Polycarbonate composition and use thereof

Abstract

The present invention belongs to the technical field of high polymer materials, and discloses a polycarbonate composition and the use thereof. By means of the cooperation between a voltage stabilizer and a compatibilizer of specific types, the product can achieve a very high PTI (withstanding more than or equal to 50 drops at 300 V) and very good flame retardancy (V-0), also has an ideal HAI and an ideal HWI, and is very suitable for small-sized thin-walled electric devices.

Description

A polycarbonate composition and its application Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to a polycarbonate composition and application thereof. Background Art

[0002] With the development of the new energy sector, the research and development of small, thin-walled electrical devices has gradually become an industry trend. The advantage of such devices is that they can gradually miniaturize new energy devices. However, the existing small, thin-walled electrical devices have difficulty in performing the insulation task of high-voltage grid voltage conversion due to the difficulty of plastic components, making the product's versatility need to be improved.

[0003] In the existing technology, PTI (proof tracking index) and flame retardancy grade are generally used to evaluate the electrical insulation and flame retardancy of plastics used in electrical devices. However, when plastics are used in high-current electrical applications, due to the high current intensity and short creepage distance, some plastic products that pass the PTI and flame retardancy tests have a high failure rate during application. Therefore, before plastic products are used, they must be evaluated using special HAI (high current arc ignition) and HWI (hot wire ignition) tests. Researchers have found that HAI and HWI performance have a low correlation with conventional PTI and flame retardancy. In order to improve the practicality of small, thin-walled electrical devices, there is an urgent need for a plastic product with high HAI and HWI performance. Summary of the Invention

[0004] Based on the defects of the prior art, the purpose of the present invention is to provide a polycarbonate composition. The composition, through the combination of specific types of voltage stabilizers and compatibilizers, can achieve extremely excellent PTI performance (number of drops ≥50 when tested at 300V) and flame retardant performance (V-0 level), while also having ideal HAI and HWI performance, making it very suitable for small thin-walled electrical devices.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A polycarbonate composition comprising the following components in parts by weight:

[0007] 40-70 parts of polycarbonate, 20-30 parts of compatibilizer, 5-15 parts of flame retardant, 0.5-5 parts of voltage stabilizer, and 0.1-5 parts of anti-dripping agent;

[0008] The voltage stabilizer is an organic epoxysiloxane modified titanate powder with a particle size D50 of 50 to 500 nm;

[0009] The compatibilizer is silicon copolymerized polycarbonate.

[0010] Preferably, the weight proportion of the polycarbonate is 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts or any two of the range values; the weight proportion of the compatibilizer is 20 parts, 22 parts, 24 parts, 25 parts, 28 parts, 30 parts or any two of the range values; the weight proportion of the flame retardant is 5 parts, 10 parts, 12 parts, 15 parts or any two of the range values; the weight proportion of the voltage stabilizer is 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or any two of the range values; the weight proportion of the anti-dripping agent is 0.1 parts, 0.2 parts, 0.5 parts, 0.6 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts or any two of the range values;

[0011] Preferably, the polycarbonate composition comprises the following components in parts by weight:

[0012] 50-60 parts of polycarbonate, 20-30 parts of compatibilizer, 8-12 parts of flame retardant, 2-3 parts of voltage stabilizer, and 0.2-4 parts of anti-dripping agent.

[0013] Polycarbonate (PC) is a relatively common plastic used in devices, but it is rarely used in small, thin-walled electrical devices. The main reason is that polycarbonate is a compound with a high carbonization rate. Although it has good flame retardancy, the carbon structure generated when an external voltage is applied will form a conductive path, resulting in poor tracking resistance of the product. The energy generated by the power supply may further cause the material to burn. Therefore, existing polycarbonate will introduce additives such as electrical performance improvers and flame retardants to ensure the product's PTI performance and flame retardancy. However, the loose molecular structure of polycarbonate itself is not conducive to the attachment of these small organic molecules or inorganic substances. As a result, once the product is used in the field of high current power supply, these additives will directly fail. Some products that pass the PTI and flame retardancy tests do not give ideal results in HAI and HWI tests.

