JPH07173213A - Catalyst for producing ethylene-propylene copolymer rubber - Google Patents

Abstract

PURPOSE:To provide a catalyst which gives a good rubber like ethylene- propylene copolymer comprising very randomly arranged ethylene and propylene units and scarecely contg. polyethylene chains and polypropylene chains by compounding a specific solid catalyst component, an arom. carboxylic ester compd., and an organoaluminum compd. CONSTITUTION:This compsn. comprises a solid catalyst component, an arom. carboxylic ester compd., and an organoaluminum compd. The solid catalyst component is obtd. by bringing a dialkoxymagnesium into contact with an electron donor having a carbonyl group and dimethylpolysiloxane in the presence of an alkylbenzene, reacting the resulting product with a titanium halide of the formula: TiX4 (wherein X is a halogen atom), washing the resulting solid substance with a hydrocarbon solvent, and bringing the substance into contact with a 5C or higher olefin.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is widely used in the field of rubber products requiring insulation, water resistance and impact resistance, for example, industrial products such as hoses and packings, electric cables and footwear, and polypropylene. It is also used for the modification of a resin composed of, for example, ethylene and propylene which are applied to automobile bumpers and films, etc., which can be obtained in a high yield of a copolymer rubber in which ethylene and propylene are randomly polymerized. The present invention relates to a high performance catalyst for producing a propylene copolymer rubber.

[0002]

2. Description of the Related Art Conventionally, as a catalyst for producing an ethylene-propylene copolymer rubber, a catalyst obtained by combining a vanadium compound soluble in a solvent during polymerization and an organoaluminum has been mainly used. Since the polymerization activity of the catalyst is low at high temperature, the polymerization is carried out at a relatively low temperature.

On the other hand, in a Ziegler catalyst containing a transition metal compound such as a titanium halide as an active ingredient, a carrier such as magnesium chloride is used to prepare a supported catalyst, which is used for homopolymerization of ethylene or propylene. Many proposals have been made that the catalytic activity can be dramatically improved. However, when such a titanium-based catalyst is used as it is for the copolymerization of ethylene and propylene, it is extremely difficult to obtain a random copolymer of ethylene and propylene in a high yield.

As a catalyst used for homopolymerization of olefins, the applicant of the present invention has disclosed, for example, JP-A-62-158704, JP-A-2-238004, and JP-A-3-21.
0306, JP-A-4-8709, etc., dialkoxy magnesium, titanium halide,
We provide catalyst components using specific electron donors as starting materials, and achieve extremely high catalytic activity. However, when a catalyst comprising the catalyst component and an organoaluminum compound is subjected to ethylene-propylene copolymerization, it is possible to maintain extremely high catalytic activity in homopolymerization, which is the intended purpose, as it is, but random polymerization is performed. A highly rubbery copolymer cannot be obtained in high yield.

Similarly, Japanese Patent Application Laid-Open No. Hei 3 (1999) -1994 relating to the prior application of the applicant of the present application.
-106910 and Japanese Patent Laid-Open No. 3-115312, a specific solid catalyst component starting from dialkoxymagnesium, titanium halide, aromatic carboxylic acid monoester and dimethylpolysiloxane, an organoaluminum compound and an ester compound. A catalyst for the production of an ethylene-propylene copolymer rubber formed by and has been proposed, and it has been reported that the ratio of crystalline polypropylene in the produced polymer is very low. There was an unsolved part that there was a large proportion of the part.

Further, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 3-2054.
In JP-A 06-06, a solid catalyst component was proposed, which uses diethoxymagnesium, tetrabutoxytitanium, an electron-donating compound having a C = O bond as a starting material. According to this, an ethylene-propylene copolymer having high random polymerizability and having no crystalline polymer and having high homogeneity can be obtained, but there is still room for improvement in catalytic activity.

[0007]

When a vanadium-based catalyst is subjected to ethylene-propylene copolymerization, the polymer yield per unit vanadium (hereinafter referred to as "catalytic activity") is low, and the resulting copolymer rubber contains Since the proportion of the residual catalyst contained is large, a step (deashing step) for removing the catalyst residual and decolorizing is unavoidable. Since this deashing process uses a large amount of alcohol or a chelating agent, a recovering device or a regenerating device for them is indispensable, and there are many resources, energy, and other incidental problems, and those skilled in the art urgently need a solution. It has become an important issue. Also,
Since the polymerization reaction is carried out at a low temperature, it is difficult to remove the heat generated during the polymerization, and there are many problems in terms of process design and operation. Further, since vanadium has toxicity, it is not preferable as a catalyst composition in consideration of safety of the produced copolymer rubber.

