JPS6337105A - Continuous polymerization of propylene - Google Patents

Abstract

PURPOSE:To continuously obtain highly crystalline polypropylene, by subjecting part of catalyst components to contact treatment with an unsaturated compound, washing the treatment product, adding other catalyst components and polymerizing the propylene batchwise in continuously polymerizing the propylene using a specific catalyst. CONSTITUTION:Propylene is continuously polymerized by using a catalyst consisting of (A) a solid catalyst containing a Ti halide supported on a carrier containing an Mg halide, (B) an organoaluminum compound, (C) a stereoregularity improving agent selected from (ortho)esters, ethers and alkoxysilane compounds and (D) a halogen-containing organoaluminum compound in a continuous polymerization zone. In the process, the components (A) and (D) are previously subjected to contact treatment with an unsaturated compound, e.g. vinylcycloalkane, etc., in an inert hydrocarbon solvent and washed. Part - all of the components (C) and (D) and 0% - part of the component (B) are added and the propylene is polymerized batchwise in an amount of 0.1 - 100g based on 1g component (A) in an inert hydrocarbon solvent. The remainders of the components (C), (D) and (B) are then introduced into the continuous polymerization zone.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of 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.

(Prior Art) Polypropylene is a general-purpose polymer with relatively excellent rigidity and transparency, and is widely used for various purposes. Additionally, for the purpose of improving the impact resistance (especially at low temperatures) of polypropylene, a method of copolymerizing it with other α-olefins such as ethylene is known (for example, Japanese Patent Publication No. 44
-20621 Publication, Special Publication No. 49-24593,
(Special Publication No. 49-12589, etc.).

Improving the rigidity of polypropylene is a common problem for propylene homopolymers and copolymers with other α-olefins, and there are methods for this purpose, such as adding various nucleating agents. Some are known.

In addition, examples of using a polymer agent as a method for preventing the used nucleating agent from bleeding from the molded product are known (for example, Japanese Patent Application Laid-Open No. 60-139710, Japanese Patent Application Laid-Open No. 60-13
9731, etc.).

[Problem that the invention seeks to solve]

The method of using a polymer nucleating agent not only prevents bleeding but also has the effect of greatly improving the rigidity and transparency when made into a film or sheet. However, the method using a polymer nucleating agent
Generally, vinyl cyclohexane or the like is polymerized on a solid catalyst, and then propylene is polymerized as a catalyst covered with a polymer nucleating agent by washing etc., or on a solid catalyst,
There are methods such as treating with vinyl cyclohexane or the like and directly polymerizing propylene. In the former case, the activity per solid catalyst is significantly reduced, and the boiling n-
There were problems such as the percentage of hebutane extraction residue (hereinafter abbreviated as Nr) 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 the case of the latter, the above-mentioned problem of decreased activity and Nl does not substantially occur during batch polymerization, but when polymerization is carried out for a long time such as continuous polymerization, there is a problem that the activity and Nl of the polymerization decrease significantly. there were.

(Means for Solving the Problems) The present inventors have intensively studied methods for solving the above problems, and have completed the present invention.

That is, the present invention is directed to a) a solid medium comprising a titanium halide supported on a carrier containing magnesium halide on at least its surface; b) two or more trialkylaluminiums or two or more bodies bonded to each other through oxygen or nitrogen atoms. an organoaluminum compound having an aluminum atom; C) a stereoregularity improver selected from esters, ethers, orthoesters, and alkoxy silicon compounds; and d)
In a method of polymerizing propylene or propylene and other α-olefins using a catalyst consisting of a halogen-containing organoaluminum compound, a) a solid medium and d) a halogen-containing organoaluminum compound are preliminarily prepared in an inert hydrocarbon solvent. Cycloalkane, 3rd or 4th position with 5 or more carbon atoms
contact treatment with at least one unsaturated compound selected from position-branched olefins, alkylvinylsilanes, and alkylarylsilanes, and then washing the contact-treated solid catalyst with an inert hydrocarbon solvent, and further C) stereoregularity. Part to all of the same agent, d) Part to all of the halogen-containing organoaluminum compound, and b) Zero to part of the organoaluminum compound, and propylene in an inert hydrocarbon solvent is a) 0 per 1 g of solid medium. This is a continuous propylene polymerization method characterized in that 1 g to 100 g of the batch-polymerized post-contact treatment mixture and the remainder of components C), d), and b) are introduced into a continuous propylene polymerization zone.

