JPS648004B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a high-performance catalyst component that acts with high activity when subjected to the polymerization of α-olefins and can obtain a stereoregular polymer in high yield. The compound, the aluminum alkoxide, and the electron donating substance are co-pulverized under pressure, the resulting solid composition is brought into contact with the titanium halide in a liquid phase or gas phase, and then washed with an inert organic solvent. The present invention relates to a method for producing a characteristic catalyst component for polymerizing α-olefins. Conventionally, solid titanium halides have been well known and widely used as catalyst components for the polymerization of α-olefins. ) was so low that a so-called deashing step was necessary to remove catalyst residues. Since this deashing process uses a large amount of alcohol or chelating agent, recovery equipment for these is indispensable, and there are many problems related to resources, energy, etc., which are important issues that those skilled in the art would like to solve as soon as possible. It was a challenge. In order to eliminate this complicated deashing process, many studies have been made and proposals have been made to increase the polymerization activity per titanium in the catalyst component, especially in the catalyst component. In particular, a recent trend is to support a transition metal compound such as titanium halide, which is an active ingredient, on a porous carrier material and expand its specific surface area. There are many proposals for dramatically increasing the polymerization activity per titanium component. Furthermore, various proposals have been made regarding the effects of improving the carrier material itself, devising a supporting method, and adding a third component. For example, according to JP-A-48-16986, JP-A No. 48-16987, and JP-A No. 48-16988, a complex of titanium halide and a specific electron-donating substance can be obtained by co-pulverizing a complex with magnesium halide. When the catalyst components obtained were subjected to the polymerization of α-olefins and the polymerization activity per titanium and the yield of stereoregular polymer were evaluated using the state of the art at the time, a considerable improvement was observed, but the catalyst The polymerization activity per titanium component has not reached a level where the demineralization step can be practically omitted, and the yield of stereoregular polymer has not yet reached a satisfactory level. In order to eliminate these drawbacks, JP-A-50-126590 discloses that a magnesium halide is brought into contact with a third component, an electron-donating substance, specifically an aromatic carboxylic acid ester, by mechanical means. discloses a method for obtaining a catalyst component by contacting the obtained solid composition with titanium tetrahalide in a liquid or gas phase. By using the catalyst component obtained by this method to polymerize α-olefins, the polymerization activity per titanium is increased to such an extent that there is almost no practical problem even if the deashing step is omitted. However, the yield of stereoregular polymers is not satisfactory, and it has not reached the level where it can be put to practical use industrially. Furthermore, as an improvement on the above-mentioned method, JP-A-52-87489 discloses that one metal compound selected from aluminum, tin, and germanium containing at least an organic group or a halogen and magnesium halide are used. A method in which pulverization is carried out in the presence of an organic acid ester has been proposed, and although this method is somewhat effective in terms of the polymerization activity per titanium and the yield of stereoregular polymer compared to the former method, the polymerization per catalyst component is When considering polymerization characteristics such as the yield of polymerization (hereinafter referred to as polymerization activity per catalyst component) and the yield of stereoregular polymers, it is found that the requirements of the increasingly sophisticated industry cannot be satisfied. However, there was still room for improvement. In addition to the catalyst components cited above, the present invention aims to improve the polymerization characteristics of this type of catalyst component, that is, the polymerization activity per catalyst component, the polymerization activity per titanium in the catalyst component, and the yield of stereoregular polymer in a well-balanced manner. This is an extremely difficult technical issue; for example, increasing the polymerization activity per titanium in order to remove titanium, which is the most avoided among the catalyst components remaining in the resulting polymer, will result in a reduction in the yield of stereoregular polymers. The general tendency is that the polymerization rate is sacrificed.Furthermore, looking at the problem of polymerization activity per catalyst component, in order to improve this value, it is necessary to increase the loading rate of titanium on the support material. Although this objective can be achieved to some extent, the yield of the stereoregular polymer decreases, and the polymerization activity per catalyst component does not necessarily improve in proportion to the increase in the amount of titanium supported.
