KR830002435B1 - Agricultural Film Manufacturing Method - Google Patents

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Description

Agricultural Film Manufacturing Method

The present invention relates to an infrared radiation sustaining property and transparency and abrasion resistance improved from the olefin, and particularly relates to a method for producing an agricultural plastic film that does not transmit infrared light but transmits visible light. The production method includes a composition comprising 100 parts by weight of olefin resin (A), at least one oxide of a metal in Groups 2, 3 and 4 of the periodic table, and 2-25 parts by weight of an acid ash compound (B) of SiO ₂ . and the ratio of the refractive index ⁽ⁿ a) of the olefin resin, the refractive index ⁽ⁿ B) for the oxide-based compound (a ⁿ / B ^n), characterized in that molded to be in the range of 0.99 to 1.02 in film.

As a conventional covering material used for silver thread or greenhouse cultivation tunnel, polyolefin resin film such as polyvinyl chloride film, polyethylene film, and copolymer film of ethylene and vinyl acetate are mainly used. Among these films, polyvinyl chloride films have been widely used in recent years because they have infrared radiation sustaining properties and are excellent in transparency, traction and durability. In using this film, however, the plasticizer contained in the film seeps out to the surface, and the film surface becomes tacky. As a result, dust adheres to the surface and greatly reduces the light transmittance, so that the greenhouse temperature does not rise. Therefore, the growth of crops is unnecessarily adversely affected. Furthermore, treating the film as a waste after use is difficult because it releases hydrogen chloride gas when the film is incinerated. Moreover, polyvinyl chloride film loses its flexibility at low temperatures, and thus its impact resistance is poor, thereby making it undurable in cold fat.

On the other hand, since the olefin resin film does not contain a plasticizer and the chemical structure is stable, there is almost no change in light transmittance over a long period of time and no harmful gas is emitted even when incinerated. The olefin resin film is superior to the polyvinyl chloride film in this respect, but inferior in infrared radiation sustainability. This is the reason why the olefin resin film is not used as a coating material for greenhouse even if it is translucent for a long time.

In recent years, the copolymer film of ethylene and vinyl acetate, which is one of the olefin resin films, has attracted attention as an agricultural coating material because of its transparency, flexibility and cold resistance. However, this is worse than polyvinyl chloride film in terms of infrared radiation persistence and abrasion resistance as previously described. Strictly speaking, when it is ventilated or the wind continues to open and close, it is destroyed by wear on the pipe parts and fixtures of the pipe-assembled greenhouse.

In general, the sustained infrared radiation of the coating material for greenhouse refers to the property that the greenhouse temperature does not decrease at night. During the day, greenhouse temperatures absorb heat from daylight and emit heat as radiant heat at night, so greenhouse temperatures are always higher than in the atmosphere. If the covering film is transmitted through the soil from the surface of the radiation is large, the radiation will go out from the greenhouse to reduce the soil temperature, resulting in a higher greenhouse temperature than the public. Therefore, the degree of infrared radiation persistence of the coated film depends on the degree of absorption or reflection of the film. The greater the extent, the better the infrared radiation sustainability.

In addition, the greenhouse coating film should have a property of preventing the accumulation of water droplets. This property refers to a property that vapors condense on the inner surface of the film in the greenhouse so that water droplets produced do not collect.

Since the olefin resin film has poor wettability to water, the film suggests that its property is bad. For this reason, in order to improve the wettability of the film, a wetting agent (fog drop preventing agent) or the like is added, but it is insufficient, and the wetting agent penetrates to the film surface remarkably to reduce the light transmittance of the film. Therefore, a film having good characteristics for avoiding collecting water droplets has not been developed until now. As a coating film made of an olefin resin having improved infrared radiation sustainability, a composition in which an inorganic filler (eg SiO ₂ , dehydrated kaolinite) is bound to an olepin resin is known. However, even though it improves the sustained infrared radiation of olefin resin film, it is insufficient compared to polyvinyl chloride film, and the most serious problem for this film is the transparency, especially the light transmittance to the parallel light of the film. This is worse than that of the polyvinyl chloride film and the copolymer film made of methylene / vinyl acetate, but the reason can be considered as follows. In other words, since there is a big difference in the refractive index between the filler and the olefin resin, light is scattered at the interface between the resin and the resin and the filler, and thus the light transmittance to parallel rays is reduced, and moreover, a common method [eg, T-die (T In the case of producing an olefin resin film by the molding method and the expansion method, the surface of the film tends to be uneven due to the inorganic filler added when the molten resin extruded from the die is removed while being cooled and solidified.

