JPH06293670A - Production of ethylene oligomer - Google Patents

Abstract

PURPOSE:To provide a process for easily producing 6C and/or 8C 1-olefins in high selectivity while suppressing the formation of polymers. CONSTITUTION:An ethylene oligomer is produced by using a catalyst consisting of a zirconium compound of the general formula Zr(ORf)nX4-n (Rf is 2-4C fluorinated alkyl group, wherein at least the beta-sites are completely substituted with fluorine; X is Cl, Br or I; (n) is positive integer of <=4) and an aluminum compound of the general formula AlRmX3-m (R is 1-20C alkyl; X is Cl, Br or I; (m) is 1, 1.5, 2 or 3).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an ethylene low polymer, more specifically, it is possible to suppress the production of a polymer and obtain a 1-olefin having 6 and / or 8 carbon atoms with high selectivity. And a method for producing a low ethylene low polymer.

[0002]

BACKGROUND OF THE INVENTION 1-Olefins having 4, 6, and 8 carbon atoms are important compounds as raw materials for copolymerization with ethylene for producing linear low density polyethylene. Conventionally, these low molecular weight 1-olefins have been obtained mainly from decomposed products of naphtha. Of these, butene-1, which is a 1-olefin having 4 carbon atoms, is supplied from a decomposed product of naphtha in a large amount and at low cost.

On the other hand, since the amount of 1-olefins having 6 and 8 carbon atoms is limited in the decomposed product of naphtha, the supply amount is always insufficient, and the 1-olefins having 6 and 8 carbon atoms are in short supply. It has been desired to develop a selective manufacturing method. As such a production method, various methods using a catalyst have been proposed so far, and, for example, a method using a catalyst composed of a zirconium compound and an aluminum compound is known to be capable of suppressing polymer by-production.

However, even if the production of polymer can be suppressed,
It has been difficult to selectively increase 1-olefins having 6 and 8 carbon atoms. For example, as a zirconium compound, Z
_{r (O-n-C 3} H 7) 4 or Zr _{[N (n-C 4 H 9} ) 2 ]
_{In the} method using ₄ (Japanese Patent Publication No. Sho 50-30042), the selectivity of 1-olefins having 6 and 8 carbon atoms is generally low, while the production of polymer is increased when the selectivity is high. was there. Further, in the method of using a zirconium compound containing a phenoxy group having an electron-withdrawing group as an organoaluminum compound as a catalyst (Japanese Patent Publication No. 2-13649), there is little polymer formation, and the number of carbon atoms is 4-8. A chain α-olefin is selectively produced, but in this method, the selectivity of an olefin having 4 carbon atoms is remarkably high, and the desired carbon number of 6 and 8 is obtained.
However, there is a problem that the 1-olefin selectivity is low.

Therefore, it has been desired to develop a method for producing an ethylene low polymer which can suppress the production of a polymer and can highly selectively obtain a 1-olefin having 6 and / or 8 carbon atoms.

[0006]

Means for Solving the Problems As a result of intensive studies in view of such circumstances, the present inventor has used a combination of a zirconium compound having a fluorinated alkoxyl group described below and an organoaluminum compound as a catalyst in a polymerization reaction of ethylene. As a result, they have found that 1-olefins having 6 and / or 8 carbon atoms can be obtained with high selectivity, and have completed the present invention.

That is, the present invention provides the following components (A) and (B) (A) the following general formula (1) Zr (ORf) _n X _4-n (1) (wherein Rf is at least at the β-position) A zirconium compound represented by (C) a fluoroalkyl group having 2 to 4 carbon atoms, all of which is substituted with fluorine, X represents a chlorine atom, a bromine atom or an iodine atom, and n represents an integer of 1 to 4) (B) The following general formula (2) AlR _m X _3-m (2) (In the formula, R represents an alkyl group having 1 to 20 carbon atoms, m represents 1, 1.5, 2 or 3, and X represents the above. Synonymous)
Ethylene is polymerized in the presence of a catalyst prepared by mixing an aluminum compound represented by the formula (1) in the presence or absence of an organic phosphorus compound, and mainly comprises a 1-olefin having 6 and / or 8 carbon atoms. A method for producing an ethylene low polymer as a component is provided.

