JPH10119213A - Agricultural film and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural film in which optical characteristics (transparency and surface glossiness) in the early stage of extension and extension workability (flexibility) are particularly excellent in comparison with the agricultural film consisting of a conventional film made of polyolefin-based resin. SOLUTION: An ethylene/α-olefin copolymer in which density is 0.885-0.940g/cm<3> and MFR is 0.1-10g/10 minutes is obtained by copolymerizing ethylene and 4-12C α-olefin. The agricultural film has a layer which is formed of the ethylene/α-olefin copolymer or of resin consisting of the mixture of this copolymer and >=40wt.% high pressure processed low density polyethylene. The whole thickness of the film is 60-160μm and haze (ASTM D 1003) is below 10% and gloss (ASTM D 523) is >=90%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an agricultural film and a method for producing the same.

[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. Among such agricultural films, a polyvinyl chloride (PVC) film has been mainly used as a house film in particular.

However, PVC films are heavy and poor in workability, and lack strength at low temperatures.
Also, the plasticizer bleeds out during use,
Dust adheres and the light transmittance decreases with time. Further, the PVC film generates a halogen-based gas at the time of incineration. Since the PVC film has the above-mentioned problems, in recent years, the use of a polyolefin resin film in place of the PVC film has been increasing.

[0004] However, conventionally used polyolefin resin films are superior to PVC films in terms of the above-mentioned problems of PVC films, but the optical properties at the initial stage of expansion are poor in PVC films, especially outside the house. It is inferior to a PVC film whose equivalent surface has been dustproofed by applying an acrylic resin or the like. Also, polyolefin resin films are less pliable than PVC films, so for users accustomed to PVC films, they have a rough feel.
It has been pointed out that it is difficult to extend and fix the house.

Accordingly, the inventors of the present invention have conducted intensive studies and have studied the copolymerization of an ethylene / α-olefin copolymer having a specific density and a melt flow rate or a high-pressure low-density polyethylene of 40% by weight or less with this copolymer. The present inventors have found that the performance of a conventionally used polyolefin resin film can be improved by forming a film using a resin composed of a mixture, thereby completing the present invention.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above. It is an object of the present invention to provide an agricultural film excellent in spreading workability and a method for producing the same.

[0007]

The agricultural film according to the present invention is obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms, has a density of 0.885 to 0.940 g / cm ³ , Resin (C) comprising ethylene / α-olefin copolymer (A) having a melt flow rate of 0.1 to 10 g / 10 min, or 40% by weight or less with said ethylene / α-olefin copolymer (A) (A) having a thickness of 60 to 200 μm, and (ii) a haze. (ASTM D 1
003) is less than 10%, and (iii) gloss (ASTM)
D 523) is 90% or more.

The agricultural film according to the present invention is a single-layer film having the above-mentioned layers or a multilayer film having two or more layers. Ethylene / α- constituting the resin (C)
The mixture of the olefin copolymer (A) or the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) is (i) a molecular weight distribution (Mw / Mn: Mw = Weight average molecular weight, Mn =
(Number average molecular weight) is in the range of 1.5 to 5.0, and (ii)
The fraction (W (% by weight)) of the n-decane soluble component at 23 ° C. and the density (d (g / cm ³ )) 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.

The ethylene / α-olefin copolymer (A) is preferably a copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms prepared using a metallocene catalyst.

[0010] The agricultural film according to the present invention is desirably formed by a water-cooled inflation method. In the resin (C), an ethylene / α-olefin copolymer (A) or an ethylene / α-olefin copolymer (A)
The antiblocking agent (D) and / or the slip agent (E) are preferably contained in an amount of 0.01 to 3.0 parts by weight based on 100 parts by weight of the mixture of the high-pressure method and the low-density polyethylene (B).

In the resin (C), ethylene · α
-100% by weight of a mixture of olefin copolymer (A) or ethylene / α-olefin copolymer (A) and high-pressure low-density polyethylene (B), antifoggant (F)
Is preferably contained in an amount of 0.01 to 5.0 parts by weight.
The antifogging agent (F) is preferably selected from the group consisting of glycerin alkyl esters, diglycerin alkyl esters, diethanol alkylamines, polyoxyethylene sorbitan esters, and mixtures thereof.

[0012] Among the agricultural films according to the present invention, preferred multilayer films are two or more multilayer films composed of an outer layer and an inner layer, or three or more layers composed of an outer layer and one or more intermediate layers and an inner layer. At least one of the outer layer and the inner layer is obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms, and has a density of 0.885 to 0.940.
g / cm ³ and the melt flow rate is 0.1 to 10
g / 10 minutes of the resin (C) comprising the ethylene / α-olefin copolymer (A) or the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene in an amount of 40% by weight or less. The multilayer film is formed of a resin (C) comprising a mixture with (B), (i) the total thickness of the film is 60 to 200 μm, and (ii) the haze (AS)
TMD 1003) is less than 10%, and (iii) gross (ASTM D 523) is 90% or more.

