JPS61151204A - Production of polyolefin - Google Patents

Abstract

PURPOSE:To improve the balance of the formed polymer among crystallinity, rigidity and yield, by prepolymerizing a specified olefin monomer by using a composite catalyst comprising a titanium catalyst component and an organoaluminum compound and carrying out the main polymerization. CONSTITUTION:At least one olefin monomer selected from among 4- methylpentene-1,3-methylpentene-1,3-methylbutene-1, ethylene and styrenic compounds is used as an olefin monomer for prepolymerization. The amount of said olefin monomer is suitably 0.02-10g per unit weight (g) of said titanium catalyst component (preferably, titanium trichloride). It is preferable to use at least one styrenic compound selected from among styrene, divinylbenzene and alkyl-substituted styrenes in which the alkyl group is a 1-10C alkyl. Examples of the olefin monomers which can be used in the main polymerization include ethylene, propylene, butene-1, hexene-1, 4-methylpentene-1, butadiene, styrene and divinylbenzene.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing polyolefin, and more specifically, in the production of polyolefin in which olefin monomers are prepolymerized and further olefin is supplied for main polymerization, The present invention relates to a method for producing a polyolefin, which allows the obtained polyolefin to be made into a polymer with excellent balance in terms of crystallinity, sardinity, and yield.

[Technical background of the invention and its problems]

For example, as a method for producing polyolefins such as polypropylene, an olefin monomer is prepolymerized using a conjugation catalyst containing a titanium catalyst component and an organoaluminum compound, and then main polymerization is performed to improve the stability of the catalyst. is known (see JP-A-55-75409 and JP-A-57-151602).

However, in these methods, for example, in the production of polypropylene, propylene is prepolymerized and then main polymerization of propylene is performed, so the resulting polypropylene does not necessarily have a satisfactory balance of crystallinity, rigidity, yield, etc. The current situation is that it cannot be worn as a kimono.

[Purpose of the invention]

The present invention solves the above-mentioned problems when producing polyolefin through a two-stage continuous process of prepolymerization and single polymerization, and provides a polyolefin with an excellent balance between crystallinity, rigidity, and yield of the resulting polymer. The purpose is to provide a manufacturing method.

[Summary of the invention]

In order to achieve the above object, the present inventors have conducted extensive research into the optimal combination of prepolymerization and main polymerization. For example, when performing main polymerization of propylene, the following We discovered that when prepolymerized with olefin monomers, the surface morphology of the resulting polymer powder is significantly different from that when prepolymerized with propylene, that is, there are many network-like cracks on the surface.3 ) It has been found that due to the specificity of this powder form, the cleaning effect etc. are significantly improved, and the crystallinity and yield are excellent. Furthermore, the inventors also learned that when the olefin monomers used in prepolymerization are limited to specific ones, the properties of the resulting polymer, such as rigidity, are improved, leading to the development of the method of the present invention.

That is, in the method for producing a polyolefin of the present invention, an olefin monomer is prepolymerized using a composite catalyst comprising a titanium catalyst component and an organoaluminum compound, and then the polyolefin to be prepolymerized is further polymerized. are 4-methylpentene-1,3-methylpentene-], 3-methylbutene-1
, ethylene, and styrene. ``First, the waste metal catalyst used in the method of the present invention is a stereoregular catalyst, and consists of a titanium catalyst component and an organoaluminum compound. Among these, titanium halides are preferred as the titanium catalyst component, and titanium trichloride is particularly preferred. Titanium trichloride is obtained by reducing titanium tetrachloride by various methods; these are further ball-killed and/or washed with a solvent (for example, washing with an inert solvent and/or an inert solvent containing a polar compound). activated; titanium trichloride or titanium trichloride eutectic (e.g. Ti
ct, core htct, ) further co-pulverized with aquine, ether, ester, sulfur, halogen derivative, organic or inorganic nitrogen compound or phosphorus compound, etc.;
can be given. Furthermore, a material in which a titanium halide is supported on a magnesium compound can also be used.

As the organoaluminum compound of other components, the following formula: A
tRnXm-n (wherein, R is an alkyl group, alkoxy group, or aryl group having 1 to 1 carbon atoms, X is a halogen atom, and n is Q
(representing a value of n≦3) is preferred. Specifically, for example, triethylaluminum, triisobutylaluminum, and tri-n-propylaluminum.

