JPH06116404A - Agricultural film - Google Patents

Abstract

PURPOSE:To obtain an agricultural film suitable for use in house culture, tunnel culture and mulch culture, and high in moisture retention and excellent in heat resistance, impact resistance, tear resistance, piercing resistance, cold resistance, light transmission, friction resistance (prevention of surface coasening) and transparency. CONSTITUTION:A resin compsn. comprising 100 pts.wt. olefin resin (e.g. an ethylene-vinyl acetate copolymer having a melt index of 0.5 to 5g/10min and a vinyl acetate unit content of 10 to 15wt.%) and 1-20 pts.wt. anhydrous amorphous aluminosilicate is formed into an agricultural film. Alternatively, an ethylene-vinyl acetate copolymer, as both the outer layers, and a compsn. comprising ultralow-density ethylene-alpha-olefin copolymer and the above-mentioned aluminosilicate, as an interlayer, are formed into an agricultural laminated film by co-extrusion.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to agricultural films. More specifically, the present invention relates to a heat-retaining property, heat resistance, impact resistance, tear resistance, puncture resistance, excellent cold resistance, and an agricultural film characterized by being highly transparent, and a method for producing the same. The film of the present invention is used for greenhouse cultivation, tunnel cultivation, mulch cultivation and the like for the purpose of forcible cultivation for agriculture.

[0002]

2. Description of the Related Art Conventionally, as a film for agriculture for greenhouse cultivation, tunnel cultivation, etc., polyvinyl chloride is low in cost, has good handleability (workability), and is excellent in transparency, durability and heat retention. Films have been used. However, since this film contains a plasticizer, when it is used for a long period of time, bleeding occurs on the film surface, dust is adsorbed there, light transmission is reduced, and not only does it give a dirty feeling. However, if you try to incinerate it after use, hydrogen chloride gas may be generated, which may cause pollution problems.It is also vulnerable to puncture breaks by protrusions and friction breaks with house aggregates, and poor cold resistance. However, it often caused a problem depending on the usage conditions. On the other hand, polyolefin-based films are also used as agricultural films, but they do not have infrared absorption ability because they do not have polar groups in the molecule, and thus are emitted from plants and soil at night, in houses, tunnel houses. Since infrared energy is dissipated to the outside world and there is a defect that it does not retain heat, there is a need for improvement. On the other hand, many heat retaining agents have been proposed, for example, phosphate compounds (Japanese Patent Publication No. 47-926).
No. 0), silicon oxide (Japanese Patent Publication No. 47-13853), silica gel (Japanese Patent Publication No. 56-18141), particle size 100 μ.
m or less anhydrous silicon dioxide (Japanese Patent Publication No. 57-4666)
No.), barium sulfate (JP-A-59-22334), hydrotalcite (JP-B-62-31744), zeolite (JP-B-61-44092) and the like. However, these heat-retaining agents do not have sufficient heat-retaining properties or contain water of crystallization, so the film is ruptured due to the foaming phenomenon due to water during film formation, and the hardness is high in crystallinity. Or the mold is worn out, the dispersibility in polyolefin is poor, or it is colored,
There is an adverse effect that the light transmittance is low and the film becomes opaque, and further improvement has been desired.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an agricultural film which is sufficiently improved in heat retention of an olefin resin film and does not have various drawbacks as in the case where the conventional heat retention agent is added. An object is to provide a film and a manufacturing method thereof.

[0004]

Means for Solving the Problems The inventors of the present invention conducted experiments by adding a large number of inorganic compounds to polyolefin, and found that when a specific inorganic compound was added, an agricultural film having various excellent performances was obtained. Obtained, and select a specific one of the polyolefin, when blending this with the specific inorganic compound, and when the film has a specific configuration, it is possible to obtain an agricultural film of further excellent performance Then, the present invention has been completed.

