A needle flame-resistant fluorine-free flame-retardant PC composite material, a preparation method and application thereof

Abstract

The application belongs to the technical field of functional polymer materials, and particularly relates to a needle flame resistant fluorine-free flame-retardant PC composite material and a preparation method and application thereof. The PC composite material comprises the following components: 2-6% of a phosphorus flame retardant, 0.5-3% of a phosphate modified methylphenyl silicone resin, 0.5-1.5% of a silane coupling agent surface modified whisker silicon, 3-6% of an acrylate coated modified butadiene styrene rubber core-shell particle toughening agent, and 83.5-94% of a PC base material. The application adopts a specific fluorine-free phosphorus-silicon synergistic flame-retardant system, a whisker silicon-phenyl silicone resin composite anti-dripping reinforcing system and an acrylate coated modified butadiene styrene rubber core-shell particle toughening system, and can simultaneously achieve high strength (tensile strength ≥ 55 MPa), high toughness (impact strength ≥ 60 KJ / m 2 ), needle flame resistance (needle flame test > 60 seconds) and high flame resistance (V0 level) characteristics. The application can be used in the fields of new energy vehicles, energy storage devices and 5G communication.

Description

Technical Field

[0001] This invention belongs to the field of functional polymer materials technology, specifically relating to a needle flame resistant, fluorine-free flame-retardant PC composite material, its preparation method, and its application. Background Technology

[0002] The global polycarbonate (PC) composite materials market continues to grow, primarily used in electronics, automotive, and aerospace industries. With the rapid increase in the penetration rate of new energy vehicles (estimated to reach 30% by 2025), the surge in new energy storage installations (CAGR exceeding 60%), and the accelerated construction of 5G base stations, the market demand for high-performance flame-retardant materials is experiencing explosive growth. Taking new energy vehicles as an example, their high-voltage electrical systems, battery pack shells, and other components must meet UL94 V0@1.5mm flame retardancy, needle flame resistance >60 seconds, and high impact resistance requirements. The amount used per vehicle can reach 10-15kg, and the global demand for flame-retardant PC for automobiles is expected to exceed 500,000 tons by 2025. The green transformation of the materials industry has become an irreversible trend. Strict restrictions on fluorinated compounds under EU RoHS and REACH regulations, as well as the high performance requirements for materials in emerging fields such as new energy vehicles, energy storage equipment, and 5G communications, pose serious challenges to traditional fluorinated flame-retardant polycarbonate (PC) materials.

[0003] Traditional fluorinated flame-retardant PCs rely on fluorinated anti-dripping agents such as polytetrafluoroethylene (PTFE) to achieve a UL94 V0 flame retardant rating. However, the fluorides released during combustion pose a persistent pollution risk, and their needle flame resistance is generally insufficient (typically <30 seconds), making it difficult to meet the comprehensive requirements of high-voltage electrical components, battery pack casings, and other applications for materials with burn-through resistance (>60 seconds), high mechanical strength, and environmental friendliness. Furthermore, traditional anti-dripping agents (such as PTFE) rely on fibrous network structures to suppress dripping, but their fluorinated nature contradicts environmental trends, and the rigid network degrades material toughness. While existing fluorine-free anti-dripping agents (such as methylphenyl silicone resin) are environmentally friendly, their uneven dispersion when used alone can lead to insufficient anti-dripping efficiency (needle flame test <30 seconds). At the same time, existing fluorine-free flame-retardant PC materials have not yet overcome technical bottlenecks, and generally suffer from problems such as low flame retardant efficiency, poor anti-dripping properties, contradiction between toughening and flame retardant performance, and insufficient substrate compatibility. As a result, it is difficult to achieve both mechanical properties (such as notched impact strength and tensile strength) and thermal stability, which seriously restricts their application in the high-end market.

[0004] From a technological trend perspective, fluorine-free flame-retardant PC has become a focus of industry research and development due to its environmentally friendly properties; however, existing products generally have performance shortcomings. For example, phosphorus-based flame-retardant PCs lack sufficient heat resistance and anti-dripping properties, while silicon-based flame-retardant PCs have low mechanical strength, and the introduction of toughening modifications often leads to a decrease in flame-retardant ratings. Furthermore, the lack of needle flame resistance further limits its application in harsh environments. Domestic enterprises urgently need to achieve import substitution through technological innovation.

