Ultra-smooth superconductive polycarbonate compound grafted blend and preparation method thereof

Abstract

The invention relates to an ultra-smooth superconductive polycarbonate compound grafted blend and a preparation method thereof. The ultra-smooth superconductive polycarbonate compound grafted blend comprises the following raw material components in parts by weight: 50-60 parts of modified polycarbonate; 10 to 15 parts of a maleic anhydride grafted polymer; 15-25 parts of a compound superconducting material; 2-5 parts of a dispersant; 0.2 to 0.3 part of a nano surface smoothing agent; and 0.9-3 parts of an antioxidant. The raw material components with specific types and contents are compounded, so that the superconductivity of the product is greatly improved, the surface smoothness and the mechanical property are considered, and meanwhile, the smooth finish capability of a high-end chip packaging carrier tape is obtained.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and relates to a composite grafted blend, specifically an ultra-smooth, superconducting polycarbonate composite grafted blend and its preparation method. Background Technology

[0002] Polycarbonate (PC) is widely used in electronic devices due to its high transparency and impact resistance. However, modified PC is easily scratched (Ra < 0.01 μm) and has strong insulation properties (volume resistivity ≥ 10). 16 The surface roughness (Ra ≥ 0.9 μm) is extremely low (Ω·cm), making it unsuitable for applications requiring conductivity or antistatic properties. Existing technologies improve conductivity by adding conductive materials (such as conductive carbon black) to PC, but filler agglomeration leads to surface roughness (Ra ≥ 0.9 μm). Alternatively, surface smoothing agents and dispersants can be added to improve surface smoothness, but the poor compatibility and dispersibility of fluoropolymers in surface smoothing agents with polycarbonate can easily lead to a decrease in mechanical properties (e.g., tensile strength ≤ 50 MPa). Furthermore, existing preparation methods (such as one-step blending) struggle to simultaneously control surface roughness and conductivity, necessitating a polycarbonate composite grafted blend that balances ultra-smoothness and superconductivity. Summary of the Invention

[0003] In view of the shortcomings of existing technical approaches, the present invention aims to provide an ultra-smooth, superconducting polycarbonate composite grafted blend.

[0004] To achieve the above objectives, the present invention provides an ultra-smooth, superconducting polycarbonate composite grafted blend, comprising the following raw material components in parts by weight: 50-60 parts of modified polycarbonate; 10-15 parts of maleic anhydride grafted polymer; 15-25 parts of composite superconducting material; 2-5 parts dispersant; 0.2-0.3 parts of nano-surface smoother Antioxidant 0.9-3 parts.

[0005] Optimally, the maleic anhydride grafted polymer is a maleic anhydride-grafted ethylene-octene copolymer, with a maleic anhydride grafting rate of 0.8-1.2% and an octene content of 25-27%.

[0006] Optimally, the preparation method of the modified polycarbonate includes the following steps: (a) Pretreatment: The polycarbonate granules are dried by forced air at 70~90℃ to achieve a moisture content of ≤0.05%; (b) Mixing: Add polycarbonate, maleic anhydride and initiator to a high-speed mixer in proportion, and mix at 800-1200 rpm for 5-10 minutes; the mass ratio of polycarbonate, maleic anhydride and initiator is 100:3-10:0.1-0.5. (c) Reactive extrusion: Extrusion is performed using a co-rotating twin-screw extruder. The zone temperatures of the co-rotating twin-screw extruder are set as follows: feeding zone 170~180℃, melting zone 190~200℃, reaction zone 200~220℃, homogenization zone 190~195℃, screw speed 200~250 rpm, residence time 2-3 min; then, a vacuum degree ≥0.08 MPa is set in the later section of the reaction zone to perform vacuum devolatilization to remove unreacted maleic anhydride monomer.

[0007] Optimally, the composite superconducting material is a composite mixture of superconducting carbon black and carbon nanotubes, wherein the particle size of the superconducting carbon black is ≤30nm and the aspect ratio of the carbon nanotubes is ≥500.

