JPS5812887B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel highly active catalyst for olefin polymerization.

A low-pressure method for producing polyethylene using a catalyst comprising an organomagnesium compound and a transition metal compound is described by K. It is already known in Ziegler's patent (Japanese Patent Publication No. 32-1
No. 546).

However, organomagnesium compounds themselves are not effectively used because they are insoluble in the inert hydrocarbon medium used in catalyst synthesis and polymerization reactions, and it has not been possible to achieve high activity.

As catalysts whose activity is enhanced by using organomagnesium compounds in a specific form, systems using organomagnesium halides, so-called complexes of Grignard reagents and ethers, or organomagnesium alkoxides are known. No. 47-40959, Japanese Unexamined Patent Publication No. 46-19274).

Although these catalysts have fairly high activity per transition metal atom, they are still insufficient in terms of residual halogens as catalysts capable of completely omitting the catalyst removal step in the polyethylene manufacturing process.

As a result of research on catalyst systems using organomagnesium, the present inventors found that a specific solid obtained by reacting a complex containing organomagnesium soluble in an inert hydrocarbon medium with a titanium or vanadium compound was used. It was discovered that an extremely excellent and highly active catalyst for olefin polymerization can be obtained by this method, and the present invention was completed.

That is, the present invention provides (i) the general formula MaMgβR'p,' R%
, r, S are 0 or a number larger than 0, and p + q +
r + s = mα + 2β, O < r + s / α
+β〈1,0, M is aluminum, zinc,
Boron, or a hydrogen atom, R1 and R2 are the same or different hydrocarbon groups having 1 to 10 carbon atoms,
, Y are the same or different groups, NR3R4, SR
5, R3 and R4 are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, and R5 is a group having 1 to 10 carbon atoms.
(11) a solid catalyst obtained by reacting a hydrocarbon-soluble complex containing an organomagnesium represented by (representing 10 hydrocarbon groups) with a titanium or vanadium compound containing at least one halogen atom; ;) This relates to an olefin polymerization catalyst comprising an organometallic compound.

The first feature of the present invention is that the catalyst efficiency is extremely high.

As is clear from the examples below, the catalyst efficiency is 200
00g polymer/solid component 17.1 hour/ethylene pressure (1 kg/cm3) or more can be reached, making it possible to completely omit the catalyst removal step.

In contrast, the efficiency of the catalysts disclosed in Japanese Patent Publication No. 47-40959 and Japanese Patent Application Laid-open No. 46-19274 is 10,000 or less, and the superiority of the catalyst of the present invention is clear.

A second feature of the present invention is that it is possible to produce a polymer with high molecular weight and high rigidity, particularly a polymer with a narrow molecular weight distribution and high impact strength.

The above characteristics of the present invention will be explained using Examples and Reference Examples described below.

In these examples, MI stands for melt index and A
According to STM D-1238, temperature 190°C, load 2.
This was measured under the condition of 16 kg.

FR means the quotient obtained by dividing the value measured at a temperature of 190° C. and a load of 2.16 kg by MI, and is one of the measures of molecular weight distribution, and the lower the value, the narrower the distribution.

As is clear from the comparison between Example 1 and Reference Example 1, when a solid catalyst is synthesized using only organomagnesium,
The performance is significantly inferior to that when the complex containing a hydrocarbon-soluble organomagnesium of the present invention is used.

When the solid catalyst of the present invention is used for polymerization, it is easy to control the molecular weight, and it is possible to produce polyethylene with a narrow molecular weight distribution.

Therefore, it is extremely advantageous for obtaining a polymer suitable for manufacturing large molded articles by injection molding.

General formula M (tMg
βR′pRAxry. (In the formula, α, β, p, q, r
, s, M, R1, R2 have the above meanings, and X1Y is N
(representing the groups R3R4 and SR5) will be explained.

The hydrocarbon group having 1 to 10 carbon atoms represented by R1 in the above formula is an alkyl group, and methyl, ethyl, proyl, phthyl, hexyl, and octyl groups are used.

1 to 1 carbon atoms represented by R2, R3, R4, R5
The hydrocarbon group of 0 is an alkyl group, a cycloalkyl group, or an allyl group, and for example, methyl, ethyl, proyl, butyl, amyl, hexyl, tesyl, cyclohexyl, phenyl group, etc. are preferably used.

The ratio β/α of magnesium to metal atom M is 0.5 to
10, preferably << is 1 to IO.

Relational expression of symbols α, β, p, q, r, s = p+q+r+s=
mα+2β indicates the stoichiometry between the valence of the metal atom and the substituent, and O < r+ s /α+β<1.0 means that the sum of X and Y is smaller than 0 and 1.0 with respect to the sum of metal atoms. Indicates that it is less than 0.

