KR101823409B1 - Biodegradable-Agriculture Mulching Film - Google Patents

Abstract

A biodegradable agricultural mulching film of the present invention comprises 40 to 90 parts by weight of poly(butylene adipate-co-terephthalate) (PBAT), 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) and 5 to 40 parts by weight of calcium carbonate (CC) having a particle size of 0.3 to 3.5 m, has an acid value of 0.3 to 3.0, and further comprises 5 to 9 parts by weight of a pigment, 0.05 to 0.45 parts by weight of an antioxidant, and 5 to 15 parts by weight of ceramic. Therefore, the biodegradable agricultural mulching film according to the present invention has effects that the biodegradable agricultural mulching film has good adaptability according to types of crop and growth duration, does not influence on growth velocity and yield of the crop, is free from a blooming phenomenon, has stabilized colors, lowers production costs, and has an appropriately smooth surface by maintaining good mechanical strength and flexibility, adjusting a biodegradation period, preventing the mulching film from being torn in a machine direction, and doubly adjusting the acid value and biodegradability rate.

Description

[0001] Biodegradable-Agriculture Mulching Film [0002]

The present invention relates to a biodegradable agricultural mulching film, and more particularly to a biodegradable agricultural mulching film comprising a mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) A biodegradable agricultural mulching film which is decomposed by microorganisms in a natural state and has a decomposition rate applicable to a growing period of a crop.

Mulching film is a thin film made of mulching, vinyl or the like. It is used to prevent soaking of soil, prevent moisture, control temperature, It is used for the purpose of suppression of weed growth, prevention of soil infectious germs, prevention of soil pollution, etc., and it is also effective to prevent the soil from being washed out due to rain.

Generally, when cultivating crops, mulching film is put on the ridges to prevent the growth of weeds and to prevent water and nutrients from evaporating, and the surface of the mulching film is cut and the seedlings of the crops are transplanted into the incision.

As for the biodegradable agricultural mulching film for cultivating the crop,

Korean Patent Registration No. 10-0903886 A biodegradable agricultural mulching film using polylactic acid and a method for producing the biodegradable agricultural mulching film using polylactic acid (June 24, 2009), comprises 10 to 55 parts by weight of polylactic acid, 7 to 15 parts by weight of calcium carbonate, 10 to 30 parts by weight of aliphatic polyester, 3 to 10 parts by weight of lactose, 1 to 5 parts by weight of ethyl acetate, 1 to 7 parts by weight of methyl methacrylate, 10 to 20 parts by weight of milk powder, 1 to 5 parts by weight of a biodegradation aid and 1 to 4 parts by weight of a photocatalyst-containing biodegradable compound are mixed with a plastic resin of LDPE, LLDPE, HDPE, LMPE, PP, PS or PE, And 40 parts by weight of the biodegradable compound were mixed with 12 parts by weight of LDPE and 48 parts by weight of LLDPE as a plastic resin and extrusion-molded.

The biodegradable agricultural mulching film using the polylactic acid according to the prior art has only biocompatible biodegradability because the synthetic resin such as low density polyethylene (LDPE) mixed with only synthetic resin is carved and fragmented to make it look like biodegradation. There is a limit to the ability to be able to.

In addition, the above-described conventional techniques have a problem in that decomposition speed is generally slow, so that even if a crop grows, it can not be decomposed.

In addition, the conventional art has a problem in that if the synthetic resin itself such as polyethylene (LDPE) is not biodegraded by microorganisms and is accumulated in the soil, environmental pollution is caused later.

In addition, when the incinerator is incinerated, environmental hormones, carbon monoxide, and toxic dioxins are produced by incomplete combustion by synthetic resins such as low density polyethylene (LDPE).

Disclosure of the Invention The present invention was conceived in order to solve the problems of the prior art described above, and it is an object of the present invention to provide a biodegradable composition comprising polybutylene adipate terephthalate (PBAT) and a biodegradable compound of polybutylene succinate adipate (PBSA) value of 0.3 ~ 3.0, which is decomposed by microorganisms in a natural state without any synthetic resin such as low density polyethylene (LDPE) or high density polyethylene (HDPE) And a biodegradable agricultural mulching film capable of preventing environmental pollution.

