JPS6079005A - Hydrogenation of living polymer - Google Patents

Abstract

PURPOSE:To hydrogenate a living polymer effectively and economically, by contacting a specified living polymer with hydrogen in the presence of bis(cyclopentadienyl)titanium compound. CONSTITUTION:A living polymer obtained by polymerizing a conjugated diene or copolymerizing a conjugated diene with a monomer copolymerizable therewith by using an organolithium as a polymerization catalyst is contacted with hydrogen in the presence of a hydrogenation catalyst comprising at least one bis(cyclopentadienyl)titanium compound of the formula (wherein R and R' are each 1-8C alkyl or the like) to effect selective hydrogenation of the unsaturated double bonds in the conjugated diene unis of the living polymer. The hydrogenation is carried out preferably by using a solution of the living polymer in an inert organic solvent, and more desirably, the hydrogenation is carried out consecutively by directly using a living polymer solution obtained by polymerizing a conjugated diene or the like in an inert solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalytic hydrogenation method for imparting weather resistance, oxidation resistance, heat resistance, etc. to a polymer made of a conjugated diene, and more specifically to a catalytic hydrogenation method for imparting weather resistance, oxidation resistance, heat resistance, etc. to a polymer made of a conjugated diene. This invention relates to a novel method for preferentially hydrogenating unsaturated double bonds in conjugated diene units of a living polymer under mild hydrogenation conditions in the presence of a specific titanium compound.

The term "living polymer" used in the present invention refers to both conjugated diene homopolymers and copolymers obtained using organolithium as a polymerization catalyst17, and has lithium at the end of the polymer, and the ability to grow by polymerizing 1,000 polymers. means a polymer having Specifically, a single conjugated diene polymer, a random and/or blocked copolymer of one or more conjugated dienes, and at least /11 conjugated dienes and other monomers capable of living copolymerization with at least one conjugated diene. Random and/or block living copolymers with - are included.

Generally, polymers obtained by polymerizing or copolymerizing conjugated dienes are widely used industrially as elastomers. However, these polymers have residual unsaturated double bonds in their polymer chains, so while they are advantageously used for vulcanization, etc., these double bonds have the disadvantage of poor stability such as weather resistance and oxidation resistance. have. In particular, Plutz copolymers obtained from conjugated dienes and vinyl-substituted aromatic hydrocarbons can be used as thermoplastic elastomers, transparent impact-resistant resins, or as modifiers for styrenic and oleic resins without vulcanization. However, due to the unsaturated double bonds in the polymer chain, it has poor weather resistance, oxidation resistance, and ozone resistance, which is a problem in the field of exterior materials that require such performance, which limits its use.

These disadvantages of poor stability can be significantly improved by hydrogenating the polymer to eliminate unsaturated double bonds in the polymer chain. Many methods have been proposed for hydrogenating hydrocarbon polymers having unsaturated double bonds for this purpose.
Catalysts used in these polymer hydrogenation reactions include (1
) Supported heterogeneous catalysts in which metals such as nickel, platinum, palladium, and ruthenium are generally supported on a carrier such as carbon, silica, alumina, silica/alumina, and diatomaceous earth, and (2) nickel, cobalt, iron, chromium, etc. A so-called Ziegler-type homogeneous catalyst obtained by reacting an organic acid salt or acetylacetone salt with a reducing agent such as organoaluminum in a solvent is generally known.

The former supported type heterogeneous catalyst generally has lower activity than the Ziegler type homogeneous catalyst, and requires severe conditions of high temperature and high pressure in order to carry out the hydrogenation reaction. In addition, since the hydrogenation reaction progresses when the hydrogenated substance comes into contact with the catalyst,
When hydrogenating a polymer, compared to hydrogenating a low-molecular compound, it becomes difficult to contact the catalyst due to the effects of the viscosity of the reaction system, steric hindrance of the polymer chain, etc. Therefore, in order to efficiently hydrogenate polymers, a large amount of catalyst is required, which is uneconomical, and the hydrogenation reaction needs to be carried out at higher temperatures and pressures.
Polymer decomposition and gelation become more likely to occur, and energy costs also increase. Additionally, when hydrogenating a copolymer of a conjugated diene and a vinyl-substituted hydrocarbon, the aromatic nucleus is also usually hydrogenated, making it difficult to selectively hydrogenate only the unsaturated double bonds of the conjugated diene unit. .

