High-temperature-resistant, high-filling, high-dispersion, flame-retardant and weather-resistant master batch for polyethylene film and preparation method thereof

Abstract

The invention relates to a high-temperature-resistant, high-filling, high-dispersion, flame-retardant and weather-resistant master batch for a polyethylene film and a preparation method of the master batch. The flame retardant disclosed by the invention has high-temperature processing resistance, meanwhile, the compound additive can play a high-dispersion flame-retardant role, and the efficient coupling agent added in the formula is beneficial to improving the filling amount of the flame-retardant master batch and the dispersity of the master batch, has a certain coating effect on the flame retardant, improves the processability of low-melt-index resin, and can be used for preparing the flame-retardant master batch. And the extrusion pressure during plastic processing is reduced, the energy consumption is reduced, and the mechanical wear is reduced.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials, specifically a high-temperature resistant, highly filled, highly dispersed flame-retardant masterbatch for polyethylene film and its preparation method. Background Technology

[0002] Polyethylene (PE) possesses excellent temperature resistance, good chemical stability, resistance to most acids and alkalis, and good processing fluidity. It is currently widely used in the woven plastics industry and municipal engineering pipe manufacturing. However, PE alone suffers from poor flame retardancy and insufficient mechanical properties during use. Therefore, PE typically undergoes necessary flame retardant and weather-resistant modifications before use. Currently, achieving both the specified flame retardant level and weather resistance requirements for PE remains a technical challenge, primarily due to the antagonistic effect between flame retardants and light stabilizers. Therefore, we perform coating treatments on flame retardants and / or light stabilizers to reduce the antagonistic effect and achieve the desired flame retardant and weather-resistant properties for PE.

[0003] Commonly used organic flame retardants in polyethylene include decabromodiphenyl ethane, decabromodiphenyl ether, ethylenebistetrabromophthalimide, melamine polyphosphate, ammonium polyphosphate, and piperazine pyrophosphate. Inorganic flame retardants mainly include antimony trioxide, magnesium hydroxide, aluminum hydroxide, and silicon-based flame retardants.

[0004] Commonly used light stabilizers in polyethylene include light stabilizer 770, light stabilizer 944, light stabilizer 119, light stabilizer 2020, and light stabilizer 622.

[0005] When flame retardants are used together with light stabilizers, there is an antagonistic effect, which can easily result in meeting mechanical properties but having low flame retardant efficiency and failing to achieve the UL-94 V-0 rating. At the same time, the combined use of organic and inorganic flame retardants can lead to problems such as poor dispersion and poor compatibility with resins. The resulting flame retardant masterbatches may have problems such as uneven dispersion of resin additives, defects on the surface of the masterbatch, increased extruder current, and high die head pressure. For example, Chinese patent CN201910512467.7 discloses a novel high-efficiency flame-retardant and weather-resistant masterbatch and its preparation method. The main components of this masterbatch are polypropylene, ammonium polyphosphate, light stabilizer 944, ultraviolet absorber 531, antioxidant B215, and processing aids, which are mixed and extruded in a certain proportion. Chinese patent CN103509263A discloses an environmentally friendly additive-type polyethylene flame-retardant masterbatch and its preparation method. The main components of this masterbatch are polyethylene, chlorinated polyethylene, decabromodiphenyl ethane, antimony trioxide, TBC flame retardant, MCA flame retardant, flame retardant synergist, lubricant, and antioxidant, which are mixed and extruded in a certain proportion. Chinese patent CN110643098 discloses a special flame-retardant and synergistic functional masterbatch for modified polyethylene and its preparation method. The main components of this masterbatch are polyethylene, decabromodiphenyl ethane, antimony trioxide, ethylene-octene copolymer, styrene-acrylonitrile copolymer coated with polytetrafluoroethylene, dispersant, and lubricant, which are mixed and extruded in a certain proportion. The above patents have problems such as the inability to achieve both flame retardancy and weather resistance at the same time, the low flame retardancy efficiency while ensuring weather resistance requirements, uneven dispersion of flame retardants, easy powdering due to high filler content, and relatively difficult processing. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature resistant, high-filling, and highly dispersed flame-retardant and weather-resistant masterbatch for polyethylene film and its preparation method. The polyethylene flame-retardant and weather-resistant masterbatch prepared by this method has the advantages of high temperature resistance, low addition amount, and excellent flame-retardant effect.

