CN116284912A - Mulching film for reducing heavy metal effective state and preparation method thereof - Google Patents

Abstract

The invention relates to a mulch that reduces the effective state of heavy metals and a preparation method thereof. The raw materials include linear low-density polyethylene, metallocene polyethylene, a reinforced and toughened masterbatch, an aging-resistant mulch masterbatch, and a non-metallic natural mineral adsorption material; preparation steps It is as follows: (1) configure the reinforcement and toughening masterbatch; (2) configure the anti-aging masterbatch of the mulch film; (3) prepare the mulch film that reduces the effective state of heavy metals: add the raw materials into the mixer according to the weight ratio and stir, and stir evenly Finally, the obtained mixture is fed into a twin-screw extruder, and then subjected to hot-melt extrusion and fed into a film blowing machine for blow molding, so as to obtain a mulch film that reduces the effective state of heavy metals. The present invention absorbs or exchanges the heavy metal ions in the soil by adding non-metallic natural mineral adsorption materials, reduces the migration and transformation ability and toxicity of heavy metals in the soil environment, fixes the heavy metals in the soil and reduces their effective state. It has the characteristics of high strength and high toughness.

Description

A kind of plastic film that reduces the effective state of heavy metals and its preparation method

technical field

The invention relates to the field of agricultural mulch films, in particular to a mulch film for reducing the effective state of heavy metals and a preparation method thereof.

Background technique

With the rapid development of China's industrialization process, during the development of industrial production and agricultural production, in the process of machinery manufacturing, chemical industry, electronic production and pesticide use, a large amount of heavy metals are lost into the natural soil, causing heavy metal pollution. Lead, copper, and chromium, which are common in heavy metal pollution, can enter the human body through water bodies and food chains, thereby endangering human health.

Soil in nature is an important basis for human survival and development, and is a vital environmental resource. Heavy metal pollution has always been the main pollutant in the soil, and has the characteristics of concealment, long-term impact, bioaccumulation and irreversibility. Public health problems and land barrenness caused by heavy metal pollution appear frequently. The remediation of contaminated soil is very difficult, not only with huge economic investment, but also with certain technical difficulties. Heavy metal pollution does not degrade with microorganisms in the soil, and after entering the human body through the food chain, it accumulates in the body, seriously threatening human health. Therefore, the heavy metal pollution of land is a problem that needs long-term attention and needs to be solved urgently. At present, the main ways of soil remediation are heat treatment method, stabilization method, electrodynamic remediation method, guest-soil method and so on. The heat treatment method has a limited range of action, and it is easy to cause the soil to lose its original ecological function. The stabilization method has a greater degree of disturbance to the soil and has an impact on the distribution of plants. The electrodynamic restoration method is more complicated and energy-intensive. Long-term sustainability, and the scope of implementation is limited, so it is very important to study the control methods of heavy metal pollution in soil.

Contents of the invention

The purpose of the present invention is to provide a mulch film for reducing the effective state of heavy metals and its preparation method, which can absorb heavy metals in the soil and reduce the effective state of heavy metals, and has the advantages of high strength and high toughness while retaining water and moisture.

To achieve the above object, the technical solution provided by the invention is:

A method for preparing a mulch film that reduces the effective state of heavy metals, which is made of the following raw materials in parts by weight: 45-60 parts of linear low-density polyethylene, 5-10 parts of metallocene polyethylene, and 8-12 parts of reinforced and toughened masterbatch , 8-12 parts of mulch anti-aging masterbatch, 15-20 parts of non-metallic natural mineral adsorption material;

The preparation steps of the mulch film that reduces the effective state of heavy metals are as follows:

(1) Configure the reinforced and toughened masterbatch, add the raw materials of the reinforced and toughened masterbatch into the mixer according to the weight ratio and stir, after fully mixing, extrude and pelletize with a twin-screw extruder to make reinforced toughening masterbatch;

