Fluorine-free flame-retardant master batch, preparation method and application

Abstract

This invention discloses a fluorine-free flame-retardant masterbatch, its preparation method, and its application. The fluorine-free flame-retardant masterbatch, by weight (100%), comprises the following components: 60-85% siloxane copolymer PC resin A, 10-30% polyboron siloxane, 2-6% porous material, 0.2-0.6% antioxidant, and 0.5-4% lubricant; the porous material is one or more of metal oxides, metal nitrides, silicates, diatomaceous earth, and silane coupling agent-modified diatomaceous earth. This invention prepares a fluorine-free flame-retardant masterbatch by synergistic use of porous materials such as polyboron siloxane and diatomaceous earth (especially silane coupling agent-modified diatomaceous earth), which is then applied to polycarbonate compositions. The resulting PC composition not only maintains high heat resistance and impact resistance but also significantly improves the CTI value and exhibits stable electrical properties, showing broad application prospects.

Description

Technical Field

[0001] This invention relates to a flame retardant masterbatch for polycarbonate, and more particularly to a fluorine-free flame retardant masterbatch, its preparation method, and its application. Background Technology

[0002] Currently, commercially available polycarbonate is bisphenol A polycarbonate (PC). As a commonly used engineering plastic, PC possesses excellent impact resistance and transparency, as well as good heat resistance, flame retardancy, and insulation properties, making it widely used in electronics, home appliances, automobiles, construction, healthcare, and agriculture. The PC main chain contains aromatic units, which produce 20-25 wt% char residue during combustion. However, its flame retardancy still needs improvement to meet the requirements of transportation, electronics, and construction. To address this challenge, many flame retardants, such as bromine, phosphorus, sulfur, silicon-containing compounds, and others, have been developed to enhance the flame retardancy of PC.

[0003] Ideal flame-retardant PC not only performs well in both small-scale and large-scale flame tests but also maintains its mechanical properties. The formation of a carbon layer is the most important condensed phase mechanism interfering with combustion. The carbon layer masks the polymer surface, thus preventing heat transfer and flame propagation; therefore, promoting charring is an effective way to reduce heat and smoke generation. The key to forming a core-shell protective layer is the rapid formation of a porous structure with good thermal oxidation resistance on the top surface of the sample in the early stages of combustion. Therefore, improving the crosslinking rate and thermal oxidation resistance of degradation products is crucial for constructing an ideal protective layer. Organosilicon compounds as flame retardants can be divided into low-molecular-weight compounds and high-molecular-weight compounds, the latter mostly being siloxanes and polysiloxane derivatives. These compounds release less toxic gas and function in the condensed phase by facilitating the formation of a silica layer. Polysiloxane flame retardants catalyze the isomerization of PC and Fries rearrangement, promoting charring formation. CN105670259 discloses a polyborosiloxane flame retardant, which is prepared by first reacting triethoxyborane, silicon tetrachloride, metallocene catalyst and co-catalyst to generate a borosiloxane intermediate, and then washing and removing small molecules from the hydrolysis products of the reaction between the polyborosiloxane intermediate and tetrachlorosilane and water. The polyborosiloxane PC composite material can achieve a V-0 rating of 1.6mm, and the tensile properties, flexural properties, impact properties and transparency of the composite material are not affected. However, the above work did not investigate the effect on the electrical properties of PC.

[0004] The carbon-forming properties of PC materials result in a relatively low tracking index (CTI). With increasingly stringent electrical performance requirements in outdoor photovoltaic and electrical products, this will limit its application in these industries. Adding phosphorus-containing flame retardants can effectively improve the CTI of PC. Patent CN109370190A uses phosphazene flame retardants to improve CTI performance. Although this approach results in a smaller decrease in heat resistance compared to conventional phosphorus flame retardants, it still leads to a reduction in heat resistance and impact resistance, and is also more expensive.

[0005] Therefore, it is necessary to develop new flame-retardant solutions that can ensure the heat resistance and impact resistance of materials and improve the CTI performance of PC materials. Summary of the Invention

[0006] To address the above technical problems, this invention proposes a fluorine-free flame retardant masterbatch, its preparation method, and its application.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] Based on a first aspect of the present invention, a fluorine-free flame retardant masterbatch is provided, comprising the following components by weight of 100%:

[0009] Siloxane copolymer PC resin A 60-85%,

[0010] Polyborosiloxane 10-30%,

[0011] Porous materials 2-6%,

[0012] Antioxidant 0.2-0.6%,

[0013] Lubricant 0.5-4%;

[0014] The porous material is one or more of the following: metal oxide, metal nitride, silicate, diatomaceous earth, and silane coupling agent modified diatomaceous earth.

