JP4651156B2 - Hollow body manufacturing method and container - Google Patents

Description

この成形条件は、エチレン・α−オレフィン共重合体層を含むパリソンのドローダウン性を改良し、早い成形スピードで、かつ高い機械的強度を持つ外観の良好な中空体を製造するために望ましい押出成形条件である。
【００８６】
中 空 体 容 器
本発明に係わる容器は、前記した製造方法に従って製造したエチレン・α−オレフィン共重合体の層を少なくとも１層含む中空体であって、エチレン・α−オレフィン共重合体の層のみからなる単層容器であってもよいし、またエチレン・α−オレフィン共重合体の層と他の樹脂層とから構成される多層容器であってもよい。
【００８７】
単層容器の製造は、通常のブロー成形方法によって行われる。多層容器を製造する場合には、複数の押出機を用意し、その先端連結部に共押出ダイを取付けて容器の製造が行われる。すなわち、その内の一台の押出機からエチレン・α−オレフィン共重合体を前述した好ましい押出条件で押出し、他の押出機から別の樹脂を任意の条件で押出し、共押出ダイを経由して多層パリソンを形成し、そのパリソンをブロー金型に挟んでブロー成形することによって多層容器を製造することができる。
【００８８】
多層容器を製造する場合には、エチレン・α−オレフィン共重合体の層と共に押出す別の樹脂層として、ポリアミド樹脂、ポリエステル樹脂、ポリカーボネート樹脂、エチレン・ビニルアルコール樹脂等のガスバリヤー性を有する樹脂の層を配置することができる。通常、それらのガスバリヤー性樹脂層はエチレン・α−オレフィン共重合体層とは接着性がよくないので、両層の中間に不飽和カルボン酸グラフト変性ポリオレフィン等を用いた接着層が設けられる。
【００８９】
容器内容物の種類によって、また容器自身への要求物性によって、エチレン・α−オレフィン共重合体の層／接着層／ガスバリヤー性樹脂層からなる３層構造体にしてもよいし、さらに前記の層間やガスバリヤー性樹脂層の外側に別の樹脂層を設けた３層以上の構造、例えば４〜５層構造にしてもよい。
【００９０】
このような単層または多層容器は、一般容器、灯油缶、工業薬品缶、ガソリンタンク、マヨネーズ容器、ケチャップ容器、食用油ボトル、バッグインボックス、ドラム缶内袋等の包装容器として、また練りワサビや練りからし等を保存するブローチューブに使用することができる。
【００９１】
【実施例】
次に本発明を実施例を通して説明するが、本発明はそれら実施例によって何ら限定されるものではない。
まず、使用したエチレン・α−オレフィン共重合体は、次に記す方法によって製造した。
【００９２】
［触媒の調製］
２５０℃で１０時間乾燥したシリカ１０ｋｇを１５４リットルのトルエンで懸濁状にした後、０℃まで冷却した。その後、メチルアミノオキサンのトルエン溶液（Ａｌ＝１．３３モル／リットル）５７．５リットルを１時間で滴下した。
この際、系内の温度を０℃に保った。引続き０℃で３０分間反応させ、次いで１．５時間かけて９５℃まで昇温し、その温度で２０時間反応させた。その後６０℃まで降温し上澄液をデカンテーション法により除去した。
【００９３】
このようにして得られた固体成分をトルエンで２回洗浄した後、トルエン１００リットルで再懸濁化した。この系内へビス（1,3-ジメチルシクロペンタジエニル）ジルコニウムジクロリドのトルエン溶液（Ｚｒ＝２７．０ミリモル／リットル）１６．８リットルを８０℃で３０分間かけて滴下し、更に８０℃で２時間反応させた。その後、上澄液を除去し、ヘキサンで２回洗浄することにより、１ｇ当り３．５ｍｇのジルコニウムを含有する固体触媒を得た。
【００９４】
［予備重合触媒の調製］
２．５モルのトリイソブチルアルミニウムを含有する８７リットルのヘキサンに、上記で得られた固体触媒８７０ｇおよび１−ヘキセン２６０ｇを加え、３５℃で５時間エチレンの予備重合を行うことにより、固体触媒１ｇ当り１０ｇのポリエチレンが予備重合された予備重合触媒を得た。
【００９５】
［重 合］
連続式流動床気相重合装置を用い、全圧２０kg/cm²-G、重合温度８０℃でエチレンと１−ヘキセンとの共重合を行った。先に調製した予備重合触媒をジルコニウム原子換算で０．３３（ミリモル/h）、トリイソブチルアルミニウムを１０（ミリモル／ｈ）の割合で連続的に供給し、重合の間一定のガス組成を維持するためにエチレン、１−ヘキセン、水素、窒素を連続的に供給した（ガス組成；１−ヘキセン／エチレン＝０．０２、水素／エチレン＝１０．５×１０^-4、エチレン濃度＝７０％）。
【００９６】
ここで得られたエチレン・α−オレフィン共重合体は、次に記す実施例１で使用し、その性状を表１に記載した。また、実施例２〜８で使用した共重合体は、その重合条件を変えた以外は前記と同様の方法で製造し、その性状を表１に併せて記載した。
【００９７】
（実施例１〜８）
表１に記載した８種類のエチレン・α−オレフィン共重合体を使用し、各々６５ｍｍφの一軸押出機に供給した。次に、表１に記載した押出条件で単層のパリソンを押出し、ブロー成形して７８０ｃｃ容量のボトルを製造した。
成形過程におけるパリソンのドローダウン性および得られた中空体の落下強度を測定し、その結果を表１に併せて記載した。
【００９８】
なお、各測定結果は、次の方法によって求めた。
（１）パリソンのドローダウン性：
スクリュー回転数３０ｒｐｍにおいて、パリソンが長さ１７ｃｍに達するまでの時間（秒）を測定した。
（２）ボトル落下強度：
円筒瓶（７８０ｃｃ）を−１８℃で落下させ、５回の試験で破壊しない高さ（ｍ）を測定した。
【００９９】
（比較例１〜３）
従来のチタン系触媒を用いて製造した３種類の線状低密度ポリエチレン（エチレン・４−メチル−１−ペンテン共重合体）を使用し、その性状を表２に記載した。用いた線状低密度ポリエチレンの種類が異なる以外は実施例１と同様に操作してボトルを成形し、その際のパリソンドローダウン性およびボトル落下強度を測定し、その結果を表２に記載した。
【０１００】
（比較例４)
比較例２で使用した線状低密度ポリエチレン８０部に高圧法低密度ポリエチレン２０部をブレンドした以外は、実施例１と同様に行い、ボトルを成形した。その際のパリソンドローダウン性およびボトル落下強度を測定し、その結果を表２に記載した。
【０１０１】
【表１】

【０１０２】
【表２】

【０１０３】
表１および表２の結果から明らかなように、この実施例１〜８では、従来の線状低密度ポリエチレンを用いた比較例１〜３と比べて、低い樹脂圧力でかつパリソンのドローダウンを抑えつつ押出成形することができ、その結果得られた中空体は、高い落下強度と低いデカン可溶成分量とを有している。また、従来の線状低密度ポリエチレンと高圧法ポリエチレンとの組成物を用いた比較例４と比べても、低い樹脂圧力でパリソンを押出すことができ、得られた中空体の落下強度は高く、またデカン可溶成分量が低い。従って、この実施例から、本発明に係わる製造方法が、押出成形性と中空体物性とをバランスよく発揮する方法であることを示している。
【０１０４】
【発明の効果】
本発明の中空体の製造方法によると、分子量分布および組成分布が狭い上に、溶融張力の高いエチレン・α−オレフィン共重合体を中空体成形材料に使用し、かつ特定の押出条件でパリソンを押出しているので、パリソンのドローダウン性が改良され、その結果、機械的強度に優れた中空体を早い成形スピードで生産することができる。また、そのエチレン・α−オレフィン共重合体はその中に低分子量成分の含有量が少ないことから、この中空体容器はその内容物への溶出量を少なくすることができ、食品を始めとする広範囲の物質の包装に利用することができる。[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for producing a hollow body including a layer of an ethylene / α-olefin copolymer and a container obtained therefrom, and more particularly, to a method for producing a hollow body having improved extrudability and mechanical strength. And a container obtained by the method.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
Containers manufactured by the hollow molding method can be used as food containers, kerosene containers, etc., and multilayer molded containers with layers of ethylene / vinyl alcohol copolymer or polyamide resin to maintain the flavor of food Is used as a soft blow container such as a mayonnaise container or ketchup container, or a blow tube is used as a kneaded wasabi container or kneaded container, or in combination with cardboard, steel cans, etc. Yes. Polyethylene is widely used as a raw material for producing them, and linear low density polyethylene (L-LDPE) is mainly used in fields requiring heat resistance and mechanical strength.
[0003]
