A bio-based low linear expansion coefficient spray-free material and a preparation method thereof

Abstract

The application provides a kind of bio-based low linear expansion coefficient spray-free material and a preparation method thereof.The spray-free material comprises the following components in parts by weight: 30-60 parts of bio-based isosorbide polycarbonate, 13-33 parts of styrene-acrylonitrile copolymer, 10-20 parts of ASA high glue powder, 10-20 parts of talc, 1-5 parts of acrylic polymer, 0-10 parts of compatibilizer, 0.1-0.5 parts of antioxidant, 0.1-0.3 parts of lubricant, 0.2-0.5 parts of weathering agent, and 0.1-0.5 parts of carbon black.The application adds talc as inorganic rigid filler in the bio-based isosorbide polycarbonate system, and cooperatively adds acrylic polymer to protect molecular chain degradation, avoids the silver wire problem caused by adding talc, reduces the linear expansion coefficient, maintains high impact toughness, meets the size matching requirements of automobile exterior parts and metal parts, and avoids the "cracking" and "bulging" problems caused by temperature difference.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a bio-based low linear expansion coefficient spray-free material and its preparation method. Background Technology

[0002] Polycarbonate (PC) is a linear polymer containing carbonate groups (-OROCO-) in its molecular chain. It has become one of the fastest-growing thermoplastic materials in terms of demand among the five major general-purpose engineering plastics, and has wide applications in various fields. PC possesses outstanding impact resistance and creep resistance, high tensile strength, flexural strength, elongation at break, and rigidity, as well as high heat and cold resistance, excellent electrical insulation, flame retardancy, UV resistance, and aging resistance. In recent years, bisphenol A (BPA) type PC has been the mainstream product in the market, widely used in bulletproof glass, food packaging, automotive transportation, aerospace, electronics, and building materials. However, BPA type PC has estrogenic effects and slow toxicity, which can harm human health. Therefore, to replace toxic BPA type PC, PC synthesized from the bio-based monomer isosorbide (ISB) has become a research hotspot. ISB-PC is characterized by being green and non-toxic, having excellent weather resistance and scratch resistance. However, its rigid molecular chain results in poor flexibility and difficult processing, requiring copolymerization or blending modification to optimize its performance.

[0003] Chinese patent CN120005366A discloses a bio-based paint-free material and its preparation method. It uses bio-based isosorbide-based polycarbonate combined with ASA high-adhesion powder and acrylonitrile-styrene polymer. Through a molecular chain structure that combines rigidity and flexibility, it maintains strength and hardness while also possessing good impact resistance. Furthermore, through the synergistic effect of its components, it also exhibits excellent heat resistance, aging resistance, and weather resistance. However, with the increasing demands for lightweighting and environmental protection in automobiles, bio-based materials and paint-free, highly weather-resistant exterior parts have become key development directions in the industry. While Chinese patent CN120005366A possesses good weather resistance and appearance, it still suffers from low impact resistance and an excessively high linear coefficient of thermal expansion. When assembled with metal parts, differences in thermal expansion and contraction can lead to cracking, bulging, and other failures. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a bio-based low linear expansion coefficient spray-free material and its preparation method, thus solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: According to a first aspect of the present invention, a bio-based low linear expansion coefficient paint-free material is provided, comprising the following components by weight: 30-60 parts of bio-based isosorbide-based polycarbonate; 13-33 parts of styrene-acrylonitrile copolymer; 10-20 parts of ASA high-colloid powder; 10-20 parts talcum powder; 1 to 5 parts of acrylic polymer; 0-10 parts of compatibilizer; 0.1 to 0.5 parts of antioxidant; 0.1 to 0.3 parts of lubricant; 0.2~0.5 parts of weather-resistant agent; 0.1 to 0.5 parts of carbon black.

[0006] Existing paint-free materials generally meet the standard requirements for automotive exterior parts in terms of mechanical properties, heat resistance, and weather resistance. However, for direct use in injection-molded exterior parts, a lower coefficient of linear expansion is needed. Adding talc significantly reduces the coefficient of linear expansion. However, both traditional PC and bio-based PC systems are susceptible to the effects of talc, leading to molecular chain degradation, "silver streaks," and decreased impact resistance. This invention incorporates an acrylic polymer along with talc. The acrylic polymer acts as a solubilizer, its flexible chain segments buffering impact stress. Simultaneously, it coats talc particles, suppressing interface defects, preventing stress concentration, and improving notched impact strength. Furthermore, the acrylic polymer and weathering agent synergistically protect the molecular chains, resulting in minimal color difference after xenon lamp aging, with a grayscale level of 4 or higher, meeting automotive exterior standards.

