CN108752718B - A wood-plastic film for blocking ink and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of food packaging materials, in particular to a wood-plastic film for blocking ink and a preparation method thereof. The wood-plastic film comprises the following components: PE, starch, nano-carbon balls, photosensitive fibers, talc powder and lubricant , the photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide. The present invention adopts anatase type nano-titanium dioxide because of its huge specific surface area and small size effect, so it has better photocatalytic degradation effect, can endow the wood-plastic film with the characteristics of photodegradation, and the formed wood-plastic film has uniform mechanical properties, Moreover, MOAH is still relatively easy to diffuse in microcrystalline cellulose, and the anatase nano-titanium dioxide evenly distributed on microcrystalline cellulose can reduce the direct contact between organic substances, thereby hindering the diffusion of MOAH in organic substances. The mobility in the wood plastic film is extremely low.

Description

A wood-plastic film for blocking ink and preparation method thereof

technical field

The invention relates to the technical field of food packaging materials, in particular to a wood-plastic film for blocking ink and a preparation method thereof.

Background technique

Mineral Oil Aromatic Hydrocarbons (MOAH) is a carcinogenic, mutagenic substance commonly found in packaging paper based on secondary fibers (especially those containing printing inks). The findings of the EU Food Safety Authority have confirmed that, during food storage or transportation, MOAH in food packaging or outer packaging can penetrate through the inner packaging film after only 2-3 months or less. Enters the gas phase and migrates to the surface/inside of the food. It is estimated that if the shelf life of food is approached, the migration rate of MOAH in packaging paper to food will reach 65%-85%. In addition, due to the semi-volatility and lipophilicity of MOAH, in addition to aluminum foil packaging, the use of polyethylene, polypropylene/composite acrylate coatings and other inner packaging not only fails to block the migration of MOAH to food, but also increases the use of plastic products. migration risk of certain components such as polyolefin oligomer saturated hydrocarbons. Therefore, even in the secondary packaging paper that is not in direct contact with food, the MOAH in it will migrate to the packaged food through the processes of adsorption, desorption, and penetration between the compartments, thereby posing a threat to the health of consumers. Moreover, plastic products are generally difficult to degrade, which is not conducive to protecting the environment. Therefore, in order to ensure that the packaged food is not contaminated by MOAH, it is quite meaningful to develop a functional film that can replace the currently commonly used plastic barrier layer, but there are very few related researches in this area.

SUMMARY OF THE INVENTION

In order to overcome the shortcomings and deficiencies existing in the prior art, the object of the present invention is to provide a wood-plastic film for blocking ink, the wood-plastic film has good barrier property to MOAH, and has high photo/biodegradability. ; Another object of the present invention is to provide a preparation method of the wood plastic film, the preparation method is simple and efficient, and is conducive to industrial promotion.

The object of the present invention is achieved through the following technical solutions:

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

Starch 20-30 servings

Nano carbon balls 10-20 copies

Photosensitive fiber 20-40 copies

10-20 servings of talcum powder

Lubricant 1-3 parts

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

The present invention adopts anatase type nano-titanium dioxide because of its huge specific surface area and small size effect, so it has better photocatalytic degradation effect, and can endow the wood-plastic film with the characteristics of photodegradation; at the same time, in order to solve the problem that anatase type nano-titanium dioxide is easy to agglomerate In the present invention, the anatase type nano-titanium dioxide is loaded on the microcrystalline cellulose, so as to greatly improve the dispersibility of the anatase type nano-titanium dioxide, the mechanical properties of the formed wood-plastic film are uniform, and the MOAH is still high in the microcrystalline cellulose. The anatase nano-TiO2, which is easy to diffuse and evenly distributed on the microcrystalline cellulose, can reduce the direct contact between organic substances, thereby hindering the diffusion of MOAH in organic substances, so the mobility of MOAH in the wood-plastic film is extremely low.

In addition, the present invention also adds an appropriate amount of starch to the PE composition to impart biodegradability to the PE composition, and adds an appropriate amount of nano-carbon balls and talc to reduce the specific gravity of the polymer material, thereby accelerating the degradation efficiency.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, ultrasonically dispersing for 2-4 hours, centrifugal washing and drying to obtain the photosensitive fiber, Wherein, the mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:6-10:100.

