JPH0153851B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a hydrogenation method capable of selectively hydrogenating olefinically unsaturated double bonds in a compound containing olefinically unsaturated double bonds. [Prior Art] Heterogeneous catalysts and homogeneous catalysts are generally known as hydrogenation catalysts for compounds having olefinic unsaturated double bonds. The former type of heterogeneous catalyst is widely used industrially, but it generally has lower activity than homogeneous catalysts, requires a large amount of catalyst to carry out the desired hydrogenation reaction, and cannot be carried out at high temperature and pressure. This makes it uneconomical. On the other hand, the latter type of homogeneous catalyst usually progresses the hydrogenation reaction in a homogeneous system, so compared to a heterogeneous system, it has higher activity and requires less catalyst use, and can perform hydrogenation at lower temperatures and pressures. However, catalyst preparation is complicated, the stability of the catalyst itself is not sufficient, the reproducibility is poor, and undesirable side reactions are likely to occur. Therefore, there is currently a strong desire to develop a hydrogenation catalyst that is highly active and easy to handle. On the other hand, in polymers containing olefinic unsaturated double bonds, while the unsaturated double bonds are advantageously used for vulcanization, etc., such double bonds have poor stability such as weather resistance and oxidation resistance. It has its drawbacks. These disadvantages of poor stability can be significantly improved by hydrogenating the polymer to eliminate unsaturated double bonds in the polymer chain. However, when hydrogenating a polymer, compared to when hydrogenating a low-molecular compound, it becomes difficult to hydrogenate due to the effects of the viscosity of the reaction system, steric hindrance of the polymer chain, etc. Furthermore, there are drawbacks such as the fact that it is extremely difficult to physically remove the catalyst after the hydrogenation is completed, and it is virtually impossible to separate it completely. Therefore, in order to hydrogenate polymers economically, it is necessary to use a highly active hydrogenation catalyst that exhibits activity in an amount that does not require deashing.
Alternatively, there is a strong desire to develop a catalyst that can be extremely easily deashed. [Problems to be solved by the present invention] The purpose of the present invention is to discover a highly active hydrogenation catalyst that is stable, easy to handle, and exhibits activity in an extremely small amount used in hydrogenation reactions. The solution to this problem is to discover a highly active hydrogenation catalyst that exhibits activity even when the amount of ash used is unnecessary, and to find a way to obtain hydrogenated polymers with excellent weather resistance, oxidation resistance, and ozone resistance. This is an issue that should be addressed. [Means and effects for solving the problems] The present invention provides a hydrogenation catalyst consisting of a titanocene diaryl compound and an alkyl lithium that exhibits extremely high hydrogenation activity of olefinic unsaturated double bonds under mild conditions, It is also based on the surprising fact that unsaturated double bonds in polymers containing olefinic unsaturated double bonds can be selectively hydrogenated under mild conditions and in a small amount that does not require deashing. It has been done. That is, the present invention provides a method for hydrogenating an olefinically unsaturated double bond-containing compound in an inert organic solvent, in which: (A) a titanocene diaryl compound represented by (a) below; (However, R ₁ to _{R 6} are hydrogen or carbon atoms 1 to 4.
represents an alkyl hydrocarbon group, R ₁ to _{R 3} and
One or more of R ₄ to _{R 6} is hydrogen. ) and (B) general formula R-Li (wherein R has 1 to 1 carbon atoms)
Six alkyl groups are shown. ) Relating to a method for hydrogenating olefins, which comprises hydrogenating an olefinically unsaturated double bond in a core compound by contacting it with hydrogen in the presence of a catalyst comprising at least one alkyllithium compound represented by . It is already known that the titanocene diaryl compound as represented by the general formula (a) according to the present invention can be stably handled in air at room temperature and can be easily isolated.
(For example, L. Summers et al., J. Am. Chem. Soc., Vol.
77, p. 3604 (1955), MDRausch et al., J.
