JPS5968306A - Production of ethylene copolymer - Google Patents

Abstract

PURPOSE:To produce a low-density ethylene/alpha-olefin copolymer in a good slurry state, by using a hydrocarbon-insoluble solid catalyst prepared by reacting a solid complex containing magnesium, titanium, and an electron donor with an organo-aluminum. CONSTITUTION:A solid complex of formula I [wherein X<1> and X<2> are each a halogen, R<1> is a (cyclo)alkyl, or aryl, D is an electron-donating compound such as an ester, alcohol or amine, n is 0.1-100, j is 2-4, k is 0-1 (j+k is equal to the valence of titanium), and m is 2-200] is reacted with an organoaluminum compound of formula II [wherein R<2> is a (cycko)alkyl, X<3> is a halogen, and i is 1-3] in a hydrocarbon solvent (preferably, one which can dissolve the product between the electron-donating compound and the organoaluuminum compound). Then, tge produced hydrocarbon-insoluble solid catalyst is combined with an organoaluminum compound (co-catalyst), and this combination is used in a polymerization reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an ethylene copolymer. More specifically, ethylene and 3 carbon atoms using a novel catalyst containing a magnesium compound and a titanium compound.
The present invention relates to a method of copolymerization with the above α-olefin.

It is known that a catalyst system containing a magnesium compound and a titanium compound can be used for the polymerization of olefins, and the present inventors previously reported in JP-A Sho-731ggda and JP-A-80-/, 3/gg'7. A solid complex catalyst for olefin polymerization containing magnesium, titanium and an electron donor compound is proposed. These catalyst systems have relatively high activity and the resulting polymers have a very narrow molecular weight distribution. When producing high-density polyethylene by slough IJ-polymerization, it has many advantages, such as the resulting polymer having a high bulk density. However, when trying to produce a copolymer with a low density (0, q, ? o y /cc or less) by copolymerizing ethylene and one olefin using a catalyst system (eg, slurry polymerization method), the slurry properties deteriorate. In addition, there was a drawback that the bulk density of the polymer decreased.

Therefore, as a result of intensive studies to improve these drawbacks, the present inventors separated the solid complex containing magnesium, titanium, and an electron donor from the reaction mixture obtained by reacting it with an organoaluminum compound. Compared to the above-mentioned solid complexes, the resulting hydrocarbon-insoluble solid has significantly higher activity and can be used as a catalyst for olefin polymerization, and also has a narrow molecular weight distribution and can be used as a low-density ethylene-α-olefin copolymer in a good slurry state. The present invention was achieved by discovering that it is possible to form a single horn by combining them.

That is, the gist of the present invention is the general formula % (%) [wherein, Xl and X2 are halogen atoms, R1 is an alkyl group, aryl group or cycloalkyl group, D is an ether,
Represents an electron donor compound selected from carboxylic acid esters, alcohols and amines. n is 0. j represents a number in the range of /~/θO, k represents a number in the range of θ~/, and j+k is a number that corresponds to the valence of titanium. m is a number in the range of 00 to 00.

] and the solid complex represented by the general formula % formula % [wherein R2 is an alkyl group, aryl group or cycloalkyl group, Indicates the number of ranges. ] using a catalyst system consisting of a combination of a stratified hydrogen-insoluble solid catalyst separated from the reaction mixture obtained by reacting with the organoaluminum compound shown in ] and a eutectic 1 non-organoaluminium compound, A method for producing an ethylene copolymer having a density θ of less than q/l/cc, characterized by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms.

To further explain the present invention in detail, the raw materials for preparing the hydrocarbon-insoluble solid catalyst used in the present invention are expressed by the general formula % () [where xl, ) (2, silver, D, n, j, k,
m is the same as defined above. As the solid complex represented by ], compound 75 in which XI and x2 are chlorine atoms, D75 is an ether, and k is O is particularly preferred.

Examples of D include those exemplified as the electron donor compound tVIIJ described later, and examples of R1 include those shown as R1 in the general formula of the halogen-containing compound of titanium described later.

Thus, such a solid complex can be prepared by co-precipitation of a rhodane-containing 111 compound of magnesium rhodide and titanium from a solution of a '6 donor compound. Here, the magnesium chloride has the general formula [where xl is the same as defined above]. ] is used.

Specific examples include anhydrous magnesium chloride, anhydrous magnesium chloride, and anhydrous magnesium iodide. Among them, anhydrous magnesium chloride is preferred.

On the other hand, a compound containing titanium has the general formula Ti is one to l
k represents the number in the range of Q −/, and j
-1-k is an external number to match the valence of titanium.

