KR20120128940A - multi-layer synthetic resin film coated hydrophilic nanoparticles for agricultural film and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A multi-layered synthetic resin film for agriculture coated with hydrophilic nano particles and a manufacturing method thereof are provided to reduce costs caused by frequently exchanging a film as the property of the film is maintained for a long time by an UV(Ultraviolet) agent. CONSTITUTION: A method for manufacturing a multi-layered synthetic resin film for agriculture coated with hydrophilic nano particles comprises following steps. An inner layer is extruded by mixing polyethylene resin, polyolefin elastomer, heat-retaining additives, and an ultraviolet agent. A middle layer is extruded by mixing EVA(Ethylene Vinyl Acetate Copolymer), heat-retaining additives, and the ultraviolet agent. The outer layer is extruded by mixing the polyethylene resin with the ultraviolet agent. A multilayer film with the inner, middle and outer layers is extruded, and the surface of the outer layer is oxidized and modified by the corona discharge. The film is impregnated with a coating solution by a dipping in-line coating method right after the corona discharge. The coating solution is evenly applied using a mayer bar. The coating solution is dried by a hot air dryer. [Reference numerals] (AA) Before the corona discharge; (BB) After the corona discharge

Description

Multi-layer synthetic resin film coated hydrophilic nanoparticles for agricultural film and method of manufacturing the same

The present invention relates to a multi-layered synthetic resin film for agriculture, and more particularly, to have a multi-layer film structure structurally, including a coating layer coated on the film surface with a corona treatment, a functional coating solution to improve physical properties and transparency The present invention relates to a synthetic resin film having an agricultural multilayer structure coated with hydrophilic nanoparticles that can be used for a long period of time and improve invincibility of the film and have excellent weather resistance.

House cultivation or tunnel cultivation is prevalent in rural areas to increase crop yields and improve the merchandise.These house cultivation or tunnel cultivation is carried out by LLDPE (Liner Low Density Poly Ethylene), LDPE (Low Density Poly Ethylene), and EVA (Ethylene). Vinyl Acetate) and PVC (Poly Vinyl Chloride) are used. When these films are used for crop cultivation, water droplets form on the surface of the film due to evaporation of water from the soil. The sunlight required for the growth of the crop is scattered by the water droplets on the film and scattered, resulting in low permeability. Generated.

In order to compensate for this, there is a method of adding a hydrophilic surfactant to the inside of the film production so that the added invincible agent soaks on the surface of the film to exhibit invincibility. In this method, the surfactant is soaked for only 3 to 6 months, so it is not unbeatable in use, and only 20-30% of the surfactant is poured out of the film, and an excessive amount of an unloading agent must be added during manufacture. Because of this, the whitening occurs, and the film must be replaced from time to time, there was a problem that the heavy burden of expenses and inconvenience.

In addition, as a method of coating a hydrophilic resin on the film, there is a method of coating a polymer of 2-hydroxy methacrylate or a hydrophilic polymer such as PVA on the polymer film, the method is easy to crack the coated resin layer and the matrix Poor adhesion at the surface tended to peel easily.

In addition, a method of forming a hydrophilic resin on the surface of the transparent material using a combination of a random copolymer or a hydrophilic polymer and a surfactant containing mostly a hydrophilic polymer portion and a small amount of a hydrophobic polymer portion to maintain film strength to water However, this may improve the strength and adhesion of the film while the invincible performance was poor.

In addition, there is a method of imparting hydrophilicity to the polymer film in the order of high frequency surface treatment, coating of hydrophilic material, and photocuring, but in this method, a chamber must be separately installed so that a light reaction can occur after coating the film and blowing off the solvent. Not only is there a hassle to do, but it is inevitable to increase the production cost of the product due to expensive equipment and maintenance costs, and there is a difficulty in storage because it is a polymer composition for photoreaction.

Enhancing the transparency of the film used in farmhouses and preventing the formation of water droplets on the surface of the film, it is sufficient to improve the transmittance of sunlight to help crop growth, and to develop agricultural films that can be used for a long time. I really need it.

In addition, all of the long-term coating films used in domestic farms are imported from Japan, which encroaches on the long-term coating film market of domestic horticultural facility farmers and increases farm management costs due to the high unit cost of long-term coating films. There is a problem that adds to the cost burden. In order to solve the farming management problem, public support funds are being invested at the government level, and as a result, it is a serious problem to leak the treasury abroad.

