JP2004018696A - Ethylene-conjugated diene copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel ethylene-conjugated diene copolymer having a specified structure. <P>SOLUTION: The ethylene-conjugated diene copolymer has a melt index (MI) of ≤1,000, a substituted or non-substituted 1,2-cyclopentane ring, a ratio of the number of the 1,2-cyclopentane ring to that of a trans-vinylene of ≥5, and simultaneously reduces the change in the melt index (MI) measured at 190°C after dipping the copolymer in a 30 wt.% hydrogen peroxide solution at 40°C for 200 hours. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ethylene-conjugated diene copolymer having a novel structure.
[0002]
[Prior art]
As the ethylene-conjugated diene copolymer, an ethylene-butadiene copolymer produced using a transition metal compound and the like are already known.
[0003]
For example, Polymer Bulletin 8,473-478 (1982) and Journal of Polymer Science: Part A: Polymer Chemistry, 26, 2487-2500 (1988), and the like, ethylene-butadiene using a catalyst composed of a solid titanium catalyst and an alkylaluminum. Copolymers have been reported. However, in these polymers, butadiene was introduced exclusively by 1,4-trans addition, so that a structure in which a large number of internal olefins were present in the main chain as transvinylene was obtained.
[0004]
Recently, for example, Japanese Patent No. 2764163, die Makromolecule Chemie 192, 2591-2601 (1991) and the like, a unique ethylene having a 1,2-cyclopentane ring in the main chain despite not using a cyclic monomer. -Butadiene copolymers have been reported. Such a cyclopentane ring is formed by polymerizing butadiene by 1,2-addition, then polymerizing one ethylene, and then re-inserting the double bond of the side chain generated by 1,2-addition. When generated, Maurizio Galimberti et al. Propose. However, these ethylene-butadiene copolymers do not have 1,2-cyclopentane rings formed selectively, but contain a considerable amount of internal olefins in the main chain formed by 1,4-addition. Had been. Due to the internal olefin in the main chain, there have been problems such as thermal degradation during molding and resin degradation after molding.
[0005]
Thus, an ethylene-conjugated diene copolymer having relatively few double bonds in the main chain and selectively having a 1,2-cyclopentane ring and having excellent thermal and chemical stability. It was difficult to get.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a novel ethylene-conjugated diene copolymer having a specific structure.
[0007]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to solve the above-described problems, and as a result, have found that ethylene-, which has a 1,2-cyclopentane ring, has little transvinylene, and is excellent in thermal and chemical stability. A conjugated diene copolymer has been found, and the present invention has been completed.
[0008]
The ethylene-conjugated diene copolymer of the present invention has a substituted or unsubstituted 1,2-cyclopentane ring, and the ratio of the number of the 1,2-cyclopentane ring to transvinylene (1,2) −number of cyclopentane rings) / (number of transvinylene)
Is 5 or more, more preferably 10 or more. Further, the number of 1,2-cyclopentane rings is at least 0.2, more preferably at least 1, per 1000 carbon atoms. The larger the number of 1,2-cyclopentane rings, the more preferable the characteristics of the polymer of the present invention are exhibited. In the preferred ethylene-conjugated diene-based copolymer of the present invention, 50% or more of the 1,2-cyclopentane rings are trans-1,2-cyclopentane.
[0009]
The ethylene-conjugated diene copolymer of the present invention has a melt index (MI) at 190 ° C. under a load of 2.16 kg of 1,000 or less, which is an index of molecular weight. When the MI is larger than 1000, that is, when the molecular weight is small, the strength as a resin becomes weak, which is not preferable.
[0010]
Further, in the preferred ethylene-conjugated diene copolymer of the present invention, the correlation between intrinsic viscosity ([η]) measured in o-dichlorobenzene at 135 ° C. and MI measured at 190 ° C. under a load of 2.16 kg is MI> 0.3 × [η] ^−5.5
It is.
[0011]
The ratio of the number average molecular weight to the weight average molecular weight (Mw / Mn) and the density, which are indicators of the molecular weight distribution, are not particularly limited.
[0012]
Further, the ethylene-conjugated diene copolymer of the present invention has a feature that it is chemically stable. When a conventional ethylene-conjugated diene-based copolymer is exposed to an oxidizing atmosphere, molecular cleavage or cross-linking occurs, and the molecular weight changes. The ethylene-conjugated diene copolymer of the present invention, which has excellent chemical stability, has a small change in MI measured at 190 ° C after immersion in a 30 wt% hydrogen peroxide solution at 40 ° C for 200 hours. That is,
| Log (MI ₁ / MI ₀ ) | <0.25
(MI ₁ is a melt index after immersion in a hydrogen peroxide solution, MI ₀ is a melt index before immersion. However, the load when measuring MI ₀ and MI ₁ is the immersion measured with a 2.16 kg load. Use 2.16 kg when the previous MI is 0.1 or more, and use a 21.6 kg load when the previous MI is less than 0.1.)
