JP3154347B2 - Method for producing elastomeric olefin copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastomeric olefin copolymer such as ethylene-propylene rubber or ethylene-propylene-diene terpolymer. Very few,
Specifically, the content of vanadium derived from the catalyst is 10 ppm.
The present invention relates to a method for producing an elastomeric olefin-based copolymer, which obtains the following.

[0002]

2. Description of the Related Art Ethylene propylene rubber and ethylene propylene
Elastomer-like olefin copolymers such as propylene / diene terpolymers generally use a transition metal compound such as a trivalent vanadium compound and an organoaluminum compound as catalysts to prepare ethylene and propylene or ethylene and propylene and non-ethylene. It has been produced by a method of copolymerizing a conjugated diene hydrocarbon. As industrial processes, a suspension polymerization method in which polymerization is performed in liquid propylene and a solution polymerization method in which polymerization is performed in an organic solvent such as n-hexane have been mainly performed.

[0003] The solution polymerization method has an advantage that almost no blockage occurs in the reactor because the olefin copolymer produced during the polymerization hardly precipitates. In addition, since the polymerization pressure is low, the design, manufacture and operation of the reactor are easy, and the transfer of the solution after the polymerization is easy. Furthermore, since the deashing operation is extremely easy, an olefin copolymer having an extremely low content of the catalyst residue (about 5 ppm) can be easily obtained. For this reason, conventionally,
The solution polymerization method was mainly performed.

However, in the solution polymerization method, since the viscosity of the polymerization solution sharply increases as the polymerization proceeds, the concentration of the olefin polymer is limited to about 7 to 10%.
The molecular weight could not be increased. Also, it was difficult to remove the heat of polymerization. Further, there is a problem that a deashing step, a coagulation step, a solvent recovery step and the like are required, and the process becomes complicated. For this reason, in recent years, it has been studied to adopt a suspension polymerization method that does not have such a disadvantage.

[0005]

[Problems to be Solved by the Invention] In the suspension polymerization method, the polymerization proceeds in a slurry state in which the olefin-based copolymer is suspended in liquid propylene in the form of particles. There is no. For this reason, compared to the solution method,
There is a possibility that the concentration and molecular weight of the olefin copolymer can be increased. Also, the removal of heat of polymerization is extremely easy due to the latent heat of vaporization of propylene. Further, it is easy to control the monomer composition ratio in the olefin copolymer.

However, in this polymerization method, since the copolymer is formed so as to enclose the catalyst, it is difficult to remove the ash after the polymerization. In addition, since the deactivation of the catalyst occurs in a short time, it has been difficult to make the concentration of the slurry of the olefin copolymer in the polymerization system (hereinafter referred to as “slurry concentration”) 15% by weight or more. For this reason, the vanadium content in the obtained olefin-based copolymer tends to increase. Industrially, it is required to further increase the productivity per unit volume, and it has been desired that the slurry concentration be 25% by weight or more.

[0007] If the content of vanadium is high, there are problems that the olefin-based copolymer is colored yellow or brown, and heat resistance, aging resistance and electrical properties are deteriorated. For this reason, it is required that the vanadium content in the olefin-based copolymer be 20 ppm or less, preferably 10 ppm or less.

[0008] In order to keep the vanadium content of the olefin copolymer obtained by the suspension polymerization method within the above range, it was initially attempted to improve the demineralization step. However, when the demineralization step is provided, the process becomes complicated, and the wastewater generated in the demineralization step needs to be treated.

Therefore, it has been studied to improve the activity of the polymerization catalyst and to reduce the vanadium content of the olefin-based copolymer itself before deashing to an extent that the deashing step is unnecessary. In order to improve the catalyst activity, it has been studied to add ethyl monochloromalonate or ethyl dichloromalonate to the polymerization system as an activator (JP-A-49-66787). However, even with this method,
Only the olefin copolymer having a high vanadium content of 20 to 100 ppm before vanadium was obtained.

According to the present invention, there is provided a method for producing an elastomeric olefin copolymer, wherein an olefin copolymer having a low vanadium content is obtained without a deashing step.
It is an object of the present invention to provide a production method capable of continuing polymerization even at a high slurry concentration of 5% by weight or more.

[0011]

The present invention relates to a method of copolymerizing ethylene, propylene and, if necessary, a non-conjugated diene hydrocarbon in liquid propylene using a vanadium compound and an organoaluminum compound as catalysts. A method for producing an elastomeric olefin copolymer, wherein (a) an alkyl monohalogenomalonate and an alkyl dihalogenomalonate are used in combination as an activator, and (b) an alkyl monohalogenomalonate is used. The alkyl dihalogenomalonate is used in the same amount or in excess. Hereinafter, the production method of the present invention will be described in detail.