[0007] Preferably, the talc powder is selected from R7, and the average particle size of the talc powder is 1~10μm.

[0008] The talc powder selected in this invention has a weak alkalinity, which can reduce the hydrolytic damage to the polycarbonate ester groups and effectively avoid the problem of silver streaks on the surface.

[0009] Preferably, the mass ratio of the talc powder to the acrylic polymer is 7.5 to 10:1.

[0010] Preferably, the molecular weight of the bio-based isosorbide polycarbonate is 20,000 to 40,000.

[0011] Preferably, the ASA high-rubber powder is of type Q900, and the butyl acrylate rubber in the ASA high-rubber powder has a particle size of 80~120nm and an organosilicon content of 2~10%. Preferably, the mass ratio of acrylonitrile to styrene in the styrene-acrylonitrile copolymer is 1:3~4.

[0012] Preferably, the antioxidant includes a primary antioxidant and a secondary antioxidant, and the mass ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 3; The primary antioxidant is selected from at least one of antioxidant 1010 and antioxidant 1076; The auxiliary antioxidant is selected from at least one of antioxidant 168, antioxidant 169F, or antioxidant 412S.

[0013] Preferably, the compatibilizer is selected from at least one of SMA, ABS graft, and SAN graft; The lubricant is selected from pentaerythritol stearate; The weather-resistant agent is selected from at least one of UV-234, UV-328, and UV-P.

[0014] According to a second aspect of the present invention, a method for preparing a bio-based low linear expansion coefficient spray-free material is provided, comprising the following steps: (1) By weight fraction, bio-based isosorbide polycarbonate, styrene-acrylonitrile copolymer, ASA high-rubber powder, talc, acrylic polymer, compatibilizer, antioxidant, lubricant, weathering agent and carbon black are added to a high-speed mixer and mixed. (2) The mixed raw materials are continuously and uniformly added to a twin-screw extruder for extrusion. The extruded strips are cooled and then pelletized to obtain the bio-based low linear expansion coefficient surface spraying material.

[0015] Preferably, the extrusion conditions using the twin-screw extruder are as follows: the screw diameter of the twin-screw extruder is 35 mm, the length-to-diameter ratio (L / D) is 36, the temperature of the main barrel is 80~120℃ in zone 1, 230~250℃ in zone 2, 240~260℃ in zone 3, 250~270℃ in zone 4, 240~260℃ in zone 5, 230~250℃ in zone 6, 220~240℃ in zone 7, 220~240℃ in zone 8, and the rotational speed of the twin screw is 300 rpm.

[0016] This invention provides a bio-based, low linear expansion coefficient, spray-free material and its preparation method. It has the following beneficial effects: This solution provides a bio-based low linear expansion coefficient paint-free material. By adding talc as an inorganic rigid filler to a bio-based isosorbide-based polycarbonate system and synergistically adding acrylic polymer to protect the molecular chain from degradation, it avoids the silver streaks problem caused by the addition of talc. While reducing the linear expansion coefficient, it can also maintain high impact toughness, meet the dimensional matching requirements of automotive exterior parts and metal components, and avoid the "cracking and bulging" problem caused by temperature differences. Detailed Implementation

[0017] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0018] The bio-based isosorbide-based polycarbonates used in the embodiments of this invention include: ① Manufactured by Mitsubishi Corporation of Japan, model number T7450A; ② Self-made, brand name DY2200, prepared by the method described in patent CN102746504 B.

[0019] Styrene-acrylonitrile copolymer, manufactured by LG Yongxing Co., Ltd., with an acrylonitrile content of 30%, model AS80HF; ASA high-colloidal powder, manufactured by Anqiu Donghai Plastics Co., Ltd., model Q900; Talc powder, manufactured by Yirui Stone Company, has an average particle size of 1-10μm and is designated as R7. Acrylic polymer, manufactured by UMG, model S601N; The standard PC used in the comparative example was manufactured by Mitsubishi Chemical Corporation, model S-2000F.

[0020] The following specific embodiments will further illustrate the bio-based low linear expansion coefficient spray-free material. However, those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified, specific conditions in the embodiments were performed under conventional conditions or conditions recommended by the manufacturer. Reagents used without a specified manufacturer are all commercially available products.

[0021] Example 1 A bio-based low linear expansion coefficient spray-free material, by weight, comprises 30 parts of bio-based isosorbide-based polycarbonate T7450A, 33 parts of styrene-acrylonitrile copolymer, 20 parts of ASA high-adhesion powder (Q900), 10 parts of talc, 2 parts of acrylic polymer, 5 parts of SMA compatibilizer, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234, and 0.3 parts of carbon black.