However, since linear low density polyethylene has a low melt tension, the parison tends to draw down at the time of extrusion molding, and thus not only is difficult to mold, but also the thickness of the molded hollow body varies. As a result, the mechanical strength may decrease. Therefore, when the formulation of blending the high-pressure low-density polyethylene with the linear low-density polyethylene is increased, the melt tension increases, but the high-pressure low-density polyethylene itself does not necessarily have high mechanical strength. For example, the drop strength may decrease.
[0004]
In addition, since conventional linear low density polyethylene is produced using a titanium-based catalyst, it has a wide molecular weight distribution and inevitably contains a low molecular weight component. Therefore, there is a concern that the low molecular weight component dissolves into the hollow body content. In that regard, the new polyethylene produced using a metallocene catalyst is characterized by a relatively narrow molecular weight distribution and composition distribution, and there is little concern about the dissolution of low molecular weight components in the hollow body contents. Absent. However, since the polyethylene also has a low melt tension, it is similarly said that it is difficult to produce a hollow molded body.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a method for producing a hollow body having improved parison drawdown properties.
Another object of the present invention is to provide a method for producing a hollow body having high mechanical strength and low solubility in the contents of the hollow body.
Furthermore, the objective of this invention is providing the container obtained by the manufacturing method.
[0006]
[Means for Solving the Problems]
That is, in the present invention, when a parison including at least one layer of an ethylene / α-olefin copolymer is extruded from an extruder die and blow-molded,
(1) The copolymer satisfies the following physical properties (a) to (e),
(A) Density (d) is 0.880-0.970 (g / cm^Three),
(B) a melt flow rate (MFR) of 0.01 to 10 (g / 10 min),
(C) The relationship between the melt tension (MT (g)) at 190 ° C. and the melt flow rate (MFR (g / 10 minutes))
MT> 2.2 × MFR^-0.84
(D) The relationship between the decane-soluble component amount ratio (W (wt%)) and the density (d) at 23 ° C.
W <80 × exp {−100 (d−0.88)} + 0.1
(E) The relationship between the temperature (Tm (° C.)) of the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) and the density (d) is
Tm <400 × d-248
[0007]
(2) Resin pressure P (kg / cm) during the parison extrusion²), Resin temperature T (° C.), extrusion rate K (kg / hour), lip cross-sectional area A (cm²) And the melt flow rate MFR (g / 10 min) of the resin under the following conditions
150 x {K / (MFR)^1.5/ (T-120) / A}^0.2≦ P
≦ 500 × {K / (MFR)^1.5/ (T-120) / A}^0.2
Relates to a method for producing a hollow body.
[0008]
Further, the present invention is a hollow body obtained by the above production method, and may be a single layer container or a multilayer container.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The method for producing a hollow body according to the present invention relates to a method for producing a hollow body including a layer of an ethylene / α-olefin copolymer, and the configuration thereof will be specifically described below.
[0010]
Ethylene / α-olefin copolymer
The hollow body molding material is a random copolymer of ethylene and an α-olefin, and the α-olefin is preferably an α-olefin having 3 to 20 carbon atoms, specifically, propylene, 1-butene, 1- Examples include pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene.
[0011]
The ethylene content in the copolymer is usually 94 to 99 mol%, preferably 96 to 98 mol%, and the comonomer α-olefin content is usually 1 to 6 mol%, preferably 2 to 4 mol%. is there. Here, the ethylene and α-olefin content is¹³It can be measured using C-NMR.
[0012]
That is, the composition of the ethylene / α-olefin copolymer is usually about a sample in which about 200 mg of the copolymer is uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube.¹³The C-NMR spectrum is obtained by measurement under the conditions of a temperature of 120 ° C., a frequency of 25.05 MHz, a spectrum width of 1500 Hz, a pulse repetition time of 4.2 sec., And a pulse width of 6 μsec.
