Needle-flame-resistant flame-retardant PC / ABS alloy material and preparation method thereof

Abstract

The invention provides a needle-flame-resistant flame-retardant PC / ABS alloy material and a preparation method thereof, and relates to the technical field of polycarbonate alloy materials. The needle-flame-resistant flame-retardant PC / ABS alloy material comprises the following raw material components in parts by weight: 100 parts of PC / ABS alloy and 1-15 parts of modified graphene, the modified graphene is a maleic anhydride grafted polymer modified by graphene chemically grafted polysiloxane; preferably, the polysiloxane modified maleic anhydride grafted polymer is chemically grafted with the graphene through a polysiloxane chain segment. The modified graphene provided by the invention can obviously improve the flame retardant property of the PC / ABS alloy, and meets the UL-94 vertical combustion V-0 grade while meeting needle flame test.

Description

Technical Field

[0001] The invention belongs to the technical field of polycarbonate alloy materials and relates to a needle flame retardant PC / ABS alloy material and a preparation method thereof. Background Art

[0002] PC / ABS alloys combine the excellent heat resistance and mechanical strength of polycarbonate (PC) with the excellent processability of ABS resin, achieving complementary performance between the two materials. They are widely used in a variety of fields, including automotive and electronic equipment. However, PC / ABS has the disadvantage of poor flame retardancy, which poses certain safety risks in its application. Furthermore, when the ABS content in the PC / ABS alloy is high, the impact resistance of the PC / ABS alloy is also insufficient.

[0003] Graphene has a flame retardant effect on polycarbonate, which is mainly reflected in the following aspects: forming a physical barrier, improving heat resistance, capturing free radicals and catalyzing carbonization. At the same time, the dispersibility of graphene has a significant impact on the flame retardant effect. Generally speaking, the better the dispersibility of graphene, the better the performance it can exert, including the flame retardant effect. CN109486155A discloses a graphene-modified halogen-free flame retardant PC / ABS material. Graphene is first added to a heated and molten halogen-free flame retardant to obtain a homogeneous graphene solution, which is then added to PC to prepare PC graphene flame retardant masterbatch. In this method, due to the large agglomeration force of graphene, graphene cannot be well dispersed, resulting in the flame retardant effect of graphene being not obvious. CN110511554A discloses a halogen-free flame-retardant nitrogen-phosphorus-silicon modified graphene / polycarbonate / ABS alloy material. The halogen-free flame retardant is formed by in-situ polymerization and grafting of octaaminopropyl cage silsesquioxane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide onto the surface of graphene oxide. However, due to the high costs of both octaaminopropyl cage silsesquioxane and graphene, the resulting halogen-free flame retardant is very expensive.

[0004] There are multiple methods for testing flame retardancy, the most demanding of which include the needle flame test and the UL-94 vertical burn test (for example, achieving a V-0 rating). These two tests have different requirements, and the test results are not equivalent. However, there are currently few reports that PC / ABS alloys can meet both the needle flame test requirements and the UL-94 vertical burn test V-0 rating after flame retardancy enhancement, as the results of these two testing methods can be somewhat inconsistent. To achieve vertical flame retardancy, organic products generally add anti-drip agents (such as PTFE) to promote carbonization and prevent dripping during combustion, thereby achieving a V-0 rating. However, excessive levels of anti-drip agents can cause the molten organic product to shrink during combustion, causing it to burn through, failing to meet the needle flame flame retardancy requirements. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a needle flame retardant PC / ABS alloy material and a preparation method thereof.

[0006] The technical solutions of the present invention are as follows:

[0007] A needle flame resistant and flame retardant PC / ABS alloy material, comprising, by weight, 100 parts of PC / ABS alloy and 1-15 parts of modified graphene;

[0008] The modified graphene is a graphene chemically grafted polysiloxane-modified maleic anhydride grafted polymer;

[0009] Preferably, the polysiloxane-modified maleic anhydride grafted polymer is chemically grafted to the graphene via polysiloxane segments.

[0010] Preferably, the preparation method of the modified graphene comprises:

[0011] Graphene oxide and double-terminated amino polysiloxane react to obtain polysiloxane-modified graphene;

[0012] The polysiloxane-modified graphene reacts with the maleic anhydride-grafted polymer to obtain the modified graphene.