The resin (C) for forming the outer layer or the inner layer
Ethylene / α-olefin copolymer (A) constituting
Alternatively, a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) is obtained by (i) GP
The molecular weight distribution (Mw / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) measured in C is 1.5 to 5.0.
(Ii) n-decane soluble component amount fraction (W (weight%)) and density (d (g / cm ³ )) at 23 ° C. 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.

Further, the ethylene / α-olefin copolymer (A) used for forming the outer layer or the inner layer is obtained by mixing ethylene prepared using a metallocene catalyst with α-olefin having 4 to 12 carbon atoms. It is preferably a copolymer.

[0015] The agricultural film comprising the multilayer film is desirably formed into a film by a water-cooled inflation method. The resin (C) for forming the outer layer or the inner layer is 100% by weight of the ethylene / α-olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). It is preferable that the antiblocking agent (D) and / or the slip agent are contained in an amount of 0.01 to 3.0 parts by weight, respectively.

The resin (C) forming the outer layer or the inner layer is an ethylene / α-olefin copolymer (A) or an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). It is preferable that the antifogging agent (F) is contained in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the mixture.

The intermediate layer constituting the multilayer film comprises an ethylene / α-olefin copolymer (A), an ethylene / vinyl acetate copolymer, a high-pressure low-density polyethylene (B),
It is preferably formed of at least one resin selected from the group consisting of an ethylene / (meth) acrylic acid copolymer and an ionomer resin.

In the method for producing an agricultural film according to the present invention, the agricultural film having a single-layer or multilayer structure having a layer formed of the resin (C) may be expanded to a bubble expansion ratio of 0.5 to 0.5.
2.0, tubular film cooling water temperature 10-60
It is characterized by being obtained by water-cooled inflation molding at a temperature of 5 ° C. and a draft rate of bubble of 5 to 100.
In this production method, in particular, a film having a layer formed of the resin (C) is extruded downward from a circular die by an inflation molding method, and then cooled by passing through a water tank to which an inorganic anti-fogging agent composition has been added. It is preferable to adopt a method in which the film is taken up while being dried, and then the film surface is dried.

[0019]

DETAILED DESCRIPTION OF THE INVENTION The agricultural film and the method for producing the same according to the present invention will be specifically described below.

The agricultural film according to the present invention comprises a resin (C) comprising an ethylene / α-olefin copolymer (A) or an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). And a layer formed of a resin (C) comprising a mixture of In this resin (C),
Additives such as an anti-blocking agent (D), a slip agent (E), and an anti-fogging agent (F) can be added. The agricultural film according to the present invention may be a single-layer film composed of such layers, or may be a multilayer film having two or more layers having such layers. Further, the agricultural film according to the present invention may be provided with a coating of an inorganic anti-fogging agent composition on at least one outer surface having a layer formed of the resin (C).

Ethylene / α-olefin copolymer (A) Ethylene / α constituting the resin (C) used in the present invention
The olefin copolymer (A) is a copolymer comprising ethylene and an α-olefin having 4 to 12 carbon atoms.

The α-olefin having 4 to 12 carbon atoms used for copolymerization with ethylene is, 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 sample tube of 10 mmφ. 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 conditions of c.

The ethylene / α-olefin copolymer (A) has a density of 0.885 to 0.940 g / cm ³ ,
Preferably it is in the range of 0.890 to 0.935 g / cm ³ , more preferably 0.895 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 123).
8-65T, 190 ℃, load 2.16kg) is 0.1-10g / 10
Min, preferably 0.1 to 5 g / 10 min, more preferably 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 5.0, preferably 1.8 to 3.5, more 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 0.025% by weight of o-dichlorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.) and BHT (manufactured by Takeda Pharmaceutical Co., Ltd.) were used as the mobile phase. 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 , Tosoh Corp.
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 density (d (g / cm ³ )) satisfy the relationship shown below.

W <80 × exp (−100 (d−0.88)) + 0.
1 Amount of n-decane soluble component of 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.

Further, the ethylene / α-olefin copolymer (A) has a temperature [Tm (° C.)] and a density [d (g / g) at the maximum peak position of an endothermic curve measured by a differential scanning calorimeter (DSC). cm ³ )] It is desirable to satisfy the relationship shown by.

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 ℃
The temperature is maintained at 200 ° C. for 5 minutes, then lowered to room temperature at 20 ° C./min, and then determined from an endothermic curve when the temperature is raised at 10 ° C./min. The measurement is performed using a DSC-7 type device manufactured by PerkinElmer.

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, indicating 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 with time, if such a film is spread as an agricultural film, it will take a long time. Can be used.

The ethylene / α-olefin copolymer (A) as 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 0.885 to 0.940 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 that 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 are connected to each other by 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 usually has a particle size of about 10 to 300 μm, preferably 20 to 200 μm. Solid.

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.

Although the properties of such a carrier differ depending on the kind and the production method, 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. This carrier may be used, if necessary, at 100 to 1000 ° C, preferably 150 to 70 ° C.
It is used after firing at 0 ° C.

Examples of the organic compound used as the fine particle carrier include (co) polymers formed mainly of α-olefins having 2 to 14 carbon atoms such as ethylene and 4-methyl-1-pentene; Alternatively, a (co) polymer produced mainly from vinylcyclohexane and styrene can be exemplified.

