Flame-retardant polyethylene cable material and production method thereof
A novel cable material composition and process using hydrogen oxide aluminum and phosphorus-nitrogen flame retardants addresses the mechanical degradation issue in low-smoke, halogen-free cables, ensuring enhanced mechanical properties and reduced flame retardant use.
Patent Information
- Application Number
- CN202510498564.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-07-15
AI Technical Summary
In order to meet the low smoke and halogen-free requirements, the addition of a large amount of inorganic flame retardants has caused the cracking performance of the material to be greatly reduced and cannot meet the use requirements.
Aluminum hydroxide, treated magnesium hydroxide and phosphorus-nitrogen flame retardant are used, combined with high-density polyethylene resin and maleic anhydride grafted polyethylene resin, and the flame retardant polyethylene cable material is prepared through specific kneading and extrusion granulation processes to ensure flame retardant performance while improving cracking performance.
On the premise of ensuring flame retardant performance, the environmental stress cracking time of flame retardant polyethylene is extended by more than 260 hours, improving mechanical properties, processing properties and heat resistance, and greatly reducing the use of flame retardant.
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Figure CN120310097A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of cable materials, and specifically to a flame-retardant polyethylene cable material and a production method thereof. Background Art
[0002] Wiring cables are widely used in various industries of the national economy and are closely related to people's daily lives. They play a crucial role in fields such as power transmission and signal control. The vast majority of insulating and sheathing materials for wires and cables are organic polymer materials. Polyethylene is widely used in insulating and sheathing materials for wires and cables due to its excellent insulation, wear resistance, easy processing, corrosion resistance, and long service life. However, its defects such as easy degradation at high temperatures and flammability under fire conditions will further increase the fire losses. Therefore, it must be flame-retarded to be safely used in insulating and sheathing materials for wires and cables.
[0003] The polyethylene sheathing material is a commonly used thermoplastic plastic with light weight, non-toxic and environmentally friendly, and excellent electrical insulation performance. It is widely used in the field of wires and cables. Since most of the previous wires and cables were PVC products, PVC products are toxic and harmful and not environmentally friendly. After burning, they will release a large amount of toxic and harmful gases, causing great harm. In order to meet the two requirements of low smoke and halogen-free, a large amount of inorganic flame retardants are added to low-smoke and halogen-free polyolefin cables, resulting in a significant decrease in the cracking performance of the materials and failing to meet the requirements. Summary of the Invention
[0004] (I) Technical Problems to be Solved In view of the deficiencies of the prior art, the present invention provides a flame-retardant polyethylene cable material and a production method thereof, mainly to solve the problem that in order to meet the two requirements of low smoke and halogen-free, a large amount of inorganic flame retardants are added to existing low-smoke and halogen-free polyolefin cables, resulting in a significant decrease in the cracking performance of the materials and failing to meet the requirements.
[0005] (II) Technical Solutions To achieve the above object, the present invention provides the following technical solutions: A flame-retardant polyethylene cable material, comprising the following components: 10-15 parts of aluminum hydroxide, 10-15 parts of filler, 20-30 parts of phosphorus-nitrogen flame retardant, 50-60 parts of high-density polyethylene resin, 45-55 parts of grafted polyethylene resin, 6-9 parts of antioxidant, 3-6 parts of surface modifier, and 7-10 parts of lubricant.
[0006] Further, the high-density polyethylene resin is a high-density polyethylene resin with a melt index of 0.2-0.3 g / 10 min, and the grafted polyethylene resin is a polyethylene resin grafted with maleic anhydride, and the grafting rate is 0.7-1%.
[0007] Based on the foregoing solution, the surface modifier refers to a highly concentrated silicone masterbatch made by dispersing 70 - 80% by mass of silicone powder on a polyethylene carrier with a mass percentage of 30 - 40%.
[0008] As a further solution of the present invention, the phosphazene flame retardant is any one of melamine, melamine polyphosphate, diphenylguanidine pyrophosphate, melamine orthophosphate, ammonium polyphosphate, melamine phosphate ester salt, bis(neopentyl glycol)m-phenylene diamine bisphosphate, and neopentyl glycol phosphate melamine salt.
