JPH0549690B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polybutadiene having a novel structure and a method for producing the same. Polybutadiene with a high cis-1,4 bond content (high-cis polybutadiene) and its production method have been known for a long time. It is widely used industrially as a general-purpose rubber such as industrial rubber. One way to produce this type of rubber is to
Polymerization methods for diene monomers using rare earth metal compounds have also been studied, and the physical properties of polybutadiene have also been clarified (presented at the International Conference of Rubber Producers (IISRP) Annual Meeting, held in Madrid, Spain, 1981). . A method of polymerizing diene monomers using rare earth metal compounds is described, for example, in Kautachuk und Gummi.
Kunststoffe, Vol. 22, No. 6, 1969, pp. 293-297
Page or Journal of Polymer Science, Volume 18,
1980, pages 3345 to 3357. According to this method, it is possible to obtain polybutadiene having a high content of cis-1,4 bonds with controlled molecular weight and molecular weight distribution, and Polybutadiene is also known for its physical properties such as excellent adhesiveness. However, this polybutadiene has poor processability in general rubber applications, particularly during roll kneading or extrusion, and as a raw material for impact-resistant polystyrene, it has drawbacks such as high solution viscosity when dissolved in styrene monomer. Was. Furthermore, there are storage and transportation problems due to the large cold flow, so it has not been used industrially. This seems to be due to the fact that this polybutadiene is very linear and has almost no branched structure, based on the cited document. This is a unique phenomenon that always occurs under certain polymerization conditions, and there was no known method for obtaining polybutadiene with a branched structure using this catalyst system. The present invention solves at once the problems of polybutadiene obtained using a catalyst containing the above-mentioned rare earth metal compound as a main component, and provides a new polybutadiene having excellent practical performance and a method for producing the same. That is, the polybutadiene of the present invention has the following properties.
It satisfies conditions (a) to (e). (a) Weight average molecular weight (w) measured by gel permeation chromatography (GPC)
is 50,000 to 1 million, w and number average molecular weight (n)
(b) The 1,2 bond unit fraction measured by ¹ H-NMR is 1.0% or less (c) Using an L rotor, Mooney viscosity (ML) measured at °C is 10-120 (d) 5% styrene solution viscosity (SV) at 25 °C
is 15 centipoise or more (e) The relationship between ML and SV satisfies the following formulas () and () logSV=1.52logML+A ……() A≦−0.09 ……() And this polybutadiene rubber mainly contains rare earth metal compounds. A polymer obtained by polymerizing a butadiene monomer in the presence of a catalyst as a component is reacted with tetrahalomethane represented by the following formula () or with an organoaluminum compound represented by the following formula (). It can be obtained by letting CX ₄ ...() (In the formula, C is carbon, X is chlorine, bromine, iodine,
Or it represents fluorine, and they may all be the same element or different elements. ) AlR ¹ _3-o Hn ... () (In the formula, n is 0, 1 or 2, R ¹ is a hydrocarbon group having 1 to 8 carbon atoms, and H is hydrogen.) Polybutadiene of the present invention is a well-known method, gel permeation chromatography (GPC).
Weight average molecular weight measured by 50,000 to 100
10,000, preferably 150,000 to 600,000. When the weight average molecular weight is less than 50,000, physical properties such as impact resilience, abrasion resistance, and tensile strength are significantly reduced;
Those with a weight average molecular weight of 1 million or more are processable,
In particular, extrusion processability is poor and undesirable. The molecular weight distribution in the present invention is also measured by GPC and is expressed as w/n (where w is the weight average molecular weight and n is the number average molecular weight).
It is limited to 1.5 to 5.0, preferably 1.8 to 3.5.
It is difficult to obtain polybutadiene with a molecular weight distribution of 1.5 or less using a catalyst mainly composed of rare earth metal compounds, while polybutadiene with a molecular weight distribution of 5.0 or more has poor physical properties such as impact resilience and abrasion resistance. This is undesirable because it causes deterioration. ¹ H-NMR (PMR) of the polybutadiene of the present invention
The 1,2 bond unit fraction measured by is 1.0% or less,
It is preferably 0.8% or less.