[0008] Ideally, the dispersant is a block copolymer dispersant.

[0009] Ideally, the nano-surface smoother is nano-polytetrafluoroethylene powder.

[0010] Ideally, the antioxidant is a mixture of antioxidant Super Q and antioxidant TMB-6 in a mass ratio of 2:1.

[0011] Another objective of this invention is to provide a method for preparing the above-mentioned ultra-smooth, superconducting polycarbonate composite grafted blend, comprising the following steps: (a) Raw material pretreatment: The compound superconducting material, dispersant and nano surface smoother are mixed according to the formula ratio and stirred at room temperature for 10-15 minutes to obtain the first mixture; (b) Premixing: Add the modified polycarbonate, maleic anhydride grafted polymer and antioxidant in the prescribed amount to a high-speed mixer and mix at room temperature for 5-10 minutes to obtain a premix. (c) Melt blending: The premix and the first mixture are added to a twin-screw extruder, and the screw speed is controlled at 200~400 rpm and the temperature of each zone is 220~240℃ for melt blending; (d) Post-processing: The extruded material from the twin-screw extruder is water-cooled, pelletized, and dried at 90-100℃ for 4-6 hours.

[0012] Another object of the present invention is to provide an application of the above-mentioned ultra-smooth superconducting polycarbonate composite grafted blend for the manufacture of chip packaging carrier tape.

[0013] Due to the application of the above technical solutions, this invention has the following advantages compared with the prior art: The ultra-smooth, superconducting polycarbonate composite grafted blend of this invention, through the use of specific types and amounts of raw material components, greatly increases the superconducting performance of the product. Furthermore, while balancing surface smoothness and mechanical properties, it achieves the "smoothness" capability of high-end chip packaging carriers. The ultra-smooth, superconducting polycarbonate composite grafted blend of this invention meets the following requirements: surface roughness of high-end chip packaging carriers meets Ra≤0.02μm and volume resistivity meets ≤102 Ω·cm. This combination of two important parameters (ultra-smoothness and superconductivity) ultimately aims to ensure that chips are not subject to physical damage or electrostatic discharge during transportation, storage, and mounting, while simultaneously meeting the high-precision requirements of automated production. This extends the service life of high-end chips and is suitable for national defense and military scientific research. There are certain technical problems because the above two important parameters are not met: (1) When polycarbonate carrier tape is molded, it needs to be demolded from the mold. If the surface is too smooth, it may be difficult to demold due to "vacuum adsorption". A roughness of Ra≤0.02μm can avoid demolding problems and prevent the chip from sticking too much to the carrier tape (especially for chip pins that are easy to oxidize, moderate roughness can reduce the contact area and reduce the risk of sticking). (2) Volume resistivity (ρᵥ)≤102Ω·cm measures the superconductivity of the material. 10³Ω·cm belongs to "static dissipation material" (between conductors 10 Ω·cm and 10 Ω·cm). -6 The core objective is to control electrostatic discharge (ESD) damage to the chip (between ~10²Ω·cm and 10¹²Ω·cm for insulators). Detailed Implementation

[0014] This invention relates to an ultra-smooth, superconducting polycarbonate composite grafted blend, comprising the following raw material components in parts by weight: 50-60 parts modified polycarbonate; 10-15 parts maleic anhydride grafted polymer; 15-25 parts composite superconducting material; 2-5 parts dispersant; 0.2-0.3 parts nano-surface smoother; and 0.9-3 parts antioxidant. By using specific types and amounts of raw material components for blending, the superconducting performance of the product is greatly increased. Furthermore, while maintaining surface smoothness and mechanical properties, it achieves the "smoothness" of high-end chip packaging carriers. The ultra-smooth, superconducting polycarbonate composite grafted blend of this invention meets the following requirements: surface roughness of high-end chip packaging carriers ≤ Ra ≤ 0.02 μm, and volume resistivity ≤ 10 Ω·cm. 2 The combination of these two important parameters (ultra-smoothness and super-conductivity) Ω·cm ultimately aims to ensure that the chip is not subject to physical damage or electrostatic discharge during the entire process of transportation, storage, and mounting, while also being compatible with the high-precision requirements of automated production. This can extend the operating life of high-end chips and is suitable for national defense and military scientific research.