Therefore, there is an urgent need for development of a coating film and its production technology which can have the same level as the long-term coating film that is imported and can lower the production cost of the product.

Therefore, the first technical problem to be solved by the present invention is to modify the surface by corona treatment of the film surface in order to prevent whitening due to the functional additive in the existing additive film, to coat the functional coating solution, and to add a UV agent mechanical properties To provide a method for producing a multilayer structure synthetic resin film coated with hydrophilic nanoparticles excellent in transparency, processability, and weatherability.

The second technical problem to be solved by the present invention is a film comprising a coating layer coated with a corona treatment surface and a functional coating solution, which improves invincibility, transparency, coating weather-resistant hydrophilic nanoparticles It is to provide a multi-layered synthetic resin film.

The present invention to achieve the first object,

(a) mixing and melting polyethylene resin, polyolefin-based elastomer, heat-insulating additive and UV agent to extruding the inner layer, and extrusion-molding the middle layer by mixing and melting ethylene vinyl acetate copolymer, heat-insulating additive and UV agent, and polyethylene resin and UV Extruding the outer layer by mixing and melting the agent; and (b) extruding the multilayer film formed of the inner, middle, and outer layers through co-extrusion during the extrusion, and simultaneously oxidizing and modifying the outer layer surface through corona discharge treatment. And forming a coating layer by a deeping in-line coating method of impregnating the coating solution immediately after the corona discharge treatment, and (c) uniformly coating the surface coating solution using the Mayer No. 8-12 after surface coating of the coating solution. And (d) drying with a hot air drier; a method of manufacturing a multilayer structure synthetic resin film coated with hydrophilic nanoparticles comprising a. To provide.

According to an embodiment of the present invention, the polyethylene resin may be selected from low density polyetherene resin (LDPE), linear low density polyethylene resin (LLDPE), metallocene-linear low density polyethylene resin (m-LLDPE), or a mixture thereof. Can be.

According to another embodiment of the present invention, the inner layer may include 40-45 wt% polyethylene resin, 45-55 wt% polyolefin-based elastomer, 1-3 wt% thermal insulation additive, and 3-7 wt% UV agent. .

According to another embodiment of the present invention, the middle layer may include 75-85% by weight of ethylene vinyl acetate, 10-20% by weight of thermal additives, and 3-7% by weight of UV agent.

According to another embodiment of the present invention, the outer layer may include 93-97 wt% of polyetherene resin and 3-7 wt% of UV agent.

According to another embodiment of the present invention, in the step (a), the melting temperature of the inner layer is 170 to 190 ° C, the melting temperature of the middle layer is 150 to 180 ° C, and the melting temperature of the outer layer is 145 to 170 ° C. Can be.

According to another embodiment of the present invention, the step (b) may be modified by oxidizing the outer layer film surface by corona discharge treatment at a strength of 8.5-9.5 A, 75-85 V, 38-42 dyne.

According to another embodiment of the present invention, the functional coating solution may be a mixed solution containing an acrylic resin, alcohol and silica particles, the thickness of the coating layer may be 1-10 ㎛.

According to another embodiment of the present invention, the step (d) may be dried to a temperature of 90-110 ℃ while passing the coated film through a hot air dryer at a rate of 5-15 m / min.

The present invention to achieve the second technical problem,

(Iii) an inner layer comprising a polyethylene resin, a polyolefin-based elastomer, a heat insulating additive and a UV agent, (ii) a middle layer comprising an ethylene vinyl acetate copolymer, a thermal additive and a UV agent, and (iii) a polyethylene resin and a UV agent. The outer layer and (iii) a coating layer coated with a functional coating solution after the corona discharge treatment, the thickness ratio between the inner layer, middle layer and outer layer is 1: 1.2-1.5: 0.8-1.2, the thickness of the coating layer is 1- It provides a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that 10㎛, the total thickness is 0.1-0.2mm.