It is difficult to accurately analyze the geometrical isomer structure (microstructure) of polybutadiene, which has extremely few 1,2 bonds, using ^an infrared spectrometer. use,
It was determined by the method shown in Kobunshi, Vol. 30, pp. 845-851 (published in 1981). When the 1,2 bond unit fraction exceeds 1%, the polybutadiene rubber of the present invention is superior to conventional polybutadiene rubbers obtained by using catalysts containing nickel, cobalt, titanium, etc. as main components. The physical properties such as tackiness, impact resilience, abrasion resistance, etc. deteriorate to the same extent as these, which is not preferable. The Mooney viscosity (ML) measured at 100°C using the L rotor of the polybutadiene of the present invention is
10-120, preferably 15-60. If the Mooney viscosity is less than this range, it will be difficult to handle the product, and if it exceeds this range, the processability, especially the extrusion processability, will be extremely poor, which is not preferred. The polybutadiene of the present invention has a solution viscosity (SV) of 5% by weight styrene solution at 25°C of 15 cps or more,
Preferably from 25 to 400 cps. Solution viscosity
If it is less than 15 cps, the physical properties as a rubber, such as the impact strength when used as a raw material for impact-resistant polystyrene, are insufficient and are therefore undesirable. Furthermore, too high solution viscosity is also undesirable because it reduces solubility in styrene, productivity, etc. in this application. The polybutadiene of the present invention is required to have a Mooney viscosity (ML) and a solution viscosity (SV) within the limited ranges described above, and further satisfy the relationship shown in formulas () and (). . logSV=1.52 logML+A ... () A≦-0.09 ... () A particularly preferable range is when A is -7.78 to -0.20. Molecular weight distribution of conventional butadiene obtained using a catalyst mainly composed of rare earth metal compounds
1.5 to 5.0, the A value of formula () is in the range of 0.1 to 0.6, and conventionally this A value is in the range of 0.1 to 0.6 with any catalyst.
No values were obtained with values below 0.1 (this is shown as region 1 in Figure 1). The present invention achieves this by changing the relationship between ML and SV by reacting a polymer (active polymer or deactivated polymer) with tetrahalomethane, or tetrahalomethane and an organoaluminum compound. , is the polymer thus obtained (this is shown as region 2 in FIG. 1). ML and SV
If the relationship is outside this range, the physical properties aimed at by the present invention, especially the improvement of processability, will be insufficient, and for general rubber applications, the processability of roll extrusion will be insufficient, and for HIPS rubber, the solubility of rubber in styrene will be insufficient. unsatisfactory and undesirable. Moreover, the polybutadiene of the present invention preferably has:
Toluene insoluble matter is 5 per 100g of polybutadiene
mg or less, more preferably 3 mg or less. Such toluene-insoluble components are generally called gels, and their presence is undesirable as it inhibits production depending on the application and further reduces the appearance and strength of the product. The polybutadiene of the present invention is produced by first polymerizing butadiene monomer in the presence of a catalyst containing a rare earth metal compound as a main component, and then reacting the resulting polymer by adding and mixing tetrahalomethane or an organoaluminum compound with it. It can be obtained by letting In order to clarify this manufacturing method, a flowchart of the manufacturing process is shown in FIG. Catalysts containing rare earth metal compounds as main components generally consist of the following three components. (a) At least one of carboxylates, alcoholates, phenolates, phosphates, and phosphites of cerium, lanthanum, praseodymium, neodymium, or gadolinium; (b) Organoaluminum represented by the general formula ALR ² _3-o Hn Compound (n is 0, 1 or 2, R ² is a hydrocarbon group having 1 to 8 carbon atoms, H is hydrogen) (c) Lewis acid, especially Lewis acid containing a halogen element. The polymerization is carried out in the presence or absence of an inert solvent at a temperature range of -30°C to 150°C, preferably 10 to 120°C, and the reaction format may be either batchwise or continuous. In the present invention, the tetrahalomethane to be reacted with a polymer obtained by polymerizing a butadiene monomer in the presence of the above-mentioned catalyst is represented by the general formula (). CX ₄ ...() (In the formula, C is carbon, X is chlorine, bromine, iodine,
