JP3766860B2 - Irrigation tube - Google Patents

Description

【０１１８】
（７）農業用マルチフィルムとの密着性評価
農業用マルチフィルムとして、以下のものを用いた。
ある年の６月に、畝を有する畑において、畝の中央部に本発明の灌水チューブを設置し、その上に厚さ３０μｍの農業用透明マルチフィルム（高圧法ポリエチレンからなる）をかぶせて用い、メロンのトンネル栽培を行った。１週間毎に灌水を行い、その際に灌水チューブとマルチフィルムが密着しているかどうかを調べ、○、△、×で密着の度合いおよび灌水ムラについて目視で評価した。
○ 密着なし、灌水ムラなし
△ 密着有り、灌水ムラやや有り
× 密着有り、灌水不能（密着により灌水孔がふさがって灌水できない状態）
【０１１９】
【表２】

[0001]
[Industrial application fields]
The present invention relates to a novel irrigation tube, and more specifically, heat sealability, heat seal strength, repeated pressure fatigue strength, excellent tensile creep resistance and impact strength of the heat seal portion, high fracture water pressure, and lower density. However, the present invention relates to an irrigation tube that maintains strength, does not cause close contact with other films during use, and has excellent workability.
[0002]
[Prior art]
In recent years, irrigation tubes using high-pressure polyethylene or ethylene / vinyl acetate copolymer have been used for irrigation instead of hard synthetic resin tubes. These irrigation tubes expand and exhibit a cylindrical shape when water is passed, and have a flat shape when water is not passed. Therefore, they are easier to store, transport, and store than conventional hard synthetic resin tubes. It has the characteristic that it can be freely adapted to any shape of the irrigation area, or changes in the format between strains, and is beginning to be widely adopted for cultivation of vegetables.
[0003]
Conventional irrigation tubes made of high-pressure polyethylene or ethylene / vinyl acetate copolymer have a problem in that peeling occurs at the heat seal portion of the irrigation tube by repeating the water / non-water cycle.
[0004]
The present inventors previously used an ethylene / α-olefin random copolymer having a specific melt index, a specific density and a melting point as the outer layer of the irrigation tube (Japanese Patent Publication No. 63-37607), or a specific one. It has been found that an irrigation tube having a good repeated pressure fatigue strength can be obtained by using a composition of an ethylene / α-olefin random copolymer and a high pressure polyethylene (JP-B-64-7732). However, the required characteristics for films in recent years have become increasingly severe, and further improvements in tube properties have been demanded.
[0005]
[Problems to be solved by the invention]
The present invention is intended to meet the above requirements, and is excellent in heat sealability, heat seal strength, repeated pressure fatigue strength, tensile creep resistance of the heat seal portion, impact strength, high fracture water pressure, An object of the present invention is to provide an irrigation tube that maintains strength even at a lower density and does not cause close contact with other films during use and has excellent workability.
[0006]
[Means for Solving the Problems]
  The irrigation tube according to the present invention has a plurality of irrigation holes having at least one continuous heat seal portion extending along the length direction and arranged at appropriate intervals in the length direction. A thermoplastic resin irrigation tube which expands when passing through water and assumes a cylindrical shape, but becomes flat when not passing through water, wherein the thermoplastic resin is [A] (i) melt flow rate 0.01 to 10 g / 10 min, (ii) density is0.905 to 0.930g / cm³(Iii) The ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn measured by GPC is in the range of 1.5 to 3.5, and (iv) the n-decane soluble part at 23 ° C. ( W: wt%) and density (d: g / cm³)
[Expression 2]
W <80 × exp (−100 (d−0.88)) + 0.1
(V) When the average value of the number of branches on the high molecular weight side according to GPC-IR is B1, and the average value of the number of branches on the low molecular weight side is B2, B1 ≧ B2 and ethylene and carbon Medium to low pressure ethylene / α-olefin copolymer consisting of α-olefin having 4 to 12 atoms, and [B]Density is 0.910 to 0.935 g / cm ³ ofA irrigation tube comprising 0 to 80% by weight of high pressure polyethylene.
[0007]
The component [A] is preferably an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms in the presence of a metallocene catalyst. The metallocene compound (I) used as a component of the metallocene catalyst is preferably a metallocene compound represented by the following general formula [1] or [2].
[Chemical Formula 3]
MK (L1) X-2 ... [1]
[Wherein M is a transition metal selected from Group IVB of the periodic table, K and L1 are ligands coordinated to the transition metal atom, and ligand K is the same or different indenyl group, substituted A bidentate ligand in which an indenyl group or a partial hydride thereof is bonded via a lower alkylene group or a substituted silylene group, and the ligand L1 is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, aryloxy A group, a halogen atom, a trialkylsilyl group or a hydrogen atom, and X is the valence of the transition metal atom M. ]
[0008]
[Formula 4]
M (L2) X [2]
[Wherein, M is a transition metal atom selected from Group VIB of the periodic table, L2 is a ligand coordinated to transition metal atom M, and at least two of these ligands L2 are: A substituted cyclopentadienyl group having at least one substituent selected from a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, or a hydrocarbon group having 3 to 10 carbon atoms, Substitution) The ligand L2 other than the cyclopentadienyl group is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and X is a transition metal atom. The valence of M. ]
[0009]
Next, the irrigation tube according to the present invention will be described.
[0010]
[[A] Medium-low pressure ethylene / α-olefin copolymer]
The medium / low pressure ethylene / α-olefin copolymer used in the present invention is an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms.
[0011]
Specific examples of such α-olefins include butene-1, pentene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1, and dodecene-1. Of these, hexene-1, 4-methylpentene-1, and octene-1 are preferable.
[0012]
The copolymer has a melt flow rate (ASTM D1238; 190 ° C., 2.16 kg, hereinafter referred to as MFR) in the range of 0.01 to 10 g / 10 min, preferably 0.5 to 5 g / 10 min. If the MFR is less than 0.01, the fluidity is inferior and the moldability is poor. If the MFR exceeds 10, the mechanical properties such as impact resistance and tear strength are inferior.
[0013]
  The density of this copolymer is0.905g / cm³more than0.930g / cm³Less thanGoodPreferably 0.905g / cm³~ 0.925g / cm³Range. Density is 0.880 g / cm³In the following, it is not preferable because the tensile strength and rigidity are low, 0.940 g / cm³The above is not preferable because of poor impact resistance.
[0014]
The ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn measured by GPC of the ethylene / α-olefin copolymer used in the present invention is in the range of 1.5 to 3.5.
