CN1130382C - Catalyst composition for hydrogenation of conjugated diene polymer and method for hydrogenation of the polymer - Google Patents

Abstract

The present invention relates to a process for hydrogenating a conjugated diene polymer comprising hydrogenating the polymer in the presence of hydrogen and a hydrogenation catalyst composition comprising: at least one titanium compound of formula : (b) at least one silane selected from the group consisting of: (i) a monomeric silane of formula (i): (ii) a polymeric silane of formula (ii): (iii) a cyclic silane of formula (iii): (iv) a silazane of formula (iv) or (v): and optionally (c) at least one metal compound, R in the above formulae¹、R²、Cp*、X₁、X₂、X₃、R、n、R^a、R^b、R^cAnd the like are described in the specification.

Description

Catalyst composition for hydrogenation of conjugated diene polymer and method for hydrogenation of the polymer

The present invention relates to an improved catalyst composition for the hydrogenation of conjugated diene polymers, wherein the conjugated diene polymers are obtained from the polymerization or copolymerization of conjugated diene monomers such as butadiene or isoprene made by polymerization. In particular, the present invention relates to catalyst compositions for the hydrogenation of conjugated diene polymers having good activity, high selectivity and low cost.

In particular, the present invention relates to a catalyst composition for hydrogenation of conjugated diene polymers (prepared by polymerization or polymerization of conjugated diene monomers) and a catalyst composition for hydrogenation of the conjugated diene polymers method to improve the weatherability, heat resistance and oxidation resistance of polymers.

The polymerization or copolymerization of conjugated dienes (eg, butadiene, isoprene) to prepare synthetic rubbers has been widely used industrially for commercial manufacture. Basically, these polymers can be prepared using emulsification (free-radical polymerization) or solution (anionic polymerization) methods. Both methods result in conjugated diene polymers (copolymers) containing unsaturated double bonds in the polymer backbone. These unsaturated double bonds can be vulcanized to improve the toughness of the material. However, since these unsaturated double bonds are easily oxidized, the material has the disadvantage of being unstable under high temperature or weathering test (exposed to ozone). In particular, it is considered necessary to improve the thermal stability and Defects of insufficient weather stability.

Deficiencies in thermal stability and weathering stability can be improved by removing or reducing unsaturated double bonds on polymer bonds. By hydrogenating olefinically unsaturated double bonds, more stable polymers with almost aliphatic structures can be obtained. In general, heterogeneous or homogeneous catalysts can be used to reduce unsaturated double bonds. Heterogeneous catalysts have lower hydrogenation activity, so higher reaction temperatures, higher reaction pressures and larger amounts of heterogeneous catalysts are required during the reaction, so they are less economical. In addition to the above-mentioned problems, the harsh reaction conditions also cause hydrogenation not only on the olefin double bonds that need to be reacted, but also on the arene double bonds. As a result, undesired polymer structures are produced which contain undesired partial cyclohexyl structures (derived from hydrogenation of benzene rings on the polymer backbone) and have undesired semi-crystalline properties. Therefore, there is an urgent need in the industry to develop a homogeneous catalyst system that can be used to hydrogenate polymers of conjugated dienes and has high activity and high selectivity (does not hydrogenate the double bonds of aromatic hydrocarbons).

The method of using dicyclopentadienyl titanium compound as reaction catalyst is a known efficient homogeneous hydrogenation reaction (as disclosed in the following literature: M.F.Sloan et al. in Journal of American Chemical Society 1965, 85, 4014-4018 , Y.Tajima, et al.inJournal of Organic Chemistry, 1968, 33, 1689-1690, British patent 2, 134, 909, Japanese patent 61, 28507) This catalyst system has good activity and excellent selectivity for hydrogenating olefinic double bonds. However, the reaction was difficult to reproduce due to the poor stability of this catalyst system.