On the other hand, the latter Ziegler-type homogeneous catalyst usually performs the hydrogenation reaction in a homogeneous system, so it generally has higher activity than supported-type heterogeneous catalysts, requires less catalyst, and can be used at lower temperatures and pressures. It has the characteristic of being capable of additive reactions. In addition, if hydrogenation conditions are selected, it is possible to hydrogenate the unsaturated double bonds of the conjugated diene units of a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon to a considerable degree preferentially. is also used. However, Ziegler-type homogeneous catalysts generally do not develop hydrogenation activity unless the catalyst components are mixed in advance and reduced before use, which is difficult and has poor reproducibility, and furthermore, the reduced catalyst itself has poor stability. To,
There is a problem in that it is necessary to adjust the catalyst immediately before each hydrogenation reaction. In addition, particularly when hydrogenating a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon, hydrogenation selectivity of the unsaturated double bond of the conjugated diene unit with respect to the aromatic nucleus moiety has not yet been sufficiently achieved. For example, under conditions that completely hydrogenate the unsaturated double bonds of a conjugated diene unit, it is inevitable that the aromatic nucleus will be hydrogenated to some extent, and conversely, under conditions that completely suppress the hydrogenation of the aromatic nucleus, The hydrogenation rate of unsaturated double bonds in conjugated diene units no longer increases. Therefore, there is currently a strong desire to develop a catalyst that selectively hydrogenates only the unsaturated double bonds of conjugated diene units.

Furthermore, the current Ziegler-type hydrogenation catalyst is expensive and requires a double deashing process to remove the catalyst residue after hydrogenation. A highly active hydrogenation catalyst that exhibits activity even when the amount of ash used is unnecessary.
Alternatively, there is a strong desire to develop a catalyst that can be extremely easily deashed.

In view of this situation, the present inventors investigated the amount of lead in a highly selective hydrogenation catalyst that hydrogenates only unsaturated double bonds in conjugated diene units for conjugated diene polymers or copolymers. A catalyst consisting of titanium dichloride (pentadienyl) and an alkyl lithium compound has extremely high activity against the polymer with good reproducibility even when used in small amounts, and is particularly effective in selecting hydrogenation of unsaturated double bonds in conjugated diene units. We have already applied for a patent (Patent @5r-bri No. 75).

The inventors of the present invention have conducted further intensive studies on a method for efficiently and economically hydrogenating polymers by further improving the activity of this prior application's polymer hydrogenation catalyst system. When the obtained or ping polymer is used as a polymerization catalyst, bis(cyclopentagenyl)titanium compound can be used alone without using a combination of a titanium compound and a reducing metal compound such as an alkyllithium compound as a hydrogenation catalyst. The present invention was completed based on the discovery that even when present in a small amount, the polymer exhibits extremely high hydrogenation activity and selectivity for hydrogenation of unsaturated double bonds in conjugated diene units.

That is, the present invention provides a method for hydrogenating a living polymer in an inert organic solvent, in which a conjugated diene is polymerized using a captive organolithium as a polymerization catalyst, or a conjugated diene and a heptamer copolymerizable with the conjugated diene are copolymerized. The living polymer obtained by polymerization is represented by the general formula ((4Hs)z T%'R (where R
, R' is a group selected from \R' alkyl group, allyl group, alkoxy group, allyloxy group, halogen group, and carbonyl group having 5 carbon atoms, and R and R' may be the same or different. . ) is brought into contact with hydrogen in the presence of a hydrogenation catalyst consisting of at least one bis(cyclopentagenyl) titanium compound represented by The present invention relates to a method for catalytic hydrogenation of a lipping polymer, which is characterized by hydrogenation.

The hydrogenation catalyst used in the present invention, which uses a bis(cyclopentagenyl) titanium compound in combination with a reducing organometallic compound, has hydrogenation activity toward unsaturated double bonds of low-molecular-weight organic compounds. Already known (e.g. WLF, 5loan et al., J. Am., Che.
Tn, Sat, , gs volume, 4! o) 41~qoi
tr page (/f A !r year), Y, TajimB
et al., J, org, Chew, Volume 33, 1/6g
9-/690 pages (lqbt year), etc.). However, these titanium compounds alone have no hydrogenation activity, and there are no examples of using living polymers as reducing organometallic compounds, and no prior art suggesting the use thereof has been disclosed at all.

However, the advantage of the polymer hydrogenation method of the present invention is that by using a living polymer having reducible lithium as the hydrogenated polymer, bis(cyclopentadienyl)
Hydrogenation activity is expressed and hydrogenation progresses simply by the presence of a small amount of a titanium compound alone; therefore, only a /m type catalyst component is required as a new catalyst component, and in combination with a reducing organic compound such as the aluminum alkyl mentioned above. It has higher activity than the systems used in other systems, has extremely high hydrogenation selectivity for unsaturated double bonds in conjugated diene units, and can be hydrogenated continuously without isolating the polymer after polymerization. 71 Tongue I To Ayu Navy No. 6 t＼η1 Thick Su 11 Sheep h People Ka →It is surprising that it has become possible to hydrogenate polymers efficiently and economically, as it can be used as a catalyst component. It is the right thing to do.

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 at least seven types of conjugated dienes, a conjugated diene, and at least 1 m of an onfin monomer capable of living copolymerization. be done.