Examples include diethylaluminium monochloride, diethylaluminium monobromide, diethylaluminium monoiodide, diethylaluminium monoethoxide, diisobutylaluminum monoisobutoxide, diethylaluminium monohydride, diisobutylaluminum monohydride, ethylaluminum sesquichloride, etc. , one or more of these can be used.

In the catalyst used in the method of the present invention, the molar ratio of Al1 is 0
．． 1 to 1000 is preferred. However, if electron-donating compounds such as alcohols, aldehydes, ethers, esters, lactones, ketones, amines, amides, organophosphorus compounds, organosilicon compounds, thiols, thioethers, and thioesters are included as catalyst components, the catalytic activity increases. It is unsuitable because it reduces the

In the method of the present invention, prepolymerization is carried out under the following conditions. First, the olefin monomers used are 4-methylpentene-1,3-methylpentene-1,3-methylbutene-1, ethylene, and styrenes. Examples of styrenes include styrene, divinylbenzene, and alkyl-substituted styrene substituted with an alkyl group having 1 to 10 carbon atoms. Each of these may be used alone, or two
The above methods may be used in appropriate combinations.

Propylene, hexene, octene and desenato are not suitable for use at this stage. This is because the object of the present invention is not achieved.

The prepolymerized amount of these olefin monomers is the unit weight (f) of the titanium catalyst component of the composite catalyst described above m 0.0
It is preferable that the amount corresponds to 2 to 10 f, particularly 0.05 to 3. Preferably it is an Of/f-titanium catalyst component. .

If the prepolymerized amount is less than 0.02 f/l-titanium catalyst component, neither the stereoregularity, that is, the crystallinity nor the rigidity of the polyolefin obtained after main polymerization will improve. Furthermore, if the amount increases (10 t/f-titanium catalyst component), the catalyst activity will be relatively reduced, making it impossible to obtain a polyolefin with high rigidity.

(γ) Regarding the reaction conditions during prepolymerization, first, the concentration of the olefin monomer is set to 0.5 to 500 at/l-solvent.

Preferably 5 to 200 rd/solvent. The solvent used is preferably an aliphatic, alicyclic, or aromatic inert hydrocarbon, and specific examples include bentayhexane, heptane, cyclohexane, and benzene-toluene.

The temperature is 0 to 100°C, preferably 10 to 90°C,
The pressure is 0.01-30Kf/(vl, preferably 0.0
It is 9/- from 5 to 15. Prepolymerization time is 0.5~
2000 minutes, preferably 2 to 600 minutes.

Preliminary polymerization and thorough polymerization are carried out, and the olefin monomer used at this time is, for example, ethylene.

Propylene, butene-1, hexene-1, heptene-1
, octene-1, decene-1; 4-methylpentene-1,3-methylpentene-1
, 3-methylbutene-1;
Examples include diolefins such as butadiene, isoprene, and chloroprene; styrenes such as styrene, divinylbenzene, and the alkyl-substituted styrenes mentioned above. These can be used alone or in an appropriate combination of two or more.

The reaction temperature is 0 to 100°C, preferably 30 to 90°C, and the pressure is 0.01 to 4 B'l/cIIs, preferably 0.
05-40 with 4/cfII, and the reaction time was 1-40.
The duration may be 3000 minutes, preferably 10 to 120 minutes.

As the preliminary polymerization and main polymerization methods, known methods can be applied, such as slurry polymerization.

Examples include solution polymerization, gas phase polymerization, and liquid phase polymerization using an olefin monomer as a medium.

- When the surface of the polyolefin obtained by the method of the present invention is observed using an electron microscope, it is found that there are many network cracks. Therefore, the cleaning effect is significantly improved,
O provides excellent crystallinity and yield [Examples of the invention] Examples 1 to 10. Comparative Examples 1 to 8 2 t of dehydrated n-heptane was charged into a stainless steel polymerization reactor with an internal volume of 5 t, and 0.4 F titanium trichloride was added.
, diethylarual is nium chloride 5wt (At/
Ti -15.4 mol 1 mol) was added as a catalyst and mixed, and then the dehydrated and purified prepolymerized olefin monomer shown in the table was added in a predetermined amount of polymerization, and the mixture was stirred for 20~ Prepolymerization was carried out at 60'C for 30-90 minutes.