Generally speaking, agricultural coating film should transmit more than 80-85% of incident light, that is, the total light transmittance of this film should be more than 80-85%. However, even if the total dose is satisfactory, crop growth is greatly affected by the parallel or scattered rays through which the film is projected. For example, in recent years the following points have become increasingly clear. In general, parallel rays are good for the growth of general fruits, including summer crops (eg tomatoes, cucumbers, watermelons), while scattered rays pose problems for fruit growth and pigmentation, but edible herbs (eg lettuce, cabbage). Rather seedlings and rice growth is rather good because it promotes the growth of leaves. Rather, farmers often use transparent polyvinyl chloride films that transmit the parallel rays well for the cultivation of fruits and edible herbs other than rice. This is because the growth of crops in the greenhouse is clearly visible from the outside.

For the reasons mentioned so far, conventional methods for improving the infrared radiation persistence of polyolefin films by adding special inorganic fillers to polyolefins, although previously proposed, have not been generally used.

In order to solve this problem in recent years, by adding a special high molecular weight compound such as polyacetal to the polyolefin to improve the light transmittance of parallel light and to improve the infrared radiation persistence, it is still insufficient to improve the infrared radiation persistence. It is.

As a result of thorough research, the inventors of the present invention have been able to produce agricultural olefin films at low prices, without the drawbacks of conventional olefin resin films as an agricultural plastic film, and having infrared radiation sustainability, parallel light transmission and abrasion resistance, and no water droplet generation. . As a result, an olefin resin film was produced by molding an oxide compound powder and a composition using an olefin resin having a refractive index substantially the same as that of the olefin resin in the film.

The primary feature of the present invention is that polyvinyl chloride is significantly reduced in opacity by preventing light scattering at the interface between the resin and the filler by adding a filler having the same refractive index as that of the olefin resin even if the inorganic filler is added to the olefin resin. The transparent olefin resin film which is excellent in the light transmittance of parallel rays is improved by improving the poor infrared radiation persistence which a conventional polyolefin film has compared with the infrared radiation persistence of a film.

As a secondary feature of the present invention, an olefin resin film having a significantly improved performance can be manufactured at a price not much different from that of a conventional agricultural olefin resin film. Since it can be produced by a conventional method, it can be secured at a low price. The conventional method can be applied as it is by adding this compound to an olefin resin together with other additives used in the manufacture of conventional agricultural plastic films. This is because there is a point and film forming is easy.

The third feature of the present invention is that it is easy to incinerate the composition according to the present invention and does not release harmful gases such as hydrogen chloride even upon incineration, so that the composition according to the present invention mainly composed of olefins is easy to be disposed of after use.

These features are advantages of the present invention over conventional methods. The details of the present invention are as follows.

As the olefin resin (a) used in the present invention, a homopolymer of α-olefin, a copolymer of α-olefin (main component) and other units (e.g. polyethylene, polypropylene, copolymer of ethylene / propylene, ethylene / butene Copolymers of ethylene / 4-methyl-1-pentene, copolymers of ethylene / vinyl acetate and copolymers of ethylene / acrylic acid, among these polymers, transparency required as an agricultural plastic film, the gritty consideration of the weather resistance and the density value (20 ℃) is 0.910-0.935g / cm ³ of a copolymer of polyethylene or methylene / α- olefin may be a density of 0.918-0.928g / cm ^3, a density (20 ℃) In the copolymer of ethylene / vinyl acetate having a content of 0.918-0.962 g / cm ³ , the density is 0.920-0.950 g / cm ^{3 and} preferably contains about 30 wt.% Of vinyl acetate. A set of ones of a vinyl acid containing 5-25wt.%, Especially the ones that need in the transparency, flexibility and weather resistance.

The method for producing a copolymer of polyethylene and ethylene / α-olefin is not particularly limited and may be used in the present invention as long as it is a polymer made by any one of the conventional high pressure, medium pressure and low pressure methods. The melt index of these olefin resins is not particularly limited and may be in a range generally used in film processing. In particular, it is preferable to use a melt index of 0.1-10 g / 10 min, and more preferably 0.5-7 g / 10 min. This melt index is the value measured by the method of ASTMD 1238-73E.

The oxide compound used in the present invention is composed of at least one of oxides of metals belonging to Groups 2, 3 and 4 in the periodic table and SiO ₂ and is represented by the following chemical formula.

_{(SiO 2) x · (MαOβ} ) y · nH 2 O or _{(SiO 2) x · (MαOβ} ) y · (RγOδ) z · nH 2 O

In the above formula, M and R are metals belonging to group 2, 3, and 4, respectively, in the periodicity, α and γ are 1 or 2, β and δ are each an integer of 1-3, n is 0 or positive, x, y And z are both positive values determined accordingly to the refractive index of the oxide compound as close to the olefin resin as possible according to the gist of the present invention.

