JPS584929B2 - Polymerization method of α-olefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for polymerizing ethylene and copolymerizing ethylene with other olefins.

More specifically, the present invention relates to a novel method for low-pressure polymerization of ethylene using a catalyst synthesized using a novel compound, an organic boron-magnesium complex.

A low-pressure method for producing polyethylene using a catalyst consisting of an organomagnesium compound and a transition metal compound is described by K. It is already known in Ziegler's patent (Japanese Patent Publication No. 32-15
No. 46).

However, since organomagnesium compounds themselves are insoluble in the inert hydrocarbon medium used in catalyst synthesis and polymerization reactions, they are not used effectively and have not succeeded in obtaining high activity.

Furthermore, it is well known to those skilled in the art that organic boron compounds do not form ethylene polymerization catalysts even when reacted with transition metal compounds.

As catalysts whose activity is enhanced by using organomagnesium compounds in specific forms, systems using organomagnesium halides, so-called complexes of Grignard reagents and ethers, or organomagnesium alkoxides are known.

(Special Publication No. 47-40959, Japanese Patent Publication No. 46-19274
issue).

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

As a result of intensive research on catalyst systems using organomagnesium compounds, the present inventors discovered that a catalyst system soluble in an inert hydrocarbon medium was synthesized by reacting a specific organomagnesium compound and an organoboron compound under specific conditions. The present inventors have discovered that an extremely highly active catalyst can be obtained by combining a specific solid component obtained by reacting an organoboron monomagnesium complex with a titanium or vanadium compound with an organoaluminium compound, leading to the present invention. .

That is, the present invention provides IAl(I) general formula BQ! MgβR1pR2q [In the formula, α and β are numbers larger than 1, β/α is 0.5 to 10
, p and q are 0 or a number larger than 0, and p+q
=3α+2β, and Rl and R2 represent the same or different hydrocarbon groups having 1 to 10 carbon atoms. R3 and R4 are hydrogen or have 1 to 10 carbon atoms
A hydrocarbon-insoluble compound produced by reacting a reaction product with a chain or cyclic siloxane compound having a hydrocarbon group with a titanium or vanadium compound containing at least one halogen atom. General formula klR5m Z3 -m [In the formula, R5 is a hydrocarbon group having 1 to 20 carbon atoms, Z is a group selected from hydrogen, halogen, alkoxy, allyloxy or siloxy group, and m is 2 to α-, which is characterized in that ethylene or ethylene and other olefins are polymerized using a catalyst obtained by reacting an organoaluminum compound represented by
This relates to a method for polymerizing olefins.

As stated above, the present invention provides a novel catalytic process for the polymerization of ethylene using a novel organoboron-magnesium complex as one component.

The first feature of the present invention is that it has an extremely high catalytic effect.

As is clear from the examples below, the catalyst efficiency is 200
00 g of polyethylene/1 g of solid component per hour/ethylene pressure (1~) 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.

The second feature of the present invention is that it is possible to produce an excellent polymer with high molecular weight and high rigidity, and furthermore, by modifying the catalyst component, the molecular weight and molecular weight spectroscopy can be easily controlled.

These performances of the present invention are exhibited by reacting a hydrocarbon-insoluble solid obtained by the reaction of a novel organoboron monomagnesium complex with a specific titanium or panadium compound with a specific organoaluminum compound, but in particular, The key component is a hydrocarbon soluble organoboron monomagnesium complex.

The present inventors have already filed a patent application for a method for polymerizing olefin using an organoaluminum or organozinc-organomagnesium complex.

However, the organoaluminium and organozinc compounds that are the constituent components of these complexes have high reactivity with titanium or vanadium compounds, and therefore participate in the solid-forming reaction.

In contrast, in the complex of the present invention, the reactivity of the organic boron compound with the titanium or vanadium compound is extremely low;
The reaction proceeds substantially due to the magnesium component.

Therefore, compared to the complexes of the prior applications, the complexes of the present invention show significantly less variation in catalyst performance due to composition, which is an extremely significant advantage when producing on an industrial scale.