The multi-layered synthetic resin film coated with the hydrophilic nanoparticles according to the present invention can not only prevent the whitening phenomenon occurring in the conventional additive film as a coating film, but also has excellent deficiency, transparency, scratch resistance, and blocking resistance. Therefore, the growth of crops is promoted to increase farm income, and the addition of UV agent keeps its properties for a long time, so that the film can be used for a long time, thus reducing the cost of frequent film replacement in farms. Excellent workability and stability in manufacturing. In addition, the commercialization of the coating film according to the present invention can replace Japanese imports in the market for long-term coating film for facility horticulture. In addition, in order to reduce the farm management cost burden caused by the use of such expensive Japanese imports in horticultural farms, public funds are supported by local governments, but the present invention can block the outflow of public funds. In addition, it can reduce the farming management cost of the farm, and due to the durability that can be used for a long time can not only reduce the replacement cost, but also to suppress the emission of waste vinyl and the emission of carbon dioxide generated during film production.

1 is an image showing the results of atomic force microscopy (AFM) analysis of the film surface characteristics before and after the corona treatment according to the present invention.
Figure 2a is an image showing the results of coating and oiliness evaluation according to the initial coating, 10 days, 20 days, 30 days after coating the coating agent after 6.2 A corona treatment.
Figure 2b is an image showing the coating properties and oiliness evaluation results according to the initial coating, 10 days, 20 days, 30 days after the coating of the coating agent after the corona treatment with 8.2 A.
3 is a graph showing the weather resistance evaluation results of the film according to the present invention.

Hereinafter, the present invention will be described in more detail.

The agricultural multilayer synthetic resin film according to the present invention is characterized in that the coating is not an additive film coated with a functional coating agent by corona treatment of the film surface, and the compatibility of the film and the coating liquid when the coating liquid is coated on the film surface Since the peeling phenomenon may occur when low, the present invention is characterized by generating a radical by performing a corona treatment on the surface of the film to improve the bonding with the coating solution.

In addition, in the case of the conventional additive film, the additives added to provide functionality have problems of whitening and shortening of life due to surface migration, but the present invention maintains transparency by surface coating a functional coating solution and a UV agent. It is characterized by the fact that it can produce a film that can be used for a long time by adding.

Method for producing a multilayer structure synthetic resin film coated with a hydrophilic nanoparticles according to the present invention is (a) by mixing and melting a polyethylene resin, a polyolefin-based elastomer, a heat insulating additive and a UV agent to extruding the inner layer, an ethylene vinyl acetate copolymer, a heat insulating additive And extruding the middle layer by mixing and melting the UV agent, and extruding the outer layer by mixing and melting the polyethylene resin and the UV agent. (b) Extrusion of the multilayer film formed into the inner, middle, and outer layers through co-extrusion during extrusion, and at the same time, the surface of the outer layer is oxidized and modified through corona discharge treatment, and deeping impregnated in the coating liquid immediately after the corona discharge treatment. Forming a coating layer by an in-line coating method; (c) homogenizing the surface coating solution using Mayer Nos. 8-12 after surface coating of the coating solution; And (d) drying with a hot air drier.

The inner layer includes a polyethylene resin, a polyolefin-based elastomer, a thermal insulation additive, and a UV agent, the middle layer includes an ethylene vinyl acetate copolymer, a thermal additive, and a UV agent, and the outer layer includes a polyethylene resin and a UV agent. It is done. In addition, the thickness ratio between the inner layer, the middle layer and the outer layer is 1: 1.2-1.5: 0.8-1.2, the thickness of the coating layer is characterized in that the total thickness is 0.1-0.2 mm.

The inner layer is composed of UV layer, middle layer is thermal insulation layer, and outer layer is oil remnant layer (coating layer), and each layer's UV layer is a layer to prevent oxidation by light, and middle layer is to improve physical properties and thermal insulation of film. Insulation layer, outer layer is a layer for preventing the shaking and deflection of the bubble and coating during film production.

Assuming that the ratio of each layer is 100, the inner layer is preferably 30%, the middle layer is 40%, the outer layer is 30%.

The present invention has been derived from the following experiments by limiting the composition of the synthetic resin film of each layer and its content ratio by the following experiments, when out of the specific content ratio, physical properties such as mechanical properties, transparency, opening properties, invincibility, etc. It was confirmed that significantly lowered.

The inner layer comprises 40-45% by weight of polyethylene resin, 45-55% by weight of polyolefin elastomer, 1-3% by weight of heat-insulating additive, and 3-7% by weight of UV agent, and the middle layer is 75-85% by weight of ethylene vinyl acetate. 10-20% by weight of the thermal insulation additive and 3-7% by weight of the UV agent, wherein the outer layer is characterized in that it comprises 93-97% by weight of polyetherene resin and 3-7% by weight of the UV agent.