Or it represents fluorine, and they may all be the same element or different elements. ) These compounds include carbon tetrachloride, carbon tetrabromide,
Carbon tetraiodide, carbon trichloride monobromide (CBrCl ₃ )
Examples include compounds in which X is chlorine, bromine, or iodine, and these may be used in combination. Further, tetrahalomethane and an organoaluminum compound can also be used together, and this organoaluminum compound is represented by the general formula (). AlR ¹ _3-o Hn ... () (In the formula, n is 0, 1 or 2, R ¹ is a hydrocarbon group having 1 to 8 carbon atoms, and H is hydrogen.) This compound is as follows: Examples include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, and the like. Preferred amounts of tetrahalomethane and organoaluminum compound used in the present invention are 0.1 to 30 mmol, preferably 0.6 to 6 mmol and 0 to 30 mmol, respectively, per 100 g of butadiene monomer to be reacted. If the amount is less than this, the reaction will not progress sufficiently, and on the other hand, the use of more than this is unnecessary and may produce toluene-insoluble matter (gel), which is not preferable. This reaction is carried out at below 160°C, preferably at 70°C.
It is preferred to carry out the reaction at a temperature of 0.degree. C. to 130.degree. C. with stirring for 0.1 to 10 hours, preferably 0.2 to 5 hours. Furthermore, this reaction
Sterically hindered phenolic antioxidants represented by 4-methylphenol, amine antioxidants represented by dialkylphenylenediamine,
This can effectively occur even in the presence of a stabilizer that does not react with organoaluminum or has low reactivity, and it is also possible to add the stabilizer in advance. The polybutadiene of the present invention can be produced relatively easily by the above reaction, but it can also be produced by other methods.
It can be obtained by (a) a method of reacting with a Lewis acid such as a boron trifluoride ether complex, and (b) a method of reacting with an organic peroxide such as lauroyl peroxide. However, all of these methods generate a large amount of toluene-insoluble matter (gel) and require severe reaction conditions, so that they are industrially inferior to the method of the present invention. The polybutadiene of the present invention can be obtained as a product through a known deactivation process, followed by conventional solvent removal and drying processes. The polybutadiene of the present invention has extremely good adhesion as a raw material rubber, has good impact resilience and abrasion resistance, and has excellent roll wrapability and processability during extrusion, and can be used alone or blended with other diene rubbers. It is used in tires such as treads, carcass, sidewalls, and bead parts, as well as in hoses, tubes, belts, anti-vibration rubber, and various industrial products. It is also suitable as a toughening agent for polystyrene-based resins, and is particularly useful as a toughening agent for styrene-based resins in the form of lumps or a combination of lump-suspension systems because of its low solution viscosity when dissolved in styrene. Next, the present invention will be explained with reference to Examples and Comparative Examples. Example 1 5.3 kg of hexane solution containing 800 g of 1,3-butadiene was charged into 10 autoclaves purged with dry nitrogen gas, and then neodymium phosphate (Nd(P ₁ ) ₃ [however, P ₁ is shows. ] 1.6 mmol and 20 mmol of diisobutylaluminum hydride were added, and the mixture was stirred at room temperature for 15 minutes. After this, 3.6 mmol of ethylaluminum sesquichloride [Al(C ₂ H ₅ ) _1.5 Cl _1.5 ] was added,
Polymerization was initiated by raising the temperature to 80°C and stirring. After polymerization for 2 hours, the temperature was raised to 100°C, 20 ml of a hexane solution containing 8 mmol of carbon tetrachloride was added, and the mixture was reacted for 1 hour. After this, the contents in the autoclave were reduced to 2%
The polymer was extracted into methanol containing BHT (2,6-di-t-butyl-4-methylphenol), coagulated, and dried. The properties of the obtained polymer are shown in Table 1. In Examples and Comparative Examples, the Mooney viscosity was ML ₁₊₄ (100°C) measured using an L rotor, and the solution viscosity was 5% by weight styrene solution viscosity at 25°C. The 1,2 bond unit content was determined using ¹ H-NMR at 400 MHz according to the method described in Kobunshi, Vol. 30, pp. 845-851 (published in 1981). The weight average molecular weight w and molecular weight distribution w/n are determined using a high performance liquid chromatograph (column HSG) manufactured by Shimadzu Corporation.