On the other hand, the randomness of the copolymer obtained by using the titanium-based catalyst is generally poor, and a large proportion of the long chain portion of ethylene or propylene remains unsolved. Among those proposed as the titanium-based catalyst for ethylene-propylene copolymer, the system in which magnesium chloride is used as a carrier substance is the mainstream, but in addition to its poor random polymerizability, its catalytic activity is far from sufficient. In addition, chlorine contained in magnesium chloride, which occupies the main stream as a carrier substance, has a drawback that it has an adverse effect on a produced polymer similarly to chlorine in titanium halides, and therefore, chlorine is practically affected. However, there remains a problem that the activity is required to be negligible, or the concentration of magnesium chloride itself must be kept low.

The object of the present invention is to contain no toxic vanadium compound, little influence of residual chlorine, excellent random polymerizability while maintaining high catalytic activity during copolymerization, and chain of ethylene and propylene monomers. An object of the present invention is to provide a catalyst for producing an ethylene-propylene copolymer rubber capable of giving a good quality rubber polymer having a small amount of parts.

[0010]

[Means for Solving the Problems] A catalyst for producing a polymer rubber of both ethylene and propylene according to the present invention for achieving the above object comprises the following (A), (B) and (C): Characterize above. (A) (a) dialkoxymagnesium is contacted with (b) an electron-donating compound having a C═O bond and (d) dimethylpolysiloxane in the presence of alkylbenzene,
Then, (e) a solid substance obtained by reacting with a titanium halide represented by the general formula TiX ₄ (X is a halogen element) is washed with a hydrocarbon solvent, and (f) is contacted with an olefin having 5 or more carbon atoms. Solid catalyst component thus obtained, (B) aromatic carboxylic acid ester compound, (C) organoaluminum compound

In the present invention, (a) dialkoxymagnesium (hereinafter, simply referred to as "A") constituting the solid catalyst component (A)
Examples of (a) substance) include diethoxymagnesium, dipropoxymagnesium, dibutoxymagnesium, diphenoxymagnesium and the like, and among them, diethoxymagnesium is preferable.

(B) Alkylbenzene (hereinafter simply referred to as "(b)
Examples of the “substance” may include toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene, and the like, but it is also possible to use a mixture of these in an arbitrary ratio.

Examples of the electron-donating compound having a C═O bond (c) (hereinafter sometimes simply referred to as “(c) substance”) include carboxylic acid ester, dicarboxylic acid diester, carboxylic acid anhydride, and ketone. Can be mentioned. Among these, as carboxylic acid esters, methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, ethyl propionate, methyl butyrate, ethyl crotonic acid, methyl benzoate, ethyl benzoate, benzoic acid. Examples include propyl, butyl benzoate, octyl benzoate, methyl toluate and ethyl toluate. The dicarboxylic acid diesters are preferably phthalic acid diesters such as dimethyl phthalate, diethyl phthalate,
Examples thereof include dipropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate and ethyl propyl phthalate. Examples of carboxylic acid anhydrides include acetic anhydride, benzoic anhydride, toluic anhydride, maleic anhydride, and phthalic anhydride. Examples of the ketones include formaldehyde, acetaldehyde, butyraldehyde, acrylaldehyde, benzaldehyde, acetone, ethyl methyl ketone, 4-heptanone, 2,6-dimethyl-4-heptanone, methyl vinyl ketone, acetophenone, cyclopentanone and the like. .

As the dimethylpolysiloxane (d) (hereinafter sometimes simply referred to as “(d) substance”), those having a viscosity at 25 ° C. of 10 to 50 cSt are used.

(E) Titanium halide (hereinafter referred to simply as "(e)
Examples of the "substance" include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, etc., among which titanium tetrachloride is preferable.

(F) An olefin having 5 or more carbon atoms (hereinafter,
(Sometimes referred to simply as "(f) substance") is a liquid at room temperature, such as pentene, hexene, octene, nonene,
Decene, methylbutene, methylpentene, methylhexene, ethylpentene, ethylhexene, dimethylhexene, dimethylpentene, styrene, dimethylstyrene,
Examples thereof include vinylcyclopentane and vinylcyclohexane.

As the aromatic carboxylic acid ester compound (B) used in the present invention, methyl benzoate,
Ethyl benzoate, propyl benzoate, butyl benzoate,
Examples include octyl benzoate, methyl toluate, ethyl toluate and the like.

The organoaluminum compound (C) used in the present invention is triethylaluminum,
Trialkylaluminums such as triisobutylaluminum; Dialkylaluminum halides such as diethylaluminum chloride and dibutylaluminum chloride; Alkylaluminum dihalides such as ethylaluminum dichloride and propylaluminum dichloride; Alkylaluminum sesquichlorides such as ethylaluminum sesquichloride and butylaluminum sesquichloride Halides; alkyl aluminum alkoxides such as diethyl aluminum ethoxide and dibutyl aluminum butoxide; alkyl aluminum hydrides such as diethyl aluminum hydride, dibutyl aluminum hydride and ethyl aluminum dihydride; and mixtures thereof.

