High-strength degradable plastic film

Abstract

The high-strength degradable plastic film comprises a film body composed of multiple layers of symmetrical composite structures, and one side of the film body is fixedly provided with a first reinforcing layer, a first degradation layer and a first anti-pulling layer in sequence; a second reinforcing layer, a second degradation layer and a second anti-pulling layer are sequentially and fixedly mounted on the other side of the film body, the first reinforcing layer and the second reinforcing layer are compounded through hot pressing to form a middle reinforcing core layer, and a zigzag staggered structure is arranged on the edge of the middle reinforcing core layer; relates to the technical field of films. Through the arrangement of the first reinforcing layer and the second reinforcing layer, the strength of the film body can be improved, the situation that the softness is large is avoided, the degradation degree of the film body can be improved through cooperation of the first degradation layer and the second degradation layer, and the situation that the film body pollutes the environment is avoided; in addition, the first anti-pulling layer and the second anti-pulling layer are combined, so that the anti-pulling effect of the film body can be improved, and the situation that the film body is easily broken is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and specifically to a high-strength degradable plastic film. Background Art

[0002] For a thin film, when one-dimensional linear scale of a solid or a liquid is much smaller than the other two dimensions, such a solid or liquid is called a film. Generally, films can be divided into two categories. One is a film with a thickness greater than one micrometer, called a thick film, and the other is a film with a thickness less than one micrometer, called a thin film.

[0003] A Chinese patent with the publication number CN216808681U discloses a degradable plastic film, which includes a microbial degradation layer. Above the microbial degradation layer, there is a hardness strengthening layer. Above the hardness strengthening layer, there is an adhesion layer. Below the microbial degradation layer, there is a running layer. The thickness of the microbial degradation layer is 12 ± 2 um, and the thickness of the hardness strengthening layer is 18 ± 2 um. In this degradable plastic film, the microbial degradation layer is made of microbial degradation plastic, which can play a role in degradation. Moreover, with the addition of the hardness strengthening layer, the strength of the film is improved, and it also has the function of degradation, improving the practicability of the film. However, there are still certain defects in the above patent. Although its strength is hardened through the hardness strengthening layer, its tensile property is not good, and it is prone to breakage when being pulled, reducing the practicability of the film. Therefore, we propose a high-strength degradable plastic film to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength degradable plastic film to solve the problems raised in the background art above and overcome the existing technical defects.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: A high-strength degradable plastic film, including a film body composed of a symmetric multi-layer composite structure. On one side of the film body, a first strengthening layer, a first degradation layer, and a first anti-tensile layer are sequentially and fixedly installed. On the other side of the film body, a second strengthening layer, a second degradation layer, and a second anti-tensile layer are sequentially and fixedly installed. Among them, the first strengthening layer and the second strengthening layer form an intermediate enhanced core layer through hot pressing and compounding, and its edge is provided with a serrated staggered structure; Nano calcium carbonate particles with a degradation rate 30% higher than that of a common polylactic acid layer are evenly dispersed in the first degradation layer and the second degradation layer. The first degradation layer is arranged between the first strengthening layer and the first anti-tensile layer, and the second degradation layer is arranged between the second strengthening layer and the second anti-tensile layer; Both the first anti-tensile layer and the second anti-tensile layer are made of modified polyethylene, and their surfaces are treated by plasma to form micron-level grooves to enhance the interfacial bonding force.

[0006] A production method of a high-strength degradable plastic film, including

[0007] Step S1: The modified polyethylene particles are melt co-extruded to form a first tensile layer and a second tensile layer, and plasma surface treatment is carried out synchronously during molding;

[0008] Step S2: Nano calcium carbonate particles are added to the polylactic acid melt, and a first degradation layer and a second degradation layer are prepared by the casting method, and a microporous array is formed by laser drilling on the surfaces of the first degradation layer and the second degradation layer;

[0009] Step S3: Boron phosphide and graphene nanoribbons are mixed and then hot-pressed into a film. After cutting, they are laminated with the first degradation layer or the second degradation layer through a bio-based adhesive.

[0010] Step S4: The first reinforcement layer and the second reinforcement layer, the first degradation layer and the second degradation layer, and the first tensile layer and the second tensile layer are thermally compounded with the film body at 80 °C, 120 °C or 150 °C respectively by using a gradient heating process, and finally a film material is obtained through cold roll shaping.

[0011] As a further scheme of the present invention: a high-strength degradable plastic film, the bottom surfaces of the first reinforcement layer or the second reinforcement layer are respectively connected to the upper surface of the film body through a co-extrusion molding process to form a chemical bond, and a wavy transition structure is provided at the connection interface.