Wherein, the particle size distribution D50 of the microcrystalline cellulose is 60-100 μm, the crystallinity measured by X-ray diffraction is 74.25-78.63%, and the BET specific surface area is 84-119 m ² /g. MOAH is easier to diffuse in the non-crystalline area of microcrystalline cellulose, but too high crystallinity of microcrystalline cellulose will easily lead to poor compatibility between microcrystalline cellulose and PE and other raw materials, so the crystallinity of microcrystalline cellulose is 74.25-78.63. % can not only effectively reduce the mobility of MOAH, but also improve the mechanical strength of the wood-plastic film.

Wherein, the average particle size of the anatase type nano titanium dioxide is 34-64 nm. Further defining the particle size distribution, specific surface area and particle size of anatase type nano-titanium dioxide of microcrystalline cellulose can be beneficial to the uniform distribution of anatase type nano-titanium dioxide on microcrystalline cellulose.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: take bamboo fiber powder, carry out pre-carbonization treatment in an inert gas atmosphere, namely obtain a carbon precursor, after the carbon precursor is cooled to room temperature, immersed in a mass concentration of 6%- 10% potassium hydroxide aqueous solution for 0.5-1.5h, then take out the carbon precursor and freeze-dry it, and then place the freeze-dried carbon precursor in an inert gas atmosphere for activation treatment to obtain carbon nanospheres.

The present invention utilizes bamboo fiber as the raw material of the carbon nanospheres, so no harmful substances remain in the production process, and the produced carbon nanospheres have porous properties, which can play the role of adsorbing MOAH, thus helping to improve the wood-plastic film. Barrier properties to MOAH.

Wherein, in the preparation method of carbon nanospheres, the conditions of the pre-carbonization treatment are: raising the temperature to 400-600°C at a heating rate of 8-10°C/min, and then maintaining the temperature for 40-70min; the conditions of the activation treatment are: 8-10°C/min The heating rate of -12°C/min was increased to 1050-1300°C, and then kept for 1-3h. Through the immersion treatment of potassium hydroxide solution and the control of activation conditions, a large number of hydroxyl groups of bagasse cellulose are exposed, so it has lower particle size and higher pore volume after carbonization.

Wherein, the average particle size of the carbon nanospheres is 76.3-92.7 nm, and the average pore volume is 56.7-72.9 cm ³ /g.

Wherein, the talc powder is composed of the first flake talc powder and the second flake talc powder in a ratio of 1-2:1 by weight, and the average particle size of the first flake talc powder is 17-29 μm, and the length is 17-29 μm. The diameter ratio is 2.7-4.5:1, the average particle size of the second flake talc powder is 67-88 μm, and the aspect ratio is 1.4-2.5:1.

In the present invention, talc can act as both a lubricant and an anti-blocking agent to form a rough and uneven structure on the surface of the wood-plastic film, thereby reducing the adhesion between the wood-plastic film and food. In the present invention, flake talc powders with different average particle sizes and aspect ratios are used in combination, and the first flake talc powder has a lower particle size and a higher aspect ratio, which can effectively improve the melt fluidity of PE. , which is conducive to the mixing and dispersion of PE and inorganic substances. The second flake talc has a higher particle size and a lower aspect ratio, and has better dispersibility in PE, which is conducive to the generation of rough planes of the wood-plastic film.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

The beneficial effects of the present invention are:

1. The present invention adopts anatase type nano-titanium dioxide because of its huge specific surface area and small size effect, so it has better photocatalytic degradation effect, which can endow the wood-plastic film with the characteristics of photodegradation; at the same time, in order to solve the problem of anatase type nano-titanium dioxide. To solve the problem of easy agglomeration, the present invention loads anatase nano-titanium dioxide on microcrystalline cellulose, thereby greatly improving the dispersibility of anatase nano-titanium dioxide, forming a wood-plastic film with uniform mechanical properties, and MOAH in microcrystalline cellulose. It is still relatively easy to diffuse, and the anatase nano-titanium dioxide evenly distributed on the microcrystalline cellulose can reduce the direct contact between organic substances, thereby hindering the diffusion of MOAH in organic substances, so the mobility of MOAH in wood plastic film is extremely high. Low;

2. In addition, the present invention also adds an appropriate amount of starch to the PE composition to impart biodegradability to the PE composition, and adds an appropriate amount of nano-carbon balls and talc to reduce the specific gravity of the polymer material, thereby accelerating the degradation efficiency. .

Detailed ways

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below with reference to the examples, and the contents mentioned in the embodiments are not intended to limit the present invention.

