JPH0124804B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing ethylene copolymer rubber with good processability, high tensile strength, and excellent randomness in a high yield using a Ziegler catalyst soluble in a solvent. It is.

As a catalyst for producing a rubber-like copolymer by randomly copolymerizing two or more types of olefins, a combination catalyst of a homogeneous vanadium compound and an organoaluminum compound has conventionally been widely used.

However, these homogeneous vanadium catalysts are generally very easily deactivated during polymerization, and their activity is not very high at practical polymerization temperatures of 30 to 60°C.

On the other hand, a combination catalyst of a titanium compound and an organoaluminum compound is generally known as a catalyst that is relatively less deactivated during polymerization. However, when this titanium compound is used as a catalyst, each olefin is likely to be homopolymerized, forming a mixture of individual homopolymers, or copolymerizing into a block shape. Therefore, the production of rubber-like elastic copolymers using titanium-based catalysts has not been successful so far.

Recently, several patents have been submitted for producing ethylene/α-olefin copolymer rubber using titanium-based catalysts. Examples include JP-A-49-51381, JP-A-50-117886,
There are Japanese Patent Application Laid-open No. 53-104687, etc. These attempts to randomly copolymerize ethylene and α-olefin using a combination catalyst of a solid catalyst component supporting a titanium compound on a carrier and an organoaluminum compound component; Due to poor properties, some of the copolymer precipitates in the hydrocarbon solvent during polymerization. Therefore, it is difficult to perform solution polymerization using these catalysts.

Furthermore, the produced copolymer is plastic-like and difficult to use in the rubber field. Therefore, the present inventors thought that it would be difficult to produce a random copolymer of olefin using a solid titanium-based catalyst, and attempted to research a method using a titanium compound in a solution state.

However, titanium compounds that are soluble in organic solvents and have olefin polymerization activity include titanium tetrachloride, titanium triacetylacetonate, and tetrabutoxytitanium. When two or more types of olefins are copolymerized, a mixture of their respective homopolymers or a block copolymer is likely to be produced, and a rubber-like copolymer cannot be obtained.

The present inventors thought that in order to perform random copolymerization, it would be necessary to reduce titanium tetrachloride in advance while keeping it in a liquid state.

A method for reducing titanium tetrachloride while keeping it in a liquid state in a hydrocarbon solvent is disclosed in JP-A-51-16298;
As disclosed in JP-A-51-76196 and JP-A-52-148490, a method is known in which titanium tetrachloride is reduced with an organoaluminum compound in the presence of ether.

In the method disclosed in these publications, titanium trichloride is precipitated by heating the reduced titanium tetrachloride liquid produced as described above or by adding a liberating agent, and after separation from ether, this is subjected to stereoregular polymerization of propylene. It is used as a commercial catalyst. In the titanium tetrachloride-reduced liquid mentioned above, ether exists in an amount equal to or more than titanium, but in this state where titanium coexists with an electron donor in an amount equal to or more than that, olefin is generally Their activity as polymerization catalysts is usually extremely low or non-existent.

However, when we copolymerized ethylene and α-olefin using a liquid obtained by reducing the titanium tetrahalide described above in a hydrocarbon solvent in the presence of ether and using it as a catalyst in combination with an organoaluminum compound, we surprisingly found that It was discovered that a substantially amorphous rubber-like elastic copolymer that exhibits high activity, excellent randomness, good processability, and high tensile strength can be obtained, and the present invention was achieved.

That is, the present invention is based on (A) the general formula TiX ₄ (where X is
Using a liquid obtained by treating titanium tetrahalide represented by (Cl, Br, I) with an organoaluminum compound in a hydrocarbon solvent in the presence of ether, and (B) a catalyst consisting of the organoaluminum compound. Ethylene and propylene or/and butene
1. A method for producing an ethylene copolymer rubber is provided, which further comprises copolymerizing a non-conjugated polyene as required.

The present invention will be explained in more detail below.

The catalyst component (A) used in the present invention is a liquid composition obtained by treating titanium tetrahalide with an organoaluminum compound in a hydrocarbon solvent in the presence of ether.

The titanium tetrahalide mentioned above includes titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide, and mixtures thereof can also be used.

The ether used in the present invention has the general formula R ¹ OR ² ...
Ethers represented by (1) (wherein R ¹ and R ² are the same or different alkyl groups, alkenyl groups, or aralkyl groups having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms) are used. , Specific examples thereof include the following ethers.

