Ultra-highly weather-resistant ASA resin composition and preparation method therefor

Abstract

The present invention relates to an ultra-highly weather-resistant ASA resin composition and a preparation method therefor. The composition comprises the following components: 30-60 parts by weight of SAN resin, 20-40 parts by weight of ASA rubber powder, 5-20 parts by weight of PVDF resin, 5-20 parts by weight of a compatibilizer, 2-5 parts by weight of fluorosilicone rubber, 0.5-2.0 parts by weight of a processing aid, 0.5-2.0 parts by weight of a weathering agent, and 0.5-2.0 parts by weight of a colorant. The present invention is the first to combine fluorosilicone rubber and PVDF resin. In one aspect, the fact that fluorosilicone rubber has a low molecular weight and tends to migrate to the surface of the product during formation processing to form a weather-resistant protective layer is utilized to further improve the weather resistance of the product. In another aspect, the present invention creatively finds that the fact that fluorosilicone rubber and PVDF resin are similar in polarity enables fluorosilicone rubber to promote, to a certain extent, the migration of PVDF to the surface of the product, thereby achieving a synergistic effect that significantly improves the weather resistance of the resin system.

Description

A high weather-resistant ASA resin composition and its preparation method Technical Field

[0001] This invention belongs to the field of polymer materials technology and relates to an ultra-high weather-resistant ASA resin composition and its preparation method. Background Technology

[0002] In modern industrial production and daily life, many materials need to be used in outdoor environments for extended periods, such as building materials, automotive exterior parts, and outdoor furniture. These materials not only need good mechanical and processing properties, but also need to maintain their original physical and chemical properties under prolonged exposure to natural environmental factors such as ultraviolet radiation, temperature changes, and humidity. This requires the materials themselves to have high weather resistance. ASA material is a high-performance engineering plastic that combines the weather resistance of acrylates, the rigidity of acrylonitrile, and the processing properties of styrene. Compared to traditional ABS materials, ASA materials have a significant advantage in weather resistance, thus performing better in outdoor applications.

[0003] Despite the already good weather resistance of ASA materials, OEMs are increasingly demanding even higher weather resistance ASA materials to extend product life, improve customer satisfaction, reduce maintenance costs, and promote product innovation. For example, Volkswagen has proposed a requirement for ASA materials that meet two-cycle weather resistance standards for the exterior trim (PV3929), which is twice the current material standard. This poses new challenges to the weather resistance of ASA materials and requires more superior weather-resistant modification solutions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of existing technologies and provide an ultra-high weather-resistant ASA resin composition and its preparation method. This invention is the first to combine fluorosilicone rubber with PVDF resin. On the one hand, fluorosilicone rubber, with its low molecular weight, tends to migrate to the product surface during molding and processing, forming a weather-resistant protective layer and further improving the product's weather resistance. On the other hand, this invention creatively discovers that because fluorosilicone rubber and PVDF resin have similar polarities, fluorosilicone rubber can promote the migration of PVDF to the product surface to a certain extent, thereby producing a synergistic effect in improving weather resistance and significantly enhancing the weather resistance of the resin system.

[0005] The objective of this invention can be achieved through the following methods:

[0006] In a first aspect, the present invention provides an ultra-high weather-resistant ASA resin composition comprising the following components in parts by weight:

[0007] As one embodiment of the present invention, the SAN resin is a styrene-acrylonitrile copolymer with an acrylonitrile content of 20-40 wt.%.

[0008] In one embodiment of the present invention, the ASA adhesive powder is a core-shell acrylonitrile-styrene-acrylate copolymer; wherein the core layer is acrylate, the shell layer is acrylonitrile-styrene copolymer, and the core layer content is 40-70 wt.%. Preferably, the acrylate is butyl acrylate rubber.

[0009] Furthermore, the acrylonitrile content in the shell is 20–40 wt.%.

