A polycarbonate composition resistant to cyclic vibration and preparation method thereof

Abstract

The invention discloses a polycarbonate (PC) composition with anti-cyclic vibration and a preparation method thereof, wherein the composition mainly comprises the following components: 50-70 parts by weight of PC; 25-45 parts by weight of polymethyl methacrylate (PMMA); 1-3 parts by weight of brominated carbonate oligomer; and 1-3 parts by weight of PMMA cross-linked microspheres. The outstanding feature of the PC composition is good anti-cyclic vibration performance, and the PC composition has good tie rod performance during the extrusion granulation preparation process.

Description

Technical Field

[0001] The invention relates to a PC composition resistant to cyclic vibration and a preparation method thereof. The PC composition has good cyclic vibration resistance and good stringing performance in an extrusion granulation preparation process, and belongs to the field of materials. Background Art

[0002] PC / PMMA alloy is a modified material prepared by mixing PC and PMMA in a certain proportion. PC / PMMA alloy realizes the complementary performance of PC and PMMA materials: on the one hand, PC improves the heat resistance and impact resistance of PMMA; on the other hand, PMMA reduces the cost of PC and reduces the internal stress of PC products.

[0003] Chinese patent CN114479415B introduces a PC / PMMA alloy and its preparation method, which contains 35-75 parts of polycarbonate, 15-40 parts of polymethyl methacrylate, 2-6 parts of styrene-acrylate copolymer, 1-2.5 parts of SAN resin, 1.5-3.5 parts of polyether block polyamide resin, 1-2.5 parts of surface-treated nano-silicon dioxide, 3-9 parts of modified silicon nitride powder, 0.1-0.4 parts of tris(2,4-di-tert-butylphenyl)phosphite, and 0.05-0.15 parts of poly{(6-morpholinyl-5-triazine-2,4-diyl)(2,2,6,6-tetramethylpiperidinyl)iminohexamethylene[(2,2,6,6-tetramethylpiperidinyl)-imino]}. The alloy has the characteristics of high hardness, high impact strength, high tensile strength and good toughness.

[0004] Chinese patent CN114316552A introduces weather-resistant heat-insulating PC / PMMA composite materials and their preparation methods, which are composed of 60% to 80% polycarbonate, 10% to 20% polymethyl methacrylate, 1% to 5% composite toughening agent, 0.5% to 4% compound compatibilizer, 0.1% to 0.5% chain extender, 1% to 6% coupling agent, 0.1% to 0.3% antioxidant, 0.5% to 12% nano ATO, 5% to 20% thermal conductive filler, 0.05% to 0.3% lubricant, and 0.2% to 1% ultraviolet absorber. The material has good mechanical properties, weather resistance and heat insulation properties, and good light transmittance.

[0005] Although the above PC / PMMA alloy or composite material has shown good performance, since the melt viscosity of PC is much higher than that of PMMA, during the preparation of PC / PMMA alloy or composite material by twin-screw extruder, the die discharge material often swells, causing unsmooth traction granulation, such as broken strands during production. At the same time, the large difference in melt viscosity between PC and PMMA will also cause uneven mixing between PC and PMMA, resulting in deviations in product performance (such as anti-cyclic vibration). Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the present invention provides a PC composition resistant to cyclic vibration and a preparation method thereof. The PC composition prepared by the present invention has excellent surface hardness.

[0007] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0008] A PC composition resistant to cyclic vibration, comprising the following components:

[0009] 50-70 parts by weight of PC;

[0010] 25-45 parts by weight of polymethyl methacrylate (PMMA);

[0011] 1-3 parts by weight of brominated carbonate oligomer;

[0012] 1-3 parts by weight of PMMA cross-linked microspheres.

