MXPA97001870A - Process for the hydrogenation of conjugated diameter polymers and catalyzing compositions adequate to be used in mi - Google Patents

Abstract

The present invention relates: provides a catalyst composition for the hydrogenation of polymers containing ethylenic unsaturation which comprise at least: (a) a titanium compound of the formula (See Formula) wherein A1 represents an optionally substituted indenyl group, the formula (See Formula) wherein the substituents R1 and R2 may be the same or different and each may be selected from halogen, phenyl, which may optionally support one or more substituents, the same or different, between lower alkyl, alkoxy, phenoxy, phenylalkoxy, benzyl and bulky substituents containing one or more heteroatoms such as bis (lower alkyl) silyl, -NPhs, -NHPh, -BPh2 and -B (OPh) 2, where n may be a number of 0 at 4 and m can be a number from 0 to 3, or wherein A2 has the same meaning as A1 or alternatively represents an optionally substituted cyclopentadiene group, and wherein L1 and L2 can be or different and each may be selected from hydrogen, halogen, lower alkyl, phenyl, aralkyl, having from 7 to 10 carbon atoms, lower alkoxy group, phenyloxy, phenylalkoxy group having from 7 to 10 carbon atoms, carboxyl , carbonyl, a coordination group B-diketone, a group -CH2P (phenyl) 2, -CH2 Si (lower alkyl) 3 or -P (phenyl) 2; and (b) and an alkali metal hydride, added as is or prepared in situ in the solution of the polymer from the living polymer finished in alkali metal and / or from the further addition of an alkali metal alkyl, and a process for the hydrogenation of polymers containing ethylenic unsaturation.

Description

PROCESS FOR THE HYDROGENATION OF CONJUGATED DIAMETER POLYMERS AND CATALYZER COMPOSITIONS ADEQUATE TO BE USED IN THE SAME FIELD OF THE INVENTION The present invention relates to a process for the hydrogenation of polymers of conjugated dienes and catalyst compositions suitable for use therein. More particularly, the invention relates to a process for the hydrogenation of polymers and copolymers of conjugated diene polymers, using a catalyst composition for hydrogenation comprising at least one titanium compound and an alkali metal compound. Numerous catalysts are known for the hydrogenation of compounds containing unsaturated double bonds, catalysts which can be classified into two groups: (1) heterogeneous catalysts, which consist, in general, of a metal such as Ni, Pd, Pt, Ru, etc., optionally deposited on a support such as carbon, silica, alumina, carbonate REF: 24203 calcium, etc .; and (2) homogeneous catalysts such as (a) Ziegler catalysts, which consist of a combination of an organic salt of Ni, Co, Fe, Cr, etc., and a reducing agent such as for example organoaluminum compounds, and (b) ) Organometallic compounds, single-component, Ru, Rh, Ti, La, etc. Heterogeneous catalysts are widely used in industry, but compared to homogeneous catalysts, they are less active and hence, to perform the desired hydrogenation with these heterogeneous catalysts, large amounts of catalyst are needed and the reaction must be carried out at pressures and temperatures relatively high The homogeneous catalysts are generally more active; a small amount of catalyst is sufficient, and the hydrogenation reaction can be carried out under moderate conditions of pressure and temperature. Polymers of conjugated dienes such as 1,3-butadiene and isopropene and the copolymers of these dienes, with vinylaromatic monomers, for example with styrene, are widely used in the industry as elastomers. These polymers contain double bonds in their chain, which allow their vulcanization, but whose presence causes a low resistance to aging and oxidation. Some block copolymers of conjugated dienes and vinylaromatic hydrocarbons are used without vulcanization as thermoplastic elastomers, as impact-resistant transparent resins, or as modifiers or compatibilizers of polystyrene resins and polyolefins. However, these copolymers have a low resistance to aging and oxidation by oxygen and by ozone, atmospheric, due to the presence of double bonds in their chain. Hence, the use of these copolymers is limited in applications that require exposure to the external environment. The resistance to oxidation by oxygen and ozone, and, in general, resistance to aging, can be considerably improved by the hydrogenation of these polymers to obtain a total or partial saturation of the double bonds. Numerous processes have been proposed for the hydrogenation of polymers containing olefinic double bonds. Generally two types of processes are involved: those in which the heterogeneous, supported catalysts mentioned above are used, and those that use homogeneous catalysts of the Ziegler type or organometallic compounds of rhodium and titanium. In processes using heterogeneous, supported catalysts, the polymer to be hydrogenated is first dissolved in a suitable solvent and then contacted with hydrogen in the presence of the heterogeneous catalyst. The contact of the reactants with the catalyst is difficult due to the relatively high viscosity of the polymer solution, steric impediments of the polymer chain, and the high adsorption of the polymer which, once hydrogenated, tends to remain on the surface of the catalyst, interfering with access to the active centers of the non-hydrogenated polymer. Hence, to carry out the complete hydrogenation of the double bonds, large quantities of the catalyst and severe reaction conditions are required. Usually this causes the decomposition and gelation of the polymer. Furthermore, in the hydrogenation of conjugated diene copolymers with vinylaromatic hydrocarbons, the aromatic nuclei are also hydrogenated, and it is difficult to carry out selective hydrogenation of the double bonds of the polydiene units. Likewise, the physical separation of the catalyst from the solution of the hydrogenated polymer is extremely difficult, and in some cases complete elimination is impossible due to the strong adsorption of the polymer on the heterogeneous catalyst. In processes using Ziegler-type catalytic systems (as mentioned above), the reaction takes place substantially in a homogeneous medium, and therefore the hydrogenation of the copolymers can be carried out under low pressure and temperatures. Furthermore, by a suitable selection of the hydrogenation conditions it is possible to selectively hydrogenate the double bonds of the poly (conjugated diene) blocks and without hydrogenating the aromatic rings of the poly (vinylaromatic hydrocarbon) blocks. However, the removal of the catalyst residues, from the reaction product - which is absolutely necessary because these residues have an unfavorable effect on the stability of the hydrogenated polymers - is a complicated and expensive step. Other processes using other homogeneous catalysts, for example the rhodium compounds described in US Pat. No. 3,898,208 and JP 01,289,805 have the disadvantage of the high cost of rhodium catalysts. It is known that catalysts for hydrogenation in which one of the components is a cyclopentadienyl titanium derivative (US Patent No. 4,501,857) are used - necessarily in the presence of organolithium compounds - for the hydrogenation of the olefinic double bonds of the polymers of conjugated dienes. European Patent Application 0460725 describes the use of a similar catalyst system for the hydrogenation of polymers that have been synthesized by means of an organolithium compound and which have been terminated by the addition of hydrogen, the presence of the hydride being lithium formed in the final reaction, necessary in this case to generate an active catalyst. Examples of both publications that use the compound bis (cyclopentadieni 1) titanium dichloride (Cp2TiCl2). In European Patent Applications No. 0549063 A and No. 0532099 A further further improvements of this concept are described, using a molar ratio of alkali metal hydride to titanium in the finished polymer solution, of at least 6: 1 and using as an additional promoter, during hydrogenation, an alkyl benzoate. The examples of the earlier and endorsed publications actually used only the compound Cp2TiCl2, which appears to be very poorly soluble in the applied indus tri alment e solvents. In British Patent Application No. 2,159,819 A it is indicated that species of the type Cp2TiR2 type (R = alkylaryl groups) are catalysts capable of selectively hydrogenating the double bonds of the polymers and copolymers of conjugated dienes, without requiring the presence of an organolithium compound. European Patent Application No. 0434469 A2 describes the use of an extraordinarily complex catalyst system, comprising a bis-cyclopentadienyl titanium compound in combination with an organometallic compound of aluminum or magnesium and alkali metals in the presence of alkali metal alkoxides and polar compounds of the ether, acetone, sulfoxide, etc. type The catalytic system is capable of hydrogenating the double bonds of the polymers and copolymers of conjugated dienes. An alleged improvement, further, of the latter idea is described in European Patent Application No. 0544304 A, using a catalyst composition comprising (a) a bis (cyclopentadienyl) compound of a transition metal and in particular bis (cyclopentadienyl) dichloride. ) titanium or dibenzyl bis (cyclopentadienyl) titanium, (b) at least one polar compound selected from the group consisting of compounds containing the carbonyl group and compounds containing the epoxy group, and in particular esters of a monobasic or a dibasic acid, lactone compounds, lactam compounds, and epoxy compounds such as glycidyl ether, glycidyl-n-butyl ethers, glycidyl ether, glycidyl methacrylate, glycidyl ether; 1,2-butylene oxide, cyclohexene oxide and (c) an organic lithium compound and in particular n-butyllithium, sec-butyllithium, t-butylthio thio, phenyllithium, n-hexylthi thio, p-tolylthi io, xylillithium, 1,4-di-t-thiobutane, alkylendylium and living polymers having lithium at their terminals, and preferably, in addition (d) An organometallic reducing compound selected from the group consisting of aluminum compounds, compounds of zinc and magnesium compounds, such as diethylaluminum, tri-i-butylaluminum, diethylaluminum chloride, and aluminum, diethylaluminum chloride, ethyl aluminum dichloride, tri-i-propoxide and aluminum tri-i-butoxide. The molar ratio between components (a) and (b) indicates to be smaller than 1 / 0.5 and more preferably from 1/2 to 1/30: the molar ratio between components (a) and (c) indicate to be 1 / 1 to 1/40 and much more preferable 1/3 to 1/30. Other alleged improvements, arising from this idea of the use of titanium compounds as catalytic ingredients of hydrogenation, are described in European Patent Applications No. 0545844 A and No. 0601953 A, wherein the cyclopentadienyl ligands are completely ethylated or they are linked together by a dimethylsilylene group and where the other R ligands represent an alkoxide group, containing from 1 to 20 carbon atoms, or a halogen atom or the ligands CH2PPh2, PPh or CH2SiMe3 or PhOR. However, said processes do not provide any significant advantage over the prior art discussed at the beginning. To obtain more economical hydrogenation processes, the industry in the present days feels the need to have homogeneous catalysts available, which are more effective than those currently known, which are stable, and active in concentrations that are low enough to avoid costly step of removing the catalyst residues from the hydrogenated polymer. Therefore, an objective of the present invention is formed by an improved hydrogenation process as described hereinabove. It will be appreciated that another object of the present invention is formed by a catalyst composition for use in that process. As a result of extensive research and experimentation that desired catalyst and process has surprisingly been found.

