JP3424337B2 - Method for producing ethylene-α-olefin copolymer rubber - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an ethylene-α-olefin copolymer rubber.

[0002]

2. Description of the Related Art A method of copolymerizing ethylene and .alpha.-olefin or ethylene, .alpha.-olefin and a non-conjugated diene compound using a so-called Ziegler catalyst composed of a vanadium compound and an organoaluminum compound is known. Also, reacting the vanadium compound and alcohol,
A method for synthesizing a vanadium compound containing an alkoxy group is also known. By the way, as a specific method of using a vanadium compound containing an alkoxy group, in an inert hydrocarbon solvent containing an organoaluminum compound, a vanadium compound and an alcohol are separately charged into a polymerization tank and mixed to be used for polymerization. There is a way. However, this method has a problem that the polymerization activity of the catalyst is significantly reduced. As another method, a solution obtained by previously mixing an inert hydrocarbon solution containing a vanadium compound and an inert hydrocarbon solution containing an alcohol in a batch type mixing tank is an inert carbon containing an organoaluminum compound. There is a method of supplying it in a hydrogen fluoride solution and using it for polymerization. However, according to this method, a reaction by-product of the vanadium compound and the alcohol becomes a precipitate and is deposited inside the mixing tank, which causes a problem that the catalytic activity is lowered. As a method for solving such a problem, Japanese Patent Publication No. Sho 49-14542 discloses
A method of suppressing a side reaction by bubbling a mixed solution containing a vanadium compound and an alcohol with an inert gas such as nitrogen to remove a protic acid in the liquid is disclosed. However, the method requiring such an additional operation requires neutralization of a gas containing a large amount of corrosive substances, and since an inert hydrocarbon solvent evaporates, environmental problems that lead to air pollution occur. Alternatively, the concentration of the catalyst fluctuates, and thus readjustment is required to obtain the target concentration, which is inconvenient from an industrial viewpoint.

[0003]

In view of the above situation, the main problems to be solved by the present invention are to solve the problems of the conventional techniques, maintain the activity of the polymerization catalyst at a sufficiently high level, and A reaction by-product of a vanadium compound and an alcohol does not form a precipitate and is not deposited inside the apparatus, and does not require an additional operation such as bubbling. The point is to provide a manufacturing method.

[0004]

That is, the present invention provides a vanadium compound-containing solution and an alcohol-containing solution in an amount of 10 to 10.
A mixed solution is obtained by stirring and mixing for 300 seconds, and the mixed solution is immediately supplied to a polymerization tank containing an organoaluminum compound, and ethylene and α-olefin or ethylene, α-olefin and non-conjugated diene compound are supplied in the polymerization tank. The present invention relates to a method for producing an ethylene-α-olefin-based copolymer rubber in which the above is copolymerized.

The details will be described below. Ethylene of the present invention
The α-olefin copolymer rubber is a copolymer rubber composed of ethylene and α-olefin or a copolymer rubber composed of ethylene, α-olefin and a non-conjugated diene compound.

Examples of α-olefins include propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, isobutylene and 4-methylpentene-1. Further, as the non-conjugated diene, 1,4-pentadiene, 1,4-hexadiene, 1,5-cyclooctadiene, 6-methyl-
Examples include 4,7,8,9-tetrahydroindene, dicyclopentadiene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene and the like. These non-conjugated dienes may be used alone or in combination of two or more.

The amount ratio of ethylene, α-olefin and non-conjugated diene compound in the copolymer rubber is not particularly limited, but is, for example, 40 to 95 mol% of ethylene, 5 to 60 mol% of α-olefin and non-conjugated diene. The compound may be 0 to 10 mol%. In order for the copolymer rubber targeted by the present invention to have sufficient rubber elasticity, ethylene of 45 to 80 mol%, α-olefin of 20 to 55 mol% and non-conjugated diene compound of 0 to 5 mol% are used. Preferably.