[0007] Therefore, the technical solution adopted by the present invention is: a high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film, comprising the following materials in the following proportions by weight: 20-30 parts of linear low-density polyethylene (LLDPE8320), 60-70 parts of flame retardant, 10-20 parts of light stabilizer, 0.1-1 parts of coupling agent, 0.1-1 parts of nano zinc oxide, 0.1-1 parts of lubricant, and 0.2-1 parts of antioxidant; The coupling agent is a plastic powder processing additive containing a multi-hydroxyl structure, with a melting temperature of 50~60℃ and a decomposition temperature of ≥330℃.

[0008] Furthermore, the coupling agent is a plastic processing aid containing a multi-hydroxyl structure, commercially available model: TMA-13 ​​produced by Jiangsu Tianma High-Tech New Materials, with a hydroxyl content of ≥9.5wt% and a molecular weight of 800-1200g / mol. This additive can improve the processing rheology of low melt index resins, enhance filler dispersibility, improve surface gloss, effectively reduce extrusion temperature, and reduce gel formation during extrusion, thereby improving film quality.

[0009] Furthermore, the melt index of the linear low-density polyethylene resin is between 1 and 20 g / 10 min.

[0010] Furthermore, the flame retardant is one or more of the following: decabromodiphenyl ethane, ethylene bis(tetrabromophthalimide), decabromodiphenyl ether, piperazine pyrophosphate, antimony trioxide, ammonium polyphosphate, and melamine cyanurate.

[0011] Furthermore, the light stabilizer is one or more of light stabilizer 944, light stabilizer 770, light stabilizer 622, light stabilizer 2020, and light stabilizer 119.

[0012] Furthermore, the nano zinc oxide is commercially available: nano zinc oxide produced by Shandong Xingya New Materials, a powder additive with a specific surface area >15m² / g, a particle size of 30-50nm, high product fineness, and certain UV resistance and flame retardant synergistic function.

[0013] Furthermore, the lubricant is one or more of ethylene bis-stearamide, silicone powder, zinc stearate, calcium stearate, stearic acid, and polyethylene wax.

[0014] Furthermore, the antioxidant is a compound of hindered phenolic antioxidant 1010 and phosphite antioxidant 168. The compounding ratio is 1:1.

[0015] A method for preparing a high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film, comprising the following steps: 1) Add the resin, coupling agent, and flame retardant from the above formula to a high-speed mixer and stir at room temperature for 15-25 minutes.

[0016] 2) Add the light stabilizer, lubricant, and antioxidant to step 1) and continue to stir at high and low speeds at room temperature for 8-15 minutes using a high-speed mixer.

[0017] 3) The material that was mixed evenly in step (2) was added through the main feed port of the twin-screw extruder for extrusion granulation. The temperature of each zone from the feeding section to the die surface was controlled between 80°C and 185°C.

[0018]

[0019] The advantages of this invention are: the flame retardant of this invention has the performance of high temperature processing resistance, and the compounded additives can play a highly dispersed flame retardant role. The high-efficiency coupling agent added in this formula is conducive to improving the filling amount and dispersibility of the flame retardant masterbatch, while also playing a certain coating effect on the flame retardant, improving the processability of low melt index resin, making the filler more uniformly dispersed, reducing the extrusion pressure during plastic processing, reducing energy consumption, and reducing mechanical wear. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below through embodiments; however, the present invention is not limited to these embodiments.