DESCRIPTION OF THE INVENTION Accordingly, the present invention relates to a catalyst composition for the hydrogenation of polymers containing ethylenic unsaturation, which comprises at least: (a) a titanium compound of the formula A2 L2 wherein Ax represents an indenyl group, optionally substituted, of the formula wherein the substituents Rx and R2 may be the same or different and each may be selected from halogen, phenyl which may optionally carry one or more substituents, the same or different, lower alkyl, lower alkoxy, phenoxy, phenylalkoxy, benzyl, and a bulky substituent containing one or more heteroatoms such as tri- (lower alkyl) si1 i lo, ~ Nph2, ~ NHPh, ~ Bph2 and ~ B (0Ph) 2, where n can be an integer of 0 a, preferably from 0 to 2 and more preferably from 0 to 1 and n can be an integer from 0 to 3, preferably from 0 to 2 and more preferably from 0 to 1, wherein A2 has the same meaning as Ax or alternatively represents a group optionally substituted cyclopentadienyl, and wherein Lx and L2 may be the same or different and each may be selected from hydrogen, halogen and preferably chloro, lower alkyl, phenyl, aralkyl, having from 7 to 10 carbon atoms, alkoxy group lower, phenyloxy, phenylalkoxy group having from 7 to 10 carbon atoms, carboxyl, carbonyl, a coordination group B-diketone, a ~ CH2P (phenyl) 2 / -CH2 Si (lower alkyl or ~ P (phenyl) 2; and (b) an alkali metal hydride, added as such or prepared in situ in the polymer solution from the living polymer ending in alkali metal and / or from the additionally added alkali metal alkyl. The molar ratio of the alkali metal to titanium is preferably at least 2: 1. As the alkali metal hydride, lithium hydride is preferably used. The polymerization initiator to be used for the initial living polymer of at least one conjugated diene and the optional additional amounts of the alkali metal compound to form additional alkali metal hydride are preferably organolithium compounds. These compounds are preferably selected from methyllithium, ethyllithium, n-propylation, n-butyllithium, sec-butyllithium, tertbutyllithium, n-hexyllithium, phenyllithium, t-tolylitol, xylillithium, 1,4-dilithi. thiobutane, alqui lendili tio, or a reaction product of butyllithium and divinylbenzene. Particularly preferred are n-butyllithium, sec-butyllithium, tert-butyl, and phenyllithium. Most preferred are the terbutiumium, sec-butyllithium or n-butyllithium The molar ratio of lithium hydride to titanium in the catalyst composition is preferably at least 6 and more preferably is in the range of 6 to 25. The titanium compound (a) is usually used in amounts of 5 to 100 mg per kg of conjugated diene polymer to be hydrogenated, and preferably in amounts of 20 to 60 mg / kg of conjugated diene polymer. a) Preferred Li and L2 ligands are selected from chlorine, bromine, carbonyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, trimethylsilyloxy, benzyl, phenyl, hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, tert-butoxy, sec-butoxy, pentoxy, neopentoxy, phenoxy, phenylmethoxy, phenylethoxy, and a CH2P (phenyl) group 2. More preferably Li and L2 are both, in the catalyst component of titanium, chlorine, benzyl, phenyl, methoxy, ethoxy, isopropoxy, tert-butoxy , n-butoxy, phenoxy or a CH2P (phenyl) 2 group, and more preferably both are chloro. The ring (A2) of cyclopentadienyl, if present, can be optionally substituted by one or more groups, the same or different, which can be selected from halogen or phenyl which optionally can contain one or more substituents, the same or different , lower alkyl, lower alkoxy, phenoxy, phenylalkoxy, benzyl and a bulky substituent containing one or more heteroatoms such as tri (lower alkyl) silyl,? / NP _, ~ NHPh, ~ BPh2 and ~ B (0Ph) 2. When one or more, and preferably one or two, of the symbols R represent phenyl, it may be optionally substituted by one or more substituents selected from lower alkyl, halogen, preferably fluorine or chlorine, and lower alkoxy. Examples thereof are para-tertiary butyl phenyl, pentafluorophenyl, dichlorophenyl, 3,5 di (t-butyl) -4-methoxy phenyl, and tr i f luorophenyl. With the terms "lower alkyl" and "lower alkoxy" as used throughout this specification, it is understood that these groups contain from 1 to 4 carbon atoms.

