JP2004018697A - Method for producing ethylene-conjugated diene copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ethylene-conjugated diene copolymer which has a conjugated diene incorporated into a copolymer main chain as a 1,2-cyclopentane ring with high selectivity, simultaneously has a structure having a reduced inner olefin, and excels in thermal and chemical stability. <P>SOLUTION: The ethylene-conjugated diene copolymer is obtained by polymerizing ethylene and a conjugated diene in the presence of a catalyst composed of a solid catalyst, as component (A), obtained by adding a specified oxygen-containing organic compound (iv) to a solid catalyst to be obtained by the reaction of a magnesium-containing compound (i), a homogeneous solution (ii) containing an oxygen-containing organic compound of titanium, and a halogenated organoaluminum compound (iii) and an organoaluminum compound as component (B). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a novel ethylene-conjugated diene copolymer. More specifically, the present invention relates to a method for producing an ethylene-conjugated diene copolymer having a specific structure by copolymerizing ethylene and a conjugated diene in the presence of a specific catalyst.
[0002]
[Prior art]
As a method for producing an ethylene-conjugated diene copolymer, a method for producing an ethylene-butadiene copolymer using a transition metal compound is already known.
[0003]
For example, Polymer @ Bulletin 8,473-478 (1982) includes SiO₂To TiCl₄A method for producing an ethylene-butadiene copolymer in the presence of a solid catalyst treated with a catalyst and an alkylaluminum is described. Also, in Journal of Polymer Science: Part A: Polymer Chemistry, 26, 2487-2500 (1988), magnesium chloride was co-ground and TiCl₄A method for producing an ethylene-butadiene copolymer in the presence of a catalyst consisting of an alkylaluminum and a catalyst treated with the above. However, polymers polymerized with these solid titanium catalysts called Ziegler catalysts have a main chain in the form of internal olefins, that is, transvinylene, because butadiene is introduced into the copolymer exclusively by 1,4-trans addition. A copolymer having a double bond introduced therein is produced. For this reason, there have been problems such as thermal deterioration at the time of molding processing, and changes in physical properties of molded articles with the passage of time.
[0004]
Recently, for example, Japanese Patent No. 2764163, die Makromolecule Chemie 192, 2591-2601 (1991), and the like, when an ethylene-butadiene copolymer is produced in the presence of a metallocene catalyst and an aluminoxane catalyst, a cyclic monomer is produced. It has been reported that a unique polymer having a 1,2-cyclopentane ring in the main chain can be produced despite the use of no. Such 1,2-cyclopentane ring is formed by polymerizing butadiene by 1,2-addition, then by polymerizing one ethylene, and then re-inserting a vinyl group formed in a side chain by 1,2-addition. Maurizio @ Galimberti et al. Propose. However, even when an ethylene-butadiene copolymer is produced by this method, a 1,2-cyclopentane ring is not formed selectively, and a considerable amount of butadiene is added to the copolymer by 1,4-cyclopentane. It was incorporated by an addition reaction and was contained in the main chain in the form of an internal olefin, that is, in the form of transvinylene. For this reason, as in the case of the ethylene-butadiene copolymer using the Ziegler catalyst, it was insufficient to solve various problems such as thermal deterioration during molding.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing an ethylene-conjugated diene-based copolymer having a specific structure by copolymerizing ethylene and a conjugated diene in the presence of a specific catalyst.
[0006]
That is, the present invention provides a method for producing an ethylene-conjugated diene-based copolymer having a structure in which a conjugated diene is incorporated with high selectivity as a 1,2-cyclopentane ring in a copolymer main chain and has a structure with a small amount of internal olefin. It is in.
[0007]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, by copolymerizing ethylene and a conjugated diene in the presence of a catalyst composed of a specific solid transition metal catalyst and an organoaluminum compound, a conjugated diene was obtained. Is incorporated into the main chain of the copolymer as a 1,2-cyclopentane ring with high selectivity, and found a method capable of producing an ethylene-conjugated diene copolymer having a structure having a small amount of internal olefins, and the present invention It was completed.
[0008]
That is, the present invention provides, as the component (A), at least one member selected from the group consisting of (i) metal magnesium and an organic hydroxide compound, an oxygen-containing organic compound of magnesium, and a halogen-containing compound of magnesium; A solid catalyst obtained by reacting a homogeneous solution containing an oxygen-containing organic compound of titanium with (iii) an organoaluminum halide compound, and (iv) two or more solid catalysts at any stage of the preparation of the solid catalyst. From a solid catalyst prepared by a method of adding at least one member selected from an ether compound having an oxygen atom, a polyether compound, an ester compound, and a diketone compound (hereinafter, referred to as an oxygen-containing organic compound) and an organoaluminum compound as the component (B) Ethylene and the following general formula (1) in the presence of a catalyst
CH₂= CH-CH = CH (C_mH_{2m + 1}) (1)
(M is an integer of 0 or more.)
