JPH01172405A - Manufacture of ethylene polymer - Google Patents

Abstract

PURPOSE:To produce the title polymer having a narrow molecular weight distribution, a high purity and a high quality, by using a catalyst system comprising an organic aluminum compound and a solid catalyst component obtained by reducing a reaction product of a Ti compound, a V compound, an Si compound and a furfural compound with an organic aluminum compound. CONSTITUTION:A Ti compound (A) of formula I (wherein R<1> is 1-16C alkyl; X is halogen; and n is 0-2), one or more chlorides (B) of V selected from the group consisting of VOCl3, VCl3 and VCl4, an Si compound (C) having an Si-O linkage (e.g., hexamethyldisiloxane) and an alcohol compound (D) of formula R<2>-OH (wherein R<2> is a 1-30C alkyl) are mixed together and reacted in such a manner that the relations of formulae II and III are satisfied. The reaction product is reduced with 0.1-10mol. of an organic aluminum compound for 1mol. of the component (A) plus the component (B) to produce a solid catalyst component (E) insoluble in hydrocarbons. The component (E), an organic aluminum compound (F) and, if desired, a third component such as an electron donating compound are blended together to obtain a catalyst system. Ethylene and, if desired, an alpha-olefin are (co)polymerized using the above catalyst system.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing an ethylene-based polymer having a narrow molecular distribution. , relates to a method for producing an ethylene polymer with a narrow molecular m distribution.

[Conventional technology]

Ethylene polymers have excellent mechanical properties and are easy to process, so they are used in films, tapes, and sheets.

It is processed and used in a wide variety of molded products such as fibers, hollow molded products, and injection molded products. In these products,
In order to obtain a material with excellent transparency, impact resistance, etc., it is preferable to use a polymer with a narrow molecular m distribution. In addition, when producing ethylene polymers, especially co-m polymers, in order to prevent fouling (polymer adhesion to the walls of the polymerization vessel) and bridging, and to ensure stable operation, it is necessary to control the molecular distribution. is narrow, especially for very low molecules [preferably, the presence of tetrameres P is small.

As a method for obtaining an ethylene polymer with a narrow molecular m distribution, a method using a catalyst formed from a vanadium catalyst component and an organoaluminum compound is known, but this method has the drawback of low polymerization activity. In addition, many methods have been proposed for obtaining ethylene polymers with a narrow molecular m distribution using a catalyst formed from a highly active titanium catalyst component containing magnesium, titanium, and halogen as essential components and an organoaluminum compound. For example, JP-A-60-10410
Publication No. 3, Japanese Unexamined Patent Publication No. 58-1706M.

There are Japanese Patent Laid-Open No. 59-204603, etc.

Furthermore, catalysts containing titanium compounds and vanadium compounds as catalyst components are disclosed in Japanese Patent Publication No. 55-14084, Japanese Patent Application Laid-open No. 47-35077, etc.
It is difficult to obtain polymers with sufficiently narrow distribution.

[Problem that the invention seeks to solve]

Up until now, many methods have been proposed for producing ethylene polymers with a narrow molecular m distribution. Also, when extraction is performed using a solvent (for example, n-hexane), a considerable amount of extraction valves (extremely low molecular ff1ffi combinations) are present. The presence of these extremely low molecular weight polymers is a source of smoke and bad odor when the polymer is molded and processed, as well as fouling and bridging when the polymer is manufactured.

The above phenomenon becomes even more remarkable in copolymers obtained by copolymerizing ethylene and α-olefin.

Particularly in medium density polyethylene and low density polyethylene obtained by copolymerizing ethylene with relatively prolific α-olefins, the extraction valve by solvent increases.

The extraction valve is composed of an extremely low molecular weight polymer and/or an extremely low density polymer, and the presence of stones in the extremely low density portion is determined by the width of the density distribution (branching degree distribution) that occurs during copolymerization. .

Therefore, an object of the present invention is to provide a method for producing an ethylene polymer having a narrow molecular m distribution and a low content of an extremely low molecular m polymer and/or an extremely low molecular m polymer.

