JP3326772B2 - Method for hydrogenating olefinically unsaturated polymer and hydrogenation catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for hydrogenating olefinically unsaturated polymers and a hydrogenation catalyst. More specifically, olefinically unsaturated polymers have weather resistance, heat resistance,
The present invention relates to a hydrogenation method for imparting properties such as oxidation resistance and a hydrogenation catalyst having high hydrogenation activity.

[0002]

2. Description of the Related Art Olefinically unsaturated bond-containing polymers represented by conjugated diene polymers are widely and industrially used generally as elastomers and the like. However, the olefinically unsaturated bonds in these polymers are:
Although it is advantageously used for vulcanization and the like, it is a cause of impairing weather resistance, heat resistance, and the like, and has a drawback of limiting the applications of polymers.

The inferior weather resistance and heat resistance are as follows.
This is significantly improved by hydrogenating the polymer to eliminate olefinically unsaturated bonds in the polymer chain. For this purpose, as a method of hydrogenating an olefinically unsaturated bond-containing polymer, a method using a supported heterogeneous catalyst in which a metal such as nickel, platinum, and palladium is supported on a carrier such as carbon, silica, and alumina, ,nickel,
It is known to use a homogeneous catalyst obtained by reacting an organometallic compound such as cobalt or titanium with a reducing compound such as organoaluminum, organomagnesium or organolithium in a solvent.

[0004]

However, the former supported heterogeneous catalyst generally has lower activity than the homogeneous catalyst, and requires a high temperature to perform a hydrogenation (hereinafter sometimes referred to as hydrogenation) reaction. Requires severe conditions of high pressure.
In addition, the hydrogenation reaction proceeds when the product to be hydrogenated comes into contact with the catalyst, so when hydrogenating a polymer, the viscosity of the reaction system and the steric hindrance of the polymer are lower than when hydrogenating a low molecular weight compound. And contact with the catalyst becomes difficult. Therefore, in order to hydrogenate the polymer efficiently, a large amount of catalyst is required, which is uneconomical, and a higher temperature, high pressure hydrogenation reaction is required, so that decomposition and gelation of the polymer are likely to occur. At the same time, energy costs increase. In the hydrogenation of a copolymer of a conjugated diene and a vinyl-substituted hydrocarbon, usually, an aromatic nucleus is also hydrogenated,
There is a disadvantage that it is difficult to selectively hydrogenate only the unsaturated double bond of the conjugated diene unit.

[0005] On the other hand, the latter homogeneous catalyst usually has a higher activity and a smaller amount of catalyst used than the supported heterogeneous catalyst because the hydrogenation reaction usually proceeds in a homogeneous system.
There is a feature that the hydrogenation reaction can be performed at lower temperature and lower pressure.

If hydrogenation conditions are selected, it is also possible to preferentially hydrogenate unsaturated double bonds of conjugated diene units of a copolymer of a conjugated diene and a vinyl-substituted aromatic hydrocarbon. However, the homogeneous catalyst has a problem that reproducibility is poor because the hydrogenation activity greatly changes depending on the reduction state of the catalyst, and it is difficult to obtain a constant high hydrogenated polymer. Further, since the catalyst component is liable to be changed into an inert substance by impurities, the hydrogenation activity is reduced by impurities in the reaction system. This also causes the hydrogenation by the homogeneous catalyst to have difficulty in obtaining reproducibility. The inability to obtain a highly hydrogenated polymer with good reproducibility is a major obstacle to industrial use of a hydrogenation reaction with a homogeneous catalyst for the purpose of improving the weather resistance and heat resistance of the polymer.

Further, in the conventional hydrogenation of a polymer with a homogeneous catalyst, the rate of the hydrogenation reaction cannot be said to be sufficiently high. In addition, the hydrogenation activity is reduced due to the reduced state of the catalyst and impurities in the system, and the reaction rate is further reduced. Therefore, there is a problem in industrially hydrogenating a polymer using a homogeneous catalyst.

Accordingly, there is a strong demand for the development of a highly active hydrogenation catalyst which is hardly affected by impurities in the reaction system and which can obtain a high hydrogenation rate polymer stably at a high speed regardless of the catalyst preparation conditions. Is the current situation.