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. For example, a carrier may be co-pulverized with various organic compounds (preferably oxygen-containing organic compounds) and magnesium halide, and then titanium tetrachloride, titanium trichloride, or the like may be mixed with various solvents. A method in which magnesium halide is solubilized in a hydrocarbon solvent such as ether, alcohol, or amide, or a halogenated hydrocarbon solvent, and then oxygenated with a precipitant such as titanium halide or silicon halide. A method in which magnesium halide is precipitated by treatment in the presence or absence of an organic compound, etc., and then used as a carrier with or without contact with an oxygen-containing organic compound, etc., to support titanium halide in the same manner as described above, Organomagnesium is contacted with alcohol and alkoxy silicon, and the obtained solid component is then further contacted with a halogen-containing compound, and then used as a carrier with or without contact treatment with an oxygen-containing organic compound, etc., in the same manner as described above. Examples include a method of supporting titanium halide, and a method of producing a carrier by allowing an inert solid such as alumina or silica to be present when precipitating a solid from a solution of the magnesium compound, and then supporting titanium halide. .

Preferred examples of the oxygen-containing organic compound include carboxylic acid esters, ethers, alkoxy silicones, 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 (C□Hs) Jl-0-AI (CtHs) tA
1-Lee AI(Cs[l5)i, 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 tetraethoxysilane, triethoxyethylsilane, triethoxyphenylsilane, trimethoxyphenylsilane, and trimethoxyvinylsilane.

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

Vinylcycloalkane used in the present invention, carbon number 5
Examples of the above olefins, alkylvinylsilanes and alkylarylsilanes branched at the 3- or 4-position include vinylcyclohexane, vinylcyclopenkune, vinylcyclobutane, 3-methylbutene-1,4-methylpentane,
4-methylhexene, 4.4-dimethylpentene, 4.
Examples include 4-dimethylhexene, vinylnaphthalene, trimethylvinylsilane, triethylvinylsilane, dimethylethylvinylsilane, trimethylallylsilane, triethylallylsilane, dimethylethylallylsilane, and especially vinylcyclohexane, 3-methylbutene-
1,4,4-dimethylpentene, 4,4-dimethylhexene, triditylvinylsilane, trimethylallylsilane, etc. can be preferably used.

In the present invention, in advance, a) a solid medium and d) a halogen-containing organoaluminum compound are mixed in an inert hydrocarbon solvent with a vinylcycloalkane, an olefin branched at the 3rd or 4th position having 5 or more carbon atoms, an alkylvinylsilane, and an alkylarylsilane. The solid catalyst is then washed with an inert hydrocarbon solvent. Examples of inert hydrocarbon solvents include aliphatic hydrocarbon residues such as butane, penkune, hexane, heptane, nonane, decane, and dodecane, ring hydrocarbon compounds such as cyclohexane and methylcyclohexane, benzene, toluene, xylene, and ethylbenzene. Examples include aromatic hydrocarbon compounds such as , cumene, and diisopropylbenzene.

As a solid medium, the titanium content is 0.0001 to 10g.
/ 1! The halogen-containing organoaluminum compound has a concentration of 0.001 to 10% relative to the titanium content in the antiisomer catalyst.
Preferably in the presence or absence of a stereoregularity improver selected from esters, ethers, orthoesters, and alkoxy silicon compounds in an amount equal to or less than 0 times the mole of the halogen-containing organoaluminum compound. Vinyl cycloalkane in an amount of 0.01 times or more by weight or more in the antiisomer catalyst, an olefin branched at the 3rd or 4th position having 5 or more carbon atoms,
A contact treatment is carried out with at least one unsaturated compound selected from alkylvinylsilanes and alkylarylsilanes.

