PBT / brominated PC alloy and preparation method and application thereof

Abstract

The invention discloses a PBT (Polybutylece Terephthalate) / brominated PC (Polycarbonate) alloy, which comprises the following components in parts by weight: 40-50 parts of PBT; 30 to 40 parts of brominated PC; 2-10 parts of an anti-ultraviolet agent; 10 to 15 parts of a toughening agent; 0.2 to 0.5 part of an anti-dripping agent; the viscosity-average molecular weight range of the brominated PC is 13000 to 80000, and the molar ratio of the bisphenol A to the tetrabromobisphenol A is (80 to 40) to (20 to 60); the anti-ultraviolet agent is selected from a copolymer of styrene-N-phenyl maleimide and maleic anhydride. The brominated PC with specific parameters and the anti-ultraviolet agent are selected, so that V-0 flame retardance can be realized, and the anti-ultraviolet PC alloy has the advantage of good anti-ultraviolet performance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a PBT / brominated PC alloy and a preparation method and application thereof. Background Art

[0002] Polybutylene terephthalate (PBT) is a crystalline thermoplastic with the advantages of fast crystallization speed, chemical resistance and good fluidity, but its main disadvantage is low toughness. Polycarbonate (PC) is a transparent and colorless thermoplastic. Its biggest advantage is high toughness and good dimensional stability, but its fluidity and solvent resistance are poor. PBT and PC alloy can overcome the shortcomings of PC such as poor chemical resistance and poor molding processability, and at the same time make up for the disadvantage of poor toughness of PBT, and obtain good comprehensive performance. However, PBT and PC are both polyester materials. Under high temperature and high shear processing conditions, serious ester exchange reactions will occur between the two, thus affecting the performance of the alloy material, and causing the alloy material to produce obvious yellowing during the molding process, affecting its use.

[0003] The existing technology solves the defects of insufficient heat resistance and solvent resistance by adding brominated PC. For example, Chinese patent application CN116355367A discloses a flame retardant PBT composition. The components of the PBT composition include, by weight: 35-45 parts of PBT, 20-30 parts of brominated PC, 5-10 parts of isosorbide copolymerized PC, 2-6 parts of antimony flame retardant, 0.1-0.4 parts of ester exchange inhibitor, and 2-5 parts of talc. Among them, the glass transition temperature of brominated PC is 160-175°C. However, the flame retardant PBT composition also has UV yellowing resistance, which needs further optimization. Summary of the invention

[0004] The object of the present invention is to overcome the above technical defects and provide a flame retardant and UV yellowing resistant PBT / brominated PC alloy.

[0005] The present invention is achieved through the following technical solutions: A PBT / brominated PC alloy, comprising the following components in parts by weight: PBT 40-50 parts; Brominated PC 30-40 parts; 2-10 parts of UV-resistant agent; 10-15 parts of toughening agent; Anti-dripping agent 0.2-0.5 parts; The viscosity average molecular weight of the brominated PC is in the range of 13000-80000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (80-40): (20-60); The anti-ultraviolet agent is selected from the copolymer of styrene-N-phenylmaleimide and maleic anhydride.

[0006] The viscosity average molecular weight of the brominated PC of the present invention can range from 13000, 15000, 20000, 25000, 30000, 35000, 40000, 45000, 50000, 55000, 60000, 65000, 70000, 75000, 80000, etc., and the molar ratio of bisphenol A:tetrabromobisphenol A can range from 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, etc.

[0007] In the PBT / brominated PC alloy of the present invention, the content of PBT can be 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, etc., the content of brominated PC can be 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, etc., the content of the anti-ultraviolet agent can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., the content of the toughening agent can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc., and the content of the anti-dripping agent can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0008] Preferably, the viscosity average molecular weight of the brominated PC is in the range of 20,000-60,000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (70-50): (30-50).

