JPS6154807B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for polymerizing butadiene, particularly to a method for polymerizing butadiene to obtain high-cis 1.4 polybutadiene with a narrow molecular weight distribution. In recent years, methods for producing polybutadiene containing a high proportion of cis-1 and 4 bonds have been widely studied, and this polybutadiene has excellent physical properties such as heat generation, abrasion resistance, and cold resistance, so it has been used as a general-purpose rubber. Widely used industrially. In order to obtain cis-polybutadiene with excellent physical properties, catalysts containing nickel, cobalt, iron, titanium, etc. as main components are being studied. For example, a method for polymerizing butadiene using a catalyst containing nickel as a main component has already been published as Special Publication No. 36-17996, No. 36-22300.
No. 37-8193 and No. 38-4197. In general, catalysts whose main component is nickel compounds are
It is known that the content of cis 1,4-bonds is several percent higher than that of catalysts whose main component is a titanium compound, and that they exhibit excellent rubber physical properties. However, it is also well known that the known nickel-based catalysts have a broader molecular weight distribution than titanium-based catalysts.
On the other hand, polybutadiene is often used in mixtures with other rubbers such as natural rubber for applications such as tires. Therefore, the present inventors conducted studies to obtain a polybutadiene more suitable for such uses, and as a result, they polymerized it using a nickel-based catalyst to maintain a high cis 1,4-bond content while improving the molecular weight distribution. It has been found that the narrowed polybutadiene has excellent compatibility with other rubbers. Therefore, as a result of intensive research into a method to obtain polybutadiene with a high content of cis 1,4 bonds and a narrow molecular weight distribution using a catalyst mainly composed of nickel, we found that benzenesulfonic acid or alkylbenzene as a component of the catalyst could be used as a catalyst. The present invention was achieved by discovering that adding sulfonic acid or a salt thereof is effective. That is, the present invention provides a method for polymerizing butadiene using a catalyst containing a compound as component (A), a boron halide compound as component (B), and an organometallic compound selected from lithium or aluminum metal as component (C). , is a method for polymerizing butadiene characterized by coexisting a benzenesulfonic acid group or an alkylbenzenesulfonic acid group. According to the polymerization method of the present invention, polybutadiene with a narrow molecular weight distribution can be obtained while maintaining a high content of cis 1,4 bonds. Examples of the nickel compound as the catalyst (A) component of the present invention include organic carboxylates such as nickel octenoate, nickel stearate, nickel benzoate, nickel toluate, nickel ethylbenzoate, and nickel naphthenate, and organic salts such as nickel acetylacetone. Examples include complex compounds and nickel salts of alkylbenzenesulfonic acids. Among these, particularly preferred are nickel naphthenate, nickel alkylbenzenesulfonate, nickel octenoate, and the like. As the compound of the catalyst (B) component, boron halides such as boron trifluoride and boron trichloride, and boron halide complex compounds such as boron trifluoride etherate are used. Among these, particularly preferred are boron trifluoride and boron trifluoride etherate. As the organometallic compound selected from lithium or aluminum metals as the catalyst component (C), n-butyllithium, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, etc. are used. Among these, especially n-
Butyllithium and triethylaluminum are preferred. The compound having an alkylbenzenesulfonic acid group is benzenesulfonic acid or alkylbenzenesulfonic acid or an alkali metal salt thereof. Examples of alkylbenzenesulfonic acids or salts thereof include o-toluenesulfonic acid, m-toluenesulfonic acid, p-toluenesulfonic acid, ethylbenzenesulfonic acid, cumenesulfonic acid, t
- alkylbenzenesulfonic acids such as butylbenzenesulfonic acid, octylbenzenesulfonic acid, dodecylbenzenesulfonic acid, or lithium, sodium, potassium, rubidium,