Within the spirit and scope of the present invention, the oxide has the following formula,

(SiO ₂ ) _x (M ¹ αOβ) _y1 (M ² αOβ) _y2 . … … … (M ^m αOβ) _ym ⁿ H ₂ O

It may also contain small amounts of impurities such as other metal oxides. Examples of such metal elements are B, Be, Mg, Ca, Ba, Al, Zn, Ti, Zr, Pb and S _n . Among these elements, Al, Ti, Mg, and Ca are particularly easy to control in terms of refractive index and price, and can be suitably used.

In general, the refractive index of the olefin resin used in the present invention is in the range of 1.48-1.52. As an example of an oxide exhibiting fusion that is as close as possible to the above, there is aluminum silicate having the formula:

_{(SiO 2) x · (Al} 2 O 3) y · nH 2 O

y/x

1에서 0.01

y/x

0.43인 것이 좋고 또한 n은 0 또는 양수로서 y가 1일때 40이하의 양수인 것이 좋다.In the above equation, x and y are positive numbers that satisfy the following conditions. 0.05

y / x

1 to 0.01

y / x

It is preferable that it is 0.43 and n is 0 or a positive number, and when y is 1, it is good that it is a positive number of 40 or less.

y/x

0.34에서 0.05

y/x

0.18인 것이 좋고 또한 n은 1 또는 양수로서 y가 1일때 150이하의 양수인 것이 좋다. 산화물에 속하는 것중 규산마그네슘의 예로서는(SiO₂)_x·(MgO)_y·nH₂O의 화학식을 가진 것이있는데 x와 y는 다음의 조건을 만족시키는 양수들이다. 즉 0.025

y/x

0.5에서 0.1

y/x

0.33인 것이 좋고 또한 n은 0 또는 양수로서 y가 1일때 30이하의 양수인 것이 좋다.Titanium silicate may be exemplified among the oxides, and the chemical formula is (SiO ₂ ) _x (TiO ₂ ) _y · nH ₂ O, where x and y are positive numbers satisfying the following conditions. 0.01

y / x

0.34 to 0.05

y / x

0.18 is preferable and n is 1 or a positive number, and when y is 1, it is preferable that it is a positive number of 150 or less. Examples of magnesium silicate belonging to the oxide include (SiO ₂ ) _x · (MgO) _y · nH ₂ O, where x and y are positive numbers satisfying the following conditions. 0.025

y / x

0.5 to 0.1

y / x

0.33 is good, and n is 0 or a positive number, and when y is 1, a positive number of 30 or less is preferable.

In the case of an oxide such as calcium silicate, the chemical formula (SiO ₂ ) _x (CaO) _y. NH ₂ O has the formula x and y are positive numbers satisfying the following conditions. That is, it is preferable that 0.05 = y / x = 0.35 to 0.08 = y / x = 0.21, and n is 0 or a positive number and a positive number of 40 or less when y is one.

Among these oxides, suitable for use in the present invention in transparency uses one or more as amorphous rather than crystalline.

ⁿA/ⁿB

1,02에서 0.995

ⁿA/ⁿB

1.01인 것이 좋다.ⁿA/ⁿB의 값이 위의 범위밖에 있게 되면 제조된 필름을 통과하는 평행광선의 투광도는 저하된다.In particular, the refractive index ( ⁿ A) of the olefin resin used in the present invention is measured by using a D-ray of a sodium lamp at a relative humidity of 65% at 25 ° C., so that the refractive index ( ⁿ B) of the oxide satisfies the following conditions. And measure. 0.99

ⁿ A / ⁿ B

1,02 to 0.995

ⁿ A / ⁿ B

1.01 is good. ^If the value of ⁿ A / ⁿ B is out of the above range, the light transmittance of parallel light passing through the produced film is lowered.

Considering the processability for oxides, anhydrides are much better than hydrated gels, but hydrated gels are much more desirable in terms of improving infrared radiation persistence, which is the object of the present invention. Especially hydrated gels with the ability to absorb large amounts of water are better. For example, a hydrated gel that can absorb more than 10wt% (usually 20wt% or more) of water at 25 ° C and 65% relative humidity is preferred. The reason why the infrared radiation persistence is improved is that the infrared light transmittance of the oxide itself is synergistically improved by infrared rays of moisture. Moreover, the effect of preventing the formation of water droplets on the film to which the absorbent hydrated gel is added. Therefore, the use of wetting agents commonly added to agricultural plastic films helps to maintain this effect, as these wetting agents are gradually released.

In general, hydrated gels are much more desirable than anhydrides for the above reasons, but anhydrides should be used considering that they improve the infrared radiation persistence to the extent required.

In view of the above, amorphous aluminum silicate gel having the following properties and compositions is particularly used in the present invention.