The most preferred titanium compounds are bis (1-indenyl) thienyl dichloride, bis (1-indenyl) titanium diphenoxide, bis (l-indenyl) titanium dimethoxide, bis (1-methylindenyl) titanium dichloride, dichloride of bis (5,6-dimethoxy-indenyl) titanium, bis (dimethoxyindenyl) titanium dichloride, bis (trimetyl-i-i) lindeni dichloride, 1) titanium, (dimethoxyindenyl) dichloride (cyclopenta-dienyl) titanium, (dimethoxyindenyl) (indenyl) titanium dichloride, dichloride (ethoxyindenyl) (indenyl) titanium, dimethoxide (methoxyindenyl) (indenyl) titanium, dichloride (1-indenyl) (cyclopentyl adienyl) titanium, (1-indenyl) (cyclopentadienyl) titanium dimethoxide, and (1-indenyl) diphenoxide (cyclopentadienyl) titanium. It will be appreciated that another aspect of the present invention is formed by a process for the hydrogenation of polymers containing ethylenic unsaturation (CC double bonds) by contacting a solution of the polymer, in intensive contact with hydrogen in the presence of at least the components (a) and (b) of the catalyst composition. According to a more preferred embodiment of the hydrogenation process of the present invention, one or more promoters (c) can be presented in addition to the aforementioned catalyst components (a) and (b). Said promoters (c) can be selected from polar ketone compounds, ketone compounds containing hydroxy groups, aldehyde compounds, ester compounds, lactone compounds, lactam compounds, epoxies and an organometallic reducing compound. Of the aforementioned promoters, ketone compounds, ketone compounds containing hydroxy groups, aldehyde compounds, ester compounds and epoxy compounds are especially preferred. Specific examples of preferred ketone compounds include acetone, diethyl ketone, di-n-propyl ketone, di-i-propyl ketone, di-sec-butyl ketone, di-t-butyl ketone, methylt-il-ketone, i-propylmethyl-ketone. i-butyl ethyl ketone, 2-pentanone, 3-hexanone, 3-decanone, diacetyl, acetophenone, 4'-methoxyaceto-phenone, 4 '-methylacetophenone, propiophenone, benzophenone, 4-methoxybenzophenone, 4, -dimethoxy -benzophenone, benzylphenyl ketone, benzylacetone, benzoylacetone, cyclopentanone, cyclohexanone, 4-methylcyclohexanone, 1,2-cyclohexanedione, cycloheptanone, and acetylacetone. Ketone compounds containing hydroxy groups are defined as compounds containing both a hydroxy group and a carbonyl ketone group in the molecule. Specific examples of the preferred compounds are hydroxyacetone, acetoin, 4-hydroxy-2-butanone, 3-hydroxy-3-methyl-2-butanone, 5-hydroxy-2-butanone, diacetone alcohol, 4- (p-hydroxyphenyl) ) -2-butanone, 2-hydroxyacetophenone, 2 '-hydroxyacetophenone, 3'-hydroxyacetophenone, 4' -hydroxyacetophenone, 4'-hydroxy-3 '-methoxyacetophenone, 2-hydroxyphenylethyl ketone, 4' -hydroxypropiophenone, 2 ', 4 '-dihydroxyacetophenone, 2,', 5 '-dihydroxy-acetophenone, 2', 6 '-dihydroxyacetophenone, 3', 5'-dihydroxyacetophenone, 2 ', 3', 4'-trihydroxy-acetophenone, 2-hydroxybenzophenone, 4 - hydroxybenzophenone, 2-hydroxy-4-methoxybenzo-phenone, 2-hydroxy-4-n-octyloxy-benzafenone, 2,2'-dihydroxybenzophenone, 2,4-dihydroxybenzophenone 4,4'-dihydroxybenzophenone, 2, 2 '- dihydroxy-4-methoxybenzophenone, 2 ', 4' -trihydroxybenzophenone, and benzoin. As aldehyde compounds, either aliphatic or aromatic compounds can be used. The aliphatic group in the aliphatic aldehyde compounds can be any, either saturated or unsaturated and linear or branched. Examples which are given as preferred aldehyde compounds are formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, i-butyl-aldehyde, n-valeraldehyde, i-valeraldehyde, pivalaldehyde, n-capronaldehyde, 2-ethylhexaldehyde, n-heptaldehyde , n-capryl aldehyde, pelargonaldehyde, n-caprinal-dehyde, n-undecylaldehyde, lauryl aldehyde, tridecylaldehyde, myristyl aldehyde, pentadecyl-aldehyde, pal itylaldehyde, margarylaldehyde, stearylaldehyde, glyoxal, succinaldehyde, benzaldehyde, o-tulualdehyde, m-tulualdehyde, p-tulualdehyde, a-naphthaldehyde, β-naphthaldehyde, and phenylacetynaphthalaldehyde. Examples of ester compounds are esters formed by a monobasic acid, for example formic acid, acetic acid, propionic acid, butyric acid, caprionic acid, pelargonic acid, lauric acid, palmitic acid, stearic acid, isostearic acid, cyclohexylpropionic acid, acid cyclohexyl caprionic, benzoic acid, phenylbutyric acid, etc., a dibasic acid, for example oxalic acid, maleic acid, malonic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, cebasic acid, acid itaconic, phthalic acid, isophthalic acid, terephthalic acid, azelaic acid, etc., or a polybasic acid, for example 1,2,3-propanedicarboxylic acid, 1,3,5-n-pentanedicarboxylic acid, etc., and an alcohol, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, amyl alcohol , hexyl alcohol, octyl alcohol, phenol, cresol, 1,3-butanediol, 1,4-butanediol, piniacol, pentaerythritol, etc. Specific examples of the lactone compounds are, β-propiolactone, β-butyrolactone, e-caprolactone, αα, β-crotonlactone, ββ, β-cotonlactone, coumarin, phthalide, α-pyrone, sidonone, fluoran, and the like . As specific examples of lactam compounds, β-propiolactam, 2-pyrrolidone, 2-piperidone, e-caprolactam, n-heptanolactam, 8-octanolactam, 9-nonanolactam, 1 O-decanolactam, 2-quinolone, 1-isoquinolone, oxinadol , iso-indigo, isatin, hydantoin, and quinolidinone. Specific examples of the preferred epoxy compounds include 1,3-butadiene monoxide, 1,3-butadiene dioxide, 1,2-butylene oxide, cyclohexane oxide, 1,2-epoxy-cyclododecane, 1-2. epoxidecane 1,2-epoxy-eicosane, 1,2-epoxyheptane, 