JPS641479B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to solid complexes for olefin polymerization. Specifically, the present invention relates to a solid complex suitable for advantageously producing a polyolefin having a high bulk density and good fluidity during molding, and a method for producing the same. In recent years, with the development of applications for polyolefins and the progress of processing technology, polyolefins with high molecular weight (low melt index) and good fluidity during molding have become particularly suitable for molding, for example, blow molded products. requested. However, polyolefins obtained using conventionally known Ziegler catalysts, such as polymerization catalyst systems consisting of organoaluminum compounds and transition metal compounds such as titanium or vanadium, generally have poor fluidity during molding under high loads. This is not sufficient and has the drawback of causing melt fractures on the skin of the molded product. As a result of intensive research in order to obtain a polyolefin that does not have such drawbacks, the present inventors have produced a new solid complex as a transition metal compound, and by using this complex, it has a high bulk density and can be used even in the high molecular weight region. The present inventors have discovered that it is possible to obtain a polyolefin that exhibits good fluidity and excellent processability, and has completed the present invention. That is, the present invention has the following features: 1 General formula, [Mgp・Tiq・Vr]Xa・nY (in the formula,
X is a halogen atom, Y is an ether, p+
q+r=1, 0.17<p/q+r<20, 5.5<
r/q<57, 2<a≦3, 1≦n≦3. )
A solid complex represented by Mg atoms, Ti atoms, V atoms, halogen atoms, and ether molecules. 2 By co-precipitating from an ether solution containing a halogenated magnesium ether complex, a halogenated titanium ether complex, and a halogenated vanadium ether complex, the general formula [Mgp・Tiq・Vr]Xa・nY (wherein, X is a halogen Atom, Y indicates ether, p+q+r
=1, 0<P/q+r<50, 3<r/q<70,
2<a≦3, 1≦n≦3. ) A method for producing a solid complex composed of Mg atoms, Ti atoms, V atoms, halogen atoms, and ether molecules. It is. To explain the present invention in detail, the novel complex of the present invention has the general formula [Mgp・Tiq・Vr]Xa・
Mg atom, Ti atom, V atom, represented by nY,
A solid complex composed of a halogen atom and an ether molecule can be easily prepared by co-precipitation from an ether solution containing a halogenated magnesium ether complex, a halogenated titanium ether complex, and a halogenated vanadium ether complex. It can also be prepared by a method in which magnesium halide, titanium halide, and vanadium halide are mixed and then subjected to ether complexation to co-precipitate, or by a method in which mixing and ether complexation are simultaneously carried out to co-precipitate. can. Each of the ether complexes used in the method of the present invention, that is, the halogenated magnesium ether complex, the halogenated titanium ether complex, and the halogenated vanadium ether complex, can be prepared using the method described in the literature (J. Inorg. Nucl. Chem., 24 ( 1962) 1105 and
It can be prepared according to Nat. Urwissenschaften, 46 (1959) 171). That is, for example, titanium trihalide is mixed with excess ether and dissolved or extracted under reflux to prepare an ether solution of an ether complex of titanium trihalide. A 2-ether complex of titanium trihalide can be prepared by adding a 3-ether complex or a hydrocarbon solvent such as n-hexane to the 3-ether complex.
In addition, 3-ether complex of titanium trihalide
A 1-ether complex of titanium trihalide can be obtained by heat treatment at a temperature range of 75 to 150°C. Of course, by changing the heat treatment conditions, it is also possible to prepare a solid complex in which a portion of the 3-ether complex or 2-ether complex remains. Methods for co-precipitating the desired solid complex from the ether solution containing each ether complex prepared by the above method include a method of cooling the ether solution, a method of removing the ether by evaporation, or a method of using a hydrocarbon solvent. A method such as adding a poor solvent can be adopted. In this case as well, the coordination number of the complex can be changed by changing the conditions, as described when preparing each ether complex. The ether used in preparing the solid complex of the present invention consisting of Mg atoms, Ti atoms, V atoms, halogen atoms and ether molecules can be used as a complexing agent for halides of magnesium, titanium or vanadium, and Any solvent may be used as long as it acts as a solvent for the ether complex, and examples thereof include aliphatic ethers, alicyclic ethers, and aromatic ethers. Particularly advantageous are aliphatic ethers such as diethyl ether, diisopropyl ether, dibutyl ether, diamyl ether, and ethyl-n-butyl ether, and alicyclic ethers such as tetrahydrofuran and dioxane. The general formula thus obtained, [Mgp・Tiq・Vr]
