Eco-friendly multi-layer mulching film with biodegradable plastic

Abstract

The present invention experimentally confirmed that when a mulching film comprising a pulp layer (110) and a biodegradable plastic layer (210) is applied to soil, the biodegradability of the mulching film is excellent. Therefore, it is expected that by using the mulching film of the present invention for crop cultivation, labor for removing the mulching film can be reduced, and an eco-friendly mulching film that does not require landfilling or incineration can be provided.

Description

Technology Field

[0001] The present invention relates to an eco-friendly mulching film comprising biodegradable plastic, and more specifically, to an eco-friendly mulching film with a multilayer structure comprising biodegradable plastic. Background Technology

[0002] Generally, mulching is the process of covering or protecting the soil using materials such as tree bark, fallen leaves, and rice straw to aid plant growth. The effects of mulching include weed suppression, prevention of topsoil erosion, inhibition of soil moisture evaporation, maintenance of soil temperature, promotion of the growth of beneficial microorganisms, and soil fertility.

[0003] In many rural areas of Korea, polyethylene film or paper is used as a mulching film on the ground when cultivating crops. In particular, polyethylene mulching is known to have the effect of increasing crop yields by raising soil temperature during periods of low temperatures.

[0004] However, non-biodegradable mulching films, such as polyethylene mulching films, are difficult to collect and dispose of, causing soil and air pollution. Although numerous studies and technologies regarding eco-friendly mulching films have been published for a long time to address this issue, the results obtained when cultivating crops in rural areas have not been satisfactory, and many technologies are still being developed to resolve this problem.

[0005] Consequently, mulching films made from biodegradable plastic materials such as PLA, PCL, or PVA have been developed. However, although these materials decompose by microorganisms upon contact with soil, they do not last long enough from crop growth to harvest. Furthermore, the physical properties of the mulching film deteriorate, causing it to be blown away by the wind or crack, which prevents it from fulfilling its mulching function when used alone, presenting many problems.

[0006] To solve the problems of such single-layer films, the inventors fabricated a multilayer film capable of compensating for the disadvantages among biodegradable materials, confirmed high strength and preservation under natural environmental conditions, and further confirmed that crop cultivation without abnormalities is possible. The problem to be solved

[0007] The inventors confirmed that when a mulching film comprising a pulp layer and a biodegradable plastic layer was applied to soil, the biodegradability of the mulching film was excellent.

[0008] Accordingly, the objective of the present invention is to provide a mulching film comprising a pulp layer and a biodegradable plastic layer adhered to at least one surface of the pulp layer, wherein the pulp layer and the biodegradable plastic layer are adhered with an adhesive. means of solving the problem

[0009] The present invention relates to a mulching film composed of a pulp layer and a biodegradable plastic layer.

[0010] The present invention will be described in more detail below.

[0011] One embodiment of the present invention relates to a mulching film comprising a pulp layer and a biodegradable plastic layer adhered to at least one surface of the pulp layer, wherein the pulp layer and the biodegradable plastic layer are adhered with an adhesive.

[0012] The above pulp layer may be made of kraft paper, but is not limited thereto.

[0013] The above kraft paper is 40 to 100 g / m² 2 It may have a basis weight of, preferably 40 to 90 g / m² 2 , 40 to 80 g / m² 2 , 40 to 70 g / m² 2 , 40 to 60 g / m² 2 , 50 to 100 g / m² 2 , 50 to 90 g / m² 2, 50 to 80 g / m² 2 , 50 to 70 g / m² 2 , 50 to 60 g / m² 2 , 60 to 100 g / m² 2 , 60 to 90 g / m² 2 , 60 to 70 g / m² 2 , 70 to 100 g / m² 2 , 70 to 90 g / m² 2 , 70 to 80 g / m² 2 , 80 to 100 g / m² 2 , 80 to 90 g / m² 2 , 90 to 100 g / m² 2 It may have a basis weight of, for example, 60 to 80 g / m² 2 It may have a basis weight, but is not limited to this.

[0014] In the present invention, the mulching film may have at least one other biodegradable plastic layer bonded to at least one surface with an adhesive.

[0015] In the present invention, the biodegradable plastic layer may be one or more selected from the group consisting of pulp paper, cellophane paper, polylactic acid (PLA), polycaprolactone (PCL), polyester urethane (PEU), aliphatic polyester (AP), aromatic / aliphatic copolyester (Alo / Ali copolyester), propanediol (Bio-PDO), cellulose acetate (CA), polyglycolic acid (PGA), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyvinyl alcohol (PVA), thermoplastic (TPS), polyhydroxyvalerate (PHV), polyhydroxyalkanoate (PHA), and mixtures thereof, but is not limited thereto.

