A high-strength and stable PC / PBT alloy material and its preparation method

Abstract

The present invention discloses a high-strength and stable PC / PBT alloy material and its preparation method, belonging to the technical field of alloy material processing, and is used to solve the technical problem that the cold resistance, weather resistance, impact resistance and hydrolysis resistance of the existing PC / PBT alloy need to be further improved; the cold-resistant, weather-resistant, high-impact and high-hydrolysis-resistant stable PC / PBT alloy of the present invention comprises the following raw material components in parts by weight: 20-50 parts of polycarbonate, 10-40 parts of silicone-containing polycarbonate, 30-70 parts of polybutylene terephthalate, and 5-30 parts of weather-resistant toughening and compatibilizing modifier. The present invention selects to use silicone-containing polycarbonate copolymer to partially replace the traditional polycarbonate, prepares an optimized weather-resistant toughening and compatibilizing modifier, and improves the formula to finally prepare a PC / PBT alloy material with cold resistance, weather resistance, high impact resistance and high hydrolysis resistance stability.

Description

Technical Field

[0001] The present invention relates to a high-strength and stable PC / PBT alloy material and a preparation method thereof, belonging to the technical field of alloy material processing. Background Art

[0002] As an engineering plastic, polycarbonate generally refers to aromatic polycarbonate in amorphous copolymers. Its special molecular structure endows it with excellent comprehensive properties, such as high impact resistance and creep resistance, excellent rigidity and good dimensional stability, and can meet certain low-temperature requirements. However, PC also has many deficiencies at the same time, such as poor fluidity and difficulty in processing into thin-walled parts, sensitivity to notches, easy stress cracking, poor solvent resistance and wear resistance, etc.;

[0003] Polybutylene terephthalate, as a semi-crystalline engineering plastic, has good processing fluidity and excellent chemical resistance, but its molding shrinkage rate is large, the glass transition temperature is low and the heat resistance is poor. Therefore, the PC / PBT alloy prepared by blending polycarbonate and polybutylene terephthalate has the advantages of dimensional stability, easy processing and molding, high rigidity, creep resistance, heat resistance and chemical resistance.

[0004] Although the PC / PBT alloy has the above advantages, it still has deficiencies in weather resistance, cold resistance and hydrolysis resistance. For example, Chinese Patent CN104927335 discloses a high-toughness and high-heat-resistant PC / PBT resin composition. In this method, an acrylate toughener is selected, and the heat resistance and weather resistance need to be improved. Moreover, during the processing and use, the toughener will decompose into small molecules that promote the transesterification of the PC / PBT resin composition, reducing the material properties and making it difficult to meet the use under long-term high and low temperature and high weather resistance conditions;

[0005] Chinese Patent CN109265955 discloses a high-impact and high-weather-resistant PC / PBT resin composition and a preparation method thereof. It selects POE-g-GMA as the toughener of the system. The dosage of POE-g-GMA has a great influence on the properties of the material. When the addition amount is insufficient, the low-temperature impact performance of the material needs to be further improved. When the addition amount is excessive, it will significantly reduce the rigidity and heat resistance of the material, and the weather resistance and hydrolysis stability will also be significantly reduced;

[0006] Chinese Patent CN104004339 discloses a PC / PBT / AES alloy material, which selects an E-MA-GMA copolymer as the toughener. Among them, the reaction mechanism of the ternary alloy is more complex. Using only the E-MA-GMA copolymer cannot completely solve the compatibility problem, and the performance of cold resistance, weather resistance and hydrolysis resistance obtained only by using AES needs to be further improved.

[0007] Then, the traditional formulation design and preparation technology of PC / PBT alloy materials cannot meet the increasingly high usage requirements. For example, new energy applications such as 5G antenna covers, charging piles, and exterior decorations of new energy vehicles, as well as Internet of Things applications such as drone brackets, all put forward higher requirements for material selection. Therefore, it is necessary to prepare a PC / PBT alloy with more excellent comprehensive performance. Summary of the Invention

[0008] The purpose of the present invention is to provide a PC / PBT alloy with high cold resistance, weather resistance, high impact resistance, and high hydrolysis stability, which is used to solve the technical problem that the cold resistance, weather resistance, impact resistance, and hydrolysis resistance of the existing PC / PBT alloy need to be further improved.

[0009] The purpose of the present invention is achieved through the following technical solutions: A PC / PBT alloy with high cold resistance, weather resistance, high impact resistance, and high hydrolysis stability, comprising the following raw material components in parts by weight:

[0010]

[0011]

[0012] Furthermore, the viscosity-average molecular weight of the polycarbonate is between 12,000 and 30,000, the silicon content in the silicon-containing polycarbonate is 5-10 wt%, and the intrinsic viscosity of the polybutylene terephthalate is 0.8-1.2 dl / g.

[0013] Furthermore, the polycarbonate is one or more of bisphenol A polycarbonate, tetrabromobisphenol A polycarbonate, tetrafluorobisphenol A polycarbonate, bisphenol S polycarbonate, and bisphenol AP polycarbonate.

[0014] Furthermore, the silicon-containing polycarbonate refers to a copolymer of siloxane and polycarbonate;

[0015] Furthermore, the preparation method of the silicon-containing polycarbonate includes the following steps:

[0016] A1. Put bisphenol A and N,N-dimethylformamide into a reaction kettle, stir at room temperature for 10-15 minutes. After the stirring ends, raise the temperature of the reaction kettle to 50-100 °C, and slowly introduce phosgene into it, and keep the reaction at a constant temperature for 2-4 hours to obtain a reaction precursor solution;

[0017] Reaction equation:

[0018]

[0019] Reaction principle: Phosgene reacts with the hydroxyl group of bisphenol A at high temperature to generate a polycarbonate precursor.