Examples of the organoaluminum compound catalyst component (d) optionally used in the preparation of the catalyst for olefin polymerization include trialkylaluminum such as trimethylaluminum, alkenylaluminum 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.

In carrying out the polymerization, the metallocene-based olefin polymerization catalyst as described above is generally used in a concentration of transition metal atoms in the polymerization reaction system of 10 ^-8 to 10 ^-3 gram atoms / liter, preferably ^Preferably, it is used in an amount of from 10 ^-7 to 10 ^-4 gram atoms / 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 -50 to 100 ° C, preferably 0 to 90 ° C, and 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 k.
g / cm ² under pressure.

The polymerization can be carried out in any of a batch system, a semi-continuous system and a continuous system. In the present invention, in the preparation of the ethylene / α-olefin copolymer (A), if necessary, (1) multistage polymerization, (2) multistage polymerization of a liquid phase and a gas phase, or (3) a liquid phase For example, performing polymerization in the gas phase after preliminarily polymerizing the above. 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, or the supply amounts and ratios (molar ratios) of ethylene and α-olefin.

The metallocene catalyst used in the copolymerization step [1] and / or [2] is added to the metallocene catalyst component (a) and the organoaluminum oxy compound catalyst component (b), and the organoaluminum 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) High-pressure low-density polyethylene (B) constituting a mixture of the ethylene / α-olefin copolymer (A) used in the present invention and the high-pressure low-density polyethylene (B) Is the melt flow rate (MFR; ASTM D 1238, 190 ° C, load 2.16k)
g) is 0.1 to 100 g / 10 min, and the density is 0.915 to
Preferably, the swell ratio is 0.935 g / cm ³ and the swell ratio is 60% or less.

The density of the high-pressure method 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 melt flow rate measurement is measured with a micrometer as the sample diameter (mm). 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)

The high-pressure low-density polyethylene (B) as described above 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% by weight based on the total amount of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). 40% by weight, preferably 1
To 35% by weight, more preferably 5 to 30% by weight.

The anti-blocking agent (D) The agricultural film according to the present invention is formed by a water-cooled inflation method or the like. In the ethylene / α-olefin copolymer (A) or the mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), 100 parts by weight
It is advisable to add 0.01 to 3.0 parts by weight, preferably 0.1 to 2.5 parts by weight, particularly preferably 0.5 to 1.5 parts by weight of the antiblocking agent (D).

Specific examples of the anti-blocking agent include natural silica, synthetic silica, zeolite, amorphous zeolite, diatomaceous earth, and talc. Among them, silica, zeolite and the like are preferably used.

Slip Agent (E) The slip agent (E) used as required in the present invention is, for example, erucamide, stearamide, palmitamide, oleamide, ethylenebisstearic acid. Amide, lithium stearate, magnesium stearate, calcium stearate, 12-
And calcium hydroxystearate.
Among them, stearic acid amide, erucic acid amide and the like are preferably used. The slip agent (E) is ethylene α
-0.01 to 100 parts by weight of a mixture of the olefin copolymer (A) or the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B).
It is advisable to add 3.0 parts by weight, preferably 0.1 to 2.0 parts by weight, particularly preferably 0.3 to 1.5 parts by weight.

Antifogging agent (F) Examples of the antifogging agent (F) optionally used in the present invention include an organic antifogging agent and an inorganic antifogging agent. The following examples can be given as types of organic anti-fog agents. Sorbitan monostearate, sorbitan distearate, sorbitan monopalmitate, sorbitan dipalmitate, sorbitan monobehenate, sorbitan dibehenate, sorbitan monolaurate, sorbitan monolaurate, and other sorbitan-based surfactants; glycerin monolaurate; Glycerin-based surfactants such as glycerin dilaurate, diglycerin monopalmitate, diglycerin dipalmitate, glycerin monostearate, glycerin distearate, diglycerin monostearate, and diglycerin distearate; polyethylene glycol monostearate; Polyethylene glycol-based surfactants such as polyethylene glycol monopalmate; trimethylolpropane-based fields such as trimethylolpropane monostearate Surfactants: pentaerythritol surfactants such as pentaerythritol monopalmitate; polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan distearate, mono and distearate of sorbitan-diglycerin condensate, and alkanol alkylamine interface Activators and the like. These can be used alone or in combination of two or more.

Preferred examples of the antifogging agent (F) include
A glycerin alkyl ester represented by the following formula (I),
An antifogging agent comprising a diglycerin alkyl ester represented by the following formula (II), a diethanol alkylamine represented by the following formula (III), and a polyoxyethylene sorbitan ester can be exemplified.

[0074]

Embedded image

R¹, R^Two And R^Three Are independent
A hydrogen atom or an acyl group having 12 to 22 carbon atoms
It is. R¹, R^Two And R^Three As the acyl group of
Physically, C₁₁H_{twenty three}CO-, C ₁₃H₂₇CO-, C_FifteenH₃₁
CO-, C₁₇H₃₅CO-, C₁₉H₃₉CO-
It is. Above all, C_FifteenH₃₁CO-, C₁₇H₃₅CO-preferred
New Glycerin alkyl preferably used in the present invention
As the ester, specifically, glycerin palmitate
(Including mono-, di- and triesters), glycerin
Stearates (including mono, di and triester)
And so on.