In 1985, Kishimoto et al disclosed in USP 4,501,857 that hydrogenation of olefinic double bonds was carried out in the presence of at least one biscyclopentadienyl titanium compound and at least one hydrocarbon lithium compound, wherein the hydrocarbon lithium compound can be combined with anion Active chain ends are used in combination. In 1987, Kishimoto et al disclosed in US P 4,673,714 that a biscyclopentadienyl diaryl titanium compound was used to hydrogenate a conjugated diene polymer without adding an alkyllithium compound. Both of the above-mentioned methods use a high concentration of biscyclopentadienyl titanium compound as a catalyst and are therefore very uneconomical. In 1990, Teramoto et al disclosed in USP 4,980,421 that a similar hydrogenation activity could be obtained using the same titanium compound in combination with an alkoxy compound. In 1991, Chamberlain et al. disclosed in USP 5,039,755 that hydrogen gas was used to terminate the active bond, followed by the addition of a dicyclopentadienyl titanium compound to allow the hydrogenation reaction to proceed. The problem with the above method is that the hydrogen gas is not very effective at terminating active bond ends, so the hydrogenation reaction is difficult to reproduce. In 1992, Chamberlain et al disclosed a similar hydrogenation method in USP 5,132,372 and 5,173,537, which used hydrogen to terminate the active bond end, then added dicyclopentadienyl titanium compound and additional catalyst promoter (methyl benzoate), In order to make the hydrogenation of the conjugated diene polymer more efficient.

All of the above catalyst compositions use alkyllithium (static in situ generated lithium hydride) or alkoxylithium compounds to activate biscyclopentadienyltitanium compounds for more efficient hydrogenation of conjugated diene polymers. It must be noted that the reduction of biscyclopentadienyl titanium compounds from Ti(IV) to Ti(III) can also be initiated in the presence of lithium, which will lead to the decomposition of catalyst components and the reduction of catalyst activity and stability. Therefore, from an economical point of view, it is highly desirable to develop a catalyst composition that avoids the decomposition of the reactive catalyst (biscyclopentadienyl titanium compound) and provides stable and efficient hydrogenation results using only a small amount of catalyst. .

An object of the present invention is to provide a catalyst composition for hydrogenation of conjugated diene polymers, which has high hydrogenation activity and selectivity. And have a minimum amount of catalyst components.

Another object of the present invention is to provide a method for hydrogenating conjugated diene polymers, which has high hydrogenation activity and selectivity in the absence of lithium hydrocarbon compounds.

The present invention relates to a kind of catalyst composition, it comprises:

(a) at least one titanium compound, as shown in formula (a):

In the formula, R ^{and R} can be the same or different, representing a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group, an alkoxy group or a carbonyl group,

Cp* represents a cyclopentadienyl group or a derivative of the formula C ₅ R ₅ , where R ₅ may be the same or different, representing a hydrogen atom, an alkyl group, an aralkyl group and an aryl group;

(b) at least one silane selected from the group consisting of:

(i) monomeric silane, as shown in the following formula (i):

In the formula, X ₁ , X ₂ and X ₃ can be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group, an alkoxy group, an acyloxy group or a carboxyl group,

(ii) polymeric silane, as shown in formula (ii):

In the formula, R can be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group, and n≥0,

(iii) Cyclic silane, as shown in formula (iii):

In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group, and n is an integer of 2-5,

as well as

(iv) silazanes, as shown in formula (iv) or (v):

In the formula, R ^a , R ^b , and R ^c may be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group; and optionally including

(c) at least one metal compound selected from the group consisting of organoaluminum compounds, organomagnesium compounds, organolithium compounds, organozinc compounds, lithium hydride and formula LiOR ³ , wherein R ³ represents alkyl, aryl, aralkyl or Cycloalkyl.

An advantage of the catalyst composition according to the invention is that the catalyst composition has a higher reactivity for the hydrogenation of olefinic double bonds. Thus, the total amount of titanium species added to the reaction can be reduced, thereby providing a more economical reaction. Another advantage of the catalyst composition of the present invention is that, due to the improved stability of the catalyst system, a high conversion of the olefinic double bond of the conjugated diene polymer and a high selectivity can be obtained.

The present invention provides a catalyst composition for hydrogenation of a conjugated diene polymer having high reactivity, selectivity and stability. The catalyst compositions disclosed herein use commercially available ingredients (silane ingredients) resulting in improved catalyst stability, catalyst activity, and conversion. As a result, the total amount of catalyst components can be reduced, which can lead to lower manufacturing costs for the hydrogenation process.

The present invention also relates to a process for hydrogenating a conjugated diene polymer comprising: hydrogenating the polymer in the presence of hydrogen and a hydrogenation catalyst composition comprising:

(a) at least one titanium compound, as shown in formula (a):

In the formula, R ^{and R} can be the same or different, representing a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group, an alkoxy group or a carbonyl group,

Cp ^* represents a cyclopentadienyl group or a derivative of the formula C ₅ R ₅ , where R ₅ may be the same or different, representing a hydrogen atom, an alkyl group, an aralkyl group and an aryl group;

(b) at least one silane selected from the group consisting of:

(i) monomeric silane, as shown in the following formula (i):

