Continuous glass fiber-reinforced thermoplastic composite material and method of making and use thereof

Abstract

The application discloses a continuous glass fiber reinforced thermoplastic composite material and a preparation method and application thereof, and the continuous glass fiber reinforced thermoplastic composite material comprises the following components in parts by weight: 34-81 parts of polypropylene; 15-60 parts of surface modified continuous glass fiber; and 2-6 parts of a compatilizer; the surface modified continuous glass fiber is coated with flat glass fiber powder on the surface. The application can improve the characteristics of melt molecular chain segment orientation and crystallization orientation caused by the orientation of the continuous glass fiber by coating the flat glass fiber powder on the surface of the continuous glass fiber, so that the cracking problem of metal insert injection molding after high-low temperature cold and hot cycle and the warping defect of the workpiece are solved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a glass fiber reinforced thermoplastic composite material, its preparation method, and its application. Background Technology

[0002] Long glass fiber reinforced polypropylene (LFT-PP) possesses high strength, high rigidity, excellent impact resistance and creep resistance, while also exhibiting low density, low warpage, and outstanding dimensional stability. By forming a three-dimensional network structure within the matrix using long glass fibers (length > 3mm), it significantly improves mechanical properties (strength increased by more than 20% compared to traditional short glass fibers) and achieves weight reduction of 20-50%. However, it has inherent drawbacks such as low surface hardness, flammability (oxygen index 17.4%), and poor compatibility with glass fiber interfaces. LFT-PP is primarily used in lightweight automotive structural components (such as front-end modules, tailgate inner panels, battery trays, etc.), high-load-bearing components in home appliances (such as washing machine drums, air conditioner fan impellers), and functional electronic components (such as 5G base station antenna covers, electrical control boxes). It is gradually replacing metals and engineering plastics (such as nylon) to reduce costs, and its applications are expanding into military packaging, energy storage equipment housings, and other fields. While LFT-PP boasts excellent overall strength, stiffness, and lightweight properties, certain applications require localized areas to withstand extremely high loads (such as bolted connections, hinge structures, and electrical interfaces). In these cases, its performance cannot match that of metal, necessitating integration through metal insert structures. For example, automotive structural components like rearview mirror brackets, engine underbody protection plates, and seatbelt anchors utilize inserts to provide reliable pull-out force and thread strength. Similarly, washing machine drum bushings, high-pressure water pump housings, and electronic connectors achieve long-term stability and functional integration through inserts.

[0003] However, LFT-PP injection molding with metal inserts presents several problems, such as differences in shrinkage rates due to the orientation of the glass fiber in the injection flow direction, stress concentration around the insert due to differences in the coefficient of thermal expansion, poor glass fiber wetting affecting the bonding between the material and the metal interface, and weak weld lines around the metal insert. As LFT-PP applications become increasingly widespread, these problems with metal insert injection molded products seriously affect product reliability and lifespan, and currently, no technology has been disclosed that can overcome these issues.

[0004] At the same time, LFT-PP also has a relatively obvious warping defect.

[0005] CN119798845A discloses a long glass fiber reinforced polypropylene material with high weld line strength and its preparation method, which introduces short, flat glass fibers to enhance the strength of the weld joint, hinder microcrack propagation, and improve tensile and shear strength. CN116622156A discloses a multi-scale, low-warpage, high weld line strength long glass fiber reinforced recycled polypropylene composite material and its preparation method, which introduces flat, long glass fibers to improve warpage deformation and increase weld line strength. CN113667214B ​​involves spraying a suspension of riveted ultra-short glass fibers onto the surface of continuous glass fibers after unrolling and baking at high temperature, causing the ultra-short fibers to adhere and improving the unidirectional transverse tensile strength of the composite material. The above-disclosed patents do not address the issue of LFT-PP metal insert injection molding. Summary of the Invention

[0006] The purpose of this invention is to provide a continuous glass fiber reinforced thermoplastic composite material with low warpage and no cracking after high and low temperature thermal cycling of metal insert injection molding, as well as its preparation method and application.