The thermal insulation additive is added to the ethylene vinyl acetate copolymer resin (EVA) and blended, characterized in that to improve the thermal insulation power and transparency of the film. General agricultural film insulating additives can be used.

The UV agent may use an additive of the HALS (Hindered Amine Light Stabilizer) system, and serves to stop the photooxidation reaction by removing the free radicals generated during the photolysis reaction, and is added to the ethylene vinyl acetate copolymer resin (EVA) for compounding. It serves to prevent premature oxidation of the film.

The outer layer may be coated with a functional coating to improve invincibility, that is, to increase the hydrophilic effect, the functional coating is characterized in that the mixed solution containing an acrylic resin, alcohol and silica particles. Coating on the surface of the outer layer serves to improve the invincibility and anti-fog.

The melting temperature of the inner layer is 170-190 ℃, the melting temperature of the middle layer is 150-180 ℃, the melting temperature of the outer layer is characterized in that the 145-170 ℃.

It was prepared using a 1800mm extruder, the melting temperature, cylinder and die temperature conditions were adjusted according to the characteristics of the resin entering the base resin in each layer.

Step (c) is characterized in that by modifying the surface of the outer layer by the corona discharge treatment at the strength of 7.5-8.5 A, 65-75 V, 35-40 dyne.

The high frequency generated from the corona discharge processor ionizes the air between the discharge electrode and the processing roll to generate charged particles.These particles oxidize the surface of the film by colliding with the film surface located between the electrode and the processing roll, thereby forming a coating agent. It improves the adhesion of the to enable a stable coating.

In the present invention, it was confirmed by the AFM (atomic forced microscopy) analysis that the unevenness of the film surface was uniformly and deeply modified after the corona treatment, the generation of negative ions on the film surface increased. The results are shown in Figure 1 below.

2A and 2B show the results of evaluating the coating property and the oil repellency of the coating solution according to the corona treatment strength. When the corona strength is low (FIGS. 2A and 6.2 A), the scratching property is insufficient and the peeling phenomenon occurs between the coating agent and the film. In order to achieve a stable corona discharge effect, a discharge intensity of at least 8.5 A (about 38 dyne) should be maintained.

The functional coating was coated at the same time as the film production using the In Line Coating facility, and at this time, the in-line coating method of the deeping method in which the film was impregnated into the coating liquid during the manufacturing of the film, that is, immediately after the corona discharge treatment. It was carried out through. After coating the surface of the coating solution, the thickness of the coating was adjusted using Mayer Nos. 8-12 to obtain a uniform surface.

This prevents unevenness of the coating film thickness of some parts of the agricultural film to be thick and some parts, and minimizes the phenomenon that water droplets form on the surface of the film due to moisture evaporation by making the thickness of the coating film optimal. This is to obtain useful effects such as being excellent and providing an excellent environment for crops to grow.

In addition, the present invention was derived from the hot air drying step by adjusting the hot air temperature to obtain the optimum drying conditions, it is preferable to dry at a temperature of 90-110 ℃ while passing through the hot air dryer at a rate of 5-15 m / min.

Drying of the coating liquid did not proceed normally at the hot air temperature of 90 ° C. or lower. As a result, the coating liquid residues were adsorbed on the nip-roll of the dryer, causing the coating layer to fall off or agglomerate.

The present invention is an inner layer comprising a polyethylene resin, polyolefin elastomer, a heat insulating additive and a UV agent, a middle layer comprising an ethylene vinyl acetate copolymer, a heat insulating additive and a UV agent, and an outer layer comprising a polyethylene resin and a UV agent, the outer layer It provides a synthetic resin film coated with a hydrophilic nanoparticles having a multi-layer structure including a coating layer coated on the surface with a functional coating solution after the corona discharge treatment, the outer layer film surface is coated with a functional coating agent after the corona discharge treatment, the inner layer, the middle layer And the thickness ratio between the outer layer is 1: 1.2-1.5: 0.8-1.2, the thickness of the coating layer is 1-10 ㎛, characterized in that the total thickness is 0.1-0.2 mm.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, these examples are intended to illustrate the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited thereby.

<Examples>

(1) LDPE 1, LDPE 2, LDPE 3, LLDPE, m-LLDPE, EPPE, POE, EVA, warming agent and UV having physical properties as shown in the following [Table 1] in the comparative example and the embodiment according to the present invention Agent was used.