[Means for solving problems]

As a result of many studies to solve the above problems, the inventor of the present invention found that (^) (1) - Formula TL(OR') an alkyl group, X represents a halogen atom, and n is 0.1 or 2); and (2) selected from the group consisting of vanadium oxytrichloride, vanadium trichloride, and vanadium tetrachloride. at least one vanadium chloride (V), (3) a silicon-based compound (S) having an SL-0 bond, and (4) - formula R'-0H
(In the formula, R2 is an alkyl group having at most 30 carbon atoms) A hydrocarbon-insoluble solid obtained by reducing a reaction product with an alcohol compound (R) represented by (5) an organoaluminum compound. obtained from a catalyst component and (B) an organoaluminum compound, and the above-mentioned compounds (T), (V),
(S) and (R) are each represented by the following formula (where [S], [R], [month and [V] are respectively expressed in moles), (S), (R), (
T) and (V) are used. The present invention has been achieved by discovering that an ethylene polymer having all of the above-mentioned problems can be obtained by a method using a catalyst system that satisfies the above conditions.

In the present invention, the titanium compound (T) used to obtain the solid catalyst component has the formula TL(OR).

X (wherein R1 is an alkyl group having at most 16 carbon atoms, X is a halogen atom, and n is 0.1 or 2
It is. ), and representative examples thereof include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, methoxytitanium trichloride, dimethoxytitanium dichloride, 1-oxytitanium trichloride, and jetoxytitanium dichloride.

Propoxy titanium trichloride, dipropoxy titanium dichloride, isopropoxy titanium trichloride,
Examples include butoxytitanium trichloride and isobutoxytitanium trichloride.

The silicon-based compound (S) having an SL -0 bond is represented by formulas (I) to (I[I).

5i(ORJntR'...(I)-ra R5(R2SiO) o Si R3...(II)
(R2sio) q...(III)
In the formula, B3. R4 and Be may be the same or different, and are alkyl groups having at most 20 carbon atoms.

A hydrocarbon group selected from the group consisting of a cycloalkyl group, an aryl group, and an aralkyl group, and B
S, Ha and R' may be the same or different, and are the above hydrocarbon groups or halogen atoms.

m is an integer from O to 4, p is an integer from 1 to 1000, and q is an integer from 2 to 1000.

Representative silicon compounds represented by formula (I) include tetramethoxysilane, dimethyldimethoxysilane, dimethylje+-=t-disilane, tetraethoxysilane, triethoxyethylsilane, jetoxydiethylsilane, and ethoxysilane. Triethylsilane, tetrapropoxysilane, dibroboxydibrobylsilane, tetra-isobutoxysilane, di-impropoxy-di-isopropylsilane, dimethoxydiethylsilane, jetoxydibutylsilane, tetra-n-butoxysilane, di- n-butoxy-di-n-butylsilane, tetra-secondary-butoxysilane, tetrahexoxysilane, tetraoctoxysilane, tetraphenoxysilane, tetracresylsilane, trimethoxychlorosilane, dimethoxydichlorosilane, dimethoxydibromosilane , triethoxychlorosilane, jetoxydibromosilane, dibutoxydichlorosilane, dicyclopentoxydiethylsilane, jetoxydiphenylsilane, 3,5-dimethylphenoxytrimedylsilane, methylphenyl-bis(
2-chloroethoxy)silane, dimethoxydibenzylsilane, tri-n-propylallyloxysilane, allyl(
tris(2-chloroethoxy)silane and trimethoxy-3-ethoxypropylsilane.

In addition, typical silicon-based compounds represented by formula (I) include hexamethyldisiloxane, octamethyltrisiloxane, tetracosamethylundecasiloxane, 3-hydroheptamethyltrisiloxane, and hexaphenyldisiloxane. Siloxane, hexacyclohexyldisiloxane, 1,3-dimethyldisiloxane, hexachlorodisiloxane, octaethyltrisiloxane, hexachlorodisiloxane, 1,3-dichlorotetramethyldisiloxane)-1,3-dimethyl-1. 3-diphenyldisiloxane, 1,3-allylte]-ramethyldisiloxane, 1,3-dibenzyltetramethyldisiloxane, 2,2,4,4-tetraphenyl-2,4-
Disilar 1-oxacyclopentane, 1.1.3.3-
Mention may be made of tetramethyldisiloxane and hexachlorodisiloxane.

Further, typical silicon-based compounds represented by formula (III) include 1,3,5-trimethylcyclotrisiloxane, hexamethylcyclotrisiloxane, octamethylsifurothi-1-lasiloxane, and pentamethylchlorotrisiloxane. Cyclo-disiloxane, 1,3,5-trimethyl 1
- rifhenylcyclotrisiloxane, hexaphenylcyclotrisiloxane, 1,3,5-tribenzyltrimethylcyclotridiOxane and 1,3,5-allyltrimethylcyclo1-disiloxane.