A hydrogenation reaction using a bis (cyclopentadienyl) transition metal compound as one component of a catalyst component used in the present invention is already known [for example, MF Sloa].
n. et al., J. Am. Chem. Soc., 85, 4014-4018 (1965); Y. T.
ajima et al., J. Org. Chem., 33,1689-1690 (1968), JP-A-59-133203, JP-A-61-28507.
No., etc.]. However, even if these known methods are used, the above-mentioned problem cannot be solved. In addition, these publications do not disclose any technique suggesting a method for solving the problem.

The present invention has been made in view of the above-mentioned conventional technical problems, and selectively hydrogenates olefinically unsaturated bonds in a polymer chain at a high rate under mild conditions. An object of the present invention is to provide a hydrogenation method and a hydrogenation catalyst which are hardly affected by impurities, have extremely high activity, and can obtain a constant high hydrogenated polymer.

[0011]

According to the present invention, the above objects and advantages of the present invention are as follows: (a) the following formula (1)

[0012]

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(Where M ¹ is a transition metal atom selected from the group consisting of titanium, zirconium and hafnium, and R ¹ and R ² are the same or different and are an alkyl group, an aryl group, an aralkyl group, an alkoxy group , An allyloxy group, an acyloxyl group, a carbonyl ligand, a β-diketone ligand or a halogen atom)

The compound comprises a bis (cyclopentadienyl) transition metal compound represented by the formula (b), a ketone compound and (c) an organolithium compound, and per equivalent of the ketone carbonyl group of the ketone compound (b). The olefinically unsaturated polymer is contacted with hydrogen in the presence of a hydrogenation catalyst having a lithium atom ratio of 1 equivalent or more to selectively hydrogenate the olefinically unsaturated bonds of the olefinically unsaturated polymer. This is achieved by a method for hydrogenating an olefinically unsaturated polymer, which is characterized in that:

Specific examples of the bis (cyclopentadienyl) transition metal compound which is the component (a) used in the present invention include bis (cyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) titanium diethyl, Bis (cyclopentadienyl) titanium di-n-
Butyl, bis (cyclopentadienyl) titaniumdi-
sec-butyl, bis (cyclopentadienyl) titanium dihexyl, bis (cyclopentadienyl) titanium dioctyl, bis (cyclopentadienyl) titanium dimethoxide, bis (cyclopentadienyl) titanium diethoxide, bis (cyclo) Pentadienyl) titanium dibutoxide, bis (cyclopentadienyl)
Titanium diphenyl, bis (cyclopentadienyl)
Titanium di-m-tolyl, bis (cyclopentadienyl) titanium di-p-tolyl, bis (cyclopentadienyl) titanium di-2,4-xylyl, bis (cyclopentadienyl) titanium di-4-ethyl Phenyl, bis (cyclopentadienyl) titanium di-4-
Butylphenyl, bis (cyclopentadienyl) titanium di-4-hexylphenyl, bis (cyclopentadienyl) titanium diphenoxide, bis (cyclopentadienyl) titanium difluoride, bis (cyclopentadienyl) titanium dichloride, Bis (cyclopentadienyl) titanium dibromide, bis (cyclopentadienyl) titanium diiodide, bis (cyclopentadienyl) titanium dicarbonyl, bis (cyclopentadienyl) methyltitanium chloride, bis (cyclopentadienyl) ) Methoxytitanium chloride, bis (cyclopentadienyl) ethoxytitanium chloride, bis (cyclopentadienyl) isopropoxytitanium chloride, bis (cyclopentadienyl) phenoxytitanium chloride Chloride, bis (cyclopentadienyl) titanium dibenzyl, bis (cyclopentadienyl) titanium diacetate, bis (cyclopentadienyl) titanium diacetylacetonate,

Bis (cyclopentadienyl) zirconium dimethyl, bis (cyclopentadienyl) zirconium diethyl, bis (cyclopentadienyl) zirconium di-n-butyl, bis (cyclopentadienyl) zirconium di-sec-butyl , Bis (cyclopentadienyl) zirconium dihexyl, bis (cyclopentadienyl) zirconium dioctyl, bis (cyclopentadienyl) zirconium dimethoxide, bis (cyclopentadienyl) zirconium diethoxide, bis (cyclopentadienyl) ) Zirconium dibutoxide, bis (cyclopentadienyl) zirconium diphenyl, bis (cyclopentadienyl) zirconium di-m-tolyl, bis (cyclopentadienyl) zirconium di-p
-Tolyl, bis (cyclopentadienyl) zirconium di-2,4-xylyl, bis (cyclopentadienyl)
Zirconium di-4-ethylphenyl, bis (cyclopentadienyl) zirconium diphenoxide, bis (cyclopentadienyl) zirconium difluoride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dibromide ,
Bis (cyclopentadienyl) zirconium diiodide, bis (cyclopentadienyl) zirconium dicarbonyl, bis (cyclopentadienyl) methyl zirconium chloride,