Molar ratio of Al ₂ O ₃ / SiO ₂ = 0.08-0.33 (preferably 0.15-0.25)

Water absorption at 25 ℃ and 65% RH: 10wt.% Or more (preferably 20wt.% Or more)

In the use of oxides, oxides in fine powder with an average particle size of 20 mu or less are required, but 10 mu or less is preferable. When an olefin resin film containing an oxide is used alone, the average particle size of the oxide should be 10 μm or less, and it is preferable to set it to 5 μm or less, and particularly suitable oxides have an average particle size of 3 μm or less and do not contain coarse particles of 10 μm or less. . When the average particle size is out of the above range, the film produced is uneven in surface and the properties of the film are degraded, resulting in poor light transmittance and appearance of parallel rays.

The mixing ratio of oxide to olefin resin depends on each example of the present invention and also on the degree of infrared radiation persistence required. However, generally 2-25 parts by weight based on 100 parts of the olefin resin of the oxide is preferably 3-15 parts by weight, more preferably 3-10 parts by weight. If the amount is 2 parts by weight or less, the effect of improving the infrared radiation persistence and preventing the generation of water droplets is not so small. When the amount is 25 parts by weight or more, the strength of the produced film is lowered. For example, when the olefin resin film according to the present invention is used alone, the addition of 3-10 parts by weight of oxide sufficiently improves the infrared radiation sustainability. On the other hand, when using an olefin resin film as a laminated film bonded to both sides of the resin film, it is necessary to appropriately adjust the amount within the above range according to the composition of the laminate and the required performance.

In carrying out the process of the present invention, the olefin resin and the oxide powder are mixed and pelletized by a general method using a roll mixer Banbury mixer or an extruder. Film processing temperature is usually 130˚-250 ℃. When the hydrated oxide absorbs water, the hydrated oxide is first dried and then put into processing.

When the olefin resin film containing the oxide according to the present invention is used alone, pellets are formed into a film using universal processing methods such as tubular processing, calendar ring, and T-die processing. In forming an olefin resin into a film, an oxide is effectively dispersed when a dispersant is added to the resin. The dispersant includes sorbitan fatty acid esters (e.g. sorbitan monostearate) and glycerin fatty acid esters (e.g. glycerin monostearate). The amount of the dispersant added is based on 100 parts by weight of the olefin resin (a). 0.2-2 weight part. It is also effective to add suitable stabilizers, ultraviolet absorbers, antistatic agents and wetting agents as necessary.

Furthermore, in the present invention, a film made of an olefin resin (a) to which an oxide is added is laminated on one or both sides (good on both sides) with a film of a lamination resin made of ionomer (C) or olefin resin (D). You can. In this case, the surface nonuniformity at the time of film forming is improved by laminating the resin film which does not add a filler to both surfaces or one side of the film made of olefin resin (A). As a result, the internal opacity is reduced to obtain a transparent film having a better parallel light beam. In addition, by laminating a resin film having excellent abrasion resistance without fillers on both or one side of the film made of an olefin resin (A), the wear resistance of the laminated surface can be further improved, and the traction property of the film is also improved to be comparable to that of a polyvinyl chloride film. .

Among the iono resins (C) for laminating a film made of an olefin resin (A) is a copolymer of α-olefin / α, β-unsaturated carboxylic acid having a structure in which metal ions are crosslinked. Commercially available resin, Surlyn (DuPont), uses this type of resin as ethylene for α-olefin and methacrylic acid for α, β-unsaturated carboxylic acid. 5 mol% and Na ⁺ or Zn ⁺⁺ is used as a metal ion. Ionomer resins suitable for use in the present invention are of Na ⁺ or Zn ⁺⁺ type having a density of 0.935-0.975 g / cm ³ and a melt index of 0.5-7 g / 10 min.

As the olefin resin (D) laminated on the film made of the olefin resin (A), an olefin resin used for the resin (A) is particularly preferred. Greenhouse cladding materials (e.g. films) are bands that hold the material to the frame due to repeated opening and closing operations during aeration or wind, or heat and sunlight generated during wear and the framework of the greenhouse (e.g. iron pipes, bamboo). Rubbing against) deteriorates and destroys them.

Therefore, as a material having good heat resistance and abrasion resistance and hardly generating heat during friction, an olefin resin (la) laminated on a film of resin (a) is suitable. For example, an ethylene / 2-olefin having a density of 0.910-0.935 g / cm ³ (preferably 0.918-0.933 g / cm ³ ) and a melt index of 0.1-4 g / 10 min (preferably 0.4-2 g / 10 min) Copolymers or polyethylenes are suitable.

The method for producing such polyethylene is not particularly limited, but the conventional method is much better because the ethylene / α-olefin copolymer made by the medium pressure method or the low pressure method has better heat resistance and durability than the polyethylene made by the high pressure method. In particular, copolymers of ethylene / butene, copolymers of ethylene / pentene, copolymers of ethylene / hexene, copolymers of ethylene / methyl-1-pentene and ethylene / octene made by low to medium pressure methods using transition metal catalysts Copolymers are preferred.

