JP3968800B2 - Irrigation tube - Google Patents

Description

【０１１９】
（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）
【０１２０】
【表２】

[0001]
[Industrial application fields]
The present invention relates to a novel irrigation tube, and more specifically, it is excellent in repeated pressure fatigue strength and impact strength, has high breaking water pressure, and maintains strength even at a lower density, and adheres to other films during use. The present invention relates to an irrigation tube that is difficult to cause 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]
By the way, it is not easy to provide a small hole only on one side of the manufactured continuous tube. Therefore, as a method of manufacturing a perforated tube, conventionally, after punching by mechanical punching or laser light on a synthetic resin tape, the same shape of tape and the edges of each other are heat sealed to form a laminated tube shape. A method for forming the film is known.
However, conventional irrigation tubes made of high-pressure polyethylene or ethylene / vinyl acetate copolymer are much more durable in terms of durability against heat-seal damage and delamination due to repeated water-non-water cycle. There was a need for improvement.
[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 an irrigation tube having such a heat seal portion (Japanese Patent Publication No. 63). -37607), or by using a composition of a specific ethylene / α-olefin random copolymer and high-pressure polyethylene (Japanese Patent Publication No. 64-7732), an irrigation tube having good repeated pressure fatigue strength can be obtained. Have found.
As a solution to the problem that the seam part bursts when a large water pressure is applied because the seam part (heat seal part) is present in the tube itself, the present inventors first made an extrusion molding. It was proposed to use a tube formed by drilling with a laser beam in a pre-formed seamless tube.
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 repeated pressure fatigue strength and impact strength, has high breaking water pressure, and maintains strength even at a lower density. An object of the present invention is to provide a irrigation tube having excellent workability without causing close contact with the irrigation tube.
[0006]
[Means for Solving the Problems]
  The irrigation tube according to the present invention has a large number of irrigation holes arranged at appropriate intervals in the length direction, and expands when passing water and exhibits a cylindrical shape, but is flat when not passing water. A thermoplastic resin irrigation tube having no heat seal portion extending along the length direction., [A] (i) Melt flow rate is0.5-5g / 10min, (ii) density is0.905 to 0.925g / cm³(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, 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 A medium to low pressure ethylene / α-olefin copolymer consisting of an α-olefin having 4 to 12 atoms, and 50 to 50% by weight;
[B] High-pressure polyethylene 0-50% by weightIs obtained by extruding from a die having a cylindrical extrusion port into a tube and perforating with laser light on one sideThis is an irrigation tube.
[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 3]
MK (L₁)_X-2    ... [1]
[Wherein M is a transition metal selected from Group IVB of the periodic table, and K and L₁Is a ligand coordinated to a transition metal atom, and the ligand K is a group in which the same or different indenyl group, substituted indenyl group or a partial hydride thereof is bonded via a lower alkylene group or substituted silylene group. Bidentate ligand, ligand L₁Is a C1-C12 hydrocarbon group, alkoxy group, aryloxy group, halogen atom, trialkylsilyl group or 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, and L₂Is a ligand coordinated to the transition metal atom M, of which at least two ligands L₂Is 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. Ligand L other than (substituted) cyclopentadienyl group₂Is a C1-C12 hydrocarbon group, alkoxy group, aryloxy group, trialkylsilyl group, halogen atom or hydrogen atom, and X is the valence of the transition metal atom 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 is, 0. 905 g / cm³~ 0.925g / cm³Is in the range.
[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 polystyrene has a molecular weight of Mw <1000 and Mw> 4 × 10.⁶ For Tosoh Corporation, 1000 <Mw <4 × 10⁶ The pressure chemical company make was used.
[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, the low molecular region 15%, 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, and K and L₁Is a ligand coordinated to a transition metal atom, and the ligand K is a group in which the same or different indenyl group, substituted indenyl group or a partial hydride thereof is bonded via a lower alkylene group or substituted silylene group. Bidentate ligand, ligand L₁Is a C1-C12 hydrocarbon group, alkoxy group, aryloxy group, halogen atom, trialkylsilyl group or 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]