Bis (cyclopentadienyl) hafnium dimethyl, bis (cyclopentadienyl) hafnium diethyl, bis (cyclopentadienyl) hafnium di-
n-butyl, bis (cyclopentadienyl) hafnium di-sec-butyl, bis (cyclopentadienyl) hafnium dihexyl, bis (cyclopentadienyl) hafnium dimethoxide, bis (cyclopentadienyl)
Hafnium diethoxide, bis (cyclopentadienyl) hafnium dibutoxide, bis (cyclopentadienyl) hafnium diphenyl, bis (cyclopentadienyl) hafnium di-m-tolyl, bis (cyclopentadienyl) hafnium di-p- Tolyl, bis (cyclopentadienyl) hafnium-2,4-xylyl, bis (cyclopentadienyl) hafnium diphenoxide,
Bis (cyclopentadienyl) hafnium difluoride, bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) hafnium dibromide, bis (cyclopentadienyl) hafnium diiodide, bis (cyclopentadienyl) Hafnium dicarbonyl, bis (cyclopentadienyl) methylhafnium chloride and the like can be mentioned. These compounds can be used alone or in combination.

Among these bis (cyclopentadienyl) transition metal compounds, the hydrogenation activity for olefinically unsaturated bonds in the polymer is high, and the unsaturated bonds are preferably selectively hydrogenated under mild conditions. More preferred are bis (cyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) titanium di-n-
Butyl, bis (cyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) titanium diphenyl, bis (cyclopentadienyl) titanium di-
p-tolyl, bis (cyclopentadienyl) titanium dicarbonyl, bis (cyclopentadienyl) titanium dibenzyl, bis (cyclopentadienyl) isopropoxytitanium chloride, bis (cyclopentadienyl) zirconium dichloride, bis ( (Cyclopentadienyl) zirconium dibromide, bis (cyclopentadienyl) zirconium diphenyl, bis (cyclopentadienyl) zirconium di-p-tolyl, bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) Examples include hafnium dibromide, bis (cyclopentadienyl) hafnium diphenyl, and bis (cyclopentadienyl) hafnium di-p-tolyl.

The component (b) is a ketone compound. Specific examples of the ketone compound include acetone, diethyl ketone,
Di-n-propyl ketone, diisopropyl ketone, di-
n-butyl ketone, di-sec-butyl ketone, di-t
-Butyl ketone, methyl ethyl ketone, isopropyl methyl ketone, isobutyl methyl ketone, 2-pentanone, 3-hexanone, 3-decanone, diacetyl, acetophenone, 4'-methoxyacetophenone, 4'-methylacetophenone, propiophenone, benzophenone, 4-methoxy Benzophenone, 4,4'-dimethoxybenzophenone, benzylphenylketone, benzylacetone, benzyl, benzoylacetone, dibenzoylmethane, cyclopentanone, cyclohexanone, 4-
Preferred examples include methylcyclohexanone, 1,2-cyclohexanedione, cycloheptanone, and acetylacetone.

Next, as specific examples of the organic lithium as the component (c), methyl lithium, ethyl lithium, n-
Propyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, n-hexyllithium, phenyllithium, p-tolyllithium, xylyllithium, 1,4-dilithiobutane, alkylenedilithium, butyllithium and divinylbenzene And the like. In addition to these low molecular weight organic lithium compounds, living polymers having a terminal lithium can be used as the organic lithium compound of the component (c).

Particularly preferred among these are n-butyllithium, sec-butyllithium, t-butyllithium, phenyllithium and living polymers having a terminal lithium.

The hydrogen catalyst used in the present invention comprises the above components (a), (b) and (c), and if necessary, the following component (d) can be further used as one component.

As the component (d), a reducing organic metal compound selected from the group consisting of an aluminum compound, a zinc compound and a magnesium compound is used. Specific examples of these include, as aluminum compounds, trimethylaluminum, triethylaluminum, triisobutylaluminum, triphenylaluminum, diethylaluminum chloride, ethylaluminum dichloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, diethylaluminum hydride, diisobutylaluminum hydride , Tri (2-ethylhexyl) aluminum, aluminum triisopropoxide, aluminum tri-t-butoxide, diethylaluminum ethoxide and the like.

