A polycarbonate composition, its preparation and use

Abstract

The application discloses a polycarbonate composition and a preparation method and application thereof, and belongs to the technical field of high polymer materials, and comprises the following components in parts by weight: 100 parts of polycarbonate, 4-42 parts of first siloxane copolymerized polycarbonate, 2-21 parts of second siloxane copolymerized polycarbonate, 3.5-11 parts of first montmorillonite, 1.8-9 parts of second montmorillonite, and 0.08-1.1 parts of sulfonate flame retardant; the mass percentage of siloxane in the first siloxane copolymerized polycarbonate is less than 6%; the mass percentage of siloxane in the second siloxane copolymerized polycarbonate is greater than 9%; the average particle size of the first montmorillonite is 8-15 mu m; and the average particle size of the second montmorillonite is 0.5-5 mu m. The application effectively improves the flame retardant property of the polycarbonate, and the vertical burning level of 1.5 mm reaches V-0, meanwhile, the needle flame test can be met, and the application also has excellent transparency and high toughness, and is very suitable for preparing electronic and electrical products.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a polycarbonate composition, its preparation method, and its application. Background Technology

[0002] Polycarbonate (PC) is a high-performance engineering plastic with excellent overall properties, including high mechanical strength, good impact toughness, dimensional stability, good heat resistance, and good electrical insulation. It has wide applications in home appliances, digital products, IT products, and other fields. Due to these superior properties, PC is widely used in electronics, home appliances, office automation systems, power tools, batteries, charging stations, laptops, and other industries and products. The application of PC in these products also places certain demands on its flame-retardant properties.

[0003] For products in industries such as audio and communications, the mandatory national standard GB4943.1-2022 "Audio-visual, information technology and communication technology equipment, Part 1: Safety requirements" was officially promulgated on July 19, 2022, fully replacing the requirements of GB4943.1-2011 and GB 8898-2011. Among the changes regarding material flame retardancy, the addition of stringent needle flame test requirements is a significant improvement. Currently available halogen-free flame-retardant PC materials cannot meet both the 1.5mm V-0 flame retardant safety requirements and the needle flame test requirements. This failure is mainly manifested by dripping during vertical burning tests or perforation during needle flame burning. Existing halogen-free flame-retardant PC materials typically exhibit one of these two failure modes. Furthermore, achieving V-0 flame retardancy with a thickness below 1.5mm currently requires the use of an anti-dripping agent, PTFE, to prevent dripping and ignition failure during combustion. However, PTFE (polytetrafluoroethylene) severely affects the material's transparency and cannot meet increasingly stringent environmental regulations regarding low-fluorine and fluorine-free content.

[0004] Therefore, this application is submitted. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a polycarbonate composition, its preparation method and application. The polycarbonate composition achieves a V-0 vertical burning rating at 1.5mm, meets the needle flame test, and has excellent transparency. It also has high toughness and is very suitable for manufacturing electronic and electrical products, especially for manufacturing speakers and communication equipment.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A polycarbonate composition comprising the following components in parts by weight: 100 parts polycarbonate, 4-42 parts first siloxane copolymer polycarbonate, 2-21 parts second siloxane copolymer polycarbonate, 0.08-1.1 parts sulfonate flame retardant, 3.5-11 parts first montmorillonite, and 1.8-9 parts second montmorillonite;

[0008] The mass percentage of siloxane in the first siloxane copolymer polycarbonate is ≤6%;

[0009] The second siloxane copolymer polycarbonate contains ≥9% siloxane by mass;

[0010] The average particle size of the first montmorillonite is 8–15 μm;

[0011] The average particle size of the second montmorillonite is 0.5–5 μm.