[0014] Based on this technical dilemma, the inventors introduced titanate powder treated with organic epoxysiloxane of specific small particle size into the matrix resin of the polycarbonate composition as a voltage stabilizer in the technical solution of the present invention. This substance can effectively form a circuit barrier in the process of polycarbonate being electrified to form a carbon circuit, and can also effectively serve as an inorganic flame retardant synergist to assist the flame retardant in jointly exerting a flame retardant effect, so that the product has good electrical insulation and flame retardant properties. However, the introduction of this component is far from enough to enable the product to achieve high HAI and HWI performance, because in the process of large current electrification, the titanate powder must maintain extremely high dispersion and position stability in order to maintain normal electrical insulation and flame retardant synergistic effects. Otherwise, if the titanate agglomerates, not only will a catalytic effect be formed locally, but also some of the aggregates will be The carbonate matrix degrades and may also cause charge concentration due to the introduction of defects, resulting in an amplification effect. Therefore, the inventors first modified the titanate powder with organic epoxysiloxane to introduce Si-O groups and epoxy groups, wherein the epoxy groups react with the polycarbonate resin so that the titanate powder can effectively adhere to the matrix resin. At the same time, silicon copolymer polycarbonate is introduced as a compatibilizer. On the one hand, this compatibilizer can effectively compatibility with the modified titanate powder due to the Si-O groups, and on the other hand, it can be directly compatible with the matrix resin, thereby improving the dispersibility of the titanate powder. Under the action of the compatibilizer, the modified titanate powder can effectively help the matrix polycarbonate resin achieve good electrical insulation and flame retardancy, and achieve excellent results in HAI and HWI tests under high current.

[0015] However, since titanate powder and polycarbonate matrix resin are still two different phases, the above-mentioned improvements have extremely high requirements on the size and addition amount of titanate powder. If the size is too large or too small, or the addition amount is too much, the modification effect will not be able to compensate for the heterogeneous effect of the two. Not only will the product fail to achieve the expected excellent HAI performance and HWI performance, it may even affect the product's conventional PTI and flame retardant properties.

[0016] More preferably, in the polycarbonate composition, the weight percentage of polycarbonate is ≥50 wt%.

[0017] Preferably, the polycarbonate is bisphenol A polycarbonate.

[0018] Preferably, the polycarbonate has a melt flow rate of 3 to 26 g / 10 min at 300° C. and a load of 1.2 kg, as measured according to ISO 1133-2012.

[0019] More preferably, the polycarbonate has a melt flow rate of 3 to 20 g / 10 min at 300° C. and a load of 1.2 kg, as measured according to ISO 1133-2012.

[0020] Preferably, the number average molecular weight of the polycarbonate is 22,000 to 30,000.

[0021] Preferably, the number average molecular weight of the polycarbonate is 22,000, 24,000, 25,000, 28,000, 30,000, or a value within the range of any two of the above.

[0022] The number average molecular weight of the polycarbonate of the present invention can be directly measured by gel permeation chromatography.

[0023] More preferably, the polycarbonate has a terminal hydroxyl content of less than 100 ppm and a BPA (bisphenol A) content of less than 20 ppm.

[0024] The terminal hydroxyl group and BPA in the polycarbonate are quantitatively analyzed by infrared spectroscopy to determine their contents.

[0025] It should be noted that the polycarbonate described in the present invention is not limited to the above-mentioned types. Those skilled in the art may adopt polycarbonates of other different fluidities, molecular weights and chemical compositions according to actual needs to impart improvements in mechanical properties, aging resistance and processing properties to the product, without affecting the PTI performance, flame retardancy, HAI and HWI performance concerned by the present invention.

[0026] Preferably, the flame retardant is a halogen-free flame retardant.

[0027] More preferably, the halogen-free flame retardant is at least one of a phosphorus-based flame retardant, a sulfonate flame retardant, an organosilicon flame retardant, and an inorganic filler flame retardant.

[0028] More preferably, the halogen-free flame retardant is a phosphorus-based flame retardant, and the phosphorus content of the phosphorus-based flame retardant is ≥10 wt %.