[0013] More preferably, the weight ratio of the graphene oxide to the double-terminated amino polysiloxane is 1:0.1-10.

[0014] More preferably, the double-terminated amino polysiloxane structure is as shown in the following formula (1):

[0015] NH2R 1 SiMe2(OSiMeR 2 ) n OSiMe2R 1 NH2(1)

[0016] Among them, R 1 is selected from C2-C6 divalent alkyl or substituted C3-C10 divalent alkyl, R 2 Selected from C1-C12 alkyl, aromatic group and its derivatives, cycloalkyl group and its derivatives, Me represents methyl, n=5-100.

[0017] More preferably, the graphene oxide and the double-terminated amino polysiloxane are further reduced after the reaction, and the reducing agent used for the reduction is selected from one or a combination of two or more of sodium borohydride, hydrogen, glucose, hydrazine hydrate, dimethylhydrazine and ascorbic acid and its salts.

[0018] More preferably, the weight ratio of the polysiloxane-modified graphene to the maleic anhydride grafted polymer is 1:0.2-3.

[0019] More preferably, the grafting rate of the maleic anhydride grafted polymer is 1-10 wt%.

[0020] More preferably, the maleic anhydride grafted polymer is selected from one or a combination of two or more of maleic anhydride grafted ABS, maleic anhydride grafted EVA, maleic anhydride grafted SEBS, maleic anhydride grafted SAN and maleic anhydride grafted POE.

[0021] Preferably, the raw material components further comprise one or a combination of two or more of 0.5-5 parts of phosphorus-based flame retardant, 0.1-1 parts of antioxidant, 0.1-1 parts of anti-ultraviolet agent and 0-0.1 parts of anti-dripping agent.

[0022] A method for preparing the needle flame resistant flame retardant PC / ABS alloy material according to any of the above embodiments comprises mixing the raw material components uniformly, adding them to a screw extruder for melt extrusion, and forming them (such as cooling and pelletizing) to obtain the needle flame resistant flame retardant PC / ABS alloy material.

[0023] The beneficial effects of the present invention are:

[0024] (1) The modified graphene of the present invention combines the flame retardant properties of graphene and polysiloxane structures. Furthermore, through chemical bonding, the performance is more stable and has better flame retardant properties. It can also meet the requirements of the needle flame retardancy test and the UL-94 vertical combustion V0 rating, and does not drip or burn even with very low amounts of anti-drip agents. The modified graphene also contains a maleic anhydride grafted polymer structure, which makes the modified graphene compatible with PC / ABS and can better exert the flame retardant properties of the modified graphene.

[0025] (2) The modified graphene of the present invention is compounded with a phosphorus-based flame retardant to further enhance the flame retardant effect and further improve the flame retardant properties of PC / ABS. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0027] In order to improve the effect of graphene as a flame retardant, the present invention provides a needle flame retardant PC / ABS alloy material, wherein the raw material components, by weight, include 100 parts of PC / ABS alloy and 1-15 parts of modified graphene;

[0028] There are no specific restrictions on the weight ratio of PC to ABS in PC / ABS alloys. Typically, the weight ratio of PC to ABS can be 85:15-97:3. For PC / ABS alloys, a blend of PC resin and ABS resin can be used, for example, by obtaining PC resin and ABS resin separately from the market and then mixing the two materials. To improve the impact resistance of the needle-flame-retardant PC / ABS alloy, a compatibilizer and / or toughening agent, such as maleic anhydride-grafted ABS (ABS-g-MAH) or maleic anhydride-grafted PE (PE-g-MAH), can also be added. The amount of compatibilizer used can be 1-5% of the weight of the PC / ABS alloy.

[0029] The modified graphene is a graphene chemically grafted polysiloxane-modified maleic anhydride grafted polymer, that is, the polysiloxane-modified maleic anhydride grafted polymer is grafted onto graphene;

[0030] In some embodiments, the polysiloxane-modified maleic anhydride grafted polymer is chemically grafted to graphene via polysiloxane segments.