Simply increasing the loading rate of titanium on the supporting material is insufficient to further increase the polymerization activity per catalyst component, and therefore it is necessary to selectively support titanium that is effective for polymerization activity per catalyst component. required. The present inventors have made a proposal based on their extensive research to solve the problems remaining in the prior art. That is, the feature of the present invention is that (a) the general formula
Magnesium halide represented by MgX ₂ (wherein X is a halogen element) and (b) general formula Al
(OR)mX ₃ -m (in the formula, R is an alkyl group or an aryl group, and one or two selected from gaseous olefins and inert gases.
(d) The solid composition obtained by co-pulverizing by mechanical means under pressure with at least one gas
Contact with a titanium halide represented by TiX ₄ (wherein X is a halogen element) in a liquid or gas phase, and then use an inert organic solvent until the presence of a halogen element is no longer recognized in the cleaning solution. After washing, the solid and liquid are separated and dried, or an appropriate amount of an inert organic solvent is added to form a slurry, which is used as it is as a catalyst component for the polymerization of α-olefins. According to the present invention, by co-pulverizing a magnesium halide, an aluminum alkoxide, and an electron-donating substance under pressure, the polymerization activity per catalyst component is obtained when the solid composition obtained is contacted with a titanium halide. This makes it possible to selectively support effective titanium in the catalyst, which increases the polymerization activity per titanium in the catalyst component without sacrificing the polymerization activity per catalyst component and the yield of stereoregular polymer. This will have the effect of increasing the amount by an astonishing amount. As a conventional trend in the technical field of a method for producing a supported catalyst component for polymerizing α-olefins,
Efforts have been made to further increase the loading of titanium, an active ingredient. However, as mentioned above, it is not necessarily the case that the polymerization activity per catalyst component increases in proportion to the amount of titanium supported; as a result, the polymerization activity per titanium supported in the catalyst component increases. As the titanium content increases,
In fact, it will tend to decline. Due to this fact, the titanium content in the produced polymer, which is said to have the most adverse effect on the produced polymer and is avoided, increases, resulting in the need for a complicated deashing process. For the above reasons, it is desirable that the titanium component contained in the catalyst component selectively support titanium that is effective for polymerization activity per catalyst component when subjected to polymerization, and as a result, the polymerization activity per titanium in the catalyst component increases. The so-called deashing step of removing titanium from the resulting polymer can be omitted. The present invention has been made with attention to these points, and as a result, the polymerization properties, especially the polymerization activity per titanium in the catalyst component, have been dramatically increased, and the yield of stereoregular polymers has also been improved. It was also effective in maintaining a high level of performance. The magnesium halide represented by the general formula MgX ₂ (wherein X is a halogen element) used in the present invention is anhydrous MgCl ₂ , MgBr ₂ ,
Among them, MgCl ₂ is preferable, such as MgI ₂ . General formula Al(OR) used in the present invention
Aluminum alkoxides represented by mX ₃ -m (in the formula, R is an alkyl group or an aryl group, X is a halogen element, and m is an integer of 1 to 3) are aluminum methoxide, aluminum ethoxide, aluminum isopropoxy Among them, aluminum isopropoxide is preferred. The electron-donating substance used in the present invention is selected from organic compounds containing at least one atom selected from oxygen, nitrogen, sulfur, and phosphorus atoms in its molecule, such as ether, ester,