[0012] As a further scheme of the present invention: a high-strength degradable plastic film, a bio-based adhesive layer is provided between the first reinforcement layer and the first degradation layer and between the second reinforcement layer and the second degradation layer. The adhesive layer is made by blending starch and polyhydroxyalkanoate PHA, and its thickness is 5-10 μm.

[0013] As a further scheme of the present invention: a high-strength degradable plastic film, further comprising graphene nanoribbons, the graphene nanoribbons are respectively arranged between the first degradation layer and the first tensile layer and between the second degradation layer and the second tensile layer. A boron phosphide layer with a proportion of 0.5-1.5 wt% is doped inside the graphene nanoribbon, and the tensile strength of the boron phosphide layer is increased to 1.8 times that of a common boron phosphide material layer.

[0014] As a further scheme of the present invention: a high-strength degradable plastic film, periodic microporous arrays are respectively provided on the surfaces of the second degradation layer or the first degradation layer, the pore diameter is 20-50 μm, and the pore spacing is 1.5-2 times the pore diameter, which is used to accelerate the penetration of the degradation liquid.

[0015] As a further scheme of the present invention: a high-strength degradable plastic film, the total thickness of the film body is 100-200 μm.

[0016] As a further solution of the present invention: a high-strength degradable plastic film, wherein a degradation promoter containing Bacillus is sprayed on the surface of the film body, and the spraying amount is 0.1-0.3 mg / cm 2 .

[0017] Compared with the prior art, the beneficial effects of the present invention include:

[0018] Through the arrangement of the first strengthening layer and the second strengthening layer, the present invention can improve the strength of the film body, avoid the situation of too large softness, and cooperate with the first degradation layer and the second degradation layer to improve the degradability of the film body, avoiding the situation of environmental pollution. In addition, combined with the first tensile layer and the second tensile layer, the present invention can improve the tensile effect of the film body, avoiding the situation of easy rupture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The disclosure of the present invention will be described with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings, the same reference numerals are used to refer to the same components. Among them:

[0020] Figure 1 Schematically shows a three-dimensional structure diagram of a film body according to an embodiment of the present invention;

[0021] Figure 2 Schematically shows a bottom view of a film body according to an embodiment of the present invention;

[0022] Figure 3 Schematically shows a side view of a film body according to an embodiment of the present invention;

[0023] Figure 4 Schematically shows a top view of a film body according to an embodiment of the present invention;

[0024] Reference numerals in the figure: 1, film body; 2, first strengthening layer; 3, first degradation layer; 4, first tensile layer; 5, second strengthening layer; 6, second degradation layer; 7, second tensile layer. DETAILED DESCRIPTION OF THE INVENTION

[0025] It is easy to understand that according to the technical solution of the present invention, without changing the essence of the present invention, those of ordinary skill in the art can propose various structural ways and implementation ways that can be mutually replaced. Therefore, the following detailed description and the accompanying drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as all of the present invention or as a limitation or restriction on the technical solution of the present invention.

[0026] According to the embodiments of the present invention, it is shown in combination with Figures 1 - 4 shown.

[0027] A high-strength degradable plastic film, comprising a film body 1 composed of a symmetric multi-layer composite structure. On one side of the film body 1, a first strengthening layer 2, a first degradation layer 3 and a first tensile layer 4 are successively fixedly installed. On the other side of the film body 1, a second strengthening layer 5, a second degradation layer 6 and a second tensile layer 7 are successively fixedly installed. Among them, the first strengthening layer 2 and the second strengthening layer 5 are hot-pressed and compounded to form an intermediate strengthening core layer, and a serrated staggered structure is provided at its edge; nano-calcium carbonate particles with a degradation rate 30% higher than that of a common polylactic acid layer are uniformly dispersed in the first degradation layer 3 and the second degradation layer 6. The first degradation layer 3 is arranged between the first strengthening layer 2 and the first tensile layer 4, and the second degradation layer 6 is arranged between the second strengthening layer 5 and the second tensile layer 7; both the first tensile layer 4 and the second tensile layer 7 are made of modified polyethylene, and their surfaces are treated by plasma to form micron-level grooves to enhance the interfacial bonding force.