Example 1

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

25 servings of starch

15 carbon nano balls

Photosensitive fiber 30 servings

15 parts talcum powder

2 parts lubricant

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, carrying out ultrasonic dispersion for 3 hours, centrifugal washing and drying to obtain the photosensitive fiber, wherein, The mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:8:100.

Wherein, the particle size distribution D50 of the microcrystalline cellulose is 80 μm, the crystallinity measured by X-ray diffraction is 76.41%, and the BET specific surface area is 102 m ² /g

Wherein, the average particle size of the anatase type nano titanium dioxide is 49 nm.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: taking bamboo fiber powder and carrying out pre-carbonization treatment in an inert gas atmosphere to obtain a carbon precursor; In the potassium hydroxide aqueous solution for 1 hour, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment to obtain nano carbon spheres.

Wherein, in the step B, the conditions of the pre-carbonization treatment are: raising the temperature to 500°C at a heating rate of 9°C/min, and then maintaining the temperature for 55 minutes; the conditions of the activation treatment are: raising the temperature to 1170°C at a heating rate of 10°C/min , and then kept for 2h, the average particle size of the carbon nanospheres was 84.5nm, and the average pore volume was 64.1cm ³ /g.

Wherein, the talc powder is composed of the first flake talc powder and the second flake talc powder in a weight ratio of 1.5:1, the average particle size of the first flake talc powder is 23 μm, and the aspect ratio is 3.6 : 1, the average particle size of the second flake talc powder is 78 μm, and the aspect ratio is 1.9:1.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

Example 2

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

20 servings of starch

10 carbon nano balls

Photosensitive fiber 20 servings

10 parts talcum powder

Lubricant 1 part

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, ultrasonically dispersing for 2 hours, centrifugal washing and drying to obtain the photosensitive fiber, wherein, The mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:6:100.

Wherein, the particle size distribution D50 of the microcrystalline cellulose is 60 μm, the crystallinity measured by X-ray diffraction is 74.25%, and the BET specific surface area is 84 m ² /g

Wherein, the average particle size of the anatase type nano titanium dioxide is 34 nm.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: taking bamboo fiber powder, carrying out pre-carbonization treatment in an inert gas atmosphere, that is, obtaining a carbon precursor, and after the carbon precursor is cooled to room temperature, immersed in a 6% mass concentration of In the potassium hydroxide aqueous solution for 0.5h, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment to obtain carbon nanospheres.

Wherein, in the step B, the conditions of the pre-carbonization treatment are: raising the temperature to 400°C at a heating rate of 8°C/min, and then maintaining the temperature for 40 minutes; the conditions of the activation treatment are: raising the temperature to 1050°C at a heating rate of 8°C/min , and then incubated for 1 h, the average particle size of the carbon nanospheres was 76.3 nm, and the average pore volume was 56.7 cm ³ /g.

Wherein, the talc powder is composed of the first flaky talc powder and the second flaky talc powder in a weight ratio of 1-2:1, the average particle size of the first flaky talc powder is 17 μm, and the aspect ratio is 17 μm. is 4.5:1, the average particle size of the second flake talc is 67 μm, and the aspect ratio is 2.5:1.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

Example 3

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

30 servings of starch

20 carbon nano balls

Photosensitive fiber 40 servings

20 parts talcum powder

Lubricant 3 parts

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, carrying out ultrasonic dispersion for 4 hours, centrifugal washing and drying to obtain the photosensitive fiber, wherein, The mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:10:100.

Among them, the particle size distribution D50 of the microcrystalline cellulose is 100 μm, the crystallinity measured by X-ray diffraction is 78.63%, and the BET specific surface area is 119 m ² /g

Wherein, the average particle size of the anatase-type nano-titania is 64 nm.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: taking bamboo fiber powder, carrying out pre-carbonization treatment in an inert gas atmosphere, that is, obtaining a carbon precursor, after the carbon precursor is cooled to room temperature, immersed in a 10% mass concentration of In the potassium hydroxide aqueous solution for 1.5 hours, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment to obtain nano-carbon spheres.

Wherein, in the step B, the conditions of the pre-carbonization treatment are: raising the temperature to 600°C at a heating rate of 10°C/min, and then maintaining the temperature for 70 minutes; the conditions of the activation treatment are: raising the temperature to 1300°C at a heating rate of 12°C/min , and then incubated for 3h, the average particle size of the carbon nanospheres was 92.7 nm, and the average pore volume was 72.9 cm ³ /g.