[0005] Chinese Patent No. CN 118931150 B discloses a fluorine-free flame-retardant PC material and its preparation method, comprising the following raw materials by weight percentage: 10-15% silicone PC, 0.1-1% anti-aging agent, 2-6% fluorine-free flame retardant, and the balance being PC; the fluorine-free flame retardant is composed of at least three of the following: polydiphenyloxyphosphazene, tetraphenylbisphenol A diphosphate, polydimethylsiloxane, and methacrylate-based phenyl polymer complex. When polydiphenyloxyphosphazene, tetraphenylbisphenol A diphosphate, polydimethylsiloxane, and methacrylate-based phenyl polymer complex are compounded, they have a synergistic effect, and together with silicone PC, the resulting PC material possesses excellent flame retardant properties, light transmittance, anti-aging properties, and physical properties. However, the composition of this fluorine-free flame-retardant PC material is relatively complex, resulting in higher costs. Summary of the Invention

[0006] In view of the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a fluorine-free flame-retardant PC composite material resistant to needle flame.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned needle flame resistant fluorine-free flame-retardant PC composite material.

[0008] Another objective of this invention is to provide the application of the above-mentioned needle flame resistant fluorine-free flame-retardant PC composite material in the fields of new energy vehicles, energy storage equipment, and 5G communication.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A needle-flame resistant, fluorine-free flame-retardant PC composite material, comprising the following components by weight percentage:

[0011] 2-6% phosphorus-based flame retardant;

[0012] Phosphate ester modified methylphenyl silicone resin 0.5-3%;

[0013] 0.5-1.5% of silane coupling agent is used to surface-modify whisker silicon.

[0014] Acrylic ester-coated modified styrene-butadiene rubber core-shell particle toughening agent 3-6%;

[0015] PC substrate content: 83.5-94%;

[0016] The phosphate-modified methylphenyl silicone resin is prepared by the following method:

[0017] Methylphenyl hydrogen-containing silicone oil and hydroxyethyl methacrylate phosphate were added to toluene solvent and mixed and dissolved. Then, a hydrosilylation catalyst was added and heated to catalyze the reaction. After the reaction was completed, the solvent was removed to obtain phosphate-modified methylphenyl silicone resin.

[0018] Furthermore, the phosphorus-based flame retardant is bisphenol A-bis(diphenyl phosphate) (BDP). The present invention preferably uses BDP flame retardant, whose phenoxy side chain can enhance the π-π interaction with PC materials, resulting in better compatibility with PC materials.

[0019] Furthermore, the weight ratio of the phosphorus-based flame retardant to the phosphate-modified methylphenyl silicone resin is 2-4:1.

[0020] This invention uses phosphate-modified methylphenyl silicone resin as a silicon-based synergistic flame retardant. The introduction of phosphate groups can enhance its flame retardancy and anti-dripping properties. On the other hand, the fluorine-free phosphorus-silicon synergistic flame retardant system of the above-mentioned phosphorus-based flame retardant and phosphate-modified methylphenyl silicone resin has better compatibility and can form a dense silicon-phosphorus composite carbon layer, thereby achieving a good synergistic flame retardant effect and achieving a higher flame retardant level with a smaller amount of additive.

[0021] Furthermore, the silane coupling agent surface-modified whisker silicon refers to whisker silicon surface-modified using the silane coupling agent KH-550 (γ-aminopropyltriethoxysilane).

[0022] This invention utilizes the preferred silane coupling agent KH-550 to modify the surface of whisker silicon. The introduced alkyl and amino groups enhance the compatibility and hydrogen bonding with the PC substrate, thereby improving the interfacial compatibility between whisker silicon and PC materials and enhancing the reinforcing effect.

[0023] Furthermore, in the preparation of the phosphate-modified methylphenyl silicone resin, the methylphenyl hydrogen-containing silicone oil used is a commercially available raw material commonly used in the art. This application preferably uses a weight-average molecular weight M... w A methylphenyl hydrogen-containing silicone oil with a molecular weight of 5000-20000, a phenyl content of 10-40 wt%, and a hydrogen content of 0.1-0.3 wt%. Its weight-average molecular weight M... w The phenyl content and hydrogen content can be controlled by the content of the end-capping agent, the content of phenyl comonomer, and the content of hydrogen-containing monomers during the polymerization process.