After the prepolymerization, the temperature of the polymerization reactor was raised to 65°C, the gas phase was sufficiently replaced with propylene, and a calculated amount of hydrogen was introduced to obtain a predetermined intrinsic viscosity. Propylene was continuously supplied so that the total pressure was kept constant at 90 Kt/cIIIG, and main polymerization was carried out at 65° C. for 60 minutes.

Then, 80- of n-butanol was added thereto to stop the polymerization reaction and perform catalytic decomposition. Unreacted propylene was removed to separate the produced polypropylene, which was washed with n-hebutane and dried to obtain a powdery polymer.

The surface condition of each powder obtained was observed using a scanning electron microscope, and the intrinsic viscosity, isotactic pentad fraction, and tensile modulus were measured according to the following specifications.

Intrinsic viscosity: Measured in tetralin at 135°C Tensile modulus:
Isotactic pentad fraction according to JIS K6758: A, M by Zambelli
aoromolaulas, 6.925 (197
3), that is, the isotactic fraction in pentad units in a polypropylene molecular chain measured by the method using C-NMR. This value represents the fraction of one propylene monomer unit located at the center of a chain in which five consecutive propylene monomer units are meso-bonded.

However, regarding peak assignment, Maeromola
aulss, 8. 687 (1975), based on the correction board of the above-mentioned document. Specifically, C-N
m in the total absorption peak in the methyl carbon region of the MR spectrum
Isotactic pentad units were measured as the intensity fraction of the mm peak.

Note that the value of the isotactic pentad fraction shown is the value of the obtained crystalline polymer itself, and is not the value of the polymer after extraction and two fractionation.

The above results are summarized in the table. The yield of each polymer is also listed.

Example 2 and Comparative Example 2. Example 3 and Comparative Example 8. When comparing Example 4 and Comparative Example 4, which each have approximately the same intrinsic viscosity, it can be seen that the polymer of Example has significantly high rigidity (tensile modulus).

〔Effect of the invention〕

As is clear from the above explanation, the method of the present invention can produce polyolefins with a good balance of crystallinity, rigidity, and yield. It is particularly effective when applied to the production of propylene polymers or copolymers with other olefins,
Its industrial value is great as it provides materials for films, automobile parts, home appliances, general miscellaneous goods, etc.

Procedural amendment January 25, 1985 Manabu Shiga, Commissioner of the Patent Office1, Indication of the case, Patent Application No. 270949 filed in 19822, Name of the invention Process for producing polyolefin3, Person making the amendment Relationship to the present case Patent applicant name: Idemitsu Petrochemical Co., Ltd. 4, agent 7, the detailed description of the invention column in the supplementary statement of contents is amended as follows.

(1) "The yield will be better" stated in the second line of page 4 of the specification will be corrected to "the balance of the yield will be better."

(g) "
As a result, a polyolefin with high rigidity cannot be obtained. ”
is corrected as ``decreases and the rigidity does not improve.''

(3) "120 minutes" written on page 9, line 7 of the specification
1200 minutes”.

(4) "Product with excellent yield" described on page 9, line 15 of the specification is corrected to "product with excellent balance in yield."

Claims (1)

[Claims] 1. A method for producing a polyolefin in which an olefin monomer is prepolymerized using a composite catalyst consisting of a titanium catalyst component and an organoaluminum compound, and then further main polymerization is performed, wherein the olefin monomer to be prepolymerized comprises: A method for producing a polyolefin, characterized in that the polyolefin is at least one selected from the group consisting of 4-methylpentene-1,3-methylpentene-1,3-methylbutene-1, ethylene, and styrenes. 2. The method for producing a polyolefin according to claim 1, wherein the prepolymerized amount of the olefin monomer is 0.02 to 10 g per unit weight (g) of the titanium catalyst component. 3. The styrenes include styrene, divinylbenzene,
Claim 1: One or more alkyl-substituted styrenes substituted with an alkyl group having 1 to 10 carbon atoms
A method for producing a polyolefin as described in Section 1.