When the solid complex represented by Xa·nY is used as a catalyst for olefin polymerization, it is possible to advantageously produce a polyolefin having high polymerization activity, high bulk density, and a wide molecular weight distribution with good processability. However, its magnesium content is
As the molar ratio of Mg/Ti+V increases, the polymerization activity decreases, so as is clear from the examples, the magnesium content is selected from the range of 0.17≦Mg/Ti+V≦20. Furthermore, as is clear from Comparative Examples 5 and 6 described later, when the V/Ti molar ratio is smaller or larger than 3, it is not possible to obtain a polyolefin with a wide molecular weight distribution, which is the objective of the present invention. As is clear from the examples, the content of vanadium and vanadium is selected from the range of 5.5≦V/Ti≦57. On the other hand, the organoaluminum compounds used as the second catalyst component include dialkylaluminum monohalides such as diethylaluminum monochloride, alkylaluminum sesquihalides such as ethylaluminum sesquichloride, monoalkoxydialkylaluminums such as diethylaluminum monoethoxide, and triethylaluminum monohalides. Examples include aluminum, trialkylaluminum such as triisobutylaluminum, and trioctylaluminum. In particular, triethyaluminum and triisobutylaluminum are preferably used. The ratio of the solid complex of the present invention, which is the first catalyst component, and the organoaluminum compound, which is the second catalyst component, is 1 to 10 moles in terms of the number of moles of the second component per mole of transition metal in the first component. It is preferable to choose from a range. The olefin used in the polymerization reaction has the general formula R-CH=CH ₂ (wherein, R represents a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, and R may have a substituent. ) is an α-olefin represented by the following. In particular, linear or branched α-olefins having 2 to 10 carbon atoms are preferred. Specifically, for example, ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-
1, octene-1, and the like. The polymerization reaction is carried out by bringing the catalyst and the olefin or olefin mixture into contact at a predetermined temperature and pressure in the presence or absence of an inert solvent. Inert solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane and isooctane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, aromatic hydrocarbons such as benzene and toluene, and others commonly used in polymerization reactions. Any solvent that can be used can be used. Polymerization temperature and pressure can be selected from a wide range, but usually the temperature is 30 to 150℃ and normal pressure to 100℃.
Performed at atmospheric pressure. At that time, by allowing hydrogen to exist in the polymerization reaction zone, the molecular weight of the resulting polymer can be adjusted as desired even when the polymerization temperature is low. As detailed above, the novel general formula of the present invention,
[Mgp・Tiq・Vr] A high bulk density is achieved by polymerizing olefins using a solid complex represented by Xa・nY, which is composed of Mg atoms, Ti atoms, V atoms, halogen atoms, and ether molecules. It is possible to obtain a polyolefin with high efficiency, which has the following properties and has good processability in a high molecular weight region.
Furthermore, the obtained polyolefin has a wide molecular weight distribution, so it is suitable for blow molding, and the molded product has a smooth skin and an extremely good appearance. Furthermore, the wall thickness of the molded product can be advantageously controlled by adjusting the die swell during molding within a wide range of molecular weight distribution. The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In the examples, "flow rate ratio (hereinafter abbreviated as "FR")" was used as a measure representing the breadth of molecular weight distribution. FR is a value indicating the dependence of melt viscosity on shear stress, and is the ratio of melt index measured at shear stress of 10 ⁶ dyne/cm ² and 10 ⁵ dyne/cm ² , respectively, according to ASTM-D-1238-57T. It is expressed as The larger the value of FR, the broader the molecular weight distribution. Also, die swell is 190℃,
This is a relative representation of the degree of expansion of the extrudate when polyolefin is extruded from a constant nozzle at a constant shear rate. Production examples (a) to (c) (a) Preparation of magnesium chloride ether complex Using a Soxhlet extractor, 10 g of commercially available bulk anhydrous MgCl ₂ was added to dehydrated and deoxygenated tetrahydrofuran (hereinafter referred to as "THF") under an argon gas atmosphere. A reflux extraction operation was performed using 250 ml (omitted). about 20
After some time, almost no MgCl ₂ solids were visible. This extract was concentrated to about 100 ml, allowed to cool to room temperature, and then dried under a stream of dry nitrogen gas to obtain a white powdery solid. The chemical analysis values (% by weight) of the obtained solid were as follows.

