JP3914502B2 - Co-catalyst for olefin polymerization and method for producing modified methylaluminoxane for olefin polymerization catalyst - Google Patents

Description

【００８３】
実施例 8
(2) シリカ担持触媒の調製
十分に乾燥し、窒素置換したガラス製のフラスコにシリカ(比表面積 292m²/g,表面水酸基量 3.2mmol/g, 平均粒径42μm) 7gとトルエン200mlを添加し、懸濁状態とした。これに、実施例1の修飾メチルアルミノキサン調製物を80mmolを室温で30分かけて滴下した。その後、溶液を80℃にまで昇温し、その温度で1時間熟成した。上澄み液を除去し、トルエンで洗浄することにより、シリカに修飾メチルアルミノキサンを担持した固体を得た。
【００８４】
次に、ジルコノセンジクロライド 0.55mmolをトルエンに溶解した溶液を室温で上記で得られた固体触媒スラリー溶液中へ滴下し、その温度で2時間熟成を行った。上澄み液を除去し、乾燥トルエンで洗浄することにより、1g当たり0.090mmolのZrと4.95mmolのAlを含有する固体触媒を得た。
【００８５】
(3) エチレン重合評価
磁気撹拌装置を持つ1000mlのオートクレーブにヘキサン500mlを導入し、系内をエチレンで置換した。その後、系内を70℃へ昇温した。TIBAL 0.89mmolを添加し、上記で調製した固体触媒を20mg導入した後に、エチレン圧0.78MPaで30分間重合を行った。濾過によりポリマーを回収し、減圧下に60℃で6時間乾燥することにより、ポリエチレンを得た。このときのエチレン重合活性は、720kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００８６】
実施例 9
(2) シリカ担持触媒の調製
実施例2で得た修飾メチルアルミノキサンを用いた以外は、実施例8記載の方法と同様にして固体触媒を調製した。固体触媒は、1g当たり0.093mmolのZrと5.65mmolのAlを含有する。
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、662kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００８７】
実施例 10
(1) 修飾メチルアルミノキサン調製物の合成
撹拌装置を有する内容積5Lのセパラブルフラスコに、TIBAL 50.0g(0.25mol)、トルエン1200gを入れた。この溶液に-5℃で水1.4g(0.07mol)を滴下した。この反応液にTMAL 180.0g(2.50mol)を投入し、50℃加熱熟成を1時間行った。この溶液に同温度で水33.8g(1.88mol)を添加した。この反応液をさらに50℃加熱熟成を1時間行った。
【００８８】
析出した固形分をガラスフィルターで濾過除去し、修飾メチルアルミノキサン溶液を得た。この溶液のAl原子基準で示す収率は86%であった。修飾メチルアルミノキサンの加水分解発生ガスのガスクロ分析により求めたMe/iBu比、¹H-NMRより求めた未反応TMALおよび修飾メチルアルミノキサン由来のメチル基と未反応TIBALおよび修飾メチルアルミノキサン由来のイソブチル基のそれぞれのモル分率を表2にまとめた。
【００８９】
(2) シリカ担持触媒の調製
上記で得た修飾メチルアルミノキサンを用いた以外は、実施例8記載の方法と同様にして固体触媒を調製した。固体触媒は、1g当たり0.07mmolのZrと5.95mmolのAlを含有していた。
【００９０】
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、770kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００９１】
比較例 6
(2) シリカ担持触媒の調製
比較例1で用いた市販の修飾メチルアルミノキサンのヘキサン溶液を用いた以外は、実施例8記載の方法と同様にして固体触媒を調製した。固体触媒は、1g当たり0.087mmolのZrと5.80mmolのAlを含有していた。
【００９２】
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、357kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００９３】
比較例 7
(2) シリカ担持触媒の調製
市販の修飾メチルアルミノキサンのトルエン溶液を用いた以外は、実施例8記載の方法と同様にして固体触媒を調製した。ここで用いた修飾メチルアルミノキサンの¹H-NMRより求めた未反応TMALおよび修飾メチルアルミノキサン由来のメチル基と未反応TIBALおよび修飾メチルアルミノキサン由来のイソブチル基のそれぞれのモル分率を表2にまとめた。得られた固体触媒は、1g当たり0.080mmolのZrと4.80mmolのAlを含有していた。
【００９４】
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、189kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００９５】
比較例 8
(2) シリカ担持触媒の調製
比較例3で用いた市販のポリメチルアルミノキサンを用いたこと以外は、実施例8記載の方法と同様にして固体触媒を調製した。固体触媒は、1g当たり0.068mmolのZrと4.56mmolのAlを含有していた。
【００９６】
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、323kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００９７】
比較例 9
(2) シリカ担持触媒の調製
比較例3で用いた市販のポリメチルアルミノキサンを減圧下に濃縮することにより調製した濃縮PMAOを用いたこと以外は、実施例8記載の方法と同様にして固体触媒を調製した。このとき使用した濃縮ポリメチルアルミノキサンの¹H-NMR測定により求めた未反応TMALおよびポリメチルアルミノキサン由来のメチル基のそれぞれのモル分率は、Me(PMAO) 68.7mol%, Me(TMAL) 31.3mol%であった。固体触媒は、1g当たり0.084mmolのZrと5.43mmolのAlを含有していた。
【００９８】
(3) エチレン重合評価
上記で調製した固体触媒を用いたこと以外は、実施例8記載の方法と同様にエチレン重合を実施した。このときのエチレン重合活性は、492kg-PE/mol-Zr・atm・hrであった。この際、重合容器壁や攪拌羽へのポリマーの付着は認められなかった。
【００９９】
【表２】

【０１００】
【発明の効果】
本発明における修飾メチルアルミノキサン調製物は、アルミノキサン由来のメチル基を高い割合で含み、かつアルミノキサン由来のメチル基以外のアルキル基を低い割合で含む。これと遷移金属化合物とを組合せて調製したオレフィン重合触媒は、重合活性が高くかつ安定した活性を示す。
【図面の簡単な説明】
【図１】本発明に従い得られた修飾メチルアルミノキサン調製物の¹H-NMRチャートである。[0001]
[Industrial application fields]
  The present invention relates to olefin polymerization using a novel modified methylaluminoxane preparation.HelpThe present invention relates to a catalyst, a method for producing a modified methylaluminoxane preparation for an olefin polymerization catalyst, and an olefin polymerization method using the novel modified methylaluminoxane preparation as a polymerization catalyst component.