OrganometallChem., vol. 10, p. 127 (1967)
In addition, the present inventors discovered that such titanocene diaryl compounds alone have high hydrogenation activity, and have already filed a patent application (Japanese Patent Application No.
76614). The present inventors further improved the activity of this prior application's olefin hydrogenation catalyst system and, as a result of further intensive studies on a method for efficiently and economically hydrogenating olefins, discovered that The inventors have discovered that a hydrogenation catalyst exhibits even higher hydrogenation activity under selected conditions than when a titanocene diaryl compound is used alone, leading to the completion of the present invention. The olefinic unsaturated double bond hydrogenation catalyst component (A) according to the present invention has the general formula (a) It is indicated by. However, R ₁ to _{R 6} represent hydrogen or an alkyl hydrocarbon group having 1 to 4 carbon atoms, and R ₁ to _{R 3}
and one or more of R ₄ to R ₆ is hydrogen. those in which the alkyl carbon group has 5 or more carbon atoms, and
If R ₁ to R ₃ or R ₄ to _{R 6} are all alkyl groups, it is difficult to synthesize in good yield due to steric hindrance and the storage stability at room temperature is also poor, which is not preferable. Furthermore, it is difficult to synthesize a compound in which the alkyl hydrocarbon group is ortho to titanium. A specific example of such a hydrogenation catalyst is diphenylbis(η
-diclopentadienyl) titanium, di-m-
Tolylbis(η-cyclopentadienyl) titanium, di-p-tolylbis(η-cyclopentadienyl) titanium, di-3,4-xylylbis(η-cyclopentadienyl) titanium, bis(4-ethylphenyl)bis (η-cyclopentadienyl) titanium, bis(4-butylphenyl)bis(η-cyclopentadienyl) titanium, and the like. Compounds with a larger number of carbon atoms in the alkyl carbon group have lower storage stability, while better solubility in certain types of organic solvents. (enyl) titanium is most preferred. The hydrogenation catalyst component (A) of the present invention has an extremely good solubility in various organic solvents compared to other titanocene compounds, and can be used as a solution and is easy to handle, making it extremely useful in industry. It's advantageous. On the other hand, as the catalyst component (B), an organometallic compound capable of reducing the titanocene diaryl compound of the catalyst component (A), such as an organolithium compound, an organoaluminium compound, an organozinc compound, an organomagnesium compound, etc., may be used singly or together. The polymer can be hydrogenated by using it in combination with. However, in order to express high activity and selectively hydrogenate olefinic unsaturated double bonds,
The use of organolithium compounds, especially alkyllithium compounds, is essential. That is, the object of the present invention can be suitably achieved by using a titanocene diaryl compound in combination with an alkyl lithium compound, and surprisingly, olefinic unsaturated double It is possible to hydrogenate bonds almost quantitatively and preferentially. As such catalyst component (B), an alkyllithium compound represented by the general formula R-Li (wherein R represents an alkyl group having 1 to 6 carbon atoms) is preferably used, and specific examples include is methyllithium, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec
-butyllithium, isobutyllithium, n-pentyllithium, n-hexyllithium, and the like. These may be used in combination of two or more types, or may be a mutual complex of two or more types. In order to exhibit the highest hydrogenation activity and selectively hydrogenate olefinically unsaturated double bonds, n-butyllithium is most preferred. The catalyst of the present invention can be applied to all compounds having olefinically unsaturated double bonds. For example, 1-butene, 1,3-butadiene, cyclopentene, 1,3-pentadiene, 1-hexene,
It can be suitably used for hydrogenating cyclohexene, 1-methylcyclohexene, styrene, and the like. On the other hand, since the hydrogenation catalyst of the present invention has high hydrogenation activity and selectivity, it is particularly suitable for hydrogenation of polymers having unsaturated double bonds. Although the present invention can be applied to all polymers having unsaturated double bonds, preferred embodiments include conjugated diene polymers, copolymers of conjugated dienes and olefin monomers, norbornene polymers, and cyclopentene polymers. etc. In particular, conjugated diene polymers and hydrogenated copolymers of conjugated dienes and simple olefins are industrially useful as elastic bodies and thermoplastic elastomers. Conjugated dienes used in the production of such conjugated diene polymers generally include conjugated dienes having from 4 to about 12 carbon atoms, and specific examples include 1,3-butadiene, isoprene,
2,3-dimethyl-1,3-butadiene, 1,3
-Pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-
Examples include octadiene. From the viewpoint of obtaining an elastic body that can be industrially advantageously developed and has excellent physical properties, 1.