The vanadium compound-containing solution is obtained by dissolving the vanadium compound in an inert hydrocarbon solvent.
The vanadium compound is preferably a vanadium halide compound, and examples thereof include vanadium tetrachloride, vanadium tetrabromide and vanadium oxyhalide represented by the general formula VOY ₃ (Y represents halogen). Examples of vanadium bromide include vanadium oxytrichloride and vanadium oxytribromide. Of these, vanadium oxytrichloride is preferable. Examples of the inert hydrocarbon solvent include hexane and heptane. The concentration of the vanadium compound in the solution is not particularly limited, but is usually 0.01 to 5.0 mol / l.

The alcohol-containing solution is prepared by dissolving alcohol in an inert hydrocarbon solvent, but in some cases 100% alcohol may be used as it is. As the alcohol, various alcohols such as aromatic alcohol and aliphatic alcohol are used, but the number of carbon atoms is 1 to 12.
Alcohol having an aliphatic hydrocarbon skeleton of is preferable.
Specifically, methyl alcohol, ethyl alcohol, n-
Propyl alcohol, iso-propyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, te
rt-butyl alcohol, iso-butyl alcohol,
iso-amyl alcohol, n-hexyl alcohol,
n-heptyl alcohol, 2-ethylhexanol, n
-Octyl alcohol, dodecyl alcohol and the like can be mentioned. Also, diols and polyols can be used, and examples thereof include ethylene glycol and propylene glycol. Examples of the inert hydrocarbon solvent include hexane and heptane. The concentration of the alcohol compound in the solution is not particularly limited, but is usually 0.01 to 5.0 mol / l.
Is.

In the present invention, the vanadium compound-containing solution and the alcohol-containing solution are stirred and mixed for 10 to 300 seconds to obtain a mixed solution, and the mixed solution is immediately supplied to the polymerization tank containing the organoaluminum compound,
In the polymerization tank, ethylene and α-olefin or ethylene, α-olefin and non-conjugated diene compound are copolymerized.

The mixing ratio of the vanadium compound and the alcohol in the mixed solution is an alcohol / vanadium compound molar ratio of usually 1/1 to 3/1, preferably 1/1 to 1
It is 2/1. If the proportion of alcohol is too small, the desired vanadium compound containing an alkoxy group cannot be obtained sufficiently. On the other hand, when the proportion of alcohol is too large, unreacted alcohol is mixed in the polymerization tank, which causes catalyst deactivation.

The vanadium compound-containing solution and the alcohol-containing solution may be used for 10 to 300 seconds, preferably 15 to 300 seconds.
By stirring and mixing for a second, a mixed solution is formed and immediately supplied to the polymerization tank. When the mixing time is too short, it is difficult in terms of equipment to allow the reaction of the vanadium compound and the alcohol to proceed sufficiently, and as a result, the activity of the resulting catalyst becomes insufficient. On the other hand, when the value is excessively large, a precipitation product is generated, which causes a decrease in catalyst activity and clogging of the catalyst introduction pipe.

As a method for stirring and mixing the vanadium compound-containing solution and the alcohol-containing solution, there may be mentioned a method of mixing them in a pipe using an orifice, a line mixer, a static mixer, a mixing nozzle or the like. Here, as preferable specific operating conditions, the inner diameter of the pipe is 0.1 to 5
cm, flow rate of fluid in piping 0.01-200 ml / se
c, length of pipe from mixing point to polymerization tank 20 to 500
The temperature is 0 cm, and the temperature of the fluid in the pipe is −80 to 100 ° C.

The mixed solution thus obtained is immediately supplied to a polymerization tank containing an organoaluminum compound. As the organoaluminum compound of the general formula R _n AlX _3-n
(R represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, X represents halogen, and n represents a real number of 0 <n ≦ 3.) Are preferable, and examples thereof include trimethylaluminum and triethylaluminum. , Tri-iso-butyl aluminum, trioctyl aluminum, diethyl aluminum monochloride, diethyl aluminum monobromide, ethyl aluminum sesquichloride, i
Examples thereof include so-butyl aluminum sesquichloride, n-butyl aluminum sesquichloride, ethyl aluminum dichloride and the like. The amount of the organoaluminum compound used in the polymerization tank is usually 2 to 200 mol, preferably 3 to 50 mol, per 1 mol of the vanadium compound.