[0029] More preferably, the phosphorus-based flame retardant is at least one of DOPO (also known as DOP, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), TPP (triphenyl phosphate), BDP (bisphenol A bis(diphenyl phosphate)), RDP (resorcinol(diphenyl phosphate)), phosphazene, and phosphate.

[0030] Preferably, the anti-dripping agent is at least one of polytetrafluoroethylene and styrene-acrylonitrile copolymer.

[0031] More preferably, the polycarbonate further comprises at least one of the following components in weight percentage: 0.01 to 1 part of an antioxidant, 0.01 to 1 part of a lubricant, 0.01 to 1 part of a reinforcing filler, and 0.01 to 1 part of a colorant.

[0032] Based on the actual needs of the product, those skilled in the art can appropriately introduce some components commonly introduced into polycarbonate products without affecting the performance of the product, such as antioxidants to improve the aging resistance of the product, lubricants to improve the processing performance of the product, reinforcing fillers to improve the rigidity of the product, and colorants to give the product various colors, etc.

[0033] Preferably, the organic epoxysiloxane is at least one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, (3-epoxypropoxypropyl)methyldiethoxysilane, and (3-epoxypropoxypropyl)triethoxysilane.

[0034] More preferably, the organoepoxysiloxane is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0035] Different types of organoepoxysiloxanes have different effects on the positional stability and uniform dispersion of titanate powders. When the above preferred types are selected, the overall performance of the product is better.

[0036] Preferably, in the organoepoxysiloxane-modified titanate powder, the mass ratio of the organoepoxysiloxane to the titanate powder is (1:99) to (5:95).

[0037] More preferably, in the organoepoxysiloxane-modified titanate powder, the mass ratio of the organoepoxysiloxane to the titanate powder is (1:99) to (3:97).

[0038] As mentioned above, organoepoxysiloxane can effectively react with polycarbonate and is compatible with silicon copolymer polysiloxane. As the content of organoepoxysiloxane increases, its effect becomes stronger. In order to maintain a balance between the adhesion and uniformity of the modified titanate, the organoepoxysiloxane modified titanate powder with the above preferred ratio has the best effect.

[0039] More preferably, the organoepoxysiloxane-modified titanate powder is obtained by mixing titanate powder with organoepoxysiloxane.

[0040] More preferably, the preparation method of the organoepoxysiloxane-modified titanate powder is: uniformly spraying the organoepoxysiloxane on the surface of the titanate powder at 20-30° C. and mixing for 0.1-0.3 h until uniform, thereby obtaining the organoepoxysiloxane-modified titanate powder.

[0041] It should be noted that the organo-epoxysiloxane modified titanate powder of the present invention can be a homemade product, and those skilled in the art can also purchase commercially available products with similar technical effects according to actual needs.

[0042] Preferably, the particle size D50 of the organo-epoxysiloxane-modified titanate powder is within the range of one or any two of 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, and 500 nm.

[0043] More preferably, the particle size D50 of the organo-epoxysiloxane modified titanate powder is 100 to 300 nm.

[0044] More preferably, the titanate is barium titanate, and the barium titanate is in a cubic phase.

[0045] When the particle size D50 of the organoepoxysiloxane modified titanate powder is within the above range, the comprehensive performance of the product is optimal.

[0046] Preferably, the particle size D50 of the organo-epoxysiloxane-modified titanate powder is determined by calcining the product in a muffle furnace to obtain an ash consisting entirely of inorganic filler, followed by testing using the method specified in GB / T 19077.1, "Particle Size Analysis by Laser Diffraction Method." Specifically, the inorganic filler, after removal of organic matter, is added to a 2% sodium hexametaphosphate solution to prepare a mixture with a solid-to-liquid ratio of 1 g / 100 mL. The mixture is then ultrasonically treated at 400 W for 80 seconds at room temperature, and testing is performed after dispersion is complete.

[0047] Preferably, the silicon co-polycarbonate is polydimethylsiloxane co-polycarbonate.

[0048] Preferably, the content of polydimethylsiloxane (PDMS) in the polydimethylsiloxane co-polycarbonate is 3-12%.