[0020] A2. Add the reaction precursor solution, hydroxy silicone oil with a molecular weight of 1200 - 3600, and sodium carbonate into a reaction kettle. Raise the temperature of the reaction kettle to 100 - 150 °C, keep the temperature for reaction for 2 - 4 h, and perform post-treatment to obtain a silicone-containing polycarbonate.

[0021] Reaction equation:

[0022]

[0023] Reaction principle: Under alkaline conditions, the halogen group in the polycarbonate precursor reacts with the hydroxyl group in the hydroxy silicone oil to generate a chain structure, obtaining a silicone-containing polycarbonate.

[0024] Furthermore, in step A1, the dosage ratio of bisphenol A, phosgene, and N,N-dimethylformamide is 12 - 15 g : 8 - 9 g : 80 - 100 mL, and the stirring rate is 120 - 180 rpm; in step A2, the dosage ratio of hydroxy silicone oil with a molecular weight of 1200 - 3600, sodium carbonate, and the reaction precursor solution is 6 - 13 g : 1 - 2 g : 18 - 20 mL, and the stirring rate is 120 - 180 rpm. The post-treatment includes: pouring the reaction solution into deionized water to form a polycarbonate precipitate, filtering with suction to collect the filter cake, washing the filter cake with dichloromethane, and placing the filter cake in a drying oven at 80 °C for vacuum drying until the filter cake reaches a constant weight to obtain a silicone-containing polycarbonate.

[0025] Furthermore, the weather-resistant toughening and compatibilizing modifier is one or both of AES-g-GMA or EPDM-co-SAG.

[0026] Furthermore, the preparation method of AES-g-GMA includes the following steps:

[0027] B1. Add azobisisobutyronitrile, glycidyl methacrylate, and N,N-dimethylformamide into a reactor. Raise the temperature of the reaction kettle to 80 - 120 °C, keep the temperature for reaction for 2 - 4 h to obtain a reaction precursor solution;

[0028] B2. Add N-bromosuccinimide and the reaction precursor solution into the reaction kettle. Raise the temperature of the reaction kettle to 80 - 120 °C, keep the temperature for reaction for 2 - 4 h to obtain a halogenated precursor solution;

[0029] Halogenated precursor synthesis reaction equation:

[0030]

[0031] Halogenated precursor synthesis reaction principle: Azobisisobutyronitrile acts as a radical initiator to initiate the cleavage of the olefin double bond and then undergoes a radical addition reaction. N-bromosuccinimide selectively reacts with the radical formed by the cleavage of the double bond to form a halogenated chain structure.

[0032] B3. Add the halogenated precursor solution, acrylonitrile-ethylene propylene diene monomer-styrene copolymer ring, anhydrous aluminum trichloride, and N,N-dimethylformamide into a reaction kettle. Raise the temperature of the reaction kettle to 50 - 100 °C, keep the temperature for reaction for 2 - 4 h, and obtain AES-g-GMA through post-treatment.

[0033] Synthesis reaction equation of AES-g-GMA:

[0034]

[0035] Synthesis reaction principle of AES-g-GMA: In the presence of anhydrous aluminum trichloride, a Lewis acid, an electrophilic substitution reaction occurs on the aromatic ring when an aromatic hydrocarbon reacts with a haloalkane, and its hydrogen atom is replaced by a halogen to form an aromatic hydrocarbon.

[0036] Furthermore, in step B1, the dosage ratio of azobisisobutyronitrile, glycidyl methacrylate, and N,N-dimethylformamide is 1 - 2 g:5 - 8 g:40 - 50 mL, and the stirring rate is 120 - 180 rpm; in step B2, the dosage ratio of N-bromosuccinimide and the reaction precursor solution is 4 - 5 g:40 - 50 mL; in step B3, the dosage ratio of the halogenated precursor solution, acrylonitrile-ethylene propylene diene monomer-styrene copolymer ring, anhydrous aluminum trichloride, and N,N-dimethylformamide is 40 - 50 mL:50 - 400 g:20 g:1000 mL. The post-treatment includes: after the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 100 - 150 rpm, set the temperature to 30 - 40 °C, rotary evaporate until the system reaches a constant weight to obtain a residue, wash the residue with deionized water 3 - 5 times, and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain AES-g-GMA.

[0037] Furthermore, the preparation method of EPDM-co-SAG includes the following steps:

[0038] C1. Add styrene, acrylonitrile, glycidyl methacrylate, and toluene into a reaction kettle, and stir at room temperature for 15 - 20 min to obtain a reaction solution;

[0039] C2. Add the reaction solution and benzoyl peroxide into the reaction kettle, raise the temperature of the reaction kettle to 70 - 80 °C, keep the temperature for reaction for 6 - 12 h, and obtain a styrene-acrylonitrile-glycidyl methacrylate random copolymer through post-treatment.

[0040] Reaction equation:

[0041]

[0042] Reaction principle: Benzoyl peroxide is used as a radical initiator to initiate the radical addition reaction after the double bonds of styrene, acrylonitrile, and glycidyl methacrylate are broken, and a styrene-acrylonitrile-glycidyl methacrylate random terpolymer is prepared.

[0043] C3. Add the styrene-acrylonitrile-glycidyl methacrylate random terpolymer, ethylene propylene diene monomer (EPDM), toluene, and benzoyl peroxide into a reaction kettle. Raise the temperature of the reaction kettle to 120 - 150 °C, keep the temperature for reaction for 4 - 6 h, and perform post-treatment to obtain EPDM-co-SAG.

