Flame-retardant polycarbonate and preparation method therefor

Abstract

The present application relates to the technical field of polymer materials. Disclosed are a flame-retardant polycarbonate and a preparation method therefor. By introducing a compounded siloxane copolymerized polycarbonate and a flame retardant into a polycarbonate resin, the flame-retardant polycarbonate of the present application not only ensures the initial flame retardancy of thin-walled products, but also exhibits high transparency and resistance to heat and humidity. After long-term exposure to humid and hot environments, the flame-retardant polycarbonate can still maintain high flame retardancy and transparency.

Description

A flame-retardant polycarbonate and its preparation method Technical Field

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

[0002] Polycarbonate possesses high mechanical strength and excellent electrical insulation. Furthermore, by adding flame retardants, most polycarbonate products also exhibit ideal flame retardancy, making them widely used in fields with high safety requirements, such as electrical components, batteries, home appliances, and new energy sources. Currently, thin-walled polycarbonate products (below 1mm) with a UL94 V-0 flame retardant rating primarily use anti-dripping agents such as polytetrafluoroethylene (PTFE) as functional additives. However, these additives can severely impact the product's transparency and processability, thus limiting its application range.

[0003] Furthermore, current flame-retardant polycarbonate products have poor resistance to humid heat. If flame-retardant polycarbonate products are exposed to humid heat for a long time, their flame-retardant properties will gradually decrease or even fail, and their transparency will also decrease further. Summary of the Invention

[0004] Based on the deficiencies of existing technologies, the purpose of this application is to provide a flame-retardant polycarbonate. By introducing a compounded siloxane copolymerized polycarbonate and a flame retardant into the polycarbonate resin, the flame-retardant polycarbonate of this application not only ensures the initial flame-retardant performance of thin-walled products, but also has high transparency and resistance to damp heat. Even after long-term exposure to damp heat environments, it can still maintain high flame-retardant performance and transparency.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] A flame-retardant polycarbonate comprising the following components in parts by weight:

[0007] 100 parts polycarbonate, 15-95 parts siloxane copolymerized polycarbonate, and 0.1-1 parts flame retardant;

[0008] The siloxane copolycarbonate includes siloxane copolycarbonate 1 and siloxane copolycarbonate 2;

[0009] The flame-retardant polycarbonate satisfies |a1-a2|≥4% and |b1-b2|≤15℃;

[0010] Where a1 is the mass content of siloxane in siloxane copolymer polycarbonate 1, and b1 is the heat distortion temperature of siloxane copolymer polycarbonate 1.

[0011] a2 is the mass content of siloxane in siloxane copolymer polycarbonate 2, and b2 is the heat distortion temperature of siloxane copolymer polycarbonate 2.

[0012] The flame retardant is a sulfonic acid flame retardant and a phenylsiloxane flame retardant.

[0013] Polycarbonate possesses good mechanical strength and processing properties, but its flame retardancy and resistance to damp heat are not ideal. Furthermore, its transparency is easily affected by external factors and its composition, leading to whitening or fogging during processing or use. Therefore, in this application, to improve the product's hydrolysis resistance and flame retardancy, a siloxane copolymer polycarbonate and a sulfonic acid flame retardant are compounded together. The former significantly improves the hydrolysis and oxidation resistance of polycarbonate, while the latter achieves good flame retardancy without compromising the product's transparency. Meanwhile, during the research and development process, the inventors noticed that if only one type of siloxane copolycarbonate is used for product compounding, the hydrolysis resistance and oxidation resistance of the product remain constant at different stages (processing, humid and hot environments). Therefore, it is necessary to introduce siloxane copolycarbonates with different amounts of siloxane to achieve a gradient in the hydrolysis resistance and oxidation resistance of the product under humid and hot environments. After establishing this gradient, the compatibility and dispersibility of different siloxane copolycarbonates need to be considered when compounding, so their processing characteristics cannot differ significantly. Therefore, in the technical solution of this application, the compounded siloxane copolycarbonates need to control a certain difference in siloxane content to form a gradient; at the same time, the difference in heat distortion temperature between the two needs to be controlled within a specific range to avoid the components from not overlapping due to excessive differences in processing characteristics during processing, which would cause the sulfonic acid flame retardant to be squeezed out of the product surface during processing. Ultimately, this ensures that the product maintains high transparency and flame retardant performance both after processing and under long-term humid and hot environments.

