KR101494762B1 - Film composition for agriculture - Google Patents

Abstract

More particularly, the present invention relates to a film composition for agricultural use, which has excellent mechanical strength, weather resistance, heat resistance, pesticide resistance and electric field workability and is excellent in transparency and warmth while maintaining long-term ultraviolet blocking effect at a wavelength of 280 to 380 nm Agar film composition which can increase the yield of crops and reduce the cost of coating labor and material by providing agricultural films which can be used for a long time by preventing discoloration, degeneration and oxidation of agricultural films due to long-term exposure to ultraviolet rays .

Description

[0002] Film composition for agriculture [0003]

The present invention relates to an agricultural film composition, and more particularly, to an agricultural film composition which is excellent in long-term ultraviolet ray shielding effect at a wavelength of 280 to 380 nm and prevents discoloration, degradation and oxidation of an agricultural film due to long- ≪ / RTI >

Agricultural films have functions such as light transmittance, warmth and weatherability to protect crops from changes in the environment of vinyl houses and to produce high quality, high-income agricultural products stably.

The choice of agricultural film is an important factor that affects the quality and yield of farming. Polyethylene (PE) film, polyvinyl chloride (PVC) film, ethylene vinyl acetate (EVA) film and the like are used for agricultural film. Physical properties and durability of film such as transparency, thermal conductivity and tensile strength, Economy is considered. Particularly, since the PO-based resin has a smaller density than the chloroethylene resin, it is lightweight, less poisonous gas is generated even when it is incinerated, and moreover needs to be processed according to extrusion of lay-flat tubing A large-sized film which is not used can be provided at low cost and is actively used.

Among them, ultraviolet ray absorbing function is an important function that agricultural film has to have. Sun ray has many light such as ultraviolet ray, visible ray and infrared ray. Among these rays, the growth of plants such as visible rays is strengthened or the growth and yield of fruits are increased However, it is necessary to block the near ultraviolet rays in the range of 280 to 380 nm to slow down the activity of pests, thereby suppressing the occurrence of insects such as gray fungus, mites, and mites that may occur in the house. It is known to promote and delay the aging of crops.

As a method for obtaining the blocking effect in the near ultraviolet region, a method of adding a large amount of ultraviolet absorber to a plastic film constituting a vinyl house is mainly used. When a large amount of ultraviolet absorber is used, Is transferred to the surface of the film to be crystallized, and the film is whitened.

Accordingly, although methods for reducing the amount of the ultraviolet absorber have been developed in the past, they have been effective in blocking ultraviolet rays, but they have a problem in that the transparency of the film is lowered and the affinity with the synthetic resin forming the film is not easy. Permeability is not satisfied. In addition, the conventional agricultural film including the ultraviolet absorber has a tendency to migrate to the outside with the passage of time, which hinders the light transmittance, and the discoloration, degeneration and oxidation phenomenon And the physical properties inherent to the film are reduced, thereby shortening the life span, as well as deteriorating the nutrients, taste and flavor of the crop.

In particular, agriculture houses are becoming bigger each year, and film field work to cover houses with film requires a lot of labor, while the number of agricultural workers is decreasing year by year and aging is progressing, It is a difficult situation to secure hands on. Therefore, it is required to develop long-term agricultural film which is excellent in long-lasting ultraviolet shielding and slows down discoloration, degeneration and oxidation of film, so that the field work is easy and the period of service until replacement can be secured for more than 2 years .

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an agricultural film having excellent long-term ultraviolet ray exposure effect at a wavelength of 280 to 380 nm for suppressing the occurrence of pests and diseases, Which can be used for a long period of time by preventing discoloration, degeneration, oxidation and the like of the film, which is excellent in transparency and warmth.

In order to solve the above-described problems,

Wherein 0.5 to 5.0 parts by weight of titanium dioxide (TiO ₂ ) and 0.5 to 5.0 parts by weight of zinc oxide (ZnO ₂ ) are contained in 100 parts by weight of the thermoplastic resin.

According to a preferred embodiment of the present invention, the mixing weight ratio of the titanium dioxide (TiO ₂ ) and the zinc oxide (ZnO ₂ ) may be 2: 8 to 8: 2.

According to another preferred embodiment of the present invention, the average particle diameter of the titanium dioxide (TiO ₂ ) and the zinc oxide (ZnO ₂ ) may be 10 to 50 nm.