1 Dialkyl ether Di-n-hexyl ether, di-n-octyl ether, di-n-decyl ether, di-n-dodecyl ether, di-n-tridecyl ether, hexyl octyl ether, dicyclohexyl ether, etc. 2 Dialkenyl ether bis (1-octenyl)ether, bis(1-
dicynyl) ether, 1-octenyl-9-dicinyl ether, etc. 3 Diaralkyl ether Bis(benzyl) ether, etc. 4 Alkyl alkenyl ether n-octyl-1-decynyl ether, n-decyl-1-decynyl ether, etc. 5 Alkylaralkyl ether n-octylbenzyl ether, n-decylbenzyl ether, etc.6 Alkenylaralkyl ether 1-octenylbenzyl ether, etc. Among these ethers,
Particularly preferred are those in which R ¹ and R ² are linear alkyl groups.

The organoaluminum compound used as a reducing agent for titanium tetrahalide in the present invention _has the general formula AlR _n
hydrocarbon group, X is halogen or carbon number 1-12
Organoaluminum compounds having an alkoxy group of 1≦m≦3 are generally suitable. Also,
Two or more types of compounds may be combined. Specific examples of organoaluminum compounds include triethylaluminum, tri-n-propylaluminum, tri-i-butylaluminum, tri-n-
Examples include octyl aluminum, tri-(2-methylpentyl) aluminum, di-i-butyl aluminum hydride, ethyl aluminum sesquichloride, diethylaluminum chloride, ethyl aluminum dichloride, diethylaluminium ethoxide, diethylaluminium iodide, and the like. Among these organoaluminum compounds, trialkylaluminum is particularly preferred.

In addition, when reducing titanium tetrahalide with an organoaluminum compound, it is also possible to use a small amount of an organometallic compound of groups 1 to 10 of the periodic table, such as butylmagnesium iodide, other than the organoaluminum compound.

Hydrocarbon solvents that can be used in preparing the catalyst component (A) include n-pentane, n-hexane, n-
Saturated aliphatic hydrocarbons having 5 to 20 carbon atoms such as heptane, n-octane, n-decane, and liquid paraffin are most suitable, but saturated alicyclic hydrocarbons having 5 to 12 carbon atoms such as cyclohexane, methylcyclohexane, etc. , benzene, toluene, and other aromatic hydrocarbons having 6 to 9 carbon atoms. Two or more of these hydrocarbon solvents can also be used in combination.

The reduction treatment of titanium tetrahalide with an organoaluminum compound can be carried out by any method as long as the above-mentioned ether is present during the reduction. Examples of such methods include the following methods. .

a. A method of adding an organoaluminum compound to a homogeneous liquid consisting of titanium tetrahalide and ether.

b A method of adding a homogeneous liquid material consisting of an organoaluminum compound and ether to titanium tetrahalide.

c. A method of adding a uniform liquid substance consisting of an organoaluminium compound and an ether to a uniform liquid substance consisting of a titanium tetrahalide and an ether.

The contact between the titanium tetrahalide and the organoaluminum compound is usually carried out at a temperature of 80°C or lower, preferably 50°C or lower. If the contact temperature is low, the temperature may be raised after contact and ripening may be performed.

It is also possible to have a small amount of α-olefin, such as propylene, butene-1, hexene-1, etc., present when titanium tetrahalide is reduced with an organoaluminum compound.

Further, the molar ratio of titanium tetrahalide and ether used in these methods is preferably 1:
The ratio is in the range of 0.2 to 1:20, particularly preferably 1:0.5 to 1:5.

Furthermore, the molar ratio between titanium tetrahalide and the organoaluminum compound as a reducing agent is as follows:
It is expressed as a molar ratio with respect to the organoaluminum compound represented by (2), and is in the range of 1:0.2 to 1:5, preferably 1:0.3 to 1:2. It is also possible to add a small amount of an inorganic halide to promote solubilization of the reduced product of titanium tetrahalide.

The catalyst component (B) used in the present invention is an organoaluminum compound. As the organoaluminum compound, an organoaluminum compound represented by the general formula (2) shown above is generally suitable.

The quantitative ratio of catalyst component (A) and catalyst component (B) used is expressed as an atomic ratio of titanium to aluminum, and is usually in the range of 1:0.2 to 1:200, preferably 1:1 to Selected from a range of 1:50.

As monomers for polymerization, ethylene, propylene, and α-olefins of butene-1 are used. Ethylene copolymer rubber can be produced by copolymerizing a combination of ethylene and the above α-olefin.