By copolymerizing a conjugated diene represented by the following formula, the copolymer has a 1,2-cyclopentane ring, and has a ratio of the number of 1,2-cyclopentane rings to the number of transvinylenes.
(Number of 1,2-cyclopentane rings) / (number of transvinylene)
And a method for producing an ethylene-conjugated diene-based copolymer, characterized by producing a polymer having a molecular weight of 5 or more.
[0009]
In the present invention, at least one member selected from the group consisting of metal magnesium and an organic hydroxide compound, an oxygen-containing organic compound of magnesium and a halogen-containing compound of magnesium used in the preparation of the solid catalyst component (A) is as follows. Is mentioned.
[0010]
First, when metal magnesium and an organic hydroxide compound are used, the metal magnesium is not particularly limited, and any shape such as powder, particles, foil or ribbon can be used. Alcohols, organic silanols and phenols are suitable as the hydroxylated organic compound.
[0011]
As the alcohols, linear or branched aliphatic alcohols having 1 to 18 carbon atoms, alicyclic alcohols or aromatic alcohols can be used. Examples include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, n-hexanol, 2-ethylhexanol, n-octanol, i-octanol, n-stearyl alcohol, cyclopentanol, cyclopentanol Hexanol, ethylene glycol and the like can be mentioned.
[0012]
The organic silanol has at least one hydroxyl group, and the organic group is an alkyl group, an arylalkyl group, an aryl group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms. And alkylaryl groups. For example, trimethylsilanol, triethylsilanol, triphenylsilanol, t-butyldimethylsilanol and the like can be mentioned.
[0013]
Further, examples of the phenols include phenol, xylenol, hydroquinone, and the like.
[0014]
These hydroxylated organic compounds are used alone or as a mixture of two or more.
[0015]
In addition, when the solid catalyst component described in the present invention is obtained using magnesium metal, a substance that reacts with the magnesium metal or generates an addition compound, for example, iodine, for the purpose of accelerating the reaction. It is preferable to add one or more polar substances such as alkyl halides and the like.
[0016]
Next, when an oxygen-containing organic compound of magnesium is used, the compound belonging to the oxygen-containing organic compound of magnesium includes magnesium alkoxides such as methylate, ethylate, isopropylate, decanolate, methoxyethylate and cyclohexanolate: Magnesium alkyl alkoxides, such as ethyl ethylate: magnesium hydroalkoxides, such as hydroxymethylate: magnesium phenoxides, such as phenolate and naphtholate: magnesium carboxylates, such as acetate, stearate, benzoate, phenylacetate, phthalate , Acrylates and oleates: magnesium oximates such as butyl oximate, dimethylglyoxy Over preparative and cyclohexyloxy formate: magnesium enolate compound, for example, acetyl acetonate. These oxygen-containing organomagnesium compounds are used alone or as a mixture of two or more.
[0017]
Further, when a halogen-containing compound of magnesium is used, the halogen-containing compound of magnesium may be MgF₂, MgCl₂, MgBr₂, MgI₂, MgCl (OH) and the like. These can be used either as anhydrides or hydrates.₂Take, for example, MgCl₂, MgCl₂・ 6H₂O, MgCl₂・ 4H₂O and MgCl₂・ 2H₂O can be mentioned. These magnesium chlorides can also be used by firing at 50 to 1000 ° C. under reduced pressure or gas flow. These magnesium chlorides can be used in any of powder, particle and granular forms. Moreover, in order to improve the reactivity of magnesium chloride, it is also possible to use a material having a large surface area by pulverization by a method such as a ball mill or by dissolution-precipitation. Further, it can be used in a state of being dissolved in an organic solvent such as alcohol and tetrahydrofuran.
[0018]
In the present invention, the oxygen-containing organic compound of titanium (ii) used for preparing the solid catalyst component (A) is represented by a general formula:
[TiO_a(OR¹)_b]_l
The compound represented by is used. However, in the general formula, R¹Represents a hydrocarbon group such as a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an arylalkyl group, an aryl group and an alkylaryl group, and a and b are a ≧ 0 and b > 0 represents a number compatible with the valence of titanium, and 1 represents an integer. When b ≧ 2, one R¹And other R¹Are the same or different hydrocarbon groups within the range of a hydrocarbon group such as a linear or branched alkyl group having 1 to 20, preferably 1 to 10 carbon atoms, an arylalkyl group, an aryl group and an alkylaryl group. There may be.