L₁Is a C1-C12 hydrocarbon group, alkoxy group, aryloxy group, halogen atom, trialkylsilyl group or 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 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, t-butoxy, pentoxy, hexoxy, octoxy, etc. 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, of which at least two ligands L₂ 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. Yes,
(Substituted) Ligands other than cyclopentadienyl groups₂ 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]. L₂Is 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 atom. A substituted cyclopentadienyl group having at least one substituent selected from hydrocarbon groups of several 3 to 10.
[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], a ligand L other than the cyclopentadienyl group coordinated to the transition metal atom M₂ 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.
[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, SiO.₂ , Al₂O_Three , MgO, ZrO₂TiO₂ , B₂O_Three, CaO, ZnO, BaO, ZnO₂ , SnO₂ , ThO₂ Etc. or mixtures thereof, eg SiO₂-MgO, SiO₂-Al₂O_Three, SiO₂-TiO₂, SiO₂-V₂O_Five, SiO₂-Cr₂O_Three, SiO₂-TiO₂-MgO 2 and the like can be exemplified. Among these, SiO₂And Al₂O_ThreeAn oxide containing at least one component selected from the group consisting of as main components is preferable.
[0043]
The inorganic oxide contains a small amount of Na.₂CO_Three, K₂CO_Three, CaCO_Three , MgCO_Three , Na₂SO_Four, Al₂(SO_Four)_Three , BaSO_Four , KNO_Three , Mg (NO_Three)₂ , Al (NO_Three)_Three, Na₂O, K₂O 2, Li₂It may contain carbonates such as O 2, sulfates, nitrates, and oxide components.
[0044]
Such a carrier has different properties depending on the type and production method, but the carrier preferably used in the present invention has a specific surface area of 50 to 1000 m.²/ g, preferably 100-700 m²/ g and a pore volume of 0.3 to 2.5 cm^ThreeDesirably / 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. An organoaluminum compound such as trialkylaluminum is added to the hydrocarbon medium suspension of
And the method of reacting adsorbed water or crystal water.
(2) In a medium such as benzene, toluene, ethyl ether, tetrahydrofuran, etc.
A way to work.
[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, Al₂O_Three, SiO₂-Al₂O_Three Etc. can be exemplified.
[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-dicarboundeca) 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;
Alkyl aluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide; alkyl such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, ethylaluminum dibromide Aluminum dihalide;
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]
In order to contact the catalyst component such as the fine particle carrier (a) and the metallocene compound (I), the organoaluminum oxy compound catalyst component (b) or the compound component (c) which reacts with the metallocene compound to form an ionic complex, For example, a compound component (c) which reacts with a particulate carrier (a), a metallocene compound (I), an organoaluminum oxy compound catalyst component (b) and / or a metallocene compound in an inert hydrocarbon solvent to form an ionic complex. Etc.) and other catalyst components are 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;
Halogen hydrocarbons such as ethylene chloride, chlorobenzene, dichloromethane; or mixtures thereof
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). Usually 5 × 10^-6~ 5x10^-FourMoles, preferably 10^-Five~ 2x10^-FourUsed in molar amounts, the concentration of component (I) is about 10^-Four~ 2x10^-2Mol / liter (solvent), preferably 2 × 10^-Four-10^-2The range is 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), organoaluminum oxy compound catalyst component (b), and / or ionized ionic compound catalyst component (c), and an 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), 5 × 10 5 transition metal atoms derived from component (I) per gram of fine particle carrier^-6~ 5x10^-FourGram atoms, preferably 10^-Five~ 2x10^-FourThe amount of aluminum atoms derived from the component (b) and the component (d) per 10 g of the fine particle carrier supported in the amount of gram atoms^-3~ 5x10^-2Gram atoms, preferably 2 × 10^-3~ 2x10^-2It is preferably supported in the amount of gram atoms.
[0066]