According to another preferred embodiment of the present invention, the thermoplastic resin is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), linear ultra low density polyethylene (VLLDPE), metallocene linear low density polyethylene (M- Ethylene vinyl acetate copolymer, and the like.

According to another preferred embodiment of the present invention, 0.5 to 10.0 parts by weight of a benzotriazole-based or benzophenone-based organic ultraviolet absorber may be further added to 100 parts by weight of the thermoplastic resin.

According to another preferred embodiment of the present invention, 0.5 to 10.0 parts by weight of the light stabilizer and 0.5 to 10.0 parts by weight of the antioxidant may be further added to 100 parts by weight of the thermoplastic resin.

In addition, the present invention provides an agricultural film characterized by being manufactured by including the agricultural film composition.

According to a preferred embodiment of the present invention, the agricultural film is formed of three layers including an outer layer, an intermediate layer and an inner layer, and the outer layer may include the agricultural film composition.

According to another preferred embodiment of the present invention, the thickness of the agricultural film may be 70 to 150 탆.

According to another preferred embodiment of the present invention, the thickness of the agricultural film intermediate layer may be 50 to 90% of the entire agricultural film.

According to another preferred embodiment of the present invention, the agricultural film may have an average transmittance of 280 to 380 nm in wavelength region of 10% or less and an average transmittance of 380 to 400 nm in wavelength region of 50% or more.

INDUSTRIAL APPLICABILITY The agricultural film composition of the present invention has excellent mechanical strength, weather resistance, heat resistance, pesticide resistance and electric field workability, is excellent in transparency and warmth, and is excellent in long-term ultraviolet ray blocking effect persistence at 280 to 380 nm wavelength, Degradation and oxidation of agricultural film caused by agriculture can be prevented, thereby providing crops that can be used for a long period of time, thereby increasing yields of crops and reducing the cost of coating labor and materials.

1 is a graph showing the UV absorption of the particle size of the titanium dioxide (TiO _2).
FIG. 2 is a graph showing the permeability according to the particle size of the inorganic UV absorbers. FIG.
3 is a graph showing the ultraviolet absorptivity of UV organic absorbers and UV inorganic absorbers.

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

As described above, the conventional agricultural film including the ultraviolet absorber lowers transparency of the film, insufficient heat insulation, low persistence of ultraviolet ray shielding effect, discoloration, degeneration and oxidation of agricultural film caused by ultraviolet ray exposure, There was a problem.

Accordingly, the present invention provides an agricultural film composition comprising 0.5 to 5.0 parts by weight of titanium dioxide (TiO ₂ ) and 0.5 to 5.0 parts by weight of zinc oxide (ZnO ₂ ) based on 100 parts by weight of the thermoplastic resin, But it is also excellent in the persistence of near UV blocking effect at a wavelength of 280 to 380 nm, thereby preventing the discoloration, degeneration and oxidation of the agricultural film due to the exposure to ultraviolet rays for a long period of time.

When the amount of the titanium dioxide (TiO ₂ ) is less than 0.5 parts by weight, the ultraviolet ray shielding effect is insufficient. When the amount of the titanium dioxide is more than 5.0 parts by weight, haze phenomenon of the film may occur, ZnO ₂ ) is less than 0.5 part by weight, the ultraviolet blocking effect is also decreased. When the amount is more than 5.0 parts by weight, haze phenomenon of the film may occur and transparency of the film may be deteriorated.

In addition, the mixing weight ratio of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) may be from 2: 8 to 8: 2. If the mixing weight ratio is out of the range, the ultraviolet ray shielding effect may be reduced and the light transmittance may be deteriorated, more preferably 4: 6 to 6: 4.

The average particle diameter of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) may be 10 to 50 nm. When the average particle diameter of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) satisfies the above range, the ultraviolet ray shielding effect is excellent and the dispersibility and permeability during molding of the film can be remarkably improved (see FIGS. 1 to 2). ) When the average particle diameter of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) exceeds 50 nm, dispersion of the fine particles of the fine particles may be insufficient, resulting in whitening, and due to the photocatalytic phenomenon due to light and rain, Deterioration of the film can be promoted and the film can be hollowed. Further, the ultraviolet shielding effect may be remarkably deteriorated and the light transmittance may be deteriorated.