] is used. Specifically, titanium tetrachloride, titanium trichloride, titanium tetrabromide, titanium tribromide, titanium tetraiodide, titanium Misawa, titanium tetrafluoride, titanium trifluoride, monoethoxytrichlortitanium, monopropoxytrichlortitanium. , monobutoxytrichlorotitanium, and the like. Among them, titanium trichloride is preferred.

Next, specific examples of electron donor compounds include aliphatic ethers such as diethyl ether and dibutyl ether, cyclic ethers such as tetrahydrofuran and tetranohydrobilane, carboxylic acid esters such as ethyl acetate and ethyl benzoate, ethanol, and butanol. alcohol,
Examples include amines such as pyridine, among which tetrahydrofuran is preferred. After mixing the above-mentioned halogen-containing compounds of magnesium halide and titanium in an appropriate ratio, an excess of the electron donor compound is added and the mixture is heated at a temperature ranging from OC to the boiling point of the one-child donor compound. reacting to form a complex and dissolving the electron donor compound;
Co-precipitation is carried out by a method in which the solution is cooled and crystallized, an electron donor compound is evaporated off, or a poor solvent such as a hydrocarbon is added. Another method is to separately synthesize an electron donor compound complex of red sea bream/sium halide and an electron donor compound complex of a halogen-containing titanium compound, mix and dissolve both in the electron donor compound, and then perform the above-mentioned method. It is also possible to obtain a solid complex by co-precipitation. In addition, during co-precipitation, in the presence of inert solids such as silica and alumina,
The solid complex may be supported on a carrier. The ratio of magnesium halide to the halogen-containing compound of titanium is Mg
/Ti (atomic ratio) is in the range of 0.7 to /DO. If this value is outside the above range, the polymerization activity of the catalyst 1I-i obtained will be insufficient.

Next, the solid complex produced by the above method was prepared in a hydrocarbon solvent using the general formula % [wherein R2 represents an alkyl group, aryl group or cycloalkyl group, 2 represents a halogen atom, and i represents /~
The number is in the 30 range. ] is reacted with an organoaluminum compound shown in Specifically, the organoaluminum compounds used here include ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum monochloride, triethylaluminum,
Examples include triinobutylaluminum, among which ethylaluminum dichloride, ethylaluminum sesquichloride, and diethylaluminum monochloride are preferred.

Although the treatment temperature is not particularly limited, it is usually carried out in the temperature range from room temperature to Asυ. Hydrocarbon solvents used include aliphatic hydrocarbons such as hexane and heptane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as benzene and toluene. Particularly preferred is a soluble layer in which a reaction product of an electron donor compound and an organoaluminum compound, which is produced as a by-product during the reaction with the organic aluminum compound, is soluble.

Additionally, the amount of the organoaluminum compound to be used is determined by the molar ratio θ, /<organoaluminum compound/electron donor compound<
/.

The amount used is such that the ratio of the organoaluminum compound/separating donor compound is 0.5 s, thus obtaining a solid that is insoluble in the hydrocarbon solvent and the by-products. The reaction product of the organoaluminum compound and the electron donor compound is separated. in particular,
The solid is removed from the reaction mixture by filtration, decantation, etc. after a few minutes and then washed with an inert hydrocarbon accumulated solvent. However, the washing process and the washing may be carried out simultaneously by adding an inert hydrocarbon solvent to the reaction mixture. .

As the inert hydrocarbon solvent used here, the inert hydrocarbon solvent used previously in the reaction of the solid complex and the organoaluminum compound is used.

The remaining amount of the electron donor compound component in the hydrocarbon-insoluble solid catalyst component obtained by this operation is determined by the molar ratio of the electron donor compound and the sum of magnesium atoms and titanium atoms. ) 〈/is.

In this range, an olefin polymerization catalyst can be obtained which has extremely high activity and a narrow molecular weight distribution, and which gives a polymer with high bulk density in slurry polymerization.

Next, as an organoaluminum compound used as a cocatalyst, for example, the general formula % formula %: Also, organoaluminum compounds represented by (・t3) are highly praised. Specific examples include 11 triethylaluminum, triisobutylaluminum, and diethylaluminum monochloride. The usage ratio is usually O/~/θθ with an atomic ratio of A1./T1, preferably C/
~Uθ is used within the range.