[0076]

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 tetra esters) and diglycerin stearate (mono, di, tri and tetra esters). Esters).

[0079]

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.

Examples of the diethanolalkylamine preferably used in the present invention include diethanolstearylamine and diethanollaurylamine.

Examples of the polyoxyethylene sorbitan ester preferably used in the present invention include polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan distearate, polyoxyethylene monopalmitate, polyoxyethylene dipalmitate. Tate and the like.

In these preferred examples of the anti-fogging agent, for example, when glycerin alkyl ester, diglycerin alkyl ester and diethanol alkylamine are mixed and used, they are used in the following proportions. Glycerin alkyl ester, diglycerin alkyl ester and diethanol alkylamine 100 parts by weight of the total amount of glycerin alkyl ester is contained in a proportion of 10 to 40 parts by weight, preferably 20 to 30 parts by weight, diglycerin alkyl ester is It is contained in a proportion of 20 to 80 parts by weight, preferably 30 to 70 parts by weight, and diethanolalkylamine is contained in a proportion of 1 to 20 parts by weight, preferably 1 to 10 parts by weight.

Among such antifoggants, the following combinations are preferred. (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 (F) is added to 100 parts by weight of the ethylene / α-olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). On the other hand, 0.01 to 5.0 parts by weight, preferably 0.1 to 4.0 parts by weight, more preferably 0.1 to 4.0 parts by weight.
It is used in a proportion of 5 to 3.0 parts by weight.

On the other hand, examples of the inorganic anti-fogging agent include an inorganic anti-fogging composition containing an inorganic hydrophilic colloid substance and a binder resin component as main components.

Specific examples of the inorganic hydrophilic colloidal substance include colloidal silica, colloidal alumina, colloidal Fe (OH) ₂ , colloidal Sn (OH) ₄ ,
Colloidal TiO ₂ , colloidal BaSO ₄ , colloidal lithium silicate and the like can be mentioned. Of these, colloidal silica and colloidal alumina are particularly preferred.

Examples of the binder resin component include aqueous emulsions of acrylic resin, epoxy resin, urethane resin, polyester resin and the like.
Further, if necessary, a surfactant can be contained.

When such an inorganic antifogging agent composition is added to cooling water at the time of film formation, a layer of the inorganic antifogging agent composition can be formed on the film surface, which is advantageous. It is. Usually, a high antifogging effect can be obtained by forming the inorganic antifogging composition layer so that the thickness is 0.1 to 5 μm, preferably 0.5 to 2 μm. Therefore, the amount of addition to the film cooling water may be adjusted so as to have such a film thickness.

Other Ingredients If necessary, additives such as conventionally known weather stabilizers, antioxidants, antifoggants, inorganic compounds, antistatic agents and heat stabilizers may be added to the above resin (C). Can be blended within a range that does not impair the object 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 great 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. (15) Poly {[6-[(1,1,
3,3-tetramethylbutyl) imino] -1,3,5-triazine-
2,4-diyl] [4- (2,2,6,6-tetramethylpiperidyl) imino] hexamethylene} (trade name Chimassorb 9)
44, Ciba-Geigy)

These hindered amine light stabilizers include:
They can be used alone or in combination of two or more. The light stabilizer is ethylene / α-olefin copolymer (A) or a mixture 1 of ethylene / α-olefin copolymer (A) and high-pressure low-density polyethylene (B).
0.005 to 5 parts by weight, preferably 0.005 to 2 parts by weight, more preferably 0.01 to 5 parts by weight with respect to 00 parts by weight.
Used in a proportion of 1 part by weight.

Specific examples of the ultraviolet absorber include salicylic acid-based 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 100 parts by weight of the ethylene / α-olefin copolymer (A) or the mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). , 0.005 to 5 parts by weight,
It is preferably used in a proportion of 0.005 to 2 parts by weight, more preferably 0.01 to 1 part by weight.

Examples of the inorganic compounds that can be used include inorganic oxides, inorganic hydroxides, inorganic composite compounds and hydrotalcites containing at least one atom of Mg, Ca, Al and Si which are effective as a heat insulator. No.

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 that satisfies the condition of 0 ≦ m ≦ 2.] An inorganic composite compound represented by the following formula, or a calcined product thereof, such as hydrotalcites, may be mentioned. Among these, hydrotalcites are preferable, and a fired product of the inorganic composite compound represented by the above formula is particularly preferable.

The inorganic compounds as described above 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 above inorganic compound is based on 100 parts by weight of the ethylene / α-olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). It is used in an amount of 1 to 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 in the above ratio, a film having excellent heat retention can be obtained.

The agricultural film according to the present invention has a layer formed of the resin (C) which may contain various additives as described above. When the agricultural film according to the present invention is a single-layer film composed of a layer formed of the resin (C), the agricultural film has a thickness of 60 to 200 μm.
m, preferably in the range of 60 to 160 μm.