A specific example of the copolymerization method is as follows. That is, using an inert hydrocarbon solvent such as hexane or heptane, or liquefied propylene as a solvent, introducing an organoaluminum compound, ethylene, α-olefin and optionally a non-conjugated diene into a polymerization tank,
The temperature in the polymerization tank is -50 to 100 ° C, preferably -30.
While maintaining at a predetermined polymerization temperature of -80 ° C, the mixed solution of the present invention is supplied to a polymerization tank to carry out polymerization. The pressure during polymerization is usually atmospheric pressure to 20 atm. In addition, hydrogen, which is a molecular weight regulator, may be used in the polymerization, if necessary.

The features of the present invention are as described in the corresponding places, and the maximum features of the present invention and the operation thereof are as follows. That is, the greatest feature of the present invention is that the vanadium compound-containing solution and the alcohol-containing solution are stirred and mixed for a predetermined time and then immediately supplied to the polymerization tank, and thereby, without using an additional operation such as bubbling. The problem is that the reaction product of the vanadium compound and the alcohol becomes a precipitate and is deposited inside the device or the activity is reduced.

[0017]

The present invention will be described below with reference to examples. Example 1 1 L of heptane was charged into a separable flask having a volume of 2 L, and a mixed gas consisting of 80 mol% of ethylene and 20 mol% of butene was flowed at a rate of 5.65 NL / min in a constant temperature bath at 45 ° C. to saturate the mixture. It was Then, 0.8 mmol of ethyl aluminum sesquichloride was added into the flask. Furthermore, vanadium oxytrichloride 0.1 mmol and n
-Butyl alcohol (0.2 mmol) was mixed and stirred in the dropping funnel for 180 seconds, and then added into the flask.
Then, ethylene and butene were aerated under agitation for 20 minutes to carry out copolymerization.

Methyl alcohol 2 was added to the reaction mixture obtained.
The reaction was stopped by adding 0 ml. Thereafter, heptane was distilled off under reduced pressure, and the concentrated solution of the obtained copolymer was put into 1 liter of methyl alcohol to precipitate the polymer. Then, the precipitate was vacuum dried to obtain a white amorphous solid copolymer. The results are shown in Table 1. No gel is generated in the polymerization tank, the copolymer yield per unit amount of the vanadium compound obtained in the present invention is high, and there is no generation of a precipitate due to the reaction of the vanadium compound and the alcohol in the liquid introduction pipe, It was visually confirmed.

Comparative Example 1 Same as Example 1 except that the time for mixing vanadium oxytrichloride and n-butyl alcohol in the liquid introducing tube was 3 seconds. The results are shown in Table 1. Unlike Example 1, gel was generated in the polymerization tank, and the copolymer yield per unit amount of vanadium compound was low.

Comparative Example 2 A separable flask having a capacity of 2 liters was charged with 1 liter of heptane, and a mixed gas consisting of 80 mol% of ethylene and 20 mol% of butene was caused to flow in a constant temperature bath at 45 ° C. at a rate of 5.65 NL / min. , Saturated. A 100 ml four-necked flask equipped with a stirrer and a thermometer was depressurized, then purged with nitrogen, and charged with 2 mmol of vanadium oxytrichloride, 4 mmol of iso-propyl alcohol and 20 ml of hexane. When mixing and stirring at room temperature for 1800 seconds, a tar-like substance is generated in the flask, and it becomes impossible to transfer the reaction mixture to the separable flask through a pipe.
The polymerization could not be carried out.