[0007] This invention is achieved through the following technical solution: A continuous glass fiber reinforced thermoplastic composite material, comprising the following components by weight: Polypropylene 34-81 parts; 15-60 parts of surface-modified continuous glass fiber; 2-6 parts compatibilizer; The surface-modified continuous glass fiber is coated with flat glass fiber powder.

[0008] In the continuous glass fiber reinforced thermoplastic composite material of the present invention, the content of polypropylene can be any value or a range between 34 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, and 81 parts; the content of surface-modified continuous glass fiber can be any value or a range between 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, and 60 parts; and the content of compatibilizer can be any value or a range between 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, and 6 parts.

[0009] In the continuous glass fiber reinforced thermoplastic composite material of the present invention, polypropylene accounts for not less than 33 wt% of the total weight.

[0010] The polypropylene capable of achieving the objectives of this invention can be at least one of homopolymer polypropylene and copolymer polypropylene. Preferably, the polypropylene is a blend of homopolymer polypropylene and copolymer polypropylene, with the copolymer polypropylene accounting for 40-95 wt% of the total weight of polypropylene, more preferably 60-90 wt%. Experiments have shown that when copolymer polypropylene is blended with homopolymer polypropylene, the crystallization behavior of homopolymer polypropylene can be further suppressed, and the defects caused by the difference in linear expansion coefficients between the material and the metal leading to cracking at the melt interface can be further improved.

[0011] The melt flow index of homopolymer polypropylene or copolymer polypropylene at 230℃ / 2.16kg can be 1-60g / min (the test standard for melt flow index is ISO 1133-1-2011).

[0012] The flat glass fiber powder accounts for 0.03-0.12 wt% of the total weight of the surface-modified continuous glass fiber. The percentage of flat glass fiber powder in the total weight of the surface-modified continuous glass fiber can be any value or a range between 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, and 0.13 wt%.

[0013] The test method for determining the proportion of flat glass fiber powder in the total weight of surface-modified continuous glass fibers is as follows: The sample is placed in a muffle furnace at 500℃ for 1 hour to remove organic components. To prevent sintering, a lower temperature and longer calcination time can be used to obtain equivalent results. The ablation residue containing glass fibers and glass fiber powder is then weighed to obtain the total weight of the glass fibers and glass fiber powder. The ablation residue is placed in a 650-mesh ultrasonic sieve, and the sieve is subjected to high-frequency vibration (20-40kHz) to prevent glass fiber powder from clogging the mesh. After ultrasonic treatment for 30 minutes, the weight of the glass fiber powder below the sieve is weighed, and its proportion in the total weight of the glass fibers and glass fiber powder is calculated to obtain the percentage of flat glass fiber powder.

[0014] The average particle size of the flat glass fiber powder is less than 50 micrometers. The average particle size of the flat glass fiber powder can be 0.1-50 micrometers. Preferably less than 20 micrometers, more preferably less than 15 micrometers. In one embodiment, the average particle size of the flat glass fiber powder is 47-10 micrometers. The average particle size is obtained by laser particle size analyzer. The flat glass fiber powder is obtained by grinding flat glass fibers.

[0015] The ratio of the major axis diameter of the cross-section of the flat glass fiber to the minor axis diameter perpendicular to it is not less than 2, and can be 2-5. The major axis diameter of the cross-section can be 6-40 micrometers.

[0016] The continuous glass fiber can be a continuous round glass fiber or a continuous flat glass fiber.

[0017] The ratio of the major axis diameter of the cross-section of continuous flat glass fiber to the minor axis diameter perpendicular to it is not less than 2, and can be 2-5. The major axis diameter of the cross-section can be 6-40 micrometers.

[0018] The diameter range of the continuous circular glass fiber is 10-25 micrometers.

[0019] Preferably, the surface-modified continuous glass fiber is coated with a coupling agent and flat glass fiber powder.