(2) Extruder, corona treatment machine and hot air dryer are as follows.

Extruder is Blown Type, L / D: In 30, Middle 30, Out 30, Die: 1,800mm, Airing: 2,000mm, Roll Width: 8,800mm.

The corona treatment machine was treated with 8.5-9.5 A, 75-85 V, and 38-42 dyne strength. The hot air dryer has a capacity of 100 kW, a maximum temperature of 110 ° C, and a specification of 8,800 mm.

(3) The following Comparative Example 1 to Comparative Example 6, the constituent composition of the inner / middle / outer layer according to Example 1 according to the present invention and its content ratio are as shown in Table 1 below.

Comparative Example 1. Preparation of a multilayer synthetic resin film according to the present invention

The inner layer is a UV layer which prevents oxidation by light, and mixes 95 parts by weight of LDPE and 5 parts by weight of UV agent. The middle layer was mixed with 80 parts by weight of EVA as a supporting layer, 14 parts by weight of a thermal insulation additive for enhancing the thermal effect, and 6 parts by weight of UV. The outer layer is a layer for coating after film production. Like the inner layer, 95 parts by weight of LDPE and 5 parts by weight of UV agent were mixed.

In line coating equipment and 1,800mm extruder equipment were used. During the extrusion process, the corona treatment was performed with a corona treatment machine at 8.5 A, 38 dynes, and the functional coating was coated on the outer layer.

Melting temperature was produced under the conditions of inner layer 165 ℃, middle layer 138 ℃, outer layer 154 ℃ conditions, the extrusion process was carried out under the conditions of cylinder 154-158 ℃ and die 156-186 ℃. The time of corona treatment and coating was applied through deep in-line coating method in which the film was impregnated into the coating liquid during manufacture of the film, ie, immediately after the corona discharge treatment, and dried at 90-110 ° C. in a hot air dryer. .

Comparative Example 2. Preparation of a multilayer synthetic resin film according to the present invention

The inner layer is mixed with 70 parts by weight of m-LLDPE, 25 parts by weight of LDPE 3 and 5 parts by weight of UV agent to improve transparency and mechanical properties. The middle layer was mixed in the same ratio as in Comparative Example 1. The outer layer was mixed with 95 parts by weight of LDPE 3 and 5 parts by weight of UV agent.

As the m-LLDPE was added, the overall melting temperature was increased, and the corona treatment and the coating were performed in the In-Line corona treatment and coating method as in Comparative Example 1.

In the preparation according to Comparative Example 2, the transparency and the mechanical properties were good, but in the continuous production, the state of the film surface was severe due to the bubble shaking due to the extrusion load and the minute processing temperature change.

Comparative Example 3. Preparation of a multilayer synthetic resin film according to the present invention

The inner layer and the middle layer were the same as the mixing ratio of Comparative Example 2, except that LLDPE was used to prevent the bubble shaking due to the same extrusion load in Comparative Example 2. The outer layer was mixed with 70 parts by weight of LLDPE, 25 parts by weight of LDPE 3, and 5 parts by weight of UV, the same compounding ratio as the inner layer. Corona treatment and coating was performed in-line corona treatment and coating method as in Comparative Example 1. As a result of the experiment, bubbles dropped when working at a pulling speed of less than 14.2 m / min.

Comparative Example 4. Preparation of a multilayer synthetic resin film according to the present invention

The inner layer was mixed with 70 parts by weight of LLDPE, 24 parts by weight of LDPE 3 and 6 parts by weight of a UV agent. The middle layer was mixed with 80 parts by weight of EVA, 14 parts by weight of thermal insulation additive, and 6 parts by weight of UV agent. The outer layer was mixed with 95 parts by weight of LDPE 2 and 5 parts by weight of a UV agent. LDPE was mixed instead of LLDPE in order to improve the processability. Corona treatment and coating was performed in-line corona treatment and coating method as in Comparative Example 1.

Processing stability was improved, but the transparency was inferior to Comparative Example 2 containing the m-LLDPE.