In the formula, X ₁ , X ₂ and X ₃ can be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group, an alkoxy group, an acyloxy group or a carboxyl group,

(ii) polymeric silane, as shown in formula (ii):

In the formula, R can be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group, and n≥0,

(iii) Cyclic silane, as shown in formula (iii):

In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group, and n is an integer of 2-5,

as well as

(iv) silazanes, as shown in formula (iv) or (v):

In the formula, R ^a , R ^b , and R ^c may be the same or different, representing a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an aryloxy group or an alkoxy group; and optionally including

(c) at least one metal compound selected from organoaluminum compounds, organomagnesium compounds, organolithium compounds, organozinc compounds, lithium hydride, and formula LiOR ³ , wherein R ³ represents alkyl, aryl, aralkyl or cycloalkyl.

Cp* in the formula (a) represents a cyclopentadienyl group or a derivative of the formula C ₅ R ₅ , where R ₅ may be the same or different, and represent a hydrogen atom, an alkyl group, an aralkyl group and an aryl group. Examples of suitable Cp* are cyclopentadienyl and pentamethylcyclopentadienyl. Based on industrial convenience, it is preferable to use cyclopentadienyl as Cp*.

Examples of suitable titanium compounds of formula (a) are: biscyclopentadienyl titanium dichloride, biscyclopentadienyl titanium dibromide, biscyclopentadienyl titanium diiodide, biscyclopentadienyl titanium difluoride , dicyclopentadienyl dicarbonyl titanium, dicyclopentadienyl dimethyl titanium, dicyclopentadienyl diethyl titanium, dicyclopentadienyl dipropyl (including isopropyl) titanium, dicyclopentadiene Dibutyl (including n-butyl, sec-butyl, tert-butyl) titanium, dicyclopentadienyl dibenzyl titanium, dicyclopentadienyl diphenyl titanium, dicyclopentadienyl dimethoxy titanium , Dicyclopentadienyldiethoxytitanium, dicyclopentadienyldipropoxytitanium, dicyclopentadienyldibutoxytitanium, dicyclopentadienyldiphenoxytitanium, dicyclopentadienyldiphenoxytitanium, dicyclopentadienyldipropoxytitanium Methyl titanium chloride, dicyclopentadienyl methyl titanium bromide, biscyclopentadienyl methyl titanium iodide, biscyclopentadienyl methyl titanium fluoride, bis-pentamethylcyclopentadienyl dichloride Titanium chloride, bis-pentamethylcyclopentadienyl titanium dibromide, bis-pentamethylcyclopentadienyl titanium diiodide, bis-pentamethylcyclopentadienyl titanium difluoride, bis-pentamethylcyclopentadienyl titanium difluoride Pentadienyl dicarbonyl titanium, bis-pentamethylcyclopentadienyl dibutyl (including n-butyl, sec-butyl, tert-butyl) titanium, bis-pentamethylcyclopentadienyl dibenzyl titanium, Bispentamethylcyclopentadienyldiphenyltitanium and mixtures thereof. A preferred titanium compound is dicyclopentadienyl titanium dichloride due to easier handling, air stability, and commercial availability.

Examples of suitable monomeric silanes of formula (i) are: methyldichlorosilane, ethyldichlorosilane, propyldichlorosilane, butyldichlorosilane, phenyldichlorosilane, dimethylchlorosilane, Diethylchlorosilane, dipropylchlorosilane, dibutylchlorosilane, diphenylchlorosilane, dimethylmethoxysilane, dimethylethoxysilane, dimethylpropoxysilane, dimethyl Diethylbutoxysilane, Dimethylbenzyloxysilane, Diethylethoxysilane, Diethylpropoxysilane, Diethylbutoxysilane, Diethylbenzyloxysilane, Dipropylmethylsilane Oxysilane, Dipropylethoxysilane, Dipropylpropoxysilane, Dipropylbutoxysilane, Dipropylbenzyloxysilane, Dibutylmethoxysilane, Dibutylethoxysilane, Dibutylpropoxysilane, dibutylbutoxysilane, dibutylbenzyloxysilane, diphenylmethoxysilane, diphenylethoxysilane, diphenylpropoxysilane, diphenyl Butoxysilane, Diphenylbenzyloxysilane, Dimethylsilane, Diethylsilane, Dipropylsilane, Dibutylsilane, Diphenylsilane, Diphenylmethylsilane, Diphenylethylsilane Diphenylsilane, Diphenylpropylsilane, Diphenylbutylsilane, Trimethylsilane, Triethylsilane, Tripropylsilane, Tributylsilane, Triphenylsilane, Methylsilane, Ethylsilane, Propylsilane, Butylsilane, Phenylsilane and Methyldiacetoxysilane.