In the solid catalyst component (A) in the present invention, first, the substance (a), the substance (b), the substance (c) and the substance (d) are brought into contact with each other and then reacted with the substance (e). And washed with a hydrocarbon solvent and then contacted with the substance (f). At this time, the use ratio of each substance is arbitrarily set, but usually (a) substance 1 g, (b) substance 5 to 100 ml, (c) substance 0.05 to 1.0 ml, (d)
Substance is 0.02-1.0ml, (e) substance is 0.5-100
ml and substance (f) are used in the range of 0.01 to 10 g, respectively.

There are no particular restrictions on the order of contact of the substances (a) to (d) and the reaction means, and any reaction can be carried out. Usually, a container equipped with a stirrer is used and the temperature range is around room temperature. It is performed with stirring for 1 minute or more. Then, the reaction with the substance (e) is usually performed in the temperature range of 60 to 135 ° C., and the reaction time is generally 5 minutes or longer, preferably 1 hour or longer. In addition, the solid substance obtained at this time is newly added to
It is also one of the preferable embodiments to add the substance (e) and repeat the reaction.

The solid substance thus obtained is washed with an inert hydrocarbon solvent such as hexane or heptane,
(f) Used for contact with substances. At this time, there are no particular restrictions on the method of contacting the substance (f), temperature conditions, etc.
A general method is to add the solid substance to the substance (f) and bring them into contact with each other while stirring. Further, the substance (f) can be used by diluting it with the above-mentioned inert hydrocarbon solvent.

The solid catalyst component is usually n
-Ethylene of the present invention in combination with an organoaluminum compound of (C) and an aromatic carboxylic acid ester compound of (B) after washing with an organic solvent such as heptane or n-hexane and drying if necessary. Form a catalyst for the production of propylene copolymer rubber.

The organoaluminum compound (C) used has a molar ratio of 1 per mole of titanium atom in the catalyst component.
Used in the range of up to 1000. The aromatic carboxylic acid ester compound (B) is used in a molar ratio of 0.01 to 0.5 per mol of the organoaluminum compound.

Usually, the polymerization is carried out by slurry polymerization using hydrocarbon as a solvent, bulk polymerization using liquefied propylene as a medium, and gas phase polymerization using a mixed gas of ethylene and propylene. The polymerization temperature is 0 to 150 ° C., and the polymerization pressure is 0 to 100 kg / cm ² · G. The partial pressures of ethylene and propylene are arbitrarily adjusted so that the ethylene content in the obtained copolymer is 10 to 70 wt%.

In the ethylene-propylene copolymerization, a non-conjugated polyene monomer may be added, if necessary, and hydrogen may be added as necessary in order to control the molecular weight of the copolymer. Can also be used.

[0026]

When ethylene-propylene copolymerization is carried out in the presence of the catalyst formed according to the present invention, the random activity is high and the chain portion of ethylene and propylene monomers is high while maintaining a high catalytic activity. A small amount of good quality rubbery polymer can be obtained. Moreover, since it does not contain a toxic vanadium compound, it is highly safe, and the influence of chlorine can be reduced to such an extent that the decalcification step is not necessary due to the small amount of residual chlorine.

[0027]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples.

Example 1 (1) Preparation of solid catalyst component Capacity fully replaced with nitrogen gas and equipped with stirrer 50
10 g of diethoxymagnesium in a 0 ml round bottom flask,
60 ml of toluene was charged to make a suspension. 2.0 ml of ethyl benzoate and 1.4 ml of dimethylpolysiloxane (viscosity 20 cSt / 25 ° C.) were inserted therein and stirred at room temperature for 5 minutes. Then, add 40 ml of titanium tetrachloride into this,
After the temperature was raised to 90 ° C., the mixture was reacted with stirring for 1 hour. After completion of the reaction, wash with 90 ml of toluene twice with 100 ml of toluene,
The supernatant was removed. Further, 60 ml of toluene and 40 ml of titanium tetrachloride were newly added, and the reaction was carried out at 80 ° C. for 2 hours while stirring. Then 100 ml of heptane at 40 ℃
It was washed 5 times. The solid substance thus obtained was suspended in 100 ml of heptane in which 3 ml of 1-hexene had been previously dissolved, and the suspension was contacted at room temperature for 30 minutes while stirring, followed by washing once with 100 ml of heptane at room temperature. When the Ti content in this solid catalyst component was measured, it was 2.8 wt%
Met.