Examples of the zinc compound include diethyl zinc, bis (cyclopentadienyl) zinc, diphenyl zinc and the like.

Further, as the magnesium compound, for example, dimethylmagnesium, diethylmagnesium, methylmagnesium bromide, methylmagnesium chloride,
Ethyl magnesium bromide, ethyl magnesium chloride, phenyl magnesium bromide, phenyl magnesium chloride, t-butyl magnesium chloride and the like can be mentioned. In addition to these, a compound containing two or more kinds of reducing metals such as lithium aluminum hydride as the component (d) can also be mentioned.

Taking into account the industrial difficulty of obtaining and easy handling, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum dichloride, aluminum triisopropoxide, and aluminum tri-t-butoxide are preferred.

The composition of the catalyst used in the present invention is preferably such that the molar ratio of the catalyst (a) component / catalyst (b) component is 1 /.
0.5 or more, more preferably 1/1 to 1/40, further preferably 1/3 to 1/30. If the amount of the catalyst (b) component is less than 1 mol relative to 1 mol of the component (a), the catalytic activity is insufficient, and hydrogenation of the polymer under mild conditions tends to be difficult.

The molar ratio of the catalyst (a) component / catalyst (c) component is preferably from 1/1 to 1/50, more preferably from 1/3 to 1/40, and still more preferably from 1/3 to 1/40. / 3
5 The catalyst (c) component is used for 1 mole of the component (a),
If the amount is less than 1 mol, the hydrogenation reaction is very slow. On the other hand, if the amount exceeds 50 mol, the catalytic activity of hydrogen is maintained, but the gelation of the polymer and side reactions are liable to occur, which is not preferable.

Further, the ratio of the catalyst (b) component to the catalyst (c) component is such that the lithium atom of the component (c) is at least 1 equivalent per equivalent of the ketone carbonyl group of the component (b).

Preferably, the lithium atom of component (c) /
The equivalent ratio of the ketone carbonyl group of the component (b) is 2 or less, more preferably 1.0 to 1.6, further preferably 1.0 to 1.5, and particularly preferably 1.0. ~ 1.
4. A ketonic carbonyl group in the molecule, for example, 2
One mole of a compound containing 2 is equivalent to 2 equivalents, and a compound containing 3 is 1 equivalent of 3 equivalents.

Further, the molar ratio of the catalyst (a) component / catalyst (d) component is preferably 1/20 or less, more preferably 1/1 to 1/18, still more preferably 1/2 to 1/15.
It is. The amount of the catalyst (d) is 2 to 1 mole of the component (a).
If it is added in excess of 0 mol, the catalytic activity is rather reduced, and a highly hydrogenated polymer tends to be difficult to obtain.

Further, the preferred amount of the catalyst of the present invention is 0.005 to 50.0 mmol in terms of the component (a) per 100 g of the polymer to be hydrogenated. If the amount is less than 0.005 mmol, the hydrogenation efficiency is poor. On the other hand, if it exceeds 50 mmol, hydrogenation is possible.However, the use of more catalyst than necessary becomes uneconomical and the removal of catalyst residues from the polymer becomes complicated. It becomes disadvantageous. A more preferred range is (a)
It is 0.01 to 5 mmol in terms of components.

By using the above-mentioned catalyst of the present invention, it is possible to obtain a constant highly hydrogenated polymer irrespective of catalyst preparation conditions and conditions in the system.

The olefinically unsaturated polymer to be hydrogenated according to the present invention includes all polymers having an olefinic carbon-carbon unsaturated double bond in the polymer main chain or side chain. As a preferred representative example,
Examples include a conjugated diene polymer or a random, block or graft polymer of a conjugated diene and an olefin.

Examples of the conjugated diene polymer include conjugated diene homopolymers and copolymers obtained by copolymerizing at least one conjugated diene with each other or at least one olefin copolymerizable with the conjugated diene. Is done.

The conjugated diene used in the production of the conjugated diene polymer generally includes a conjugated diene having 4 to 12 carbon atoms. Specific examples include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, ,
5-diethyl-1,3-octadiene, 3-butyl-1,
3-octadiene, chloroprene and the like.

From the viewpoint of obtaining an elastomer which can be developed industrially and has excellent physical properties, 1,3-butadiene and isoprene are particularly preferred. Elastomers such as polybutadiene, polyisoprene and butadiene / isoprene copolymer can be used in the practice of the present invention. Is particularly preferred. In this polymer, the microstructure of the polymers is not particularly limited, and any polymer can be suitably used as an object to be hydrogenated.

