High-impact low-temperature-resistant engineering plastic composite material and preparation process thereof

Abstract

The invention relates to the technical field of plastic composite materials, in particular to a high-impact-resistance and low-temperature-resistance engineering plastic composite material and a preparation process thereof, and the high-impact-resistance and low-temperature-resistance engineering plastic composite material is prepared from the following raw materials in parts by weight: 55-85 parts of a double-resin blending system; 20 to 40 parts of a toughening system; 20 to 35 parts of a reinforcing system; 0.3 to 0.6 part of a main antioxidant; 0.2 to 0.4 part of an auxiliary antioxidant; 0.8 to 1.5 parts of an internal lubricant; 0.5 to 1.2 parts of an external lubricant; 1-3 parts of an ultraviolet screening agent; and 0.3 to 0.8 part of a migration type lubricant. According to the invention, through the synergistic effect of a double-resin blending system, the balance between excellent toughness and strength is maintained at a low temperature, through the nanoscale dispersion and low-temperature compatibility design of the specific flexibilizer, the impact resistance of the material in an extremely cold environment is significantly improved, and through the reinforcement refining treatment and interface strengthening technology, the impact resistance of the material in an extremely cold environment is greatly improved. The low-temperature crack growth is effectively inhibited, the high modulus effect is maintained, the problems that the impact strength is greatly reduced and the brittleness is increased in a low-temperature environment in the traditional engineering plastic are solved, and the application scene is wider.

Description

Technical Field

[0001] This invention relates to the field of plastic composite materials technology, specifically to high-impact, low-temperature resistant engineering plastic composite materials and their preparation process. Background Technology

[0002] Traditional engineering plastics often suffer from a significant decrease in impact strength and an increase in brittleness in low-temperature environments, making it difficult to meet the material toughness requirements of some equipment components used in cold regions or low-temperature operating conditions.

[0003] Based on this, the present invention provides a high-impact, low-temperature resistant engineering plastic composite material and its preparation process to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a high-impact, low-temperature resistant engineering plastic composite material and its preparation process, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention proposes a high-impact, low-temperature resistant engineering plastic composite material, which is composed of the following raw materials in parts by weight:

[0007] Two-resin blend system: 55-85 parts;

[0008] The dual-resin blend system is composed of polyamide 66 resin and polybutylene terephthalate resin, wherein the polyamide 66 resin comprises 40-60 parts and the polybutylene terephthalate resin comprises 15-25 parts.

[0009] Toughening system: 20-40 parts;

[0010] The toughening system is composed of a hydrogenated styrene-butadiene block copolymer elastomer and a maleic anhydride-grafted ethylene-octene copolymer, wherein the hydrogenated styrene-butadiene block copolymer elastomer comprises 12-18 parts and the maleic anhydride-grafted ethylene-octene copolymer comprises 8-12 parts.

[0011] Enhanced system: 20-35 copies;

[0012] The reinforcing system is composed of glass fiber and talc, wherein the glass fiber comprises 15-25 parts and the talc comprises 5-10 parts.

[0013] Main antioxidant: 0.3-0.6 parts;

[0014] Antioxidant supplement: 0.2-0.4 parts;

[0015] Internal lubricant: 0.8-1.5 parts;

[0016] External lubricant: 0.5-1.2 parts;

[0017] UV shielding agent: 1-3 parts;

[0018] Migration-type lubricant: 0.3-0.8 parts.

[0019] Preferably, the primary antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0020] Preferably, the auxiliary antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0021] Preferably, the internal lubricant is ethylene bis-stearamide.

[0022] Preferably, the external lubricant is polytetrafluoroethylene ultrafine powder.

[0023] Preferably, the ultraviolet shielding agent is nano-titanium dioxide.

[0024] Preferably, the migratory lubricant is erucamide.

[0025] Preferably, the glass fiber is alkali-free chopped glass fiber with surface silane treatment, and the preparation process is as follows:

[0026] A1. 50wt% silicon oxide, 15wt% aluminum oxide, 25wt% calcium oxide and 10wt% magnesium oxide are melted and drawn into wires in a platinum crucible at 1580℃, with the diameter of the single wire controlled at 9 micrometers.