[0015]
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 is 140 ° C., the mobile phase is O-dichlorobenzene (Wako Pure Chemical Industries) and BHT ( (Takeda Pharmaceutical Co., Ltd.) was used at 0.025 wt%, moved at 1.0 ml / min, the sample concentration was 0.1 wt%, the sample injection amount was 500 microliters, and a differential refractometer was used as the detector. Standard polystyrenes used were those manufactured by Tosoh Corporation for molecular weights of Mw <1000 and Mw> 4 × 10 6, and those manufactured by Pressure Chemical Co. for 1000 <Mw <4 × 10 6.
[0016]
In the ethylene / α-olefin copolymer used in the present invention, the decane-soluble part (W (wt%)) and the density (d) at 23 ° C. satisfy the relationship shown below.
[Equation 3]
W <80 × exp (−100 (d−0.88)) + 0.1
The amount of n-decane-soluble component in linear polyethylene (the smaller the amount of soluble components, the narrower the composition distribution) was measured by adding about 3 g of polyethylene to 450 ml of n-decane and dissolving at 145 ° C, then 23 ° C. The n-decane insoluble part is removed by filtration, and the n-decane soluble part is recovered from the filtrate.
[0017]
In the ethylene / α-olefin copolymer used in the present invention, when the average value of the number of branches on the high molecular weight side by GPC-IR is B1, and the average value of the number of branches on the low molecular weight side is B2, B1 ≧ B2 Meet the relationship.
Here, the average value (B1) of the number of branches on the high molecular weight side by GPC-IR is the cumulative weight fraction of the polymer elution amount fractionated by GPC by 15 to 85% (that is, 15% of the low molecular region, The average value of the values on the high molecular weight side of the measured value group of the number of branches measured in the range of the polymer elution component excluding the polymer region of 15%) divided by the molecular weight at the peak position of the GPC elution curve. is there. On the other hand, the average value (B2) of the number of branches on the low molecular weight side is the average value on the low molecular weight side among the two parts.
[0018]
The measurement conditions for B1 and B2 are as follows.
Measuring device: PERKIN ELMER 1760X
Column: TOSOH TSKgel GMH-HT (7.5 mm I.D. x 600 mm) x 1
Eluent: o-dichlorobenzene (ODCB) containing 0.05% MP-J [manufactured by Wako Pure Chemical Industries, extra pure grade]
Column temperature: 140 ° C
Sample concentration: 0.1% (weight / volume)
Injection volume (inj.volume): 100 microliters
detector: MCT
resolution: 8cm-1
Thus, the relationship between the fraction (W) and the density (d) of the n-decane soluble component, the average value (B1) of the number of branches on the high molecular weight side by GPC-IR, and the number of branches on the low molecular weight side The ethylene / α-olefin copolymer [A] having a relation to the average value (B2) of the above has a narrow composition distribution and a low raw polymer content, so that there is little stickiness. Therefore, when the ethylene / α-olefin copolymer [A] as described above is used, an irrigation tube having excellent operability such as feeding and winding can be obtained.
[0019]
[Metallocene catalyst]
The [A] medium-low pressure ethylene / α-olefin copolymer used in the present invention is produced in the presence of a metallocene catalyst. Here, the metallocene catalyst is a catalyst comprising the metallocene compound (I), preferably a metallocene compound (I), (a) a particulate carrier, (b) an organoaluminum oxy compound catalyst component and / or ( c) A component capable of reacting with the metallocene compound to form an ionic complex, and (d) an organoaluminum compound catalyst component as required.
[0020]
[Metalocene Compound (I)]
Examples of the metallocene compound (I) preferably used in the present invention include transition metal compounds represented by the following general formula [1] or [2].
[Chemical formula 5]
MK (L1) X-2 ... [1]
[Wherein M is a transition metal selected from Group IVB of the periodic table, K and L1 are ligands coordinated to the transition metal atom, and ligand K is the same or different indenyl group, substituted A bidentate ligand in which an indenyl group or a partial hydride thereof is bonded via a lower alkylene group or a substituted silylene group, and the ligand L1 is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, aryloxy A group, a halogen atom, a trialkylsilyl group or a hydrogen atom, and X is the valence of the transition metal atom M. ]
In the above general formula [1], M is a transition metal atom selected from Group IVB of the periodic table, specifically zirconium, titanium or hafnium, preferably zirconium.
[0021]
K is a ligand coordinated to a transition metal atom, and the same or different indenyl group, substituted indenyl group, or a partially hydrogenated indenyl group or substituted indenyl group is a divalent hydrocarbon such as a lower alkylene group A bidentate ligand bonded through a divalent silicon-containing group such as a group, a silylene group, or a substituted silylene group. Suitable examples of the substituted indenyl group include a lower alkyl group such as a methyl group, an ethyl group, an iso-propyl group, and an n-propyl group, or a substituent composed of a halogen such as fluorine, chlorine, bromine, and iodine. An indenyl group containing one or more.
[0022]
Specifically, ethylenebisindenyl group, ethylenebis (4,5,6,7-tetrahydro-1-indenyl) group, ethylenebis (4-methyl-1-indenyl) group, ethylenebis (5-methyl-1 -Indenyl) group, ethylenebis (6-methyl-1-indenyl) group, and ethylenebis (7-methyl-1-indenyl) group can be exemplified.
[0023]
L1 is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom.
Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group. More specifically, a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are exemplified. Group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group and other alkyl groups; cyclopentyl group, cyclohexyl group and other cycloalkyl groups Examples thereof include aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group and neophyll group.
[0024]
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a t-butoxy group, a pentoxy group, a hexoxy group, and an octoxy group. be able to.
[0025]
Examples of the aryloxy group include a phenoxy group.
Halogen atoms are fluorine, chlorine, bromine and iodine.
Examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a triphenylsilyl group.
[0026]
As the metallocene compound represented by the general formula [1],
Ethylenebis (indenyl) dimethylzirconium,
Ethylenebis (indenyl) diethylzirconium,
Ethylenebis (indenyl) diphenylzirconium,
Ethylenebis (indenyl) methylzirconium monochloride,
Ethylenebis (indenyl) ethylzirconium monochloride,
Ethylenebis (indenyl) methylzirconium monobromide,
Ethylenebis (indenyl) zirconium dichloride,
Ethylenebis (indenyl) zirconium dibromide,
Ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} dimethylzirconium,
Ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} methylzirconium monochloride,
Ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} zirconium dichloride,
Ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} zirconium dibromide,
Ethylenebis {1- (4-methylindenyl)} zirconium dichloride,
Ethylenebis {1- (5-methylindenyl)} zirconium dichloride,
Ethylenebis {1- (6-methylindenyl)} zirconium dichloride,
Ethylenebis {1- (7-methylindenyl)} zirconium dichloride,
Ethylenebis {1- (5-methoxyindenyl)} zirconium dichloride,
Ethylenebis {1- (2,3-dimethylindenyl)} zirconium dichloride,
Ethylenebis {1- (4,7-dimethylindenyl)} zirconium dichloride,
Ethylenebis {1- (4,7-dimethoxyindenyl)} zirconium dichloride,
Isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride,
Isopropylidene (cyclopentadienyl-2,7-di-t-butylfluorenyl) zirconium dichloride,
Isopropylidene (cyclopentadienyl-methylcyclopentadienyl) zirconium dichloride,
Dimethylsilylenebis (cyclopentadienyl) zirconium dichloride,
Dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride,
Dimethylsilylene bis (dimethylcyclopentadienyl) zirconium dichloride,
Dimethylsilylene bis (trimethylcyclopentadienyl) zirconium dichloride,
Dimethylsilylenebis (indenyl) zirconium dichloride,
Examples include diphenylsilylene bis (indenyl) zirconium dichloride. In the above examples, the disubstituted product of the cyclopentadienyl ring includes 1,2- and 1,3-substituted products, and the trisubstituted product includes 1,2,3- and 1,2,4-substituted products. Including. In the present invention, a metallocene compound in which zirconium metal is replaced with titanium metal or hafnium metal in the above-described zirconium compound can be used.