On the other hand, the method of the present invention is particularly suitably used for hydrogenating a copolymer obtained by copolymerizing at least one conjugated diene and at least one olefin copolymerizable with the conjugated diene.

Suitable conjugated dienes used in the production of this copolymer include the conjugated dienes described above. Examples of the olefin include all monomers copolymerizable with the conjugated diene, and a vinyl-substituted aromatic hydrocarbon is particularly preferable.

In order to obtain industrially useful and valuable elastomers and thermoplastic elastomers, copolymers of conjugated dienes and vinyl-substituted aromatic hydrocarbons are particularly important. Specific examples of the vinyl-substituted aromatic hydrocarbon used for producing the copolymer include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-
Dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylpyridine and the like can be mentioned. Of these, styrene and α-methylstyrene are particularly preferred. As specific examples of the copolymer, butadiene-styrene copolymer, isoprene-styrene copolymer, butadiene-α-methylstyrene copolymer and the like are most preferable because they give a hydrogenated copolymer having high industrial value.

In this copolymer, the monomers include random copolymers, decreasing block copolymers, complete block copolymers, and graft copolymers, which are statistically distributed throughout the polymers.

In order to obtain an industrially useful thermoplastic elastomer, the content of the vinyl-substituted aromatic hydrocarbon should be 5 to 9
5% by weight is preferred. Further, as for the vinyl bond of the conjugated diene unit, 10% by weight or more of the entire conjugated diene unit is preferable because of excellent polymer performance after hydrogenation.

The polymer used in the hydrogenation reaction of the present invention generally has a molecular weight of about 1,000 to 1,000,000, and is a so-called branched type which is coupled with a coupling agent in addition to a linear type. Type, radial type or star type block polymers.

Specific examples of the coupling agent include divinylbenzene, tetrachlorosilane, methyldichlorosilane, butyltrichlorosilane, (dichloromethyl) trichlorosilane, (dichlorophenyl) trichlorosilane, 1,2-bis (trichlorosilyl) ethane, Hexachlorodisilane, 1,2,3,4,7,7-hexachloro-
6-methyldichlorosilyl-2-norbornene, octachlorotrisiloxane, trichloromethyltrichlorosilane, tetrachlorotin, butyltrichlorotin, tetrachlorogermanium, 1,2-dibromoethane, epoxidized linseed oil, tolylene diisocyanate, and the like. Can be

Further, a polyketone compound can be used as a coupling agent. When a polyketone compound is used as a coupling agent, it can be used as a component of the catalyst (b) of the present invention, including a component used for coupling. Therefore, it is possible to carry out the hydrogenation reaction economically and efficiently, which is industrially extremely useful.

In the living anionic polymerization, a polymer whose terminal is modified with a polar group and a polymer whose polymer is modified with a polar group by other means are also included. Examples of the polar group to be modified include a hydroxyl group, a carboxyl group, an ester group, an isocyanate group, a urethane group, an amide group, a urea group, and a thiourethane group.

Polymers produced by any other known polymerization methods such as anionic polymerization, cationic polymerization, coordination polymerization, radical polymerization or solution polymerization, and emulsion polymerization can be used.

Further, a polymer of a cyclic olefin obtained by ring-opening polymerization using a metathesis catalyst such as molybdenum or tungsten is also included in the polymer having an olefinically unsaturated bond used in the present invention.

Specific examples of the monomers constituting the polymer include cyclobutene, cyclopentene, cyclooctene, 1,5-cyclooctadiene, 1,5,9-cyclododecatriene, norbornene and 5-methyl-norbornene. Cycloalkene such as methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, phenyl 5-norbornene-2-carboxylate, 2-
Methyl-5-norbornene-2-carboxylate, 3
Butyl-5-norbornene-2-carboxylate, dimethyl 5-norbornene-2,3-dicarboxylate, cyclohexyl 5-norbornene-2-carboxylate, aryl 5-norbornene-2-carboxylate, 5-
Norbornene-2-yl acetate, 5-norbornene-2-nitrile, 3-methyl-5-norbornene-2-
Nitrile, 2,3-dimethyl-5-norbornene-2,3
-Dinitrile, 5-norbornene-2-carboxylic acid amide, N-methyl-5-norbornene-2-carboxylic acid amide, N, N-diethyl-5-norbornene-2-carboxylic acid amide, N, N-dimethyl-2 -Methyl-5-norbornene-2,3-dicarboxylic amide, 5-norbornene-2,3-dicarboxylic anhydride (hymic anhydride), 2,3-dimethyl-5-norbornene-2,3-dicarboxylic imide , N-phenyl-2-methyl-5-norbornene-2,3-dicarboxylic imide, 5-methyl-5-carboxycyclohexylbicyclo [2.2.
1.]-2-Heptene, 5-methyl-5-carboxy (4-t-butylcyclohexyl) bicyclo [2.2.
. 1] - 2-heptene, 8-methyl 8-carboxy-cyclohexyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10]
-3-dodecene, 5-methyl-5-carboxytricyclo [5.2.1.0 ^2,6 ] decyl-8'-bicyclo [2.2.
1.] Norbornene derivatives such as 2-heptene can be used.