[0027] A2. Fibers chopped to 3 mm were placed in an argon:oxygen mixture of 95:5 and subjected to low-temperature plasma treatment for 120 seconds at a vacuum of 10⁻² Pascal and a radio frequency power of 35 kW to increase the surface hydroxyl density to 8.2 / m².

[0028] A3. Mix γ-aminopropyltriethoxysilane with nano-silica sol at a mass ratio of 1:0.8, and hydrolyze for 60 minutes under ultrasonic power of 800 W and temperature of 45℃ to form a composite treatment solution with a solid content of 22%.

[0029] A4. Immerse the plasma-treated fibers in a hydrolysate and treat them for 25 minutes in an ultrasonic field with a frequency of 28 kHz and a power density of 0.5 W / cm³, while controlling the immersion temperature at 50°C.

[0030] A5. Surface-treated alkali-free short-cut glass fibers were prepared by microwave gradient curing:

[0031] A51. Three-stage microwave curing is employed:

[0032] First stage: 800 watts power, 80℃ drying for 5 minutes;

[0033] Second stage: 1200 watts power, 110℃ reaction for 8 minutes;

[0034] Third stage: 500 watts power, 150℃ crosslinking for 10 minutes.

[0035] Based on the above-mentioned high-impact, low-temperature resistant engineering plastic composite material, this invention also proposes a preparation process for the high-impact, low-temperature resistant engineering plastic composite material, comprising the following steps:

[0036] S1. First, add 40-60 parts of polyamide 66 resin and 15-25 parts of polybutylene terephthalate resin to a high-speed mixer and premix for 5 minutes at 800 rpm under nitrogen protection and at 80°C. Then add 12-18 parts of hydrogenated styrene-butadiene block copolymer elastomer and 8-12 parts of maleic anhydride-grafted ethylene-octene copolymer, heat to 110±5°C, and mix for 8 minutes at 1200 rpm to allow the toughening agent to melt and coat the resin. Granules; finally, add 0.3-0.6 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.2-0.4 parts of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 0.8-1.5 parts of ethylene bis-stearamide, 0.5-1.2 parts of polytetrafluoroethylene ultrafine powder, 1-3 parts of nano titanium dioxide, and 0.3-0.8 parts of erucamide, and mix at 500 rpm for 10 minutes at 60°C to obtain a premix.

[0037] S2. First, place 15-25 parts of surface-treated alkali-free chopped glass fibers in an ultrasonic impregnation tank, pre-filling the tank with a suspension of 5-10 parts of nano-grade talc powder and anhydrous ethanol; then turn on an ultrasonic field with a frequency of 40 kHz and a power density of 1.2 W / cm³, and treat for 15 minutes under a vacuum of 0.08 MPa to embed the talc powder into the gaps between the fiber bundles; finally, after centrifugal dehydration, dry in a 100℃ hot air circulating box until the moisture content is ≤0.05%;

[0038] S3. First, feed the premixed material and the treated reinforcement into a co-rotating twin-screw extruder, using a seven-zone gradient temperature control:

[0039] Zone 1: 220±5℃; Zone 2: 240±5℃; Zone 3: 260±5℃; Zone 4 (Melting Section): 275±3℃; Zone 5: 265±3℃; Zone 6: 250±3℃; Zone 7: 235±3℃;

[0040] Then, the screw speed is controlled at 280 rpm and the torque is 65%. 0.5±0.1 MPa supercritical carbon dioxide is injected into the fourth zone to expand and mix the material. Finally, the material is pelletized underwater at 25℃ to obtain composite material particles with a particle size of 3 mm. The particles are then vacuum dried at -0.095 MPa and 80℃ until the moisture content is ≤0.02%.

[0041] S4. First, load the granules into a mold preheated to 110±5℃ using a mold temperature controller, and pre-press for 30 seconds at 10 MPa pressure; then start the variable frequency vibration device with a frequency of 25±2 Hz and an amplitude of 0.5±0.1 mm, while simultaneously raising the temperature to 235℃ at a rate of 5℃ / min, increasing the holding pressure to 25 MPa, and calculating the holding time based on the product wall thickness of 1.5 minutes / mm; finally, use gradient pressure reduction cooling.