-40, 50, 60). Cold flow properties are measured by attaching a rectangular parallelepiped rubber sample with a vertical axis of 1 inch and a height of 3 inches on a glass plate with a 30° inclination, and holding a triangular ruler perpendicular to the slope at the point of maximum flow. It is expressed as the time required for the flow to reach 4 cm. Toluene insoluble matter is polybutadiene sample
Add 1.9Kg of toluene to 100g and shake for 16 hours.
Pass it through a wire mesh of 200 mesh, and heat the wire mesh to 90℃1.
After vacuum drying for an hour, it was weighed and the weight (mg) of toluene-insoluble matter relative to the polybutadiene sample was determined from the difference from the weight of the wire mesh before drying. Example 2 A catalyst-containing monomer solution prepared in the same manner as in Example 1 was heated to 65°C and polymerized for 2 hours. followed by 90℃
8 ml of a hexane solution containing 8 mmol of diisobutylaluminum hydride and 20 ml of a hexane solution containing 8 mmol of carbon tetrabromide were added.
The reaction was allowed to proceed for 30 minutes. The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Example 3 20 g of a hexane solution containing 6 g of 1,3-butadiene was charged into a 300 ml pressure-resistant glass bolt whose air was replaced with dry nitrogen gas, followed by neodymium phosphate.
Nd(P ₁ ) ₃ [However, P ₁ is shows. ] 1.6 mmol and 26.4 mmol of diisobutylaluminum hydride were added, and a preliminary reaction was carried out at room temperature for 15 minutes. Thereafter, 3.2 mmol of ethylaluminum sesquichloride (Al(C ₂ H ₅ ) _1.5 Cl _1.5 ) was added, and the mixture was aged at room temperature for 3 hours. The aged catalyst prepared in advance was added to an autoclave containing the same 1,3-butadiene solution as in Example 1, and polymerization was carried out at 65°C for 2 hours. followed by 120℃
After raising the temperature to , 20 ml of a hexane solution containing 8 mmol of carbon tetrachloride was added and reacted for 1 hour. The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Example 4 Neodymium phosphate Nd (P ₂ ) ₃ [However, P ₂ is shows. ] 1.6 mmol diisobutylaluminum hydride, 21.6 mmol diisobutylaluminum hydride, and 4.24 mmol ethylaluminum sesquichloride [Al(C ₂ H ₅ ) _1.5 Cl _1.5 ] were used to polymerize 1,3-butadiene at 65° C. for 2 hours in the same manner as in Example 1. Subsequently, the temperature was raised to 120°C, 6 ml of a hexane solution containing 5.6 mmol of carbon tetrachloride was added, and the mixture was reacted for 1 hour. The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Example 5 Neodymium phosphate Nd (P ₂ ) ₃ [However, P ₂ is shows. ] 1.6 mmol of triisobutylaluminum, 112 mmol of ethylaluminum sesquichloride [Al(C ₂ H ₅ ) 2 Cl 2 ], and 3.2 mmol of ethylaluminum sesquichloride [Al(C 2 H 5 ) ₂ Cl ₂ ] were used to prepare an aged catalyst in the same manner as in Example 3. Polymerization was carried out at ℃ for 2 hours. followed by 100℃
5 ml of a hexane solution containing 2.4 mmol of carbon trichloride-bromide was added, and the mixture was allowed to react for 1 hour.