The catalyst used for the production of the ethylene / α-olefin copolymer [A] is the fine particle carrier (a), metallocene compound (I), organoaluminum oxy compound catalyst component (b) and / or ionized ions as described above. It may be a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst component such as an organoaluminum compound (d), which is further used if 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 10% at the concentration of transition metal atoms in the polymerization reaction system.^-8-10^-3Gram atom / liter, preferably 10^-7-10^-FourIt 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 normal pressure to 100 kg / cm² , Preferably 2-50kg / cm² 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) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC).^Three )]
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. 0.935g / cm^ThreeAnd particularly preferably 0.920 to 0.930 g / cm.^Threebelongs to.
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 50% by weight, [B] is 0 to 50% by weight, and [A] 90 to 70 More preferably, it is 10% by weight and 10 to 30% by weight. If [A] is less than 50% by weight, the effect of improving impact strength and breaking water pressure is not sufficient.
[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 by a ribbon blender and a Henschel mixer and then granulated by an extruder, or a method in which the resin is directly melt-mixed by a Banbury mixer, a kneader, two rolls, etc., and then granulated by 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 film obtained by extruding the composition from a die having a cylindrical extrusion port and molding it. A tube that does not have a heat seal portion in the longitudinal direction is held in a cylindrical state, and the tube is transported in the longitudinal direction, and a laser beam is focused on a side surface of the tube at a predetermined interval, and is sequentially punched. Can do. During this time, air or gas may be inserted into the tube.
In the perforated tube obtained here, the perforated portion and the non-perforated portion do not need to be color-coded black and non-black, respectively, but may be color-coded as such or may be black as a whole. In this case, carbon black is preferably dispersed inside at a ratio of 0.5% by weight or more.
In addition, the laser beam generator that focuses on the side surface of the tube is a device that condenses excitation light on an excitation body that is substantially formed of YAG, and emits the collected light with near-infrared light. Various laser light generators can be used.
[0081]
The thickness of the film to be used is usually 50-1000 μm, preferably 150-700 μm.
[0082]
Since the irrigation tube thus obtained does not have a heat seal portion and is manufactured from a specific thermoplastic resin, the irrigation pressure 1 is repeatedly applied to the pressure fatigue strength (1.2 m long tube). .0kg / cm²In this method, the water is not passed for 2 minutes, and the water-non-water-passing cycle is repeated to see how many times the tube breaks).
[0083]
In addition, the impact strength is excellent, the breaking water pressure is high, and the strength is maintained even at a lower density. 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, the irrigation tube in which the content ratio of the ethylene / α-olefin copolymer [A] is increased is not easily brought into close contact with other films during use, and is excellent in workability.
[0084]
The irrigation tube of the present invention, ie, the flexible structure for irrigation, can spray not only water but also liquid fertilizer, agricultural chemicals, herbicides, and other chemicals, and can also be used in a relatively shallow soil. Medium irrigation also has wide applicability.
[0085]
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 0.5 to 10 parts by weight with respect to 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. , Preferably 1-6 parts by weight.
[0086]
Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples.
[0087]
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 is 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, gradually cooling to room temperature over 1 hour, and then the density gradient tube. 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
Irrigation pressure of 1.0kg / cm on a 1.2m long tube²Then, after passing water at 35 ° C. for 2 minutes, the water is not passed for 2 minutes, and the water flow-non-water flow cycle is repeated to see how many times the tube is broken.
(4) 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 according to ASTM-D1922.
(5) Dirt impact strength
The dart impact strength of the film was determined according to the JIS-K7124 dart impact test method.
[0088]
[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.
[0089]
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.
[0090]
[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, prepolymerization of ethylene for 5 hours at 35 ° C. A prepolymerized catalyst in which 10 g of polyethylene per polymer was prepolymerized was obtained.
[0091]