The present invention relates to ethylene, propylene, and
This is a method for producing an elastomeric olefin copolymer, that is, an ethylene-propylene rubber or an ethylene-propylene-diene terpolymer, by copolymerizing a non-conjugated diene-based hydrocarbon as required. Then, with the vanadium compound and the organoaluminum compound as catalysts, while propylene, which is one component of the monomer, is liquefied, ethylene and, if necessary, a non-conjugated diene-based hydrocarbon are supplied to perform suspension polymerization. Yes, as an activator, an alkyl monohalogenomalonate and an alkyl dihalogenomalonate are added to the polymerization system such that the latter becomes excessive, thereby greatly improving the polymerization activity of the catalyst. It is.

In the present invention, the activator has the effect of improving the polymerization activity of the catalyst by returning the vanadium compound in the catalyst to the state where oxidation at the beginning of polymerization has progressed. Ethylene and propylene are polymerized with vanadium ions as active points to form an elastomeric olefin-based copolymer.In the absence of an activator, the vanadium compound is gradually reduced by the organoaluminum compound as the polymerization proceeds. It is reduced and eventually becomes divalent or less, and loses polymerization activity.

The alkyl monohalogenomalonates and alkyl dihalogenomalonates of the activators are:
It is preferable to add after mixing in advance. The activator may be added continuously from the start to the end of the polymerization, or may be added plural times during the polymerization. However, it is not preferable to add the whole amount at once at the start of polymerization.

The method for producing an olefin copolymer of the present invention can be applied to either a batch method or a continuous method. The polymerization temperature is preferably in the range of −30 to 100 ° C., and particularly preferably in the range of 0 to 70 ° C.

Hereinafter, the proportions of ethylene, propylene and non-conjugated diene, and the proportions of the catalyst and the activator in the present invention will be described.

The molar ratio of ethylene, propylene and non-conjugated diene to be charged during the polymerization is such that ethylene is 1 and propylene is preferably in the range of 0.01 to 100, particularly preferably 0.05 to 50. The conjugated diene is 0-1
A range of 0 is preferred.

Among the components of the catalyst, the vanadium compound is
0.0005 to 0.5 per 100 g of liquefied propylene
00 mmol is preferable, and in particular, 0.001-0.
A range of 050 mmol is preferred. When the ratio of the vanadium compound is less than 0.0005 mmol, there arises a problem that the productivity of the olefin-based copolymer is extremely reduced. On the other hand, when it exceeds 0.500 mmol, there is a problem that productivity of the olefin-based copolymer becomes extremely high and it becomes difficult to remove polymerization heat.

The ratio of the vanadium compound to the organoaluminum compound is 0.002 to 0.2 (V / Al (mol /
mol)), particularly preferably from 0.005 to 0.5 mol.
A range of 1 (V / Al (mol / mol)) is preferable.
If the ratio of the vanadium compound to the organoaluminum compound is less than 0.002, there is a possibility that a problem occurs that the reduction reaction of the vanadium compound with respect to the organoaluminum compound is too strong and the catalytic activity decreases.
On the other hand, when it is more than 0.2, the reduction reaction of the vanadium compound by the organoaluminum compound becomes insufficient, and there is a problem that the yield of the olefin-based copolymer decreases.

As the activator, an alkyl monohalogenomalonate and an alkyl dihalogenomalonate are used in combination, and the alkyl dihalogenomalonate is used in an amount equal to or higher than that of the alkyl monomalonate. There must be. If the amount of the alkyl dihalogenomalonate is smaller than that of the alkyl monomalonate, sufficient catalytic activity cannot be obtained, so that the object of the present invention cannot be achieved.

The amount of the activator added is determined by the amount of the vanadium compound 1
The range of 0.05 to 150 mol is preferable to the mol. When the amount of the activator added is less than 0.05 mol per 1 mol of the vanadium compound, the effect of the addition is small, and almost no improvement in the yield of the olefin copolymer is observed. On the other hand, when the amount is more than 150 mol, the active site is deactivated by the activator during the polymerization reaction, which is not preferable.

In the present invention, a non-conjugated diene hydrocarbon which can be used as a monomer, a vanadium compound and an organoaluminum compound which can be used as a catalyst, an alkyl monohalogenomalonate and an alkyl dihalogenomalonate which can be used as an activator, This will be specifically described below.

