JPH11292993A - Agricultural film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an agricultural film capable of manifesting excellent anti- fogging persistence, transparency, tear strength and tensile strength, useful for covering materials for forcing cultivation in agriculture by including a specific filler and an anti-fogging agent in specific ratios into a specific ethylene based copolymer. SOLUTION: This agricultural film includes (A) 100 pts.wt. of an ethylene-α- olefin copolymer [e.g.; obtained by polymerizaing ethylene and an α-3 to 18C olefin copolymer using a metallocene catalyst, having a melt flow rate of 0.1 to 50 g/10 minutes, a density (D1 ) of 0.88 to 0.928 g/cm<3> , an extrapolated end of melting temperature of the melting peak obtained by differential scanning calorimetry (Tem) of 50 to 130, and satisfies the relation of Tem<=286D1 -137], (B) 0.05 to 1 pt.wt. of a basic magnesium carbonate of the formula: nMgCO3 .Mg(OH)2 .mH2 O ((m) is 0 to 3; (n)is 3 to 5), and 0.1 to 5 pts. of an anti-fogging agent (e.g.; a nonionic, an anionic or a cationic surfactant).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an agricultural polyethylene film having excellent antifogging durability, transparency, tear strength, impact strength and tensile strength.

[0002]

2. Description of the Related Art In house cultivation, tunnel cultivation, mulch cultivation, and the like for the purpose of forcing cultivation on agriculture, agricultural films composed of various thermoplastic resins are generally used in large quantities as covering materials. Films that are mainly used include, for example, polyvinyl chloride film, polyethylene film, ethylene-vinyl acetate copolymer film, and among others, polyvinyl chloride film has transparency, toughness, heat retention, and anti-fogging continuity. It has excellent properties and is used most often.

However, in the case of a polyvinyl chloride film, since the film weight in the same volume is heavy and sticky, it is inferior in terms of house expansion workability, and the film adheres to the plasticizer due to dust adhesion. There is a problem that transparency is deteriorated, that is, a so-called dust-proof property is inferior, and a problem that toxic gas is generated during incineration of waste. Polyethylene film, on the other hand, is superior in cost, spreadability, dustproofness and disposal, but is inferior in antifogging durability, transparency, toughness, and heat retention compared to polyvinyl chloride film. There is.

In particular, agricultural poly made of an ethylene polymer has no polar group, and thus has a problem in imparting anti-fogging properties and maintaining anti-fogging properties. In general, when an agricultural film that does not have anti-fog properties is used as a covering material such as a house or a tunnel, moisture evaporated from soil is condensed on the inner surface of the film due to a temperature difference between the inside and outside of the coated film to form water droplets, The water droplets cause the film to become cloudy and reflect a portion of the sun's rays, thereby reducing the amount of light transmitted through the film, thereby reducing the effect of increasing the temperature in the house or tunnel. In addition, water droplets condensed on the inner surface of the film fall on cultivated crops, and have adverse effects such as damaging young shoots and seedlings and causing disease. For these adverse effects, a mixture of a surfactant and a surfactant exhibiting the action of an antifogging agent is used in the film, and this antifogging agent prevents evaporated water from remaining as water droplets on the film surface, It acts to spread the water droplets in a film form and flow down along the inner surface of the film. An agricultural film having antifogging property is one in which a kneaded antifogging agent diffuses and leaches along the surface from the inside of the film and is coordinated on the film surface to exert a surface active effect. However, since the antifogging agent coordinated on the film surface is washed away by water drops during use, it is necessary to always transfer the antifogging agent from the inside of the film toward the surface in order to maintain the antifogging property of the film. .
The longer the antifogging effect of the antifogging film, that is, the longer the antifogging effect, the more preferable the antifogging film.

In order to produce such a film having a long antifogging effect, a large amount of an antifogging agent is generally added at the time of film production, or a film having a slow transition speed from the inside of the film to the surface after the film is formed. Attempts have been made to selectively use fogging agents. However, the former method, in which a large amount of antifogging agent is added during film production, is effective for maintaining the antifogging property, but the amount of transfer to the surface after film formation is severe, and the transparency is reduced due to whitening of the antifogging agent. And there is a problem such as stickiness between films, it is actually difficult to increase the amount to a certain amount or more, and also in the case of the latter method, there is an anti-fog effect, and this anti-fog effect has been No antifogging agent has been found to last