[0009] Furthermore, the antioxidant is any one of polyhydroxypentaerythritol ester, antioxidant 1010, and antioxidant 1098, and the filler is treated magnesium hydroxide.
[0010] The present invention also provides a method for producing a flame-retardant polyethylene cable material, comprising the following steps: S1: Filler processing, adding vinyltrimethoxysilane diluted with alcohol to magnesium hydroxide, treating at 60 - 70 °C for 15 - 20 min, and then transferring it to a sealed polyethylene packaging bag for standby to obtain treated magnesium hydroxide; S2: Mixing, adding aluminum hydroxide, phosphazene flame retardant, antioxidant, surface modifier, and lubricant into a kneader at a temperature of 110 - 115 °C and kneading for 5 - 8 min to obtain a mixed material; S3: Pelletizing, placing the mixed material in S2 and the treated magnesium hydroxide into a high-speed mixer with a rotation speed of 1000 - 1100 r / min and mixing for 5 - 10 min, and then extruding through a twin-screw extrusion granulation unit to obtain a composite flame-retardant masterbatch; S4: Screening, adding the composite flame-retardant masterbatch in S3 into a screening machine, and screening the composite flame-retardant masterbatch that meets the particle size; S5: Material preparation, placing the screened composite flame-retardant masterbatch into a kneader, adding high-density polyethylene resin and grafted polyethylene resin for kneading, then performing two-stage extrusion granulation, and finally air-cooling to obtain the flame-retardant polyethylene cable material.
[0011] Based on the foregoing solution, the lubricant is any one of polyethylene wax and barium stearate.
[0012] As a further solution of the present invention, the particle size of the composite flame-retardant masterbatch in S3 is 30 - 50 μm.
[0013] (III) Beneficial effects Compared with the prior art, the present invention provides a flame-retardant polyethylene cable material and a production method, having the following beneficial effects: 1. By adding aluminum hydroxide, treated magnesium hydroxide, and a phosphorus-nitrogen flame retardant, the present invention overcomes the defect of poor cracking performance caused by adding three types of flame retardants while ensuring the flame retardancy, extends the environmental stress cracking resistance time of flame-retardant polyethylene to more than 260 hours, and enables the flame-retardant polyethylene cable material to have better environmental stress cracking resistance performance after forming a cable sheath.
[0014] 2. By adding high-density polyethylene resin, the present invention can improve the crosslinking density, which can not only improve the flame retardancy and smoke suppression performance in the system but also inhibit agglomeration, effectively improving the mechanical properties, processing properties, and heat resistance.
[0015] 3. The present invention significantly reduces the usage amount of the flame retardant, ensures the mechanical properties, processing properties, environmental stress cracking resistance, etc. of the cable material while guaranteeing the flame retardant effect of the cable material, and the preparation method is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic flow structure diagram of a production method of a flame-retardant polyethylene cable material proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0018] Example 1 Referring to Figure 1 , a flame-retardant polyethylene cable material includes the following components: 10 parts of aluminum hydroxide, 10 parts of filler, 20 parts of phosphorus-nitrogen flame retardant, 50 parts of high-density polyethylene resin, 45 parts of grafted polyethylene resin, 6 parts of antioxidant, 3 parts of surface modifier, and 7 parts of lubricant. By adding aluminum hydroxide, treated magnesium hydroxide, and a phosphorus-nitrogen flame retardant, the present invention overcomes the defect of poor cracking performance caused by adding three types of flame retardants while ensuring the flame retardancy, extends the environmental stress cracking resistance time of flame-retardant polyethylene to more than 260 hours, and enables the flame-retardant polyethylene cable material to have better environmental stress cracking resistance performance after forming a cable sheath.