The contact treatment is usually carried out at 0 to 100° C. for several minutes to several hours, and then the solid catalyst is washed with the above-mentioned inert hydrocarbon solvent by filtration or static separation. At this time, it is preferable to conduct the contact treatment under conditions such that the unsaturated compound reacts and adheres to the homogeneous catalyst at a weight ratio of 0.001 to 200.

The solid catalyst subjected to the contact treatment and washing treatment is then treated with C) part to all of the stereoregularity improver, d) part to all of the halogen-containing organoaluminum compound, and b) zero to part of the organoaluminum compound. Additionally, propylene is polymerized in batches of a) 0.18 to 100 g per g of solid medium in an inert hydrocarbon solvent. This reaction is carried out in the same inert hydrocarbon solvent as described above with a solid catalyst concentration of usually 0.01 to 100.
g/R, carried out under conditions such that 0.1 to 100 g of propylene is polymerized with a solid catalyst at a temperature of 0°C to 50°C.
What is important here is that the amount used in the continuous polymerization of propylene for each of the above components a), b), C) and d) is that component a) is the entire amount, component C) is part to the entire amount, and component d) is the amount used in the continuous polymerization of propylene. Part to full amount, b) Component is 0 to part of propylene series Vt
It is used for batchwise contact with a small amount of propylene prior to polymerization, and preferably component b) contains 0 to 10% C.
) component is 5 to 100%, d) component is 20 to 100%, particularly preferably b) component is 0%, and C) component is 10 to 10%.
0%, component d) is 50 to 100% during contact treatment with a small amount of propylene in 0 batches, and if a large amount of component b) is used, during continuous propylene polymerization, a decrease in activity or N
On the other hand, if the amount of component C) used is too small, it will lead to a decrease in Nl during continuous polymerization of propylene, which is undesirable. Furthermore, if the amount of component d) used is too small, it will lead to a decrease in Nl during continuous polymerization of propylene. Not only does this result in a decrease in Nl during polymerization, but the effect of batch polymerization of a small amount of propylene prior to continuous polymerization of propylene is almost eliminated.In this case, the amount of polymerized propylene per solid catalyst light is 0.0
If it is less than 1g, the bulk specific gravity of the polypropylene obtained during continuous polymerization will decrease significantly, and if it is more than 100g, the equipment for batch polymerization will become bulky, and it will be difficult to charge the slurry into the continuous polymerization zone. becomes.

In the present invention, propylene polymerization is continuously performed by continuously introducing the above-mentioned catalyst into a continuous propylene polymerization zone. The conditions for the continuous 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 pressure ~50Kg/cd
It is common to do so.

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.

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

〔Example〕

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

Experimental Example 1 Production of Solid Catalyst I A vibratory mill equipped with four grinding pots each having an internal volume of 41 and containing 9 kg of steel balls each having a diameter of 12 AU was prepared. 300 g of magnesium chloride, 60 ml of tetraethoxysilane and 45+*l of α,α,α-trichlorotoluene were added to each pot under a nitrogen atmosphere, and the mixture was ground for 40 hours.

3 kg of the above pulverized material and 1 titanium tetrachloride were placed in a 501 reactor.
01 and toluene 101 were added, stirred at 80°C for 1 hour, separated by standing, and the supernatant was removed twice. The solid content was then washed with n-hebutane to reduce the solid catalyst A by %. Obtained. This solid catalyst component contained 1.5 wt.chi. of titanium.

Experimental Example 2 Production of Solid Catalyst 2 2.8 J of kerosene 3112-ethylhexyl alcohol, 276 ml of ethyl benzoate, and 570 g of magnesium chloride were put into a reactor No. 101, stirred at 130°C for 1 hour to make a homogeneous solution, and then put into a reactor No. 501. The homogeneous solution was transferred to -20°C, charged with 121 titanium tetrachloride over 1 hour, heated to 90°C over 2 hours to precipitate the solid catalyst, and further heated at 90°C. It was treated for 2 hours.

