JPS62275111A - Continuous polymerization of propylene - Google Patents

Abstract

PURPOSE:To produce a highly crystalline polypropylene continuously, by polymerizing propylene by using a catalyst comprising four compounts which are subjected to a specified treatment. CONSTITUTION:In a process for polymerizing propylene or copolymerizing propyelne with other olefins by using a catalyst, comprising a solid catalyst (a) formed by allowing a carrier containing a magnesium halide on at least its surface to support a titanium halide, an organoaluminum compound (b) having two or more Al atoms bonded together through O or N, a stereoregularity improver (c) selected from among an ester, an ether, an orthoester and an alkoxy silicon compound and a halogen-containing organoaluminum compound (d), component (a), part or the whole of component (c), part or the whole of component (d) and 0 to part of component (b) are precontacted with a vinylcycloalkane and/or a 5C or higher olefin branched at position 3 or 4 in an inert hydrocarbon solvent. The treated mixture, the remaining portions of component (c) and (d) and component (b) are fed to a propylene polymerization zone.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for polymerizing propylene. Specifically, the present invention relates to a method for continuously producing highly crystalline polypropylene using a specific catalyst.

[Conventional technology]

Polypropylene is a general-purpose polymer that has relatively good rigidity and good visibility, and is widely used for various purposes. In addition, a method is known in which polypropylene is copolymerized with other α-olefins such as ethylene in order to improve its impact resistance (especially at low temperatures) (for example,
4-20621 Publication, Special Publication No. 49-24593, Special Publication No. 49-12589, etc.).

Improving the rigidity of polypropylene, whether it is a propylene homopolymer or a copolymer with other α-olefins, is effective in improving its physical properties, and adding various nucleating agents is already effective for this purpose. known, and several examples are known.

In addition, there are known examples of using polymer nucleating agents that do not bleed the nucleating agents etc. from polypropylene molded articles and exhibit even greater effects (for example, JP-A-60-139710; Japanese Patent Publication No. 60-139731
Publications, etc.).

[Problem that the invention seeks to solve]

The method using the polymer nucleating agent described above is extremely superior, and the rigidity and transparency of films, sheets, etc. are greatly improved.

However, in a method in which vinyl cyclohexane or the like is polymerized on a solid catalyst, and then propylene is polymerized after washing etc. to make the catalyst covered with a polymer nucleating agent, the activity per solid catalyst is significantly reduced, and the resulting polypropylene is There were problems such as the boiling n-heptane extraction residue rate (hereinafter abbreviated as ■!) decreased significantly, and when the obtained polymer was made into a molded product, the appearance of the molded product was poor. On the other hand, in a method in which propylene is treated with vinylcyclohexane etc. under the original conditions for polymerizing propylene without repeated washing etc., and propylene is directly polymerized, the problem of the above-mentioned decrease in activity and II is substantially avoided during batch polymerization. Although this does not occur, when continuous polymerization is carried out, there is a problem that if it is continued as it is, the polymerization activity and II will be significantly reduced.

[Means for solving problems]

The inventors of the present invention have conducted extensive studies on methods for solving the above problems, and have completed the present invention.

That is, the present invention provides a) a solid catalyst comprising a titanium halide supported on a carrier containing magnesium halide at least on its surface, b)) a realkyl aluminum or two or more of them bonded to each other through oxygen or nitrogen atoms. C) a stereoregularity improver selected from esters, ethers, orthoesters, and alcoquine silicon compounds; and d) a halogen-containing organoaluminum compound. and other α-olefins, in which a) solid catalyst and C)
Part to all of the stereoregularity improver, d) part to all of the halogen-containing organoaluminum compound, and b) O to part of the organoaluminum compound, in an inert hydrocarbon solvent, vinylcycloalkane and/or Propylene is characterized in that after contact treatment with an olefin branched at the 3rd or 4th position having 5 or more carbon atoms, the treated mixture, the remainder of components C) and d), and component b) are introduced into a propylene polymerization zone. This is a polymerization method.

