JP3198663B2 - Method for producing ultra-high molecular weight elastomeric olefin copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a composition having a weight average molecular weight of 10
The present invention relates to a method for producing an ultrahigh molecular weight elastomeric olefin-based copolymer having a molecular weight of at least 100,000.

[0002]

2. Description of the Related Art Ethylene propylene rubber and ethylene propylene
As a process for producing an elastomeric olefin-based copolymer such as a propylene-diene terpolymer, a solution polymerization method in which copolymerization of ethylene or propylene is performed in a solvent such as n-hexane, and a solution polymerization method in liquid propylene The main method was suspension polymerization.

[0003] The solution polymerization method has the advantage that almost no clogging occurs in the reactor because the olefin-based copolymer produced by the polymerization hardly precipitates. There is also an advantage that the operation of removing the catalyst from the olefin-based copolymer is easy.

For this reason, the solution polymerization method has conventionally been the mainstream. However, in the solution polymerization method, when the polymerization proceeds and the concentration or molecular weight of the olefin copolymer in the polymerization solution increases, the viscosity of the polymerization solution sharply increases, and it becomes difficult to stir or remove the heat of polymerization. There were drawbacks. For this reason, the concentration of the olefin-based copolymer in the polymerization solution is about 7 to 10%, which is the limit that can be industrially implemented, and polymerization cannot be continued until the molecular weight becomes too high.

On the other hand, in the suspension polymerization method, the produced olefin copolymer is in a state of being suspended in particles in liquid propylene, so that even if the molecular weight of the olefin copolymer increases, the polymerization Does not increase and stirring is easy. Further, the heat of polymerization is effectively removed by the evaporation of liquid propylene during the polymerization.

[0006] For this reason, recently, the suspension polymerization method has been actively studied. Further, in order to increase the activity per unit weight of the catalyst, an alkyl monohalogenomalonate and an alkyl dihalogenomalonate are used in combination as an activator, and the latter is used in the same amount as the former or in excess of the former. (Japanese Patent Application 4-
108309).

[0007]

[Problems to be Solved] However, since the polymerization has been performed under the condition that the supply pressure of ethylene, one of the monomers, is kept constant, an ultrahigh molecular weight olefin copolymer having a molecular weight of about 1,000,000 is obtained. It was difficult.

[0008] It is an object of the present invention to provide a method capable of producing an ultrahigh molecular weight elastomeric olefin-based copolymer by a suspension polymerization method.

[0009]

The present invention uses a vanadium compound and an organoaluminum compound as catalysts, and uses an alkyl monohalogenomalonate and / or an alkyl dihalogenomalonate as an activator, ethylene and propylene, and optionally A method of polymerizing a non-conjugated diene by a suspension polymerization method, wherein the polymerization is carried out while increasing the supply pressure of ethylene.

In the suspension polymerization method, a pressure higher than the vapor pressure of propylene at that temperature is applied to the polymerization system so that propylene remains liquid at a predetermined polymerization temperature, and ethylene is supplied at a pressure higher than the pressure. The polymerization is carried out while performing. The ethylene supply pressure refers to the pressure applied to ethylene at this time.

In the present invention, the ethylene supply pressure is increased during the polymerization.

The method of the present invention is applicable to both suspension polymerization in a batch system and suspension polymerization in a continuous system. Hereinafter, the case of suspension polymerization in a batch system will be described as an example. .

[0013] In batch propylene and non-conjugated diene in the reactor such as an autoclave, and catalyst feed, and an activating agent, and finally feeding ethylene at a predetermined ethylene feed pressure P _1, the polymerization system rapidly heating Then, polymerization starts. According polymerization system is heated, the internal pressure of the autoclave is increased, so that beyond the first ethylene feed pressure P _1. Then, the supply of ethylene stops and the polymerization stops, so that the temperature of the polymerization system decreases. When P ₂ increases the ethylene feed pressure at this point, because again the polymerization is initiated, the polymerization system is heated, accordingly the internal pressure of the autoclave is increased. When the internal pressure of the autoclave exceeds P ₂ , the supply of ethylene stops and polymerization stops.
The temperature of the polymerization system decreases. This point further with P ₃ increases the ethylene feed pressure and the polymerization is resumed.

[0014] In a continuous mode, for example in a multi-tank polymerization method, the ethylene feed pressure is P ₁ in the first vessel th in the second tank first and higher pressure P ₂ than in the third vessel P ₂ methods such as the higher pressure P ₃ than are possible.

The width of increase in ethylene supply pressure per stage is preferably in the range of 0.1 to 5 kg / cm ² . When the increase per step is smaller than 0.1 kg / cm ² , it becomes difficult to obtain an ultrahigh molecular weight elastomeric olefin copolymer. On the other hand, if the width of increase per step is larger than 5 kg / cm ² , the polymerization may proceed too rapidly as soon as the ethylene supply pressure is increased, and a runaway reaction may occur.

The ethylene supply pressure P at the start of polymerization
₁ is 0.1 to 5 higher than the propylene vapor pressure at this time.
The pressure is preferably set to be higher by kg / cm ² .