(2) Configure anti-aging masterbatch of mulch film: add the raw materials of anti-aging masterbatch of mulch film into the internal mixer according to the weight ratio, mix and banbury in the internal mixer, extrude and pelletize with twin-screw extruder, and make mulch film Anti-aging masterbatch;

(3) Preparation of mulch film that reduces the effective state of heavy metals: add linear low-density polyethylene, metallocene polyethylene, reinforced and toughened masterbatch, anti-aging masterbatch of mulch film and non-metallic natural mineral adsorption material into the mixer according to the weight ratio After stirring, the mixture obtained after stirring evenly is added to a twin-screw extruder for hot-melt extrusion, and then blown by a film blowing machine to obtain a mulch film that reduces the effective state of heavy metals;

The reinforcing and toughening masterbatch is made of the following raw materials in parts by weight: 18-22 parts of polyadipate/butylene terephthalate PBAT, 13-17 parts of toughening compatibilizer, modified calcium sulfate 55-65 parts of whiskers, 1-3 parts of dispersant, 1-2 parts of lubricant, 1-3 parts of antioxidant;

The aging-resistant masterbatch of the film is made of the following raw materials in parts by weight: 88-93 parts of low-density high-pressure polyethylene, 2-4 parts of light stabilizer, 1-4 parts of antioxidant, 1-2 parts of ultraviolet absorber 1-2 parts, 1-2 parts of dispersant, 1-2 parts of lubricant;

The non-metallic natural mineral adsorption material adopts one or a mixture of sepiolite, montmorillonite and bentonite; the non-metallic natural mineral adsorption material is granule or powder, or a mixture of granule and powder.

In step (1) and step (3), the rotation speed of the mixer is 80-100 rpm, and the heat mixing temperature is 180-250°C.

In step (2), the temperature of the internal mixer is 105-115°C, and the processing temperature of each zone of the twin-screw extruder is 150-170°C.

In step (3), the processing temperature in each zone of the twin-screw extruder is 180-220° C., and the screw speed is 80-100 rpm.

In step (3), the temperature of the three parts in the front section of the film blowing machine is controlled to 60°C, 80°C, and 90°C in sequence, and the temperature of the three parts in the rear section of the barrel is controlled to 100°C, 100°C, and 90°C in sequence, and the inflation The ratio is 1.5-2:3, the traction ratio is 4-4.5:6, and the screw speed of the film blowing machine is 50-80rpm.

The preparation process of the modified calcium sulfate whisker is as follows: After the modifier is diluted 45-55 times with a diluent, the calcium sulfate whisker is added for shaking, filtered, washed and dried; wherein the modified The agent is titanate coupling agent NDZ-201, the diluent is acetone solution, and the mass ratio of the diluted modifying agent to calcium sulfate whisker is 1:50-55.

In non-metallic natural mineral adsorption materials, the particle size is 100-1000 μm, and the powder particle size is 50-100 μm.

Described toughening compatibilizer adopts nylon toughening compatibilizer 8505, the mixing of one or more in glycidyl methacrylate; Described dispersant adopts modified hydroxy magnesium stearate; The lubricant is oleic acid amide; the antioxidant is one or a mixture of antioxidant hp-136, antioxidant 1010 or antioxidant 168; the light stabilizer is polymeric A high molecular weight hindered amine light stabilizer; the ultraviolet absorber is a benzophenone ultraviolet absorber.

The invention also protects the mulch film for reducing the effective state of heavy metals prepared by the above method.

Compared with prior art, the beneficial effect of the present invention is:

The non-metallic natural mineral adsorption material is added to the mulch film for reducing the effective state of heavy metals in the preparation of the present invention, and the heavy metal ions in the soil are adsorbed or exchanged to reduce the migration and transformation ability and toxicity of heavy metals in the soil environment, thereby fixing the heavy metal ions in the soil. Heavy metals and reduce their effective state to achieve the purpose of environmental governance.