1,2-epoxy-hexadecane, 1,2-epoxyoctadecane, 1,2-epoxy-octane, diglycidyl ether of ethylene glycol, 1,2-epoxy-heptane, 1, 2-epoxy-tetradecane, hexamethylene oxide, isobutylene oxide, 1,7-octadien-diepoxide, 2-phenylpropylene oxide, propylene oxide, trans-stilbene oxide, epoxylated styrene oxide, 1,2-polybutadiene, epoxylated linasse oil, glycidyl methyl ether, glycidyl n-butyl ether, glycidyl glycol ether, glycidyl methacrylate, and glycidyl acrylate. A suitable molar ratio of component (a) to component (c) consists of a polar ketone compound, a hydroxyketone compound, an aldehyde compound, an ester compound, a lactone compound, a lactam compound or an epoxy compound, range of 10 to 1/2 and more preferably in the range of 5 to 1 and most preferably in the range of 2 to 1. A reducing organic metal compound is selected from the group consisting of aluminum compounds, zinc compounds, and magnesium compounds. Specific examples of the aluminum compounds are: trimethylaluminum, triethylalumium, tri- butylaluminum, triphenylaluminum, diethylaluminum chloride, ethylaluminum dichloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, aluminum hydride, hydride butyl aluminum, tri (2-ethex 1) aluminum, aluminum tri-i-propoxide, aluminum tri-t-butoxide, and diethylaluminum ethoxide. Examples of zinc compounds are: diethyl zinc, zinc bis (cyclopentadienyl), and diphenyl zinc; and examples of the magnesium compounds are: dimethyl magnesium, diethyl magnesium, methyl magnesium bromide, methyl magnesium chloride, ethyl magnesium bromide, ethyl magnesium chloride, phenyl magnesium bromide, phenyl magnesium chloride, and sodium chloride. -butyl magnesium. In addition to these compounds, compounds containing two or more reducing metals, such as lithium aluminum hydride, can be used as component (c). Of the above compounds, triethyl aluminum, tri-i-butyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, aluminum tri-i-propoxide, and aluminum tri-butoxide are preferred from the aspect of their availability and its ease of use. The molar ratio of component (a) and (c) is preferably greater than 1/20, more preferably 1 / 1-1 / 18 and most preferably 1 / 2-1 / 15. Polymers with a high degree of hydrogenation are obtained in accordance with the process of the present invention, where it has surprisingly been found that the catalyst system shows significantly higher activity in combination with high selectivity, resulting in a higher hydrogenation rate. high of the initial polymer or allowing the use of smaller concentrations of the catalyst per part by weight of the polymer, compared to the homogeneous Ti catalyst of the prior art, for hydrogenation processes. On the other hand, this catalyst is dosed with greater accuracy and shows excellent reproducibility. A clear advantage of the process of the present invention is formed by the fact that there appears to be no distinction during hydrogenation between the different types of CC double bonds, ie those pendant vinyl groups in the 1,2-position, those in the main chain without including C atoms, substituted, and those in the main chain comprising C atoms, substituted. As the catalyst system of the present process is applied in a significantly lower concentration, its concentration in the hydrogenated final product is much lower. The hydrogenation process can be carried out at partial pressures of the hydrogen which are in a range of 1 to 50 bar and preferably 1 to 35 bar. Included in the olefinically unsaturated polymers to be hydrogenated by the catalyst composition of the present invention are all polymers containing olefinically unsaturated carbon-carbon double bonds in the polymer backbone or in the side chains. Typical examples are polymers of conjugated dienes and polymers of conjugated dienes and olefins, grafting, blocks or random. Included in the above conjugated diene polymers are the homopolymers of conjugated dienes and copolymers produced from conjugated dienes or from at least one conjugated diene and at least one olefin copolymerizable with the conjugated diene. Given as typical examples of conjugated dienes used for the production of these conjugated diene polymers are conjugated dienes having from 4 to 12 carbon atoms. Specific examples are 1,3-butadiene, isopropene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1, 3-pentadiene, 1/3-pentadiene, 1, 3-hexadiene, 4,5-diethyl-1, 3-octadiene, 3-butyl-1,3-octadiene, and chloroprene. Particularly preferred are 1,3-butadiene and isopropene from the aspect of the manufacture of elasto-eros having superior characteristics and industrial advantages. Elastomers such as polybutadiene, polyisopropene, butadiene / isopropene copolymers are especially preferred polymeric materials for use in the present invention. There are no specific limitations for the microstructures of polymers. All these materials are suitable materials in the application of hydrogenation using the catalyst composition of the present invention. The aforementioned copolymers are produced from at least one conjugated diene and from at least one olefin copolymerizable with the conjugated diene, they are also suitable as polymer materials to which hydrogenation is applied using the catalyst composition of the present invention. The conjugated diene monomers described above are used for the manufacture of this type of copolymers. Some copolymerizable olefins with these conjugated dienes are usable for the manufacture of the copolymer, and the vinyl-substituted aromatic hydrocarbons are particularly preferred.