[0010] As one embodiment of the present invention, the PVDF resin is a homopolymer of vinylidene fluoride or a copolymer of it with other monomers; the other monomers include one or more of tetrafluoroethylene, hexafluoropropylene, and trifluorochloroethylene, and the content of the other monomers does not exceed 10 wt.%.

[0011] As one embodiment of the present invention, the compatibilizer is a homopolymer of methyl methacrylate or a copolymer of it with other monomers; the other monomers include one or more of ethyl methacrylate, butyl methacrylate, styrene, and acrylonitrile, and the content of the other monomers does not exceed 10 wt.%.

[0012] In one embodiment of the present invention, the weight-average molecular weight of the fluorosilicone rubber is 500,000 to 2,000,000. The fluorosilicone rubber of the present invention is γ-trifluoropropylmethylpolysiloxane.

[0013] As one embodiment of the present invention, the processing aid is a composition of antioxidants, lubricants and / or release agents.

[0014] Preferably, the antioxidant includes at least one of antioxidant 168, antioxidant 1010, and antioxidant 1076; the lubricant includes at least one of lubricant EBS, lubricant PETS, and stearate; and the mold release agent includes a silicone mold release agent.

[0015] As one embodiment of the present invention, the weathering agent includes one or more of salicylic acid esters, benzophenone, benzotriazole UV absorbers, and hindered amine free radical scavengers.

[0016] As one embodiment of the present invention, the colorant includes (commonly available) black powder.

[0017] Secondly, the present invention provides a method for preparing an ultra-high weather-resistant ASA resin composition, comprising the following steps:

[0018] S1. Premix the raw materials to obtain a premix;

[0019] S2. The premixed material is melt-extruded, cooled and granulated using a twin-screw extruder to obtain the final product.

[0020] In one embodiment of the present invention, in step S1, the premixing is carried out using a high-speed mixer.

[0021] In one embodiment of the present invention, in step S2, the extrusion temperature of the twin-screw extruder is 180-260℃ and the screw speed is 200-500 r / min.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The PVDF resin used in this invention has excellent weather resistance and durability. Introducing it into ASA resin can significantly improve its weather resistance. PMMA and PVDF have good compatibility. Adding PMMA as a compatibilizer can improve the compatibility between PVDF and ASA and avoid the product from delamination problems.

[0024] 2. This invention is the first to combine fluorosilicone rubber with PVDF resin. On the one hand, it utilizes the low molecular weight of fluorosilicone rubber, which tends to migrate to the product surface during molding and processing, forming a weather-resistant protective layer and further improving the weather resistance of the product. On the other hand, this invention creatively discovers that because fluorosilicone rubber and PVDF resin have similar polarities, fluorosilicone rubber can promote the migration of PVDF to the product surface to a certain extent, thereby producing a synergistic effect in improving weather resistance and significantly enhancing the weather resistance of the resin system.

[0025] 3. The ASA resin composition prepared by this invention has excellent weather resistance. After 3000h weather resistance test, the gray level is ≥4, the color difference is ≤2.0, and there are no obvious appearance defects, which meets the standard requirements of Volkswagen exterior decoration for two cycles. At the same time, the preparation method is simple and low in cost, which is very suitable for industrial production. Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, providing detailed implementation methods and specific operating procedures, which will help those skilled in the art to further understand the present invention. It should be noted that the scope of protection of the present invention is not limited to the following embodiments; any adjustments and improvements made under the concept of the present invention are all within the scope of protection of the present invention.

[0027] The raw materials used in the examples and comparative examples are as follows:

[0028] SAN resin: Model 300H;

[0029] ASA adhesive powder: Model XC500A;

[0030] PVDF resin: Model DS206;

[0031] Compatibilizer: Polymethyl methacrylate, model SX304;

[0032] Fluorosilicone rubber: Model FVMQ 1002;

[0033] Processing aids: Antioxidant 168 / Antioxidant 1010 / Lubricant EBS (mass ratio 1:1:3);

[0034] Weather resistant agent: Tinuvin 770DF;

[0035] Colorant: Commercially available black powder.