3-butadiene and isoprene are particularly preferred. Furthermore, as the olefin monomer copolymerizable with at least one conjugated diene, vinyl-substituted aromatic hydrocarbons are particularly preferred. That is, in order to fully exhibit the effect of the present invention of selectively hydrogenating only the unsaturated double bonds of the conjugated diene unit, and to obtain industrially useful and valuable elastomers and thermoplastics, it is necessary to Of particular interest are copolymers of vinyl-substituted aromatic hydrocarbons and vinyl-substituted aromatic hydrocarbons. Specific examples of vinyl-substituted aromatic hydrocarbons used include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p- Examples include aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, and styrene is particularly preferred. As specific examples of copolymers, butadiene/styrene copolymers, isoprene/styrene copolymers, etc. are most preferred since they provide hydrogenated copolymers with high industrial value. Among such copolymers, a block copolymer provides a hydrogenated polymer that is industrially most useful as a thermoplastic elastomer, but a block copolymer having at least one block mainly consisting of a conjugated diene is preferred. Coalescence is particularly preferably used because it yields a hydrogenated polymer that is superior in processability, compatibility with other olefin polymers, adhesive properties, etc., as compared to products that do not have a conjugated diene block at the end. A preferred embodiment of the hydrogenation reaction of the present invention is carried out in a solution in which a compound having an olefinically unsaturated double bond or the above polymer is dissolved in an inert organic solvent. Of course, in the case of low molecular weight compounds that are liquid at room temperature, such as cyclohexene and cyclooctene, the hydrogenation reaction can be carried out without dissolving them in a solvent, but in order to carry out the reaction uniformly and under mild conditions, a solution dissolved in a solvent is required. It is preferable to carry out at "Inert organic solvent" means a solvent that does not react with any participant in the hydrogenation reaction. A suitable solvent is
For example, aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane, alicyclic hydrocarbons such as cyclohexene and cycloheptane, and ethers such as diethyl ether and tetrahydrofuran may be used alone or in mixtures. be. Aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene can also be used as long as aromatic double bonds are not hydrogenated under the selected hydrogenation reaction conditions. In the hydrogenation reaction of the present invention, the hydrogenation product solution is generally maintained at a predetermined temperature under hydrogen or an inert atmosphere, a hydrogenation catalyst is added with or without stirring, and then hydrogen is added. This is carried out by introducing gas and pressurizing it to a predetermined pressure. What is an inert atmosphere?
For example, it means an atmosphere that does not react with any member of the hydrogenation reaction, such as helium, neon, or argon. Air and oxygen are not preferred because they oxidize catalyst components and cause catalyst deactivation. Further, nitrogen is not preferred because it acts as a catalyst poison during the hydrogenation reaction and reduces the hydrogenation activity. In particular, it is most preferable that the inside of the hydrogenation reactor be in an atmosphere containing only hydrogen gas. On the other hand, the catalyst is prepared by combining the catalyst component (A) and the catalyst component in advance.