Using the catalyst system thus prepared, ethylene and an α-olefin having 3 or more carbon atoms are copolymerized. As the α-olefin having 3 or more carbon atoms, rl, propylene, butene-/, pentene-/, hexene-7, cumethylbentene-/, octene-/, etc. are used 1, α-8
The content of Refine is such that the density of the copolymer is 0.9/q/
It is selected so that Cc does not drop. In this case, the content of α-olefin varies depending on the type of α-olefin, but it is usually about 100%. r-20fii4 or higher.

The polymerization reaction is carried out in an inert solvent by solution polymerization or 771
Either slurry monopolymerization or gas phase polymerization in the absence of a solvent can be used. This is usually carried out by supplying the olefin mixture in the presence of an inert solution H and maintaining it at a predetermined temperature and pressure: h7. Examples of inert solvents include aliphatic hydrocarbon solutions such as propane, isobutane, normal butane, normal pentane, normal hexane, normal octane, etc., or mixtures thereof, cyclopentane, cyclohexane, etc. Among them, IJi group hydrocarbons with 3 or 1 carbon atoms are preferred. Polymerization reactions usually involve O
C ~ temperature of melting point of ethylene copolymer, and normal pressure ~10
Selected from the pressure range of 0 atmospheres.

In addition, in the method of the present invention, when hydrogen is present in the polymerization reaction zone, the effect of controlling the molecular weight by hydrogen is large, and it is possible to easily produce a polymer with a desired molecular weight.The amount of hydrogen to be present is , differs depending on the polymerization conditions and the desired molecular weight of the ethylene copolymer, so it is necessary to adjust the amount introduced accordingly.

Furthermore, in addition to the above method, the effects of the present invention can be further enhanced by pretreating or prepolymerizing the catalyst component for ethylene copolymerization with an olefin prior to ethylene copolymerization.

In the present invention, examples of olefins that can be used in the pretreatment or prepolymerization of catalyst components with olefins include those previously used in the polymerization of olefins and mixtures thereof. Further, the olefin used in the pretreatment or prepolymerization may be different from the olefin used in the polymerization.

The amount of polymerization in the prepolymerization is θOV per hydrocarbon-insoluble catalyst component constituting the catalyst system, preferably θOV to 100%. , more preferably S or left 01.

According to the method of the present invention as described above, the catalyst system has very high activity and the slurry properties of the copolymer are good. Also,
The resulting copolymer has a narrow molecular weight distribution and the molded product has good transparency. Furthermore, when copolymerizing higher α-olefins, it is possible to obtain a polymer with a high α-olefin content even if the α-olefin used has a low Y or Y content because of its good co-acidization property. have.

Next, the present invention will be explained in more detail by way of examples.
The present invention is not limited to the following examples unless the gist thereof is summarized in 8A. In the examples, the polymerization activity ratio of the catalyst
fiK=(f polymer)/(7・catalyst) (br)
Expressed as (kg, / crl / fin pressure), the polymerization activity KTi per titanium is KTi = (f polymer) / (f -
Ti) (hr) (ky/d olefin pressure).

Also, the melt index is kE3TM, -D, /S
3g −, based on t7T/90”Q, 2/l, kg
It is expressed in M-work measured by load. Furthermore, the flow rate ratio (hereinafter abbreviated as FR), which is a measure of molecular distribution, is a value indicating the dependence of solution viscosity on shear stress, and is determined by ASTM, D-/2.1-&?
According to T, shear stress / 0” d, yne /7 and t
o'ayne/mK It is expressed as the ratio of the melt index measured by O'ayne, and it is said that the larger PR is, the wider the molecular weight distribution is, and the smaller PR is, the narrower the molecular weight/distribution is. Haze is JIS K 710 for pressed pieces with thickness / +nm
1 jill was determined according to 3.

In addition, the density (ρ) of the polymer was measured by JIS K t7Aθ density gradient tube method, and the bulk density (ρB) was determined according to JIS K67.
．． 2/.

Production example (I) Production of MgO1□・GataTHF Using a Soxhlet extractor, commercially available bulk anhydrous Mg
Tetrahydrofuran (hereinafter abbreviated as -F[TH:FJ), which has been dehydrated and deoxygenated at pO1□/θ2, 2! A reflux extraction operation was performed using ioml. After about 20 hours, almost no MgO1 solid was observed. This extract is approximately /θθm
/! The mixture was concentrated in a small volume, allowed to cool to room temperature K, and then dried under a stream of nitrogen gas to obtain a white powdery solid. The chemical analysis values (weight %) of the obtained solid were as follows.