[0036] The preparation methods for the examples and comparative examples are as follows:

[0037] (1) Weigh the raw materials according to the weight proportions in Table 1 and premix them using a high-speed mixer;

[0038] (2) The premix obtained in step (1) is melt-extruded through a twin-screw extruder at an extrusion temperature of 180-260℃ and a screw speed of 400r / min, and then cooled and granulated.

[0039] Table 1. Raw material ratios for examples and comparative examples.

[0040] Weather resistance testing was conducted according to PV3929 standard, with a total irradiance of 800 MJ / m². 2 (3000h), the test results are listed in Table 2.

[0041] Table 2 Weathering test results of the examples and comparative examples

[0042] As shown in Example 7 and Comparative Example 5, the addition of PVDF significantly improved the weather resistance of ASA resin. Furthermore, Examples 1-4 show that the weather resistance of ASA resin gradually increased with the increase of the PVDF ratio. Comparative Example 2 shows that simply adding PVDF did not significantly improve the weather resistance of ASA resin, and the product exhibited delamination and peeling issues. Examples 4-7 show that increasing the amount of fluorosilicone rubber reduced color difference after weathering tests, further improving the weather resistance. Comparative Examples 1-5 and Example 7 demonstrate that simply adding PVDF and a compatibilizer, or adding only fluorosilicone rubber, can improve the weather resistance of ASA resin to some extent, but its weather resistance effect is far inferior to that of simultaneously adding PVDF and fluorosilicone rubber.

[0043] The ASA resin composition prepared by this invention has excellent weather resistance. After 3000h weather resistance test, the gray level is ≥4, the color difference is ≤2.0, and there are no obvious appearance defects, which meets the standard requirements of Volkswagen exterior decoration for two cycles.

[0044] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A high weather-resistant ASA resin composition, characterized in that, The components include the following parts by weight:

2. The ASA resin composition according to claim 1, characterized in that, The SAN resin is a styrene-acrylonitrile copolymer with an acrylonitrile content of 20–40 wt.%.

3. The ASA resin composition according to claim 1, characterized in that, The ASA adhesive powder is a core-shell structured acrylonitrile-styrene-acrylate copolymer; wherein the core layer is acrylate with a core content of 40-70 wt.%; and the shell layer is an acrylonitrile-styrene copolymer with an acrylonitrile content of 20-40 wt.%.

4. The ASA resin composition according to claim 1, characterized in that, The PVDF resin is a homopolymer of vinylidene fluoride or a copolymer of it with other monomers; the other monomers include one or more of tetrafluoroethylene, hexafluoropropylene, and trifluorochloroethylene, and the content of other monomers does not exceed 10 wt.%.

5. The ASA resin composition according to claim 1, characterized in that, The compatibilizer is a homopolymer of methyl methacrylate or a copolymer of it with other monomers; the other monomers include one or more of ethyl methacrylate, butyl methacrylate, styrene, and acrylonitrile, and the content of the other monomers does not exceed 10 wt.%.

6. The ASA resin composition according to claim 1, characterized in that, The weight-average molecular weight of the fluorosilicone rubber is 500,000 to 2,000,000.

7. The ASA resin composition according to claim 1, characterized in that, The processing aid is a composition of antioxidants, lubricants and / or release agents, wherein the antioxidants include at least one of antioxidant 168, antioxidant 1010 and antioxidant 1076, the lubricants include at least one of lubricant EBS, lubricant PETS and stearate, and the release agents include silicone release agents.

8. The ASA resin composition according to claim 1, characterized in that, The weathering agent includes one or more of salicylate, benzophenone, benzotriazole UV absorbers, and hindered amine free radical scavengers; the colorant includes black powder.

9. A method for preparing the ASA resin composition according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Premix the raw materials to obtain a premix; S2. The premixed material is melt-extruded, cooled and granulated using a twin-screw extruder to obtain the final product.

10. The preparation method according to claim 9, characterized in that, In step S2, the extrusion temperature of the twin-screw extruder is 180-260℃, and the screw speed is 200-500 r / min.

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