That is, the present invention relates to an olefin resin 1
00 parts by weight and anhydrous amorphous aluminosilicate 1-2
The present invention relates to an agricultural film obtained by forming a resin composition comprising 0 parts by weight. The present invention also has a melt index of 0.
5-5g / 10 minutes, vinyl acetate content 10-15% by weight
The present invention relates to an agricultural film obtained by forming a resin composition comprising 100 parts by weight of the ethylene-vinyl acetate copolymer and 1 to 20 parts by weight of anhydrous amorphous aluminosilicate.
The present invention also has a melt index of 0.5 to 5 g / 1.
0 minutes, both outer layers of ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 15% by weight, and a density of 0.
910 g / ml or less, melting point 116 ° C. or more, 1% modulus 1200 kg / cm ² or less, n-hexane extract 10
Weight% or less, melt index 0.8 to 10 g / 10
Ultra low density ethylene-α-olefin copolymer 1
00 parts by weight and anhydrous amorphous aluminosilicate 1-2
A laminated film composed of 0 parts by weight of an intermediate layer, wherein the thickness of the intermediate layer occupies at least 35 to 90% of the total thickness of the laminated film, and the total thickness of the laminated film is 50 to 200 μm. It also relates to an agricultural laminated film, characterized in that Further, the present invention has a melt index of 0.5 to 5 g / 10 minutes and a vinyl acetate content of 5 to 1
Both outer layers consisting of 5 wt% ethylene-vinyl acetate copolymer, density 0.910 g / ml or less, melting point 116
℃ or more, 1% modulus 1200 kg / cm ² or less, n
-Extra low density ethylene having a hexane extract content of 10% by weight or less and a melt index of 0.8 to 10 g / 10 minutes-α-
The present invention relates to a method for producing an agricultural laminated film, which comprises producing 100 parts by weight of an olefin copolymer and an intermediate layer composed of 1 to 20 parts by weight of anhydrous amorphous aluminosilicate by a coextrusion method.

In the present invention, the olefin resin means
Homopolymer of ethylene, copolymer of ethylene and other α-olefin, copolymer of ethylene and vinyl acetate or ethyl acrylate, homopolymer of α-olefin other than ethylene, copolymerizable with α-olefin It means a copolymer with a vinyl monomer. Such olefin resins include, for example, high pressure low density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), high density polyethylene, medium density polyethylene, gas phase method. There are linear low-density polyethylene, vapor phase ultra-low-density polyethylene, ethylene-propylene rubber, ethylene-propylene-diene rubber, isobutylene-isoprene rubber, polypropylene, polybutene-1 and the like, and these may be used alone or in combination of two or more. You may use it.