[0013]
The ethylene / α-olefin copolymer used in the present invention has a density of 0.880 to 0.970 (g / cm^Three), Preferably 0.890-0.940 (g / cm^Three). When the density is within this range, a hollow body excellent in low-temperature impact resistance, rigidity, and chemical resistance is obtained, which is desirable. The density was measured at 23 ± 0.1 ° C. in accordance with D method of JIS K-7112.
[0014]
Further, the melt flow rate (MFR) of the copolymer is 0.01 to 10 (g / 10 min), preferably 0, measured at 190 ° C. under a 2.16 kg load in accordance with ASTM D-1238. 0.05 to 9 (g / 10 min). When the MFR value is within this range, a hollow body having a high molding speed and a good appearance can be obtained.
[0015]
Further, this copolymer has a melt tension (MT (g)) and a melt flow rate (MFR (g / 10 min)) at 190 ° C.
MT> 2.2 × MFR^-0.84
Preferably, MT> 4.0 × MFR^-0.84
It is desirable to satisfy the relationship represented by the above, and if it is within this range, the drawdown property of the parison is improved and the mechanical strength of the hollow body is improved.
[0016]
In addition, melt tension is calculated | required by measuring the stress when extending | stretching a molten polymer at a fixed speed. That is, the resin pellets are supplied to an MT measuring machine (manufactured by Toyo Seiki Seisakusho), the resin temperature is 190 ° C., the extrusion speed is 15 (mm / min), the winding speed is 10 to 20 (m / min), and the nozzle diameter is 2.09 mmφ. , And measured under the condition of a nozzle length of 8 mm.
[0017]
On the other hand, in this copolymer, it is desirable that the amount of decane-soluble component (W (%)) at 23 ° C. and the density (d) satisfy the following relationship.
W <80 × exp {−100 (d−0.88)} + 0.1
Preferably, W <60 × exp {−100 (d−0.88)} + 0.1
When W and d are in the above relationship, this ethylene / α-olefin copolymer indicates that the amount of low molecular weight component is small, and the low molecular weight found in conventional linear low density polyethylene is shown. The amount of elution into the hollow body content due to bleeding out of the component to the hollow body wall surface can be further reduced, and the sticky feeling on the hollow body surface is also reduced.
[0018]
The amount of decane-soluble component (W) was determined by adding about 3 g of copolymer to 450 ml of n-decane, dissolving at 145 ° C., cooling to 23 ° C., removing the n-decane insoluble part by filtration, and removing n-decane from the filtrate. -Each of the soluble component amount and the insoluble component amount was measured by the operation of recovering the decane soluble part, and the W value was obtained from the following formula.
W = {(n-decane soluble component amount) / (n-decane soluble component amount + insoluble component amount)} × 100 (% by weight)
[0019]
Further, in this copolymer, the temperature (Tm (° C.)) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) and the density (d) have the following relationship.
Tm <400 × d-248
Preferably Tm <450 × d-297
It is preferable that Tm and d have the above relationship, because the composition distribution of the ethylene / α-olefin copolymer is narrow, and the mechanical strength of the hollow body is improved.
[0020]
Here, the temperature measurement of the maximum peak position by DSC was performed using a DSC-7 machine manufactured by PerkinElmer. That is, about 5 mg of a copolymer sample is packed in an aluminum pan, heated to 200 ° C. at a rate of 10 (° C./min), held there for 5 minutes, and then cooled to room temperature at a rate of 10 (° C./min). Then, the endothermic curve was measured while raising the temperature again at 10 (° C./min), and the temperature at the position showing the maximum peak was determined from the obtained endothermic curve.
[0021]
The ethylene / α-olefin copolymer may be a copolymer having at least one peak in addition to the maximum peak in the endothermic curve measured by DSC. As shown in the examples described later, in addition to a copolymer having one peak, a copolymer having two or three peaks around 105 ° C., around 113 ° C., and around 123 ° C. is used. Also good.
[0022]
The ethylene / α-olefin copolymer satisfying the above-mentioned conditions (a) to (e) is a hollow body molding material having excellent mechanical strength, and has a good extrusion or blow moldability and is hollow. Suitable for body production.
[0023]
Further, this copolymer has a component that does not elute at less than 100 ° C. in a temperature rising dissolution test (TREF), and the amount thereof is preferably 10% by weight or less, and preferably 8% by weight or less. When the amount of the insoluble component is within the range, the bleed-out product from the hollow molded body to the content is small, which is preferable in that the bleed-out during the hot filling of the content is reduced. The linear low density polyethylene produced using a conventional titanium catalyst contains a large amount of insoluble components as shown in the comparative example described later in this temperature rising dissolution test, and its molecular structure is hollow molding. It seems to be related to the elution phenomenon due to bleed-out from the body to the contents.
[0024]
In the temperature elution test, a copolymer sample was dissolved in o-dichlorobenzene at a concentration of 200 mg / 40 ml, and 7.5 ml was injected at 140 ° C. into a column (2.14 cmφ × 15 cm) packed with glass beads (100 μmφ). Cooling to 25 ° C. at a temperature drop rate of 10 (° C./hour), and then continuously increasing o-dichlorobenzene at a constant flow rate of 1.0 (ml / min) while raising the temperature at a temperature rise rate of 15 (° C./hour). The components to be eluted were detected online and the elution curve was drawn.
[0025]
Further, in this copolymer molecule, it is preferable that long chain branches having 6 or more carbon atoms determined by NMR measurement are present in a number exceeding 3 per 1000 carbon atoms. Thus, when the copolymer molecule has many long-chain branches, the melt tension is increased, the parison draw-down property is improved, and the extrusion moldability is improved. However, the conventional linear low-density polyethylene has a small number of long-chain branches, which is considered to be a cause of easy drawdown.
[0026]
The copolymer preferably has a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio (Mw / Mn) of 2.8 to 15, preferably 3.0 to 10. The value of Mw / Mn is a rough indication of the molecular weight distribution. If the Mw / Mn value is within this range, the molecular weight distribution is relatively narrow and the amount of low molecular weight polymer is small. There is little stickiness and dissolution in the hollow body content can be reduced.
