阅读说明：本技术 一种聚乙烯色母粒及其制备方法 (Polyethylene color master batch and preparation method thereof ) 是由 李杭明 周佳佳 于 2020-05-13 设计创作，主要内容包括：本发明公开了一种聚乙烯色母粒,由如下重量份的原料制备而成：改性颜料20-70份、基体树脂20-30份、无机纳米晶3-5份、纳米蒙脱土1-2份、分散剂7-15份、有机硅季铵盐抗菌剂0.5-1份、抗氧化剂0.6-0.8份、光稳定剂1-2份、助剂0.1-0.2份；本发明还公开了所述聚乙烯色母粒的制备方法。本发明通过对颜料进行改性,使颜料更易于分散到PE树脂中,形成色度均匀、纯度高的色母粒,通过无机纳米晶的适量添加,提高树脂基体的拉伸强度,改善色母粒的力学性能和流动性,通过功能性添加剂的辅配,赋予色母粒良好的抗菌、抗氧化和光稳定性能,提高色母粒的使用寿命,得到的聚乙烯色母粒分散性能好、着色力强,具有广阔的应用前景。(The invention discloses a polyethylene color master batch which is prepared from the following raw materials in parts by weight: 20-70 parts of modified pigment, 20-30 parts of matrix resin, 3-5 parts of inorganic nanocrystalline, 1-2 parts of nano montmorillonite, 7-15 parts of dispersant, 0.5-1 part of organosilicon quaternary ammonium salt antibacterial agent, 0.6-0.8 part of antioxidant, 1-2 parts of light stabilizer and 0.1-0.2 part of auxiliary agent; the invention also discloses a preparation method of the polyethylene color master batch. According to the invention, the pigment is modified, so that the pigment is easier to disperse in the PE resin, a color master batch with uniform chromaticity and high purity is formed, the tensile strength of a resin matrix is improved by adding a proper amount of inorganic nanocrystalline, the mechanical property and the fluidity of the color master batch are improved, the color master batch is endowed with good antibacterial, antioxidant and light stability by the auxiliary matching of the functional additive, the service life of the color master batch is prolonged, and the obtained polyethylene color master batch has good dispersibility, strong tinting strength and wide application prospect.)

1. The polyethylene color master batch is characterized by being prepared from the following raw materials in parts by weight: 20-70 parts of modified pigment, 20-30 parts of matrix resin, 3-5 parts of inorganic nanocrystalline, 1-2 parts of nano montmorillonite, 7-15 parts of dispersant, 0.5-1 part of organosilicon quaternary ammonium salt antibacterial agent, 0.6-0.8 part of antioxidant, 1-2 parts of light stabilizer and 0.1-0.2 part of auxiliary agent;

the polyethylene color master batch is prepared by the following steps:

step S1, adding inorganic nanocrystalline, nano montmorillonite and half dispersant into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the grinding particles is controlled to be 0.2-0.4 μm;

s2, sequentially adding the matrix resin, the ground product obtained in the step S1, the modified pigment and the other half of the dispersing agent into a low-speed stirrer, mixing at room temperature at 100r/min for 3-5min, adding the organosilicon quaternary ammonium salt antibacterial agent, the antioxidant, the light stabilizer and the auxiliary agent into the mixture, and mixing at a high speed of 2000r/min for 8-10min by using a high-speed mixer;

step S3, transferring the mixture obtained in the step S2 into a pressurized internal mixer, and carrying out pressurized internal mixing for 16-22min under the conditions of 10-15kg of pressure and 110-135 ℃;

step S4, plasticizing and extruding the mixture subjected to pressure banburying by using a screw extruder, setting the temperature of 5 temperature zones in the extruder to be 165 ℃, 175 ℃, 190 ℃, 185 ℃ and 190 ℃, and setting the rotating speed of a main machine to be 600-;

and step S5, granulating the extrudate after the extrudate is hardened by using a granulator, sieving the extrudate by using a fine vibrating screen to remove irregular products, ventilating, and completely cooling and drying the color master batch to obtain the polyethylene color master batch.

2. The polyethylene color masterbatch according to claim 1, wherein the matrix resin comprises polyethylene resin, polypropylene resin and polyamide resin, and the mass ratio of the polyethylene resin to the polypropylene resin to the polyamide resin is 10:2-3: 1.2-1.4.