Furthermore, the copolymer of ethylene / vinyl acetate preferably has a vinyl acetate content of 20 wt.% Or less (preferably 10 wt.% Or less) and a melt index of 0.1-3 g / 10 min (preferably 0.1-1.5 g / 10 min).

In the copolymer of ethylene / acrylic acid, the content of acrylic acid in the copolymer is preferably 30 wt.% Or less but preferably 25 wt.% Or less.

In order to apply the film of the lamination resin made of ionomer resin (C) or the olefin resin (D) to the film of the olefin resin (A) containing an oxide, a conventional lamination method is used. For example, the film may be separately formed and laminated by dry lamination or heat lamination. An extrusion lamination is used to laminate the resin for lamination onto a film made of resin (a) containing an oxide, and the multi lamination film extrusion method is performed. The resin for lamination is molded into a laminated film. Of these methods, the last method is appropriate in terms of ease of molding, adhesive strength between layers, transparency, and production cost. In addition, to increase the width of the film for agriculture, it is necessary to use a multi-layer film extrusion method. When the laminated film is made into three layers, the resin of each outer layer of the laminated film should be different from each other. However, in order to consider the cost of the extruder, it is sufficient to use the same type of resin for general use.

The film thickness of the olefin resin (a) containing the oxide and the thickness of the layer of the resin (c) or (d) are determined depending on the end use and purpose. In general, however, the thickness of the resin (a) should be in the range of about 30-200μ even if it depends on the degree of infrared radiation persistence and the mixing ratio of oxide to olefin resin (a). On the other hand, in the thickness of the layer of resin (C) or (D), it is sufficient to make the thickness which can reduce internal opacity of a resin (A) film and improve abrasion resistance about 10-20 micrometers normally.

In the resin (C) or (D) layer of the laminated film thus prepared, as in the case of the resin (A) film, suitable stabilizers, ultraviolet absorbers, antistatic agents and, if necessary, water droplets can be prevented from occurring in the layer. It is effective to add additives.

In using the olefin resin film according to the present invention as a greenhouse coating film, there are advantages as follows. That is, the infrared radiation persistence of the film is greatly improved to be comparable to that of the polyvinyl chloride film, and has the same light transmittance as that of the polyvinyl chloride film, and light transmittance with little change over time than the polyvinyl chloride film. In addition, in view of improving the infrared radiation persistence by adding the organic premise, it has much better light transmittance of parallel rays than the conventional olefin resin film and has the same wear resistance and toughness as the polyvinyl chloride film. Therefore, the olefin resin film according to the present invention is extremely good to be used as an agricultural plastic film.

The present invention is described in detail according to the embodiment, it should be noted that the present invention is not limited to the embodiment.

The infrared radiation persistence shown in each example and the comparative example was measured as follows. In other words, using a test box (30cm × 30cm × 30cm) made of insulating film on one side and aluminum plate on the other side, put the block heated to 100 ℃ in this box and adjust the temperature change in the box. thermistor). The temperature difference (ΔT ° C.) obtained by subtracting the final measurement value from the previous measurement by using a test box using plate glass (a thickness of about 2 mm) instead of the test film was regarded as infrared radiation persistence.

Transparency was expressed by total transparency and internal opacity as a scale measured using a hazemeter according to JIS K6714.

The light transmittance of parallel rays was calculated | required using the following formula.

Transmittance of Parallel Rays = Total Transmittance-Internal Opacity

The refractive index of the inorganic powder was measured by immersion method, and the refractive index of the polymer film was measured using an Abbe's refracto-meter. Measurements were made using the D-ray of sodium lamps indoors maintained at 25 ° C. and 65% RH.

Wear resistance measurements were made as follows. In other words, the test film of known weight is attached to the circular part of the cylinder (200ømm) so as not to wrinkle, and it is vertically downward with respect to the film which adhered the surface polished well with # 180 sand paper of the iron ring-shaped rotor (100ømm). Press to press the film 20mm below the initial film position, pour water (20cc) on the film surface so that the temperature change is not severe during friction, and the time required to break the film by rotating the rotor at 240rpm 1 The degree of reduction in film weight per hour was measured.

The water droplet prevention test was performed as follows. That is, 100 cc of water (30 ° C.) was placed in a beaker, covered with a test film, and immersed in a constant temperature of use (30 ° C.) and placed in the sun. After a certain period of time was observed and the results are shown according to the following criteria.

○: No water droplets generated ×: Water droplets generated throughout

△: locally generated droplets

The method for synthesizing the oxide-based compound according to the present invention is not particularly limited and the characteristics of the oxide may be within the scope of the present invention.