[0027]
Among these metallocene compounds represented by the general formula [1],
Ethylenebis (indenyl) zirconium dichloride,
Dimethylsilylenebis (indenyl) zirconium dichloride,
Diphenylsilylenebis (indenyl) zirconium dichloride
Is particularly preferred.
[0028]
Another preferred embodiment of the metallocene compound (I) is a metallocene compound represented by the following formula [2].
[0029]
M (L2) X ... [2]
[Wherein M is a transition metal atom selected from Group IVB of the periodic table;
L2 is a ligand coordinated to the transition metal atom M, and at least two of these ligands L2 are a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, or A substituted cyclopentadienyl group having at least one substituent selected from a hydrocarbon group having 3 to 10 carbon atoms,
The ligand L2 other than the (substituted) cyclopentadienyl group is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom,
x is the valence of the transition metal atom M. ]
M in the above formula [2] is the same as M in the above general formula [1]. L2 is a ligand coordinated to the transition metal atom M, and at least two of these ligands L2 are a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, or a carbon. A substituted cyclopentadienyl group having at least one substituent selected from hydrocarbon groups having 3 to 10 atoms.
[0030]
In addition, the substituted cyclopentadienyl group may have two or more substituents, and the two or more substituents may be the same or different. When the substituted cyclopentadienyl group has two or more substituents, at least one substituent may be a hydrocarbon group having 3 to 10 carbon atoms, and the other substituents are methyl group, ethyl group Or it is a C3-C10 hydrocarbon group. Further, the substituted cyclopentadienyl groups coordinated to the transition metal atom M may be the same or different.
[0031]
Examples of the hydrocarbon group having 3 to 10 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group.
As the alkyl group, specifically, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, A decyl group etc. are mentioned.
[0032]
Specific examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.
Specific examples of the aryl group include a phenyl group and a tolyl group.
[0033]
Specific examples of the aralkyl group include a benzyl group and a neophyll group.
Of these, an alkyl group is preferable, and an n-propyl group and an n-butyl group are particularly preferable.
[0034]
In the present invention, the cyclopentadienyl group coordinated to the transition metal atom M is preferably a substituted cyclopentadienyl group, more preferably a cyclopentadienyl group substituted with an alkyl group having 3 or more carbon atoms, A substituted cyclopentadienyl group is more preferred, and a 1,3-substituted cyclopentadienyl group is particularly preferred.
[0035]
In the above formula [2], the ligand L2 other than the cyclopentadienyl group coordinated to the transition metal atom M is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group. A group, a halogen atom or a hydrogen atom.
[0036]
Specific examples thereof are the same as the specific examples of the hydrocarbon group having 1 to 12 carbon atoms, the alkoxy group, the aryloxy group, the trialkylsilyl group, and the halogen atom described above in the transition metal compound represented by the general formula [1]. Groups and atoms.
[0037]
Specific examples of the transition metal compound represented by the general formula [2] include bis (cyclopentadienyl) zirconium dichloride,
Bis (methylcyclopentadienyl) zirconium dichloride,
Bis (ethylcyclopentadienyl) zirconium dichloride,
Bis (n-propylcyclopentadienyl) zirconium dichloride,
Bis (n-butylcyclopentadienyl) zirconium dichloride,
Bis (n-hexylcyclopentadienyl) zirconium dichloride,
Bis (methyl-n-propylcyclopentadienyl) zirconium dichloride,
Bis (methyl-n-butylcyclopentadienyl) zirconium dichloride,
Bis (dimethyl-n-butylcyclopentadienyl) zirconium dichloride,
Bis (n-butylcyclopentadienyl) zirconium dibromide,
Bis (n-butylcyclopentadienyl) zirconium methoxychloride,
Bis (n-butylcyclopentadienyl) zirconium ethoxy chloride,
Bis (n-butylcyclopentadienyl) zirconium butoxychloride,
Bis (n-butylcyclopentadienyl) zirconium diethoxide,
Bis (n-butylcyclopentadienyl) zirconium methyl chloride,
Bis (n-butylcyclopentadienyl) zirconium dimethyl,
Bis (n-butylcyclopentadienyl) zirconium benzyl chloride,
Bis (n-butylcyclopentadienyl) zirconium dibenzyl,
Bis (n-butylcyclopentadienyl) zirconium phenyl chloride,
Bis (n-butylcyclopentadienyl) zirconium hydride chloride
Etc.
[0038]
In the above examples, the di-substituted product of the cyclopentadienyl ring includes 1,2- and 1,3-substituted products, and the tri-substituted product is 1,2,3- and 1,2,4-substituted products. including. In addition, in the above-described zirconium compound, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can be used.
[0039]
Among these transition metal compounds,
Bis (n-propylcyclopentadienyl) zirconium dichloride,
Bis (n-butylcyclopentadienyl) zirconium dichloride,
Bis (1-methyl-3-n-propylcyclopentadienyl) zirconium dichloride,
Bis (1-methyl-3-n-butylcyclopentadienyl) zirconium dichloride
Bis (1,3-dimethyl-cyclopentadienyl) zirconium dichloride
Bis (1,3-di-n-butyl-cyclopentadienyl) zirconium dichloride
Is particularly preferred.
[0040]
In the present invention, the metallocene compound (I) is preferably reacted with (a) a particulate carrier, (b) an organoaluminum oxy compound catalyst component and / or (c) a transition metal compound to form an ionic complex. Component (A) can be used together with an organoaluminum compound catalyst component as needed to copolymerize ethylene / α-olefin to produce a medium / low pressure ethylene / α-olefin copolymer of component [A]. Can be manufactured.
[0041]
[Particulate carrier (a)]
In the preparation of the metallocene catalyst, the particulate carrier (a) is preferably used. The particulate carrier (a) is an inorganic or organic compound and is a granular or particulate solid having a particle size of usually about 10 to 300 μm, preferably 20 to 200 μm.