The copolymers of conjugated dienes and vinyl-substituted aromatic hydrocarbons are of particular importance for the production of industrially useful and valuable elastomers or thermoplastic elastomers. Specific examples of vinyl substituted aromatic hydrocarbons used in the manufacture of this type of copolymers are styrene, α-methylstyrene, t-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminostyrene. , N, N-diethyl-p-aminoetylstyrene, and vinylpyridine. Of these, styrene and a-methylstyrene are particularly preferred. The specific copolymers which give industrially valuable hydrogenated copolymers are the butadiene / styrene copolymers, the isopropene / styrene copolymers, and the butadiene / α-methylstyrene copolymers. These copolymers include random copolymers in which the monomers are randomly distributed throughout the polymers, block copolymers, progressively reduced, block-block copolymers, and bonded copolymers and preferably butadiene-styrene block copolymers, block copolymers isopropene-styrene or block copolymers of butadiene / isopropene-styrene, linearly or radially, of branches or multiple arms. For the manufacture of industrially useful thermoplastic elastomers, a preferable amount of vinyl-substituted aromatic hydrocarbons is in the range of 15 to 45% by weight. A content of vinyl bonds in the conjugated diene units of 10% or more of the total conjugated diene units is desirable to obtain hydrogenated polymers with superior characteristics. The polymers that are also included, which are used in the hydrogenation process using the catalyst composition of the present invention, are those of the linear type, as well as of the irido, or radial, or star type produced by coupling using a coupling agent. Also included in the polymers to be hydrogenated in accordance with the present invention are those having terminals modified with polar groups, after living anionic polymerization or by other means. The hydroxy group, carbonyl group, ester group, isocyanate group, urethane group, amide group, urea group and the thiourethane group can be used as polar groups. In addition to the aforementioned polymers, any of the polymers manufactured by any of the polymerization methods can be used in the present invention, for example, anion polymerization, cation polymerization, coordination polymerization, radical polymerization, solution polymerization, polymerization in emulsion, or the one you like. In addition, the manufacture of cyclo-olefin polymers by open-ring polymerization using a metathesis catalyst, such as molidene and tungsten, are included in polymers having olefinically unsaturated bonds. In the hydrogenation reaction using the catalyst composition of the present invention, the oleophilically unsaturated polymers can be hydrogenated in a condition where they are dissolved in a hydrocarbon solvent, or perhaps the oleophilically unsaturated polymers are produced by polymerization in a solvent of hydrocarbon and being able to be hydrogenated successively. The hydrocarbon solvents that are used in the hydrogenation reaction can be aliphatic hydrocarbons, for example, pentane, hexane, heptane, octane, etc .; alicyclic hydrocarbons, for example, cyclopentane, methyl-cyclopentane, cyclohexane, etc., or aromatic solvents such as toluene. These hydrocarbon solvents may contain 20% by weight or a smaller amount of ethers such as diethyl ether, tetrahydrofuran, dibutyl ether, diethoxypropane, and dioxane. There are no restrictions as regards the concentration of the polymers in carrying out the hydrogenation reaction in the present invention. Usually, however the concentration of the polymer is in the range of 1 to 30% by weight, and preferably in the range of 3 to 20% by weight. The hydrogenation reaction is carried out, after the addition of the hydrogenation catalyst composition under an inert gas atmosphere, for example, nitrogen or argon, or under a hydrogen atmosphere, by supplying hydrogen, with or without stirring while that the temperature of the polymer solution is maintained at a specific temperature. A suitable temperature for the hydrogenation reaction is in the range of 0 to 150 °. A temperature lower than 0 ° C is not economical, from a temperature lower than 0 ° C the activity of the catalyst decreases, but also the hydrogenation rate is retarded. If the temperature is higher than 150 ° C, otherwise, not only the polymers tend to decompose or gel, but also the aromatic rings are hydrogenated at the same time, leading to poor selective hydrogenation. Preferably, the temperature is in the range of 20 to 140 °, and more preferably in the range of 50 to 130 ° C. In the hydrogenation reaction using the catalyst composition of the present invention, the reaction is carried out at a comparably higher temperature, resulting in a higher reaction rate and a higher yield. The hydrogenation reaction is carried out for a period of time in a range of 1 minute to 5 hours. The greater the amount of the catalyst composition and the higher the pressure, the shorter the reaction time. It will be appreciated that another aspect of the present invention is formed by the titanium catalyst components (a) according to formula I. These catalyst components (a) are new compounds except (1-indenyl) (cyclopentadienyl) titanium dichloride and unsubstituted bis (1-indenyl) titanium dichloride. These compounds are prepared by methods, which are known in principle, for example, from Organometallic Chemistry, Section 4, pages 156-158 (1965), Organometal 1 ics 1984 (3), 223, and J. Am Chem. Soc. 1990, 112, 2030. More particularly preferred are the titanium compounds of the formula I, wherein two indenyl groups are substituted by lower alkyl or lower alkoxy or halogen or wherein an indenyl substituent and an optionally substituted cyclopentadienyl group are they substitute for groups specified above. The invention will now be illustrated by means of the following examples.