[0049] More preferably, the content of polydimethylsiloxane (PDMS) in the polydimethylsiloxane co-polycarbonate is 6-12%.

[0050] More preferably, the content of polydimethylsiloxane (PDMS) in the polydimethylsiloxane co-polycarbonate is 6-9%.

[0051] At the stated PDMS content, the compatibilizer exhibits optimal compatibilizing effects, and the product can achieve optimal high-current test performance.

[0052] Preferably, the polydimethylsiloxane in the polydimethylsiloxane co-polycarbonate can be directly detected by infrared spectroscopy.

[0053] Preferably, the weight average molecular weight of the silicon copolymer polycarbonate is 15,000 to 25,000.

[0054] More preferably, the silicon co-polycarbonate is prepared by the preparation method of PC / PDMS-2 with reference to CN1751096A. Specifically, the preparation method of the silicon co-polycarbonate is as follows:

[0055] The method comprises mixing dichloromethane, deionized water, polycarbonate resin and methyltributylammonium chloride in a stirred reactor, adding phosgene to the resulting mixture, and continuously adding aqueous sodium hydroxide solution to maintain the pH of the mixture at 6 to 7;

[0056] Dissolve a proportion of polydimethylsiloxane in dichloromethane and add it to the mixture, raise the pH to 10.5-11.5 and mix and react for 8-12 minutes, add polycarbonate resin, dichloromethane and deionized water to the resulting reactant and continue the reaction until the residual chloroformate is removed;

[0057] p-Cumylphenol (PCP) and triethylamine are added into the mixture to carry out phosgenation reaction. After the reaction is completed, the mixture is centrifuged and purified to obtain the silicon copolymer polycarbonate.

[0058] Those skilled in the art may also adopt the preparation methods of other products in CN1751096A, or other currently known methods to prepare the silicon copolymer polycarbonate product, as long as the PDMS content in the product meets the requirements of the product of the present invention.

[0059] Another object of the present invention is to provide a method for preparing the polycarbonate composition, comprising the following steps:

[0060] After the components are uniformly mixed, they are melt-extruded and granulated in a twin-screw extruder to obtain the polycarbonate composition.

[0061] The preparation method of the polycarbonate composition of the present invention has simple operating steps and can realize industrial-scale production.

[0062] Preferably, the temperature range of the twin-screw extruder is set to: 220-280°C, the screw speed is 200-600r / min, and the screw length-diameter ratio is 48:1.

[0063] Another object of the present invention is to provide use of the polycarbonate composition in the preparation of small thin-walled electrical devices.

[0064] The polycarbonate composition of the present invention has excellent electrical insulation properties (excellent PTI) and flame retardant properties, and can achieve a drop count of 50 or more when tested at 300V in a PTI test. The flame retardant rating of a 1.5mm thick polycarbonate composition strip of the present invention reaches V-0, and the HAI and HWI levels at a thickness of 1.5mm can reach the highest level of 0. It has excellent comprehensive performance and is very suitable for manufacturing plastic components (such as film sheaths, component insulation shells, etc.) of small thin-walled electrical devices that need to be exposed to high current power conversion.

[0065] The beneficial effect of the present invention is that the present invention provides a polycarbonate composition, which, by combining specific types of voltage stabilizers and compatibilizers, can achieve extremely excellent PTI performance (number of drops ≥50 when tested at 300V) and flame retardant performance (V-0 level) while also having ideal HAI and HWI performance, making it very suitable for small thin-walled electrical devices. DETAILED DESCRIPTION

[0066] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments and comparative examples. Its purpose is to understand the content of the present invention in detail, rather than to limit the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the protection scope of the present invention. The experimental reagents and instruments involved in the implementation of the present invention are all commonly used ordinary reagents and instruments unless otherwise specified.

[0067] Examples 1 to 20

[0068] An embodiment of a polycarbonate composition and its application according to the present invention, wherein the components of the polycarbonate composition are shown in Table 1.

[0069] The preparation method of the polycarbonate composition comprises the following steps:

[0070] All the components in the formula are mixed uniformly in a high-speed mixer, and then fed into a twin-screw extruder from a main feeding port for melt blending, extrusion and granulation to obtain the polycarbonate composition.