Wherein, the talc powder is composed of the first flaky talc powder and the second flaky talc powder in a weight ratio of 1-2:1, the average particle size of the first flaky talc powder is 29 μm, and the aspect ratio is 29 μm. is 2.7:1, the average particle size of the second flake talc is 88 μm, and the aspect ratio is 1.4:1.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

Example 4

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

23 servings of starch

12 carbon nano balls

Photosensitive fiber 25 servings

13 parts talcum powder

Lubricant 1.5 parts

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, carrying out ultrasonic dispersion for 2.5 hours, centrifugal washing and drying to obtain the photosensitive fiber, wherein , the mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:7:100.

Wherein, the particle size distribution D50 of the microcrystalline cellulose is 70 μm, the crystallinity measured by X-ray diffraction is 75.82%, and the BET specific surface area is 95 m ² /g

Wherein, the average particle size of the anatase type nano titanium dioxide is 40 nm.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: taking bamboo fiber powder, carrying out pre-carbonization treatment in an inert gas atmosphere, that is, obtaining a carbon precursor, and after the carbon precursor is cooled to room temperature, immersed in a 7% mass concentration of In the potassium hydroxide aqueous solution for 0.8h, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment to obtain nano carbon spheres.

Wherein, in the step B, the conditions of the pre-carbonization treatment are: raising the temperature to 450°C at a heating rate of 8.5°C/min, and then maintaining the temperature for 50 minutes; the conditions of the activation treatment are: raising the temperature to 1100°C at a heating rate of 9°C/min , and then kept for 1.5h, the average particle size of the carbon nanospheres was 82.7nm, and the average pore volume was 60.4cm ³ /g.

Wherein, the talc powder is composed of the first flaky talc powder and the second flaky talc powder in a weight ratio of 1-2:1, the average particle size of the first flaky talc powder is 20 μm, and the aspect ratio is 20 μm. is 4:1, the average particle size of the second flake talc is 72 μm, and the aspect ratio is 2.2:1.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

Example 5

A wood-plastic film for blocking ink, comprising the following raw materials in parts by weight:

PE 100 copies

Starch 28 servings

17 carbon nano balls

Photosensitive fiber 35 servings

18 parts talcum powder

Lubricant 2.5 parts

The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide.

Wherein, the preparation method of the photosensitive fiber includes the following steps: adding anatase type nano-titanium dioxide and microcrystalline cellulose into deionized water, carrying out ultrasonic dispersion for 3.5 hours, centrifugal washing and drying to obtain the photosensitive fiber, wherein , the mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:9:100.

The particle size distribution D50 of the microcrystalline cellulose is 90 μm, the crystallinity measured by X-ray diffraction is 77.23%, and the BET specific surface area is 108 m ² /g

Wherein, the average particle size of the anatase type nano titanium dioxide is 54 nm.

Wherein, the preparation method of the carbon nanospheres comprises the following steps: take bamboo fiber powder, carry out pre-carbonization treatment in an inert gas atmosphere, namely obtain a carbon precursor, after the carbon precursor is cooled to room temperature, immersed in a 9% mass concentration of In the potassium hydroxide aqueous solution for 1.2 hours, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment to obtain nano-carbon spheres.

Wherein, in the step B, the conditions of the pre-carbonization treatment are: raising the temperature to 550°C at a heating rate of 9.5°C/min, and then maintaining the temperature for 60 minutes; the conditions of the activation treatment are: raising the temperature to 1200°C at a heating rate of 11°C/min , and then kept for 2.5h, the average particle size of the carbon nanospheres was 86.6nm, and the average pore volume was 70.9cm ³ /g.

Wherein, the talc powder is composed of the first flaky talc powder and the second flaky talc powder in a weight ratio of 1.8:1, the average particle size of the first flaky talc powder is 25 μm, and the aspect ratio is 3.1 : 1, the average particle size of the second flake talc powder is 80 μm, and the aspect ratio is 1.8:1.

Wherein, the lubricant is polyethylene wax.

The above-mentioned preparation method of a wood-plastic film for blocking ink: after mixing and dispersing each raw material, melt extrusion and granulation, and then producing the wood-plastic film for blocking ink by a calendering method.

Comparative Example 1

This comparative example is a commercially available conventional PE film.