3, it can be seen that titanium dioxide (TiO ₂ ) has an excellent ultraviolet ray absorption ratio in the range of 280 to 300 nm, but has a slightly lower ultraviolet ray absorption rate in the range of 300 to 380 nm. Therefore, the ultraviolet ray absorbing effect can be enhanced in the near ultraviolet region of 280 to 380 nm by mixing zinc oxide (ZnO ₂ ) so as to satisfy the mixing weight ratio of the present invention.

The thermoplastic resin may be selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), linear low density polyethylene (VLLDPE), metallocene linear low density polyethylene (M-LLDPE), ethylene vinyl acetate And the like may be used alone or in combination. When a metallocene linear low density polyethylene (M-LLDPE) resin is used, a film excellent in flexibility, tensile strength and tear strength can be obtained.

The organic UV absorbent may further comprise 0.5 to 10.0 parts by weight of benzotriazole or benzophenone based on 100 parts by weight of the thermoplastic resin. When the amount is less than 0.5 part by weight, the ultraviolet ray absorbing effect may be reduced in the range of 270 to 310 nm near ultraviolet ray. If the amount is more than 10.0 parts by weight, outward transfer may occur and side effects such as decrease in light transmittance and contamination may occur.

Examples of the benzophenone system include dihydroxy benzophenone, 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone ( methoxybenzophenone, hydroxy-4-methoxybenzophenone-5-sulfonic acid or 2-hydroxy-4-n-octylbenzophenone, And more preferably 2, 4-dihydroxybenzophenone or 2, 2 ', 4, 4'-tetrahydroxybenzophenone can be mixedly used. The benzotriazole system includes 2- (2'-hydroxy-5- tert -butylphenylbenzotriazole), 2- (2'-hydroxy-5'-methylphenyl Methylphenylbenzotriazole, 2- (2'-hydroxy) -3'-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole.

The thermoplastic resin may further comprise 0.5 to 10.0 parts by weight of a light stabilizer and an antioxidant in 100 parts by weight of the thermoplastic resin. When the amount is less than 0.5 part by weight, the antioxidant effect of the film is decreased, so that the degradation can not be prevented and the durability is lowered. When the amount is more than 10.0 parts by weight, the light transmittance may be lowered due to external transition.

The light stabilizer may be a conventionally used light stabilizer, but may more preferably comprise a hindered amine compound. The hindered amine compound may have a molecular weight of 1000 or more, more preferably a molecular weight of 2000 to 5000. If the number average molecular weight of the hindered amine compound is less than 1000, bleeding out easily occurs and the persistence of the effect may be deteriorated.

The oxidant inhibitor may be a conventionally used antioxidant having an effect as a heat stabilizer, but more preferably a metal salt of a carboxylic acid, a phenol-based sulfurizing agent, an organic phosphorous ester ( ester), and the like can be used singly or in combination.

The anti-fogging agent is not particularly limited, but it is more preferable to use an antifogging agent such as glycerol ester, sorbitan ester, polyglycerol ester, ethoxy Polyhydric alcohols such as ethoxylated sorbitan esters and glycerin oleic acid esters, unsaturated fatty acids, esters, and the like.

The agricultural film composition may further contain an anti-fogging agent. The anti-fogging agent is not particularly limited, but may be more preferably a silicone surfactant, a fluorine-based surfactant or the like.

In addition, the present invention provides an agricultural film characterized by being manufactured by including the agricultural film composition.

The total thickness of the agricultural film may be from 70 to 150 mu m. When the thickness is less than 70 μm, the mechanical strength of the agricultural film is lowered, which may easily cause fracture or weathering of the heavy wind. If the thickness is more than 150 μm, the handling property of the agricultural film is lowered, Work can be difficult.

The agricultural film may have a near ultraviolet region average transmittance of 280 to 380 nm of 10% or less and an average transmittance of light of a wavelength region of 380 to 400 nm of 50% or more. INDUSTRIAL APPLICABILITY The agricultural film of the present invention provides a practical agricultural film excellent in transparency without bleeding out to the resin surface, good in light transmittance, and particularly excellent in weatherability in an acid condition.

The agricultural film of the present invention may be a tubular film process, a T-die process, a calendar process or the like, and more preferably a tubular film process, film process according to the present invention.