In the general formula (1) of the component (A), Rf is, for example, --CH ₂ CF ₃ , --CH (CF ₃ ) ₂ or --CH _2.
CF ₂ CF ₃ and the like.

Specific examples of the zirconium compound represented by the general formula (1) include tetrakis (2,2,2-trifluoroethoxy) zirconium and chlorotris (2).
2,2-trifluoroethoxy) zirconium, dichlorobis (2,2,2-trifluoroethoxy) zirconium, trichloro (2,2,2-trifluoroethoxy) zirconium, tetrakis (2,2,2-trifluoro-1) -Trifluoromethylethoxy) zirconium, chlorotris (2,2,2-trifluoro-1-trifluoromethylethoxy) zirconium, dichlorobis (2,2,2-trifluoro-1-trifluoromethylethoxy) zirconium, trichloro ( 2,2,2-
Trifluoro-1-trifluoromethylethoxy) zirconium, tetrakis (2,2,3,3,3-pentafluoropropoxy) zirconium, chlorotris (2,2
2,3,3,3-Pentafluoropropoxy) zirconium, dichlorobis (2,2,3,3,3-pentafluoropropoxy) zirconium and trichloro (2,2
2,3,3,3-pentafluoropropoxy) zirconium and the like can be mentioned.

The zirconium compound as the component (A) may be used alone or as a mixture of two or more,
The amount of the zirconium compound used is 0.001 to 10 mmol, preferably 0.01 to 1 mmol, relative to 1 mol of ethylene.
Is.

Specific examples of the aluminum compound represented by the general formula (2) of the component (B) include dimethyl aluminum chloride, diethyl aluminum chloride, dipropyl aluminum chloride, diisopropyl aluminum chloride, dibutyl aluminum chloride, diisobutyl aluminum chloride, dihexyl. Aluminum chloride, didodecyl aluminum chloride, diethyl aluminum bromide, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide, ethyl aluminum dichloride, ethyl aluminum dibromide and the like can be mentioned.

The catalyst used in the production method of the present invention is prepared by mixing the above-mentioned components (A) and (B). The preparation method is as follows: 1 mol of zirconium compound (1) and aluminum compound (2) It is preferable to mix in a hydrocarbon solvent using 0.1 to 200 molar equivalents. In this case, a small amount of the following organic phosphorus compound may be added as the third component.

Examples of the organic phosphorus compound include triethylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tricyclohexylphosphine and bis (1,2-diphenylphosphino).
Examples thereof include ethane, tributyl phosphite, triphenyl phosphite, tributyl phosphate and triphenyl phosphate.

In the present invention, ethylene is polymerized using the above-mentioned catalyst under the pressure of ethylene of 1 to 100 kg / cm ² and the temperature of -20 to 100 ° C. in the presence or absence of a solvent. To react.

The solvent is not particularly limited as long as it is a non-polar hydrocarbon solvent, for example, an aromatic hydrocarbon solvent containing benzene, toluene, xylene, etc., an aliphatic hydrocarbon solvent containing pentane, hexane, octane, etc., cyclohexane. Examples thereof include an alicyclic hydrocarbon solvent containing a. Of these, an aromatic hydrocarbon solvent in which the zirconium compound is more easily dissolved is preferable.

[0016]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto. In the following examples, a hydrocarbon having 4 carbon atoms will be abbreviated as a C ₄ component and a hydrocarbon having 6 carbon atoms will be abbreviated as a C ₆ component.

