A PBT composite material, its preparation method and application

Abstract

The present invention discloses a PBT composite material, its preparation method and application, belonging to the technical field of polymer engineering plastics; the PBT composite material provided by the present invention comprises the following components in parts by mass: 30-60 parts of PBT resin, 25-40 parts of alkali-free glass fiber, 12-20 parts of aluminum diethylphosphinate, 2-8 parts of melamine polyphosphate, and 1-4 parts of phosphate ester. The PBT composite material provided by the present invention still has excellent flame retardant performance when prepared into thin-wall (≤0.4 mm) products, and the obtained products have excellent fluidity, and have good tensile strength and impact strength; moreover, the preparation method provided by the present invention is simple and is conducive to actual production.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer engineering plastics, and particularly relates to a PBT composite material, a preparation method thereof and an application thereof. Background Art

[0002] Brominated flame retardants have the advantages of high flame retardancy efficiency, good flame retardancy stability, good compatibility, excellent mechanical properties, etc. However, halogenated flame retardants pose a great threat to the environment and humans. Compared with the existing halogenated flame retardant systems, the halogen-free flame retardant system has obvious advantages in terms of density, smoke density, toxicity, CTI, etc. Therefore, halogen-free flame retardants will be the major trend of future development. In addition, with the continuous development of material technology, market products show another development trend, that is, miniaturization and thin-walling. The advantages of thin-walling are obvious. At the same time, there are also many molding problems restricting its development. In recent years, the maturity of various new molding processes and mold flow analysis technologies has greatly promoted the application of thin-walled products. More and more customers have put forward the requirements of miniaturization and thin-walling (≤0.4 mm), and the market capacity is very large.

[0003] In the prior art, there have been a lot of research results on halogen-free flame retardant reinforced PBT. Generally speaking, the flame retardancy efficiency of halogen-free flame retardants is weaker than that of halogenated flame retardants, and the amount of flame retardant required to reach the same flame retardancy level is relatively high. The compatibility of halogen-free flame retardants with resins is poor, and the particle size is large, resulting in obvious reduction of mechanical properties and fluidity. Fluidity and mechanical properties are the most critical technical indicators of thin-wall technology. Only when the performance is excellent enough can the thin-walled products have sufficient strength to meet the use requirements, and only when the fluidity is relatively high can the thin-walled products be successfully molded. At present, the thinnest flame retardancy grade reported in the halogen-free system is 0.8 mm V-0. In Chinese Patent CN108676330A, melamine cyanurate MCA and aluminum hypophosphite are compounded to obtain a PBT product with 0.8 mm V-0 flame retardancy. However, aluminum hypophosphite itself has poor thermal stability, and phosphine is easily released during the processing. Phosphine is very harmful to the human body and there is also a risk of ignition, so it is not suitable as a flame retardant for ultra-thin halogen-free systems. The current mainstream halogen-free flame retardants on the market, such as Exolit OP1230 of Clariant, whose core component is aluminum diethylphosphinate, has good thermal stability after being protected by diethyl groups and has a good synergistic flame retardancy effect with melamine polyphosphate (MPP). After compounding, it can reach a relatively high flame retardancy grade (0.8 mm). However, when the amount of flame retardant is further increased, the fluidity is very poor, resulting in uneven dispersion of the flame retardant, unstable flame retardancy, and poor performance at the same time. That is, the current halogen-free flame retardant technology cannot balance the ultra-thin flame retardancy grade (≤0.4 mm) and high flow and high performance. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a PBT composite material which can still meet good flame retardancy performance in an ultra-thin state (≤0.4 mm), and at the same time has good fluidity and mechanical properties, and a preparation method and application thereof.

[0005] To achieve the above object, in the first aspect of the present invention, the present invention provides a PBT composite material, and the PBT composite material comprises the following components in parts by mass: 30-60 parts of PBT resin, 25-40 parts of alkali-free glass fiber, 12-20 parts of aluminum diethylphosphinate, 2-8 parts of melamine polyphosphate, and 1-4 parts of phosphate ester.

[0006] In the PBT composite material provided by the present invention, aluminum diethylphosphinate, melamine polyphosphate (MPP) and phosphate ester in a specific mass fraction range are simultaneously added into the PBT resin matrix, and can be mutually compounded. With the addition of a certain amount of alkali-free glass fiber, the obtained composite material still has excellent flame retardancy performance when prepared into a thin-wall (≤0.4 mm) product, and the product obtained in the thin-wall state has excellent fluidity, and has good tensile strength and impact strength.