[0022] The preparation method is as follows: The above-mentioned raw materials were added to a high-speed mixer and mixed for 5 minutes. The mixed raw materials were then continuously and evenly fed into a twin-screw extruder for extrusion. The screw diameter of the twin-screw extruder was controlled to be 35 mm, the length-to-diameter ratio (L / D) was 36, and the temperature of the main barrel was set as follows: Zone 1: 80~120℃, Zone 2: 230~250℃, Zone 3: 240~260℃, Zone 4: 250~270℃, Zone 5: 240~260℃, Zone 6: 230~250℃, Zone 7: 220~240℃, Zone 8: 220~240℃. The rotation speed of the twin screw was 300 rpm. After cooling, the extruded material was pelletized to obtain a bio-based low linear expansion coefficient coating-free material.

[0023] Example 2 A bio-based low linear expansion coefficient spray-free material, by weight parts, comprises 43 parts of bio-based isosorbide-based polycarbonate T7450A, 20 parts of styrene-acrylonitrile copolymer, 15 parts of ASA high-adhesion powder (Q900), 15 parts of talc, 2 parts of acrylic polymer, 5 parts of SMA compatibilizer, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234, and 0.3 parts of carbon black.

[0024] Example 3 A bio-based low linear expansion coefficient spray-free material, by weight parts, comprises 41 parts of bio-based isosorbide-based polycarbonate T7450A, 20 parts of styrene-acrylonitrile copolymer, 15 parts of ASA high-rubber powder of type Q900, 20 parts of talc, 2 parts of acrylic polymer, 2 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234 and 0.3 parts of carbon black.

[0025] Example 4 A bio-based low linear expansion coefficient spray-free material, by weight parts, comprises 53 parts of bio-based isosorbide-based polycarbonate DY2200, 15 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-rubber powder of type Q900, 15 parts of talc, 2 parts of acrylic polymer, 5 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.2 parts of UV-234 and 0.3 parts of carbon black.

[0026] Example 5 A bio-based low linear expansion coefficient spray-free material, by weight parts, comprises 60 parts of bio-based isosorbide-based polycarbonate DY2200, 13 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-adhesion powder of type Q900, 15 parts of talc, 2 parts of acrylic polymer, 0 parts of compatibilizer, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234 and 0.3 parts of carbon black.

[0027] Example 6 A bio-based low linear expansion coefficient spray-free material, by weight parts, comprises 53 parts of bio-based isosorbide-based polycarbonate DY2200, 15 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-rubber powder of type Q900, 15 parts of talc, 2 parts of acrylic polymer, 10 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234 and 0.3 parts of carbon black.

[0028] Comparative Example 1 A bio-based paint-free material, by weight, comprises 45 parts of ordinary PC, 30 parts of styrene-acrylonitrile copolymer, 20 parts of ASA high-adhesion powder (model A600N), 5 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234, and 0.3 parts of carbon black.

[0029] Comparative Example 2 A bio-based paint-free material, by weight, comprises 55 parts of bio-based isosorbide-based polycarbonate T7450A, 15 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-rubber powder of type Q900, 15 parts of talc, 5 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234 and 0.3 parts of carbon black.

[0030] Comparative Example 3 A bio-based paint-free material, by weight, comprises 53 parts of bio-based isosorbide-based polycarbonate DY2200, 15 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-adhesion powder (model A600N), 15 parts of talc, 2 parts of acrylic polymer, 5 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234, and 0.3 parts of carbon black.

[0031] Comparative Example 4 A bio-based paint-free material, by weight, comprises 55 parts of bio-based isosorbide-based polycarbonate DY2200, 15 parts of styrene-acrylonitrile copolymer, 10 parts of ASA high-rubber powder of type Q900, 15 parts of talc, 5 parts of SMA, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.3 parts of pentaerythritol stearate, 0.5 parts of UV-234 and 0.3 parts of carbon black.