[0042] Preferably, the gradient depressurization cooling in step S4 specifically comprises:

[0043] First stage: Cooling to 180°C under 15 MPa pressure, at a cooling rate of 30°C / minute;

[0044] Second stage: Cooling to 80°C under 5 MPa pressure at a cooling rate of 15°C / minute.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] This invention achieves a balance between excellent toughness and strength at low temperatures through the synergistic effect of a dual-resin blend system. By employing nanoscale dispersion and low-temperature compatibility design of specific toughening agents, it significantly enhances the impact resistance of materials in extremely cold environments. Through refined reinforcement and interface strengthening technology, it effectively suppresses low-temperature crack propagation and maintains high modulus. The introduction of supercritical fluid-assisted dispersion during melt blending ensures uniform distribution and good compatibility of the toughening agent within the matrix. Dynamic hot pressing combined with gradient cooling optimizes the internal crystalline structure, eliminates internal stress, and improves dimensional stability. The synergistic protection of composite antioxidants and a stabilizing system ensures the reliability of the material for long-term use in harsh temperature-changing environments. This invention solves the problem of significantly reduced impact strength and increased brittleness often seen in traditional engineering plastics at low temperatures, broadening its application scenarios. Detailed Implementation

[0047] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] I. Materials:

[0049] Unless otherwise specified, all components of the high-impact, low-temperature resistant engineering plastic composite material of this invention are commercially available.

[0050] This invention proposes a high-impact, low-temperature resistant engineering plastic composite material, which is composed of the following raw materials in parts by weight:

[0051] Two-resin blend system: 55-85 parts;

[0052] The dual-resin blend system is composed of polyamide 66 resin and polybutylene terephthalate resin, wherein the polyamide 66 resin comprises 40-60 parts and the polybutylene terephthalate resin comprises 15-25 parts.

[0053] Toughening system: 20-40 parts;

[0054] The toughening system is composed of a hydrogenated styrene-butadiene block copolymer elastomer and a maleic anhydride-grafted ethylene-octene copolymer, wherein the hydrogenated styrene-butadiene block copolymer elastomer comprises 12-18 parts and the maleic anhydride-grafted ethylene-octene copolymer comprises 8-12 parts.

[0055] Enhanced system: 20-35 copies;

[0056] The reinforcing system is composed of glass fiber and talc, wherein the glass fiber comprises 15-25 parts and the talc comprises 5-10 parts.

[0057] Main antioxidant: 0.3-0.6 parts;

[0058] Antioxidant supplement: 0.2-0.4 parts;

[0059] Internal lubricant: 0.8-1.5 parts;

[0060] External lubricant: 0.5-1.2 parts;

[0061] UV shielding agent: 1-3 parts;

[0062] Migration-type lubricant: 0.3-0.8 parts.

[0063] It should also be noted that the main antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0064] It should also be noted that the auxiliary antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0065] It should also be noted that the internal lubricant is ethylene bis-stearamide.

[0066] It should also be noted that the external lubricant is polytetrafluoroethylene ultrafine powder.

[0067] It should also be noted that the ultraviolet shielding agent is nano-titanium dioxide.

[0068] It should also be noted that the migrating lubricant is erucamide.

[0069] It should also be noted that the glass fiber is a surface-treated, alkali-free, short-cut glass fiber, and the preparation process is as follows:

[0070] A1. 50wt% silicon oxide, 15wt% aluminum oxide, 25wt% calcium oxide and 10wt% magnesium oxide are melted and drawn into wires in a platinum crucible at 1580℃, with the diameter of the single wire controlled at 9 micrometers.

[0071] A2. Fibers chopped to 3 mm were placed in an argon:oxygen mixture of 95:5 and subjected to low-temperature plasma treatment for 120 seconds at a vacuum of 10⁻² Pascal and a radio frequency power of 35 kW to increase the surface hydroxyl density to 8.2 / m².

[0072] A3. Mix γ-aminopropyltriethoxysilane with nano-silica sol at a mass ratio of 1:0.8, and hydrolyze for 60 minutes under ultrasonic power of 800 W and temperature of 45℃ to form a composite treatment solution with a solid content of 22%.

[0073] A4. Immerse the plasma-treated fibers in a hydrolysate and treat them for 25 minutes in an ultrasonic field with a frequency of 28 kHz and a power density of 0.5 W / cm³, while controlling the immersion temperature at 50°C.