[0019]
Specific examples of the oxygen-containing organic compound of titanium include titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-i-propoxide, titanium tetra-n-butoxide, and hexa-i-propoxydititanate. And the like. Furthermore, these oxygen-containing organic compounds of titanium are used alone or as a mixture of two or more.
[0020]
In the present invention, the organoaluminum halide compound (iii) used in the preparation of the solid catalyst component (A) includes a compound represented by the general formula:
R² _pAlX_3-p
Is used. However, in the general formula, R²Represents a hydrocarbon group having 1 to 20, preferably 1 to 8 carbon atoms, X represents a halogen atom, and p represents a number of 0 <p <3, preferably a number of 0 <p ≦ 2. Represent. Also, R²Is preferably selected from linear or branched alkyl groups, cycloalkyl groups, arylalkyl groups, aryl groups and alkylaryl groups.
[0021]
Specific examples of the halogenated organoaluminum compound include dimethylaluminum chloride, diethylaluminum chloride, diethylaluminum bromide, dipropylaluminum chloride, ethylaluminum dichloride, i-butylaluminum dichloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, i -Isobutylaluminum sesquichloride, a mixture of triethylaluminum and aluminum trichloride, and the like.
[0022]
These organoaluminum halide compounds can be used alone or as a mixture of two or more.
[0023]
The amount of the magnesium compound (i) and the amount of the titanium compound (ii) used in the present invention must be such that they can form a homogeneous solution. If the catalyst is prepared under the condition that a homogeneous solution cannot be formed, the subsequent reaction becomes difficult, and problems such as deterioration of the powder shape of the obtained catalyst and insufficient polymerization activity occur. On the other hand, when the oxygen-containing organic compound of titanium is increased, a uniform solution is easily formed. However, if the oxygen-containing organic compound of titanium is too large, the amount of titanium residue in the polymer increases, which may cause problems such as coloring of the product.
[0024]
From these facts, the use amount of these reactants is that the oxygen-containing organic compound of titanium (ii) is in the range of 0.1 to 2 mol / mol with respect to the magnesium component (i). preferable.
[0025]
The present invention uses a solid catalyst obtained by reacting the homogeneous solution containing magnesium, titanium and the like obtained by the method exemplified above with the organoaluminum halide compound (iii).
[0026]
The amount of the organoaluminum halide compound (iii) is not particularly limited, as long as it is at least an amount sufficient to precipitate the solid catalyst.
[0027]
The present invention is characterized by using a solid catalyst prepared by the method (iv) of adding an oxygen-containing organic compound at any step of preparing the solid catalyst. By using the catalyst produced by this method, in the copolymerization of ethylene and a conjugated diene, the conjugated diene is incorporated with high selectivity as a 1,2-cyclopentane ring in the copolymer main chain, and the internal olefin is incorporated. The ability to form a copolymer having a small structure is improved.
[0028]
As the oxygen-containing organic compound of (iv), at least one member selected from an ether compound having two or more oxygen atoms, a polyether compound, an ester compound, and a diketone compound is used.
[0029]
The ether compound having two or more oxygen atoms is not particularly limited. For example, dioxane, dimethoxyethane, dimethoxypropane, dimethoxybutane, diethoxyethane, diethoxypropane, diethoxybutane, dimethyldimethoxypropane, diethyldimethoxypropane , Dibutyldimethoxypropane, ethylbutyldimethoxypropane, dimethoxytetrahydrofuran, tetramethoxypropane, and polyether compounds such as polyethylene methyl ether.
[0030]
The ester compound having two or more oxygen atoms is not particularly limited, and examples thereof include ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, and butyl propionate.
[0031]
The diketone compound having two or more oxygen atoms is not particularly limited, and includes, for example, acetylacetone, benzoylacetone, dibenzoylmethane, acetonylacetone and the like.
[0032]
The above-mentioned oxygen-containing organic compound (iv) may be used alone, or two or more kinds may be mixed or reacted. In addition, ether compounds having two or more oxygen atoms, polyether compounds, and the like, because the rate of elution of the oxygen-containing organic compound (iv) into the polymerization reaction solvent during the polymerization reaction is small, and the change over time of the catalyst is small. Is particularly preferred.