The agricultural film according to the present invention, which is such a single-layer film, has a haze (ASTM D 100
3) is less than 10% and the gloss (ASTM D
523) is 90% or more.

The agricultural film having a single layer structure according to the present invention as described above comprises an ethylene / α-olefin copolymer (A), and if necessary, a high-pressure low-density polyethylene (B), an antiblocking agent (A). D), a slip agent (E), an anti-fogging agent (F), the above-mentioned other additives, and other components are mixed, melt-mixed with a Banbury mixer or a roll mill, an extruder, and the like. Can be manufactured.

For film formation, an inflation method or a T-die method can be used, and for cooling, an air cooling method or a water cooling method can be adopted. In particular, when the water-cooled inflation molding method is adopted, an agricultural film excellent in optical properties and spreadability can be manufactured.

The water-cooling inflation molding conditions are as follows: the melting temperature of the resin is usually 150 to 200 ° C., and the expansion ratio of the bubble (the ratio of the die diameter to the bubble diameter after the water-cooled jacket; bubble diameter / die diameter) is 0. 0.5 to 2.0, the cooling water temperature is 10 to 60 ° C., and the draft rate of the bubble (the ratio of the flow rate of the resin at the die exit to the molding speed; molding speed / flow rate of the resin) is 5 to 100. It is preferred that When the expansion ratio of the bubble is within the above range, the bubble is stable and the moldability is good. When the cooling water temperature is within the above range, the film does not curl, and the film has good optical characteristics. When the draft rate is within the above range, bubbles are stable and the optical characteristics of the film are good.

A film having a layer formed of the resin (C) is extruded downward from a circular die by an inflation molding method, and then passed through a water tank to which the above-mentioned inorganic anti-fogging agent composition has been added, and cooled. Then, the film surface is dried, and a film of the inorganic antifogging agent composition can be formed on the film surface.

The agricultural film according to the present invention may be a multi-layer film having a layer formed of the resin (C) as described above, in addition to the single-layer film described above. As the agricultural film having a multilayer structure according to the present invention, for example, a multilayer film including the following outer layer, one or more intermediate layers, and an inner layer is particularly preferable.

Outer Layer and Inner Layer The outer layer and / or the inner layer constituting the multilayer film is composed of a resin (C) composed of an ethylene / α-olefin copolymer (A) or 40% by weight of ethylene / α-olefin (A). It is formed of a resin (C) comprising a mixture with the following high-pressure method low-density polyethylene (B). When the inner layer is formed of resin (C), the outer layer may be formed of resin (C) or may be formed of a resin other than resin (C). When the outer layer is formed of the resin (C), the inner layer may be formed of the resin (C) or may be formed of a resin other than the resin (C). In the present invention, it is desirable that both the outer layer and the inner layer are formed of the resin (C).

The resin (C) is as described above. If necessary, the resin (C) contains the above-mentioned anti-blocking agent (D), slip agent (E) and anti-fogging agent (F). And further conventionally known weather stabilizers, antioxidants,
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 purpose of the present invention.

Intermediate Layer The intermediate layer constituting the multilayer film is composed of ethylene α-
Olefin copolymer (A), ethylene-vinyl acetate copolymer, high-pressure low-density polyethylene (B), ethylene
It is preferably formed of one or more resins selected from the group consisting of a (meth) acrylic acid copolymer and an ionomer resin. Here, the ethylene / vinyl acetate copolymer has a vinyl acetate content of 3 to 50% by weight, preferably 5 to 50% by weight.
The ethylene / (meth) acrylic acid copolymer has an ethylene content of 99 to 70% by weight.
%, Preferably from 98 to 75% by weight. Further, as the ionomer resin, for example, the above ethylene / (meth) acrylic acid copolymer may be Na ⁺ , Zn
^{++ and the} like. In the present invention, a resin (C) comprising an ethylene / α-olefin copolymer (A) or a mixture of an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B) is used. Is particularly preferred.

The resin forming the intermediate layer may be composed of the above-described resin alone, or may be composed of two or more resins. Further, molding waste such as ears and defective products generated during film formation can be collected and reused for this intermediate layer. In addition, if necessary, the above-mentioned additives such as an antifogging agent, an antioxidant, a weather resistance stabilizer, and an inorganic compound are added to the resin for forming an intermediate layer within a range that does not impair the object of the present invention. can do.

The multilayer film composed of the outer layer, the intermediate layer and the inner layer as described above has a thickness of the outer layer of usually 3 to 100 μm.
m, preferably 10 to 80 μm, more preferably 20
And the thickness of the entire intermediate layer is 10 to 1 μm.
50 μm, preferably 20 to 120 μm, more preferably 30 to 100 μm, and the thickness of the inner layer is 3 to
100 μm, preferably 10-80 μm, more preferably 20-70 μm, and the total thickness of these layers is 60-200 μm, preferably 60-160
in the range of μm.