When a film containing an ethylene-vinyl acetate copolymer as a main component is applied to an agricultural film, transparency and heat retention are improved as compared with the above-mentioned polyethylene film, but compared with a polyvinyl chloride film. However, there is a problem that it still cannot be reached. When polyethylene or ethylene-vinyl acetate copolymer having these problems is used as an agricultural film, attempts to improve the heat retention of the film by adding an inorganic additive having a high infrared absorbing ability have been made. For example, as an inorganic additive, silica powder (Japanese Patent Publication No. 47-1)
3853), magnesium compounds (Japanese Patent Publication 3-5)
No. 0791), hydrotalcite (JP-B 62-62)
No. 31744) has been proposed. However, agricultural films made of polyethylene resins such as polyethylene and ethylene-vinyl acetate copolymer, although the heat retention of the film has been improved, are still more transparent than polyvinyl chloride film. Insufficient toughness.

In order to improve the toughness of such a polyethylene resin film, agricultural films utilizing the toughness of linear low-density polyethylene have recently been devised. For example, Japanese Unexamined Patent Publication (Kokai) No. 58-160146 proposes an agricultural multilayer film in which a base layer mainly composed of linear low-density polyethylene and a polyethylene resin layer formed by a conventional production method are laminated. I have. Although this agricultural multilayer film has been improved to some extent in terms of toughness, in addition to insufficient improvement in the fold strength, which is a drawback during blown film molding, in addition to transparency, polychlorinated There is a problem that it is inferior to a vinyl film.

Japanese Patent Application Laid-Open No. 1-182037 discloses that an outer layer is formed of a polyethylene resin containing a linear ethylene-α-olefin copolymer as a main component, and an inner layer is formed of an ethylene-vinyl acetate copolymer. A multilayer agricultural film formed of a polyethylene resin as a main component has been proposed. Agricultural multilayer films described in this publication are also not sufficiently satisfactory in toughness and transparency as in the above-mentioned multilayer film described in JP-A-58-160146. Since it is a film, there is a problem that curling occurs in the film product. Therefore, in order to solve these problems, compared with the conventional agricultural multilayer film described above, the same antifogging durability and transparency as a polyvinyl chloride film, and,
There is a demand for an agricultural film having higher toughness.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an agricultural film excellent in antifogging durability, transparency, tear strength and tensile strength.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to overcome the problems of the prior art, and as a result, have found that a specific filler and ethylene-α-olefin containing an anti-fogging agent have been obtained. It has been found that the above object can be achieved by a polyethylene resin as a polymer, and the present invention has been completed. That is, the present invention relates to (1) 100 parts by weight of an ethylene-α-olefin copolymer and 0.05 to 0.05% of a basic magnesium carbonate represented by the following general formula (I).
An agricultural film comprising 1.0 part by weight and 0.1 to 5.0 parts by weight of one or more antifogging agents. nMgCO ₃ .Mg (OH) ₂ .mH ₂ O (I) (in the formula, n = 3 to 5, m = 0 to 3) In addition, the present invention provides the ethylene-α-olefin copolymer, Melt flow rate is in the range of 0.1 to 50 g / 10 min, density (D ₁ ) is in the range of 0.880 to 0.928 g / cm ³ , obtained by differential scanning calorimetry (DSC). The extrapolated melting end temperature (Tem) of the melting peak to be obtained is 50 to 130 ° C.
Is an ethylene-α-olefin copolymer for which the relation between the extrapolated melting end temperature (Tem) and the density (D ₁ ) satisfies the relational expression Tem ≦ 286D ₁ -137. Film. Further, the present invention provides the ethylene-
An agricultural film in which the α-olefin copolymer is a polymer produced using a metallocene catalyst. The present invention is also an agricultural film, wherein the ethylene-α-olefin copolymer is a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms. Further, the present invention is a multilayer film of at least three layers in which the ethylene-α-olefin copolymer is disposed in an inner layer or an outer layer or both layers, and the intermediate layer olefin resin includes Mg, Ca, Al,
And an inorganic film containing at least one atom selected from the group consisting of Si and Si in an amount of 1 to 20% by weight.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. 1. Ethylene-α-olefin copolymer The ethylene-α-olefin copolymer used in the present invention has the following physical properties.

MFR JIS-K7210 190 ℃, load 2.16kg
(Melt flow rate) at 0.1 to 50 g
/ 10 minutes, preferably 0.3 to 20 g / 10 minutes, more preferably 0.5 to 8 g / 10 minutes. If the MFR is larger than the above range, the strength is reduced and the film formation becomes unstable. When the MFR is smaller than the above range,
The resin pressure increases and the moldability deteriorates.