[0033]
The amount of the oxygen-containing organic compound (iv) to be used is preferably 0.01 ≦ oxygen-containing compound / Mg ≦ 20, and more preferably 0.1% by mole ratio of the oxygen-containing organic compound and the magnesium compound (i). It is particularly preferable that 01 ≦ oxygen-containing compound / Mg ≦ 10. If this ratio is less than 0.01, the conjugated diene may not be incorporated as a 1,2-cyclopentane ring, and if it is greater than 20, the polymerization activity may be reduced.
[0034]
The addition of the oxygen-containing organic compound (iv) to the solid catalyst is not limited to a specific stage of the preparation of the solid catalyst, and can be added at any stage. For example, a method of coexisting in the step of preparing a homogeneous solution containing the magnesium compound (i) and the titanium compound (ii), a method of adding the homogeneous solution itself, a method of adding the homogeneous solution and the organoaluminum halide (iii) A method in which the compound is added during the reaction or a method in which the solution is added to the solid catalyst after the reaction of the homogeneous solution with the organoaluminum halide compound (iii) is completed.
[0035]
The reaction conditions for the preparation of the homogeneous solution, the reaction of the homogeneous solution with the organoaluminum halide compound (iii) and the reaction of adding the oxygen-containing organic compound (iv) are not particularly limited, and are usually -50 to 300. C., preferably 0 to 200 ° C., usually for 0.5 to 50 hours, preferably 1 to 6 hours in an inert gas atmosphere at normal pressure or under pressure. Further, for example, a method of reacting (iii) an organoaluminum halide compound in multiple stages as disclosed in JP-A-7-41513 is also possible.
[0036]
Preparation of the solid catalyst of the present invention, that is, preparation of a homogeneous solution containing the above magnesium compound (i) and titanium compound (ii), reaction of the homogeneous solution with (iii) organoaluminum halide compound, and (iv) In the reaction with the oxygen-containing organic compound, an inert solvent can be used as a diluent. In particular, when the amount of the homogeneous solution containing the magnesium compound of (i) and the titanium compound of (ii) is insufficient, or when the subsequent reaction becomes extremely viscous and the reaction becomes difficult, it is inert. Preferably, the catalyst preparation is performed in the presence of an organic solvent.
[0037]
As the inert organic solvent, any of those commonly used in the art can be used, and examples thereof include aliphatic, alicyclic or aromatic hydrocarbons, or halogen derivatives thereof, and mixtures thereof. For example, hexane, heptane, cyclohexane, toluene, xylene, monochlorobenzene and the like are preferably used.
[0038]
The solid catalyst component (A) thus obtained can be used for the polymerization reaction without removing the remaining unreacted substances and by-products, or after removing them by filtration or a gradient method.
[0039]
The solid catalyst component (A) can be subjected to polymerization as it is in a suspended state, but may be separated from the solvent in some cases, and may be further heated at normal pressure or reduced pressure to prepare the solid catalyst. The solvent used in step (i) can be removed and used in a dry state.
[0040]
As the organic aluminum compound (B), an aluminum compound having a linear or branched alkyl group having 1 to 20 carbon atoms is used. Specifically, for example, trimethylaluminum, triethylaluminum, tri-i-butylaluminum, tri-n-butylaluminum, tri-n-decylaluminum and the like can be mentioned. In addition, an alkyl aluminum hydride having an alkyl group having 1 to 20 carbon atoms can be used. Specific examples of such a compound include di-i-butylaluminum hydride. Further, an alkylaluminum halide having an alkyl group having 1 to 20 carbon atoms, for example, ethylaluminum sesquichloride, diethylaluminum chloride, di-i-butylaluminum chloride, or an alkylaluminum alkoxide, for example, diethylaluminum ethoxide and the like can also be used. .
[0041]
The conjugated diene used in the present invention has the following general formula (1)
CH₂= CH-CH = CH (C_mH_{2m + 1}) (1)
(M is an integer of 0 or more.)
Is represented by Such a conjugated diene is not particularly limited, and examples thereof include 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 1,3-octadiene. Among them, 1,3-butadiene which is inexpensive and has good copolymerizability is preferable.
[0042]
In the present invention, in addition to ethylene and a conjugated diene, the following general formula (2) is used for the purpose of adjusting the density of the copolymer and the like.
CH₂= CH (C_nH_{2n + 1}) (2)
(N is an integer of 1 or more.)
It is also possible to use an α-olefin represented by Specific examples of such an α-olefin include propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and the like.