As the polymerization catalyst used for producing such a conjugated diene living polymer, a hydrocarbon having at least seven lithium atoms bonded in the molecule is used, such as n-propyllithium, imp μpyllithium, n-butyllithium, n-butyllithium, etc. Organ-butyl lithium-t@r meeting-butyl +l +
h A n-pe・i 4- & II monolithium such as lithium, benzyl lithium, etc., or/, 41-
Dilithio-n-butane, l, s-dilithiopenkune, l
, 2-dilithiodiphenylethane% /l dilithio/, /, ? , diratetraphenylbutane, /, J- or /, F-bis(l-lithio-7,3-dimethylpentyl)benzene, 83- or /, 41-bis(/-lithio-3-methylpentyl)benzene Dilithium dilithium is preferably used, and the polymerization catalyst may be a lithium oligomer or α,ω-dilithium oligomer obtained using these organolithiums. Particularly common are
Examples include n-butyllithium and di-butyllithium. These organolithiums may be used in ls or as a mixture of one or more kinds, and may be added not only 7 times but also in - or more times during the polymerization. The amount of organolithium to be used is appropriately selected depending on the molecular weight of the desired polymer, but in general, a
θO3 to S morch.

Conjugated dienes used in the production of the conjugated diene living polymers subjected to hydrogenation of the present invention generally include conjugated dienes having from 1 to about 72 carbon atoms, and specific examples include 1. 3-butadiene, isoprene, 2
．． Examples include 3-dimethyl-3-butadiene, l,3-pentadiene, λ-methyl-3-pentadiene, 1f3-hexashev, 'I,g-diethyl-1,3-octadiene, 3-dimethyl-3-octadiene, and the like.

From the viewpoint of obtaining an elastomer that can be industrially advantageously developed and has excellent physical properties, /, 3-butadiene, and isoprene are particularly preferred, and elastomers such as butadiene living polymer, isoprene living polymer, and butadiene/isoprene living copolymer can be used in the present invention. Particularly preferred for implementation. In such a living polymer, there are no particular restrictions on the microstructure of the polymer chain, and any structure can be suitably used. However, if there are too few 8-1 vinyl bonds, the solubility of the polymer after hydrogenation will decrease, and the microstructure will not be uniformly hydrated. Since solvents are limited for carrying out the addition, a lipping polymer containing about 30 or more such bonds is more preferred.

On the other hand, the method of the present invention is particularly suitably used for hydrogenation of a living copolymer obtained by copolymerizing at least seven types of conjugated dienes and at least seven types of heptamers copolymerizable with the conjugated dienes. Suitable conjugated dienes used in the production of such living copolymers include the above-mentioned conjugated dienes, and examples of heptamers include all heptamers that can be living copolymerized with conjugated dienes, especially vinyl. Substituted aromatic hydrocarbons are 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 Living copoly-q- with vinyl-substituted aromatic hydrocarbon is special! : 31j It is essential. Specific examples of vinyl-substituted aromatic hydrocarbons used in the production of such living copolymers include styrene, t-butylstyrene,
α-methylstyrene, 0-methylstyrene, p-methylstyrene, divinylbenzene, /, l-diphenylethylene, vinylnaphthalene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-7mino Examples include ethylstyrene, 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, a vinyl-substituted aromatic hydrocarbon content of 5% to 1% by weight is preferred;
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, complete block copolymers, and graft copolymers in which the monomers are statistically distributed throughout the polymer chain. In order to obtain industrially useful thermoplastic elastomers, Living's rock polymers having at least one conjugated diene polymer block and at least one vinyl-substituted aromatic hydrocarbon polymer block are particularly important.

Among such living Boothk copolymers, a Boothk copolymer having a vinyl-substituted aromatic hydrocarbon polymer block content (a) of 70% by weight or more to 90% by weight based on the entire polymer is particularly preferred. When the weight is less than 70% or more than 90% by weight, it becomes difficult to obtain a thermoplastic elastomer or thermoplastic resin with good physical properties.

Vinyl-substituted aromatic hydrocarbon polymer block content (a
), L. M. Kolthoff et al., J-Poly
The content (a) is expressed as the content of ZP polymer in the total polymer.

In the living block copolymer, the conjugated diene polymer stock may contain a small amount of vinyl-substituted aromatic hydrocarbon, and the vinyl-substituted hydrocarbon polymer stock may contain a small amount of conjugated diene. good. In addition to linear living block copolymers, so-called branched, radial, or square-type boot block copolymers that are partially coupled with a coupling agent can also be used as long as living lithium remains in the polymer chain. Included.

Furthermore, the living block copolymer preferably used in the present invention has a conjugated diembutsulk microstructure of 30 to 70% by weight of 7,2-vinyl bonds and O to 30% of /, 41-bonds (cis bonds and trans bonds). Particularly preferred is weight. Poly 1-, which falls within this range, has good rubber elasticity after the hydrogenation reaction due to the olefin partial force τ, and is not only industrially useful, but also has good solubility in the solvent after the hydrogenation reaction and can be easily dissolved in solution. The viscosity is low, recovery of the hydrogenated polymer and solvent removal are easy, and the hydrogenated polymer can be produced economically.