The catalyst of the present invention comprising the bis (cyclopentadienyl) transition metal compound (a), the ketone compound (b) and the organolithium compound (c) described above, The catalysts of the present invention comprising the components (a) to (c) and the reducing organometallic compound of the component (d) all have good reproducibility and high hydrogenation activity.

After these catalyst components are mixed in advance, they may be added to the hydrogenation reaction system or may be separately added to the system in an arbitrary order. For example, a method in which the component (b) is added to a living polymer having lithium at the terminal and reacted, and then the component (a) or a component obtained by previously mixing the components (a) and (d) is added and hydrogenated. Alternatively, a reaction product obtained by previously reacting the components (b) and (c) is added to the system, and the component (a) or a mixture of the components (a) and (d) is separately added to the system, and water is added. A water addition reaction can be carried out by the method of adding.

When the respective components are mixed in advance, it is desirable to carry out the mixing in an inert atmosphere. Here, the inert atmosphere means an atmosphere that does not react with any participant of a hydrogenation reaction such as nitrogen, helium, neon, or argon. Air and oxygen are not preferred because they oxidize the catalyst and cause deactivation of the catalyst. When the catalyst is preliminarily mixed, the mixing can be performed in a hydrogen atmosphere in addition to the inert atmosphere.

The hydrogenation reaction of the present invention is carried out in a state where the olefinically unsaturated polymer is dissolved in a hydrocarbon solvent, or after the olefinically unsaturated polymer is produced by polymerization in a hydrocarbon solvent, Subsequent hydrogenation can also be carried out. Here, examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; aliphatic hydrocarbons such as cyclopentane, methylcyclopentane, and cyclohexane; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. Hydrogen can be used. These hydrocarbon solvents may contain ethers such as diethyl ether, tetrahydrofuran and dibutyl ether in a range of 20% by weight or less.

The concentration of the polymer at the time of performing the hydrogenation reaction of the present invention is not particularly limited, but is usually 1 to 30% by weight, preferably 3 to 20% by weight. In the hydrogenation reaction, the above-mentioned catalyst for hydrogenation is added in an atmosphere of an inert gas such as nitrogen or argon or hydrogen, and then hydrogen is supplied under pressure at a pressure of 1 to 100 kg / cm ² , and the polymer solution is further added. Is maintained at a predetermined temperature, and is carried out with or without stirring.

The pressure of hydrogen used in the hydrogenation reaction is as follows:
Preferably it is 1-100 kg / cm < ² > G, more preferably 4-20 kg / cm < ² > G. If it is less than 1 kg / cm ² G, the hydrogenation rate becomes slow, while if it exceeds 100 kg / cm ² G, gelation of the polymer and unnecessary side reactions tend to occur easily, which is not preferable.

The temperature range suitable for the hydrogenation reaction is as follows:
The temperature is 0 to 150 ° C. If the temperature is lower than 0 ° C, the activity of the catalyst decreases, and the hydrogenation rate becomes slow, requiring a large amount of the catalyst. Therefore, it is not economical. This is not preferable because hydrogenation of the aromatic nucleus portion also easily occurs and hydrogenation selectivity decreases.
It is preferably in the range of 20 to 140 ° C, and more preferably in the range of 70 to 130 ° C.

The hydrogenation reaction time of the present invention is from 1 minute to 10 minutes.
The reaction time is shorter as the amount of the hydrogenation catalyst is larger and the hydrogen pressure is higher. The hydrogenation reaction of the present invention can be carried out by any of a batch method and a continuous method. By the hydrogenation reaction of the present invention, a polymer in which 80% or more, preferably 90% or more of the olefinically unsaturated double bond is hydrogenated is obtained. However, the hydrogenation of the aromatic nucleus double bond, if present, is less than 5% and is substantially not hydrogenated. In addition, in the hydrogenation reaction of the present invention, the polymer hardly causes molecular breakage.

