Comparative Example 1 has poor warpage performance due to too few carbon nanotube functional masterbatches; Comparative Example 2 has weak dispersibility due to too many carbon nanotube functional masterbatches; Comparative Example 3 has poor wettability in the substrate due to the lack of pre-oxidation treatment of carbon nanotubes, which easily produces appearance pitting defects; Comparative Example 4 has easy agglomeration in the substrate due to the lack of functional masterbatches of carbon nanotubes, which is not easy to disperse, and is prone to appearance pitting defects. At the same time, its high-temperature performance and warpage performance are poor, and it is easy to warp and deform.

[0062] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-temperature resistant and low-warpage PMMA alloy resin material, characterized in that, The components include the following parts by weight: 40-60 parts of PMMA resin 20-35 parts toughening agent 10-30 parts of carbon nanotube functional masterbatch Weather resistant agent 0.1-1.5 parts, Antioxidant 0.1-1 part, 0.3-1.0 parts of black pigment; The carbon nanotube functional masterbatch comprises the following components in parts by weight: 80-90 parts AS resin, 10-15 parts carbon nanotubes, 5-10 parts compatibilizer, and 1-2 parts dispersant. The carbon nanotubes mentioned are multi-walled carbon nanotubes that have undergone oxidation pretreatment, with a diameter of 10-20 nm and a length of 4-6 micrometers; the oxidation pretreatment involves oxidizing the carbon nanotubes in an acid solution.

2. The PMMA alloy resin material according to claim 1, characterized in that, The PMMA resin has a light transmittance of ≥90% and a melt flow rate of 10-35 g / 10min at 220℃ and 10kg.

3. The PMMA alloy resin material according to claim 1, characterized in that, The toughening agent includes one or more of ASA, ACR, and EMA resins.

4. The PMMA alloy resin material according to claim 1, characterized in that, The AS resin has a relative molecular weight of 80,000-160,000, an acrylonitrile content of 25-32%, and a light transmittance of ≥85%.

5. The PMMA alloy resin material according to claim 1, characterized in that, The compatibilizer includes one or more of styrene-maleic anhydride and styrene-methacrylate-maleic anhydride resin, wherein the maleic anhydride content is 10-25%; the dispersant includes one or more of polar polyolefin wax, catalyst ester wax, amide wax, silicone powder, stearic acid, and butyl stearate.

6. The PMMA alloy resin material according to claim 1, characterized in that, The aforementioned carbon nanotube functional masterbatch was prepared using the following method: A1. Carbon nanotubes are pretreated by oxidation in an acid solution; A2. Weigh the pretreated carbon nanotubes, AS resin, compatibilizer, and dispersant according to the proportions and premix them to obtain a premix. A3. After extruding and granulating the premixed material, carbon nanotube functional masterbatch is obtained.

7. The PMMA alloy resin material according to claim 1, characterized in that, The weathering agent includes one or more of UV absorbers and hindered amine weathering agents; the antioxidant includes one or more of 2,6-di-tert-butyl-p-cresol, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, tris(2,4-di-tert-butyl)phosphite, and tetrakis(2,4-di-tert-butylphenyl)4,4'-biphenyl diphosphate.

8. A method for preparing the PMMA alloy resin material as described in claim 1, characterized in that, Includes the following steps: S1. Weigh 40-60 parts of PMMA resin, 20-35 parts of toughening agent, 10-30 parts of carbon nanotube functional masterbatch, 0.1-1.5 parts of weathering agent, 0.1-1 parts of antioxidant, and 0.3-1 parts of black pigment according to the following weight proportions, and premix evenly to obtain a premix. S2. Add the premixed material to a twin-screw extruder, melt and plasticize it, then extrude it, cool and extrude it to obtain PMMA alloy resin material.

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