3. The polyethylene color masterbatch according to claim 1, wherein the dispersant is a compound prepared by compounding polyethylene wax and zinc stearate according to a mass ratio of 1: 0.2-0.3.

4. The polyethylene color masterbatch according to claim 1, wherein the antioxidant is a compound prepared by compounding a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1: 0.8-1.

5. The polyethylene color masterbatch according to claim 1, wherein the modified pigment is prepared by the following method:

(1) weighing 20g of pigment, 60g of deionized water and 1g of sodium hexametaphosphate, fully pulping, adding 5g of modifying treatment agent, heating to 72 ℃, keeping the temperature at 400r/min, and stirring for 55-60 min;

(2) naturally cooling, cooling to 25-28 ℃, filtering, washing the filter cake with deionized water for 3-4 times, and drying the wet material in a vacuum drying oven at 105 ℃ for 5-6 hours to obtain a dry material;

(3) and (3) crushing the dry materials by using an ultrafine crusher, crushing the dry materials by 50g for 1min every batch, crushing the dry materials again after 3min intervals, and crushing the dry materials for 3 times in total to obtain the modified pigment.

6. The polyethylene color masterbatch of claim 5, wherein the pigment is one of rutile type titanium dioxide, benzimidazolone yellow, anthraquinone orange, quinacridone red, phthalocyanine blue, phthalocyanine green, and benzimidazolone brown.

7. The polyethylene color masterbatch according to claim 5, wherein the modifying treatment agent comprises pentaerythritol stearate, graphite powder, and ethanol, and the mass ratio of the pentaerythritol stearate to the graphite powder to the ethanol is 1.5-2: 0.4-0.6:8, adding pentaerythritol stearate into ethanol, completely dissolving, adding graphite powder, putting into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the ground particles is controlled to be 0.2-0.4 μm.

8. The polyethylene color masterbatch according to claim 1, wherein the inorganic nanocrystal is prepared by the following method:

(1) 6.14g of Na were weighed₂CO₃The powder was dissolved in 50m L water and 0.1 mol/L mol of CaCl was added slowly₂Reacting the solution with the temperature of 120m L in a water bath at 83 ℃ for 2h, centrifuging and washing reactants, and drying the obtained precipitate to obtain a precursor;

(2) calcining the precursor at 750 ℃ for 4h to obtain calcium oxide nanocrystals;

(3) mixing stearic acid and ethanol according to the mass ratio of 1:24-28, stirring until the stearic acid and the ethanol are completely dissolved to prepare a stearic acid ethanol solution;

(4) adding calcium oxide nanocrystal into stearic acid/ethanol solution at a ratio of 1g to 5-7m L, refluxing in water bath for 65-70min, filtering the obtained precipitate, and vacuum drying at 110 deg.C for 3-4h to obtain inorganic nanocrystal.

9. The preparation method of the polyethylene color master batch is characterized by comprising the following steps:

step S1, adding inorganic nanocrystalline, nano montmorillonite and half dispersant into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the grinding particles is controlled to be 0.2-0.4 μm;

s2, sequentially adding the matrix resin, the ground product obtained in the step S1, the modified pigment and the other half of the dispersing agent into a low-speed stirrer, mixing at room temperature at 100r/min for 3-5min, adding the organosilicon quaternary ammonium salt antibacterial agent, the antioxidant, the light stabilizer and the auxiliary agent into the mixture, and mixing at a high speed of 2000r/min for 8-10min by using a high-speed mixer;

step S3, transferring the mixture obtained in the step S2 into a pressurized internal mixer, and carrying out pressurized internal mixing for 16-22min under the conditions of 10-15kg of pressure and 110-135 ℃;

step S4, plasticizing and extruding the mixture subjected to pressure banburying by using a screw extruder, setting the temperature of 5 temperature zones in the extruder to be 165 ℃, 175 ℃, 190 ℃, 185 ℃ and 190 ℃, and setting the rotating speed of a main machine to be 600-;

and step S5, granulating the extrudate after the extrudate is hardened by using a granulator, sieving the extrudate by using a fine vibrating screen to remove irregular products, ventilating, and completely cooling and drying the color master batch to obtain the polyethylene color master batch.