[0044] Synthesis reaction principle of EPDM-co-SAG: Benzoyl peroxide is used as a radical initiator to initiate the radical addition reaction after the double bond of EPDM is broken, and further addition reaction occurs with the radicals on the styrene-acrylonitrile-glycidyl methacrylate random terpolymer to prepare EPDM-co-SAG.

[0045] Furthermore, in step C1, the dosage ratio of styrene, acrylonitrile, glycidyl methacrylate, and toluene is 8 - 10 g : 3 - 5 g : 3 - 5 g : 50 mL, and the stirring rate is 120 - 180 rpm; in step C2, the dosage ratio of benzoyl peroxide and the reaction solution is 0.2 g : 50 mL. The post-treatment is as follows: after the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 100 - 150 rpm, set the temperature to 70 - 80 °C, rotary evaporate until the system reaches a constant weight to obtain a residue, wash the residue with deionized water 3 - 5 times, and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain the styrene-acrylonitrile-GMA random terpolymer; in step C3, the dosage ratio of the styrene-acrylonitrile-GMA random terpolymer, EPDM, toluene, and benzoyl peroxide is 5 - 6 g : 10 - 15 g : 0.2 g : 50 mL. The subsequent operation includes: after the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 100 - 150 rpm, set the temperature to 70 - 80 °C, rotary evaporate until the system reaches a constant weight to obtain a residue, wash the residue with deionized water 3 - 5 times, and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain EPDM-co-SAG.

[0046] Furthermore, the weather-resistant toughening and compatibilizing modifier is at least one of AES-g-GMA or EPDM-co-SAG. In AES-g-GMA, the content of glycidyl methacrylate is 2 - 10 wt%; in EPDM-co-SAG, the content of EPDM is 60 - 75 wt%, and the content of glycidyl methacrylate is 3 - 12%.

[0047] Further, the hydrolysis stabilizer is one or more of epoxy chain extenders and carbodiimides. The epoxy chain extender is one or more of styrene-acrylic-glycidyl methacrylate, styrene-acrylate-glycidyl methacrylate, acrylate-glycidyl methacrylate, styrene-acrylonitrile-glycidyl methacrylate, and styrene-glycidyl methacrylate copolymer, with a weight average molecular weight of 5,000 - 100,000 and an epoxy equivalent of 200 - 500 g / mol; the carbodiimide is a polymeric carbodiimide.

[0048] Further, the transesterification inhibitor is a phosphate or phosphoric acid ester transesterification inhibitor, including but not limited to one or more of dioctyl phosphate, disodium dihydrogen pyrophosphate, diisooctyl phosphate, sodium dihydrogen phosphate, and triphenyl phosphite.

[0049] Further, the light stabilizer is one or more of benzotriazoles, benzophenones, salicylates, benzoates, cyanoacrylates, organonickel complexes, and hindered amine light stabilizers.

[0050] Further, the antioxidant is one or more of phosphite antioxidants and hindered phenol antioxidants, and the lubricant is one or more of silicone, stearates, polyethylene wax, pentaerythritol stearate, and ethylene bisstearamide.

[0051] The present invention also provides a method for preparing a high-strength and stable PCPBT alloy material, comprising the following steps:

[0052] S1. Mix polycarbonate, silicon-containing polycarbonate, polybutylene terephthalate, weather-resistant toughening and compatibilizing modifier, hydrolysis stabilizer, transesterification inhibitor, light stabilizer, antioxidant, and lubricant evenly in proportion to obtain a premix.

[0053] S2. Feed the premix into the main feeding port of a twin-screw extruder, and obtain a modified alloy material through melt blending, devolatilization extrusion, and cooling pelletization.

[0054] Further, the process parameters of melt blending are: the temperature of the feeding section is 180 - 220 °C, the temperature of the plasticizing section is 200 - 240 °C, the temperature of the homogenizing section is 220 - 260 °C, the screw speed is 300 - 600 rpm, the length-diameter ratio of the extruder is 36:1 - 60:1, and at least one vacuum devolatilization port is provided at the end of the extruder.

[0055] The present invention has the following beneficial effects:

[0056] 1. In the process of preparing a high-strength and stable PC / PBT alloy material, the present invention selects a silicone-containing polycarbonate copolymer to partially replace the traditional polycarbonate, which makes up for the disadvantages of traditional polycarbonate in many aspects. Although traditional polycarbonate performs well in many applications, it has some limitations in terms of weather resistance, hydrolysis resistance, low-temperature resistance, and chemical resistance. The silicone polycarbonate copolymer not only maintains the excellent physical properties and processability of polycarbonate but also significantly improves the comprehensive performance of the material. The silicone polycarbonate copolymer has excellent weather resistance and can be exposed to the outdoor environment for a long time without losing performance stability, which gives it a longer service life and less maintenance requirements in outdoor applications. The silicone polycarbonate copolymer exhibits excellent hydrolysis resistance and is not easily degraded by moisture, making it suitable for applications in humid or high-humidity environments. The silicone polycarbonate copolymer also has excellent low-temperature characteristics and can maintain its physical properties at extremely low temperatures, so it has broad application potential in cold regions or cooling equipment. Blending the silicone polycarbonate copolymer with polybutylene terephthalate not only expands the application range of the material but also further optimizes its physical properties and processing characteristics. This alloy material is not only more stable and reliable in structure but also exhibits more excellent comprehensive performance in practical applications, meeting the market demand for high-performance and multi-functional materials.