[0007] Preferably, in the PBT composite material, the mass percentage of PBT resin is between 38-45%, the mass percentage of aluminum diethylphosphinate is between 10-20%, the mass percentage of melamine polyphosphate is between 1.5-8%, and the mass percentage of phosphate ester is between 0.5-5%.

[0008] As a preferred embodiment of the PBT composite material of the present invention, in the PBT composite material, the mass ratio of aluminum diethylphosphinate, melamine polyphosphate and phosphate ester is aluminum diethylphosphinate: melamine polyphosphate: phosphate ester = (14-16):(4-6):(2-3).

[0009] The inventors have found through research that when further selecting aluminum diethylphosphinate, melamine polyphosphate and phosphate ester within the above mass ratio range, the compounding effect among the three is better, and the comprehensive performance of the obtained product is better.

[0010] As a preferred embodiment of the PBT composite material of the present invention, at least one of the following (a)-(d):

[0011] (a) The glass fiber is alkali-free glass fiber treated with a coupling agent, and the diameter is 5-20 μm;

[0012] (b) The average particle size of the aluminum diethylphosphinate is 8-42 μm;

[0013] (c) The average particle size of the melamine polyphosphate is 7-10 μm;

[0014] (d) The intrinsic viscosity of the PBT resin is 0.6 - 1.15 dL / g.

[0015] Exemplarily, the diameter of the glass fiber can be 5.0μm, 5.5μm, 6.0μm, 6.5μm, 7.0μm, 7.5μm, 8.0μm, 8.5μm, 9.0μm, 9.5μm, 10.0μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, etc., as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0016] Exemplarily, the average particle size of the aluminum diethyl phosphinate can be 8μm, 8.5μm, 9μm, 9.5μm, 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, 20.5μm, 21μm, 21.5μm, 22μm, 22.5μm, 23μm, 23.5μm, 24μm, 24.5μm, 25μm, 25.5μm, 26μm, 26.5μm, 27μm, 27.5μm, 28μm, 28.5μm, 29μm, 29.5μm, 30μm, 30.5μm, 31μm, 31.5μm, 32μm, 32.5μm, 33μm, 33.5μm, 34μm, 34.5μm, 35μm, 35.5μm, 36μm, 36.5μm, 37μm, 37.5μm, 38μm, 38.5μm, 39μm, 39.5μm, 40μm, etc., as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0017] Exemplarily, the average particle size of the melamine polyphosphate can be 7.0μm, 7.2μm, 7.4μm, 7.6μm, 7.8μm, 8.0μm, 8.2μm, 8.4μm, 8.6μm, 8.8μm, 9.0μm, 9.2μm, 9.4μm, 9.6μm, 9.8μm, 10.0μm, etc., as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0018] Exemplarily, the intrinsic viscosity of the PBT resin may be 0.6 dL / g, 0.62 dL / g, 0.65 dL / g, 0.67 dL / g, 0.7 dL / g, 0.72 dL / g, 0.75 dL / g, 0.77 dL / g, 0.8 dL / g, 0.82 dL / g, 0.85 dL / g, 0.87 dL / g, 0.9 dL / g, 0.92 dL / g, 0.95 dL / g, 0.97 dL / g, 1.0 dL / g, 1.02 dL / g, 1.04 dL / g, 1.06 dL / g, 1.08 dL / g, 1.10 dL / g, 1.12 dL / g, 1.15 dL / g, etc., as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0019] Preferably, the diameter of the glass fiber is 7 - 17 μm. More preferably, the diameter of the glass fiber is 10 - 13 μm.

[0020] Preferably, the average particle size of the aluminum diethylphosphinate is 10 - 40 μm. More preferably, the average particle size of the aluminum diethylphosphinate is 20 - 30 μm.

[0021] Preferably, the average particle size of the melamine polyphosphate is 8 - 10 μm.

[0022] The inventors have found through research that when the average particle sizes of the aluminum diethylphosphinate and the melamine polyphosphate are further selected to be 20 - 30 μm and 8 - 10 μm respectively, and when the diameter of the E-glass fiber is selected to be 10 - 13 μm, the flame retardant performance of the obtained product is more excellent, and the fluidity and mechanical properties of the obtained product are also better.

[0023] Preferably, the intrinsic viscosity of the PBT resin is 0.67 - 1.05 dL / g. More preferably, the intrinsic viscosity of the PBT resin is 0.7 - 1.00 dL / g.