[0007] In the present invention, anhydrous amorphous aluminosilicate is an acid and heat-treated product of zeolite substantially having a zeolite particle state. The zeolite as a raw material is such that the zeolite structure is decomposed by acid treatment, and in general, SiO ₂ / Al ₂
Zeolites having an O ₃ (molar ratio) of about 5 or less are preferred. Such zeolites include A-type zeolite, P
Type zeolite, X type zeolite, Y type zeolite, sodalite, analcime and the like are mentioned, and A type zeolite is particularly preferable. The acid treatment of zeolite is carried out by adding an acid or an acidic substance to an aqueous slurry of raw material zeolite to adjust the pH to a weak acidity of 4.5, preferably 5 to 7 even if the pH of the slurry is low. If the pH value of the zeolite slurry is less than 4.5, the particle state of the zeolite is significantly changed, or the entire particles are dissolved / disappeared and the skeleton of the raw material zeolite is destroyed, which is unsuitable. Is higher than 9, the degree of amorphization becomes insufficient. The acid treated amorphous aluminosilicate is then at least 200 ° C. or higher, preferably 2
It is substantially dehydrated in the temperature range of 50 to 500 ° C. to obtain anhydrous amorphous aluminosilicate. The average particle size of the anhydrous amorphous aluminosilicate is in the range of 0.5 to 5 μm, and the particle size portion within the range of 0.5 to 1.5 times the average particle size is 50% or more of the whole. It is preferable to have a particle size distribution, and the particle shape is preferably such that the particle surface is substantially spherical or has a rounded shape with no corners and is smooth. The anhydrous amorphous aluminosilicate in the present invention is clearly distinguished from the starting material zeolite by X-ray diffraction in terms of its physical properties. For example, the cation exchange ability peculiar to zeolite is substantially lost. Further, although a normal dried product retains water, it does not substantially condensate like zeolite when heated and dehydrated. In the present invention, "amorphous" means that no diffraction line is recognized from the diffraction pattern of X-ray diffraction,
It includes those in which the height of the diffraction line is reduced to ½ or less of that of zeolite and it is substantially amorphized. The anhydrous amorphous aluminosilicate of the present invention has a refractive index of 1.35 to 1.
Since it is adjusted to 53, which is close to the refractive index of the olefin resin, it has good light transmittance and does not impair the transparency of the film. In the present invention, the olefin resin 1
To 100 parts by weight of anhydrous amorphous aluminosilicate 1
A resin composition containing about 20 parts by weight is formed into an agricultural film. If the amount of anhydrous amorphous aluminosilicate is less than 1 part by weight, the heat retaining property is insufficient, and if it exceeds 20 parts by weight, the film forming property of the film is deteriorated, and the transparency and light transmittance of the obtained film are The mechanical strength is reduced, which is not desirable. Usually, when a heat retaining agent is added to a polyolefin-based resin, it is not desirable to add 15 parts by weight or more to reduce the mechanical strength of the film. Therefore, 15
When blending in an amount of at least parts by weight, it is desirable to use the above ultra-low density ethylene-α-olefin copolymer as the olefin resin.

In the present invention, ultra-low density ethylene-α-
Olefin copolymer (hereinafter also referred to as VLDPE)
Is a special polyethylene resin developed by Union Carbide Chemical and Plastics Company of the United States, to which the inventors of the present invention belong and which has a technical tie-up with Nippon Unicar Co., Ltd., which is the applicant of the present application. This is described in detail in Japanese Patent Publication No. 59-230011. The density of VLDPE used in the present invention is 0.910 g / ml or less, and if it exceeds this, the crystallinity increases and the transparency of the film deteriorates, which is not desirable. Further, the melting point of VLDPE is 116 ° C. or higher, and if it is lower than this, the heat resistance is insufficient and the mechanical strength is also insufficient. The 1% modulus of VLDPE is 12
It is less than 00 kg / cm ² , and if it exceeds this, the abrasion resistance is deteriorated. Furthermore, the n-hexane extractable content of VLDPE is 10% by weight or less, and if it exceeds this range, the low molecular weight polymer bleeds on the film surface, and dust adheres to it, which undesirably impairs the light transmittance. The melt index of VLDPE is 0.8 to 10 g / 10 minutes,
If it is less than 0.8 g / 10 minutes, the extrusion characteristics are poor, while on the other hand,
If it exceeds / 10 minutes, mechanical properties are deteriorated, which is not desirable.
In the present invention, the ultra-low density ethylene-α-olefin copolymer is the following continuous ethylene copolymer production method:
Temperature in the fluidized bed reaction zone is 10 to 80 ° C. and 7000 k
At a pressure of Pa or lower, (a) ethylene and at least one higher α having 3 to 8 carbon atoms, wherein the molar ratio of higher α-olefin: ethylene is 0.35: 1 to 8.0: 1.
A gas mixture containing an olefin and (b) at least 25 mol% of at least one diluent gas is represented by the formula: Mg _m Ti (OR) _n X _p [ED] _q , where R is a carbon atom. Represents an aliphatic or aromatic hydrocarbon group having 1 to 14 carbon atoms or a group COR ', R'represents an aliphatic or aromatic hydrocarbon group having 1 to 14 carbon atoms, X
Is selected from the group consisting of chlorine atom, bromine atom, iodine atom and mixtures thereof, and ED is an organic group selected from the group consisting of alkyl esters of aliphatic or aromatic acids, aliphatic ethers, cyclic ethers and aliphatic ketones. It represents an electron-donating compound, m is 0.5 to 56, n is 0, 1 or 2, p is 2 to 116, and q is 2 to 85. ) Is continuously contacted with particles of a catalyst system consisting of a precursor composition, said precursor composition is diluted with an inert carrier material and the following formula: Al (R ′) _d X ′ _e H _f (In the formula, X ′ represents a chlorine atom or a group OR ″, R ′ and R ″ represent a saturated hydrocarbon group having 1 to 14 carbon atoms, e is 0 to 1.5, and f is 0 or 1 and d
+ E + f = 3. ) Is completely activated with an organoaluminum compound represented by the formula (4), and the activation compound has a total aluminum: titanium molar ratio in the reaction zone of 10:
It is preferably produced by using an amount of 1 to 400: 1.