[0074] A5. Surface-treated alkali-free short-cut glass fibers were prepared by microwave gradient curing:

[0075] A51. Three-stage microwave curing is employed:

[0076] First stage: 800 watts power, 80℃ drying for 5 minutes;

[0077] Second stage: 1200 watts power, 110℃ reaction for 8 minutes;

[0078] Third stage: 500 watts power, 150℃ crosslinking for 10 minutes.

[0079] II. Process:

[0080] Based on the above-mentioned high-impact, low-temperature resistant engineering plastic composite material, this invention also proposes a preparation process for the high-impact, low-temperature resistant engineering plastic composite material, comprising the following steps:

[0081] S1. First, add 40-60 parts of polyamide 66 resin and 15-25 parts of polybutylene terephthalate resin to a high-speed mixer and premix for 5 minutes at 800 rpm under nitrogen protection and at 80°C. Then add 12-18 parts of hydrogenated styrene-butadiene block copolymer elastomer and 8-12 parts of maleic anhydride-grafted ethylene-octene copolymer, heat to 110±5°C, and mix for 8 minutes at 1200 rpm to allow the toughening agent to melt and coat the resin. Granules; finally, add 0.3-0.6 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.2-0.4 parts of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 0.8-1.5 parts of ethylene bis-stearamide, 0.5-1.2 parts of polytetrafluoroethylene ultrafine powder, 1-3 parts of nano titanium dioxide, and 0.3-0.8 parts of erucamide, and mix at 500 rpm for 10 minutes at 60°C to obtain a premix.

[0082] S2. First, place 15-25 parts of surface-treated alkali-free chopped glass fibers in an ultrasonic impregnation tank, pre-filling the tank with a suspension of 5-10 parts of nano-grade talc powder and anhydrous ethanol; then turn on an ultrasonic field with a frequency of 40 kHz and a power density of 1.2 W / cm³, and treat for 15 minutes under a vacuum of 0.08 MPa to embed the talc powder into the gaps between the fiber bundles; finally, after centrifugal dehydration, dry in a 100℃ hot air circulating box until the moisture content is ≤0.05%;

[0083] S3. First, feed the premixed material and the treated reinforcement into a co-rotating twin-screw extruder, using a seven-zone gradient temperature control:

[0084] Zone 1: 220±5℃; Zone 2: 240±5℃; Zone 3: 260±5℃; Zone 4 (Melting Section): 275±3℃; Zone 5: 265±3℃; Zone 6: 250±3℃; Zone 7: 235±3℃;

[0085] Then, the screw speed is controlled at 280 rpm and the torque is 65%. 0.5±0.1 MPa supercritical carbon dioxide is injected into the fourth zone to expand and mix the material. Finally, the material is pelletized underwater at 25℃ to obtain composite material particles with a particle size of 3 mm. The particles are then vacuum dried at -0.095 MPa and 80℃ until the moisture content is ≤0.02%.

[0086] S4. First, load the granules into a mold preheated to 110±5℃ using a mold temperature controller, and pre-press for 30 seconds at 10 MPa pressure; then start the variable frequency vibration device with a frequency of 25±2 Hz and an amplitude of 0.5±0.1 mm, while simultaneously raising the temperature to 235℃ at a rate of 5℃ / min, increasing the holding pressure to 25 MPa, and calculating the holding time based on the product wall thickness of 1.5 minutes / mm; finally, use gradient pressure reduction cooling.

[0087] It should also be noted that the gradient depressurization cooling in step S4 specifically involves:

[0088] First stage: Cooling to 180°C under 15 MPa pressure, at a cooling rate of 30°C / minute;

[0089] Second stage: Cooling to 80°C under 5 MPa pressure at a cooling rate of 15°C / minute.

[0090] Example 1: In this example, based on the material composition of Example 1 in Table 1, a high-impact, low-temperature resistant engineering plastic composite material is prepared through the following steps:

[0091] S1. Preparation of premix:

[0092] The resin was put into a high-speed mixer (nitrogen protection, oxygen content ≤100ppm, 80℃) and premixed at 800r / min for 5min.