Thereafter, the supernatant was removed by static separation, and 121 titanium tetrachloride was added and heat-treated at 80°C for 1 hour.
Solid catalyst B was obtained by washing with No. 1 seven times. This solid catalyst component contained 2.6 wLχ of titanium.

Example 1 30 g of solid catalyst A obtained in the above experimental example, 213 ml of diethylaluminium chloride, 2 methyl p-)ruylates
0m1. Vinylcyclohexane 2001 and n-heptane 11 were added and stirred at 40°C for 2 hours.Then, the mixture was filtered and washed with n-heptane to obtain a catalyst in which 0.3g/g of vinylcyclohexane was polymerized per solid catalyst. This catalyst slurry was put into a 501 autoclave, and then
- Add 20 J of hebutane, 213 ml of diethylaluminum chloride, and 50 mj of methyl p-toluate,
100g of propylene was fed and treated at 30°C for 1 hour. When a portion was sampled and analyzed, 1.8 g of propylene was polymerized per solid catalyst.

After putting 75Kg of propylene into an autoclave with an internal volume of 5001 and raising the temperature to 75℃, the hydrogen concentration was 3.5N.
Then, the above mixed slurry was charged as a solid catalyst with 2.5 g/h of hydrogen, 2.5 sl of p-)methyl ruylate, 7 ml of triethylaluminum/
Further, 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 Nl. 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 Table-1.

The yield of polypropylene per solid catalyst is calculated from the titanium content in the powder, the intrinsic viscosity is 135℃ tetralin solution, and the percentage of boiling n-hebutane extraction residue is extracted for 6 hours with a pre-type extractor. It was calculated by The melting point and crystallization temperature were measured at 10°C using a differential scanning calorimeter.
The measurement was performed by increasing or decreasing the temperature by /sin.

Comparative Example 1 The same procedure as Example 1 was carried out except that the treatment with vinylcyclohexane was not performed. The results are shown in Table-1.

Comparative Example 2 After treatment with vinylcyclohexane, continuous polymerization was carried out using the solid catalyst slurry without filtration and washing. However, the amount of methyl phosphate used was 4 ml. The results are shown in Table 1.

Example 2 The same procedure as Example 1 was carried out except that solid catalyst B was used as the solid catalyst and allyltrimethylsilane was used.

The polymerized amount of allyltrimethylsilane was 0.1 g/g solid catalyst. The results are shown in Table-1.

Example 3 The same procedure as Example 1 was carried out except that 4,4-dimethylpentene-1 was used in place of vinylcyclohexane. Display the results -
Shown in 1.

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 Table-1.

Comparative Example 4 The same procedure as in Example 1 was carried out, except that 228 ml of triethyl aluminum was used instead of 213 mj of diethyl aluminum chloride for the treatment with vinylcyclohexane. The results are shown in Table-1.

〔Effect of the invention〕

By carrying out the method of the present invention, it is possible to obtain polypropylene with high Nl and high crystallinity without polymerization activity, which is of great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a flow chart diagram of a catalyst used for continuous polymerization of propylene.

Claims (1)

[Claims] a) a solid medium comprising titanium halide supported on a carrier containing magnesium halide at least on its surface; b) trialkylaluminum or an organic material 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, a) a solid medium and d) a halogen-containing organoaluminum compound are preliminarily selected from vinylcycloalkanes, olefins branched at the 3- or 4-position having 5 or more carbon atoms, alkylvinylsilanes, and alkylarylsilanes in an inert hydrocarbon solvent. Then, the contact-treated solid catalyst is washed with an inert hydrocarbon solvent, and further c) part to all of the stereoregularity improver, and d) halogen-containing organoaluminum. Adding part to all of the compound and b) 0 to part of the organoaluminum compound,
propylene in an inert hydrocarbon solvent a) 1 g of solid medium
A method for continuous polymerization of propylene, characterized in that after polymerizing in batches of 0.1 g to 100 g per unit, the treated mixture and the remainder of components c), d), and b) are introduced into a continuous polymerization zone of propylene.