The l of conjugated diene units in the polymer and the covinyl bond content (b) are calculated using the infrared absorption spectrum by the Hampton method (R, R, Hampton, Anal, Ch.
em, second? Vol. 9, p. 3 (79119)), the proportion of hecoffinyl bonds in the conjugated diene units was calculated and converted to the weight proportion in the total polymer. In the case of butadiene/styrene copolymer, the wavelengths used were cis-7, da(721m-1) of butadiene,
Trough; x, -i, xi (ri6ri m-1), /, 2
-vinyl (9/ /crn-') styrene (499mm
-'), which gives the concentration of each component.

The molecular weight of the living polymer used in the hydrogenation reaction of the present invention is not particularly limited, but it generally has a number average molecular weight of about /θ00 to about 1 million. It may be manufactured by a method.

In the hydrogenation reaction of the living polymer according to the present invention, R is a furkyl group having carbon atoms/-g, a 7lyl plate alkoxy group,
A group selected from an allyloxy group, a Hagun group, and a carbonyl group, and R and R' may be the same or different. )
It is at least one type of bis(cyclopentagenyl) titanium compound represented by: Specific examples of such titanium compounds include bis(cyclopentagenyl)
Titanium dimethyl, bis(cyclopentagenyl) titanium diethyl, bis(cyclopentagenyl titanium di-n-butyl, bis(cyclopentagenyl) titanium di-56C-7'thyl, bis(cyclopentagenyl) titanium jetoxide , bis(cyclopentagenyl) titanium jetoxide, bis(cyclopentagenyl) titanium jetoxide, bis(cyclopentagenyl) titanium diphenyl, bis(cyclopentagenyl) titanium diphenoxide, bis(cyclopentagenyl) ) titanium dib2mite, bis(cyclopentagenyl) titanium dichloride, bis(
cyclopentagenyl) titanium dicarbonyl, bis(cyclopentagenyl) titanium dicarbonyl, bis(cyclopentagenyl) titanium dicarbonyl,
Examples include bis(cyclopentagenyl) titanium chloride methyl, bis(cyclopentagenyl) titanium chloride ethoxide, bis(cyclopentagenyl) titanium chloride phenoxide, etc., which may be used independently or in combination with each other. It is possible to selectively hydrogenate the unsaturated double bonds of the conjugated diene units of the chilbing polymer. Among these titanium compounds, bis(cyclopentane Preferred examples include bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)titanium di-n-butyl, bis(cyclopentadienyl)titanium dichloride, and bis(cyclopentadienyl)titanium dicarbonyl.Such titanium compounds are In general, many of them are unstable and decompose with air, oxygen, light, and heat, and for industrial use, they must be handled in a cool, dark place under an inert atmosphere. ) Titanium diclide has high stability, excellent polymer hydrogenation activity and selectivity, and is most preferably used.

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 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 swelling hydrogens such as n-hexane, n-hebutane 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. The hydrogenation reaction of the present invention is carried out at a concentration of the living polymer relative to the solvent/-0% by weight, preferably u3 to 23% by weight, so that the living polymer to be subjected to the hydrogenation reaction is not completely deactivated by moisture or impurities in the solvent. , it is necessary to retain lithium.

The hydrogenation reaction of the present invention is generally carried out by maintaining the lubricating polymer solution at a predetermined temperature, adding a hydrogenation catalyst with or without stirring, and then introducing hydrogen gas to pressurize it to a predetermined pressure. It is carried out by The hydrogenation catalyst may be added to the living polymer solution as it is, or may be added as a solution in an inert organic solvent as described above. In order for the hydrogenation reaction to proceed uniformly and quickly, it is preferable to add it as a solution.

Furthermore, it is necessary to handle the hydrogenation catalyst under an inert atmosphere. An inert atmosphere means an atmosphere that does not react with any of the hydrogenation reactants, such as helium, neon, argon, and the like. Air and oxygen are not preferred because they oxidize or decompose the hydrogenation catalyst, leading to deactivation of the catalyst.

Furthermore, when adding the hydrogenation catalyst to the living polymer solution, it is a preferred embodiment to do so in a hydrogen atmosphere in order to maximize the hydrogenation activity and allow the hydrogenation reaction of the polymer to proceed quickly and uniformly.

On the other hand, the amount of the hydrogenation catalyst added is preferably in the range of 110 mmol aoo per 1001 of the lubricating polymer.

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 10 mmol or more is added, and its use is not limited, but the hydrogenation effect does not substantially change even when 10 mmol or more is added; Not only is the use of catalysts uneconomical, but
Deashing and removal under hydrogenation reaction conditions are required, resulting in disadvantages such as double-tracking of the process. Further, if the amount is less than 0,000 molar, the catalyst is likely to be deactivated due to impurities and the like, making it difficult to proceed with quantitative hydrogenation. A more preferable amount of hydrogenation catalyst added is θ0/~2 mmol per 7002 of the peeling polymer.