According to the process of the invention, any proportion of unsaturated double bonds in the polymer can be hydrogenated. Further, the hydrogenation catalyst of the present invention can be used for hydrogenating olefins such as styrene. The polymer hydrogenated by the method of the present invention removes the catalyst residue from the polymer solution as needed, adds an antioxidant, throws the polymer solution into hot water together with steam, and removes the solvent. A method of recovering the polymer by steam distillation, collecting the polymer in the form of a crumb, a method of flowing the polymer solution over a heating roll and evaporating the solvent to recover the polymer, or a method of recovering the polymer solution from alcohol, acetone, or the like. The polymer can be isolated from the polymer solution by, for example, pouring into a solvent and precipitating and recovering the polymer.

In the hydrogenation method of the present invention, the amount of the catalyst used is small, so that the catalyst residue is small, and the catalyst residue has little effect on the weather resistance and heat resistance of the polymer. Can be excluded.

[0060]

According to the present invention, the disadvantages of the conventional homogeneous hydrogenation catalysts are improved, and by using the catalyst of the present invention to which a bis (cyclopentadienyl) transition metal compound and a ketone compound are added, the system can be improved. A highly hydrogenated polymer which is hardly affected by impurities, has high hydrogenation activity, and is stable at a high speed can be provided.

[0061]

EXAMPLES The present invention will now be described more specifically with reference to examples, but the present invention is not limited thereto. Incidentally, the vinyl bond content of the conjugated diene-based polymer in the examples was determined by the Hampton method [RR Hampton, Anal. Chem., Vol. 29, p. 923, using an infrared absorption spectrum.
(1949)].

Example 1 A 10 l autoclave was charged with 5 kg of degassed and dehydrated cyclohexane and 1 kg of 1,3-butadiene.
15 g of tetrahydrofuran and 1.1 g of n-butyllithium were added, and the polymerization temperature was raised from 50 ° C. After the conversion reaches almost 100%, the living Li
The amount was determined to be 13.4 mmol. In this system, 2.56 g of benzophenone was added to the autoclave and stirred for 10 minutes. From the change in the color of the polymer solution, it was confirmed that there was no living lithium terminal lithium as a living anion. 0.13 g of n-butyllithium was added, and a component obtained by previously mixing 0.42 g of bis (cyclopentadienyl) titanium dichloride and 1.22 g of diethylaluminum chloride dissolved in 10 ml of toluene under a nitrogen atmosphere was charged. After stirring, hydrogen gas was supplied at a pressure of 8 kg / cm ² G.
The reaction was performed at 90 ° C. for 4 hours to obtain a hydrogenated polymer having a hydrogenation rate of 94%. The 1,2-vinyl bond content of the polymer before hydrogenation was 39%, and the number average molecular weight was 100,000.

Comparative Example 1 Polymerization and hydrogenation were carried out in the same manner as in Example 1 except that benzophenone was not added. The hydrogenation rate of the obtained hydrogenated polymer was 52%.

Example 2 A 10-liter autoclave was charged with 5 kg of degassed and dehydrated cyclohexane, 300 g of styrene and 700 g of 1,3-butadiene, and 15 g of tetrahydrofuran and 1.1 g of n-butyllithium were added.
Polymerization at a temperature rising from 0 ° C. was performed. After the conversion reached almost 100%, the amount of living Li was measured and found to be 13.5 mmol. 0.71 g of acetone is added to this system,
Further, 1.06 dissolved in 0.36 g of bis (cyclopentadienyl) titanium dichloride and 10 ml of toluene.
g of diethylaluminum chloride was previously mixed in a nitrogen atmosphere, and the components were charged into an autoclave and stirred. Hydrogen gas is supplied at a pressure of 8 kg / cm ² G,
The reaction was performed at 90 ° C. for 3 hours. The hydrogenation rate of the obtained hydrogenated polymer was 93%, the content of the 1,2-vinyl bond of the polymer before hydrogenation was 36%, and the number average molecular weight was 950,000.