[0042]
Of these, porous oxides are preferred as the inorganic carrier. Specifically, SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ZnO2, SnO2, ThO2, etc. or mixtures thereof such as SiO2- Examples thereof include MgO, SiO2-Al2O3, SiO2-TiO2, SiO2-V2O5, SiO2-Cr2O3, SiO2-TiO2-MgO. Among these, oxides mainly containing at least one component selected from the group consisting of SiO2 and Al2O3 are preferable.
[0043]
The inorganic oxide includes small amounts of Na2CO3, K2CO3, CaCO3, MgCO3, Na2SO4, Al2 (SO4) 3, BaSO4, KNO3, Mg (NO3) 2, Al (NO3) 3, Na2O, K2O, Li2O, etc. It may contain carbonate, sulfate, nitrate and oxide components.
[0044]
Such a carrier has different properties depending on its kind and production method, but the carrier preferably used in the present invention has a specific surface area of 50 to 1000 m2 / g, preferably 100 to 700 m2 / g and a pore volume of 0. It is desirable to be 3 to 2.5 cm3 / g.
[0045]
This carrier is used after being calcined at 100 to 1000 ° C., preferably 150 to 700 ° C., if necessary.
In addition, the organic compound used as the particulate carrier is produced mainly from an α-olefin having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene, 4-methyl-1-pentene (co-). Examples thereof include a polymer, or a polymer or copolymer produced mainly from vinylcyclohexane or styrene.
[0046]
[Organic aluminum oxy compound catalyst component (b)]
A typical example of the organoaluminum oxy compound catalyst component (b) used for the preparation of the metallocene catalyst is aluminoxane. Specifically, the formula
-Al (R) O- [wherein R is an alkyl group]
In general, methylaluminoxane, ethylaluminoxane, methylethylaluminoxane, or the like having about 3 to 50 repeating units is used.
[0047]
Such an aluminoxane can be prepared by a conventionally known production method, and can be obtained by reaction of at least one organoaluminum compound such as trialkylaluminum with water. Specifically, the following aluminoxane production methods can be mentioned.
(1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, first cerium chloride hydrate, etc. A method of reacting an organoaluminum compound with adsorbed water or crystal water by adding an organoaluminum compound such as trialkylaluminum to the hydrocarbon medium suspension.
(2) A method of allowing water, ice or water vapor to act directly on an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether or tetrahydrofuran.
[0048]
Of these methods, the method (1) is preferably employed.
The aluminoxane may contain a small amount of an organic metal component other than aluminum. Further, the solvent or the unreacted organoaluminum compound may be removed by distillation from the recovered solution of the above aluminoxane and then redissolved in the solvent.
[0049]
Specifically, as an organoaluminum compound used in preparing aluminoxane,
Trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tritert-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecyl Trialkylaluminum such as aluminum;
Tricycloalkylaluminum such as tricyclohexylaluminum, tricyclooctylaluminum;
Dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride;
Dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride;
Dialkylaluminum alkoxides such as dimethylaluminum methoxide and diethylaluminum ethoxide;
Dialkylaluminum aryloxides such as diethylaluminum phenoxide
Etc. Of these organoaluminum compounds, trialkylaluminum and tricycloalkylaluminum are particularly preferred.
[0050]
[Component (c) capable of reacting with a metallocene compound to form an ionic complex]
As a catalyst component that can be used in combination with the metallocene compound (I), a component (c) that can further react with the metallocene compound to form an ionic complex, for example, Lewis acids and ions described in USP-547718 Compounds and carborane compounds.
Lewis acids include triphenylboron, tris (4-fluorophenyl) boron, tris (p-tolyl) boron, tris (o-tolyl) boron, tris (3,5-dimethylphenyl) boron, tris (pentafluorophenyl) ) Boron, MgCl2, Al2O3, SiO2-Al2O3 and the like.
[0051]
Examples of ionic compounds include triphenylcarbenium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, ferrocenium tetra Examples include (pentafluorophenyl) borate.
[0052]
The carborane compounds include dodecaborane, 1-carbaundecaborane, bis n-butylammonium (1-carbedodeca) borate, tri-n-butylammonium (7,8-dicarboundaca) borate, tri-n-butylammonium (trideca Examples include hydride-7-carbaoundeca borate.
[0053]
The compound component (c) which reacts with such a metallocene compound to form an ionic complex can be used alone or in combination of two or more.
[0054]
[Organic aluminum compound catalyst component (d)]
As the organoaluminum compound catalyst component (d) used as necessary in the preparation of the metallocene catalyst, specifically,
Trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, tri-2-ethylhexylaluminum;
Alkenyl aluminum such as isoprenyl aluminum;
Dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide;
Alkylaluminum sesquichlorides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide;
Alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, ethylaluminum dibromide;
Alkyl aluminum hydrides such as diethyl aluminum hydride and diisobutyl aluminum hydride
Etc. can be exemplified.
[0055]
 [Preparation of metallocene catalyst]
The metallocene catalyst used in the preparation of the medium / low pressure ethylene / α-olefin copolymer [A] of the present invention is preferably the above-mentioned metallocene compound (I), particulate carrier (a), organoaluminum oxy It is composed of a compound catalyst component (b) and / or a compound component (c) that reacts with the metallocene to form an ionic complex and, if necessary, an organoaluminum compound catalyst component (V).
[0056]
For contacting a catalyst component such as a compound component (c) which reacts with the particulate carrier (a) and the metallocene compound (I) and / or the organoaluminum oxy compound catalyst component (b) or the metallocene compound to form an ionic complex. Reacts with the particulate carrier (a), the metallocene compound (I) and / or the organoaluminum oxy compound catalyst component (b) and / or the metallocene compound, for example, in an inert hydrocarbon solvent to form an ionic complex. A catalyst component such as the compound component (c) is mixed.
[0057]
Specifically, as the inert hydrocarbon solvent,
Aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, kerosene;
Cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane;
Aromatic hydrocarbons such as benzene, toluene, xylene;
Halogenated hydrocarbons such as ethylene chloride, chlorobenzene, dichloromethane;
Or a mixture of these
Etc.
[0058]
Compound component that reacts with fine particle carrier (a), metallocene compound (I), organoaluminum oxy compound catalyst component (b) and / or metallocene compound to form an ionic complex when preparing the metallocene catalyst as described above ( c) The order of contact of the catalyst components such as the organoaluminum compound component (d) used as necessary is arbitrarily selected, but preferably the particulate carrier (a), the organoaluminum oxy compound catalyst component (b) and The catalyst component such as the ionized ionic compound catalyst component (c) is mixed and contacted, and then the metallocene compound component (I) is mixed and contacted.