[0071] When the components are melt-blended and extruded, the temperature zones of the twin-screw extruder are set to 200-220°C in zone 1, 210-230°C in zone 2, 215-235°C in zone 3, 215-235°C in zone 4, 215-235°C in zone 5, 220-245°C in zone 6, 220-245°C in zone 7, 220-245°C in zone 8, 220-240°C in zone 9, 220-240°C in zone 10, 210-230 in zone 11, and 200-220°C in zone 12. The screw speed is 400 rpm and the screw aspect ratio is 48:1.

[0072] Comparative Examples 1 to 9

[0073] The difference between the comparative examples and the examples is only in the types and proportions of the components, as shown in Table 2.

[0074] Among the components described in each embodiment and comparative example,

[0075] The polycarbonate 1 is a product of model 1300-03NP produced by LG Chem, with a melt flow rate of 3.5 g / 10 min at 300° C. and a load of 1.2 kg, and a number average molecular weight of 30,000;

[0076] The polycarbonate 2 is a product of model 1300-10NP produced by LG Chem, with a melt flow rate of 11.5 g / 10 min at 300° C. and a load of 1.2 kg, and a number average molecular weight of 26,500;

[0077] The polycarbonate 3 is a product of model 1300-22NP produced by LG Chem, with a melt flow rate of 23.2 g / 10 min at 300° C. and a load of 1.2 kg, and a number average molecular weight of 22,000;

[0078] The flame retardant is a phosphate ester, a halogen-free phosphorus flame retardant with a phosphorus content of 9.1 wt%, and is produced by Daihachi, Japan, with a model number of PX200.

[0079] The anti-dripping agent is commercially available polytetrafluoroethylene;

[0080] The voltage stabilizer 1 is a homemade organic epoxysiloxane-modified titanate powder, which is prepared by weighing cubic barium titanate (IV) purchased from Sigma-Aldrich, barium titanate powder with a particle size D50 of 100 nm and a purity of >99% after secondary screening, and organic epoxysiloxane 1, then evenly spraying the organic epoxysiloxane 1 on the surface of the barium titanate powder at a mass ratio of 2:98, and stirring at 25°C for 0.2h until uniform.

[0081] The voltage stabilizer 2 differs from the voltage stabilizer 1 only in that the organo-epoxysiloxane 1 is replaced by the organo-epoxysiloxane 2;

[0082] The voltage stabilizer 3 differs from the voltage stabilizer 1 only in that the organo-epoxysiloxane 1 is replaced by the organo-epoxysiloxane 3;

[0083] The voltage stabilizer 4 differs from the voltage stabilizer 1 only in that the organoepoxysiloxane 1 is replaced by organosiloxane;

[0084] The voltage stabilizer 5 differs from the voltage stabilizer 1 only in that the mass ratio of the organoepoxysiloxane 1 to the barium titanate powder is 1:99;

[0085] The voltage stabilizer 6 differs from the voltage stabilizer 1 only in that the mass ratio of the organoepoxysiloxane 1 to the barium titanate powder is 3:97;

[0086] The voltage stabilizer 7 differs from the voltage stabilizer 1 only in that the mass ratio of the organoepoxysiloxane 1 to the barium titanate powder is 5:95;

[0087] The voltage stabilizer 8 differs from the voltage stabilizer 1 only in that the barium titanate powder is not modified by the introduction of the organo-epoxysiloxane, that is, the mass ratio of the organo-epoxysiloxane 1 to the barium titanate powder is 0:100;

[0088] The voltage stabilizer 9 differs from the voltage stabilizer 1 only in that the barium titanate powder is a powder of the same type produced by the same manufacturer and having a particle size D50 of 120 nm after secondary screening;

[0089] The voltage stabilizer 10 differs from the voltage stabilizer 1 only in that the barium titanate powder is a screened powder of the same type produced by the same manufacturer with a particle size D50 of 300 nm.