In the present invention, a) many examples of the solid catalyst are already known, including a solid catalyst formed by supporting titanium halide on a carrier containing magnesium halide, which provides polypropylene with high activity and high stereoregularity. There are no particular restrictions. For example, a method in which various organic compounds (preferably oxygen-containing organic compounds) and magnesium halides are co-pulverized is used as a carrier, and then the carrier is contacted with titanium tetrachloride, titanium trichloride, or diluted titanium trichloride with various solvents. , magnesium halide is solubilized in a hydrocarbon solvent or halogenated hydrocarbon solvent with ether, alcohol, amide, etc., and then solubilized with a precipitant such as titanium halide or silicon halide in the presence or absence of an oxygen-containing organic compound, etc. A method in which titanium halide is supported in the same manner as described above by treating it in the presence of alcohol to precipitate magnesium halide, and then using it as a carrier with or without contact with an oxygen-containing organic compound, etc., to support titanium halide in the same manner as above.
Contact treatment is carried out with alkoxy silicon, and then the obtained solid component is further contacted with a halogen-containing compound and then used as a carrier with or without contact treatment with an oxygen-containing organic compound, and titanium halide is supported in the same manner as described above. For example, there is a method in which a solid is precipitated from a solution of a magnesium compound as described above, in which an inert solid such as alumina or silica is made to be present to prepare a carrier, and then a titanium halide is supported on the carrier.

Preferred examples of the oxygen-containing organic compound include carboxylic acid esters, ethers, alkoxysilicone, and orthocarboxylic acid esters.

In the present invention, as component b), trialkylaluminum such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum, or a mixture thereof, or the above-mentioned trialkylaluminum and water according to a known method, Compounds obtained by reaction with ammonia or primary amines, such as (CJs)! Al-0-AI (CzHs) z, (
Cz)Is) 2A1-N-^1(CtHs)z, etc.

In the present invention, the esters, ethers, orthoesters, and alkoxy silicon compounds that are component C) include:
Specifically, esters such as ethyl acetate, methyl acrylate, methyl methacrylate, ethyl benzoate, methyl toluate, triethyl phosphate, triphenyl phosphate,
Ethers such as diethyl ether, diisoamyl ether, diphenyl ether, dinaphthyl ether, methyl orthoformate, ethyl orthoformate, methyl orthoacetate,
Examples include ortho esters such as methyl orthobenzoate and ethyl orthobenzoate, and alkoxy silicones such as tetraethoquinosilane, triethoxyethylsilane, triethoxyquinophenylsilane, trimethoxyphenylsilane, and trimethoxyvinylsilane.

In the present invention, the halogen-containing aluminum compound as component d) includes diethylaluminum chloride, diethylaluminium bromide, diethylaluminium iodide, dimethylaluminum chloride, dipropylaluminum chloride, dipropylaluminum bromide, diethylaluminum sesquichloride, diethyl aluminum Examples include aluminum sesquibromide, dipropylaluminum sesquichloride, ethylaluminum dichloride, propylaluminum dichloride, and dialkylaluminum halide is particularly preferably used.

The vinylcyclobutane used in the present invention and the olefin branched at the 3rd or 4th position having 5 or more carbon atoms include vinylcyclohexane, vinylcyclobutane, vinylcyclobutane, 3-methylbutene-114-methylpentene, 4-methylhexene, 4° 4-dimethylpentene, 4
．． Examples include 4-dimethylhexene and vinylnaphthalene, among which vinylcyclohexane, 3-methylbutene-1,4,4-dimethylpentene, and 4,4-dimethylhexene are preferably used.