[0002]
[Prior art]
[Patent Document 1]
JP-A-58-19309
[Patent Document 2]
JP 60-35005 A
[Patent Document 3]
JP 62-234009
[Patent Document 4]
JP 63-234009
[Patent Document 5]
JP-A 64-66214
[Patent Document 6]
JP-A-1-207355
[Patent Document 7]
JP 2000-119278
[Patent Document 8]
JP 2000-119279 A
[Patent Document 9]
JP 2000-119280 A
[Patent Document 10]
JP-A-60-260602
[Patent Document 11]
JP 63-89506 A
[Patent Document 12]
JP-A 63-178108
[Patent Document 13]
JP-A-1-315407
[Patent Document 14]
Japanese Patent Laid-Open No. 2-22308
[Patent Document 15]
JP 60-35006 A
[Patent Document 16]
JP 60-35007 A
[Patent Document 17]
Japanese Unexamined Patent Publication No. 60-35008
[Patent Document 18]
JP 61-108610 A
[Patent Document 19]
JP 61-296008 A
[Non-Patent Document 1]
Macromolecules, 32, 9078 (1999)
[Non-Patent Document 2]
Journal of American Chemical Society (J. Am. Chem. Soc). 118,11664 (1996)
[Non-Patent Document 1]
Organometallics, 18, 65 (1999)
[0003]
Aluminoxane is a condensation product that is generally prepared by partial hydrolysis reaction of an organoaluminum compound and water, and is useful as a co-catalyst component for efficiently activating transition metal compounds that are the main catalyst in the production of olefin polymers. It is known that It is widely known that polymethylaluminoxane using trimethylaluminum as a raw material organoaluminum compound exhibits particularly excellent promoter performance. Examples of these include [Patent Document 1], [Patent Document 2], [Patent Document 3], [Patent Document 4], [Patent Document 5], and [Patent Document 6].
[0004]
In addition, proposals have been made regarding modified aluminoxanes having two or more types of alkyl groups. For example, as shown in [Patent Document 7], [Patent Document 8], [Patent Document 9], etc., a tetraalkyldialuminoxane having a C2 or higher alkyl group and trimethylaluminum are mixed, and then a hydrolysis reaction is performed. A modified methylaluminoxane has been proposed. The modified methylaluminoxane synthesized by these methods is soluble not only in aromatic hydrocarbon solvents but also in aliphatic hydrocarbon solvents. It can be widely used for manufacturing and the like. In addition, these modified methylaluminoxanes exhibit good storage stability, the synthesis reaction is mild, and the reaction control is easy. However, the modified methylaluminoxane produced by the methods proposed so far has low activity compared to polymethylaluminoxane, and improvement has been desired.
[0005]
Methods for solubilizing polymethylaluminoxane in aliphatic hydrocarbon solvents have been proposed in [Patent Document 10], [Patent Document 11], [Patent Document 12], [Patent Document 13], and [Patent Document 14]. Yes. A typical method is to produce polymethylaluminoxane in an aromatic hydrocarbon solvent, and then contact alkylaluminum other than trimethylaluminum to improve solubility in the solvent. However, in such a method, in the case of replacing the solvent with an aliphatic hydrocarbon solvent, the aromatic hydrocarbon solvent having a relatively high boiling point must be removed by an operation such as distillation under reduced pressure. Even if the solvent substitution is performed by such a method, it is inevitable that the aromatic hydrocarbon solvent remains about several weight%. Such solvent replacement work may be effective at the laboratory level, but it is extremely difficult to manufacture for industrial use.
There has been proposed a method in which a solid catalyst component in which a transition metal compound and an aluminoxane are supported on a solid carrier such as silica, alumina, and magnesium chloride is applied to suspension polymerization or gas phase polymerization. Known examples of these include [Patent Document 10], [Patent Document 11], [Patent Document 12], [Patent Document 13], and [Patent Document 14].
[0006]
As the aluminoxane used for the preparation of the solid catalyst as described above, polymethylaluminoxane was used in most of the known examples described above. Since polymethylaluminoxane is very reactive compared to other organoaluminum compounds, trimethylaluminum as a raw material is difficult to control the partial hydrolysis reaction and is similar to the insoluble aluminum hydroxide produced by the local hydrolysis reaction. Inorganic aluminum compounds cause a reduction in aluminum recovery yield. Furthermore, polymethylaluminoxane has a problem in terms of storage stability because it tends to reduce the solubility of polymethylaluminoxane in the solvent due to the progress of the association, so that insoluble matter is easily generated. For these reasons, it has been desired to develop a modified methylaluminoxane having a high aluminum recovery rate and excellent storage stability.
[0007]
However, the modified methylaluminoxane known so far has a higher activity per solid catalyst compared to the activity of a solid catalyst prepared using polymethylaluminoxane when used in a supported catalyst using silica or the like as a carrier. Since it becomes extremely low, it has not been actively developed into a supported catalyst system. This low activity is caused by the presence of the alkylaluminum compound having a C2 or higher alkyl group and / or the modified methylaluminoxane having a C2 or higher alkyl group present in the modified methylaluminoxane is not suitable for the preparation of the supported catalyst. It can be thought that it was because of.
[0008]
Recently, a polymerization catalyst system in which the modified methylaluminoxane exhibits a cocatalyst performance comparable to or exceeding that of polymethylaluminoxane has been found, and the development of the modified methylaluminoxane as a cocatalyst for polymerization has attracted attention. . Examples of these include [Non-patent document 1], [Non-patent document 2], and [Non-patent document 3].
[0009]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a catalyst for olefin polymerization using a modified methylaluminoxane that stably exhibits high activity comparable to or exceeding that when polymethylaluminoxane is used.
[0010]
[Means for Solving the Problems]
As a result of continual research to solve the above-described problems of the prior art, the present inventors have found that a specific modified methyl group obtained from the reaction of two or more types of organoaluminum compounds with a condensing agent such as water as an oxygen source. The inventors have found that the above problems can be solved by aluminoxane, and have completed the present invention.
The present invention relates to the following gist.
[0011]
  (1) General formula (I)
        R¹ _mAlX_3-m     (I)
(Where R¹Represents a C2-C20 linear or branched alkyl group, alkenyl group, or aryl hydrocarbon group, X represents a hydrogen atom, a halogen atom, an alkoxy group, or an allyloxy group, and 0 <m ≦ 3. )
A modified methylaluminoxane preparation prepared from an organoaluminum compound represented by formula (II) and trimethylaluminum, wherein the aluminoxane moiety is relative to the total number of moles of C2-C20 hydrocarbon groups and methyl groups present in the modified methylaluminoxane preparation. Polymerization in which the mole fraction of methyl groups derived from styrene is 65 mol% or moreHelpcatalyst.
[0012]
  (2) The modified methylaluminoxane preparation has a mole fraction of C2 to C20 hydrocarbon groups derived from aluminoxane sites with respect to the total number of moles of C2 to C20 hydrocarbon groups and methyl groups present therein. % Olefin polymerization according to (1)Helpcatalyst.
[0013]
  (3) The organoaluminum compound represented by the general formula (I) is at least one selected from triisobutylaluminum, tri-n-hexylaluminum and tri-n-octylaluminum (1) or (2) Olefin polymerization as described inHelpcatalyst.
[0014]
(4) The modified methylaluminoxane used in the olefin polymerization catalyst, characterized in that it is a solid catalyst in which a transition metal compound and a modified methylaluminoxane preparation are supported on a particulate carrier is any one of (1) to (3) An olefin polymerization catalyst which is the modified methylaluminoxane according to claim 1.