[0028] In this embodiment, the bottom surface of the first strengthening layer 2 is connected to the upper surface of the film body 1, and the upper surface of the first strengthening layer 2 is connected to the bottom surface of the first degradation layer 3, which can improve the connection firmness between the first strengthening layer 2 and the film body 1. The upper surface of the first degradation layer 3 is connected to the bottom surface of the first tensile layer 4. The upper surface of the second strengthening layer 5 is connected to the bottom surface of the film body 1, which can improve the stability of the second strengthening layer 5 and the film body 1. The bottom surface of the second strengthening layer 5 is connected to the upper surface of the second degradation layer 6, and the bottom surface of the second degradation layer 6 is connected to the upper surface of the second tensile layer 7, which can improve the connection strength of the second degradation layer 6.

[0029] A production method of a high-strength degradable plastic film, comprising

[0030] Step S1: Melting and co-extruding modified polyethylene particles to form the first tensile layer 4 and the second tensile layer 7, and synchronously performing plasma surface treatment during molding. The plasma surface treatment can improve the bonding strength between the tensile layer and other layers and reduce interfacial defects;

[0031] Step S2: Adding nano-calcium carbonate particles to the polylactic acid melt, and preparing the first degradation layer 3 and the second degradation layer 6 by the casting method. And forming a microporous array on the surfaces of the first degradation layer 3 and the second degradation layer 6 by laser drilling. The degradation rate of the polylactic acid layer is enhanced by the nano-calcium carbonate, and the microporous array formed by laser drilling promotes the penetration of the degradation liquid;

[0032] Step S3: Mix boron phosphide and graphene nanoribbons and hot-press them into a film. After cutting, stack them with the first degradation layer 3 or the second degradation layer 6 through a bio-based adhesive.

[0033] Step S4: The first strengthening layer 2 and the second strengthening layer 5, the first degradation layer 3 and the second degradation layer 6, and the first tensile layer 4 and the second tensile layer 7 are thermally compounded with the film body 1 at 80 °C, 120 °C or 150 °C respectively by means of a gradient heating process. The gradient heating process can ensure that each layer of material is compounded at the optimal temperature, avoiding performance degradation caused by local overheating. Finally, the film material is obtained through cold roll shaping.

[0034] As a further solution of the present invention: A high-strength degradable plastic film, the bottom surface of the first strengthening layer 2 or the second strengthening layer 5 is respectively connected with the upper surface of the film body 1 through a co-extrusion molding process to form a chemical bond, and a wavy transition structure is provided at the connection interface. This wavy transition structure can increase the interface contact area, enhance the interlayer bonding force, and prevent peeling.

[0035] As a further solution of the present invention: A high-strength degradable plastic film, a bio-based adhesive layer is provided between the first strengthening layer 2 and the first degradation layer 3, and between the second strengthening layer 5 and the second degradation layer 6. The adhesive layer is made by blending starch and polyhydroxyalkanoate PHA, and its thickness is 5-10 μm. After blending, starch and polyhydroxyalkanoate PHA are degradable and compatible with polylactic acid, realizing the problem of pollution improvement of traditional adhesives.

[0036] As a further solution of the present invention: A high-strength degradable plastic film further includes graphene nanoribbons. The graphene nanoribbons are respectively arranged between the first degradation layer 3 and the first tensile layer 4, and between the second degradation layer 6 and the second tensile layer 7. The interior of the graphene nanoribbons is doped with a boron phosphide layer with a proportion of 0.5-1.5 wt%. The tensile strength of this boron phosphide layer is increased to 1.8 times that of an ordinary boron phosphide material layer. The combination of graphene nanoribbons and the boron phosphide layer can form a conductive network and improve the mechanical properties of the material.

[0037] As a further solution of the present invention: A high-strength degradable plastic film, the surface of the second degradation layer 6 or the first degradation layer 3 is respectively provided with a periodic microporous array. This microporous array can promote the diffusion of the degradation liquid through capillary action, shortening the degradation period. The pore diameter is 20-50 μm, and the pore spacing is 1.5-2 times the pore diameter, which is used to accelerate the penetration of the degradation liquid.

[0038] As a further solution of the present invention: A high-strength degradable plastic film, the total thickness of the film body 1 is 100-200 μm.

[0039] As a further solution of the present invention: a high-strength degradable plastic film, on the surface of the film body 1, a degradation promoter containing Bacillus is sprayed, and the Bacillus secretes enzymes to accelerate the hydrolysis of polylactic acid. The spraying amount is controlled to avoid excessive degradation affecting the storage period, and the spraying amount is 0.1 - 0.3 mg / cm 2 .