[0057] 2. In the process of preparing a high-strength and stable PC / PBT alloy material, through the optimized design of the formula, the present invention selects the copolymer and / or graft copolymer of AES and GMA with originality as the toughening and compatibilizing modifier of the material. Utilizing the special molecular structure characteristics and impact resistance of AES, by grafting GMA, GMA can form a cross-linked structure in the matrix. This structure can effectively absorb and disperse stress, thereby improving the toughness of the material. Moreover, the vinyl and epoxy groups in the molecule have high reactivity, and these functional groups can fully react with the terminal carboxyl groups of polycarbonate and polybutylene terephthalate, providing better compatibility and toughness and forming covalent bonds. This chemical reaction can firmly bind the modifier to the matrix material, thereby enhancing the mechanical properties and compatibility of the material. Compared with traditional MBS, POE-g-GMA, EMA-co-GMA, and EBA-co-GMA, it has excellent weather resistance and excellent thermal stability, and does not decompose small-molecule substances that promote the degradation of polycarbonate and polybutylene terephthalate during processing and use, reducing the service life of the material. Through the combined use of this compatibilizing and toughening modifier and the silicone-containing polycarbonate, the weather resistance and cold resistance of the PC / PBT alloy are further improved.

[0058] 3. In the process of preparing a high-strength and stable PC / PBT alloy material, an organosilicon group is introduced into the carbonate, which increases the length of the structural unit, reduces the rigidity of the large benzene ring, and increases the flexibility of the molecular chain. Therefore, the fluidity of the polycarbonate material is significantly improved. In addition, the structural characteristics of the siloxane also greatly improve the hydrolysis resistance of the polycarbonate, and it has excellent properties such as resistance to high and low temperatures, electrical insulation, oxidation stability, weather resistance, flame retardancy, water repellency, corrosion resistance, non-toxic and odorless, and physiological inertness. An epoxy chain extender is selected as the hydrolysis stabilizer of the PC / PBT alloy, which significantly improves the hydrolysis resistance of the material. The high reactivity of the epoxy chain extender can cross-link with the matrix material, enhancing the structural stability of the material. At the same time, the synergistic effect of the epoxy chain extender and carbodiimide enables the PC / PBT alloy material to exhibit better durability and stability in harsh environments, effectively preventing the progress of the hydrolysis reaction. This optimized scheme not only improves the hydrolysis resistance of the PC / PBT alloy material but also broadens its application scope, especially in application scenarios that require long-term exposure to high-temperature and high-humidity environments, showing broad prospects. Detailed Embodiments

[0059] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0060] It should be noted that the raw materials used in the following embodiments and comparative examples are shown in Table 1 below:

[0061] Table 1 - Raw Material Table for Embodiments and Comparative Examples

[0062]

[0063]

[0064] Example 1

[0065] This example provides a preparation method of a silicon-containing polycarbonate for a high-strength and stable PC / PBT alloy material, including the following steps:

[0066] Take bisphenol A, N,N-dimethylformamide, and phosgene in a dosage ratio of 12 g:8 g:100 mL. Put bisphenol A and N,N-dimethylformamide into a reaction kettle, stir at room temperature for 10 min, with a stirring rate of 120 rpm. After stirring, raise the temperature of the reaction kettle to 50 °C, and slowly introduce phosgene into it, and keep the reaction at a constant temperature for 2 h to obtain a reaction precursor solution;

[0067] Hydroxy silicone oil with a molecular weight of 1653.24, sodium carbonate and the reaction precursor solution were added to the reaction kettle in a dosage ratio of 3 g: 2 g: 20 mL. The temperature of the reaction kettle was raised to 100 °C, and the reaction was carried out under insulation for 2 h. The reaction solution was poured into deionized water to form a polycarbonate precipitate. The filter cake was collected by suction filtration, washed with dichloromethane, and placed in a drying oven at 80 °C for vacuum drying until the filter cake reached a constant weight to obtain a silicon-containing polycarbonate.

[0068] Example 2

[0069] This example provides a preparation method of a silicon-containing polycarbonate for a high-strength and stable PC / PBT alloy material, including the following steps:

[0070] Bisphenol A, N,N-dimethylformamide and phosgene were taken in a dosage ratio of 12 g: 8 g: 100 mL. Bisphenol A and N,N-dimethylformamide were put into the reaction kettle and stirred at room temperature for 15 min with a stirring rate of 180 rpm. After the stirring ended, the temperature of the reaction kettle was raised to 100 °C, and phosgene was slowly introduced into it. The reaction was carried out under insulation for 4 h to obtain a reaction precursor solution;

[0071] Hydroxy silicone oil with a molecular weight of 2468.73, sodium carbonate and the reaction precursor solution were added to the reaction kettle in a dosage ratio of 13 g: 2 g: 18 mL. The temperature of the reaction kettle was raised to 150 °C, and the reaction was carried out under insulation for 4 h. The reaction solution was poured into deionized water to form a polycarbonate precipitate. The filter cake was collected by suction filtration, washed with dichloromethane, and placed in a drying oven at 80 °C for vacuum drying until the filter cake reached a constant weight to obtain a silicon-containing polycarbonate.