The aluminum silicate gel used in the present invention can also be prepared by the following method. That is, distilled water (170kg) was put in a stainless steel reactor, and NaOH (28) was added to water glass (150kg, JIS No., 3rd grade) and 8% solution of aluminum sulfate (200kg) at a speed of 1.3-1.5kg / min. At the same time as stirring and dropping (滴加) to keep the temperature at 30 ℃.

The pH of the solution is maintained between 5-6 and after the addition is complete, the reaction solution is stirred for 1 hour under the same conditions to terminate the reaction. The prepared slurry is separated into a solid and a liquid by a centrifugal filter, and the water-soluble component is removed by repeatedly washing the solid portion with distilled water. Finally, the wet cake is dried at 120 ° C. for 24 hours to obtain an aluminum silicate gel having a chemical formula of Al ₂ O ₃ · (SiO ₂ ) _4.5 · nH ₂ O. The gel had a refractive index of 1.493 and an absorbed water content at 25 ° C. and 65% RH of 21%.

Example 1

100 parts by weight of copolymer of ethylene / vinyl acetate containing 15% by weight of vinyl acetate [melt index: 2 g / 10 min, refractive index (nA), 1.498]], aluminum silicate gel (refractive index (nB): 1.493, 25 ° C. and 65 Adsorption amount in% RH: 21%, Average particle size: 4μ, Al ₂ O ₃ 26wt.%, SiO ₂ 67%, Burning loss 7wt.% When dried for 2 hours at 150 ℃] 5 parts by weight and dispersant (glycerine Monostearate) 0.3 parts by weight was mixed at 150 ° C. for 8 minutes using a Brabender Plastograph, and then pressed at 170 ° C. to prepare a film having a thickness of 100 μm. The film prepared as shown in Table 1 was transparent, excellent in infrared radiation persistence, and free of water droplets.

Example 2

A copolymer of ethylene / vinyl acetate containing 25 wt.% Of vinyl acetate acetate [melt index: 2 g / 10 min, refractive index (nA): 1.489] is used instead of the copolymer of ethylene / vinyl acetate containing 15 wt.% Of vinyl acetate. It carried out similarly to the method of Example 1. In this manner, a film having a thickness of 100 µ was produced. The properties of the film were measured in the same manner and the results are shown in Table 1.

Example 3

Instead of the copolymer of ethylene / vinyl acetate, it carried out similarly to the method of Example 1 using the low density polyethylene [melt index: 1.8 g / 10min., Refractive index (nA): 1.515] of density 0.924. The properties of the thus produced film were measured in the same manner. The results are as in Table 1.

Example 4

It carried out similarly to the method of Example 1 except using 15 weight part of aluminum silicate gels. The properties of the produced film were measured in the same way. The results are as in Table 1.

Example 5

100 parts by weight of a copolymer of ethylene / vinyl acetate containing 15% by weight of vinyl acetate [refractive index (nA): 1.498], aluminum silicate [refractive index (nB): 1.494, 25 ° C. and 65% RH. , Average particle size: 3μ, (composition) SiO ₂ 72wt.%, Al ₂ O ₃ 27.5wt.%, Impurity 0.5wt.%] 5 parts by weight and 0.3 parts by weight of dispersant (glycerine monostearate) Brabender plastora After mixing at 150 ° C. for 8 hours using a raff, the film was pressurized at 170 ° C. to form a film having a thickness of 100 μ. The film was transparent with excellent infrared radiation persistence as shown in Table 1.

Example 6

Titanium silicate gel instead of aluminum silicate gel [refractive index (nB): 1.502, adsorption water at 25 ° C and 65% RH: 28%, average particle size: 4μ, (composition) TiO ₂ 13.7wt.%, SiO ₂ 82.5wt .%, Burn loss: 3.8 wt.%] Was carried out in the same manner as in Example 1. The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Example 7

In the same manner as in Example 1, except that calcium silicate gel (refractive index (nB): 1,501, 25 ° C and 65% RH of adsorption water amount: 26%, average particle size: 3.7 µ) was used instead of the aluminum silicate gel. Carried out. The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Example 8

The same procedure as in Example 1 was carried out except that magnesium silicate gel (refractive index (nB): 1.500, 25 ° C. and 65% RH adsorption amount: 29%, average particle size: 4 µ) was used instead of the aluminum silicate gel. . The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Comparative Example 1-3

In each case, it carried out like Example 1-3, without using an aluminum silicate gel. The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Comparative Example 4

The same procedure as in Example 1 was carried out except that silica gel [refractive index nB): 1.465, adsorption amount at 29 DEG C and 65% RH: 29%, average particle size: 4 µ was used instead of the aluminum silicate gel. The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Comparative Example 5

Instead of aluminum silicate gel, use anhydrous kaolinite [composition: Al ₂ O ₃ · 2 SiO ₂ · 2H ₂ O, refractive index: 1.560, 25 ° C. and 65% RH adsorption amount: 3.0%, average particle size: 4 μ] Other than the method of Example 1, it carried out similarly. The properties of the films thus prepared were measured in the same manner and the results are shown in Table 1.