[0090] The voltage stabilizer 11 differs from the voltage stabilizer 1 only in that the barium titanate powder is a product of the same type produced by the same manufacturer and has a particle size D50 of 50 nm after secondary screening;

[0091] The voltage stabilizer 12 differs from the voltage stabilizer 1 only in that the barium titanate powder is the same type of product produced by the same manufacturer and has a particle size D50 of 450 nm after secondary screening;

[0092] The voltage stabilizer 13 differs from the voltage stabilizer 1 only in that the barium titanate powder is a powder of the same type produced by the same manufacturer and has a particle size D50 of 25 nm after secondary screening;

[0093] The voltage stabilizer 14 differs from the voltage stabilizer 1 only in that the barium titanate powder is a powder of the same type produced by the same manufacturer and has a particle size of D50 = 850 nm after secondary screening;

[0094] The voltage stabilizer 15 is a modified composite phosphate with a model number of PK5001 produced by Guangdong Chendong New Materials Co., Ltd.

[0095] The organoepoxysiloxane 1 is 3-(2,3-epoxypropoxy)propyltrimethoxysilane with the model number KBM-403 produced by Shin-Etsu of Japan;

[0096] The organoepoxysiloxane 2 is (3-glycidoxypropyl)methyldiethoxysilane, model KBE-402, produced by Shin-Etsu of Japan;

[0097] The organoepoxysiloxane 3 is (3-glycidoxypropyl)triethoxysilane with model KBE-403 produced by Shin-Etsu of Japan;

[0098] The organosiloxane is a silicone with a model number of MB50-002 produced by Dow Corning;

[0099] The silicon copolymer polycarbonate 1 was prepared in-house, and was prepared using the preparation method of PC / PDMS-2 with reference to CN1751096A. The PDMS content was ultimately regulated by controlling the amount of polydimethylsiloxane monomer added. The preparation method is as follows:

[0100] A mixture of 15 L of dichloromethane, 15 L of deionized water, 6.94 mol of bisphenol A polycarbonate resin, and 100 mL of methyltributylammonium chloride was prepared in a stirred reactor. Phosgene was added to the mixture at a rate of 100 g / min until 1050 g of phosgene was delivered as measured by a totalizer connected to a mass flow meter. The pH was maintained at 6-7 by continuously adding 50 wt% aqueous sodium hydroxide solution. When the phosgene addition was complete, the reactor was flushed with nitrogen to remove excess phosgene. The phosgene in the sample was then measured using phosgene paper and the chloroformate was determined. The concentration of chloroformate was measured to be 0.24 mol / L. Dimethylsiloxane was added and dissolved in 1 L of dichloromethane and added to the reactor. The pH is raised to 10.5-11.5 to allow the dimethylsiloxane and dichloroformate oligomer to react completely, and then 27 mol of bisphenol A polycarbonate resin, 20 L of dichloromethane, and 20 L of deionized water are added to the reactor, and the reaction mixture is stirred until all residual chloroformate disappears. 1.33 mol of p-cumylphenol and 75 mL of triethylamine are added to the reactor, and 3225 g of phosgene is added to the reaction mixture to carry out a phosgenation reaction at a pH of 10.5-11.5. Finally, the reaction mixture is transferred to a centrifugal feed tank and purified by seven centrifugations, washed twice with hydrochloric acid and four times with deionized water, and then steam dried to obtain the silicon copolymer polycarbonate 1 with a PDMS content of 6%.

[0101] The polydimethylsiloxane was prepared by referring to CN1751096A and adopting the preparation method of eugenol-terminated polydimethylsiloxane in the preparation of PC / PDMS-1.

[0102] The silicon co-polycarbonate 2 is prepared by the same preparation method as the silicon co-polycarbonate 1, the only difference being the amount of polydimethylsiloxane monomer added. The PDMS content of the silicon co-polycarbonate 2 is 9%.

[0103] The silicon co-polycarbonate 3 is prepared by the same preparation method as the silicon co-polycarbonate 1, the only difference being the amount of polydimethylsiloxane monomer added. The PDMS content of the silicon co-polycarbonate 3 is 3%.

[0104] The silicon co-polycarbonate 4 is prepared by the same preparation method as the silicon co-polycarbonate 1, the only difference being the amount of polydimethylsiloxane monomer added. The PDMS content of the silicon co-polycarbonate 4 is 12%.