[0027]
The value of Mw / Mn was calculated by measuring Mw and Mn of the copolymer using GPC. GPC measurement conditions were carried out using a GPC model ALC-GPC-150C manufactured by Waters, using PSK-GMH-HT manufactured by Tosoh as a column, and 140 ° C. using an o-dichlorobenzene solvent.
[0028]
The ethylene / α-olefin copolymer has an antioxidant, a weather resistance stabilizer, a light stabilizer, a heat stabilizer, an antistatic agent, a lubricant, a pigment, a dye, a nucleus within a range not impairing the object of the present invention. Additives such as an agent, a plasticizer, and a hydrochloric acid absorbent can be blended as necessary. The above-mentioned various additives are blended into the ethylene / α-olefin copolymer as necessary and mixed in advance using a Henschel mixer, tumbler, ribbon mixer, Banbury mixer, single screw extruder, twin screw extruder, etc. It is desirable to use for blow molding.
[0029]
              Process for producing ethylene / α-olefin copolymer
  The ethylene / α-olefin copolymer having the physical properties described above is an olefin polymerization catalyst component (A) ~ (D) And supplying ethylene and an α-olefin having 3 to 20 carbon atoms to the polymerization system.
(A) Transition metal compounds of group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton
(B) Organoaluminum oxy compounds
(C) Carrier
(D) If necessary, organoaluminum compound
[0030]
  First, the olefin polymerization catalyst will be described.
[(ATransition metal compounds]
  This compound serving as the center of the catalyst system is a group IV transition metal compound containing a ligand having a cyclopentadienyl skeleton, and is represented by the following general formula.
                    ML_{1 (x)}  ・ ・ ・ ・ ・ ・ ・ (I)
[0031]
(Wherein M represents a transition metal selected from Group IV of the periodic table, specifically zirconium, titanium or hafnium, preferably zirconium,
L₁Indicates a ligand coordinated to a transition metal atom,
At least two of these ligands L₁Is a cyclopentadienyl group or a substituted cyclopentadienyl group having one or more substituents selected from a hydrocarbon group having 2 to 10 carbon atoms,
Other ligands L₁Is 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,
Each ligand and each substituent may be the same or different, and x represents the valence of the transition metal atom M. )
[0032]
Examples of transition metal compounds represented by such a general formula 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,
[0033]
Bis (n-butylcyclopentadienyl) zirconium methoxychloride,
Bis (n-butylcyclopentadienyl) zirconium ethoxy chloride,
Bis (n-butylcyclopentadienyl) zirconium butoxychloride,
Bis (n-butylcyclopentadienyl) zirconium ethoxide,
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,
[0034]
Bis (dimethylcyclopentadienyl) zirconium dichloride,
Bis (diethylcyclopentadienyl) zirconium dichloride,
Bis (methylethylcyclopentadienyl) zirconium dichloride,
Bis (dimethylethylcyclopentadienyl) zirconium dichloride,
Bis (dimethylcyclopentadienyl) zirconium dibromide,
Bis (dimethylcyclopentadienyl) zirconium methoxychloride,
Bis (dimethylcyclopentadienyl) zirconium ethoxy chloride,
Bis (dimethylcyclopentadienyl) zirconium butoxychloride,
Bis (dimethylcyclopentadienyl) zirconium diethoxide,
[0035]
Bis (dimethylcyclopentadienyl) zirconium methyl chloride,
Bis (dimethylcyclopentadienyl) zirconium dimethyl,
Bis (dimethylcyclopentadienyl) zirconium benzyl chloride,
Bis (dimethylcyclopentadienyl) zirconium dibenzyl,
Bis (dimethylcyclopentadienyl) zirconium phenyl chloride,
Bis (dimethylcyclopentadienyl) zirconium hydride chloride
Etc.
[0036]
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 zirconium compound as described above, a transition metal compound in which the zirconium metal is replaced with titanium metal or hafnium metal can also be used.
[0037]
Among the transition metal compounds represented by these general formulas, the following compounds are particularly preferable.
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-dimethylcyclopentadienyl) zirconium dichloride
Bis (1,3-diethylcyclopentadienyl) zirconium dichloride
Bis (1-methyl-3-ethylcyclopentadienyl) zirconium dichloride
[0038]
The transition metal compound used may be a mixture of two or more transition metal compounds represented by the above general formula.
Specifically, a combination of bis (1,3-n-butylmethylcyclopentadienyl) zirconium dichloride and bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, bis (1,3-n-propyl Combination of methylcyclopentadienyl) zirconium dichloride and bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride and bis (1,3-dimethylcyclopentadiene) Examples include combinations with (enyl) zirconium dichloride.
[0039]
The transition metal compound includes a transition metal compound represented by the general formula (I) and a transition metal compound represented by the following general formula:
MKL_{2 (x-2)}  (II)
And a mixture thereof.
[0040]
Wherein M is a transition metal atom selected from Group IV of the same periodic table as described above, and K and L₂Represents a ligand coordinated to a transition metal atom, and ligand K is a bidentate ligand in which the same or different indenyl group, substituted indenyl group or a partial hydride thereof is bonded via a lower alkylene group. There,
Ligand L₂Is a C1-C12 hydrocarbon group, alkoxy group, aryloxy group, halogen atom, trialkylsilyl group or hydrogen atom, and x represents the valence of the transition metal atom M. )
[0041]
Specific examples of the transition metal compound represented by such a general formula include the following compounds.
Ethylene bis (indenyl) zirconium dichloride
Ethylene bis (4-methyl-1-indenyl) zirconium dichloride
Ethylene bis (4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride
[0042]
  Transition compounds used (A) Is preferably used in combination with at least one selected from transition metal compounds represented by general formula (I) and at least one selected from transition metal compounds represented by general formula (II). . When used in combination, the molar ratio (I) / (II) is in the range of 99/1 to 50/50, preferably 97/3 to 70/30, more preferably 95/5 to 75/25. It is desirable to be used in such an amount ratio.
[0043]
[(B) Organoaluminum oxy compound]
  The organoaluminum oxy compound may be a conventionally known benzene-soluble organoaluminum oxy compound or a benzene-insoluble organoaluminum oxy compound as disclosed in JP-A-2-276807. The organoaluminum oxy compounds can be used alone or in combination of two or more.