[0012] This invention creatively combines the above-mentioned raw materials, using polycarbonate as the matrix. Through the combined action of the first siloxane copolymer polycarbonate, the second siloxane copolymer polycarbonate, the first montmorillonite, the second montmorillonite, and the sulfonate flame retardant, the flame retardant properties of polycarbonate are effectively improved. The vertical burning rating of 1.5mm reaches V-0, while also meeting the needle flame test requirements. It also has excellent transparency and high toughness, making it very suitable for manufacturing electronic and electrical products, especially for manufacturing speakers and communication equipment.

[0013] In the polycarbonate matrix system of this invention, the first siloxane copolymer polycarbonate component with low siloxane content can migrate to the carbon layer surface to form a dense isolation layer, while the second siloxane copolymer polycarbonate component with high siloxane content mainly plays a reinforcing role during the char formation process, forming a robust support layer and isolation layer within the carbon layer. Furthermore, the high siloxane content results in poor dispersion, affecting the material's transparency. The first and second montmorillonite components can form a physical barrier at high temperatures, preventing flame spread and oxygen entry. The carbon layer formed by the siloxane copolymer polycarbonate component complements the physical barrier formed by the montmorillonite, while the organosilicon polymer network formed by the siloxanes... The intertwined physical barriers formed by the network structure and montmorillonite enhance the flame retardant and mechanical properties of PC. The migration and enrichment of siloxane copolymer polycarbonate further promotes the dispersion and flame retardant effect of montmorillonite in PC. Different particle sizes of first and second montmorillonite, combined with siloxane copolymer polycarbonate and second siloxane copolymer polycarbonate with different siloxane contents, allow silicon to participate in the formation of a carbon layer structure during combustion. This results in a higher strength carbon layer, which better insulates against heat and oxygen, achieving rapid flame retardancy. Simultaneously, it improves the dispersibility of sulfonate flame retardants in the system, effectively enhancing flame retardancy and transparency.

[0014] The amount of the first siloxane copolycarbonate is 4 to 42 parts, for example, it can be 4 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 36 parts, 38 parts, 40 parts, 42 parts or any two of these values.

[0015] Preferably, the amount of the first siloxane copolycarbonate is 5 to 40 parts.

[0016] The amount of the second siloxane copolycarbonate is 2 to 21 parts, for example, it can be 2 parts, 2.5 parts, 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 16 parts, 18 parts, 20 parts, 21 parts or any two of these values.

[0017] Preferably, the amount of the second siloxane copolycarbonate is 2.5 to 20 parts.

[0018] The amount of the first montmorillonite is 3.5 to 11 parts, for example, it can be 3.5 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts or any two of these values.

[0019] Preferably, the amount of the first montmorillonite is 4 to 10 parts.

[0020] The amount of the second montmorillonite is 1.8 to 9 parts, for example, it can be 1.8 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or any two of these values.

[0021] Preferably, the amount of the first montmorillonite is 2 to 8 parts.

[0022] The amount of the sulfonate flame retardant is 0.08 to 1.1 parts, for example, it can be 0.08 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts or any two of these values.

[0023] Preferably, the amount of the sulfonate flame retardant is 0.1 to 1 part.

[0024] Preferably, the polycarbonate composition comprises the following components in parts by weight: 100 parts polycarbonate, 5 to 40 parts first siloxane copolymer polycarbonate, 2.5 to 20 parts second siloxane copolymer polycarbonate, 4 to 10 parts first montmorillonite, 2 to 8 parts second montmorillonite, and 0.1 to 1 part sulfonate flame retardant.

[0025] Preferably, the weight ratio of the first montmorillonite to the second montmorillonite is (0.5-5):1.

[0026] Preferably, the weight ratio of the first montmorillonite to the second montmorillonite is (1-2):1.

[0027] The average particle size of the first and second montmorillonite was obtained according to GB / T 19077.

[0028] Preferably, the aspect ratio of the first montmorillonite is 150 to 500, for example, it can be 150, 200, 250, 300, 350, 400, 450, 500 or any two of these values.

[0029] Preferably, the aspect ratio of the second montmorillonite is 150 to 500, for example, it can be 150, 200, 250, 300, 350, 400, 450, 500 or any two of these values.