The present invention relates to a biodegradable agricultural mulching film comprising 40 to 90 parts by weight of polybutylene adipate terephthalate (PBAT), 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) and 5 to 40 parts by weight of calcium carbonate (CC) ≪ / RTI >

Further, the mulching film of the present invention has an acid value of 0.3 to 3.0.

The acid value of the present invention may be adjusted by mixing at least one of potassium hydroxide (KOH), sodium hydroxide, calcium hydroxide, sodium carbonate anhydrous and potassium carbonate anhydrous. .

Further, the calcium carbonate (CC) of the present invention has a particle size of 0.3 to 3.5 mu m.

Further, the mulching film of the present invention further contains 0.05 to 0.45 parts by weight of an antioxidant.

Further, the mulching film of the present invention further comprises 5 to 15 parts by weight of ceramic.

The present invention relates to a polyurethane resin composition comprising 40 to 90 parts by weight of a polybutylene adipate terephthalate (PBAT) and 5 to 20 parts by weight of a polybutylene succinate adipate (PBSA), which has good mechanical strength and flexibility, It is effective.

The present invention also relates to a mulching film composed of polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA), which tear in the machine direction but does not contain polybutylene adipate terephthalate (PBAT) and poly Butylene sulphonate adipate (PBSA) contains calcium carbonate (CC) to prevent the mulching film from tearing in the machine direction.

In addition, the present invention has an effect that the rate of biodegradation is controlled by adjusting the acid value of 0.3 to 3.0 in the period of biodegradability, and thus the adaptability is good depending on the kind of the crop and the growth period, and the growth rate and yield of the crop are not affected.

The present invention also relates to a process for the preparation of the compound of formula (I), wherein the acid value is at least one kind selected from the group consisting of potassium hydroxide (KOH), sodium hydroxide, calcium hydroxide, sodium carbonate anhydrous and potassium carbonate anhydrous And it is easy to control the acid value.

Further, the present invention has the effect that the particle size of calcium carbonate (CC) is 0.3 to 3.5 탆, the production cost is low and the surface of the mulching film is smooth.

In addition, the present invention includes 0.05 to 0.45 parts by weight of an antioxidant, so that there is no blooming phenomenon and the color is stable.

In addition, the present invention provides a biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable biodegradable It is completely biodegradable by the microbial metabolism, activates the soil microorganisms and is not harmful to the soil ecosystem.

Also, since the synthetic resin such as low density polyethylene (LDPE) is not used, the present invention has an effect that the melting time of the composition is low and the processing time is shortened.

In addition, the present invention does not require collecting mulching film after crop harvesting and thus reduces labor or incineration, and reduces carbon dioxide (CO2) by about 30% compared with polyethylene (PE) at incineration have.

In addition, the present invention has the effect of improving the acidic soil even when calcium carbonate (CC) is contained in the soil, and supplying nutrients of calcium to plants and fruits.

Figure 1: Production concept diagram of the present invention.
Figure 2: Photograph of the biodegradation state according to the period of use for each crop in the example of the present invention.
Figure 3: Hazard test graph of earthworms on biodegradable compounds on soil ecosystem.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The biodegradable agricultural mulching film of the present invention can be produced by mixing polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate-co-butylene adipate (PBSA) : Calcium Carbonate) and it can prevent environmental pollution even when incinerated. When it is used as mulching, it is decomposed by microorganisms in natural state after a certain time regardless of moisture of soil due to acid value.

The production process of the biodegradable agricultural mulching film of the present invention will be briefly described as follows. An extruder 1 having a hopper and a heater and a blown film forming device 2 A plurality of rollers and a mulching film which allow the cylindrical tube 3 to be completely folded to form a two-ply mulching film, while the guide plate 4 for narrowing the upper part of the cylindrical tube 3 lifted in the film A mulching film cutter 30 configured to cut the mulching film 20 in the longitudinal direction, a mulching film cutter 30 configured to cut the mulching film 20 in the longitudinal direction, a mulching film cutter 30 configured to cut the cut mulch film in the longitudinal direction, (7).

40 to 90 parts by weight of polybutylene adipate terephthalate (PBAT), 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) and 5 to 40 parts by weight of calcium carbonate (CC) are added to the hopper of the extruder 1 And a mixture of terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) was further added with potassium hydroxide (KOH) so that the acid value was 0.3 to 3.0, The melted synthetic resin is extruded through a blown film forming device 2 at a temperature of 115 to 240 ° C while being upwardly extruded into a small diameter mulching film.

