JP2002128824A - Modified diene-based elastomer and the method of producing the same and rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modified diene-based elastomer which is excellent in impact resilience and fuel consumption suppressing property and is also excellent in processibility, provide a method of producing the same, and provide a rubber composition using the elastomer. SOLUTION: This modified diene-based elastomer is obtained by reaction of an amine compound represented by general formula (1) (wherein, R1, R2, and R3 represent each a 1-8 C alkyl group; R4 represents a 1-8 C alkoxy or alkyl group; n represents an integer of 1-8) with an active conjugated diene-based polymer having an alkali metal end which is obtained by polymerization of a conjugated diene monomer or the conjugated diene monomer and an aromatic vinyl monomer by the use of an alkali metal-based catalyst in a hydrocarbon solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified diene polymer rubber, a method for producing the same, and a rubber composition. More specifically, the present invention relates to a modified diene-based polymer rubber having excellent rebound resilience, and hence excellent fuel economy and excellent processability, a method for producing the same, and a rubber composition using the polymer rubber. It is.

[0002]

2. Description of the Related Art Conventionally, a styrene-butadiene copolymer obtained by an emulsion polymerization method has been known as a rubber for automobile tires. However, the copolymer has a problem that it is inferior in rebound resilience properties and is therefore not preferable from the viewpoint of fuel saving. Therefore, many attempts have been made for the improvement. For example, in a hydrocarbon solvent,
A method has been proposed in which butadiene and styrene are copolymerized in the presence of a microstructure modifier comprising a Lewis base such as ether using an organolithium compound as a polymerization initiator (for example, see JP-A-60-72907). ). Furthermore, Japanese Patent Publication No. 2540901 discloses a method of reacting a specific acrylamide compound with an alkali metal terminal to obtain a modified diene copolymer rubber having improved fuel efficiency. However, the demand for improved fuel economy has become more sophisticated in light of recent environmental considerations, and conventional copolymers are not always satisfactory when illuminated to such recent high demand levels. Was not.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to provide a modified diene-based polymer rubber which is excellent in rebound resilience, and therefore excellent in fuel economy and processability. It is an object of the present invention to provide a production method thereof and a rubber composition using the polymer rubber.

[0004]

That is, the first aspect of the present invention is to polymerize a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal catalyst. The present invention relates to a modified diene-based polymer rubber obtained by reacting an active conjugated diene-based polymer having an alkali metal terminal obtained as described above with an amine compound represented by the following general formula (1). (Wherein, R ₁ , R ₂ and R ₃ represent an alkyl group having 1 to 8 carbon atoms, R ₄ represents an alkoxy group or an alkyl group having 1 to 8 carbon atoms, and n is an integer of 1 to 8) The second invention of the present invention relates to an alkali obtained by polymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal-based catalyst. For an active conjugated diene polymer having a metal terminal, the above-mentioned general formula (1)
The present invention relates to a method for producing a modified diene-based polymer rubber in which an amine compound represented by the following formula is reacted. A third aspect of the present invention relates to a rubber composition containing the modified diene-based polymer rubber in an amount of 10% by weight or more in a rubber component.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The modified diene polymer rubber of the present invention is obtained by polymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal catalyst. The modified diene polymer rubber obtained by reacting the active conjugated diene polymer having an alkali metal terminal with the amine compound represented by the general formula (1).

As conjugated diene monomers, 1.3-butadiene, isoprene, 1,3-pentadiene (piperin), 2,3-dimethyl-1,3-butadiene, 1,3
-Hexadiene and the like, and among these, 1.3-butadiene and isoprene are preferred from the viewpoint of the physical properties of the obtained copolymer and the availability in industrial practice.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, divinylnaphthalene and the like. Styrene is preferred from the viewpoint of physical properties and availability in industrial practice.

The hydrocarbon solvent is one that does not deactivate the alkali metal catalyst, and the suitable hydrocarbon solvent is selected from aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons. Propane having 2 to 12 pieces,
n-butane, iso-butane, n-pentane, iso-
Pentane, n-hexane, cyclohexane, propene,
1-butene, iso-butene, trans-2-butene,
Cis-2-butene, 1-pentene, 2-pentene, 1-
Hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like can be mentioned. Also,
These solvents can be used as a mixture of two or more kinds.