[0059]
When the organoaluminum compound catalyst component (d) is used, the particulate carrier (a) and the organoaluminum oxy compound catalyst component (b) are mixed and contacted, then the metallocene compound (I) is mixed and contacted, and further the organoaluminum compound The catalyst component (d) is mixed and contacted.
[0060]
The catalyst components used when the catalyst components are mixed and brought into contact with the particulate carrier are used, for example, in the following proportions.
When the particulate carrier (a), the metallocene compound (I) and the organoaluminum oxy compound catalyst component (b) are mixed and contacted, the component (I) is converted into transition metal atoms per 1 g of the particulate carrier (a). It is usually used in an amount of 5 × 10 −6 to 5 × 10 −4 mol, preferably 10 −5 to 2 × 10 −4 mol, and the concentration of component (I) is about 10 −4 to 2 × 10 −2. The range is mol / liter (solvent), preferably 2 × 10 −4 to 10 −2 mol / liter (solvent).
[0061]
In the organoaluminum oxy compound catalyst component (b), the atomic ratio [Al / transition metal] between the aluminum atom in the component (b) and the transition metal atom in the component (I) is usually 10 to 500, preferably 20 to 200. Is used in such an amount that
[0062]
When the organoaluminum compound catalyst component (d) is used, the component (b) is used in the same amount as described above, and the component (d) is composed of aluminum atoms in the component (d) and aluminum in the component (b). It is used in such an amount that the atomic ratio to the atom [Al of component (d) / Al of component (b)] is usually 0.02 to 3, preferably 0.05 to 1.5.
[0063]
When the ionized ionic compound catalyst component (c) is used, the component (c) has a molar ratio of the component (I) to the component (c) [component (I) / component (c)] of usually 0.01 to 10. The amount is preferably 0.1 to 5.
[0064]
Particulate carrier (a), metallocene compound (I) and organoaluminum oxy compound catalyst component (b), and / or ionized ionic compound catalyst component (c), and organoaluminum compound (d) used as necessary The mixing temperature when the catalyst components are mixed and contacted is usually −50 ° C. to 150 ° C., preferably −20 ° C. to 120 ° C., and the contact time is 1 minute to 50 hours, preferably 10 minutes to 25 hours.
[0065]
When the solid catalyst thus obtained contains, for example, an organoaluminum compound catalyst component (d) in addition to the metallocene compound (I) and the organoaluminum oxy compound catalyst component (b), The transition metal atom derived from the component (I) per 1 g of the fine particle carrier is supported in an amount of 5 × 10 −6 to 5 × 10 −4 gram atom, preferably 10 −5 to 2 × 10 −4 gram atom. Of aluminum atoms derived from component (b) and component (d) per gram of the carrier in an amount of 10 <-3> to 5 * 10 <-2> gram atoms, preferably 2 * 10 <-3> to 2 * 10 <-2> gram atoms. It is desirable that
[0066]
The catalyst used for the production of the ethylene / α-olefin copolymer [A] includes the fine particle carrier (a), metallocene compound (I) and organoaluminum oxy compound catalyst component (b), and / or ionization as described above. An ionic compound catalyst component (c) may be a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst component such as an organoaluminum compound (d) used as necessary. The prepolymerization can be performed by introducing an olefin into an inert hydrocarbon solvent in the presence of the above components.
Examples of the olefin used in the prepolymerization include α-olefins having 3 to 20 carbon atoms such as ethylene, propylene and 1-butene. Among these, ethylene used in the polymerization or a combination of ethylene and α-olefin is particularly preferable.
A conventionally known method can be employed as the prepolymerization method.
[0067]
[Preparation of medium-low pressure ethylene / α-olefin copolymer]
The medium / low pressure ethylene / α-olefin copolymer [A] used in the present invention is, for example, in the gas phase, slurry, or solution in the presence of a metallocene catalyst containing the metallocene compound (I) as described above. It can be obtained by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms under various conditions in the liquid phase.
[0068]
In the slurry polymerization method or the solution polymerization method, an inert hydrocarbon may be used as a solvent, or the olefin itself may be used as a solvent.
As an inert hydrocarbon solvent used in the slurry polymerization method and the solution polymerization method, specifically,
Aliphatic hydrocarbons such as propane, butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, and octadecane;
Cycloaliphatic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, cyclooctane;
Aromatic hydrocarbons such as benzene, toluene, xylene;
Petroleum fractions such as gasoline, kerosene and light oil
Etc. Of these inert hydrocarbon solvents, aliphatic hydrocarbons, alicyclic hydrocarbons, and petroleum fractions are preferred.
[0069]
When carrying out the polymerization, the metallocene catalyst as described above is usually at a concentration of transition metal atoms in the polymerization reaction system of 10 @ -8 to 10 @ -3 gram atoms / liter, preferably 10 @ -7 to 10 @ -4. It is preferably used in an amount of gram atoms / liter.
[0070]
Further, in the polymerization, in addition to the organoaluminum oxy compound catalyst component (b) and the organoaluminum compound catalyst component (d) supported on the carrier, an unsupported organoaluminum oxy compound catalyst component (b) and / or An organoaluminum compound catalyst component (d) may be used. In this case, an unsupported organoaluminum oxy compound catalyst component (b) and / or an aluminum atom (Al) derived from the organoaluminum compound catalyst component (d) and a transition metal atom derived from the metallocene catalyst component (A) ( The atomic ratio [Al / M] with M) is in the range of 5-300, preferably 10-200, more preferably 15-150.
[0071]
The polymerization temperature in the slurry polymerization method is usually in the range of −50 to 100 ° C., preferably 0 to 90 ° C., and the polymerization temperature in the solution polymerization method is usually in the range of −50 to 500 ° C., preferably 0 to 400 ° C. is there. The polymerization temperature in the gas phase polymerization method is usually in the range of 0 to 120 ° C, preferably 20 to 100 ° C.
[0072]
The polymerization pressure is usually from normal pressure to 100 kg / cm @ 2, preferably from 2 to 50 kg / cm @ 2, and the polymerization can be carried out in any of batch, semi-continuous and continuous systems.
[0073]
In the present invention, when preparing the above-mentioned medium / low pressure ethylene / α-olefin copolymer [A], (1) multistage polymerization, (2) liquid phase and gas phase multistage polymerization, or (3) Means such as prepolymerization in the liquid phase and then polymerization in the gas phase can be employed.
Examples of the multistage polymerization method include a multistage polymerization method including the following steps [a] and [b].
[a] A step of producing an ethylene / α-olefin copolymer [a-1] by copolymerizing ethylene and an α-olefin having 4 to 12 carbon atoms in the presence of the metallocene catalyst.