[0013] The PC composition resistant to cyclic vibration described in the present invention, the PC is one or more of aromatic PC and aliphatic PC, preferably the aromatic PC is bisphenol A type PC. Preferably, when the test conditions are 300°C and 1.2kg, the melt index of PC is between 7-20g / 10min. The higher the melt index of PC, the better the fluidity of PC, and the better the fluidity of the composition; however, the higher the melt index of PC, the lower the molecular weight of PC, and the worse the impact performance of the composition. Therefore, the advantage of limiting the melt index of PC is to comprehensively balance the fluidity and impact performance of the composition. For example, the PC with the Wanhua brand A1107 has a melt index of 10g / 10min when the test conditions are 300°C and 1.2kg, and its cantilever beam notched impact strength (ISO 180) is 75kJ / m 2 ; The PC of Wanhua brand A1227 has a melt index of 20g / 10min at 300℃ and 1.2kg, and its Izod notched impact strength (ISO 180) is 15kJ / m 2 .

[0014] The PC composition resistant to cyclic vibration of the present invention has a melting point of PMMA between 2 and 15 g / 10 min when the test conditions are 230° C. and 3.8 kg.

[0015] In the cyclic vibration resistant PC composition of the present invention, the brominated carbonate oligomer is a tetrabromobisphenol A carbonate oligomer with a molecular weight of 2000-4000, such as BC52 and BC58 produced by Lanxess.

[0016] The cyclic vibration resistant PC composition of the present invention has a particle size of 10-20 μm of PMMA cross-linked microspheres, such as MP-90 produced by Kaneka Corporation and EXM-5 produced by Sekisui Corporation.

[0017] The PC composition resistant to cyclic vibration of the present invention may further optionally contain 0-5 parts of other additives; the other additives are selected from one or more combinations of flame retardants, toughening agents, compatibilizers, antioxidants, lubricants, ultraviolet absorbers, light stabilizers, heat stabilizers, metal passivators, plasticizers, anti-adhesive agents, colorants, coupling agents, nucleating agents, foaming agents, antibacterial agents, mildew inhibitors, acid scavengers, hydrolysis resistant agents, chain extenders, flow modifiers, matting agents, antistatic agents, reinforcing agents, fillers, antifogging agents, light diffusers, infrared absorbers, fluorescent brighteners and laser marking agents.

[0018] The antioxidant is a combination of one or more of hindered phenols, phosphites, thioesters, benzofurans, acryl-modified phenols and hydroxylamine antioxidants.

[0019] The lubricant is a combination of one or more of fatty alcohols, metal soaps, fatty acids, fatty acid esters, montanic acid and its derivatives, amide waxes, saturated hydrocarbons, polyolefin waxes and its derivatives, organic silicon and silicone powder, organic fluorine, etc.

[0020] The ultraviolet absorber is a combination of one or more of benzophenone, benzotriazole, triazine, benzoate, cyanoacrylate and phenylimidazole.

[0021] The low-odor polycarbonate alloy material of the present invention can selectively use the above-mentioned additives according to the product performance characteristics, and achieve the purpose of improving the processing performance and thermal oxidation aging resistance of the polycarbonate alloy.

[0022] The present invention also provides a method for preparing the above-mentioned cyclic vibration-resistant PC composition, comprising the following steps:

[0023] (1) Premixing: PC, PMMA, brominated carbonate oligomer, PMMA cross-linked microspheres and optional additives are weighed according to a proportion and mixed to obtain a premix;

[0024] (2) Extrusion: The premix is ​​added to the extruder through the main feed port. All raw materials are mixed in the extruder and extruded from the extruder die. After strand granulation, a PC composition resistant to cyclic vibration is obtained.

[0025] In the present invention, the temperature of the conveying section of the twin-screw extruder is 210-240°C, the temperature of the plasticizing section is 240-270°C, the temperature of the metering section is 240-270°C, the screw speed is 200-600rpm, and the vacuum degree of the vacuum pumping device of the twin-screw metering section is less than -0.7 bar.