[0024] Furthermore, in the preparation of the phosphate-modified methylphenyl silicone resin, the amount of hydroxyethyl methacrylate phosphate added is 3-20% of the mass of the methylphenyl hydrogen-containing silicone oil.

[0025] The hydroxyethyl methacrylate phosphate ester is a commonly used commercial raw material in this field. Its structural formula is as follows:

[0026]

[0027] This invention employs a composite anti-dripping enhancement technology combining phosphate-modified methylphenyl silicone resin with silane coupling agent-modified surface-modified whisker silicon. On one hand, the introduction of phosphate groups enhances the flame-retardant and anti-dripping properties of the silicone resin. On the other hand, the phosphate-modified methylphenyl silicone resin forms a dynamic hydrogen-bonded crosslinking network and a covalent crosslinking network (phosphate groups react with amino groups for crosslinking) with the silane coupling agent-modified surface-modified whisker silicon, synergistically enhancing the resin. Simultaneously, a "brick-and-mortar" reinforced structure flame-retardant and anti-dripping composite char layer is constructed, achieving a needle flame test duration >60 seconds with a tensile strength ≥55 MPa and an impact strength ≥60 KJ / m. 2 .

[0028] Furthermore, in the preparation of the phosphate-modified methylphenyl silicone resin, the hydrosilylation catalyst is a chloroplatinic acid solution; the temperature of the heating catalytic reaction is 70-90℃, and the time is 2-8h.

[0029] Further, the acrylate-coated modified styrene-butadiene rubber core-shell particle toughening agent is MBS core-shell particles or diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles. More preferably, it is diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles.

[0030] The diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particles are prepared by the following method:

[0031] Methyl methacrylate, styrene, 2-hydroxyethyl methacrylate diphenyl phosphate and an initiator were added to styrene-butadiene rubber latex, and the polymerization reaction was initiated by heating. The mixture was then spray-dried to obtain styrene-butadiene rubber core-shell particles modified with diphenyl phosphate-grafted acrylate.

[0032] Furthermore, in the preparation of the diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles, the weight ratio of methyl methacrylate, styrene, and 2-hydroxyethyl methacrylate diphenyl phosphate is 60-80:18-30:2-10.

[0033] Furthermore, in the preparation of the diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles, the total amount of methyl methacrylate, styrene, and 2-hydroxyethyl methacrylate diphenyl phosphate added is 50-100% of the solid content in the styrene-butadiene rubber latex.

[0034] Furthermore, in the preparation of the diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles, the initiator is potassium persulfate or ammonium persulfate; and the heating temperature is 60–80°C.

[0035] The introduction of flame retardants (such as BDP) and reinforcing agents (such as whisker silicon) reduces the toughness of PC materials. While MBS core-shell particles can improve impact strength, their elastomeric phase easily becomes a weak point in combustion, leading to a decrease in flame retardant performance. Flame retardancy and toughening present a trade-off, making it difficult to simultaneously satisfy high toughness (notched impact ≥60KJ / m). 2 This invention addresses the requirements for V0 flame retardancy by preferentially using diphenyl phosphate grafted with acrylate to coat modified styrene-butadiene rubber core-shell particles. The grafted diphenyl phosphate not only provides synergistic flame retardancy but also improves interfacial compatibility with phosphorus-based flame retardants (such as BDP), thus solving the problems of interfacial incompatibility between ACR (acrylate rubber) and flame retardants, and the combustion initiated by the toughening phase.

[0036] The preparation method of the above-mentioned needle flame resistant fluorine-free flame-retardant PC composite material includes the following steps:

[0037] Phosphorus-based flame retardant, phosphate-modified methylphenyl silicone resin, silane coupling agent surface-modified whisker silicon, acrylate-coated styrene-butadiene rubber core-shell particle toughening agent and PC resin are mixed evenly and then fed into a twin-screw extruder for melt mixing and extrusion to obtain needle flame resistant fluorine-free flame retardant PC composite material.