In the present invention, prior to the polymerization of propylene, the contact treatment with the vinyl compound is carried out in an inert hydrocarbon medium such as pentane, hexane, heptane, nonane, decane, cyclohexane, benzene, toluene, xylene, ethylbenzene, etc. Usually 0~70℃, preferably 10~60℃
Performed at °C. The contact time is generally several minutes to several hours, and the concentration of the vinyl compound is 0.1 to 10
0g/1 is common. Preferably, the reaction temperature, reaction time, and liquid phase concentration of the vinyl compound are such that the vinyl compound is polymerized by 0.001 to 200 times the weight of the solid light. The important points here are a), b), and C) above.
and d) of the amounts used in the propylene polymerization of each component, component a) is the entire amount, component C) is a part to the entire amount, d
Component) is used in a part to the entire amount, component b) is used in 0 to a part in contact with the vinyl compound to precede the polymerization of propylene, and preferably component b) is used in a proportion of 0 to 10%, and component C) is used in a proportion of 0 to 10%. 5
~100%, component d) 20-100%, particularly preferably component b) 0%, component C) 10-100%, d)
The ingredients are to be used in an amount of 50 to 100%. When a large amount of component (b) is used during the contact treatment with the vinyl compound, it is not preferable because it leads to a decrease in activity and a decrease in I+ during propylene polymerization. If the amount of component C) used is too small, it will lead to a decrease in I+ during propylene polymerization, which is not preferable. d
If the amount of component ) used is too small, not only will I+ be lowered during the polymerization of propylene, but the effect of polymerizing the vinyl compound in advance of the polymerization of propylene will almost disappear. This treatment is preferably carried out batchwise.

In the present invention, propylene polymerization is continuously carried out by continuously introducing the above-mentioned catalyst into the propylene polymerization zone.

The conditions for the propylene polymerization zone may be any of solvent polymerization, bulk polymerization, and gas phase polymerization, and the polymerization temperature is 0 to 90°C, preferably 30 to 80°C, and the polymerization pressure is normal. It is generally carried out at a pressure of ~50 kg/-.gauge.

Polymerization of propylene in the polymerization zone includes not only propylene homopolymerization but also random copolymerization with other α-olefins such as ethylene and butene-1, or block copolymerization.

Furthermore, in the present invention, a molecular weight regulator such as hydrogen can be used prior to the polymerization of propylene and during the polymerization of the vinyl compound or the polymerization of propylene.

〔Effect of the invention〕

By implementing the method of the present invention, it is possible to obtain polypropylene with high II and high crystallinity without impairing polymerization activity, and it is industrially advantageous.

〔Example〕

The present invention will be explained below with reference to Examples.

Experimental Example 1 Production of Solid Catalyst A vibrating mill containing 4 pulverization pots with an internal volume of 41 and containing 9 kg of steel balls with a diameter of 12 mm is prepared. Each pot is charged with 300 g of magnesium chloride and tetrafluoride under a nitrogen atmosphere. 60 ml of ethoxysilane and 45 ml of α, α, α-trichlorotoluene were added and pulverized for 40 hours.

3 kg of the above pulverized material and 10 titanium tetrachloride were placed in a reactor No. 501.
1 and toluene IOA were added, the mixture was stirred at 80° C. for 1 hour, and then separated by standing and the supernatant was removed twice. The solid content was then washed with 40β of n-heptane to obtain a solid catalyst. This solid catalyst component contained 1.6 wt.chi. of titanium.

Experimental Example 2 Production of Solid Catalyst 2 In a 10L reactor, 31.2-ethylhexyl alcohol, 2.81 g of kerosene, 276+ nl of ethyl benzoate, and 570 g of magnesium chloride were added, stirred at 130°C for 1 hour to form a homogeneous solution, and 5ON The homogeneous solution was transferred to a reactor, cooled to -20°C, charged with 12A titanium tetrachloride over 1 hour, heated to 90°C over 2 hours to precipitate the solid catalyst, and then It was treated at 90°C for 2 hours. Thereafter, the mixture was left to stand for separation to remove the supernatant, and 12ffi of titanium tetrachloride was added thereto, followed by heat treatment at 80° C. for 1 hour. Then, after standing to separate and removing the supernatant, the solid content was dissolved in n-hebutane 4
Solid catalyst B was obtained by washing with 01 7 times. This solid catalyst component contained 2.6 wt.chi. of titanium.