[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 and a density of 0.921 g / cm.^Three The 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 and a density of 0.915 g / cm.^Three The 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 and a density of 0.920 g / cm.^Three The melt 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 3.2. .
[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 and a density of 0.920 g / cm.^Three The melt 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 with MFR 0.5 g / 10 min (density: 0.926 g / cm^Three) (Mirason ACE30N, Mitsui Polychemical KK, registered trademark).
[0108]
[Example 1]
The medium / low pressure ethylene / 1-hexene copolymer (A-1) obtained in Reference Example 1 was formed into a film (folding width 50 mm, thickness 0.21 mm) with an inflation method film forming apparatus, and YAG was formed on one side of the film. Irrigation holes were drilled using laser light to obtain irrigation tubes. This irrigation tube was subjected to repeated pressure fatigue strength tests.
The results are shown in Table 1.
[0109]
[Example 2]
The medium-low pressure ethylene / 1-hexene copolymer (A-1) produced in Reference Example 1 and the high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min are (A-1) / (B) of 80/20. The mixture was melt-kneaded using a twin screw extruder so as to obtain a ratio of Using this pellet, a film was formed in the same manner as in Example 1 and evaluated.
The results are shown in Table 1.
[0110]
[Example 3]
In Example 2, a film was molded and evaluated in the same manner as in Example 2 except that the ratio of A-1 / B was 60/40. The results are shown in Table 1.
[0111]
[Comparative Example 1]
In Example 2, a film was molded and evaluated in the same manner as in Example 2 except that the ratio of A-1 / B was 20/80. The results are shown in Table 1.
[0112]
[Example 4]
A film was molded and evaluated in the same manner as in Example 1 except that the medium / low pressure ethylene / 1-hexene copolymer (A-2) produced in Reference Example 2 was used. The results are shown in Table 1.
[0113]
[Example 5]
The medium-low pressure ethylene / 1-hexene copolymer (A-2) produced in Reference Example 2 and the high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min are (A-2) / (B) of 80/20. It melt-kneaded using the biaxial extruder so that it might become a ratio, and was pelletized. Using this pellet, a film was formed in the same manner as in Example 1 and evaluated.
The results are shown in Table 1.
[0114]
[Example 6]
The medium-low pressure ethylene / 1-hexene copolymer (A-3) produced in Reference Example 3 and the high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min are (A-3) / (B) of 80/20. It melt-kneaded using the biaxial extruder so that it might become a ratio, and was pelletized. Using this pellet, a film was formed in the same manner as in Example 1 and evaluated.
The results are shown in Table 1.
[0115]
[Comparative Example 2]
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 Reference Example 4 was used. The results are shown in Table 1.
[0116]
[Comparative Example 3]
The medium-low pressure ethylene / 1-hexene copolymer (A-4) produced in Reference Example 4 and the high-pressure polyethylene (B) having an MFR of 0.5 g / 10 min are (A-4) / (B) of 80/20. It melt-kneaded using the biaxial extruder so that it might become a ratio, and was pelletized. Using this pellet, a film was formed in the same manner as in Example 1 and evaluated.
The results are shown in Table 1.
[0117]
[Comparative Example 4]
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.
[0118]
[Table 1]

[0119]
(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 due to adhesion and cannot be irrigated)
[0120]
[Table 2]

Claims (4)

It has a large number of irrigation holes arranged at appropriate intervals in the length direction, and expands along the length direction. In the irrigation tube made of thermoplastic resin that does not have a heat seal part ,
[ A] (i) The melt flow rate is 0.5 to 5 g / 10 min, (ii) the density is 0.905 to 0.925 g / cm ³ , and (iii) the weight average molecular weight Mw measured by GPC; The ratio Mw / Mn of the number average molecular weight Mn is in the range of 1.5 to 3.5, and (iv) n-decane soluble part (W: wt%) and density (d: g / cm ³ ) at 23 ° C. And

(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 100 to 50% by weight of α-olefin having 4 to 12 atoms,
[B] High-pressure polyethylene 0-50% by weight
A irrigation tube obtained by extruding a thermoplastic resin consisting of: from a die having a cylindrical extrusion port into a tube and perforating with laser light on one side thereof . [A] The irrigation tube according to claim 1, wherein the component (A) is obtained by a metallocene catalyst. The irrigation tube according to claim 2 , 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 according to any one of claims 1 to 3 , wherein the density of the high-pressure polyethylene of component (B) is 0.910 to 0.935 g / cm ³ .