[0093] Add toughening agent, heat to 110℃, and mix at 1200r / min for 8min;

[0094] Add the additives and mix at 500 r / min for 10 min at 60℃;

[0095] S2. Fiber reinforcement treatment:

[0096] Glass fiber is impregnated with a talc / ethanol suspension (solid content 30%);

[0097] Ultrasonic treatment (40kHz, 1.2W / cm) 3 (Vacuum 0.08MPa) for 15 minutes;

[0098] Centrifuge to dehydrate (3000 r / min), and dry at 100℃ until the moisture content is ≤0.05%;

[0099] S3. Extrusion granulation:

[0100] Seven-zone extruder: 220℃ / 240℃ / 260℃ / 275℃ / 265℃ / 250℃ / 235℃;

[0101] Supercritical CO2 injection (0.5 MPa, 31 °C);

[0102] Underwater pelletizing (25℃), vacuum drying (-0.095MPa, 80℃);

[0103] S4. Dynamic hot pressing molding:

[0104] Preheat the mold to 110℃ and pre-press it at 10MPa for 30 seconds;

[0105] Vibration heating (25Hz, 0.5mm amplitude, 5℃ / min) to 235℃, holding pressure at 25MPa;

[0106] Gradient step-down cooling:

[0107] 15MPa to 180℃ (30℃ / min);

[0108] 5MPa to 80℃ (15℃ / min).

[0109] Example 2: In this example, the amount of polyamide 66 resin is 40 parts, the amount of polybutylene terephthalate resin is 15 parts, and other process parameters are the same as in Example 1;

[0110] Example 3: In this example, the amount of polyamide 66 resin is 60 parts, the amount of polybutylene terephthalate resin is 25 parts, and other process parameters are the same as in Example 1;

[0111] Example 4: In this example, the extruder screw speed is 260 rpm, and the other material components and process parameters are the same as in Example 1;

[0112] Example 5: In this example, the extruder screw speed is 300 rpm, and the other material components and process parameters are the same as in Example 1.

[0113] Table 1: Material Composition Parameters (Parts by Mass) of Examples

[0114]

[0115]

[0116] Comparative Example 1: In this comparative example, the amount of polyamide 66 resin was 35 parts, the amount of polybutylene terephthalate resin was 15 parts, and other process parameters were the same as in Example 1.

[0117] Comparative Example 2: In this comparative example, the amount of polyamide 66 resin was 65 parts, the amount of polybutylene terephthalate resin was 25 parts, and other process parameters were the same as in Example 1.

[0118] Comparative Example 3: In this comparative example, the amount of hydrogenated styrene-butadiene block copolymer elastomer was 10 parts, and other process parameters were the same as in Example 1;

[0119] Comparative Example 4: In this comparative example, the amount of glass fiber was 12 parts, and other process parameters were the same as in Example 1;

[0120] Comparative Example 5: In this comparative example, the extruder screw speed was 240 rpm, and the other material components and process parameters were the same as in Example 1.

[0121] Table 2: Comparative Example Material Composition Parameters (Parts by Mass)

[0122]

[0123]

[0124] III. Performance Testing:

[0125] The components of the examples and comparative examples were prepared into composite material samples according to the process flow, and the following performance tests were performed:

[0126] a. Low-temperature impact strength: Notched impact strength of a simply supported beam at -40℃ (ISO 179);

[0127] b. Modulus retention rate: Flexural modulus retention rate at -30℃ (GB / T 9341);

[0128] c. Melt flow rate: 275℃ / 2.16kg (ISO 1133);

[0129] d. Thermal cycling: -40℃ to 85℃ for 1000 cycles (IEC 60068-2-14);

[0130] The performance parameters of the composite materials prepared in Examples 1-6 are shown in Table 3:

[0131] Table 3: Performance Data Table of Examples

[0132] Performance indicators Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[-40 °C impact strength (kJ / m 2 )]]> 26.8 23.5 25.2 24.1 24.9 Modulus retention rate at -30℃ (%) 92 90 91 89 88 Melt flow rate (g / 10min) 20.5 22.1 18.3 18.8 22.8 Hot and cold cycle throughput pass pass pass pass pass

[0133] The performance parameters of the composite materials prepared in Comparative Examples 1-6 are shown in Table 4:

[0134] Table 4: Comparative Performance Data Table

[0135]

[0136] IV. Data Analysis:

[0137] Example group (23.5-26.8kJ / m) 2 Comparison ratio (14.3-19.5kJ / m) 2The 28-45% higher impact strength is mainly due to the interpenetrating network formed by the dual resin blend system (55-85 parts) in the examples, which inhibits low-temperature brittle fracture. The elastomer (glass transition temperature <-60°C) in the toughening system (20-30 parts) effectively absorbs impact energy. The modulus retention rate is significantly different (88-92% in examples vs. 70-82% in comparative examples). This is mainly because the glass fiber (15-25 parts) in the reinforcing system (20-35 parts) provides a rigid skeleton, and the talc (5-10 parts) blocks crack propagation. In comparative example 4, the retention rate drops to 70% when the glass fiber is insufficient. The melt flow rate (18.3-22.8 g / 10 min in examples) is more balanced than that in comparative example 2, avoiding flow obstruction caused by excessive resin (15.2 g / 10 min) and overflow caused by insufficient resin in comparative example 1 (25.3 g / 10 min).