[0015]
  (5) the transition metal compound is represented by the general formula (II)
      MR²R³R⁴R⁵       (II)
(Where M isOf titanium, zirconium or hafniumIndicates transition metal element, R², R³ , R⁴, R⁵Together represent an organic group having a cycloalkadienyl skeleton, an alkyl group, an alkoxy group, an aryloxy group, an alkylsilyl group, an alkylamide group, an alkylimide group, an alkylamino group, an alkylimino group, and a halogen atom. )
(4) The olefin polymerization catalyst as described in (4) above.
[0016]
(6) A method for producing the modified methylaluminoxane preparation according to any one of (1) to (4), which comprises the general formula (I)
R¹ _mAlX_3-m      (I)
(R¹Represents a C2-C20 linear or branched alkyl group, alkenyl group, aryl group or other hydrocarbon group, X represents a hydrogen atom, a halogen atom, an alkoxy group or an allyloxy group, and 0 <m ≦ 3 . )
A process for producing the modified methylaluminoxane preparation, wherein the addition of trimethylaluminum and the hydrolysis reaction after the addition are performed in multiple stages after hydrolysis of the organoaluminum compound represented by formula (1).
[0017]
(7) The method for preparing an olefin polymerization catalyst according to (5), wherein the particulate carrier is contacted with the modified methylaluminoxane preparation and then contacted with the transition metal compound.
[0018]
(8) An olefin polymerization method using a catalyst system comprising a transition metal compound and the modified methylaluminoxane described in (1) to (3) or a solid catalyst described in (4).
[0019]
That is, the present invention relates to the general formula (I)
R¹ _mAlX_3-m                      (I)
(Where R¹Represents a C2-C20 linear or branched alkyl group, alkenyl group, or aryl hydrocarbon group, X represents a hydrogen atom, a halogen atom, an alkoxy group, or an allyloxy group, and 0 <m ≦ 3. )
A modified methylaluminoxane preparation prepared from an organoaluminum compound represented by formula (II) and trimethylaluminum, wherein the aluminoxane moiety is based on the total number of moles of C2-C20 hydrocarbon groups and methyl groups present in the modified methylaluminoxane preparation. The present invention relates to a catalyst component comprising a modified methylaluminoxane preparation in which the molar fraction of methyl groups derived from is at least 65 mol% and an arbitrary transition metal compound, and an olefin polymerization solid catalyst having these supported on a solid support.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[0021]
The modified methylaluminoxane in the present invention is a composition containing an organoaluminum compound of the general formula (I) and trimethylaluminum that are unreacted raw materials in addition to the target modified methylaluminoxane (in the present invention, “modified methylaluminoxane preparation”). Generically referred to as “thing”.
[0022]
Therefore, in the above item (1), “the C2-C20 hydrocarbon group present in the modified methylaluminoxane preparation” means the C2-C20 hydrocarbon group and the modified methylaluminoxane present in the modified methylaluminoxane molecule. A combination of C2 to C20 hydrocarbon groups in the unreacted organoaluminum compound remaining in the preparation. The “methyl group” in the above item (1), which is the target of the total number of moles, is the methyl group in the aluminoxane moiety of the modified methylaluminoxane molecule and the methyl group in trimethylaluminum as an unreacted raw material contained in the modified methylaluminoxane preparation. Are combined.
[0023]
The modified methylaluminoxane in the present invention is a general formula (III)
-[(R¹) AlO]_n-[(Me) AlO]_p-(III)
(Where R¹Is the same as defined above, and n and p represent an integer of 1 to 60. ) Is assumed to be a compound consisting of units represented by The modified methylaluminoxane in the present invention may be a chain structure or a cyclic structure as long as it contains the above unit. In addition, the structural unit of modified methylaluminoxane-(R¹) AlO − and — (Me) AlO − may have a block-like bond as shown in the general formula (III), or a bond that is random or a mixture thereof. In addition, R in the general formula (III)¹Does not represent one type of hydrocarbon group, but may be a mixture of a plurality of specifically exemplified hydrocarbon groups.
[0024]
R in the general formula (III)¹As more specifically, ethyl group, propyl group, n-butyl group, isobutyl group, t-butyl group, amyl group, isoamyl group, n-hexyl group, isohexyl group, n-octyl group, isooctyl group An aryl group such as an alkyl group such as phenyl group and tolyl group, and the like can be mentioned, and an n-butyl group, an isobutyl group, an n-hexyl group, an n-octyl group, and an isooctyl group are more preferable.
[0025]
The organoaluminum compound used in the production of the modified methylaluminoxane preparation of the present invention has the general formula (I)
R¹ _mAlX_3-m      (I)
(Where R¹And m are the same as defined above.
[0026]
R in the general formula (I)¹More specifically, as shown, ethyl group, propyl group, n-butyl group, isobutyl group, t-butyl group, amyl group, isoamyl group, n-hexyl group, isohexyl group, n-octyl group, isooctyl group And an alkyl group such as a group, and an aryl group such as a phenyl group and a tolyl group. Examples of X include halogen atoms of fluorine, chlorine, bromine and iodine, alkoxy groups such as methoxy group and ethoxy group, and allyloxy groups such as phenoxy group.
[0027]
Specific examples of such organoaluminum compounds include trimethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and other aluminum alkyls such as triphenyl Examples thereof include triarylaluminums such as aluminum and tritylaluminum, and halogen-containing alkylaluminums such as dimethylaluminum chloride and diethylaluminum chloride. Desirable modified methylaluminoxane preparations can be prepared by using these organic alkylaluminums alone or in combination. In the preparation of modified methylaluminoxane preparations, the most preferred organoaluminum compounds and combinations thereof are trimethylaluminum and trialkylaluminum, more particularly trimethylaluminum and triisobutylaluminum, tri-n-hexylaluminum or tri-n-octylaluminum and It is a combination of these.
[0028]
Previously proposed modified methylaluminoxane preparations have been defined primarily by the molar ratio of methyl groups to C2-C20 hydrocarbon groups present in the modified methylaluminoxane preparation. In general, polymethylaluminoxane using trimethylaluminum as a single raw material exhibits high promoter performance when olefin polymerization is performed using a promoter such as a metallocene catalyst, whereas trimethylaluminum of the above general formula (I) Aluminoxanes using other organoaluminum compounds as raw materials exhibit almost no promoter performance except for some catalyst systems such as chromium complexes. From this point of view, it is presumed that the higher the molar ratio of methyl groups to C2-C20 hydrocarbon groups present in the modified methylaluminoxane preparation, the higher the promoter performance. However, as described above, the modified methylaluminoxane preparation contains the organoaluminum compound of general formula (I) and trimethylaluminum that are unreacted raw materials in addition to the target modified methylaluminoxane. When there is a difference in the residual degree, the above-mentioned estimation does not hold, and as a method that leads to a more accurate evaluation of the promoter performance of the modified methylaluminoxane preparation, a C2-C20 hydrocarbon group present in the modified methylaluminoxane preparation is used. And the method defined by the mole fraction of methyl groups derived from the aluminoxane moiety to the total moles of methyl groups is superior to the molar ratio of methyl groups to C2-C20 hydrocarbon groups present in the modified methylaluminoxane preparation. I found.