[0024] The intrinsic viscosity of the PBT resin is measured with reference to GB / T 14190 - 2017.

[0025] The inventors have found through research that when the intrinsic viscosity of the PBT resin is further selected to be 0.7 - 1.0 dL / g, the added aluminum diethylphosphinate, melamine polyphosphate and phosphate ester can be better dispersed in the resin matrix, thereby achieving more excellent comprehensive effects.

[0026] Preferably, the coupling agent is at least one of a silane coupling agent with an epoxy end group and a silane coupling agent with an amino end group.

[0027] As a preferred embodiment of the PBT composite material of the present invention, the phosphate ester is at least one of triphenyl phosphate (TPP), aryl phosphate (PX-220), resorcinol bis(diphenyl phosphate) (SOL-DP), bisphenol A bis(diphenyl phosphate) (BDP), resorcinol bis[bis(2,6-dimethylphenyl) phosphate] (RDX), resorcinol bis(diphenyl phosphate) (RDP), and phenoxycyclophosphazene.

[0028] Preferably, the phosphate ester is resorcinol bis(diphenyl phosphate) (RDP).

[0029] As a preferred embodiment of the PBT composite material of the present invention, the PBT composite material further comprises 0.001 - 4 parts of a toughening agent and 0.001 - 1 part of a processing aid.

[0030] As a preferred embodiment of the PBT composite material of the present invention, the toughening agent is at least one of ethylene-acrylate-glycidyl methacrylate terpolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate, and glycidyl methacrylate grafted ethylene-octene copolymer.

[0031] As a preferred embodiment of the PBT composite material of the present invention, the processing aid comprises at least one of an antioxidant and a lubricant.

[0032] Preferably, the lubricant is at least one of aliphatic carboxylic acid esters and polyolefin waxes; the antioxidant is a hindered phenol antioxidant.

[0033] In the second aspect of the present invention, the present invention also provides a preparation method of the PBT composite material, and the preparation method comprises the following steps: weighing and mixing the dried raw materials and feeding them into a twin-screw extruder, and obtaining the PBT composite material through extrusion, strand drawing, cooling, pelletizing, and drying.

[0034] As a preferred embodiment of the preparation method of the present invention, the drying process of the PET resin and the PBT resin is as follows: placing the PBT resin at 125 - 135°C and drying for 4 - 6 hours; until the moisture content < 0.03%.

[0035] As a preferred embodiment of the preparation method of the present invention, the parameters of the twin-screw extruder are as follows: the feeding speed is 450 - 800 kg / hour; the temperatures of each section of the screw from the feeding port to the head are 220 - 230°C, 230 - 240°C, 230 - 240°C, 240 - 250°C, 250 - 260°C, 240 - 250°C, 240 - 250°C, 230 - 240°C, 220 - 230°C; the screw speed is 250 - 400 rpm.

[0036] In the third aspect of the present invention, the present invention also provides the application of the PBT composite material in ultra-thin (≤0.4 mm) electronic components.

[0037] Exemplarily, the application of the PBT composite material in a cooling fan, a relay, and a capacitor.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] A PBT composite material provided by the present invention uses a PBT resin as a matrix, and at the same time adds aluminum diethylphosphinate, melamine polyphosphate, and phosphate ester within a specific mass fraction range for compounding, as well as a certain amount of alkali-free glass fiber. The obtained composite material still has excellent flame retardancy when prepared into a thin-wall (≤0.4 mm) product. That is, the composite material provided by the present invention can achieve an ultra-high-level flame retardant effect even with a small amount of flame retardant added; and the obtained product has excellent fluidity, and has good tensile strength and impact strength; specifically, when the obtained product is prepared into a test sample with a thickness of 0.4 mm, the flame retardant grade of the sample is V-0 or V-1, the average burning time is within 7.5 s, the longest burning time is within 15.6 s, the tensile strength is above 105 MPa, and the impact strength is 7.2 kJ / m 2 Above, the melt index is above 8.9; and the preparation method of the composite material provided by the present invention is simple, which is beneficial to actual production. Detailed implementation manners

[0040] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0041] The reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in the art unless otherwise specified.