[0138] In summary, the main reason why the embodiment passed the cold and hot cycle test is that the antioxidant combination (0.3-0.6 parts main + 0.2-0.4 parts auxiliary) inhibits low-temperature oxidative embrittlement and avoids stress cracking when the toughening of Comparative Example 3 is insufficient. Therefore, the rationality of the component range of the embodiment of the present invention is verified.

[0139] Furthermore, because the dual-resin blend system of Example 1 (70 parts PA6650 parts + 20 parts PBT) balances strength and low-temperature ductility, the toughening system (25 parts elastomer + 10 parts graft copolymer) forms a nanoscale island structure (particle size 80±20nm), and the reinforcing system (27.5 parts glass fiber + 7.5 parts talc) achieves an interfacial bonding strength of 45MPa (monofilament pull-out method), and through the following synergistic processes: screw speed 280r / min: glass fiber breakage rate ≤1.5% (conventional ≥8%); supercritical CO2 injection: promotes toughening agent dispersion, maintaining tough fracture at -50℃; vibration hot pressing (25Hz): crystallinity increased to 55%, 13% higher than static molding, reaching the peak of comprehensive performance, Example 1 is the best embodiment of the present invention.

[0140] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0141] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-impact, low-temperature resistant engineering plastic composite material, characterized in that, It is composed of the following raw materials in parts by weight: Two-resin blend system: 55-85 parts; The dual-resin blend system is composed of polyamide 66 resin and polybutylene terephthalate resin, wherein the polyamide 66 resin comprises 40-60 parts and the polybutylene terephthalate resin comprises 15-25 parts. Toughening system: 20-40 parts; The toughening system is composed of a hydrogenated styrene-butadiene block copolymer elastomer and a maleic anhydride-grafted ethylene-octene copolymer, wherein the hydrogenated styrene-butadiene block copolymer elastomer comprises 12-18 parts and the maleic anhydride-grafted ethylene-octene copolymer comprises 8-12 parts. Enhanced system: 20-35 copies; The reinforcing system is composed of glass fiber and talc, wherein the glass fiber comprises 15-25 parts and the talc comprises 5-10 parts. Main antioxidant: 0.3-0.6 parts; Antioxidant supplement: 0.2-0.4 parts; Internal lubricant: 0.8-1.5 parts; External lubricant: 0.5-1.2 parts; UV shielding agent: 1-3 parts; Migration-type lubricant: 0.3-0.8 parts.

2. The high-impact, low-temperature resistant engineering plastic composite material according to claim 1, characterized in that, The primary antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

3. The high-impact, low-temperature resistant engineering plastic composite material according to claim 2, characterized in that, The auxiliary antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

4. The high-impact, low-temperature resistant engineering plastic composite material according to claim 1, characterized in that, The internal lubricant is ethylene bis-stearamide.

5. The high-impact, low-temperature resistant engineering plastic composite material according to claim 4, characterized in that, The external lubricant is polytetrafluoroethylene ultrafine powder.

6. The high-impact, low-temperature resistant engineering plastic composite material according to claim 4, characterized in that, The ultraviolet shielding agent is nano-titanium dioxide.

7. The high-impact, low-temperature resistant engineering plastic composite material according to claim 1, characterized in that, The migratory lubricant is erucamide.