[0015] In some preferred examples, the melt index of the siloxane copolymer PC resin A at a test temperature of 300°C and 1.2 kg is 15-35 g / 10 min, preferably 15-30 g / 10 min, and more preferably 15-25 g / 10 min;

[0016] Preferably, in the siloxane copolymer PC resin A, the mass content of siloxane copolymer units is 4-10%, more preferably 4-9%, and more preferably 5-9%.

[0017] In some preferred examples, the porous material is silane coupling agent modified diatomaceous earth, wherein the mass ratio of silane coupling agent to diatomaceous earth is 1:(2-9), preferably 1:(2-8), and more preferably 1:(2-7.5).

[0018] Preferably, the silane coupling agent in the silane coupling agent modified diatomaceous earth is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0019] In this invention, polyborosiloxane can be prepared by referring to any existing publicly available technology, such as "Wu Yanjin, Wu Mingjun, Li Meijiang. Research progress on preparation and application of polyborosiloxane". Polymer Bulletin. 2(2012):5.

[0020] The following is a feasible example of preparing polyborosiloxane provided by the present invention:

[0021] Octamethylcyclotetrasiloxane (D4), boric acid, tetraethyl silicate, and hydrochloric acid are dissolved in an organic solvent and stirred continuously. The mixture is heated at 60-75°C for 3-5 hours, then kept at 100-120°C for 2-3 hours. The solvent is removed by vacuum distillation, and the mixture is cooled to below 60°C and dried under vacuum to obtain a powdered solid product, namely polyborosiloxane.

[0022] Preferably, the mass ratio of octamethylcyclotetrasiloxane (D4), boric acid, and tetraethyl silicate is 1:(0.05-0.55):(0.08-0.3).

[0023] Preferably, the hydrochloric acid is a hydrochloric acid solution with a concentration of 36.0-38.0%, and the amount of hydrochloric acid solution used is 10-30% of the total mass of the raw materials.

[0024] Preferably, the organic solvent is selected from one or more of diethylene glycol dimethyl ether, methyl tert-butyl ether, propylene glycol dimethyl ether, and triethylene glycol dimethyl ether.

[0025] In this invention, the introduction of polyborosiloxane not only brings considerable flame retardant properties to PC materials, but also unexpectedly reveals that the synergistic use of polyborosiloxane and porous materials such as diatomaceous earth can improve the CTI performance of materials without sacrificing their impact resistance. In particular, when used in combination with diatomaceous earth modified by silane coupling agents within a certain proportion range, the resulting flame retardant masterbatch significantly improves the CTI performance of PC compositions, and has broad application prospects in electronic appliances and outdoor photovoltaic products with high safety requirements.

[0026] Based on a second aspect of the present invention, a method for preparing a fluorine-free flame retardant masterbatch as described above is also provided, comprising the following steps: thoroughly mixing siloxane copolymer PC resin A, polyboron siloxane, porous material, antioxidant, and lubricant, followed by extrusion and granulation to obtain a fluorine-free flame retardant masterbatch;

[0027] Preferably, the extrusion temperature is 245-270℃ and the extrusion speed is 100-200rpm.

[0028] Based on a third aspect of the invention, a polycarbonate composition is also provided, comprising the following components based on a total weight of 100%:

[0029] PC resin 68-90%,

[0030] Siloxane copolymer PC resin B 6-20%,

[0031] The fluorine-free flame retardant masterbatch mentioned above in this invention is 1.5-18%.

[0032] Antioxidant 0.2-0.6%,

[0033] Lubricant 0.5-2%.

[0034] Other additives: 0-6%.

[0035] In some preferred examples, the PC resin has a melt index of 3-65 g / 10 min, preferably 5-65 g / 10 min, and more preferably 5-50 g / 10 min, at a test temperature of 300°C and 1.2 kg.