[0043]
The ethylene-conjugated diene-based copolymer produced according to the present invention has a conjugated diene incorporated in the copolymer main chain as a 1,2-cyclopentane ring with high selectivity, and is obtained by a generally known reaction. It is characterized by a structure in which the amount of transvinylene produced by a certain 1,4-addition is small, that is, the internal olefin is small. Therefore, in order to exhibit this characteristic, the ratio of the number of 1,2-cyclopentane rings to the number of transvinylenes is required.
(Number of 1,2-cyclopentane rings) / (number of transvinylene)
Is 5 or more, more preferably 10 or more.
[0044]
Further, the number of 1,2-cyclopentane rings in the copolymer main chain is preferably at least 0.2, more preferably at least 1, per 1000 carbons.
[0045]
In addition, the change in the melt index (MI) value after immersion treatment in a 30% by weight aqueous hydrogen peroxide solution at 40 ° C. for 200 hours was observed.
| Log (MI₁/ MI₀) | <0.25
(MI₁Is the MI value measured at 190 ° C. after the hydrogen peroxide water immersion treatment, MI₀Represents the MI value measured at 190 ° C. before the hydrogen peroxide water immersion treatment. Also, MI₀, MI₁Both values represent values measured at a measurement load of 2.16 kg. However, the MI with a measured load of 2.16 kg₀When the value is 0.01 or less, it represents a measured value at a measured load of 21.6 kg. )
It is good.
[0046]
The molecular weight is preferably 1000 or more in number average molecular weight.
[0047]
The ratio of the number average molecular weight to the weight average molecular weight (Mw / Mn), which is an index of the density and molecular weight distribution, is not particularly limited.
[0048]
Here, the ethylene-conjugated diene-based copolymer having the physical property values in the above-described range has excellent thermal and chemical stability.
[0049]
The polymerization conditions for producing the ethylene-conjugated diene copolymer of the present invention can be performed under general reaction conditions for olefin polymerization. That is, polymerization is carried out at a temperature of 20 to 300 ° C. in a continuous or batch manner. The polymerization pressure is not particularly limited, but it is suitable to use under pressure, particularly 0.15 to 200 MPa. When the polymerization is carried out in the presence of an inert solvent, any one commonly used as an inert solvent can be used.
[0050]
When the polymerization is carried out in a gas phase in the absence of an inert solvent, the reaction is carried out at a temperature lower than the melting point of the polymer in the presence of an olefin gas.
[0051]
As a reactor used in the polymerization step, a fluidized bed type stirrer, a stirred tank type stirrer, and the like, which are commonly used in the technical field, can be appropriately used. When a fluidized-bed stirrer is used, the reaction is performed while the reaction system is kept in a fluidized state by blowing gaseous olefin and / or inert gas into the system. When a stirring tank type stirrer is used, various types of stirrers such as an squid type stirrer, a screw type stirrer, and a ribbon type stirrer can be used as the stirrer.
[0052]
The molecular weight of the produced polymer can be adjusted by a known means, that is, a method of allowing an appropriate amount of hydrogen to be present in the reaction system.
[0053]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
[0054]
The polymerization operation, reaction, and solvent purification were all performed under an inert gas atmosphere. The solvents used for the reaction were all purified, dried and deoxygenated by known methods in advance. Furthermore, the compound used for the reaction was synthesized and identified by a known method.
[0055]
[Physical property measurement]
HLMI / MI value: The ratio of high load melt index (HLMI) to melt index (MI) is used as a measure of molecular weight distribution. When the HLMI / MI value is small, the molecular weight distribution is considered to be narrow. The HLMI was measured according to JIS-K-7210 (1995), condition 7. The MI was measured in accordance with JIS-K-7210 (1995) Condition 4.
[0056]
Density: A sample resin was immersed in hot water at 100 ° C. for 1 hour, and then allowed to cool to room temperature, and measured using a density gradient tube kept at 23 ° C.
[0057]
Trans vinylene group: 964 cm of FT-IR^-1Was calculated from the peak. The double bond between the terminal vinyl group and the vinylidene group was also measured by FT-IR at 908 cm.^-1, 888cm^-1Was calculated from each peak.
[0058]
Number of 1,2-cyclopentane rings: based on the assignment of die \ Makromolecule \ Chemie \ 192,2591-2601 (1991)¹³It was determined by C-NMR. The number of trans-cyclopentane rings, 23.0 ppm, 30.3 ppm, 31.0 ppm, and 23.0 ppm were obtained from the area ratios corresponding to the signals having chemical shifts of 24.5 ppm, 32.7 ppm, 35.8 ppm, and 46.4 ppm. The number of cis-cyclopentane rings was calculated from the area ratio corresponding to each signal of 0 ppm.