[0105] The polycarbonate 4 is a product of model 1300-10NP produced by LG.

[0106] Unless otherwise specified, the components and raw materials used in the examples and comparative examples of the present invention are all commercially available raw materials, and the components and raw materials used in each parallel experiment are all of the same kind.

[0107] Table 1

[0108] Table 2

[0109] In order to verify the performance of the polycarbonate composition of the present invention, the products prepared in each embodiment and comparative example were subjected to the following performance tests. The specific steps are as follows:

[0110] (1) HAI test: The products of each embodiment and comparative example were injection molded into samples with a size of 50 mm * 50 mm * 3.2 mm, and then subjected to a 240 V / 32.5 A arc test according to the UL746A-2020 standard. The HAI level was then determined, and the levels were divided into 0 to 4 levels, where level 0: NA ≥ 120; level 1: 60 ≤ NA < 120; level 2: 30 ≤ NA < 60; level 3: 15 ≤ NA < 30; level 4: 0 ≤ NA < 15;

[0111] (2) HWI test: The products of each embodiment and comparative example were injection molded into samples with a size of 127 mm * 13 mm * 6.35 mm, and then tested with a heating wire using a current of 60 A / 1.5 V and a linear power density of 0.25 W / mm according to ASTM D3874-2020. The HWI level was then determined, and the levels were divided into 0 to 5 levels, where level 0: IT ≥ 120; level 1: 60 ≤ IT < 120; level 2: 30 ≤ IT < 60; level 3: 15 ≤ IT < 30; level 4: 7 ≤ IT < 15; level 5: 0 ≤ IT < 7;

[0112] (3) Flame retardant rating test of a polycarbonate composition strip of the present invention having a thickness of 1.5 mm: the test and determination were performed according to the UL94-2023 standard;

[0113] (4) PTI 300V test: Test and judge according to ASTM D3638 standard.

[0114] The test results are shown in Tables 3 and 4.

[0115] Table 3

[0116] Table 4

[0117] As can be seen from Tables 3 and 4, the polycarbonate compositions of the present invention exhibit highly desirable electrical insulation and flame retardant properties. Not only do they achieve over 50 drops at 300V in a conventional PTI test, but they also achieve a flame retardant rating of V-0 at 1.5mm. Furthermore, their HAI rating can reach a maximum of 0 (0-1) and HWI can reach a maximum of 0 (0-1). This performance is far superior to the product of Comparative Example 8, which was prepared using existing electrical property modifiers. Furthermore, the polycarbonate compositions are not limited to a single base polycarbonate. As can be seen from the products of Examples 1 and 4-5, polycarbonates of varying fluidity and molecular weight can be used as bases to prepare polycarbonate compositions that achieve the aforementioned technical effects, as long as they are formulated according to the present invention. The performance of the products of Examples 1 and 6-8 indicates that the silicon copolymer polycarbonate used as a compatibilizer has a direct impact on product performance. The flame retardant properties of the products also vary with the PDMS content of this component, with the overall performance of the products being even better when the PDMS content is within the range of 6-9%. On the other hand, a comparison between Example 1 and Examples 9-10 shows that, in addition to the compatibilizer, the key component of the product of the present invention, the organo-epoxysiloxane-modified titanate powder, varies depending on the type of modified organo-epoxysiloxane, resulting in different group structures on the surface of the titanate powder, and thus varying the product performance. When 3-(2,3-epoxypropoxy)propyltrimethoxysilane is selected as the organo-epoxysiloxane, the product achieves the best overall performance. Similarly, a comparison between Example 1 and Examples 11-13 shows that, when the organo-epoxysiloxane type is selected, the amount of organo-epoxysiloxane used will also lead to variations in the uniformity and dispersibility of the prepared modified titanate powder in the product. A content of 1-3 wt% can achieve the best HAI, HWI, and PTI performance, achieving the best overall performance. In contrast, the product of Comparative Example 1, which does not include modified titanate, not only fails to meet the HAI and HWI test standards, but also fails to meet the PTI index. Although the product in Comparative Example 3 incorporates a modified titanate, the corresponding compatibilizer is simply an ordinary polycarbonate of the same molecular weight. This fails to effectively achieve interaction between the matrix resin and the modified titanate, resulting in poor product performance. The organosiloxane in the modified titanate in Comparative Example 4 does not contain epoxy groups, which prevents it from interacting well with the polycarbonate. Consequently, the modified titanate fails to adhere well to the matrix resin. Although the product meets the PTI standard, it fails the HAI and HWI tests. The titanate in Comparative Example 5 remains unmodified. Although a compatibilizer is introduced, the titanate lacks reactive and actionable groups on its surface, leading to agglomeration and poor overall product performance.According to the performance change patterns of the products of Comparative Example 6, Example 16, Example 14, Example 1, Example 15, Example 17 and Comparative Example 7, it can be seen that when the particle size of the voltage stabilizer in the product is too small, the interaction force between the modified titanate particles is too large, and the particles are prone to agglomeration, so the electrical insulation and synergistic flame retardant effects cannot be well exerted. As the particle size gradually increases, the performance of the product is significantly improved, especially when the particle size D50 reaches the range of 100 to 300 nm, the product can achieve the best comprehensive performance. However, when the particle size of the modified titanate is further increased, the force of the matrix resin on the particles becomes smaller, and the density between the particles becomes lower, and the performance of the product begins to decline, especially when the particle size D50 is greater than 500 nm, the performance of the product is poor and cannot meet the use standard. On the other hand, it can be seen from Example 1 and Examples 18 to 20 and Comparative Example 2 that when the particle size of the modified titanate is appropriate, this component cannot be added in large quantities. Otherwise, as shown in Comparative Example 2, when it is added in excess, the forces between the inorganic phase and the organic phase are unbalanced, and the modified titanate agglomerates over a large area. Not only does the product fail to achieve the expected electrical insulation properties, but it also has a reverse weakening effect on the electrical insulation properties of the matrix polycarbonate, and its performance is even worse than that of the product in Comparative Example 1.