Example 2 From the bottom of a 10-liter stainless steel autoclave equipped with a stirrer, 10 kg of hexane and 0.2 of ethylene were added per hour.
0 kg, 0.81 kg of propylene, and 5-ethylidene-2-norbornene were supplied at a rate of 0.03 kg, and hydrogen was supplied at a rate of 0.05 mol%. Ethyl aluminum sesquichloride was continuously fed as a catalyst at a rate of 3.86 g / hr, and vanadium oxytrichloride,
The n-butyl alcohol was passed through a pipe connected to a static mixer T3-17 (17 elements, inner diameter 0.34 cm, length 10 cm) manufactured by Noritake Company, at a rate of 0.68 g and 0.29 g / h in the pipe. Continuously mixed and fed. Here, the molar ratio of n-butyl alcohol / vanadium oxytrichloride is 1.
0, the flow rate in the pipe of the vanadium compound-containing solution and the alcohol-containing solution per unit time is 1.94 ml / sec,
The length of the pipe from the mixing point of the vanadium compound-containing solution and the alcohol-containing solution to the polymerization tank was 300 cm, and the time to reach the polymerization tank inlet after mixing the vanadium compound-containing solution and the alcohol-containing solution was 14.0 sec. The polymerization temperature was 55 ° C. The reaction solution was continuously withdrawn, a polymerization terminator was added, and then a copolymer was deposited by steam stripping and dried. Thus, 320 g of an hourly copolymer was obtained. This copolymer has an ethylene content of 58% by weight, an iodine value of 9.4, and a Mooney viscosity of ML _{1 + 4.}
It was 67 ° C at 100 ° C. The copolymer obtained in the present invention was blended in the following blending ratio and press-vulcanized at 160 ° C. for 30 minutes. The blending ratio is 50 parts by weight of carbon black, 15 parts by weight of paraffin oil, 5 parts by weight of zinc white, 1 part by weight of stearic acid, and accelerator T with respect to 100 parts by weight of the copolymer.
S and M were 1 and 0.25 parts by weight, respectively, and sulfur was 1 part by weight. The physical properties of the vulcanized rubber were measured according to JIS K6301, and the strength at break was 148 kgf / c.
m ² , elongation at break 410%, JIS-A hardness 65, tear strength 37 kgf / cm, compression set (−20 ° C. × 22)
Hr) was 31%.

Examples 3 to 5 The same procedure as in Example 1 was carried out except that the conditions shown in Table 2 were used.
The conditions and results are shown in Table 3.

[0023]

[Table 1]

* 1 n-BuOH: normal butyl alcohol VOCl ₃ : vanadium oxytrichloride * 2 Stirring and mixing time: Stirring and mixing time of vanadium compound-containing solution and alcohol-containing solution * 3 Catalyst efficiency: Copolymer (g) obtained ) / Vanadium compound used (mmol) * 4 Gel generation: Presence of gel in the polymerization tank

[0025]

[Table 2] ------------------ Example 2 3 4 5 Polymerization conditions Hexane kg / h 10 10 10 10 Ethylene kg / h 0.20 0.21 0.21 0.22 Propylene kg / h 0.81 0.80 0.80-Butene-1 kg / h---0.38 ENB kg / h * 5 0.03 0.03 0.03-Hydrogen mol% 0.05 0.05 0.05 0.30 EASC g / h * 6 3.86 0.99 1.07 3.57 VOCl ₃ g / h * 7 0.68 0.23 0.25 0.63 Alcohol type * 8 Bu Et Et Et flow rate g / h 0.29 0.07 0.12 0.20 Alcohol / VOCl ₃ molar ratio 1.0 1.2 1.8 1.8 Mixture flow rate ml / sec 1.94 1.32 0.68 0.28 Pipe length cm 300 69 69 48 Mixing time sec 14 20 39 65.5 Polymerization temperature ℃ 55 46 46 60 Catalytic efficiency * 9 76 241 228 83 Gel generation * 10 None None None None − − − − − − − −−−−−−−−−−−−−−−−−−−−−−−--

[0026]