Example 9

100 parts of copolymers of ethylene / vinyl acetate containing 15% by weight of vinyl acetate [melt index: 2 g / 10 min, refractive index (nA): 1.498], aluminum silicate gel (refractive index (n _B ): 1.493, 25 ° C. and 65% Adsorption amount at RH: 21%, average particle size: 4μ, (composition) (SiO ₂ ) _x · (Al ₂ O ₃ ) _y · nH ₂ O, y / x is 0.23, dried at 150 ° C. for 2 hours Composition of Al ₂ O 26wt.%, SiO ₂ 67wt.%, Burning loss: 7wt.%] 8 parts by weight and 0.3 parts by weight of a dispersant (glycerine monostearate) in a 5L Banbury mixer temperature of 130-150 ℃ After mixing for 10 minutes, the pellets were molded using an extruder. The resulting mixture is hereinafter referred to as filler mixed resin.

A multi-layered film production extruder equipped with a die for manufacturing a three-layer film (diameter: 150 mm) was used to prepare a three-layer transparent film having a sandwich structure. The intermediate channel of this die (temperature 190 ℃) was supplied with a filler mixture at a rate of 9kg / hr through a 40mm ø extruder, while the other channels and internal channels of this die (temperature 190 ℃) were extruded (melting zone: 215 ℃). Hi-milan 1650 (a copolymer of Zn-ion ethylene / methacrylic acid having a density of 0.95 and a molten resin of 1.5 as manufactured by Mitsui Polychemical Co.) was supplied at a rate of 4.2 kg / hr. The resin supplied to the film was loaded on the same die to form a three-layered sandwich-like film, the tube shape of which had a blow-up ratio of 2.4 and a distance of the front line. A three-layered transparent film with a sandwich structure, produced under conditions of 200 mm and take-off speed of 4.9 m / min [plane width of layer: 365 mm, thickness: 0.013 mm (inner layer), 0.05 mm (Middle layer) and 0.013 mm (outer layer)] were manufactured.

The resulting film was measured for infrared radiation persistence, total light transmittance, parallel light transmittance, internal opacity, tear strength, puncture impact strength, and wear resistance as shown in Table 2. In addition, the effect of inhibiting water droplet generation was measured, and even after 3 months, the effect was good.

Example 10

Instead of High Milan 1650, High Milan 1707 (density 0.95 g / cm ³ , melt index; 0.9 g / 10 min, copolymer of Na ion type ethylene / methacrylic acid) was introduced into the die through an extruder (melting zone: 220 ° C.). It carried out similarly to the method of Example 9 except having supplied to the channel and the external channel. The physical properties of the film thus prepared are shown in Table 2.

Example 11

Instead of High Milan 1650, Sumikaten F208-1 (Sumitomo Chemical Co., Ltd., a high-pressure low-density polyethylene with a density of 0.925 g / cm ³ and a melt index of 1.7 g / 10 min) was added to the extruder (melting zone: 173 ° C). A transparent film was prepared according to Example 9 except that the feed was supplied to the inner and outer channels of the die (temperature 168 ° C.). The physical properties of this film are shown in Table 2.

Example 12

Copolymer of ethylene / 4-methyl-1-pentene prepared using a Ziegler catalyst instead of High Milan 1650 (density 0.920 g / cm ³ , melt index: 2 g / 10 min, 4-methyl-1-pentene content: 9 wt. %) Was carried out in the same manner as in Example 9 except for supplying the inner and outer channels of the die (temperature: 168 ° C) through an extruder (melting zone: 175 ° C). Physical properties of the transparent film thus prepared are as shown in Table 2.

Example 13

Instead of High Milan 1650, a copolymer of ethylene / vinyl acetate (density 0.94 g / cm ³ , melt index: 0.6 g / 10 min, vinyl acetate content: 15 wt.%) Was passed through an extruder (melt zone: 175 ° C.) : 168 degreeC) It carried out similarly to the method of Example 9 except having supplied to the inner channel and the outer channel. The physical properties of the transparent film thus prepared are as shown in Table 2.

Example 15

Instead of High Milan 1650, a copolymer of ethylene / acrylic acid (melt index: 10g / 10min, acrylic acid content: 20wt.%) Was passed through an extruder (melt: 170 ° C) to the internal and external channels of the die (temperature: 168 ° C). It carried out similarly to the method of Example 9 except having supplied to. The physical properties of the transparent film thus prepared are as shown in Table 2.