[0059]
MI₁/ MI₀: MI₁Was measured at 190 ° C. after immersing the sample resin in 30 wt% aqueous hydrogen peroxide at 40 ° C. for 200 hours. MI₀Was measured at 190 ° C. for the sample resin before the immersion in the hydrogen peroxide solution. Note that MI₀, MI₁The values were both measured under a measurement load of 2.16 kg in accordance with JIS-K-7210 (1995) Condition 4. However, the MI with a measured load of 2.16 kg₀When the value was 0.01 or less, the measurement was performed at a measured load of 21.6 kg in accordance with the condition 7 of JIS-K-7210 (1995).
[0060]
Example 1
[Preparation of solid catalyst component]
In a 3 l glass flask equipped with a stirrer, 30.0 g (1.23 mol) of metallic magnesium powder and 42.0 g (0.123 mol) of titanium tetrabutoxide were placed, and n-butanol @ 100 in which 1.5 g of iodine was dissolved was added. 1.6 g (1.36 mol) and 2-ethyl-hexanol (176.9 g (1.36 mol)) were added at 90 ° C. over 2 hours, and further removed at 140 ° C. under a nitrogen blanket while removing generated hydrogen gas. Stirred for hours. To this was added 2100 ml of hexane to obtain a homogeneous solution.
[0061]
61.9 g (equivalent to 0.042 mol as Mg) of this homogeneous solution was placed in a separately prepared 500 ml glass flask, and 0.76 g (0.008 mol) of 1,2-dimethoxyethane was added thereto, followed by stirring at 60 ° C. for 1 hour. Was done. The obtained homogeneous solution was cooled to 45 ° C, 47 ml of a hexane solution containing 0.13 mol of i-butylaluminum dichloride was added, and the mixture was stirred at 70 ° C for 1 hour. Hexane was added to the product, and the product was washed seven times by a gradient method. Thus, a solid catalyst component suspended in hexane was obtained. A part thereof was collected, the supernatant was removed, and the resultant was dried under a nitrogen atmosphere and subjected to elemental analysis. As a result, it was found that Ti was 3.3% by weight.
[0062]
[Ethylene-butadiene copolymerization]
The inside of a stainless steel electromagnetically stirred autoclave having an inner volume of 2 liters was sufficiently replaced with nitrogen, 1.2 liters of hexane was charged, and the internal temperature was adjusted to 80 ° C. Thereafter, a slurry containing 0.22 g (1.1 mmol) of tri-i-butylaluminum and 154 mg of the solid catalyst component obtained above was sequentially added. After adjusting the internal pressure of the autoclave to 0.1 MPa, 0.5 MPa of hydrogen and 48 g of 1,3-butadiene were added, and then polymerization was performed for 1.5 hours while continuously adding ethylene so that the internal pressure of the autoclave became 1.2 MPa. Was done. After completion of the polymerization, the system was cooled, the unreacted gas was expelled, the polymer was taken out, separated from the solvent by filtration and dried.
[0063]
As a result, the melt index (MI) value measured under a load of 2.16 kg was 3.1 g / 10 min, the HLMI / MI was 31, and the density was 0.948 g / cm.³215 g of an ethylene-butadiene copolymer was obtained. As for the number of 1,2-cyclopentane rings in this polymer, trans was 1.8 per 1,000 carbon atoms and cis was 0.20. The number of transvinylene groups was 0.17 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 12.
[0064]
The number of terminal vinyl groups was 0.09 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0065]
[Immersion test in hydrogen peroxide solution]
200 ml of 30 wt% aqueous hydrogen peroxide and 15 g of the copolymer obtained from the above [ethylene-butadiene copolymerization] were placed in a 300 ml glass flask equipped with a reflux tube, and immersed at 40 ° C. for 200 hours. After filtering the hydrogen peroxide solution, the resultant was washed seven times with water and dried under vacuum. The melt index (MI) of the polymer after immersion measured at a load of 2.16 kg₁) Value is 2.50 g / 10 min, and | log (MI₁/ MI₀) | = 0.096.
[0066]
Comparative Example 1
[Preparation of solid catalyst component]
A catalyst was prepared in the same manner as in Example 1, except that 1,2-dimethoxyethane was not used.
[0067]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 1, except that the solid catalyst component was changed to 20 mg of the solid catalyst component prepared in the above [Preparation of solid catalyst component].