Technical Field

The invention belongs to the technical field of color master batches, and particularly relates to a polyethylene color master batch and a preparation method thereof.

Background

The color master batch is a plastic colorant which is well dispersed by a high proportion of pigment or additive and thermoplastic resin, and the selected resin has good wetting and dispersing effects on the colorant and has good compatibility with the material to be colored. Color masterbatch tinting is the most commonly used plastic tinting process today. The colorant dispersed in the carrier is simply mixed with the natural color master batch color resin to be used for manufacturing plastic products.

With the continuous development of the plastic industry, the demand of plastics is also greatly increased. Because the plastics are not easy to decompose and recycle, the wastes thereof also become harmful garbage to pollute the environment. The development and use of degradable plastics is therefore the direction of development in the production of plastics.

The polyethylene color master batch is a granular color master batch prepared by using polyethylene as a carrier, the content of the pigment can reach 10-60%, and the pigment is uniformly loaded in the resin in an excessive amount, so that the dispersing performance and the coloring efficiency of the pigment are greatly improved, and the polyethylene color master batch has the advantages of simplicity in operation, low cost, no pollution to the environment and the like. The pigment is directly loaded on the resin matrix in the production process of the existing polyethylene color master batch, so that the dispersibility of the pigment cannot meet the production requirement of a PE product, and meanwhile, the obtained polyethylene color master batch has single function and cannot meet the diversified development of the PE product.

Disclosure of Invention

The invention aims to provide a polyethylene color master batch and a preparation method thereof, which can be used for modifying a pigment to enable the pigment to be easily dispersed in PE resin to form a master batch with uniform chroma and high purity, improving the tensile strength of a resin matrix by adding a proper amount of inorganic nanocrystalline, further increasing the strength and rigidity of the master batch, improving the mechanical property and the fluidity of the master batch, endowing the master batch with good antibacterial, antioxidant and light stability by the auxiliary matching of functional additives such as an organosilicon quaternary ammonium salt antibacterial agent, an antioxidant, a light stabilizer and the like, prolonging the service life of the master batch, and enabling the obtained polyethylene color master batch to have good dispersibility and strong tinting strength and have wide application prospects in aspects of PE wire insulated cables, PE pipes and the like.

The purpose of the invention can be realized by the following technical scheme:

the polyethylene color master batch is prepared from the following raw materials in parts by weight: 20-70 parts of modified pigment, 20-30 parts of matrix resin, 3-5 parts of inorganic nanocrystalline, 1-2 parts of nano montmorillonite, 7-15 parts of dispersant, 0.5-1 part of organosilicon quaternary ammonium salt antibacterial agent, 0.6-0.8 part of antioxidant, 1-2 parts of light stabilizer and 0.1-0.2 part of auxiliary agent;

the polyethylene color master batch is prepared by the following steps:

step S1, adding inorganic nanocrystalline, nano montmorillonite and half dispersant into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the grinding particles is controlled to be 0.2-0.4 μm;

s2, sequentially adding the matrix resin, the ground product obtained in the step S1, the modified pigment and the other half of the dispersing agent into a low-speed stirrer, mixing at room temperature at 100r/min for 3-5min, adding the organosilicon quaternary ammonium salt antibacterial agent, the antioxidant, the light stabilizer and the auxiliary agent into the mixture, and mixing at a high speed of 2000r/min for 8-10min by using a high-speed mixer;

step S3, transferring the mixture obtained in the step S2 into a pressurized internal mixer, and carrying out pressurized internal mixing for 16-22min under the conditions of 10-15kg of pressure and 110-135 ℃;

step S4, plasticizing and extruding the mixture subjected to pressure banburying by using a screw extruder, setting the temperature of 5 temperature zones in the extruder to be 165 ℃, 175 ℃, 190 ℃, 185 ℃ and 190 ℃, and setting the rotating speed of a main machine to be 600-;

and step S5, granulating the extrudate after the extrudate is hardened by using a granulator, sieving the extrudate by using a fine vibrating screen to remove irregular products, ventilating, and completely cooling and drying the color master batch to obtain the polyethylene color master batch.