[0020] Surface-modified continuous glass fibers can be commercially available products or obtained by self-production. For example, they can be coated onto the surface of continuous glass fibers using conventional coating methods in the art, thereby achieving the coating of flat glass fiber powder onto the surface of continuous glass fibers. For example, a self-production method can be the spraying method in the art, specifically: Step A, grinding flat glass fibers to obtain flat glass fiber powder with a preset average particle size, mixing it evenly with an optional coupling agent (the weight ratio of coupling agent to flat glass fiber powder is 0.01-0.2:1), and pre-treating it at 15-40℃ for 15-60 min; Step B, mixing the flat glass fiber powder obtained in Step A with water, stirring evenly, preparing a 0.2-2wt% suspension solution, dispersing it evenly (ultrasonic treatment can be performed), to obtain a flat glass fiber powder suspension; Step C, spraying the flat glass fiber powder suspension onto the surface of continuous glass fibers, and drying it by baking at a high temperature of 400-500℃ to obtain surface-modified continuous glass fibers.

[0021] Surface-modified continuous glass fibers can also be prepared by immersion method. The difference from the above method is that step C is to immerse the continuous glass fibers in a suspension of flat glass fiber powder so that the flat glass fiber powder adheres to the surface of the continuous glass fibers.

[0022] The compatibilizer is selected from polar monomer-grafted olefin polymers; the polar monomer is selected from at least one of maleic anhydride groups, acrylic acid groups, and acrylate derivative groups; the olefin polymer is selected from at least one of polyethylene, polypropylene, ethylene-α-olefin copolymers, and styrene-butadiene copolymers. The grafting rate ranges from 0.2wt% to 2wt%. For maleic anhydride and acrylic acid group grafting, a titration method is used, i.e., saponification with excess alkali solution, followed by back titration with acid solution, and the neutralization amount is calculated to obtain the grafting rate. For acrylate grafting, the sample is hot-pressed into a film, and the carbonyl characteristic peak (≈1730 cm⁻¹) is tested. -1 ) and polymer internal standard peaks (such as 841 cm⁻¹ in PP) -1 The grafting rate is calculated by converting the absorbance ratio of the two light sources using an empirical formula.

[0023] Acrylic ester derivatives may have groups such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, dimethylaminoethyl acrylate, acrylamide, or hexafluorobutyl acrylate.

[0024] Specifically, the compatibilizer is selected from maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted ethylene-α-olefin copolymer, maleic anhydride-grafted styrene-butadiene copolymer, acrylic group-grafted polyethylene, acrylic group-grafted polypropylene, acrylic group-grafted ethylene-α-olefin copolymer, acrylic group-grafted styrene-butadiene copolymer, etc.

[0025] The amount of coupling agent can be selected from 0-0.5 parts, for example, 0.01-0.5 parts. The coupling agent is selected from at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents.

[0026] Silane coupling agents can be selected from aminosilane coupling agents, epoxysilane coupling agents, methoxysilane coupling agents, and vinylsilane coupling agents.

[0027] The titanate coupling agent is selected from at least one of monoalkoxy pyrophosphate type titanate coupling agents, monoalkoxy type titanate coupling agents, coordination type titanate coupling agents, and chelation type titanate coupling agents; specifically, it can be bis(triethanolamine) titanate diisopropyl ester; or optionally, bis(triethanolamine) titanate diisopropyl ester.

[0028] The aluminate coupling agent is selected from at least one of monoalkoxy pyrophosphate type aluminate coupling agents, monoalkoxy type aluminate coupling agents, coordination type aluminate coupling agents, and chelation type aluminate coupling agents.

[0029] You may choose to add 0-2 parts of an additive, such as 0.01-2 parts, depending on the actual needs; the additive is selected from at least one of antioxidants, light stabilizers, and lubricants.

[0030] The antioxidants are hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants. The hindered phenolic antioxidant is selected from one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], (2,4,6-trioxo-1,3,5-triazine-1,3,5(2H,4H,6H)-triyl)trivinyltris[3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, and 1,3,5-(3,5-di-tert-butyl-4-hydroxybenzyl)-triazine-2,4,6-(1H,3H,5H)-trione. The phosphite antioxidant is tris(2,4-di-tert-butylphenyl) phosphite and / or pentaerythritol di(2,4-di-tert-butylphenyl) phosphite. The thioester antioxidant is bis(octadecyl) thiodipropionate and / or dilauryl thiodipropionate.