[0038] The above-mentioned needle flame resistant fluorine-free flame retardant PC composite materials are used in new energy vehicles, energy storage equipment, 5G communication and other fields.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] (1) A specific fluorine-free phosphorus-silicon synergistic flame retardant system is adopted, which has the advantages of being fluorine-free and environmentally friendly, having high flame retardant efficiency and being resistant to burn-through. It also has good compatibility with PC substrate and has little impact on the mechanical properties of composite materials.

[0041] (2) A specific whisker-silicon-phenylsilicon resin composite anti-drip reinforcement system is adopted to synergistically enhance anti-drip properties while reducing the degradation of material toughness, achieving a needle flame test time >60 seconds and tensile strength ≥55MPa, and impact strength ≥60KJ / m. 2 .

[0042] (3) A specific acrylate-coated modified styrene-butadiene rubber core-shell particle toughening system is adopted to achieve a balance between toughening and flame retardant properties, resolving the contradiction of "one gaining at the expense of the other" between flame retardancy and toughening, while simultaneously meeting the requirements of high toughness (notched impact ≥60KJ / m). 2 (and V0 flame retardant requirements) Detailed Implementation

[0043] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0044] Example 1

[0045] A needle-flame resistant, fluorine-free flame-retardant PC composite material, comprising the following components by weight percentage:

[0046] Phosphorus-based flame retardant BDP 4%;

[0047] 1.5% of phosphate-modified methylphenyl silicone resin;

[0048] 1% surface-modified whisker silicon using aminosilane coupling agent KH-550;

[0049] Diphenyl phosphate grafted with acrylate-coated modified styrene-butadiene rubber core-shell particle toughening agent 4.5%;

[0050] PC resin 89%.

[0051] The phosphate-modified methylphenyl silicone resin is prepared by the following method:

[0052] 100 parts by weight of methylphenyl hydrogen silicone oil (weight average molecular weight M) w 12 parts by weight of hydroxyethyl methacrylate phosphate (10000, phenyl content 28wt%, hydrogen content 0.2wt%) and hydroxyethyl methacrylate phosphate were added to toluene solvent and mixed and dissolved. Then, chloroplatinic acid solution catalyst (0.01 parts based on chloroplatinic acid content) was added and heated to 80℃ for 5 hours to catalyze the reaction. After the reaction was completed, the solvent was removed under reduced pressure to obtain phosphate-modified methylphenyl silicone resin.

[0053] The diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particles are prepared by the following method:

[0054] Methyl methacrylate, styrene, diphenyl methacrylate-2-hydroxyethyl phosphate, and ammonium persulfate initiator were added to styrene-butadiene rubber latex in a weight ratio of 70:24:6:0.5 and mixed evenly. The total amount of methyl methacrylate, styrene, and diphenyl methacrylate-2-hydroxyethyl phosphate added was 75% of the solid content of the styrene-butadiene rubber latex. The mixture was heated to 70°C to initiate the polymerization reaction for 5 hours. After the reaction was completed, the mixture was spray-dried to obtain styrene-butadiene rubber core-shell particles modified with diphenyl phosphate-grafted acrylate.

[0055] The preparation method of the needle flame resistant fluorine-free flame-retardant PC composite material is as follows:

[0056] The phosphorus-based flame retardant BDP, phosphate-modified methylphenyl silicone resin, aminosilane coupling agent KH-550 surface-modified whisker silicon, diphenyl phosphate grafted acrylate-coated styrene-butadiene rubber core-shell particle toughening agent, and PC resin are mixed evenly according to the above weight percentage ratio. Then, the mixture is fed into a twin-screw extruder for melt compounding and extrusion. The screw speed is 300 rpm, and the extruder temperature is controlled at 250-280℃ to obtain a needle flame resistant fluorine-free flame-retardant PC composite material.

[0057] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this embodiment was tested and found to have a tensile strength of 72 MPa, a tensile elongation at break of 115%, and a notched impact strength of 83.6 KJ / m. 2 Needle flame test (IEC60695-11-5): >60S; Heat distortion temperature: 154℃; Flame retardant rating: V0@1.5mm, 5VA@3.0mm.

[0058] Example 2

[0059] A needle-flame resistant, fluorine-free flame-retardant PC composite material, comprising the following components by weight percentage:

[0060] Phosphorus-based flame retardant BDP 5%;

[0061] 1.5% of phosphate-modified methylphenyl silicone resin;

[0062] Surface-modified 0.5% whisker silicon with aminosilane coupling agent KH-550;

[0063] 3% diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particle toughening agent;

[0064] 90% PC resin.