As the alkali metal catalyst, lithium,
Examples include metals such as sodium, potassium, rubidium, and cesium, hydrocarbon compounds containing these metals, and complexes of these metals with polar compounds. In addition, as a preferable thing as an alkali metal catalyst, 2
Lithium or sodium compounds having up to 20 carbon atoms can be mentioned, for example, ethyllithium, n-propyllithium, iso-
Propyl lithium, n-butyl lithium, sec-butyl lithium, t-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium 4- Examples thereof include cyclopentyl lithium, 1,4-dilithio-butene-2, sodium naphthalene, sodium biphenyl, potassium-tetrahydrofuran complex, potassium diethoxyethane complex, and sodium salt of α-methylstyrene tetramer.

In the present invention, an amine compound represented by the following general formula (1) is used.

Wherein R ₁ , R ₂ and R ₃ have 1 to 8 carbon atoms.
R ₄ represents an alkoxy group or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 1 to 8. Preferably, R ₁ and R ₂ are a methyl group, R ₃ is a methyl group, an ethyl group, a propyl group or a butyl group,
R ₄ is a methoxy group, an ethoxy group, a propoxy group or a butoxy group, and n = 1. Specific examples of the amine compound include 1,1-dimethoxytrimethylamine,
1,1-diethoxytrimethylamine, 1,1-di-n
-Propoxytrimethylamine, 1,1-di-iso-
Propoxytrimethylamine, 1,1-di-n-butoxytrimethylamine, 1,1-di-tert-butoxytrimethylamine, 1,1-diethoxytriethylamine, 1,1-di-n-propoxytriethylamine,
1,1-di-iso-propoxytriethylamine,
1,1-di-n-butoxytriethylamine, 1,1-
Di-tert-butoxytriethylamine and the like can be mentioned, but from the viewpoint that fuel efficiency can be remarkably improved by adding a small weight, 1,1-dimethoxytrimethylamine having a small molecular weight is preferable.

The modified diene-based polymer rubber of the present invention is obtained by polymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal-based catalyst. Is obtained by reacting the amine compound represented by the general formula (1) with an active conjugated diene polymer having

As the polymerization monomer, only a conjugated diene monomer may be used, or a conjugated diene monomer and an aromatic vinyl monomer may be used in combination. When a conjugated diene monomer and an aromatic vinyl monomer are used in combination, the ratio of both is preferably 50/50 to 90/10, more preferably 55/45 to 85/15 by weight ratio of conjugated diene monomer / aromatic vinyl monomer. It is. If the ratio is too low, the polymer rubber becomes insoluble in the hydrocarbon solvent and uniform polymerization may not be possible, while if the ratio is too high, the strength of the polymer rubber may decrease.

At the time of polymerization, it is possible to use commonly used ones such as an alkali metal catalyst, a hydrocarbon solvent, a randomizer, and a regulator for the vinyl bond content of a conjugated diene unit. , No particular restrictions.

In order to adjust the vinyl bond content of the conjugated diene portion, various compounds can be used as the Lewis basic compound.
It is preferable in terms of industrial availability. Examples of the ether compound include cyclic ethers such as tetrahydrofuran, tetrahydropyran and 1,4-dioxane; aliphatic monoethers such as diethyl ether and dibutyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether;
Aliphatic ethers such as diethylene glycol dibutyl ether; and aromatic ethers such as diphenyl ether and anisole. Examples of the tertiary amine compound include triethylamine, tripropylamine,
In addition to tributylamine, etc., N, N, N ', N'-
Examples include tetramethylethylenediamine, N-diethylaniline, pyridine, quinoline and the like.

The amount used in the production by adding the amine compound of the present invention to the active conjugated diene polymer having an alkali metal terminal is usually per mole of the alkali metal catalyst used in adding the alkali metal. 0.1 to 10 mol, preferably 0.2 to 5 mol. If the amount is too small, the effect of improving fuel economy is small, and if it is too large, the solvent remains in the polymerization solvent, so that when the solvent is recycled, a separation step from the solvent is required. It is not economically preferable.

Since the reaction between the amine compound and the active conjugated diene polymer having an alkali metal terminal occurs rapidly, the reaction temperature and the reaction time can be selected from a wide range, but generally from room temperature to 100 ° C. , Several seconds to several hours. The reaction may be performed by bringing the alkali metal-containing diene polymer into contact with the amine compound.For example, the diene polymer is polymerized using an alkali metal catalyst, and the amine compound is added to the polymer solution. A method of adding a fixed amount can be exemplified as a preferable embodiment, but is not limited to this method.

The resulting modified diene polymer rubber has an amino group or an amino group and an alkoxy group introduced at the molecular terminal. After the completion of the reaction, the modified diene polymer rubber is subjected to the coagulation method used in the production of rubber by ordinary solution polymerization, such as addition of a coagulant or steam coagulation from the reaction solvent, and the coagulation temperature is also limited at all. Not done.