Non-metallic natural mineral adsorption materials not only have a complex porous structure, can absorb heavy metal ions, but also can be used as "mineral fertilizers", which can enhance the activity of soil enzymes and microorganisms, improve the metabolic respiration rate of soil microorganisms, improve the quality of soil environment, Increase crop resistance and optimize the effect of yield structure. Therefore, while improving the performance of the mulch film, it can absorb heavy metals in the soil and realize the value-added restoration of the soil.

The type of non-metallic natural mineral adsorption material in the present invention can be selected according to different situations of soil heavy metal pollution, and one or more mixed non-metallic natural mineral adsorption materials can be selected according to needs. When sepiolite is selected as the non-metallic natural mineral adsorption material, the effective state of cadmium and zinc in the soil will be greatly reduced, and the water-fixing performance of the mulch film will be improved; when the non-metallic natural mineral adsorption material is montmorillonite, the arsenic and copper metals in the soil The effective state of the metal will be greatly reduced; when the non-metallic natural mineral adsorption material is bentonite, the effective state of the lead and zinc metals in the soil will be greatly reduced.

The mulch film in the effective state of reducing heavy metals of the present invention is prepared by adding a strengthening and toughening masterbatch and an anti-aging masterbatch of the mulch film. The prepared mulch film not only has the water retention and moisture retention of ordinary polyethylene mulch film, but also has high strength and high toughness. advantage.

Among them, the PBAT added in the strengthening and toughening masterbatch is made of terephthalic acid, adipic acid and butanediol as raw materials, and is polymerized in situ by using a high-efficiency titanium-based catalyst, and the butanediol adipate segment forms a The elastic soft segment, the butylene terephthalate chain segment forms a hard segment, which is applied to the preparation of mulch film, has excellent thermal oxygen aging resistance and UV resistance, and has excellent mechanical properties, melt strength and processing performance ; PBAT is a polar molecule, which has good compatibility with materials such as modified calcium sulfate whiskers and toughening compatibilizers; the molecular chain of PBAT contains relatively few tertiary carbon atoms, and has good weather resistance; It still has good toughness and ductility at low temperature, and has good environmental stress resistance.

Detailed ways

The above-mentioned content of the present invention will be described in further detail below by the form of the embodiment, but this should not be interpreted as the scope of the above-mentioned theme of the present invention being limited to the following embodiments, all technologies realized based on the above-mentioned content of the present invention belong to scope of the invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified, and the reagents, methods and equipment used are conventional reagents, methods and equipment in this technical field unless otherwise specified.

In the following examples, the toughening compatibilizer is glycidyl methacrylate, selected from Arkema AX8900 in France; the non-metallic natural mineral adsorption material has many options, selected from Anbang Mining The product; the preferred Saudi Arabian manufacturer of the linear low density polyethylene, the product grade is 222WT; the preferred Exxon manufacturer of the metallocene polyethylene, the product grade is 8656; the modified calcium sulfate whisker The preparation process is as follows: after the modifier is diluted 45-55 times with a diluent, calcium sulfate whiskers are added to shake, filtered, washed and dried; the modifier is titanate coupling agent NDZ-201 ; Described diluent is acetone solution; The mass ratio of described modifying agent and calcium sulfate whisker is 1:50-55; The 2420F product of described low-density high-pressure polyethylene preferred CNOOC Shell Petrochemical Co., Ltd.; The dispersant is modified magnesium hydroxystearate, selected from the product KPW-12P of Tianjin Hydrobond High-Tech Chemical Co., Ltd.; the lubricant is oleic acid amide, selected from the product of Jiangxi Zhilian Plastic Chemical Technology Co., Ltd. ; The antioxidant is antioxidant 1010 or antioxidant 168, selected from Shanghai Magic Nuclear New Material Technology Co., Ltd.; the light stabilizer is light stabilizer 622 and light stabilizer 944, selected from Beijing Tiangang Agent limited liability company; Described ultraviolet absorber is ultraviolet absorber 531, is selected from Tianjin Tianda Tianhai Technology Development Co., Ltd.