[0009] More preferably, the viscosity average molecular weight of the brominated PC is in the range of 25,000-45,000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (65-55): (35-45).

[0010] Brominated polycarbonate can be a commercial product or can be obtained by the triphosgene method, which is specifically as follows: add bisphenol A, tetrabromobisphenol A, and a solvent to a reactor equipped with an agitator, a condenser, triphosgene, and a sodium hydroxide dropping device, add a sodium hydroxide solution under stirring, and stir until the tetrabromobisphenol A is completely dissolved. Then add a 1,2-dichloroethane solution of triphosgene dropwise. After all the additions are completed, stir and react at 25-30°C for 2-3 hours. After the reaction is completed, the solution is allowed to stand, the organic phase is separated, the organic phase is repeatedly washed with deionized water, and the organic phase is added to methanol for precipitation to obtain brominated polycarbonate. The molar ratio of bisphenol A:tetrabromobisphenol A in brominated PC is controlled by controlling the amount and molar ratio of bisphenol A and tetrabromobisphenol A.

[0011] The solvent may be 1,2-dichloroethane, chloroform, etc. The solvent is only used as a medium and does not participate in the reaction. The amount of solvent has no effect on the final result, and it is sufficient to be able to completely dissolve. There is no clear regulation on the amount of solvent, but the economic efficiency needs to be considered.

[0012] The test method for the viscosity average molecular weight of brominated PC is as follows: weigh 4-10 mg of sample and place it in a glass bottle, add 1 mL of hexafluoroisopropanol according to the ratio of 1 mg sample to dissolve and let it stand for about 12 hours; if the sample is not completely dissolved after standing, place it on a heating plate or steam bath to heat it to completely dissolve. Then use a syringe with an organic nylon filter to filter the sample solution and place it in a glass bottle. Then enter the gel permeation chromatograph (GPC) for testing.

[0013] The toughening agent is selected from at least one of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer, silicone acrylate toughening agent, and methyl methacrylate-butadiene-styrene copolymer toughening agent.

[0014] Preferably, the toughening agent is selected from silicone acrylate toughening agents.

[0015] By weight, the invention also includes 0.05-0.5 parts of an ester exchange inhibitor, wherein the ester exchange inhibitor is selected from zinc dihydrogen phosphate.

[0016] The anti-dripping agent is selected from polytetrafluoroethylene.

[0017] By weight, those skilled in the art can choose to add 0-2 parts of auxiliary agents according to actual needs, and the auxiliary agents are selected from one or more of antioxidants and lubricants. The antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants or thioester antioxidants.

[0018] The preparation method of the PBT / brominated PC alloy of the present invention comprises the following steps: according to the proportion, each component is mixed uniformly, and extruded and granulated by a twin-screw extruder to obtain the PBT / brominated PC alloy. The temperature of the screw is set as follows: the temperature of the first zone is 200-220°C, the temperature of the second zone is 220-230°C, the temperature of the third zone is 230-240°C, the temperature of the fourth zone is 230-240°C, the temperature of the fifth zone is 230-240°C, the temperature of the sixth zone is 230-240°C, the temperature of the seventh zone is 240-250°C, the temperature of the eighth zone is 240-250°C, the temperature of the ninth zone is 230-240°C, and the main engine speed is 300-400 rpm.

[0019] The PBT / brominated PC alloy of the present invention is used for preparing flame-retardant parts such as electrical appliance housings and automobile accessories.