[0068]
As a result, the melt index (MI) value measured at a load of 2.16 kg was 1.3 g / 10 min, HLMI / MI was 39, and density was 0.947 g / cm.³171 g of an ethylene-butadiene copolymer was obtained. This polymer is¹³No chemical shift of the 1,2-cyclopentane ring could be detected in C-NMR. The number of transvinylene groups was 3.18 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 0.
[0069]
The number of terminal vinyl groups was 0.19 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0070]
[Immersion test in hydrogen peroxide solution]
An immersion test in aqueous hydrogen peroxide was performed in the same manner as in Example 1, except that the copolymer was the polymer obtained in the above [Ethylene-butadiene copolymerization]. As a result, the melt index (MI) of the immersed polymer measured at a load of 2.16 kg was measured.₁) Value is 0.68 g / 10 min, and | log (MI₁/ MI₀) | = 0.27.
[0071]
Example 2
[Preparation of solid catalyst component]
A catalyst was prepared in the same manner as in Example 1, except that 1.8 g (0.008 mol) of 2,2-dibutyl-1,3-dimethoxypropane was used in place of 1,2-dimethoxyethane. .
[0072]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 1, except that the solid catalyst component was changed to 103 mg of the solid catalyst component prepared in the above [Preparation of solid catalyst component].
[0073]
As a result, the melt index (MI) value measured under a load of 2.16 kg was 3.4 g / 10 min, the HLMI / MI was 25, and the density was 0.948 g / cm.³227 g of an ethylene-butadiene copolymer was obtained. Regarding the number of 1,2-cyclopentane rings in this polymer, trans was 2.6 per 1000 carbon atoms and cis was 0.07. The number of transvinylene groups was 0.17 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 16.
[0074]
The number of terminal vinyl groups was 0.09 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0075]
[Immersion test in hydrogen peroxide solution]
An immersion test in aqueous hydrogen peroxide was performed in the same manner as in Example 1, except that the copolymer was the polymer obtained in the above [Ethylene-butadiene copolymerization]. As a result, the melt index (MI) of the immersed polymer measured at a load of 2.16 kg was measured.₁) Value is 2.4 g / 10 min, and | log (MI₁/ MI₀) | = 0.16.
[0076]
Example 3
[Preparation of solid catalyst component]
45.0 g (1.85 mol) of metallic magnesium powder and 126 g (0.370 mol) of titanium tetrabutoxide were placed in a 3 liter glass flask equipped with a stirrer, and n-butanol dissolved in 2.3 g of iodine (151 g (2 0.04 mol) and 2-265 g (2.04 mol) of 2-ethyl-hexanol were added at 90 ° C. over 2 hours, and the mixture was stirred at 140 ° C. for 2 hours under a blanket of nitrogen while removing generated hydrogen gas. To this was added 2100 ml of hexane to obtain a homogeneous solution.
[0077]
80 g of this homogeneous solution (equivalent to 0.085 mol as Mg) was placed in a separately prepared 500 ml glass flask, and diluted with 70 ml of hexane. To this homogeneous solution was added 100 ml of a hexane solution containing 0.17 mol of diethylaluminum chloride at 45 ° C, and the mixture was stirred at 70 ° C for 1 hour. After cooling to 45 ° C., 1.1 g (0.012 mol) of 1,2-dimethoxyethane was added, and the mixture was stirred for 1 hour. To this, 126 ml of a hexane solution containing 0.34 mol of i-butylaluminum dichloride was added, and the mixture was stirred at 70 ° C. for 1 hour. Hexane was added to the product, and the product was washed seven times by a gradient method. Thus, a solid catalyst component suspended in hexane was obtained. A part thereof was collected, the supernatant was removed, and the resultant was dried under a nitrogen atmosphere and subjected to elemental analysis. As a result, it was found that Ti was 4.2% by weight.
[0078]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 1, except that the solid catalyst component was changed to 102 mg of the solid catalyst component prepared in the above [Preparation of solid catalyst component].
[0079]
As a result, the melt index (MI) value measured under a load of 2.16 kg was 3.2 g / 10 min, the HLMI / MI was 28, and the density was 0.948 g / cm.³125 g of an ethylene-butadiene copolymer was obtained. As for the number of 1,2-cyclopentane rings in this polymer, trans was 2.0 per 1,000 carbon atoms and cis was 0.15. The number of transvinylene groups was 0.19 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 11.
[0080]
The number of terminal vinyl groups was 0.08 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0081]
[Immersion test in hydrogen peroxide solution]
An immersion test in aqueous hydrogen peroxide was performed in the same manner as in Example 1, except that the copolymer was the polymer obtained in the above [Ethylene-butadiene copolymerization]. As a result, the melt index (MI) of the immersed polymer measured at a load of 2.16 kg was measured.₁) Value is 2.8 g / 10 min, and | log (MI₁/ MI₀) | = 0.061.
