JP3342627B2 - Agricultural film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to agricultural films.

[0002]

BACKGROUND OF THE INVENTION In house cultivation, tunnel cultivation, and mulch cultivation for the purpose of forcing cultivation on agriculture, agricultural films composed of various thermoplastic resins are generally used in large quantities as a covering material. Such agricultural films include, for example, a polyvinyl chloride film, an ethylene / vinyl acetate copolymer film, a polyethylene film, and the like. Among them, the polyvinyl chloride film has a heat retaining property, transparency, toughness (mechanical strength). It is most often used because of its excellent properties.

[0003] However, the polyvinyl chloride film has some problems such as the dust-proofing property and the spreadability being slightly inferior, and the generation of toxic gas at the time of incineration disposal. Here, "heat retention" means the temperature inside the house, tunnel, etc. (air temperature and ground temperature) by absorbing and reflecting the radiation emitted at night from the earth whose temperature has risen by absorbing solar heat during the day and absorbing it at night. Refers to the ability to maintain

[0004] The term "dustproofness" refers to the ability of a film to prevent a decrease in the transparency of a film due to adhesion of dust or the like after a certain period of use. Further, the “stretching workability” indicates whether the film is easy to handle due to stickiness.

On the other hand, a film containing an ethylene / vinyl acetate copolymer as a main component is superior to a polyvinyl chloride film in terms of waste treatment, but is inferior in toughness.
Insufficient spreadability and dust resistance.

When polyethylene is applied to an agricultural film, this film has improved workability and dust-proofing properties as compared with the above-mentioned film containing ethylene / vinyl acetate copolymer as a main component, but it is still in use. Inadequate,
There is a problem that the toughness is inferior to that of the linear ethylene / α-olefin copolymer film.

Further, as an agricultural film in which the heat retaining property of a polyolefin resin film is improved by an additive, there is a coating film obtained by adding silicon oxide to low-density polyethylene or ethylene / vinyl acetate copolymer.

[0008] However, such an agricultural film has improved toughness compared to a polyvinyl chloride film, although the heat insulation of the polyethylene resin film is improved.
Insufficient transparency.

[0009] 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, JP-A-58-160146 discloses an antifogging method in which a base layer mainly composed of linear low-density polyethylene and a layer made of a polyethylene resin or the like produced by a conventional production method containing a surfactant are laminated. Agricultural multilayer films having good properties have been proposed. Although the toughness of the agricultural multilayer film is improved, the use of a resin or an additive having a higher heat retaining property has not been studied, so that the heat retaining property of the agricultural multilayer film is considerably inferior to that of a polyvinyl chloride film.

Japanese Patent Application Laid-Open No. 1-182037 discloses an agricultural multilayer (laminated) film. The agricultural multilayer film has an outer layer whose main component is a linear ethylene / α-olefin copolymer. The inner layer is formed of a polyethylene resin having an ethylene / vinyl acetate copolymer as a main component, an inorganic compound, and an antifogging agent. JP 1
The agricultural multi-layer film described in -182037 has good heat retention, dustproofness, spreadability, transparency,
It is said to have both weather resistance and extremely excellent toughness.

However, the conventional multilayer film for agriculture as described above has room for improvement in antifogging durability, dust resistance, toughness and the like. Therefore, as compared with the above-mentioned conventional agricultural films (single-layer and multilayer films), there is a demand for an agricultural film which has a small degree of deterioration of the anti-fogging continuity over time, and is excellent in dust resistance and toughness. .

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide an agricultural film which is less susceptible to aging over time than the conventional agricultural films described above, and which is excellent in dust resistance and toughness. I have.

[0013]

SUMMARY OF THE INVENTION The agricultural film according to the present invention comprises [I]
It is obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms, and has a density of 0.905 to 0.935 g / c.
m ³ and the melt flow rate is 0.1 to 10 g / 1.
0 minute ethylene / α-olefin copolymer (A) 1
00 parts by weight, or 100 parts by weight of a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, and [II] the following formula (I) Ethylene containing 0.05 to 5 parts by weight of an anti-fogging agent (C) comprising a glycerin alkyl ester represented by the following formula (II), a diglycerin alkyl ester represented by the following formula (II) and a diethanol alkylamine represented by the following formula (III): And a layer formed of the copolymer composition (1), and the ethylene / α-olefin copolymer (A) or the ethylene / α-olefin copolymer (A) and a high-pressure low-density copolymer. The mixture with the polyethylene (B) has the molecular weight distribution (Mw /
Mn: Mw = weight average molecular weight, Mn = number average molecular weight) is in the range of 1.5 to 3.5, and (ii) n- at 23 ° C.
The decane soluble component amount fraction (W (% by weight)) and density (d) are: W <80 × exp (−100 (d−0.88)) + 0.
(Iii) When the average value of the number of branches on the high molecular weight side by GPC-IR is B ₁ and the average value of the number of branches on the low molecular weight side is B ₂ , B ₁ ≧ B ₂ It is characterized by having.

[0014]

Embedded image

[In the formula (I), R ¹ , R ² and R ³ are
Each independently represents a hydrogen atom or 12 to 22 carbon atoms
Is an acyl group. ]

[0016]

Embedded image

[In the formula (II), R ⁴ , R ⁵ , R ⁶ and R
⁷ is each independently a hydrogen atom or a carbon atom
To 22 acyl groups. ]

[0018]

Embedded image

[In the formula (III), R ⁸ is a group having 12 carbon atoms.
To 22 alkyl groups. The agricultural film according to the present invention may have a single-layer structure or a multilayer structure including two or more layers.

The preferred agricultural film having a single layer structure according to the present invention contains the above-mentioned ethylene / α-olefin (A), antifogging agent (C) and, if necessary, high-pressure low-density polyethylene (B). A monolayer film comprising a layer formed of the ethylene-based copolymer composition (1), wherein the film has (i) an Elmendorf tear strength of 90 kg / cm or more in the MD direction and a TD direction 90 kg
/ Cm and at least, (ii) dart impact strength in the thickness 100μm is equal to or greater than 450 g, (iii) tensile strength at break is at 350 kg / cm ² or more in the MD direction, and, 350 kg / cm ² in TD direction That is all.

Further, the preferred agricultural film having a multilayered structure according to the present invention is [I] ethylene and C 4 -C 12.
Of α-olefins having a density of 0.9
An ethylene / α-olefin copolymer (D) having a melt flow rate of 25 to 0.940 g / cm ³ and a melt flow rate of 0.1 to 10 g / 10 minutes, or the ethylene / α-olefin copolymer (D) Outer layer consisting of an ethylene-based copolymer composition (2) containing a mixture of a low-density polyethylene (B) and a high-pressure low-density polyethylene (B) in an amount of not more than 40% by weight, [II] ethylene and α- having 4 to 12 carbon atoms. An ethylene / α-olefin copolymer (E) obtained by copolymerizing an olefin, having a density of 0.880 to 0.910 g / cm ³ and a melt flow rate of 0.1 to 10 g / 10 min. 100 parts by weight or the ethylene / α-olefin copolymer (E)
And 100 parts by weight of a high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, a glycerin alkyl ester of the formula (I), a diglycerin alkyl ester of the formula (II) and Formula (III)
An intermediate layer comprising an ethylene-based copolymer composition (3) containing 0.05 to 5 parts by weight of an antifogging agent (C) comprising diethanolalkylamine represented by the following formula: and [III] ethylene and 4 carbon atoms. And α-olefins having a density of 0.905 to 0.935 g / cm.
³ , and the melt flow rate is 0.1 to 10 g / 10
Ethylene-α-olefin copolymer (A) 10
0 parts by weight, or 100 parts by weight of a mixture of the ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, and glycerin represented by the formula (I) Alkyl ester, diglycerin alkyl ester represented by the formula (II) and
I) a multilayer film comprising an ethylene-based copolymer composition (1) containing 0.05 to 5 parts by weight of an antifogging agent (C) comprising diethanolalkylamine represented by the following formula: Ethylene-α- forming the outer layer
Olefin copolymer (D) or ethylene / α-olefin copolymer (D) and high-pressure low-density polyethylene (B)
(D _D or d _DB ) of the mixture with ethylene / α-olefin copolymer (A) or ethylene / α-olefin copolymer (A) forming the inner layer and high-pressure low-density polyethylene (B) Is the density (d _A or d _AB ) of d _D
Alternatively, d _DB ≧ d _A or d _AB .