Example 1 Preparation of bis (1-methylindenyl) titanium 1.36g of 1-met ilindinili tio is added (lO.lmmol) to a solution of 0.91g TiCl4 (4.8mmol) in 50ml dichloromethane at -20 ° C. The mixture is allowed to warm to room temperature and is stirred for another hour, centrifuged and the clear solution is then decanted and evaporated in vacuo. The remainder is washed with pentane / di-ethyl ether and pentane to give the desired product, 80 mg of the pure product is isolated (0.2mmol), 2%.

Example 2 Preparation of bis (1- (pentafluorurophenyl) indenyl) -titanium dichloride 1.34g of 1- (pentafluorurophenyl) indenyl lithium (4.7mmol) is added to a solution of 0.42g of TiCl4 (2.2mmol) in 40ml of dichloromethane at -20 ° C. The mixture is allowed to warm to room temperature and is stirred for another hour, centrifuged, the clear solution is then decanted and evaporated in vacuo. The remainder is washed with hexane to give the desired product. An isomer is isolated, 265mg (0.4mmol), 17%.

EXAMPLE 3 Preparation of bis (5,6-di? T? Ethoxy indenyl) titanium dichloride 1.04g of 5,6-dimethoxyindenyl lithium (4.1mmol) is added to a solution of 0.38g of titanium chloride (IV) (2.0mmol) in 40ml of dichloromethane at -20 ° C. The mixture is allowed to warm to room temperature, stirred for another hour and centrifuged. The clear solution is then decanted and the solvents are evaporated by vacuum. The remainder is washed with diethyl ether (2 x 30ml) and the remainder is extracted with 40ml of dichloromethane. The solvent is evaporated to give 590mg of the desired product (63%).

Example 4 Preparation of bis (1-indenyl) dimethylsilyltitanium dichloride Add? -utilitium (6.1g, 1.6M in hexane) to a stirred solution of dimethylsilyl-bis-indene (2g) in dry hexane (40ml) at -70 ° C. The reaction mixture is allowed to warm to room temperature and is stirred for 20 hours. The white precipitate is isolated, washed with pentane, and subsequently dried under reduced pressure. The powder obtained is added slowly to a solution of TiCl4 (1.5g) in dichloromethane (60ml) at -70 ° C. The reaction mixture is allowed to warm to room temperature and is stirred for another hour. The formed solids are removed by centrifugation. The remaining solution is evaporated until the volatile components are removed. The crude product is washed 3 times with pentane and dried under reduced pressure. Crystallization is induced from dichloromethane with hexane, yielding 60 mg (2%) rac + meso-bis (1-indenyl) dimethylsilylthio-tanium dichloride as a very dark brown powder.

Example 5 Preparation of bis (1-indenyl) ethylene titanium dichloride 0.96g of TiCl4 (5.07mmol) is dissolved in 40ml of CH2C12, cooled to -40 ° C and 1.36g of bis- (1-indenyl) ethylene bis-lithium (5.07mmol) is added as a solid. After stirring for 2 hours at room temperature, the reaction mixture is centrifuged to remove the LiCl. The CH2C12 layer is evaporated to dryness giving (1-indenyl) ethylentitanium dichloride as brown crystals which are washed twice with hexane.

Example 6 Preparation of SBS block copolymer terminated in hydrogen A batch of 30L of polystyrene-polybutadiene-polystyrene (SBS) block copolymer of 70,000 molecular weight is prepared in a stainless steel reactor by sequential anionic polymerization using sec-butylthio as the initiator. The polymerization is carried in cyclohexane, to which 140 ppm of diethoxypropane at 18% by weight solids are added. The 1,2-content of the SBS polymer is 40.4% by weight. At the end the polymerization reactor is cooled to hydrogen jet for 2 hours to conclude the living polymer SBS-Li and produces SBS and LiH. The LiH content of the batch is determined to make 2.2 moles / liter.

Example 7 Hydrogenation of SBS block copolymer on bis (indenyl) titanium dichloride A stainless steel reactor is charged, with 190g of SBS cement, prepared as described in example 6. The reactor temperature is set at 70 °. C and the reactor is pressurized to 10 bar of hydrogen for the saturated cement. Meanwhile a suspension of 14mg is prepared (0, 04 mmol) of bisindenyl titanium dichloride in 10 ml of cyclohexane. The catalyst suspension is added to the reactor and the hydrogen pressure is raised to 50 bar. Immediately a strong exothermic reaction occurs (T = 82 ° C). The hydrogenation is allowed to continue for 3 hours, during which period the samples are removed from the reactor and analyzed by H1-NMR to determine the conversion of the olefinic double bonds. The conversion is determined as 72% by weight after 15 minutes, 75% by weight after 60 minutes and 77% by weight after 180 minutes EXAMPLE 8 Hydrogenation of SBS block copolymer with bis (indenyl) titanium dichloride A stainless steel reactor is charged with 800g of SBS cement, prepared as described in example 6. The reactor temperature is set at 50 ° C and the reactor is pressurized to 10 bar of hydrogen for the saturated cement. Meanwhile, a suspension of 29mg (0.084mmol) of bisindenyl titanium dichloride in 1Oml of cyclohexane is prepared. The catalyst suspension is added to the reactor and the hydrogen pressure is raised to 50 bar. Immediately an exothermic reaction occurs. The hydrogenation is allowed to continue for 3 hours, during which period the samples are removed from the reactor and analyzed by H1-NMR to determine the conversion of the olefinic double bonds. Following the same procedure, two more processes are carried out with 58mg (0.168mmol) and 87mg (0.252mmol) of bisindeniltitanium dichloride. The results are summarized in Table 1.

Table 1 Result of Hydrogenation with different amounts of bis indenyl titanium dichloride aonv to Conv. to Conv. to Quantity 15 min. 60 min 180 min (mmol) (% by weight) (% by weight) (% by weight) 0. 084 15 46 88 0.168 22 88 90 0.252 27 89 91 Comparative example Hydrogenation of SBS block copolymer with bis (cyclopentadienyl) titanium dichloride A stainless steel reactor is charged with 800gr of SBS cement, prepared as described in example 6. The reactor temperature is set at 50 ° C and the reactor is pressurized to 10 bar of hydrogen for the saturated cement. Meanwhile, a suspension of 21mg (0.084mmol) of biscyclopentadienylthiyl dichloride in 1Oml of cyclohexane is prepared. The catalyst suspension is added to the reactor and the hydrogen pressure is raised to 50 bar. The hydrogenation is allowed to continue for 3 hours period during which samples are taken from the reactor and analyzed by H1-NMR to determine the conversion of olefinic double bonds. The conversion is determined to be 22% by weight after 15 minutes, 51% by weight after ßO minutes and 60% by weight after 10 minutes, which is considerably lower than the same amount of bisindenyl titanium dichloride.

