A PBT composite material resistant to low-temperature impact and moisture heat aging and a preparation method thereof

Abstract

The application belongs to the technical field of high polymer materials, and relates to a PBT composite material with low-temperature impact resistance and moisture and heat aging resistance and a preparation method thereof.According to a proportioning, glass fibers are added into a double-screw extruder through a main feeding port B, and PBT, a styrene-acrylonitrile-silicone copolymer, silicone master granules, an organic silicone toughening agent and other raw materials are added into the double-screw extruder through a main feeding port A, and then the materials are melt-extruded and granulated, so that the PBT composite material with low-temperature impact resistance and moisture and heat aging resistance is obtained.The application significantly improves the low-temperature impact resistance and moisture and heat aging resistance of the PBT composite material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and relates to a PBT composite material resistant to low-temperature impact and moisture heat aging and a preparation method thereof. BACKGROUND

[0002] New energy vehicles have the advantages of energy saving, environmental protection and low noise, and the development of the new energy vehicle industry is vigorously supported by the country, and the number of new energy vehicles is rapidly increasing. As an indispensable part of the new energy vehicle industry, the development potential of the charging gun field is extremely huge. Due to the vast territory of China, the charging gun is often exposed to extremely harsh environments, which puts extremely strict requirements on the materials used. Especially the gun head of the charging gun, not only has to meet the low-temperature use environment, but also has to meet the high-temperature and high-humidity use environment.

[0003] Polybutylene terephthalate (PBT) is a semi-crystalline engineering plastic with good mechanical properties, electrical insulation properties and chemical resistance, and has great application potential in the field of charging gun heads. However, due to the existence of PBT benzene ring structure, stress concentration is easily generated, resulting in poor low-temperature impact resistance; at the same time, the existence of ester group causes PBT to have obvious insufficient moisture heat aging resistance, so the application in the field of charging gun heads is greatly limited. SUMMARY

[0004] The purpose of the present application is to solve the problems existing in the prior art, and to provide a PBT composite material resistant to low-temperature impact and moisture heat aging and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A PBT composite material resistant to low-temperature impact and moisture heat aging contains 100 parts of PBT, 8-20 parts of SAS (i.e. styrene-acrylonitrile-silicone copolymer), 1-2 parts of silicone master batch, 5-8 parts of silicone-based toughening agent, 15-20 parts of poly (5-bromobenzyl acrylate), 4-6 parts of phosphazene flame retardant, and 10-30 parts of glass fiber, in terms of weight fraction, wherein the carrier resin of the silicone master batch is PC.

[0007] In the styrene-acrylonitrile-silicone copolymer, the styrene component and the acrylonitrile component have polarity, while the silicone component has no polarity. The styrene component and the acrylonitrile component with polarity have good compatibility with PBT with polarity, while the silicone component with no polarity has poor compatibility with PBT with polarity. This leads to the fact that, in the process of melt blending, the styrene component and the acrylonitrile component enter the inside of the composite material, while the silicone component floats on the surface of the composite material. The silicone component can significantly improve the hydrophobicity of the composite material, and further improve the moisture heat aging resistance of the composite material.

[0008] The styrene-acrylonitrile-silicone copolymer is introduced into the composite material in the prior art mainly to improve the heat resistance of the composite material (the material's resistance to heat on a macro level, which specifically concerns the temperature at which the material reaches a certain deformation under load, i.e., the heat distortion temperature), and antibacterial property. The styrene-acrylonitrile-silicone copolymer is introduced into the composite material based on the motivation of improving the moisture heat aging resistance of the composite material for the first time in the present application.

[0009] During the melt blending, the carrier resin PC of the silicone masterbatch and the silicone will both migrate to the surface of the composite material. PC has a higher hydrolysis reaction activity than PBT and is more prone to hydrolysis. PC, as a sacrificial protective substance, protects PBT from the influence of moisture at high temperatures. At the same time, the silicone can significantly improve the hydrophobicity of the composite material, further improving the moisture heat aging resistance of the composite material.

[0010] The silicone masterbatch is introduced into the composite material in the prior art mainly to disperse lubrication, such as assisting dispersion, easy demolding, and increasing scratch resistance. The silicone masterbatch is introduced into the composite material based on the motivation of improving the moisture heat aging resistance of the composite material for the first time in the present application.