It is preferable to use a mixture with (B) because it has high activity. The hydrogenation reaction can also be carried out by adding either the catalyst component (A) or the catalyst component (B) separately into the hydrogenated product solution first, but the reaction with the alkyl lithium of the catalyst component (B) Hydrogenating olefins is not preferred because side reactions occur and the yield of the desired hydrogenation reaction decreases. It is necessary to handle the catalyst component (B) under the above-mentioned inert atmosphere. Although the catalyst component (A) is stable even in air, it is preferable to handle it under an inert atmosphere. Further, although each catalyst component may be used as it is, it is preferable to use it as a solution of the inert organic solvent because it is easier to handle. As the inert organic solvent used when the solution is used, the various solvents mentioned above that do not react with any of the participants in the hydrogenation reaction can be used. Preferably, it is the same solvent as used in the hydrogenation reaction. When premixing the catalyst components or adding the catalyst components to the hydrogenation reactor, it is most preferable to do so under a hydrogen atmosphere. When using the catalyst component (A) and catalyst component (B) mixed in advance, -
It is preferable to prepare immediately before the hydrogenation reaction at a temperature of 30°C to 100°C, preferably -10°C to 50°C, but if stored under a hydrogen atmosphere or an inert atmosphere, it will last for about one week even at room temperature. Within this range, the hydrogenation activity can be used without changing the substantial hydrogenation activity. The mixing ratio of each catalyst component to exhibit high hydrogenation activity and hydrogenation selectivity is the ratio of the number of moles of lithium in the catalyst component (B) to the number of moles of titanium in the catalyst component (A) (hereinafter referred to as Li/Ti). (molar ratio) is approximately 20 or less. A quantitative hydrogenation reaction can be carried out even when the Li/Ti molar ratio is 0, but it requires higher temperature and higher pressure conditions, and if the Li/Ti molar ratio exceeds 20, it is expensive and does not substantially improve the activity. Not only is it uneconomical to use an excessive amount of catalyst component (B), but also
This is not preferable because it tends to cause unnecessary side reactions.
A Li/Ti molar ratio in the range of 0.5 to 10 is most suitable for significantly improving hydrogenation activity. A sufficient amount of the catalyst to be added is 0.005 to 20 mmol per 100 g of hydrogenated material. With this addition amount range, it is possible to preferentially hydrogenate the olefinic unsaturated double bonds of the hydrogenated product, and hydrogenation of aromatic double bonds does not substantially occur, so hydrogenation selection is extremely high. sexuality is realized. The hydrogenation reaction is possible even when the amount exceeds 20 mmol, but using more catalyst than necessary becomes uneconomical and has disadvantages such as complicating deashing and removal of the catalyst after the hydrogenation reaction. In addition, the preferred amount of catalyst added to quantitatively hydrogenate the unsaturated double bonds of the conjugated diene units of the polymer under selected conditions is
It is 0.05 to 5 mmol per 100 g. The hydrogenation reaction of the present invention is carried out using elemental hydrogen, more preferably introduced in gaseous form into the hydrogenate solution. It is more preferable that the hydrogenation reaction is carried out under stirring, so that the introduced hydrogen can be brought into contact with the hydrogenated substance sufficiently quickly. The hydrogenation reaction is generally carried out at a temperature range of 0 to 150°C. Below 0°C, the activity of the catalyst decreases and the hydrogenation rate slows down, requiring a large amount of catalyst, which is not economical.
Temperatures exceeding .degree. C. are not preferred because side reactions, decomposition, and gelation are likely to occur together, and hydrogenation of the aromatic nucleus portion is also likely to occur, resulting in a decrease in hydrogenation selectivity. More preferably, the temperature is in the range of 20 to 120°C. The pressure of hydrogen used in hydrogenation reaction is 1 to 100
Kg/cm ² is preferred. If the pressure is less than 1 Kg/cm ² , the hydrogenation rate slows down and practically reaches a plateau, making it difficult to increase ^the hydrogenation rate. This is not desirable because it has no meaning and causes unnecessary side reactions and gelation. More preferable hydrogenation pressure is 2~
30Kg/cm ² , but the optimum hydrogen pressure is selected in correlation with the amount of catalyst added, etc., and in practice, the hydrogen pressure should be selected on the high pressure side as the above-mentioned preferred amount of catalyst becomes smaller. is preferred. The hydrogenation reaction time of the present invention is usually several seconds to 50 hours. The hydrogenation reaction time is appropriately selected within the above range by selecting other hydrogenation reaction conditions. From a solution subjected to a hydrogenation reaction using the catalyst of the present invention, the hydrogenated object can be easily separated by chemical or physical means such as distillation or precipitation.