[0015] This application presents an ultra-smooth, superconducting polycarbonate composite grafted blend, with a surface roughness reduced to 0.015 μm and a volume resistivity reduced from 10¹⁰.6 Ω·cm decreased to 10 2 Ω·cm (meets superconductivity standards); tensile strength remains above 85MPa (55MPa for pure PC), and notched impact strength is increased by 40% (reaching 60kJ / m²). Its ultra-smooth properties reduce dust adsorption (surface energy ≤20mN / m), and its superconductivity eliminates electrostatic damage (volume resistivity ≤10). 2 Ω·cm), suitable for chip packaging carrier tape.

[0016] The maleic anhydride-grafted polymer is a maleic anhydride-grafted ethylene-octene copolymer with a maleic anhydride grafting rate of 0.8-1.2% and an octene content of 25-27%. It is produced by modifying ethylene-octene copolymer (ENGAGE™ 8452 series) with maleic anhydride. The specific operation method refers to the melt method in "Maleic Anhydride-Grafted Ethylene-1-Octene Copolymer and Its Application, China Plastics". The reaction conditions are a rotation speed of 50 r / min, a reaction time of 10 min, and a reaction temperature of 180°C. The mass ratio of ethylene-octene copolymer, maleic anhydride, and initiator (diisopropylbenzene peroxide) is 100:1-5:0.05-0.2. Specifically, the maleic anhydride-grafted polymer used in the embodiments of this application is prepared by the following process: the reaction conditions are a rotation speed of 50 r / min, a reaction time of 10 min, and a reaction temperature of 180°C. The mass ratio of ethylene-octene copolymer, maleic anhydride, and initiator (diisopropylbenzene peroxide) is 100:1:0.1.

[0017] The preparation method of the modified polycarbonate includes the following steps: (a) Pretreatment: Polycarbonate particles (Makrolon 2805) are dried by forced air at 70~90℃ to achieve a moisture content ≤0.05%; (b) Mixing: Polycarbonate, maleic anhydride and initiator are added to a high-speed mixer in proportion and mixed at 800~1200 rpm for 5~10 minutes; the mass ratio of polycarbonate, maleic anhydride and initiator is 100:3~10:0.1~0.5; (c) Reactive extrusion: Extrusion is performed using a co-rotating twin-screw extruder, wherein the zone temperature settings of the co-rotating twin-screw extruder are: feeding zone 170~180℃, melting zone 190~200℃, reaction zone 200~240℃, homogenization zone 190~195℃, screw speed 200~250 rpm, residence time 2-3 minutes; subsequently, a vacuum degree ≥0.08 is set in the latter part of the reaction zone. MPa was used for vacuum devolatilization to remove unreacted maleic anhydride monomers. Specifically, the modified polycarbonate used in the embodiments of this application was prepared according to the following process: (a) Pretreatment: Polycarbonate particles were dried in a forced-air dryer at 80°C for 4 hours to achieve a moisture content ≤0.05%; (b) Mixing: Polycarbonate (PC, 100 kg, grade ENGAGE™ 8180), maleic anhydride (4 kg), and initiator (0.3 kg, dicumyl peroxide) were added to a high-speed mixer in proportion and mixed at 800~1200 rpm for 5~10 minutes; (c) Reactive extrusion: Extrusion was performed using a co-rotating twin-screw extruder (length-to-diameter ratio 44:1). The zone temperature settings of the co-rotating twin-screw extruder were as follows: feeding zone 170~180°C, melting zone 190~200°C, reaction zone 200~240°C, homogenization zone 190~195°C, and screw speed 200~250 rpm. rpm, residence time 2-3 min; then set a vacuum degree ≥0.08 MPa in the latter part of the reaction zone to perform vacuum devolatilization to remove unreacted maleic anhydride monomers to obtain grafted PC (i.e. PC-g-MAH).