The agricultural film may be formed of three layers including an outer layer, an intermediate layer and an inner layer. In the three-layer co-extrusion method according to the infiltration method, the resin compositions for the outer layer (A), the intermediate layer (B) and the inner layer (C) are supplied to three extruders and melt- kneaded in each extruder, A resin composition in a molten state is supplied to a circulative die, and a compressed air is supplied from a circulation die to a cylindrical shape at the same time of co-extrusion molding and a compressed air is supplied from the center of the circular die. A long cylindrical film can be wound and taken out. (MFR) of 0.8 to 2.5 g / 10 min and a density (MFR) of 0.8 to 2.5 g / 10 min can be supplied to the extruder for the intermediate layer (B) density low density polyethylene (LLDPE), low density metallocene polyethylene (M-LDPE), and ethylene vinyl acetate copolymer having a density of 0.917 to 0.925 g / cm 3. If the melt index (MFR) is less than 0.8 g / 10 min, the molding stability of the agricultural film may deteriorate, and if it exceeds 2.5 g / 10 min, the mechanical strength of the agricultural film may be lowered. If the density is less than 0.917 g / cm 3, the molding stability of the agricultural film may be deteriorated. If it exceeds 0.925 g / cm 3, the tear strength of the agricultural film may be lowered.

The inner layer (C) may be used alone or in combination with a linear low density polyethylene (LLDPE) in consideration of anti-fogging properties and flexibility, more preferably ethylene vinyl acetate ) Copolymer may be used alone.

The ethylene vinyl acetate copolymer used in the outer layer (A), the intermediate layer (B) and the inner layer (C) of the film may have a melt index (MFR) of 0.5 to 4.0 g / the content of the vinyl acetate component may be 5 to 20% by weight, and more preferably 12 to 15% by weight. When the content of the vinyl acetate component in the ethylene vinyl acetate copolymer is less than 5% by weight, the flexibility is lowered and the generation of fine cracks on the surface of the agricultural film can not be prevented, If it exceeds 20% by weight, blocking of agricultural film may easily occur.

Although the thickness ratio of the outer layer A, the intermediate layer B and the inner layer C is not limited, the composition ratio of the film is 1: 2: 1 in consideration of the flexibility, tensile strength, tear strength, light transmittance, 1: 3: 1, and 1: 4: 1 are preferable.

The thickness of the intermediate layer may be 50 to 90% of the total thickness of the agricultural film. If the ratio of the thickness of the intermediate layer to the total thickness of the agricultural film is less than 50%, the mechanical strength and weather resistance may be significantly deteriorated. If the ratio exceeds 90%, the surface of the agricultural film may be cracked due to ultraviolet rays or moisture. (Crack) may occur. When a crack occurs on the surface of an agricultural film, an acidic substance such as sulfur or a lime-sulfur mixture or an alkaline substance, which is sprayed as pesticide through the crack penetrates with moisture It is possible to remarkably accelerate degradation of the physical properties of the agricultural film.

Hereinafter, the present invention will be described in more detail with reference to examples. It is to be understood that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention, and it is to be understood by those skilled in the art that the present invention is not limited thereto It will be obvious.

≪ Example 1 >

The first extruder outer layer (A) was coated with 100 parts by weight of LG Chem SEETEC S318 linear low density polyethylene (LLDPE) (density: 0.918-0.922g / cm3, MFR: 0.8-1.2g / 10min) particale size) a nano (nano) qualified Croda Chemical company Solasorb (plastic uv protection) product Solasorb100 titanium dioxide (TiO _2), Croda Chemical company Solasorb 5 parts by weight for 200 of zinc oxide (ZnO _2), respectively, of 2-10-50nm (2'-hydroxy-5'-methylphenylbenzotriazole, 2.5 parts by weight as a light stabilizer, hindered amine compound Ciba Specialty Chemical Company, , Trade name: TINUVIN NOR 371, number average molecular weight: 3200)

2.5 parts by weight of a phenol-based sulfurizing agent was used as an oxidant inhibitor. Ethylene vinyl acetate copolymer (density: 0.931 g / cm3, MFR: (Density: 0.918 g / 10 min., Vinyl acetate content 12%, product of Hanwha Petrochemical 2050), Daerim Petrochemical Metolocene linear low density polyethylene (M-LLDPE) XP- cm3 and a melt index (MFR) of 1.5 g / 10 min) were fed into a first extruder