[0026] The positive effect of the present invention is that the brominated carbonate oligomer and the PMMA cross-linked microspheres have a synergistic effect. By adding the brominated carbonate oligomer and the PMMA cross-linked microspheres at the same time, stable traction granulation and uniform mixing of PC and PMMA in the extrusion preparation process of the PC composition are achieved, and good anti-cyclic vibration performance is presented.

[0027] The main reason for achieving the above effect is that the brominated carbonate oligomer and PMMA cross-linked microspheres synergistically reduce the melt viscosity gap between PC and PMMA. There is a significant difference in the melt viscosity of PC and PMMA. The huge viscosity will not only cause the unsmooth traction granulation during the preparation of PC / PMMA alloy through a twin-screw extruder, such as broken bars; it will also cause uneven mixing of PC and PMMA, large PC and PMMA domain sizes, and product performance deviations. In order to reduce the melt viscosity gap between PC and PMMA, it is necessary to reduce the melt viscosity of the PC domain or increase the melt viscosity of the PMMA domain.

[0028] In this patent, the composition and structure of the brominated carbonate oligomer are closer to PC, and during the mixing process in the extruder, it will be mainly dispersed in the PC phase domain. However, the brominated carbonate oligomer is an oligomer, and its molecular weight is significantly lower than that of PC, and its melt viscosity is also significantly lower than that of PC. Therefore, the addition of brominated carbonate oligomer will reduce the melt viscosity of the PC phase domain. The composition and structure of PMMA cross-linked microspheres are closer to PMMA, and during the mixing process in the extruder, it will be mainly dispersed in the PMMA phase domain. The PMMA cross-linked microspheres have a cross-linked structure, which will increase the melt viscosity of PMMA.

[0029] This patent utilizes the structural characteristics of brominated carbonate oligomers and PMMA cross-linked microspheres to guide the selective dispersion of brominated carbonate oligomers and PMMA cross-linked microspheres, thereby effectively narrowing the melt viscosity gap between PC and PMMA, achieving stable traction granulation during the twin-screw extrusion preparation of the composition, and uniform mixing of PC and PMMA, and exhibiting good anti-cyclic vibration performance. DETAILED DESCRIPTION

[0030] For better understanding and implementation, the present invention is further described below in conjunction with embodiments, but the present invention is not limited to the listed embodiments, and should also include any other known changes within the scope of the rights claimed by the present invention.

[0031] The raw materials of Comparative Examples and Examples are as follows:

[0032] A1073: Bisphenol A type PC, melt flow index is 7g / 10min (300℃, 1.2kg), produced by Wanhua Chemical Group Co., Ltd.

[0033] A1107: bisphenol A type PC, melt flow index is 10g / 10min (300℃, 1.2kg), produced by Wanhua Chemical Group Co., Ltd.

[0034] A1227: Bisphenol A type PC, melt flow index is 20g / 10min (300℃, 1.2kg), produced by Wanhua Chemical Group Co., Ltd.

[0035] HD01: PMMA, melt flow index is 2g / 10min (230℃, 3.8kg), produced by Wanhua Chemical Group Co., Ltd.

[0036] HD03: PMMA, melt flow index is 4g / 10min (230℃, 3.8kg), produced by Wanhua Chemical Group Co., Ltd.

[0037] SF01: PMMA, melt flow index is 15g / 10min (230℃, 3.8kg), produced by Wanhua Chemical Group Co., Ltd.