[0031] The lubricant may be at least one of fluorosilicone polymer lubricants, stearate lubricants, fatty acid lubricants, and stearate ester lubricants; the stearate lubricant is selected from at least one of calcium stearate, magnesium stearate, and zinc stearate; the fatty acid lubricant is selected from at least one of fatty acids, fatty acid derivatives, and fatty acid esters; and the stearate ester lubricant is selected from pentaerythritol stearate.

[0032] The present invention discloses a method for preparing a continuous glass fiber reinforced thermoplastic composite material, comprising the following steps: mixing polypropylene and a compatibilizer uniformly; adding the mixture to the main feed port of a twin-screw extruder, extruding the molten material into an impregnation die for melt impregnation with surface-modified continuous glass fibers (temperature 240-260℃), cooling, curing, and pelletizing to obtain a glass fiber reinforced polypropylene composite material. The particle length range is 5-20 mm, wherein the twin-screw extruder has a temperature of 170-250℃ and a screw speed of 450-500 rpm.

[0033] The application of the continuous glass fiber reinforced thermoplastic composite material of the present invention is used to prepare injection-molded parts containing metal inserts.

[0034] The present invention also relates to an injection-molded part containing a metal insert, wherein the injection-molded structural part of the part comprises a component made of the above-mentioned continuous glass fiber reinforced thermoplastic composite material.

[0035] The present invention has the following beneficial effects: Surface-modified continuous glass fibers can improve the defects caused by the orientation of glass fibers on both sides of the weld line, which leads to the orientation and crystallization behavior of molecular chain segments. This causes the polypropylene melt to be oriented and epiphytic crystallized along the glass fiber surface, resulting in significant discontinuities in the arrangement or distribution of molecular chain segments at the melt interface. This effectively improves the defects caused by the difference in linear expansion coefficients between the material and the metal under thermal cycling, which leads to cracking at the melt interface. Detailed Implementation

[0036] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0037] The raw materials for this invention are sourced as follows: Homopolymer polypropylene A: 17g / 10min, PP M17HN, Hainan Petrochemical; Homopolymer polypropylene B: 32g / 10min, PP 320 powder, Maoming Petrochemical; Homopolymer polypropylene C: 55g / 10min, PP H9018H, Lanzhou Petrochemical; Copolymer polypropylene A: 9g / 10min, PP M09, Wuhan Petrochemical; Copolymer polypropylene B: 25g / 10min, PP EP548R, Zhenhai Petrochemical; Copolymer polypropylene C: 35g / 10min, PP K9930H(FP), Guangzhou Petrochemical; Flat glass fiber powder is made by grinding flat glass fibers of grade ECS301HP-3-M4 (Chongqing International Composite Materials Co., Ltd.) using a ball mill to obtain the following specific average particle size: Flat glass fiber powder A: average particle size is 47.2 micrometers; Flat glass fiber powder B: average particle size is 19.0 micrometers; Flat glass fiber powder C: average particle size is 10.6 micrometers; Round glass fiber powder: The average particle size after grinding round glass fibers is 31.4 micrometers (the grade of round glass fiber is ECS301HP-3, Chongqing International Composite Materials Co., Ltd.). Glass micro powder: average particle size 6.3 micrometers, T836, Anmi Micro-Nano New Materials (Guangzhou) Co., Ltd.; Continuous circular glass fiber: EDR240-T838D, with a diameter of 17 micrometers, made by Taishan Glass Fiber; Continuous flat glass fiber: TFG-1000-T838J, major axis diameter 18 micrometers, minor axis diameter 4 micrometers, Taishan glass fiber; Surface-modified continuous circular glass fiber A: Flat glass fiber powder C accounts for 0.03 wt% of the surface-modified continuous circular glass fiber, and is self-made; Surface-modified continuous round glass fiber B-1: Flat glass fiber powder C accounts for 0.08 wt% of the surface-modified continuous round glass fiber, and is self-made; Surface-modified continuous circular glass fiber B-2: Flat glass fiber powder B accounts for 0.08 wt% of the surface-modified continuous circular glass fiber, and is self-made; Surface-modified continuous circular glass fiber B-3: Flat glass fiber powder A accounts for 0.08 wt% of the surface-modified continuous circular glass fiber, and is self-made; Surface-modified continuous round glass fiber C: Flat glass fiber powder C accounts for 0.12 wt% of the surface-modified continuous round glass fiber, and is self-made; Surface-modified continuous flat glass fiber: Flat glass fiber powder C accounts for 0.10 wt% of the surface-modified continuous flat glass fiber, and is self-made; Surface-modified continuous circular glass fiber D: 0.08 wt% of the surface-modified continuous circular glass fiber, self-made; Surface-modified continuous circular glass fiber E: Glass micro powder accounts for 0.08 wt% of the surface-modified continuous circular glass fiber, and is self-made; The method for making the above-mentioned surface-modified continuous glass fiber is as follows: flat glass fiber powder (D and E are respectively round glass fiber powder and glass micro powder) is mixed evenly with coupling agent (KH-550) at a ratio of 1:0.03, then pretreated at 25℃ for 30 min, then mixed with water and stirred evenly to prepare a 0.2-2wt% suspension solution, which is then ultrasonically treated to disperse evenly to obtain a flat glass fiber powder suspension; the flat glass fiber powder suspension is sprayed onto the surface of continuous round (or flat) glass fiber, and then baked and dried at a high temperature of 400-500℃ to obtain surface-modified continuous glass fiber.