When the small diameter mulching film upwardly extruded through the blown film forming device 2 is raised and air is supplied into the small diameter mulching film through the blower, the mulching film is expanded by the air pressure blown, do.

The mulching film is conveyed in a state in which both sides are adjacent to each other with the inclined guide plate 4 having a predetermined inclination angle so that the upper portion is narrowed, and then the inside air is completely drawn out by the stitching roller 5, The film is cut in the longitudinal direction by the cutting knife of the mulching film cutter 30 and the through holes are formed in the film by the punch knife of the mulching film perforator 50 And is completed with a biodegradable agricultural mulching film and wound on the winder 7.

The chips or powders injected into the hopper of the extruder 1 become molten resin and are discharged as a single cylindrical film having a constant width in the blown film forming apparatus 2 while being cooled by the air blown by the air ring, In the film folded and folded by the rollers 6, a part of the film is cut in the longitudinal direction by the cutting knife of the film cutter 30 and the through holes are drilled at predetermined intervals by the punch knife of the mulching film perforator 50, ), The biodegradable agricultural mulching film of the present invention is formed.

The polybutylene adipate terephthalate (PBAT) is somewhat poor in melt processability and flexibility as compared with polybutylene succinate adipate (PBSA), has good mechanical strength, and is a polymer of an aromatic polyester (thermoplastic polymer) It has biodegradability which is decomposed into carbon dioxide and water by microorganisms etc. in the soil by decomposition.

The polybutylene adipate terephthalate (PBAT) is an aromatic polyester resin comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2), and has a weight average molecular weight of 80,000 to 300,000 .

The polybutylene adipate terephthalate (PBAT) is commercially available from EnPol of Korea Lotte Fine Chemicals Co., Ltd., Biomax of DuPont of France, Origo-Bi of Novamont of Italy, and Easter Bio of Eastman Chemical of USA, .

Although the polybutylene succinate adipate (PBSA) is somewhat more flexible than polybutylene adipate terephthalate (PBAT), it lacks mechanical strength and has a too fast hydrolysis rate, And is biodegradable as a polymer of an aliphatic polyester thermoplastic polymer and decomposed into carbon dioxide and water by microorganisms in the soil or the like.

The polybutylene succinate adipate (PBSA) is an aliphatic polyester resin comprising a first repeating unit represented by the following formula (3) and a second repeating unit represented by the following formula (4), and has a weight average molecular weight of 50,000 to 200,000 .

The above-mentioned polybutylene succinate adipate (PBSA) is commercially available as SG-100, SG-200 of SK General Chemical Co., Ltd., G-4460 of IRE CHEMICAL Co., Ltd. of Korea, Bionore of Japan Showa High Polymer Co., Enforu of lreChemical Co., Ltd. of Japan and Ecoflex of BASF of Germany are commercially available.

The present invention is characterized by comprising 40 to 90 parts by weight of polybutylene adipate terephthalate (PBAT), 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) and 5 to 40 parts by weight of calcium carbonate (CC) 47 to 84 parts by weight of polybutylene adipate terephthalate (PBAT), 8 to 17 parts by weight of polybutylene succinate adipate (PBSA) and 8 to 36 parts by weight of calcium carbonate (CC).

The present invention relates to a polypropylene resin composition comprising a polybutylene adipate terephthalate (PBAT) and a polybutylene succinate adipate (PBSA) in an appropriate ratio, having excellent biodegradability and mechanical strength, It can be used as biodegradable agricultural mulching film.

The present invention relates to a biodegradable composition comprising only biodegradable compounds based on polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA), and is capable of decomposing to a size such that the polymer is low- Is completely biodegraded by microbial metabolism, so that soil microorganisms are activated and not harmful to the soil ecosystem.

Since the synthetic resin such as low density polyethylene (LDPE) is not used in the present invention, the processing time is shortened because the melting temperature of the composition is low and the mulching film may not be collected or incinerated after the crop is harvested. Or the incineration cost is reduced, and carbon dioxide (co2) is reduced by 30% as compared with polyethylene when incinerated.