[0072] Example 3

[0073] This example provides a preparation method of a silicon-containing polycarbonate for a high-strength and stable PC / PBT alloy material, including the following steps:

[0074] Bisphenol A, N,N-dimethylformamide and phosgene were taken in a dosage ratio of 12 g: 9 g: 80 mL. Bisphenol A and N,N-dimethylformamide were put into the reaction kettle and stirred at room temperature for 15 min with a stirring rate of 180 rpm. After the stirring ended, the temperature of the reaction kettle was raised to 100 °C, and phosgene was slowly introduced into it. The reaction was carried out under insulation for 4 h to obtain a reaction precursor solution;

[0075] Add hydroxyl silicone oil with a molecular weight of 3261.45, sodium carbonate, and the reaction precursor solution to the reaction kettle in a dosage ratio of 9 g: 2 g: 18 mL. Raise the temperature of the reaction kettle to 150 °C, keep the temperature for reaction for 4 h, pour the reaction solution into deionized water to form polycarbonate precipitate, filter by suction to collect the filter cake, wash the filter cake with dichloromethane, place the filter cake in a drying oven at 80 °C and dry it under vacuum until the filter cake reaches a constant weight to obtain silicon-containing polycarbonate.

[0076] Example 4

[0077] This example provides a preparation method of AES-g-GMA for high-strength and stable PC / PBT alloy materials, including the following steps:

[0078] Add azobisisobutyronitrile, glycidyl methacrylate, and N,N-dimethylformamide to the reactor in a dosage ratio of 2 g: 5 g: 50 mL. Raise the temperature of the reaction kettle to 80 °C, keep the temperature for reaction for 2 h to obtain a reaction precursor solution;

[0079] Add N-bromosuccinimide and the reaction precursor solution to the reaction kettle in a dosage ratio of 4 g: 50 mL. Raise the temperature of the reaction kettle to 80 °C, keep the temperature for reaction for 2 h to obtain a halogenated precursor solution.

[0080] Add the halogenated precursor solution, acrylonitrile-ethylene propylene diene terpolymer ring, anhydrous aluminum trichloride, and N,N-dimethylformamide to the reaction kettle in a dosage ratio of 40 mL: 400 g: 20 g: 1000 mL. Raise the temperature of the reaction kettle to 50 °C, keep the temperature for reaction for 2 h. After the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 100 rpm, set the temperature to 30 °C, rotary evaporate until the system reaches a constant weight to obtain a residue, wash the residue with deionized water 3 times and then place it in a drying oven at 80 °C and dry it under vacuum until the residue reaches a constant weight to obtain AES-g-GMA.

[0081] Example 5

[0082] This example provides a preparation method of AES-g-GMA for high-strength and stable PC / PBT alloy materials, including the following steps:

[0083] Add azobisisobutyronitrile, glycidyl methacrylate, and N,N-dimethylformamide to the reactor in a dosage ratio of 2 g: 58 g: 40 mL. Raise the temperature of the reaction kettle to 120 °C, keep the temperature for reaction for 4 h to obtain a reaction precursor solution;

[0084] Add N-bromosuccinimide and the reaction precursor solution to the reaction kettle in a dosage ratio of 5 g: 50 mL. Raise the temperature of the reaction kettle to 120 °C, keep the temperature for reaction for 4 h to obtain a halogenated precursor solution.

[0085] The halogenated precursor solution, acrylonitrile-ethylene propylene diene monomer-styrene copolymer ring, anhydrous aluminum trichloride, and N,N-dimethylformamide were added to the reaction kettle according to the dosage ratio of 50 mL:50 g:20 g:1000 mL. The temperature of the reaction kettle was raised to 100 °C, and the reaction was carried out under insulation for 4 h. After the reaction was completed, the reaction solution was placed in a rotary evaporator, the rotation speed was adjusted to 150 rpm, and the temperature was set to 40 °C. Rotary evaporation was carried out until the system reached a constant weight to obtain a residue. The residue was washed 5 times with deionized water and then placed in a drying oven at 80 °C for vacuum drying until the residue reached a constant weight to obtain AES-g-GMA.

[0086] Example 6

[0087] This example provides a preparation method of AES-g-GMA for a high-strength and stable PC / PBT alloy material, including the following steps:

[0088] Azobisisobutyronitrile, glycidyl methacrylate, and N,N-dimethylformamide were added to the reactor according to the dosage ratio of 2 g:6 g:45 mL. The temperature of the reaction kettle was raised to 100 °C, and the reaction was carried out under insulation for 4 h to obtain a reaction precursor solution;

[0089] N-bromosuccinimide and the reaction precursor solution were added to the reaction kettle according to the dosage ratio of 5 g:40 mL. The temperature of the reaction kettle was raised to 120 °C, and the reaction was carried out under insulation for 4 h to obtain a halogenated precursor solution.

[0090] The halogenated precursor solution, acrylonitrile-ethylene propylene diene monomer-styrene copolymer ring, anhydrous aluminum trichloride, and N,N-dimethylformamide were added to the reaction kettle according to the dosage ratio of 50 mL:200 g:20 g:1000 mL. The temperature of the reaction kettle was raised to 75 °C, and the reaction was carried out under insulation for 4 h. After the reaction was completed, the reaction solution was placed in a rotary evaporator, the rotation speed was adjusted to 150 rpm, and the temperature was set to 40 °C. Rotary evaporation was carried out until the system reached a constant weight to obtain a residue. The residue was washed 5 times with deionized water and then placed in a drying oven at 80 °C for vacuum drying until the residue reached a constant weight to obtain AES-g-GMA.