Furthermore, in the living polymer hydrogenation reaction according to the present invention, the ratio of lithium in the living polymer to titanium in the hydrogenation catalyst (hereinafter referred to as Li/Ti molar ratio) also influences the hydrogenation activity. The lithium content 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 polymer. Therefore, the Li/Ti molar ratio depends on the living polymer used in the hydrogenation reaction. Although it is uniquely determined depending on the properties and the amount of catalyst added, in order to realize high hydrogenation activity and high hydrogenation selectivity for unsaturated double bonds of conjugated diene units, the Li/T1 molar ratio = 0. A range of / to lθO is suitable. Furthermore, the range of Li/Ti molar ratio from λ to θ is most suitable because it significantly improves the hydrogenation activity. This Li
/Ti molar ratio, in some cases, a part of the peeling polymer may be deactivated with water, alcohol, or a halide, or organic lithium used as a polymerization catalyst may be added to the living polymer before hydrogenation. The lithium concentration in the living polymer solution may be adjusted by

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 -20°C to 100°C.

Below -20°C, the activity of the catalyst decreases and the hydrogenation rate slows down, requiring a large amount of catalyst, which is not economical.
Hydrogenated polymers tend to become insolubilized and precipitate.

On the other hand, temperatures above 100° C. are undesirable because the catalyst is deactivated, polymer decomposition and gelation are likely to occur, 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 20-0°C.

Although the pressure of hydrogen used in the hydrogenation reaction is not particularly limited, it is preferably l~/o kg/cd.

If it is less than 1 kgAr1, the hydrogenation rate slows down and practically reaches a plateau, making it difficult to increase the hydrogenation rate, / 0
If it is more than 0 kgAd, the hydrogenation reaction will almost complete at the same time as the pressure is increased, which is essentially meaningless, and unnecessary side reactions and gelation will be caused, which is not preferable. A more preferable hydrogenation pressure is Col 3
However, the optimum hydrogen pressure is selected in correlation with the hydrogenation conditions such as the amount of catalyst added, and in practice, as the amount of hydrogenation catalyst decreases, the hydrogen pressure should be selected on the high pressure side. preferable.

The hydrogenation reaction time of the present invention is usually several seconds to SO dark time. 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 by any method such as a batch method or a continuous method. The progress of the hydrogenation reaction can be monitored by tracking the amount of hydrogen absorbed.

By the method of the present invention, it is possible to obtain a hydrogenated polymer in which the unsaturated double bonds of the conjugated diene units of the polymer are hydrogenated by 30 or more, preferably by 90 or more. 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! It is possible to obtain a selectively hydrogenated hydrogenated copolymer in which the hydrogenation rate of the aromatic nucleus portion is 0% or more, preferably qotlr or more, and log or less. If the hydrogenation rate of the conjugated diene unit is less than 10%, the effects 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,
Even if the aromatic core portion is hydrogenated, no remarkable effect of improving physical properties is observed, and in the case of Plutz copolymers in particular, the originally excellent processability and moldability deteriorate. 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 for industry.

The hydrogenation rate of the polymer can be determined by measuring the ultraviolet absorption spectrum and infrared absorption spectrum when the polymer contains an aromatic nucleus moiety, or by measuring the infrared absorption spectrum when it does not contain an aromatic nucleus moiety. In other words, the hydrogenation rate of the aromatic nucleus part is calculated from the following formula by measuring the content of the aromatic nucleus part in the polymer from the absorption of the aromatic nucleus part in the ultraviolet absorption spectrum (for example, mμ in the case of styrene). Ru.

In addition, the hydrogenation rate of the conjugated diene unit can be determined from the infrared absorption spectrum using the Pantston method as described above. concentration ratio r
It is calculated from the aromatic nucleus content before and after hydrogenation determined by ultraviolet absorption spectrum.

Hydrogenation of Conjugated Diene Units in Polymers Catalyst residues are removed as necessary from the polymer solution subjected to the hydrogenation reaction by the method of the present invention, and the hydrogenated polymer is easily isolated from the solution. be able to. for example,
A method in which the polymer is precipitated and recovered by adding 77 tons or a polar solvent such as alcohol, which is a poor solvent for the hydrogenated polymer, to the reaction solution after hydrogenation, and the reaction solution is poured into a hot water with stirring, and then distilled together with the solvent. This can be carried out by a method of recovering, or 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 is separated and removed from the polymer during the isolation process of the hydrogenated polymer. Therefore, no special operations are required to deash or remove the catalyst, and it can be carried out with an extremely simple process.

As described above, according to the present invention, a conjugated diene polymer can be hydrogenated under mild conditions using a highly active catalyst, and in particular, unsaturated double bonds in a conjugated diene unit of a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon can be hydrogenated. It became possible to hydrogenate 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 only one type of catalyst component is required, and even a small amount can be added. It exhibits high activity and therefore does not require deashing of the catalyst after hydrogenation, making it possible to carry out the process efficiently in an economical and simple process, which is extremely useful industrially.