The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Comparative Examples 1 to 5 Neodymium phosphate Nd (P ₁ ) ₃ [However, P ₁ is shows. ] 1.6 mmol of triisobutylaluminum, 48 mmol of ethylaluminum sesquichloride [Al(C ₂ H ₅ ) _1.5 Cl 1.5 ] and 3.2 mmol of ethylaluminum sesquichloride [Al(C 2 H 5 ) 1.5 Cl _1.5 ]. The polymer was then coagulated in methanol containing 2% BHT and dried. (Comparative Example 1) Neodymium acid salt (Nd(P ₁ ) ₃ [However, P ₁ is shows. ] 0.8 mmol of diisobutylaluminum hydride, 16 mmol of ethylaluminum sesquichloride [Al(C _{2 H 5 ) 1.5 Cl 1.5 ], and 1.84 mmol of ethylaluminum sesquichloride [Al(C 2 H 5} ) 1.5 Cl _1.5 ] A ripened catalyst was prepared in the same manner as in Example 3, and 65 mmol of 1,3-butadiene was prepared. Polymerization was carried out at ℃ for 2 hours.
Thereafter, a dried polymer was obtained in the same manner as in Comparative Example 1. (Comparative Example 2) Neodymium phosphate Nd (P ₂ ) ₃ [However, P ₂ is shows. ] 1.6 mmol of triisobutylaluminum, 32 mmol of triisobutylaluminum, and 5.6 mmol of diethylaluminum monobromide [Al(C ₂ H ₅ ) ₂ Br] were prepared in the same manner as in Example 3, and 1,3-butadiene was heated at 65°C. Polymerization was carried out for 2 hours. After this comparative example 1
A dry polymer was obtained in the same manner as above. (Comparative Example 3) A matured catalyst was prepared in the same manner as in Example 3 using 4.8 mmol of neodymium versatate, 80 mmol of triisobutylaluminum, and 10 mmol of ethylaluminum sesquichloride (Al(C ₂ H ₅ ) _1.5 Cl _1.5 ). The prepared 1,3-butadiene was polymerized at 80° C. for 2 hours. Thereafter, a dried polymer was obtained in the same manner as in Comparative Example 1.
(Comparative Example 4) 1.6 mmol of neodymium versatate, 28 mmol of diisobutylaluminum hydride, diethylaluminum monochloride [Al
(C ₂ H ₅ ) ₂ Cl] Using 5.2 mmol, 1,3-butadiene was polymerized at 90° C. for 2 hours in the same manner as in Example 1. Subsequently, the temperature was raised to 100°C, 20 ml of a hexane solution containing 8 mmol of carbon tetrachloride was added, and the mixture was allowed to react for 1 hour. Thereafter, a dried polymer was obtained in the same manner as in Example 1.
(Comparative Example 5) The properties of the polymers obtained in Comparative Examples 1 to 5 were
Shown in the table. Example 6 1,3 butadiene was polymerized in the same manner as in Example 4,
Subsequently, after raising the temperature to 120° C., 10 ml of a toluene solution containing 16 mmol of boron trifluoride ether complex was added and reacted for 1 hour. The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Example 7 1,3 butadiene was polymerized in the same manner as in Example 5,
Subsequently, after raising the temperature to 100°C, 30 ml of a hexane solution containing 8 mmol of lauroyl peroxide was added.
Allowed time to react. The properties of the dried polymer obtained by the same method as in Example 1 are shown in Table 1. Table 1 shows that among the polybutadiene produced by the method of the present invention, the molecular weight distribution (w/n) is 1.5.
The value of A of ~5.0 is −0.09 or less (Examples 1 to 5), and the molecular weight distribution (w/ It is clear that when n) is larger than 5.0 (Comparative Example 5), the value of A is 0.1 or more. Furthermore, as shown in Examples 6 and 7, the polybutadiene of the present invention can be produced using boron trifluoride ether complexes, lauroyl peroxide, etc.; The produced polybutadiene contains a large amount of toluene-insoluble matter (gel), and the polybutadiene obtained using the boron trifluoride ether complex has problems such as being colored yellow. Polybutadiene is more preferred.