[0036] In some preferred examples, the melt index of the siloxane copolymer PC resin B at a test condition of 300°C and 1.2 kg is 0.1-5 g / 10 min, preferably 0.2-4 g / 10 min, and more preferably 0.2-3 g / 10 min;

[0037] Preferably, in the siloxane copolymer PC resin B, the mass content of siloxane copolymer units is 12-35%, more preferably 12-32%, and even more preferably 15-30%.

[0038] In some preferred examples, the other additives include any one or more of ultraviolet absorbers and toughening agents.

[0039] Based on a fourth aspect of the present invention, a method for preparing the polycarbonate composition as described above is also provided, comprising the following steps: fully mixing PC resin, siloxane copolymer PC resin B, the fluorine-free flame retardant masterbatch mentioned above, antioxidant, lubricant, and other additives, then extruding and pelletizing to obtain the polycarbonate composition.

[0040] Preferably, the extrusion temperature is 250-300℃ and the extrusion speed is 150-400rpm.

[0041] In the fluorine-free flame retardant masterbatch and polycarbonate composition provided above in this invention, the antioxidant may be selected from one or more of hindered phenols, phosphites, thioesters, benzofurans, acryloyl-modified phenols, and hydroxylamine antioxidants, including but not limited to one or more of 1076, 168, and PEP-36.

[0042] The lubricant may be selected from one or more of fatty alcohols, fatty acids, fatty acid esters, lignite acid and its derivatives, amide waxes, saturated hydrocarbons, polyolefin waxes and their derivatives, organosilicon and silicone lubricants, including but not limited to one or more of pentaerythritol stearate and montan wax 6901.

[0043] The ultraviolet absorbers include, but are not limited to, one or more of the following: benzophenones, benzotriazoles, triazines, benzoic acid esters, cyanoacrylates, and phenylimidazolium ultraviolet absorbers.

[0044] The impact modifiers include, but are not limited to, one or more of the following: styrene-butadiene-acrylonitrile copolymer (ABS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene-styrene copolymer (MBS), acrylate-styrene-acrylonitrile copolymer (ASA), methyl methacrylate-butadiene copolymer (MB), acrylonitrile-ethylene-propylene rubber-styrene copolymer (AES), styrene-butadiene copolymer (SB), methyl methacrylate-acrylate copolymer (MA), and methyl methacrylate-acrylate-styrene copolymer (MAS).

[0045] Based on a fifth aspect of the invention, the application of the polycarbonate composition as described above in electronic appliances and outdoor photovoltaic equipment is also provided.

[0046] This invention utilizes porous materials such as polyboron siloxane and diatomaceous earth (especially diatomaceous earth modified with silane coupling agent) to prepare fluorine-free flame-retardant masterbatch, which is then applied to polycarbonate compositions. The resulting PC composition material not only maintains high heat resistance and impact resistance, but also significantly improves the CTI value and exhibits stable electrical properties, showing broad application prospects. Detailed Implementation

[0047] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0048] The main raw materials used in the following embodiments of the present invention are as follows. Unless otherwise specified, other raw materials were purchased through commercial channels.

[0049] PC resin (PC-1): CLARNATE 2100, melt index (300℃, 1.2kg) = 8.5g / 10min, Wanhua Chemical Group Co., Ltd.

[0050] PC resin (PC-2): CLARNATE 2220, melt index (300℃, 1.2kg) = 20g / 10min, Wanhua Chemical Group Co., Ltd.

[0051] PC resin (PC-3): CLARNATE 2350, melt index (300℃, 1.2kg) = 35g / 10min, Wanhua Chemical Group Co., Ltd.

[0052] Siloxane copolymer PC resin (Si-PC-A1): CLARNATE S2440, siloxane copolymer unit content is 7.5wt%, melt index (300℃, 1.2kg) = 20g / 10min, Wanhua Chemical Group Co., Ltd.

[0053] Siloxane copolymer PC resin (Si-PC-A2): CLARNATE S2340, siloxane copolymer unit content is 9wt%, melt index (300℃, 1.2kg) = 15g / 10min, Wanhua Chemical Group Co., Ltd.

[0054] Siloxane copolymer PC resin (Si-PC-A3): CLARNATE S2630, siloxane copolymer unit content is 5wt%, melt index (300℃, 1.2kg) = 32g / 10min, Wanhua Chemical Group Co., Ltd.

