JPS635402B2 - - Google Patents

Description

[Detailed description of the invention]

[Prior Art] In polymers obtained by polymerizing or copolymerizing conjugated dienes, unsaturated double bonds are advantageously used for vulcanization, etc., but on the other hand, such double bonds have poor weather resistance, heat resistance,
It has the disadvantage of poor stability such as oxidation resistance. These drawbacks are significantly improved by hydrogenating the polymer. However, when hydrogenating a polymer, it is difficult to hydrogenate due to the effects of the viscosity of the reaction system, steric hindrance of the polymer, etc., and a large amount of catalyst is required and the hydrogenation reaction needs to be carried out at high temperature and high pressure. Further, 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 the polymer economically, it is necessary to use an amount that does not require deashing,
At present, there is a strong desire to develop a highly active hydrogenation catalyst that can selectively hydrogenate olefinic unsaturated double bonds under mild conditions. [Problems to be solved by the present invention] The present invention selectively hydrogenates the olefinic unsaturated double bonds of a polymer obtained by polymerizing or copolymerizing a conjugated diene in a small amount and under mild conditions. The problems to be solved are to discover a highly active hydrogenation catalyst that can do this, and to find a way to obtain hydrogenated polymers with excellent stability such as weather resistance, heat resistance, and oxidation resistance. It is something. [Means and effects for solving the problems] The present invention provides a hydrogenation catalyst comprising a titanocene diaryl compound and an alkyl lithium for the hydrogenation of a living polymer containing an olefinic unsaturated group obtained by using an alkyl lithium as a polymerization catalyst. The surprising fact is that when used, it shows extremely high hydrogenation activity and can selectively hydrogenate unsaturated double bonds in the living polymer under mild conditions and in an amount used that does not require deashing. It was based on. That is, the present invention provides a method for hydrogenating a living polymer in an inert organic solvent, in which (A) a conjugated diene is polymerized using an organolithium as a polymerization catalyst, or a conjugated diene and a monomer copolymerizable with the conjugated diene are copolymerized. The living polymer obtained by polymerization is combined with (B) at least one titanocene diaryl compound shown in (a) below. (However, R ₁ to _{R 6} are hydrogen or have 1 to 1 carbon atoms.
4, and one or more of R ₁ to R ₃ and R ₄ to _{R 6} is hydrogen. ) and (C) General formula R-Li (wherein R has 1 carbon atom
~6 alkyl groups are shown. ) in contact with hydrogen in the presence of a hydrogenation catalyst consisting of at least one alkyllithium compound represented by
The present invention relates to a method for catalytic hydrogenation of living polymers, which comprises selectively hydrogenating unsaturated double bonds of conjugated diene units in the living polymers. It is already known that the titanocene diaryl compound represented by the general formula (a) according to the present invention can be handled stably in air at room temperature and is easily isolated (for example, L. Summers et al., J. Am.Chem.Soc., No.
Volume 77, page 3604 (1955), MDRausch et al., J.
Organometall Chem., Vol. 10, p. 127 (1967)
etc). 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 have conducted intensive studies on a method for efficiently and economically hydrogenating living polymers containing olefinic unsaturated groups using this earlier application's olefin hydrogenation catalyst system. 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 (B) 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
-cyclopentadienyl) 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. The storage stability of a compound with a larger number of carbon atoms in the alkyl carbon group decreases, while the solubility in certain types of organic solvents becomes better. most preferred is enyl) titanium. On the other hand, as the catalyst component (C), an organometallic compound capable of reducing the titanocene diaryl compound of the catalyst component (B), such as an organolithium compound, an organoaluminum compound, an organozinc compound, an organomagnesium compound, etc., may be used singly or together. Living polymers can be hydrogenated by using them in combination with . However, it expresses high activity,
In order to selectively hydrogenate olefinically unsaturated double bonds in living polymers, the use of organolithium 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 alkyllithium compound, and surprisingly, the olefinic properties in the living polymer can be reduced by adding a small amount of catalyst and under mild conditions. It is possible to hydrogenate unsaturated double bonds almost quantitatively and preferentially. As such catalyst component (C), an alkyllithium compound represented by the general formula R--Li (where R represents an alkyl group having 1 to 6 carbon atoms) is preferably used, and specific examples include Methyllithium, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec
-butyllithium, isobutyllithium, n-pentyllithium, n-hexyllithium, etc. These may be used in combination of two or more types, or may be a mutual complex of two or more types. n-butyllithium is most preferred since it exhibits the highest hydrogenation activity and selectively hydrogenates olefinic unsaturated double bonds in the living polymer. Although the present invention can be applied to all hydrocarbon living polymers polymerized with organolithium and having unsaturated double bonds in the polymer, a preferred embodiment is a conjugated diene obtained by polymerizing or copolymerizing a conjugated diene. It is a diene living polymer.