[0091] Example 7

[0092] This example provides a preparation method of EPDM-co-SAG for a high-strength and stable PC / PBT alloy material, including the following steps:

[0093] Styrene, acrylonitrile, glycidyl methacrylate, and toluene were added to the reaction kettle according to the dosage ratio of 8 g:3 g:5 g:50 mL. Stirring was carried out at room temperature for 15 min, and the stirring rate was 120 rpm to obtain a reaction solution;

[0094] The reaction solution and benzoyl peroxide were added to the reaction kettle at a dosage ratio of 50 mL:0.2 g. The temperature of the reaction kettle was raised to 70 °C, and the reaction was carried out under insulation for 6 h. After the reaction was completed, the reaction solution was placed in a rotary evaporator, the rotation speed was adjusted to 100 rpm, the temperature was set at 70 °C, and rotary evaporation was carried out until the system reached a constant weight to obtain a residue. The residue was washed 3 times with deionized water and then placed in a drying oven at 80 °C for vacuum drying until the residue reached a constant weight, obtaining a styrene-acrylonitrile-GMA random copolymer;

[0095] The styrene-acrylonitrile-glycidyl methacrylate random copolymer, ethylene propylene diene monomer rubber, toluene and benzoyl peroxide were added to the reaction kettle at a dosage ratio of 5 g:15 g:0.2 g:50 mL. The temperature of the reaction kettle was raised to 150 °C, and the reaction was carried out under insulation for 4 h. After the reaction was completed, the reaction solution was placed in a rotary evaporator, the rotation speed was adjusted to 100 rpm, the temperature was set at 70 °C, and rotary evaporation was carried out until the system reached a constant weight to obtain a residue. The residue was washed 3 times with deionized water and then placed in a drying oven at 80 °C for vacuum drying until the residue reached a constant weight, obtaining EPDM-co-SAG.

[0096] Example 8

[0097] This example provides a preparation method of a high-strength and stable PC / PBT alloy material EPDM-co-SAG, including the following steps:

[0098] Styrene, acrylonitrile, glycidyl methacrylate and toluene were added to the reaction kettle at a dosage ratio of 10 g:3 g:5 g:50 mL, and stirred at room temperature for 15 min with a stirring rate of 180 rpm to obtain a reaction solution;

[0099] The reaction solution and benzoyl peroxide were added to the reaction kettle at a dosage ratio of 50 mL:0.2 g. The temperature of the reaction kettle was raised to 70 °C, and the reaction was carried out under insulation for 9 h. After the reaction was completed, the reaction solution was placed in a rotary evaporator, the rotation speed was adjusted to 150 rpm, the temperature was set at 80 °C, and rotary evaporation was carried out until the system reached a constant weight to obtain a residue. The residue was washed 5 times with deionized water and then placed in a drying oven at 80 °C for vacuum drying until the residue reached a constant weight, obtaining a styrene-acrylonitrile-GMA random copolymer;

[0100] Add styrene-acrylonitrile-glycidyl methacrylate terpolymer, ethylene propylene diene monomer (EPDM), toluene and benzoyl peroxide into a reaction kettle according to the dosage ratio of 6 g: 10 g: 0.2 g: 50 mL. Raise the temperature of the reaction kettle to 135 °C and keep the temperature for reaction for 5 h. After the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 125 rpm, set the temperature to 80 °C, and rotary evaporate until the system reaches a constant weight to obtain a residue. Wash the residue 5 times with deionized water and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain EPDM-co-SAG.

[0101] Example 9

[0102] This example provides a preparation method of a high-strength and stable PC / PBT alloy material EPDM-co-SAG, including the following steps:

[0103] Add styrene, acrylonitrile, glycidyl methacrylate and toluene into a reaction kettle according to the dosage ratio of 10 g: 5 g: 5 g: 50 mL, stir at room temperature for 20 min, and the stirring rate is 180 rpm to obtain a reaction solution;

[0104] Add the reaction solution and benzoyl peroxide into a reaction kettle according to the dosage ratio of 50 mL: 0.2 g. Raise the temperature of the reaction kettle to 80 °C and keep the temperature for reaction for 12 h. After the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 150 rpm, set the temperature to 80 °C, and rotary evaporate until the system reaches a constant weight to obtain a residue. Wash the residue 5 times with deionized water and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain a styrene-acrylonitrile-GMA terpolymer.

[0105] Add styrene-acrylonitrile-glycidyl methacrylate terpolymer, ethylene propylene diene monomer (EPDM), toluene and benzoyl peroxide into a reaction kettle according to the dosage ratio of 6 g: 15 g: 0.2 g: 50 mL. Raise the temperature of the reaction kettle to 150 °C and keep the temperature for reaction for 6 h. After the reaction is completed, place the reaction solution in a rotary evaporator, adjust the rotation speed to 150 rpm, set the temperature to 80 °C, and rotary evaporate until the system reaches a constant weight to obtain a residue. Wash the residue 5 times with deionized water and then place it in a drying oven at 80 °C for vacuum drying until the residue reaches a constant weight to obtain EPDM-co-SAG.

[0106] Prepare a high-strength and stable PC / PBT alloy material

[0107] Weigh each raw material according to the formula dosages described in Table 2 and Table 3 below, put the weighed raw materials into a mixer and mix them evenly to obtain a premix; then put the premix into a twin-screw extruder, and obtain the PC / PBT alloy material of the present application through melt blending, devolatilization extrusion and cooling pelletization.

[0108] The parameters used in melt extrusion are as follows: the length-diameter ratio of the screw of the extruder is 48:1, a vacuum port is provided in the ninth and eleventh zones of the extruder respectively, the temperature of the feeding section is 200 °C, the temperature of the plasticizing section is 220 °C, the temperature of the homogenizing section is 240 °C, and the screw speed is 400 rpm.