It is. Such a copolymer is less susceptible to thermal degradation during molding and has excellent weather resistance.
[0013]
As a method for producing the ethylene-conjugated diene copolymer of the present invention, any method may be used as long as the ethylene-conjugated diene copolymer of the present invention is obtained.
[0014]
For example, a method of producing by copolymerizing ethylene and a conjugated diene in the presence of a solid titanium catalyst and a catalyst comprising an organoaluminum compound can be exemplified. Such a solid titanium catalyst is obtained, for example, by reacting a homogeneous solution containing metal magnesium, an organic hydroxide compound and an oxygen-containing organic compound of titanium with a specific oxygen-containing organic compound and an organoaluminum halide compound. A solid catalyst and the like can be exemplified.
[0015]
Further, for example, in the presence of a transition metal complex such as a metallocene compound, or a catalyst having the same supported on an inorganic or polymer carrier, and a catalyst comprising methylaluminoxane or an ionized ionic compound, ethylene and a conjugated diene are used. Can also be exemplified.
[0016]
Among these, a more preferable production method is a solid catalyst obtained by reacting a homogeneous solution containing a metal magnesium, an organic hydroxide compound and an oxygen-containing organic compound of titanium with a specific ether compound and an organoaluminum halide compound. And a method of producing the catalyst in the presence of a catalyst comprising an organoaluminum compound.
[0017]
The conjugated diene used for the polymerization of the ethylene-conjugated diene polymer of the present invention is represented by the following general formulas (1) and (2).
_{CH 2 = CH-CH = CH} (C m H 2m + 1) (1)
(M is an integer of 0 or more.)
_{CH 2 = CH-C (C} n H 2n + 1) = CH 2 (2)
(N is an integer of 1 or more.)
Is represented by Examples of such a conjugated diene include, for example, 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 1,3-octadiene for the diene of the general formula (1). Examples of the diene of the general formula (2) include isoprene and 2-ethyl-1,3-butadiene. Among them, 1,3-butadiene is more preferable.
[0018]
The ethylene-conjugated diene copolymer of the present invention may contain a comonomer in addition to ethylene and the conjugated diene. Such comonomers include:
_{CH 2 = CH (C p H} 2p + 1) (3)
(P is an integer of 1 or more.)
Α-olefin represented by the following formula: Specific examples of comonomers include α-olefins such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene.
[0019]
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.
[0020]
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.
[0021]
As the reactor used for producing the polymer of the present invention, any one usually used in the technical field, such as a fluidized bed stirrer or a stirred tank stirrer, can be used as appropriate. 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.
[0022]
Further, the molecular weight of the polymer can be adjusted by a known method, that is, a method of allowing an appropriate amount of hydrogen to be present in the reaction system.
[0023]
【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.
[0024]
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.
[0025]
The melt index (MI), which is a measure of the molecular weight, was measured under a condition 4 of JIS K-7210 (1995) using a load of 2.16 kg. The high load melt index (HLMI) was measured under a condition 7 of JIS K-7210 (1995) at a load of 21.6 kg. HLMI / MI is the ratio of this HLMI to MI and is a measure of the molecular weight distribution. When the HLMI / MI value is small, the molecular weight distribution is considered to be narrow.
[0026]
Intrinsic viscosity ([η]) was measured in o-dichlorobenzene at 135 ° C.
[0027]
The density was measured by immersing the sample resin in hot water at 100 ° C. for 1 hour and then cooling it to room temperature using a density gradient tube kept at 23 ° C.
[0028]
The amount of the transvinylene group was calculated from the peak of FT-IR at 964 cm ⁻¹ . For reference, the amount of double bonds such as a terminal vinyl group and a vinylidene group was calculated from peaks of FT-IR at 908 cm ⁻¹ and 888 cm ⁻¹ . Such a technique is a method well known to those skilled in the art.
[0029]
The number of 1,2-cyclopentane rings was determined by ¹³ C-NMR based on the assignment of die Makromolecule Chemie 192, 2591-2601 (1991). The number of trans-1,2-cyclopentane rings, 23.0 ppm, 30.3 ppm, and 31.3 ppm were determined 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-1,2-cyclopentane rings was calculated from the area ratio corresponding to each signal of 0 ppm and 23.0 ppm.
