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CN-122011547-A - High-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath and preparation method thereof

CN122011547ACN 122011547 ACN122011547 ACN 122011547ACN-122011547-A

Abstract

The invention belongs to the field of polyolefin sheath materials, and discloses a high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath and a preparation method thereof, wherein the high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath comprises, by weight, 45-65 parts of a polyolefin composite substrate, 35-55 parts of a multi-component composite flame retardant, 4-9 parts of a special compatilizer, 0.8-2.5 parts of an antioxidant, 0.5-2 parts of a lubricant, 1.5-5 parts of a high-efficiency flame-retardant synergist and 1-3 parts of vermiculite-sepiolite composite powder.

Inventors

  • JI WEIQIANG
  • JI KUNFU
  • JI QIUPING

Assignees

  • 江苏嘉瑞科技有限公司

Dates

Publication Date
20260512
Application Date
20260130

Claims (7)

  1. 1. The high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath is characterized by comprising, by weight, 45-65 parts of a polyolefin composite base material, 35-55 parts of a multi-component composite flame retardant, 4-9 parts of a special compatilizer, 0.8-2.5 parts of an antioxidant, 0.5-2 parts of a lubricant, 1.5-5 parts of a high-efficiency flame-retardant synergist and 1-3 parts of vermiculite-sepiolite composite powder; The polyolefin composite substrate is a blend of high-density polyethylene, ethylene-vinyl acetate copolymer and polyolefin elastomer, and the weight ratio of the high-density polyethylene to the ethylene-vinyl acetate copolymer to the polyolefin elastomer is 4:1:0.5-6:2:1; The multi-component composite flame retardant is a compound of magnesium hydroxide, aluminum hydroxide, nano hydroxyapatite and microencapsulated ammonium polyphosphate, and the weight ratio of the magnesium hydroxide to the aluminum hydroxide to the nano hydroxyapatite to the microencapsulated ammonium polyphosphate is 2:2:0.8:1-3:3:1.2:1.8; the special compatilizer is glycidyl methacrylate grafted ethylene-octene copolymer; The efficient flame retardant synergist is a compound of diethyl aluminum phosphinate and zirconia, the weight ratio of the diethyl aluminum phosphinate to the zirconia is 3:1-5:2, and the weight ratio of vermiculite to sepiolite in the vermiculite-sepiolite composite powder is 1:0.5-1:1.5.
  2. 2. The high flame retardant low smoke zero halogen flame retardant polyolefin sheath of claim 1, wherein the nano hydroxyapatite has a particle size of 50-200nm.
  3. 3. The high flame retardant low smoke zero halogen flame retardant polyolefin jacket of claim 1, wherein the vermiculite-sepiolite composite powder has a particle size of 1-5 μm.
  4. 4. The high flame retardant low smoke zero halogen flame retardant polyolefin sheath of claim 1, wherein the antioxidant is a compound of antioxidant 1076 and antioxidant 626 in a weight ratio of 1:1-2:1, and the lubricant is ethylene bis stearamide.
  5. 5. The preparation method of the high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath is characterized by comprising the following steps of: s1, preparation of raw materials: S1-1, preparing a polyolefin composite substrate, namely adding high-density polyethylene, ethylene-vinyl acetate copolymer and polyolefin elastomer into a high-speed mixer according to a weight ratio of 4:1:0.5-6:2:1, and mixing for 8-15min at 60-80 ℃ and a rotating speed of 600-800rpm to obtain the polyolefin composite substrate; s1-2, preparing a multi-element composite flame retardant, namely adding magnesium hydroxide, aluminum hydroxide, nano hydroxyapatite and microencapsulated ammonium polyphosphate into a conical mixer according to the weight ratio of 2:2:0.8:1-3:3:1.2:1.8, and mixing for 30-45min at room temperature and the rotating speed of 200-300rpm to obtain the multi-element composite flame retardant; S1-3, preparing a special compatilizer, namely adding an ethylene-octene copolymer, glycidyl methacrylate and dicumyl peroxide into a double-screw extruder according to the weight ratio of 100:3-5:0.2-0.5, carrying out melt grafting reaction at 160-180 ℃ under the condition of the screw rotating speed of 80-120rpm, extruding, and granulating to obtain the glycidyl methacrylate grafted ethylene-octene copolymer; S1-4, preparing the efficient flame-retardant synergist, namely adding aluminum diethyl phosphinate and zirconium oxide into a three-dimensional mixer according to a weight ratio of 3:1-5:2, and mixing for 20-30min at room temperature and a rotating speed of 400-600rpm to obtain the efficient flame-retardant synergist; S1-5 vermiculite-sepiolite composite powder is prepared by mixing vermiculite and sepiolite according to a weight ratio of 1:0.5-1:1.5, adding the mixture into a ball mill, taking ethanol as a dispersion medium, adopting a ball material ratio of 5:1-8:1, rotating at 300-400r/min, ball milling for 2-3h, and drying at 80-100 ℃ for 3-4h after filtering to obtain the vermiculite-sepiolite composite powder; S2, pretreating raw materials, namely adding gamma-aminopropyl triethoxysilane into the multi-component composite flame retardant prepared in the step S1-2, wherein the addition amount of the gamma-aminopropyl triethoxysilane is 0.8-1.5wt% of the total weight of the multi-component composite flame retardant, drying the multi-component composite flame retardant in a baking oven at 110-125 ℃ for 3-5h, and cooling the multi-component composite flame retardant to room temperature to obtain the modified composite flame retardant; S3, mixing and plasticizing, namely adding the polyolefin composite substrate prepared in the step S1-1 and the special compatilizer prepared in the step S1-3 into a high-speed mixer, mixing for 6-12min at the temperature of 85-100 ℃ and the rotating speed of 900-1300rpm, adding the modified composite flame retardant, the antioxidant, the lubricant, the efficient flame retardant synergist prepared in the step S1-4 and the vermiculite-sepiolite composite powder prepared in the step S1-5, and mixing for 10-18min at the temperature of 95-110 ℃ and the rotating speed of 1200-1600rpm to obtain a premix; S4, melt blending extrusion, namely adding premix into a double-screw extruder, setting the temperature of each section to be 145-165 ℃ first region, 165-180 ℃ second region, 180-195 ℃ third region, 190-205 ℃ fourth region and 185-200 ℃ machine head, wherein the screw rotating speed is 35-65rpm, and the vacuum degree is-0.06-0.09 MPa, and performing melt blending extrusion; S5, molding, namely extruding the extruded material through a die, cooling with circulating cooling water at 25-32 ℃, towing by a tractor at a towing speed of 8-18m/min, and granulating by a granulator to obtain sheath particles, wherein the sheath is prepared by extrusion molding of the sheath particles, and the molding temperature is 170-190 ℃.
  6. 6. The process of claim 5, wherein the twin screw extruder in S4 has an aspect ratio of 38:1 to 42:1 and a screw compression ratio of 2.8:1 to 3.8:1.
  7. 7. The process according to claim 5, wherein the die in S5 has a die opening diameter of 25 to 55mm, a die core diameter of 12 to 32mm and a die temperature of 180 to 195 ℃.