The resin forming the outer layer, the intermediate layer, and the inner layer may have (i) a molecular weight distribution (M
w / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) is in the range of 1.5 to 3.5, and (ii) n-decane soluble component fraction at 23 ° C. (W (weight%)) ) And density (d) are: W <80 × exp (−100 (d−0.88)) + 0.
(Iii) When the average value of the number of branches on the high molecular weight side by GPC-IR is B ₁ and the average value of the number of branches on the low molecular weight side is B ₂ , B ₁ ≧ B ₂ Preferably, there is. Here, resin is ethylene / α
-Refers to an olefin copolymer or a copolymer of an ethylene / α-olefin copolymer and a high-pressure low-density polyethylene.

Furthermore, the agricultural film having a multilayer structure as described above has (i) an Elmendorf tear strength of 90 kg / cm or more in the MD direction and 90 kg / cm in the TD direction.
/ Cm and at least, (ii) dart impact strength in the thickness 100μm is equal to or greater than 900 g, (iii) tensile strength at break is at 350 kg / cm ² or more in the MD direction, and, 350 kg / cm ² in TD direction It is preferable that it is above.

[0024]

DETAILED DESCRIPTION OF THE INVENTION The agricultural film according to the present invention will be specifically described below. The agricultural film according to the present invention is an ethylene-based copolymer composition containing an ethylene / α-olefin copolymer (A), an antifogging agent (C) and, if necessary, a high-pressure low-density polyethylene (B). Things (1)
Having a layer formed by: The agricultural film according to the present invention may be a film having a single-layer structure composed of such layers (single-layer film), or a film having a multilayer structure of two or more layers having such layers ( Multilayer film).

[Ethylene / α-olefin copolymer (A)] The ethylene / α-olefin copolymer (A) constituting the ethylene copolymer composition (1) used in the present invention comprises ethylene and carbon It is a copolymer comprising an α-olefin having 4 to 12 atoms.

As the α-olefin having 4 to 12 carbon atoms used for copolymerization with ethylene, specifically, 1-olefin
Butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene and the like. Among them, α-olefins having 4 to 10 carbon atoms, particularly α-olefins having 4 to 6 carbon atoms are preferred.

In the present invention, the above-mentioned ethylene / α-olefin copolymer (A) can be used alone or in combination of two or more. The ethylene / α-olefin copolymer (A) used in the present invention has a constitutional unit derived from ethylene of 50% by weight or more and 100% by weight or more.
Less than 55, preferably from 99 to 99% by weight, more preferably from 65 to 98% by weight, particularly preferably from 70 to 96% by weight, wherein the constituent units derived from α-olefins having 4 to 12 carbon atoms comprise 50 or less. Wt% or less, preferably 1-4
Desirably, it is present in an amount of 5% by weight, more preferably 2 to 35% by weight, particularly preferably 4 to 30% by weight.

The composition of the ethylene / α-olefin copolymer is usually determined by measuring the ¹³ C-NMR spectrum of a sample obtained by uniformly dissolving about 200 mg of the copolymer in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube. 120
° C, measurement frequency 25.05 MHz, spectrum width 150
0 Hz, pulse repetition time 4.2 sec., Pulse width 6 μse
It is determined by measuring under the measurement conditions of c.

The ethylene / α-olefin copolymer (A) has a density of 0.905 to 0.935 g / cm ³ ,
It is preferably in the range of 0.908 to 0.935 g / cm ³ , more preferably 0.910 to 0.930 g / cm ³ , particularly preferably 0.925 to 0.930 g / cm ³ .

The density is 2.16 at 190 ° C.
The strand obtained at the time of melt flow rate (MFR) measurement under a kg load is heat-treated at 120 ° C. for 1 hour, gradually cooled to room temperature over 1 hour, and measured with a density gradient tube.

The ethylene / α-olefin copolymer (A) has a melt flow rate (MFR; ASTM).
D 1238-65T, 190 ° C, load 2.16 kg)
Is 0.1 to 10 g / 10 min, preferably 0.1 to 5 g
/ 10 min, more preferably in the range of 0.5 to 2 g / 10 min.

The molecular weight distribution of the ethylene / α-olefin copolymer (A) measured by GPC (Mw / M
n: Mw = weight average molecular weight, Mn = number average molecular weight)
It is in the range of 1.5 to 3.5, preferably 2.0 to 3.0.

The molecular weight distribution (Mw / Mn) was measured as follows using GPC-150C manufactured by Millipore. The separation column is TSK GNH HT,
The column size is 72 mm in diameter and 600 mm in length,
The column temperature was 140 ° C., and the mobile phase used was O-dichlorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.025% by weight of BHT (manufactured by Takeda Pharmaceutical Company Limited) as an antioxidant. The sample was moved at 0 ml / min, the sample concentration was 0.1% by weight, the sample injection amount was 500 microliter, and a differential refractometer was used as a detector. Standard polystyrene is
For a molecular weight of Mw <1000 and Mw> 4 × 10 ⁶ , use a product of Tosoh Corporation, and use a product of 1000 <Mw <4 × 10 6
About ⁶ , the product made by Pressure Chemical Company was used.

The ethylene / α-olefin copolymer (A) has an n-decane soluble component fraction at 23 ° C. (W
(% By weight)) and the density (d) satisfy the relationship shown below.

W <80 × exp (−100 (d−0.8
8)) +0.1 In addition, the amount of n-decane soluble component of the ethylene / α-olefin copolymer (the smaller the soluble component, the narrower the composition distribution)
Is about 3 g of ethylene / α-olefin copolymer.
After adding to 450 ml of n-decane and dissolving at 145 ° C., 23
It cools to ° C, removes an n-decane insoluble part by filtration, and collect | recovers n-decane soluble part from a filtrate.

The ethylene / α-olefin copolymer has a temperature [Tm (° C.)] and a density [d at the maximum peak position of an endothermic curve measured by a differential scanning calorimeter (DSC).
(G / cm ³ )] and the relationship represented by Tm <400 × d-250, preferably Tm <450 × d-297, more preferably Tm <500 × d-344, and particularly preferably Tm <550 × d-391. It is desirable to satisfy

The temperature (Tm) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) is as follows:
Approximately 5mg of sample is packed in aluminum pan and 200 ℃ at 10 ℃ / min
The temperature is kept at 200 ° C. for 5 minutes, then the temperature is lowered to room temperature at 20 ° C./min, and then determined from an endothermic curve when the temperature is raised at 10 ° C./min. Measurements made by PerkinElmer
Use a DSC-7 type device.

As described above, the relationship between the fraction (W) of the n-decane soluble component and the density (d), and the temperature (Tm) at the maximum peak position in the endothermic curve measured by the differential scanning calorimeter (DSC) ) And the density (d) have the above-mentioned relationship, it can be said that the ethylene / α-olefin copolymer has a narrow composition distribution.

Further, the ethylene / α-
The olefin copolymer (A) satisfies B ₁ ≧ B ₂ when the average value of the number of branches on the high molecular weight side by GPC-IR is B ₁ and the average value of the number of branches on the low molecular weight side is B ₂ .

Here, the average value (B ₁ ) of the number of branches on the high molecular weight side by GPC-IR means that the cumulative weight fraction of the elution amount of the high molecular weight fractionated by GPC is 15 to 85%.
The measurement value group of the number of branches measured for each fraction in the range of (ie, the high molecular weight region excluding 15% and the high molecular weight region excluding 15%) was divided into two by the molecular weight at the peak position of the GPC elution curve. It is the average of the values on the high molecular weight side. On the other hand, the average value of the number of branches on the low molecular weight side (B
₂ ) is the average value on the low molecular weight side of the two parts.