[0065] The phosphate-modified methylphenyl silicone resin is prepared by the following method:

[0066] 100 parts by weight of methylphenyl hydrogen silicone oil (weight average molecular weight M) w The hydroxyethyl methacrylate phosphate (10000, phenyl content 28wt%, hydrogen content 0.2wt%) and 3 parts by weight were added to toluene solvent and mixed and dissolved. Then, chloroplatinic acid solution catalyst (0.01 parts based on chloroplatinic acid content) was added and heated to 80℃ for 4 hours to catalyze the reaction. After the reaction was completed, the solvent was removed under reduced pressure to obtain phosphate-modified methylphenyl silicone resin.

[0067] The diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particles are prepared by the following method:

[0068] Methyl methacrylate, styrene, diphenyl methacrylate-2-hydroxyethyl phosphate, and ammonium persulfate initiator were added to styrene-butadiene rubber latex in a weight ratio of 75:20:5:0.5 and mixed evenly. The total amount of methyl methacrylate, styrene, and diphenyl methacrylate-2-hydroxyethyl phosphate added was 50% of the solid content of the styrene-butadiene rubber latex. The mixture was heated to 70°C to initiate the polymerization reaction for 5 hours. After the reaction was completed, the mixture was spray-dried to obtain styrene-butadiene rubber core-shell particles modified with diphenyl phosphate-grafted acrylate.

[0069] The preparation method of the needle flame resistant fluorine-free flame-retardant PC composite material is the same as that in Example 1.

[0070] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this embodiment was tested and found to have a tensile strength of 58 MPa, a tensile elongation at break of 102%, and a notched impact strength of 65.9 KJ / m. 2 Needle flame test (IEC60695-11-5): >60S; Heat distortion temperature: 141℃; Flame retardant rating: V0@1.5mm, 5VA@3.0mm.

[0071] Example 3

[0072] A needle-flame resistant, fluorine-free flame-retardant PC composite material, comprising the following components by weight percentage:

[0073] Phosphorus-based flame retardant BDP 3%;

[0074] 1% phosphate-modified methylphenyl silicone resin;

[0075] 1% surface-modified whisker silicon using aminosilane coupling agent KH-550;

[0076] 5% diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particle toughening agent;

[0077] 90% PC resin.

[0078] The phosphate-modified methylphenyl silicone resin is prepared by the following method:

[0079] 100 parts by weight of methylphenyl hydrogen silicone oil (weight average molecular weight M) w The hydroxyethyl methacrylate phosphate (10000, phenyl content 28wt%, hydrogen content 0.2wt%) and 8 parts by weight were added to toluene solvent and mixed and dissolved. Then, chloroplatinic acid solution catalyst (0.01 parts based on chloroplatinic acid content) was added and heated to 80℃ for 4 hours to catalyze the reaction. After the reaction was completed, the solvent was removed under reduced pressure to obtain phosphate-modified methylphenyl silicone resin.

[0080] The diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particles are prepared by the following method:

[0081] Methyl methacrylate, styrene, diphenyl methacrylate-2-hydroxyethyl phosphate, and ammonium persulfate initiator were added to styrene-butadiene rubber latex in a weight ratio of 80:18:2:0.5 and mixed evenly. The total amount of methyl methacrylate, styrene, and diphenyl methacrylate-2-hydroxyethyl phosphate added was 100% of the solid content of the styrene-butadiene rubber latex. The mixture was heated to 70°C to initiate the polymerization reaction for 5 hours. After the reaction was completed, the mixture was spray-dried to obtain diphenyl phosphate-grafted acrylate-coated modified styrene-butadiene rubber core-shell particles.

[0082] The preparation method of the needle flame resistant fluorine-free flame-retardant PC composite material is the same as that in Example 1.

[0083] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this embodiment was tested and found to have a tensile strength of 66 MPa, a tensile elongation at break of 110%, and a notched impact strength of 74.6 KJ / m. 2 Needle flame test (IEC60695-11-5): >60S; Heat distortion temperature: 152℃; Flame retardant rating: V0@1.5mm, 5VA@3.0mm.