Examples include ketones, amines, phosphines, phosphinamides, and the like. More specifically, aliphatic ethers such as diethyl ether, aromatic ethers such as anisole, aliphatic carboxylic acid esters such as ethyl acetate and methyl methacrylate, ethyl benzoate, methyl toluate, ethyl toluate,
Examples include aromatic carboxylic acid esters such as ethyl anisate and diethyl phthalate, ketones such as acetone, phosphines such as triphenylphosphine, and phosphinamides such as hexaphosphineamide. Among these, aromatic carboxylic acid esters are particularly preferred. The general formula TiX ₄ used in the present invention (in the formula
is a halogen element. Examples of the titanium halide represented by ) include TiCI ₄ , TiBr ₄ , TiI ₄ and the like, with TiCl ₄ being particularly preferred. Furthermore, it is not prohibited to use this titanium halide in the form of a complex with the above-mentioned electron donating substance. Examples of the inert organic solvent used in the present invention include saturated aliphatic and aromatic hydrocarbon compounds such as hexane, heptane, octane, cyclohexane, benzene, and toluene. It is desirable to use one that has been sufficiently dehydrated using Kyura sieves or the like. The ratio of each component to be used is arbitrary and not particularly limited as long as it does not adversely affect the performance of the catalyst component produced, but the aluminum alkoxide is usually 0.001 to 1 mole per mole of magnesium halide. , preferably 0.005-0.5
The electron-donating substance is used in an amount of 0.01 to 10 mol, preferably 0.05 to 1 mol. The method of contacting the magnesium halide with the aluminum alkoxide and the electron-donating substance in the present invention is carried out by mechanical treatment, but a conventional pulverizer capable of crushing the powder under pressure, such as a ball mill or a vibration mill, is used. , a tower-type mill, an impact mill, etc., may be selected arbitrarily. In the mechanical pulverization treatment of the present invention, each component, that is, the material to be processed, is sufficiently removed from moisture and air when charged, and then operated at normal pressure while being protected in an inert gas atmosphere such as nitrogen or argon. Pulverization treatment is carried out under pressure using one or more gases selected from olefins and inert gases. As the gaseous olefins, ethylene, propylene, 1-butene, 4-methylpentene-1, etc. are suitable. The inert gas may be arbitrarily selected from nitrogen, argon, carbon dioxide, helium, etc. as long as it does not adversely affect the production of the present catalyst component. The pressure during pressurization is not particularly limited, but is determined by the allowable pressure of the crusher, and is usually 1.
The preferred range is ~20 Kg/cm ² ·G. Although the pulverization treatment time naturally varies depending on the capacity of the pulverizer, it is usually preferable to carry out the treatment in a range of 0.5 to 100 hours. The temperature during the pulverization treatment is not particularly limited as long as the object to be treated can be pulverized, but is usually preferably 80° C. or lower. Furthermore, the order of contacting each component is also arbitrary, and can be freely selected to be added separately, simultaneously, or sequentially and dividedly. However, the timing of pressurization is at or after the time when each component has finally been added. The catalyst component of the present invention is obtained by contacting the thus obtained solid composition with a titanium halide in a liquid or gas phase to support titanium, and then washing with an inert organic solvent. The contact between the titanium halide and the magnesium halide treatment product, ie, the solid composition, is usually carried out at a temperature in the range of 20 to 100°C using a container equipped with a cooling device and equipped with a stirrer. The contact treatment time is arbitrary as long as the titanium in the titanium halide is sufficiently supported on the solid composition, but it is usually carried out for 0.5 to 10 hours. After the treatment, the resulting slurry composition is washed with an inert organic solvent. At this time, the time when halogen elements are no longer detected in the cleaning solution is considered to be the end of cleaning, and the solid and liquid are separated and dried.