[0038] Compatibilizer A: Maleic anhydride grafted polypropylene: CMG5701, Jia Yi Rong Polymer (Shanghai) Co., Ltd. Compatibilizer B: Acrylic group grafted polyethylene: HG540, Jiangxi Weike Oil & Chemical Co., Ltd.; Compatibilizer C: Glycidyl methacrylate grafted ethylene-α-olefin copolymer: SOG-03, Jia Yi Rong Polymer (Shanghai) Co., Ltd.; Coupling agent: aminopropyltriethoxysilane, KH-550; Antioxidants: MIANOX330 and MIANOX PEPQ are compounded in a ratio of 1:1; 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, MIANOX330, Nanjing Milan Chemical Co., Ltd.; tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylyl diphosphite, MIANOX PEPQ, Nanjing Milan Chemical Co., Ltd.; Lubricants: Fluorosilicone polymer lubricant, Javachem03MC, Zhejiang Jiahua Fine Chemical Co., Ltd.; Preparation method of continuous glass fiber reinforced thermoplastic composite for examples and comparative examples, including the following steps: Mix polypropylene and compatibilizer evenly; Add the above-mentioned evenly mixed materials into the main feeding port of a twin-screw extruder, extrude the molten materials into an impregnation mold to carry out melt impregnation with surface-modified continuous glass fibers (temperature 240 - 260 °C), cool, cure, and pelletize. The pellet length range is 10 mm to obtain a continuous glass fiber reinforced thermoplastic composite. Among them, for the twin-screw extruder: the temperature is 170 - 250 °C, and the screw speed is 450 - 500 rpm.

[0039] Testing methods for each item: High and low temperature cycling stress cracking test method: Inject the sample into an injection molding mold to form a square plate of 100 mm × 100 mm × 2 mm, and place a steel disc with a diameter of 60 mm and a thickness of 1.8 mm on the side far from the sprue in the mold. The tangent of the disc is 10 mm away from the side far from the sprue, and it is centered with the sample and the sprue position. The thermal cycling test stores the sample in a high and low temperature environmental chamber for one cycle (12 hours), including the following multiple temperature and humidity intervals: (1) Heating section: It takes 60 min to heat from 23 °C to 80 °C, maintaining a relative humidity of 80%; (2) Constant temperature section: Store at a relative humidity of 80% and a temperature of 80 °C for 240 min; (3) Cooling section: It takes 120 min to cool from 80 °C to -40 °C; (4) Constant temperature section: Store at a temperature of -40 °C for 240 min; (5) Heating section: It takes 60 min to heat from -40 °C to 23 °C, and the relative humidity is restored to 30%. Note: After each cycle of the thermal cycling test for the plastic-metal insert sample, observe whether there is cracking around the metal insert. When cracking occurs, stop the test and record the number of cycle times. ≥ 10 times without cracking is qualified, and the more times the better. In this invention, the maximum number of tests is 15 times. No cracking at the 15th time indicates > 15 times.