[b] In a polymerization vessel different from the polymerization vessel in which the copolymerization reaction is performed, in the presence of the metallocene olefin polymerization catalyst and [a-1], ethylene and an α- having 4 to 12 carbon atoms A process for producing an ethylene / α-olefin copolymer [a-2] by copolymerizing with olefin
[0074]
In this multi-stage polymerization method, first, the above-mentioned ethylene / α-olefin copolymer [a-1] is produced using a plurality of polymerizers connected in series, and then the ethylene / α-olefin copolymer [a-] is produced. The ethylene / α-olefin copolymer [a-1] is introduced into a polymerizer different from the polymerizer used for the production of 1], and ethylene / α-olefin copolymer [a-1] is introduced in the presence of the ethylene / α-olefin copolymer [a-1]. An α-olefin copolymer [a-2] can be produced. In addition, ethylene / α-olefin copolymer [a-2] is first produced, and then ethylene / α is added to a polymerizer different from the polymerizer used for producing ethylene / α-olefin copolymer [a-2]. -The olefin copolymer [a-2] can be introduced to produce the ethylene / α-olefin copolymer [a-1] in the presence of the ethylene / α-olefin copolymer [a-2]. .
[0075]
Also, a plurality of polymerizers are connected in parallel, and in each polymerizer, ethylene / α-olefin copolymers [a-1] and [a-2] are produced, respectively, and then both copolymers are blended. You can also.
[0076]
The copolymer [A] used in the present invention has a temperature [Tm (° C.)] and a density [d (g / cm 3)] of the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC),
Tm <400 × d−250
Preferably Tm <450 × d-297
More preferably, Tm <500 × d-344
Particularly preferably, Tm <550 × d−391
It is desirable to satisfy the relationship indicated by.
[0077]
[High pressure polyethylene]
The high-pressure polyethylene [B] used in the present invention can be synthesized, for example, by a so-called high-pressure method in which ethylene is synthesized by radical polymerization at 1000-2000 atm and 200-300 ° C. The high pressure polyethylene [B] used in the present invention preferably has an MFR (190 ° C.) of 0.1 to 10 g / 10 min, particularly preferably 0.5 to 5.0 g / 10 min, and a density of preferably 0.910. To 0.935 g / cm @ 3, particularly preferably 0.920 to 0.930 g / cm @ 3.
The high-pressure polyethylene referred to in the present invention is not only a homopolymer of ethylene but also a range that does not impair the object of the present invention, for example, a small amount of other polymerizable monomer of 10% by weight or less, such as vinyl acetate, A copolymer of acrylic acid ester or the like and ethylene may be used.
[0078]
The blend ratio of the copolymer [A] and the high-pressure polyethylene [B] in the present invention is such that [A] is 100 to 20% by weight, [B] is 0 to 80% by weight, and [A] 90 to 20 It is more preferable that they are 10% by weight and 10% to 80% by weight. When [A] is less than 20% by weight, the effect of improving repeated fatigue strength is not sufficient. When used as a normal irrigation tube, the ratio of copolymer [A] to high-pressure polyethylene [B] is 20 parts by weight to 80 parts by weight to 60 parts by weight to 40 parts by weight. When tear resistance, rigidity, etc. are required, it can be dealt with by increasing the proportion of the copolymer [A].
[0079]
In addition, a weather resistance stabilizer, a heat resistance stabilizer, an antifogging agent, an antiblocking agent, a slip agent, a lubricant, a pigment, a dye, and the like may be added to the above composition as long as the characteristics are not impaired.
Various known methods can be used to obtain the composition as described above. For example, there are a method in which each resin is mixed with a ribbon blender and a Henschel mixer and then granulated with an extruder, or a method in which the resin is directly melt-mixed with a Banbury mixer, a kneader, two rolls, etc. and then granulated with an extruder. Also, at the time of film forming, the copolymer [A] and high-pressure polyethylene [B] are mixed with the ribbon blender, Henschel mixer, etc., and then introduced into a raw material supply section such as a hopper of a film forming machine to form a film. The tape-like thermoplastic resin composition film may be obtained directly.
[0080]
In order to obtain an irrigation tube, that is, a flexible structure for irrigation using such a composition, for example, a large number of irrigation holes (holes are round holes, polygonal holes or slit-like holes in the length direction of the film). Two continuous films made of a continuous film made of the tape-like composition provided with the tape-like composition, and laminating the two tape-like articles while moving the laminated tape-like parts. Obtained by continuous heat sealing.
[0081]
Further, for example, a continuous film made of the tape-like composition provided with a number of irrigation holes in the length direction of the film (the holes may be any shape such as a round hole, a polygonal hole or a slit-like hole) and a tape not provided More preferred is a irrigation tube obtained by laminating a continuous film made of the above-mentioned composition and continuously heat-sealing both widthwise ears while running the laminated tape.
[0082]
The thickness of the film to be used is usually 50-1000 μm, preferably 150-500 μm.
Examples of the method for providing the irrigation hole at a predetermined position and a predetermined length include a method using laser light irradiation, a method using a cutter blade, and a method using a hot needle.
In order to prevent clogging of the irrigation holes, when a water-permeable and water-insoluble sheet-like material is used as the inner layer, a water-permeable and water-insoluble nonwoven fabric is used between the tape-like films when the tape-like film is laminated. After laminating so that a continuous tape-like material is positioned, the both-ear portions in the width direction of the laminated tape-like material are heat-sealed.
[0083]
Since the irrigation tube thus obtained is excellent in heat sealability and heat seal strength, it can be repeatedly subjected to pressure fatigue strength (through a 1.2 m long tube at an irrigation pressure of 1.0 kg / cm2 for 2 minutes. After that, the method of making the water non-flowing state for 2 minutes and repeating the water flow-non-water flow cycle to see how many times the tube breaks is also excellent.
[0084]
Moreover, it has excellent creep resistance and impact strength of the heat seal part, high breaking water pressure, strength is maintained even at a lower density, and excellent transparency. Moreover, when using the conventional irrigation tube, when using the agricultural multi film simultaneously, there existed a fault that an irrigation tube and a multi film closely_contact | adhere. However, in the present invention, in particular, in the case of an irrigation tube having an increased content of the ethylene / α-olefin copolymer [A], it does not cause close contact with other films during use and has excellent workability. .
[0085]
The irrigation tube of the present invention, that is, the flexible structure for irrigation, is not only water, but also liquid fertilizer, water-soluble insecticide, acaricide, water-soluble fungicides, virusicide, water-soluble herbicide, dustproof agent, It can be drained or irrigated containing other drugs, and has a wide range of applicability that enables underground irrigation in relatively shallow soil.
[0086]
In addition, in order to prevent clogging due to the propagation of organisms in the tube, it is preferable to block visible light by coloring. Carbon black is preferably used for coloring. The carbon black is 1 to 10 parts by weight, preferably 100 parts by weight of the total amount of the medium-low pressure ethylene / α-olefin copolymer as the [A] component and the high-pressure polyethylene as the [B] component. Is used in a proportion of 2-6 parts by weight.