Although the example in which the ethylene supply pressure is increased stepwise has been described above, in the present invention, the ethylene supply pressure may be continuously increased.

Hereinafter, the vanadium compound and the organoaluminum compound as the catalyst, the activator, and the monomer will be described.

As the vanadium compound, trivalent, tetravalent,
Alternatively, pentavalent ones are preferable, and divalent or lower ones are not preferable. This is because a vanadium compound having two or less valences no longer has an action as a polymerization catalyst. Trivalent, tetravalent, or five
Examples of the multivalent vanadium compound include VOCl ₃ , VC
l ₃ , VCl ₄ , V (AcAc) _{3 and the} like (AcAc
Represents acetylacetonate). Of these vanadium compounds, V (AcAc) ₃ is particularly preferred. This is because an elastomeric olefin copolymer having a low chlorine content can be obtained.

As the organic aluminum compound, an alkyl aluminum halide, a trialkyl aluminum or the like is preferable. Examples of such a substance include dimethylaluminum chloride, diethylaluminum chloride, ethylaluminum sesquichloride, triethylaluminum, trimethylaluminum, triisopropylaluminum, triisobutylaluminum and the like.

As the activator, an alkyl monohalogenomalonate and / or an alkyl dihalogenomalonate is used, and it is preferable to use both of them. It is particularly preferable to use the latter in the same amount as the former or in excess of the former. This is because the catalyst activity becomes high, and an elastomeric olefin-based copolymer with very little catalyst residue can be obtained.

As the alkyl monohalogenomalonate, methyl monochloromalonate, ethyl monochloromalonate, methyl monobromomalonate, ethyl monobromomalonate and the like are used. As the alkyl dihalogenomalonate, methyl dichloromalonate, ethyl dichloromalonate, methyl dibromomalonate, ethyl dibromomalonate and the like are used.

As the monomer, non-conjugated dienes can be used, if necessary, in addition to ethylene and propylene. Non-conjugated dienes include, for example, 5-ethylidene-2
-Norbornene, 2,5-norbornadiene, 2-methylenenorbornene, 2-ethylnorbornene, 5-methylenenorbornene, 5- (2-butenyl) -2-norbornene, bicyclo [3,2,0] heptadiene, tetrahydroindene, alkyl Tetrahydroindene, dicyclopentadiene, 9,10-dihydrodicyclopentadiene, 6-methyl-1,5-heptadiene, 1,4-
Hexadiene, 1,5-hexadiene and the like are used.

Hereinafter, the quantitative relationship between the monomer, the catalyst, the activator and the like will be described.

In the catalyst, the amount of the vanadium compound is preferably in the range of 0.0005 to 0.500 mmol, particularly preferably in the range of 0.001 to 0.050 mmol per 100 g of propylene. 0.0005 mm of vanadium compound
If it is less than ol, there is a problem that productivity is extremely reduced. On the other hand, if it exceeds 0.50 mmol, the polymerization proceeds too quickly, and there is a problem that the heat of polymerization cannot be completely removed only by the latent heat of vaporization of liquid propylene.

The ratio of the vanadium compound to the organoaluminum compound is 0.002 to 0.2 (V / Al (mol / mo
l)) is preferable, and especially 0.005 to 0.1 (V /
Al (mol / mol)) is preferable. The ratio of the vanadium compound to the organoaluminum compound is 0.002.
When it is less than (V / Al (mol / mol)), the vanadium compound is excessively reduced by the aluminum compound, and the catalytic activity decreases. On the other hand, 0.2 (V / Al (mo
(l / mol)), the reduction of the vanadium compound becomes insufficient, so that the progress of the polymerization becomes too slow, and the productivity of the elastomeric olefin copolymer decreases.

The amount of the activator added is determined by the amount of the vanadium compound 1
The range of 0.05 to 150 mol per mol is preferred. The amount of the activator added is 0.0 per mol of the vanadium compound.
If it is less than 5 mol, there is almost no effect of addition, while 150
When the amount is larger than mol, the active sites are deactivated by the added activator, which is not preferable.

Further, diethyl zinc or hydrogen may be added as a chain transfer agent.

In the present invention, the polymerization temperature is from -30 to 1
The range of 00 ° C is preferred, and the range of 0 to 70 ° C is particularly preferred.

[0030]

According to the method of the present invention, the molecular weight by weight is 10
Ultrahigh molecular weight olefin copolymers of up to 10,000 or more can be easily obtained by a suspension polymerization method.

[0031]

EXAMPLES The present invention will be specifically described with reference to the following examples.