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

In these examples, Mw indicates the weight average molecular weight, and Mw indicates the number average molecular weight, which were measured by gel permeation chromatography (GPC).

Moreover, the ratio Mw/Mn of weight average molecular weight and number average molecular weight is
It is one of the measures of molecular weight distribution, and the lower the value, the narrower the molecular weight distribution.

As is clear from the comparison between Example 1 and Comparative Example 1, when a solid titanium compound is synthesized using only organomagnesium, the reaction between the hydrocarbon-soluble organoboron monomagnesium complex of the present invention and a siloxane compound is The performance is significantly inferior to that using a material.

The complex of the present invention modified by reacting with a siloxane compound has substantially the same solubility in a hydrocarbon medium as the complex before modification.

When this is used for the synthesis of the hydrocarbon-insoluble reaction product (A), it is easy to control the molecular weight during polymerization (easy to produce polyethylene with a low molecular weight), and it is possible to produce polyethylene with a narrow molecular weight distribution.

Therefore, a polymer suitable for manufacturing large molded articles by injection molding is obtained.

General formula used in the catalyst of the present invention: BQMgA1pR”
q [in the formula, α, β, p, qs Rlt R2 represent the above-mentioned meanings] (1) 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, propyl, butyl, hexyl, and octyl groups are used.

The hydrocarbon group having 1 to 10 carbon atoms represented by R2 is an alkyl group, a cycloalkyl group, or an allyl group, such as methyl, ethyl, propyl, butyl, amyl, hexyl, decyl, cyclohexyl, phenyl. Basics etc. are used profusely.

The ratio β7 of magnesium to boron is 0.5 to 10
, preferably from 1 to 10.

The % formula p+q=3α+2β for the symbols α, β, p, and q indicates the stoichiometry between the valence of the metal atom and the substituent.

This complex consists of an organic boron compound represented by the general formula BRA or BR↓Hl' is the above-mentioned hydrocarbon group] and a general formula R
An organomagnesium compound represented by 2MgQ, MgR [R2 is the above-mentioned hydrocarbon group, Q is a halogen] in an inert hydrocarbon medium such as hexane, heptane, cyclohexane, benzene, toluene, etc., at room temperature to 150°C. It can be synthesized by reacting at a temperature of

As the alkyl group bonded to boron, methyl, ethyl, and propyl groups are particularly preferred in that they readily provide hydrocarbon-soluble complexes.

The structure of this complex is not clear, but as mentioned above, Mg
Since Ri is insoluble in an inert hydrocarbon medium, but this complex is soluble, a complex consisting of a boron component and a magnesium component is formed, and it is presumed to be a single complex or a complex mixture.

Next, the general formula used for the reaction with the complex The siloxane compound (11) will be explained.

The substituents represented by R3 and R4 are hydrogen or a hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, octyl, cyclohexyl, phenyl, etc. group is recommended.

These compounds can be used in the form of dimeric or more chain or cyclic compounds comprising one or more types of structural units.

Specific compounds include, for example, symmetrical dihydrotetramethyldisiloxane, hexamethyldisiloxane, pentamethyltrihydrotrisiloxane, cyclic methylhydrotetrasiloxane, (methyl end-capped) polymethylhydrosiloxane, polydimethylsiloxane, ( Polyphenylhydrosiloxane (methyl end-capped), polymethylphenylsiloxane, etc. are used.

The reaction of the organoboron monomagnesium complex with the siloxane is carried out in an inert reaction medium (eg hexane, heptane, benzene, toluene) at a temperature of 0 to 150°C.

Although there are many unclear points regarding the reaction route and reaction products, the formation of Si-{)-Mg bonds and bonds is confirmed from infrared spectroscopy and magnetic resonance spectroscopy.

The reaction ratio is Si-0/Mg in the range of 0.3 to 5, preferably 0.5 to 2.

The ratio of Si-{)-Mg bonds and Mg atoms present in the complex is preferably 0.8 or less.