The following examples are prepared according to this preparation step: (1) raw material preparation; (2) configuration strengthening and toughening masterbatch: PBAT, toughening compatibilizer, modified calcium sulfate whisker, dispersant, lubricant, antioxidant According to the amount added according to the formula, it is added into the mixer for stirring, and it is made by twin-screw extrusion and granulation after being fully mixed; the speed of the mixer is 80-100rpm, and the heat mixing temperature is 180-250°C; (3) Equipped with anti-aging plastic film Masterbatch: Add low-density high-pressure polyethylene, light stabilizer, antioxidant, ultraviolet absorber, dispersant, and lubricant into the internal mixer according to the formula addition amount, mix and banbury in the internal mixer, and then twin-screw extrude and pelletize made; the temperature of the internal mixer is 105-115°C, and the processing temperature of each zone of the twin-screw extruder is 150-170°C; (4) linear low-density polyethylene, metallocene polyethylene, mulch aging-resistant Tough masterbatch and non-metallic natural mineral adsorption materials are added to the mixer according to the formula and stirred. After the mixture is evenly stirred, the mixture is added to the twin-screw extruder, and after hot-melt extrusion, it is added to the blown film machine for blow molding. Get a high-strength recyclable film that can absorb heavy metals; the speed of the mixer is 80-100rpm, and the temperature of the heat mix is 180-250°C; The temperature of the three parts in the rear section of the cylinder is controlled to 100°C, 100°C, and 90°C in sequence, the inflation ratio is 1.5-2:3, the traction ratio is 4-4.5:6, and the screw speed of the film blowing machine is 50-80rpm.

Example 1:

A mulch film for reducing the effective state of heavy metals, made of the following raw materials in parts by weight: 54 parts of linear low-density polyethylene, 6 parts of metallocene polyethylene, 10 parts of anti-aging masterbatch for mulch film, 10 parts of reinforced and toughened masterbatch, 20 parts of non-metallic natural mineral adsorption material, the non-metallic natural mineral adsorption material selects sepiolite; described reinforcing and toughening masterbatch is made of the following raw materials in parts by weight: 22 parts of PBAT, 17 parts of toughening compatibilizer, 65 parts of modified calcium sulfate whiskers, 3 parts of dispersant, 2 parts of lubricant, and 3 parts of antioxidant; the anti-aging masterbatch of mulching film is made of the following raw materials in parts by weight: 93 parts of low-density high-pressure polyethylene , 4 parts of light stabilizer, 4 parts of antioxidant, 2 parts of ultraviolet absorber, 2 parts of dispersant, 2 parts of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Example 2:

A mulch film for reducing the effective state of heavy metals, made of the following raw materials in parts by weight: 55 parts of linear low-density polyethylene, 5 parts of metallocene polyethylene, 12 parts of anti-aging masterbatch for mulch film, 12 parts of reinforced and toughened masterbatch, 16 parts of non-metallic natural mineral adsorption material, the non-metallic natural mineral adsorption material selects sepiolite; the described reinforcement and toughening masterbatch is made of the following raw materials in parts by weight: 20 parts of PBAT, 15 parts of toughening compatibilizer, modified 60 parts of calcium sulfate whiskers, 2 parts of dispersant, 1.5 parts of lubricant, and 2 parts of antioxidant; the anti-aging masterbatch of plastic film is made of the following raw materials in parts by weight: 90 parts of low-density high-pressure polyethylene, 3 parts of light stabilizer, 2 parts of antioxidant, 1.5 parts of ultraviolet absorber, 1.5 parts of dispersant, 1.5 parts of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Example 3:

A mulch film for reducing the effective state of heavy metals, made of the following raw materials in parts by weight: 60 parts of linear low-density polyethylene, 5 parts of metallocene polyethylene, 8 parts of anti-aging masterbatch for mulch film, 8 parts of reinforced and toughened masterbatch, 19 parts of non-metallic natural mineral adsorption materials, montmorillonite is selected as the non-metallic natural mineral adsorption materials; the reinforced and toughened masterbatch is made of the following raw materials in parts by weight: 18 parts of PBAT, 13 parts of toughening compatibilizer, 55 parts of modified calcium sulfate whiskers, 1 part of dispersant, 1 part of lubricant, and 1 part of antioxidant; the anti-aging masterbatch of mulching film is made of the following raw materials in parts by weight: 88 parts of low-density high-pressure polyethylene , 2 parts of light stabilizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of dispersant, 1 part of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Example 4

A mulch film for reducing the effective state of heavy metals is made of the following raw materials in parts by weight: 55 parts of linear low-density polyethylene, 8 parts of metallocene polyethylene, 10 parts of anti-aging masterbatch for mulch film, 10 parts of reinforced and toughened masterbatch, 17 parts of non-metallic natural mineral adsorption materials, montmorillonite is selected as the non-metallic natural mineral adsorption materials; the reinforced and toughened masterbatch is made of the following raw materials in parts by weight: 18 parts of PBAT, 13 parts of toughening compatibilizer, 55 parts of modified calcium sulfate whiskers, 1 part of dispersant, 1 part of lubricant, and 1 part of antioxidant; the anti-aging masterbatch of mulching film is made of the following raw materials in parts by weight: 88 parts of low-density high-pressure polyethylene , 2 parts of light stabilizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of dispersant, 1 part of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Example 5

A mulch film for reducing the effective state of heavy metals, made of the following raw materials in parts by weight: 60 parts of linear low-density polyethylene, 9 parts of metallocene polyethylene, 8 parts of anti-aging masterbatch for mulch film, 8 parts of reinforced and toughened masterbatch, 15 parts of non-metallic natural mineral adsorption material, bentonite is selected as the non-metallic natural mineral adsorption material; the reinforced and toughened masterbatch is made of the following raw materials in parts by weight: 18 parts of PBAT, 13 parts of toughening compatibilizer, modified 55 parts of calcium sulfate whiskers, 1 part of dispersant, 1 part of lubricant, and 1 part of antioxidant; the anti-aging masterbatch of the mulch film is made of the following raw materials in parts by weight: 88 parts of low-density high-pressure polyethylene, light 2 parts of stabilizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of dispersant, 1 part of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Example 6

A mulch film for reducing the effective state of heavy metals, made of the following raw materials in parts by weight: 55 parts of linear low-density polyethylene, 7 parts of metallocene polyethylene, 10 parts of anti-aging masterbatch for mulch film, 10 parts of reinforced and toughened masterbatch, 18 parts of non-metallic natural mineral adsorption material, bentonite is selected as the non-metallic natural mineral adsorption material; the reinforced and toughened masterbatch is made of the following raw materials in parts by weight: 18 parts of PBAT, 13 parts of toughening compatibilizer, modified 55 parts of calcium sulfate whiskers, 1 part of dispersant, 1 part of lubricant, and 1 part of antioxidant; the anti-aging masterbatch of the mulch film is made of the following raw materials in parts by weight: 88 parts of low-density high-pressure polyethylene, light 2 parts of stabilizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of dispersant, 1 part of lubricant.

The above-mentioned materials were processed according to the above-mentioned preparation method, and finally blow-molded to obtain a mulch film with a width of 1.2 meters and a thickness of 0.012 um.