Furthermore, the hydrogenated polymer obtained by the method of the present invention is
It is used as an elastomer, thermoplastic elastomer, or thermoplastic resin with excellent weather resistance and snow resistance, and it can also be used with additives such as ultraviolet absorbers, oils, and fillers.
It is used in blends with other elastomers and resins and is extremely useful industrially.

The present invention will be specifically explained below with reference to Examples.

The present invention is not limited thereto).

Examples of decomposition of each living polymer used in the examples are shown in the following reference examples.

In the autoclave of Reference Example No. 21, cyclohexane 5Oly,t
, 3-Ptadi3-Mo/Ma1001Sn-Butyllithium 0039 was added, and polymerization was carried out at 60° C. for 3 hours with stirring to synthesize living polybutadiene. The living polybutadiene obtained had living lithium of 7 mmol QA per 100 g of polymer, and when a portion was isolated and analyzed, it contained 13% /, 2-vinyl bonds, and had a number average molecular weight of 7 mmol as determined by GPC. There was approximately 10,000 living polybutadiene.

Reference Example Polymerization was carried out in the same manner as in Reference Example 1, except that isopre/ was used instead of 3-butadiene, and a living polymer of 100
It has 0.44 mmol living lithium per g, /
A living polyisoprene having 2-vinyl bonds and a number average molecular weight of about 10,000 was obtained.

Reference Example 3 Living polygetadiene was synthesized by polymerizing in the same manner as in Reference Example 1, except that teF-trahydrofuran was further added by 40 times the mole of n-butyllithium. This product had 066 mmol of living lithium per 100 f of polymer, 1,2-vinyl bond tr3ts, and a number average molecular weight of about 1S million.

Reference example dacyclohexanda Oθf, /, 3-butadiene monomer toy, styrene monomer 3θt, n-dutyllithium QO3f and tetrahydrofuran a? t was simultaneously added to the autoclave and polymerized at 90°C for 2 hours.

The resulting polymer is a completely random living copolymer of butadiene/styrene, with alI per 1002 of the polymer.
It had living lithium of t mmol, a hecovinyl bond gold content of butadiene units of sO%, and a number average molecular weight of 0,000.

Reference Example S In an autoclave, cyclohexane yoot, styrene monomer/St and n-butyllithium 0. //? was added and polymerized at 60°C for 3 hours, and then 701 of 1,3-butadiene monomer was added and polymerized at 60°C for 3 hours. Finally, styrene monomer 1St was added and polymerized at 60°C for 3 hours to obtain bound styrene content, yo'4, pulsing styrene content of 2911 butadiene units, and covinyl bound gold content/3t (total polymer equivalent). A styrene-butadiene-styrene polymer copolymer having a number average molecular weight of about 60,000 was obtained. The adhesive lithium in this polymer is 16g! It was remol/polymer 100f.

Reference Example 6 The amount of styrene monomer is +Of (total got>, /,
A living block copolymer containing a high amount of styrene was synthesized in the same manner as in Reference Example S except that the amount of 3-butadiene monomer was 209. The obtained styrene-butadiene-styrene type living block copolymer has a bound styrene content g O% and a blocked styrene content ? , f
%, butadiene units/, covinyl bonded gold content lS ti (3 ti in terms of total polymer), number average molecular weight of about 60,000, living lithium it, s mmol/polymer lθ02
It was something that I had.

Reference Example In Reference Example S, polymerization was carried out in exactly the same manner except that 35 times the mole of tetrahydrofuran relative to n-butyllithium was added, and the content of bound styrene was 30%, the content of blocked styrene was 2A;%, and the butadiene unit was 2%. - A styrene-stadiene-styrene type submersible polymer having a vinyl bond content of 3g91r and a number average molecular weight of about 60,000 was synthesized. The living lithium content in this polymer is tt
z mmol/1009 polymer.

Reference Example G In a vessel-type reactor with a stirrer with volume/l and height/diameter = Hiro, cyclohexane was added as follows: /JθOt/'br, 1.3-butadiene monomer: l/θf/11r s n -butyllithium ( n-BuLi) 133 t/hr,
Tetrahuman P 757 (THF) [:n-BuLi/T
HF = 70 molar ratio] was continuously supplied from the bottom of the reactor, and styrene monomer 90 t/mole ratio was supplied from the top of the reactor.
The living polymer solution was continuously taken out from the reactor.

The obtained living copolymer has a butadiene-styrene structure, has a bound styrene content of 3θ, a blocked styrene content of 102%, and a butadiene unit/2-vinyl bound gold content of 410 mA (calculated as a total polymer, 2 t). %),
The number average molecular weight was approximately 1/2 million. This product contained θSS mmol of living lithium per 100 g of polymer.

Reference example t Cyclohexane 1100% in autoclave? ,/,3
-butadiene monomer 73r% n-butyl lithium airy and tetrahydrofuran in molar ratio n-B
uLi/THF was added at a ratio of 0, polymerized at 70°C, and then styrene monomer coat was added for 30
Then, 3-butadiene monomer 72 was added for 75 minutes, and finally styrene monomer, 10f, was added and mixed for 30 minutes.
A styrenic living block polymer was synthesized.