[0016] In the present invention, the biodegradable plastic layer may have a thickness of 10 μm to 70 μm, preferably 10 μm to 60 μm, 10 μm to 50 μm, 20 μm to 70 μm, 20 μm to 60 μm, 20 μm to 50 μm, 30 μm to 70 μm, or 30 μm to 60 μm, and may have a thickness of, for example, 30 μm to 50 μm, but is not limited thereto.

[0017] In the present invention, the adhesion of each layer may be achieved using a dry lamination machine, a coating machine, or a comma coating machine, but is not limited thereto.

[0018] In the present invention, the adhesive comprises a water-soluble urethane composition comprising 60 parts by weight of polyol, 3 to 9 parts by weight of dimethylol butanoic acid (DMBA), 1 to 5 parts by weight of isocyanate, and 2 to 6 parts by weight of a chain extender, and graphite dispersed in the water-soluble urethane composition, wherein the weight ratio of the water-soluble urethane composition to the graphite may be 3 to 6:4 to 7, but is not limited thereto.

[0019] In the present invention, the water-soluble urethane adhesive may further comprise starch or polycarbonate.

[0020] In the present invention, the starch or polycarbonate may be included in an amount of 1 to 10 weight percent relative to the total weight of the water-soluble urethane adhesive, but is not limited thereto.

[0021] The moisture permeability of the multilayer mulching film can be improved by mixing starch or polycarbonate with the above-mentioned water-soluble urethane adhesive as described above.

[0022] If the content of the above starch or polycarbonate is less than 1 weight%, the moisture permeability effect of the mulching film may not be sufficient.

[0023] If the content of the above starch or polycarbonate is greater than 10 weight%, the coating ability and penetration ability may be reduced.

[0024] In the present invention, the water-soluble urethane adhesive may form a layer with a thickness of 5 to 30 μm, but is not limited thereto.

[0025] If the application thickness of the above water-soluble urethane adhesive is less than 5 μm, the adhesive strength is insufficient, and the layers may not be sufficiently bonded.

[0026] If the application thickness of the above-mentioned water-soluble urethane adhesive is greater than 30 μm, the economic efficiency of producing the mulching film decreases, and the thickness of the mulching film may be uneven. Effects of the invention

[0027] The present invention experimentally confirmed that when a mulching film comprising a pulp layer and a biodegradable plastic layer is treated on soil, the biodegradability of the mulching film is excellent.

[0028] Therefore, it is expected that by using the mulching film of the present invention for crop cultivation, labor for removing the mulching film can be reduced, and an eco-friendly mulching film that does not require landfilling or incineration can be provided. Brief explanation of the drawing

[0029] FIG. 1 schematically illustrates a cross-section of a mulching film in which a biodegradable plastic layer (210) is bonded to a pulp layer (110) according to one embodiment of the present invention. FIG. 2 schematically illustrates a cross-section of a mulching film in which two or more biodegradable plastic layers are bonded to a pulp layer (110) according to one embodiment of the present invention. Specific details for implementing the invention

[0030] The present invention has been described in detail below through the following examples. However, these examples are merely illustrative of the invention, and the scope of the invention is not limited by these examples.

[0032] Example 1. Fabrication of multilayer mulching film

[0033] The pulp layer (110) has a basis weight of 60 g / m² 2 Kraft paper was used, and cellophane paper with a thickness of 30 μm was used as the biodegradable plastic layer (210). To bond the two layers, an adhesive was applied between the two layers to a thickness of 30 μm, and a dry lamination machine was used to bond each layer to produce a mulching film as shown in FIG. 1.

[0034] In the manner described above, various types of multilayer mulching films were produced by adhering different biodegradable plastic materials other than cellophane, such as PLA, PCL, PEU, AP, Alo / Ali, Bio-PDO, CA, PGA, PBS, PHB, PVA, TPS, PHV, or PHA, to one side of the pulp layer.

[0036] Example 2. Measurement of rainwater waterproofing phenomenon, soil moisture change, physical property change, and degradation of multilayer mulching film

[0037] The multilayer mulching films obtained through Example 1 were treated on soil for 3 months, and the rainwater waterproofing phenomenon, soil moisture change, physical property change, and decomposition of the mulching paper according to the type of film were measured and the extent is shown in the table below.