In such a multilayer film, the ratio of the thickness of each of the outer layer [I], the entire intermediate layer [II] and the inner layer [III] (outer layer [I] / intermediate layer [II] / inner layer [II]
I]) is from 0.2 to 4/1 to 10/1, preferably from 0.1 to 4/1.
It is desirable to be 5/2 / 2-6 / 1.

The multilayer film as described above has a haze (A)
STM D 1003) is less than 10% and gloss (ASTM D 523) is 90% or more.

In such a multilayer film, the polyethylene resin used in each layer and the above-mentioned additives and other components are mixed and melt-mixed using a Banbury mixer or a roll mill, an extruder or the like. Can be prepared by laminating an outer layer, an intermediate layer and an inner layer. In this case, it is preferable to employ a water-cooled inflation molding method, and the molding conditions are the same as the water-cooled inflation molding conditions for the above-mentioned single-layer agricultural film.

[0115]

According to the present invention, an agricultural film having excellent optical properties, especially in the initial stage of spreading, and spreading workability can be obtained as compared with a conventional agricultural film made of a polyolefin resin film. That is, an agricultural film having excellent transparency and surface gloss and excellent flexibility can be obtained.

Since the agricultural film according to the present invention has the above-described 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.

[0117]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

The evaluation of the agricultural films in Examples and Comparative Examples was performed as follows. (1) Haze (Haze) The haze, which is an index of the transparency of the film, is ASTM D
It was measured according to 1003. (2) Gloss (gloss) The gloss of the film was measured according to ASTM D523. In addition, the gloss of the whole multilayer film was measured from the inner layer side formed with the resin (C) of the present invention at an angle of the film of 20 °. (3) Opening After the inflation molding, the opening of the tubular film folded between two rolls was opened with a finger to examine the difficulty of opening.

[0119]

[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 l 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 has 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.

[0123] B ₁ above was measured for this copolymer with GPC-IR analysis was 12.2 / 1000 C-(per 1000 carbon atoms 12.2), B ₂ is 9.9 / 1
000C.

[0124]

Reference Example 2 An ethylene / 1-hexene copolymer as shown in Table 1 was obtained in the same manner as in Reference Example 1.

[0125]

[Table 1]

[0126]

Example 1 Using the resins shown in Table 1 and the phenolic antioxidants, phosphorus antioxidants, calcium stearate, weather stabilizers, slip agents and antiblocking agents shown in Table 2, Under the conditions shown, a thickness of 100 μm
Was formed under the following conditions by a water-cooled inflation molding method. However, among the following three-layer machines,
Only one layer was used. [Water-cooled inflation molding conditions] Molding machine: Water-cooled three-layer machine manufactured by Placo Die diameter: 150 mm φ Lip width: 2.5 mm Molding temperature: 160 ° C Bubble expansion ratio: 0.93 Draft rate of bubble: 23 Cooling water temperature : 25 ° C. Sizing height: 350 mm Table 2 shows the physical properties of the film obtained as described above.

[0127]

Comparative Example 1 Using the resins shown in Table 1 and the phenolic antioxidants, phosphorus antioxidants, calcium stearate, weather stabilizers, slip agents and antiblocking agents shown in Table 2, Under the conditions shown, a thickness of 100 μm
Was formed under the following conditions by an air-cooled inflation molding method. However, one of the following three-layer machines
Only layers were used. [Air-cooled inflation molding conditions] Molding machine: 3-layer machine manufactured by Placo Die diameter: 75 mmφ Lip width: 1.0 mm Molding temperature: 190 ° C. Bubble expansion ratio: 1.8 Whitening height: 400 mm Obtained as described above Table 2 shows the physical properties of the obtained film.

[0128]

[Table 2]

[0129]

Examples 2 to 4 Resins shown in Table 1 (phenolic antioxidant [trade name: Irganox 3114, manufactured by Ciba-Geigy]] 0.05% by weight, phosphorus-based antioxidant [trade name: Irgaphos 168, manufactured by Ciba-Geigy] 0.10% by weight and calcium stearate [Nippon Oil & Fats Co., Ltd.]
And 0.10% by weight), and a 100 μm-thick three-layer film was molded under the following conditions by a water-cooled inflation molding method under the conditions shown in Table 3. [Water-cooled inflation molding conditions] Molding machine: Water-cooled three-layer machine manufactured by Placo Die diameter: 150 mm φ Lip width: 2.5 mm Molding temperature: 160 ° C Bubble expansion ratio: 0.94 Draft rate of bubble: 24 Cooling water temperature : 25 ° C. Sizing height: 350 mm Thickness: 100 μm in total layer (inner layer / intermediate layer / outer layer = 20)
(μm / 60 μm / 20 μm) Table 3 shows the physical properties of the film obtained as described above.