This material has a bound styrene content of q o elk, a block styrene content of 33 t, a butadiene unit of 1.2-vinyl bound gold content of 3 slrc, calculated as a total polymer of 30 q5, and a number average molecular weight of approximately 60,000, per living polymer/θo2. tb
It had z mmol of living lithium.

Reference Example/θ/, A styrene-isoprene-Styrene y-type living boot stick copolymer was synthesized in exactly the same manner as in Reference Example S, except that isoprene was used instead of 3-butadiene.

This product has living lithium of 16 S mmol per 100 g of living polymer, the bound styrene content is 30 grams, the grox styrene content is 10 grams, and the 4-co-vinyl bond content of isoprene units is 10 grams (total weight). The number average molecular weight was approximately 60,000 (Ls) in terms of coalescence.

Reference Example/1 74,703 moles of triethyl was added to a cyclohexane solution containing 03 moles of butyllithium, and the mixture was stirred at room temperature for 1 hour. Next, m-diisopropenylben 4 was added, and stirring was continued for a few hours at room temperature, and l,3-bis(/
A solution of -lithio-/,3-dimethylpentyl)benzene in cyclohexane was obtained. The purity of this dilithium was better than 9, and the active lithium concentration was 200 millimoles/f.

Cyclohexane poof, /, J in autoclave
-Butadiene monomer? Of and the dilithium catalyst solution synthesized above t. qot (as active lithium tO
mmol) and polymerized at 60°C for 3 hours. Next,
Styrene monomer 302 was added and polymerized at 60°C for 3 hours, resulting in a bonded styrene content of 30%, a Purtux styrene content of 9%, a getadiene unit of /,2, and a vinyl bond content of 2.
o9! A styrene-butadiene-styrene type silicone block polymer having a number average molecular weight of about 1,000 g was obtained. The living lithium in this polymer was so mmol/polymer lθθt.

Reference example/: 1 cyclohexane 4Ioor, i in autoclave
,,y-butadiene monomer 100? and reference examples//
A cyclohexane solution of /,3-bis(/-lithio-7,3-dimethylpentyl)benzene 2009 (θ mmol as active lithium) was added and heated at 60°C with stirring.
The mixture was polymerized for 3 hours to synthesize silicone polybutadiene. This material has a number average molecular weight of about too, 1, 33 covinyl bonds, and the living lithium corresponding to the polymer lθθ is 33. θ mmol.

Each living polymer solution obtained in Example/-/CoReference Example/and- was diluted with purified and dried toluene, and each living polymer solution obtained in Reference Examples 3 to 1 was diluted with purified and dried cyclohexane. It was diluted, adjusted to 1) Ping polymer concentration S and weight, and subjected to hydrogenation reaction.

100 of the above living polymer solution (living polymer amount so?) was charged into a sufficiently dried autoclave with a capacity of 1 liter and equipped with a stirrer, and after desilvering under reduced pressure, the mixture was replaced with hydrogen and stirred.
It was maintained at 10°C.

Then, as a hydrogenation catalyst, a toluene solution of bis(cyclopentagenyl)titanium dichlorite at a concentration of 10 mmol/100 was used. o. 1 (catalyst amount o.xos recell)
into the autoclave,! ;． Dry gaseous hydrogen of 1,000 kg/ctl was supplied, and the hydrogenation reaction was carried out for one hour with stirring. In all cases, hydrogen absorption was substantially completed within 30 minutes, and the reaction solution was a uniform low viscosity solution with a slightly black to grayish black color. 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. After being separated from the oven, it was dried to obtain a white hydrogen polymer. Table 1 summarizes the hydrogenation conditions, hydrogenation rate, and properties of the obtained hydrogenated polymer.

As shown in Table 1, the conjugated diene units of all polymers were quantitatively hydrogenated, and the styrene units were hardly hydrogenated, indicating extremely good activity and selectivity.

(Leaving space below) Examples 73 to 17 The styrene-butadiene-styrene type living copolymer synthesized in Reference Example 7 was diluted with purified and dried cyclohexane to make the polymer concentration 70% by weight, and the ping polymer solution tooot (polymer amount 100f) was dried. . 2
4. The system was purged with dry hydrogen gas and maintained at 0°C.

Next, a toluene solution of various titanium compounds shown in the table as a hydrogenation catalyst was added to the living polymer ioot so that the amount of hydrogenation catalyst was o, sos mol (
Living I, i/Ti molar ratio = 3.3), yo0Iai/
Dry hydrogen gas of cJi was supplied, and the hydrogenation reaction was carried out at 0° C. for 1 hour with stirring.

After hydrogenation, the polymer was treated in the same manner as in Example 1, and the properties of the hydrogenated polymer were examined.

On the other hand, as a comparative example, a hydrogenation reaction was carried out in the same manner using a titanium compound other than the bis(cyclopentagenyl)titanium compound. The results are shown in the table.