Among these silicon-based compounds, those in which n3a3 and R4 in formula (I) are represented by an alkyl group, phenyl group, or aralkyl group having at most 8 carbon atoms are preferred. Further, in the formula (II), ns, R6 and R2 are preferably represented by an alkyl group having at most 4 carbon atoms, a phenyl group, or a halogen atom, and p is generally preferably 4 or less. Said (Ill)
In the formula, R8 is preferably a hydrogen atom, an alkyl group having 4 or less carbon atoms, a phenyl group, or a vinyl group, and q is generally preferably 10 or less.

These suitable silicon-based compounds include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, butrafrezylsilane,
Mention may be made of hexamethyldisilokylene, diethoxydimedylsilane, phenyltriethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and diphenyljethoxysilane.

Further, the alcoholic compound (R) is represented by the formula R2-Ko (in the formula, R2 is an alkyl group having at most 30 carbon atoms), and R2 is an alkyl group having 4 or more carbon atoms. is preferably used. Representative examples of these include n-butyl alcohol, n-pentyl alcohol, cyclohexyl alcohol, 2-ethylhexyl alcohol, n-octyl alcohol, decyl alcohol, dodecyl alcohol, stearyl alcohol, and the like.

In the catalyst system of the present invention, first, the above-mentioned titanium compound (shun), at least one vanadium chloride (v) selected from the group consisting of vanadium oxytrichloride, vanadium trichloride and vanadium tetrachloride, and the above silicon-based compound are combined. (S)
A reaction product is produced by reacting the compound and the alcohol compound (R). This reaction product! I+! In the production, only one type of each reaction component may be used, or two or more types may be used in combination. Furthermore, in producing this reaction product, the reaction components may be reacted simultaneously, or two or more of them may be reacted and then other components may be reacted. The reaction ratio of each reaction component is strictly determined, and the use of compounds (T), (V), (S) and (R) must satisfy the formula.

Here, [Ding], [V], [81 and [R]
are titanium compounds (■) and vanadium chloride (V
), silicon compounds (S) and alcohol compounds (
R) used, and these quantities are expressed in moles.

(S)
The ratio of the usage amount of component (R) to the total usage amount of component (R) is 2.
-10, and if this ratio is less than 2, a polymer with a sufficiently narrow molecular weight distribution cannot be obtained. Moreover, when it exceeds 10, the catalyst activity decreases by 8. On the other hand, the ratio of the component (V) to the seasonal component must be in the range of 0.1 to 5, and if it is outside this range, the molecular weight distribution will be sufficiently narrow.
Not only is coalescence not possible, but the catalytic activity is reduced.

The reaction temperature and time of these reaction components are - generally 0.
~150°C for 10 minutes to 5 hours, preferably 2
The temperature is 0 to 100°C for 30 minutes to 2 hours.

Although this reaction can be carried out in the absence of an inert solvent, in order to ensure uniformity of the reaction, inert solvents such as n-hexane, n-hebutane, cyclohexane, benzene, toluene and xylene are usually used. It is preferable to do it inside.

A solid catalyst component can be obtained by reducing the reaction product obtained by the above method with an organoaluminum compound. The organoaluminum compound used in this reduction reaction has the formula NR3 or #RY
(However, R8 is r3-r an alkyl group having at most 8 carbon atoms, Y is a halogen atom, and r is 1, 1.5 or 2.). Examples of NR3 include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisobutylaluminum and trihexylaluminum. /VRr2Y includes dimethylaluminum monochloride, dimethylaluminum monobromide, diethylaluminium monochloride, di-n-propylaluminum monochloride, diisopropylaluminium monochloride, di-
n-Butylaluminum monochloride.

Mention may be made of di-isobutylaluminum chloride and diethylaluminum monobromide.

NR1,5Yl,5 is methylaluminum sesquichloride, ethylaluminum sesquichloride,
Ethylaluminum sesquibromide.

Mention may be made of n-propylaluminium sesquichloride, n-butylaluminum sesquichloride, isobutylaluminum sesquichloride and isopentylaluminum sesquichloride.

#R' Y 2 is methylaluminum dichloride, methylaluminum dibromide, ethylaluminum dichloride, ethylaluminum dichloride, ethylaluminum dichloride, n-propylaluminum dichloride.

Mention may be made of isoprobylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride and n-pentylaluminum dichloride.

In this reduction reaction, the reaction ratio of the organoaluminum compound with respect to 1 mol of the total amount of the titanium compound and vanadium chloride used in producing the reaction product is as follows:
Generally from 0.1 to 10 mol, especially from 0.5 to 3.
0 mol is preferred.