In addition, to facilitate the vulcanization of copolymer rubber,
Non-conjugated polyene monomers can be copolymerized with the olefin monomers. The non-conjugated polyene is selected from arbitrary types such as cross-linked hydrocarbon compounds, monocyclic compounds, heterocyclic compounds, chain compounds, and spiro-type compounds. Specifically, dicyclopentadiene, tricyclopentadiene, 5-methyl-2,5-norbornadiene,
5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-isopropylidene-
2-norbornene, 5-isopropenyl-2-norbornene, 5-(1-butenyl)-2-norbornene, 5-(2'-butenyl)-2-norbornene,
cyclooctadiene, vinylcyclohexene,
1,5,9-cyclododecatriene, 6-methyl-4,7,8,9-tetrahydroindene, 2,
2'-dicyclopentenyl, trans-1,2-divinylcyclobutane, 1,4-hexadiene,
Examples include 1,6-octadiene and 6-methyl-1,5-heptadiene.

Polymerization temperature is usually 0~120℃, preferably 20~80℃
It is ℃. Polymerization pressure usually ranges from normal pressure to 50 kg/cm ² . In general, a solution polymerization method in which copolymerization is carried out in a good solvent for the copolymer is suitable for the copolymerization. As the solvent at that time, hydrocarbon solvents such as n-hexane and n-heptane are often used. Copolymerization may be batch polymerization or continuous polymerization. The molecular weight of the copolymer can be arbitrarily adjusted by using hydrogen as necessary.

Next, the present invention will be explained in more detail with reference to Examples.

In addition, the measured values of various physical properties of the copolymer in the examples are as follows: Mooney viscosity: preheating for 1 minute, measurement for 4 minutes, temperature
By measuring at 100℃, propylene content by infrared absorption spectrum, iodine number by titration method, 100% modulus, tensile strength, elongation at break,
and Shore A hardness are values determined by a measuring method according to JIS K6301.

In the Examples and Comparative Examples below, the infrared absorption spectra at 730 cm ^-1 (absorption due to crystallinity of polyethylene) and 720 cm ^-1 ((-CH ₂ )−
The intensity ratio with respect to the absorption by skeletal vibration of ₀ is expressed as shown in FIG. 2, the area of each area is determined, and the random index (RI) is determined by calculation using the following formula.

RI (%) = (area of B) / (area of A + B) × 100 Example 1 (1) Preparation of catalyst component (A) In a 200 ml three-neck flask that has been thoroughly dried and purged with nitrogen, 10 mmol of titanium tetrachloride and n- heptane 50ml
15 mmol of di-n-dodecyl ether was added over 10 minutes at room temperature with stirring, and the mixture was further stirred for 1 hour.
A solution of n-dodecyl ether in n-heptane was obtained. This was cooled to 0°C, and 5 mmol of tri-i-butylaluminum was gradually added dropwise over 1 hour.
Thereafter, the temperature was raised to 20°C over 1 hour, and the mixture was further aged at 20°C for 2 hours to obtain a dark brown homogeneous solution.

(2) Copolymerization A stirring blade, a three-way pot, a gas blowing tube, and a thermometer were attached to the separable flask in Step 3, and the flask was sufficiently purged with nitrogen and dried. 2000 ml of n-hexane, which had been dried and degassed with molecular sieves, was placed in this flask. A mixed gas of 4/min of ethylene, 6/min of propylene, and 1/min of hydrogen, which had been dried through a molecular sieve, was bubbled through a gas blowing tube into a flask whose temperature was controlled at 35° C. for 10 minutes. After this, tri-i-butylaluminum
7.0 mmol and the aforementioned catalyst component (A) in terms of titanium
0.7 mmol was added, and the mixed gas was passed through at the flow rate to start copolymerization. The temperature during polymerization was maintained at 35°C, and copolymerization was carried out for 30 minutes. 50 ml of methanol was added to the polymerization solution to stop the copolymerization. The solution during copolymerization was homogeneous, and no precipitation of copolymer was observed during copolymerization. After adding 1 part of water and stirring thoroughly, a solid rubber was obtained by steam stripping. The yield of copolymer was 58 g. The RI value determined from the infrared absorption spectrum of the copolymer was 1.0%.

The physical properties of the copolymer obtained in this example are as follows.

Propylene content = 44wt% ML ¹⁰⁰ ₁₊₄ = 68 100% modulus = 10Kg/cm ² Tensile strength = 33Kg/cm ² Elongation at break = 2700% Shore A hardness = 51 Comparative example 1 Tetrachloride in place of catalyst component (A) Copolymerization was carried out in the same manner as in Example 1 except that titanium was used as it was as a catalyst. During copolymerization, a large amount of copolymer precipitated and copolymerization proceeded in a slurry state. The copolymer yield is 8g, and the propylene content in the copolymer is
It was 38wt%. Furthermore, the RI value determined from the infrared absorption spectrum of the copolymer was 3.1%.