[0030] The method for testing the aspect ratio of the first and second montmorillonite samples is as follows: After drying, the samples are photographed using a scanning electron microscope (SEM) at a magnification of 400-1000x. The SEM images are opened using Nano Measurer software. Multiple samples (e.g., 50-200) are selected from the SEM images, and their lengths and diameters are marked using the software. The software automatically generates a measurement report, thus obtaining the aspect ratio. Preferably, the mass percentage of siloxane in the first siloxane copolymer polycarbonate is 0.5-6%, for example, it can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, or any two of these values.

[0031] Preferably, the mass percentage of siloxane in the first siloxane copolymer polycarbonate is 2-6%.

[0032] Preferably, the mass percentage of siloxane in the second siloxane copolycarbonate is 9-25%, for example, it can be 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% or any two of these values.

[0033] Preferably, the mass percentage of siloxane in the second siloxane copolymer polycarbonate is 9-20%.

[0034] Preferably, the weight ratio of the second siloxane copolycarbonate to the first siloxane copolycarbonate is 1:(1 to 9), for example, it can be 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or any two of these values.

[0035] The first siloxane copolycarbonate has a melt index of 5 to 30 g / min at 300℃ / 1.2 kg, for example, it can be 5 g / min, 6 g / min, 8 g / min, 10 g / min, 12 g / min, 15 g / min, 18 g / min, 20 g / min, 25 g / min, 30 g / min or any two of these values, and the test standard is ISO1133-2011.

[0036] The melt flow index of the second siloxane copolycarbonate at 300℃ / 1.2kg is 5 to 30 g / min, for example, it can be 5 g / min, 6 g / min, 8 g / min, 10 g / min, 12 g / min, 15 g / min, 18 g / min, 20 g / min, 25 g / min, 30 g / min or any two of these values, and the test standard is ISO1133-2011.

[0037] Preferably, the weight ratio of the second siloxane copolymer polycarbonate to the first siloxane copolymer polycarbonate is 1:(1.5-4). By controlling the weight ratio of the two within this range, the relationship between the strength and density of the carbon layer can be balanced, so as to achieve a carbon layer that is both strong and difficult to destroy and has good insulation performance, so that the flame can be extinguished quickly.

[0038] Preferably, the weight ratio of the sum of the first siloxane copolymer polycarbonate and the second siloxane copolymer polycarbonate to the sulfonate flame retardant is (18-300):1. By controlling the weight ratio of the two within this range, the dispersibility of the sulfonate flame retardant can be effectively improved. At the same time, within this range, the char formation rate and the progress of silicon participation in char formation can be balanced, thereby forming an excellent carbon layer and achieving a good flame retardant effect.

[0039] Preferably, the weight ratio of the sum of the weights of the second siloxane copolycarbonate and the first siloxane copolycarbonate to the weight of the sulfonate flame retardant is (37-150):1.

[0040] In the polycarbonate composition of the present invention, the polycarbonate content by weight is not less than 55%.

[0041] Preferably, in the polycarbonate composition of the present invention, the polycarbonate content by weight is 58-84%, for example, it can be 58%, 60%, 65%, 70%, 75%, 76%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 93%, or any two of these values.

[0042] Preferably, the polycarbonate has a melt flow index of 3 to 60 g / min at 300°C / 1.2 kg, for example, it can be 3 g / min, 5 g / min, 6 g / min, 8 g / min, 10 g / min, 12 g / min, 15 g / min, 18 g / min, 20 g / min, 25 g / min, 30 g / min, 35 g / min, 40 g / min, 45 g / min, 50 g / min, 55 g / min, 60 g / min or any two of these values, and the test standard is ISO1133-2011.