[0029]
Furthermore, the modified methylaluminoxane preparations studied and prepared under various conditions were evaluated based on the above specified method. At the same time, the co-catalyst performance of the modified methylaluminoxane preparation in homogeneous polymerization and the modified methylaluminoxane and transition metal catalyst in the solid state were evaluated. By comparing the polymerization performance of the solid catalyst component supported on the support, it is higher than that of the conventional modified methylaluminoxane when it is 65 mol% or more, and has a specific activity comparable to or exceeding that of polymethylaluminoxane. I found.
[0030]
When the specified value by the above-mentioned specifying method is less than 65 mol%, the promoter performance exceeding the commercially available modified methylaluminoxane is not exhibited.
[0031]
In olefin polymerization using a metallocene catalyst or the like as a main catalyst, trimethylaluminum and an organoaluminum compound having a C2 to C20 hydrocarbon group represented by the general formula (I) generally exhibit almost no promoter performance. In olefin polymerization, since the number of moles of aluminum in the promoter relative to the number of moles of the metallocene catalyst is set to a constant value, the presence of aluminum derived from the polymethylaluminoxane component contributing to the development of the promoter performance is large. It is more advantageous, that is, it is advantageous that there are few organoaluminum components. Similarly, when it is supported on a support, it is advantageous that the proportion of aluminum derived from the polymethylaluminoxane component is large, that is, it is advantageous that the amount of organoaluminum component is small.
[0032]
Moreover, since these organoaluminum compounds have an effect | action as a polymerization chain transfer agent, when the objective is preparation of a high molecular weight body, it is better that there are few.
[0033]
From the above viewpoint, it has been found that the modified methylaluminoxane specified in (1) is highly active in olefin polymerization when used in combination with a transition metal compound or when they are used for preparing a supported catalyst.
[0034]
Also, when the mole fraction of C2-C20 hydrocarbon groups derived from the aluminoxane moiety to the total number of moles of C2-C20 hydrocarbon groups and methyl groups present in the modified methylaluminoxane preparation exceeds 15 mol% Does not exhibit co-catalytic performance over that of commercially available modified methylaluminoxane, and the molecular weight of the resulting polymer is reduced.
[0035]
In the modified methylaluminoxane in the present invention, any inert hydrocarbon can be used as a solvent. Examples of aliphatic hydrocarbons include saturated hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, isooctane and purified kerosene, and cyclic such as cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, and cycloheptane. Examples include aliphatic hydrocarbons, aromatic hydrocarbons such as benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Among these compounds, preferred are n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and toluene.
[0036]
As a synthesis method of the modified methylaluminoxane preparation according to the present invention, any known method can be used. A typical synthesis method is as shown below. For example, after a certain amount of hydrolysis of the organoaluminum compound of the general formula (I), trimethylaluminum is introduced, and then a certain amount of hydrolysis is performed. The modified methylaluminoxane preparation prepared by such a method does not particularly require post-reaction treatment, but if necessary, for example, for the purpose of adjusting the aluminum concentration, the solvent and the residual residual organoaluminum compound under reduced pressure. It is also possible to distill off low boiling point compounds such as Furthermore, heat treatment can also be performed during the reaction as needed.
[0037]
Examples of the form of water used for the hydrolysis reaction include water droplets, water vapor, crystal water of inorganic compounds and water diluted with an inert gas such as nitrogen or an inert hydrocarbon solvent.
[0038]
The molar ratio of trimethylaluminum used for the synthesis of the modified methylaluminoxane preparation and the organoaluminum compound of the general formula (I) can be arbitrarily set in the range of 0.5 to 30: 1. The preferred molar ratio depends on the type of organoaluminum compound of the above general formula (I) used as a modifier, but by adjusting it in the range of 2 to 20: 1, the balance between aluminum recovery and promoter performance is excellent. Modified methylaluminoxane preparations can be prepared.
[0039]
The molar ratio of water used as a condensing agent to the organoaluminum compound of the general formula (I) is in the range of 0.1 to 1.5: 1 depending on the chain length of the hydrocarbon group of the organoaluminum compound of the general formula (I). Can be adjusted.
[0040]
Regarding the reaction temperature, it can be carried out between −50 to 50 ° C., preferably −30 to 30 ° C.
[0041]
The modified methylaluminoxane preparation solution after completion of the reaction is preferably stirred and aged for a while while maintaining the reaction temperature, but can also be aged by heating at a temperature lower than the boiling point of the reaction solvent. The concentration of the modified methylaluminoxane in the inert hydrocarbon solvent may be in the range of 1 to 40% by weight, preferably 5 to 25% by weight, and more preferably 5 to 20% by weight.
[0042]
In the modified methylaluminoxane, the organoaluminum compound of the above general formula (I) and trimethylaluminum, which are raw materials that have not been hydrolyzed, remain and are also included in the modified methylaluminoxane preparation of the present invention. For example, when isobutyl group is used as the hydrocarbon group, the molar ratio of methyl group / isobutyl group present in the modified methylaluminoxane preparation (hereinafter abbreviated as Me / iBu ratio) is the hydrolysis of the modified methylaluminoxane preparation. The components that are sometimes generated can be determined by quantitative analysis using a gas chromatograph.
[0043]
The modified methylaluminoxane preparation according to the present invention comprises trimethylaluminum inherent as unreacted raw materials and the mole fraction of methyl groups derived from the aluminoxane moiety (respectively abbreviated as Me (TMAL) and Me (modified methylaluminoxane)), C2 ~ The residual organoaluminum compound having a hydrocarbon group of C20 and the mole fraction of hydrocarbon groups of C2 or higher derived from the aluminoxane moiety (R (AlR, respectively)_Three), R (abbreviated as modified methylaluminoxane)).
[0044]
The molar fraction of each component in the modified methylaluminoxane described above is the amount of the modified methylaluminoxane preparation.¹It can be determined from the area ratio that can be attributed to each component by H-NMR measurement. Specific Me (modified methylaluminoxane) of the modified methylaluminoxane preparation when trimethylaluminum (hereinafter abbreviated as TMAL) and triisobutylaluminum (hereinafter abbreviated as TIBAL) are used for two types of organoaluminum compounds, The method for determining the molar fraction of Me (TMAL), iBu (modified methylaluminoxane), iBu (TIBAL) is exemplified.
[0045]
First, d₈Of methylaluminoxane preparation modified with -THF¹An H-NMR measurement is performed.¹The H-NMR measurement was performed at a measurement temperature of 24 ° C. using a Gemini 2000 NMR measurement apparatus manufactured by 300 MHz Varian Technologies Japan Limited.¹An example of the H-NMR chart is shown in FIG.