The measurement conditions for B ₁ and B ₂ are as follows. Measuring device: Perkin Elmer 1760X Column: TSK gel GMH-HT (7.5mmI.
D. × 600 mm) × 1 Eluent (eluent): o-dichlorobenzene (ODCB) containing 0.05% of MP-J [ex. Wako Pure Chemical Industries, Ltd., ex
tra pure grade] Column temperature: 140 ° C. Sample concentration: 0.1% (weight / volume) Injection volume (inj.volume): 100 microliter detector: MCT Resolution: 8 cm ^-1 The B ₁ and B ₂ is the Ethylene and α in such a relationship
-The olefin copolymer (A) has a narrow composition distribution and a small amount of a low polymer, and thus has a low stickiness. Therefore, when the above-mentioned ethylene / α-olefin copolymer (A) is used, an agricultural film excellent in dustproofness can be obtained.

Further, since the film made of the ethylene / α-olefin copolymer (A) has a very small decrease in light transmittance over time, if such a film is used as an agricultural film, it will be used for a long time. It is possible to expand.

The ethylene / α-olefin copolymer (A) described above is disclosed in JP-A-6-9724 and JP-A-6-9724.
In the presence of a so-called metallocene-based olefin polymerization catalyst containing a metallocene catalyst component described in JP-A-136195, JP-A-6-136196, JP-A-6-207057, etc., ethylene and carbon atoms having 4 carbon atoms are used.
To 12 α-olefins so that the resulting copolymer has a density of 0.880 to 0.910 g / cm ³ .

Such a metallocene catalyst generally has at least one ligand having a cyclopentadienyl skeleton.
Metallocene catalyst component (a) comprising a transition metal compound of Group IVB of the periodic table, an organoaluminum oxy compound catalyst component (b), a particulate carrier (c), and, if necessary, an organoaluminum compound catalyst component (d ), An ionized ionic compound formed from the catalyst component (e).

The metallocene catalyst component (a) preferably used in the present invention is a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton. Examples of such a transition metal compound include a transition metal compound represented by the following general formula [I].

ML ¹ _x ... [I] In the formula, x is the valence of the transition metal atom M. M is a transition metal atom selected from Group IVB of the periodic table, and specifically, zirconium, titanium, and hafnium. Among them, zirconium is preferred.

L ¹ is a ligand which coordinates to the transition metal atom M, and at least one of these ligands L ¹
Is a ligand having a cyclopentadienyl skeleton.
As the ligand L ¹ having a cyclopentadienyl skeleton coordinated to the transition metal atom M as described above, specifically,
Cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, tetramethylcyclopentadienyl group, pentamethylcyclopentadienyl group, methylethylcyclopentadienyl group And an alkyl-substituted cyclopentadienyl group such as hexylcyclopentadienyl group, or an indenyl group, a 4,5,6,7-tetrahydroindenyl group or a fluorenyl group. These groups are
It may be substituted with a halogen atom, a trialkylsilyl group or the like.

When the compound represented by the above general formula [I] contains two or more groups having a cyclopentadienyl skeleton, two of the groups having a cyclopentadienyl skeleton correspond to ethylene, propylene or the like. An alkylene group,
It may be bonded through a substituted alkylene group such as isopropylidene diphenylmethylene or the like, or a silylene group or a substituted silylene group such as a dimethylsilylene group, a diphenylsilylene group or a methylphenylsilylene group.

The ligand L ¹ other than the ligand having a cyclopentadienyl skeleton is a hydrocarbon group having 1 to 12 carbon atoms; an alkoxy group such as a methoxy group; an aryloxy group such as a phenoxy group; a trimethylsilyl group; A trialkylsilyl group such as a triphenylsilyl group; SO ₃ R (R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group such as a methyl group, a cycloalkyl group such as a cyclopentyl group, an aryl group such as a phenyl group, and an aralkyl group such as a benzyl group.

Specific examples of the ligand represented by SO ₃ R include a P-toluenesulfonato group, a methanesulfonato group, and a trifluoromethanesulfonato group. As the organoaluminum oxy compound catalyst component (b), aluminoxane is preferably used. Specifically, methylaluminoxane, ethylaluminoxane, methylethylaluminoxane having a repeating unit represented by the formula -Al (R) O-, wherein R is an alkyl group, is usually about 3 to 50. Are used.

Such an aluminoxane can be prepared by a conventionally known production method. The particulate carrier (c) used in the preparation of the catalyst for olefin polymerization is an inorganic or organic compound and has a particle size of usually 10 to 300 μm.
And preferably 20 to 200 μm in the form of granules or fine particles.

As the inorganic carrier, a porous oxide is preferable. Specifically, SiO ₂ , Al ₂ O ₃ , MgO, Zr
O ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, S
Examples thereof include nO _{2 and the} like or a mixture thereof. The inorganic oxide contains a small amount of a carbonate such as Na ₂ CO _3, a sulfate such as Al ₂ (SO ₄ ) ₃ , a nitrate such as KNO ₃ , and an oxide such as Li ₂ O. No problem.

The properties of such a carrier differ depending on the kind and the production method, but the carrier preferably used in the present invention has a specific surface area of 50 to 1000 m ² / g, preferably 1 to 1,000 m ² / g.
00-700 m ² / g, and the pore volume is 0.3-2.
It is preferably 5 cm ³ / g.

The carrier may be 100 to 100 if necessary.
It is used by firing at 0 ° C, preferably 150 to 700 ° C. Examples of the organic compound used as the particulate carrier include a (co) polymer formed mainly of an α-olefin having 2 to 14 carbon atoms such as ethylene and 4-methyl-1-pentene, or vinylcyclohexane. And (co) polymers formed mainly of styrene.

Examples of the organoaluminum compound catalyst component (d) optionally used in the preparation of the olefin polymerization catalyst include trialkylaluminums such as trimethylaluminum, alkenylaluminums such as isoprenylaluminum, and dimethylaluminum. Examples thereof include dialkylaluminum halides such as chloride, alkylaluminum sesquihalides such as methylaluminum sesquichloride, alkylaluminum dihalides such as methylaluminum dichloride, and alkylaluminum hydrides such as diethylaluminum hydride.

Examples of the ionized ionic compound catalyst component (e) include triphenylboron, MgCl ₂ , and Al described in US Pat. No. 5,321,106.
Lewis acids such as ₂ O ₃ and SiO ₂ —Al ₂ O ₃ ; ionic compounds such as triphenylcarbenium tetrakis (pentafluorophenyl) borate; carborane compounds such as dodecaborane and bis-n-butylammonium (1-carbedodeca) borate Is mentioned.

The ethylene / α-olefin copolymer (A) used in the present invention comprises the above-mentioned metallocene catalyst component (a), organoaluminum oxy compound catalyst component (b), particulate carrier (c), If necessary, in the presence of an olefin polymerization catalyst containing an organoaluminum compound catalyst component (d) and an ionized ionic compound catalyst component (e), a gas phase or a slurry or solution liquid phase may be used under various conditions. , Ethylene and α- with 4 to 12 carbon atoms
It can be obtained by copolymerizing with an olefin.

In the slurry polymerization method or the solution polymerization method, an inert hydrocarbon may be used as a solvent, or an olefin itself may be used as a solvent. When carrying out the polymerization, the above-mentioned metallocene-based olefin polymerization catalyst is usually used in a concentration of 10 ^-8 , based on the concentration of the transition metal atom in the polymerization reaction system.
10 ^-3 gram atom / liter, preferably 10 ^{-7 -1
Preferably,} it is used in an amount of ^0-4 grams atom / liter.

In the polymerization, in addition to the organoaluminum oxy compound catalyst component (b) and the organoaluminum compound catalyst component (c) supported on the carrier, the unsupported organoaluminum oxy compound catalyst component (b) And / or an organoaluminum compound catalyst component (c) may be used. In this case, an aluminum atom (Al) derived from the unsupported organoaluminum oxy compound catalyst component (b) and / or the organoaluminum compound catalyst component (c) and a transition metal atom derived from the metallocene catalyst component (a) ( M) and the atomic ratio [Al
/ M] is in the range of 5 to 300, preferably 10 to 200, and more preferably 15 to 150.