The density according to JIS-K7112 is 0.880 to 0.9.
28 g / cm ³ , preferably 0.885 to 0.926 g
/ Cm ³ , more preferably 0.890 to 0.924 g /
cm ³ . If the density is larger than the above range, transparency and impact strength will be poor. On the other hand, if the density is too low, the stiffness of the film deteriorates and the film surface becomes sticky, which is not preferable.

The differential melting curve obtained by differential scanning calorimetry (DSC) has one melting peak and the melting peak has an extrapolated melting end temperature (Tem) of 5
The temperature ranges from 0 to 130 ° C, preferably from 60 to 127 ° C, particularly preferably from 70 to 124 ° C. Further, the temperature (Te
As for the relationship between m) and the density (D1) of the copolymer itself, it is necessary to satisfy the following relational expression: Tem ≦ 286D1-137. Preferably, Tem ≦ 429D1-2
71, and most preferably, Tem ≦ 571D1-404.

If there is no peak in the differential melting curve,
It is not preferable because stickiness occurs when the film is formed. The differential melting curve preferably has one peak, and when there are two or more peaks, the transparency, impact strength, and tensile strength are undesirably poor. If the peak extrapolation melting end temperature (Tem) is smaller than the above range, blocking tends to occur when the film is formed. On the other hand, if the temperature is higher than the above range, transparency, impact strength, and tensile strength become poor, which is not preferable. In addition, components that melt at temperatures other than the melting temperature of the peak may be recognized, but those having extremely slow melting behavior are not recognized as peaks.

2. Production of Ethylene-α-Olefin Copolymer The ethylene-α-olefin copolymer used in the present invention can be produced by various methods, but preferably is disclosed in JP-A-58-19309 and JP-A-59-95292.
Nos. 60-35005, 60-35006, 60-35007, 60-35008, 60-
No. 35009, No. 61-130314, JP-A-3-1
No. 63088, European Patent Application Publication No. 42
Using metallocene catalysts, metallocene / alumoxane catalysts such as described in U.S. Pat. No. 0,436, U.S. Pat. No. 5,055,438, and WO09 / 04257, or For example, a catalyst composed of a metallocene compound as disclosed in International Publication WO09 / 07123 and the like and a compound which reacts with the metallocene compound described below to be a stable ion is used. It can be produced by copolymerizing ethylene as a component and α-olefin as a subsidiary component.

The compound which becomes a stable ion by reacting with the metallocene catalyst is an ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, and these react with the metallocene compound. It becomes a stable ion to form a polymerization active species. Among them, the ionic compound is represented by the following formula (II). [Q] ^{m +} [Y] ^m− (m is an integer of 1 or more) (II) A cation component of the Q ionic compound in the formula, for example, a carbonium cation, a tripylium cation, an ammonium cation, an oxonium cation , A sulfonium cation, a phosphonium cation, and a metal cation or an organic metal cation that can be easily reduced. These cations are described in
Not only a cation capable of providing a proton as disclosed in the 501950 publication or the like, but also a cation that does not provide a proton may be used. Specific examples of these cations include triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, indenium,
Triethylammonium, tripropylammonium,
Tributylammonium, N, N'-dimethylammonium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, tri (dimethylphenyl) phosphonium, tri (methylphenyl) phosphonium, triphenylsulfonium, triphenyloxonium, triethyl Oxonium, pyrylium, silver ion, gold ion, platinum ion, palladium ion, mercury ion, ferrocenium ion and the like.

On the other hand, Y in the formula is an anionic component of the ionic compound. This is a component that reacts with the metallocene compound to form a stable anion, such as an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, an organic phosphorus compound anion, an organic arsenic compound anion, and an organic antimony compound anion. No. Specific examples of these include tetraphenylboron, tetrakis (3,4,5-trifluorophenyl) boron, tetrakis (3,5-di (3,5-di (trifluoromethyl) phenyl)) Boron, tetrakis (3,5- (t-butyl) phenyl) boron, tetrakis (pentafluorophenyl) boron,
Tetraphenylaluminum, tetrakis (3,4,5
-Trifluorophenyl) aluminum, tetrakis (3,5-di (trifluoromethyl) phenyl) aluminum, tetrakis (3,5-di (t-butyl) phenyl) aluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium , Tetrakis (3,4,5-trifluorophenyl) gallium, tetraphenylgallium, tetrakis (3,4,5-trifluorophenyl) gallium, tetrakis (3,5-di (trifluoromethyl) phenyl) gallium, tetrakis (3,5-di (t-butyl) phenyl) gallium, tetrakis (pentafluorophenyl) gallium, tetraphenyl phosphorus, tetrakis (pentafluorophenyl)
Phosphorus, tetraphenylarsenic, tetrakis (pentafluorophenyl) arsenic, tetraphenylantimony, tetrakis (pentafluorophenyl) antimony, decaborate, undecaborate, carbadodecaborate, decachlorodecaborate and the like.