[0040] In this embodiment, the first degradation layer 3 and the second degradation layer 6 can improve the strength and the easy degradation effect of the film body 1. The first tensile layer 4 and the second tensile layer 7 can increase the tensile effect of the film body 1 and avoid the situation of easy breakage thereof.

[0041] Working principle: First, the first strengthening layer 2 and the second strengthening layer 5 can increase the strength of the film body 1. The first degradation layer 3 and the second degradation layer 6 can improve the aging of the degradation of the film body 1. At the same time, the first tensile layer 4 and the second tensile layer 7 can provide high-performance tensile quality for the film body 1. The above is the entire usage process of the present invention.

[0042] The technical scope of the present invention is not limited to the content described above. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A high-strength degradable plastic film, characterized in that, It includes a film body (1) composed of a symmetric multi-layer composite structure. On one side of the film body (1), a first strengthening layer (2), a first degradation layer (3), and a first anti-tearing layer (4) are successively and fixedly installed. On the other side of the film body (1), a second strengthening layer (5), a second degradation layer (6), and a second anti-tearing layer (7) are successively and fixedly installed, where the first strengthening layer (2) and the second strengthening layer (5) form an intermediate reinforcement core layer through hot pressing and compounding, and a serrated staggered structure is provided at its edge; nanoscale calcium carbonate particles with a degradation rate 30% higher than that of ordinary polylactic acid layers are uniformly dispersed in the first degradation layer (3) and the second degradation layer (6). The first degradation layer (3) is arranged between the first strengthening layer (2) and the first anti-tearing layer (4), and the second degradation layer (6) is arranged between the second strengthening layer (5) and the second anti-tearing layer (7); both the first anti-tearing layer (4) and the second anti-tearing layer (7) are made of modified polyethylene, and micron-level grooves are formed on their surfaces through plasma treatment to enhance the interfacial bonding force between layers.

2. The high-strength degradable plastic film according to claim 1, characterized in that The bottom surface of the first strengthening layer (2) or the second strengthening layer (5) is respectively connected to the upper surface of the film body (1) through a co-extrusion molding process to form a chemical bond, and a wavy transition structure is provided at the connection interface.

3. The high-strength degradable plastic film according to claim 2, wherein Bio-based adhesive layers are provided between the first strengthening layer (2) and the first degradation layer (3), and between the second strengthening layer (5) and the second degradation layer (6). The adhesive layer is made by blending starch and polyhydroxyalkanoate PHA, and its thickness is 5 - 10 μm.

4. A high-strength degradable plastic film according to claim 3, characterized in that, It also includes graphene nanoribbons. The graphene nanoribbons are respectively arranged between the first degradation layer (3) and the first anti-tearing layer (4), and between the second degradation layer (6) and the second anti-tearing layer (7). Boron phosphide layers with a proportion of 0.5 - 1.5 wt% are doped inside the graphene nanoribbons, and the tensile strength of the boron phosphide layer is increased to 1.8 times that of an ordinary boron phosphide material layer.

5. A high-strength degradable plastic film according to claim 4, characterized in that, Periodic microporous arrays are respectively provided on the surfaces of the second degradation layer (6) or the first degradation layer (3).

6. The high-strength degradable plastic film according to claim 5, wherein The total thickness of the film body (1) is 100 - 200 μm.

7. The high-strength degradable plastic film according to claim 6, wherein, The surface of the thin film body (1) is sprayed with a degradation promoter containing Bacillus, and the spraying amount is 0.1 - 0.3 mg / cm 2 .

8. The production method of a high-strength degradable plastic film according to claim 7, characterized in that, It includes Step S1: Melting and co-extruding modified polyethylene particles to form the first anti-tearing layer (4) and the second anti-tearing layer (7), and synchronously performing plasma surface treatment during molding; Step S2: Adding nanoscale calcium carbonate particles to polylactic acid melt, preparing the first degradation layer (3) and the second degradation layer (6) by the casting method, and forming microporous arrays on the surfaces of the first degradation layer (3) and the second degradation layer (6) by laser drilling; Step S3: Mixing boron phosphide and graphene nanoribbons and hot pressing them into a film, and after cutting, laminating them with the first degradation layer (3) or the second degradation layer (6) through a bio-based adhesive. Step S4: Using a gradient heating process to thermally compound the first strengthening layer (2) and the second strengthening layer (5), the first degradation layer (3) and the second degradation layer (6), and the first anti-tearing layer (4) and the second anti-tearing layer (7) with the film body (1) at 80°C, 120°C, or 150°C respectively, and finally obtaining the film material through cold roll shaping.

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