[0087]
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
[0088]
In the reference examples, examples and comparative examples, the basic physical properties of the copolymer and the physical properties of the film were evaluated as follows.
(1) Density
The density of the copolymer was determined by measuring the melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg, heat-treating the strand at 120 ° C. for 1 hour, and gradually cooling to room temperature over 1 hour. Measured with
(2) Melt flow rate (MFR)
The melt flow rate of the copolymer was measured according to ASTM D 1238 (190 ° C., load 2.16 kg).
(3) Repetitive pressure fatigue strength
After passing water at 35 ° C for 2 minutes at an irrigation pressure of 1.0 kg / cm2 through a 1.2 m long tube, the tube was put into a non-water-permeable state for 2 minutes. How to see if the tube breaks
(4) Tensile creep
In accordance with the method of ASTM-D2990, 2991, the sample width was 15 mm (including the heat seal part in the width direction at the center in the tensile direction), the load was 1.5 kg, the temperature was 40 ° C., and the time until cutting was measured.
(5) Heat seal strength
The heat sealing conditions were a temperature of 220 ° C., a pressure of 2 kg / cm 2, a pressurization time of 2 seconds, and a tensile peel or cutting strength of a test piece having a width of 15 mm was measured at a pulling speed of 200 mm / min.
(6) Elmendorf tear strength
The Elmendle tear strength was determined by conducting a tear strength test in the MD direction and the TD direction of the original film in accordance with ASTM-D1922.
[0089]
[Reference Example 1]
[Preparation of metallocene catalyst]
10 kg of silica dried at 250 ° C. for 10 hours was suspended in 154 liters of toluene, and then cooled to 0 ° C. Thereafter, 57.5 liters of a toluene solution of methylaluminoxane (Al; 1.33 mol / liter) was added dropwise over 1 hour. At this time, the temperature in the system was kept at 0 ° C. Subsequently, the mixture was reacted at 0 ° C. for 30 minutes, then heated to 95 ° C. over 1.5 hours and reacted at that temperature for 20 hours. Thereafter, the temperature was lowered to 60 ° C., and the supernatant was removed by a decantation method.
[0090]
The solid component thus obtained was washed twice with toluene and then resuspended in 100 liters of toluene. 16.8 liters of a toluene solution (Zr; 27.0 mmol / liter) of bis (1-methyl-3-n-butylcyclopentadienyl) zirconium dichloride was dropped into the system at 80 ° C. over 30 minutes. The reaction was further carried out at 80 ° C. for 2 hours. Thereafter, the supernatant was removed and washed twice with hexane to obtain a solid catalyst containing 3.5 mg of zirconium per 1 g.
[0091]
[Preparation of prepolymerization catalyst]
By adding 870 g of the solid catalyst obtained above and 260 g of 1-hexene to 87 liters of hexane containing 2.5 mol of triisobutylaluminum, and preliminarily polymerizing ethylene at 35 ° C. for 5 hours, 1 g of the solid catalyst was obtained. A prepolymerized catalyst in which 10 g of polyethylene was prepolymerized was obtained.
[polymerization]
Using a continuous fluidized bed gas phase polymerization apparatus, ethylene and 1-hexene were copolymerized in the presence of the prepolymerization catalyst to obtain an ethylene / 1-hexene copolymer.
[0092]
The ethylene / 1-hexene copolymer obtained as described above has a 1-hexene content of 8.4% by weight, a density of 0.921 g / cm 3, and a melt flow rate (MFR; ASTM D 1238). -65T, 190 ° C, load 2.16 kg) was 2.1 g / 10 min, and the molecular weight distribution (Mw / Mn) measured by GPC was 2.0.
[0093]
In addition, this copolymer has a maximum peak one temperature [Tm] of an endothermic curve measured by a differential scanning calorimeter (DSC) of 116 ° C., and the n-decane soluble component fraction [W] at room temperature. Was 0.22% by weight.
[0094]
The B1 measured by GPC-IR analysis of this copolymer (hereinafter sometimes abbreviated as A-1) is 14.2 / 1000 C (14.2 per 1000 carbon atoms), and B2 is 13. It was 8 / 1000C.
[0095]
[Reference Example 2]
Using a continuous fluidized bed gas phase polymerization apparatus, ethylene and 1-hexene were copolymerized in the presence of the prepolymerization catalyst described in Reference Example 1 to obtain an ethylene / 1-hexene copolymer.
[0096]
The ethylene / 1-hexene copolymer obtained as described above has a 1-hexene content of 9.9% by weight, a density of 0.915 g / cm 3, and a melt flow rate (MFR; ASTM D 1238). −65T, 190 ° C., load 2.16 kg) was 2.2 g / 10 min, and the molecular weight distribution (Mw / Mn) measured by GPC was 2.1.
[0097]
Further, this copolymer has a maximum peak one temperature [Tm] of an endothermic curve measured by a differential scanning calorimeter (DSC) of 108 ° C., and the n-decane soluble component fraction [W] at room temperature. Was 0.33% by weight.
[0098]
The above-mentioned B1 measured by GPC-IR analysis of this copolymer (hereinafter sometimes abbreviated as A-2) was 16.7 / 1000C, and B2 was 16.3 / 1000C.
[0099]
[Reference Example 3]
Using an apparatus in which two continuous fluidized bed gas phase polymerization apparatuses are connected in series, ethylene and 1-hexene are copolymerized in the presence of the prepolymerization catalyst described in Reference Example 1 above. A hexene copolymer (A-3) was obtained.
[0100]
The ethylene / 1-hexene copolymer obtained as described above has a 1-hexene content of 8.7% by weight, a density of 0.920 g / cm 3, and a melt flow rate (MFR; ASTM D 1238). -65T, 190 ° C., load 2.16 kg) was 2.0 g / 10 min, and molecular weight distribution (Mw / Mn) measured by GPC was 3.2.
[0101]
Further, this copolymer has a maximum peak one temperature [Tm] of an endothermic curve measured by a differential scanning calorimeter (DSC) of 114 ° C., and the n-decane soluble component fraction [W] at room temperature. Was 0.29% by weight.
[0102]
The above-mentioned B1 measured by GPC-IR analysis of this copolymer was 15.0 / 1000C, and B2 was 13.4 / 1000C.
[0103]
[Reference Example 4]
In the presence of Ziegler-type Ti-based polymerization catalyst (magnesium-supported Ti-based catalyst and alkylaluminum), ethylene and 4-methyl-1-pentene were copolymerized to produce ethylene 4-methyl-1-pentene copolymer ( A-4) was obtained.