[0032] The performance of the paint-free materials prepared in Examples 1 to 6 and Comparative Examples 1 to 4 of the present invention was tested in the following ways: (1) Tensile property test: conducted in accordance with ISO 527-2 standard, with a sample size of 170×10×4mm and a tensile speed of 50mm / min; (2) Notched impact performance test: conducted in accordance with ISO 179-1 standard, with a sample size of 80×10×4mm; (3) Bending performance test: conducted in accordance with ISO 178 standard, with a sample size of 80×10×4mm and a bending speed of 2mm / min; (4) Melt flow rate test: conducted in accordance with ISO 1133-1 standard, test conditions are 260℃ / 5kg; (5) Linear expansion coefficient test: The linear expansion coefficient of the paint-free material was tested by thermomechanical analysis (TMA) in accordance with ISO 11359 standard. The test temperature was 23~80℃, the sample size was 10×10×3mm, the heating rate was 5℃ / min, and the CLTE value of the melt in the parallel flow (MD) direction and the perpendicular flow (TD) direction was tested. (6) Xenon lamp accelerated aging test to test weather resistance: The SAE J2412 was used to conduct the light aging test, and the test conditions are as follows: Irradiance: (0.55±0.01) W / (m²) 2 ·nm)@340nm; Light intensity: 3.8h, blackboard temperature: (89±2.5)℃, relative humidity: (50±10)%% Darkness: 1 hour, blackboard temperature: (38±2.5)℃, relative humidity: (95±10)%% Filter: Quartz / Boro; Irradiation dose: 2500 kJ / m 2 .

[0033] The test results are shown in Table 1: Table 1

[0034] As can be seen from the data in Table 1, the present invention, through the synergistic effect of talc and acrylic polymer, significantly reduces the linear expansion coefficient while taking into account high impact toughness, weather resistance and processability, thus overcoming the contradiction between low linear expansion coefficient and low toughness in traditional materials.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bio-based, low linear expansion coefficient, spray-free material, characterized in that: The bio-based low linear expansion coefficient paint-free material comprises the following components by weight: 30-60 parts of bio-based isosorbide-based polycarbonate; 13-33 parts of styrene-acrylonitrile copolymer; 10-20 parts of ASA high-colloid powder; 10-20 parts talcum powder; 1 to 5 parts of acrylic polymer; 0-10 parts of compatibilizer; 0.1 to 0.5 parts of antioxidant; 0.1 to 0.3 parts of lubricant; 0.2~0.5 parts of weather-resistant agent; 0.1 to 0.5 parts of carbon black; The talc powder is selected from R7, and the average particle size of the talc powder is 1~10μm.

2. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The mass ratio of talc to acrylic polymer is 7.5 to 10:

1.

3. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The bio-based isosorbide-based polycarbonate has a molecular weight of 20,000 to 40,000.

4. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The ASA high-rubber powder is of type Q900, and the butyl acrylate rubber in the ASA high-rubber powder has a particle size of 80~120nm and an organosilicon content of 2~10%.

5. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The mass ratio of acrylonitrile to styrene in the styrene-acrylonitrile copolymer is 1:3~4.

6. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The antioxidant includes a primary antioxidant and a secondary antioxidant, and the mass ratio of the primary antioxidant to the secondary antioxidant is 1:1~3; The primary antioxidant is selected from at least one of antioxidant 1010 and antioxidant 1076; The auxiliary antioxidant is selected from at least one of antioxidant 168, antioxidant 169F, or antioxidant 412S.

7. The bio-based low linear expansion coefficient paint-free material according to claim 1, characterized in that: The compatibilizer is selected from at least one of SMA, ABS graft, and SAN graft; The lubricant is selected from pentaerythritol stearate; The weather-resistant agent is selected from at least one of UV-234, UV-328, and UV-P.

8. A method for preparing a bio-based low linear expansion coefficient spray-free material according to any one of claims 1 to 7, characterized in that: Includes the following steps: (1) By weight fraction, bio-based isosorbide polycarbonate, styrene-acrylonitrile copolymer, ASA high-rubber powder, talc, acrylic polymer, compatibilizer, antioxidant, lubricant, weathering agent and carbon black are added to a high-speed mixer and mixed. (2) The mixed raw materials are continuously and uniformly added to a twin-screw extruder for extrusion. The extruded strips are cooled and then pelletized to obtain the bio-based low linear expansion coefficient non-coating material.

9. The method for preparing a bio-based low linear expansion coefficient spray-free material according to claim 8, characterized in that: The extrusion parameters of the twin-screw extruder are as follows: the screw diameter of the twin-screw extruder is 35mm, the length-to-diameter ratio (L / D) is 36, the temperature of the main barrel is 80~120℃ in zone 1, 230~250℃ in zone 2, 240~260℃ in zone 3, 250~270℃ in zone 4, 240~260℃ in zone 5, 230~250℃ in zone 6, 220~240℃ in zone 7, and 220~240℃ in zone 8, and the rotational speed of the twin screw is 300 rpm.

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