[0044]
Such an organoaluminum oxy compound can be prepared, for example, by the method described below.
(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, and cerium chloride hydrate To an organic aluminum compound such as trialkylaluminum, which is reacted with the suspension in a hydrocarbon medium, and recovered as a hydrocarbon solution.
[0045]
(2) A method in which water, ice, or water vapor is allowed to act directly on an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran to recover it as a hydrocarbon solution.
[0046]
(3) A method in which an organotin oxide such as dimethyltin oxide or dibutyltin oxide is reacted with an organoaluminum compound such as trialkylaluminum in a medium such as decane, benzene, or toluene.
[0047]
Specific examples of the organoaluminum compound used in preparing the aluminum oxy compound include the following compounds, which can be used alone or in combination of two or more.
(1) Trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tritert-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum Trialkylaluminum such as tridecylaluminum
[0048]
(2) Tricycloalkylaluminum such as tricyclohexylaluminum and tricyclooctylaluminum
(3) Dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride
(4) Dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride
[0049]
(5) Dialkylaluminum alkoxides such as dimethylaluminum methoxide and diethylaluminum ethoxide
(6) Dialkylaluminum aryloxides such as diethylaluminum phenoxide
Of these, the use of trialkylaluminum is particularly preferable.
[0050]
Further, as this organoaluminum compound, a general formula
(I-C_FourH₉)_xAl_y(C_FiveH_Ten)_z
(X, y, z are positive numbers and z ≧ 2x)
Isoprenylaluminum represented by the formula can also be used.
[0051]
Solvents used in the preparation of aluminum oxy compounds include aromatic hydrocarbons such as benzene, toluene, xylene, cumene, and cymene, and aliphatic carbonization such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane, and octadecane. Hydrogen, cyclopentane, cyclohexane, cyclooctane, methylcyclopentane, and other alicyclic hydrocarbons, petroleum fractions such as gasoline, kerosene, and light oil, or halogens of the above aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons And hydrocarbon solvents such as chlorinated compounds and brominated compounds. In addition, ethers such as ethyl ether and tetrahydrofuran can also be used. Of these solvents, aromatic hydrocarbons are particularly preferable.
[0052]
The benzene-insoluble organoaluminum oxy compound is insoluble or hardly soluble in benzene because the Al component dissolved in benzene at 60 ° C. is 10% or less, preferably 5% or less in terms of Al atom.
[0053]
[(C) Carrier]
  The carrier used is an inorganic or organic compound, and a granular or particulate solid having a particle size of 10 to 300 μm, preferably 20 to 200 μm is used. Of these, porous oxides are preferred as the inorganic carrier, specifically, SiO.₂, Al₂O_Three, MgO, ZrO₂TiO₂, Sb₂O_Three, CaO, ZnO, BaO, ThO₂Etc. or mixtures thereof, eg SiO₂-MgO, SiO₂-Al₂O_Three, SiO₂-TiO₂, SiO₂-V₂O_Five, SiO₂-Cr₂O_Three, SiO₂-TiO₂-MgO etc. can be illustrated. Among these, SiO₂And Al₂O_ThreeThose having at least one component selected from the group consisting of as a main component are preferred.
[0054]
Such a carrier has different properties depending on the type and production method, but the carrier preferably used has a specific surface area of 50 to 1000 (m²/ G), preferably 100 to 700 (m²/ G), and the pore volume is 0.3 to 2.5 (cm^Three/ G). The carrier may be used after calcining at 100 to 1000 ° C., preferably 150 to 700 ° C., if necessary.
[0055]
Other usable carriers include granular or particulate solids of organic compounds having a particle size of 10 to 300 μm. These organic compounds include (co) polymers mainly composed of α-olefins having 2 to 14 carbon atoms such as ethylene, propylene, 1-butene and 4-methyl-1-pentene, or vinylcyclohexane and styrene as the main components. And a polymer or copolymer.
[0056]
[(D) Organoaluminum compound]
  The organoaluminum compound added as needed can exemplify a compound represented by the following general formula.
                R_{1 (n)}AlX_(3-n)  .... (III)
(Wherein R₁Represents a hydrocarbon group having 1 to 12 carbon atoms,
        X represents a halogen atom or a hydrogen atom,
        n is 1-3. )
[0057]
R₁As, for example, an alkyl group, a cycloalkyl group or an aryl group, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, A cyclopentyl group, a cyclohexyl group, a phenyl group, a tolyl group and the like.
[0058]
Specific examples of such organoaluminum compounds include the following compounds.
(1) Trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum
(2) Alkenyl aluminum such as isoprenyl aluminum
(3) Dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide
[0059]
(4) Alkyl aluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide
(5) Alkyl aluminum dihalides such as methyl aluminum dichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride, ethyl aluminum dibromide
(6) Alkyl aluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride
[0060]
  Organic aluminum compounds (D) As a compound represented by the following general formula
                R_{1 (n)}AlY_(3-n)  (IV)
Can also be used.
[0061]
(Wherein R₁Is R in the general formula (III)₁Represents a hydrocarbon group similar to
Y is -OR₂Group, -OSi (R_Three)_ThreeGroup, -OAl (R_Four)₂Group, -N (R_Five)₂Group, -Si (R₆)_ThreeGroup or -N (R₇) Al (R₈)₂Group,
n is 1-2,
R₂, R_Three, R_FourAnd R₈Is a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, a phenyl group, etc.
R_FiveIs a hydrogen atom, methyl group, ethyl group, isopropyl group, phenyl group, trimethylsilyl group, etc.
R₆And R₇Is a methyl group, an ethyl group or the like. )
[0062]
As such an organoaluminum compound, specifically, the following compounds are used.
