JPS649330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an ethylene copolymer rubber with good processability, high tensile strength, and excellent randomness in good yield using a Ziegler catalyst soluble in a solvent. More specifically, the present invention relates to a method of randomly copolymerizing ethylene and propylene or/and budene-1 using solubilized titanium trihalide.

As a catalyst for producing a rubbery 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 a practical polymerization temperature 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, resulting in a mixture of each homopolymer, or even if copolymerized, it is easy to copolymerize in blocks. Therefore, the production of rubbery copolymers using titanium-based catalysts has not been successful to date.

However, 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, JP-A-53-104687, etc. These attempts to copolymerize ethylene and α-olefin in a random manner using a combination catalyst of a solid catalyst component supporting a titanium compound on a carrier and an organoaluminium compound component, but the random copolymerization of the produced copolymer 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 believed that it would be difficult to produce a random copolymer of olefins using a solid titanium-based catalyst, and attempted to improve the randomness of the copolymer by using a titanium compound in a solution state. He conducted intensive research.

As a result, the present inventors used a combination catalyst of a liquid composition obtained by preparing titanium trihalide in a halogenated hydrocarbon solvent in the presence of an ether and an organoaluminum compound to produce ethylene and propylene or/and butene. When copolymerizing -1, it surprisingly showed extremely high activity, excellent randomness, and good processability.
It was discovered that an olefin copolymer rubber with high tensile strength can be obtained, and the present invention was accomplished based on this finding.

That is, the present invention uses (A) a liquid obtained by dissolving a solid halogenated titanium compound in a halogenated hydrocarbon solvent in the presence of ether, and (B) a catalyst consisting of an organoaluminum compound to dissolve ethylene and propylene or The present invention provides a method for producing an ethylene copolymer rubber, characterized by copolymerizing / and butene-1.

The present invention will be explained in more detail below.

The catalyst component (A) that can be used in the present invention is a liquid obtained by dissolving a solid halogenated titanium compound in a halogenated hydrocarbon solvent in the presence of ether. As the titanium trihalide, titanium trichloride, titanium tribromide, and titanium triiodide can be suitably used. Among them, titanium trichloride is the most preferred compound. There are the following methods for producing titanium trichloride, but the method is not limited to titanium trichloride produced by these methods.

Generally, titanium tetrachloride is reduced by (1) metal aluminum, magnesium, titanium, etc.;
(2) A method of reducing with hydrogen, or (B) a method of reducing with an organometallic compound.

Titanium trichloride produced by these methods is pure
It does not have to be TiCl ₃ ; it may be, for example, one with a reducing agent chloride added, or one with such auxiliary components introduced after the fact, and a small amount of unreduced of titanium tetrachloride and/or overreduced titanium dichloride. Among these titanium trichlorides, titanium trichloride obtained by reduction with metal aluminum, an organoaluminum compound, or an organomagnesium compound is preferable, and these titanium trichlorides have a higher Therefore, it is easily soluble in halogenated hydrocarbon solvents in the presence of ether and can give more concentrated solutions.

The ether used in the present invention has the general formula R ¹ OR ² ...
(1) (wherein R ¹ and R ² are the same or different alkyl groups having 1 to 12 carbon atoms, alkenyl groups, aralkyl groups,
or aryl group) are used, and specific examples thereof include the following ethers.

1 Dialkyl ether Diethyl ether, di-n-propyl ether, di-n-butyl ether, di-n-hexyl ether, di-n-octyl ether, di-n-
Decyl ether, di-n-dodecyl ether, hexyl octyl ether, etc. 2 Dialkenyl ether Bis(1-octenyl) ether, Bis(1-
decynyl) ether, 1-octenyl-9-decynyl ether, etc. 3 Diaralkyl ether Bis(benzyl) ether, etc. 4 Alkyl alkenyl ether n-octyl-1-decynyl ether, etc. 5 Alkyl aralkyl ether n-octyl benzyl ether, n- Decylbenzyl ether, etc.6 Aralkyl alkenyl ether, 1-octenylbenzyl ether, etc. Among these ethers, those in which R ¹ and R ² in the general formula (1) are linear alkyl groups are particularly preferred. The molar ratio of titanium trihalide to ether used generally ranges from 1:5 to 1:0.1;
Preferably it is in the range of 1:2 to 1:0.2. In this case, the treatment temperature of the solid titanium halide compound and the ether is -30°C to 120°C, preferably 0°C.
~60℃. The treatment time for the ether and the solid titanium halide compound is not particularly limited, but in order to completely dissolve the titanium trihalide, it is preferable to conduct the treatment for 10 minutes or more.