[0019] In the present invention, the high-density polyethylene resin is a high-density polyethylene resin with a melt index of 0.2 g / 10 min, the grafted polyethylene resin is a maleic anhydride-grafted polyethylene resin with a grafting rate of 0.7%, the surface modifier refers to a highly concentrated silicone masterbatch made by dispersing 70% by mass of silicone powder in 30% by mass of a polyethylene carrier, the phosphorus-nitrogen flame retardant is dipentaerythritol diphenyl diphosphate, the antioxidant is antioxidant 1098, and the filler is treated magnesium hydroxide.
[0020] The present invention also provides a method for producing a flame-retardant polyethylene cable material, comprising the following steps: S1: Filler processing. Vinyltrimethoxysilane diluted with alcohol is added to magnesium hydroxide, and it is treated at 70 °C for 15 min, and then transferred to a sealed polyethylene packaging bag for standby to obtain the treated magnesium hydroxide. S2: Mixing. Aluminum hydroxide, phosphorus-nitrogen flame retardant, antioxidant, surface modifier and lubricant are added to an internal mixer at a temperature of 115 °C and mixed for 5 min to obtain a mixed material. S3: Pelletizing. The mixed material in S2 and the treated magnesium hydroxide are placed in a high-speed mixer rotating at 1100 r / min and mixed for 5 min, and then extruded through a twin-screw extrusion granulation unit to obtain a composite flame-retardant masterbatch. S4: Screening. The composite flame-retardant masterbatch in S3 is added to a screening machine, and the composite flame-retardant masterbatch meeting the particle size is screened by the screening machine. S5: Material preparation. The screened composite flame-retardant masterbatch is placed in an internal mixer, and high-density polyethylene resin and grafted polyethylene resin are added for mixing, and then double-stage extrusion granulation is carried out, and finally air cooling is carried out to obtain the flame-retardant polyethylene cable material. By adding high-density polyethylene resin, the crosslinking density can be increased. In the system, it can improve the flame-retardant and smoke-suppressing properties, while also inhibiting agglomeration, effectively improving the mechanical properties, processing properties and heat resistance, and greatly reducing the amount of flame retardant used. While ensuring the flame-retardant effect of the cable material, the mechanical properties, processing properties, environmental stress cracking resistance and other properties of the cable material are ensured, and the preparation method is simple and easy to operate.
[0021] In particular, the lubricant is polyethylene wax, and the particle size of the composite flame-retardant masterbatch in S3 is 30 μm.
[0022] Example 2 Refer to Figure 1, A flame-retardant polyethylene cable compound, comprising the following components: 13 parts of aluminum hydroxide, 12 parts of filler, 25 parts of phosphorus-nitrogen flame retardant, 55 parts of high-density polyethylene resin, 50 parts of grafted polyethylene resin, 7 parts of antioxidant, 5 parts of surface modifier and 8 parts of lubricant. By adding aluminum hydroxide, treated magnesium hydroxide and phosphorus-nitrogen flame retardant, while ensuring the flame-retardant performance, the defect of poor cracking performance caused by adding three types of flame retardants is overcome, and the environmental stress cracking time of the flame-retardant polyethylene is extended, exceeding two hundred and sixty hours. After the flame-retardant polyethylene cable compound forms a cable sheath, it has better environmental stress cracking resistance.
[0023] In the present invention, the high-density polyethylene resin is a high-density polyethylene resin with a melt index of 0.2 g / 10 min, the grafted polyethylene resin is a maleic anhydride-grafted polyethylene resin with a grafting rate of 0.9%, the surface modifier refers to a highly concentrated silicone masterbatch made by dispersing 75% by mass of silicone powder on 35% by mass of polyethylene carrier, the phosphorus-nitrogen flame retardant is ammonium polyphosphate, the antioxidant is antioxidant 1010, and the filler is treated magnesium hydroxide.