Mg CI CH analysis value /to/ 3. '1. g, 33
．． ．． 3 111 (b) Production of T j, 013.3THF Using a Soxhlet extractor, T under nitrogen gas atmosphere.
J, C1, (Ti1l, reduced with hydrogen) 67 was extracted under reflux with 300 ml of dehydrated and deoxygenated THF. After about 70 hours, most of TiO'l was dissolved and T
The HF phase became a rich purple-brown color.

Blue solid crystals were precipitated by allowing this to cool day and night, which were washed with purified n-hexane and dried at room temperature under a stream of nitrogen gas to obtain a sky blue solid powder. The analytical values (% by weight) of the solid obtained by recrystallizing this product multiple times using purified THF are shown.

Ti 01 analysis value /3. Calculated value for l cog (Til13・,? THF) /,
? , o B, Example 7 MgO synthesized in Production Example (a) in a flask purged with nitrogen in advance],, -/, &THF! ,),,Omm
ol, then dehumidified and deoxidized THFll.
Add grul, MgO1,...! i TT(F'
was dissolved. Next, separately, Tj synthesized in Production Example (b),
O]s・JTHF /,,? mmo! ';c preparation,
Next, dehumidified and deoxidized THvqH, lf was added to Ti1l.
, @, 7T) IF was dissolved in IT4.

Next, the above two solutions were mixed and reacted for 7 hours using JO'QI/C, and then purified n-hexane (3 gkπe) was heated at the same temperature.
was added dropwise over 20 minutes with stirring, producing a white precipitate. The obtained precipitate was thoroughly washed with purified normal hexane to obtain a normal hexane slurry. C in the slurry at this time? + Ti:] Dark W rj O,,?
mot/lノ/l/? It was luhexane.

The compositional formula of the obtained precipitate is Mg, oTiC:L83(TH
F) was as.

Room for this normal hexane slurry? 1% diethylaluminium chloride li under stirring, 2. Q mmot
was added dropwise over 20 minutes, and then stirred at g 5 r for 7 hours. The obtained precipitate was thoroughly washed with purified normal hexane to obtain a normal hexane slurry of the solid catalyst component.

Next, add 0.11 mmof triethylaluminum to a λl autoclave that has been previously purged with nitrogen.

Pure side mixed butane left θθrnI! and butene-7250m
g was prepared and the temperature was raised in a yor'keep. After heating up, add 2 hydrogen
, if kg/aft were introduced, and the above solid catalyst component (1) was introduced together with ethylene to initiate polymerization. Absorption of ethylene is observed as the polymerization progresses, but total FE?
, II kyt / art 7'l yofu f
7- / concentrated 1j / /, /mo1% butene-l-
Additional ethylene mixed gas was introduced. After 7 hours, ethanol was introduced under pressure to stop the polymerization. j =, hL-chi Tz table-
11・GashiγL.

Example 1: 'Mg (31□・/, s THF If K, Om
mol 'e preparation, then dehumidified and deoxygenated THFI
Add I left R1 and JC! 12.85TH'F was dissolved. Similarly, in another flask, the Ti synthesized in Production Example (b)
113.3THF! Add TiC! 13
．． ．． 3 THF was dissolved.

Next, both the above solutions were mixed and reacted at 30C for 7 hours,
Seihei 1 normal hexane J90d'f at the temperature after the reaction
! : When slowly added dropwise over 20 minutes while stirring, a pale blue precipitate was formed. The obtained precipitate was thoroughly washed with purified normal hexane to obtain a normal hexane slurry. At this time, the [:Mg+Ti] concentration in the slurry is 0.3
It is mol/l normal hexane. The compositional formula of the obtained precipitate is approximately Mg, oTil122- (THF),
Corresponding to fC.

7. Press diethyl aluminum chloride (g) into this n-hexane slurry four times at room temperature. Ommot was added dropwise and reacted for 7 hours in b and 5c. After cooling, it was thoroughly washed with n-hexane to obtain a n-hexane slurry of solid catalyst components.

Next, the autoclave was replaced with nitrogen in advance and 21 ft.
Triethylaluminum θ, / , ? mmoz.

Purified mixed butane 6Sθrttl and/-butene io.

ml was charged and the temperature was raised at θCt. After raising the temperature, hydrogen was introduced at 1 kP/cl, and the above solid catalyst component, 0, was introduced together with ethylene to initiate polymerization. As the polymerization progressed, a butene-/-ethylene mixed gas having a butene-7 concentration of 9 Jrnol was added to the reactor at a rate of 0.5 kg/dK so that the total pressure reached t, a kg/dK. After 7 hours, ethanol was press-injected 1. *
stopped. The results obtained are shown in Table-/.