[0011] The addition of the silicone-based toughening agent can effectively improve the low-temperature impact resistance of the composite material, and further increase the silicon content on the surface of the composite material, thereby further improving the moisture heat aging resistance of the composite material.

[0012] Poly(penta bromobenzyl acrylate) has good compatibility with PBT. Compared with other halogen flame retardants, it achieves the same flame retardant effect with a small amount of addition and small influence on the mechanical properties of the material, thereby improving the impact resistance of the material, especially the low-temperature impact resistance.

[0013] The phosphazene flame retardant can fully fuse with PBT, increasing the movement ability of the PBT molecular chain, thereby reducing the internal stress of PBT. The reduction of internal stress not only ensures excellent low-temperature impact resistance, but also has some beneficial effects on improving the moisture heat aging resistance.

[0014] The glass fiber can be hydrolysis-resistant glass fiber to further improve the hydrolysis resistance of the composite material.

[0015] As a preferred technical solution:

[0016] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance as described above has a PBT with a specific viscosity of 0.8-1.3.

[0017] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C. 3 / 10 min.

[0018] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C.

[0019] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C.

[0020] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C. 2 The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C. 2 The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C.

[0021] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C.

[0022] Advantages:

[0023] The PBT composite material with low-temperature impact resistance and moisture heat aging resistance has a melt flow rate of 3-21 cm under a load of 10 kg at 220 DEG C. DETAILED DESCRIPTION

[0024] The application will be further described below in connection with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope defined by the appended claims.

[0025] The following are the test methods of the relevant performance indicators in each embodiment:

[0026] CTI value: The sample to be tested is cut into a disc with a thickness of 3 mm and a diameter of 100 mm, and tested according to the IEC 60112 standard.

[0027] Notched impact strength, notched impact strength retention: The sample to be tested is dried in a forced air oven at 110℃ for 4 hours, then injection molded into a standard sample bar, and then tested according to the ISO 179 standard; the calculation formula of the notched impact strength retention is as follows:

[0028] Notched impact strength retention = a c1 / a c0 × 100%;

[0029] In the formula, a c0 is the notched impact strength of the original sample bar at a specific temperature (23℃ or -40℃), with a unit of kJ / m 2 ; a c1 is the notched impact strength of the original sample bar after the hydrothermal aging treatment (placed at a relative humidity of 85% and a temperature of 85℃ for 240h) at the same specific temperature, with a unit of kJ / m 2 .

[0030] UL94: Tested according to the UL94 standard, wherein the thickness of the sample to be tested is 1.6 mm.

[0031] Example 1

[0032] A preparation method of a PBT composite material resistant to low-temperature impact and hydrothermal aging, the specific steps are as follows:

[0033] (1) Preparation of raw materials;

[0034] Glass fiber: The manufacturer is Chongqing International Composite Material Co., Ltd., and the brand is ECS303HK-3-K;

[0035] Poly (5-bromovaleryl acrylate): The manufacturer is ICL Dead Sea Industries Co., Ltd., and the brand is FR1025;

[0036] Hexaphenoxycyclotriphosphazene;

[0037] PBT: the manufacturer is Xinjiang Lanshan Tunhe Co., Ltd., the brand is TH6100, and the intrinsic viscosity is 1.0;

[0038] SAS: the manufacturer is UMG Co., Ltd., the brand is S351, and the melt flow rate under the condition of 220 ℃ and 10 kg load is 21 cm 3 / 10 min;

[0039] Silicone master batch: the manufacturer is Dow Corning Co., Ltd., the brand is HMB-1903, and the carrier resin is PC;

[0040] Silicone-acrylic high-weather-resistance impact modifier: the manufacturer is Mitsubishi Rayon Co., Ltd., the brand is SX-006;

[0041] (2) The glass fiber is added into the twin-screw extruder through the main feeding port B, and the poly (penta bromobenzyl acrylate), hexaphenoxy cyclotriphosphazene, PBT, SAS, silicone master batch and silicone-acrylic high-weather-resistance impact modifier are added into the twin-screw extruder through the main feeding port A, and then the low-temperature-impact-resistant and wet-heat-aging-resistant PBT composite material is obtained by melt extrusion granulation; wherein the rotating speed of the twin-screw extruder is 450-600 rpm, and the temperature is 220-230 ℃.