[0014] On the other hand, to ensure that flame retardants can fully exert their properties and maintain the initial flame retardancy of the product, while maintaining low migration and high compatibility stability of the flame retardant components during hydrothermal treatment, it is necessary to further introduce silicon-containing phenylsiloxane flame retardants into sulfonic acid flame retardants and polycarbonate (PC) / silicone copolymer PC systems. This component not only acts as a bridge between sulfonic acid flame retardants and the matrix resin, enabling high compatibility among the components, but also encapsulates the sulfonic acid flame retardants, preventing their precipitation and inactivation, thus ensuring high flame retardancy after hydrothermal treatment. Choosing other types of flame retardants or their combinations not only fails to guarantee the product's transparency and flame retardancy, but also may result in a lower performance retention rate after hydrothermal treatment.

[0015] Preferably, in the flame-retardant polycarbonate, the weight parts of the siloxane copolymer polycarbonate are 15 parts, 20 parts, 25 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 85 parts, 90 parts, and 95 parts, or any two of these values; and the weight parts of the flame retardant are 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, and 1 part, or any two of these values.

[0016] Preferably, in the flame-retardant polycarbonate, the total mass content of polycarbonate and siloxane copolymerized polycarbonate is ≥90%, more preferably ≥95%.

[0017] Preferably, |a1-a2| = 4% to 15%, and / or, |b1-b2| = 1 to 15°C.

[0018] More preferably, the range of |a1-a2| is one or any two of the following: 4%, 5%, 6%, 8%, 10%, 11%, 12%, 13%, 13.5%, 14%, 14.5%, and 15%.

[0019] More preferably, |b1-b2| is a range of one or any two of the following: 1℃, 2℃, 4℃, 5℃, 8℃, 9℃, 10℃, 12℃, 13℃, and 15℃.

[0020] Preferably, the polycarbonate includes at least one of bisphenol A type polycarbonate, bisphenol F type polycarbonate, and bisphenol S type polycarbonate, and more preferably bisphenol A type polycarbonate.

[0021] The flame-retardant polycarbonate described in this application can achieve excellent resistance to damp heat, flame retardancy, and transparency with fewer additives. This not only effectively controls production costs but also broadens the range of subsequent processing of the product, resulting in high product processing plasticity.

[0022] Preferably, the siloxane content of the siloxane copolymer polycarbonate 1 and siloxane copolymer polycarbonate 2 can be determined and confirmed by, but is not limited to, the following method: Referring to "Determination of Low Molecular Weight Polysiloxane Content in Room Temperature Vulcanized Silicone Rubber by Gas Chromatography" in Chemical Technology and Development 2018-47-3, 5g of sample is ultrasonically dissolved in 20mL of cyclohexane for 20min, and then refluxed at 50℃ for 10h. 10g of the resulting clear solution is weighed and 1 drop of n-hexadecane is added. Then, according to the parameters set in the reference, the siloxane content in the sample is determined by direct injection gas chromatography with a flame ionization detector (FID detector).

[0023] Preferably, the heat distortion temperatures of the siloxane copolycarbonate 1 and siloxane copolycarbonate 2 are obtained according to ASTM D648-2007 under a pressure of 1.82 MPa. The specific method is as follows: the sample (127 mm × 13 mm × 6.4 mm) is placed upright on a simply supported beam support, and a bending stress of 1.82 MPa is applied perpendicular to the edge of the sample. Then, the sample is immersed in silicone oil and heated uniformly at a rate of 2 ± 0.2 °C / min while keeping the medium fully stirred. When the bending deformation at the midpoint of the sample reaches 0.25 mm, the temperature at this time is recorded immediately, which is the heat distortion temperature.

[0024] Preferably, in the flame-retardant polycarbonate, the weight parts of siloxane copolymer polycarbonate 1 and / or siloxane copolymer polycarbonate 2 are 4 to 50 parts.

[0025] Preferably, the siloxane copolycarbonate 1 and siloxane copolycarbonate 2 have a siloxane mass content of ≥3%;

[0026] More preferably, the siloxane content of the siloxane copolymer polycarbonate 1 and / or siloxane copolymer polycarbonate 2 is 6% to 20% by mass, more preferably a range of one or any two of 6%, 7%, 8%, 10%, 12%, 15%, 18%, and 20%.