Alternatively, an appropriate amount of an inert organic solvent may be further added to form a slurry, and the slurry may be used as it is as a catalyst component for polymerizing α-olefins in the present invention. These series of operations in the present invention are preferably carried out in the absence of oxygen, moisture, and the like. The catalyst component produced as described above has the general formula
AlRmX ₃ -m (in the formula, R is hydrogen or has 1 to 10 carbon atoms)
is an alkyl group, X is a halogen element, and m is an integer of 1 to 3. ) to form a catalyst for polymerizing α-olefins. The organoaluminum compound used is used in a weight ratio of 1 to 300, preferably 1 to 100, based on the titanium atomic weight of the catalyst component. Further, it is not prohibited to add a third component such as an aromatic carboxylic acid ester during the polymerization. The polymerization process can be carried out either in the presence of an inert organic solvent or in the presence of a liquid olefin monomer. The polymerization temperature is 200°C or less, preferably 100°C or less, and the polymerization pressure is 100Kg/cm ² ·G or less, preferably 50Kg/cm ² ·G or less. Olefins that can be polymerized singly or copolymerized using the catalyst component produced by the method of the present invention include ethylene, propylene, 1-butene, 4-methyl-pentene-1, and the like. The present invention will be specifically explained below using Examples and Comparative Examples. Example 1 [Preparation of catalyst component] 30 g of commercially available anhydrous magnesium chloride and 1.2 g of aluminum isopropoxide were mixed with 15 g of aluminum isopropoxide in a nitrogen atmosphere.
A stainless steel ball of mmφ was charged into a vibrating mill pot with a capacity of 1.2 filled with 3/5 of the total volume, and the vibration frequency was
Grinding was carried out for 1 hour at 1430 v.pm and a shaking width of 3.5 mm. After grinding, add ethyl benzoate while maintaining nitrogen atmosphere.
After charging 9.5 g of the vibrating mill pot with propylene gas and sealing it under pressure until the internal pressure of the vibrating mill pot reached 5 kg/cm ² ·G, the mill pot was further pulverized for 17 hours under the same conditions. Incidentally, all of these pulverization treatments were performed at room temperature. TiCl ₄ 50 in a 200 ml round bottom flask with a cooling device, well purged with nitrogen gas and equipped with a stirrer.
ml and the solid composition obtained by the pulverization process.
10 g was charged, and a stirring reaction was carried out at 65° C. for 2 hours. After the reaction was completed, the mixture was cooled to room temperature, left to stand, and the supernatant liquid was removed by decantation. Next, wash with 100ml of dehydrated normal heptane repeatedly.
When chlorine was no longer detected in the cleaning solution, the cleaning was completed and the catalyst component was used. At this time, when the solid and liquid in the catalyst component was separated and the titanium content in the solid was measured, it was found to be 1.37% by weight. [Polymerization] Dehydrated n-heptane in an autoclave with an internal volume of 1.5 and a stirring device completely purged with nitrogen gas.
500 ml of the reactor was charged, and while maintaining a nitrogen gas atmosphere, 20 mg of triethylaluminum was charged, followed by 1.01 mg of the catalyst component as titanium atoms. After that, the temperature was raised to 60℃ and propylene gas was introduced, and the temperature was increased to 4Kg/cm ² .
Propylene polymerization was carried out for 2 hours while maintaining the pressure of G. After the polymerization was completed, the obtained solid polymer was filtered, heated to 80°C, and dried under reduced pressure. On the other hand, the liquid was concentrated to obtain a polymer soluble in the polymerization solvent. Let the amount of polymer dissolved in the polymerization solvent be (A), and the amount of solid polymer be (B). In addition, the obtained solid polymer was extracted with boiling normal heptane for 6 hours to obtain a polymer insoluble in normal heptane.