At least one alkali metal salt such as cesium is used. Among these, particularly preferred are dodecylbenzenesulfonic acid and its potassium salt. Also, nickel salts of alkylbenzenesulfonic acids can be used. When using a nickel alkylbenzenesulfonic acid salt, it can be used as component (A), and by combining it with components (B) and (C), the effects of the present invention can be achieved without further adding an alkylbenzenesulfonic acid compound. can be obtained. Although there are no particular limitations on the conditions for preparing the catalyst of the present invention, the catalyst may be prepared by mixing these catalyst components in the presence of a small amount of butadiene or other conjugated diolefin, for example. Furthermore, it is particularly effective to use a compound containing an alkylbenzenesulfonic acid group, ie, a nickel salt of alkylbenzenesulfonic acid such as nickel dodecylbenzenesulfonic acid, as the nickel compound of the catalyst (A) among the above catalyst components. Among aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons, the polymerization solvent used in the present invention is preferably one that is liquid at room temperature, such as benzene, toluene, xylene, pentane, hexane,
Particularly preferred are heptane, octane, nonane, decane, cyclohexane, cycloheptane, and the like. These polymerization solvents can also be used as a mixture of two or more. The composition ratio of the catalyst components to be used is benzenesulfonic acid group or alkylbenzenesulfonic acid group
_-SO3- , (C)/(B)=0.05-5.0 (molar ratio), (A)/(C)=0.01-7.0 (molar ratio) ( _R.SO3 ^- )/(A)
= 0.05 to 10.0 (molar ratio) is good, more preferably (C) / (B) = 0.5 to 1.5 (molar ratio) (A) / (C) = 0.05 to
1.0 (molar ratio) (R·SO ₃ ⁻ )/(A)=0.1 to 5 (molar ratio). The composition ratio of the catalyst is important; if only one of the above components (A), (B), and (C) is used in a significantly large amount or in a significantly small amount, the polymerization activity will be significantly reduced. or lose its activity altogether. Furthermore, if the (R.SO ₃ ^- ) component is used in an extremely large amount, the polymerization activity will decrease, and if it is used in an extremely small amount, the effect of narrowing the molecular weight distribution will be small. The (R SO ^3- ) component is added to the polymerization solvent, but if the compound has poor solubility, it may be reacted with component (A), (B), or (C) in advance, or it may be dissolved. Also good. Polymerization involves butadiene with the above catalyst in the liquid phase at -30°C.
The contact is carried out at a temperature of -150°C, preferably 0°C - 100°C. At this time, it is preferable to carry out the reaction in an inert gas stream containing neither oxygen nor moisture. By the method of the present invention, polybutadiene with improved compatibility with other rubbers such as natural rubber can be produced. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 3 200 ml of dehydrated and purified toluene was placed in a 300 ml pressure-resistant glass bottle that had been dried and purged with nitrogen. Separately, a 0.01 mol/toluene solution of potassium dodecylbenzenesulfonate dissolved in toluene (variety) was added, followed by 36 g of butadiene. In this system, 0.0295 mol of nickel naphthenate/0.55 mol of toluene solution was added.
ml (0.0162 mmol) and 0.295 mol/of boron trifluoride etherate, 0.86 ml (0.254 mmol) of toluene solution
mol), and 0.416 mol/n-butyllithium
, 0.44 ml (0.183 mmol) of n-hexane solution was added, and the mixture was polymerized for 2 hours in a polymerization tank at 50°C. After the polymerization was completed, 0.4 g of an antiaging agent (2,6-di-t-butyl-p-cresol) was added, and the mixture was coagulated with methanol and dried with a roll at 100°C. The results are summarized in Table 1, and gel permeation chromatography (GPC curve) showing the molecular weight distribution is shown in FIG. GPC measurements were carried out using ALC201/402 models manufactured by Waters in a tetrahydrofuran solvent. Comparative Example 1 The same operation as in Example 1 was carried out except that potassium dodecylbenzenesulfonate was not used. The results are shown in Table 1, and the GPC curve is shown in Figure 1.