(1) R_{1 (n)}Al (OR₂)_(3-n) A compound represented by
For example, dimethylaluminum methoxide, diethylaluminum ethoxide, diisobutylaluminum methoxide,
[0063]
(2) R_{1 (n)}Al (OSi (R_Three)_Three)_(3-n) A compound represented by
For example, Et₂Al (OSi Me_Three), (Iso-Bu)₂Al (OSiMe_Three),
(Iso-Bu)₂ Al (OSiEt_Three)Such;
(3) R_{1 (n)}Al (OAl (R_Four)₂)_(3-n) A compound represented by
For example, Et₂AlOAlEt₂ , (Iso-Bu)₂AlOAl (iso-Bu)₂ Such;
(4) R_{1 (n)}Al (N (R_Five)₂)_(3-n) A compound represented by
For example, Me₂AlNEt₂ , Et₂AlNHMe, Me₂AlNHEt, Et₂AlN (SiMe_Three)₂, (Iso-Bu)₂AlN (SiMe_Three)₂Such;
[0064]
(5) R_{1 (n)}Al (Si (R₆)_Three)_(3-n)A compound represented by
For example (iso-Bu)₂AlSi Me_Three Such;
(6) R_{1 (n)}Al (N (R₇) Al (R₈)₂)_(3-n)A compound represented by
For example, Et₂AlN (Me) AlEt₂, (Iso-Bu)₂AlN (Et) Al (iso-Bu)₂Such.
[0065]
Among the organoaluminum compounds represented by the general formulas (III) and (IV), the general formula (R₁)_ThreeAl, (R₁)_nAl (OR₂)_(3-n), (R₁)_nAl (OAl (R_Four)₂)_(3-n)Are preferred, particularly R₁Is an isoalkyl group and n = 2 is preferred.
[0066]
[Catalyst preparation method]
  The olefin polymerization catalyst is a component (A),component(B), And carrier (C), Ingredients as needed (D). The contact order of each component at this time is arbitrarily selected, but is preferably a carrier (C) And ingredients (B) And then the ingredients (A) In contact with the mixture, and if necessary, the ingredients (D) Are mixed and contacted.
[0067]
The contact of each component can be performed in an inert hydrocarbon solvent. Specifically, as the inert hydrocarbon medium used for the preparation of the catalyst, propane, butane, pentane, hexane, heptane, octane, decane, dodecane are used. Aliphatic hydrocarbons such as kerosene; cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane Alternatively, a mixture thereof can be used.
[0068]
  component(A),component(B), Carrier (C), And optionally ingredients (D)) In mixing contactA) Is the carrier (C) Normally 5 x 10 per gram^-6~ 5x10^-FourMoles, preferably 10^-Five~ 2x10^-FourUsed in molar amounts, the concentration of component (a) is about 10^-Four~ 2x10^-2(Mol / liter), preferably 2 × 10^-Four-10^-2(Mol / liter). Component (b) aluminum and component (AThe atomic ratio (Al / transition metal) with the transition metal in () is usually 10 to 500, preferably 20 to 200. Aluminum atom (Al-d) and component (d) used as necessary (d)BThe atomic ratio (Al-d / Al-b) of aluminum atoms (Al-b) is usually in the range of 0.02 to 3, preferably 0.05 to 1.5. component(A),component(B), Carrier (C), And optionally ingredients (D) Is usually −50 to 150 ° C., preferably −20 to 120 ° C., and the contact time is 1 minute to 50 hours, preferably 10 minutes to 25 hours.
[0069]
  The olefin polymerization catalyst thus obtained is a carrier (C) Ingredients per gram (A) Derived from 5 × 10 transition metal atoms^-6~ 5x10^-FourGram atoms, preferably 10^-Five~ 2x10^-FourSupported in the amount of gram atoms and also a carrier (C) Ingredients per gram (B) And ingredients (D) Derived from 10 aluminum atoms^-3~ 5x10^-2Gram atoms, preferably 2 × 10^-3~ 2x10^-2It is preferably supported in the amount of gram atoms.
[0070]
  The olefin polymerization catalyst is also a component (A),component(B), Carrier (C), And optionally ingredients (D) May be a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of. Pre-polymerization is the component (A),component(B), Carrier (C) And optional ingredients (D) In the presence of an olefin in an inert hydrocarbon solvent.
[0071]
Examples of the olefin used in the prepolymerization include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene. , 1-decene, 1-dodecene, 1-tetradecene and the like. Among these, ethylene used in the polymerization or a combination of ethylene and an α-olefin is particularly preferable.
[0072]
  When prepolymerizing, the components (A) Is usually 10^-6~ 2x10^-2(Mol / liter), preferably 5 × 10^-Five-10^-2Used in the amount of (mol / liter)A) Is the carrier (C) Normally 5 x 10 per gram^-6~ 5x10^-FourMoles, preferably 10^-Five~ 2x10^-FourUsed in molar amounts. component(B) Aluminum and ingredients (AThe atomic ratio (Al / transition metal) with the transition metal in () is usually 10 to 500, preferably 20 to 200. Ingredients used as needed (D) Aluminum atoms (Al-d) and components (BThe atomic ratio (Al-d / Al-b) of aluminum atoms (Al-b) is usually in the range of 0.02 to 3, preferably 0.05 to 1.5. The prepolymerization temperature is -20 to 80 ° C, preferably 0 to 60 ° C, and the prepolymerization time is 0.5 to 100 hours, preferably about 1 to 50 hours.
[0073]
  The prepolymerization catalyst is prepared, for example, by the following method. That is, the carrier (C) In an inert hydrocarbon. Next, an organoaluminum oxy compound (component (B)) And react for a predetermined time. The supernatant is then removed and the resulting solid component is resuspended in an inert hydrocarbon. Transition metal compound (component (A)) And the reaction is performed for a predetermined time, and then the supernatant is removed to obtain a solid catalyst component. Subsequently, organoaluminum compound (component (DThe prepolymerized catalyst is obtained by adding the solid catalyst component obtained above to the inert hydrocarbon containing)) and introducing the olefin therein.
[0074]
  The olefin copolymer produced by the prepolymerization is a carrier (C) An amount of 0.1 to 500 g per gram, preferably 0.2 to 300 g, more preferably 0.5 to 200 g is desirable. The prepolymerization catalyst includes a carrier (C) Ingredients per gram (A) Is about 5 × 10 as a transition metal atom.^-6~ 5x10^-FourGram atoms, preferably 10^-Five~ 2x10^-FourSupported in the amount of gram atoms, components (B) And ingredients (D) Derived from aluminum atoms (Al)A) Derived from the transition metal atom (M) derived from (3), the molar ratio (Al / M) is preferably 5 to 200, preferably 10 to 150.