[0020] The present invention has the following beneficial effects: The present invention can effectively reduce the transesterification of PBT and brominated PC by selecting brominated PC with specific parameters, thereby reducing the transesterification reaction between the PBT molecular chain and the polycarbonate molecular chain and improving the anti-ultraviolet performance. This is because the brominated PC molecular chain contains a specific content of tetrabromobisphenol A units, which reduces the activity of the molecular chain and reduces the transesterification. At the same time, by adding an anti-ultraviolet agent, the anti-ultraviolet property can be further improved. Therefore, the PBT / brominated PC alloy of the present application can have the advantages of V-0 flame retardancy and anti-ultraviolet property at the same time. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0022] The sources of raw materials used in the present invention are as follows: PBT resin-A: brand GX121, intrinsic viscosity 1.0dl / g, from the Engineering Plastics Plant of Yizheng Branch of Sinopec Asset Management Co., Ltd.; PBT resin-B: brand GL236, intrinsic viscosity 1.3dl / g, from the Engineering Plastics Plant of Yizheng Branch of Sinopec Asset Management Co., Ltd.; The molar ratio of brominated PC-1: bisphenol A: tetrabromobisphenol A is 80:20, the viscosity average molecular weight is 70000, and it is homemade; The molar ratio of brominated PC-2: bisphenol A: tetrabromobisphenol A is 70:30, the viscosity average molecular weight is 58500, and it is homemade; The molar ratio of brominated PC-3: bisphenol A: tetrabromobisphenol A is 65:35, the viscosity average molecular weight is 43000, and it is homemade; The molar ratio of brominated PC-4: bisphenol A: tetrabromobisphenol A is 55:45, the viscosity average molecular weight is 26000, and it is homemade; The molar ratio of brominated PC-5: bisphenol A: tetrabromobisphenol A is 50:50, the viscosity average molecular weight is 23000, and it is homemade; The molar ratio of brominated PC-6: bisphenol A: tetrabromobisphenol A is 40:60, the viscosity average molecular weight is 14600, and it is homemade; The molar ratio of brominated PC-7: bisphenol A: tetrabromobisphenol A is 90:10, the viscosity average molecular weight is 75000, and it is homemade; The molar ratio of brominated PC-8: bisphenol A: tetrabromobisphenol A is 30:70, the viscosity average molecular weight is 10500, and it is homemade; The preparation method of the above-mentioned brominated PC is as follows: prepare a reactor equipped with an agitator, a condenser, triphosgene and a sodium hydroxide dropping device, add bisphenol A, tetrabromobisphenol A, and 1,2-dichloroethane, add sodium hydroxide solution under stirring, and stir until tetrabromobisphenol A is completely dissolved after adding. Then add a 1,2-dichloroethane solution of triphosgene dropwise. After all the dropwise additions are completed, stir and react at 25-30°C for 2-3 hours. After the reaction is completed, let the solution stand, separate the organic phase, repeatedly wash the organic phase with deionized water, add the organic phase to methanol for precipitation, and obtain brominated PC. The molar ratio of bisphenol A:tetrabromobisphenol A in brominated PC is controlled by controlling the amount and molar ratio of bisphenol A and tetrabromobisphenol A.

[0023] Brominated PC-9: Tetrabromobisphenol A carbonate oligomer, brand BC-58, bromine content 58%, Great Lakes Chemical Company, USA; Anti-ultraviolet agent A: copolymer of styrene-N-phenylmaleimide and maleic anhydride, brand name DENKA IPMS-NB, produced by Nippon Denka Co., Ltd.

[0024] Anti-ultraviolet agent B: copolymer of styrene-N-phenylmaleimide and maleic anhydride, brand name HW-330, Jiaxing Huawen Chemical Co., Ltd.

[0025] Styrene-N-phenylmaleimide: brand name MS-NIP, Shanghai Better Chemical Co., Ltd.

[0026] Styrene-maleic anhydride copolymer: brand name SMA-700, Jiaxing Huawen Chemical Co., Ltd.

[0027] Toughening agent A: ethylene-methyl acrylate-glycidyl methacrylate terpolymer, brand name LOTADERAX8900, GMA content is 8%, Arkema, France.

[0028] Toughener B: Ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer, brand name Elvaloy® PTW, GMA content is 5%, DuPont Company, USA.