[0082]
Example 4
[Preparation of solid catalyst component]
50.0 g (2.06 mol) of metallic magnesium powder and 210 g (0.617 mol) of titanium tetrabutoxide were placed in a 3 liter glass flask equipped with a stirrer, and n-butanol {320 g (4 .32 mol) was added at 90 ° C. over 2 hours, and the mixture was stirred at 140 ° C. for 2 hours under a nitrogen blanket while excluding further generated hydrogen gas. To this was added 2100 ml of hexane to obtain a homogeneous solution.
[0083]
91 g of this homogeneous solution (equivalent to 0.096 mol as Mg) was placed in a separately prepared 500 ml glass flask, and diluted with 70 ml of hexane. To this homogeneous solution was added 210 ml of a hexane solution containing 0.58 mol of i-butylaluminum dichloride at 45 ° C, and the mixture was stirred at 70 ° C for 1 hour. Hexane was added to the product, and the product was washed seven times by a gradient method. 1.7 g (0.019 mol) of 1,2-dimethoxypropane was added thereto, and the mixture was stirred at 45 ° C. for 2 hours, hexane was added to the product, and the resultant was washed seven times by a gradient method. Thus, a solid catalyst component suspended in hexane was obtained. A part thereof was collected, the supernatant was removed, and the resultant was dried under a nitrogen atmosphere and subjected to elemental analysis. As a result, it was found that Ti was 8.5% by weight.
[0084]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 1, except that the solid catalyst component was changed to 100 mg of the solid catalyst component prepared in the above [Preparation of solid catalyst component].
[0085]
As a result, the melt index (MI) value measured under a load of 2.16 kg was 2.7 g / 10 min, the HLMI / MI was 34, and the density was 0.948 g / cm.³95 g of an ethylene-butadiene copolymer was obtained. As for the number of 1,2-cyclopentane rings in this polymer, trans was 1.6 per 1,000 carbon atoms and cis was 0.10. The number of transvinylene groups was 0.23 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 7.4.
[0086]
The number of terminal vinyl groups was 0.13 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0087]
【The invention's effect】
According to the production method of the present invention, an ethylene-conjugated diene-based copolymer having a structure in which a conjugated diene is incorporated with a high selectivity as a 1,2-cyclopentane ring in a copolymer main chain and has a small amount of internal olefins Is obtained. Such an ethylene-conjugated diene copolymer is excellent in thermal and chemical stability.
[Brief description of the drawings]
FIG. 1 is a flowchart of catalyst preparation in the present invention.

Claims (3)

In the presence of a catalyst component comprising a transition metal compound and an organometallic compound, in producing an ethylene-conjugated diene-based copolymer,
(A) As a component,
(I) a homogeneous solution containing at least one member selected from the group consisting of metallic magnesium and a hydroxylated organic compound, an oxygen-containing organic compound of magnesium, and a halogen-containing compound of magnesium, and (ii) at least one kind of an oxygen-containing organic compound of titanium. iii) a solid catalyst obtained by reacting with an organoaluminum halide compound, and (iv) an ether compound, a polyether compound, or an ester compound having two or more oxygen atoms at any stage of the preparation of the solid catalyst. And a solid catalyst prepared by a method of adding at least one member selected from diketone compounds and a catalyst comprising an organoaluminum compound as the component (B),
Ethylene and the following general formula (1)
_{CH 2 = CH-CH = CH} (C m H 2m + 1) (1)
(M is an integer of 0 or more.)
By copolymerizing a conjugated diene represented by
It has a 1,2-cyclopentane ring, and the ratio of the number of 1,2-cyclopentane rings to the number of transvinylenes (the number of 1,2-cyclopentane rings) / (the number of transvinylenes)
The method for producing an ethylene-conjugated diene-based copolymer, characterized by producing a polymer having a molecular weight of 5 or more. Ethylene, a conjugated diene represented by the general formula (1), and the following general formula (2)
_{CH 2 = CH (C n H} 2n + 1) (2)
(N is an integer of 1 or more.)
The method for producing an ethylene-conjugated diene-based copolymer according to claim 1, wherein an α-olefin represented by the following formula is copolymerized. 3. The method for producing an ethylene-conjugated diene copolymer according to claim 1, wherein the conjugated diene represented by the general formula (1) is 1,3-butadiene.

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