In order to facilitate the test, the thicknesses of the wood-plastic films of Examples 1-5 and the PE film of Comparative Example 1 were controlled at 30-40 μm, and the shape was a square of 5cm*5cm, and then the tensile strength and elongation at break were measured according to the national standard. Test, according to DIN EN14338, the film is tested for the migration amount of MOAH; and the artificial natural environment degradation test and artificial accelerated photodegradation test, artificial natural environment degradation test: after the film is placed in the natural environment for 120 days, the quality loss of the film is tested artificial accelerated photodegradation test: after irradiating the film with a 3mw/ ^cm2 UV lamp for 240 hours, the mass loss rate of the film was tested. The test results are as follows:

As can be seen from the above examples and comparative examples, although the commercially available conventional PE film has good tensile strength and elongation at break, MOAH is prone to migrate and penetrate the PE film to contaminate food, and the degradability is also poor; and Although the tensile strength and elongation at break of the wood-plastic film of the present invention are relatively reduced, it can still meet the requirements of packaging films, and has good insulation effect on MOAH and good degradability, and the addition of talc powder will make wood plastic films The film has anti-blocking properties, so it has broad application prospects in the field of food packaging.

The above-mentioned embodiment is a preferred implementation scheme of the present invention. In addition, the present invention can also be implemented in other ways, and any obvious replacements are within the protection scope of the present invention without departing from the concept of the present invention.

Claims (8)

1. a wood-plastic film for blocking ink, is characterized in that: comprise the raw material of following weight portion: PE 100 copies Starch 20-30 servings Nano carbon balls 10-20 copies Photosensitive fiber 20-40 copies 10-20 servings of talcum powder Lubricant 1-3 parts The photosensitive fiber is composed of anatase type nano-titanium dioxide and microcrystalline cellulose loaded with anatase type nano-titanium dioxide; The preparation method of the carbon nanospheres comprises the following steps: taking bamboo fiber powder and performing pre-carbonization treatment in an inert gas atmosphere to obtain a carbon precursor, and after the carbon precursor is cooled to room temperature, immersed in a mass concentration of 6%-10%. In the potassium hydroxide aqueous solution for 0.5-1.5h, then the carbon precursor is taken out and freeze-dried, and then the freeze-dried carbon precursor is placed in an inert gas atmosphere for activation treatment, that is, carbon nanospheres are obtained; In the preparation method of carbon nanospheres, the conditions of the pre-carbonization treatment are: raising the temperature to 400-600°C at a heating rate of 8-10°C/min, and then maintaining the temperature for 40-70min; the conditions of the activation treatment are: 8-12°C The heating rate of ℃/min was increased to 1050-1300 ℃, and then kept for 1-3h. 2. a kind of wood plastic film for blocking ink according to claim 1, is characterized in that: the preparation method of described photosensitive fiber comprises the steps: adding anatase type nano titanium dioxide and microcrystalline cellulose to deionized In water, ultrasonically disperse for 2-4h, centrifugally wash and dry to obtain the photosensitive fiber, wherein the mass ratio of anatase nano-titanium dioxide, microcrystalline cellulose and deionized water is 1:6-10:100. 3. A wood-plastic film for blocking ink according to claim 2, wherein the particle size distribution D50 of the microcrystalline cellulose is 60-100 μm, and the crystallinity measured by X-ray diffraction is 74.25-78.63 %, the BET specific surface area is 84-119 m ² /g. 4 . The wood-plastic film for blocking ink according to claim 2 , wherein the average particle size of the anatase nano-titanium dioxide is 34-64 nm. 5 . 5. A wood-plastic film for blocking ink according to claim 1, characterized in that: the average particle size of the carbon nanospheres is 76.3-92.7nm, and the average pore volume is 56.7-72.9cm ³ /g . 6. a kind of wood plastic film for blocking ink according to claim 1, is characterized in that: described talc is composed of the first sheet-shaped talc powder and the second sheet-shaped talc powder by weight ratio 1-2:1 The average particle size of the first flake talc powder is 17-29 μm, the aspect ratio is 2.7-4.5:1, the average particle size of the second flake talcum powder is 67-88 μm, the long diameter The ratio is 1.4-2.5:1. 7 . The wood-plastic film for blocking ink according to claim 1 , wherein the lubricant is polyethylene wax. 8 . 8. the preparation method of a kind of wood plastic film for blocking ink described in any one of claim 1-7, it is characterized in that: after each raw material is mixed and dispersed, carry out melt extrusion granulation, then by calendering method The wood-plastic film for blocking ink is produced.