A particularly preferred range is 0.2 to 0.8.

These complexes are composed of organomagnesium compounds represented by the general formulas R1MgQ, R4Mg (R1 has the above-mentioned meaning and Q is a halogen), and organomagnesium compounds represented by the general formulas MR2m or MR2.
m, H (M, R2, m have the above-mentioned meanings) in an inert hydrocarbon medium such as hexane, heptane, cyclohexane, benzene, toluene, etc. at room temperature to 150 ° C. It is synthesized by reacting it with an imine, amine, mercabutane or dithio compound.

Furthermore, this complex has MgX2, R1Mg) (and MR2m
, MR2m-1H, or R1MgX, MgR' and R2
It can be synthesized by reaction with nMXm-n (in the formula, M, Rl, R2, and X are as described above, and n is a number from 0 to m).

The structure of the complex is not clear, but as mentioned above, organomagnesium compounds are insoluble in inert hydrocarbon media, whereas this complex is soluble, so a complex consisting of an organometallic component and a magnesium component is formed. and
Presumed to be a single complex or a mixture of complexes.

Titanium or vanadium compounds containing at least one halogen atom (component (ii)) include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, ethoxytitanium trichloride, propoxytitanium trichloride, and butoxytitanium trichloride. Single halides, oxyhalides, and alkoxyhalides of titanium and vanadium, such as titanium trichloride, dibutoxytitanium dichloride, tributoxytitanium monochloride, vanadium tetrachloride, vanadyl trichloride, monobutoxyvanadyl dichloride, dibutoxyvanadyl dichloride, etc. Or a mixture is used.

Preferred compounds are those containing three or more halogens, and titanium tetrahalide is particularly preferred.

The reaction of organomagnesium-containing complexes with titanium or vanadium compounds can be carried out using an inert reaction medium, aliphatic hydrocarbons such as hexane, heptane, aromatic hydrocarbons such as benzene, toluene, xylene, cyclohexyl, methylcyclohexane, etc. Among alicyclic hydrocarbons such as 1
It is carried out at temperatures up to 50°C, preferably at low temperatures below 50°C.

The reaction ratio of the two types of catalyst components is 0.05 to 50 mol, preferably 0.2 to 10 mol, especially 0.2 to 10 mol of the organomagnesium complex based on the sum of magnesium atoms and metal atoms per mol of titanium or vanadium compound. Preferably 0
．． A range of 5 to 5 moles is recommended to obtain high activity.

In order to achieve particularly good catalytic efficiency, the most preferred method is simultaneous addition, in which the two catalyst components are simultaneously introduced into the reaction zone and reacted.

The composition and structure of the solid catalyst obtained by the above reaction vary widely depending on the type of starting materials and reaction conditions, but are approximately within the following ranges.

The Ti+V/Mg molar ratio in the solid catalyst is 0.1 to 5, M/
Mg ratio is 0 to 2, X+Y/Ti+V ratio is 0.1 to 1.0
is within the range of

In addition, this solid catalyst has an extremely large specific surface area, and B. 50m2/g or more when measured using the E,T method40
It shows high values up to 0 m2/g.

It is also possible to further react the solid catalyst of the present invention with a halide such as aluminum, silicon, tin, titanium, vanadium, etc. to adjust particle characteristics, molecular weight, molecular weight distribution, etc. of the resulting polymer.

The organometallic compound is preferably a compound belonging to groups 1 to 2 of the periodic table, and in particular a complex containing an organoaluminium compound and an organomagnesium compound.

As the organic aluminum compound, the general formula AIR6jZ
3j (wherein R6 is a hydrocarbon group having 1 to 20 carbon atoms,
(2 is a group selected from hydrogen, halogen, alkoxy, allyloxy, and siloxy groups, and t is a number from 2 to 3) is used alone or as a mixture.

The hydrocarbon group having 1 to 20 carbon atoms represented by R6 in the above formula includes aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons.

Specific examples of these compounds include triethylaluminum, trinormalpropylaluminum,
triisoglobilaluminum, trin-butylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, tridodecylaluminum, trihexadecylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum ethoxide, Recommended are diisobutylaluminum ethoxide, dioctylaluminum butoxide, diisobutylaluminum octyloxide, diethylaluminum chloride, diisobutylaluminum chloride, dimethylhydroxyaluminum dimethyl, ethylmethylhydroxyaluminum diethyl, ethyldimethylsiloxyaluminum diethyl, etc., and mixtures thereof.