[0040] Warpage deformation degree test: Inject the sample into an injection molding mold to form a square plate of 100 mm × 100 mm × 2 mm, and fix it on a special fixture for testing warpage. Use a laser rangefinder to measure the four corners of the sample plate, and determine the warpage deformation degree according to the degree of deviation of the four corners from the horizontal plane.

[0041] Table 1: Weight contents and test results of each component in the continuous glass fiber reinforced thermoplastic composites of Examples 1-14 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Homopolymer Polypropylene A 50 30 Homopolymer polypropylene B 50 Homopolymer polypropylene C 50 Copolymer Polypropylene A 50 20 Copolymer Polypropylene B 50 Copolymer polypropylene C 50 Surface-modified continuous circular glass fiber A 40 40 40 40 40 40 40 Compatibilizer A 4 4 4 4 4 4 4 Coupling agent 0.3 0.3 0.3 0.3 0.3 0.3 0.3 antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 0.3 lubricant 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Number of cycles, times 11 10 10 12 12 11 13 Warping deformation, mm 1.0 1.2 1.5 0.3 0.4 0.4 0.5 Continued from Table 1: Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Homopolymer Polypropylene A 20 5 2.5 Homopolymer polypropylene B 15 14 24 32 Homopolymer polypropylene C Copolymer Polypropylene A 30 45 47.5 Copolymer Polypropylene B Copolymer polypropylene C 35 21 36 48 Surface-modified continuous circular glass fiber A 40 40 40 40 60 40 15 Compatibilizer A 4 4 4 4 6 4 2 Coupling agent 0.3 0.3 0.3 0.3 0.3 0.3 antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 lubricant 0.3 0.3 0.3 0.3 0.3 0.3 Number of cycles, times >15 >15 >15 14 >15 >15 >15 Warping deformation, mm 0.4 0.3 0.2 0.2 0.8 0.5 0.4 As can be seen from Examples 1-11, the preferred blending ratio of homopolymer polypropylene / copolymer polypropylene results in better resistance to high and low temperature cyclic stress cracking and warpage of less than 1 mm.

[0042] Table 2: Weight contents and test results of each component in the continuous glass fiber reinforced thermoplastic composites of Examples 15-21 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Homopolymer polypropylene B 15 15 15 15 15 15 15 Copolymer polypropylene C 35 35 35 35 35 35 35 Surface-modified continuous circular glass fiber A 40 40 Surface-modified continuous circular glass fiber B-1 40 Surface-modified continuous circular glass fiber B-2 40 Surface-modified continuous circular glass fiber B-3 40 Surface-modified continuous circular glass fiber C 40 Surface-modified continuous flat glass fiber 40 Compatibilizer A 4 4 4 4 4 Compatibilizer B 4 Compatibilizer C 4 Coupling agent 0.3 0.3 0.3 0.3 0.3 0.3 0.3 antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 0.3 lubricant 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Number of cycles, times >15 14 12 >15 >15 >15 >15 Warping deformation, mm 0.3 0.3 0.5 0.2 0.1 0.4 0.4 As can be seen from Examples 9 / 15-18, the average particle size of the preferred flat glass fiber powder results in better resistance to high and low temperature cyclic stress cracking and anti-warping performance.

[0043] The continuous glass fiber reinforced thermoplastic composite material of the present invention has a cycle count of not less than 10 times and a warpage deformation of not more than 1.7 mm.