[0029] Toughener C: silicone acrylate toughener, brand name METABLEN S-2001, Mitsubishi Corporation; Toughener D: methyl methacrylate-butadiene-styrene copolymer toughener, brand EM500, LG Company of South Korea; Zinc dihydrogen phosphate: brand BUDIT T21, Budenheim, Germany; Polytetrafluoroethylene: anti-drip agent, commercially available; Antioxidant: 1:1 mixture of RIANOX1010 and RIANOX 168, Tianjin Anlong New Materials Co., Ltd. Embodiment and comparative example Preparation method of PBT / brominated PC alloy: according to the ratio, each component is mixed evenly, and extruded and granulated by a twin-screw extruder to obtain PBT / brominated PC alloy. The temperature of the screw is set as follows: the temperature of zone 1 is 200-220°C, the temperature of zone 2 is 220-230°C, the temperature of zone 3 is 230-240°C, the temperature of zone 4 is 230-240°C, the temperature of zone 5 is 230-240°C, the temperature of zone 6 is 230-240°C, the temperature of zone 7 is 240-250°C, the temperature of zone 8 is 240-250°C, the temperature of zone 9 is 230-240°C, and the main engine speed is 300-400 rpm.

[0030] Various test methods: (1) Flame retardancy: According to UL94 standard, 0.8 mm specimens were injection molded and the flame retardancy was measured using a combustion box.

[0031] (2) Resistance to UV yellowing: The sample was injection molded into a square plate according to ASTM G155-2013 standard, with a blackboard temperature of 63±2.5℃ and a light intensity of 0.35W / m 2 @340nm, 102min illumination, 18min illumination + spraying, irradiation time 1200h. The test equipment is produced by ATLAS in the United States, model CI4000. The color difference change value is calculated by the following formula:

[0032] L1, a1, b1: test values ​​before xenon lamp aging; L2, a2, b2: test values ​​after xenon lamp aging; The color difference test equipment is produced by X-Rite, USA, model number is Color-Eye 7000A.

[0033] Table 1: Content of each component and test results of PBT / brominated PC alloy in Example 1-7 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PBT Resin-A 40 45 40 40 40 40 PBT resin-B 50 Brominated PC Label 1 1 1 2 3 4 5 Brominated PC content 40 35 40 40 40 40 40 UV inhibitor A 5 10 2 5 5 5 5 Toughener A 13 15 10 13 13 13 13 Zinc dihydrogen phosphate 0.2 0.5 0.1 0.2 0.2 0.2 0.2 Polytetrafluoroethylene 0.3 0.4 0.5 0.3 0.3 0.3 0.3 Antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 Flame retardant V-0 V-0 V-0 V-0 V-0 V-0 V-0 UV yellowing resistance 2.59 1.92 3.63 2.45 2.37 2.40 2.50 It can be seen from Examples 1 / 4 / 5 / 6 / 7 / 8 that the brominated PC with the preferred repeating unit has better resistance to UV yellowing.

[0034] Table 2: Content of each component and test results of PBT / brominated PC alloys in Examples 8-12 Example 8 Example 9 Example 10 Embodiment 11 Example 12 PBT Resin-A 40 40 40 40 40 Brominated PC-1 40 40 40 40 Brominated PC-6 40 UV inhibitor A 5 5 5 5 UV inhibitor B 5 Toughener A 13 13 Toughener B 13 Toughener C 13 Toughener D 13 Zinc dihydrogen phosphate 0.2 0.2 0.2 0.2 0.2 Polytetrafluoroethylene 0.3 0.3 0.3 0.3 0.3 Antioxidants 0.3 0.3 0.3 0.3 0.3 Flame retardant V-0 V-0 V-0 V-0 V-0 UV yellowing resistance 2.69 2.49 2.57 2.46 2.63 It can be seen from Examples 1 / 10-12 that the toughening agent is preferably a silicone acrylate toughening agent.