Example 3 Polymerization was carried out in the same manner as in Example 1, and after the conversion reached almost 100%, the amount of living Li was measured to be 13.5 mmol. In this system, dibenzoylmethane 1.0
8 g was added, and a mixture of 0.40 g of bis (cyclopentadienyl) titanium dichloride and 1.16 g of diethylaluminum chloride dissolved in 10 ml of toluene was added in a nitrogen atmosphere. The mixture was stirred, and 8 kg of hydrogen gas was added. / Cm ² G at a pressure of 90
The reaction was carried out at a temperature of 3 ° C. for 3 hours. The degree of hydrogenation of the obtained hydrogenated polymer was 92%, the content of the 1,2-vinyl bond of the polymer before hydrogenation was 37%, and the number average molecular weight was 950,000.

Example 4 Polymerization was carried out in the same manner as in Example 1, and after the conversion reached almost 100%, the amount of living Li was measured and found to be 13.4 mmol. 0.58 g of acetone was added to the system, and 0.43 g of bis (cyclopentadienyl) was further added.
A solution prepared by dissolving titanium dibenzyl in 10 ml of toluene was charged into the system, and after stirring, 8 kg / cm ² G of hydrogen gas was added.
And the reaction was carried out at 90 ° C. for 3 hours. The hydrogenation rate of the obtained hydrogenated polymer was 93%, the 1,2-vinyl bond content of the polymer before hydrogenation was 38%, and the number average molecular weight was 1
It was 10,000.

Example 5 Polymerization was carried out in the same manner as in Example 2, and after the conversion reached almost 100%, the amount of living Li was measured.
Mmol. 0.24 g of water was added to the system and 2
Stirred for 0 minutes. From the change in the color of the polymer solution, it was confirmed that there was no living lithium terminal lithium as a living anion. Although the number average molecular weight of the polymer obtained at this time was 103,000, it was confirmed that the color of styryllithium was not added by further adding 100 g of styrene, and that the molecular weight distribution did not change before and after the addition of styrene.

Next, 1.58 g of diisopropyl ketone dissolved in 20 ml of cyclohexane and 0.93 g of n-butyllithium were previously reacted for 20 minutes under a nitrogen atmosphere, and bis (cyclopentadienyl) titanium was further added. A component in which 0.36 g of dichloride and 1.05 g of diethylaluminum chloride dissolved in 10 ml of toluene were mixed in advance in a nitrogen atmosphere was charged into an autoclave and stirred. 8 kg of hydrogen gas
/ Cm ² G, and the reaction was carried out at 90 ° C. for 4 hours. The hydrogenation rate of the obtained hydrogenated polymer was 91%, and the 1,2-vinyl bond content of the polymer before hydrogenation was 39%.

Example 6 In Example 5, 0.95 g of diisopropyl ketone was added in an amount of 1.58 g.
Polymerization and hydrogenation were carried out in the same manner as in Example 5 except that The hydrogenation rate of the obtained hydrogenated polymer was 63%.

[0070]

The hydrogenated polymer obtained according to the present invention comprises:
Used as a thermoplastic elastomer or thermoplastic resin with excellent weather resistance, heat resistance, and oxidation resistance.Used with additives such as ultraviolet absorbers, oils, primers, etc., and blended with other elastomers and resins. It is industrially useful. Further, it is possible to selectively hydrogenate the olefinically unsaturated bond-containing polymer used in the present invention at a very high rate and at a high conversion rate under mild conditions.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuhiko Takemura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-3-223305 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 8/00-8/50

Claims (3)

(57) [Claims] (A) The following formula (1): (Where M ¹ is a transition metal atom selected from the group consisting of titanium, zirconium and hafnium, and R ¹ and R ² are the same or different and are an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an allyloxy group , An acyloxyl group, a carbonyl ligand, a β-diketone ligand or a halogen atom), a (b) ketone compound and (c) an organolithium compound. And contacting the olefinically unsaturated polymer with hydrogen in the presence of a hydrogenation catalyst wherein the lithium atom of the organolithium compound (c) is at least 1 equivalent per equivalent of the ketone carbonyl group of the ketone compound (b). Characterized in that the olefinically unsaturated bond of the olefinically unsaturated polymer is selectively hydrogenated. Hydrogenation of olefinically unsaturated polymers to be. 2. The method according to claim 1, wherein the hydrogenation catalyst is (a) or (b).
2. The composition according to claim 1, further comprising (d) a reducing organometallic compound selected from the group consisting of an aluminum compound, a zinc compound and a magnesium compound, in addition to the component (c).
The method described in. 3. The hydrogenation catalyst according to claim 1 or 2.