In particular, if necessary, catalyst residues are removed from the polymer solution subjected to the hydrogenation reaction by the method of the present invention.
Hydrogenated polymers can be easily isolated from solution. For example, a method in which a polar solvent such as acetone or alcohol, which is a poor solvent for the hydrogenated polymer, is added to the reaction solution after hydrogenation to precipitate and recover the polymer; This can be carried out by distilling and recovering the solvent together with the solvent, or by directly heating the reaction solution and distilling off the solvent. The hydrogenation method of the present invention is characterized in that the amount of hydrogenation catalyst used is small. Therefore, even if the hydrogenation catalyst remains in the polymer, it does not significantly affect the physical properties of the hydrogenated polymer obtained, and even during the isolation process of the hydrogenated polymer, most of the catalyst is decomposed. , removed and removed from the polymer, no special operations are required to demineralize or remove the catalyst.
It can be implemented in an extremely simple process. [Effects of the Invention] As described above, the method of the present invention makes it possible to efficiently hydrogenate olefinically unsaturated double bonds, and in particular, to use polymers having olefinically unsaturated double bonds as highly active catalysts. Therefore, it has become possible to hydrogenate under mild conditions and to hydrogenate extremely selectively the unsaturated double bonds in the conjugated diene units of the copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon. . In addition, the hydrogenated polymer obtained by the method of the present invention can be used as an elastic body, thermoplastic elastic body, or thermoplastic resin with excellent weather resistance and oxidation resistance, and can also be used as an ultraviolet absorber, oil, filler, etc. It is used with additives or blended with other elastomers or resins, making it extremely useful industrially. [Examples] The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto. Reference example 1 1 with stirrer, dropping funnel and reflux condenser
200 ml of anhydrous ether was added to a three-necked flask.
The apparatus was replaced with dry helium, and 17.4 g (2.5 moles) of lithium wire was cut into the flask.
A small amount of a solution of 157 g/(1 mol) of bromobenzene in 300 ml of ether was added dropwise at room temperature, and then the entire amount of the ether solution of bromonzene was gradually added under reflux. After the reaction was completed, the reaction solution was passed under a helium atmosphere to obtain a colorless and transparent phenyllithium solution. 99.6 g (0.4 mol) of dichlorobis(cyclopentadienyl)titanium was placed in a two-three-necked flask equipped with a stirrer and a dropping funnel purged with dry helium.
and 500 ml of anhydrous ether were added. The previously synthesized phenyl ether solution was stirred at room temperature for about 2 hours.
It dripped in time. The reaction mixture is separated in air,
After washing the insoluble portion with dichloromethane, the solution and washing solution were combined and the solvent was removed under reduced pressure. After dissolving the residue in a small amount of dichloromethane, petroleum ether was added for recrystallization. Separate the obtained crystals, concentrate the liquid again, and repeat the above procedure to obtain diphenylbis(η-cyclopentadienyl).