Let this amount be (C). Polymerization activity (D) per catalyst component is calculated using the formula (D) = [(A) + (B)] (g) / amount of catalyst component (
g) Polymerization activity (E) per titanium in the catalyst component, expressed as
is expressed by the formula (E)=(D)/titanium content ratio in the catalyst component, and the yield (F) of the crystalline polymer is expressed by the formula (F)=(C)/(B)×100(%). Further, the total crystalline polymer yield (stereoregular polymer yield) (G) was determined from the formula (G)=(C)/(A)+(B)×100(%). The results obtained are shown in Table 1. Example 2 A catalyst component was prepared in the same manner as in Example 1, except that the pulverization time after addition of ethyl benzoate was changed to 27 hours. Incidentally, the titanium content of the solid component at this time was 1.30% by weight. During the polymerization, 0.92 mg of the obtained catalyst component as titanium atoms was charged, and the experiment was carried out in the same manner as in Example 1. The results obtained are shown in Table 1. Example 3 A catalyst component was prepared in the same manner as in Example 2, except that the pressure applied by propylene gas was changed to 2 kg/cm ² ·G. Incidentally, the titanium content of the solid component at this time was 1.51% by weight. During the polymerization, 1.08 mg of the obtained catalyst component was charged as titanium atoms, and an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Example 4 A catalyst component was prepared in the same manner as in Example 1, except that ethylene gas was used instead of propylene gas for pressurization. Incidentally, the titanium content of the solid component at this time was 1.35% by weight. During the polymerization, 0.89 mg of the obtained catalyst component was charged as titanium atoms, and an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Comparative Example 1 A catalyst component was prepared in the same manner as in Example 1, except that pressurization with propylene gas was not performed. In addition, the titanium content of the solid component at this time was 1.71
It was in weight%. During polymerization, 1.30 mg of the obtained catalyst component as titanium atoms was charged, and an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1. Comparative Example 2 A catalyst component was prepared in the same manner as in Example 1 except that aluminum isopropoxide was not added. In addition, the titanium content of the solid component at this time is
It was 1.04% by weight. During the polymerization, 0.76 mg of the obtained catalyst component as titanium atoms was charged, and an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1.

【table】

[Table] As is clear from Table 1, magnesium halide, which is a carrier material, is co-pulverized with an aluminum alkoxide and an electron-donating substance under pressure using propylene gas, etc. When α-olefins were polymerized using the catalyst component prepared by the method of the present invention in which the solid composition was brought into contact with titanium tetrahalide and then washed with an inert organic solvent, the polymerization characteristic values were In particular, the polymerization activity per titanium in the catalyst component is significantly improved. Furthermore, it is particularly noteworthy that the polymerization activity per catalyst component and the yield of stereoregular polymer (yield of total crystalline polymer) are maintained at a high level. The reason for this is not clear, but when supporting titanium, the active ingredient, on magnesium halide, which is a carrier material, in the process of treating the magnesium halide with aluminum alkoxides and electron-donating substances, propylene gas etc. Therefore, by performing the pretreatment of the present invention method of pressurizing and co-pulverizing, it was possible to selectively support titanium, which is effective for polymerization activity per catalyst component, and as a result, the above-mentioned effects were obtained. It can be said that To be more specific, treating magnesium halides with aluminum alkoxides and further with electron-donating substances contributes to maintaining the yield of stereoregular polymers at a high level. , by pulverizing the treatment process by mechanical means under pressure with propylene gas, etc., titanium effective for polymerization activity per catalyst component is selectively supported upon contact with titanium tetrahalide. It is presumed that this was achieved. That is, when magnesium halide, which is a carrier material, is treated with an aluminum alkoxide and an electron-donating substance, it is denatured by crushing under pressure with propylene gas, etc., and the polymerization activity per catalyst component is modified. It was able to selectively support effective titanium, and due to its synergistic effect, the desired target polymerization activity per catalyst component and the yield of stereoregular polymer were maintained at a high level, while the catalyst component It has a surprisingly high polymerization activity per titanium content, and is expected to be a highly practical catalyst component industrially.

[Brief explanation of the drawing]

FIG. 1 is a flow chart for explaining the present invention.

Claims (1)

[Claims] 1 (a) a magnesium halide represented by the general formula MgX ₁ (wherein X is a halogen element);
(b) Aluminum alkoxides represented by the general formula Al(OR) _n X _1-n (wherein R is an alkyl group or an aryl group, c) aromatic carboxylic acid ester;
Co-pulverization is carried out by mechanical means under pressure with one or more gases selected from gaseous olefins and inert gases, and the resulting solid composition is (d) with the general formula TiX ₄ (in the formula 1. A method for producing a catalyst component for polymerizing α-olefins, which comprises contacting titanium halide represented by (X is a halogen element) in a liquid phase or gas phase, and then washing with an inert organic solvent.