Examples 9-11 Hydrogenation of SBS block ecopolymers with substituted bis (indenyl) titanium dichloride compounds Following the example as described in example 7, three more hydrogenation experiments using 0.04 mmoles of the catalysts prepared in examples 1-3. Results are shown in table 2.

Table 2 Hydrogenation results with different indenyl titanium catalysts From conv. 15 min. conv. 60 min. conv.180 min. catalyst: (% by weight) (by weight) (% by weight) Example 1 47 79 81 Example 2 7 12 20 Example 3 27 91 96 Examples 12-14 Hydrogenation of SBS block copolymer with bis (indenyl) titanium dichloride in the presence of dimethyloxalate A stainless steel reactor is charged with 190gr of SBS cement, prepared as described in example 6. 4.7mg (0.04mmol) of dimethyloxalate in lOml of cyclohexanone are added to the reactor. The reactor temperature is set at 70 ° C and the reactor is pressurized to 10 bar of hydrogen for the saturated cement. Meanwhile a suspension of 14mg (0.04mmol) of bisindeniltitanium dichloride in lOml of cyclohexanone is prepared. The catalyst suspension is added to the reactor and the hydrogen pressure is raised to 50 bar. The hydrogenation reaction is allowed to continue for 3 hours, during which period the samples are removed from the reactor and analyzed by H1-NMR to determine the conversion of the olefinic double bonds. The results are shown in table 3.

Table 3 Substations of the hydrogenation with bi-indenyl chloride di-chloride modified with dimethoxalate modifier / Ti ccoonnvv .. 1155mmiinn .. ccoonnvv .. 6600 mmiiinnn conv.180 min (% by weight) (% in peessoo)) (% by weight) 1: 1 2200 5 555 83 0. 5: 1 7766 8 833 88 0.75: 1 7777 8 800 87 Eg bundles 15-16 Hydrogenation of the SBS block copolymer with bis (indenyl) titanium dichloride bridge compounds Following the same procedure as described in example 7, two more hydrogenation experiments are performed using 0.04 mmol of the catalysts of examples 4 and 5. The results are shown in table 4.

Table 4 Result of hydrogenation with compounds with bisindeniltitanium bridge catalyst conv.l5min. conv.60min. conv.ldO in. (% by weight) (% by weight) (% by weight) Example 4 29 33 36 Example 5 32 47 48 It will be appreciated that from these examples in relation to Examples 7-12 that the introduction of a bridging substituent between the indenyl groups does not necessarily improve the hydrogenation process.

Example 17 Hydrogenation of the SBS block copolymer with (indenyl) (cyclopentadienyl) titanium dichloride A stainless steel reactor is charged with 800g of SBS cement prepared as described in example 6. The reactor temperature is set at 50 ° C and the reactor is pressurized to 10 bar of hydrogen for the saturated cement. Meanwhile, a suspension of 0.109 mmoles of (indenyl) (cyclopentadienyl) titanium dichloride in lOml of cyclohexanone is prepared. The catalyst substraction is added to the reactor and the hydrogen pressure is raised to 50 bar. Immediately an exothermic reaction occurs. The hydrogenation is allowed to continue for 3 hours, during which period the samples are removed from the reactor and analyzed by H2 NMR to determine the conversion of the olefinic double bonds. Following the same procedure, 2 more processes are carried out with 0.109mmol of (5-methoxyindenyl) (cyclopentadienyl) -y (5,6-dimethoxyindenyl) (cyclopentadienyl) titanium dichloride. The results are summarized in table 5 Table 5 Result of hydrogenation with optional substituents of (indenyl) dichlorides (cyclopentadienyl) titanium Catalyst conv. 15 min conv. 60 min. Conv. 180 min (% by weight) (% by weight) (% by weight) IndCpTiCl2 17 70 98 MeOIndCpTiC12 13 37 96 (MeO) 2IndCpTiCl2 13 37 99 It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims (19)

1. A catalyst composition for the hydrogenation of polymers containing ethylenic unsaturations, characterized in that it comprises at least: (a) a titanium compound of the formula wherein Ai represents an optionally substituted indenyl group of the formula wherein the substituents Rx and R2 may be the same or different and each may be selected from halogen, phenyl, which may optionally support one or more substituents, the same or different, lower alkyl, alkoxy, phenoxy, phenylalkoxy, benzyl and a bulky substituent containing one or more heteroatoms such as tri (lower alkyl) silyl, ~ Nph2, ~ NHPh, ~ Bth2 and ~ B (OPh) 2, where n can be an integer from 0 to 4, and wherein m it can be an integer from 0 to 3, where A2 has the same meaning as Ai or alternatively represents an optionally substituted cyclopentadienyl group, and wherein Lx and L2 can be the same or different and each can be selected from hydrogen, halogen, lower alkyl, phenyl, aralkyl, having from 7 to 10 carbon atoms, a lower alkoxy group, phenyloxy, phenylalkoxy group having from 7 to 10 carbon atoms, carboxyl, carbonyl, a coordination group B- disectona, a gru po ~ CH2P (phenyl) 2, -CH2 Si (lower alkyl) 3 or ~ P (phenyl) 2; and (b) an alkali metal hydride, added as such or prepared in situ in the polymer solution from the living polymer terminated in alkali metal and / or from the added alkali metal alkyl in additional form.

2. The catalyst composition according to claim 1, characterized in that the molar ratio of the alkali metal: titanium is at least 2: 1.

3. The catalyst composition according to claim 1 or 2, characterized in that the alkali metal hydride is lithium hydride.

4. The catalyst composition according to the re-fractionation 3, characterized in that the molar ratio of lithium to titanium hydride is in the range of 6 to 25.

5. The catalyst composition according to any one of claims 1 to 4, characterized in that the ligands Lx and L2 in component (a) are selected from chlorine, bromine, carbonyl, methyl, ethyl, n-propyl, isopropyl , n-butyl, tert-butyl, sec-butyl, trimethylsilyloxy, benzyl, phenyl, hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, tert-butoxy, sec-butoxy, pentoxy, neopentoxy, phenoxy, phenylmethoxy, phenylethoxy and a CH2P (phenyl) 2 group.