Obtained titanium. The yield was 120g (90% yield). The obtained crystals are orange-yellow needle-shaped, have good solubility in toluene and cyclohexene, melting point 147°C, elemental analysis values: C, 79.5; H,
6.1; Ti was 14.4. Reference Example 2 Synthesized in the same manner as Reference Example 1 except that p-bromotoluene was used instead of bromobenzene, and di-p-
Tolylbis(η-cyclopentadienyl)titanium was obtained (yield 87%). This substance is yellow crystalline, has good solubility in toluene and cyclohexa, melting point 145℃, elemental analysis value: C,
80.0; H, 6.7; Ti, 13.3. Reference Example 3 Di-3,4-xylylbis(η-cyclopentadienyl)titanium was synthesized in the same manner as Reference Example 1 except that 4-bromo-o-xylene was used instead of bromobenzene (yield rate 83%). This product was in the form of yellow crystals, had good solubility in toluene and cyclohexane, had a melting point of 155°C, and had elemental analysis values: C, 80.6; H, 7.2; Ti, 12.2. Reference Example 4 Synthesis was carried out in the same manner as in Reference Example 1 except that p-bromoethylbenzene was used instead of bromobenzene to obtain bis(4-ethylphenyl)bis(η-cyclopentadienyl)titanium (yield 80%). ). This substance is a yellow crystal, has good solubility in toluene and cyclohexane, has a melting point of 154℃,
Elemental analysis values: C, 80.4; H, 7.3; Ti, 12.3. Reference example 5 500 ml of cyclohexane in the autoclave of 2
g, 100 g of 1,3-butadiene monomer, and 0.05 g of n-butyllithium were added, and polymerization was carried out at 60° C. for 3 hours with stirring to synthesize a butadiene homopolymer. The obtained butadiene polymer has 13 1,2-vinyl bonds.
% and the weight average molecular weight measured by GPC is approximately
It was 150,000. Reference Example 6 Polymerization was carried out in the same manner as in Reference Example 1, except that isoprene was used instead of 1,3-butadiene, to obtain an isoprene polymer having 10% of 1,2-vinyl bonds and a weight average molecular weight of about 150,000. Reference Example 7 Cyclohexane 400g, 1,3-butadiene monomer 70g, styrene monomer 30g, n-butyllithium 0.03g and tetrahydrofuran 0.9g
were simultaneously added to the autoclave and polymerized at 40°C for 2 hours. The obtained polymer is a completely random copolymer of butadiene/styrene, with 1,2-butadiene units.
It had a vinyl bond content of 50% and a weight average molecular weight of 200,000. Reference example 8 400g of cyclohexane in an autoclave,
15g of styrene monomer and 0.11g of n-butyllithium
g was added, polymerized at 60℃ for 3 hours, and then 1,3-
70g of butadiene monomer was added and polymerized at 60°C for 3 hours. Finally, add 15g of styrene monomer,
Polymerized at 60℃ for 3 hours, bound styrene content 30%,
Styrene with a blocked styrene content of 29.5%, a 1,2-vinyl bond content of butadiene units of 13% (9% in terms of total polymer), and a weight average molecular weight of approximately 60,000.
A butadiene-styrene type block copolymer was obtained. Reference Example 9 In Reference Example 8, except that 35 times the molar amount of tetrahydrofuran was added to n-butyllithium, the same method was used to prepare a compound with a bound styrene content of 30%, a blocked styrene content of 24%, and a butadiene unit of 1,
2-vinyl bond content 39% (23% based on total polymer)
A styrene-butadiene-styrene type block copolymer was synthesized. Reference example 10 2000g of cyclohexane in an autoclave,
Add 65 g of 1,3-butadiene monomer, 0.75 g of n-butyllithium, and tetrahydrofuran at a molar ratio of n-BuLi/THF = 1/40, and heat at 70°C.
Polymerize for 45 minutes, then add 100g of styrene monomer
for 30 minutes, then butadiene monomer 235
g for 75 minutes, and finally styrene monomer.
100 g was added and polymerized for 30 minutes to synthesize a butadiene-styrene-butadiene-styrene type block copolymer. This product contains 40% bound styrene, 33% blocked styrene, and 1,2-butadiene units.