[0130]

Comparative Examples 2 and 3 Resins shown in Table 1 (phenolic antioxidant [trade name Irganox 3114, manufactured by Ciba-Geigy]] 0.05% by weight, phosphorus-based antioxidant [trade name Irgafos 168, manufactured by Ciba-Geigy] ] 0.1
0% by weight and 0.10% by weight of calcium stearate (manufactured by NOF CORPORATION) under the conditions shown in Table 3 to form a 100 μm-thick three-layer film by the air-cooled inflation molding method described below. Molded under the conditions. [Air-cooled inflation molding conditions] Molding machine: 3-layer machine made by Placo Die diameter: 75 mmφ Lip width: 1.0 mm Molding temperature: 190 ° C. Bubble expansion ratio: 1.8 Whitening height: 400 mm Thickness: Total layer 100 μm (Inner layer / Intermediate layer / Outer layer = 20
(μm / 60 μm / 20 μm) Table 3 shows the physical properties of the film obtained as described above.

[0131]

[Table 3]

Resins (I) and (II) in Table 3 are phenolic antioxidants [trade name Irganox 31]
14, 0.05% by weight of Ciba Geigy], 0.10% by weight of a phosphorus antioxidant [trade name Irgafos 168, Ciba Geigy] and 0.10% by weight of calcium stearate [Nippon Yushi Co., Ltd.] .

The additives in Table 3 are as follows. Weatherproof stabilizer: trade name Chimasorb 944, manufactured by Ciba Geigy; HALS-based stabilizer Hydrotalcite: trade name DHT-4A, manufactured by Kyowa Chemical Co., Ltd .; heat insulator nonionic surfactant (Examples 2, 3, comparison) Example 2,
3): A mixture consisting of 20% of glycerin monostearate, 60% of diglycerin mono and distearate, and 20% of polyoxyethylene sorbitan mono and distearate; antifogging agent Nonionic surfactant (Example 4): glycerin Mixture consisting of 25% monostearate, 70% diglycerin mono and distearate and 5% diethanolstearylamine; antifoggant

[0134]

Example 5 The formation of a single-layer film was repeated by the method described in Example 1. At this time, 1% of colloidal silica (trade name: Snowtex 20, manufactured by Nissan Chemical Industries, Ltd.) was used as an inorganic anti-fog agent in the cooling water of the blown film.
And 3% of an acrylic resin-based emulsion (resin content 30%), and the tubular film extruded downward from the circular die was cooled. Thereafter, the film was dried in a dryer set at 100 ° C. for 30 minutes to form a film of the antifogging agent composition on the outer surface of the tubular film.

The film obtained in this manner and the film obtained in Example 1 were evaluated for antifogging properties as follows. That is, 100 ml of 50 ° C. hot water was put into a 300 ml beaker, and the mouth of the beaker was covered with the film. In the film obtained in Example 5, the mouth of the beaker was covered with the surface side on which the coating of the antifogging agent composition was formed facing the inner surface of the beaker. Thereafter, the beaker was placed in a refrigerator at 5 ° C., and after 10 minutes, removed from the refrigerator, and the state of water droplets on the film surface on the beaker side was visually observed. Table 4 shows the results.

[0136]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/00 B32B 27/00 Z 27/18 27/18 C // B29C 55/28 B29C 55/28 C08L 23/08 C08L 23 / 08 B29K 23:00 B29L 7:00 9:00

Claims (31)