The halogenated hydrocarbon solvent used in preparing the catalyst component (A) generally includes halides of aliphatic hydrocarbons having 1 to 10 carbon atoms, halides of alicyclic hydrocarbons having 5 to 12 carbon atoms, and carbon number 6~
9 aromatic hydrocarbon halides.
Two or more of these halogenated hydrocarbon solvents may be used in combination. Specific examples of these halogenated hydrocarbons are shown below.

1 Halogenated aliphatic hydrocarbons Methylene chloride, chloroform, carbon tetrachloride, monochloroethane, ethyl iodide, 1,2-
dichloroethane, 1,1-dichloroethane, 1,
1,2-trichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethylene, n-butyl chloride, n-butyl iodide, etc.2 Halogenated alicyclic hydrocarbons Chlorcyclohexane etc. 3. Halides of aromatic hydrocarbons Chlorobenzene, benzene bromide, benzene iodide, etc. Among these halogenated hydrocarbons, halides of aliphatic hydrocarbons are preferred. It is also possible to add a small amount of a hydrocarbon solvent and use a mixed solvent. It is also possible to add a small amount of halogen or inorganic halide, such as iodine, bromine, iodine trichloride, etc., to promote solubilization of the solid halogenated titanium compound.

The organoaluminum compound of the catalyst component (B) has the general formula AlR _n X _3-n (2) (R is hydrogen or a hydrocarbon group having 1 to 12 carbon atoms, and Organoaluminum compounds of the group 1≦m≦3) are generally suitable. Two or more types of organoaluminum compounds may be combined. Specific organoaluminum compounds include, for example, triethylaluminum, tri-n
-propyl aluminum, tri-i-butyl aluminum, tri-n-octyl aluminum, tri(2-methylpentyl) aluminum, di-i
-butylaluminum hydride, ethylaluminum sesquichloride, diethylaluminum chloride, ethylaluminum dichloride, diethylaluminum ethoxide, diethylaluminium iodide, and the like. Among these organoaluminum compounds, trialkylaluminum is particularly preferred. The ratio of the catalyst component (A) and catalyst component (B) used is expressed by the atomic ratio of titanium to aluminum, and is usually 1:0.2 to 1:
200, preferably within the range of 1:1 to 1:50.

Ethylene copolymer rubber can then be produced by copolymerizing ethylene and propylene or/and butene-1.

Furthermore, in order to facilitate vulcanization, a non-conjugated polyene monomer can be copolymerized with the olefin monomer. 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,
Examples include 8,9-tetrahydroindene, 2,2'-dicyclopentenyl, trans-1,2-divinylcyclobutane, 1,4-hexadiene, 1,6-octadiene, and 6-methyl-1,5-heptadiene. Among these non-conjugated polyenes, 5-
Ethylidene-2-norbornene and dicyclopentadiene are preferred. Copolymerization temperature is usually 0~120℃,
Preferably it is 20-80°C. The copolymerization pressure is usually in the range of 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. The physical properties of the copolymers in the examples were determined by measuring the propylene content using an infrared absorption spectrum, the iodine number using a titration method, and the Mooney viscosity at a temperature of 100°C, preheating for 1 minute, and measurement for 4 minutes. Also,
100% modulus, tensile strength, elongation at break, and Shore A hardness are values determined by a measuring method according to JIS K6301.

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

RI (%) = (Area of B) / (Area of A + B) × 100 Example 1 (1) Preparation of catalyst component (A) 1 Production of titanium trichloride Four titanium trichloride were placed in a 200 ml three-necked flask that had been thoroughly dried and purged with nitrogen. 50 mmol of titanium chloride and 50 ml of n-hexane
25 mmol of triethylaluminum was gradually added dropwise over 1 hour at 0°C with stirring, then the temperature was raised to 20°C over 1 hour, and the mixture was aged at 20°C for 2 hours. The precipitated solid titanium trichloride was filtered and n-
It was thoroughly washed with hexane and then dried to obtain reddish-purple titanium trichloride.

2 Dissolution of titanium trichloride 2 g of titanium trichloride (10.1 mmol titanium equivalent) obtained as described above was placed in a 200 ml flask under nitrogen, 50 ml of 1,2-dichloroethane was added, and di-n-octyl was added under stirring. 20 mmol of ether was added. When stirring was continued for 1 hour at 20°C, dark brown titanium trichloride di-n-octyl ether, 1,
A 2-dichloroethane solution was obtained.

