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CN-121975236-A - High-hardness scratch-resistant polypropylene composite material and preparation method thereof

CN121975236ACN 121975236 ACN121975236 ACN 121975236ACN-121975236-A

Abstract

The invention discloses a high-hardness scratch-resistant polypropylene composite material and a preparation method thereof, and relates to the technical field of high polymer materials. According to the invention, a proper amount of carboxylated and crosslinked PMMA microspheres are added to compound with modified inorganic nanoparticles, so that the obtained polypropylene composite material has high surface hardness, excellent scratch resistance and excellent mechanical properties, and can effectively inhibit abnormal rise of surface glossiness after scratch, thereby maintaining the appearance consistency of a polypropylene product after scratch.

Inventors

  • WU ZHONGTAO
  • WANG GANG
  • LI SHANG

Assignees

  • 重庆会通科技有限公司

Dates

Publication Date
20260505
Application Date
20260108

Claims (10)

  1. 1. The high-hardness scratch-resistant polypropylene composite material is characterized by comprising, by mass, 44% -74% of polypropylene, 5% -15% of POE, 10% -20% of aminosilane coupling agent modified talcum powder, 3% -8% of aminosilane coupling agent modified inorganic nano particles, 2% -4% of carboxylated crosslinked PMMA microspheres, 3% -7% of compatilizer, 0.4% -0.8% of antioxidant, 0.3% -0.6% of lubricant, 0.3% -0.6% of light stabilizer, 0.5% -1% of toner and 1% -2% of scratch-resistant agent, wherein the sum of the mass percentages of the raw materials is 100%; The particle size D50 of the carboxylated and crosslinked PMMA microspheres is 3-8 mu m.
  2. 2. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the mesh number of the aminosilane coupling agent modified talcum powder is 2000-3000 mesh.
  3. 3. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the aminosilane coupling agent modified inorganic nanoparticles are selected from aminosilane coupling agent modified nanosilica, aminosilane coupling agent modified nanosilica carbonate or a combination thereof, and the particle size D50 is 40-100 nm.
  4. 4. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein in the aminosilane coupling agent modified talcum powder, the mass ratio of the aminosilane coupling agent to the talcum powder is 2-10:100; in the amino silane coupling agent modified inorganic nano particles, the mass ratio of the amino silane coupling agent to the inorganic nano particles is 5-20:100.
  5. 5. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the preparation method of the carboxylated cross-linked PMMA microspheres comprises the steps of adding methyl methacrylate, acrylic acid and ethylene glycol dimethacrylate into a mixed solvent of ethanol and water, uniformly stirring, adding azobisisobutyronitrile, and stirring in a nitrogen atmosphere at 60-75 ℃ for reaction for 8-12 h, wherein the molar ratio of the methyl methacrylate to the acrylic acid is 1:0.5-1, the mass of the ethylene glycol dimethacrylate is 0.1-0.3% of the sum of the mass of the methyl methacrylate and the mass of the acrylic acid, and the mass of the azobisisobutyronitrile is 0.1-0.3% of the sum of the mass of the methyl methacrylate and the mass of the acrylic acid.
  6. 6. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the polypropylene is a copolymerized polypropylene and has a melt flow rate of 5-100 g/10min at 230 ℃ and 2.16 kg.
  7. 7. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the melt flow rate of the POE at 190 ℃ and 2.16kg is 1-5 g/10min.
  8. 8. The high-hardness scratch-resistant polypropylene composite material according to claim 1, wherein the compatilizer is maleic anhydride grafted polypropylene, and the grafting rate is 0.8% -1.5%.
  9. 9. A method for preparing the high-hardness scratch-resistant polypropylene composite material according to any one of claims 1 to 8, comprising the following steps: (1) Weighing raw materials according to mass percentage, and uniformly mixing to obtain premix; (2) And (3) carrying out melt extrusion on the premix through a double-screw extruder, and then cooling and granulating to obtain the polypropylene composite material.
  10. 10. The method for preparing the high-hardness scratch-resistant polypropylene composite material according to claim 9, wherein the processing temperature of the twin-screw extruder is 180-210 ℃, and the screw rotating speed is 300-400 rpm.