Example 1 30 g of solid catalyst A obtained in the above experimental example, 213 ml of diethylaluminum chloride, 2 ρ-methyl toluate
0 ml, vinylcyclohexane 200 ml and n
-Hebutane 11 was added and stirred at 40°C for 2 hours.

A portion of the sample was analyzed for the amount of vinylcyclohexane polymerized using the solid catalyst, and it was found to be 0.3 g/g.

75Kg of propylene was placed in an autoclave with an internal volume of sooe, and after heating it to 75℃, the hydrogen concentration was 3.5N.
Hydrogen was charged so that the amount was 1. Next, the above mixed slurry was used as a solid catalyst at 2.5 g/h, methyl p-toluate 4 ml/h, and triethylaluminum 7 ml.
Liquefied propylene was charged at 75 kg/h, and while the slurry was withdrawn at 75 kg/h, hydrogen was introduced so that the hydrogen concentration in the gas phase was 3.5 Nff. Polymerization was continued for 15 hours at °C.

Powder taken out from the slurry 10 hours after the start of polymerization was analyzed. The results are shown in the table.

The yield of polypropylene using solid catalyst light is calculated from the titanium content in the powder, and the intrinsic viscosity is 135°C tetralin? At 8W, the percentage of boiling n-hebutane extraction residue is:
It was calculated by extracting for 6 hours using a TIζ river type extractor. The melting point and crystallization temperature were measured using a differential scanning calorimeter by increasing the temperature at 10° C./+nin or by tel-in.

Comparative Example 1 The same pond as in Example 1 was used in which the contact treatment prior to the polymerization of propylene was carried out in the absence of the vinyl compound hexane.

The results are shown in the table.

Example 2 The same procedure as in Example 1 was carried out except that solid catalyst B was used as the solid catalyst and 3-methylbutene-■ was used instead of vinylcyclohexane. The polymerization amount of 3-methylbutene-1 is 0.
It was 4g/g solid catalyst. The results are shown in the table. Example 3 The same procedure as Example 1 was carried out except that 4,4-dimethylpentene-1 was used in place of vinylcyclohexane. The results are shown in the table.

Comparative Example 2 The same procedure as Example 2 was carried out except that 3-methylpentene-1 was not used. The results are shown in the table.

Comparative Example 3 The entire amount of all the components added during propylene polymerization was used in the first stage of contact, and when introducing the autoclave into the autoclave for propylene polymerization, the nozzle was set as a double tube, and the treated catalyst was charged from the inner tube. Moreover, by charging n-hebutane to the outside, clogging of the catalyst charging nozzle was prevented and polymerization was carried out. The results are shown in the table.

Leap x I7) There is no history in the pure E content. (A) Transition combined pressure component Procedural formalities (method) March 12, 1986

Claims (1)

[Claims] a) a solid catalyst comprising titanium halide supported on a carrier containing magnesium halide on at least its surface; b) trialkylaluminum or an organic compound having two or more aluminum atoms bonded to each other via oxygen or nitrogen atoms; Polymerizing propylene or propylene and other α-olefins using a catalyst consisting of an aluminum compound, c) a stereoregularity improver selected from esters, ethers, orthoesters, and alkoxy silicon compounds, and d) a halogen-containing organoaluminum compound. In the method, in advance, a) solid catalyst, c) part to all of the stereoregularity improver, d) part to all of the halogen-containing organoaluminum compound, and b) 0 to part of the organoaluminum compound are mixed with inert carbon. After contact treatment with a vinylcycloalkane and/or an olefin branched at the 3- or 4-position having 5 or more carbon atoms in a hydrogenated solvent, the treated mixture and c),
A method for continuously polymerizing propylene, which comprises introducing the remainder of component d) and component b) into a propylene polymerization zone.