Such conjugated diene living polymers include living copolymers obtained by copolymerizing a conjugated diene homopolymer and a conjugated diene with each other or with at least one conjugated diene and at least one olefin monomer capable of living copolymerization with the conjugated diene. Included. As the polymerization catalyst used in the production of such conjugated diene living polymers, hydrocarbons having at least one lithium atom bonded in the molecule are used, such as n-propyllithium, isopropyllithium, n-butyllithium, sec- Monolithium such as butyllithium, tert-butyllithium, n-pentyllithium, benzyllithium, etc., or 1,4-dilithio-n-butane,
1,5-dilithiopentane, 1,2-dilithiodiphenylethane, 1,4-dilithio-1,1,
4,4-tetraphenylbutane, 1,3- or 1,4-bis(1-lithio-1,3-dimethylpentyl)benzene, 1,3- or 1,4-bis(1-lithio-3- Dilithium such as methylpentyl)benzene is preferably used, and the polymerization catalyst may be a lithium oligomer or an α,ω-dilithium oligomer obtained using these organic lithium. Particularly common examples include n-butyllithium, sec-butyllithium, and the like.
These organolithiums may be used alone or in combination of two or more, and may be used not only once during polymerization, but also in combinations of two or more types.
It may be added in two or more portions during the polymerization. The amount of organic lithium to be used is selected as appropriate depending on the molecular weight of the desired polymer, but is generally 0.005 to 5 mol% based on the total amount of monomers used.
It is. Conjugated dienes used in the production of the conjugated diene living polymers to be subjected to hydrogenation of the present invention generally include conjugated dienes having from 4 to about 12 carbon atoms, and specific examples include 1, 3-butadiene, isoprene, 2,3-dimethyl-1,
Examples include 3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, etc. It will be done. From the viewpoint of obtaining an elastomer that can be industrially advantageously developed and has excellent physical properties, 1,3-butadiene and isoprene are particularly preferred, and elastomers such as butadiene living polymer, isoprene living polymer, and butadiene/isoprene living copolymer are used in the present invention. Particularly preferred for implementation. On the other hand, the method of the present invention is particularly suitably used for hydrogenating a living copolymer obtained by copolymerizing at least one conjugated diene and at least one monomer copolymerizable with the conjugated diene. Suitable conjugated dienes used in the production of such living copolymers include the conjugated dienes described above, and one monomer includes all monomers that can be living copolymerized with the conjugated diene, especially vinyl-substituted aromatic carbonized Hydrogen is preferred. In other words, 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 thermoplastic elastomers, it is necessary to Of particular interest are living copolymers with vinyl-substituted aromatic hydrocarbons. Specific examples of vinyl-substituted aromatic hydrocarbons used in the production of such living copolymers include styrene, t-butylstyrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, Examples include enylethylene, vinylnaphthalene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, and styrene is particularly preferred. As specific examples of living copolymers, butadiene/styrene living copolymers, isoprene/styrene living copolymers, etc. are the most preferred since they provide hydrogenated copolymers with high industrial value. In such a living copolymer, the vinyl-substituted aromatic hydrocarbon content is preferably 5% to 95% by weight; outside this range, it becomes difficult to obtain the characteristics of a thermoplastic elastomer. Living copolymers according to the method of the invention include random copolymers, tapering block copolymers, fully block copolymers, and graft copolymers in which the monomers are statistically distributed throughout the polymer chain. Living block copolymers having at least one conjugated diene polymer block and at least one vinyl-substituted aromatic hydrocarbon polymer block are particularly important for obtaining industrially useful thermoplastic elastomers. A preferred embodiment of the hydrogenation reaction of the present invention is carried out in a solution in which a living polymer is dissolved in an inert organic solvent, and more preferably in a living polymer solution obtained by polymerizing a conjugated diene or the like in an inert solvent. The hydrogenation reaction is carried out continuously as it is. "Inert organic solvent" means a solvent that does not react with any participant in the polymerization or hydrogenation reaction. Suitable solvents include, for example, n-pentane,
These include aliphatic hydrocarbons such as n-hexane, n-heptane and n-octane, alicyclic hydrocarbons such as cyclohexane and cycloheptane, and ethers such as diethyl ether and tetrahydrofuran, singly or in mixtures. 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 living polymer concentration relative to the solvent is 1 to 50% by weight, preferably 3 to 50% by weight.