The polymerization temperature in the slurry polymerization method is usually in the range of -50 to 100 ° C., preferably 0 to 90 ° C. The polymerization temperature in the solution polymerization method is usually -50 to 50 ° C.
0 ° C, preferably in the range of 0 to 400 ° C. Further, the polymerization temperature in the gas phase polymerization method is usually in the range of 0 to 120 ° C, preferably 20 to 100 ° C.

The polymerization pressure is usually from normal pressure to 100 kg /
cm ² , preferably ² to 50 kg / cm ² under pressure, and the polymerization can be carried out in any of a batch system, a semi-continuous system, and a continuous system.

In the present invention, when preparing the ethylene / α-olefin copolymer (A), if necessary,
(1) Multistage polymerization, (2) Multistage polymerization of liquid phase and gas phase, or (3)
Means such as performing polymerization in a gas phase after performing preliminary polymerization in a liquid phase can be employed. In the present invention,
The multi-stage polymerization of the above (1) is preferred.

Examples of the multi-stage polymerization include the following multi-stage polymerization. [1] A metallocene catalyst component comprising at least one compound selected from transition metal compounds of Group IVB of the periodic table containing a ligand having a cyclopentadienyl skeleton represented by the general formula [I]; In the presence of a metallocene catalyst containing an aluminum oxy compound catalyst component, ethylene is copolymerized with an α-olefin having 4 to 12 carbon atoms to produce an ethylene / α-olefin copolymer (A-1). Step [2] In a polymerization vessel different from the polymerization vessel in which the copolymerization reaction is performed, the above-mentioned general formula [I]
A metallocene catalyst component comprising at least one compound selected from transition metal compounds of Group IVB of the Periodic Table containing a ligand having a cyclopentadienyl skeleton represented by the following formula: and an organoaluminum oxy compound catalyst component Ethylene and carbon atoms of 4 to
And α-olefin of 12
And a step of producing an olefin copolymer (A-2). However, the manufacturing conditions in the step [1] are different from the manufacturing conditions in the step [2]. Such production conditions include, for example, the type and amount of the metallocene catalyst component, the type and amount of the organoaluminum oxy compound catalyst component, and the molar ratio of ethylene to α-olefin.

The metallocene catalyst used in the copolymerization step [1] and / or [2] is added to the metallocene catalyst component (a) and the organic aluminum oxy compound catalyst component (b), and the organic aluminum compound catalyst component (d). ) Or a solid catalyst in which the metallocene catalyst component (a) and the organoaluminum catalyst component (b) are supported on the fine-particle carrier (c). These metallocene-based catalysts are prepolymerized catalysts obtained by prepolymerizing an olefin onto a solid catalyst component in which a metallocene catalyst component (a) and an organoaluminum catalyst component (b) are supported on a particulate carrier (c). You may. Further, these metallocene-based catalysts include a catalyst comprising the above-mentioned solid catalyst (solid catalyst component) and an organoaluminum compound catalyst component (d), or the above-mentioned prepolymerization catalyst (preliminary polymerization catalyst component) and an organoaluminum compound catalyst component (d). ) May be used.

In this multi-stage polymerization method, the above-mentioned ethylene / α-olefin copolymer (A-1) is first produced using a plurality of polymerization vessels connected in series, and then the ethylene / α-olefin copolymer is produced.
-The ethylene / α-olefin copolymer (A-1) is introduced into a polymerization vessel different from the polymerization vessel used for producing the olefin copolymer (A-1), and the ethylene / α-olefin copolymer (A The ethylene / α-olefin copolymer (A-2) can be produced in the presence of -1).

Further, a plurality of polymerization reactors are connected in parallel, and in each polymerization reactor, ethylene / α-olefin copolymers (A-1) and (A-2) are produced, respectively. Can also be blended.

In the present invention, the ethylene / α-olefin copolymer (A) is used based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). , 60 to 100 parts by weight, preferably 65 to 99 parts by weight, more preferably 70 to 95 parts by weight.
Used in parts by weight.

[High-Pressure Low-Density Polyethylene (B)] The high-pressure low-density polyethylene (B) constituting the ethylene copolymer composition (1) used in the present invention has a melt flow rate (MFR; ASTM D1238). , 190 ° C, load 2.16 kg) for 0.1 to 100 g / 10 min, density 0.915 to 0.935 g / cm ³ , swell ratio 60
% Is preferable.

The density of the high-pressure low-density polyethylene (B) can be determined by the same method as that for measuring the density of the ethylene / α-olefin copolymer (A) described above. The swell ratio is obtained as follows.

The diameter at a position 5 mm from the tip of the strand obtained at the time of measuring the melt flow rate is measured with a micrometer as the diameter (mm) of the sample. Then, the swell ratio is calculated by the following equation.

Swell ratio (%) = [(L ₁ / L ₀ ) −1] × 100 L ₁ : sample diameter (mm) L ₀ : orifice diameter (= 2.0955 mm) Polyethylene (B) can be produced by a conventionally known high-pressure method.

In the present invention, the high-pressure low-density polyethylene (B) is used in an amount of 0 to 100 parts by weight based on the total amount of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). 40 parts by weight, preferably 1
To 35 parts by weight, more preferably 5 to 30 parts by weight.

[Anti-fogging agent (C)] The anti-fogging agent (C) constituting the ethylene copolymer composition (1) used in the present invention.
Is composed of a glycerin alkyl ester represented by the following formula (I), a diglycerin alkyl ester represented by the following formula (II), and a diethanolalkylamine represented by the following formula (III).

[0075]

Embedded image

R ¹ , R ² and R ³ are each independently a hydrogen atom or an acyl group having 12 to 22 carbon atoms. As the acyl group of R ¹ , R ² and R ³ , specifically, C ₁₁ H ₂₃ CO—, C ₁₃ H ₂₇ CO—, C ₁₅ H ₃₁
CO-, C ₁₇ H ₃₅ CO-, like C ₁₉ H ₃₉ CO-. Among them, C ₁₅ H ₃₁ CO— and C ₁₇ H ₃₅ CO— are preferred.

Specific examples of the glycerin alkyl ester preferably used in the present invention include glycerin palmitate (including mono, di and triester), glycerin stearate (including mono, di and triester) and the like. Can be

[0078]

Embedded image

In the formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷
Is independently a hydrogen atom or a carbon atom number of 12 to
22 acyl groups. As the acyl group of R ⁴ , R ⁵ , R ⁶ and R ⁷ , specifically, C ₁₁ H ₂₃ CO—, C _{13
H 27 CO-, C 15 H 31} CO-, C 17 H 35 CO-, C 19 H
₃₉ CO- and the like. Among them, C ₁₅ H ₃₁ CO-,
C ₁₇ H ₃₅ CO- is preferred.

Examples of the diglycerin alkyl ester preferably used in the present invention include diglycerin palmitate (including mono, di, tri and tetraester) and diglycerin stearate (mono, di, tri and tetraester). Esters).

[0081]

Embedded image

R ⁸ is an alkyl group having 12 to 22 carbon atoms, specifically, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl. , Lauryl group, stearyl group and the like. Among them, octadecyl, lauryl and stearyl groups are preferred.

As the diethanolalkylamine preferably used in the present invention, specifically, diethanolstearylamine, diethanollaurylamine and the like can be mentioned.

In the antifogging agent (C), the glycerin alkyl ester is 10 to 40 parts by weight, preferably 20 to 30 parts by weight, based on 100 parts by weight of the total amount of the glycerin alkyl ester, diglycerin alkyl ester and diethanol alkylamine. Parts by weight, the diglycerin alkyl ester is contained in a proportion of 20 to 80 parts by weight, preferably 30 to 70 parts by weight, and the diethanolalkylamine is contained in a proportion of 1 to 20 parts by weight, preferably 1 to 10 parts by weight. Included in percentage.

The antifogging agent (C) preferably used in the present invention
Is, for example, as follows. (1) An antifogging agent comprising glycerin stearate, diglycerin stearate, and diethanolstearylamine. (2) An anti-fogging agent comprising glycerin palmitate, diglycerin palmitate, and diethanolstearylamine. (3) An antifogging agent comprising glycerin laurate, diglycerin laurate, and diethanolstearylamine. (4) An antifogging agent comprising glycerin behenate, diglycerin behenate, and diethanolstearylamine. (5) Any mixture of the above (1) to (4).