[0055] Siloxane copolymer PC resin (Si-PC-B1): CLARNATE S2060, siloxane copolymer unit content is 20wt%, melt index (300℃, 1.2kg) = 1.3g / 10min, Wanhua Chemical Group Co., Ltd.

[0056] Siloxane copolymer PC resin (Si-PC-B2): CLARNATE S2080, siloxane copolymer unit content is 30wt%, melt index (300℃, 1.2kg) = 0.4g / 10min, Wanhua Chemical Group Co., Ltd.

[0057] Lubricant (WAX-1): Pentaerythritol tetrastearate, Faji Chemicals (Zhangjiagang) Co., Ltd.

[0058] Antioxidant (AO-1): A composite antioxidant consisting of tris[2,4-di-tert-butylphenyl]phosphite and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester in a weight ratio of 4:1.

[0059] Octamethylcyclotetrasiloxane (D4), 98.0%, Inno Chemical Technology Co., Ltd.

[0060] Boric acid (BA), Aladdin Industries (China).

[0061] Tetraethyl silicate (TEOS), Aladdin Industrial Co., Ltd. (China).

[0062] Diethylene glycol dimethyl ether (99.5%), Shanghai Aladdin Biochemical Technology Co., Ltd.

[0063] Hydrochloric acid (HCl, 36.0-38.0%), Wanhua Chemical Group Co., Ltd.

[0064] Diatomaceous earth-R, unmodified diatomaceous earth, Sinopharm Chemical Reagent Co., Ltd.

[0065] γ-glycidoxypropyltrimethoxysilane, commercially available.

[0066] Distearate isopropyl aluminum ester, commercially available.

[0067] The performance testing methods mainly used in the following embodiments of the present invention are as follows:

[0068] (1) Notched impact strength of cantilever beam: Under 23℃ conditions, a 4.0mm thick injection-molded cantilever beam test specimen was used, and a 2.0mm deep notch was prepared using a notching machine. The impact strength of the notched cantilever beam was determined according to GB / T1043.1-2008, expressed as kJ / m. 2 Record the results.

[0069] (2) Heat distortion temperature: Tested at 23℃ according to ISO 75 standard, and the results are recorded in ℃.

[0070] (3) Flame retardancy test: Two types of samples, 127*12.7*3.0mm and 127*12.7*1.5mm, and a 150*150*3.0mm sample were injection molded. Pretreatment and flame retardancy performance were performed according to UL94 standard, and the results were recorded as V0, V1, V2, HB, 5VB and 5VA.

[0071] (4) Relative Tracking Index Test: Prepare a 90*80*3.0mm sample and test the relative tracking index (CTI) of the sample according to the IEC60112 standard. Record the results in V. The higher the CTI, the better the electrical performance.

[0072] [Preparation Example 1]

[0073] 23.73 g of D4, 1.24 g of boric acid, 2.08 g of TEOS, and 3 ml of hydrochloric acid were dissolved in 100 ml of diethylene glycol dimethyl ether. The solution was heated to 70 °C for 4 hours with magnetic stirring, and then kept at 120 °C for 2 hours. The solvent was removed by vacuum distillation, and then dried under vacuum at 60 °C to obtain a powdered solid product, polyborosiloxane, denoted as PBS-1.

[0074] 14.83 g of D4, 3.09 g of boric acid, 2.08 g of TEOS, and 4 ml of hydrochloric acid were dissolved in 100 ml of diethylene glycol dimethyl ether. The solution was heated to 65 °C for 4 hours with magnetic stirring, and then kept at 110 °C for 2 hours. The solvent was removed by vacuum distillation, and then dried under vacuum at 60 °C to obtain a powdered solid product, polyborosiloxane, designated PBS-2.

[0075] 8.90 g of D4, 4.64 g of boric acid, 2.08 g of TEOS, and 4 ml of hydrochloric acid were dissolved in 100 ml of diethylene glycol dimethyl ether. The mixture was heated to 60 °C for 4 hours with magnetic stirring, and then kept at 100 °C for 2 hours. The solvent was removed by vacuum distillation, and then dried under vacuum at 60 °C to obtain a powdered solid product, polyborosiloxane, designated PBS-3.