[0024] The present invention also provides a method for producing a flame-retardant polyethylene cable compound, comprising the following steps: S1: Filler processing, adding vinyltrimethoxysilane diluted with alcohol to magnesium hydroxide, treating at 65 °C for 17 min, and then transferring it to a sealed polyethylene packaging bag for standby to obtain treated magnesium hydroxide; S2: Mixing, adding aluminum hydroxide, phosphorus-nitrogen flame retardant, antioxidant, surface modifier and lubricant to a mixer at 113 °C and mixing for 6 min to obtain a mixed material; S3: Pelletizing, placing the mixed material in S2 and treated magnesium hydroxide in a high-speed mixer at a rotation speed of 1050 r / min and mixing for 7 min, and then extruding through a twin-screw extrusion granulation unit to obtain a composite flame-retardant masterbatch; S4: Screening, adding the composite flame-retardant masterbatch in S3 to a screening machine, and screening the composite flame-retardant masterbatch with a qualified particle size through the screening machine; S5: Material preparation, placing the screened composite flame-retardant masterbatch in a mixer and adding high-density polyethylene resin and grafted polyethylene resin for mixing, then double-stage extrusion granulation, and finally air-cooling to obtain the flame-retardant polyethylene cable compound. By adding high-density polyethylene resin, the cross-linking density can be increased, which can improve the flame-retardant and smoke-suppressing performance in the system, while also inhibiting agglomeration, effectively improving the mechanical properties, processing properties and heat resistance, and significantly reducing the usage amount of the flame retardant. While ensuring the flame-retardant effect of the cable compound, the mechanical properties, processing properties, environmental stress cracking resistance and other properties of the cable compound are ensured, and the preparation method is simple and easy to operate.
[0025] In particular, the lubricant is barium stearate, and the particle size of the composite flame retardant masterbatch in S3 is 40 μm.
[0026] Example 3 Reference Figure 1 , a flame retardant polyethylene cable material, comprising the following components: 15 parts of aluminum hydroxide, 15 parts of filler, 30 parts of phosphorus-nitrogen flame retardant, 60 parts of high-density polyethylene resin, 55 parts of grafted polyethylene resin, 9 parts of antioxidant, 6 parts of surface modifier and 10 parts of lubricant. By adding aluminum hydroxide, treated magnesium hydroxide and phosphorus-nitrogen flame retardant, while ensuring the flame retardant performance, the defect of poor cracking performance caused by adding three types of flame retardants is overcome, and the environmental stress cracking time of the flame retardant polyethylene is extended, exceeding two hundred and sixty hours. After the flame retardant polyethylene cable material forms a cable sheath, it has better environmental stress cracking resistance.
[0027] In the present invention, the high-density polyethylene resin is a high-density polyethylene resin with a melt index of 0.3 g / 10 min, the grafted polyethylene resin is a maleic anhydride-grafted polyethylene resin with a grafting rate of 1%, the surface modifier refers to a high-concentration silicone masterbatch made by dispersing 80% by mass of silicone powder on a polyethylene carrier with a mass percentage of 40%, the phosphorus-nitrogen flame retardant is melamine, the antioxidant is polyhydroxy pentaerythritol ester, and the filler is treated magnesium hydroxide.
[0028] The present invention also provides a method for producing a flame retardant polyethylene cable material, comprising the following steps: S1: Filler processing, adding vinyltrimethoxysilane diluted with alcohol to magnesium hydroxide, treating at 60 °C for 20 min, and then transferring it to a sealed polyethylene packaging bag for standby to obtain treated magnesium hydroxide; S2: Mixing, adding aluminum hydroxide, phosphorus-nitrogen flame retardant, antioxidant, surface modifier and lubricant to a kneader at a temperature of 110 °C and kneading for 8 min to obtain a mixture; S3: Pelletizing, placing the mixture in S2 and the treated magnesium hydroxide in a high-speed mixer with a rotation speed of 1000 r / min and mixing for 10 min, and then extruding through a twin-screw extrusion granulation unit to obtain a composite flame retardant masterbatch; S4: Screening, adding the composite flame retardant masterbatch in S3 to a screening machine, and screening the composite flame retardant masterbatch with a conforming particle size through the screening machine; S5: Material preparation. The screened composite flame retardant masterbatch is placed in a mixer and high-density polyethylene resin and grafted polyethylene resin are added for mixing. Then, it is extruded and pelletized in a two-stage process, and finally air-cooled to obtain the flame retardant polyethylene cable material. By adding high-density polyethylene resin, the crosslinking density can be increased. In the system, it can improve the flame retardant and smoke suppression performance, while also inhibiting agglomeration, effectively improving the mechanical properties, processing properties and heat resistance, and significantly reducing the amount of flame retardant used. While ensuring the flame retardant effect of the cable material, the mechanical properties, processing properties, environmental stress cracking resistance and other properties of the cable material are also guaranteed, and the preparation method is simple and easy to operate.