The antifogging agent (C) is used in an amount of preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). Is used in a proportion of 0.1 to 4 parts by weight, more preferably 0.5 to 3 parts by weight.

[Other Components] In the above-mentioned ethylene copolymer composition (1), if necessary, a conventionally known weather resistance stabilizer, antioxidant, antifog, inorganic compound, antistatic agent,
Additives such as heat stabilizers can be blended within a range that does not impair the purpose of the present invention.

The weather stabilizer is roughly classified into an ultraviolet absorber and a light stabilizer. The light stabilizer is more effective for a thin agricultural film and has a large effect of improving the weather stability. As the light stabilizer, a conventionally known light stabilizer can be used,
Among them, hindered amine light stabilizers (HALS; Hinder
ed Amine Light Stabilizers) are preferably used.

The following compounds are specifically used as the hindered amine stabilizer. (1) bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, (2) dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-succinate Tetramethylpiperidine polycondensate, (3) tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, (4) 2,2,6, 6-tetramethyl-4-piperidinyl benzoate, (5) bis- (1,2,6,6-tetramethyl-4
-Piperidinyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, (6) bis (N-
Methyl-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, (7) 1,1 ′-(1,2-ethanediyl) bis (3,3,
5,5-tetramethylpiperazinone), (8) (mixed
2,2,6,6-tetramethyl-4-piperidyl / tridecyl)-
1,2,3,4-butanetetracarboxylate, (9) (mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate ,
(10) Mixed {2,2,6,6-tetramethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3-9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl｝ -1,2,
3,4-butanetetracarboxylate, (11) mixed {1,2,2,6,6-pentamethyl-4-piperidyl / β, β,
β ', β'-tetramethyl-3-9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, (12 ) N, N'-Bis (3-aminopropyl) ethylenediamine-2-4-bis [N-butyl-N-
(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6
-Chloro-1,3,5-triazine condensate, (13) of N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 1,2-dibromoethane Condensate, (14)
[N- (2,2,6,6-tetramethyl-4-piperidyl) -2-methyl-2- (2,2,6,6-tetramethyl-4-piperidyl) imino] propionamide and the like.

These hindered amine light stabilizers include:
They can be used alone or in combination of two or more. The light stabilizer is used in an amount of 0.005 to 5 parts by weight, preferably 0.005 to 5 parts by weight, based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). 2 parts by weight, more preferably 0.0
It is used in a ratio of 1 to 1 part by weight.

Specific examples of the ultraviolet absorber include salicylic acid ultraviolet absorbers such as phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4 -Methoxybenzophenone, 2-hydroxy-4
-Octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy- Benzophenone UV absorbers such as 5-sulfobenzophenone; 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, (2'-hydroxy-3 ', 5'
-Di-tert-butylphenyl) benzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5- Benzotriazole-based absorbents such as chlorobenzotriazole and 2- (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole; 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate And cyanoacrylate-based ultraviolet absorbers such as ethyl-2-cyano-3,3'-diphenylacrylate.

The ultraviolet absorber is used in an amount of 0.005 to 5 parts by weight based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B).
It is used at a ratio of 0.005 to 2 parts by weight, preferably 0.01 to 1 part by weight.

Inorganic compounds include Mg, which is effective as a heat insulator,
Examples include inorganic oxides, inorganic hydroxides, and hydrotalcites containing at least one atom of Ca, Al and Si.

Specifically, SiO ₂ , Al ₂ O ₃ , Mg
Inorganic oxides such as O and CaO; Al (OH) ₃ , Mg (O
H) ₂ , inorganic hydroxides such as Ca (OH) ₂ ; Formula M 2 ⁺ _{1 -x} Al _x (OH) ₂ (A ⁿ⁻ ) _{x / n} · mH ₂ O wherein M ²⁺ is mg, a divalent metal ion of Ca or Zn, a ^{n-is Cl -, Br -, I -} , NO 3 2-, C
10 ^4- , SO ₄ ^2- , CO ₂ ^2- , SiO ₃ ^2- , HPO
Anions such as ₄ ²⁻ , HBO ₃ ²⁻ , and PO ₄ ²⁻ ;
Is a numerical value satisfying the condition 0 <x <0.5, and m
Is a numerical value satisfying the condition of 0 ≦ m ≦ 2], and hydrotalcites such as a calcined product thereof. Among these, hydrotalcites are preferable, and a fired product of the inorganic composite compound represented by the above formula is particularly preferable.

The above inorganic compounds can be used alone or in combination of two or more. The average particle size of the inorganic compound is desirably 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less.

When the average particle size of the inorganic compound is within the above range, a film having good transparency can be obtained. The inorganic compound is used in an amount of 1 to 20 parts by weight, preferably 1 to 18 parts by weight, more preferably 2 to 100 parts by weight based on 100 parts by weight of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). It is used in a proportion of up to 15 parts by weight.

When the inorganic compound is used in the above ratio, a film having excellent heat retention can be obtained. The agricultural film according to the present invention has a layer composed of the ethylene copolymer composition (1) as described above.

When the agricultural film according to the present invention is a single-layer film comprising a layer formed of the above-mentioned ethylene-based copolymer composition (1), the agricultural film usually has a thickness of 30 to 200 μm. Preferably 40 to 180 μm,
More preferably, it is in the range of 50 to 150 μm.

The agricultural film according to the present invention, which is such a single-layer film, has the following physical properties and characteristics. (I) Elmendorf tear strength is 90 kg in MD direction
/ Cm or more, preferably 100 kg / cm or more,
And 90 kg / cm or more in the TD direction, preferably 10 kg / cm or more.
0 kg / cm or more. (Ii) The dirt impact strength at a thickness of 100 μm is 4
It is 50 g or more, preferably 500 g or more. (Iii) The tensile strength at break is 350 kg / c in the MD direction.
m ² or more, preferably 400 kg / cm ² or more,
And it is 350 kg / cm ² or more, preferably 400 kg / cm ² or more in the TD direction.

The agricultural film having a single-layer structure according to the present invention as described above can be prepared from the above-described ethylene copolymer composition (1) by, for example, film formation by an inflation method or a T-die method. .

The film forming by the inflation method is carried out by extruding the ethylene copolymer composition (1) through a slit die and expanding it by a predetermined air flow. The resin temperature at the time of extruding the ethylene-based copolymer composition (1) is preferably 190 to 250 ° C.

As described above, the agricultural film according to the present invention comprises the above-mentioned ethylene copolymer composition (1).
It may be a multilayer structure having a layer formed by: As the agricultural film having a multilayer structure according to the present invention, for example, a three-layer laminated film including the following outer layer, intermediate layer, and inner layer is particularly preferable.

Outer Layer The outer layer constituting the above three-layer laminated film is made of ethylene α
-It is formed from an ethylene copolymer composition (2) containing an olefin copolymer (D) and a high-pressure low-density polyethylene (B).

[Ethylene / α-olefin copolymer (D)] The ethylene / α-olefin copolymer (D) forming the outer layer of the three-layer laminated film is composed of ethylene and α-olefin having 4 to 12 carbon atoms. It is a copolymer comprising an olefin, and has a density of 0.925 to 0.940 g / cm ³ , preferably 0.925 to 0.935 g / cm ³ , except that the above-mentioned agricultural monolayer film is formed. It is the same as the ethylene / α-olefin copolymer (A) used in this case.

The ethylene / α-olefin copolymer (D) is prepared in the same manner as the above-mentioned method for producing the ethylene / α-olefin copolymer (A) in the presence of a metallocene-based olefin polymerization catalyst. In addition, ethylene can be produced by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms such that the density of the obtained copolymer is 0.925 to 0.940 g / cm ³ .

In the present invention, the ethylene / α-olefin copolymer (D) is used based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (D) and the high-pressure low-density polyethylene (B). , 60 to 100 parts by weight, preferably 65 to 99 parts by weight, more preferably 70 to 95 parts by weight.
Used in parts by weight.