[0042] The low-temperature-impact-resistant and wet-heat-aging-resistant PBT composite material finally obtained is composed of 10 parts of glass fiber, 15 parts of poly (penta bromobenzyl acrylate), 4 parts of hexaphenoxy cyclotriphosphazene, 100 parts of PBT, 8 parts of SAS, 1 part of silicone master batch and 5 parts of silicone-acrylic high-weather-resistance impact modifier, by weight;

[0043] The CTI value of the low-temperature-impact-resistant and wet-heat-aging-resistant PBT composite material is 350 V, the notched impact strength at 23 ℃ is 10.3 kJ / m 2 , the notched impact strength at-40 ℃ is 8 kJ / m 2 , and the UL94 reaches V0 level; after the low-temperature-impact-resistant and wet-heat-aging-resistant PBT composite material is placed under the condition of 85% relative humidity and 85 ℃ for 240 h, the notched impact strength retention rate at 23 ℃ is 80%, the notched impact strength retention rate at-40 ℃ is 82%, and the UL94 still reaches V0 level.

[0044] Comparative Example 1

[0045] A preparation method of a PBT composite material, and the difference from Example 1 is that the hexaphenoxy cyclotriphosphazene is replaced by the same mass of poly (penta bromobenzyl acrylate) (same as Example 1).

[0046] The notched impact strength at 23 ℃ of the finally obtained PBT composite material is 9.2 kJ / m 2The notched impact strength at -40℃ is 5.4 kJ / m. 2 After being placed at a relative humidity of 85% and a temperature of 85℃ for 240 hours, the PBT composite material retained 74% of its notched impact strength at 23℃ and 70% of its notched impact strength at -40℃.

[0047] Compared with Example 1, the mechanical properties, low-temperature impact resistance, and damp heat aging resistance of the PBT composite material of Comparative Example 1 were significantly worse. This is because although pentabromobenzyl acrylate has good compatibility with PBT, its excessive addition affected the continuity of PBT.

[0048] Comparative Example 2

[0049] A method for preparing a PBT composite material differs from Example 1 only in that: pentabromobenzyl polyacrylate is replaced with an equal mass of hexaphenoxycyclotriphosphazene.

[0050] The final PBT composite material has a notched impact strength of 6.5 kJ / m at 23°C. 2 The notched impact strength at -40℃ is 4.5 kJ / m. 2 After being placed at a relative humidity of 85% and a temperature of 85℃ for 240 hours, the PBT composite material retained 55% of its notched impact strength at 23℃ and 45% of its notched impact strength at -40℃.

[0051] Compared with Example 1, the mechanical properties, low-temperature impact resistance, and damp heat aging resistance of the PBT composite material in Comparative Example 2 were significantly worse. This is because hexaphenoxycyclotriphosphazene, as a halogen-free flame retardant, has a much lower char-forming ability and flame retardant efficiency than polypentabromobenzyl acrylate, and its compatibility with PBT is also much lower than that of polypentabromobenzyl acrylate. Ultimately, this leads to a decrease in the mechanical properties of the PBT composite material, and precipitation also occurs under high temperature and high humidity conditions, thus affecting the damp heat aging resistance of the PBT composite material.

[0052] Comparative Example 3

[0053] A method for preparing a PBT composite material differs from Example 1 only in that: pentabromobenzyl polyacrylate is replaced with an equal mass of brominated epoxy resin (manufacturer: Jiangsu Xingsheng Chemical Co., Ltd., brand name: EP-25K).

[0054] The final PBT composite material has a notched impact strength of 10.1 kJ / m at 23°C. 2 The notched impact strength at -40℃ is 6.2 kJ / m. 2The PBT composite material was placed in a condition of 85% relative humidity and 85°C for 240h, and the notched impact strength retention rate was 73% at 23°C and 68% at -40°C.

[0055] Compared with Example 1, the low-temperature impact resistance and the wet heat aging resistance of the PBT composite material of Comparative Example 3 are obviously deteriorated. This is because the brominated epoxy resin, as the most common halogen flame retardant, has high cost performance, but its compatibility with PBT is obviously poorer than that of poly (pentabromobenzyl acrylate), thereby causing the mechanical properties of the composite material, especially the mechanical properties at low temperature, to obviously decrease. In addition, the halogen group in the brominated epoxy resin is insufficient in strength, and is prone to chain scission reaction under high temperature and high humidity conditions, thereby causing the wet heat aging resistance of the composite material to be poor.