[0084] Example 4

[0085] A needle-flame resistant, fluorine-free flame-retardant PC composite material, comprising the following components by weight percentage:

[0086] Phosphorus-based flame retardant BDP 6%;

[0087] 3% phosphate-modified methylphenyl silicone resin;

[0088] 1.5% of aminosilane coupling agent KH-550 was used to surface-modify whisker silicon.

[0089] Diphenyl phosphate grafted with acrylate as a toughening agent for styrene-butadiene rubber core-shell particles, 6%;

[0090] PC resin 83.5%.

[0091] The phosphate-modified methylphenyl silicone resin is prepared by the following method:

[0092] 100 parts by weight of methylphenyl hydrogen silicone oil (weight average molecular weight M) w The hydroxyethyl methacrylate phosphate (10000, phenyl content 28wt%, hydrogen content 0.2wt%) and 20 parts by weight of hydroxyethyl methacrylate phosphate were added to toluene solvent and mixed and dissolved. Then, chloroplatinic acid solution catalyst (0.01 parts based on chloroplatinic acid content) was added and heated to 80℃ for 6 hours to catalyze the reaction. After the reaction was completed, the solvent was removed under reduced pressure to obtain phosphate-modified methylphenyl silicone resin.

[0093] The diphenyl phosphate-grafted acrylate-coated styrene-butadiene rubber core-shell particles are prepared by the following method:

[0094] Methyl methacrylate, styrene, diphenyl methacrylate-2-hydroxyethyl phosphate, and ammonium persulfate initiator were added to styrene-butadiene rubber latex in a weight ratio of 60:30:10:0.5 and mixed evenly. The total amount of methyl methacrylate, styrene, and diphenyl methacrylate-2-hydroxyethyl phosphate added was 100% of the solid content of the styrene-butadiene rubber latex. The mixture was heated to 70°C to initiate a polymerization reaction for 5 hours. After the reaction was completed, the mixture was spray-dried to obtain styrene-butadiene rubber core-shell particles modified with diphenyl phosphate-grafted acrylate.

[0095] The preparation method of the needle flame resistant fluorine-free flame-retardant PC composite material is the same as that in Example 1.

[0096] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this embodiment was tested and found to have a tensile strength of 80 MPa, a tensile elongation at break of 116%, and a notched impact strength of 86.7 KJ / m. 2 Needle flame test (IEC60695-11-5): >60S; Heat distortion temperature: 160℃; Flame retardant rating: V0@1.5mm, 5VA@3.0mm.

[0097] Example 5

[0098] A needle flame resistant, fluorine-free flame-retardant PC composite material, compared with Example 1, uses an equal amount of MBS core-shell particles (methyl methacrylate and styrene copolymer coated modified styrene-butadiene rubber core-shell particles) instead of diphenyl phosphate grafted acrylate coated modified styrene-butadiene rubber core-shell particles as toughening agent, while the rest are the same.

[0099] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this embodiment was tested and found to have a tensile strength of 69 MPa, a tensile elongation at break of 108%, and a notched impact strength of 75.3 KJ / m. 2 Needle flame test (IEC60695-11-5): <60S; Heat distortion temperature: 149℃; Flame retardant rating: V1@1.5mm.

[0100] The comparison results with Example 1 show that the toughening agent of styrene-butadiene rubber core-shell particles modified by diphenyl phosphate grafting acrylate can significantly improve the toughening and flame retardant effects compared with MBS core-shell particles.

[0101] Comparative Example 1

[0102] A needle-flame resistant, fluorine-free flame-retardant PC composite material, compared with Example 1, uses an equal amount of methylphenyl silicone resin (weight-average molecular weight M). w (10000, phenyl content 28wt%) replaces phosphate ester modified methylphenyl silicone resin, the rest are the same.

[0103] The needle-flame resistant, fluorine-free flame-retardant PC composite material obtained in this comparative example was tested and found to have a tensile strength of 53 MPa, a tensile elongation at break of 86%, and a notched impact strength of 52.4 KJ / m. 2 Needle flame test (IEC60695-11-5): <60S; Heat distortion temperature: 126℃; Flame retardant rating: V1@1.5mm.