[0042] PBT-1: GX111, intrinsic viscosity is 0.73 dL / g, Yizheng, Jiangsu;

[0043] PBT-2: GX121, intrinsic viscosity is 0.98 dL / g, Yizheng, Jiangsu;

[0044] PBT-3: GX110, intrinsic viscosity is 0.67 dL / g, Yizheng, Jiangsu;

[0045] PBT-4: GX122J, intrinsic viscosity is 1.05 dL / g, Yizheng, Jiangsu;

[0046] Aluminum diethylphosphinate 1: average particle size is 20 μm, Clariant, Switzerland;

[0047] Aluminum diethylphosphinate 2: average particle size is 30 μm, Clariant, Switzerland;

[0048] Diethylaluminum hypophosphite 3: average particle size 10 μm, Clariant, Switzerland;

[0049] Diethylaluminum hypophosphite 4: average particle size 40 μm, Clariant, Switzerland;

[0050] Inorganic aluminum hypophosphite: M-116, average particle size 5 μm, Shanghai Meilaipo Chemical Material Technology Co., Ltd.;

[0051] MPP-1: BUDIT 3141, average particle size 8 μm, Budenheim, Germany;

[0052] MPP-2: FR-NP, average particle size ≤ 6 μm, Weidong, Shouguang, Shandong;

[0053] MPP-3: average particle size 20 μm, Sichuan Fine Chemical Research Institute;

[0054] Melamine cyanurate (MCA): MCA-01, average particle size 0.05-0.6 mm, Sichuan Fine Chemical Research Institute;

[0055] Phosphate 1: RDP, Zhejiang Wansheng Chemical;

[0056] Phosphate 2: BDP, Zhejiang Wansheng Chemical;

[0057] Phosphate 3: PX-200, Japan Daihachi Chemical;

[0058] Glass fiber 1: diameter 10 μm, ECS10-4.5-T436H, Taishan Glass Fiber Co., Ltd.

[0059] Glass fiber 2: diameter 13 μm, ECS13-4.5-534A, Jushi Group Co., Ltd.

[0060] Glass fiber 3: diameter 7 μm, ECS7-4.5-T436S, Taishan Glass Fiber Co., Ltd.

[0061] Glass fiber 4: diameter 17 μm, EDR17-2000-988A, Jushi Group Co., Ltd.

[0062] Toughening agent: ethylene-acrylate-glycidyl methacrylate terpolymer, commercially available;

[0063] Antioxidant: Antioxidant 1010, commercially available,

[0064] Lubricant: polyethylene wax, commercially available;

[0065] The toughening agent, antioxidant and lubricant used in the parallel experiments of the embodiment and the comparative example are consistent;

[0066] Among them, the products of aluminum diethylphosphinate with different average particle sizes were obtained by purchasing the OP1230 product from Clariant of Switzerland and then obtaining products with different average particle sizes through grinding and / or screening. Among them, screening was carried out using sieves with corresponding different mesh numbers respectively to obtain samples with the required average particle size; the average particle size test method of the product was: using a laser particle size analyzer to test the particle size of the sample, and the particle size analysis instrument model was MS2000E of MALVERN Company in the United Kingdom (UK).

[0067] Examples 1-19 and Comparative Examples 1-7

[0068] The component contents (parts by weight) of Examples 1-19 and Comparative Examples 1-7 of the present invention are shown in Tables 1-3;

[0069] Table 1

[0070]

[0071]

[0072] Table 2

[0073]

[0074] Table 3

[0075]

[0076] The preparation methods of Examples 1-19 and Comparative Examples 1-7 are as follows:

[0077] Weigh the dried raw materials and add them to a mixer to mix evenly, and then feed them into a twin-screw extruder. Adjust the feeding amount of the twin-screw extruder to 600 kg / hour, and after extrusion, strand drawing, cooling, pelletizing, and drying, obtain a PBT composite material; among them, the drying process of the PBT resin is: place the PBT resin at 130 °C and dry it for 5 hours; the parameters of the twin-screw extruder are: the temperatures of each section of the screw from the feeding port to the head are 230 °C, 240 °C, 240 °C, 250 °C, 260 °C, 250 °C, 240 °C, 230 °C, 220 °C respectively; the screw speed is 400 rpm.