[Table] Polymers obtained in Example 1, Comparative Examples 2 and 5, and commercially available high-cis polybutadiene (trade name: BR01)
(manufactured by Japan Synthetic Rubber Co., Ltd.), product name NiPol-1220S (manufactured by Nippon Zeon Co., Ltd.), product name Ubepol-15HB (manufactured by Ube Industries, Ltd.)
) was used as a raw material rubber and kneaded using a small laboratory Banbury mixer and an 8-inch roll according to the formulation shown in Table 2. The obtained unvulcanized rubber composition
It was vulcanized at 141°C for 40 minutes and subjected to physical property measurements. The measurements were performed using the method shown below. (1) Hardness, tensile strength, elongation, 300% modulus;
In accordance with JIS-K-6301. (2) Abrasion resistance; evaluated using a pico abrasion tester,
Expressed as an index with BR01 as 100. (3) Impact resilience: Measured at 20°C according to JIS-K-6301. (4) Gutudoritsuchi heat generation: Using a Gutsudoritsu flexometer, a test was conducted under the conditions of a load of 48 pounds, a displacement of 0.225 inches, a start of 50°C, and a rotation speed of 1800 rpm, and the difference in temperature rise after 20 minutes was expressed. (5) Roll processability: Using a 6-inch roll with a clearance of 6 mm, the state of rubber clinging to the roll at 60°C was observed and evaluated using a 5-point method.
Here, 5 indicates the best roll tightness, and the smaller the score, the more roll separation occurs, and 1 indicates the most roll separation. (6) Extrusion processability: Using an extruder with a 65 mm diameter Garvey die, the condition of the extruded skin was observed and evaluated using a 5-point method. Here, 5 indicates that the extruded skin is flat and has no roughness, and as the score decreases, the extruded skin has more roughness, and 1 indicates that the extruded skin has the most roughness. The results obtained are shown in Table 3. It is clear that the polybutadiene of the present invention has excellent processability and vulcanization properties.

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【table】 [Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship region between Mooney viscosity and solution viscosity of polybutadiene. In the figure, Region 1: A related region represented by conventional polybutadiene obtained using a catalyst containing a rare earth compound with a molecular weight distribution of 1.5 to 5.0; Region 2:
2 is a flow chart showing the manufacturing process of the present invention.

Claims (1)

[Scope of Claims] 1. The following, the main component of which is a rare earth metal compound:
A polymer obtained by polymerizing a butadiene monomer in the presence of a catalyst consisting of and components is reacted with tetrahalomethane represented by the following formula () or with an organoaluminum compound represented by the following formula (). A method for producing polybutadiene that satisfies the following conditions (a) to (e). At least one carboxylate, alcoholate, phenolate, phosphate, or phosphite of cerium, lanthanum, praseodymium, neodymium, or gadolinium, an organoaluminum compound represented by the general formula Al R ² _3-o Hn (n is 0, 1 or 2, R ² is a hydrocarbon group having 1 to 8 carbon atoms, H is hydrogen), Lewis acid containing a halogen element, CX ₄ () (wherein, C is carbon, X is chlorine, bromine, iodine,
Or it represents fluorine, and they may all be the same element or different elements. ) Al R ¹ _3-o Hn () (In the formula, n is 0, 1 or 2, R ¹ is a hydrocarbon group having 1 to 8 carbon atoms, and H is hydrogen.) (a) Gelperm Weight average molecular weight (
w) is 50,000 to 1,000,000, and the molecular weight distribution expressed as the ratio (w/n) of w to number average molecular weight (n) is 1.5 to 5.0. (b) 1,2 bond unit measured by ¹ H-NMR fraction is 1.0% or less; (c) Mooney viscosity (ML) measured at 100°C using an L rotor is 10 to 120; (d) 5% styrene solution viscosity (SV) at 25°C.
is 15 centipoise or more, (e) The relationship between ML and SV satisfies the following formulas () and (), log SV=1.52logML+A () A≦−0.09 ()