(i) The total integrated value of the Me group and methylene group peaks of the modified methylaluminoxane appearing at about 0.5 ppm to -1 ppm is defined as I (modified methylaluminoxane). (ii) A methylene group peak derived from TIBAL near 0 ppm is cut out by tangent line-A, and its integrated value I (TIBAL-iBu) is obtained. Similarly, a methylene group peak derived from the lower modified methylaluminoxane separated by tangent-A is cut out, and its integrated value I (modified methylaluminoxane-iBu) is obtained.
(iii) In the same manner as (ii), a Me group peak derived from TMAL at around -0.8 ppm is cut out by tangent line -B, and its integrated value I (TMAL-Me) is obtained. Similarly, the Me group peak derived from the lower modified methylaluminoxane separated by tangent-B is cut out, and the integral value I (modified methylaluminoxane-Me) is obtained.
(iv) Each integral value obtained in (ii) and (iii) is divided by the number of protons of each group, and then normalized to obtain Me (modified methylaluminoxane), Me (TMAL), iBu (modified Calculate the molar fraction of methylaluminoxane) and iBu (TIBAL).
[0046]
In addition, as a method for cutting out each peak, it can be easily performed by curve fitting, baseline correction, or the like.
As the transition metal compound that can be used for preparing the polymerization catalyst in combination with the modified methylaluminoxane preparation of the present invention, a known catalyst known as an olefin polymerization catalyst can be used. Such transition metal compounds include, for example, the general formula (II)
MR²R^ThreeR^FourR^Five            (II)
(Wherein, M represents a transition metal element, R², R^Three , R^Four, R^FiveTogether represent an organic group having a cycloalkadienyl skeleton, an alkyl group, an alkoxy group, an aryloxy group, an alkylsilyl group, an alkylamide group, an alkylimide group, an alkylamino group, an alkylimino group, and a halogen atom. ).
[0047]
  Specific examples of M in the general formula (II) include titanium and zirconium.OrHafniuInis there.
[0048]
In the general formula (II), a preferable transition metal compound is a metallocene compound in which one or two ligands having a cycloalkadienyl skeleton are coordinated. Examples of ligands having a cycloalkadienyl skeleton include cyclopentadienyl, methylcyclopentadienyl, ethylcyclopentadienyl, butylcyclopentadienyl, dimethylcyclopentadienyl, and pentamethyl. Examples of the alkyl-substituted cyclopentadienyl group such as cyclopentadienyl group, indenyl group, and fluorenyl group can be exemplified, and the cycloalkadienyl group is bridged by a divalent substituted alkylene group, a substituted silylene group or the like. Also good.
[0049]
The ligand other than the ligand having a cycloalkadienyl skeleton is a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, an alkylsilyl group, an amino group, an imino group, a halogen atom or a hydrogen atom. is there. Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group. Specifically, examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Group, isopropyl group, butyl group and the like are exemplified. Cycloalkyl group is exemplified by cyclopentyl group, cyclohexyl group and the like, and aryl group is exemplified by phenyl group, tolyl group and the like, and aralkyl group. Examples thereof include a benzyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group, and examples of the aryloxy group include a phenoxy group. These groups may be substituted with a halogen atom or the like. Examples of the alkylsilyl group include a trimethylsilyl group and a triethylsilyl group. Examples of the halogen include fluorine, chlorine, bromine and iodine.
[0050]
Specific examples of the transition metal compound containing a ligand having a cycloalkadienyl skeleton in the case where M in the general formula (II) is zirconium are exemplified. Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium monobromide monohydride, bis (cyclopentadienyl) methylzirconium hydride, bis (cyclopentadienyl) ethylzirconium hydride, bis ( Cyclopentadienyl) phenyl zirconium hydride, bis (cyclopentadienyl) benzyl zirconium hydride, bis (cyclopentadienyl) neopentyl zirconium hydride, bis (methylcyclopentadienyl) zirconium monochloride hydride, bis (Indenyl) zirconium monochloride hydride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconi Mudibromide, bis (cyclopentadienyl) methyl zirconium monochloride, bis (cyclopentadienyl) ethyl zirconium monochloride, bis (cyclopentadienyl) cyclohexyl zirconium monochloride, bis (cyclopentadienyl) phenyl zirconium monochloride, Bis (cyclopentadienyl) benzylzirconium monochloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (l-butylcyclopentadienyl) zirconium dichloride, bis (indenyl) ) Zirconium dichloride, bis (indenyl) zirconium dibromide, bis (cyclopentadienyl) zirconium dimethyl, bis (cyclopentadienyl) Zirconium diphenyl, bis (cyclopentadienyl) zirconium dibenzyl, bis (cyclopentadienyl) zirconium monomethoxymonochloride, bis (cyclopentadienyl) zirconium monoethoxymonochloride, bis (methylcyclopentadienyl) zirconium mono Examples include ethoxy monochloride, bis (cyclopentadienyl) zirconium monophenoxy monochloride, bis (fluorenyl) zirconium dichloride, and the like.
[0051]
Further, M in the general formula (II) is zirconium, includes at least two or more ligands having a cycloalkadienyl skeleton, and the ligand having at least two cycloalkadienyl skeletons. Specific examples of the transition metal compound bonded via an alkylene group such as ethylene and propylene, a substituted alkylene group such as isopropylidene and diphenylmethylene, a substituted silylene group such as silylene group and dimethylsilylene, and the like are exemplified. Ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) diethylzirconium, ethylenebis (indenyl) diphenylzirconium, ethylenebis (indenyl) methylzirconium monochloride, ethylenebis (indenyl) ethylzirconium monochloride, ethylenebis (indenyl) methyl Zirconium monobromide, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) zirconium bromide and the like can be mentioned.
[0052]
One type of these transition metal compounds may be used in homogeneous polymerization, or two or more types may be used for the purpose of adjusting the molecular weight distribution. In the case of preparing a solid catalyst in advance, only one kind of these transition metal compounds may be used, or two or more kinds may be used for the purpose of adjusting the molecular weight distribution.
[0053]
In the present invention, the fine particle carrier used for preparing the solid catalyst is an inorganic compound and a fine particle having a particle shape of 5 to 200 μm is used. As an inorganic compound of the fine particle carrier, for example, SiO₂, Al₂O_Three, MgO, TiO₂And the like, and mixtures thereof, preferably SiO₂It is. Moreover, even if it is an organic compound, if it has reaction points, such as a hydroxyl group which aluminoxane can adsorb | suck, it can utilize.
[0054]
The amount of hydroxyl groups on the surface of the fine particle carrier used in the present invention can be in the range of 0.1 to 4 mmol / g, preferably 1.0 to 3.0 mmol / g. The surface hydroxyl group can be easily measured by, for example, contacting the fine particle carrier with trimethylaluminum and measuring the amount of methane gas generated by the reaction.
[0055]
The amount of the modified methylaluminoxane preparation supported on the fine particle carrier in the present invention can be generally controlled by the surface hydroxyl group amount. The amount of the modified methylaluminoxane supported on the solid catalyst in the present invention is in the range of 3 to 10 mmol / g, preferably 4 to 8 mmol / g. Since the surface hydroxyl amount in this patent is measured by the amount of methane gas generated as described above, the amount of methane gas generated by the reaction with a compound having active hydrogen such as water or alcohol adsorbed on the fine particle carrier is also particularly distinguished. Not done. However, the amount of the modified methylaluminoxane supported is in the range of 3 to 10 mmol / g as long as the surface hydroxyl group amount obtained by including methane gas generated from adsorbed water or the like falls within the above-mentioned range.