Further, the matrix resin comprises polyethylene resin, polypropylene resin and polyamide resin, and the mass ratio of the polyethylene resin to the polypropylene resin to the polyamide resin is 10:2-3: 1.2-1.4.

Further, the dispersing agent is a compound formed by compounding polyethylene wax and zinc stearate according to the mass ratio of 1: 0.2-0.3.

Further, the antioxidant is a compound formed by compounding a hindered phenol antioxidant and a phosphite antioxidant according to the mass ratio of 1: 0.8-1.

Further, the modified pigment is prepared by the following method:

(1) weighing 20g of pigment, 60g of deionized water and 1g of sodium hexametaphosphate, fully pulping, adding 5g of modifying treatment agent, heating to 72 ℃, keeping the temperature at 400r/min, and stirring for 55-60 min;

(2) naturally cooling, cooling to 25-28 ℃, filtering, washing the filter cake with deionized water for 3-4 times, and drying the wet material in a vacuum drying oven at 105 ℃ for 5-6 hours to obtain a dry material;

(3) and (3) crushing the dry materials by using an ultrafine crusher, crushing the dry materials by 50g for 1min every batch, crushing the dry materials again after 3min intervals, and crushing the dry materials for 3 times in total to obtain the modified pigment.

Further, the pigment is one of rutile titanium dioxide, benzimidazolone yellow, anthraquinone orange, quinacridone red, phthalocyanine blue, phthalocyanine green and benzimidazolone brown.

Further, the modification treatment agent comprises pentaerythritol stearate, graphite powder and ethanol, wherein the mass ratio of the pentaerythritol stearate to the graphite powder to the ethanol is 1.5-2: 0.4-0.6:8, adding pentaerythritol stearate into ethanol, completely dissolving, adding graphite powder, putting into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the ground particles is controlled to be 0.2-0.4 μm.

Further, the inorganic nanocrystal is prepared by the following method:

(1) 6.14g of Na were weighed₂CO₃The powder was dissolved in 50m L water and slowly added to 0.1mo l/L CaCl₂Reacting the solution with the temperature of 120m L in a water bath at 83 ℃ for 2h, centrifuging and washing reactants, and drying the obtained precipitate to obtain a precursor;

(2) calcining the precursor at 750 ℃ for 4h to obtain calcium oxide nanocrystals;

(3) mixing stearic acid and ethanol according to the mass ratio of 1:24-28, stirring until the stearic acid and the ethanol are completely dissolved to prepare a stearic acid ethanol solution;

(4) adding calcium oxide nanocrystal into stearic acid/ethanol solution at a ratio of 1g to 5-7m L, refluxing in water bath for 65-70min, filtering the obtained precipitate, and vacuum drying at 110 deg.C for 3-4h to obtain inorganic nanocrystal.

A preparation method of polyethylene color master batches comprises the following steps:

step S1, adding inorganic nanocrystalline, nano montmorillonite and half dispersant into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the grinding particles is controlled to be 0.2-0.4 μm;

s2, sequentially adding the matrix resin, the ground product obtained in the step S1, the modified pigment and the other half of the dispersing agent into a low-speed stirrer, mixing at room temperature at 100r/min for 3-5min, adding the organosilicon quaternary ammonium salt antibacterial agent, the antioxidant, the light stabilizer and the auxiliary agent into the mixture, and mixing at a high speed of 2000r/min for 8-10min by using a high-speed mixer;

step S3, transferring the mixture obtained in the step S2 into a pressurized internal mixer, and carrying out pressurized internal mixing for 16-22min under the conditions of 10-15kg of pressure and 110-135 ℃;

step S4, plasticizing and extruding the mixture subjected to pressure banburying by using a screw extruder, setting the temperature of 5 temperature zones in the extruder to be 165 ℃, 175 ℃, 190 ℃, 185 ℃ and 190 ℃, and setting the rotating speed of a main machine to be 600-;

and step S5, granulating the extrudate after the extrudate is hardened by using a granulator, sieving the extrudate by using a fine vibrating screen to remove irregular products, ventilating, and completely cooling and drying the color master batch to obtain the polyethylene color master batch.