If the reaction ratio of the organoaluminum compound is less than 0.1 mol per 1 mol of the total amount of titanium and vanadium chloride, the effect of the reduction reaction will be low; on the other hand, if the reaction ratio of the organoaluminum compound exceeds 10 mol. , it is uneconomical as it involves loss of organoaluminum compounds.

Although the reaction temperature in this reduction reaction varies depending on the type of organoaluminum compound, it is generally from -20 to +
The temperature is 150°C, preferably 0 to +70°C. When the reaction temperature is 150° C. or higher, excessive reaction occurs, and the function of the catalyst generally tends to deteriorate. On the other hand, below -20℃,
Reaction speed is slow.

Although the reaction time varies depending on the reaction rate, the reaction ratio of the organoaluminum compound to the titanium compound, and when an inert solvent is used, the concentration of the organoaluminum compound to the solvent, etc., 15 minutes to 5 hours is generally sufficient.

The solid catalyst component obtained by the reduction reaction is a solid that is insoluble in hydrocarbons (for example, hexane,
It can be used as a slurry after washing several times with heptane) or as a powder after drying.

Using a catalyst system obtained by a conventional method from the solid catalyst component and the organoaluminum compound prepared as 1B'lJ as described above, or this 0-organic aluminum compound and the third component, in the presence or absence of an inert solvent. The polymerization of the present invention can be achieved by carrying out the monopolymerization of ethylene or the copolymerization of ethylene and an α-olefin.

Typical organoaluminum compounds used in this polymerization include trimethylaluminum, triethylaluminum, tripropylaluminum, and triisobutylaluminum.

Examples thereof include trialkylaluminums such as trihexylaluminum and trioctylaluminum, alkylaluminum hydrides such as diethylaluminum hydride and schizubdel aluminum hydride, and dialkylaluminum halides such as dimethylaluminum chloride and diethylaluminum chloride.

The amount of organoaluminum compound used is generally 0.1 to 10 mmol, preferably 0.1 to 10 mmol per 1 J of inert solvent.
It is 3-3 mmol.

Inert solvents include unsaturated aliphatic hydrocarbons such as butane, pentane, hexane, heptane, cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene.

Further, the third component is an electron-donating compound, which is well known as a modifier for polymerization activity, crystallinity, etc. in olefin polymerization.

The α-olefin used as a comonomer when copolymerizing with ethylene has at most 20 carbon atoms,
Preferably it is 12 α-olefins, typical examples of which include propylene, butene-1,4-methylpentene-1, hexene-1 and octene-1. (The above α− occupied in the ethylene copolymer
The proportion of olefin is generally preferably 20 mol% or less, particularly preferably 15 mol% or less.

In carrying out the method of the present invention, the polymerization temperature and pressure are not particularly limited, and commonly used conditions can be applied, but generally the temperature range is from room temperature to 300°C, and from
A total pressure of 300 atm is employed, and the process is carried out by a gas phase method, a suspension method, or a solution method. Further, if necessary, hydrogen or the like may be allowed to coexist in the polymerization reaction system in order to adjust the molecular weight.

Next, the present invention will be explained in more detail by referring to Examples and Comparative Examples.

〔Example〕

(Example 1) (1) Production of solid catalyst component A 300CC three-necked flask equipped with a thermometer and a stirrer was sufficiently purged with nitrogen, and the flask was filled with n-hebutane 30-
1 Titanium tetrachloride 20mm0+, vanadium oxytrichloride 2Qmmol, hequinamethylsidiloxane 60imol
and n-butyl alcohol 6Q+1111101 were added, and the reaction was carried out at 50°C for 2 hours. Then, ethylaluminum sesquichloride 5011111101 was added to 4
It was added dropwise at 0°C. After the dropwise addition was completed, stirring was continued at 40°C for 2 hours. After thoroughly washing the generated insoluble solid with n-hebutane, it was dried under reduced pressure at 40°C to obtain a solid catalyst component.

(2) Polymerization of ethylene 10R1J of the solid catalyst component obtained by the above method, 5 mmol of triisobutylaluminum Q, and 500 ae of isobutane were charged into a 1.0 J autoclave made of stainless steel and purged with nitrogen, and the reaction system was raised to 90°C. It was warm. Then, after increasing the hydrogen pressure by 2 K9/cIA gauge pressure,
Pressure-inject ethylene and reduce the ethylene partial pressure to 5Kg/ctrr<
Polymerization was carried out for 1 hour while maintaining the pressure at the same gauge pressure (hereinafter the same). Then, the polymerization was terminated by discharging the contained gas to the outside of the system. As a result, 123 g of a white powdery polymer was obtained. Polymerization activity is ethylene 1 atm,
1 hour.