As the electrophilic compound, among the compounds known as Lewis acid compounds, those which react with metallocene compounds to form stable ions to form polymerization active species are used, and various metal halide compounds are used. And metal oxides known as solid acids. Specific examples of those that correspond to these include magnesium halides and Lewis acidic inorganic compounds.

As the α-olefin to be copolymerized, an α-olefin having 3 to 18 carbon atoms is used in many cases. Specifically, propylene, 1-butene, 1-
Pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene and the like. , Preferably having 4 carbon atoms
-12, particularly preferably 6-10 carbon atoms. In many cases, one of the above-mentioned α-olefins is selected and used, but if desired, two or more of them can be used in combination. When the α-olefin is copolymerized with ethylene, the α-olefin is 2 to 50% by weight, preferably 3 to 35% by weight, particularly preferably 5 to 25% by weight, and 50 to 98% by weight of ethylene.
It is preferably 65 to 97% by weight, particularly preferably 75 to 9%.
It is desirable to copolymerize with 5% by weight.

Examples of the copolymerization method include a gas phase method, a slurry method, a solution method, and a high pressure ionic polymerization method. Among these, a solution method and a high-pressure ionic polymerization method are preferable, and a high-pressure ionic polymerization method that can further exert the effects of the present invention is particularly preferable. This high pressure ionic polymerization method is described in JP-A-56-18607 and JP-A-58-18607.
225106, the method described in each gazette,
Specifically, the pressure is 100 kg / cm ² or more, preferably 300 to 2,000 kg / cm ² , and the temperature is 125 ° C. or more, preferably 130 to 250 ° C., particularly preferably 15 ° C.
This is a method for producing an ethylene-based polymer performed under reaction conditions of 0 to 200 ° C.

3. Basic Magnesium Carbonate The basic magnesium carbonate according to the present invention has the following general formula (I): nMgCO ₃ .Mg (OH) ₂ .mH ₂ O (I) (where n = 3 to 5, m = 0 to 0) 3) and a white powder having an average particle diameter of 0.3 to 0.5 μm, typically 3MgCO ₃ .Mg (OH) ₂ .3H ₂ O 5MgCO ₃ .Mg (OH) ₂・ There is 2H ₂ O. This basic magnesium carbonate is used in an amount of 0.05 to 1.0 part by weight, preferably 0.08 to 0.5 part by weight, based on 100 parts by weight of the ethylene-α-olefin copolymer resin.
Parts by weight, particularly preferably 0.1 to 0.3 parts by weight. When the addition amount is less than the above range, the effect of improving the anti-fogging sustaining performance is small, and when it exceeds the above range, the transparency of the film is impaired, and the anti-fogging sustaining performance also becomes saturated, and economically. Is also not preferred.

4. Antifogging agent As the antifogging agent used in the present invention, generally used antifogging agents can be used. For example, nonionic, anionic, and cationic surfactants are used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate, polyoxyethylene sorbitan monopalmitate, glycerin monolaurate, glycerin monopalmitate, glycerin mono Stearate, glycerin monooleate, pentaerythritol monolaurate, sorbitan monopalmitate, sorbitan monobehenate, sorbitan distearate, diglycerin monooleate, triglycerin dioleate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate , Sodium butylnaphthalenesulfonate, cetyltrimethylammonium chloride, dodecylamine hydrochloride, Acrylic acid lauryl amide ethyl phosphate, triethyl cetyl ammonium iodide, oleyl amino diethylamine hydrochloride, and basic pyridinium salt of dodecylpyridinium sulfate salts. Of these, particularly preferred are those having 14 carbon atoms.
To 22 of fatty acids and polyhydric alcohols such as sorbitan, sorbitol, glycerin, polyglycerin, and propylene glycol, and nonionic surfactants mainly containing an alkylene oxide adduct thereof.

The amount of the anti-fogging agent added to the agricultural film of the present invention is 100% of ethylene-α-olefin copolymer resin.
0.1 to 5.0 parts by weight, preferably 0.1 parts by weight, based on parts by weight.
The amount is 3 to 4.0 parts by weight, particularly preferably 0.5 to 3.0 parts by weight. When the amount of the anti-fogging agent is less than the above range, the anti-fogging property is not sufficiently developed, and when the amount exceeds the above-mentioned range, the transfer to the surface of the anti-fogging agent becomes noticeable immediately after film formation, and the film is sticky. And transparency decrease.