[0076] [Preparation Example 2]

[0077] 100g of diatomaceous earth-R was added to 1L of ethanol aqueous solution with a mass concentration of 40% and mixed. The mixture was ultrasonically dispersed for 40min. Then, under magnetic stirring (350r / min), acetic acid was added to adjust the pH to 5.1. 25g of γ-glycidoxypropyltrimethoxysilane was added, the temperature was raised to 75℃, and the reaction was stirred for 5h. After the reaction was completed, the mixture was allowed to stand and cool, filtered, washed three times with ethanol, and dried under vacuum at 60℃ to obtain modified diatomaceous earth-M1.

[0078] 50g of diatomaceous earth-R was added to 1L of ethanol aqueous solution with a mass concentration of 40% and mixed. The mixture was ultrasonically dispersed for 40min. Then, under magnetic stirring (350r / min), acetic acid was added to adjust the pH to 5.1. 25g of γ-aminopropyltriethoxysilane was added, and the temperature was raised to 75℃. The mixture was stirred and reacted for 5h. After the reaction was completed, the mixture was allowed to stand and cool, filtered, washed three times with ethanol, and dried under vacuum at 60℃ to obtain modified diatomaceous earth-M2.

[0079] 200g of diatomaceous earth-R was added to 1L of ethanol aqueous solution with a mass concentration of 40% and mixed. The mixture was ultrasonically dispersed for 40min. Then, under magnetic stirring (350r / min), acetic acid was added to adjust the pH to 5.1. 25g of γ-methacryloyloxypropyltrimethoxysilane was added, and the temperature was raised to 75℃. The mixture was stirred and reacted for 5h. After the reaction was completed, the mixture was allowed to stand and cool, filtered, washed three times with ethanol, and dried under vacuum at 60℃ to obtain modified diatomaceous earth-M3.

[0080] 100g of diatomaceous earth-R was added to 1L of ethanol aqueous solution with a mass concentration of 40% and mixed. The mixture was ultrasonically dispersed for 40min. Then, under magnetic stirring (350r / min), acetic acid was added to adjust the pH to 5.1. 15g of γ-glycidoxypropyltrimethoxysilane was added, and the temperature was raised to 75℃. The reaction was continued to be stirred for 5h. After the reaction was completed, the mixture was allowed to stand and cool, filtered, washed three times with ethanol, and dried under vacuum at 60℃ to obtain modified diatomaceous earth-M4.

[0081] 100g of diatomaceous earth-R was added to 1L of ethanol aqueous solution with a mass concentration of 40% and mixed. The mixture was ultrasonically dispersed for 40min. Then, under magnetic stirring (350r / min), acetic acid was added to adjust the pH to 5.1. 25g of distearate was added, the temperature was raised to 75℃, and the reaction was stirred for 5h. After the reaction was completed, the mixture was allowed to stand and cool, filtered, washed three times with ethanol, and dried under vacuum at 60℃ to obtain modified diatomaceous earth-D1.

[0082]

Example 1

[0083] The following method was used to prepare fluorine-free flame retardant masterbatch:

[0084] 1.687 kg Si-PC-A1, 0.2 kg PBS-1, 0.08 kg modified diatomaceous earth-M1, 0.003 kg AO-1, ​​and 0.03 kg WAX-1 were mixed using a pulverizer. The mixture was then added to a Buss mixer for extrusion and granulation. The extrusion temperature was 245-270℃ and the rotation speed was 200 rpm to obtain the fluorine-free flame-retardant masterbatch PBSMB-1.

[0085]

Example 2

[0086] The following method was used to prepare fluorine-free flame retardant masterbatch:

[0087] 1.507 kg Si-PC-A2, 0.4 kg PBS-2, 0.06 kg modified diatomaceous earth-M2, 0.003 kg AO-1, ​​and 0.03 kg WAX-1 were mixed using a pulverizer. The mixture was then added to a Buss mixer for extrusion and granulation. The extrusion temperature was 245-270℃ and the rotation speed was 150 rpm to obtain the fluorine-free flame-retardant masterbatch PBSMB-2.

[0088]

Example 3

[0089] 1.247 kg Si-PC-A3, 0.6 kg PBS-3, 0.12 kg modified diatomaceous earth-M3, 0.003 kg AO-1, ​​and 0.03 kg WAX-1 were mixed using MIXACO. The mixture was then added to a Buss mixer for extrusion and granulation. The extrusion temperature was 245-270℃ and the rotation speed was 100 rpm to obtain the fluorine-free flame-retardant masterbatch PBSMB-3.