[0043] Preferably, the polycarbonate has a melt flow index of 6 to 30 g / min at 300°C / 1.2 kg. In particular, when the polycarbonate has a melt flow index of 6 to 30 g / min at 300°C / 1.2 kg is within this range, the carbon layer formed in the early stage of combustion will not be destroyed by gravity, which is conducive to the faster formation of a strong and thicker carbon layer and achieves a better flame retardant effect.

[0044] Preferably, the sulfonate flame retardant comprises at least one of potassium 3-benzenesulfonylbenzenesulfonate, sodium 2,4,5-trichlorobenzenesulfonate, tetraethylammonium perfluoroethanesulfonate, diphenyl sulfone-3-sulfonate, diphenyl sulfone-3,3'-disulfonate, 2,5-dichlorobenzenesulfonate, potassium perfluoroalkyl sulfonate, benzenesulfonylbenzenesulfonate, and sodium p-toluenesulfonate.

[0045] Preferably, the polycarbonate composition of the present invention may further include at least one of antioxidants, nucleating agents, toughening agents, mineral powders, lubricants, colorants, weathering agents, antistatic agents, flame retardants, and ultraviolet light absorbers.

[0046] The polycarbonate composition of the present invention may include antioxidants, and suitable antioxidants include, but are not limited to, at least one of thioester antioxidants, hindered phenolic antioxidants, hydroxylamine antioxidants, phosphite antioxidants, and phosphate antioxidants.

[0047] The polycarbonate composition of the present invention can be a nucleating agent, and suitable nucleating agents include, but are not limited to, at least one of α-crystalline nucleating agents and β-crystalline nucleating agents. The α-crystalline nucleating agent includes at least one of organophosphate α-crystalline nucleating agents, organocarboxylate α-crystalline nucleating agents, and sorbitol α-crystalline nucleating agents; the β-crystalline nucleating agent includes at least one of aromatic amide β-crystalline nucleating agents and organocarboxylic acid β-crystalline nucleating agents.

[0048] The polycarbonate composition of the present invention may include a toughening agent, and suitable toughening agents include, but are not limited to, ethylene-octene copolymers, maleic anhydride-grafted POE, maleic anhydride-grafted SEBS, and combinations thereof.

[0049] The polycarbonate composition of the present invention may include mineral powder, and suitable mineral powders include, but are not limited to, calcium carbonate, kaolin, magnesium hydroxide, borax, and combinations thereof.

[0050] The polycarbonate composition of the present invention may include colorants, suitable colorants including but not limited to carbon black, titanium dioxide, zinc sulfide, iron oxide red, titanium yellow, and combinations thereof.

[0051] The polycarbonate composition of the present invention may include a lubricant, and suitable lubricants include, but are not limited to, polyethylene wax, fatty acid esters, hyperbranched amides, and combinations thereof.

[0052] The polycarbonate composition of the present invention may include weathering agents, and suitable weathering agents include, but are not limited to, hindered amine light stabilizers and combinations thereof.

[0053] The polycarbonate composition of the present invention may include an antistatic agent, and suitable antistatic agents include, but are not limited to, zinc oxide, manganese dioxide, chromium trioxide, and combinations thereof.

[0054] The polycarbonate composition of the present invention may include flame retardants, suitable flame retardants including but not limited to brominated polymers (e.g., brominated polystyrene), metal dialkyl phosphites (e.g., tris(diethylphosphite)aluminum), metal hydroxides (e.g., magnesium hydroxide), aromatic phosphates (e.g., resorcinol di(diphenyl phosphate) and bisphenol A di(diphenyl phosphate)), and combinations thereof.

[0055] The polycarbonate composition of the present invention may include ultraviolet light absorbers, suitable ultraviolet light absorbers including but not limited to hydroxybenzophenones, benzotriazoles, hydroxybenzotriazines, cyanoacrylates, nanoscale inorganic materials (e.g., titanium oxide, cerium oxide, and zinc oxide), and combinations thereof.