[5] Multilayer film The multilayer film provided in the present invention is a multilayer film having at least three or more layers in which the above-mentioned ethylene-α-olefin copolymer containing basic magnesium carbonate and an antifogging agent is disposed in an inner layer or an outer layer or both layers. A film in which an inorganic compound containing at least one atom selected from the group consisting of Mg, Ca, Al, and Si is blended in the intermediate layer olefin resin at a ratio of 1 to 20% by weight. is there. As the olefin resin used for the intermediate layer, a high-pressure low-density polyethylene, a linear low-density polyethylene, an ethylene-vinyl acetate copolymer resin, or the like is preferably used, and the ethylene-α-olefin used in the present invention is used. Even if a copolymer is used, there is no problem.

The inorganic compound to be filled in the intermediate layer olefin resin may be in any form of an oxide, a hydroxide or a complex compound.
O ₂ , Al ₂ O ₃ , MgO, CaO, Al (OH) ₃ , Mg
(OH) ₂ , Ca (OH) ₂ , and the following general formula (II)
Examples of the compound represented by I) and a substance obtained by calcining the compound and referred to as hydrotalcites are included. M ²⁺ _1-x Al _x (OH) ₂ (A ⁿ⁻ ) _{x / n} · mH ₂ O (III) wherein M ²⁺ is a divalent metal ion selected from the group consisting of Mg, Ca and Zn And x and m satisfy the following conditions. 0 <x <0.5, 0 ≦ m ≦ 2 Of these, preferred are hydrotalcites, and particularly preferred is a calcined product of the compound represented by the general formula (III) (usually calcined at 200 to 300 ° C.). is there. One or two or more of these inorganic compounds can be used in combination. These inorganic compounds have an average particle size of 10 μm or less,
Preferably it is 5 μm or less, particularly preferably 3 μm or less. If the average particle size is too large, the transparency of the film is impaired, which is not preferable.

6. Other Components and Additives In the ethylene-α-olefin copolymer forming the film of the present invention, various known auxiliary additive components generally used for resin compositions, if necessary, for example, antioxidants Agents (among others, phenolic and phosphorus antioxidants are preferred), light stabilizers, antiblocking agents, slip agents, heat stabilizers, ultraviolet absorbers, neutralizers, colorants,
Pigments, nucleating agents and the like can be blended. Also, in order to improve the moldability when molding the film,
An ethylene polymer, for example, a high-pressure low-density polyethylene, an ethylene-vinyl acetate copolymer, or the like can be added as needed. In this case, the addition amount is preferably 5 to 15% by weight as long as the toughness of the base ethylene-α-olefin copolymer is not practically impaired.

7. Production of film The agricultural film of the present invention is obtained by molding an ethylene-α-olefin copolymer blended with a predetermined additive by a known molding method, that is, air-cooled inflation film molding, T-die film molding, water-cooled inflation film molding, or the like. A suitable film can be obtained. The thickness of the film is 30
To 200 μm, preferably 50 to 180 μm, more preferably 70 to 150 μm,
Also, as a multilayer composition ratio in the case of a multilayer film,
The thickness of the outer layer is 5 to 100 μm, preferably 10 to 80 μm
m, more preferably in the range of 15 to 60 μm, and the thickness of the intermediate layer is 10 to 150 μm, preferably 20 to 12 μm.
0 μm, more preferably in the range of 30 to 100 μm, and the thickness of the inner layer is 5 to 100 μm, preferably 10 to 100 μm.
Those having a diameter of 80 μm, more preferably 15 to 60 μm are preferable. The film of the present invention can be subjected to various treatments such as corona discharge treatment, flame treatment, stretching treatment, and liquid agent application treatment as required.