[0056] Example 2

[0057] A preparation method of a PBT composite material with low-temperature impact resistance and wet heat aging resistance, and the specific steps are as follows:

[0058] (1) Preparation of raw materials;

[0059] Glass fiber: the manufacturer is Chongqing International Composite Material Co., Ltd., and the model is ECS303HK-3-K;

[0060] Poly (pentabromobenzyl acrylate): the manufacturer is ICL Dead Sea Industries Co., Ltd., and the model is FR1025;

[0061] Hexaphenoxy cyclotriphosphazene;

[0062] PBT: the manufacturer is Changchun Chemical (Jiangsu) Co., Ltd., and the model is 1100-211X, with a specific viscosity of 1.3;

[0063] SAS: the manufacturer is UMG Co., Ltd., and the model is TW-15G, with a melt flow rate of 3 cm 3 / 10min at 220°C under a load of 10 kg;

[0064] Silicone master batch: the manufacturer is Dow Corning Co., Ltd., and the model is HMB-1903, with a carrier resin of PC;

[0065] Silicone-acrylic high-weather-resistant impact modifier: the manufacturer is Mitsubishi Rayon Co., Ltd., and the model is SX-006;

[0066] (2) adding glass fiber into the twin-screw extruder through the main feeding port B, and adding poly (5-bromobenzyl acrylate), hexaphenoxycyclotriphosphazene, PBT, SAS, silicone master batch and silicone-acrylic high weather resistance impact modifier into the twin-screw extruder through the main feeding port A, melt extrusion granulation, to obtain the PBT composite material with low-temperature impact resistance and wet heat aging resistance; wherein the rotating speed of the twin-screw extruder is 450-600 rpm, and the temperature is 220-230℃.

[0067] The PBT composite material with low-temperature impact resistance and wet heat aging resistance finally obtained comprises, by weight fraction, 20 parts of glass fiber, 17 parts of poly (5-bromobenzyl acrylate), 5 parts of hexaphenoxycyclotriphosphazene, 100 parts of PBT, 10 parts of SAS, 1.5 parts of silicone master batch and 8 parts of silicone-acrylic high weather resistance impact modifier;

[0068] The PBT composite material with low-temperature impact resistance and wet heat aging resistance has a CTI value of 300 V, a notched impact strength of 10.6kJ / m 2 at 23℃, a notched impact strength of 8.9kJ / m 2 at-40℃, and UL94 reaches V0 level; after being placed under the condition of 85% relative humidity and 85℃ for 240h, the PBT composite material with low-temperature impact resistance and wet heat aging resistance has a notched impact strength retention rate of 79% at 23℃, a notched impact strength retention rate of 76% at-40℃, and UL94 still reaches V0 level.

[0069] Example 3

[0070] A preparation method of a PBT composite material with low-temperature impact resistance and wet heat aging resistance, and the specific steps are as follows:

[0071] (1) preparation of raw materials;

[0072] Glass fiber: the manufacturer is Chongqing International Composite Material Co., Ltd., and the model is ECS303HK-3-K;

[0073] Poly (5-bromobenzyl acrylate) : the manufacturer is ICL Dead Sea Industries Co., Ltd., and the model is FR1025;

[0074] Hexaphenoxycyclotriphosphazene;

[0075] PBT: the manufacturer is Changchun Chemical (Jiangsu) Co., Ltd., the model is 1200-211D, and the intrinsic viscosity is 0.75;

[0076] SAS: the manufacturer is UMG Co., Ltd., the model is E259B, and the melt flow rate under the condition of 220℃ and 10kg load is 15cm 3 / 10min;

[0077] Silicone masterbatch: the manufacturer is Dow Corning Corporation, the brand is HMB-1903, and the carrier resin is PC;

[0078] Silicon-acrylic high weather resistance impact modifier: the manufacturer is Mitsubishi Rayon Co., Ltd., the brand is SX-006;

[0079] (2) The glass fiber is added to the twin-screw extruder through the main feeding port B, and the poly (5-bromobenzyl acrylate), hexaphenoxy cyclotriphosphazene, PBT, SAS, silicone masterbatch and silicon-acrylic high weather resistance impact modifier are added to the twin-screw extruder through the main feeding port A, and then the low-temperature impact resistance and wet heat aging resistant PBT composite material is obtained by melt extrusion granulation; wherein the rotating speed of the twin-screw extruder is 450-600 rpm, and the temperature is 220-230℃.