[0038] rainwater waterproofing phenomenon change in soil moisture Change in physical properties Exploded view natural polymer pulp middle middle award award Pulp + Cellophane award award middle middle Pulp + PLA award award under under Pulp + PCL award award award award Pulp + PEU award award under under Pulp+AP award award middle Symptoms Pulp + Alo-Ali award award middle middle Pulp + Bio-PDO award award under under Pulp + CA award award under under Pulp + PGA award award under under Pulp + PBS award award middle middle Pulp + PHB award award middle middle Pulp + PVA under under award award Pulp + TPS middle middle award award Pulp + PHA award award middle middle Pulp + PHV award award middle middle

[0040] Example 3. Measurement of moisture permeability of a multilayer mulching film fabricated using a water-soluble urethane adhesive

[0041] To improve the moisture permeability of the multilayer mulching film, a mulching film was fabricated using a water-soluble urethane adhesive.

[0042] The above-mentioned water-soluble urethane adhesive comprises a water-soluble urethane composition comprising 60 parts by weight of polyol, 6 parts by weight of dimethylol butanoic acid (DMBA), 3 parts by weight of isocyanate, and 4 parts by weight of a chain extender, and graphite dispersed in the water-soluble urethane composition, wherein the weight ratio of the water-soluble urethane composition to the graphite is 3:7.

[0043] In addition, starch or polycarbonate was mixed into the above-mentioned water-soluble urethane adhesive at a ratio of 10% by weight relative to the total weight of the mixture. The adhesive prepared in the above manner was applied between kraft paper and cellophane paper at a thickness of 30 μm to produce a multilayer mulching film in the same manner as in Example 1, and then moisture permeability was checked.

[0044] The moisture permeability of the mulching films produced in this way was measured, and the results are shown in the table below.

[0045] Types of adhesives breathability General adhesive under Water-soluble urethane adhesive middle Water-soluble urethane adhesive + starch award Water-soluble urethane adhesive + polycarbonate award

[0046] Through the experimental results above, it was confirmed that mulching films produced using adhesives mixed with starch or polycarbonate in water-soluble urethane adhesives exhibit excellent moisture permeability. Explanation of the symbols

[0047] 110: Pulp layer 210: First biodegradable plastic layer 220: Second biodegradable plastic layer 310: First adhesive layer 320: Second adhesive layer 330: Third adhesive layer

Claims

Claim 1 A mulching film comprising: a pulp layer; and a biodegradable plastic layer adhered to at least one surface of the pulp layer; wherein the pulp layer and the biodegradable plastic layer are adhered with an adhesive, and the adhesive comprises a water-soluble urethane composition comprising 60 parts by weight of polyol, 3 to 9 parts by weight of dimethylol butanoic acid (DMBA), 1 to 5 parts by weight of isocyanate, and 2 to 6 parts by weight of a chain extender, and graphite dispersed in the water-soluble urethane composition, wherein the weight ratio of the water-soluble urethane composition to the graphite is 3 to 6: 4 to 7, and the adhesive further comprises starch or polycarbonate. Claim 2 In claim 1, the pulp layer is a mulching film made of kraft paper. Claim 3 In paragraph 2, the kraft paper is 40 to 100 g / m² 2 A mulching film having a basis weight. Claim 4 In claim 1, the mulching film is a mulching film having at least one other biodegradable plastic layer bonded to at least one surface with an adhesive. Claim 5 A mulching film according to claim 4, wherein the biodegradable plastic layer is one or more selected from the group consisting of polylactic acid (PLA), polycaprolactone (PCL), polyester urethane (PEU), aliphatic polyester (AP), aromatic / aliphatic copolyester (Alo / Ali copolyester), propanediol (Bio-PDO), cellulose acetate (CA), polyglycolic acid (PGA), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyvinyl alcohol (PVA), thermoplastic (TPS), polyhydroxyvalerate (PHV), polyhydroxyalkanoate (PHA), and mixtures thereof. Claim 6 A mulching film according to claim 1, wherein the biodegradable plastic layer has a thickness of 10 μm to 70 μm. Claim 7 delete Claim 8 delete Claim 9 A mulching film according to claim 1, wherein the starch or the polycarbonate is included in an amount of 1 to 10 weight percent relative to the total weight of the adhesive. Claim 10 A mulching film according to claim 1, wherein the adhesive forms a layer with a thickness of 5 to 30 μm.

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