Comparative Example 5. Preparation of a multilayer synthetic resin film according to the present invention

60 parts by weight of LDPE 3 and 40 parts by weight of EPPE were mixed in the inner layer. The reason for mixing EPPE (Easy Processing Polyethylene) is to facilitate the extrusion process while retaining the physical properties of m-LLDPE. The mixed raw material of the middle layer was the same as in Comparative Example 4, but 5 parts by weight of the UV agent was mixed instead of 15 parts by weight of the thermal insulation additive. The outer layer was the same as that of the comparative example 4. Corona treatment and coating was performed in-line corona treatment and coating method as in Comparative Example 1.

The workability and processing stability were good, but the transparency of the film was not improved and the purging work for the raw material change after the completion of the production required relatively long purging time due to the relatively low fluidity in the screw compared to other resins.

Comparative Example 6. Preparation of a multilayer synthetic resin film according to the present invention

45 parts by weight of LDPE 2, 50 parts by weight of POE, and 5 parts by weight of UV agent were mixed into the inner layer. This is to improve transparency by mixing POE resin. The outer layer was mixed similarly to the said comparative example 5. Corona treatment and coating was performed in-line corona treatment and coating method as in Comparative Example 1.

Transparency was somewhat improved, but the opening was not good compared to other resins. In the summer months when the processing temperature and atmospheric temperature rise, there is a high possibility of poor openness, because it is weak in heat due to the characteristics of POE resin.

Example 1. Preparation of a multilayer synthetic resin film according to the present invention

43 parts by weight of LDPE 2, 50 parts by weight of POE, and 5 parts by weight of UV agent were mixed in the inner layer, and 2 parts by weight of thermal insulation additive was mixed to solve the opening problem by prescribing an inorganic additive. In the meantime, the outer layer was the same as that of the said comparative example 6. Corona treatment and coating was performed in-line corona treatment and coating method as in Comparative Example 1. Experimental results showed good opening properties.

Evaluation Example 1. Evaluation of Properties of Synthetic Resin Film According to the Present Invention

(1) Comparative Example 1 is a composition and processing conditions of the existing raw materials, Examples 2 to 7 are always carried out to supplement the existing disadvantages and to derive the optimum conditions.

Comparative Example 2 is characterized by blending extruded LLDPE resin in the inner layer, it can implement excellent transparency and mechanical properties according to the characteristics of the metallocene resin, but in the continuous production Bubble shaking and fine due to the overload of extrusion There was a serious problem in the state of the film surface caused by the change of processing temperature.

Comparative Example 3 is a characteristic element for maintaining the transparency of the LLDPE and improving the stability of the extrusion process, the processability is improved, but there was a problem that the bubble falls when working at a pulling speed of 14.2m / min or less .

In Comparative Example 4, by using LDPE instead of LLDPE in the outer layer, workability was improved (pullability was improved) and stability was greatly improved, but there was a problem in that transparency was lowered compared to LLDPE resin.

In Comparative Example 5, EPPE, which is currently commercialized in Japanese coating films, is applied, which is easy to be extruded, has good workability and processing stability, but does not improve the transparency of the film and purging work for changing raw materials after production is completed. There is a problem that long purging time is required because the fluidity is relatively low compared to the other resin.

Comparative Example 6 is characterized by blending an elastomer (POE resin) as a characteristic element, the transparency is improved, but the opening is unstable compared to other resins, and thus, during the summer work start to increase the processing temperature and atmospheric temperature relatively There may be a configuration problem.

Comparative Example 7 as a characteristic element that solved the opening problem by prescribing inorganic additives and adding the POE resin, it was confirmed that the above-mentioned problems were overcome and showed the optimum physical properties.

(2) Example 1 according to the present invention as a characteristic element that solved the opening problem by adding a POE resin by prescribing an inorganic additive, overcoming the above problems and showing the optimum physical properties [Table 2 ] And [Table 3].

(3) Workability and workability evaluation

(4) quality characteristics evaluation

As shown in [Table 2] and [Table 3], Comparative Example 1 has good processing stability and workability, while quality characteristics such as transparency drop and coating instability are lowered. In Comparative Example 2, the LLDPE was blended into the inner layer and extruded, and showed excellent transparency and mechanical properties. However, the continuous production caused a lot of bubble shaking and film surface change due to the overload of the extrusion. Therefore, in order to maintain the transparency and to improve the stability of the extrusion process was prepared in Comparative Example 3, the phenomenon that the bubble falls during the work under the take-up speed of 14.2m / min, and the coating and drying when the uptake speed is adjusted up There are problems in the process, such as, but prepared by blending the LDPE to the outer layer as in Comparative Example 4, the workability is improved, but the problem that the transparency is lowered. Comparative Example 5 has a problem in that the processing stability is good but the transparency of the film is poor, and a long time is required during the purging operation. In Comparative Example 6, the transparency was improved, but the opening property was unstable, and thus the problem of opening property was expected at the time of raising the processing temperature and the atmospheric temperature.