[0078] Effect Example

[0079] The effect examples of the present invention verify the performance of the products prepared in Examples 1-19 and Comparative Examples 1-7; prepare test specimens by injection molding according to the corresponding standards (the thickness of the specimens is 0.4 mm); the test items include the following aspects:

[0080] 1. Tensile strength was tested according to the ISO 527-1-2012 standard;

[0081] 2. The Izod impact strength of the cantilever beam was tested according to the ISO 180-2007 standard;

[0082] 3. The melt index was tested according to the ASTM D 1238 standard, and the test conditions were 250 °C / 2.16 Kg;

[0083] 4. The flame retardancy performance was tested according to the UL 94-1985 standard. The thickness of the specimen was 0.4 mm, and the flame retardant grade was recorded. At the same time, the burning time of 5 standard splines was tested, and the longest time and average time of T1+T2 were recorded, denoted as T longest and T average respectively. T average represents the average flame retardant ability of the material, and T longest represents the flame retardant stability of the material. In addition, the flame retardant grade of the specimen with a thickness of 0.4 mm was tested;

[0084] The test results are shown in Table 4;

[0085] Table 4

[0086]

[0087]

[0088] As can be seen from Table 3, when the technical solution of the present invention is adopted, the obtained product has excellent comprehensive effects, can not only meet the flame retardant requirements of thin-walled products, but also has excellent mechanical properties and fluidity; specifically, the obtained product has a flame retardant grade of V-1 or V-0, where T average is below 7.5 s, T longest is below 15.6 s, the tensile strength is above 105 MPa, and the impact strength is above 7.2 kJ / m 2 above, and the melt index is above 8.9 g / 10 min; when the selected parameters are within the preferred range of the present invention, the obtained product has a flame retardant grade of V-0, where T average is between 3.5 - 5.7 s, T longest is between 5.4 - 7.8 s, the tensile strength is between 115 - 118 MPa, and the impact strength is between 7.5 - 9.5 kJ / m 2 between, and the melt index is between 8.9 - 13.8 g / 10 min;

[0089] As can be seen from Examples 1 and 3, the mass parts of aluminum diethyl phosphinate, melamine polyphosphate, and phosphate ester will affect the performance of the product. When the mass ratio of aluminum diethyl phosphinate: melamine polyphosphate: phosphate ester = (14 - 16):(4 - 6):(2 - 3) is further selected, the obtained product has better comprehensive performance; the obtained product has a flame retardant grade of V-0, where T average is below 4.2 s, T longest is below 6.5 s, the tensile strength is above 114 MPa, and the impact strength is above 8.2 kJ / m 2The above, the melt index is 10.1 g / 10 min or more;

[0090] It can be seen from Example 1 and Comparative Examples 1-3 that when any one of aluminum diethylphosphinate and melamine polyphosphate is missing, although the melt index of the obtained product increases, the flame retardancy of the product significantly decreases, the flame retardancy grade cannot reach V-2, and the average flame retardancy ability and flame retardancy stability also significantly decrease, T average > 30 s, T longest > 30 s, and when melamine polyphosphate is not added, the tensile strength and impact strength of the obtained product also significantly decrease; when phosphate ester is not added, although the flame retardancy grade of the obtained product changes little, the average flame retardancy ability and flame retardancy stability also significantly decrease, and the fluidity of the obtained product significantly becomes worse, and the melt index decreases by 72.13% compared with Example 1; it can be seen from Example 1 and Comparative Examples 4-5 that when the total mass parts of aluminum diethylphosphinate, melamine polyphosphate and phosphate ester remain unchanged, but the relative mass parts of the three change, if not within the addition parts range defined in the present invention, the average flame retardancy ability and flame retardancy stability of the obtained product significantly decrease, compared with Example 1, the increase rate of T average is more than 351.43%, and the increase rate of T longest is more than 335.19%; it can be seen from Example 1 and Comparative Examples 6-7 that when an analog is used to replace aluminum diethylphosphinate, the average flame retardancy ability and flame retardancy stability of the obtained product significantly decrease, compared with Example 1, the increase rate of T average is more than 371.43%, and the increase rate of T longest is more than 377.78%, and the tensile strength and impact strength also show a certain downward trend. When a similar product is used to replace melamine polyphosphate, although the fluidity of the obtained product significantly increases, the flame retardancy significantly decreases, the flame retardancy grade cannot reach V-2, and the average flame retardancy ability and flame retardancy stability also significantly decrease, T average > 30 s, T longest > 30 s, and at the same time, the tensile strength and impact strength of the obtained product also significantly decrease, compared with Example 1, the tensile strength decreases by 17.24%, and the impact strength decreases by 17.65%;