For drying the crumb separated from the reaction system, band dryers, extrusion dryers and the like used in the production of ordinary synthetic rubber can be used, and the drying temperature is not limited at all.

Thus, the modified diene polymer rubber of the present invention is obtained.

The modified diene polymer rubber preferably has a Mooney viscosity (ML _{1 + 4} ) of 10 to 200,
More preferably, it is 20 to 150. If the Mooney viscosity is too low, the mechanical properties such as the tensile strength of the vulcanized product may decrease, while if the viscosity is too high, the miscibility is poor when used in combination with other rubbers, and processing operability is difficult. And the mechanical properties of the vulcanized product of the obtained rubber composition may be reduced.

The vinyl bond content of the conjugated diene portion of the modified diene polymer rubber is preferably from 10 to 70%, more preferably from 15 to 60%. When the content is too low, the glass transition temperature of the polymer becomes too low, and when used as a polymer for tires, the grip performance may be poor. On the other hand, when the content is too high, the glass transition temperature of the polymer becomes low. The temperature may rise and the rebound resilience may be poor.

The modified diene polymer rubber of the present invention is a rubber composition containing other rubber components, various additives and the like.

Other rubber components include emulsion-polymerized styrene-butadiene copolymer rubber, polybutadiene rubber by solution polymerization (anionic polymerization catalyst, ziegler type catalyst), butadiene-isoprene rubber copolymer rubber, styrene-butadiene copolymer Rubber, and natural rubber,
One or more of these rubbers are selectively used depending on the purpose. Here, when another rubber component is used, the proportion of the modified diene polymer rubber of the present invention in the total rubber component is preferably at least 10% by weight, more preferably at least 20% by weight. If the proportion of the modified diene polymer rubber of the present invention is too small, the degree of improvement in rebound resilience will be small, and workability will not be improved.

As the additives, those suitable for the purpose of use of the rubber composition may be selected from those commonly used in the rubber industry, and are not particularly limited. Usually, the vulcanization system is sulfur,
Stearic acid, zinc white, various vulcanization accelerators (thiazole-based, thiuram-based, sulfenamide-based, etc.) or organic peroxides, etc. As reinforcing agents, various grades of carbon black, silica such as HAF, ISAF, etc. As fillers, calcium carbonate, talc and the like are used, and as other additives, extender oil, processing aids, antioxidants and the like are used. The type and amount of these additives are selected according to the purpose of use of the rubber composition, and are not particularly limited in the present invention.

In order to obtain a rubber composition, the rubber component and various additives may be kneaded using a mixer such as a roll or a Banbury. The rubber composition is vulcanized and provided for use.

Since the rubber composition of the present invention has excellent rebound resilience, it can be optimally used for automobile tires having excellent fuel economy. Further, the rubber composition of the present invention is for shoe soles, flooring agents,
It can be used as a raw rubber for various kinds of industrial uses such as for vibration-proof rubber.

[0028]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 A stainless steel polymerization reactor having an inner volume of 20 liters was washed,
After drying and purging with dry nitrogen, 1,3-butadiene 1
420 g, 580 g of styrene, tetrahydrofuran 1
22 g, hexane 10.2 kg, and n-butyllithium (n-hexane solution 11.0 mmol) were added, and polymerization was carried out at 65 ° C. for 3 hours with stirring. After completion of polymerization, 1,1
After adding 11.0 mmol of -dimethoxytrimethylamine and reacting with stirring for 30 minutes, 10 ml of methanol was added and the mixture was further stirred for 5 minutes. Thereafter, the contents of the polymerization reaction vessel were taken out, and 10 g of 2,6-di-tert-phthyl-p-cresol (Sumilyzer BH manufactured by Sumitomo Chemical Co., Ltd.).
T: the same applies hereinafter), and most of the hexane was evaporated, followed by drying under reduced pressure at 55 ° C. for 12 hours to obtain a polymer rubber.

Comparative Example 1 A stainless steel polymerization reactor having an inner volume of 20 liters was washed,
After drying and purging with dry nitrogen, 1,3-butadiene 1
420 g, 580 g of styrene, tetrahydrofuran 1
22 g, hexane 10.2 kg, and n-butyllithium (n-hexane solution 11.1 mmol) were added, and polymerization was performed at 65 ° C. for 3 hours with stirring. After polymerization is completed, N, N
-Dimethylaminopropyl acrylamide 11.1 m
mol, and reacted for 30 minutes with stirring.
1 methanol was added and stirred for another 5 minutes. Thereafter, the contents of the polymerization reaction vessel were taken out and 10 g of 2,6 was removed.
-Di-tert-phthyl-p-cresol was added and most of the hexane was evaporated, followed by drying under reduced pressure at 55 ° C for 12 hours,
A polymer rubber was obtained.