[0038] BC52: Tetrabromobisphenol A carbonate oligomer, a brominated carbonate oligomer with a molecular weight of 2500, produced by Lanxess;

[0039] BC58: Tetrabromobisphenol A carbonate oligomer, a brominated carbonate oligomer with a molecular weight of 3500, produced by LANXESS;

[0040] MP-90: PMMA cross-linked microspheres, produced by Zhongyuan Company, with a particle size of 10 μm;

[0041] EXM-5: PMMA cross-linked microspheres, produced by Sekisui Co., Ltd., with a particle size of 20 μm;

[0042] 1010: Antioxidant, produced by BASF AG;

[0043] 168: Antioxidant, produced by BASF AG;

[0044] PETS: Pentaerythritol stearate, lubricant, produced by Lonza, USA;

[0045] The material preparation process is as follows: whether it is a comparative example or an example, according to the corresponding formula, PC, PMMA, brominated carbonate oligomer, PMMA cross-linked microspheres and optional additives are weighed in proportion, the temperature of the conveying section of the twin-screw extruder is controlled to be 210-240°C, the temperature of the plasticizing section is 240-270°C, the temperature of the metering section is 240-270°C, the screw speed is controlled to be 200-600rpm, and the vacuum degree of the vacuum device of the twin-screw metering section is controlled to be less than -0.7 bar. All the raw materials are mixed in an extruder, extruded from the extruder die, and the PC composition with anti-cyclic vibration is obtained through strand granulation.

[0046] During the extruder production process, the sliver performance is characterized by the number of sliver breaks per 10 hours of production.

[0047] The performance test is as follows:

[0048] Cyclic vibration resistance test: The PC composition is injection molded into a plate with a threaded hole. The plate size is 150mm*150mm*3mm and the threaded hole diameter is 6mm. The plate is connected to the iron rod by screws. The iron rod performs circular arc cyclic motion around the fulcrum, with a cycle angle of 10° and a cycle frequency of 5 times / second. The cyclic reciprocating motion of the iron rod realizes the cyclic vibration of the plate. When cracks appear on the plate, the test ends and the cyclic vibration time is recorded.

[0049] The formulations and properties of the polycarbonate compositions of Comparative Examples 1-6 and Examples 1-5 are detailed in Table 1.

[0050] Table 1 Formulation and properties of the polycarbonate compositions of Comparative Examples 1-6 and Examples 1-5

[0051]

[0052] By comparing Examples 1-5 and Comparative Examples 1-6, it can be found that the PC / PMMA composition is very easy to break during the extrusion process, and the anti-cyclic vibration performance is poor (see Comparative Examples 1-3); adding brominated carbonate oligomers alone, or adding PMMA cross-linked microspheres alone, has no obvious effect on the PC / PMMA composition's tie performance, anti-cyclic vibration performance, etc. (see Comparative Examples 4-6); after adding brominated carbonate oligomers and PMMA cross-linked microspheres at the same time, the PC / PMMA composition's tie performance is significantly improved, the number of extrusion breakages in 10 hours is sharply reduced, and the anti-cyclic vibration performance is also significantly improved (see Examples 1-5). The above results show that brominated carbonate oligomers and PMMA cross-linked microspheres have a synergistic effect, achieving stable traction granulation (lower extrusion breakage frequency) during the extrusion preparation of the composition, and uniform mixing of PC and PMMA, and presenting good product performance (more prominent anti-cyclic vibration performance).

[0053] The main reason for achieving the above effect is that the brominated carbonate oligomer and PMMA cross-linked microspheres synergistically reduce the melt viscosity gap between PC and PMMA. Due to their structural characteristics, the brominated carbonate oligomer and PMMA cross-linked microspheres are mainly dispersed in the PC phase domain and PMMA phase domain, respectively, thereby effectively narrowing the melt viscosity gap between PC and PMMA, achieving stable traction granulation during the twin-screw extrusion preparation of the composition, and uniform mixing of PC and PMMA, and presenting good product performance.

[0054] Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments, and that various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and that these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A polycarbonate composition resistant to cyclic vibration, characterized in that: The composition comprises the following components: 50-70 parts by weight of PC; 25-45 parts by weight of polymethyl methacrylate (PMMA); 1-3 parts by weight of brominated carbonate oligomer; 1-3 parts by weight of PMMA cross-linked microspheres; the molecular weight of the brominated carbonate oligomer is 2000-4000.