The invention has the beneficial effects that:

(1) the pigment is modified by the modifying treatment agent, the modified pigment is compounded with the matrix resin for granulation, the modifying treatment agent comprises pentaerythritol stearate, graphite powder and ethanol, the aggregation state of the pigment can be changed from a microstructure, the pigment can be dispersed uniformly in a micro-scale manner, and the modifying treatment agent has certain affinity with the pigment and the PE resin, so that the wettability of the PE resin on the pigment is changed, the pigment can be dispersed into the PE resin more easily, the pigment is dispersed better, and the prepared color master batch has higher purity and better performance;

(2) according to the invention, a proper amount of inorganic nanocrystals are added into the raw materials of the polyethylene color master batch, and the surfaces of the inorganic nanocrystals are modified by stearic acid, so that the activity of nanoparticles can be improved, the charges and the polarities of the surfaces of the particles are reduced, and the phenomenon of agglomeration caused by electrostatic coupling or hydrogen bond between the nanoparticles is prevented, and the nanoparticles are uniformly dispersed in a resin matrix; the inorganic nanocrystalline has smaller size and can play a role of a nucleating agent in a resin matrix, so that the inorganic nanocrystalline is well combined with polymer molecules, and the interfacial force among the molecules is consumed, thereby increasing the fluidity of the resin matrix; meanwhile, the addition of the inorganic nanocrystalline reduces the stress concentration in the polyethylene, increases the crack propagation path and lightens the external load, and the surface of the inorganic nanocrystalline is modified, so that chemical bonding and molecular winding are generated between calcium oxide and the polyethylene, and the addition of the inorganic nanocrystalline can improve the tensile strength of a resin matrix and increase the strength and rigidity of the matrix;

(3) according to the invention, the pigment is modified, so that the pigment is easier to disperse in PE resin to form color master batches with uniform chromaticity and high purity, the tensile strength of a resin matrix is improved by adding a proper amount of inorganic nanocrystalline, the strength and rigidity of the color master batches are further increased, the mechanical property and the fluidity of the color master batches are improved, the color master batches are endowed with good antibacterial, antioxidant and light stability by the auxiliary matching of functional additives such as an organic silicon quaternary ammonium salt antibacterial agent, an antioxidant, a light stabilizer and the like, the service life of the color master batches is prolonged, and the obtained polyethylene color master batches have good dispersibility and strong tinting strength and have wide application prospects in aspects of PE wire insulated cables, PE pipes and the like.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The polyethylene color master batch is prepared from the following raw materials in parts by weight: 20-70 parts of modified pigment, 20-30 parts of matrix resin, 3-5 parts of inorganic nanocrystalline, 1-2 parts of nano montmorillonite, 7-15 parts of dispersant, 0.5-1 part of organosilicon quaternary ammonium salt antibacterial agent, 0.6-0.8 part of antioxidant, 1-2 parts of light stabilizer and 0.1-0.2 part of auxiliary agent;

the matrix resin comprises polyethylene resin, polypropylene resin and polyamide resin, and the mass ratio of the polyethylene resin to the polypropylene resin to the polyamide resin is 10:2-3: 1.2-1.4;

the dispersing agent is a compound formed by compounding polyethylene wax and zinc stearate according to the mass ratio of 1: 0.2-0.3;

the antioxidant is a compound formed by compounding a hindered phenol antioxidant and a phosphite ester antioxidant according to the mass ratio of 1: 0.8-1;

the light stabilizer is any one of an ultraviolet absorber, a hindered amine light stabilizer and a nickel-containing stabilizer;

the auxiliary agent is any one of calcium stearate, zinc stearate, barium stearate and magnesium stearate;

the modified pigment is prepared by the following method:

(1) weighing 20g of pigment, 60g of deionized water and 1g of sodium hexametaphosphate, fully pulping, adding 5g of modifying treatment agent, heating to 72 ℃, keeping the temperature at 400r/min, and stirring for 55-60 min;

(2) naturally cooling, cooling to 25-28 ℃, filtering, washing the filter cake with deionized water for 3-4 times, and drying the wet material in a vacuum drying oven at 105 ℃ for 5-6 hours to obtain a dry material;