The ethylene-vinyl acetate copolymer (hereinafter also referred to as EVA) used in the present invention has a melt index of 0.5 to 5 g / 10 minutes, and a melt index of 0.5 g.
If it is less than / 10 minutes, the extrusion properties will be poor, and if it exceeds 5 g / 10 minutes, the mechanical properties will be poor, which is not desirable. The vinyl acetate content is usually 10 to 15% by weight.
If it is less than 15% by weight, the transparency of the film is deteriorated, and when the film is stretched as a tunnel house, the handleability of the film is deteriorated, and if it exceeds 15% by weight, the mechanical strength of the film is deteriorated, which is not preferable. .
Further, in the present invention, when EVA is used in combination with VLDPE to form a laminated film, EVA has a vinyl acetate content of 5
~ 15% by weight. This is because the laminated film has flexibility even when the vinyl acetate content is less than 10% by weight. Furthermore, the relationship between the melting point (MP, unit ° C) of EVA used in the present invention and the vinyl acetate content (VA, unit weight%) is represented by the following formula: MP = 114-1.44VA, and the molecular weight distribution (M It is particularly desirable that _w / M _n ) is less than 4, and those having this numerical range have a melting point of 2 to 2 as compared with EVA having the same vinyl acetate content outside the above range.
It is 5 ° C higher and has excellent heat resistance and mechanical strength.

In the case of a monolayer film, the agricultural film of the present invention can be produced by a conventional inflation method or the like,
Further, in the case of a three-layer film, it can be produced by a coextrusion molding machine using each resin composition for the intermediate layer and both outer layers, and in this case, for example, an inflation method using a circular die, a T-die method using a flat die, Applicable. The reason why a three-layer structure including an intermediate layer and both outer layers when VLDPE is used in combination in the present invention is described below. First, when VLDPE is used alone to form a film, the extrusion processability is poor, and even if it is extruded, melt fracture occurs, a film with a smooth surface cannot be obtained, and the produced film is severely blocked and difficult to handle. Met. If the present inventors use VLDPE as an intermediate layer and coextrude resin layers on both sides thereof, it is difficult to form a VL by itself.
It was found that DPE can be formed into a film, and this was adopted as the intermediate layer. Next, the specific EVA was adopted as both outer layers of the VLDPE intermediate layer because EVA is superior in transparency as compared with high-pressure low density polyethylene and the like.
However, in the case of EVA, the transparency and cold resistance increase as the vinyl acetate (VA) content increases, but the blocking property and mechanical properties deteriorate, so the above range was set.

The thickness of the film of the present invention is 50 to 200 μm in both single layer and laminated layers,
If it is less than m, the mechanical strength is insufficient, and it becomes difficult to handle the film. If it exceeds 200 μm, the quality is excessive and the economy is poor, which is not desirable. In the case of a laminated film, the ratio of the intermediate layer to the whole film, that is, the ratio of thickness is 35 to 90%, and when it is less than 35%, transparency, mechanical properties, cold resistance, abrasion resistance, and economy are obtained. When the content exceeds 90%, coextrusion becomes impossible. The thickness of each outer layer may be the same or different.