[0090]

Example 4

[0091] The fluorine-free flame retardant masterbatch PBSMB-4 was prepared according to essentially the same formulation and method as in Example 1, except that the modified diatomaceous earth-M1 was replaced with an equal amount of modified diatomaceous earth-M4.

[0092] Comparative Example 1

[0093] The fluorine-free flame retardant masterbatch PBSMB-5 was prepared according to essentially the same formulation and method as in Example 1, except that the modified diatomaceous earth-M1 was replaced with an equal amount of modified diatomaceous earth-D1.

[0094] Comparative Example 2

[0095] The fluorine-free flame retardant masterbatch PBSMB-6 was prepared according to essentially the same formulation and method as in Example 1, except that the modified diatomaceous earth-M1 was replaced with an equal amount of diatomaceous earth-R.

[0096] Comparative Example 3

[0097] The fluorine-free flame retardant masterbatch PBSMB-7 was prepared according to essentially the same formulation and method as in Example 1, except that modified diatomaceous earth-M1 was not added.

[0098]

Application Examples 1-6

[0099] Referring to the formulations in Table 1, the raw materials were mixed and melt-blended using a Coperion STS-35 twin-screw extruder. The processing temperatures were 230°C in zone 1, 260°C in zone 2, 285°C in zone 3, 280°C in zone 4, 275°C in zones 5 to 9, and 280°C at the die head. After extrusion, the materials were pelletized to obtain the polycarbonate compositions in each application example.

[0100] Table 1. Formulations of polycarbonate compositions in Application Examples 1-6

[0101]

[0102]

Comparative Application Example 1

[0103] The polycarbonate composition was prepared according to the method in Application Example 1, except that the fluorine-free flame retardant masterbatch PBSMB-1 was replaced with an equal amount of PBSMB-5.

[0104]

Comparative Application Example 2

[0105] The polycarbonate composition was prepared according to the method in Application Example 1, except that the fluorine-free flame retardant masterbatch PBSMB-1 was replaced with an equal amount of PBSMB-6.

[0106]

Comparative Application Example 3

[0107] The polycarbonate composition was prepared according to the method in Application Example 1, except that the fluorine-free flame retardant masterbatch PBSMB-1 was replaced with an equal amount of PBSMB-7.

[0108] [Comparative Application Example 4]

[0109] The polycarbonate composition was prepared according to the method in Application Example 1, except that the fluorine-free flame retardant masterbatch PBSMB-1 was not added.

[0110] The polycarbonate compositions obtained in the above application examples and comparative application examples were subjected to the performance tests shown in Table 2, and the results are as follows.

[0111] Table 2. Performance Test Results

[0112]

[0113] The experimental results in Table 2 show that the polycarbonate composition prepared using the fluorine-free flame-retardant masterbatch provided by the present invention has excellent flame-retardant properties and a significantly improved CTI value, while maintaining good mechanical properties. This has significant advantages over the schemes in the comparative application examples.

[0114] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A fluorine-free flame retardant masterbatch, characterized in that, Based on a total weight of 100%, it contains the following components: Siloxane copolymer PC resin A 60-85%, Polyborosiloxane 10-30%, Porous materials 2-6%, Antioxidant 0.2-0.6%, Lubricant 0.5-4%; The porous material is silane coupling agent modified diatomaceous earth.

2. The fluorine-free flame retardant masterbatch according to claim 1, characterized in that, The melt flow index of the siloxane copolymer PC resin A is 15-35 g / 10 min under the test conditions of 300℃ and 1.2 kg.

3. The fluorine-free flame retardant masterbatch according to claim 2, characterized in that, The melt flow index of the siloxane copolymer PC resin A is 15-30 g / 10 min under the test conditions of 300℃ and 1.2 kg.

4. The fluorine-free flame retardant masterbatch according to claim 2, characterized in that, The melt index of the siloxane copolymer PC resin A is 15-25 g / 10 min under the test conditions of 300℃ and 1.2 kg.

5. The fluorine-free flame retardant masterbatch according to claim 2, characterized in that, In the siloxane copolymer PC resin A, the mass content of siloxane copolymer units is 4-10%.

6. The fluorine-free flame retardant masterbatch according to claim 5, characterized in that, In the siloxane copolymer PC resin A, the mass content of siloxane copolymer units is 4-9%.