6. The catalyst composition according to claim 5, characterized in that Lx and L2 are both chloro, benzyl, phenyl, methoxy, ethoxy, isopropoxy, tert-butoxy, n-butoxy, phenoxy p a group CH2P (phenyl) 2.

7. The catalyst composition according to claim 6, characterized in that Lx and L2 are both chlorine.

8. The catalyst composition according to any of claims 1 to 7, characterized in that component (a) is selected from the group consisting of bis (l-indenyl) titanium dichloride, bis (1-indenyl) titanium , diphenoxide, bis (1-indenyl) titanium dimethoxide, bis (1-methylindenyl) thianedium dichloride, bis (5,6-dimethoxy-indenyl) titanium dichloride, bis (dimethoxy-denyl) titanium dichloride, dichloride bis (dimethylsilylindenyl) titanium, (dimethoxyindenyl) (cyclopentadienyl) titanium dichloride, (dimethoxydenyl) (indenyl) titanium dichloride, (dimethoxyindenyl) (indenyl) titanium, (methoxyindenyl) (indenyl) titanium dichloride, dimethoxide (methoxyindenyl) (indenyl) titanium, (1-indenyl) (cyclopentadienyl) titanium dichloride, dimethoxide (1-indenyl) (cyclopentadienyl) titanium, and (1-indenyl) (cyclopentadienyl) titanium diphenoxide.

9. The catalyst composition according to any of claims 1 to 8, characterized in that it comprises in addition to the components (a) and (b) one or more promoters (c), which are selected from groups consisting of polar ketone compounds, ketone compounds containing hydroxy groups, aldehydic compounds, ester compounds, lactone compounds, lactam compounds and epoxy compounds.

10. The catalyst composition according to claim 9, characterized in that it comprises a promoter selected from the group consisting of ketone compounds containing hydroxy groups, aldehyde compounds, ester compounds and epoxy compounds.

11. The catalyst composition according to claim 9 or 10, characterized in that the molar ratio of component (a) to component (c) is in the range of 10 to 1/2.

12. The catalyst composition according to claim 11, characterized in that the molar ratio is in the range of 2 to 1.

13. The catalyst composition according to any of claims 1 to 9, characterized in that it comprises in addition to the components (a) and (b) one or more promoters (c), which represent a metallic organic reducing compound, is selected from the group consisting of aluminum compounds, zinc compounds, and magnesium compounds.

14. The catalyst composition according to claim 13, characterized in that the molar ratio of component (a) and (c) is in the range of 1/1 to 1/18.

15. The catalyst composition according to claim 14, characterized in that the molar ratio of component (a) and (c) is in the range of 1/2 to 1/15.

16. The process for the hydrogenation of polymers containing ethylenic unsaturation, characterized in that it consists in contacting a polymer solution, with hydrogen in the presence of at least the catalyst composition according to any of claims 1 to 15.

17. The titanium compound, characterized in that it has the formula wherein i represents an indenyl group, optionally substituted, of the formula wherein the substituents Ri and R2 may be the same or different and each may be selected from halogen, phenyl, which may optionally support one or more substituents, the same or different, lower alkyl, alkoxy, phenoxy, phenylalkoxy, benzyl and bulky substituents containing one or more heteroatoms such as tri (lower alkyl) silyl, ~ NPh2, ~ NHPh, ~ BPh2 and ~ B (0Ph) 2, where n can be an integer from 0 to 4 and m can be an integer from 0 to 3, or wherein A2 has the same meaning as io alternatively represents an optionally substituted cyclopentadienyl substrate group, and wherein Lx and L2 may be the same or different and each may be selected from hydrogen, halogen, lower alkyl, phenyl, aralkyl, having from 7 to 10 carbons, lower alkoxy group, phenyloxy, phenylalkoxy group having from 7 to 10 carbon atoms, carboxyl, carbonyl, a coordination group B-diketone, a group po ~ CH2P (phenyl) 2, -CH2 Si (lower alkyl) 3 or ~ P (phenyl) 2.

18. The titanium compound according to claim 17, characterized in that Lx and L2 in component (a) are selected from chlorine, bromine, carbonyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl , sec-butyl, trimethylsilyloxy. benzyl, phenyl, hexyl, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, tert-butoxy, secbutoxy, pentoxy, neopentoxy, phenoxy, phenylmethoxy, phenylethoxy and a group CH2P (phenyl) 2.

19. The titanium compound according to claim 18, characterized in that Lx and L2 are both chloro, benzyl, phenyl, methoxy, ethoxy, isopropoxy, tert-butoxy, n-butoxy, phenoxy or a group CH2P (phenyl) 2. SUMMARY OF THE INVENTION The present invention provides a catalyst composition for the hydrogenation of polymers containing ethylenic unsaturation which comprise at least: (a) a titanium compound of the formula wherein Ai represents an optionally substituted indenyl group of the formula írn wherein the substituents Ri and R2 may be the same or different and each may be selected from halogen, phenyl, which may optionally support one or more substituents, same or different, between lower alkyl, alkoxy, phenoxy, phenylalkoxy, benzyl and bulky substituents containing one or more heteroatoms such as bis (lower alkyl) silyl, ~ NPh2, ~ NHPh, ~ BPh2 and ~ B (0Ph) 2, wherein n may be a number from 0 to 4 and m may be a number from 0 to 3, or wherein A2 has the same meaning as Ai or alternatively represents an optionally substituted cyclopentadiene group, and wherein Li and L2 may be the same or different and each may be selected from hydrogen, halogen, lower alkyl, phenyl, aralkyl, having from 7 to 10 carbon atoms, lower alkoxy group, phenyloxy, phenylalkoxy group having from 7 to 10 carbon atoms, carboxyl , carbonyl, a coordination group B-diketone, a group ~ CH2P (phenyl) 2, -CH2 Si (lower alkyl) 3 or ~ P (phenyl) 2; and (b) and an alkali metal hydride, added as is or prepared in situ in the solution of the polymer from the living polymer finished in alkali metal and / or from the further addition of an alkali metal alkyl; and a process for the hydrogenation of polymers containing ethylenic unsaturation.