It is necessary that the living polymer subjected to the hydrogenation reaction is not completely deactivated by moisture or impurities in the solvent and retains lithium. In the hydrogenation reaction of the present invention, a living polymer 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 gas is introduced. This is carried out by applying pressure to a predetermined pressure. Inert atmospheres include, for example, helium, neon,
This means an atmosphere that does not react with any participating bodies in the hydrogenation reaction, such as argon. Air and oxygen are not preferred because they oxidize or decompose the hydrogenation catalyst, leading to deactivation of the catalyst. On the other hand, the catalyst is prepared by combining the catalyst component (B) and the catalyst component in advance.
It is preferable to use a mixture with (C) because it has high activity. The hydrogenation reaction can be carried out by adding either the catalyst component (B) or the catalyst component (C) separately to the living polymer first, but in order to obtain high activity, it is recommended to use them mixed in advance. is preferred. It is necessary to handle the catalyst component (C) under the above-mentioned inert atmosphere. Although the catalyst component (B) 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 (B) and catalyst component (C) 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. When the catalyst components are added in advance, the mixing ratio of each catalyst component to achieve high hydrogenation activity and hydrogenation selectivity is determined by the number of lithium moles in the catalyst component (C),
The ratio of catalyst component (B) to the number of moles of titanium (below
Li/Ti molar ratio) is approximately 20 or less. Li/
Quantitative hydrogenation reaction can be carried out even when the Ti molar ratio is 0, but it requires higher temperature and higher pressure conditions.
Furthermore, if the Li/Ti molar ratio exceeds 20, it is not only uneconomical due to excessive use of an expensive catalyst component (C) that does not contribute to substantial activity improvement, but also undesirable as it tends to invite unnecessary side reactions. . Li／Ti
A molar ratio in the range of 0.5 to 10 is most suitable for significantly improving hydrogenation activity. In addition, in the hydrogenation reaction of the living polymer according to the present invention, since reducing lithium is also present in the living polymer, the catalyst component (C) during the hydrogenation reaction is
The ratio of the total lithium amount, which is the sum of the lithium amount in the living polymer and the lithium amount in the living polymer, to the titanium of the catalyst component (B) affects the hydrogenation activity. In order to achieve high hydrogenation activity and high hydrogenation selectivity for unsaturated double bonds in conjugated diene units, the ratio between the total number of lithium moles in the hydrogenation reaction system and the number of moles of titanium in the catalyst component (B) must be adjusted. The ratio (hereinafter referred to as total Li/Ti molar ratio) is approximately
It ranges from 0.5 to 25. Furthermore, total Li/Ti molar ratio =
The range of 1 to 15 is optimal because it significantly improves hydrogenation activity. The amount of lithium in the living polymer varies depending on the molecular weight of the living polymer, the functional number of the organolithium used as a polymerization catalyst, and the deactivation rate of the living. Part of the polymer is water or alcohol,
This is carried out by adjusting the total lithium concentration by deactivating it with a halogen compound or the like or adding organic lithium as a catalyst component (C) to the living polymer in advance. On the other hand, the amount of hydrogenation catalyst added is