Polylactic acid (PLA) is formed by polymerization of a lactide monomer obtained by fermentation of biomass. This polymer resin material is very brittle, so that a mulching film is produced using polylactic acid (PLA) only (PLA) and thermoplastic starch (TPS) are different from each other in melting temperature, so that the melting temperature of the mulching film is higher than that of the thermoplastic starch (TPS) The polylactic acid (PLA) is in the form of water to form a mulching film, and the thermoplastic resin is not well-formed, which makes it difficult to form a mulching film.

In addition, since the mulching film is used in the nose, if the thermoplastic starch (TPS) is used for the mulching film, the water content of the nose is different even in the natural state, the biodegradable rate of the mulching film is different according to the nose, Mulching films using starch (TPS) are less practical.

The present invention relates to polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA) which are easier to thermoplastic than polylactic acid (PLA) in order to solve problems of polylactic acid (PLA) ) As a base.

If the biodegradable agricultural mulching film is composed only of polybutylene adipate terephthalate (PBAT), it tends to form in the machine direction (MD) when the polybutylene adipate terephthalate (PBAT) Is melted and kneaded in an appropriate amount of 5 to 40 parts by weight, the mechanical strength of the film is increased and no formation occurs.

When the amount of the calcium carbonate (CC) is less than 5 parts by weight, the toughness, strength and softness of the film become inferior. When the amount of the calcium carbonate (CC) is more than 40 parts by weight, the strength of the film increases, do.

The aromatic / aliphatic polyester-based biodegradable resin such as polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA) can be produced by increasing the molecular weight by using an isocyanate chain extender, To increase the mechanical strength. In the present invention, the role of the isocyanate chain extender is to take charge of calcium carbonate (CC), thereby increasing the mechanical strength.

When the mulching film is composed of only polybutylene adipate terephthalate (PBAT), it tends to form in a running direction (MD direction: mechanical direction). When 40 to 90 parts by weight of polybutylene adipate terephthalate (PBAT) 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) and 5 to 40 parts by weight of calcium carbonate (CC) are melted and kneaded, the strength of the film is increased and no formation occurs.

The mulching film is torn in the mechanical direction to prevent the formation of calcium carbonate (CC), that is, the formation of the mulching film stops at the place of the calcium carbonate (CC), and the polybutylene adipate terephthalate (PBAT) When CCA is decomposed and decomposed, calcium carbonate (CC) is decomposed and absorbed into the soil by water, and calcium carbonate (CC) is decomposed into soil Even if left untreated, it will improve the acid soil and provide the nutrients of calcium to plants and fruits.

The above-mentioned calcium carbonate (CC) is a main component of calcareous fertilizer and serves to improve the acidic soil and to supply the calcium component to plants and fruits, and also to provide a calcium component such as limestone, marble, calcite, bamboo, chalk, Shell, egg shell, and coral. The calcium carbonate (CC) is formed in the form of an acicular, a triangular, a hexahedron, a sphere, a plate or a prism.

The above-mentioned calcium carbonate (CC) is divided into a dry product (powder) according to whether it contains water or not, and according to the physicochemical treatment method, the calcium carbonate (PCC: Precipitated Light Calcium Carbonate) and the heavy calcium carbonate : Ground Calcium Carbonate). The present invention uses heavy calcium carbonate (GCC), which is made by dry milling and does not involve a chemical reaction.

The calcium carbonate (CC) has a particle size of 0.3 to 3.5 mu m, and the particle size of calcium carbonate (CC) is preferably 0.6 to 3.0 mu m. When the amount of the calcium carbonate (CC) particles is less than 0.3 μm, the surface of the mulching film becomes smooth, but the processing of the calcium carbonate (CC) becomes difficult, the unit price of the calcium carbonate (CC) becomes high, μm, the processing of calcium carbonate (CC) is easy, but the film surface becomes very rough. The particle size of the above-mentioned calcium carbonate (CC) is 0.3 to 3.5 mu m, and the production cost is low and the surface of the mulching film becomes smooth.

The heavy calcium carbonate (GCC) fine powder can be obtained by mixing raw ore ore with a raw material such as Jaw Crush, Roll Crush, Hammer Mill, Rod Mill, Ball Mill or Cone Crusher ) Or the like, or a dry grinding process in which raw ore is crushed by using a jaw crush, a roll crush, a hammer mill, a rod mill, a ball mill or a cone After crushing repeatedly by using a crusher or the like, the slurry is passed through a wet cyclone to concentrate the slurry of the fine particles selected by the wet centrifugal separator to prepare wet crushed calcium carbonate, or the slurry is spray- After the wet grinding process using a spray-dryer, the calcium carbonate (CC) is classified through a vibrating screen or a classifier so as to have a required particle size, that is, an average particle size of 0.3 to 3.5 μm.