[High-pressure low-density polyethylene (B)] The high-pressure low-density polyethylene (B) forming the outer layer of the three-layer laminated film is a high-pressure low-density polyethylene used for forming the above-mentioned single-layer agricultural film. Polyethylene (B)
Is the same as

In the present invention, the high-pressure low-density polyethylene (B) may be added, if necessary, to 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (D) and the high-pressure low-density polyethylene (B). On the other hand, 0 to 40 parts by weight, preferably 1 to 35 parts by weight, more preferably 5 to
Used in a proportion of 30 parts by weight.

[Other Components] In the ethylene copolymer composition (2) for forming the outer layer, if necessary, the above antifogging agent (C) and a conventionally known weather resistance stabilizer and antioxidant may be used. Additives such as an antifog, an inorganic compound, an antistatic agent and a heat stabilizer can be blended within a range that does not impair the object of the present invention.

The weathering stabilizers used in forming the outer layer are the same as the weathering stabilizers (ultraviolet absorbers, light stabilizers) used as necessary in forming the above-mentioned single-layer agricultural film. The light stabilizer is used in an amount of 0.005 to 5 based on 100 parts by weight of the total of the ethylene / α-olefin copolymer (D) and the high-pressure low-density polyethylene (B).
It is used at a ratio of 0.005 to 2 parts by weight, preferably 0.01 to 1 part by weight. Also,
The ultraviolet absorber is used in an amount of 0.005 to 5 parts by weight, preferably 0.005 to 2 parts by weight, based on 100 parts by weight of the total of the ethylene / α-olefin copolymer (D) and the high-pressure low-density polyethylene (B). Parts by weight, more preferably 0.01
It is used in a proportion of １1 part by weight.

The antifogging agent (C) used here is the same as the antifogging agent (C) used for forming the above-mentioned single-layer agricultural film. Antifogging agent (C) is ethylene
With respect to 100 parts by weight of the total amount of the α-olefin copolymer (D) and the high-pressure low-density polyethylene (B), 0.0
5 to 5 parts by weight, preferably 0.1 to 4 parts by weight, more preferably 0.5 to 3 parts by weight.

The inorganic compound used here is the same as the inorganic compound used as needed when forming the above-mentioned single-layer agricultural film. Inorganic compounds are
1 to 100 parts by weight of ethylene / α-olefin copolymer (D) and high-pressure low-density polyethylene (B)
It is used in a proportion of 20 parts by weight, preferably 1 to 18 parts by weight, more preferably 2 to 15 parts by weight. When the inorganic compound is used at the above ratio when forming the outer layer,
A three-layer laminated film having excellent heat retention can be obtained.

Intermediate Layer The intermediate layer constituting the three-layer laminated film is made of ethylene.
It is formed from an ethylene copolymer composition (3) containing an α-olefin copolymer (E), an antifogging agent (C) and, if necessary, a high-pressure low-density polyethylene (B).

[Ethylene / α-Olefin Copolymer (E)] The ethylene / α-olefin copolymer (E) forming the intermediate layer of the three-layer laminated film is composed of ethylene and α-olefin having 4 to 12 carbon atoms. A copolymer comprising an olefin and an ethylene / α-olefin copolymer as described above except that the density is 0.880 to 0.910 g / cm ³ , preferably 0.890 to 0.905 g / cm ³ Same as the polymer (A).

The ethylene / α-olefin copolymer (E) is prepared in the same manner as the above-mentioned method for producing the ethylene / α-olefin copolymer (A) in the presence of a metallocene olefin polymerization catalyst. The copolymer can be produced by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms such that the density of the obtained copolymer is 0.880 to 0.910 g / cm ³ .

In the present invention, the ethylene / α-olefin copolymer (E) is used based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B). , 60 to 100 parts by weight, preferably 65 to 99 parts by weight, more preferably 70 to 95 parts by weight.
Used in parts by weight.

[High-Pressure Low-Density Polyethylene (B)] The high-pressure low-density polyethylene (B) forming the intermediate layer of the three-layer laminated film is a high-pressure low-density polyethylene used for forming the above-mentioned single-layer agricultural film. Same as the density polyethylene (B).

In the present invention, the high-pressure low-density polyethylene (B) is from 0 to 100 parts by weight in total of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B). 40 parts by weight, preferably 1
To 35 parts by weight, more preferably 5 to 30 parts by weight.

[Anti-fogging agent (C)] The anti-fogging agent (C) added to the ethylene / α-olefin copolymer (E) for forming the intermediate layer and the high-pressure low-density polyethylene (B) is as described above. This is the same as the antifogging agent (C) used for forming the agricultural film having a single-layer structure.

The antifogging agent (C) is used in an amount of preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B). Is used in a proportion of 0.1 to 4 parts by weight, more preferably 0.5 to 3 parts by weight.

[Other Components] In the ethylene copolymer composition (3) for forming the intermediate layer, if necessary, conventionally known weather resistance stabilizers, antioxidants, inorganic compounds, anti-fog agents, electrifications, etc. Additives such as an inhibitor and a heat stabilizer can be blended within a range that does not impair the object of the present invention.

The weather-resistant stabilizer used in forming the intermediate layer is the same as the weather-resistant stabilizer (ultraviolet absorber, light stabilizer) used as necessary in forming the above-mentioned single-layer agricultural film. The light stabilizer is used in an amount of 0.005 to 5 based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B).
It is used at a ratio of 0.005 to 2 parts by weight, preferably 0.01 to 1 part by weight. The ultraviolet absorber is used in an amount of 0.005 to 5 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B).
005 to 2 parts by weight, more preferably 0.01 to 1 part by weight.

The inorganic compound used in forming the intermediate layer is the same as the inorganic compound used as necessary in forming the above-mentioned single-layer agricultural film.
The inorganic compound is used in an amount of 1 to 7.0 parts by weight based on 100 parts by weight of the total amount of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B). When the inorganic compound is used at the above ratio when forming the intermediate layer, a three-layer laminated film excellent in heat retention can be obtained.

[0124] inner layer constituting the inner layer the three-layer laminated film, containing ethylene · alpha-olefin copolymer described above (A), anti-fogging agent (C) and high-pressure low-density polyethylene optionally (B) From the ethylene copolymer composition (1). The composition (1) is as described above.

In the present invention, the density of the resin forming the outer layer (d _D or d _DB ) and the density of the resin forming the inner layer (d _A or d _AB ) are d _D or d _DB ≧ d _A or d _AB is satisfied. Here, resin is ethylene / α
-Refers to an olefin copolymer or a copolymer of an ethylene / α-olefin copolymer and a high-pressure low-density polyethylene.

Accordingly, the anti-fogging agent (C) contained in the intermediate layer gradually moves to the inner layer made of a resin having a low density, so that the anti-fogging property of the inner layer can be maintained. If the density of the ethylene · alpha-olefin copolymer for forming the inner layer (A) is too smaller than 0.905 g / cm ^3, greater stickiness of the inner surface of the film, poor sliding of pipe house, stretched workability Tends to be impaired.

The agricultural film according to the present invention, which is a three-layer laminated film as described above, has a thickness of the outer layer of usually 3 to 1
00 μm, preferably 10 to 80 μm, more preferably 20 to 70 μm, and the thickness of the intermediate layer is 10 to
150 μm, preferably 20 to 120 μm, more preferably 30 to 100 μm, and the thickness of the inner layer is 3 μm.
To 100 μm, preferably 10 to 80 μm, more preferably 20 to 70 μm, and the total thickness of these layers is 30 to 200 μm, preferably 50 to 18 μm.
0 μm, more preferably in the range of 70 to 150 μm.

In such a three-layer laminated film,
Ratio of the thicknesses of the outer layer [I], the intermediate layer [II] and the inner layer [III] (outer layer [I] / intermediate layer [II] / inner layer [III])
Is from 0.2 to 4/1 to 10/1, preferably from 0.5 to 2
/ 2 to 6/1.