[0029] Particularly, the lubricant is polyethylene wax, and the particle size of the composite flame retardant masterbatch in S3 is 50 μm.
[0030] In the description of this article, it should be noted that relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.
Claims
1. A flame-retardant polyethylene cable compound, characterized in that, It includes the following components: 10 - 15 parts of aluminum hydroxide, 10 - 15 parts of filler, 20 - 30 parts of phosphorus-nitrogen flame retardant, 50 - 60 parts of high-density polyethylene resin, 45 - 55 parts of grafted polyethylene resin, 6 - 9 parts of antioxidant, 3 - 6 parts of surface modifier, and 7 - 10 parts of lubricant.
2. The flame-retardant polyethylene cable compound according to claim 1, characterized in that, The high-density polyethylene resin is a high-density polyethylene resin with a melt index of 0.2 - 0.3 g / 10 min. The grafted polyethylene resin is a maleic anhydride-grafted polyethylene resin, and the grafting rate is 0.7 - 1%.
3. A flame-retardant polyethylene cable compound according to claim 2, characterized in that, The surface modifier refers to a highly concentrated silicone masterbatch made by dispersing 70 - 80% by mass of silicone powder in 30 - 40% by mass of a polyethylene carrier.
4. A flame-retardant polyethylene cable compound according to claim 3, characterized in that, The phosphorus-nitrogen flame retardant is any one of melamine, melamine polyphosphate, di-melamine pyrophosphate, melamine orthophosphate, ammonium polyphosphate, melamine phosphate ester salt, bis(dineopentyl glycol)m-phenylene diamine bisphosphate, and neopentyl glycol phosphate melamine salt.
5. A flame-retardant polyethylene cable compound according to claim 4, wherein, The antioxidant is any one of polyhydroxypentaerythritol ester, antioxidant 1010, and antioxidant 1098. The filler is treated magnesium hydroxide.
6. A production method of flame-retardant polyethylene cable compound, characterized in that, It includes the following steps: S1: Filler processing. Add vinyltrimethoxysilane diluted with alcohol to magnesium hydroxide, treat it at 60 - 70 °C for 15 - 20 min, and then transfer it to a sealed polyethylene packaging bag for standby to obtain treated magnesium hydroxide. S2: Mixing. Add aluminum hydroxide, phosphorus-nitrogen flame retardant, antioxidant, surface modifier, and lubricant to an internal mixer at a temperature of 110 - 115 °C and mix for 5 - 8 min to obtain a mixed material. S3: Pelletizing. Place the mixed material in S2 and the treated magnesium hydroxide in a high-speed mixer with a rotational speed of 1000 - 1100 r / min and mix for 5 - 10 min, and then extrude it through a twin-screw extrusion granulation unit to obtain a composite flame retardant masterbatch. S4: Screening. Add the composite flame retardant masterbatch in S3 to a screening machine, and screen the composite flame retardant masterbatch with a qualified particle size through the screening machine. S5: Material preparation. Place the screened composite flame retardant masterbatch in an internal mixer, add high-density polyethylene resin and grafted polyethylene resin and mix, then perform two-stage extrusion granulation, and finally air-cool to obtain a flame retardant polyethylene cable material.
7. A production method of a flame-retardant polyethylene cable material according to claim 6, characterized in that, The lubricant is any one of polyethylene wax and barium stearate.
8. A production method of a flame-retardant polyethylene cable material according to claim 7, characterized in that, The particle size of the composite flame retardant masterbatch in S3 is 30 - 50 μm.