[0056]
The amount of the transition metal compound supported on the particulate carrier can be controlled by the shape of the particulate carrier, the amount of surface hydroxyl groups, and the amount of the modified methylaluminoxane preparation. The amount of the transition metal compound supported on the solid catalyst in the present invention is in the range of 0.03 to 0.3 mmol / g, preferably 0.05 to 0.15 mmol / g. When the amount of the transition metal compound supported on the solid catalyst is smaller than 0.03 mmol / g, the polymerization activity per 1 mol of the transition metal compound tends to be rather high, but the polymerization activity per weight of the solid catalyst becomes small, Polymer productivity and solid catalyst preparation costs are increased. Further, when the amount of the transition metal compound supported on the solid catalyst is larger than 0.3 mmol / g, both the activity per weight of the solid catalyst and the polymerization activity per 1 mol of the transition metal compound are lowered. This phenomenon can be considered to be because the transition metal compound is deposited in a cluster on the surface of the carrier as a result of the excessive transition metal compound being carried on the surface of the particulate carrier. That is, it is understood that efficient contact between the transition metal compound and the modified methylaluminoxane as the promoter is inhibited, and as a result, the polymerization activity per solid catalyst is lowered.
[0057]
The solid catalyst for olefin polymerization of the present invention can be prepared by bringing (A) a transition metal compound and (B) a modified methylaluminoxane preparation into contact with a solid support in a suitable inert hydrocarbon solvent. The method for preparing the solid catalyst for olefin polymerization of the present invention can be any method, but the most preferable method is to contact the particulate carrier and the modified methylaluminoxane in a solvent and then contact the transition metal compound.
[0058]
The temperature for preparing the olefin polymerization catalyst is 0 to 200 ° C, and preferably 30 to 100 ° C.
[0059]
The time for contacting the transition metal compound and the modified methylaluminoxane preparation with the solid carrier may be in the range of 0.5 to 10 hours, preferably 0.5 to 2 hours.
[0060]
In preparing the olefin polymerization catalyst according to the present invention, any inert hydrocarbon can be used as a solvent. Examples of aliphatic hydrocarbons include saturated hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, isooctane and purified kerosene, and cyclic such as cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, and cycloheptane. Examples include aliphatic hydrocarbons, aromatic hydrocarbons such as benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Among these compounds, preferred are n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and toluene.
[0061]
Homogeneous polymerization using the modified methylaluminoxane preparation of the present invention and polymerization using a supported catalyst prepared using the modified methylaluminoxane preparation of the present invention include solution polymerization using a solvent and solvent as the polymerization mode. It exhibits suitable performance in any method such as bulk polymerization or gas phase polymerization. Moreover, in any method of continuous polymerization and batch polymerization, preferable performance is exhibited, and hydrogen as a molecular weight regulator can be used as necessary.
[0062]
About the monomer used for superposition | polymerization, it can be used for the copolymerization of the olefin type monomer individually and those combined. Specific examples include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-decene, 1-hexadecene, 1-octadecene and 1-eicocene, bisfluoroethylene, trifluoroethylene , Halogen-substituted olefins such as tetrafluoroethylene and hexafluoropropene, and cyclic olefins such as cyclopentene, cyclohexene and norbornene.
[0063]
【Example】
EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples. The following reaction was performed in a nitrogen gas atmosphere, and all solvents were used after dehydration. Moreover, ion-exchange water was used for water.
[0064]
Example 1
(1) Synthesis of modified methylaluminoxane preparation
In a 5 L separable flask having a stirrer, 315.2 g (1.59 mol%) of triisobutylaluminum (TIBAL) and 1219.2 g of n-hexane were placed. To this solution was added 20.1 g (1.11 mol) of water at -5 ° C. To this reaction liquid, 183.2 g (2.54 mol) of trimethylaluminum (TMAL) was added, followed by aging at 50 ° C. for 1 hour. Further, 36.7 g (2.04 mol) of water was added to this solution at the same temperature.
[0065]
To the above reaction solution, 82.8 g (1.15 mol) of TMAL was further added, followed by aging at 50 ° C. for 1 hour. To this solution was added 24.81 g (1.38 mol) of water at -5 ° C. Further, this reaction solution was aged at 50 ° C. for 1 hour.
The precipitated gel component was removed by filtration with a glass filter to obtain an n-hexane solution of modified methylaluminoxane. The yield of this solution based on Al atoms was 80%. Me / iBu ratio determined by gas chromatographic analysis of gas generated during hydrolysis of modified methylaluminoxane,¹Table 1 summarizes the molar fractions of methyl groups derived from unreacted TMAL and modified methylaluminoxane preparations and isobutyl groups derived from unreacted TIBAL and modified methylaluminoxane preparations as determined by 1 H-NMR.
(2) Evaluation of ethylene polymerization
250 ml of toluene was introduced into a 500 ml four-necked flask equipped with a magnetic stirrer and heated to 34 ° C. To this, 0.16 g of a modified methylaluminoxane solution in n-hexane in terms of Al atom was added, and dicyclopentadienylzirconium dichloride (Cp) was added so that the Al / Zr molar ratio was 5000.₂ZrCl₂) And ethylene gas was blown in while raising the temperature to 40 ° C. Ten minutes later, the supply of ethylene gas was stopped, and methanol was added to deactivate the catalyst. The produced polyethylene was filtered and dried, and the polymerization activity was determined.⁶g-PE / mol-Zr · atm · hr.
[0066]
Example 2
(1) Synthesis of modified methylaluminoxane preparation
In Example 1, the modified methylaluminoxane was synthesized in the same manner as in Example 1 except that the amount of water added was changed so that the addition ratio of water and TMAL added in the second time was 1.0. The results are summarized in Table 1.
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 58 × 10.⁶g-PE / mol-Zr · atm · hr.
Example Three
(1) Synthesis of modified methylaluminoxane preparation
In Example 1, a modified methylaluminoxane was synthesized in the same manner as in Example 1 except that the amount of TMAL charged in the second time was changed to 114.6 g (1.59 mol). The results are summarized in Table 1.
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 70 × 10.⁶g-PE / mol-Zr · atm · hr.
Example Four
(1) Synthesis of modified methylaluminoxane preparation
TIBAL 315.2 g (1.59 mol%) and n-hexane 1219.2 g were placed in a 5 L separable flask equipped with a stirrer. To this solution was added 20.1 g (1.11 mol) of water at -5 ° C. To this reaction solution, 183.2 g (2.54 mol) of TMAL was added, followed by heating at 50 ° C. for 1 hour. Further, 36.7 g (2.04 mol) of water was added to this solution at the same temperature. The gel component in the reaction solution was removed by filtration with a glass filter.