[0075]
The prepolymerization can be performed either batchwise or continuously, and can be performed under reduced pressure, normal pressure, or increased pressure. In the prepolymerization, the intrinsic viscosity [η] measured in decalin at least 135 ° C. in the presence of hydrogen is in the range of 0.2 to 7 (dl / g), preferably 0.5 to 5 (dl / g). It is desirable to produce a prepolymer such as
[0076]
[Polymerization method]
The ethylene / α-olefin copolymer used in the present invention is obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of the olefin polymerization catalyst or the prepolymerization catalyst as described above. can get.
[0077]
Copolymerization of ethylene and α-olefin is performed in a gas phase or a slurry liquid phase. In slurry polymerization, an inert hydrocarbon compound may be used as a solvent, or olefin itself may be used as a solvent.
[0078]
Specific examples of the inert hydrocarbon solvent used in the slurry polymerization include aliphatic hydrocarbons such as butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, and octadecane; cyclopentane, methylcyclopentane, cyclohexane, Examples thereof include alicyclic hydrocarbons such as cyclooctane; aromatic hydrocarbons such as benzene, toluene and xylene; petroleum fractions such as gasoline, kerosene and light oil. Of these inert hydrocarbon media, aliphatic hydrocarbons, alicyclic hydrocarbons, petroleum fractions and the like are preferable.
[0079]
When the slurry polymerization method or the gas phase polymerization method is used, the olefin polymerization catalyst or the prepolymerization catalyst as described above is usually 10% as the transition metal atom concentration in the polymerization reaction system.^-8-10^-3(Gram atoms / liter), preferably 10^-7-10^-FourIt is preferably used in an amount of (gram atoms / liter).
[0080]
  In addition, the component (B) And the same organoaluminum oxy compounds and / or organoaluminum compounds (D) May be added. At this time, an aluminum atom (Al) derived from the organoaluminum oxy compound and the organoaluminum compound, and a transition metal compound (AThe atomic ratio (Al / M) with the transition metal atom (M) derived from) is in the range of 5 to 300, preferably 10 to 200, more preferably 15 to 150.
[0081]
When carrying out the slurry polymerization method, the polymerization temperature is usually in the range of −50 to 100 ° C., preferably from 0 to 90 ° C. When carrying out the gas phase polymerization method, the polymerization temperature is usually from 0 to 120 degreeC, Preferably it is the range of 20-100 degreeC.
[0082]
The polymerization pressure is usually normal pressure to 100 (kg / cm²), Preferably 2-50 (kg / cm²The polymerization can be carried out in any of batch, semi-continuous and continuous systems, and can also be conducted in multiple stages such as two-stage polymerization.
Furthermore, the polymerization can be carried out by using one or a plurality of polymerization vessels and dividing the copolymer into two or more stages having different reaction conditions.
[0083]
Method for producing hollow body
In the method for producing a hollow body according to the present invention, the ethylene / α-olefin copolymer having the above-mentioned physical properties is supplied to a blow molding machine, and is sent to a tip die while being melted in an extruder. Is a method of extruding as a parison and then blow-molding it between sandwiched molds.
[0084]
During the parison extrusion molding, it is preferable to proceed with the molding operation by adjusting the resin pressure to the range described below as the extrusion conditions for the molten molding material.
That is, the resin pressure P (kg / cm²), Resin temperature T (° C.), extrusion rate K (kg / hour), die lip cross-sectional area A (cm²) And the melt flow rate MFR (g / 10 minutes) of the resin, the resin pressure P is adjusted to a range represented by the following relational expression.
[0085]

This molding condition improves the drawdown property of the parison containing the ethylene / α-olefin copolymer layer, and is desirable for producing a hollow body having a good appearance and a high mechanical strength at a high molding speed. It is a molding condition.
[0086]
Medium volume container
The container according to the present invention is a hollow body including at least one layer of an ethylene / α-olefin copolymer manufactured according to the above-described manufacturing method, and is a single layer composed of only an ethylene / α-olefin copolymer layer A container may be sufficient and the multilayer container comprised from the layer of an ethylene-alpha-olefin copolymer and another resin layer may be sufficient.
[0087]
The production of the single layer container is performed by a normal blow molding method. In the case of manufacturing a multilayer container, a plurality of extruders are prepared, and a container is manufactured by attaching a coextrusion die to the tip connecting portion. That is, an ethylene / α-olefin copolymer is extruded from one of the extruders under the preferable extrusion conditions described above, and another resin is extruded from another extruder under arbitrary conditions, via a coextrusion die. A multilayer container can be manufactured by forming a multilayer parison and then blow-molding the parison between blow dies.
[0088]
When producing a multilayer container, as another resin layer to be extruded together with the ethylene / α-olefin copolymer layer, a resin having gas barrier properties such as polyamide resin, polyester resin, polycarbonate resin, ethylene / vinyl alcohol resin, etc. Layers can be arranged. Usually, these gas barrier resin layers do not have good adhesion to the ethylene / α-olefin copolymer layer, and therefore an adhesive layer using an unsaturated carboxylic acid graft-modified polyolefin or the like is provided between the two layers.
[0089]
Depending on the type of container contents and the required physical properties of the container itself, a three-layer structure comprising an ethylene / α-olefin copolymer layer / adhesive layer / gas barrier resin layer may be used. You may make it the structure of 3 layers or more which provided another resin layer in the interlayer and the outer side of the gas barrier resin layer, for example, 4-5 layer structure.
[0090]
Such single-layer or multi-layer containers can be used as packaging containers for general containers, kerosene cans, industrial chemical cans, gasoline tanks, mayonnaise containers, ketchup containers, edible oil bottles, bag-in-boxes, inner bags for drums, It can be used for a blow tube for storing kneaded mash.
[0091]
【Example】
EXAMPLES Next, although this invention is demonstrated through an Example, this invention is not limited at all by these Examples.
First, the ethylene / α-olefin copolymer used was produced by the method described below.
[0092]
[Preparation of 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 methylaminooxane (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.
[0093]
The solid component thus obtained was washed twice with toluene and then resuspended in 100 liters of toluene. To this system, 16.8 liters of a toluene solution of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride (Zr = 27.0 mmol / liter) was added dropwise at 80 ° C. over 30 minutes, and further at 80 ° C. The reaction was performed 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 gram.