Example 3 Anhydrous MgO 1°/
3. A' mmo/ was prepared, then dehumidified and deoxygenated ethyl acetate 33 was added to Mg, C! 12 is dissolved to form a colorless homogeneous solution, 17. Similarly, add Ti to another flask.
1l, (Ti1l, ring-formed with hydrogen)/, J
Prepare J mmoz, then dehumidify and deoxygenate ethyl acetate, 30rrtl! dissolved in

Next, the above two solutions were mixed and reacted at 60C for 7 hours. After the reaction, purified normal hexane and 2tθml were added to 4+1
! When the solution was slowly added dropwise over 20 minutes, a pale sky blue precipitate was formed. The precipitate was thoroughly washed with purified normal hexane to form a normal hexane slurry. In the slurry at this time (7) (Mg+Ti'l concentration is 0
．． /mol/l normal hexane. The chemical analysis values (weight factors) of the obtained precipitate were Mgg, 0%, Ti /,!
;'I regret that, C1, 21J Ochi.

The composition formula calculated assuming that the remainder is ethyl acetate is approximately Q
+. Compatible with TiC1-73・(ethyl acetate) 2°.

Cononormal hexane sulfur IJ -K diethylaluminum monochloride under stirring at room temperature 33. Ommot,
f was added dropwise and reacted in ASC for 1 hour.

After cooling, it was thoroughly washed with n-hexane, and 2. J
A solid catalyst component f was obtained.

Next, polymerization was carried out using the above solid catalyst component under exactly the same polymerization conditions as in Example C. The results obtained are shown in Table-7.

In Examples 1 to 1, ethyl aluminum dichloride or triethyl aluminum was used instead of diethyl aluminum chloride as the organoaluminum compound to be reacted with the solid complex. Polymerization was carried out under the following polymerization conditions.

The results obtained are shown in Table-/.

A copolymer was obtained in the same manner as in Example 6 to Example 7 except that the type and amount of α-olefin to be copolymerized with ethylene were changed as shown in Table 7. The results are shown in Table-/.

Comparative Example/Example/Polymerization was carried out under similar polymerization conditions using the solid complex as a solid catalyst component without reacting it with diethylaluminium chloride. Table of results obtained.
/It was shown to.

Comparative example-''-MgO12!; 2. Ommo7, Ti(31,/
, J mmo7 and TIF , ), , Ommo,!
was ground using a vibrating mill at room temperature for 10 hours. The compositional formula of the obtained product is Mg40TiO1g4 (THF)
1. Corresponds to l+. To this, normal hexane was added to form a slurry, and then diethylaluminum chloride, ommot, was added dropwise to an orange while stirring at room temperature, and 6SC
So/1 Terama stirred. The obtained precipitate was washed with normal hexane, and the solid catalyst component was washed with normal hexane IJ-
tT4. Polymerization was carried out using this solid catalyst component under the same polymerization conditions as in Example 11/. The results obtained are shown in Table-/.

From the results in Table 2, it can be seen that when copolymerization of ethylene and monoolefin is carried out using the catalyst component according to the method of the present invention, the copolymer has a narrow molecular blocking distribution, good transparency of the molded product, and a good slurry. It is clear that it can be obtained with good properties and high activity.

Claims (3)

[Claims] (1) General formula % Formula % () [In the formula, XI and X2 are halogen atoms, R1 is an alkyl group, aryl group or cycloalkyl group, and an electron selected from DU ether, carboxylic acid ester, alcohol and amine Represents a donor compound. nryo0.7~io
〆′J in the range of θ, j is the number in the range of λ, k is 1
It represents a number in the range of 0 to /, and is a number such that j+k corresponds to the valence of titanium. m is a number ranging from ko to aOO. ] and a solid complex represented by the general formula % Formula % [In the formula, R2 represents an alkyl group, an aryl group, or a cycloalkyl group, x8 represents a \rogen atom, and 1 represents a number in the range of / to 3. ] Using a catalyst system consisting of a combination of a hydrocarbon-insoluble solid catalyst separated from a reaction mixture obtained by total reaction with an organoaluminum compound shown in ] and a cocatalyst organoaluminum compound, ethylene and carbon atoms A method for producing an ethylene copolymer having a density of less than 1.0.9/y/cc, which comprises copolymerizing three or more α-olefins. (2) Hydrocarbon insoluble (1 solid catalyst or inert carbon!
The manufacturing method according to claim 1, wherein the molten metal is washed with a melt. (3) *The manufacturing method according to claim 1 or 2, wherein the polymerization temperature is below the melting point of the ethylene copolymer.