Comparative example 1

The preparation method of conventional polyethylene film, the main raw materials are 60 parts of linear low density polyethylene and 40 parts of metallocene polyethylene. Its preparation method is to finish by conventional preparation method, does not add reinforced and toughened masterbatch, mulch anti-aging masterbatch and non-metallic natural mineral adsorption material, and the specification is identical with embodiment 1-6 (the width is 1.2 meters, and thickness is 0.012um) . The linear low-density polyethylene and metallocene polyethylene are added into the mixer for stirring according to the dosage of the formula, and the obtained mixture is fed into the twin-screw extruder, and then subjected to hot-melt extrusion and film blowing to obtain a conventional polyethylene film. Wherein the speed of the mixer is 80-100rpm, and the heat mixing temperature is 180-250°C. The processing temperature of the twin-screw extruder is 180-220°C, and the screw speed is 80-100rpm. The temperature of the three parts in the front section of the film blowing machine is controlled to 60°C, 80°C, and 90°C in sequence, and the temperature of the three parts in the rear section of the barrel is controlled to 100°C, 100°C, and 90°C in sequence, and the inflation ratio is (1.5-2 ): 3, the traction ratio is (4-4.5): 6, and the screw speed is 50-80rpm.

Table 1 Performance evaluation table of a high-strength recyclable plastic film that can absorb heavy metals

Analysis of test results:

1. Analysis of the mechanical properties of the product: Comparing Examples 1-6 with Comparative Example 1, it can be analyzed from Table 1 that the reinforcement and toughening masterbatch, mulch anti-aging masterbatch and non-metallic natural Mineral adsorption material can improve the mechanical properties of the product.

2. As "mineral fertilizer", the non-metallic natural mineral adsorption material promotes soil enzyme activity analysis: compare examples 1-6 with comparative example 1, it can be analyzed from Table 1 that the non-metallic natural minerals added in examples 1-6 Mineral adsorption materials increase the average yield of crops and play the role of "mineral fertilizer".

3. reduce soil heavy metal effective state analysis: compare embodiment 1-6 with comparative example 1, can analyze by table 1, the non-metallic natural mineral adsorption material that embodiment 1-6 adds reduces the effective state of heavy metal in soil state, and according to the different types of non-metallic natural mineral adsorption materials, the types of heavy metals that reduce the effective state are also different. In particular, when sepiolite is selected as the non-metallic natural mineral adsorption material, the effective state of cadmium and zinc metals in the soil will decrease; when the non-metallic natural mineral adsorption material is selected from montmorillonite, the effective state of arsenic and copper metals in the soil will be reduced ; When bentonite is selected as the non-metallic natural mineral adsorption material, the effective state of lead and zinc metals in the soil will be reduced.