Comparative Example 2 A 20 liter stainless steel polymerization reactor was washed.
After drying and purging with dry nitrogen, 1,3-butadiene 1
420 g, 580 g of styrene, tetrahydrofuran 1
22 g, hexane 10.2 kg, and n-butyllithium (n-hexane solution 11.5 mmol) were added, and polymerization was carried out at 65 ° C. for 3 hours with stirring. 10m after completion of polymerization
1 methanol was added and stirred for another 5 minutes. Thereafter, the contents of the polymerization reaction vessel were taken out and 10 g of 2,6 was removed.
-Di-tert-phthyl-p-cresol was added and most of the hexane was evaporated, followed by drying under reduced pressure at 55 ° C for 12 hours,
A polymer rubber was obtained.

Each of the polymer rubbers obtained in Example 1, Comparative Example 1 and Comparative Example 2 was measured and evaluated as follows. Mooney viscosity of polymer rubber Measured at 100 ° C. in accordance with JIS K-6300. Vinyl content of polymer rubber Measured by infrared spectroscopy. Styrene content of polymer rubber Measured by a refractive index method. Processability of polymer rubber A 6-inch roll was adjusted to a temperature of 50 ° C., and the gap between the rolls was changed to 0.7 mm, 1.0 mm, and 2.0 mm. The condition was observed, and a score was given according to the criteria in Table 2. Rebound resilience of vulcanized rubber According to the composition in Table 1, kneaded with a Labo Plastomill to obtain a compounded rubber, formed into a sheet with a 6-inch roll, and vulcanized at 160 ° C. for 15 minutes. To obtain a vulcanized rubber. The rebound resilience of the vulcanized rubber at 60 ° C. was measured using a Lupke Resilience Tester.

Table 3 shows the measurement and evaluation results.

[0033]

[Table 1] * 1: Using N-339 * 2: Anticanine 3C (antiaging agent manufactured by Sumitomo Chemical Co., Ltd.) * 3: Succinol CZ (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) * 4: Sannoc N (Ouchi Shinko Chemical Industry Co., Ltd.) Made)

[0034]

[Table 2]

[0035]

[Table 3] * 1 Modified compound A: 1,1-dimethoxytrimethylamine B: N, N-dimethylaminopropylacrylamide

Example 2 In order to confirm reproducibility, polymerization was carried out under the same conditions as in Example 1, and after completion of polymerization, 1,1-dimethoxytrimethylamine was added in 1 part.
After adding 1.0 mmol and reacting with stirring for 30 minutes, 10 ml of methanol was added and the mixture was further stirred for 5 minutes. Thereafter, the contents of the polymerization reaction vessel are taken out and 10 g is taken out.
2,6-di-t-phthyl-p-cresol was added and most of the hexane was evaporated, followed by drying under reduced pressure at 55 ° C. for 12 hours to obtain a polymer rubber, which was evaluated.

Example 3 As an amine compound added after polymerization in Example 2, 1,1-dimethoxytrimethylamine was added in an amount of 33 mmol.
The same procedure was followed except that 1 was added to obtain a polymer rubber, which was evaluated.

Example 4 As an amine compound added after the polymerization in Example 2, 1,1-diethoxytrimethylamine was used in an amount of 11.0 m
Except for adding mol, the same treatment was carried out to obtain a polymer rubber, which was evaluated.

Example 5 As an amine compound added after polymerization in Example 2, 1,1-di-n-propoxytrimethylamine was used.
The same procedure was followed except that 1.0 mmol was added to obtain a polymer rubber, which was evaluated.

Example 6 As an amine compound to be added after polymerization in Example 2, 1,1-di-n-butoxytrimethylamine was used.
Except for adding 1.0 mmol, the same procedure was followed to obtain a polymer rubber and evaluate it.

Comparative Example 3 A stainless steel polymerization reactor having an inner volume of 20 liters was washed,
After drying and purging with dry nitrogen, 1,3-butadiene 1
420 g, styrene 580 g, tetrahydrofuran 12
2 g, hexane 10.2 kg, n-butyl lithium (n
9.8 mmol) in hexane.
Polymerization was performed at 5 ° C. for 3 hours. After completion of the polymerization, 10 ml of methanol was added, and the mixture was further stirred for 5 minutes. Thereafter, the contents of the polymerization reaction vessel were taken out and 10 g of 2,6-di-t was removed.
After adding -phthyl-p-cresol and evaporating most of the hexane, the polymer was dried under reduced pressure at 55 ° C. for 12 hours to obtain a polymer rubber, which was evaluated.