Example 1 A 50 cm ³ autoclave was thoroughly dried, and the air inside was replaced with argon. Then, 0.1 g (0.2 mm) of tetrakis (2,2,2-trifluoroethoxy) zirconium was used.
benzene solution containing ol) and a benzene solution containing 0.36 g (3 mmol) of diethylaluminum chloride were introduced into the autoclave by using a syringe and stirred for 30 minutes for activation. After that, the reaction was carried out at an internal temperature of 10 ° C. and a maximum ethylene pressure of 30 kg / cm ² .
During the reaction, when the pressure in the autoclave dropped to 1 kg / cm ² or less, ethylene was immediately injected up to 30 kg / cm ² and the reaction was continued. After 60 minutes, the reaction was stopped, the gas remaining in the autoclave was collected in a gas buret, the catalyst was deactivated with methanol, and then methylcyclohexane was added to the liquid reaction product as an internal standard substance, and the gas phase and liquid phase were added. Each phase was quantified by gas chromatography. The product yield and composition are shown in Table 1.

Example 2 The reaction was carried out under the same conditions as in Example 1 except that the reaction temperature was changed to 30 ° C. The yield and composition of the product are also shown in Table 1.

Example 3 The reaction was carried out under the same conditions as in Example 2 except that the amount of diethylaluminum chloride was changed to 0.24 g (2 mmol). The yield and composition of the product are also shown in Table 1.

Example 4 In Example 2, the zirconium compound was a mixture of 77 mol% dichlorobis (2,2,2-trifluoroethoxy) zirconium and 23 mol% chlorotris (2,2,2-trifluoroethoxy) zirconium, Furthermore, the amount of diethylaluminum chloride was 0.67 g.
The reaction was carried out under the same conditions as in Example 2 except that (5.6 mmol) was used. The yield and composition of the product are also shown in Table 1. The yield of the product increased more than twice as compared with Example 2.

Example 5 The reaction was carried out under the same conditions as in Example 1 except that the reaction temperature in Example 1 was 50 ° C. The yield and composition of the product are also shown in Table 1.

Comparative Example 1 The reaction was carried out under the same conditions as in Example 5 except that the zirconium compound in Example 5 was changed to 0.2 mmol of tetrabutoxyzirconium. The yield and composition of the product are also shown in Table 1. Compared with Example 5, the composition ratio of the polymer was high and the yield of the product was reduced to 1/2 or less.

Example 6 In Example 5, the pressure of ethylene was kept constant at 30 kg during the reaction.
/ Cm ² was maintained and the reaction time was 30 minutes, and the reaction was carried out under the same conditions as in Example 5. The yield and composition of the product are also shown in Table 1.

[0024] In all the Examples and Comparative Examples above, C ₄ -C ₈ almost 100% in each 1 ratio of olefin C ₄ component ingredients, about 90% C ₆ components, approximately in C ₈ components It was 80%.

[0025]

[Table 1]

[0026]

EFFECTS OF THE INVENTION The production method of the present invention suppresses the formation of a polymer, while at the same time 1-having 6 and / or 8 carbon atoms
Olefin can be obtained highly selectively and easily. Therefore, it is possible to stably supply the 1-olefin having 6 carbon atoms and 8 carbon atoms, which is difficult to supply in an amount corresponding to the demand, only from the decomposed product of naphtha.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C07C 11/107 9280-4H // C07B 61/00 300

Claims (1)

[Claims] 1. The following components (A) and (B) (A) The following general formula (1) Zr (ORf) _n X _4-n (1) (In the formula, at least all β-positions of Rf are fluorine-substituted. A C2-4 fluorinated alkyl group, X represents a chlorine atom, a bromine atom or an iodine atom, and n represents an integer of 1 to 4) (B) the following general formula (B): 2) AlR _m X _3-m (2) (In the formula, R represents an alkyl group having 1 to 20 carbon atoms, m represents 1, 1.5, 2 or 3, and X has the same meaning as above.)
Ethylene is polymerized in the presence of a catalyst prepared by mixing an aluminum compound represented by the formula (1) in the presence or absence of an organic phosphorus compound, and mainly comprises a 1-olefin having 6 and / or 8 carbon atoms. A method for producing an ethylene low polymer as a component.