[0056] The present invention also provides a method for preparing a polycarbonate composition, comprising the following steps:

[0057] According to the formula, the raw materials are placed in a high-speed mixer and mixed evenly to obtain a premix. The premix is ​​then melted, dispersed, and blended, and then extruded, cooled, dried, and pelletized to obtain a polycarbonate composition.

[0058] The present invention also provides an application of a polycarbonate composition in the preparation of electronic and electrical appliances.

[0059] The polycarbonate composition of this invention achieves a V-0 vertical flaming rating of 1.5mm, meets the needle flame test, and also has excellent transparency and high toughness, making it very suitable for manufacturing electronic and electrical products, especially speakers and communication equipment.

[0060] The beneficial effects of this invention are as follows: This invention uses polycarbonate as a matrix, and under the combined action of first siloxane copolymer polycarbonate, second siloxane copolymer polycarbonate and sulfonate flame retardant, it effectively improves the flame retardant performance of polycarbonate, achieving a vertical burning rating of V-0 at 1.5mm, while also meeting the needle flame test, and possessing excellent transparency and high toughness, making it very suitable for manufacturing electronic and electrical products, especially for manufacturing speakers and communication equipment. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0063] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0064] The raw materials used in the examples and comparative examples are described below:

[0065] Polycarbonate-1: Melt flow rate of 30 g / 10 min at 300℃ / 1.2 kg, Mitsubishi, Japan, grade PCH-3000F.

[0066] Polycarbonate-2: The melt flow rate at 300℃ / 1.2kg is 6g / 10min, Lihua Yiweiyuan Chemical, grade PC WY-106BR.

[0067] Polycarbonate-3: Melt flow rate of 3 g / 10 min at 300℃ / 1.2 kg, Mitsubishi, Japan, grade PC 7030PJ.

[0068] Polycarbonate-4: Melt flow rate of 60 g / 10 min at 300℃ / 1.2 kg, Wanhua Chemical, grade PC 2600.

[0069] Siloxane Copolycarbonate-1 (Si-PC-1): 6% siloxane by mass, Idemitsu, Japan, brand name Tarflon FG1760.

[0070] Siloxane Copolycarbonate-2 (Si-PC-2): Siloxane content 3% by mass, Idemitsu, Japan, brand name Tarflon Neo Rc1700.

[0071] Siloxane Copolycarbonate-3 (Si-PC-3): 2% siloxane by mass, Idemitsu, Japan, brand name Tarflon FG1720.

[0072] Siloxane Copolycarbonate-4 (Si-PC-4): Siloxane content 20% by mass, Wanhua Chemical, grade PC6300.

[0073] Siloxane Copolycarbonate-5 (Si-PC-5): 9% siloxane by mass, Idemitsu, Japan, brand name Tarflon Neo AG2530.

[0074] Siloxane Copolycarbonate-6 (Si-PC-6): Siloxane content 7.4% by mass, LG Chem, grade SP8010T.

[0075] Montmorillonite was purchased from Xianfeng Nanotechnology, model PGV. After grinding and sieving, montmorillonite 1 to 6 with different particle size distributions were obtained.

[0076] Montmorillonite-1: average particle size is 15 μm.

[0077] Montmorillonite-2: average particle size is 8 μm.

[0078] Montmorillonite-3: average particle size is 5 μm.

[0079] Montmorillonite-4: average particle size is 0.5 μm.

[0080] Montmorillonite-5: average particle size is 20 μm.

[0081] Montmorillonite-6: average particle size is 0.1 μm.

[0082] Sulfonate flame retardant - 1:3-benzenesulfonylbenzenesulfonate potassium, commercially available.

[0083] Sulfonate flame retardant-2: Sodium 2,4,5-trichlorobenzenesulfonate, commercially available.

[0084] PTFE: Polytetrafluoroethylene AD541, Changshu Zhenfu New Materials Co., Ltd.

[0085] The testing standards for raw material parameters are as follows:

[0086] In this invention, the melt flow rate of polycarbonate was measured according to the ISO 1133-2011 method.