Classification is a method of separating solid particles by particle size, in which fine pulverized calcium carbonate (CC) powder is sieved by a fine sieve mesh or a pulverized calcium carbonate (CC) By separating the coarse particles through the classifier using the difference, the amount of coarse particles is reduced to obtain a fine calcium carbonate (CC) powder having a good particle size distribution.

The biodegradable agricultural mulching film has an acid value of 0.3 to 3.0, and preferably has an acid value of 0.8 to 2.5 in a biodegradable agricultural mulching film. If the acid value is less than 0.3, the film will not be decomposed even after crop harvest because the rate of biodegradation of the film is slow. When the acid value is 3.0 or more, the rate of biodegradation of the film becomes very fast, It is impossible to maintain the temperature of the liquid. The biodegradable agricultural mulching film has a good adaptability according to the kind of the crop and the growth period (for example, 3 months, 6 months, 8 months) and the growth of crops It does not affect speed and yield.

The acid value is the amount of the acid component in the biodegradable agricultural mulching film and is the number of potassium hydroxide (KOH: potassium hydroxide) necessary to neutralize the acidic component of 1 g of the sample in mg unit, as the number of the polybutylene adipate terephthalate PBAT) and calcium carbonate (CC). The hydrolysis stability is generally better when the acid value is lower, and the acid value is determined by the alkali catalyst.

The potassium hydroxide (KOH) is a white solid of an inorganic compound, and has strong property of absorbing moisture and carbon dioxide, and has a high solubility of potassium carbonate which is generated when water and carbon dioxide are absorbed, and 1, 2 and 4 water flames exist. 35.5 캜 and -32.7 캜, respectively, and the transition temperature therebetween is 32.5 캜 and -33 캜.

In addition to potassium hydroxide (KOH), sodium hydroxide, calcium hydroxide, sodium carbonate anhydrous and potassium carbonate anhydrous may be used as the alkali catalyst, It is determined by mixing more than one species and it is easy to adjust the acid value.

The amount of the alkali catalyst to be added is 0.01 to 0.25 parts by weight based on 100 parts by weight of the mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) 0.06 to 0.20 parts by weight is added.

When the addition amount of the alkali catalyst is less than 0.01 part by weight, the acid value of the mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) becomes 3.0 or more, When the addition amount of the catalyst is 0.25 parts by weight or more, the acid value of the mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) is 0.3 or less.

Wherein the biodegradable agricultural mulching film comprises 0.05 to 0.45 parts by weight of an antioxidant per 100 parts by weight of a mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) And preferably 0.09 to 0.40 part by weight of the antioxidant.

If the antioxidant is less than 0.05 part by weight based on 100 parts by weight of the mixture of adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC), the plate- (blooming) occurs. When the amount of the antioxidant is more than 0.45 part by weight, the color is stabilized at a high temperature during the melt extrusion of the biodegradable agricultural mulching film, so that there is no blooming and the oxidation by heat is suppressed.

The antioxidant may be a conventional synthetic compound such as hindered phenol, hindered amine, sulfur compound, phosphorus compound or the like, natural compound of ascorbic acid or its derivative or apple compound. Representative examples of the hindered phenol antioxidant include tetrakis (methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) methane (Tetrakis (3,5-di-tert-butyl-4-hydroxyphenyl) propionate methane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) or a combination thereof.

Further comprises 5 to 15 parts by weight of ceramics to 100 parts by weight of the mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) The ceramic is composed of 8 to 13 parts by weight of ceramic powder having a particle size of 200 to 600 mesh and preferably 300 to 400 mesh.

When the amount of the ceramic is less than 5 parts by weight, the strength of the product is lowered and the strength of the product is lowered. When the amount of the ceramic is more than 15 parts by weight, the strength is increased but the decomposition time is long. When the ceramic particle size is less than 200 mesh, The surface roughness of the mulching film becomes poor due to the large particle diameter. When the ceramic is more than 600 mesh, the surface area of the particles is large, so the far infrared ray radiation effect is enhanced and the workability is good, but the processing cost is high because of special precision milling.