Unlike the Comparative Examples 1 to 6, the film according to the present invention is excellent in workability such as bubble stability and continuous workability, but also has low extrusion load, and quality in transparency and thickness stability.

Evaluation Example 2 Surface Modification Effect According to Corona Treatment According to the Present Invention

AFM (atomic forced microscopy) analysis was performed on the film surface prepared according to Example 1 before and after the corona discharge treatment. Scan size 50.00 μm, scan rate 0.3863 Hz, image data (height), data scale was performed at 300 nm. The results are shown in Figure 1 below.

Rms (Rq) (Root Mean Aquare) increased roughly 300% from 27.097 nm before treatment to 81.403 nm after treatment, improving roughness overall, and Rmax (maximum height roughness) was also treated at 315.19 nm before treatment. Then increased about 170% to 541.86 nm.

Through the corona discharge treatment according to the present invention it can be seen that the irregularities of the film surface is uniformly and deeply modified to have a uniform coating property and excellent adhesion.

Evaluation Example 3 Evaluation of Coating Properties and Oil Dropability According to Corona Treatment Strength

Corona treatment was performed by varying the corona discharge intensity during the extrusion process of the film prepared according to Example 1 to evaluate the coating property and oil repellency according to the corona treatment strength, the results are shown in Figure 2a and 2b. .

Figure 2a is performed with a discharge intensity of 6.2 A, from the left side is the image showing the initial coating, 10 days of coating, 20 days of coating, 30 days of coating.

Figure 2b is performed with a discharge intensity of 8.2 A, from the left side is the image showing the initial coating, 10 days of coating, 20 days of coating, 30 days of coating.

When the corona strength is low, there is a phenomenon that the initial wettability decreases, but as a result of the change over time, there was no peculiar characteristic of the remains phenomenon according to the corona strength. The scratchability was satisfactory in the 8.2 A corona discharge, but the coating and film were peeled off due to the lack of the scratch property in the corona discharge of 6.2 A or less. Therefore, it can be seen that the discharge intensity of at least 8.5 A is required for the stable corona discharge effect.

It can be seen that due to the corona discharge treatment according to the present invention has excellent scratching of the coating agent exhibits a stable oil and fat effect.

Evaluation Example 4. Evaluation of Weatherability of Film According to UV Stabilizer Content According to the Present Invention

In the present invention, the film was prepared by adding a UV-HALS-based UV agent in order to improve the problem of shortening the life of the film appearing in the conventional additive film, and evaluated the weather resistance thereof. Weather resistance test equipment was used UV2000 (ATLAS), the results are shown in Figure 3 below.

UV agents used in the preparation of the film according to the present invention were evaluated by adding 600, 800, 1000, 1200, 1400, 1600 ppm content. By the 1000 ppm dose the half-life of the film increased and then remained at a similar level.

In Korea, the average daily dose is 150 kj / m2, and UV (0.55 W / m2) is 300 kj / m2 when irradiated for 1 hour with UV (0.55 W / m2). 1) and the like, the energy carried out is an average of 200 kj / m 2 per hour. That is, one hour is similar to the condition of 1.5 days of open field.

Therefore, it can be seen that the weather resistance of 1300 hours of the film produced according to the embodiment of the present invention has a durability of about 5.3 years, corresponding to 1950 days of the open field, and excellent weather resistance.