2. The cyclic vibration resistant polycarbonate composition according to claim 1, characterized in that: The PC is one or more of aromatic PC and aliphatic PC.

3. The cyclic vibration resistant polycarbonate composition according to claim 1, characterized in that: When the test conditions are 300° C. and 1.2 kg, the melting point of the PC is between 7 and 20 g / 10 min.

4. The cyclic vibration resistant polycarbonate composition according to claim 2, characterized in that: The aromatic PC is bisphenol A type PC.

5. The cyclic vibration resistant polycarbonate composition according to claim 1, characterized in that: When the test conditions are 230° C. and 3.8 kg, the melt index of the PMMA is between 2 and 15 g / 10 min.

6. The cyclic vibration resistant polycarbonate composition according to any one of claims 1 to 5, characterized in that: The brominated carbonate oligomer is tetrabromobisphenol A carbonate oligomer.

7. The cyclic vibration resistant polycarbonate composition according to any one of claims 1 to 5, characterized in that: The brominated carbonate oligomer is BC52 or BC58 produced by Lanxess.

8. The cyclic vibration resistant polycarbonate composition according to any one of claims 1 to 5, characterized in that: The particle size of the PMMA cross-linked microspheres is 10-20 μm.

9. The cyclic vibration resistant polycarbonate composition according to any one of claims 1 to 5, characterized in that: The PMMA cross-linked microspheres are MP-90 produced by Kaneka Corporation or EXM-5 produced by Sekisui Corporation.

10. The cyclic vibration resistant polycarbonate composition according to any one of claims 1 to 5, characterized in that: The invention also contains 0-5 parts of other additives; the other additives are selected from one or more combinations of flame retardants, toughening agents, compatibilizers, antioxidants, lubricants, ultraviolet absorbers, light stabilizers, heat stabilizers, metal passivators, plasticizers, anti-adhesive agents, colorants, coupling agents, nucleating agents, foaming agents, antibacterial agents, mildew inhibitors, acid scavengers, hydrolysis resistant agents, chain extenders, flow modifiers, matting agents, antistatic agents, reinforcing agents, fillers, antifogging agents, light diffusers, infrared absorbers, fluorescent brighteners and laser marking agents.

11. The cyclic vibration resistant polycarbonate composition according to claim 10, characterized in that: The antioxidant is a combination of one or more of hindered phenols, phosphites, thioesters, benzofurans, acryl-modified phenols, and hydroxylamine antioxidants; and / or the ultraviolet absorber is a combination of one or more of benzophenones, benzotriazoles, triazines, benzoates, cyanoacrylates, and phenylimidazoles.

12. The cyclic vibration resistant polycarbonate composition according to claim 10, characterized in that: The lubricant is a combination of one or more of fatty alcohols, metal soaps, fatty acids, fatty acid esters, montanic acid and its derivatives, amide waxes, saturated hydrocarbons, polyolefin waxes and its derivatives, organic silicon and silicone powder, and organic fluorine.

13. The method for preparing a polycarbonate composition resistant to cyclic vibration according to any one of claims 1 to 12, characterized in that: The following steps are involved: (1) Premixing: PC, PMMA, brominated carbonate oligomer, PMMA cross-linked microspheres and optional additives are weighed according to a proportion and mixed to obtain a premix; (2) Extrusion: The premix is ​​added to the extruder through the main feed port, all the raw materials are mixed in the extruder, extruded from the extruder die, and granulated to obtain a polycarbonate composition resistant to cyclic vibration.

14. The preparation method according to claim 13, characterized in that: The temperature of the conveying section of the extruder is 210-240° C., the temperature of the plasticizing section is 240-270° C., the temperature of the metering section is 240-270° C., the screw speed is 200-600 rpm, and the vacuum degree of the vacuum pumping device in the metering section is less than -0.7 bar.

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