[0029]

The present invention will be described more specifically with reference to the following examples and comparative examples. [1] Measurement and evaluation methods of physical properties Measurement and evaluation of physical properties in Examples and Comparative Examples were performed by the following methods. (1) Method of measuring physical properties (a) MFR: Measured according to JIS-K7210. (B) Density: measured according to JIS-K7112. (C) Extrapolation melting end temperature (Tem) of the melting peak by differential scanning calorimetry (DSC): 5 mg of a sample was weighed from a 100 μm film formed by hot pressing,
It was set in an RDC220 differential scanning calorimeter manufactured by Seiko Denshi Kogyo KK, heated to 170 ° C., kept at that temperature for 5 minutes, and then cooled to -10 ° C. at a rate of 10 ° C./min. Next, after holding for 1 minute, the temperature was raised at a rate of 10 ° C. /
The temperature was raised to 170 ° C. in minutes and the measurement was performed. As a result,
The temperature was raised from 10 ° C to 170 ° C to obtain a DSC curve. JI
According to S-K7121, the temperature at the intersection of the line obtained by extending the high-temperature-side baseline of the DSC curve to the low-temperature side and the tangent drawn at the point where the gradient becomes maximum on the high-temperature curve of the melting peak is extrapolated. The melting end temperature (Tem) was set.

(2) Evaluation method (a) Haze: Measured according to JIS-K7105. (B) Vertical tensile break strength: measured in accordance with JIS-K6781. (C) Vertical Elmendorf tear strength: JIS-Z170
2 was measured. (D) Punching impact strength: Measured according to JIS-P8134, by attaching a 13 mm hemispherical metal glossy part with a specular gloss to the tip of the arcuate arm of the pendulum. (E) Anti-fogging property: Each evaluation film was coated on a mini-house (width 2 m, depth 3 m, height 2 m) installed in a test field of Nippon Polychem Co., Ltd. in Yokkaichi, Mie Prefecture, and from September 1996 An expansion test was conducted for 8 months until May 1997, and the state of water droplets adhering to the inner surface of the film was observed over time to evaluate the antifogging property. <Three-step evaluation> ：: A water film is formed on the entire inner surface of the film, and the flowing state is maintained. Δ: Large water droplets adhered to part of the inner surface of the film. ×: Fine water droplets adhered to almost the entire inner surface of the film, and the droplet function was lost.

[II] Preparation of ethylene-α-olefin copolymer The ethylene-α-olefin copolymer used in Examples and Comparative Examples was prepared as follows. (1) Preparation of component A (a) Preparation of catalyst The catalyst was prepared by the method described in JP-A-61-130314. That is, to 2.0 mmol of the complex ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, methylalumoxane manufactured by Toyo Stouffer was added 1,000 times as much as the complex, and the mixture was diluted to 10 liters with toluene. The catalyst solution was prepared by dilution. (B) Polymerization A mixture of ethylene and 1-hexene was supplied to a continuous autoclave type continuous reactor having an internal volume of 1.5 liters so that the composition of 1-hexene became 75% by weight, and the pressure in the reactor was increased. Was maintained at 1300 kg / cm ² and the reaction was carried out at a temperature of 150 ° C. After the completion of the reaction, the MFR is 2.2 g / 10
Ethylene-1-hexene copolymer having a melting point of 0.910 g / cm ³ , one melting peak by differential scanning calorimetry (DSC), and an extrapolated melting end temperature (Tem) of 108 ° C. I got (C) Mixing of additives The obtained copolymer is appropriately added with an antioxidant Toshitail ganox 1076 (manufactured by Ciba-Geigy) and P-EPQ (manufactured by Sando) and Chimassorb 944LD (manufactured by Ciba-Geigy) as a weathering stabilizer. Component A was prepared.

(2) Preparation of Component B Using the same catalyst and reactor as in (1), polymerization was carried out by changing the supply amount of 1-hexene, the pressure and temperature in the reactor,
MFR 2.2 g / 10 min, density 0.895 g / cm
^{In 3} , an ethylene-1-hexene copolymer having one melting peak by differential scanning calorimetry (DSC) and having an extrapolated melting end temperature (Tem) of 98 ° C. was obtained. Irganox 1076 was added as an antioxidant to the obtained copolymer.
Component B was prepared by mixing appropriate amounts of Cimasorb 944LD (manufactured by Ciba-Geigy) and P-EPQ (manufactured by Sando) and Chimassorb 944LD (manufactured by Ciba-Geigy) as a weathering stabilizer.

(3) Preparation of component C Using the same catalyst and reactor as in (1), polymerization was carried out by changing the supply amount of 1-hexene, the pressure and temperature in the reactor,
MFR 2.2 g / 10 min, density 0.905 g / cm
^{In 3} , there was one melting peak by differential scanning calorimetry (DSC) and the extrapolated melting end temperature (Tem) was 105 ° C.
Was obtained as the ethylene-1-hexene copolymer. Irganox 107 was added to the resulting copolymer as an antioxidant.
6 (manufactured by Ciba-Geigy), P-EPQ (manufactured by Sando), and Chimassorb 944LD (manufactured by Ciba-Geigy) as weathering stabilizers were added in appropriate amounts to prepare Component C.