(2) Polyethylene 200 ml of n-heptane was charged into a separable flask equipped with a stirrer and having an inner volume of 300 ml, which was completely replaced with a mixed gas of ethylene and propylene, and kept under a mixed gas atmosphere of ethylene and propylene. While adding 1.7 mmol of triisobutylaluminum and 0.2 of methyl p-toluate.
8 mmol was charged. The flow rates of ethylene and propylene were set to 1.0 l / min and 0.8 l / min, respectively, the temperature in the system was raised to 60 ° C, 5 mg of the solid catalyst component was charged, and the temperature was raised to 60 ° C. Polymerization was carried out at normal pressure for 15 minutes while maintaining. The termination of the polymerization was carried out by adding 2 ml of ethanol, and the suspension of the obtained copolymer was prepared by adding 60 ml of ethanol in a flask equipped with a stirrer with a volume of 1000 ml prepared in advance.
The mixture was charged into 0 ml, 10 ml of hydrochloric acid was added, and the mixture was stirred overnight. The produced solid copolymer was separated by filtration, heated to 80 ° C. and dried under reduced pressure to obtain 4.3 g of ethylene-propylene copolymer rubber.

(3) Evaluation of Physical Properties The ethylene-propylene copolymer produced as described above has an activity per gram of catalyst of 860 g / g-cat. Thirty
It became 700 g / g-cat. As a result of 13 C-NMR analysis, the propylene content in the copolymer was 51% by weight, the random fraction was 67%, and the randomness determined by IR was 100%.

The randomness of the obtained ethylene-propylene copolymer was analyzed by 13 C-NMR and IR as follows. The attribution of each peak in NMR is reported by CJ Carman et al. [Macromolecules, vol.10, P536
(1974)]. The NMR random fraction was calculated from the triad distribution of ethylene and propylene monomer units by the following formula. NMR random fraction (%) = 100- (PPP + EE
E) where PPP and EEE are the proportions (mol percent) of the propylene and ethylene triads, respectively. Randomness by IR is the method of Luongo et al. [J.Appl.P]
olym.Sci, vol3, P302 (1960)], 995 cm ^-1 and 97
The ratio (%) of the amorphous portion of the methyl group of propylene was shown from the absorbance ratio with 4 cm ^-1 .

Example 2 2,6-Dimethyl-4 instead of 2.0 ml of ethyl benzoate
-A solid catalyst component was prepared in the same manner as in Example 1 except that 2.5 ml of heptanone was used. At this time, the Ti content in the solid catalyst component was 3.4 wt%. Polymerization was carried out in the same manner as in Example 1 except that the solid catalyst component was used and the same amount of ethyl benzoate was used instead of methyl p-toluate. Evaluation was carried out in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 Instead of ethyl benzoate, the same amount of isopropyl benzoate,
A solid catalyst component was prepared in the same manner as in Example 1 except that the same amount of 4-methyl-1-pentene was used instead of 1-hexene. At this time, the Ti content in the solid catalyst component was 3.4 wt%. Polymerization was performed in the same manner as in Example 1 except that the solid catalyst component was used, and was evaluated in the same manner as in Example 1. The obtained results are also shown in Table 1.

Comparative Example 1 A solid catalyst component was prepared and polymerized in the same manner as in Example 1 except that the catalyst treatment with 1-hexene was not carried out and methyl p-toluate was not used during the polymerization. The results evaluated in the same manner as in Example 1 are also shown in Table 1.

[0035]

[Table 1]

[0036]

As described above, when ethylene-propylene copolymerization is carried out using the catalyst according to the present invention, the catalyst residue in the produced copolymerization can be suppressed to an extremely low level because the catalyst has a very high activity. Moreover, since the amount of residual chlorine is very small, the effect of chlorine on the produced copolymer can be reduced to the extent that no deashing step is required. Further, since the component does not contain a vanadium compound, the safety of the solid catalyst component itself or the obtained copolymer is high. In addition, when the catalyst of the present invention is used, it is possible to obtain a good rubber-like polymer having a high random polymerizability and a small number of chain portions of ethylene and propylene monomers.
Furthermore, the copolymer obtained by this catalyst generally has a narrow molecular weight distribution, and since the production ratio of low-molecular weight polymer is small, the polymer does not adhere in the reactor during the polymerization stage, which is an operational addition to the process. Mellitism is brought at the same time.

[Brief description of drawings]

FIG. 1 is a schematic flowchart illustrating the configuration of a catalyst of the present invention.

Claims (1)

[Claims] 1. A catalyst for producing an ethylene-propylene copolymer rubber, comprising the following (A), (B) and (C): (A) (a) dialkoxymagnesium is contacted with (b) an electron-donating compound having a C═O bond and (d) dimethylpolysiloxane in the presence of alkylbenzene,
Then, (e) a solid substance obtained by reacting with a titanium halide represented by the general formula TiX ₄ (X is a halogen element) is washed with a hydrocarbon solvent, and (f) is contacted with an olefin having 5 or more carbon atoms. Solid catalyst component thus obtained, (B) aromatic carboxylic acid ester compound, (C) organoaluminum compound