A range of 0.005 to 20 mmol per 100 g is preferred. Within this addition amount range, it is possible to preferentially hydrogenate the unsaturated double bonds of the conjugated diene units of the living polymer, and hydrogenation of the aromatic nucleus double bonds does not substantially occur, so the hydrogenation rate is extremely high. Hydrogenation selectivity is achieved. Hydrogenation of the living polymer is possible even when added in an amount exceeding 20 mmol, and this does not limit its use, but even if added in an amount exceeding 20 mmol, the hydrogenation effect does not substantially change; On the other hand, using more catalyst than necessary is not only uneconomical, but also causes disadvantages such as complicating the process because it requires deashing and removal of the catalyst after the hydrogenation reaction. Further, if it is less than 0.005 mmol, the catalyst is likely to be deactivated due to impurities, etc., making it difficult to proceed with quantitative hydrogenation. A more preferable amount of hydrogenation catalyst added is in the range of 0.05 to 5 mmol per 100 g of living polymer. The hydrogenation reaction of the present invention is carried out using elemental hydrogen, more preferably introduced in gaseous form into the living polymer solution. More preferably, the hydrogenation reaction is carried out under stirring, so that the introduced hydrogen can be brought into contact with the polymer quickly enough. The hydrogenation reaction is generally carried out at a temperature range of 0°C to 150°C.
If it is below 0°C, the activity of the catalyst decreases and the hydrogenation rate becomes slow, requiring a large amount of catalyst, which is not economical, and the hydrogenated polymer tends to become insolubilized and precipitate. On the other hand, temperatures exceeding 150°C are undesirable because they cause deactivation of the catalyst, tend to cause decomposition and gelation of the polymer, and also cause hydrogenation of the aromatic nucleus to occur, resulting in a decrease in hydrogenation selectivity. . More preferably, the temperature is in the range of 20 to 120°C. Although the pressure of hydrogen used in the hydrogenation reaction is not particularly limited, it is preferably 1 to 100 kg/cm ² .
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. A more preferable hydrogenation pressure is 2 to 30 Kg/ ^cm2 ,
The optimum hydrogen pressure is selected in correlation with hydrogenation conditions such as the amount of catalyst added, and it is preferable to select a higher hydrogen pressure as the amount of hydrogenation catalyst becomes smaller. 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. The hydrogenation reaction of the present invention may be carried out in any manner such as batchwise or continuous. The progress of the hydrogenation reaction can be monitored by tracking the amount of hydrogen absorbed. By the method of the present invention, the unsaturated double bonds in the conjugated diene units of the polymer are 50% or more, preferably 90% or more.
% or more hydrogenated polymer can be obtained. More preferably, when a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon is hydrogenated, the hydrogenation rate of the unsaturated double bond of the conjugated diene unit is
A selectively hydrogenated hydrogenated copolymer can be obtained in which the hydrogenation rate of the aromatic nucleus portion is 50% or more, preferably 90% or more, and 10% or less. If the hydrogenation rate of the conjugated diene unit is less than 50%, the effect of improving weather resistance, oxidation resistance, and heat resistance will not be sufficient. In addition, in the case of a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon, no remarkable effect of improving physical properties is observed even if the aromatic nucleus moiety is hydrogenated, and especially in the case of a block copolymer, the originally excellent processability is not observed. , moldability deteriorates.
Furthermore, hydrogenation of the aromatic nucleus portion consumes a large amount of hydrogen and requires a hydrogenation reaction at high temperature, high pressure, and for a long time, making it difficult to carry out economically. The polymer hydrogenation catalyst according to the present invention has extremely excellent selectivity, and the aromatic nucleus portion is not substantially hydrogenated, so that it is extremely advantageous industrially. If necessary, catalyst residues can be removed from the polymer solution subjected to the hydrogenation reaction by the method of the present invention, and the hydrogenated polymer can be easily isolated from the 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, or a method in which the reaction solution is poured into boiling water with stirring and then distilled and recovered together with the solvent. This can be carried out by a method of 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 most of the catalyst decomposes and decomposes during the isolation process of the hydrogenated polymer.