Example/It-12 The styrene-butadiene-styrene-producing Bingpuk polymer synthesized in Reference Example S was diluted with dry cyclohexane to a concentration of S% by weight, and hydrogenated in the same manner as in Example 1.

However, the amount of bis(cyclopentadienyl)titanium dichloride used as the hydrogenation catalyst is as shown in Table 3. The results are shown in Table 3.

Example 23-2g The butadiene-styrene-butadiene-styrene type living block polymer synthesized in Reference Example 9 was diluted with dry cyclohexane to a concentration of 10% by weight, and this living polymer solution (tooofc polymer (2 amounts of 10of)) was charged into a dry autoclave. , Hydrogenation was carried out in the same manner as in Example 1 under various conditions shown in Table D. The results are shown in Table 1.

A styrene-butadiene-styrene type submersible polymer was synthesized in exactly the same manner as in Reference Example S. When a part of this living polymer was taken out from the autoclave and analyzed, it was found that the amount of bound styrene was 4g, so %, the content of blocked styrene was 9%, and the butadiene unit was /,! -Vinyl bond/3 chains, number average molecular weight was approximately 60,000 ◎ After polymerization, the slipping polymer was placed in an autoclave at 60°C.
While stirring, a toluene solution of bis(Schiff-pentagenyl)titanium dichloride at a concentration of 1 mmol/10 mm was added as a hydrogenation catalyst (living L1/TI ratio 44 t, 1), and immediately YoOkg/
C1i dry hydrogen gas was supplied, and the hydrogenation reaction was carried out at 60° C. for 2 hours with stirring. Substantial hydrogen absorption was completed in about 73 minutes, and the reaction solution was a slightly grayish black homogeneous viscous solution. The solution was treated in the same manner as in Example 7 to obtain a hard thermoplastic elastomer-like polymer. When the hydrogenation rate was determined to be -, the hydrogenation rate of butadiene units was 99%, the hydrogenation rate of styrene units was less than 1 inch, and the hydrogenated polymer had a molecular weight of about 60,000. As shown in this example, even if continuous L di 1,1 mer hydrogenation was performed following J polymerization, the hydrogenation activity and hydrogenation selectivity of the butadiene unit did not change at all.

Example 30.

Synthesized in Reference Example S: Styrene-butadiene □ Styrene-type Subbing Polymer was diluted with dry cyclohexane to a concentration of 3 weight≦ or Polymer Solution T
oooy (polymer amount got >) was charged into a dry 21 autoclave, and the atmosphere was replaced with dry hydrogen gas.

To this was added a solution of benzyl coolide in cyclohexane with a concentration of 50 mmol/100 wt.
Stir for a minute, Living Lithium A4! o mmol/polymer 10Of pasting polymer obtained 0 Then Example 1? Hydrogenation was carried out in exactly the same manner.

As a result, the living Li/Ti-1 ratio during the hydrogenation reaction was about d/. After hydrogenation, the same treatment as in Example 1 was carried out to obtain a white polymer. The hydrogenation rate of the butadiene unit □ of this product is 9t, the hydrogenation i of the styrene unit is more than 1,
The results showed that hydrogenation is possible even if part of the living lithium is deactivated. Furthermore, compared to Example 7, the hydrogenation rate of butadiene units was improved, and the living Li during hydrogenation was
It was shown that the /Ti molar ratio influenced the activity.

Comparative Example 3 The living polymer solution made of styrene-butadiene-styrene obtained in Reference Example t was diluted with dry cyclohexane to give a polymer concentration/Qfp of 10oOf (polymer amount toot) and was dried.
The autoclave was charged, and the inside of the system was purged with dry hydrogen gas.

This is a cyclohexane solution of pesozirc pride with a concentration of 1/DO-! Od was added and stirred at room temperature for about 10 minutes. . The yellow-red living color of the BORIMER solution immediately lost color and became slightly yellow and transparent. When this polymer was analyzed, all of the living lichens had already been deactivated.

Next! The hydrogenation reaction was carried out in exactly the same manner as in Example 1/4I,
A white bolomer was obtained in the same manner as in Example 1. After this, the hydrogenation rate of the butadiene monomer is 79 g or less, the hydrogenation rate of the styrene unit is also 1- or less, and the polymer that does not have living lithium is not hydrogenated with the titanium compound of the present invention. The results were shown.

Claims (1)

[Claims] (1) In the method of hydrogenating a living polymer in an inert organic solvent, (A) a conjugated diene is polymerized using an organolithium as a polymerization catalyst, or a conjugated diene is copolymerized with a conjugated diene. The living polymer obtained by polymerization is /R (B) general formula (C,)I5\-Tl (however, R, R'
is a group selected from alkyl, allyl, alkoxy, allyloxy, halogen, and carbonyl groups, and R and R' may be the same or different. ) is brought into contact with hydrogen in the presence of a hydrogenation catalyst consisting of at least seven types of bis(cyclopentagenyl)titanium compounds represented by A method for catalytic hydrogenation of a lipping polymer characterized by hydrogenation.