It was a block copolymer with a vinyl bond content of 35% (30% in terms of total polymer) and a weight average molecular weight of about 60,000. Examples 1 to 4 1-hexene and cyclohexene were diluted with cyclohexane, adjusted to a concentration of 15%, and subjected to hydrogenation reaction. 1000 g of the above olefin compound solution was charged into a sufficiently dried autoclave with a capacity of 2 and equipped with a stirrer, degassed under reduced pressure, replaced with hydrogen, and maintained at 60° C. with stirring. Next, 100 ml of a cyclohexane solution containing 4 mmol each of the compounds obtained in Examples 1 to 4 as the catalyst component (A) and cyclohexane containing 8 mmol of n-butyllithium (manufactured by Honjo Chemical Co., Ltd.) as the catalyst component (B) were added. The entire amount of the catalyst solution (Li/Ti molar ratio = 2) mixed with 20 ml of solution at 0°C under a hydrogen pressure of 2.0 Kg/cm ² was charged into an autoclave, and 5.0 Kg/cm ² of dry gaseous hydrogen was supplied. The hydrogenation reaction was carried out under stirring for 2 hours. After the reaction solution was returned to normal temperature and pressure, the hydrogenation rate was determined by gas chromatography analysis. The results of hydrogenation of 1-hexene and cyclohexene using each hydrogenation catalyst are summarized in a table. As shown in the table, no matter which hydrogenation catalyst was used, the olefinic unsaturated double bonds were hydrogenated almost quantitatively, showing extremely good hydrogenation activity.

[Table] Examples 5 to 10 The various polymers obtained in Reference Examples 5 to 10 were diluted with purified and dried cyclohexane, adjusted to a polymer concentration of 5% by weight, and subjected to a hydrogenation reaction. 1000 g of the above various polymer solutions were charged into a sufficiently dried autoclave with a capacity of 2 and equipped with a stirrer, and after degassing under reduced pressure, the autoclave was replaced with hydrogen and maintained at 90° C. with stirring. Next, 50 ml of a cyclohexane solution containing 0.2 mmol of the catalyst component (A) obtained in Reference Example 2 and 10 ml of a cyclohexane solution containing 0.8 mmol of n-butyllithium as the catalyst component (B) were heated at 0°C with 2.0 Kg/cm ² of hydrogen. The entire amount of the catalyst solution (Li/Ti molar ratio = 4) mixed under pressure was placed in an autoclave, and 5.0 kg/cm ² of dry gaseous hydrogen was supplied to carry out a hydrogenation reaction for 2 hours with stirring. The reaction solution was returned to room temperature and pressure, taken out from the autoclave, and a large amount of methanol was added to precipitate the polymer, which was dried separately to obtain a white hydrogenated polymer. The hydrogenation rate of the obtained hydrogenated polymer was determined from the infrared absorption spectrum (details on how to determine the hydrogenation rate can be found in Japanese Patent Application No. 58-6718, Japanese Patent Application No. 186983, Japanese Patent Application No.
59-76614) shown in the table.

[Table] Example The butadiene-styrene-butadiene-styrene block copolymer synthesized in Reference Example 10 was diluted to 5% by weight with purified and dried cyclohexane.
1000 g of this solution was charged into an autoclave and hydrogenated in the same manner as in Example 5 under various conditions shown in the table. The results are shown in the table. In addition, a comparative example was prepared by carrying out a hydrogenation reaction under the same conditions shown in the table except that n-butyllithium as the catalyst component (B) was not used and only the catalyst component (A) was used as the hydrogenation catalyst.

【table】

Claims (1)

[Claims] 1. A method of hydrogenating an olefinic unsaturated double bond-containing compound in an inert organic solvent, comprising: (A) a titanocene diaryl compound represented by (a) below; (However, R ₁ to _{R 6} are hydrogen or carbon atoms 1 to 4.
represents an alkyl hydrocarbon group, R ₁ to _{R 3} and
One or more of R ₄ to _{R 6} is hydrogen. ) and (B) General formula R-Li (wherein R has 1 to 1 carbon atoms)
Six alkyl groups are shown. 1. A method for hydrogenating olefins, which comprises hydrogenating an olefinic unsaturated double bond in the compound by contacting it with hydrogen in the presence of a catalyst comprising at least one of the alkyllithium compounds represented by the formula.