Non-conjugated diene hydrocarbons include 5-ethylidene-2-norbornene, 2,5-norbornadiene, 2-methylenenorbornene, 2-ethylnorbornene, 5-methylenenorbornene, and 5- (2-butenyl)
-2-norbornene, bicyclo [3,2,0] heptadiene, tetrahydroindene, alkyltetrahydroindene, dialkyltetrahydroindene, dicyclopentadiene, 9,10-dihydro-dicyclopentadiene, 11-ethyl-1,11-tridecadiene, 6-methyl-1,5-heptadiene, 1,4-hexadiene,
1,5-hexadiene and the like can be used.

As the vanadium compound, for example, VO
Cl ₃ , VCl ₃ , VCl ₄ , V (AcAc) _{3 and the} like are used (AcAc indicates acetylacetonate).
Of these vanadium compounds, V (AcAc) ₃ is particularly preferred. This is because an olefin copolymer having a low chlorine content can be obtained.

As the organic aluminum compound, a trialkyl aluminum or an alkyl aluminum halide is used. As such, for example, triethylaluminum, trimethylaluminum, triisopropylaluminum, triisobutylaluminum,
Examples thereof include diethylaluminum chloride, dimethylaluminum chloride, and ethylaluminum sesquichloride.

Examples of the alkyl monohalogenomalonate and the alkyl dihalogenomalonate include ethyl monochloromalonate, methyl monochloromalonate, ethyl monobromomalonate, methyl monobromomalonate, ethyl dichloromalonate, and methyl dichloromalonate. , Ethyl dibromomalonate and methyl dibromomalonate.

Further, in the present invention, dialkyl zinc or hydrogen may be used as a chain transfer agent.

[0028]

The present invention will be described below in detail with reference to examples.

[0029]

Example 1 A 2-liter stainless steel autoclave was charged with 500 g of liquid propylene and 5-ethylidene-
7 ml of 2-norbornene, 2.9 mmol of diethylaluminum chloride, and 0.1 mmol of diethylzinc
Was charged. Next, the polymerization temperature was set to 25 ° C., and while stirring the contents, ethylene was supplied at a pressure 2 atmospheres higher than the internal pressure of the autoclave, and 0.02 mmol
of vanadium triacetylacetonate in toluene 4
The solution dissolved in cc was injected under pressure to initiate polymerization. The polymerization was carried out for 45 minutes. As an activator, a mixture of ethyl monochloromalonate and ethyl dichloromalonate mixed at a molar ratio of 3: 7 was used, and 0.14 mmol of this mixture was used.
Was dissolved in toluene to make 15 ml, and the solution was continuously added from the start to the end of the polymerization. After 45 minutes, 20 ml of water was added, the supply of ethylene was stopped, and unreacted liquid propylene and ethylene were released to the outside.
The polymerization was stopped. The slurry concentration when the polymerization was stopped was 27.9.
% By weight. The slurry concentration is It was calculated by the following formula. By polymerization for 45 minutes, 130 g of an elastomeric copolymer was obtained. When the vanadium content in the copolymer was calculated from the amount of vanadium triacetylacetonate used in the polymerization, 7.8 p
pm. The ethylene content was 69.5% by weight, the propylene content was 25.8% by weight, and the 5-ethylidene-2-norbornene content was 4.7% by weight. The number average molecular weight Mn was 327,000, the weight average molecular weight Mw was 847,000, and Mw / Mn was 2.6. The composition of the copolymer was measured by ¹ H-NMR, and the molecular weight was measured by GPC.

[0030]

Example 2 A copolymer was obtained in the same manner as in Example 1 except that the molar ratio of ethyl monochloromalonate to ethyl dichloromalonate was 1: 9. The slurry concentration at the end of the polymerization was 33.6% by weight. The copolymer yield was 13
The vanadium content calculated from 6 g of the used vanadium triacetylacetonate was 7.5 ppm. The ethylene content was 70.3% by weight, the propylene content was 26.0% by weight, and the 5-ethylidene-2-norbornene content was 3.7% by weight. The number average molecular weight Mn is 306,100, and the weight average molecular weight Mw is 841,
500, and Mw / Mn = 2.7.