Next, titanium or vanadium compounds Oii) containing at least one halogen atom include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, ethoxytitanium trichloride, proboxytitanium trichloride, butoxytitanium trichloride, Dibutoxytitanium dichloride, tributoxytitanium monochloride, vanadium tetrachloride, vanadyl trichloride, monobutoxyvanadyl dichloride, dibutoxyvanadyl monochloride, and other halides, oxyhalides, and alkoxyhalides of titanium and vanadium are used alone or in mixtures. It will be done.

The reaction of the reactant of the organoboron monomagnesium complex with the siloxane and the titanium or vanadium compound can be carried out using an inert reaction medium such as an aliphatic hydrocarbon such as hexane, heptane, an aromatic hydrocarbon such as benzene, toluene, xylene, cyclohexane, etc. , in a cycloaliphatic hydrocarbon such as methylcyclohexane, at temperatures up to 150°C, preferably at low temperatures below 20°C.

The reaction ratio of the two types of catalyst components is 0.0 based on the magnesium atom of the reaction product of the organic boron monomagnesium complex and siloxane to 1 mol of the titanium or vanadium compound.
A range of 5 to 50 mol, especially 0.2 to 5 mol, is recommended to obtain high activity.

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

The hydrocarbon-insoluble reaction product obtained by the reaction can be used as is if the reaction is completed, but it is desirable to separate it from the reaction solution in order to improve the reproducibility of the polymerization.

As the organoaluminum compound (compound) which is another component of the catalyst of the present invention, compounds represented by the general formula AtR5mZ3-m are used alone or as a mixture.

The hydrocarbon group having 1 to 20 carbon atoms represented by R5 in the above formula includes aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons.

In addition, the group represented by Z represents hydrogen, a halogen atom, an alkoxy, allyloxy, or a siloxy group, and m
indicates a number of 2 to 3.

Specific examples of these compounds include triethylaluminum, trin-propylaluminum,
Tri-isopropyl aluminum tri-normal butyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum, tridecyl aluminum, tridodecyl aluminum, trihexadecyl aluminum diethylaluminium hydride, diisobutyl aluminum hydride, diethylaluminum ethoxide, diisobutyl aluminum Recommended ethoxides are dioctylaluminum butoxide, diisobutylaluminum octyloxide, diethylaluminum chloride, diisobutylaluminum chloride, dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminum diether, 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 Z is introduced into trialkyl aluminum or dialkyl aluminum hydride, the activity tends to decrease, but each exhibits characteristic polymerization behavior,
It is possible to produce useful polymers under high activity.

For example, by introducing an alkoxy group, the occurrence of scale within the polymerization vessel is reduced and molecular weight adjustment becomes easy.

The reaction between the catalyst component and the catalyst component of the present invention can be carried out in advance, prior to polymerization, by adding both catalyst components into the polymerization system and allowing the reaction to proceed simultaneously with the progress of polymerization under polymerization conditions. It's okay.

Further, the reaction ratio of the catalyst component is preferably in the range of 1 to 3,000 mmol of component (6) per 1 g of the prisoner component.

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 carbonization such as cyclohexane or methylcyclohexane. The polymerization can be carried out at a temperature of room temperature to 150° C. by introducing hydrogen and hydrogen into the reactor and pressurizing ethylene to 1 to 50° C. under an inert atmosphere.

On the other hand, in gas phase polymerization, ethylene is mixed using a fluidized bed, moving bed, or a stirrer to ensure good contact between the ethylene and the catalyst under conditions of a pressure of 1 to 50 °C and a temperature of room temperature to 120 °C. It is possible to carry out the polymerization by arranging various means.

Furthermore, in order to adjust the molecular weight of the polymer, it is also possible to add hydrogen, halogenated hydrocarbons, or organometallic compounds that are likely to cause chain transfer.

The catalyst of the present invention can also be used for polymerization in the coexistence of monoolefins such as propylene and butene-1-sexene-1, and for efficiently polymerizing propylene.

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

In addition, Mw, Mn, and Mw/Mn in the examples have the above-mentioned meanings, and the catalyst efficiency is expressed as the amount of polymer produced in g per 1 g of solid component, 1 hour, and 1 to 1 ethylene pressure.