[0104]
The ethylene-4-methyl-1-pentene copolymer obtained as described above has a 4-methyl-1-pentene content of 7.3% by weight, a density of 0.920 g / cm 3, The flow rate (MFR; ASTM D 1238-65T, 190 ° C., load 2.16 kg) was 2.0 g / 10 min, and the molecular weight distribution (Mw / Mn) measured by GPC was 3.6.
[0105]
In addition, this copolymer has a maximum peak one temperature [Tm] of an endothermic curve measured by a differential scanning calorimeter (DSC) of 122 ° C., and the n-decane soluble component fraction [W] at room temperature. Was 8.5% by weight.
[0106]
The above-mentioned B1 measured by GPC-IR analysis of this copolymer was 10.3 / 1000C, and B2 was 13.9 / 1000C.
[0107]
High pressure polyethylene (B) component
High-pressure polyethylene (density: 0.926 g / cm 3) (Mirason ACE30N, Mitsui Polychemical KK, registered trademark) having an MFR of 0.5 g / 10 min was used.
[0108]
[Example 1]
The medium-low pressure ethylene / 1-hexene copolymer (A-1) film (width 42 mm, thickness 0.2 mm) obtained in Production Example 1 was provided with irrigation slits in the length direction of the film. These films are run continuously so that a continuous tape-like article of nonwoven fabric made of thermoplastic synthetic fibers is located between the ones that are not punched and the ones that are not perforated. Then, both edge portions in the width direction were continuously heat-sealed to obtain a flexible structure for irrigation. Using this structure, a repeated pressure fatigue strength test and a tensile creep test were conducted.
The results are shown in Table 1.
Table 1 also shows the test results of the tear strength and heat seal strength of the raw film.
[0109]
[Example 2]
The medium-low pressure ethylene / 1-hexene copolymer (A-1) produced in Production Example 1 and the high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min are (A-1) / (B) 50/50. The mixture was melt-kneaded using a twin screw extruder so as to obtain a ratio of A film was formed using the pellets and evaluated in the same manner as in Example 1. The results are shown in Table 1.
[0110]
[Example 3]
In Example 2, it carried out like Example 2 except having made it the ratio of A-1 / B becoming 30/70. The results are shown in Table 1.
[0111]
[Example 4]
The same procedure as in Example 1 was performed using the medium / low pressure ethylene / 1-hexene copolymer (A-2) produced in Production Example 2. The results are shown in Table 1.
[0112]
[Example 5]
The same procedure as in Example 3 was performed using the medium-low pressure ethylene / 1-hexene copolymer (A-2) produced in Production Example 2. The results are shown in Table 1.
[0113]
[Example 5]
In Example 3, it carried out similarly to Example 3 using the medium-low pressure method ethylene 1-hexene copolymer (A-3) manufactured by manufacture example 3 instead of A-1. The results are shown in Table 1.
[0114]
[Comparative Example 1]
The same procedure as in Example 1 was carried out except that the medium-low pressure ethylene / 4-methylpentene-1 copolymer (A-4) produced in Production Example 3 was used. The results are shown in Table 1.
[0115]
[Comparative Example 2]
In Example 3, it carried out like Example 3 except having used A-4 instead of A-1. The results are shown in Table 1.
[0116]
[Comparative Example 3]
The same procedure as in Example 1 was performed using high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min. The results are shown in Table 1.
[0117]
[Table 1]

[0118]
(7) Adhesion evaluation with agricultural multi-film
The following were used as agricultural multi-films.
In June of a year, in a field with straw, the irrigation tube of the present invention was installed in the middle of the straw, and a transparent multi-film for agriculture (made of high-pressure polyethylene) with a thickness of 30 μm was used on it. And melon tunnel cultivation. Irrigation was performed every week, and it was examined whether or not the irrigation tube and the multi-film were in close contact, and the degree of adhesion and irrigation unevenness were visually evaluated with ○, Δ, and ×.
○ No adhesion, no irrigation unevenness
△ Adhesion, irrigation unevenness slightly
× Adhesion, non-irrigation (state where irrigation holes are blocked by adhering to prevent irrigation)
[0119]
[Table 2]

Claims (5)

It has at least one continuous heat seal part extending along the length direction, and has a large number of irrigation holes arranged at appropriate intervals in the length direction. In the thermoplastic resin irrigation tube that is cylindrical when it is not water-permeable, the thermoplastic resin has a [A] (i) melt flow rate of 0.01 to 10 g / 10 min, (ii ) The density is 0.905 to 0.930 g / cm ³ , and (iii) the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn measured by GPC is in the range of 1.5 to 3.5. (Iv) n-decane soluble part (W: wt%) and density (d: g / cm ³ ) at 23 ° C.
[Expression 1]
W <80 × exp (−100 (d−0.88)) + 0.1
(V) When the average value of the number of branches on the high molecular weight side according to GPC-IR is B1, and the average value of the number of branches on the low molecular weight side is B2, B1 ≧ B2 and ethylene and carbon 100 to 20% by weight of a medium to low pressure ethylene / α-olefin copolymer comprising an α-olefin having 4 to 12 atoms, and [B] a high pressure polyethylene 0 having a density of 0.910 to 0.935 g / cm ^3. An irrigation tube comprising ˜80% by weight. 2. The irrigation tube according to claim 1, wherein the density of the component [A] is 0.905 g / cm ³ or more and 0.925 g / cm ³ or less. The irrigation tube according to claim 1 or 2, wherein the component [A] is obtained with a metallocene catalyst. The irrigation tube according to claim 3, wherein the metallocene compound (I) used as a component of the metallocene catalyst is a metallocene compound represented by the following general formula [1] or [2].
[Chemical 1]
MK (L ₁ ) _x-2 [1]
Wherein M is a transition metal selected from group IVB of the periodic table, K and L ₁ are ligands coordinated to the transition metal atom, and ligand K is the same or different indenyl group, A substituted indenyl group or a partial hydrate thereof is a bidentate ligand bonded via a lower alkylene group or a substituted silylene group, and the ligand L ₁ is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group , An aryloxy group, a halogen atom, a trialkylsilyl group or a hydrogen atom, and X is the valence of the transition metal atom M. ]
[Chemical 2]
M (L ₂ ) _x [2]
[Wherein, M is a transition metal atom selected from Group VIB of the periodic table, L ₂ is a ligand coordinated to transition metal atom M, and at least two of these ligands L ₂ Is a substituted cyclopentadienyl group having at least one substituent selected from a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, or a hydrocarbon group having 3 to 10 carbon atoms. The ligand L ₂ other than the substituted cyclopentadienyl group is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and X is a transition metal. The valence of atom M. ] The irrigation tube is composed of two inner and outer layers, the inner layer is located on the inner side of the outer layer, and is a flexible inner layer made of a water-permeable and water-insoluble sheet fixed to the outer layer. Item 5. The irrigation tube according to any one of Items 1 to 4 .