100 parts by weight of a Daerim Petrochemical XP-9200 meta rosene linear low density polyethylene (M-LLDPE) copolymer (density: 0.918 g / cm3, MFR: 1.5 g / 10 min) 18 parts by weight of a 2050 ethylene vinyl acetate copolymer (density: 0.931 g / cm3, MFR: 0.8 g / 10 min, vinyl acetate content: 12%) were mixed with a mixing extruder Lt; / RTI >

Ethylene vinyl acetate copolymer (density: 0.929 g / cm 3, MFR: 0.8 g / 10 min) was added to the third extruder inner layer (C) %), 1.7 parts by weight of an antifogging agent polyglycerol ester and ethoxylated sorbitan ester, respectively. The remainder was added with 63 parts by weight of 2050 ethylene vinyl acetate copolymer (density: 0.931 g / cm 3, MFR: 0.8 g / 10 min vinyl acetate content 12%)

The first to third extruders were all connected, melted and kneaded, and then pushed onto a die. Three layers of co-extrusion molding were conducted by a tubular film process so that the thickness ratio between the A, B and C layers was 1: 4: An agricultural film having a size of 150 mu m was obtained.

≪ Example 2 >

Layer was coextruded with a tubular film process so that the thickness ratio was 1: 3: 1.

≪ Example 3 >

Except that a three layer co-extrusion molding was carried out by an inflation method (tubular film process) such that the thickness ratio was 1: 2: 1.

<Example 4>

The procedure of Example 1 was repeated except that 2.5 parts by weight of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) were added to the first extruder outer layer (A).

&Lt; Example 5 >

Layer was coextruded in a tubular film process so that the thickness ratio was 1: 3: 1.

&Lt; Example 6 >

Layer was co-extruded in a tubular film process so that the thickness ratio was 1: 2: 1.

&Lt; Example 7 >

(LLDPE) (density: 0.918-0.922) was used instead of Daelim Petrochemical Metolose Linear Low Density Polyethylene (M-LLDPE) XP-9200 copolymer in the first extruder outer layer (A) g / cm &lt; 3 &gt;, and a melt index (MFR) of 0.8-1.2 g / 10 min) were further added.

&Lt; Example 8 >

An ethylene vinyl acetate copolymer (density: 0.931 g / m &lt; 2 &gt;) was prepared in the same manner as in Example 1 except that Daelim Petrochemical Metolose Linear Low Density Polyethylene (M-LLDPE) XP- cm3, a melt index (MFR) of 0.8 g / 10 min, a vinyl acetate content of 12%, Hanwha Petrochemical 2050) was further added.

&Lt; Example 9 >

The procedure of Example 1 was repeated except that the particle size of titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) was 1 to 5 μm in the first extruder outer layer (A).

&Lt; Comparative Example 1 &

Except that titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) were not contained in the first extruder outer layer (A).

&Lt; Comparative Example 2 &

(TiO ₂ ) and zinc oxide (ZnO ₂ ) were not contained in the first extruder outer layer (A), and as a light stabilizer, a hindered amine compound (trade name: TINUVIN NOR 371, number average Except that a hindered amine compound (trade name: CHIMASSORB 944, number-average molecular weight: 2000) was used in place of the polyether-modified polyolefin resin (MW: 3200).

&Lt; Comparative Example 3 &

Except that titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) are not included in the first extruder outer layer (A) and the hindered amine compound is not included as a light stabilizer. Was prepared in the same manner as in Example 1.

&Lt; Comparative Example 4 &

The third extruder inner layer (C) was produced in the same manner as in Comparative Example 3, except that the extruder inner layer (C) was the same as in Example 9.

&Lt; Comparative Example 5 &

Except that 10 parts by weight of titanium dioxide (TiO ₂ ) was contained in the first extruder outer layer (A), and zinc oxide (ZnO ₂ ) was not included.

&Lt; Comparative Example 6 >

Except that 10 parts by weight of zinc oxide (ZnO ₂ ) was contained in the first extruder outer layer (A), and titanium dioxide (TiO ₂ ) was not included.

&Lt; Comparative Example 7 &

Except that aluminum oxide (Al ₂ O ₃ ) was used instead of zinc oxide (ZnO ₂ ) in the first extruder outer layer (A).