[0018] The composite superconducting material is a mixture of superconducting carbon black and carbon nanotubes, wherein the superconducting carbon black has a particle size ≤30nm and the carbon nanotubes have an aspect ratio ≥500. The dispersant is a block copolymer dispersant (such as Disperbyk-2150 or MAT100). The nano-surface smoother is nano-polytetrafluoroethylene powder (such as Chemours TF-9207 or Daikin AD-900, with a particle size of 0.1-1μm). The antioxidant is a mixture of antioxidant Super Q and antioxidant TMB-6 in a mass ratio of 2:1.

[0019] The preparation method of the above-mentioned super-smooth superconducting polycarbonate composite grafted blend includes the following steps: (a) Raw material pretreatment: the composite superconducting material, dispersant and nano surface smoother are mixed according to the formula ratio and stirred at room temperature (room temperature, the same below) for 10-15 min to obtain the first mixture; (b) Premixing: the modified polycarbonate, maleic anhydride grafted polymer and antioxidant of the formula amount are added to a high-speed mixer and mixed at room temperature for 5-10 min to obtain the premix; (c) Melt blending: the premix and the first mixture are added to a twin-screw extruder, and the screw speed is controlled at 200~400 rpm and the temperature of each zone is 220~240℃ to carry out melt blending; (d) Post-treatment: the extruded material from the twin-screw extruder is water-cooled, pelletized and dried at 90-100℃ for 4-6 h.

[0020] The aforementioned ultra-smooth, superconducting polycarbonate composite grafted blends are used to manufacture chip packaging carrier tapes.

[0021] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions not specified are conventional conditions in this industry.

[0022] Examples 1-3, Comparative Examples 1-7 Examples 1-3 and Comparative Examples 1-7 respectively provide a polycarbonate composite grafted blend for ultra-smooth, superconducting, high-end chip packaging carrier tape. The raw material composition is shown in Table 1, and the materials are prepared according to the following steps: (a) Raw material pretreatment: The compound superconducting material, dispersant and nano surface smoother are mixed in proportion and stirred at 25°C for 15 min to obtain the first mixture; (b) Premixing: Modified polycarbonate, maleic anhydride grafted polymer and antioxidant are added to a high-speed mixer and mixed at 25°C for 10 min to obtain a premix; (c) Melt blending: The premix and the first mixture are added to a twin-screw extruder (length-to-diameter ratio 1:44), and the screw speed is controlled at 250 rpm and the temperature of each zone is 220~240℃ (this temperature range has little effect on product performance) for melt blending. (d) Post-processing: The extruded material from the twin-screw extruder is water-cooled, pelletized, and dried at 90°C for 4 hours.

[0023] Table 1. Ultrasmooth, superconducting polycarbonate composite grafted blends of Examples 1-3 and Comparative Examples 1-7 (Unit: kg)

[0024] Note: In Examples 1-3 and Comparative Examples 1-7, the modified polycarbonate and maleic rod grafted polymer were prepared according to the aforementioned method; the compounded superconducting material was a mixture of superconducting carbon black (brand name VXC72) and carbon nanotubes (brand name LGCNT-100) in a mass ratio of 1:1; the dispersant was Disperbyk-2150; the nano-surface smoother was Chemours TF-9207; and the antioxidant was a mixture of antioxidant Super Q and TMB-6 in a mass ratio of 2:1. In Comparative Example 6, unmodified polycarbonate resin (brand name Makrolon 2805) was used, and in Comparative Example 7, the dispersant was (brand name: Sun Ace ZINC STEARATE).