[0031] The modified graphene of the present invention has the following characteristics: (1) both graphene and polysiloxane have flame retardant effects and can synergistically exert flame retardant properties, thereby further improving the flame retardant properties; (2) the maleic anhydride grafted polymer has good compatibility with the PC / ABS alloy, thereby improving the compatibility of the modified graphene with the PC / ABS alloy and improving the dispersibility of the graphene in the PC / ABS alloy; and (3) the polysiloxane segments with good flexibility and good low-temperature resistance are well dispersed in the PC / ABS alloy through the maleic anhydride grafted polymer, thereby further improving the impact resistance and low-temperature resistance of the PC / ABS alloy.

[0032] For example, the weight ratio of the modified graphene can be 1 part, 3 parts, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 13 parts, 15 parts, etc., without any particular limitation. Further, the weight ratio of the modified graphene can be 3-15 parts.

[0033] In some embodiments, the method for preparing modified graphene includes:

[0034] Graphene oxide and double-terminated amino polysiloxane react to obtain polysiloxane-modified graphene;

[0035] The polysiloxane-modified graphene reacts with the maleic anhydride-grafted polymer to obtain the modified graphene.

[0036] Graphene oxide (GO) has abundant surface active groups such as hydroxyl, epoxy, and carboxyl groups, which react with primary amino groups. In this invention, after the biamino-terminated polysiloxane reacts with GO, the resulting polysiloxane-modified graphene also contains amino groups at the other end of the polysiloxane chain. These amino groups can further react with the maleic anhydride-grafted polymer, chemically bonding the graphene / polysiloxane / maleic anhydride-grafted polymer together for synergistic efficacy.

[0037] In some embodiments, the weight ratio of graphene oxide to biamino-terminated polysiloxane is 1:0.1-10. For example, the weight ratio can be any value in the range of 1:0.1, 1:0.3, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, etc., without particular limitation. If the weight of biamino-terminated polysiloxane is too low, the remaining primary amino groups after reaction with GO will be too low, which is not conducive to the subsequent reaction with maleic anhydride grafted polymer. Furthermore, from the perspective of improving reaction efficiency and saving raw materials, the weight ratio of graphene oxide to biamino-terminated polysiloxane can be 1:0.3-3. There is no particular limitation on graphene oxide, and for example, it can be Hummers method GO.

[0038] In some embodiments, the dual-terminated amino polysiloxane structure is shown in the following formula (1):

[0039] NH2R 1 SiMe2(OSiMeR 2 ) n OSiMe2R 1 NH2(1)

[0040] Among them, R 1 is selected from C2-C6 divalent alkyl or substituted C3-C10 divalent alkyl, R 2 Selected from C1-C12 alkyl, aromatic group and its derivatives, cycloalkyl group and its derivatives, Me represents methyl, n = 5-100. The average polymerization degree n of the double-terminal amino polysiloxane is within the above range, and the double-terminal amino polysiloxane has good reactivity and performance. Further, n = 10-70. For example, the double-terminal amino polysiloxane can be double-terminal aminopropyl polydimethylsiloxane (R in the above formula (1) 2 is methyl), double-terminated aminopropyl methylphenyl polysiloxane (R in the above formula (1) 2 is a combination of methyl and phenyl groups, such as phenyl groups with a content of 5-20 mol%), double-terminated aminopropylmethylpropyl polysiloxane (R in the above formula (1) 2There is no particular restriction on the source of the double-terminated aminopolysiloxane, which can be directly obtained from the market or prepared according to existing technologies, as known to those skilled in the art. For example, 1,3-diaminopropyl-1,1,3,3-tetramethyldisiloxane is used as the end-capping agent, and siloxane ring bodies (such as octamethylcyclotetrasiloxane D4, tetramethyltetraphenylcyclotetrasiloxane D4) are used. Ph The product is obtained by ring-opening polymerization of tetramethylammonium siloxane (commonly known as ammonium gel or alkali gel) at a certain temperature (e.g., 110-120°C) with tetramethylammonium siloxane (commonly known as ammonium gel or alkali gel) as a catalyst. The temperature is then raised to a higher temperature (e.g., 135-140°C) to decompose and destroy the catalyst, and low-boiling products are removed under reduced pressure. The average degree n can be determined or adjusted based on other conditions, such as the molar ratio of the end-capping agent to the siloxane ring.