[0012]

The present invention will be described in more detail based on the following examples. Synthesis example (preparation of anhydrous amorphous aluminosilicate) 50 g of Na-A type zeolite was weighed in a 500 ml beaker, and 200 g of water was added to prepare a slurry having a zeolite concentration of 20%. The pH of this slurry was 11.
It was 7. 250% 4% sulfuric acid while stirring the slurry
g was gradually added over about 5 minutes, and after the addition was completed, the mixture was further stirred for 1 hour (during which the pH of the slurry was always kept at 4 or higher), followed by filtration, washing with water, drying and pulverization by a conventional method. , An acid-treated Na-A type zeolite was obtained. An X-ray diffraction (XRD) analysis of this acid-treated product confirmed that no diffraction peak was observed and the product was an amorphous aluminosilicate. Next, this acid-treated product was heat-treated at a temperature of about 300 ° C. for 2 hours for dehydration and pulverization to obtain anhydrous amorphous aluminosilicate. The average particle size is 2.9 μm, and the particle size distribution is 82.0% in the range of 0.5 to 1.5 times the average particle size, the Ca ion exchange capacity is 28.4 mgCaO / g, and the equilibrium pH is 8. .5, refractive index 1.39, the composition _{Na 2 O9.4%, Al 2 O} 3 4
It was 3.8%, SiO ₂ 45.0%, and H ₂ O 1.8%. The raw material Na-A type zeolite has an average particle size of 2.8 μm, and has a particle size distribution of 87.0% in the range of 0.5 to 1.5 times the average particle size. capacity 124.0mgCaO / g, the equilibrium pH 11.2, a refractive index of 1.46, the composition _{Na 2 O16.3%, Al 2 O} 3
The content was 27.8%, SiO ₂ 33.6%, and H ₂ O 22.4%.

Example 1 Melt index (MI) 2 g / 10 minutes, density 0.9
100 parts by weight of 20 g / ml high-pressure low-density polyethylene was treated with 7 parts by weight of anhydrous amorphous aluminosilicate prepared in the above Synthesis Example after treatment with sodium stearate and blended to obtain a film having a thickness of 50 μm by an inflation molding method. It was The visible light of the obtained film (wavelength 0.4 ~
0.7 μm) has a transmittance of 75% and infrared rays (wavelength 5 to 50).
(μm) has a transmittance of 15%, which shows that it has transparency and heat retention. Regarding the heat retaining property, when an agricultural tunnel was made with the above film and the internal temperature and the outside temperature of the tunnel were measured, they were 4.3 ° C. and −, respectively.
It was 1.8 ° C., and it was confirmed that there was sufficient heat retention.

Comparative Example 1 The same experiment as in Example 1 was carried out except that the raw material zeolite was used in place of the anhydrous amorphous aluminosilicate used in Example 1, and a film could be produced by the inflation method. could not. This is because the water content of the zeolite causes a foaming phenomenon in the film, and air is ejected from there to break the film.

Example 2 100 parts by weight of an ethylene-vinyl acetate copolymer having an MI of 3 g / 10 minutes and a vinyl acetate content of 13% by weight was treated with 15 parts by weight of anhydrous amorphous aluminosilicate prepared in the synthesis example with sodium stearate. After that, they were blended and a film having a thickness of 100 μm was obtained by a calendar method. The transmittance of visible light (wavelength 0.4 to 0.7 μm) of the obtained film was 63.
%, The transmittance of infrared rays (wavelength 5 to 50 μm) was 8%, the transparency was a little inferior to that of the film of Example 1, but sufficient, and it was shown that the heat retention property was very excellent.
Regarding the heat retention, an agricultural tunnel was made with the above film, and the internal temperature and the outside temperature of the tunnel were measured. The results were 5.4 ° C and -1.8 ° C, respectively, confirming that they have excellent heat retention. It was In addition, this film was as flexible as polyvinyl chloride, the workability of spreading the film was very good, and a labor saving effect was also recognized.