(3) pulverizing the dry materials with an ultrafine pulverizer, pulverizing 50g of the dry materials for 1min every batch, pulverizing again after 3min intervals, and pulverizing for 3 times to obtain modified pigment;

wherein the pigment is one of rutile titanium dioxide, benzimidazolone yellow, anthraquinone orange, quinacridone red, phthalocyanine blue, phthalocyanine green and benzimidazolone brown;

the modifying treatment agent comprises pentaerythritol stearate, graphite powder and ethanol, wherein the mass ratio of the pentaerythritol stearate to the graphite powder to the ethanol is (1.5-2): 0.4-0.6:8, adding pentaerythritol stearate into ethanol, completely dissolving, adding graphite powder, putting into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the ground particles is controlled to be 0.2-0.4 μm;

the modifying treatment agent can change the aggregation state of the pigment from the microstructure to enable the pigment to achieve tiny and uniform dispersion, and the modifying treatment agent has certain affinity with the pigment and the PE resin, so that the wettability of the PE resin to the pigment is changed, and the pigment is more easily dispersed into the PE resin;

the inorganic nanocrystal is prepared by the following method:

(1) 6.14g of Na were weighed₂CO₃The powder was dissolved in 50m L water and 0.1 mol/L% CaCl was added slowly₂Reacting the solution with the temperature of 120m L in a water bath at 83 ℃ for 2h, centrifuging and washing reactants, and drying the obtained precipitate to obtain a precursor;

(2) calcining the precursor at 750 ℃ for 4h to obtain calcium oxide nanocrystals;

(3) mixing stearic acid and ethanol according to the mass ratio of 1:24-28, stirring until the stearic acid and the ethanol are completely dissolved to prepare a stearic acid ethanol solution;

(4) adding calcium oxide nanocrystal into stearic acid/ethanol solution at a material-liquid ratio of 1 g: 5-7m L, refluxing in water bath for 65-70min, filtering the obtained precipitate, and vacuum drying at 110 deg.C for 3-4 hr to obtain inorganic nanocrystal;

the surface of the inorganic nanocrystal is modified by stearic acid, so that the activity of the nanoparticles can be improved, the charge and polarity of the particle surface can be reduced, and the phenomenon that the nanoparticles are agglomerated due to electrostatic coupling action or hydrogen bond action is prevented, so that the nanoparticles are uniformly dispersed in a resin matrix; the inorganic nanocrystalline has smaller size and can play a role of a nucleating agent in a resin matrix, so that the inorganic nanocrystalline is well combined with polymer molecules, and the interfacial force among the molecules is consumed, thereby increasing the fluidity of the resin matrix; meanwhile, the addition of the inorganic nanocrystalline reduces the stress concentration in the polyethylene, increases the crack propagation path and lightens the external load, and the surface of the inorganic nanocrystalline is modified, so that chemical bonding and molecular winding are generated between calcium oxide and the polyethylene, and the addition of the inorganic nanocrystalline can improve the tensile strength of a resin matrix and increase the strength and rigidity of the matrix;

the preparation method of the polyethylene color master batch comprises the following steps:

step S1, adding inorganic nanocrystalline, nano montmorillonite and half dispersant into a sanding dispersion machine, and grinding at the rotating speed of 1500r/min, wherein the average grain diameter of the grinding particles is controlled to be 0.2-0.4 μm;

s2, sequentially adding the matrix resin, the ground product obtained in the step S1, the modified pigment and the other half of the dispersing agent into a low-speed stirrer, mixing at room temperature at 100r/min for 3-5min, adding the organosilicon quaternary ammonium salt antibacterial agent, the antioxidant, the light stabilizer and the auxiliary agent into the mixture, and mixing at a high speed of 2000r/min for 8-10min by using a high-speed mixer;

step S3, transferring the mixture obtained in the step S2 into a pressurized internal mixer, and carrying out pressurized internal mixing for 16-22min under the conditions of 10-15kg of pressure and 110-135 ℃;

step S4, plasticizing and extruding the mixture subjected to pressure banburying by using a screw extruder, setting the temperature of 5 temperature zones in the extruder to be 165 ℃, 175 ℃, 190 ℃, 185 ℃ and 190 ℃, and setting the rotating speed of a main machine to be 600-;

and step S5, granulating the extrudate after the extrudate is hardened by using a granulator, sieving the extrudate by using a fine vibrating screen to remove irregular products, ventilating, and completely cooling and drying the color master batch to obtain the polyethylene color master batch.