[0087] In this invention, the mass percentage of siloxane in the siloxane copolycarbonate is determined by inductively coupled plasma mass spectrometry.

[0088] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0089] Examples 1-23, Comparative Examples 1-8

[0090] The formulations of the polycarbonate compositions of Examples 1-23 and Comparative Examples 1-8 are shown in Tables 1 and 2 (all figures are parts by weight).

[0091] The preparation methods of the polycarbonate compositions in Examples 1-23 and Comparative Examples 1-8 all include the following steps:

[0092] According to the formula, the raw materials are placed in a high-speed mixer and mixed evenly to obtain a premix. The premix is ​​fed into a twin-screw extruder through a feeder. The screw speed is 500 rpm, the processing temperature is 250-280℃, and a double vacuum is used with a vacuum degree of -0.07-0.08MPa. After melting, dispersing, and blending, the polycarbonate composition is obtained after extrusion, cooling, drying, and pelletizing.

[0093] Table 1

[0094]

[0095] Table 2

[0096]

[0097]

[0098] Performance testing

[0099] Needle flame burning test: A polycarbonate composition was dried at 120℃ for 4 hours and then injection molded into a 1.5mm thick square box at 280℃. The needle flame test was conducted according to standard procedures, selecting the weakest corner as the flame application point. The needle flame height was 12mm. After burning for 60 seconds at the application point, the flame was removed. If the part was not burned through after the flame extinguished, it passed the test.

[0100] Visible light transmittance test: Take the polycarbonate composition, dry it at 120℃ for 4 hours, and then injection mold it into a 1.5mm thick square plate at 280℃. The visible light transmittance is tested using a visible light transmittance meter according to GB2680-1994.

[0101] Impact strength of cantilever beam notched section: Prepared according to ISO 180 2019 standard type A notch, take 5 standard specimens, use a 2.75J pendulum to test the energy required for the specimen to break, and calculate the impact strength value of the cantilever beam notched section.

[0102] 5VA sample test method: Prepare the sample according to UL 94 2016 standard. Use a 125mm flame and contact the sample with half the flame height. Apply flame to the sample for 5 seconds and then remove it for 5 seconds. Repeat this process 5 times. Record the burning time of the sample after the 5th flame application.

[0103] Flame retardancy rating: After baking the sample at 120℃ for 4 hours, a UL 94 standard burning test strip with a thickness of 1.5mm was injection molded at 280℃ on an injection molding machine. After molding, the strip was conditioned at 23℃ and 55% humidity for 48 hours and then subjected to a burning test according to the UL 94 standard to determine the flame retardancy rating.

[0104] Table 3

[0105]

[0106]

[0107] As shown in Table 3, this invention uses polycarbonate as the matrix and, through the combined action of the first siloxane copolymer polycarbonate, the second siloxane copolymer polycarbonate, the first montmorillonite, the second montmorillonite, and the sulfonate flame retardant, effectively improves the flame retardant properties of polycarbonate. The vertical burning rating of 1.5mm reaches V-0, and it can also meet the needle flame test, with a transparency ≥80%, a notched impact strength ≥540J / m, and a burning time of ≤40s after the 5th flame test. It is very suitable for the manufacture of electronic and electrical products, especially for the manufacture of speakers and communication equipment.

[0108] Comparing Examples 1-2 with Examples 3-4, it can be seen that the present invention further improves the flame retardant performance and obtains better notched impact strength by controlling the melt index of polycarbonate to 6-30 g / min.

[0109] Comparing Examples 1, 9, and 10 with Examples 11-12, it can be seen that the present invention further improves the flame retardant performance and notched impact strength by controlling the weight ratio of the first siloxane copolymer polycarbonate and the second siloxane copolymer polycarbonate to be 1:(1.5-4).