[0027] Preferably, the heat distortion temperature of the siloxane copolycarbonate 1 and the siloxane copolycarbonate 2 is ≤130℃;

[0028] More preferably, the heat distortion temperature of the siloxane copolymer polycarbonate 1 and / or siloxane copolymer polycarbonate 2 is 105-125°C. More preferably, it is a value within the range of one or any two of 105°C, 108°C, 110°C, 112°C, 115°C, 118°C, 120°C, 122°C, and 125°C.

[0029] When the siloxane copolymer polycarbonate 1 and siloxane copolymer polycarbonate 2 described in this application are compounded, there is no need to set specific heat distortion temperature or silicon content for each. It is sufficient to ensure that there is a gradient in the resistance to wet hot water hydrolysis and that the difference in processing characteristics between the two is within a certain range. Those skilled in the art can choose the appropriate type based on the application scenario when making actual selection.

[0030] Preferably, the siloxane copolymer polycarbonate has a melt index of 1 to 15 g / 10 min at 300°C and 1.2 kg load, according to ASTM D1238-2010.

[0031] Preferably, the polycarbonate has a melt index of 3 to 20 g / 10 min at 300°C and 1.2 kg load, according to ASTM D1238-2010.

[0032] More preferably, the melt index of the polycarbonate at 300°C and 1.2 kg load is one or any two of the following: 3 g / 10 min, 5 g / 10 min, 7 g / 10 min, 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, 18 g / 10 min, 19 g / 10 min, and 20 g / 10 min.

[0033] More preferably, the polycarbonate has a melt index of 7 to 15 g / 10 min at 300°C and a load of 1.2 kg.

[0034] Generally, the melt index of the matrix polycarbonate in a polycarbonate composition is related to its flowability, which in turn leads to different mechanical properties of the product. Those skilled in the art can select a polycarbonate with a suitable melt index as the matrix based on the actual mechanical requirements of the product. In the technical solution of this application, when the melt index of the preferred polycarbonate is within the above-mentioned range, the product exhibits better resistance to damp heat, and after long-term damp heat treatment, the product has lower haze.

[0035] Preferably, the sulfonic acid flame retardant includes at least one of potassium 3-benzenesulfonylbenzenesulfonate, sodium 2,4,5-trichlorobenzenesulfonate, and HES (hydroxyethyl sulfonic acid).

[0036] Preferably, the phenylsiloxane flame retardant includes at least one of phenylcyclosiloxane and phenyl polysilsesquioxane.

[0037] It should be noted that the specific types of sulfonate flame retardants and phenylsiloxane flame retardants described in this application are not limited to the types mentioned above. Based on the actual situation, those skilled in the art may also choose other types of sulfonate flame retardants and / or phenylsiloxane flame retardants, as long as the product has the expected transparency, flame retardancy and damp heat resistance.

[0038] More preferably, the mass ratio of the sulfonic acid flame retardant to the phenylsiloxane flame retardant is (9:1) to (1:1).

[0039] Preferably, the flame-retardant polycarbonate further includes 0.1 to 5 parts of functional additives or processing aids.

[0040] More preferably, the functional additives include, but are not limited to, at least one of antistatic agents and antibacterial agents, and the processing aids include at least one of lubricants and release agents. Those skilled in the art can add various functional additives or processing aids as needed, without affecting the transparency, flame retardancy, and damp heat resistance of the product described in this application. For example, to ensure the product also has antistatic properties during application, those skilled in the art can add an antistatic agent to the product; to improve the release effect during processing, those skilled in the art can add a small amount of lubricant or release agent to the product for lubrication.

[0041] Another object of this application is to provide a method for preparing the flame-retardant polycarbonate, comprising the following steps:

[0042] The components are added to a screw extruder for melt extrusion and granulation to obtain the flame-retardant polycarbonate.

[0043] Preferably, the temperature zones of the screw extruder are set as follows: Zone 1 270-280℃, Zone 2 270-280℃, Zone 3 280-260℃, Zone 4 280-260℃, Zone 5 280-260℃, Zone 6 270-260℃, Zone 7 270-260℃, Zone 8 265-250℃, Zone 9 260-250℃, and Zone 10 260-250℃. The screw speed is 400-600 rpm, and the screw length-to-diameter ratio is (45-50):1.