Example 1 In a 2-liter autoclave, 500 g of liquid propylene, 5-ethylidene-
14.4 ml of 2-norbornene, 2.9 mmol of diethylaluminum chloride, and 0.1 mmol of diethylzinc were charged, and the temperature was set at 20 ° C. At this time, the internal pressure of the autoclave was 11 kg / cm ² · G. While stirring the contents, supply of ethylene to the autoclave was started at a pressure of 13 kg / cm ² · G, and a solution in which 0.02 mmol of vanadium triacetylacetonate was dissolved in toluene was injected to initiate polymerization. Ethyl monochloromalonate and ethyl dichloromalonate were used as activators:
8 (molar ratio), and this mixture was used in an amount of 0.
A solution in which 15 mmol was dissolved in 15 ml of toluene was continuously supplied from the start to the end of the polymerization. When barium triacetylacetonate was added to initiate polymerization, the temperature inside the autoclave increased due to the heat of polymerization, and reached 22 ° C. after 6 minutes. Thereafter, the temperature dropped to 18 ° C. after 10 minutes. At this point, the ethylene feed pressure was increased to 14 kg / cm ² · G. When the ethylene supply pressure was increased, the temperature inside the autoclave again increased, and the temperature reached 21.3 degrees 15 minutes after the start of the polymerization. Thereafter, the temperature dropped. The temperature in the autoclave is 18
At the time of drop to 15 ° C., the ethylene supply pressure was increased to 15 kg / cm
It increased to ² · G. Increasing the ethylene supply pressure,
The temperature inside the autoclave was increased three times, and reached 20.5 degrees 37 minutes after the start of the polymerization. 45 minutes after the start of the polymerization, the supply of ethylene was stopped, and 20 ml of water was added.
After the addition, unreacted propylene and ethylene were released to the outside to terminate the polymerization. The obtained ethylene propylene
The diene terpolymer was 125 g. The ethylene / propylene / diene terpolymer copolymer has a monomer ratio of 54.2% by weight of ethylene and 31.1% of propylene.
% By weight, 14.7% of 5-ethylidene-2-norbornene
%Met. The number average molecular weight Mn is 397,000, the weight average molecular weight Mw is 1,782,000, Mw /
Mn was 4.5. The proportion of ethylene and the like was measured by ¹ H-NMR, and the molecular weight was measured by GPC.

Example 2 In a 2-liter autoclave, 500 g of liquid propylene and 5-ethylidene-
14.4 ml of 2-norbornene, 2.9 mmol of diethylaluminum chloride, and 0.1 mmol of diethylzinc were charged, and the temperature was set to 25 ° C. At this time, the internal pressure of the autoclave was 12.9 kg / cm ² · G. While stirring the contents, 14.9 kg / cm ² ·
At a pressure of G, supply of ethylene was started, and a solution in which 0.02 mmol of vanadium triacetylacetonate was dissolved in toluene was injected to initiate polymerization. As the activator, a mixture of ethyl monochloromalonate and ethyl dichloromalonate mixed at a molar ratio of 1: 9 was used, and a solution obtained by dissolving 0.15 mmol of this mixture in 15 ml of toluene was used.
It was continuously supplied from the start to the end of the polymerization. When barium triacetylacetonate was added to initiate the polymerization, the temperature inside the autoclave rose due to the heat of polymerization, and reached 28 ° C. after 3 minutes. Thereafter, the temperature dropped and reached 13 ° C. after 13 minutes. At this point, the ethylene feed pressure was increased to 15.9 kg / cm ² · G. When the ethylene supply pressure was increased, the temperature inside the autoclave again increased, and the temperature reached 28 degrees 16 minutes after the start of the polymerization. After that, the temperature dropped and after 23 minutes 23 ° C
Down to At this point, the feed pressure of ethylene was increased to 16.
When the pressure was increased to 9 kg / cm ² · G, the temperature inside the autoclave was increased three times, and after 27 minutes from the start of polymerization, 2 hours.
8 degrees has been reached. After 45 minutes from the start of the polymerization, the supply of ethylene was stopped, 20 ml of water was added, and unreacted propylene and ethylene were discharged to the outside to stop the polymerization. 129 g of an ethylene / propylene / diene terpolymer was obtained. The proportion of each monomer in the ethylene / propylene / diene terpolymer was 57.7% by weight of ethylene, 32.9% by weight of propylene, and 9.4% of 5-ethylidene-2-norbornene. Number average molecular weight Mn is 45
2,000 and a weight average molecular weight Mw of 1,840,
000, Mw / Mn = 4.1. The proportion of ethylene and the like was measured by ¹ H-NMR, and the molecular weight was measured by GPC.

Comparative Example 1 The supply pressure of ethylene was 13 kg.
/ Cm ² · G, except that it was constant. As a result, 115 g of an ethylene / propylene / diene terpolymer was obtained. The proportion of each monomer of the ethylene / propylene / diene terpolymer was 53.3% by weight of ethylene, 38.7% by weight of propylene,
5-ethylidene-2-norbornene was 8.7%. The number average molecular weight Mn was 296,000, the weight average molecular weight Mw was 795,000, and Mw / Mn was 2.7. The ratio of ethylene and the like was determined by ¹ H-NMR.
And the molecular weight was measured by GPC.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 210/00-210/18 C08F 4/68-4/685

Claims (1)

(57) [Claims] An alkyl monohalogenomalonate and / or an alkyl dihalogenomalonate are used as an activator with a vanadium compound and an organoaluminum compound as catalysts, and ethylene and propylene or ethylene and A method for obtaining an elastomeric olefin-based copolymer by copolymerizing propylene and a non-conjugated diene, wherein the polymerization is carried out while increasing the supply pressure of ethylene. A method for producing a copolymer.