Comparative Example 2 The same experiment as in Example 2 was conducted except that the raw material zeolite was used in place of the anhydrous amorphous aluminosilicate used in Example 2, and a foaming phenomenon occurred on the film surface. The surface was rough and the light transmittance was poor, and the film was damaged in a short period of time due to friction with the metal support.

Example 3 An ethylene-vinyl acetate copolymer having an MI of 2 g / 10 min and a vinyl acetate content of 10% by weight was used as a raw material for both outer layers, and the density was 0.903 g / ml, the melting point was 117 ° C., and 1
100 parts by weight of an ethylene-hexene-1 copolymer having a% modulus of 950 kg / cm ² , an n-hexane extract content of 2.8% by weight, and an MI of ² g / 10 minutes, and an anhydrous amorphous aluminosilicate (stearic acid) prepared in a synthesis example. Treated with sodium) A resin composition containing 10 parts by weight is used as a raw material for the intermediate layer, and the die temperature is 210 ° C. by an inflation method.
The thickness of the intermediate layer is 80 μm, and the thickness of both outer layers is 10 μm.
A laminated film with a total thickness of 100 μm was produced. The tensile strength of the obtained film is 75 kg / c in the longitudinal direction.
m, 93 kg / cm in the lateral direction, which was sufficiently practical. Further, the haze (JIS K-6714) was 6.2, and the transparency was also high. Heat resistance is outside temperature 80 ° C (the temperature at which the film near the steel aggregate of a greenhouse for agriculture in summer is exposed)
Was determined by measuring the tensile strength in an environment of 38 kg /
It was cm ² , and the practicability was sufficient. Furthermore, an agricultural house was made from this film, and the heat retention was evaluated by measuring the internal temperature and the outside temperature of the house.
It was 2 degreeC and -1.8 degreeC, and it was confirmed that it has excellent heat retention.

Comparative Example 3 The same experiment as in Example 3 was conducted except that the raw material zeolite was used in place of the anhydrous amorphous aluminosilicate used in Example 3, and a foaming phenomenon occurred in the intermediate layer. The light transmittance was poor, and the growth of the plants in the agricultural house made of this film was inhibited.

[0019]

As described in detail above, the agricultural film of the present invention has high light transmittance and infrared absorptivity due to the use of anhydrous amorphous aluminosilicate as a heat retaining agent. I got higher. Therefore, the agricultural film of the present invention is excellent in heat retention, enhances the growth of crops, and contributes to energy saving. Further, the film of the present invention produced by blending a specific ethylene-vinyl acetate copolymer with anhydrous amorphous aluminosilicate is similar to the physical properties of a polyvinyl chloride film which has been used as a conventional agricultural film, Especially excellent in transparency and handling during work. Moreover, in the case of the film of the present invention, a plasticizer is not used, and hydrogen chloride gas is not generated during incineration. Furthermore, the film of the present invention in which both outer layers made of a specific ethylene-vinyl acetate copolymer are laminated on an intermediate layer made of an ultra-low density ethylene-α-olefin copolymer blended with anhydrous amorphous aluminosilicate, , Excellent in heat retention, transparency, heat resistance, impact resistance, tear resistance, puncture resistance, cold resistance, etc., and is suitable as an agricultural film for greenhouse cultivation, tunnel cultivation and mulching cultivation. In the present invention, since anhydrous amorphous aluminosilicate is used, a foaming phenomenon does not occur as in the case of using other inorganic heat retaining agents, and a film having excellent performance is produced. In particular, in the case of a resin having a high melting point (polypropylene, HDPE, LLDPE, etc.), the film must be molded at a high temperature, so that it easily foams. Without adversely affecting the film. Furthermore, a high concentration of anhydrous amorphous aluminosilicate, which is a heat retaining agent, is used (1 to 100 parts by weight of olefin resin).
5 parts by weight or more), even if blended with ultra-low density ethylene-α-
By using the heat retaining agent together with the olefin copolymer, it is possible to prevent the mechanical strength of the film from lowering.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C08L 23/02 LBZ 7107-4J 23/08 LDF 7107-4J // A01G 9/14 S B29K 23: 00 B29L 7:00 4F 9:00 4F