[0030]
Example 1
[Preparation of solid catalyst component]
30.0 g (1.23 mol) of metal magnesium powder and 42.0 g (0.123 mol) of titanium tetrabutoxide were placed in a 3 l glass flask equipped with a stirrer, and n-butanol 100 in which 1.5 g of iodine was dissolved was added. 6.6 g (1.36 mol) and 176.9 g (1.36 mol) of 2-ethyl-hexanol were added at 90 ° C. over 2 hours, and further added at 140 ° C. under a nitrogen blanket while excluding hydrogen gas generated. Stirred for hours. To this was added 2100 ml of hexane to obtain a homogeneous solution.
[0031]
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 1.8 g (0.008 mol) of 2,2-dibutyl-1,3-dimethoxypropane was added. Stirring was performed at 60 ° C. for 1 hour. The obtained homogeneous solution was cooled to 45 ° C, 47 ml of a hexane solution containing 0.13 mol of isobutylaluminum 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.
[0032]
[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 triisobutylaluminum and 103 mg of the solid catalyst component obtained above was sequentially added. After adjusting the internal pressure of the autoclave to 0.1 MPa, adding 0.5 MPa of hydrogen and 48 g of 1,3-butadiene, and then polymerizing for 1.5 hours while continuously adding ethylene so that the internal pressure of the autoclave becomes 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.
[0033]
As a result, 227 g of an ethylene-butadiene copolymer having a melt index of 3.4 g / 10 min, HLMI / MI of 25, [η] of 1.13 dl / g, and a density of 0.948 g / cm ³ were 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.
[0034]
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).
[0035]
[Immersion test in hydrogen peroxide solution]
In a 300 ml glass flask equipped with a reflux tube, 200 ml of 30 wt% hydrogen peroxide solution and 15 g of the copolymer obtained by the above-mentioned [ethylene-butadiene copolymerization] were placed, immersed for 200 hours at 40 ° C. . After filtering the hydrogen peroxide solution, the resultant was washed seven times with water and dried under vacuum. The MI of the polymer after immersion measured under a load of 2.16 kg was 2.4 g / 10 minutes, and | log (MI ₁ / MI ₀ ) | = 0.16.
[0036]
Comparative Example 1
[Ethylene-butadiene copolymerization]
After replacing a 2 l stainless steel autoclave with nitrogen, a toluene solution of methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) corresponding to 1 l of toluene, 20 μmol of biscyclopentadienyl dichloride, and 10 mmol of aluminum was prepared. In addition, after adjusting the internal pressure of the autoclave to 0.1 MPa, 48 g of 1,3-butadiene was added, and then polymerization was performed for 30 minutes while continuously adding ethylene so that the internal pressure of the autoclave became 0.7 MPa. The polymerization was stopped by adding ethanol, and after cooling, the unreacted gas was expelled to remove the polymer, which was separated from the solvent by filtration and dried.
[0037]
As a result, 31 g of an ethylene-butadiene copolymer having a melt index of 0.45 g / 10 min, HLMI / MI of 29, [η] of 0.92 dl / g, and a density of 0.939 g / cm ³ was obtained. The number of 1,2-cyclopentane rings in this polymer was 2.1 per 1000 carbon atoms in trans. The number of transvinylene groups was 1.0 per 1000 carbon atoms. Therefore, (the number of 1,2-cyclopentane rings) / (the number of transvinylenes) was 2.1.
[0038]
The number of terminal vinyl groups was 0.11 per 1000 carbon atoms, and the number of vinylidene groups was below the detection limit (<0.05).
[0039]
[Immersion test in hydrogen peroxide solution]
A dipping 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 MI measured at a load of 2.16 kg was 0.21 g / 10 min, and | log (MI ₁ / MI ₀ ) | = 0.33.
[0040]
Example 2
[Preparation of solid catalyst component]
A catalyst was prepared in the same manner as in Example 1 except that 0.76 g (0.008 mol) of 1,2-dimethoxyethane was used instead of 2,2-dibutyl-1,3-dimethoxypropane in Example 1. did.
[0041]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 1, except that the solid catalyst component was 154 mg of the solid catalyst prepared in the above [Preparation of solid catalyst component].
[0042]
As a result, 215 g of an ethylene-butadiene copolymer having a melt index of 3.1 g / 10 min, an HLMI / MI of 31, [η] of 1.15 dl / g, and a density of 0.948 g / cm ³ 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.
[0043]
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).
[0044]
[Immersion test in hydrogen peroxide solution]
A dipping 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]. The MI measured under a load of 2.16 kg was 2.50 g / 10 min, and | log (MI ₁ / MI ₀ ) | = 0.096. .
[0045]
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 put into a 3 liter glass flask equipped with a stirrer, and 151 g (2) of n-butanol in which 2.3 g of iodine was dissolved. 0.04 mol) and 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 further removing generated hydrogen gas. To this was added 2100 ml of hexane to obtain a homogeneous solution.