<Experimental Example>

1. Sunscreen persistence

The average transmittance of the total light at a wavelength of 300 to 380 nm was measured with a spectral photometer U3500 by using a multilayer film obtained by three-layer inflation molding.

5% or less:?, 5 - 10%: O, 10% or more: X

Ultraviolet cut persistence in ultraviolet (280-3800 nm) Example 1 ◎ Example 2 ◎ Example 3 ◎ Example 4 ◎ Example 5 ◎ Example 6 ◎ Example 7 ◎ Example 8 ◎ Example 9 ○ Comparative Example 1 × Comparative Example 2 × Comparative Example 3 × Comparative Example 4 × Comparative Example 5 ○ Comparative Example 6 × Comparative Example 7 ○

As can be seen from Table 1, Examples 1 to 9 containing titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) were superior to those of Comparative Examples 1 to 7 in terms of persistence of ultraviolet blocking. When titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) are not contained or only titanium dioxide (TiO ₂ ) alone or zinc oxide (ZnO ₂ ) alone is contained, the ultraviolet blocking persistence is remarkably lowered, Also, when titanium oxide (TiO ₂ ) is mixed with aluminum oxide (Al ₂ O ₃ ), the ultraviolet shielding effect is also lowered and the effect of ultraviolet shielding is improved by mixing titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) Able to know.

Further, the nano titanium dioxide (TiO ₂₎ and zinc oxide (ZnO ₂₎ 1 to titanium dioxide of 5um (TiO ₂₎ and zinc oxide-described titanium dioxide nano than Example 9 mixed with (ZnO ₂₎ instead of (TiO ₂ ) And zinc oxide (ZnO ₂ ) were mixed in Examples 1 to 8, respectively.

2. Influence of ultraviolet (UV) exposure on absorbent

The film was exposed to a weather resistance tester (manufactured by The Q-PANEL COMPANY) for 1000 hours, and the discoloration degree, degree of degradation and degree of oxidation of the film were measured.

Decolorization, Degradation, Oxidation degree 5% or less: ◎

Degree of discoloration, degeneration, oxidation 10-15% or less: ○

Degradation, Degradation, Degree of oxidation 45-50% or more: ×

Degree of oxidation of film discoloration and degradation at 300 - 380 nm Example 1 ◎ Example 2 ◎ Example 3 ◎ Example 4 ◎ Example 5 ◎ Example 6 ◎ Example 7 ◎ Example 8 ◎ Example 9 ○ Comparative Example 1 ○ Comparative Example 2 × Comparative Example 3 ○ Comparative Example 4 × Comparative Example 5 × Comparative Example 6 ○ Comparative Example 7 ×

_{The thickness of the film was 150 mu m, UV 광도도 Comparative experiment in}

As can be seen from Table 2, when titanium dioxide (TiO ₂ ) and zinc oxide (ZnO ₂ ) are not contained or only titanium dioxide (TiO ₂ ) alone or zinc oxide (ZnO ₂ ) discoloration of titanium when compared to the (TiO ₂₎ when a mixture of aluminum oxide (Al ₂ O ₃₎ in hayeoteul mixing titanium dioxide (TiO ₂₎ and zinc oxide (ZnO ₂₎ film also, degradation degree, that even a low oxidation appear.

Further, the nano titanium dioxide (TiO ₂₎ and zinc oxide (ZnO ₂₎ 1 to titanium dioxide of 5um (TiO ₂₎ and zinc oxide-described titanium dioxide nano than Example 9 mixed with (ZnO ₂₎ instead of (TiO ₂ ) And zinc oxide (ZnO ₂ ) were mixed, the discoloration degree, degree of degradation and degree of oxidation of the films were low.

3. Thermal insulation

The average temperature and humidity were measured at 30 minute intervals.