In summary, it can be seen from the data in Table 1 that a mulch film that reduces the effective state of heavy metals in Examples 1-6 of the present invention better reduces the migration and transformation ability and toxicity of heavy metals in the soil environment, and enhances the mechanical properties. And play the role of "mineral fertilizer", truly realize the soil value-added restoration.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any skilled person who is familiar with the profession, without departing from the scope of the technical solutions of the present invention, according to the technical essence of the present invention, Any simple modifications, equivalent replacements and improvements made in the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. A method for preparing a mulch film that reduces the effective state of heavy metals, characterized in that: it is made of the following raw materials in parts by weight: 45-60 parts of linear low-density polyethylene, 5-10 parts of metallocene polyethylene, reinforced and toughened 8-12 parts of masterbatch, 8-12 parts of mulch anti-aging masterbatch, 15-20 parts of non-metallic natural mineral adsorption material; The preparation steps of the mulch film that reduces the effective state of heavy metals are as follows: (1) Configure the reinforced and toughened masterbatch, add the raw materials of the reinforced and toughened masterbatch into the mixer according to the weight ratio and stir, after fully mixing, extrude and pelletize with a twin-screw extruder to make reinforced toughening masterbatch; (2) Configure anti-aging masterbatch of mulch film: add the raw materials of anti-aging masterbatch of mulch film into the internal mixer according to the weight ratio, mix and banbury in the internal mixer, extrude and pelletize with twin-screw extruder, and make mulch film Anti-aging masterbatch; (3) Preparation of mulch film that reduces the effective state of heavy metals: add linear low-density polyethylene, metallocene polyethylene, reinforced and toughened masterbatch, anti-aging masterbatch of mulch film and non-metallic natural mineral adsorption material into the mixer according to the weight ratio After stirring, the mixture obtained after stirring evenly is added to a twin-screw extruder for hot-melt extrusion, and then blown by a film blowing machine to obtain a mulch film that reduces the effective state of heavy metals; The reinforcing and toughening masterbatch is made of the following raw materials in parts by weight: 18-22 parts of polyadipate/butylene terephthalate PBAT, 13-17 parts of toughening compatibilizer, modified calcium sulfate crystal 55-65 parts of whiskers, 1-3 parts of dispersant, 1-2 parts of lubricant, 1-3 parts of antioxidant; The aging-resistant masterbatch of the film is made of the following raw materials in parts by weight: 88-93 parts of low-density high-pressure polyethylene, 2-4 parts of light stabilizer, 1-4 parts of antioxidant, 1-2 parts of ultraviolet absorber 1-2 parts, 1-2 parts of dispersant, 1-2 parts of lubricant; The non-metallic natural mineral adsorption material adopts one or more mixtures of sepiolite, montmorillonite and bentonite; Non-metallic natural mineral adsorption materials are granules or powders, or a mixture of granules and powders. 2. The preparation method of the mulch film that reduces the effective state of heavy metals according to claim 1, characterized in that: in step (1) and step (3), the speed of the mixer is 80-100rpm, and the heat mixing temperature is 180-250°C . 3. The preparation method of the mulch film that reduces the effective state of heavy metals according to claim 1, characterized in that: in step (2), the temperature of the internal mixer is 105-115 ° C, and the processing temperature in each district of the twin-screw extruder is at 150-150 ° C. 170°C. 4. The preparation method of the mulch film for reducing the effective state of heavy metals according to claim 1, characterized in that: in step (3), the processing temperature of each zone of the twin-screw extruder is 180-220°C, and the screw speed is 80-100rpm. 5. The method for preparing a mulch film that reduces the effective state of heavy metals according to claim 1, characterized in that: in step (3), the temperatures of the three parts in the front section of the film blowing machine are sequentially controlled to 60°C, 80°C, and 90°C , the temperature of the three parts in the back section of the barrel is controlled to 100°C, 100°C, and 90°C in sequence, the inflation ratio is 1.5-2:3, the traction ratio is 4-4.5:6, and the screw speed of the film blowing machine is 50-80rpm. 6. the preparation method of the mulch film that reduces heavy metal effective state according to claim 1 is characterized in that: the preparation process of described modified calcium sulfate whisker is: after modifying agent is diluted 45-55 times with diluent, Calcium sulfate whiskers are added for shaking, filtered, washed and dried; wherein the modifier is titanate coupling agent NDZ-201, the diluent is acetone solution, and the diluted The mass ratio of modifier to calcium sulfate whisker is 1:50-55. 7. The method for preparing a mulch film for reducing the effective state of heavy metals according to claim 1, characterized in that: in the non-metallic natural mineral adsorption material, the particle size is 100-1000 μm, and the powder particle size is 50-100 μm. 8. the preparation method of the mulch film that reduces the effective state of heavy metals according to claim 1, is characterized in that: described toughening compatibilizer adopts one of nylon toughening compatibilizer 8505, glycidyl methacrylate The mixture of one or several kinds; the dispersant adopts modified hydroxy magnesium stearate; the lubricant is oleic acid amide; the antioxidant is antioxidant hp-136, antioxidant 1010 or One or more mixtures of antioxidants 168; the light stabilizer is a polymeric high molecular weight hindered amine light stabilizer; the ultraviolet absorber is a benzophenone ultraviolet absorber. 9. The mulch film that reduces the effective state of heavy metals prepared by the method according to any one of claims 1-8.