[0067]
To the above filtrate, 82.8 g (1.15 mol) of TMAL was added, followed by heating at 50 ° C. for 1 hour. To this solution was added 24.81 g (1.38 mol) of water at -5 ° C. This reaction solution was aged at 50 ° C. for another hour.
[0068]
The precipitated gel component was removed by filtration with a glass filter to obtain an n-hexane solution of modified methylaluminoxane. The yield of this solution based on Al atoms was 72%. Me / iBu ratio determined by gas chromatographic analysis of gas generated during hydrolysis of modified methylaluminoxane,¹Table 1 summarizes the molar fractions of the unreacted TMAL and modified methylaluminoxane-derived methyl groups and the unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR.
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 63 × 10⁶g-PE / mol-Zr · atm · hr.
Example Five
(1) Synthesis of modified methylaluminoxane preparation
TIBAL 315.2 g (1.59 mol%) and n-hexane 1219.2 g were placed in a 5 L separable flask equipped with a stirrer. To this solution was added 20.1 g (1.11 mol) of water at -5 ° C. To this reaction solution, 266 g (3.69 mol) of TMAL was added, followed by aging at 50 ° C. for 1 hour. Further, 61.5 g (3.42 mol) of water was added to this solution at the same temperature, and aging was performed at 50 ° C. for 1 hour.
[0069]
The precipitated gel component was removed by filtration with a glass filter to obtain an n-hexane solution of the modified methylaluminoxane preparation. The yield of this solution based on Al atoms was 79%. Modified methylaluminoxane preparation Me / iBu ratio determined by gas chromatographic analysis of gas generated during hydrolysis,¹Table 1 summarizes the molar fractions of methyl groups derived from unreacted TMAL and modified methylaluminoxane preparations and isobutyl groups derived from unreacted TIBAL and modified methylaluminoxane preparations as determined by 1 H-NMR.
[0070]
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 59 × 10⁶g-PE / mol-Zr · atm · hr.
[0071]
Example 6
(1) Synthesis of modified methylaluminoxane
In Example 1, a modified methylaluminoxane was synthesized in the same manner as in Example 1 except that 583.0 g (1.59 mol) of tri-n-octylaluminum was used instead of TIBAL. The results are summarized in Table 1.
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 72 × 10⁶g-PE / mol-Zr · atm · hr.
[0072]
Example 7
(1) Synthesis of modified methylaluminoxane
In Example 1, a modified methylaluminoxane was synthesized in the same manner as in Example 1 except that toluene was used in place of the n-hexane solvent and 156.3 g (2.23 mol) of TMAL charged in the second time was used. It was. The results are summarized in Table 1.
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as described in Example 1, the polymerization activity was 73 × 10.⁶g-PE / mol-Zr · atm · hr.
[0073]
Comparative example 1
(2) Evaluation of ethylene polymerization
Polymerization evaluation was performed in the same manner as described in Example 1 except that a commercially available hexane solution of modified methylaluminoxane was used. The Me / iBu ratio determined by gas chromatography analysis of the hydrolyzed gas of the commercially available modified methylaluminoxane used here,¹Table 1 summarizes the molar fractions of the unreacted TMAL and modified methylaluminoxane-derived methyl groups and the unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR. Polymerization activity is 37 × 10⁶g-PE / mol-Zr · atm · hr.
[0077]
Comparative example Three
(2) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in Example 1 except that a commercially available polymethylaluminoxane was used instead of the modified methylaluminoxane of Example 1. Of the polymethylaluminoxane used here¹The molar fractions of unreacted TMAL and methyl group derived from polymethylaluminoxane determined by H-NMR were 52.3 mol% Me (PMAO) and 47.7 mol% Me (TMAL), respectively. Polymerization activity is 62 × 10⁶g-PE / mol-Zr · atm · hr.
[0078]
Comparative example Four
A methylaluminoxane component was synthesized in the same manner as in Example 12 of JP-A-2000-119279. That is, 40 g (TIBAL 0.050 mol) of a 25% toluene solution of TIBAL was charged in a 100 ml flask thoroughly dried and purged with nitrogen under a nitrogen atmosphere. The 100 ml flask was equipped with a magnetic stirring stirrer chip and a temperature resistor for measuring the temperature of the reaction solution. At a reaction temperature of 0 to 0 ° C., 1.099 g (0.061 mol) of water was added with stirring. After the addition of water, the reaction solution was heated to 75 ° C. to produce a viscous gel. To this reaction solution, 3.63 g (0.050 mol) of TMAL was added and reacted at 80 ° C. for 1 hour. In the obtained reaction solution, formation of gel-insoluble matter was observed, and the aluminum concentration of the supernatant reaction solution was measured and found to be 3.51 wt%. The aluminum recovery yield based on the Al recovery rate was determined to be 58.9%. In addition, the Me / iBu ratio obtained by gas chromatography analysis of the hydrolyzed gas of the obtained supernatant liquid,¹Table 1 summarizes the molar fractions of the unreacted TMAL and modified methylaluminoxane-derived methyl groups and the unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR.
[0079]
(2) Evaluation of ethylene polymerization
The polymerization evaluation was carried out in the same manner as in the method described in Example 1. As a result, the obtained polymer had a trace amount.
[0080]
Comparative example Five
A methylaluminoxane component was synthesized in the same manner as in Comparative Example 4 except that n-hexane was used as the solvent, and the aluminum recovery yield based on the Al recovery rate was determined to be 94.8%. In addition, the Me / iBu ratio obtained by gas chromatography analysis of the hydrolyzed gas of the obtained supernatant liquid,¹Table 1 summarizes the molar fractions of the unreacted TMAL and modified methylaluminoxane-derived methyl groups and the unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR.
[0081]
(2) Evaluation of ethylene polymerization
Polymerization evaluation was carried out in the same manner as the method described in Example 1, the polymerization activity was 8 × 10⁶g-PE / mol-Zr · atm · hr.
[0082]
[Table 1]

[0083]
Example 8
(2) Preparation of silica supported catalyst
Thoroughly dry and nitrogen-substituted glass flask with silica (specific surface area 292 m²/ g, surface hydroxyl group amount 3.2 mmol / g, average particle size 42 μm) 7 g and toluene 200 ml were added to form a suspended state. To this, 80 mmol of the modified methylaluminoxane preparation of Example 1 was added dropwise at room temperature over 30 minutes. Thereafter, the solution was heated to 80 ° C. and aged at that temperature for 1 hour. The supernatant was removed and washed with toluene to obtain a solid carrying modified methylaluminoxane on silica.
[0084]
Next, a solution of 0.55 mmol of zirconocene dichloride dissolved in toluene was dropped into the solid catalyst slurry solution obtained above at room temperature, and aging was performed at that temperature for 2 hours. The supernatant was removed and washed with dry toluene to obtain a solid catalyst containing 0.090 mmol of Zr and 4.95 mmol of Al per 1 g.