[Table] Examples 4 to 6 The same operation as in Example 1 was performed except that sodium dodecylbenzenesulfonate (variable) was used in place of the potassium dodecylbenzenesulfonate used in Example 1. The results are summarized in Table 2, and the GPC curve is shown in Figure 2. Examples 7 and 8 The same operations as in Example 1 were carried out except that dodecylbenzenesulfonic acid (variable) was used in place of the potassium dodecylbenzenesulfonate used in Example 1. The results are summarized in Table 3, and the GPC curve is shown in Figure 3. Examples 9 and 10 The same operations as in Example 1 were carried out, except that sodium para-toluenesulfonate (variable) was used in place of the potassium dodecylbenzenesulfonate used in Example 1. The results are summarized in Table 4,
The GPC curve is shown in Figure 4.

【table】

【table】

【table】

[Table] Examples 11 and 12 200 ml of dehydrated and purified toluene was placed in a 300 ml glass pressure-resistant bottle that had been dried and purged with nitrogen. Separately, a 0.01 mol/toluene solution (variety) of potassium dodecylbenzenesulfonate dissolved in toluene was added. Next, 36 g of butadiene was added. In this system, 0.0295 mol of nickel naphthenate/1.18 ml of toluene solution was added.
(0.0348 mmol) and boron trifluoride etherate.
0.295mol/toluene solution 0.86ml (0.254mmol),
Furthermore, 0.54 ml (0.159 mmol) of a 0.295 mol/toluene solution of triethylaluminum was added, and polymerization was carried out for 2 hours in a polymerization tank at 50°C. Antiaging agent after completion of polymerization (2,6-di-t-butyl-p-cresol)
After adding 0.4 g and coagulating with methanol, it was dried with a roll at 100°C. The results are summarized in Table 5, and the GPC curve is shown in FIG. Comparative Example 2 The same operation as in Example 11 was carried out except that potassium dodecylbenzenesulfonate was not used. The results are shown in Table 5 and FIG.

[Table] Example 13 200 ml of dehydrated and purified toluene was placed in a 300 ml glass pressure-resistant container that had been dried and purged with nitrogen. Then 36 g of dry butadiene was added. In this, 0.55 ml (0.0162 mmol) of a 0.0295 mol/toluene solution of nickel dodecylbenzenesulfonate and 1.03 ml of a 0.295 mol/toluene solution of boron trifluoride etherate.
ml (0.34 mmol) and 0.416 of n-butyllithium
0.44 ml (0.183 mmol) of mol/n-hexane solution was added. A polymerization reaction of these mixtures was carried out at 50°C for 2 hours. 2.6 as an anti-aging agent after polymerization
After adding 0.4 g of -di-t-butyl-p-cresol and coagulating with methanol, the mixture was dried by rolling at 100°C. Polymerization yield is 98%, Mooney viscosity is
43.5, and as a result of measurement by infrared absorption method (Morero method), the cis 1,4-bond content was 93.5%. The GPC curve of this product is shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a GPC curve showing the molecular weight distribution of butadiene obtained in Examples 1 to 3 and Comparative Example 1;
Figure 2 is a GPC curve based on Examples 4 to 6 and Comparative Example 1, and Figure 3 is based on Examples 7 to 8 and Comparative Example 1.
GPC curves, Figure 4 is GPC curves according to Examples 9-10 and Comparative Example 1, Figure 5 is GPC curves according to Examples 11-12 and Comparative Example 2, Figure 6 is GPC curves according to Example 13 and Comparative Example 1. It is a figure showing a curve.

Claims (1)

[Claims] 1 Butadiene in a hydrocarbon solvent using a catalyst containing (A) a nittel compound, (B) a boron halide compound, and (C) an organometallic compound selected from the metals lithium and aluminum. When polymerizing,
A method for polymerizing butadiene, which comprises coexisting a benzenesulfonic acid group or an alkylbenzenesulfonic acid group. 2 (A) Alkylbenzenesulfonic acid nickel salt,
A method for polymerizing butadiene, which comprises polymerizing butadiene using a catalyst containing (B) a boron halide compound and (C) an organometallic compound selected from the metals lithium and aluminum.