[0041] There are some defects in the structure of graphene oxide, which can be reduced by reduction. In some embodiments, after the reaction of graphene oxide and double-terminated amino polysiloxane, reduction is also carried out, and the reducing agent used for reduction is selected from one or a combination of two or more of sodium borohydride, hydrogen, glucose, hydrazine hydrate, dimethylhydrazine and ascorbic acid and its salts. Whether it is polysiloxane-modified graphene or polysiloxane-modified graphene reacted with maleic anhydride grafted polymer, a reducing agent can be used for reduction. The reduction reaction of graphene oxide is known to those skilled in the art. For example, in an organic solvent (butyl acetate, etc.), an excess reducing agent (for example, the weight ratio of reducing agent to graphene oxide is 2-5:1) is used to react at a certain temperature (for example, 80-100°C) for several hours (for example, several hours to dozens of hours).

[0042] Maleic anhydride grafted polymer refers to a process in which maleic anhydride monomers are grafted onto a polymer by a free radical polymerization reaction or other methods. Maleic anhydride grafted onto a polymer generally acts as a compatibilizer and toughening agent. In some embodiments, the weight ratio of polysiloxane-modified graphene to maleic anhydride grafted polymer is 1:0.2-3. For example, the weight ratio can be 1:0.2, 1:0.3, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.7, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.5, 1:2.7, 1:2.8, 1:3, etc. In order to further improve the effect of the maleic anhydride grafted polymer, the weight ratio of polysiloxane-modified graphene to maleic anhydride grafted polymer can be 1:0.5-2. Maleic anhydride grafted to the polymer has good compatibility with polycarbonate, and the maleic anhydride group can also chemically react with the hydroxyl group, carboxyl group, etc. in polycarbonate, so that the modified graphene can also be chemically bonded with polycarbonate / ABS.

[0043] In some embodiments, the grafting rate of the maleic anhydride grafted polymer is 1-10wt%. The grafting rate of the maleic anhydride grafted polymer refers to the ratio of the weight of the maleic anhydride monomer successfully grafted onto the polymer backbone after the grafting reaction to the weight of the initial polymer. For example, the grafting rate can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, 10wt%, etc. Further, the grafting rate of the maleic anhydride grafted polymer can be 1-6wt%.

[0044] In some embodiments, the maleic anhydride grafted polymer is selected from one or a combination of two or more of maleic anhydride grafted ABS, maleic anhydride grafted EVA, maleic anhydride grafted SEBS, maleic anhydride grafted SAN and maleic anhydride grafted POE, and these maleic anhydride grafted polymers can be directly obtained from the market.

[0045] In some embodiments, the raw material components further include one or a combination of two or more of 0.5-5 parts of a phosphorus-based flame retardant, 0.1-1 parts of an antioxidant, 0.1-1 parts of an anti-ultraviolet agent, and 0-0.1 parts of an anti-dripping agent.

[0046] The present invention further discovered that the addition of a phosphorus-based flame retardant can further improve flame retardancy. There are no specific limitations on phosphorus-based flame retardants, and they can be directly obtained from the market. Examples include organic phosphorus-based flame retardants such as triethyl phosphate, resorcinol bis(diphenyl phosphate) RDP, DOPO, and its derivatives. There are no specific limitations on antioxidants, and examples include Antioxidant 1010 and Antioxidant 168. There are no specific limitations on UV inhibitors, and examples include UV327, UV328, and UV-P. Anti-drip agents include polytetrafluoroethylene powder, silicone resin powder, and silicone rubber powder.

[0047] In another aspect, the present invention provides a method for preparing the needle-flame-resistant flame-retardant PC / ABS alloy material described in any of the above embodiments, comprising uniformly mixing the raw material components, adding the components to a screw extruder for melt extrusion, and forming the components (e.g., cold cutting or pelletizing) to obtain the needle-flame-resistant flame-retardant PC / ABS alloy material. The needle-flame-resistant flame-retardant PC / ABS alloy material of the present invention can be prepared according to conventional processing methods for PC / ABS alloy materials, for example, the raw material components are pre-dried at 90-120°C to a moisture content of no more than 0.1wt% (e.g., 0.02wt%, 0.05wt%, etc.), the melt temperature can be 210-260°C, and the nozzle temperature can be 250°C.