Insulation Temperature

Film type House temperature Average Weekly (08-18 hours) Night (18-07 hours) General film 10.1b ^z 23.2b 0.9b Example 1 11.6a 24.4a 1.4a Example 2 11.5a 24.4a 1.6a Example 3 11.2a 24.2a 1.5a Example 4 12.4a 24.9a 1.9a Example 5 12.2a 24.8a 1.9a Example 6 11.8a 24.6a 1.8a Example 7 11.2a 24.2a 1.6a Example 8 12.5a 25.1a 1.9a Example 9 11.6a 24.3a 1.8a Comparative Example 1 11.7a 24.6a 1.8a Comparative Example 2 11.0a 23.9a 1.5a Comparative Example 3 11.2a 24.2a 1.6a Comparative Example 4 11.6a 24.7a 1.9a Comparative Example 5 11.6a 24.6a 1.8a Comparative Example 6 11.3a 24.7a 1.9a Comparative Example 7 11.7a 24.3a 1.8a

_{z DMRT  .05 * Temperature and humidity survey period: '11. 3. 8 ~ 3. 14 (7 days), every 30 minutes Data  Save}

4. Transparency

The haze value of the agricultural film immediately after the production was measured in accordance with the haze meter &quot; MDH2000 &quot;, and the transparency was evaluated according to the following criteria.

?: Haze value was less than 10%.

?: Haze value was not less than 10% and less than 15%.

X: Haze value was 20% or more.

Haze less than 15% Has a haze value of more than 15% and less than 25% Greater than 25% haze Example 1 ○ Example 2 ○ Example 3 ○ Example 4 ◎ Example 5 ◎ Example 6 ◎ Example 7 ○ Example 8 ◎ Example 9 ○ Comparative Example 1 ◎ Comparative Example 2 ○ Comparative Example 3 ○ Comparative Example 4 ◎ Comparative Example 5 ◎ Comparative Example 6 ◎ Comparative Example 7 ◎

5. Blocking

10 sheets of test pieces of 10 cm in length and 10 cm in length were cut from the agricultural film, and 10 sheets of superposed test pieces were placed in a 60 ° C oven for 6 hours. After a lapse of 6 hours time course, the laminated sheet was taken out from the oven and the state of the laminated sheet was judged based on the following criteria.

?: The test pieces were easily peeled off without fusion.

B: Some test pieces were welded together.

X: Most of the test pieces were welded together.

No fusing between test specimens; ○ Some of the specimens were fusion-bonded: Most of the specimens are welded together: x Example 1 ○ Example 2 ○ Example 3 ○ Example 4 ○ Example 5 ○ Example 6 ○ Example 7 ○ Example 8 ○ Example 9 ○ Comparative Example 1 ○ Comparative Example 2 ○ Comparative Example 3 ○ Comparative Example 4 ○ Comparative Example 5 ○ Comparative Example 6 ○ Comparative Example 7 ○

As can be seen from Tables 3 to 5, Examples 1 to 9 show excellent values of transparency, warmth, and blocking properties without deteriorating the UV-shielding effect as well as the UV-absorbing agent.

Claims (11)

0.5 to 5.0 parts by weight of titanium dioxide (TiO ₂ ) and 0.5 to 5.0 parts by weight of zinc oxide (ZnO ₂ ) relative to 100 parts by weight of the thermoplastic resin,
The mixed weight ratio of the titanium dioxide (TiO ₂ ) and the zinc oxide (ZnO ₂ ) is 4: 6 to 6: 4, and the average particle diameter of the titanium dioxide (TiO ₂ ) and the zinc oxide (ZnO ₂ ) is 10 to 50 nm ,
The thermoplastic resin may be at least one selected from the group consisting of linear low density polyethylene (LLDPE), linear ultra low density polyethylene (VLLDPE), metallocene linear low density polyethylene (M-LLDPE), and ethylene vinyl acetate Including,
A benzotriazole-based or benzophenone-based organic ultraviolet absorber, a light stabilizer, and an antioxidant. delete delete delete The agricultural film composition according to claim 1, which comprises 0.5 to 10.0 parts by weight of an organic ultraviolet absorber based on 100 parts by weight of the thermoplastic resin. The agricultural film composition according to claim 1, wherein 0.5 to 10.0 parts by weight of a light stabilizer and 0.5 to 10.0 parts by weight of an antioxidant are added to 100 parts by weight of the thermoplastic resin. An outer layer, an intermediate layer and an inner layer, and the outer layer comprises the agricultural film composition according to any one of claims 1 to 5 and has a thickness of 70 to 150 탆,
Wherein the thickness of the intermediate layer is 50 to 90% of the entire agricultural film. delete delete delete The agricultural film according to claim 7, wherein the agricultural film has an average wavelength transmittance of 280 to 380 nm of 10% or less and an average transmittance of 380 to 400 nm of wavelength region of 50% or more.

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