(2) Copolymerization The separable flask from step 3 was equipped with a stirring blade, a three-way pot, a gas blowing tube, and a thermometer, and was thoroughly purged with nitrogen and dried. 2000 ml of n-hexane, which had been dried and degassed with molecular sieves, was placed in this flask. Dry ethylene 4 through the gas blowing pipe
/min, propylene 6/min and hydrogen 1
/min of mixed gas was bubbled through the flask whose temperature was controlled at 35°C for 10 minutes. Tri-i-butylaluminum 7.0mmol and catalyst component (A) in terms of titanium
Copolymerization was started by adding 0.7 mmol. The temperature during copolymerization was maintained at 35°C and copolymerization was carried out for 30 minutes. Thereafter, 50 ml of methanol was added to stop the copolymerization. water 1
After stirring thoroughly, a solid rubber was obtained by steam stripping.

The copolymer yield was 52 g, the propylene content in the copolymer was 44 wt%, and the RI determined from the infrared absorption spectrum of the copolymer (see Figure 2) was 0.7.

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

ML100℃ 1+4=73 100% modulus = 11Kg/cm ² Tensile strength = 35Kg/cm ² Elongation at break = 2600% Shore A hardness = 53 Comparative example 1 Solid titanium trichloride produced in Example 1 in place of titanium trichloride solution Copolymerization was carried out in the same manner as in Example 1 except that the compound was used as a catalyst as it was. During the copolymerization, a large amount of copolymer was precipitated, and the copolymerization proceeded in a slurry state. Copolymer yield is 19
g, propylene content in the copolymer is 39wt%, RI
was 3.7.

Comparative Example 2 Same as Example 1 except that 0.7 mmol of solid titanium trichloride produced in Example 1 and 1.4 mmol of di-n-octyl ether were added separately to perform copolymerization instead of the titanium trichloride solution. Copolymerization was carried out using During the copolymerization, a large amount of copolymer was precipitated, and the copolymerization proceeded in a slurry state. Copolymer yield is 13
g, propylene content in the copolymer is 38wt%, RI
was 3.5.

Comparative Example 3 Titanium tetrachloride and di-
Copolymerization was carried out in the same manner as in Example 1, except that a 1,2-dichloroethane solution of a complex of n-octyl ether (equal moles of titanium and ether) was used. During the copolymerization, a large amount of copolymer was precipitated, and the copolymerization proceeded in a slurry state. The copolymer yield is 5
g, propylene content in the copolymer is 36wt%, RI
was 2.7.

Example 2 Ether used for dissolving titanium trichloride was di-n
A catalyst component (A) was prepared in the same manner as in Example 1 except that -butyl ether was used. Copolymerization was carried out in the same manner as in Example 1.

The copolymer yield was 50 g, the propylene content in the copolymer was 43 wt%, and the RI was 0.8.

Example 3 The same operation as in Example 1 was carried out except that chlorobenzene was used as the solvent for dissolving titanium trichloride,
A catalyst component (A) was prepared. Copolymerization was carried out in the same manner as in Example 1.

The copolymer yield was 53 g, the propylene content in the copolymer was 44 wt%, and the RI was 1.0.

Example 4 Catalyst component (A) was prepared in the same manner as in Example 1.
Example except that a hexane solution of 5-ethylidene-2-norbornene was supplied at a rate of 8 ml/min (4 mmol/min for 5-ethylidene-2-norbornene) for 25 minutes from the start of copolymerization to 5 minutes before the end. Copolymerization was carried out in the same manner as in 1. The copolymer yield is 49g, and the propylene content in the copolymer is
It was 43%, the iodine number was 14, and the RI was 0.8.

Example 5 Copolymerization was carried out in the same manner as in Example 4 except that dicyclopentadiene was supplied at a rate of 4 mmol/min in place of 5-ethylidene-2-norbornene.

The polymer yield was 47 g, the propylene content in the polymer was 43 wt%, the iodine number was 15, and the RI was 0.9.

Example 6 Catalyst component (A) was prepared in the same manner as in Example 1 except that 1 mmol of iodine was added following di-n-octyl ether during dissolution of titanium trichloride. Copolymerization was carried out in the same manner as in Example 1.

The copolymer yield was 50 g, the propylene content in the copolymer was 44 wt%, and the RI was 0.6.

Example 7 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 16 g, and the content of butene-1 in the copolymer was 12 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 absorption at 720 and 730 cm ^-1 of the infrared absorption spectrum of the copolymer produced in Example 1 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 a portion.

Claims (1)

[Scope of Claims] 1. Ethylene and A method for producing ethylene copolymer rubber, which comprises copolymerizing propylene and/or butene-1.