The ceramic may be selected from the group consisting of phyllite, quartz, white mica, sericite, iron, magnesium, chlorite, garnet, chloritoid, muscovite, biotite, Aluminum oxide, aluminum oxide, albite, sphene, apatite, tourmaline, graphite, zircon, alumina, silicon dioxide, magnesium oxide, sodium oxide, Titanium dioxide, zirconia, silicon carbide. Silicon nitride, barium titanate, and the like.

The pigment further contains 5 to 9 parts by weight, preferably 7 to 8 parts by weight, based on 100 parts by weight of the polybutylene adipate terephthalate (PBAT), the polybutylene succinate adipate (PBSA) and the mixture of calcium carbonate (CC) By weight.

When the pigment is less than 5 parts by weight, the color of the mulching film becomes lighter and the amount of sunlight is increased. When the pigment is more than 8 parts by weight, the color of the mulching film is good, but the required pigment is required.

The pigments include coarse particles or generally known metallic pigments, inorganic pigments and organic pigments in powder form. The metallic pigments include aluminum pigments, bronze pig pigments and ferric pigments. The inorganic pigments include carbon black, Cobalt green, Cobalt blue, Yellow ocher, Oxidize red iron, Viridian, Cadmium yellow and Ultra marine. blue, titanium dioxide (TiO2) or iron oxide green, and the organic pigment may be any one selected from the group consisting of Hansa yellow, colored black to use pigmented pigments, The color of the mulching film is determined.

The pigment is a powder having a particle size of 200 to 600 mesh, and preferably a powder having a particle size of 300 to 400 mesh. When the particle size is less than 200 mesh, the surface roughness of the mulching film becomes poor due to the large particle size of the powder. When the particle size is more than 600 mesh, the surface roughness is good. However, There is a high possibility of scattering into the air as a fine powder at the time of processing, and the workability is inferior.

The biodegradable agricultural mulching film of the present invention can be applied to a biodegradable agricultural mulching film which is present in nature such as polycaprolactone (PCL), polybutylene succinate (PBS) and polybutylene adipate (PBA) A biodegradable synthetic resin obtained from a natural product, and a petrochemical biodegradable synthetic resin may be further included.

The biodegradable agricultural mulching film of the present invention can be compounded with various additives such as a lubricant, a flame retardant, an antistatic agent, a heat stabilizer, a light stabilizer, an ultraviolet absorber and an antiblocking agent within the range not impairing the object of the present invention

The polybutylene adipate terephthalate (PBAT) is commercially available from Lotte Fine Chemicals Co., Ltd., Korea, and the polybutylene succinate adipate (PBSA) is commercially available from SK Chemical Co., The biodegradable agricultural mulching film was evaluated for physical properties according to the following examples.

(1) Acid value

0.5 g of the resin was dissolved in 20 ml of chloroform, and then ethanol was added thereto. The solution was titrated with 0.1 N potassium hydroxide (KOH) in an autotitrator to calculate an acid value.

(2) Tensile strength, tear strength and elongation

7.6 Tensile Strength and Elongation of KS M 3503 The tensile strength (kgf / ㎠), tear strength (kgf / cm) and elongation (%) of the specimen were measured according to the test method, (TD) perpendicular to the longitudinal direction (MD), and the lowest value was taken.

(3) Biodegradability

KS M 3100-1 The amount of carbon dioxide generated from the standard sample (cellulose) and the test sample was measured and evaluated by a method of measuring the aerobic biodegradability of the plastic under composting conditions.

Biodegradability (%) = (amount of generated carbon dioxide / theoretical amount of carbon dioxide) * 100

The biodegradable agricultural mulching film according to the present invention was prepared by using a film forming machine (Daerun Machinery Co., Ltd., 50 mm HD / PE FILM M / C) and using the extruder cylinder temperature and die temperature Was appropriately adjusted to prepare a black film having a thickness of 15 탆 at an extrusion rate of 500 rpm, a feed rate of 100 rpm, and a roll speed of 200 rpm. The compositions for Examples 1 to 6 of the present invention are shown in Table 1 below .