(4) Preparation of Component D Using the same catalyst and reactor as in (1), polymerization was carried out by changing the supply amount of 1-hexene, the pressure and temperature in the reactor,
MFR 2.0 g / 10 min, density 0.915 g / cm
^{In FIG. 3} , there is one melting peak by differential scanning calorimetry (DSC) and the extrapolated melting end temperature (Tem) is 113 ° C.
Was obtained as the ethylene-1-hexene copolymer. Irganox 107 was added to the resulting copolymer as an antioxidant.
6 (Ciba-Geigy), P-EPQ (Sand), and Chimassorb 944LD (Ciba-Geigy) as a weathering stabilizer in appropriate amounts to prepare Component D.

(5) Preparation of Component E Using the same catalyst and reactor as in (1), polymerization was carried out by changing the supply amount of 1-hexene, the pressure and temperature in the reactor,
MFR 2.0 g / 10 min, density 0.935 g / cm
^{In 3} , there was one melting peak by differential scanning calorimetry (DSC), and the extrapolated melting end temperature (Tem) was 131 ° C.
Was obtained as the ethylene-1-hexene copolymer. Irganox 107 was added to the resulting copolymer as an antioxidant.
6 (manufactured by Ciba-Geigy), P-EPQ (manufactured by Sando), and Chimassorb 944LD (manufactured by Ciba-Geigy) as weathering stabilizers were added in appropriate amounts to prepare Component E.

Example 1 100 parts by weight of the resin of the component A was mixed with basic magnesium carbonate, 3MgCO ₃ .Mg (OH) ₂ .3H ₂ O (trade name:
E-100, manufactured by Kosei Co., Ltd.) 0.2 parts by weight of sorbitan monostearate / polyglycerin monostearate / alkylamine in a ratio of 2: 1: 0.3. Using a resin mixed with 5 parts by weight, a film was formed at a temperature of 180 ° C. with a multilayer blown film forming machine manufactured by Mitsubishi Chemical Engineering Corporation. At this time, the same resin was charged into the inner layer, intermediate layer, and outer layer of the molding machine to obtain a substantially single-layer 100 μm film.
The inner layer and the outer layer each contain 0.1% of Dicalite White Filler (manufactured by Lhasa Corporation) as an anti-blocking agent.
8 parts by weight and 0.2 parts by weight of oleamide as a slip agent were blended. This film was evaluated. Table 1 shows the results.

Example 2 Except that the base resin was changed to 100 parts by weight of the component B, it was molded and evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 3 Except that the base resin was changed to 100 parts by weight of the component C, it was molded and evaluated in the same manner as in Example 1. Table 1 shows the results.

Example 4 Except that the base resin was changed to 100 parts by weight of the component D, it was molded and evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 A molding was performed and evaluated in the same manner as in Example 1 except that the amount of the basic magnesium carbonate was changed to 0.02 parts by weight. Table 1 shows the results.

Comparative Example 2 Molding and evaluation were performed in the same manner as in Example 1 except that the amount of the antifogging agent was changed to 0.05 part by weight. Table 1 shows the results.

Comparative Example 3 Molding and evaluation were performed in the same manner as in Example 1 except that the base resin was 100 parts by weight of the component E and the amount of the basic magnesium carbonate was 0. Table 1 shows the results.

Comparative Example 4 A high pressure polyethylene (Novatec LD) was used as a base resin.
ZE41, MFR 0.5g / 10min, density 0.924g
/ Cm ³ , manufactured by Nippon Polychem Co., Ltd.), and molded and evaluated in the same manner as in Example 1 except that the amount of basic magnesium carbonate added was 0. Table 1 shows the results.

Comparative Example 5 The base resin was an ethylene-vinyl acetate copolymer (Novatech EVA LV420, a vinyl acetate content of 15 wt%,
Nippon Polychem Co., Ltd.) and molded and evaluated in the same manner as in Example 1 except that the amount of basic magnesium carbonate added was 0. Table 1 shows the results.