Comparative Example 4 The same procedure as in Comparative Example 3 was carried out except that n-butyllithium (n-hexane solution 11.2 mmol) was added, and a polymer rubber was obtained and evaluated.

Tables 4 and 5 show the measurement and evaluation results of the polymer rubbers obtained in Examples 2 to 6 and Comparative Examples 3 and 4.

[0044]

[Table 4] * 1 Compound A: 1,1-dimethoxytrimethylamine C: 1,1-diethoxytrimethylamine D: 1,1-di-n-propoxytrimethylamine E: 1,1-di-n-butoxytrimethylamine * 2 Amount: in the table Numerical value = addition amount of modified compound (mol) / n
-BuLi (mol)

[0045]

[Table 5]

Example 7 The polymer rubber obtained in Example 1 was kneaded with a Labo Plastomill according to the silica compounding shown in Table 6 to obtain a compounded rubber, which was formed into a sheet by a 6-inch roll. After, 16
Vulcanization was performed under the conditions of 0 ° C. × 45 minutes. The processability of the rubber composition and the rebound resilience of the vulcanized rubber were measured and evaluated. The results are shown in Table 7.

Comparative Example 5 The procedure of Example 7 was repeated except that the polymer rubber obtained in Comparative Example 2 was used.

Comparative Example 6 In the same manner as in Example 7 except that a polymer rubber obtained in the same manner as in Comparative Example 3 except that n-butyllithium (9.4 mmol of an n-hexane solution) was added was used. went.

Table 7 shows the results of Example 7 and Comparative Examples 5 and 6. In each of the examples, it was shown that they had higher rebound resilience and better roll workability than the comparative examples.

[0050]

[Table 6] * 1: Ultrasil VN3-G (manufactured by Degussa) * 2: Si69 (manufactured by Degussa) * 3: X-140 (aroma oil manufactured by Kyodo Sekiyu) * 4: Antigen 3C (antiaging agent manufactured by Sumitomo Chemical Co., Ltd.) * 5: Succinol CZ (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) * 6: Succinol D (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) * 7: Sannoc N (Ouchi Shinko Chemical Co., Ltd.)

[0051]

[Table 7] * 1 Modified compound A: 1,1-dimethoxytrimethylamine B: N, N-dimethylaminopropylacrylamide

[0052]

As described above, according to the present invention, a modified diene-based polymer rubber having excellent rebound resilience, and hence excellent fuel economy and excellent processability, a method for producing the same, and use of the polymer rubber are provided. It was possible to provide a rubber composition that had been used.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiro Nakatsuji 5-1, Anesaki Beach, Ichihara City, Chiba Prefecture Sumitomo Chemical Co., Ltd. F-term (reference) 4J002 AC02W AC03W AC03X AC06W AC08W AC08X FD010 FD140 FD150 GC00 GM00 GN01 4J015 DA02 4J100 AB00Q AB02Q AB04Q AB15Q AB16Q AS01P AS02P AS03P AS04P BA27H CA01 CA04 CA27 CA31 FA08 FA19 HA35 HA55 HC45

Claims (4)

[Claims] 1. An active conjugated diene-based polymer having an alkali metal terminal, which is obtained by polymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal-based catalyst. On the other hand, a modified diene polymer rubber obtained by reacting an amine compound represented by the following general formula (1). (Wherein, R ₁ , R ₂ and R ₃ represent an alkyl group having 1 to 8 carbon atoms, R ₄ represents an alkoxy group or an alkyl group having 1 to 8 carbon atoms, and n is an integer of 1 to 8) Represents.) 2. R ₁ and R ₂ are a methyl group, R ₃ is a methyl group, an ethyl group, a propyl group or a butyl group;
The modified diene polymer rubber according to claim 1, wherein ₄ is a methoxy group, an ethoxy group, a propoxy group or a butoxy group, and n = 1. 3. An active conjugated diene polymer having an alkali metal terminal obtained by polymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an alkali metal catalyst. A method for producing a modified diene polymer rubber, which comprises reacting the amine compound represented by the general formula (1) according to claim 1. 4. A rubber composition containing the modified diene-based polymer rubber according to claim 1 in an amount of 10% by weight or more in a rubber component.