[Table 3] ------------------ Example 2 3 4 5 Polymer composition Polymer yield g / h 320 340 330 300 Ethylene content wt% 58 53 53 91 Iodine value 9.4 8.8 9.2-ML _{1 + 4} 100 ℃ 67--* 13 ML _{1 + 4} 121 ℃-83 81-Polymer physical properties * 11 Tensile strength kgf / cm ² 148 144 136-Tensile elongation% 410 330 300-Hardness JIS-A 65 80 79-Tear strength kgf / cm 37 36 36-Compression set% * 12 31 59 55---------------- −−−−−−−−−−−−−−−−−−−−−−−

[0027] * 5 ENB: 5-ethylidene-2-norbornene * 6 EASC: ethylaluminum sesquichloride * 7 VOCl _3: Type of vanadium oxytrichloride * 8 alcohol Bu: n-butyl alcohol Et: Ethyl alcohol * 9 catalytic efficiency : Copolymer obtained (g) / vanadium compound used (mmol) * 10 Gel generation: Presence or absence of gel generation in the polymerization tank * 11 Formulation is as shown in Table 5 * 12 Compression set;- 20 ° C x 22 hr * 13 MI (190 ° C) = 1.9

[0028]

[Table 4]

* 14 accelerator TS: tetrameth
Ylthiuram monosulfide * 15 Accelerator M: 2-mercaptobenzot
hiazole * 16 accelerator CZ: N-cyclohexyl-2-
benzthiazole sulfenamide * 17 accelerator BZ: zinc di-n-butyl
dithiocarbamate * 18 accelerator TT: tetramethylthiu
ram disulfide * 19 accelerator TRA: dipentamethyl
netiuram tetrasulfide

[0030]

As described above, according to the present invention, the activity of the polymerization catalyst is maintained at a sufficiently high level, and the reaction by-product of the vanadium compound and alcohol is deposited as a deposit inside the apparatus. Ethylene-α without any additional operation such as bubbling
-It was possible to provide a method for producing an olefin-based copolymer rubber.

[Brief description of drawings]

FIG. 1 is a flowchart showing a catalyst manufacturing process.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadaaki Nishiyama 5-1 Anezaki Kaigan, Ichihara City, Chiba Sumitomo Chemical Co., Ltd. (56) Reference JP-A-5-70516 (JP, A) JP-A-60- 226514 (JP, A) JP 61-4708 (JP, A) JP 43-2924 (JP, B1) JP 49-14542 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 4/60-4/70 C08F 2/00-2/60

Claims (7)

(57) [Claims] 1. A mixed solution is obtained by stirring and mixing a vanadium compound-containing solution and an alcohol-containing solution for 10 to 300 seconds, and the mixed solution is immediately supplied to a polymerization tank containing an organoaluminum compound, and in the polymerization tank. A method for producing an ethylene-α-olefin copolymer rubber, which comprises copolymerizing ethylene and α-olefin or ethylene, α-olefin and a non-conjugated diene compound. 2. The method according to claim 1, wherein the alcohol contained in the alcohol-containing solution is an alcohol having an aliphatic hydrocarbon skeleton having 1 to 12 carbon atoms. 3. The production method according to claim 1, wherein the vanadium compound-containing solution and the alcohol-containing solution are stirred and mixed by a static mixer. 4. The method according to claim 1, wherein the vanadium compound-containing solution and the alcohol-containing solution are stirred and mixed in a turbulent flow region generated by using an orifice. 5. The organoaluminum compound has the general formula R _n
The production according to claim 1, which is represented by AlX _3-n (R represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, X represents halogen, and n represents a real number of 0 <n ≦ 3). Method. 6. The production method according to claim 1, wherein the ratio of the alcohol and the vanadium compound in the mixed solution is 1/1 to 3/1 in terms of the alcohol / vanadium compound molar ratio. 7. The production method according to claim 1, wherein the vanadium compound is represented by VOY ₃ (Y represents halogen).