[0044] Table 3: Weight parts of each component and test results of comparative glass fiber reinforced polypropylene composites Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Homopolymer polypropylene B 15 15 15 15 15 Copolymer polypropylene C 35 35 35 35 35 Surface-modified continuous circular glass fiber A 40 Surface-modified continuous circular glass fiber D 40 Surface-modified continuous circular glass fiber E 40 Continuous circular glass fiber 40 Continuous flat glass fiber 40 Compatibilizer A 4 4 4 4 0.5 Coupling agent 0.3 0.3 0.3 0.3 0.3 antioxidants 0.3 0.3 0.3 0.3 0.3 lubricant 0.3 0.3 0.3 0.3 0.3 Number of cycles, times 4 3 2 9 8 Warping deformation, mm 2.3 2.2 2.3 0.8 2.0 As can be seen from Comparative Example 1 / 2, the purpose of this invention cannot be achieved when using round glass fiber ground micro powder or glass micro powder modified continuous glass fiber.

[0045] As shown in Comparative Example 5, when the compatibilizer content is too low, the resistance to high and low temperature cyclic stress cracking is poor, and the warping is severe.

Claims

1. A continuous glass fiber reinforced thermoplastic composite material, characterized in that, By weight, it includes the following components: Polypropylene 34-81 parts; 15-60 parts of surface-modified continuous glass fiber; 2-6 parts compatibilizer; The surface-modified continuous glass fiber is coated with flat glass fiber powder.

2. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The polypropylene is selected from at least one of homopolymer polypropylene and copolymer polypropylene.

3. The continuous glass fiber reinforced thermoplastic composite material according to claim 2, characterized in that, The polypropylene is a blend of homopolymer polypropylene and copolymer polypropylene, with the copolymer polypropylene accounting for 40-95 wt% of the total weight of polypropylene.

4. The continuous glass fiber reinforced thermoplastic composite material according to claim 3, characterized in that, The polypropylene is a blend of homopolymer polypropylene and copolymer polypropylene, with the copolymer polypropylene accounting for 60-90 wt% of the total weight of polypropylene.

5. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The flat glass fiber powder accounts for 0.03-0.12 wt% of the total weight of the surface-modified continuous glass fiber.

6. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The surface-modified continuous glass fiber is coated with a coupling agent and flat glass fiber powder.

7. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The average particle size of the flat glass fiber powder is less than 50 micrometers.

8. The continuous glass fiber reinforced thermoplastic composite material according to claim 7, characterized in that, The average particle size of the flat glass fiber powder is less than 20 micrometers.

9. The continuous glass fiber reinforced thermoplastic composite material according to claim 8, characterized in that, The average particle size of the flat glass fiber powder is less than 15 micrometers.

10. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The diameter of the continuous glass fiber is in the range of 10-25 micrometers, and the continuous glass fiber is selected from continuous round glass fiber and / or continuous flat glass fiber.

11. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The compatibilizer is selected from polar monomer-grafted olefin polymers; the polar monomer is selected from at least one of maleic anhydride groups, acrylic acid groups, and acrylate derivative groups; the olefin polymer is selected from at least one of polyethylene, polypropylene, ethylene-α-olefin copolymers, and styrene-butadiene copolymers.

12. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The mixture also includes 0-0.5 parts by weight of coupling agent, wherein the coupling agent is selected from at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents.

13. The continuous glass fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The product also includes 0-2 parts by weight of additives; the additives are selected from at least one of antioxidants, light stabilizers, and lubricants.

14. The method for preparing continuous glass fiber reinforced thermoplastic composite material according to any one of claims 1-13, characterized in that, The process includes the following steps: mixing polypropylene and compatibilizer evenly; adding the mixture to the main feed port of a twin-screw extruder, extruding the molten material into an impregnation die for melt impregnation with surface-modified continuous glass fibers, cooling, curing, and pelletizing to obtain a continuous glass fiber reinforced thermoplastic composite material.

15. The application of the continuous glass fiber reinforced thermoplastic composite material according to any one of claims 1-13, characterized in that, Used for manufacturing injection molded parts containing metal inserts.

16. An injection-molded part containing a metal insert, characterized in that, The injection-molded structural component of the said part includes a component made of the continuous glass fiber reinforced thermoplastic composite material as described in any one of claims 1-13.