[0044] The preparation method of the flame-retardant polycarbonate described in this application is simple, requires little equipment, and can be industrialized for large-scale production.

[0045] Another objective of this application is to provide the application of the flame-retardant polycarbonate in the fabrication of transparent electronic device components.

[0046] Preferably, the transparent electronic device component includes an electronic device housing and an electronic device insulating sheath.

[0047] Another object of this application is to provide a transparent electronic device component comprising the flame-retardant polycarbonate described herein.

[0048] The flame-retardant polycarbonate described in this application is based on a compounding of specific types of siloxane copolymer polycarbonate and flame retardants. This ensures that each component can achieve high component compatibility and chemical inertness at all stages of the product's development, from processing to exposure to humid and hot environments. This results in a product with high initial transparency and flame retardancy, as well as long-term stability. It is very suitable for transparent electronic device components that not only require transparency for easy observation of internal circuitry but also need to be resistant to humid heat and flame retardancy.

[0049] The beneficial effect of this application is that it provides a flame-retardant polycarbonate. By introducing a compounded siloxane copolymer polycarbonate and a flame retardant into the polycarbonate resin, it can not only ensure the initial flame-retardant performance of the thin-walled product, but also have high transparency and resistance to damp heat. Even after long-term damp heat environment, it can still maintain high flame-retardant performance and transparency. Detailed Implementation

[0050] To better illustrate the purpose, technical solution, and advantages of this application, the application will be further described below with reference to specific embodiments and comparative examples. These embodiments are intended to provide a detailed understanding of the content of this application, and not to limit it. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this application. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this application are all commonly used reagents and instruments.

[0051] Examples 1-16

[0052] Examples of the flame-retardant polycarbonate and its preparation method described in this application are shown in Table 1.

[0053] The method for preparing the flame-retardant polycarbonate includes the following steps:

[0054] The components are mixed evenly, and then melt-extruded and granulated in a twin-screw extruder to obtain the flame-retardant polycarbonate.

[0055] During melt extrusion of the component, the temperature zones of the screw extruder are set as follows: Zone 1 280℃, Zone 2 280℃, Zone 3 270℃, Zone 4 270℃, Zone 5 270℃, Zone 6 265℃, Zone 7 265℃, Zone 8 260℃, Zone 9 250℃, Zone 10 250℃. The screw speed is 500 rpm, and the screw length-to-diameter ratio is 48:1.

[0056] Comparative Examples 1-11

[0057] The only difference between each comparative example and the embodiment is the type and ratio of components, as shown in Table 2.

[0058] In the components described in each embodiment and comparative example,

[0059] The polycarbonate 1 is PC2100 produced by China Wanhua Chemical Group Co., Ltd., with a melt index of 10g / 10min at 300℃ and 1.2kg load;

[0060] The polycarbonate 2 is PC7030PJ manufactured by Mitsubishi Gas Chemical Co., Ltd. of Japan, with a melt index of 3 g / 10 min at 300°C and 1.2 kg load;

[0061] The polycarbonate 3 is PC2070 produced by China Wanhua Chemical Group Co., Ltd., with a melt index of 7 g / 10 min at 300℃ and 1.2 kg load;

[0062] The polycarbonate 4 is PCS3000VR manufactured by Mitsubishi Gas Chemical Co., Ltd. of Japan, with a melt index of 15 g / 10 min at 300°C and 1.2 kg load;

[0063] The polycarbonate 5 is PC2220 produced by China Wanhua Chemical Group Co., Ltd., with a melt index of 19 g / 10 min at 300℃ and 1.2 kg load;

[0064] The siloxane copolymer polycarbonate 1 is PC8000-05 produced by LG Chem Ltd. of South Korea, with a siloxane content of 6.5 wt% and a heat distortion temperature of 118°C.

[0065] The siloxane copolymer polycarbonate 2 is PC8010-10 produced by LG Chem Ltd. of South Korea, with a siloxane content of 10wt% and a heat distortion temperature of 108℃.

[0066] The siloxane copolymer polycarbonate 3 is PCFG1760 produced by Idemitsu Kosan Co., Ltd. of Japan, with a siloxane content of 6 wt% and a heat distortion temperature of 125°C.

[0067] The siloxane copolymer polycarbonate 4 is PCS1240 produced by China Wanhua Chemical Group Co., Ltd., with a siloxane content of 6wt% and a heat distortion temperature of 120℃.