7. The fluorine-free flame retardant masterbatch according to claim 5, characterized in that, In the siloxane copolymer PC resin A, the mass content of siloxane copolymer units is 5-9%.

8. The fluorine-free flame retardant masterbatch according to any one of claims 1-7, characterized in that, The porous material is silane coupling agent modified diatomaceous earth, wherein the mass ratio of silane coupling agent to diatomaceous earth is 1:(2-9).

9. The fluorine-free flame retardant masterbatch according to claim 8, characterized in that, The porous material is silane coupling agent modified diatomaceous earth, wherein the mass ratio of silane coupling agent to diatomaceous earth is 1:(2-8).

10. The fluorine-free flame retardant masterbatch according to claim 8, characterized in that, The porous material is silane coupling agent modified diatomaceous earth, wherein the mass ratio of silane coupling agent to diatomaceous earth is 1:(2-7.5).

11. The fluorine-free flame retardant masterbatch according to claim 8, characterized in that, The silane coupling agent in the silane-modified diatomaceous earth is selected from one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

12. A method for preparing a fluorine-free flame-retardant masterbatch as described in any one of claims 1-11, characterized in that, Includes the following steps: After thoroughly mixing siloxane copolymer PC resin A, polyboron siloxane, porous materials, antioxidants, and lubricants, the mixture is extruded and granulated to obtain a fluorine-free flame-retardant masterbatch.

13. The method for preparing the fluorine-free flame retardant masterbatch according to claim 12, characterized in that, The extrusion temperature is 245-270℃, and the extrusion speed is 100-200rpm.

14. A polycarbonate composition, characterized in that, Based on a total weight of 100%, it contains the following components: PC resin 68-90%, Siloxane copolymer PC resin B6-20%, The fluorine-free flame retardant masterbatch in any one of claims 1-11 is 1.5-18%. Antioxidant 0.2-0.6%, Lubricant 0.5-2%, Other additives: 0-6%.

15. The polycarbonate composition according to claim 14, characterized in that, The PC resin has a melt flow index of 3-65 g / 10 min at a test temperature of 300℃ and a weight of 1.2 kg.

16. The polycarbonate composition according to claim 15, characterized in that, The PC resin has a melt index of 5-65 g / 10 min at a test temperature of 300℃ and a weight of 1.2 kg.

17. The polycarbonate composition according to claim 15, characterized in that, The melt flow index of the PC resin at 300℃ and 1.2kg was 5-50g / 10min.

18. The polycarbonate composition according to any one of claims 14-17, characterized in that, The melt flow index of the siloxane copolymer PC resin B was 0.1-5 g / 10 min at a test temperature of 300℃ and a weight of 1.2 kg.

19. The polycarbonate composition according to claim 18, characterized in that, The melt flow index of the siloxane copolymer PC resin B was 0.2-4 g / 10 min at a test temperature of 300℃ and a weight of 1.2 kg.

20. The polycarbonate composition according to claim 18, characterized in that, The melt flow index of the siloxane copolymer PC resin B was 0.2-3 g / 10 min at a test temperature of 300℃ and a weight of 1.2 kg.

21. The polycarbonate composition according to claim 18, characterized in that, In the siloxane copolymer PC resin B, the mass content of siloxane copolymer units is 12-35%.

22. The polycarbonate composition according to claim 21, characterized in that, In the siloxane copolymer PC resin B, the mass content of siloxane copolymer units is 12-32%.

23. The polycarbonate composition according to claim 21, characterized in that, In the siloxane copolymer PC resin B, the mass content of siloxane copolymer units is 15-30%.

24. The polycarbonate composition according to any one of claims 14-17, characterized in that, The other additives include any one or more of ultraviolet absorbers and toughening agents.

25. A method for preparing a polycarbonate composition according to any one of claims 14-24, characterized in that, Includes the following steps: The polycarbonate composition is obtained by thoroughly mixing PC resin, siloxane copolymer PC resin B, fluorine-free flame retardant masterbatch as described in any one of claims 1-11, antioxidant, lubricant, and other additives, followed by extrusion and pelletizing.

26. The method for preparing the polycarbonate composition according to claim 25, characterized in that, The extrusion temperature is 250-300℃, and the extrusion speed is 150-400rpm.

27. The use of a polycarbonate composition as described in any one of claims 14-24 in electronic appliances and outdoor photovoltaic equipment.

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