[0046]
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. 126 ml of a hexane solution containing 0.34 mol of isobutylaluminum dichloride was added thereto, 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.
[0047]
[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 prepared in the above [Preparation of solid catalyst component].
[0048]
As a result, 125 g of an ethylene-butadiene copolymer having a melt index of 3.2 g / 10 min, an HLMI / MI of 28, [η] of 1.14 dl / g, and a density of 0.948 g / cm ³ 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.
[0049]
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).
[0050]
[Immersion test in hydrogen peroxide solution]
A dipping 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 MI measured at a load of 2.16 kg was 2.8 g / 10 minutes, and | log (MI ₁ / MI ₀ ) | = 0.061.
[0051]
Comparative Example 2
[Preparation of solid catalyst component]
A catalyst was prepared in the same manner as in Example 2 except that 1,2-dimethoxyethane was not used.
[0052]
[Ethylene-butadiene copolymerization]
Ethylene-butadiene copolymerization was carried out in the same manner as in Example 2, except that the solid catalyst component was changed to 20 mg of the solid catalyst prepared in the above [Preparation of solid catalyst component].
[0053]
As a result, 171 g of an ethylene-butadiene copolymer having a melt index (MI) value measured at a load of 2.16 kg of 1.3 g / 10 min, an HLMI / MI of 39, and a density of 0.947 g / cm ³ was obtained. . This polymer did not detect the chemical shift of 1,2-cyclopentane in ¹³ 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.
[0054]
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).
[0055]
[Immersion test in hydrogen peroxide solution]
A dipping 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 MI measured under a load of 2.16 kg was 0.68 g / 10 min, and | log (MI ₁ / MI ₀ ) | = 0.27.
[0056]
【The invention's effect】
The ethylene-conjugated diene copolymer of the present invention has a unique structure having a 1,2-cyclopentane ring and a large 1,2-cyclopentane ring / transvinylene ratio. Also, it has excellent chemical stability.
[0057]
The copolymer having such characteristics hardly undergoes thermal deterioration during processing, which is a problem in the conventional ethylene-conjugated diene copolymer, and the molded product is also excellent in weather resistance. Further, the polymer of the present invention having a cyclopentane ring bonded to the main chain at the 1,2-position is more suitable for use in a chemical liquid container than a conventional ethylene copolymer having a linear α-olefin as a comonomer. It also has features such as being resistant to chemicals when it comes to life.
[Brief description of the drawings]
FIG. 1 is a ¹³ C-NMR pattern of the ethylene-butadiene copolymer described in Example 1.

Claims (6)

The melt index (MI) measured at 190 ° C. under a load of 2.16 kg is 1000 or less, has a substituted or unsubstituted 1,2-cyclopentane ring, and the number of the 1,2-cyclopentane ring and transvinylene (The number of 1,2-cyclopentane rings) / (the number of transvinylenes)
Is not less than 5, and the change in melt index (MI) measured at 190 ° C. after immersion in a 30 wt% hydrogen peroxide solution at 40 ° C. for 200 hours is | log (MI ₁ / MI ₀ ) | <0. .25
(MI ₁ melt index after immersion in hydrogen peroxide, MI ₀ represents the melt index before dipping. However, the load when measuring the _MI 0, MI _1, was measured at 2.16kg load dip When the previous MI is 0.1 or more, use 2.16 kg, and when less than 0.1, use a 21.6 kg load.)
An ethylene-conjugated diene copolymer. The ethylene-conjugated diene-based copolymer according to claim 1, wherein the number of 1,2-cyclopentane rings is 0.2 or more per 1,000 carbon atoms. The ethylene-conjugated diene-based copolymer according to claim 1, wherein 50% or more of the 1,2-cyclopentane ring is trans-1,2-cyclopentane. The correlation between intrinsic viscosity ([η]) measured in o-dichlorobenzene at 135 ° C. and MI measured at 190 ° C. under a load of 2.16 kg is MI> 0.3 × [η] ^−5.5.
The ethylene-conjugated diene-based copolymer according to claim 1, wherein: The conjugated diene component has the following general formula (1) or (2)
_{CH 2 = CH-CH = CH} (C m H 2m + 1) (1)
(M is an integer of 0 or more.)
_{CH 2 = CH-C (C} n H 2n + 1) = CH 2 (2)
(N is an integer of 1 or more.)
The ethylene-conjugated diene-based copolymer according to any one of claims 1 to 4, wherein Ethylene, conjugated diene and the following general formula (3)
_{CH 2 = CH (C p H} 2p + 1) (3)
(P is an integer of 1 or more.)
The ethylene-conjugated diene copolymer according to claim 1, wherein the α-olefin represented by the formula is produced as a raw material monomer component.

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