[0094]
[Preparation of prepolymerization catalyst]
1 g of solid catalyst was obtained 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 conducting prepolymerization of ethylene at 35 ° C. for 5 hours. A prepolymerized catalyst in which 10 g of polyethylene was prepolymerized was obtained.
[0095]
[Polymerization]
Using a continuous fluidized bed gas phase polymerization system, total pressure 20kg / cm²-G, ethylene and 1-hexene were copolymerized at a polymerization temperature of 80 ° C. The pre-polymerized catalyst prepared earlier is continuously supplied at a rate of 0.33 (mmol / h) in terms of zirconium atom and triisobutylaluminum at a rate of 10 (mmol / h), and a constant gas composition is maintained during the polymerization. Therefore, ethylene, 1-hexene, hydrogen and nitrogen were continuously supplied (gas composition; 1-hexene / ethylene = 0.02, hydrogen / ethylene = 10.5 × 10^-Four, Ethylene concentration = 70%).
[0096]
The ethylene / α-olefin copolymer obtained here was used in Example 1 described below, and its properties are shown in Table 1. Moreover, the copolymer used in Examples 2-8 was manufactured by the method similar to the above except having changed the polymerization conditions, and the property was described together in Table 1.
[0097]
(Examples 1-8)
Eight types of ethylene / α-olefin copolymers described in Table 1 were used, and each was supplied to a 65 mmφ single screw extruder. Next, a single layer parison was extruded under the extrusion conditions described in Table 1, and blow molded to produce a 780 cc bottle.
The drawdown property of the parison in the molding process and the drop strength of the obtained hollow body were measured, and the results are also shown in Table 1.
[0098]
In addition, each measurement result was calculated | required with the following method.
(1) Parison drawdown:
The time (seconds) required for the parison to reach a length of 17 cm was measured at a screw speed of 30 rpm.
(2) Bottle drop strength:
The cylindrical bottle (780 cc) was dropped at −18 ° C., and the height (m) at which the cylindrical bottle (780 cc) did not break was measured in five tests.
[0099]
(Comparative Examples 1-3)
Three types of linear low density polyethylene (ethylene 4-methyl-1-pentene copolymer) produced using a conventional titanium-based catalyst were used, and the properties are shown in Table 2. The bottle was molded by operating in the same manner as in Example 1 except that the type of linear low density polyethylene used was different, and the parison drawdown property and bottle drop strength at that time were measured. The results are shown in Table 2. .
[0100]
(Comparative Example 4)
A bottle was molded in the same manner as in Example 1 except that 80 parts of the linear low density polyethylene used in Comparative Example 2 was blended with 20 parts of the high pressure method low density polyethylene. The parison drawdown property and bottle drop strength at that time were measured, and the results are shown in Table 2.
[0101]
[Table 1]

[0102]
[Table 2]

[0103]
As is clear from the results of Tables 1 and 2, in Examples 1-8, the parison drawdown was reduced at a lower resin pressure than in Comparative Examples 1-3 using conventional linear low density polyethylene. The hollow body obtained as a result can have high drop strength and low decane-soluble component amount. Moreover, compared with the comparative example 4 using the composition of the conventional linear low density polyethylene and a high pressure process polyethylene, a parison can be extruded with a low resin pressure, and the drop strength of the obtained hollow body is high. In addition, the amount of decane soluble component is low. Therefore, from this example, it is shown that the production method according to the present invention is a method that exerts a good balance between extrusion moldability and hollow body properties.
[0104]
【The invention's effect】
According to the method for producing a hollow body of the present invention, a molecular weight distribution and a composition distribution are narrow, and an ethylene / α-olefin copolymer having a high melt tension is used as a hollow body molding material. Since it is extruded, the drawdown property of the parison is improved, and as a result, a hollow body excellent in mechanical strength can be produced at a high molding speed. Further, since the ethylene / α-olefin copolymer has a low content of low molecular weight components, the hollow body container can reduce the amount of elution into its contents, including foods. It can be used for packaging a wide range of substances.

Claims (5)

When a parison including at least one layer of an ethylene / α-olefin copolymer is extruded from an extruder die and blow-molded,
(1) The copolymer satisfies the following physical properties (a) to (e),
(A) Density (d) is 0.880-0.970 (g / cm < ³ >),
(B) a melt flow rate (MFR) of 0.01 to 10 (g / 10 min),
(C) The relationship between the melt tension (MT (g)) at 190 ° C. and the melt flow rate (MFR (g / 10 minutes))
MT> 2.2 × MFR ^-0.84
(D) The relationship between the decane-soluble component amount ratio (W (wt%)) and the density (d) at 23 ° C.
W <80 × exp {−100 (d−0.88)} + 0.1
(E) The relationship between the temperature (Tm (° C.)) of the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) and the density (d) is
Tm <400 × d-248
(2) Resin pressure P (kg / cm ² ) at the time of the parison extrusion, resin temperature T (° C.), extrusion amount K (kg / hour), molding machine lip cross-sectional area A (cm ² ), and resin melt 150 × {K / (MFR) ^1.5 / (T−120) / A} ^0.2 ≦ P with the flow rate MFR (g / 10 min) under the following conditions
≦ 500 × {K / (MFR) ^1.5 / (T-120) / A} ^0.2
A method for producing a hollow body characterized by the above.   2. The hollow body according to claim 1, wherein the ethylene / α-olefin copolymer has at least one other peak in addition to the maximum peak in the endothermic curve measured by DSC. Production method.   The ethylene / α-olefin copolymer contains a component that does not elute at less than 100 ° C. in a temperature rising dissolution test (TREF), and the amount thereof is 10% by weight or less. 2. A method for producing a hollow body according to 2.   The ethylene / α-olefin copolymer has a long chain branch having 6 or more carbon atoms determined by NMR measurement in the molecule in a number exceeding 3 per 1000 carbon atoms. Item 4. A method for producing a hollow body according to any one of Items 1 to 3. The ethylene / α-olefin copolymer is (A) a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, (B) an organoaluminum oxy compound, and (C) a support, Or the manufacturing method of the hollow body in any one of Claims 1-4 obtained using the catalyst containing these (A)-(C) and also (D) organoaluminum compound .