[0109] Table 2 - Dosage table of each component in Examples 10 - 15 (parts by weight)

[0110]

[0111]

[0112] Table 3 - Dosage table of each component in Comparative Examples 1 - 7 (parts by weight)

[0113]

[0114] Performance test:

[0115] The notched Izod impact strength, tensile strength, flowability, weather resistance, and hydrolysis stability of the PC / PBT alloy materials prepared in Examples 10 - 15 and Comparative Examples 1 - 7 were tested:

[0116] For the notched Izod impact strength, with reference to the standard ASTM D256 - 1997 "Standard Test Method for Determining Izod Impact Resistance of Plastics", the prepared specimens were respectively tested at normal and low temperatures. The test temperatures included: (normal temperature) 23 ± 2 °C, (low temperature) - 40 ± 2 °C, and the humidity: 50 ± 5%.

[0117] For the tensile strength, with reference to the standard ASTM D638 - 2003 "Standard Test Method for Tensile Properties of Plastics", the tensile strength of the prepared specimens was tested. The tensile speed was: 50 mm / min, the test temperatures included: 23 ± 2 °C, and the humidity included: 50 ± 5%.

[0118] For the flowability, with reference to the standard ASTM D1238 - 13 "Test Method for Measuring Melt Flow Rate of Thermoplastics by Extrusion Plastometer", the melt flow rate (MFR) of the prepared pellets was tested. The test temperature was: 250 °C, and the pellet mass was: 5 kg.

[0119] Weather resistance test: The ultraviolet light / condensation test was adopted. The UVB - 313 type light source was selected, deionized water was used, and the relative humidity was not controlled. The test conditions of the cyclic exposure period were specifically as follows:

[0120] 8 - hour drying: Turn on the UVB - 313 type light source, and the irradiance at 310 nm was set to 0.48 W·m⁻²·nm⁻¹, and the black - label temperature was 60 ± 3 °C;

[0121] 4h Dew: Turn off the light source, and the black label temperature is 50 ± 3 °C;

[0122] After aging for 96 hours according to the above UVB, test its color difference ΔE.

[0123] Hydrolysis stability test: Take the sample particles in the examples and comparative examples, place them in a high-temperature and high-humidity box at a temperature of 100 °C and a humidity of 100% RH, and keep them for 120 h and 240 h. Take samples and test their MFR respectively. Then compare the change in the flow performance of the material before and after the accelerated high-temperature and high-humidity test and calculate its improvement rate. The calculation formula for the MFR improvement rate is as follows:

[0124] MFR improvement rate = (MFR after high-temperature and high-humidity aging - MFR of conventional test / MFR of conventional test) * 100%

[0125] Test the various properties of each example and comparative example according to the method mentioned above as shown in Table 4.

[0126] Table 4 - Performance test results table of each example and comparative example

[0127]

[0128]

[0129] Data analysis:

[0130] It can be seen from Examples 10 - 15 that the PC / PBT alloy material prepared according to the method and process of the present invention has excellent impact strength, especially excellent low-temperature impact resistance at -40 °C, and also excellent weather resistance and hydrolysis resistance; after the UVB accelerated aging test, the ΔE values are all ≤ 2.0; after the accelerated high-temperature and high-humidity aging test at 100 °C and 100% RH, the improvement in the flow performance of the material is not significant, indicating that when the material undergoes severe high-temperature and high-humidity conditions, there are few molecular chain breaks and it has stable hydrolysis resistance. Specifically, after 120 h of accelerated aging, the MFR improvement rates of the materials are all ≤ 17%, and after 240 h of accelerated aging, the MFR improvement rates of the materials are all ≤ 37%.

[0131] It can be seen from the test results of Comparative Examples 1 and 2 that after adding the same amount of POE-g-GMA or EMA-co-GMA, the impact resistance at normal and low temperatures is acceptable, but it is not as good as the weather-resistant toughening and compatibilizing modifier used in the present invention, and its weather resistance and hydrolysis resistance are even worse than those of Examples 1 and 2 of the present invention; especially after a large amount of EMA-co-GMA is used in Comparative Example 2, the flow performance of the material decreases significantly, which inhibits the high fluidity characteristics that the alloy material should have.

[0132] In Comparative Examples 3 and 4, no silicone-containing polycarbonate was used, and only conventional MBS toughening agents and acrylate toughening agents were used. The impact performance of the materials was good, but the cold resistance was insufficient, and they both showed poor performance in terms of weather resistance and hydrolysis stability, failing to meet the usage requirements under harsh conditions.

[0133] In Comparative Example 5, only unfunctionalized AES was used, and no other polyester toughening agents or compatibilizers were added. Its improvement in the compatibility of polycarbonate and polybutylene terephthalate in the alloy system was limited, resulting in very poor impact performance of the alloy material, and no improvement in cold resistance and weather resistance, and poor hydrolysis stability performance; in Comparative Example 6, after a small amount of acrylate toughening agent and AES were used in combination, since the acrylate toughening agent contains a GMA functional group, it can carry out a capping reaction with polycarbonate or polybutylene terephthalate in the alloy system, and can better improve the compatibility and impact toughness of the alloy material, but the improvement in weather resistance was limited, which may be related to the types of compatibilizers or toughening agents. Even if the content of silicone copolymer polycarbonate and AES was relatively high, the advantages of their good weather resistance were not exerted. In Comparative Example 7, without adding silicone-containing polycarbonate, the cold resistance could not show its advantages, and the weather resistance and hydrolysis stability could not meet the usage requirements under harsh outdoor conditions.

[0134] The above content is only an example and illustration of the structure of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the structure of the invention or exceed the scope defined by the claims of the present invention, they should all fall within the protection scope of the present invention.