[0025] The ultra-smooth, superconducting polycarbonate composite grafted blends obtained in Examples 1-3 and Comparative Examples 1-7 were made into sheets according to the method specified in 7.2.1 of JB / T 10437-2024 standard, and then their performance was tested according to the following test items and methods. The specific test items and methods are as follows, and the results are shown in Table 2.

[0026] Table 2 Performance of various PC chip packaging carrier tapes

[0027] Note: Volume resistivity was measured using an electrostatic resistance meter according to the JIS K7194 method of determining the resistivity of conductive plastics with a four-point probe arrangement; surface roughness Ra was tested according to ASTM D789 standard; notched impact strength was tested according to GB / T 1843-2008 standard; tensile strength was tested according to GB / T 1040 standard; surface finish was tested according to GB / T 3505 standard; and elongation at room temperature was tested according to GB / T 2951.12 standard.

[0028] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A super-smooth, superconducting polycarbonate composite grafted blend, characterized in that, It comprises the following raw material components in parts by weight: 50-60 parts of modified polycarbonate; 10-15 parts of maleic anhydride grafted polymer; 15-25 parts of composite superconducting material; 2-5 parts dispersant; 0.2-0.3 parts of nano-surface smoother; Antioxidant 0.9-3 parts.

2. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that: The maleic anhydride grafted polymer is a maleic anhydride-grafted ethylene-octene copolymer with a maleic anhydride grafting rate of 0.8-1.2% and an octene content of 25-27%.

3. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that, The method for preparing the modified polycarbonate includes the following steps: (a) Pretreatment: The polycarbonate granules are dried by forced air at 70~90℃ to achieve a moisture content of ≤0.05%; (b) Mixing: Add polycarbonate, maleic anhydride and initiator to a high-speed mixer in proportion, and mix at 800-1200 rpm for 5-10 minutes; the mass ratio of polycarbonate, maleic anhydride and initiator is 100:3-10:0.1-0.

5. (c) Reactive extrusion: Extrusion is performed using a co-rotating twin-screw extruder. The zone temperatures of the co-rotating twin-screw extruder are set as follows: feeding zone 170~180℃, melting zone 190~200℃, reaction zone 200~220℃, homogenization zone 190~195℃, screw speed 200~250 rpm, residence time 2-3 min; then, a vacuum degree ≥0.08 MPa is set in the later section of the reaction zone to perform vacuum devolatilization to remove unreacted maleic anhydride monomer.

4. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that: The composite superconducting material is a mixture of superconducting carbon black and carbon nanotubes, wherein the particle size of the superconducting carbon black is ≤30nm and the aspect ratio of the carbon nanotubes is ≥500.

5. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that: The dispersant is a block copolymer dispersant.

6. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that: The nano-surface smoother is nano-polytetrafluoroethylene powder.

7. The ultra-smooth, superconducting polycarbonate composite grafted blend according to claim 1, characterized in that: The antioxidant is a mixture of antioxidant Super Q and antioxidant TMB-6 in a mass ratio of 2:

1.

8. A method for preparing the ultra-smooth, superconducting polycarbonate composite grafted blend according to any one of claims 1 to 7, characterized in that, Includes the following steps: (a) Raw material pretreatment: The compound superconducting material, dispersant and nano surface smoother are mixed according to the formula ratio and stirred at room temperature for 10-15 minutes to obtain the first mixture; (b) Premixing: Add the modified polycarbonate, maleic anhydride grafted polymer and antioxidant in the prescribed amount to a high-speed mixer and mix at room temperature for 5-10 minutes to obtain a premix. (c) Melt blending: The premix and the first mixture are added to a twin-screw extruder, and the screw speed is controlled at 200~400 rpm and the temperature of each zone is 220~240℃ for melt blending; (d) Post-processing: The extruded material from the twin-screw extruder is water-cooled, pelletized, and dried at 90-100℃ for 4-6 hours.

9. The application of the ultra-smooth, superconducting polycarbonate composite grafted blend according to any one of claims 1 to 7, characterized in that: Packaging carrier tape used for making chips.

Images