Since the catalyst is removed and removed from the polymer, no special operations are required to deash or remove the catalyst, and it can be carried out in an extremely simple process. [Effects of the Invention] As described above, according to the present invention, it is possible to hydrogenate a conjugated diene polymer under mild conditions using a highly active catalyst, and in particular to hydrogenate a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon. It has become possible to hydrogenate unsaturated double bonds in diene units extremely selectively. Furthermore, in the method of the present invention, since a living polymer is used as a raw material, hydrogenation can be carried out continuously in the same reactor following polymerization, and even a small amount of addition shows extremely high activity. It is extremely useful industrially because it can be carried out efficiently in an economical and simple process, such as not requiring deashing of the post-catalyst. In addition, the hydrogenated polymer obtained by the method of the present invention can be used as an elastomer, thermoplastic elastomer, or thermoplastic resin with excellent weather resistance and oxidation resistance, and can also be used as an additive for ultraviolet absorbers, oils, fillers, etc. It is used by adding or blending with other elastomers and 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. Synthesis examples of each hydrogenation catalyst and each living polymer used in the examples are shown in the following reference examples. 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.
300ml ether, 157g (1 mole) bromobenzene
A small amount of the solution was added dropwise at room temperature, and then the entire amount of the bromobenzene ether solution was gradually added under reflux. After the reaction was completed, the reaction solution was filtered 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 ether solution of phenyllithium was added dropwise over about 2 hours while stirring at room temperature. The reaction mixture was separated in the air, the insoluble portion was washed with dichloromethane, the liquid and the washing liquid 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. The obtained crystals were separated, the liquid was concentrated again, and the above operation was repeated to obtain diphenylbis(η-cyclopentadienyl)titanium. The yield was 120g (90% yield). The obtained crystals are orange-yellow needle-shaped, have good solubility in toluene and cyclohexane, have a melting point of 147°C, and have an elemental analysis value of C,
79.5; H, 6.1; Ti, 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 cyclohexane, 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 of 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 the mixture was polymerized at 60° C. for 3 hours with stirring to synthesize living polybutadiene. The living polybutadiene obtained is 100g of polymer.
It contained 0.67 mmol of living lithium per polybutadiene, and when a portion was isolated and analyzed, it was found to be living polybutadiene containing 13% of 1,2-vinyl bonds and having a number average molecular weight of about 150,000 as measured by GPC. 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, and it had 0.66 mmol of living lithium per 100 g of living polymer, 10% of 1,2-vinyl bonds, and a number average Living polyisoprene with a molecular weight of approximately 150,000 was obtained. 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 resulting polymer is a completely random living copolymer of butadiene/styrene, with polymer 100
with 0.48 mmol living lithium per g;
1,2-vinyl bond content of butadiene unit 50
% and a number average molecular weight of 200,000. Reference example 8 400 g of cyclohexane, 15 g of styrene monomer and 0.11 g of n-butyllithium in an autoclave
was added and polymerized at 60°C for 3 hours, then 70g of 1,3-butadiene monomer was added and polymerized at 60°C for 3 hours. Finally, add 15g of styrene monomer and
Polymerization was carried out at ℃ for 3 hours, and the content of bound styrene was 30%, the content of blocked styrene was 29.5%, and the content of 1,2-vinyl bonds in butadiene units was 13% (calculated as 9% in terms of total polymer).
A styrene-butadiene-styrene type living block copolymer having a number average molecular weight of about 60,000 (%) was obtained. The living lithium in this polymer is
The amount was 1.65 mmol/100 g of polymer. Reference Example 9 Polymerization was carried out in exactly the same manner as in Reference Example 5, except that 35 times the mole of tetrahydrofuran was added to n-butyllithium, and the bound styrene content was 30%.