[0104] The comparison results with Example 1 show that the phosphate ester modified methylphenyl silicone resin of the present invention can achieve significantly improved synergistic reinforcement, toughening and flame retardant and needle flame resistance effects compared with conventional methylphenyl silicone resin flame retardant and anti-dripping agent.

[0105] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A needle flame resistant, fluorine-free flame retardant PC composite material, characterized in that: Comprise the following components by weight percentage: Phosphorus flame retardant 2-6%; Phosphate modified methyl phenyl silicone resin 0.5-3%; Silane coupling agent surface modified whisker silicon 0.5-1.5%; Acrylate coated modified butadiene-styrene rubber core-shell particle toughening agent 3-6%; PC base material 83.5-94%; The phosphate modified methyl phenyl silicone resin is prepared by the following method: Methyl phenyl hydrogen-containing silicone oil and hydroxyethyl methacrylate phosphate are mixed and dissolved in toluene solvent, then a silicon hydride addition catalyst is added and heated for catalytic reaction, after the reaction is completed, the solvent is removed, and the phosphate modified methyl phenyl silicone resin is obtained; The phosphorus flame retardant is bisphenol A-bis(diphenyl phosphate); the silane coupling agent surface modified whisker silicon is silane coupling agent KH-550 surface modified whisker silicon. 2.The needle flame resistant fluorine-free flame-retardant PC composite material according to claim 1, characterized in that: The weight ratio of the phosphorus flame retardant to the phosphate modified methyl phenyl silicone resin is 2-4:

1. 3.The needle flame resistant fluorine-free flame-retardant PC composite material according to claim 1, characterized in that: The methylphenyl hydrogen-containing silicone oil has a weight average molecular weight M w 5000-20000, the phenyl content is 10-40wt%, the hydrogen content is 0.1-0.3wt%; the added amount of the hydroxyethyl methacrylate phosphate is 3-20% of the mass of the methylphenyl hydrogen-containing silicone oil. 4.The needle flame resistant fluorine-free flame-retardant PC composite material according to claim 1, characterized in that: The silicon hydride addition catalyst uses chloroplatinic acid solution; the temperature of the heating catalytic reaction is 70-90℃, and the time is 2-8h.

5. The needle flame resistant, fluorine-free, flame-retardant PC composite material according to claim 1, characterized in that: The acrylate coated modified butadiene-styrene rubber core-shell particle toughening agent is MBS core-shell particles or phosphorus acid diphenyl ester grafted acrylate coated modified butadiene-styrene rubber core-shell particles.

6. The needle flame resistant, fluorine-free, flame-retardant PC composite material according to claim 1, characterized in that: The acrylate coated modified butadiene-styrene rubber core-shell particle toughening agent is phosphorus acid diphenyl ester grafted acrylate coated modified butadiene-styrene rubber core-shell particles, which are prepared by the following method: Methyl methacrylate, styrene, methyl methacrylate-2-hydroxyethyl phosphate diphenyl ester and initiator are added to butadiene-styrene latex, heated to initiate polymerization, and spray dried to obtain phosphorus acid diphenyl ester grafted acrylate coated modified butadiene-styrene rubber core-shell particles.

7. The needle flame resistant, fluorine-free, flame-retardant PC composite material according to claim 6, characterized in that: The weight ratio of methyl methacrylate, styrene, and methyl methacrylate-2-hydroxyethyl phosphate diphenyl ester is 60-80:18-30:2-10; the total amount of methyl methacrylate, styrene, and methyl methacrylate-2-hydroxyethyl phosphate diphenyl ester added is 50-100% of the solid content in the butadiene-styrene latex; the initiator is potassium persulfate or ammonium persulfate; and the heating temperature is 60-80℃.

8. The preparation method of the needle flame resistant fluorine-free flame-retardant PC composite material according to any one of claims 1-7, characterized in that: Comprise the following steps: Phosphorus flame retardant, phosphate modified methyl phenyl silicone resin, silane coupling agent surface modified whisker silicon, acrylate coated modified butadiene-styrene rubber core-shell particle toughening agent, and PC resin are mixed uniformly, then sent into a twin-screw extruder for melt mixing and extrusion, and a needle flame resistant fluorine-free PC composite material is obtained.

9. The application of a needle flame resistant fluorine-free PC composite material in any one of claims 1-7 in the fields of new energy vehicles, energy storage devices, and 5G communication.

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