Highly active catalysts can be obtained by combining these alkylaluminum compounds with the hydrocarbon-insoluble solids, and trialkylaluminum and dialkyl aluminum hydride are particularly preferred because they achieve the highest activity.

When a negative group 2 is introduced into trialkyl aluminum or dialkyl aluminum hydride, the activity tends to decrease, but each exhibits characteristic polymerization behavior and it is possible to produce useful polymers with high activity. .

For example, the molecular weight can be easily controlled by introducing an alkoxy group.

As the negative group, an alkoxy group or a siloxy group is preferable from the viewpoint of reducing halogen in the polymerization process and in the polymer.

The complex containing organomagnesium is a complex represented by the general formula MCtMgβR1,R2,XrY8 in (i).

α, β, p, q, r, s, M, R', R2
As already mentioned, X and Y are NR3R',
In addition to the group SR5, hydrogen, alkoxy, alioxy,
It represents a siloxy group, and β/α is 0.1 to 10.

Particularly preferred are complexes in which M is aluminum.

The solid catalyst component and the organometallic compound may be added DO into the polymerization system under polymerization conditions, or may be combined in advance prior to polymerization.

The ratio of the two components to be combined is preferably in the range of 1 to 3000 mmol of the organometallic compound per 1 g of the solid catalyst.

Olefins that can be polymerized using the catalysts of the invention are alpha olefins, especially ethylene.

Further, the catalyst of the present invention can be polymerized in the coexistence of monoolefins such as propylene, butene-1, and hexene-1, and dienes such as butadiene and isoprene, and can also be used to efficiently polymerize propylene. .

As the polymerization method, usual suspension polymerization, solution polymerization, and gas phase polymerization are possible.

In the case of suspension polymerization or solution polymerization, the catalyst is a polymerization solvent, such as an aliphatic hydrocarbon such as hexane or heptane, an aromatic hydrocarbon such as benzene, toluene, or xylene, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane. At the same time, 1 ethylene was introduced into the reactor under an inert atmosphere.
The polymerization can be carried out at a pressure of ~20 kg/cm3 at room temperature to 150°C.

On the other hand, in gas phase polymerization, ethylene is mixed at a pressure of 1 to 50 kg/cm2 at a temperature of room temperature to 120°C using a fluidized bed, a moving bed, or a stirrer to ensure good contact between ethylene and the catalyst. It is possible to carry out polymerization using the following methods.

The polymerization may be carried out in a single-stage polymerization using one reaction zone, or it may be carried out in a so-called multi-stage polymerization using a plurality of reaction zones.

By performing polymerization under two or more different reaction conditions, it is possible to produce polymers with a wider molecular weight distribution,
It is extremely well suited for products formed by blow molding or film molding.

Furthermore, in order to adjust the molecular weight of the polymer, it is also possible to add hydrogen, halogenated hydrocarbons, or polar metal compounds that tend to undergo chain transfer.

Furthermore, it is also possible to carry out the polymerization by combining methods such as adding a titanate ester to adjust the density.

Examples of the present invention are shown below, but the present invention is not limited to these Examples in any way.

In addition, MI and FR in the examples have the above-mentioned meanings, and the catalyst efficiency is as follows: solid component 17, 1 hour, ethylene pressure 1 kg/
It is expressed in g of polymer production per cm2.

Example 1 (1) Synthesis of hydrocarbon-soluble organometallic complex Di-n-butylmagnesium 13.80f and triethylaluminum 2
．． 85? and 100ml of hexane and 200ml of
The composition AIMg4(C2H5)3 (n-C4H9) was obtained by reacting at 80°C for 2 hours.
A complex of s was synthesized.

The flask was cooled to 10°C, and a hexane solution containing 40 mmol of diethylamine was added dropwise over 30 minutes.The reaction solution was then transferred to a pressure vessel and reacted at 100°C for 5 hours.

As a result of analysis, the composition of this complex is AIMg4((C2H5)2)1.51(C2H5
) 2.11 (n-C4H9) 7.38.

(11) Synthesis of solid catalyst Oxygen and moisture inside a 500 rug flask equipped with two dropping funnels were removed by dry nitrogen substitution, 160 ml of hexane was added, and the flask was cooled to 0°C.

Next, 80 ml of the above complex solution and 40 mmol of titanium tetrachloride
80 ml of a hexane solution containing the above was weighed into each dropping funnel, and both components were added simultaneously over 1 hour while stirring at 0°C, and the reaction was further allowed to proceed at this temperature for 3 hours.

The resulting hydrocarbon-insoluble solid was isolated, washed with hexane and dried to obtain 11.6 g of solid catalyst.