[0048] The PC / ABS alloy material obtained by the present invention has good flame retardancy and impact resistance, and can be used in the fields of automotive parts, electronic products, medical equipment, aerospace, etc.

[0049] The technical solution of the present invention is further described and illustrated below based on various preparation examples and embodiments.

[0050] Preparation Example 1-3 Preparation of modified graphene

[0051] Preparation Example 1

[0052] 1 part of Hummers GO was added to 1000 parts of butyl acetate and ultrasonically dispersed for 30 minutes. 1 part of double-terminal aminopropyl polydimethylsiloxane (n=47.2 in the above formula (1)) was added and ultrasonicated for 10 minutes. The mixture was stirred at room temperature for 1 hour, heated to 55°C and reacted for 2 hours. The mixture was centrifuged at 8000 rpm for 30 minutes, and the solid was collected and dried in an oven at 50°C overnight to obtain polysiloxane-modified GO.

[0053] 1 part of the above-mentioned polysiloxane-modified GO and 0.5 part of maleic anhydride-grafted ABS (grafting rate 1.6 wt%) were dried at 110°C to a moisture content of no more than 0.1 wt%, mixed evenly, and then transferred to a twin-screw extruder for melt extrusion at 210°C-240°C, cooled, and pelletized to obtain modified graphene particles.

[0054] Preparation Example 2

[0055] 1 part of Hummers GO was added to 1000 parts of butyl acetate and ultrasonically dispersed for 30 minutes. 0.5 parts of double-terminal aminopropyl polydimethylsiloxane (n=30.5 in the above formula (1)) was added and ultrasonicated for 10 minutes. The mixture was stirred at room temperature for 1 hour, heated to 55°C and reacted for 2 hours. 5 parts of reducing agent sodium borohydride were added, the mixture was heated to 90°C and reacted for 12 hours. The mixture was cooled to no more than 50°C and centrifuged at 8000 rpm for 30 minutes. The solid was collected and dried in an oven at 50°C overnight to obtain polysiloxane-modified GO.

[0056] One part of the above-mentioned polysiloxane-modified GO and one part of maleic anhydride-grafted ABS (grafting rate 1.2 wt%) were dried at 110°C to a moisture content of no more than 0.1 wt%, mixed evenly, and then transferred to a twin-screw extruder for melt extrusion at 210°C-240°C, cooled, and pelletized to obtain modified graphene particles.

[0057] Preparation Example 3

[0058] 1 part of Hummers GO was added to 1000 parts of butyl acetate and ultrasonically dispersed for 30 minutes. 2 parts of double-terminal aminopropyl polydimethylsiloxane (n=65.8 in the above formula (1)) were added and ultrasonicated for 10 minutes. The mixture was stirred at room temperature for 1 hour, heated to 60°C and reacted for 2.5 hours. The mixture was centrifuged at 8000 rpm for 30 minutes, and the solid was collected and dried in an oven at 50°C overnight to obtain polysiloxane-modified GO.

[0059] One part of the above-mentioned polysiloxane-modified GO and two parts of maleic anhydride-grafted ABS (grafting rate 1.6 wt%) were dried at 110°C to a moisture content of no more than 0.1 wt%, transferred to a twin-screw extruder, melt-extruded at 210°C-240°C, cooled, and pelletized to obtain modified graphene particles.

[0060] Example 1

[0061] The raw material components of the PC / ABS alloy material of this embodiment consist of 1800 parts of PC resin, 200 parts of ABS resin and 20 parts of modified graphene obtained in Preparation Example 1.

[0062] PC resin was dried at 110°C to a water content of less than 0.1 wt%. ABS resin and modified graphene were dried at 90°C to a water content of less than 0.1 wt%. After drying, the raw materials were mixed and fed into a twin-screw extruder at a melt temperature of 210-260°C and an ejection nozzle temperature of 250°C to obtain a PC / ABS alloy material.

[0063] Example 2

[0064] The difference between this embodiment and embodiment 1 is that in embodiment 1, the modified graphene is adjusted from 20 parts to 70 parts, and the remaining steps remain unchanged.