[Claims] 1. A copolymer obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms and having a density of 0.885 to 0.8.
940 g / cm ³ and a melt flow rate of 0.1
A resin (C) comprising an ethylene / α-olefin copolymer (A) having a viscosity of 10 to 10 g / 10 minutes,
A film having a layer formed of a resin (C) comprising a mixture of an olefin copolymer (A) and a high-pressure low-density polyethylene (B) in an amount of 40% by weight or less; ) Having a thickness of 60 to 200 μm,
i) An agricultural film, wherein haze (ASTM D 1003) is less than 10%, and (iii) gloss (ASTM D 523) is 90% or more. 2. The ethylene / α- component constituting said resin (C).
The olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) is (i) a molecular weight distribution (Mw / Mn: Mw = Weight average molecular weight, Mn =
(Number average molecular weight) is in the range of 1.5 to 5.0, and (ii)
The fraction (W (% by weight)) of the n-decane soluble component at 23 ° C. and the density (d (g / cm ³ )) 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 1, wherein: 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 agricultural film according to claim 1, wherein said resin (C) is formed into a film by a water-cooled inflation method. 5. The resin (C) is 100 parts by weight of an ethylene / α-olefin copolymer (A) or a mixture of an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). , The anti-blocking agent (D) and / or the slip agent (E) were each added to 0.1.
The agricultural film according to any one of claims 1 to 4, comprising 0.1 to 3.0 parts by weight. 6. The agricultural film according to claim 5, wherein the antiblocking agent (D) is silica or zeolite. 7. The agricultural film according to claim 5, wherein said slip agent (E) is stearamide or erucamide. 8. The resin (C) is 100 parts by weight of an ethylene / α-olefin copolymer (A) or a mixture of an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). On the other hand, 0.01 to
5. The composition according to claim 1, which contains 5.0 parts by weight.
8. The agricultural film according to any one of 7. 9. The antifogging agent (F) is selected from the group consisting of glycerin alkyl esters, diglycerin alkyl esters, diethanol alkylamines, polyoxyethylene sorbitan esters, and mixtures thereof. 9. The agricultural film according to 8. 10. A film having an inorganic anti-fogging composition is further provided on at least one outer surface of the film having a layer formed of the resin (C). 10. The agricultural film according to any one of 9 above. 11. The agricultural film according to claim 10, wherein said inorganic anti-fogging agent composition comprises an inorganic hydrophilic colloidal substance. 12. The agricultural film according to claim 10, wherein said inorganic anti-fogging agent composition comprises an inorganic hydrophilic colloid substance and a binder resin component. 13. The agricultural film according to claim 11, wherein the inorganic hydrophilic colloid substance is colloidal silica or colloidal alumina. 14. A multilayer film comprising at least two layers comprising an outer layer and an inner layer, or at least three layers comprising an outer layer and at least one intermediate layer and an inner layer, wherein at least one of the outer layer and the inner layer comprises ethylene and carbon atoms. It is obtained by copolymerizing α-olefins of formulas 4 to 12, and has a density of 0.885 to 0.940 g / c.
m ³ and the melt flow rate is 0.1 to 10 g / 1.
A resin (C) comprising an ethylene / α-olefin copolymer (A) for 0 minutes, or a high-pressure low-density polyethylene (B) having an amount of 40% by weight or less with the ethylene / α-olefin copolymer (A); The multilayer film is formed of a resin (C) consisting of a mixture of
(Ii) Haze (ASTM D 1003)
Is less than 10%, and (iii) gloss (ASTM D 52
3) is 90% or more of the agricultural film. 15. An ethylene · α constituting the resin (C).
-The olefin copolymer (A) or a mixture of the ethylene / α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) has a molecular weight distribution (Mw / Mn: Mw) measured by (i) GPC. = Weight average molecular weight, Mn =
(Number average molecular weight) is in the range of 1.5 to 5.0, and (ii)
The fraction (W (% by weight)) of the n-decane soluble component at 23 ° C. and the density (d (g / cm ³ )) 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 14, wherein: 16. 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 14 or 15, wherein 17. The multilayer film according to claim 14, wherein said resin (C) forms at least one of an outer layer and an inner layer by a water-cooled inflation method. Agricultural film. 18. The resin (C) is 100 parts by weight of an ethylene / α-olefin copolymer (A) or a mixture of an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). , The anti-blocking agent (D) and / or the slip agent (E) were each added to 0.1.
The agricultural film according to any one of claims 14 to 17, wherein the film is contained in an amount of from 0.1 to 3.0 parts by weight. 19. The method according to claim 1, wherein said anti-blocking agent (D) is silica or zeolite.
9. The agricultural film according to 8. 20. The agricultural film according to claim 18, wherein the slip agent (E) is stearamide or erucamide. 21. The resin (C) is 100 parts by weight of an ethylene / α-olefin copolymer (A) or a mixture of an ethylene / α-olefin copolymer (A) and a high-pressure low-density polyethylene (B). To 0.01% of the antifogging agent (F)
2. The composition according to claim 1, wherein the content is about 5.0 parts by weight.
The agricultural film according to any one of 4 to 20. 22. An intermediate layer constituting the multilayer film,
Ethylene • α-olefin copolymer (A), ethylene •
It is formed of at least one resin selected from the group consisting of a vinyl acetate copolymer, a high-pressure low-density polyethylene (B), an ethylene / (meth) acrylic acid copolymer, and an ionomer resin. Claims 14-2
2. The agricultural film according to any one of 1. 23. A multilayer film having an outer layer and / or an inner layer formed of the resin (C), wherein at least one outer surface of the multilayer film is further provided with a coating of an inorganic anti-fogging agent composition. The agricultural film according to any one of claims 14 to 22, wherein 24. The agricultural film according to claim 23, wherein the inorganic anti-fogging composition comprises an inorganic hydrophilic colloidal substance. 25. The agricultural film according to claim 23, wherein said inorganic anti-fogging agent composition comprises an inorganic hydrophilic colloid substance and a binder resin component. 26. The agricultural film according to claim 24, wherein the inorganic hydrophilic colloid substance is colloidal silica or colloidal alumina. 27. The agricultural film according to claim 1, which has a layer formed of the resin (C),
The expansion ratio of the bubble is 0.5 to 2.0, the cooling water temperature of the tubular film is 10 to 60 ° C, and the draft rate of the bubble is 5
A method for producing an agricultural film, which is obtained by water-cooled inflation molding under the conditions of 100. 28. A film having a layer formed of the resin (C) is extruded downward from a circular die by an inflation molding method, and then passed through a water tank to which an inorganic anti-fogging agent composition has been added, and taken off while cooling. The method for producing an agricultural film according to claim 27, wherein the film surface is dried thereafter. 29. The method for producing an agricultural film according to claim 28, wherein said inorganic anti-fogging agent composition comprises an inorganic hydrophilic colloidal substance. 30. The method for producing an agricultural film according to claim 28, wherein said inorganic anti-fogging agent composition comprises an inorganic hydrophilic colloid substance and a binder resin component. 31. The method for producing an agricultural film according to claim 29, wherein the inorganic hydrophilic colloid substance is colloidal silica or colloidal alumina.