[0035] It can be seen from the above examples that the PBT / brominated PC alloy of the present invention has V-0 flame retardancy and a UV yellowing resistance ΔE of less than 3.8.

[0036] Table 3: Comparative Example PBT / Brominated PC Alloy Component Content and Test Results Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 PBT Resin-A 40 40 40 40 40 50 40 Brominated PC Label 7 8 9 1 1 1 1 Brominated PC content 40 40 40 40 40 20 50 UV inhibitor A 5 5 5 0 1 5 5 Toughener A 13 13 13 13 13 13 13 Zinc dihydrogen phosphate 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Polytetrafluoroethylene 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Flame retardant V-0 V-0 V-0 V-0 V-0 V-2 V-0 UV yellowing resistance 2.94 3.12 5.65 4.37 4.36 2.11 4.68 It can be seen from Comparative Example 1 / 2 that if the molar content of the brominated PC monomer is not within the range of the present invention, the resistance to ultraviolet yellowing is poor.

[0037] It can be seen from Comparative Example 3 that the low molecular weight brominated PC commonly used in the art is easy to undergo ester exchange reaction with PBT, resulting in a serious decrease in yellowing resistance.

[0038] It can be seen from Comparative Example 4 that the UV yellowing resistance is poor when no anti-yellowing agent is contained.

[0039] It can be seen from Comparative Example 5 that when the content of the anti-yellowing agent is too low, the resistance to ultraviolet yellowing is insufficient.

[0040] It can be seen from Comparative Example 6 that if the brominated PC content is too low, the flame retardancy of V0 cannot be achieved.

[0041] It can be seen from Comparative Example 7 that if the content of brominated PC is too low, the UV yellowing resistance will be seriously reduced.

Claims

1. A PBT / brominated PC alloy, characterized in that: By weight, it includes the following components: PBT 40-50 parts; Brominated PC 30-40 parts; 2-10 parts of UV-resistant agent; 10-15 parts of toughening agent; Anti-dripping agent 0.2-0.5 parts; The viscosity average molecular weight of the brominated PC is in the range of 13000-80000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (80-40): (20-60); The anti-ultraviolet agent is selected from the copolymer of styrene-N-phenylmaleimide and maleic anhydride.

2. The PBT / brominated PC alloy according to claim 1, characterized in that: The viscosity average molecular weight of the brominated PC is in the range of 20000-60000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (70-50): (30-50).

3. The PBT / brominated PC alloy according to claim 2, characterized in that: The viscosity average molecular weight of the brominated PC is in the range of 25000-45000, and the molar ratio of bisphenol A to tetrabromobisphenol A is (65-55): (35-45).

4. The PBT / brominated PC alloy according to claim 1, characterized in that: The toughening agent is selected from at least one of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer, silicone acrylate toughening agent, and methyl methacrylate-butadiene-styrene copolymer toughening agent.

5. The PBT / brominated PC alloy according to claim 4, characterized in that: The toughening agent is selected from silicone acrylate toughening agents.

6. The PBT / brominated PC alloy according to claim 1, characterized in that: By weight, the invention also includes 0.05-0.5 parts of an ester exchange inhibitor, wherein the ester exchange inhibitor is selected from zinc dihydrogen phosphate.

7. The PBT / brominated PC alloy according to claim 1, characterized in that: The anti-dripping agent is selected from polytetrafluoroethylene.

8. The PBT / brominated PC alloy according to claim 1, characterized in that: By weight, the invention also includes 0-2 parts of auxiliary agents, wherein the auxiliary agents are selected from one or more of antioxidants and lubricants.

9. The method for preparing the PBT / brominated PC alloy according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components uniformly according to the proportion, extruding and granulating through a twin-screw extruder to obtain a PBT / brominated PC alloy.

10. The use of the PBT / brominated PC alloy according to any one of claims 1 to 8, characterized in that: Used to prepare flame-retardant parts such as electrical housings and automotive accessories.

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