[0065] Example 3

[0066] The difference between this embodiment and embodiment 1 is that in embodiment 1, the modified graphene is adjusted from 20 parts to 200 parts, and the remaining steps remain unchanged.

[0067] Example 4

[0068] The difference between this embodiment and embodiment 3 is that in embodiment 3, the raw material components further include 40 parts of flame retardant DOPO. The remaining steps remain unchanged.

[0069] Example 5

[0070] The difference between this embodiment and embodiment 1 is that in embodiment 1, the modified graphene is adjusted from 20 parts to 300 parts, and the remaining steps remain unchanged.

[0071] Comparative Example 1

[0072] The difference between this comparative example and Example 2 is that in Example 2, the modified graphene is replaced by 70 parts of the flame retardant DOPO. The remaining steps remain unchanged.

[0073] Comparative Example 2

[0074] The difference between this comparative example and Example 3 is that in Example 3, the modified graphene is replaced by 200 parts of the flame retardant DOPO. The remaining steps remain unchanged.

[0075] Comparative Example 3

[0076] The difference between this comparative example and Example 5 is that in Example 5, the modified graphene is replaced by 300 parts of the flame retardant DOPO. The remaining steps remain unchanged.

[0077] Flame retardant performance test

[0078] Needle flame retardant test: The test is conducted in accordance with the method of GB / T 5169.5-2020. The thickness of the color plate made of PC / ABS alloy material is 1mm. The combustion condition of the color plate is observed after burning for 60 seconds to check whether the color plate has perforations or cracks, and whether the gauze is ignited.

[0079] UL-94 flame retardant rating test: The test is conducted in accordance with the UL-94 combustion test standard, the sample thickness is 1.2mm, and the flame is applied to the test sample for 60 seconds each time.

[0080] Limiting Oxygen Index LOI: Tested according to the method of GB / T 2406.2-2009.

[0081] The results are shown in Table 1 below.

[0082] Table 1 Flame retardant performance test results

[0083]

[0084] The data in Table 1 demonstrate that the modified graphene of the present invention exhibits a significant flame retardant effect on PC / ABS alloys. At dosages between 1% and 15%, increasing the amount of modified graphene improves the flame retardancy of the PC / ABS alloy, meeting both needle-flame retardancy and UV-94 flame retardancy requirements. A comparison of Examples 4 and 5 with Comparative Example 3 demonstrates that the combination of modified graphene and DOPO significantly improves the material's limiting oxygen index and flame retardancy.

[0085] Example 6

[0086] The raw material components of the PC / ABS alloy material of this embodiment are composed of 1900 parts of PC resin, 100 parts of ABS resin, 40 parts of ABS-g-MAH, 160 parts of modified graphene obtained in Preparation Example 2, 20 parts of flame retardant DOPO, 10 parts of antioxidant 168, 8 parts of anti-ultraviolet agent UV327 and 1 part of anti-dripping agent polytetrafluoroethylene powder.

[0087] The PC / ABS alloy material of this embodiment was prepared according to the preparation method of Example 1, wherein ABS-g-MAH was dried at 90° C. until the water content was less than 0.1 wt %.

[0088] Example 7

[0089] The difference between this embodiment and embodiment 6 is that in embodiment 6, the modified graphene obtained in preparation example 2 is replaced by an equal weight of the modified graphene obtained in preparation example 3. The remaining steps remain unchanged.

[0090] Example 8

[0091] The difference between this embodiment and embodiment 6 is that in embodiment 6, the flame retardant DOPO is replaced by an equal weight of the flame retardant RDP. The remaining steps remain unchanged.

[0092] Example 9

[0093] The difference between this embodiment and embodiment 6 is that the flame retardant DOPO is not added in embodiment 6. The other steps remain unchanged.

[0094] Comparative Example 4

[0095] The difference between this comparative example and Example 6 is that in Example 6, the modified graphene is replaced by an equal weight of Hummers-processed GO surface-treated with trimethylsilane. The remaining steps remain unchanged.

[0096] Comparative Example 5

[0097] This comparative example differs from Example 6 in that the modified graphene in Example 6 was replaced with an equal weight of the polysiloxane-modified GO from Preparation Example 2. The remaining steps remained unchanged. The resulting PC / ABS alloy material exhibited significant incompatibility, primarily due to the incompatibility of the polysiloxane segments with the PC / ABS alloy.