Claims (15)

(a) mixing and melting polyethylene resin, polyolefin-based elastomer, heat-insulating additive and UV agent to extruding the inner layer, and extrusion-molding the middle layer by mixing and melting ethylene vinyl acetate copolymer, heat-insulating additive and UV agent, and polyethylene resin and UV Mixing and melting the agent to extrude the outer layer;
(b) Extrusion of the multilayer film formed into the inner / middle / outer layer through coextrusion during extrusion and at the same time, the surface of the outer layer is oxidized and modified through corona discharge treatment, and deeping impregnated into the coating liquid immediately after the corona discharge treatment. Forming a coating layer by an in-line coating method;
(c) homogenizing the surface coating solution using Mayer Nos. 8-12 after surface coating of the coating solution; And
(d) drying with a hot air dryer; a method of manufacturing a multilayer structure synthetic resin film coated with hydrophilic nanoparticles comprising a.
The method of claim 1,
The polyethylene resin is coated with hydrophilic nanoparticles, characterized in that it is selected from low density polyetherene resin (LDPE), linear low density polyethylene resin (LLDPE), metallocene-linear low density polyethylene resin (m-LLDPE) or a mixture thereof. A multi-layered synthetic resin film production method.
The method of claim 1,
The inner layer is a multilayer structure coated with hydrophilic nanoparticles, characterized in that it comprises 40-45% by weight of polyethylene resin, 45-55% by weight of polyolefin-based elastomer, 1-3% by weight of warming additive and 3-7% by weight of UV agent. Synthetic resin film production method.
The method of claim 1,
The middle layer is 75-85% by weight of ethylene vinyl acetate, 10-20% by weight of heat-insulating additives and 3-7% by weight of UV agent, characterized in that the multi-layered synthetic resin film manufacturing method coated with a hydrophilic nanoparticles.
The method of claim 1,
The outer layer is a method for producing a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that containing 93-97% by weight of polyetherene resin and 3-7% by weight of UV agent.
The method of claim 1,
In step (a), the melting temperature of the inner layer is 170-190 ° C, the melting temperature of the middle layer is 150-180 ° C, and the melting temperature of the outer layer is coated with hydrophilic nanoparticles, characterized in that 145-170 ° C. Multi-layered synthetic resin film production method.
The method of claim 1,
The step (b) is a method of manufacturing a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that the surface of the outer layer is modified by the corona discharge treatment to the strength of 8.5-9.5 A, 75-85 V, 38-42 dyne .
The method of claim 1,
The functional coating solution is a mixed solution containing an acrylic resin, alcohol and silica particles, the thickness of the coating layer is a method of manufacturing a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that 1-10 ㎛.
The method of claim 1,
The step (d) is a method of manufacturing a multi-layered synthetic resin film coated hydrophilic nanoparticles, characterized in that the dried film at a temperature of 90-110 ℃ while passing through the hot air dryer at a rate of 5-15 m / min.
(Iii) an inner layer comprising a polyethylene resin, a polyolefin elastomer, a heat retention additive, and a UV agent;
(Ii) a middle layer comprising an ethylene vinyl acetate copolymer, a thermal additive and a UV agent;
(Iii) an outer layer comprising a polyethylene resin and a UV agent; And
(Iii) a coating layer coated on the outer surface of the outer layer with a functional coating solution after a corona discharge treatment;
The thickness ratio between the inner layer, the middle layer and the outer layer is 1: 1.2-1.5: 0.8-1.2, the thickness of the coating layer is 1-10 ㎛, the total thickness is 0.1-0.2 mm multi-layer coated with hydrophilic nanoparticles, characterized in that Structure synthetic film.
11. The method of claim 10,
Multi-layer coated with hydrophilic nanoparticles, characterized in that selected from polyethylene low density polyethylene resin (LDPE), linear low density polyethylene resin (LLDPE), metallocene-linear low density polyethylene resin (m-LLDPE) or a mixture thereof Structure synthetic film.
11. The method of claim 10,
The inner layer is a multilayer structure coated with hydrophilic nanoparticles, characterized in that it comprises 40-45% by weight of polyethylene resin, 45-55% by weight of polyolefin-based elastomer, 1-3% by weight of warming additive and 3-7% by weight of UV agent. Synthetic film.
11. The method of claim 10,
The middle layer is a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that it comprises 75-85% by weight of ethylene vinyl acetate, 10-20% by weight of thermal additives and 3-7% by weight of UV agent.
11. The method of claim 10,
The outer layer is a multi-layered synthetic resin film coated with hydrophilic nanoparticles, characterized in that it comprises 93-97% by weight of polyetherene resin and 3-7% by weight of UV agent.
11. The method of claim 10,
The corona discharge treatment is treated with a strength of 8.5-9.5 A, 75-85 V, 38-42 dyne, and the functional coating solution is a synthetic resin film having a multi-layered structure, characterized in that the mixed solution containing acrylic resin, alcohol and silica particles. .

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