[Table] (b) Preparation of titanium trichloride ether complex Using a Soxhlet extractor, 6 g of titanium trichloride (titanium tetrachloride reduced with hydrogen),
Extraction was carried out under reflux with 300 ml of dehydrated and deoxygenated THF. After about 10 hours, the titanium trichloride was almost completely dissolved and the THF phase became a thick purple-brown solution.
This was divided into two parts, and one part was left to cool overnight to obtain a blue crystalline solid. The obtained solid was washed with purified n-hexane and dried at room temperature under a stream of dry nitrogen to obtain a sky blue solid powder. The chemical analysis values (weight %) of the obtained solid were as follows.

[Table] About twice the amount of purified n-hexane was immediately added dropwise to the remaining THF solution while stirring, and the precipitate was further washed with n-hexane and dried at room temperature under nitrogen gas flow to form a yellow-green powder. I got it. The chemical analysis values (weight %) of the obtained solid were as follows.

[Table] _1.02g of the above TiCl 3.3THF was heat treated at 120℃ under dry nitrogen gas flow for 5 hours to produce a purple powder of 0.66g.
I got g. Chemical analysis values of the obtained solid (wt%)
was as follows.

[Table] (c) Preparation of vanadium trichloride ether complex.
500 ml of THF, 20 g of VCl ₃ and a small amount of polished magnesium ribbon particles were supplied. while stirring
After refluxing under boiling for 10 hours, undissolved substances were separated through a glass filter to obtain a reddish brown solution.
Distill THF from this solution to about half its volume.
The mixture was cooled to 0° C. with stirring. The precipitated red-orange fine particles were washed with purified n-hexane and then dried at room temperature under nitrogen gas flow. The chemical analysis values (weight %) of the obtained solid were as follows.

[Table] Example 1 (Production of a new solid complex and polymerization of olefin using the complex) MgCl ₂ 1.5THF prepared in Production Examples (a) to (c),
TiCl ₃・THF and VCl ₃・3THF respectively
Weigh out 3 mmol, 2.2 mmol and 15.7 mmol, 500
ml of THF was added and stirred to obtain a clear ether solution. A powdery solid complex was obtained from this ether solution by the method (a) below. (a) Evaporate THF under a stream of purified nitrogen at approximately 50°C,
A method of drying the precipitated solid powder under the same conditions. (b) Pour the ether solution containing the ether complex into the purified n-hexane in step 5, and add the resulting precipitate to the n-hexane.
Method of thoroughly washing with hexane and then drying at room temperature. Next, purified n-hexane 3 was charged into the autoclave No. 5, and 0.60 mmol of triisobutylaluminum (hereinafter abbreviated as "TIBA") and 50 mg of the above powdered solid complex were introduced. After heating to 90℃, 1.2
Hydrogen was introduced until the total pressure reached Kg/ ^cm2 , then the total pressure was
Polymerization was started by introducing ethylene until the amount reached 12.2 Kg/cm ² . Constant pressure polymerization was carried out for 2 hours while adding ethylene as needed to maintain a predetermined total pressure. The obtained polymer was in the form of a white powder with high bulk density. The results are shown in Table-1. Examples 2 to 9 and Comparative Examples 1 to 6 Each ether complex prepared in Production Examples (a) to (c) is shown in Table-
Weigh the amount shown in 1 and Table 2, and add 500ml to this.
of THF was added and stirred to obtain a clear ether solution. A powdery solid complex was obtained from this ether solution by the method (a) or (b) above. The polymerization was carried out at constant pressure for 2 hours in the same manner as in Example 1 under the polymerization conditions shown in Tables 1 and 2. The results are shown in Table-1 and Table-2. However, for Example 5, powder X-ray diffraction was measured for the obtained solid complex. The results are shown in FIG. For comparison, TiCl ₃・3THF,
Powder X-ray diffraction was similarly performed for MgCl ₂・1.5THF and VCl ₃・3THF, and the results were analyzed in the second
3 and 4. From these results, the X-ray diffraction diagram of the solid complex obtained in Example 5 shows that TiCl ₃ 3 THF, MgCl ₂ 1.5 THF, and
It can be seen that the main peaks of each complex seen in each figure of VCl _3.3THF have disappeared. Therefore, it is considered that the solid complex obtained in Example 5 is not just a mixture but a new complex.

【table】

【table】

【table】

[Table] Example 10 In Example 5, instead of 0.40 mmol of TIBA
Ethylene polymerization was carried out in the same manner as in Example 5 except that 0.40 mmol of TEA was used.
1080 g of polyethylene with MI=0.26 and FR=55 was obtained. The skin of the molded product was extremely smooth and the die swell was small. Example 11 In Example 7, instead of 0.70 mmol of TIBA,
Ethylene polymerization was carried out in the same manner as in Example 7 except that 1.0 mmol of diethylaluminum chloride was used, and 890 g of polyethylene with MI=0.26 and FR=72 was obtained. The skin of the molded product was extremely smooth.

[Brief explanation of drawings]

FIG. 1 is a powder X-ray diffraction diagram of the solid complex obtained in Example 5. FIG. 2 is a powder X-ray diffraction diagram of TiCl _3.3THF . Figure 3 shows _MgCl2・
It is a powder X-ray diffraction diagram of 1.5THF. Figure 4 shows
It is a powder X-ray diffraction diagram of VCl _3.3THF .

Claims (1)

[Claims] 1 General formula, [Mgp・Tiq・Vr]Xa・nY (in the formula,
X is a halogen atom, Y is an ether, p+q
+r=1, 0.17≦p/q+r≦20, 5.5≦r/q
≦57, 2<a≦3, 1≦n≦3. ), a solid complex composed of Mg atoms, Ti atoms, V atoms, halogen atoms, and ether molecules. 2 By co-precipitating from an ether solution containing a halogenated magnesium ether complex, a halogenated titanium ether complex, and a halogenated vanadium ether complex, the general formula [Mgp・Tiq・Vr]Xa・nY (wherein, X is a halogen Atom, Y indicates ether, p+q+r=
1, 0.17≦p/q+r≦20, 5.5≦r/q≦57,
2<a≦3, 1≦n≦3. ), expressed as
A method for producing a solid complex composed of Mg atoms, Ti atoms, V atoms, halogen atoms, and ether molecules.