Comparative Example 2 Titanium tetrachloride and di-n- were used instead of the catalyst component (A).
Copolymerization was carried out in the same manner as in Example 1, except that a heptane solution of a dodecyl ether complex (equal moles of titanium and ether) was used. A large amount of copolymer precipitated during copolymerization, and copolymerization proceeded in a slurry state. The copolymer yield was 6 g, and the propylene content in the polymer was 36 wt%. In addition, the RI value determined from the infrared absorption spectrum of the copolymer was 2.9%.
It was hot.

Comparative Example 3 Solid titanium trichloride was obtained in the same manner as in Example 1 except that di-n-dodecyl ether was not added during the preparation of catalyst component (A). Copolymerization was carried out in the same manner as in Example 1 except that this titanium trichloride was used instead of the catalyst component (A). A large amount of polymer precipitated during copolymerization, and copolymerization proceeded in a slurry state. The copolymer yield was 14 g, and the propylene content in the copolymer was 38 wt%. The RI value determined from the infrared absorption spectrum of the copolymer was 3.8.

Example 2 Except for supplying a hexane solution of 5-ethylidene-2-norbornene at a rate of 8 ml/min (4 mmol/min for 5-ethylidene-2-norbornene) for 25 minutes from the start of polymerization to 5 minutes before the end. Copolymerization was carried out in the same manner as in Example 1. The solution during the copolymerization was homogeneous, and no polymer precipitation was observed during the copolymerization. The copolymer yield was 47 g.

Determined from the infrared absorption spectrum of the polymer
The RI value was 1.1%.

The physical properties of the copolymer obtained in this example are as follows.

Propylene content = 43wt% Yoso value = 12 ML ¹⁰⁰ ₁₊₄ = 67 100% modulus = 11Kg/cm ² Tensile strength = 35Kg/cm ² Elongation at break = 2900% Shore A hardness = 50 Example 3 5-ethylidene-2- Copolymerization was carried out in the same manner as in Example 2 except that dicyclopentadiene was supplied at a rate of 4 mmol/min instead of norbornene. The solution during copolymerization was homogeneous, and no polymer precipitation was observed during copolymerization. The copolymer yield is 48g, and the propylene content in the copolymer is
It was 43wt% and the iodine number was 12. The RI value determined from the infrared absorption spectrum of the polymer was 1.0%.

Example 4 The ether used in the preparation of catalyst component (A) was di-n-
Catalyst component (A) was prepared in the same manner as in Example 1 except that dodecyl ether was replaced with di-n-octyl ether. A dark brown homogeneous solution was obtained.
Polymerization was carried out in the same manner as in Example 1. The solution during polymerization was homogeneous, and no precipitation of copolymer was observed during polymerization. The copolymer yield was 43 g, and the propylene content in the polymer was 42 wt%. The RI value determined from the infrared absorption spectrum of the polymer was 1.2%.

Example 5 When preparing the catalyst component (A), triglyceride was used as a reducing agent.
After reduction with 5 mmol of i-butylaluminum, 1 mmol of butylmagnesium iodide (containing 3 mmol of di-n-octyl ether) prepared by reacting butyl iodide and magnesium metal in di-n-octyl ether was added for reduction. Catalyst component (A) was prepared in the same manner as in Example 1 except for the following. Polymerization was carried out in the same manner as in Example 1. The copolymer yield was 83 g, the propylene content in the copolymer was 46 wt%, and the RI value was 0.9%.

Example 6 Copolymerization was carried out in the same manner as in Example 1 except that butene-1 was used instead of propylene and a mixed gas of ethylene 2/min and butene-1 10/min was used. The yield of the copolymer was 18 g, and the content of butene-1 in the copolymer was 14 wt%.

[Brief explanation of drawings]

FIG. 1 is a flow chart that organically combines the catalyst components and preparation steps of the present invention. Figure 2 shows the infrared absorption spectrum at 720 and 730 cm ^-1 of the copolymer produced in Example 1 in order to determine the random index (RI) showing the randomness of ethylene and propylene, which is a feature of the present invention. This is an enlarged view of the absorption part.

Claims (1)

[Claims] 1 (A) Titanium tetrahalide represented by the general formula TiX ₄ (where X represents Cl, Br, or I) is treated with an organoaluminum compound in a hydrocarbon solvent in the presence of ether. and (B) an ethylene copolymer characterized by copolymerizing ethylene, propylene or/and butene-1, and optionally a non-conjugated polyene using a catalyst consisting of an organoaluminum compound. Rubber manufacturing method.