[0068] The siloxane copolymer polycarbonate 5 is PCS2060 produced by China Wanhua Chemical Group Co., Ltd., with a siloxane content of 20wt% and a heat distortion temperature of 116℃.

[0069] The flame retardant 1 is KSS-FR, potassium 3-benzenesulfonylbenzenesulfonate, manufactured by Arichem, USA.

[0070] The flame retardant 2 is sodium 2,4,5-trichlorobenzenesulfonate produced by Hubei Xinyuhong Biomedical Technology Co., Ltd.

[0071] The flame retardant 3 is a sulfonate flame retardant, HES, produced by Arichem.

[0072] The flame retardant 4 is WSFR-BDP-N2, bisphenol A-bis(diphenyl phosphate), produced by Zhejiang Wansheng Co., Ltd.

[0073] The flame retardant 5 is SP206, octaphenylcyclotetrasiloxane, produced by Liaoning Xinbang New Materials Co., Ltd.

[0074] The flame retardant 6 is POSS, an octaphenyl polysilsesquioxane produced by Hubei Maidehao Biotechnology Co., Ltd.

[0075] The flame retardant 7 is 40-001, a polysiloxane produced by Dow Corning.

[0076] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this application are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0077] In Tables 1-2 below, a represents the absolute value of the difference in siloxane content between the two siloxane copolycarbonate components in each embodiment or comparative example, and b represents the absolute value of the difference in heat distortion temperature between the two siloxane copolycarbonate components in each embodiment or comparative example.

[0078] Table 1

[0079] Table 2

[0080] To verify the performance of the flame-retardant polycarbonate described in this application, the products prepared in each embodiment and comparative example were subjected to the following performance tests, the specific steps of which are as follows:

[0081] (1) After drying the products of each embodiment and comparative example at 120℃ for 4 hours, they were pre-injected into square plates with a thickness of 100×100×1mm at 280℃. Then, the visible light transmittance and haze were tested using a visible light transmittance meter according to GB2680-1944. The samples were then placed in a constant temperature and humidity chamber at 85℃ and 85% relative humidity for 1000 hours, and the visible light transmittance and haze were tested again using the same method. Higher visible light transmittance and lower haze indicate better product transparency.

[0082] (2) After drying the products of each embodiment and comparative example at 120℃ for 4 hours, they were pre-injected into test strips with a thickness of 127×13×1mm at 280℃. Then, according to the UL94 test standard, the strips were placed in an environment of 23±2℃ and 50±5% humidity for 48 hours for temperature and humidity adjustment. Then, according to the UL 94 vertical burning standard, the strips were subjected to two flame tests of 10±1s each time. The time t1 and t2 required for the strips to extinguish after each flame test were recorded, as well as whether there was any dripping that ignited the cotton below. Five strips were tested for each sample. If the total burning time of the five strips t1+t2 does not exceed 50s and there is no dripping that ignites the strips, the flame retardancy rating of the sample is determined to be V-0; if there is no dripping that ignites the strips and the total burning time is between 50-250s, the flame retardancy rating of the sample is determined to be V-1; if there is dripping that ignites the strips and the total burning time is between 50-250s, the flame retardancy rating of the sample is determined to be V-2.

[0083] The test results are shown in Tables 3 and 4.

[0084] Table 3

[0085] Table 4

[0086] As can be seen from Tables 3 and 4, the flame-retardant polycarbonate described in this application possesses ideal flame retardancy, transparency, and resistance to damp heat. Specifically, the initial light transmittance of the product can reach 85% or higher, the haze can be maintained below 1.5%, and the initial flame retardancy rating is V-0. After prolonged damp heat treatment, the light transmittance can still be maintained at 84% or higher, the haze is within 2.2%, and the flame retardancy rating remains unchanged, demonstrating excellent overall performance. This is mainly attributed to the introduction of specific compounded siloxane copolymerized polycarbonate and a specific combination of flame retardants into the polycarbonate resin matrix of the product described in this application, achieving excellent synergistic compounding effects among the components. In contrast, the products described in Comparative Examples 1 and 2 used only one type of siloxane copolycarbonate for compounding, which could not achieve a good gradient of environmental activity (i.e., hydrolysis resistance and oxidation resistance under humid heat). Furthermore, the resulting composite resin matrix also struggled to achieve good flame retardant dispersion and compatibility. Not only was the initial flame retardancy not guaranteed, but the transparency and flame retardancy of the products significantly decreased after humid heat treatment. While Comparative Examples 3-8 used compounded siloxane copolycarbonates of the same type as the products in the examples, the gradient settings during compounding (i.e., a and b) did not meet the requirements of this application, resulting in partial... The product's initial flame retardancy rating was only V-2. After damp heat treatment, the product's light transmittance was as low as 81%, and its haze reached as high as 4.2%, indicating a significant weakening of its flame retardancy. Comparative Example 9 used only sulfonic acid flame retardants, while the compounded flame retardants in Comparative Examples 10 and 11 were not the flame retardants specified in this application. The initial flame retardancy rating of these products was low. Most importantly, these unsuitable flame retardants severely affected the product's resistance to damp heat. After damp heat treatment, the product's light transmittance was as low as 79%, and its haze even reached a maximum of 11.5%.