[0135] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0136] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and changes can be made according to the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art of the present technology can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A high-strength and stable PC / PBT alloy material, characterized in that: The invention comprises the following raw material components in parts by weight: Polycarbonate 20-50 parts; 10-40 parts of silicon-containing polycarbonate; 30-70 parts of polybutylene terephthalate; 5-30 parts of weather-resistant toughening and compatibility modifier; 0.3-3 parts of hydrolysis stabilizer; 0.05-1 part of transesterification inhibitor; Light stabilizer 0.1-1 part; Antioxidant 0.1-1 part; Lubricant 0.1-1 part; The weather-resistant toughening and compatibility modifier is one or both of AES-g-GMA and EPDM-co-SAG. The preparation method of the AES-g-GMA comprises the following steps: B1, adding azobisisobutyronitrile, glycidyl methacrylate and N,N-dimethylformamide into a reactor, raising the temperature of the reactor to 80-120° C., and keeping the temperature for 2-4 hours to obtain a reaction precursor solution; B2, adding N-bromosuccinimide and the reaction precursor solution into a reaction kettle, raising the temperature of the reaction kettle to 80-120° C., keeping the temperature for reaction for 2-4 hours, and post-treating to obtain a halogenated precursor solution; B3, adding the halogenated precursor solution, acrylonitrile-ethylene propylene diene monomer rubber-styrene copolymer, anhydrous aluminum chloride and N,N-dimethylformamide into the reactor, raising the temperature of the reactor to 50-100°C, keeping the temperature for 2-4h, and post-treating to obtain AES-g-GMA; The preparation method of the EPDM-co-SAG comprises the following steps: C1. Add styrene, acrylonitrile, glycidyl methacrylate and toluene into a reaction kettle, and stir for 15-20 minutes at room temperature to obtain a reaction solution; C2, adding the reaction solution and benzoyl peroxide into a reactor, raising the temperature of the reactor to 70-80°C, keeping the temperature for reaction for 6-12h, and post-treating to obtain a styrene-acrylonitrile-glycidyl methacrylate ternary random copolymer; C3. Add styrene-acrylonitrile-glycidyl methacrylate terpolymer, ethylene propylene diene rubber, toluene and benzoyl peroxide into a reactor, increase the temperature of the reactor to 120-150° C., keep the reaction warm for 4-6 hours, and obtain EPDM-co-SAG by post-treatment.

2. A high-strength and stable PC / PBT alloy material according to claim 1, characterized in that: The polycarbonate is one or more of bisphenol A polycarbonate, tetrabromobisphenol A polycarbonate, tetrafluorobisphenol A polycarbonate, bisphenol S polycarbonate and bisphenol AP polycarbonate.

3. A high-strength and stable PC / PBT alloy material according to claim 1, characterized in that: The preparation method of the silicon-containing polycarbonate comprises the following steps: A1. Put bisphenol A and N,N-dimethylformamide into a reaction kettle and stir at room temperature for 10-15 minutes. After stirring, raise the temperature of the reaction kettle to 50-100°C, slowly introduce phosgene into the reaction kettle, and keep the temperature for reaction for 2-4 hours to obtain a reaction precursor solution. A2. Add the reaction precursor liquid, hydroxy silicone oil with a molecular weight of 1200-3600 and sodium carbonate into the reactor, increase the temperature of the reactor to 100-150° C., keep the temperature for 2-4 hours, and post-treat to obtain silicon-containing polycarbonate.

4. A high-strength and stable PC / PBT alloy material according to claim 3, characterized in that: In step A1, the dosage ratio of bisphenol A, phosgene and N,N-dimethylformamide is 12-15g:8-9g:80-100mL, and the stirring rate is 120-180rpm; in step A2, the dosage ratio of hydroxy silicone oil with a molecular weight of 1200-3600, sodium carbonate and reaction precursor liquid is 6-8g:2-3g:18-20mL, and the stirring rate is 120-180rpm. The post-treatment includes: pouring the reaction solution into deionized water to form a polycarbonate precipitate, collecting the filter cake by suction filtration, washing the filter cake with dichloromethane, placing the filter cake in a drying furnace at a temperature of 80°C and vacuum drying until the filter cake has a constant weight, to obtain a silicon-containing polycarbonate.

5. A high-strength and stable PC / PBT alloy material according to claim 1, characterized in that: The hydrolysis stabilizer is one or more of an epoxy chain extender and a carbodiimide, and the epoxy chain extender is one or more of styrene-acrylic acid-glycidyl methacrylate, styrene-acrylate-glycidyl methacrylate, acrylate-glycidyl methacrylate, styrene-acrylonitrile-glycidyl methacrylate, and styrene-glycidyl methacrylate copolymer, and has an average molecular weight of 5000-100000 and an epoxy equivalent of 200-500 g / mol.

6. A method for preparing a high-strength and stable PC / PBT alloy material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, polycarbonate, silicon-containing polycarbonate, polybutylene terephthalate, weather-resistant toughening compatibility modifier, hydrolysis stabilizer, transesterification inhibitor, light stabilizer, antioxidant and lubricant are mixed uniformly in proportion to obtain a premix; S2. The premix is ​​fed into the main feed port of a twin-screw extruder, and the modified alloy material is obtained through melt blending, devolatilization extrusion, cooling and granulation.

7. The method for preparing a high-strength and stable PC / PBT alloy material according to claim 6, characterized in that: The melt blending process parameters are: the feeding section temperature is 180-220°C, the plasticizing section temperature is 200-240°C, the homogenizing section temperature is 220-260°C, the screw speed is 300-600rpm, the extruder aspect ratio is 36:1-60:1, and at least one vacuum devolatilization port is set at the end of the extruder.

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