Example 1 (1) Synthesis of organic boron monomagnesium complex 13.80 g of di-n-butylmagnesium and 163 g of triethylboron
g and 200 ml of n-heptane in a 500 ml flask and reacted at 50°C with stirring for 2 hours to obtain the composition BMg 6 (C2 H5 ) 3
A complex of (n C4 HQ)1 2 was synthesized.

60 ml of a heptane solution containing 50 m mo,l (based on magnesium atoms) of this complex is placed in a 200 ml flask, and 40 ml of a heptane solution containing 50 mmol of symmetrical dihydrotetramethyldisiloxane is mixed at O'C. Allowed time to react.

A portion of this solution was taken out, hydrolyzed, and the amount of gas generated was measured.

The analysis value revealed that the SiOMg/Mg of this complex was 0.15.

(2) Synthesis of hydrocarbon-insoluble solid components Oxygen and moisture inside a 500 ml flask equipped with two dropping funnels were removed by dry nitrogen substitution.
Add 60 ml of n-heptane and cool to 10°C.

Next, the above complex is 40 m m based on magnesium atoms.
80 ml of an n-heptane solution containing titanium tetrachloride and 80 ml of an n-heptane solution containing 40 mmol of titanium tetrachloride were weighed into each dropping funnel, and both components were added simultaneously over 1 hour while stirring at 10°C. , and further reacted at this temperature for 3 hours.

The resulting hydrocarbon-insoluble solid was isolated, washed with n-heptane and dried, yielding 10.5 g of solid.

(3) 5 mg of the hydrocarbon-insoluble solid synthesized in polymerization reaction (2) and 0.4 m mol of diethylaluminium hydride were mixed together with 0.8 liter of dehydrated and deaired n-heptane, and 1.5 t of the inside was vacuum degassed and replaced with nitrogen. was placed in an autoclave.

Keep the internal temperature of the autoclave at 85°C, and add hydrogen to 1.0
The mixture was pressurized to ˜gauge pressure, followed by the addition of ethylene to a pressure of 3.05˜gauge, bringing the total pressure to ˜4.0gauge.

Polymerization was carried out for 1 hour while maintaining the total pressure at 4.0 to 4.0 gauge pressure by replenishing ethylene to obtain 338 g of polymer.

Mw is 61000, Mw/Mn is 3.

4. Catalyst efficiency was 22,500.

Comparative Example 1 A catalyst was synthesized and polymerized in exactly the same manner as in Example 1, except that di-n-butylmagnesium was used instead of the organic boron monomagnesium complex, and 42 g of polymer was obtained.

Catalyst efficiency was 3500.

Examples 2 to 4 Organomagnesium complexes synthesized in the same manner as in Example 1 and siloxane compounds were reacted under the conditions shown in Table 1.

Subsequently, this reactant was reacted with titanium tetrachloride at a Mg/Ti molar ratio of 1/1 at 10° C. for 4 hours in the same manner as in Example 1 to synthesize a hydrocarbon-insoluble solid.

Polymerization was carried out in the same manner as in Example 1, except that this solid 5~ and the organoaluminum components shown in the table were used, and the results shown in the table were obtained.

Claims (1)

[Claims] 1 (i) General formula BαMgβR1pR2q [In the formula, α and β are numbers larger than 1, and β/α is 0.5 to 10
, p, q are O or a number larger than O, and p + q
=3α+2β, and R1 and R2 represent the same or different hydrocarbon groups having 1 to 10 carbon atoms. B3, R4 represent hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. A hydrocarbon-insoluble solid produced by reacting with a vanadium compound and (6) general formula A,!R3mZ3-m [wherein R3 is a hydrocarbon group having 1 to 20 carbon atoms, Z is hydrogen, halogen, alkoxy , allyloxy, or siloxy group, and m is a number from 2 to 3] Using a catalyst obtained by reacting an organoaluminum compound represented by α− characterized by polymerizing with
Method for polymerizing olefins.