Description

High-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath and preparation method thereof Technical Field The invention relates to the technical field of polyolefin sheath materials, in particular to a high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath and a preparation method thereof. Background The low-smoke halogen-free flame-retardant polyolefin sheath is widely applied to the fields of construction, rail transit, ships and the like due to the advantages of no release of halide, low smoke density and the like during combustion. However, in the prior art, the following problems are generally existed in the low-smoke halogen-free flame retardant polyolefin sheath: In order to achieve the required flame retardant effect, the addition amount of the flame retardant is large, so that the mechanical property of the material is reduced, and the tensile strength and the elongation at break are reduced; The compatibility among different components is poor, agglomeration phenomenon is easy to occur, and the uniformity and the use stability of the material are affected; The flame retardant efficiency is limited, partial products are difficult to reach the UL 94V 0 flame retardant standard, the smoke density is high, the visibility is low in fire disaster, and the personnel evacuation and rescue are not facilitated; In order to solve the problems, the invention provides the high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath and the preparation method thereof, so that the polyolefin sheath material with high flame retardance, low smoke and excellent mechanical properties is obtained, and the blank of the prior art is filled. Disclosure of Invention Aiming at the technical defects that the existing low-smoke halogen-free flame-retardant polyolefin sheath is low in flame-retardant efficiency, difficult to consider both mechanical properties and flame-retardant properties, poor in compatibility and high in smoke density, the invention provides the high-flame-retardant low-smoke halogen-free flame-retardant polyolefin sheath which is reasonable in formula and stable in preparation process and the preparation method thereof, and the synergistic improvement of flame retardance, low smoke properties and mechanical properties is realized. In order to achieve the above object, the present invention provides the following technical solutions: The technical scheme provided by the invention is as follows: the high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath comprises, by weight, 45-65 parts of a polyolefin composite base material, 35-55 parts of a multi-component composite flame retardant, 4-9 parts of a special compatilizer, 0.8-2.5 parts of an antioxidant, 0.5-2 parts of a lubricant, 1.5-5 parts of a high-efficiency flame-retardant synergist and 1-3 parts of vermiculite-sepiolite composite powder. Wherein the polyolefin composite substrate is a blend of high-density polyethylene, ethylene-vinyl acetate copolymer and polyolefin elastomer, and the weight ratio of the three is 4:1:0.5-6:2:1; The multi-component composite flame retardant is a compound of magnesium hydroxide, aluminum hydroxide, nano hydroxyapatite and microencapsulated ammonium polyphosphate, and the weight ratio of the magnesium hydroxide to the aluminum hydroxide to the nano hydroxyapatite to the microencapsulated ammonium polyphosphate is 2:2:0.8:1-3:3:1.2:1.8; the special compatilizer is glycidyl methacrylate grafted ethylene-octene copolymer; the efficient flame-retardant synergist is a compound of diethyl aluminum phosphinate and zirconium oxide, and the weight ratio of the diethyl aluminum phosphinate to the zirconium oxide is 3:1-5:2; The weight ratio of vermiculite to sepiolite in the vermiculite-sepiolite composite powder is 1:0.5-1:1.5, the particle size of nano hydroxyapatite is 50-200nm, and the particle size of the vermiculite-sepiolite composite powder is 1-5 mu m; The antioxidant is a compound of an antioxidant 1076 and an antioxidant 626, and the weight ratio of the antioxidant to the antioxidant is 1:1-2:1; The lubricant is ethylene bis stearamide. The preparation method of the high-flame-retardance low-smoke halogen-free flame-retardant polyolefin sheath comprises the following steps: S1 preparation of raw materials S1-1, preparing a polyolefin composite substrate, namely adding high-density polyethylene, ethylene-vinyl acetate copolymer and polyolefin elastomer into a high-speed mixer according to a weight ratio of 4:1:0.5-6:2:1, and mixing for 8-15min at 60-80 ℃ and a rotating speed of 600-800rpm to obtain the polyolefin composite substrate; s1-2, preparing a multi-element composite flame retardant, namely adding magnesium hydroxide, aluminum hydroxide, nano hydroxyapatite and microencapsulated ammonium polyphosphate into a conical mixer according to the weight ratio of 2:2:0.8:1-3:3:1.2:1.8, and mixing for 30-45min at room temperature and