[0098] Blank example

[0099] In Example 6, the modified graphene obtained in Preparation Example 2 was not added.

[0100] Performance test results

[0101] Needle flame retardant performance: Test according to the above needle flame retardant performance test method.

[0102] Impact strength: tested at 23°C according to the method of GB / T21189-2007.

[0103] Low temperature resistance: Test the impact strength at -30°C according to the above impact strength test method.

[0104] The results are shown in Table 2 below.

[0105] Table 2 Performance test results

[0106]

[0107] From the data in Table 2 above, it can be seen that the modified graphene of the present invention has both flame retardant and toughening effects on PC / ABS alloy, can improve the flame retardant properties and impact resistance of PC / ABS alloy materials, and also has a significant effect on improving the low temperature resistance of PC / ABS alloy materials.

[0108] As described above, the basic principles, main features, and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. In other words, equivalent changes and modifications made within the scope of the present invention and the contents of the specification should still fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A needle flame retardant PC / ABS alloy material, characterized in that: The raw material components, calculated by weight, include 100 parts of PC / ABS alloy and 1-15 parts of modified graphene; The modified graphene is a graphene chemically grafted polysiloxane-modified maleic anhydride grafted polymer; Preferably, the polysiloxane-modified maleic anhydride grafted polymer is chemically grafted to the graphene via polysiloxane segments.

2. The needle flame retardant PC / ABS alloy material according to claim 1, characterized in that: The preparation method of the modified graphene comprises: Graphene oxide and double-terminated amino polysiloxane react to obtain polysiloxane-modified graphene; The polysiloxane-modified graphene reacts with the maleic anhydride-grafted polymer to obtain the modified graphene.

3. The needle flame retardant PC / ABS alloy material according to claim 2, characterized in that: The weight ratio of the graphene oxide to the double-terminated amino polysiloxane is 1:0.1-10.

4. The needle flame retardant PC / ABS alloy material according to claim 2 or 3, characterized in that: The structure of the double-terminated amino polysiloxane is shown in the following formula (1): NH2R 1 SiMe2(OSiMeR 2 ) n OSiMe2R 1 NH2(1) Among them, R 1 is selected from C2-C6 divalent alkyl or substituted C3-C10 divalent alkyl, R 2 Selected from C1-C12 alkyl, aromatic group and its derivatives, cycloalkyl group and its derivatives, Me represents methyl, n=5-100.

5. The needle flame retardant PC / ABS alloy material according to claim 2, characterized in that: After the reaction of the graphene oxide and the double-terminated amino polysiloxane, reduction is further performed, and the reducing agent used for the reduction is selected from one or a combination of two or more of sodium borohydride, hydrogen, glucose, hydrazine hydrate, dimethylhydrazine, ascorbic acid and its salts.

6. The needle flame retardant PC / ABS alloy material according to claim 2, characterized in that: The weight ratio of the polysiloxane-modified graphene to the maleic anhydride grafted polymer is 1:0.2-3.

7. The needle flame retardant PC / ABS alloy material according to claim 2, characterized in that: The grafting rate of the maleic anhydride grafted polymer is 1-10 wt %.

8. The needle flame retardant PC / ABS alloy material according to claim 2, characterized in that: The maleic anhydride grafted polymer is selected from one or a combination of two or more of maleic anhydride grafted ABS, maleic anhydride grafted EVA, maleic anhydride grafted SEBS, maleic anhydride grafted SAN and maleic anhydride grafted POE.

9. The needle flame retardant PC / ABS alloy material according to claim 1, characterized in that: The raw material components further include one or a combination of two or more of 0.5-5 parts of a phosphorus-based flame retardant, 0.1-1 parts of an antioxidant, 0.1-1 parts of an anti-ultraviolet agent, and 0-0.1 parts of an anti-dripping agent.

10. A method for preparing the needle flame retardant PC / ABS alloy material according to any one of claims 1 to 9, characterized in that: The raw material components are mixed evenly, added into a screw extruder for melt extrusion and molding to obtain the needle flame retardant PC / ABS alloy material.

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