It was 24609 per gram of solid catalyst. The melt index of the obtained polyethylene (JIS K-676
0.190℃, 2.111ff cart, hereinafter abbreviated as old.

> is 0.729/10 minutes, and the high road melt index (190℃, 21.6 to 9 cargoes, hereinafter l1
l) 11 is abbreviated. ) was 18.3 s/10 minutes.

That is 15, their ratio 111HT/HrG, 125
, 4''(-Al'), the molecular weight distribution was narrow. In addition, n-hexane soluble fn(n- Elution (■) of hequinane by boiling point extraction was as low as 0.20%.

(Examples 2 to 5), (Comparative Examples 1 to 4) The solid catalyst components were the same as in Example 1, except that the amounts of the reaction components used were changed as shown in Table 1. I got it. Example 1 except that this solid catalyst component was in the mm shown in Table 1.
Polymerization of ethylene was carried out in exactly the same manner. The results are shown in Table 1.

(Example 6) A solid catalyst component was produced in exactly the same manner as in Example 1, except that vanadium tetrachloride was used instead of vanadium oxytrichloride, and ethylene was polymerized in the same manner as in Example 1. . The obtained 1F combined weight was 102 g, and the polymerization activity was 2040 g/solid catalyst, time, and ethylene pressure. Ml of this polymer is 1.2 g/10 min, 1
1181/old was 24°7, and the n-hexane soluble content was 0.33%.

(Examples 7 to 12), (Comparative Example 5) (1) Production of solid catalyst component In Example 1, the compounds shown in Table 2 were used as the silicon-based compound and the alcohol-based compound, respectively. The solid catalyst component was used in the same manner as in Example 1, except that Δ was used.

(2) Copolymerized nitrogen of ethylene and α-olefin.Stainless steel 1. The solid catalyst component R shown in Table 2, triisobutylaluminum 0°5mm0+, and isobutane 500d were charged into an OJ autoclave using the above method (9), and the reaction system was heated to 85°C. The pressure was injected until the pressure reached 2 Kg/cti, and after charging lυ of α-olefins of the types and types shown in Table 2, ethylene was injected until the partial pressure reached 5 Kg/cti to start polymerization.

Polymerization was carried out for 1 hour while maintaining the ethylene partial pressure at 5 Kg/crA. Then, the polymerization was terminated by discharging the contained gas to the outside of the system to obtain a white powdery polymer. The polymerization results are shown in Table 2.

〔Effect of the invention〕

As explained above, according to the method for producing an ethylene polymer of the present invention, an ethylene polymer having a narrow molecular layer distribution and in which the presence M of an extremely low molecular weight FFI polymer and an extremely low density polymer is small. can be manufactured efficiently. Therefore, the polymer! Stable operation at jJ3a is ensured, and a high-quality ethylene polymer that does not generate smoke or bad odor during polymer molding can be obtained.

[Brief explanation of the drawing]

The drawings are for this invention! FIG. 11 is a flow diagram showing the J-building method.

Claims (1)

[Claims] (A) (1) General formula Ti(OR^1)_nX_4_-_
A titanium compound (T) represented by n (in the formula, R^1 is an alkyl group having at most 16 carbon atoms, X is a halogen atom, and n is 0, 1 or 2) and (2) oxy At least one vanadium chloride (V) selected from the group consisting of vanadium trichloride, vanadium trichloride, and vanadium tetrachloride, (3) a silicon-based compound having a Si-O bond (S), and (4) general formula R ^2-O
A hydrocarbon obtained by reducing a reaction product with an alcohol compound (R) represented by H (in the formula, R^2 is an alkyl group having at most 30 carbon atoms) with an organoaluminum compound (5) The above compounds (T), (V), (S) obtained from an insoluble solid catalyst component and (B) an organoaluminum compound
and (R) are each expressed by the following formula 2≦([S]+[R])/([T]+[V])≦10,
0.1≦[V]/[T]≦5 (in the formula, [S], [R],
[T] and [V] are each expressed in moles (S)
, (R), (T) and (V). 1. A method for producing an ethylene polymer, which comprises copolymerizing ethylene alone or ethylene and an α-olefin using a catalyst system that satisfies the following.