The agricultural film according to the present invention, which is a three-layer laminated film as described above, has the following physical properties and characteristics. (I) Elmendorf tear strength is 90 kg in MD direction
/ Cm or more, preferably 100 kg / cm or more,
And 90 kg / cm or more in the TD direction, preferably 10 kg / cm or more.
0 kg / cm or more. (Ii) The dirt impact strength at a thickness of 100 μm is 9
It is at least 00 g, preferably at least 1,000 g. (Iii) The tensile strength at break is 350 kg / c in the MD direction.
m ² or more, preferably 370 kg / cm ² or more,
And it is 350 kg / cm ² or more, preferably 370 kg / cm ² or more in the TD direction.

The agricultural film according to the present invention having the three-layer structure as described above is obtained by mixing the components such as the polyethylene resin used in each layer and the above-mentioned additives.
It can be prepared by melt-mixing with a Banbury mixer or a roll mill, an extruder or the like, and then laminating an outer layer, an intermediate layer and an inner layer by a coextrusion inflation method or a coextrusion T-die method.

It is to be noted that two or four or more layers
The agricultural film according to the present invention can be prepared according to these preparation methods.

[0132]

According to the present invention, there is provided an agricultural film having excellent antifogging durability, dust resistance and toughness as compared with the conventional agricultural films (single-layer and multilayer films) described above. be able to. In addition, the agricultural film according to the present invention is lightweight, and has a small amount of low molecular weight components in the polymer used, so that it is less sticky, has excellent spreadability, and has a high degree of fusion between films at high temperatures. It has the advantage of being small. In particular, the agricultural film composed of the above-described three-layer laminated film has excellent antifogging durability because the resin forming the outer layer has a higher density than the resin forming the inner layer.

Since the agricultural film according to the present invention has the above-mentioned effects, it can be spread over agricultural and horticultural facilities such as houses and tunnels and used for a long time for cultivation of useful crops.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. In addition, the evaluation of the agricultural film in an Example and a comparative example was performed as follows. (1) Antifogging property In a constant temperature room set at 5 ° C., the inclination angle of the wooden frame 1 (the sides are plates and the upper and lower surfaces are open) of 15 ° is shown in FIG. A film sample connected by heat sealing is put on the upper surface of the film, placed in a constant temperature water bath at 30 ° C. in a wooden frame 1 under the film, and after a predetermined time, the state of water droplets adhering to the inner surface of the film is observed. Was evaluated as anti-fogging property.

<Five-grade evaluation> ：: No water droplet is observed in a flowing state. △ to 流 れ: Flow streaks remain in the flowing state.

Δ: Flow streaks and water droplets are mixed. Δ to ×: Flow streaks and water droplets are mixed, and there are many water droplets. ×: Fine water droplets adhered to almost the entire surface of the film. (2) Elmendorf tear strength: longitudinal and transverse strengths were measured by a method based on JIS Z-1702. (3) Dart Impact Strength Dart impact strength was determined by performing an impact test in accordance with JIS Z 1707 (diameter of dirt tip: 38 mm). (4) Tensile strength at break The tensile strength at break is based on JIS K6781, and is a cross-head moving speed constant tensile tester (manufactured by Instron Corporation) in the MD and TD directions of the multilayer film under the following conditions. Is a value obtained by conducting a tensile test using

[Test conditions] Sample: JIS K6781 Atmospheric temperature: 23 ° C Peeling speed: 500 mm / min

[0138]

[Reference Example 1] Preparation of ethylene / 1-hexene copolymer [Preparation of catalyst for olefin polymerization] 5.0 kg of silica dried at 250 ° C for 10 hours was suspended in 80 liters of toluene, and then cooled to 0 ° C. Cool. Thereafter, 28.7 l of a toluene solution of methylaluminoxane (Al; 1.33 mol / l) was added dropwise over 1 hour. At this time, the temperature in the system was kept at 0 ° C. Subsequently, the reaction was carried out at 0 ° C. for 60 minutes, then the temperature was raised to 95 ° C. over 1.5 hours, and the reaction was carried out at that temperature for 20 hours. Thereafter, the temperature was lowered to 60 ° C., and the supernatant was removed by a decantation method.

The solid component thus obtained was washed twice with toluene and then resuspended in 80 liters of toluene. 7.4 liters of a toluene solution of bis (1,3-n-butylmethylcyclopentadienyl) zirconium dichloride (Zr; 34.0 mmol / l) and bis (1,3-dimethylcyclopentadienyl) were introduced into the system. ) 1.0 L of a toluene solution of zirconium dichloride (Zr; 28.1 mmol / L) was added dropwise at 80 ° C over 30 minutes, and the reaction was further performed at 80 ° C for 2 hours. Thereafter, the supernatant was removed and washed twice with hexane to obtain a solid catalyst containing 3.6 mg of zirconium per gram. [Preparation of prepolymerized catalyst] In 85 liters of hexane containing 1.7 mol of triisobutylaluminum, 0.85 kg of the solid catalyst obtained above and 1-hexene 25 were added.
5 g was added, and ethylene was prepolymerized at 35 ° C. for 12 hours to obtain a prepolymerized catalyst in which 10 g of polyethylene was prepolymerized per 1 g of the solid catalyst. The intrinsic viscosity [η] of this ethylene polymer was 1.74 dl / g. [Polymerization] Using two continuous fluidized-bed gas-phase polymerization apparatuses connected in series, ethylene and 1-
Copolymerization with hexene was performed to obtain an ethylene / 1-hexene copolymer.

The ethylene / 1-hexene copolymer obtained as described above had a 1-hexene content of 7.5% by weight, a density of 0.928 g / cm ³ and a melt flow rate (MFR). ASTM D 1238-65T, 19
0 ° C., load 2.16 kg) was 1.63 g / 10 min, and the molecular weight distribution (Mw / Mn) measured by GPC
Was 3.5.

This copolymer had a temperature [Tm] of one of the maximum peaks of an endothermic curve measured by a differential scanning calorimeter (DSC) of 120 ° C., and a fraction of n-decane soluble component at room temperature. [W] was 0.25% by weight.

The above B ₁ measured by GPC-IR analysis of this copolymer was 12.2 / 1000 C (12.2 per 1000 carbon atoms), and B ₂ was 9.9 / 1
000C.

[0143]

Reference Example 2 Copolymerization of ethylene and 1-hexene was carried out in the presence of the prepolymerization catalyst described in Reference Example 1 above using two continuous fluidized bed gas phase polymerization apparatuses connected in series. An ethylene / 1-hexene copolymer was obtained.

The ethylene / 1-hexene copolymer obtained as described above has a 1-hexene content of 11% by weight, a density of 0.915 g / cm ³ and a melt flow rate (MFR; ASTM). D 1238-65T, 19
(0 ° C., load 2.16 kg) is 2.19 g / 10 min, and the molecular weight distribution (Mw / Mn) measured by GPC
Was 3.5.

This copolymer had a temperature [Tm] of one of the maximum peaks of an endothermic curve measured by a differential scanning calorimeter (DSC) of 108 ° C., and a fraction of n-decane soluble component at room temperature. [W] was 0.42% by weight.

The above-mentioned B ₁ measured by GPC-IR analysis on this copolymer was 18.6 / 1000 C,
₂ was 14.7 / 1000C.

[0147]

Reference Examples 3 and 4 An ethylene / 1-hexene copolymer as shown in Table 1 was obtained in the same manner as in Reference Example 1.

[0148]

[Table 1]

[0149]

EXAMPLES 1 AND 2 AND COMPARATIVE EXAMPLES 1 AND 2 A three-layer film having a thickness of 100 μm was blown molded under the conditions shown in Table 2 using the resins shown in Table 1. [Inflation molding conditions] Molding machine: 3-layer machine manufactured by Alpine Company Die diameter: 400 mm Molding temperature: 200 ° C Folding width: 1500 mm Thickness: All layers 100 μm (outer / intermediate / inner = 20 μm
(m / 60 μm / 20 μm) Table 3 shows the physical properties of the film obtained as described above.

[0150]

[Table 2]

[0151]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a wooden frame used in an antifogging test of a multilayer film in Examples and Comparative Examples according to the present invention.