[0031]

Example 3 In a stainless steel autoclave having a content of 2 liters, 500 g of liquid propylene and 2.5 mmol of diethylaluminum chloride were charged, and hydrogen was charged to a gauge pressure of 0.2 kg / cm ² . Next, the polymerization temperature was set to 25 ° C., and 0.02 mmol of vanadium triacetylacetonate was dissolved in 4 cc of toluene while ethylene was supplied at a pressure 2 atmospheres higher than the internal pressure of the autoclave while stirring the contents. The resulting solution was press-fitted to initiate polymerization. The polymerization was carried out for 45 minutes. A mixture of ethyl monochloromalonate and ethyl dichloromalonate in a molar ratio of 3: 7 was used as an activator, and 0.14 mmol of this mixture was dissolved in toluene to make 15 ml. Was added continuously. After 45 minutes, 20m of water
l, the supply of ethylene was stopped, and unreacted liquid propylene and ethylene were discharged to the outside to stop the polymerization. The slurry concentration at the time of termination of the polymerization was 33.4% by weight. By polymerization for 45 minutes, 145 g of an elastomeric copolymer was obtained. The content of vanadium in the copolymer, calculated from the amount of vanadium triacetylacetonate used in the polymerization, was 7.0 ppm. The ethylene content is 54.7% by weight and the propylene content is 4%.
It was 5.3% by weight. Number average molecular weight Mn is 327,0
00, the weight average molecular weight Mw is 847,000,
w / Mn = 2.6.

[0032]

Example 4 A copolymer was obtained in the same manner as in Example 3, except that the molar ratio between ethyl monochloromalonate and ethyl dichloromalonate was set to 2: 8. The slurry concentration at the end of the polymerization was 35.3% by weight. The copolymer yield was 15
The vanadium content calculated from 3 g of the used vanadium triacetylacetonate was 6.7 ppm. The ethylene content was 56.3% by weight and the propylene content was% by weight. The number average molecular weight Mn is 364
000, weight average molecular weight Mw: 882,000, Mw /
Mn was 2.4.

[0033]

Comparative Example 1 Example 1 except that the ratio of ethyl monochloromalonate to ethyl dichloromalonate was 8: 2.
A copolymer was obtained in the same manner as described above. The slurry concentration at the end of the polymerization was 15.0% by weight. The copolymer yield was 72.
g, the vanadium content calculated from the amount of vanadium triacetylacetonate used was 14.2 ppm. The ethylene content was 67.3% by weight, the propylene content was 29.4% by weight, and the 5-ethylidene-2-norbornene content was 3.3% by weight. The number average molecular weight Mn is 259,000, and the weight average molecular weight Mw is 776.
000, and Mw / Mn = 3.0.

[0034]

Comparative Example 2 A copolymer was obtained in the same manner as in Example 1 except that a mixture of ethyl monochloromalonate and ethyl dichloromalonate was added at once at the same time as the start of polymerization. The slurry concentration at the end of the polymerization was 15.0% by weight. The yield of the copolymer was 72 g, and the vanadium content calculated from the amount of vanadium triacetylacetonate used was 1 g.
It was 4.2 ppm. The ethylene content is 70.2
% By weight, the propylene content was 26.1% by weight, and the content of 5-ethylidene-2-norbornene was 3.7% by weight. The number average molecular weight Mn is 315,000, the weight average molecular weight Mw is 740,800, and Mw / Mn = 2.4.
Met.

[0035]

Comparative Example 3 Example 1 except that neither ethyl monochloromalonate nor ethyl dichloromalonate was used.
A copolymer was obtained in the same manner as described above. The slurry concentration at the end of the polymerization was 5.1% by weight. The yield of the copolymer was 25.
The vanadium content calculated from the amount of 3 g of vanadium triacetylacetonate used was 40.3 ppm. The ethylene content was 71.4% by weight, the propylene content was 25.5% by weight, and the 5-ethylidene-2-norbornene content was 3.1% by weight. The number average molecular weight Mn is 518,000 and the weight average molecular weight Mw is 3.0.
40,000, and Mw / Mn = 5.9.

[0036]

According to the production method of the present invention, the catalytic activity can be extremely increased, so that the decalcification operation can be performed without
An olefin copolymer having a vanadium content of 10 ppm or less is obtained. Further, since the slurry concentration can be increased to 25% or more, the production efficiency per unit volume can be remarkably increased as compared with the conventional case.

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Claims (1)

(57) [Claims] 1. An elastomeric olefin copolymer is produced by copolymerizing ethylene and propylene or ethylene and propylene with a non-conjugated diene hydrocarbon in liquid propylene using a vanadium compound and an organoaluminum compound as catalysts. (A) using an alkyl monohalogenomalonate and an alkyl dihalogenomalonate together as an activator; and (b) an alkyl dihalogenomalonate relative to the alkyl monohalogenomalonate. A method for producing an elastomeric olefin-based copolymer, wherein an equal amount or an excess is used.