[0045]

[Table 1]

Example 5 As an inner layer resin and an outer layer resin, 0.2 parts by weight of basic magnesium carbonate (trade name: E-100, manufactured by Kosei Co., Ltd.), 100 parts by weight of component A, and sorbitan monostearate / poly Glycerin monostearate / alkylamine is 2:
EVA (Novatech EVA LV420, a vinyl acetate content of 15 wt%, a resin containing 2.0 parts by weight of an antifogging agent mixed at a ratio of 1: 0.3,
1.0 part by weight of an antifogging agent in which sorbitan monostearate / polyglycerin monostearate / alkylamine is mixed in a ratio of 2: 1: 0.3 in 100 parts by weight of Nippon Polychem Co., Ltd., and an inorganic compound Is molded using a resin in which 10 parts by weight of hydrotalcite (trade name: DHT4A-2, manufactured by Kyowa Chemical Co., Ltd.) is blended at a temperature of 180 ° C. with a multilayer blown film forming machine manufactured by Mitsubishi Chemical Engineering Co., Ltd. Thus, a three-layer blown film comprising an inner layer of 20 μm, an intermediate layer of 60 μm, and an outer layer of 20 μm was obtained. In the inner layer and the outer layer, 0.8 parts by weight of dicalite white filler (manufactured by Rasa Shoji) as an antiblocking agent and 0.2 parts by weight of oleamide as a slipping agent were blended. This three-layer film was evaluated. Table 2 shows the results.

Example 6 The resin of the outer layer was changed to EVA (Novatec EVA LV12).
0, vinyl acetate content 3.5 wt%, Nippon Polychem Co., Ltd.
Except that the amount was 100 parts by weight, molding and evaluation were performed in the same manner as in Example 5. Table 2 shows the results.

Example 7 A resin for the intermediate layer was molded and evaluated in the same manner as in Example 5 except that the amount of the component B was changed to 100 parts by weight and the amount of hydrotalcite added was changed to 15 parts by weight. Table 2 shows the results.

Comparative Example 6 Molding and evaluation were performed in the same manner as in Example 5 except that the amount of basic magnesium carbonate added to the inner and outer layer resins was 0.02 parts by weight. Table 2 shows the results.

Comparative Example 7 A molding was performed and evaluated in the same manner as in Example 5 except that the base resin of the inner layer and the outer layer was Component E, and the amount of basic magnesium carbonate added to each layer was 0. Table 2 shows the results.

Comparative Example 8 The base resin of the inner layer and the outer layer was EVA (Novatech L.)
V120), and molded and evaluated in the same manner as in Example 5, except that the amount of basic magnesium carbonate added to each layer was set to 0. Table 2 shows the results.

Comparative Example 9 Molding and evaluation were carried out in the same manner as in Example 5, except that the amount of the antifogging agent added to the inner layer resin and the outer layer resin was 0.05 parts by weight.
Table 2 shows the results.

[0053]

[Table 2]

[0054]

The film of the present invention can be prepared from conventional agricultural films such as polyvinyl chloride film, polyethylene film, ethylene-vinyl acetate copolymer film and the like, and has good antifogging durability, transparency, tear strength and tensile strength. Excellent,
It exerts a favorable effect as an agricultural film, particularly as an agricultural multilayer film.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 3/10 C08K 3/10 3/26 3/26 C08L 23/08 C08L 23/08

Claims (5)

[Claims] 1. An ethylene-α-olefin copolymer 10
0 parts by weight contains 0.05 to 1.0 parts by weight of a basic magnesium carbonate represented by the following general formula (I) and 0.1 to 5.0 parts by weight of one or more antifogging agents. Agricultural film characterized by the following. nMgCO ₃ .Mg (OH) ₂ .mH ₂ O (I) (where n = 3 to 5 and m = 0 to 3) 2. The ethylene-α-olefin copolymer has a melt flow rate within a range of 0.1 to 50 g / 10 minutes and a density (D ₁ ) of 0.880 to 0.928 g / cm. Within the range of ³ , the extrapolative melting end temperature (Tem) of the melting peak obtained by differential scanning calorimetry (DSC) is 50 to 130 ° C.
And the relationship between the extrapolated melting end temperature (Tem) and the density (D ₁ ) satisfies the relational expression Tem ≦ 286D ₁ -137. The agricultural film according to claim 1, characterized in that: 3. The agricultural film according to claim 1, wherein the ethylene-α-olefin copolymer is a polymer produced using a metallocene catalyst. 4. The agricultural film according to claim 1, wherein the ethylene-α-olefin copolymer is a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms. 5. The method according to claim 1, wherein said ethylene-α-olefin copolymer is disposed in an inner layer, an outer layer or both layers.
A multilayer film having at least one atom selected from the group consisting of Mg, Ca, Al, and Si.
The agricultural film according to any one of claims 1 to 4, wherein the agricultural film is blended at a ratio of 20% by weight.