[0085]
(3) Evaluation of ethylene polymerization
Into a 1000 ml autoclave with a magnetic stirrer, 500 ml of hexane was introduced, and the system was replaced with ethylene. Thereafter, the temperature in the system was raised to 70 ° C. After adding 0.89 mmol of TIBAL and introducing 20 mg of the solid catalyst prepared above, polymerization was carried out at an ethylene pressure of 0.78 MPa for 30 minutes. The polymer was collected by filtration and dried at 60 ° C. under reduced pressure for 6 hours to obtain polyethylene. The ethylene polymerization activity at this time was 720 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0086]
Example 9
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as described in Example 8, except that the modified methylaluminoxane obtained in Example 2 was used. The solid catalyst contains 0.093 mmol of Zr and 5.65 mmol of Al per gram.
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 662 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0087]
Example Ten
(1) Synthesis of modified methylaluminoxane preparation
TIBAL 50.0 g (0.25 mol) and toluene 1200 g were placed in a 5 L separable flask having a stirrer. To this solution, 1.4 g (0.07 mol) of water was added dropwise at -5 ° C. To this reaction solution, 180.0 g (2.50 mol) of TMAL was added, followed by heating at 50 ° C. for 1 hour. To this solution, 33.8 g (1.88 mol) of water was added at the same temperature. This reaction solution was further aged at 50 ° C. for 1 hour.
[0088]
The precipitated solid content was removed by filtration with a glass filter to obtain a modified methylaluminoxane solution. The yield of this solution based on Al atoms was 86%. Me / iBu ratio determined by gas chromatographic analysis of the hydrolyzed gas of the modified methylaluminoxane,¹Table 2 summarizes the molar fractions of unreacted TMAL and modified methylaluminoxane-derived methyl groups and unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR.
[0089]
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as described in Example 8 except that the modified methylaluminoxane obtained above was used. The solid catalyst contained 0.07 mmol Zr and 5.95 mmol Al per gram.
[0090]
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 770 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0091]
Comparative example 6
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as in Example 8 except that the commercially available modified methylaluminoxane hexane solution used in Comparative Example 1 was used. The solid catalyst contained 0.087 mmol Zr and 5.80 mmol Al per gram.
[0092]
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 357 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0093]
Comparative example 7
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as described in Example 8, except that a commercially available toluene solution of modified methylaluminoxane was used. Of the modified methylaluminoxane used here¹Table 2 summarizes the molar fractions of unreacted TMAL and modified methylaluminoxane-derived methyl groups and unreacted TIBAL and modified methylaluminoxane-derived isobutyl groups determined by 1 H-NMR. The resulting solid catalyst contained 0.080 mmol Zr and 4.80 mmol Al per gram.
[0094]
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 189 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0095]
Comparative example 8
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as described in Example 8 except that the commercially available polymethylaluminoxane used in Comparative Example 3 was used. The solid catalyst contained 0.068 mmol Zr and 4.56 mmol Al per gram.
[0096]
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 323 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0097]
Comparative example 9
(2) Preparation of silica supported catalyst
A solid catalyst was prepared in the same manner as in Example 8, except that concentrated PMAO prepared by concentrating the commercially available polymethylaluminoxane used in Comparative Example 3 under reduced pressure was used. Of the concentrated polymethylaluminoxane used at this time¹The molar fractions of unreacted TMAL and polymethylaluminoxane-derived methyl groups determined by 1 H-NMR measurement were Me (PMAO) 68.7 mol% and Me (TMAL) 31.3 mol%, respectively. The solid catalyst contained 0.084 mmol Zr and 5.43 mmol Al per gram.
[0098]
(3) Evaluation of ethylene polymerization
Ethylene polymerization was carried out in the same manner as in the method described in Example 8, except that the solid catalyst prepared above was used. The ethylene polymerization activity at this time was 492 kg-PE / mol-Zr · atm · hr. At this time, adhesion of the polymer to the polymerization vessel wall and the stirring blade was not observed.
[0099]
[Table 2]

[0100]
【The invention's effect】
The modified methylaluminoxane preparation in the present invention contains a high proportion of aluminoxane-derived methyl groups and a low proportion of alkyl groups other than aluminoxane-derived methyl groups. An olefin polymerization catalyst prepared by combining this with a transition metal compound has a high polymerization activity and a stable activity.
[Brief description of the drawings]
FIG. 1 shows a modified methylaluminoxane preparation obtained according to the present invention.¹1 is an H-NMR chart.

Claims (8)

Formula (I)
R ¹ _m AlX _3-m (I)
(Wherein R ¹ represents a C2-C20 linear or branched alkyl group, alkenyl group, or aryl group hydrocarbon group, X represents a hydrogen atom, a halogen atom, an alkoxy group, or an allyloxy group, and 0 <m ≦ 3.)
A modified methylaluminoxane preparation prepared from an organoaluminum compound represented by the formula: The olefin polymerization co- catalyst having a molar fraction of methyl groups derived from the above is 65 mol% or more. In the modified methylaluminoxane preparation, the mole fraction of C2-C20 hydrocarbon groups derived from aluminoxane sites relative to the total number of moles of C2-C20 hydrocarbon groups and methyl groups present therein is 15 mol% or less. The olefin polymerization co- catalyst according to claim 1. The organoaluminum compound represented by the general formula (I) is at least one selected from triisobutylaluminum, tri-n-hexylaluminum and tri-n-octylaluminum. Cocatalyst for olefin polymerization.   4. The modified methylaluminoxane used in the olefin polymerization catalyst, which is a solid catalyst in which a transition metal compound and a modified methylaluminoxane preparation are supported on a fine particle carrier, according to any one of claims 1 to 3. An olefin polymerization catalyst which is a modified methylaluminoxane. The transition metal compound has the general formula (II)
MR ² R ³ R ⁴ R ⁵ (II)
(In the formula, M represents a transition metal element of titanium, zirconium or hafnium , and R ² , R ³ , R ⁴ and R ⁵ together represent an organic group having a cycloalkadienyl skeleton, an alkyl group, and an alkoxy group. And an aryloxy group, an alkylsilyl group, an alkylamide group, an alkylimide group, an alkylamino group, an alkylimino group, and a halogen atom.) catalyst. A process for producing a modified methylaluminoxane preparation according to any one of claims 1 to 5, comprising a compound of general formula (I)
R ¹ _m AlX _3-m (I)
(R ¹ represents a hydrocarbon group such as a C2-C20 linear or branched alkyl group, alkenyl group, or aryl group, X represents a hydrogen atom, a halogen atom, an alkoxy group, or an allyloxy group, and 0 <m ≦ 3)
A process for producing the modified methylaluminoxane preparation, wherein the addition of trimethylaluminum and the hydrolysis reaction after the addition are performed in multiple stages after hydrolysis of the organoaluminum compound represented by formula (1).   The method for preparing an olefin polymerization catalyst according to claim 5, wherein the particulate metal carrier is contacted with the modified methylaluminoxane preparation and then contacted with the transition metal compound.   An olefin polymerization method using a catalyst system comprising a transition metal compound and the modified methylaluminoxane according to any one of claims 1 to 3 or the solid catalyst according to claim 5.

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