A styrene-butadiene-styrene type living block polymer was synthesized, which contained 25% blocked styrene, 38% 1,2-vinyl bonds in butadiene units, and had a number average molecular weight of about 60,000. The living lithium content in this polymer was 1.65 mmol/100 g of polymer. Reference example 10 400g of cyclohexane in an autoclave, 1,
13 g of 3-butadiene monomer, 0.15 g of n-butyllithium and tetrahydrofuran in a molar ratio of n
- BuLi/THF = 1/40 ratio, 45 at 70℃
Partially polymerize, then add 20g of styrene monomer.
30 minutes, then 47 g of 1,3-butadiene monomer for 75 minutes, and finally 20 g of styrene monomer.
was added and polymerized for 30 minutes to synthesize a butadiene-styrene-butadiene-styrene type living block polymer. This product contains 40% bound styrene, 33% blocked styrene, and 1,2-butadiene units.
It had a vinyl bond content of 35% (30% based on total polymer), a number average molecular weight of about 60,000, and a living lithium content of 1.65 mmol per 100 g of living polymer. Examples 1 to 4 The living polymer solution obtained in Reference Example 8 was diluted with purified and dried cyclohexane, the living polymer concentration was adjusted to 10% by weight, and the solution was subjected to a hydrogenation reaction. 1000 g of the above living polymer solution was 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 60° C. with stirring. Next, 100 ml of a cyclohexane solution containing 0.8 mmol of each of the compounds obtained in Reference Examples 1 to 4 as the catalyst component (B), and a cyclohexane solution containing 0.16 mmol of n-butyllithium (manufactured by Honjo Chemical Co., Ltd.) as the catalyst component (C). 20 ml of the catalyst solution was mixed for about 15 minutes at 0°C in a hydrogen atmosphere of 2.0 Kg/cm ² , then the entire amount of the catalyst solution was charged into an autoclave, 8.0 Kg/cm ² of dry gaseous hydrogen was supplied, and water was mixed for 1 hour with stirring. An addition reaction was performed. The reaction solution was returned to normal temperature and pressure, taken out from the autoclave, poured into a large amount of methanol to precipitate the polymer, and dried separately to obtain a white hydrogenated polymer. The hydrogenation rate of the obtained hydrogenated polymer was determined from the infrared spectrum (details on how to determine the hydrogenation rate are given in the patent application published in 1983).
6718) shown in the table. Examples 5 to 9 Water was prepared in exactly the same manner as in Example 1, except that the living polymers of Reference Examples 5, 6, 7, 9, and 10 were used, and the compound obtained in Reference Example 2 was used as the catalyst component (B). An addition reaction was carried out. The results are shown in the table.

[Table] Examples 10 to 16 When premixing catalyst components (B) and (C), the amount of n-butyllithium was set to the n-BuLi/Ti molar ratio shown in the table, and Except for adding methanol or n-butyllithium in an amount to deactivate a portion of the living lithium in the reactor in advance to achieve the total Li/Ti molar ratio shown in the table during the addition reaction, the results are as follows. The hydrogenation reaction was carried out in exactly the same manner as in Example 2. The results are shown in the table. Examples 17 to 25 Using the living polymer obtained in Reference Example 8, the hydrogenation catalyst component (B) obtained in Reference Example 2, and n-butyllithium, Example 10 was carried out under the conditions shown in the table. The hydrogenation reaction was carried out in the same manner as in ~16. The results are shown in the table.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A method of hydrogenating a living polymer containing an olefinic unsaturated group in an inert organic solvent, wherein (A) a conjugated diene can be polymerized or copolymerized with a conjugated diene using an organolithium as a polymerization catalyst. (B) at least one titanocene diaryl compound shown in (a) below. (However, R ₁ to _{R 6} are hydrogen or have 1 to 1 carbon atoms.
4, and one or more of R ₁ to R ₃ and R ₄ to _{R 6} is hydrogen. ) and (C) General formula R-Li (wherein R has 1 carbon atom
~6 alkyl groups are shown. ) The unsaturated double bonds of the conjugated diene units in the living polymer are selectively hydrogenated by contacting with hydrogen in the presence of a catalyst comprising at least one alkyllithium compound represented by Hydrogenation method for living polymers.