[0110] Comparing Examples 1 and 13-18, it can be seen that by controlling the weight ratio of the sum of the weights of the first siloxane copolymer polycarbonate and the second siloxane copolymer polycarbonate to the weight of the sulfonate flame retardant to be (37-150):1, the flame retardant performance is further improved.

[0111] Comparing Examples 1 and 19-21, it can be seen that by controlling the weight ratio of the first montmorillonite to the second montmorillonite to be (1-2):1, the flame retardant performance and notched impact strength are further improved.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polycarbonate composition, characterized in that, It comprises the following components in parts by weight: 100 parts polycarbonate, 4-42 parts first siloxane copolycarbonate, 2-21 parts second siloxane copolycarbonate, 3.5-11 parts first montmorillonite, 1.8-9 parts second montmorillonite, and 0.08-1.1 parts sulfonate flame retardant; The mass percentage of siloxane in the first siloxane copolymer polycarbonate is ≤6%; The second siloxane copolycarbonate contains ≥9% siloxane by mass; The average particle size of the first montmorillonite is 8~15μm; The average particle size of the second montmorillonite is 0.5~5μm.

2. The polycarbonate composition according to claim 1, characterized in that, The weight ratio of the first montmorillonite to the second montmorillonite is (0.5~5):

1.

3. The polycarbonate composition according to claim 2, characterized in that, The weight ratio of the first montmorillonite to the second montmorillonite is (1~2):

1.

4. The polycarbonate composition according to claim 1, characterized in that, The first siloxane copolycarbonate contains 0.5-6% siloxane by mass; and / or The mass percentage of siloxane in the second siloxane copolymer polycarbonate is 9-25%.

5. The polycarbonate composition according to claim 4, characterized in that, The mass percentage of siloxane in the first siloxane copolymer polycarbonate is 2-6%; The mass percentage of siloxane in the second siloxane copolymer polycarbonate is 9-20%.

6. The polycarbonate composition according to claim 1, characterized in that, The weight ratio of the second siloxane copolycarbonate to the first siloxane copolycarbonate is 1:(1~9).

7. The polycarbonate composition according to claim 1, characterized in that, The weight ratio of the second siloxane copolycarbonate to the first siloxane copolycarbonate is 1:(1.5~4).

8. The polycarbonate composition according to claim 1, characterized in that, The weight ratio of the sum of the first siloxane copolycarbonate and the second siloxane copolycarbonate to the sulfonate flame retardant is (18~300):

1.

9. The polycarbonate composition according to claim 8, characterized in that, The weight ratio of the sum of the first siloxane copolycarbonate and the second siloxane copolycarbonate to the sulfonate flame retardant is (37~150):

1.

10. The polycarbonate composition according to claim 1, characterized in that, The polycarbonate has a melt flow index of 3~60 g / min at 300℃ / 1.2 kg.

11. The polycarbonate composition according to claim 10, characterized in that, The polycarbonate has a melt flow index of 6~30 g / min at 300℃ / 1.2 kg.

12. The polycarbonate composition according to claim 1, characterized in that, The sulfonate flame retardant includes at least one of potassium 3-benzenesulfonylbenzenesulfonate, sodium 2,4,5-trichlorobenzenesulfonate, tetraethylammonium perfluoroethanesulfonate, diphenyl sulfone-3-sulfonate, diphenyl sulfone-3,3'-disulfonate, 2,5-dichlorobenzenesulfonate, potassium perfluoroalkyl sulfonate, benzenesulfonylbenzenesulfonate, and sodium p-toluenesulfonate.

13. A method for preparing the polycarbonate composition according to any one of claims 1 to 12, characterized in that, Includes the following steps: According to the formula, the raw materials are placed in a high-speed mixer and mixed evenly to obtain a premix. The premix is ​​then melted, dispersed, and blended, and then extruded, cooled, dried, and pelletized to obtain a polycarbonate composition.

14. The use of the polycarbonate composition according to any one of claims 1 to 12 in the preparation of electronic and electrical appliances.

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