Search

CN-121991430-A - Low dielectric loss impact-resistant light polypropylene composite material and preparation method thereof

CN121991430ACN 121991430 ACN121991430 ACN 121991430ACN-121991430-A

Abstract

The invention relates to the technical field of high polymer materials, in particular to a low dielectric loss impact-resistant light polypropylene composite material and a preparation method thereof. The polypropylene composite material comprises 16-36 parts by weight of high-melt-index high-purity polypropylene, 20-50 parts by weight of ultra-low ash polypropylene, 25-35 parts by weight of purified and copolymerized PP-PE master batch, 6-10 parts by weight of high-compression-resistance hollow glass beads and 0.1-2 parts by weight of processing aid. The purified copolymerized PP-PE master batch is prepared by block copolymerization PP purification, blending and granulating with nano zirconia and HDPE, is matched with a nonpolar lubricant system, and finally is prepared into the low dielectric loss impact-resistant light polypropylene composite material with the dielectric constant of 2.23-2.25 (2.5 GHz) and the dielectric loss of 1.9X10 ‑4 ~2.8×10 ‑4 through a specific melt blending process, and is suitable for high-frequency communication, automatic driving sensor protection covers and other scenes.

Inventors

  • FAN MULIANG
  • XU XIAODONG
  • FU RULIN
  • HU SHUQIN
  • Quan Dunhua
  • LI LINGXIE

Assignees

  • 金旸（厦门）新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20251229
Priority Date
20251225

Claims (10)

  1. 1. The low dielectric loss impact-resistant light polypropylene composite material is characterized by comprising 16-36 parts by weight of polypropylene A material, 20-50 parts by weight of polypropylene B material, 25-35 parts by weight of purified copolymerized PP-PE master batch, 6-10 parts by weight of hollow glass beads and 0.1-2 parts by weight of processing aid; wherein the polypropylene material A is high-melt-index high-purity polypropylene, and the polypropylene material B is ultra-low ash polypropylene.
  2. 2. The low dielectric loss impact resistant light polypropylene composite material according to claim 1, wherein the purified copolymerized PP-PE master batch comprises 55-60 parts by weight of block copolymerized PP, 8-12 parts by weight of nano zirconia, 25-35 parts by weight of high density polyethylene resin, 0.05-0.2 parts by weight of high purity polyethylene wax and 0.05-0.2 parts by weight of antioxidant.
  3. 3. The low dielectric loss impact resistant light polypropylene composite material according to claim 2, wherein the purified copolymerized PP-PE masterbatch is prepared by the steps of: S101, adding dried block copolymerization PP powder and a washing solvent into a closed glass container, heating to (70+/-2) DEG C, stirring and washing for 3-4 hours, continuously introducing circulating nitrogen into the glass container during the period, filtering a sample after washing, washing at least 2 times by absolute ethyl alcohol, and vacuum drying to obtain purified block copolymerization PP powder; S102, putting the purified block copolymerization PP powder and the nano zirconia dispersion liquid into a high-speed mixer, uniformly mixing for 180-200S at the temperature of (80+/-2) DEGC, and then putting high-density polyethylene resin, high-purity polyethylene wax and an antioxidant into the mixer, and uniformly mixing for 120-150S; And S103, putting the uniform mixed material obtained in the step S102 into a double-screw extruder, and carrying out melt extrusion granulation at 190-200 ℃ and 300-320 rpm to obtain the copolymerized PP-PE master batch.
  4. 4. The low dielectric loss impact resistant light polypropylene composite material according to claim 3, wherein in step S101, the ratio of the block copolymerization PP powder to the washing solvent is 1 (5-6) by weight.
  5. 5. The low dielectric loss impact resistant light polypropylene composite material according to claim 3, wherein the block copolymerization PP powder is a solution prepared by compounding n-hexane and isopropanol according to the volume ratio of (17-21): 4-8, wherein the block copolymerization PP powder has a melt flow rate of 230 ℃ and 2.16 kg is 8.5 g/10 min, the notched Izod impact strength of 40 kJ/m 2 and ethylene content of 10wt%; the high-density polyethylene resin has a melt flow rate of 6.5 g/10 min at 190 ℃ and 2.16 kg, the nano zirconia content in the nano zirconia dispersion liquid is 30wt%, and the average grain diameter is less than 30 nm.
  6. 6. The low dielectric loss impact resistant light polypropylene composite material of claim 1, wherein the high melt index high purity polypropylene has a melt flow rate of >15 g/10 min at 230 ℃ and 2.16 kg, and the ultra low ash polypropylene has a melt flow rate of 2-5 g/10 min and an ash content of <20 ppm at 230 ℃ and 2.16 kg.
  7. 7. The low dielectric loss impact resistant light polypropylene composite material according to claim 1, wherein the hollow glass beads are high compression resistant hollow glass beads, the compression strength is not less than 180 MPa, the particle size is not more than 20 μm, and the density is not more than 0.65 g/cm 3 .
  8. 8. The low dielectric loss impact resistant light polypropylene composite material according to claim 3, wherein said processing aid comprises an antioxidant, a lubricant, a weather resistant aid and a beta nucleating agent in a weight ratio of 2:5:2:1.
  9. 9. The low dielectric loss impact-resistant light polypropylene composite material according to claim 8 is characterized in that the antioxidant is a hindered phenol antioxidant, the lubricant is obtained by compounding high-purity polyethylene wax and low-molecular-weight polytetrafluoroethylene, the weather-resistant auxiliary agent is a high-performance compound light stabilizer, and the beta nucleating agent is a rare earth compound beta nucleating agent.
  10. 10. A method for preparing the low dielectric loss impact resistant light polypropylene composite material according to any one of claims 1 to 9, comprising the following steps: s201, weighing a polypropylene material A, a polypropylene material B, a purified copolymerized PP-PE master batch and a processing aid according to parts by weight, and putting the materials into a high-speed stirrer to stir and mix uniformly at a high speed to obtain a premix; S202, feeding the premix into a parallel double-screw extruder from a main feeding hopper, feeding hollow glass beads into the parallel double-screw extruder from a side feeding port according to parts by weight, and shearing, melting, blending and extruding at 190-200 ℃ and 300-320 rpm; and S203, cooling, drying and granulating the material strips extruded by the mouth die of the parallel double-screw extruder to obtain the low dielectric loss impact-resistant light polypropylene composite material.