[0080] The low-temperature impact resistance and wet heat aging resistant PBT composite material is prepared by mixing 30 parts of glass fiber, 18 parts of poly (5-bromobenzyl acrylate), 6 parts of hexaphenoxy cyclotriphosphazene, 100 parts of PBT, 20 parts of SAS, 1 part of silicone masterbatch and 5 parts of silicon-acrylic high weather resistance impact modifier by weight;

[0081] The CTI value of the low-temperature impact resistance and wet heat aging resistant PBT composite material is 350V, the notched impact strength at 23℃ is 9kJ / m 2 , the notched impact strength at-40℃ is 7.5kJ / m 2 , and the UL94 reaches V0 level; after the low-temperature impact resistance and wet heat aging resistant PBT composite material is placed at 85% relative humidity and 85℃ for 240h, the notched impact strength retention rate at 23℃ is 82%, the notched impact strength retention rate at-40℃ is 85%, and the UL94 still reaches V0 level.

[0082] Example 4

[0083] A method for preparing a low-temperature impact resistance and wet heat aging resistant PBT composite material, the specific steps are as follows:

[0084] (1) Preparation of raw materials;

[0085] Glass fiber: the manufacturer is Chongqing International Composite Material Co., Ltd., the brand is ECS303HK-3-K;

[0086] Poly (5-bromobenzyl acrylate) : the manufacturer is ICL Dead Sea Industries Co., Ltd., the brand is FR1025;

[0087] Hexaphenoxy cyclotriphosphazene;

[0088] PBT: the manufacturer is Sinopec Yizheng Fiber Co., Ltd., the brand is GX112, and the intrinsic viscosity is 0.82;

[0089] SAS: brand TW-15G from UMG Company, melt flow rate at 220℃, 10kg load is 3cm 3 / 10min;

[0090] Silicone masterbatch: brand HMB-1903 from Dow Corning Company, carrier resin is PC;

[0091] Silicone-acrylic high weatherability impact modifier: brand SX-006 from Mitsubishi Rayon Company;

[0092] (2) The glass fiber is added into the twin-screw extruder through the main feeding port B, and the poly (5-bromobenzyl acrylate), hexaphenoxy cyclotriphosphazene, PBT, SAS, silicone masterbatch and silicone-acrylic high weatherability impact modifier are added into the twin-screw extruder through the main feeding port A, and then melt extrusion granulation is carried out to obtain the PBT composite material with low-temperature impact resistance and wet heat aging resistance; wherein the rotating speed of the twin-screw extruder is 450-600r / min, and the temperature is 220-230℃.

[0093] The PBT composite material with low-temperature impact resistance and wet heat aging resistance obtained finally is composed of 10 parts of glass fiber, 20 parts of poly (5-bromobenzyl acrylate), 5 parts of hexaphenoxy cyclotriphosphazene, 100 parts of PBT, 10 parts of SAS, 2 parts of silicone masterbatch and 6 parts of silicone-acrylic high weatherability impact modifier by weight;

[0094] The PBT composite material with low-temperature impact resistance and wet heat aging resistance has a CTI value of 300V, a notched impact strength of 9.5kJ / m 2 at 23℃, a notched impact strength of 7.7kJ / m 2 at-40℃, and UL94 reaches V0 level; after being placed at a relative humidity of 85% and a temperature of 85℃ for 240h, the PBT composite material with low-temperature impact resistance and wet heat aging resistance has a notched impact strength retention rate of 80% at 23℃, a notched impact strength retention rate of 77% at-40℃, and UL94 still reaches V0 level.