[0087] As can be seen from Examples 1 and 8-11, besides the selection of the polycarbonate blend and the specific combination of flame retardants, changes in the melt index of the base polycarbonate also alter its flowability, resulting in certain differences in the degree of component creep during processing and under humid heat conditions. When the melt index of the polycarbonate is further optimized to 7-15 g / 10 min, the haze of the product after humid heat treatment is lower, but the products described in Examples 1 and 8-11 are still superior to the comparative control products.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit the scope of protection of this application. Although this application 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 this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A flame-retardant polycarbonate, characterized in that, Includes the following components in parts by weight: 100 parts polycarbonate, 15-95 parts siloxane copolymerized polycarbonate, and 0.1-1 parts flame retardant; The siloxane copolycarbonate includes siloxane copolycarbonate 1 and siloxane copolycarbonate 2; The flame-retardant polycarbonate satisfies |a1-a2|≥4% and |b1-b2|≤15℃; Where a1 is the mass content of siloxane in siloxane copolymer polycarbonate 1, and b1 is the heat distortion temperature of siloxane copolymer polycarbonate 1. a2 is the mass content of siloxane in siloxane copolymer polycarbonate 2, and b2 is the heat distortion temperature of siloxane copolymer polycarbonate 2. The flame retardant is a sulfonic acid flame retardant and a phenylsiloxane flame retardant.

2. The flame retardant polycarbonate of claim 1, wherein, The siloxane copolycarbonate 1 and siloxane copolycarbonate 2 have a siloxane content of ≥3% by mass; and / or, the heat distortion temperature of the siloxane copolycarbonate 1 and siloxane copolycarbonate 2 is ≤130℃.

3. The flame-retardant polycarbonate as described in claim 1 or 2, characterized in that, The |a1-a2| = 4% to 15%, and / or the |b1-b2| = 1 to 15℃.

4. The flame-retardant polycarbonate according to any one of claims 1 to 3, wherein The sulfonic acid flame retardant includes at least one of potassium 3-benzenesulfonylbenzenesulfonate, sodium 2,4,5-trichlorobenzenesulfonate, and hydroxyethyl sulfonic acid, and / or the phenylsiloxane flame retardant includes at least one of phenylcyclosiloxane and phenyl polysilsesquioxane.

5. The flame-retardant polycarbonate according to any of claims 1 to 4, wherein The mass ratio of the sulfonic acid flame retardant to the phenylsiloxane flame retardant is (9:1) to (1:1).

6. The flame-retardant polycarbonate according to any one of claims 1-5, characterized in that, The polycarbonate has a melt index of 3 to 20 g / 10 min at 300°C and 1.2 kg load, and / or the siloxane copolymer polycarbonate has a melt index of 1 to 15 g / 10 min at 300°C and 1.2 kg load.

7. A process for the preparation of flame-retardant polycarbonate according to any one of claims 1 to 6, characterized in that, Includes the following steps: The components are added to a screw extruder for melt extrusion and granulation to obtain the flame-retardant polycarbonate.

8. The use of the flame-retardant polycarbonate as described in any one of claims 1 to 6 in the preparation of transparent electronic device components.

9. A transparent electronic device component, characterized by Includes the flame-retardant polycarbonate according to any one of claims 1 to 6.

10. The transparent electronic device component of claim 9, wherein the transparent electronic device component is a touch screen. The transparent electronic device components include an electronic device housing and an electronic device insulating sheath.

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