8. The high-impact, low-temperature resistant engineering plastic composite material according to claim 1, characterized in that, The glass fiber is a surface-silane-treated, alkali-free, short-cut glass fiber, and the preparation process is as follows: A1. 50wt% silicon oxide, 15wt% aluminum oxide, 25wt% calcium oxide and 10wt% magnesium oxide are melted and drawn into wires in a platinum crucible at 1580℃, with the diameter of the single wire controlled at 9 micrometers. A2. Fibers chopped to 3 mm were placed in an argon:oxygen mixture of 95:5 and subjected to low-temperature plasma treatment for 120 seconds at a vacuum of 10⁻² Pascal and a radio frequency power of 35 kW to increase the surface hydroxyl density to 8.2 / m². A3. Mix γ-aminopropyltriethoxysilane with nano-silica sol at a mass ratio of 1:0.8, and hydrolyze for 60 minutes under ultrasonic power of 800 W and temperature of 45℃ to form a composite treatment solution with a solid content of 22%. A4. Immerse the plasma-treated fibers in a hydrolysate and treat them for 25 minutes in an ultrasonic field with a frequency of 28 kHz and a power density of 0.5 W / cm³, while controlling the immersion temperature at 50°C. A5. Surface-treated alkali-free short-cut glass fibers were prepared by microwave gradient curing: A51. Three-stage microwave curing is employed: First stage: 800 watts power, 80℃ drying for 5 minutes; Second stage: 1200 watts power, 110℃ reaction for 8 minutes; Third stage: 500 watts power, 150℃ crosslinking for 10 minutes.

9. The preparation process of the high-impact, low-temperature resistant engineering plastic composite material according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. First, add 40-60 parts of polyamide 66 resin and 15-25 parts of polybutylene terephthalate resin to a high-speed mixer and premix for 5 minutes at 800 rpm under nitrogen protection and at 80°C. Then add 12-18 parts of hydrogenated styrene-butadiene block copolymer elastomer and 8-12 parts of maleic anhydride-grafted ethylene-octene copolymer, heat to 110±5°C, and mix for 8 minutes at 1200 rpm to allow the toughening agent to melt and coat the resin. Granules; finally, add 0.3-0.6 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 0.2-0.4 parts of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 0.8-1.5 parts of ethylene bis-stearamide, 0.5-1.2 parts of polytetrafluoroethylene ultrafine powder, 1-3 parts of nano titanium dioxide, and 0.3-0.8 parts of erucamide, and mix at 500 rpm for 10 minutes at 60°C to obtain a premix. S2. First, place 15-25 parts of surface-treated alkali-free chopped glass fibers in an ultrasonic impregnation tank, pre-filling the tank with a suspension of 5-10 parts of nano-grade talc powder and anhydrous ethanol; then turn on an ultrasonic field with a frequency of 40 kHz and a power density of 1.2 W / cm³, and treat for 15 minutes under a vacuum of 0.08 MPa to embed the talc powder into the gaps between the fiber bundles; finally, after centrifugal dehydration, dry in a 100℃ hot air circulating box until the moisture content is ≤0.05%; S3. First, feed the premixed material and the treated reinforcement into a co-rotating twin-screw extruder, using a seven-zone gradient temperature control: Zone 1: 220±5℃; Zone 2: 240±5℃; Zone 3: 260±5℃; Zone 4 (Melting Section): 275±3℃; Zone 5: 265±3℃; Zone 6: 250±3℃; Zone 7: 235±3℃; Then, the screw speed is controlled at 280 rpm and the torque is 65%. 0.5±0.1 MPa supercritical carbon dioxide is injected into the fourth zone to expand and mix the material. Finally, the material is pelletized underwater at 25℃ to obtain composite material particles with a particle size of 3 mm. The particles are then vacuum dried at -0.095 MPa and 80℃ until the moisture content is ≤0.02%. S4. First, load the granules into a mold preheated to 110±5℃ using a mold temperature controller, and pre-press for 30 seconds at 10 MPa pressure; then start the variable frequency vibration device with a frequency of 25±2 Hz and an amplitude of 0.5±0.1 mm, while simultaneously raising the temperature to 235℃ at a rate of 5℃ / min, increasing the holding pressure to 25 MPa, and calculating the holding time based on the product wall thickness of 1.5 minutes / mm; finally, use gradient pressure reduction cooling.

10. The preparation process of the high-impact, low-temperature resistant engineering plastic composite material according to claim 9, characterized in that, The gradient depressurization cooling in step S4 specifically involves: First stage: Cooling to 180°C under 15 MPa pressure, at a cooling rate of 30°C / minute; Second stage: Cooling to 80°C under 5 MPa pressure at a cooling rate of 15°C / minute.

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