[0095] Example 5

[0096] A preparation method of a PBT composite material with low-temperature impact resistance and wet heat aging resistance, and the specific steps are as follows:

[0097] (1) Preparation of raw materials;

[0098] Glass fiber: brand ECS303HK-3-K from Chongqing International Composite Material Co., Ltd;

[0099] Poly (5-bromobenzyl acrylate) : brand FR1025 from ICL Dead Sea Industries Ltd;

[0100] hexaphenoxycyclotriphosphazene;

[0101] PBT: the manufacturer is Nantong Xingchen Synthetic Material Co., Ltd., the brand is 1120, and the intrinsic viscosity is 1.2;

[0102] SAS: the manufacturer is UMG Co., Ltd., the brand is E259B, and the melt flow rate under the condition of 220 ℃ and 10 kg load is 15 cm 3 / 10 min;

[0103] Silicone masterbatch: the manufacturer is Dow Corning Co., Ltd., the brand is HMB-1903, and the carrier resin is PC;

[0104] Silicone-acrylic high-weather-resistant impact modifier: the manufacturer is Mitsubishi Rayon Co., Ltd., the brand is SX-006;

[0105] (2) The glass fiber is added into the twin-screw extruder through the main feeding port B, and the poly (pentabromobenzyl acrylate), hexaphenoxycyclotriphosphazene, PBT, SAS, silicone masterbatch and silicone-acrylic high-weather-resistant impact modifier are added into the twin-screw extruder through the main feeding port A, and then the low-temperature impact-resistant and wet-heat aging-resistant PBT composite material is obtained by melt extrusion granulation; wherein the rotating speed of the twin-screw extruder is 450-600 rpm, and the temperature is 220-230 ℃.

[0106] The low-temperature impact-resistant and wet-heat aging-resistant PBT composite material is composed of 30 parts of glass fiber, 15 parts of poly (pentabromobenzyl acrylate), 6 parts of hexaphenoxycyclotriphosphazene, 100 parts of PBT, 15 parts of SAS, 1.5 parts of silicone masterbatch and 7 parts of silicone-acrylic high-weather-resistant impact modifier, according to the weight fraction;

[0107] The CTI value of the low-temperature impact-resistant and wet-heat aging-resistant PBT composite material is 300 V, the notched impact strength at 23 ℃ is 8.5 kJ / m 2 , the notched impact strength at -40 ℃ is 7.5 kJ / m 2 , and the UL94 reaches V0 level; after the low-temperature impact-resistant and wet-heat aging-resistant PBT composite material is placed under the condition of 85% relative humidity and 85 ℃ for 240 h, the notched impact strength retention rate at 23 ℃ is 83%, the notched impact strength retention rate at -40 ℃ is 78%, and the UL94 still reaches V0 level.

Claims

1. A PBT composite material resistant to low-temperature impact and moisture-heat aging, characterized in that, The PBT is 100 parts, the SAS is 8-20 parts, the silicone master batch is 1-2 parts, the silicone-acrylic high weather resistance impact modifier is 5-8 parts, the polyacrylic acid pentabromobenzyl ester is 15-20 parts, the phosphazene flame retardant is 4-6 parts, and the glass fiber is 10-30 parts by weight; wherein the carrier resin of the silicone master batch is PC; the SAS is from UMG Company, and the model is S351; the silicone-acrylic high weather resistance impact modifier is from Mitsubishi Rayon Co., Ltd., and the model is SX-006; and the phosphazene flame retardant is hexaphenoxycyclotriphosphazene.

2. The PBT composite material with low-temperature impact resistance and moisture heat aging resistance according to claim 1, characterized in that, The intrinsic viscosity of the PBT is 0.8-1.

3.

3. The PBT composite material with low-temperature impact resistance and moisture heat aging resistance according to any one of claims 1-2, characterized in that, The CTI value of the PBT composite material is 300-350 V, the notched impact strength at 23 DEG C is 8.5-10.6 kJ / m 2 , the notched impact strength at -40 DEG C is 7.5-8.9 kJ / m 2 , the UL94 reaches V0 level, the notched impact strength retention rate at 23 DEG C is more than 79% after being placed at 85% relative humidity and 85 DEG C for 240 h, the notched impact strength retention rate at -40 DEG C is more than 76%, and the UL94 still reaches V0 level.

4. A method for preparing a PBT composite material with low-temperature impact resistance and moisture heat aging resistance according to any one of claims 1 to 3, characterized in that, The glass fiber is added into the twin-screw extruder through the main feeding port B, and the other components are added into the twin-screw extruder through the main feeding port A, and then the melt extrusion granulation is carried out, wherein the rotating speed of the twin-screw extruder is 450-600 rpm, and the temperature is 220-230 ℃.