(Put the solid catalyst 5rn9 synthesized in (11) and 0.4 mmol of triethylaluminum together with dehydrated and deaired hexane O.SZ into a 1.513 autoclave whose interior was vacuum degassed and replaced with nitrogen. Ta.

Keep the internal temperature of the autoclave at 85℃ and store 16kg of hydrogen.
/cm2, ethylene was pressurized to a pressure of 2.4 kg/cm2, and the total pressure was 4.7 kg/cm2 gauge pressure.

By replenishing ethylene, the total pressure is increased to 4.7 kg/cm.
Polymerization was carried out for 1 hour while maintaining the pressure at a gauge pressure of 2, to obtain a polymer of 3427.

Catalyst efficiency was 28,500, MI was 4.5, and FR was 28.

Example 2 (i) Synthesis of hydrocarbon-soluble organometallic complex In the same manner as in Example 1, (n-CaH7)Al('811c3H,7
) 2 and Mg(n-C4H9)2, the composition AI
Mg2(Sn-C3H7)2(n C3H7)(
A complex of nC4H9)2 was synthesized.

(i1) Synthesis of solid catalyst The complex synthesized in (1) and titanium tetrachloride were reacted at a molar ratio of 1:1 at -10°C for 4 hours in the same manner as in Example 1 to obtain a hydrocarbon-insoluble solid catalyst. .

(11) Polymerization Using 5 mg of the solid catalyst synthesized in (11) and 0.4 mmol of diisobutylaluminum hydride, Example 1
Polymerization was carried out in the same manner as above to obtain polymer 2451.

Catalyst efficiency was 20,400, MI was 3.2, and FR was 33.

Reference Example 1 Same as Example 1 except that di-n-butylmagnesium was used instead of the organomagnesium-containing complex, slurried in a flask, and titanium tetrachloride solution was added from the dropping funnel. Catalyst synthesis and polymerization were performed to obtain 25 g of polymer.

The catalyst efficiency was 2100. Examples 3 to 12 Complex synthesis, solid catalyst synthesis, and polymerization were carried out in the same manner as in Example 1, and the results shown in Table 1 were obtained.

The solid catalyst was synthesized using the compounds and conditions shown in Table 1.

Example 13 Polymerization was carried out using the same catalyst and the same conditions as in Example 1, except that an ethylene-propylene mixed gas containing 4% propylene was used instead of ethylene, and a polymer of 3757 was obtained.

Catalyst efficiency was 31,000, MI was 9.8, and R was 25.

Example 14 Polymerization was carried out using the same catalyst and conditions as in Example 1, except that an ethylene-butene-1 mixed gas containing 1% of buene-1 was used instead of ethylene, and a polymer of 3207 was obtained.

Catalyst efficiency was 26,600, MI was 6.9, and R was 27.

Claims (1)

[Claims] 1(1) General formula MCtMgβRbR4XrY8 (wherein,
α, β are numbers larger than 0, β/α is 0.5 to 10, p, q1r, s are numbers larger than 0 or O, p+
q + r 10s = mα+2β, O<r+s/α+
β has a relationship of 1.0, M is an aluminum, zinc, boron, or beryllium atom, R1 and R2 are the same or different hydrocarbon groups having 1 to 10 carbon atoms, and X and Y are the same or different. NR3R', SR5, R3 and R4 are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R5 is a hydrocarbon group having 1 to 10 carbon atoms) A catalyst for olefin polymerization comprising: (i1) a solid catalyst obtained by reacting a hydrocarbon-soluble complex containing magnesium with a titanium or vanadium compound containing at least one halogen atom; and (i) an organometallic compound. 2. The catalyst for olefin polymerization according to claim 1, wherein the β/α ratio is from 1 to 10. 3 The ratio of rt-37a+β is 0. 2 ~ 0. 8. The catalyst for olefin polymerization according to claim 1 or 2 of claim 1, which is 4 (Claim 1 in which the titanium or halogen compound of iD is a compound containing 34 g of halogen)
The catalyst for olefin polymerization according to items 1 to 3. 5. The catalyst for olefin polymerization according to claims 1 to 3, wherein the titanium or halogen compound in (it) is titanium tetrachloride. 6 The organometallic compound has the general formula AIRZ3-t (wherein, R6 is a hydrocarbon group having 1 to 20 carbon atoms, 2 is hydrogen,
The olefin according to claims 1 to 5, which is an organoaluminum compound represented by a group selected from halogen, alkoxy, alioxy, and siloxy groups, and t is a number from 2 to 3. Polymerization catalyst. 7. The catalyst for olefin polymerization according to claim 6, wherein the aluminum compound is trialkylaluminum or dialkylaluminum hydride.