Example 16

Aluminum silicate [refractive index (n _B ): 1.494, 25 ° C. and 65% RH adsorption amount: 3%, average particle size: 4 μ, (composition) Al instead of aluminum silica gel in the filler mixture supplied to the central channel _{. 2 O 3 27.5wt%, SiO} 2 72wt%, impurities:.. 0.5wt%] the composition was subjected to the method of example 9 except for applying using the same amount. The physical properties of the transparent film thus prepared are as shown in Table 2.

As a result of measuring the anti-droplet generation effect of this film, the effect after 3 months passed was slightly worse than the film produced in Example 9, and water droplets were locally produced.

Example 17

Titanium silicate gel [refractive index (n _B ): 1.502, adsorption at 25 ° C and 65% RH: 28%, average particle size: 4μ, instead of aluminum silica gel in the filler mixture supplied to the central channel (composition) TiO ₂ 13.7 wt.%, SiO ₂ 82.5 wt.%, And burning loss: 3.8 wt.%] Were added in the same manner as in Example 9 except that the same amount was used. The physical properties of the transparent film thus prepared are as shown in Table 2.

Example 18

Instead of a copolymer of ethylene / vinyl acetate, which is a basic resin to be supplied to the filler mixed resin supplied to the central channel, Sumikarenn F208-1 [High pressure polyethylene: density: 0.925 g / cm ³ , melt index: 1.7 g / 10 min, refractive index ( n _A ): 1.501], and the same Sumicaren F208-1 was used instead of High Milan to feed the inner and outer channels of the die channel: 168 ° C through an extruder (melting zone: 173 ° C). It carried out similarly to the method of Example 9. The physical properties of the transparent film thus prepared are as shown in Table 2.

Comparative Example 6

In the filler mixture used as an intermediate layer in Example 9, a copolymer of ethylene / vinyl acetate as a base resin was used as a 50 mm øextruder equipped with a helical die temperature of 180 ° C., a die temperature of 177 ° C., and a spiral die (diameter: 100 mm). It was molded into a tubular monolayer film through. The physical properties of the film prepared by withdrawing the monolayer film under the conditions of the blue-up ratio 2.4, the front line distance 200mm, and the take-off speed 5m / min are shown in Table 2.

Comparative Example 7

It carried out similarly to the method of Example 9 except having changed the addition amount of the aluminum silicate gel in the filler mixed resin used as an intermediate | middle layer to 5.4 weight part.

Comparative Example 8

Conducted except that the [4μ: 1.465, the adsorption quantity of from 25 ℃ and 65% RH:: 29%, average particle size, refractive index ⁽ⁿ B)] it was purified by silica gel in the same amount instead of the silicate of aluminum gel in the filler mixed resin used in the intermediate layer It carried out similarly to the method of Example 9. The physical properties of the opaque film thus prepared are shown in Table 2.

Comparative Example 9

It carried out similarly to the method of Example 11 except having used the high pressure polyethylene (density: 0.922 g / cm <^3> , melt index: 7g / 10min) instead of the polyethylene used for the outer layer and the inner layer. The physical properties of the transparent film thus prepared are as shown in Table 2.

Comparative Example 10

A copolymer of ethylene vinyl acetate having a vinyl acetate content of 17 wt.% (Density: 0.94 g / cm ³ , melt index: 3 g / 10 min) was used instead of the copolymer of ethylene and vinyl acetate used as the inner and outer layers. It carried out similarly to the method of Example 14. The physical properties of the transparent film thus prepared are as shown in Table 2.

Comparative Example 11

The physical properties of a commercially available agricultural polyvinyl chloride film (thickness: 0.075 mm) containing about 40% of plasticizer mainly composed of di-2-ethylhexyl phthalate were measured in the same manner as before. As shown.

TABLE 1

TABLE 2

Composition of film

Middle layer (0.05mm) Outer layer (0.013mm)

Table 2 (continued)

Physical properties of the film

(week)

EVA: Copolymer of ethylene / vinyl acetate

E B: Copolymer of ethylene / butene-1

LDPE: High Pressure Low Density Polyethylene

EAA: copolymer of ethylene / acrylic acid

EMP: copolymer of ethylene / 4-methyl-1-pentene

PHR: Addition amount (part by weight) based on 100 parts of basic resin

Claims (1)

Olefin Resin (A) The refractive index of the olefin resin in a composition consisting of at least one oxide of a metal in Groups 2, 3 and 4 of the periodic table and an acid ash compound (B) of ₂ to 25 parts by weight of SiO ₂ . (n _A ) Production of agricultural plastic film made of olefin resin film, characterized in that the ratio (n _A / n _B ) to the refractive index (n _B ) of the large oxide compound in the film to be in the range of 0.99-1.02 Way.