[0021] Specific embodiments and comparative examples: According to the formula in Table 1, first weigh out polyethylene, coupling agent, and flame retardant, add them to the high-speed mixer, and stir at room temperature for 20 minutes. Then weigh out light stabilizer, lubricant, and antioxidant, add them to the high-speed mixer, and mix at high and low speeds at room temperature for 10 minutes. Finally, extrude and granulate using a twin-screw extruder.

[0022] The twin-screw extruder has a length-to-diameter ratio of 48:1. The extruder temperature settings (from feed inlet to die) are: 80, 125, 155, 185, 185, 180, 185, 180, 180, 175℃. The screw speed is 300 r / min, and the feed speed is 15 r / min. The extruded granules are dried at 60℃ for 4 hours before use.

[0023]

[0024] Performance tests were conducted on polyethylene injection-molded flame-retardant specimens with more than 20% masterbatch added. The data are shown in the table below:

[0025] Comparing Examples 1, 2 and the Comparative Example in the table, adding 3 parts of light stabilizer 944 significantly reduced the flame retardant properties of the samples, while the improvement in weather resistance was limited. Adding 1 part of nano zinc oxide helped to improve the oxygen index of the material.

[0026] As can be seen from Examples 3 and 4, adding 1 part of TMA-13 ​​can significantly improve the dispersibility of flame retardant fillers, reduce the average particle size of fillers in materials, improve the flame retardant efficiency of flame retardants, and improve the weather resistance of flame retardant materials to a certain extent. At the same time, adding 1 part of TMA-13 ​​and 1 part of nano zinc oxide can help improve the flame retardant and weather resistance of materials.

Claims

1. A high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film, characterized in that: The materials, by weight, include the following proportions: 20-30 parts of linear low-density polyethylene (LLDPE8320), 60-70 parts of flame retardant, 10-20 parts of light stabilizer, 0.1-1 parts of coupling agent, 0.1-1 parts of nano zinc oxide, 0.1-1 parts of lubricant, and 0.2-1 parts of antioxidant. The coupling agent is a plastic powder processing additive containing a multi-hydroxyl structure, with a melting temperature of 50~60℃ and a decomposition temperature of ≥330℃.

2. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The coupling agent is a plastic processing aid containing a multi-hydroxyl structure. The commercially available model is TMA-13 ​​produced by Jiangsu Tianma High-Tech New Materials. The hydroxyl content is ≥9.5wt% and the molecular weight is 800-1200g / mol.

3. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The melt index of the linear low-density polyethylene resin is between 1 and 20 g / 10 min.

4. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The flame retardant is one or more of the following: decabromodiphenyl ethane, ethylenebistetrabromophthalimide, decabromodiphenyl ether, piperazine pyrophosphate, antimony trioxide, ammonium polyphosphate, and melamine cyanurate.

5. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The light stabilizer is one or more of light stabilizer 944, light stabilizer 770, light stabilizer 622, light stabilizer 2020, and light stabilizer 119.

6. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The nano zinc oxide mentioned is commercially available: nano zinc oxide produced by Shandong Xingya New Materials, with a specific surface area >15m² / g and a particle size of 30-50nm as a powder additive.

7. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The lubricant is one or more of ethylene bis-stearamide, silicone powder, zinc stearate, calcium stearate, stearic acid, and polyethylene wax.

8. The high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film according to claim 1, characterized in that, The antioxidant is a compound of hindered phenolic antioxidant 1010 and phosphite antioxidant 168, with a compounding ratio of 1:

1.

9. A method for preparing high-temperature resistant, high-filler, high-dispersion, flame-retardant, and weather-resistant masterbatch for polyethylene film, characterized in that, Follow these steps: 1) Add the resin, coupling agent, and flame retardant from the above formula to a high-speed mixer and stir at room temperature for 15-25 minutes; 2) Add the light stabilizer, lubricant, and antioxidant to step 1) and continue stirring at high and low speeds at room temperature for 8-15 minutes using a high-speed mixer; 3) The material that was mixed evenly in step (2) was added through the main feed port of the twin-screw extruder for extrusion granulation. The temperature of each zone from the feeding section to the die surface was controlled between 80°C and 185°C.

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