[Explanation of symbols]

 1 ····· Wooden frame

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08J 5/18 CES C08J 5/18 CES // C08K 3/00 C08K 3/00 5/103 5/103 5/17 5/17 C08L 23/06 C08L 23/06 23/18 23/18 (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 A01G 9/14 A01G 13/02 C08J 5/18

Claims (14)

(57) [Claims] (1) [I] ethylene and α having 4 to 12 carbon atoms
-Obtained by copolymerization with an olefin and having a density of 0.905
~0.935g / cm ³ and an ethylene · alpha-olefin copolymer melt flow rate is 0.1 to 10 g / 10 min (A) 100 parts by weight of, or the ethylene · alpha
-100 parts by weight of a mixture of the olefin copolymer (A) and the high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, [II] a glycerin alkyl ester represented by the following formula (I), An ethylene copolymer composition (1) containing a diglycerin alkyl ester represented by the formula (II) and a diethanol alkylamine represented by the following formula (III): 0.05 to 5 parts by weight (C). Wherein the ethylene / α-olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) is (I) The molecular weight distribution (Mw / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) measured by GPC is in the range of 1.5 to 3.5, and (ii) n-decane soluble at 23 ° C. Component amount fraction W (% by weight)) Density (and d), but, W <80 × exp (-100 (d-0.88)) + 0.
(Iii) When the average value of the number of branches on the high molecular weight side by GPC-IR is B ₁ and the average value of the number of branches on the low molecular weight side is B ₂ , B ₁ ≧ B ₂ Agricultural film characterized by the following: [In the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom or an acyl group having 12 to 22 carbon atoms.] [In the formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or an acyl group having 12 to 22 carbon atoms.] [In the formula (III), R ⁸ is an alkyl group having 12 to 22 carbon atoms.] 2. An ethylene copolymer composition (1) containing said ethylene / α-olefin copolymer (A), antifogging agent (C) and, if necessary, high-pressure low-density polyethylene (B). ) Is a single-layer film consisting of a layer formed by
The film has (i) an Elmendorf tear strength of 90 kg / cm or more in the MD direction and 90 kg / cm or more in the TD direction, and (ii) a thickness of 10
The dirt impact strength at 0 μm is 450 g or more, and (iii) the tensile strength at break is 350 kg /
cm ² or more and 350 kg / cm in the TD direction.
The agricultural film according to claim 1, wherein the number is ² or more. 3. The ethylene / α-olefin copolymer (A) is a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms prepared using a metallocene catalyst. The agricultural film according to claim 1 or 2, wherein 4. The antifogging agent (C) comprises 10 to 40 parts by weight of the glycerin alkyl ester, 20 to 80 parts by weight of diglycerin alkyl ester, and 1 to 20 parts by weight of diethanolalkylamine [total of these components]. The quantity is 100
Parts by weight].
4. The agricultural film according to any one of 3. 5. An ethylene / α-olefin copolymer (A) and an inorganic compound containing at least one atom of Mg, Ca, Al and Si in the ethylene copolymer composition (1). High pressure method low density polyethylene (B)
The agricultural film according to any one of claims 1 to 4, which is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total. 6. The agricultural film according to claim 1, wherein the thickness is 30 to 200 μm. 7. [I] Ethylene and α having 4 to 12 carbon atoms
-Obtained by copolymerization with olefin and having a density of 0.925
0.99 g / cm ³ and an ethylene / α-olefin copolymer (D) having a melt flow rate of 0.1 to 10 g / 10 minutes, or the ethylene / α-olefin copolymer (D). An outer layer comprising an ethylene-based copolymer composition (2) containing a mixture with a high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, [II] ethylene and an α-olefin having 4 to 12 carbon atoms And has a density of 0.880 to 0.910 g / cm ³ ,
100 parts by weight of an ethylene / α-olefin copolymer (E) having a melt flow rate of 0.1 to 10 g / 10 minutes,
Or the ethylene / α-olefin copolymer (E) and 4
100 parts by weight of a mixture with a high-pressure low-density polyethylene (B) in an amount of 0% by weight or less, and a glycerin alkyl ester represented by the formula (I);
An ethylene copolymer composition containing a diglycerin alkyl ester represented by the formula (II) and 0.05 to 5 parts by weight of an antifogging agent (C) comprising a diethanolalkylamine represented by the formula (III) An intermediate layer comprising (3), and [III] ethylene and α having 4 to 12 carbon atoms.
-Obtained by copolymerization with an olefin and having a density of 0.905
~0.935g / cm ³ and an ethylene · alpha-olefin copolymer melt flow rate is 0.1 to 10 g / 10 min (A) 100 parts by weight of, or the ethylene · alpha
-100 parts by weight of a mixture of the olefin copolymer (A) and the high-pressure low-density polyethylene (B) in an amount of 40% by weight or less, and a glycerin alkyl ester represented by the formula (I);
An ethylene copolymer composition containing a diglycerin alkyl ester represented by the formula (II) and 0.05 to 5 parts by weight of an antifogging agent (C) comprising a diethanolalkylamine represented by the formula (III) A multilayer film in which an inner layer made of (1) is laminated, and an ethylene / α-olefin copolymer (D) or an ethylene / α-olefin copolymer (D) forming the outer layer
Density (d _D or d _DB ) of a mixture of ethylene and high-pressure low-density polyethylene (B) and the ethylene / α-
Olefin copolymer (A) or ethylene / α-olefin copolymer (A) and high-pressure low-density polyethylene (B)
Is the density (d _A or d _AB ) of d _D or d _DB ≧ d
_2. The agricultural film according to claim 1, wherein the relationship satisfies _A or d _AB . 8. An ethylene / α-olefin copolymer (D) or a mixture of an ethylene / α-olefin copolymer (D) and a high-pressure low-density polyethylene (B) for forming the outer layer, and an intermediate layer The ethylene / α-olefin copolymer (E) or a mixture of the ethylene / α-olefin copolymer (E) and the high-pressure low-density polyethylene (B), which forms (i) the molecular weight distribution measured by GPC ( M
w / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) is in the range of 1.5 to 3.5, and (ii) n-decane soluble component fraction at 23 ° C. (W (weight%)) ) And density (d) are: W <80 × exp (−100 (d−0.88)) + 0.
(Iii) When the average value of the number of branches on the high molecular weight side by GPC-IR is B ₁ and the average value of the number of branches on the low molecular weight side is B ₂ , B ₁ ≧ B ₂ The agricultural film according to claim 7, which is provided. 9. The ethylene / α-olefin copolymers (D) and (E) are copolymers of ethylene and an α-olefin having 4 to 12 carbon atoms prepared using a metallocene catalyst. 9. The method according to claim 7, wherein:
2. The agricultural film according to item 1. 10. The ethylene copolymer composition (2), wherein the antifogging agent (C) is the total amount of the ethylene / α-olefin copolymer (D) and the high-pressure low-density polyethylene (B). The agricultural film according to any one of claims 7 to 9, wherein the amount is 0.05 to 5 parts by weight based on 100 parts by weight. 11. An ethylene / α-olefin copolymer (D) and an inorganic compound containing at least one atom of Mg, Ca, Al and Si in the ethylene copolymer composition (2). High pressure method low density polyethylene (B)
The agricultural film according to any one of claims 7 to 10, which is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total. 12. An ethylene / α-olefin copolymer (E) and an inorganic compound containing at least one atom of Mg, Ca, Al and Si in the ethylene copolymer composition (3). High pressure method low density polyethylene (B)
The agricultural film according to any one of claims 7 to 11, wherein 1 to 7.0 parts by weight is contained with respect to 100 parts by weight of the total amount of 13. The thickness ratio of the outer layer [I], the intermediate layer [II] and the inner layer [III] (outer layer [I] / intermediate layer [I]
I] / inner layer [III]) is 0.2 to 4/1 to 10/1, and the total thickness of these layers is 30 to 200 μm. 2. The agricultural film according to item 1. (I) Elmendorf tear strength in the MD direction is 90 kg / cm or more, and in the TD direction is 90 kg / cm or more.
The dirt impact strength at 0 μm is 900 g or more, and (iii) the tensile break strength is 350 kg / MD in the MD direction.
cm ^{2 or} more, and, agricultural film according to any one of claims 7 to 13, characterized in that in the TD direction is 350 kg / cm ² or more.