Description

Low dielectric loss impact-resistant light polypropylene composite material and preparation method thereof Technical Field The invention relates to the technical field of high polymer materials, in particular to a low dielectric loss impact-resistant light polypropylene composite material and a preparation method thereof. Background Along with the rapid popularization of the 5G technology, the advantages of high propagation speed and low delay enable the 5G technology to be widely applied to the fields of electronics, automatic driving, intelligent wearing and the like, but the characteristics of the 5G technology close to millimeter wave bands lead to poor signal penetration and large attenuation, and the 5G technology puts forward more stringent requirements on polymer materials serving as propagation media. Compared with ceramic materials, the polymer has excellent mechanical property, processability, low density and higher electric breakdown strength, and has become a core material of key components such as integrated circuits, interlayer insulating media, electronic packaging materials and the like, while polypropylene (PP) is used as a polymer with abundant raw materials, low price and excellent molding processability, has realized large-scale application in various fields such as automobiles, household appliances, buildings and the like, and naturally becomes an important candidate of materials in 5G related fields. However, polypropylene materials face two major core bottlenecks when being adapted to 5G application scenes, namely, on one hand, high-frequency communication scenes and other scenes put forward strict requirements on dielectric properties of the materials, low dielectric constant and low dielectric loss, traditional polypropylene is difficult to directly meet, on the other hand, pure polypropylene has low impact strength and insufficient toughness, and is easy to become brittle and crack when being used in an outdoor low-temperature environment, so that the application range of the polypropylene is severely limited. In order to solve the problems, the industry often adopts a melt blending mode of a thermoplastic elastomer (POE) and polypropylene to improve the shock resistance, but the interface compatibility of the POE and a PP matrix is poor, and the crystallinity of the PP is affected, so that the electrical property of a blending system is reduced, risks such as electric field distortion and partial discharge are caused, and the cooperative improvement of the mechanical property and the electrical property is difficult to realize. In the prior art, although related improvement schemes are tried, for example, part of schemes are used for preparing low dielectric loss polypropylene composite materials by adding reinforcing materials such as long glass fibers and quartz fibers, but the problem of buckling deformation of the materials is easily caused by the introduction of the reinforcing fibers, and the other schemes are used for realizing a flame retardant function by adding halogen-free flame retardants, but the addition of the flame retardants can obviously increase the dielectric loss of the materials and cannot meet the requirements of dielectric properties and other functions. However, none of these prior approaches effectively address the combined performance requirements of low dielectric loss, high impact strength, light weight, and no warp defects. Therefore, developing a polypropylene composite material which can simultaneously satisfy the characteristics of low dielectric constant, low dielectric loss, high impact strength and light weight and is not easy to generate buckling deformation in the processing process becomes a technical problem to be solved in the current 5G related material field. Disclosure of Invention The invention provides a low dielectric loss impact-resistant light polypropylene composite material for solving the technical problem that the existing polypropylene material cannot meet the comprehensive performance of low dielectric loss, high impact strength, light weight and no warping defect, and the low dielectric loss impact-resistant light polypropylene composite material comprises 16-36 parts by weight of polypropylene A material, 20-50 parts by weight of polypropylene B material, 25-35 parts by weight of purified copolymerized PP-PE master batch, 6-10 parts by weight of hollow glass beads and 0.1-2 parts by weight of processing aid; wherein the polypropylene material A is high-melt-index high-purity polypropylene, and the polypropylene material B is ultra-low ash polypropylene. In some embodiments, the purified copolymerized PP-PE master batch comprises 55-60 parts by weight of block copolymerized PP, 8-12 parts by weight of nano zirconia, 25-35 parts by weight of high-density polyethylene resin, 0.05-0.2 part by weight of high-purity polyethylene wax and 0.05-0.2 part by weight of antioxidant. Further, the purified copolymerized PP-PE master batch