[0118] 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 the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polycarbonate composition, characterized in that The composition comprises the following components in parts by weight: 40-70 parts of polycarbonate, 20-30 parts of compatibilizer, 5-15 parts of flame retardant, 0.5-5 parts of voltage stabilizer, and 0.1-5 parts of anti-dripping agent; The voltage stabilizer is an organic epoxysiloxane modified titanate powder with a particle size D50 of 50 to 500 nm; The compatibilizer is silicon copolymerized polycarbonate.

2. The polycarbonate composition according to claim 1, wherein The polycarbonate has a melt flow rate of 3 to 26 g / 10 min at 300° C. and a load of 1.2 kg, as measured according to ISO 1133-2012; and a number average molecular weight of 22,000 to 30,000.

3. The polycarbonate composition according to claim 1, wherein The flame retardant is a halogen-free flame retardant; the anti-dripping agent is at least one of polytetrafluoroethylene and styrene-acrylonitrile copolymer; preferably, the halogen-free flame retardant is at least one of a phosphorus-based flame retardant, a sulfonate flame retardant, an organosilicon flame retardant, and an inorganic filler flame retardant.

4. The polycarbonate composition according to claim 1, wherein The organic epoxysiloxane is at least one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, (3-epoxypropoxypropyl)methyldiethoxysilane, and (3-epoxypropoxypropyl)triethoxysilane.

5. The polycarbonate composition according to claim 1, wherein In the organoepoxysiloxane-modified titanate powder, the mass ratio of the organoepoxysiloxane to the titanate powder is (1:99) to (5:95).

6. The polycarbonate composition according to claim 1, wherein The silicon co-polycarbonate is dimethylsiloxane co-polycarbonate; preferably, the dimethylsiloxane content in the dimethylsiloxane co-polycarbonate is 3-12%.

7. The method for preparing the polycarbonate composition according to any one of claims 1 to 6, wherein: The following steps are involved: After the components are uniformly mixed, they are melted in a twin-screw extruder and extruded into granules to obtain the polycarbonate composition.

8. Use of the polycarbonate composition according to any one of claims 1 to 6 in the preparation of small thin-walled electrical devices.

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