The acid value according to the embodiment of the present invention is shown in Table 1 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Acid value 2.7 2.3 1.8 1.4 0.9 0.5

Table 2 shows the compositions according to the examples of the present invention.

                                                                 Unit: parts by weight division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 PBAT 93.0 82.0 71.0 60.0 49.0 38.0 PBSA 3.0 6.8 10.6 14.4 18.2 22.0 Calcium carbonate 4.0 11.2 18.4 25.6 32.8 40.0 Pigment 4.5 5.5 6.5 7.5 8.5 9.5

* Pigments are in parts by weight relative to 100 parts by weight of PBAT, PBSA and calcium carbonate.

The results of physical property evaluation according to the embodiment of the present invention are shown in Table 3 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 The tensile strength
(kgf / cm2) TD 494 789 485 480 376 368 MD 483 479 473 469 464 461 Phosphorus strength
(kgf / cm) TD 232 227 221 215 210 206 MD 198 194 187 181 176 172 Elongation (%)
TD 703 706 712 721 727 732 MD 254 259 265 274 279 283 Biodegradability (25 days,%) 83 76 68 63 60 58

As shown in Table 3, Examples 1 to 6 according to the present invention have tensile strengths in the machine direction (MD) of 461 to 483 kgf / cm 2, tear strengths of 172 to 198 kgf / cm and elongation rates of 254 to 283% It was confirmed that the biodegradability at 25 days was 58 to 83% and the biodegradability was different depending on the acid value without lowering the tensile strength and elongation.

In the photograph of the biodegradation state according to the use period of each crop in the embodiment of the present invention shown in Fig. 2, the garlic of 0.5 in acid value is the photograph of the result of biodegradation by the actual covering condition in the field of the unglazed surface of Andong city, Gyeongsangbuk- Is a photograph of the result of biodegradation by the actual covering condition performed in the field of Inje-eup, Inje-gun, Wonju-city, Gangwon-do.

The photograph of FIG. 2 shows the biodegradability of the mulching film by visually observing the degradation progress of the coated film after a certain period of time in a state covered with actual soil (Ihnjyeon myeon, Inje-gun, Jejeon-gun, (3 months), mid - term (6 months) and long - term (8 months), respectively, according to the results of observation of fungi propagated by soil microorganisms.

Approximately 95% of the biodegradable film with an acid value of 0.5 was degraded in an actual coated state for 180 days, and about 80% of the biodegradable film having an acid value of 1.4 was degraded in an actual coated state for 110 days and an acid value of 2.7 The biodegradable film degraded about 90% in the actual coating condition in the field for 90 days.

The reason for the difference between the results of the biodegradation of the physical property evaluation result and the actual biodegradation by coating was that in the evaluation of physical properties, the optimum state of microbial propagation was maintained in the laboratory, and the microbial propagation was in a good state. It was concluded that the microbial propagation conditions were not good due to the supply of natural resources, but the biodegradation was good in the landfill.

The terms or words used in the specification and claims of the present invention are not to be construed in a conventional or dictionary sense and the inventor can appropriately define the concept of the term in order to explain its invention in the best way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention.

Therefore, the embodiments described in the detailed description of the present invention and the configurations shown in the drawings are only the most preferred embodiments of the present invention, so that the scope of the present invention should not be limited to the described embodiments, It should be understood that variations may or may not be present in and on the basis of equivalents to the claims.

1: extruder 2: blown film forming device
3: tube 4: guide plate
5: Stencil roller 6: Auxiliary roller
7: Winding machine 30: Mulching film cutting machine
50: Mulching film perforator

Claims (7)

A biodegradable agricultural mulching film,
The mulching film comprises 40 to 90 parts by weight of polybutylene adipate terephthalate (PBAT), 5 to 20 parts by weight of polybutylene succinate adipate (PBSA) From 5 to 40 parts by weight of calcium carbonate (CC) and an acid value of from 0.3 to 3.0;
5 to 9 parts by weight of a pigment having a particle size of 200 to 600 mesh powder per 100 parts by weight of the mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) Wherein the biodegradable agricultural mulching film is a biodegradable agricultural mulching film.
delete delete delete delete delete The method according to claim 1,
Characterized in that the mulching film further comprises 5 to 15 parts by weight of ceramic relative to 100 parts by weight of a mixture of polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA) and calcium carbonate (CC) Biodegradable agricultural mulching film.

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