[0091] It can be seen from Example 1 and Examples 7-9 that the intrinsic viscosity of PBT resin will have an obvious impact on the performance of the product. When the intrinsic viscosity of PBT resin is not within the further preferred range, the comprehensive performance of the obtained product shows a certain downward trend. Specifically, when the intrinsic viscosity of PBT resin is further preferably 0.7-1.0 dL / g, the comprehensive effect of the obtained product is more excellent. Specifically, the flame retardancy grades of the obtained products are all V-0 grade, among which T average is below 5.7 s, T longest is below 7.8 s, the tensile strength is above 116 MPa, and the impact strength is 8.5 kJ / m 2 The above, the melt index is 8.9 g / 10 min or more;

[0092] It can be seen from Example 1 and Examples 10-12, Example 1 and Examples 13-15, Example 1 and Examples 16-17, and Example 1 and Examples 18-19 that the selection of the glass fiber diameter, the average particle size of aluminum diethylphosphinate, melamine polyphosphate, and the type of phosphate ester also affects the comprehensive performance of the product.

[0093] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A PBT composite material, characterized in that, The PBT composite material comprises the following components in parts by mass: 30 - 60 parts of PBT resin, 25 - 40 parts of alkali-free glass fiber, 12 - 20 parts of aluminum diethylphosphinate, 2 - 8 parts of melamine polyphosphate, and 1 - 4 parts of phosphate ester; The average particle size of the aluminum diethylphosphinate is 8 - 42 μm; The intrinsic viscosity of the PBT resin measured with reference to GB / T 14190 - 2017 is 0.6 - 0.98 dL / g; In the PBT composite material, the mass ratio of aluminum diethylphosphinate, melamine polyphosphate, and phosphate ester is aluminum diethylphosphinate:melamine polyphosphate:phosphate ester = (14 - 16):6:(2 - 3); Or, in the PBT composite material, the mass ratio of aluminum diethylphosphinate, melamine polyphosphate, and phosphate ester is aluminum diethylphosphinate:melamine polyphosphate:phosphate ester = 18:5:1; Or, in the PBT composite material, the mass ratio of aluminum diethylphosphinate, melamine polyphosphate, and phosphate ester is aluminum diethylphosphinate:melamine polyphosphate:phosphate ester = 12:2:1; Or, in the PBT composite material, the mass ratio of aluminum diethylphosphinate, melamine polyphosphate, and phosphate ester is aluminum diethylphosphinate:melamine polyphosphate:phosphate ester = 20:8:

4.

2. The PBT composite material according to claim 1, characterized in that, At least one of the following (a) - (c): (a) The glass fiber is alkali-free glass fiber treated with a coupling agent, with a diameter of 5 - 20 μm; (b) The average particle size of the melamine polyphosphate is 7 - 10 μm; (c) The intrinsic viscosity of the PBT resin measured with reference to GB / T 14190 - 2017 is 0.7 - 0.98 dL / g.

3. The PBT composite material according to claim 1, characterized in that, The phosphate ester is at least one of triphenyl phosphate, aryl phosphate ester, resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), resorcinol bis[bis(2,6-dimethylphenyl) phosphate], and resorcinol bis(diphenyl phosphate).

4. The PBT composite material according to claim 1, wherein The PBT composite material further comprises 0.001 - 4 parts of toughening agent and 0.001 - 1 part of processing aid.

5. The PBT composite material according to claim 4, wherein, The toughening agent is at least one of ethylene-acrylate-glycidyl methacrylate terpolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate, and glycidyl methacrylate grafted ethylene-octene copolymer.

6. The PBT composite material according to claim 4, wherein The processing aid is at least one of lubricant and antioxidant.

7. The preparation method of the PBT composite material according to any one of claims 1-6, characterized in that, The preparation method comprises the following steps: Weigh the dried raw materials and mix them, then send them into a twin-screw extruder, and obtain the PBT composite material through extrusion, strand drawing, cooling, pelletizing, and drying.

8. The preparation method according to claim 7, characterized in that, The parameters of the twin-screw extruder are: the feeding speed is 450 - 800 kg / hour; the temperatures of each section of the screw from the feeding port to the head are 220 - 230 °C, 230 - 240 °C, 230 - 240 °C, 240 - 250 °C, 250 - 260 °C, 240 - 250 °C, 240 - 250 °C, 230 - 240 °C, 220 - 230 °C; the screw speed is 250 - 400 rpm.

9. Use of the PBT composite material according to any one of claims 1-6 in ultra-thin electronic components.

Images