Claims (5)

[Claims] 1. An agricultural film comprising a resin composition comprising 100 parts by weight of an olefin resin and 1 to 20 parts by weight of anhydrous amorphous aluminosilicate. 2. A melt index of 0.5 to 5 g / 10
And a resin composition comprising 100 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 15% by weight and 1 to 20 parts by weight of anhydrous amorphous aluminosilicate. Agricultural film. 3. A melt index of 0.5 to 5 g / 10
Of ethylene having a vinyl acetate content of 5 to 15% by weight
Both outer layers made of vinyl acetate copolymer, density 0.91
0g / ml or less, melting point 116 ° C or more, 1% modulus 1
Ultra-low density ethylene-α-olefin copolymer 100 having 200 kg / cm ² or less, n-hexane extractable content of 10% by weight or less, and melt index of 0.8 to 10 g / 10 minutes.
A laminated film composed of 1 part by weight and an intermediate layer consisting of 1 to 20 parts by weight of anhydrous amorphous aluminosilicate, wherein the thickness of the intermediate layer occupies at least 35 to 90% of the total thickness of the laminated film, The total thickness of the laminated film is 5
A laminated film for agriculture, which has a thickness of 0 to 200 μm. 4. A method for continuously producing an ethylene copolymer, wherein the ultra-low density ethylene-α-olefin copolymer is as follows: at a temperature of 10 to 80 ° C. and a pressure of 7,000 kPa or less in a fluidized bed reaction zone, ) Higher α-olefin: ethylene molar ratio of 0.35: 1 to 8.0: 1, ethylene and at least one higher α-olefin having 3 to 8 carbon atoms, and (b) at least 25 mol. At least 1%
A gas mixture containing a diluent gas of the species is prepared by the following formula: Mg _m Ti (OR) _n X _p [ED] _q (wherein R is an aliphatic or aromatic hydrocarbon group having 1 to 14 carbon atoms or Represents a group COR ', where R'is 1 to 1 carbon atoms
4 represents an aliphatic or aromatic hydrocarbon group, X is selected from the group consisting of chlorine atom, bromine atom, iodine atom and mixtures thereof, ED is alkyl ester of aliphatic or aromatic acid, aliphatic ether, ring Represents an organic electron donating compound selected from the group consisting of formula ethers and aliphatic ketones, m is 0.5 to 56, n is 0, 1 or 2, p is 2 to 116, and q is 2 to 85. ) Is continuously contacted with particles of a catalyst system consisting of a precursor composition, said precursor composition is diluted with an inert carrier material and the following formula: Al (R ′) _d X ′ _e H _f (In the formula, X ′ represents a chlorine atom or a group OR ″, R ′ and R ″ represent a saturated hydrocarbon group having 1 to 14 carbon atoms, e is 0 to 1.5, and f is 0 or 1 and d + e + f = 3), and the activated compound is completely activated by an organoaluminum compound represented by the formula (1) and the molar ratio of total aluminum: titanium in the reaction zone is 10: 1 to 400: 1. The agricultural laminated film according to claim 3, which is produced by using an amount such that 5. A melt index of 0.5 to 5 g / 10
Of ethylene having a vinyl acetate content of 5 to 15% by weight
Both outer layers made of vinyl acetate copolymer, density 0.91
0g / ml or less, melting point 116 ° C or more, 1% modulus 1
Ultra-low density ethylene-α-olefin copolymer 100 having 200 kg / cm ² or less, n-hexane extractable content of 10% by weight or less, and melt index of 0.8 to 10 g / 10 minutes.
A method for producing a laminated film for agriculture, which comprises producing 1 part by weight and an intermediate layer consisting of 1 to 20 parts by weight of anhydrous amorphous aluminosilicate by a coextrusion method.