Description

High-hardness scratch-resistant polypropylene composite material and preparation method thereof Technical Field The invention relates to the technical field of high polymer materials, in particular to a high-hardness scratch-resistant polypropylene composite material and a preparation method thereof. Background The polypropylene composite material is widely applied to fields with high requirements on touch feeling and appearance such as automobile interior trim (such as door panels, instrument panels, upright posts and the like), household appliance shells and the like due to excellent mechanical properties and cost effectiveness. In general, in order to give the polypropylene composite material good toughness, an appropriate amount of polyolefin elastomer (POE) needs to be added. However, this material system has two major surface defects: (1) POE is used as an elastomer, toughness is provided, and meanwhile, the surface hardness of the material is obviously reduced, so that the material is easily scratched by hard objects such as keys, nails and the like, and the appearance is influenced; (2) Abnormal change in gloss after scratch is that when the surface of a material is scratched, it is generally desired that the scratch becomes rough and the gloss is lowered. However, when polypropylene materials are scratched, the scratched edges undergo significant plastic deformation and flow due to the viscoelasticity of the POE phase, resulting in a smooth mirror effect similar to that produced after "plowing", resulting in a higher gloss at the scratched areas than in unbreaked matte or semi-matte surfaces. Such "bright lines" or "bright marks" are visually very abrupt, severely affecting the overall aesthetics and upscale feel of the article. In the prior art, in order to improve the scratch resistance of polypropylene materials, a method of adding a silicone auxiliary agent or an erucic acid amide slipping agent is generally adopted. These methods reduce the coefficient of friction, and thus the scratch force, primarily by migration to the surface to form a lubricating layer. However, this method has limited contribution to improving the surface hardness and may cause problems such as surface tackiness, blooming, etc., and more importantly, it cannot effectively solve the problem of the rise in glossiness caused by plastic flow after scratch, and sometimes this phenomenon may be even exacerbated. Therefore, development of a polypropylene composite material capable of simultaneously realizing high surface hardness and excellent scratch resistance and fundamentally inhibiting abnormal rise of glossiness after scratch has become a technical problem to be solved urgently in the art. Disclosure of Invention Based on the technical problems in the background art, the invention provides a high-hardness scratch-resistant polypropylene composite material and a preparation method thereof, and the material has high surface hardness, excellent scratch resistance and excellent mechanical properties, and can effectively inhibit abnormal increase of surface glossiness after scratching, so that the consistency of the appearance of a product after scratching is ensured. The invention provides a high-hardness scratch-resistant polypropylene composite material, which comprises, by mass, 44% -74% of polypropylene, 5% -15% of POE, 10% -20% of aminosilane coupling agent modified talcum powder, 3% -8% of aminosilane coupling agent modified inorganic nano particles, 2% -4% of carboxylated crosslinked PMMA microspheres, 3% -7% of compatilizer, 0.4% -0.8% of antioxidant, 0.3% -0.6% of lubricant, 0.3% -0.6% of light stabilizer, 0.5% -1% of toner and 1% -2% of scratch-resistant agent, wherein the sum of the mass percentages of the raw materials is 100%; The particle size D50 of the carboxylated and crosslinked PMMA microspheres is 3-8 mu m. According to the invention, amino silane coupling agent modified talcum powder, amino silane coupling agent modified inorganic nano particles and carboxylated cross-linked PMMA (polymethyl methacrylate) microspheres with specific particle sizes are added into a polypropylene material for compounding, on one hand, the addition of the inorganic nano particles can directly improve the macroscopic hardness and modulus of the surface of the material and resist the indentation of scratch matters, so that the scratch resistance of the polypropylene material is improved, on the other hand, the inorganic nano particles and the cross-linked PMMA microspheres with proper particle sizes form a unique hard-brittle synergistic system, when the polypropylene material is scratched, the rigid inorganic nano particles provide support, and the cross-linked PMMA microspheres dispersed in a matrix are used as stress concentration points, and actively dissipate scratch energy in a mode of generating microcracks or generating brittle fracture and the like, and destroy the continuous specular reflection on a scratch path, so t