The value of n in formula (ii) is greater than or equal to 0, preferably between 0 and 100.

Examples of suitable polymeric silanes of formula (ii) are: polymethylhydrogensiloxane, polyethylhydrogensiloxane, polypropylhydrogensiloxane, polybutylhydrogensiloxane, polyphenylhydrogensiloxane and 1,1,3,3-tetramethyldisiloxane.

Examples of suitable cyclic silanes of formula (iii) are: methylhydrocyclosiloxane, ethylhydrocyclosiloxane, propylhydrocyclosiloxane, butylhydrocyclosiloxane and phenylhydrocyclosiloxane .

Examples of suitable silazanes of formula (iv) are: 1,1,3,3-tetramethyldisilazane, 1,1,3,3-tetraethyldisilazane, 1,1,3 , 3-tetrapropyldisilazane, 1,1,3,3-tetrabutyldisilazane and 1,1,3,3-tetraphenyldisilazane.

Examples of suitable organoaluminum compounds are: trimethylaluminum, triethylaluminum, triisobutylaluminum, triphenylaluminum, diethylaluminum chloride, ethylaluminum dichloride, methyl sesquichloride Aluminum (methylaluminium sesquichloride), ethylaluminum sesquichloride, diethylaluminum hydride, diisobutylaluminum hydride, triphenylaluminum, and tris(2-ethylhexyl)aluminum.

Examples of suitable organomagnesium compounds are: dimethylmagnesium, diethylmagnesium, methylmagnesium bromide, methylmagnesium chloride, ethylmagnesium bromide, ethylmagnesium chloride, phenylmagnesium bromide, phenylmagnesium chloride and di Methyl magnesium chloride.

Examples of suitable organozinc compounds are: diethylzinc, dicyclopentadienylzinc and diphenylzinc.

Examples of suitable ^LiOR compounds are: Lithium methoxide, Lithium ethoxide, Lithium n-propoxide, Lithium isopropoxide, Lithium n-butoxide, Lithium butoxide, Lithium tert-butoxide, Lithium pentoxide Oxylithium, hexyloxylithium, heptyloxylithium, octyloxylithium, phenoxylithium, 4-methylphenoxylithium, 2,6-di-tert-butyl-4-methylphenoxylithium and lithium benzyloxide.

Examples of suitable organolithium compounds are: methyllithium, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, phenyllithium , benzyllithium, dilithium compounds (such as 1,4-dilithium-n-butane), and anionically active polymers with active lithium on the polymer bond.

The lithium hydride of the present invention can be used in its native form, or can be produced statically in situ, ie, a living conjugated diene polymer with active lithium ends which are hydrogenated with hydrogen to produce lithium hydride. For good hydrogenation activity, it is preferred to use static in situ generated lithium hydride.

Even in the absence of metal compound (c), ie, only titanium compound (a) and silane (b) are used, the catalyst composition can still show good hydrogenation activity and selectivity.

The molar ratio of silane (b) to titanium compound (a) may be 0.01/1 to 200/1, preferably 0.1/1 to 100/1. The silanes (b) according to the invention improve the stability of the catalyst system resulting in high conversion and high selectivity of olefinic double bonds and reproducible hydrogenation. The stability of the catalyst composition with high hydrogenation activity may be due to the formation of a biscyclopentadienylsilyl titanium complex of the formula:

In the formula, A* is a silicone group derived from silane (b), for example

Metal compound (c) can be used as an additional catalyst component of titanium compound (a) and silane (b) for other purposes, for example to mitigate the negative influence of impurities in conjugated diene polymers during hydrogenation the goal of. Polar compounds such as tetrahydrofuran, triethylamine, N,N,N',N'-tetramethylethylenediamine and ethylene glycol dimethyl ether can also be used as additional catalyst components.

Wherein the molar ratio of silane (b) to titanium compound (a) is 0.01/1 to 200/1. The molar ratio of the metal compound (c) to the titanium compound (a) may be 0/1 to 100/1, preferably 0.5/1 to 25/1, most preferably 1/1 to 10/1. If the molar ratio (c)/(a) is greater than 100/1, it tends to cause gelation of the polymer and undesired secondary reactions, thereby reducing catalyst activity.

The catalyst composition of the present invention having the above molar ratio has higher reactivity to olefinic double bonds. Therefore, the total amount of titanium component added to the reaction can be reduced, providing a more economical reaction process.

It is known that conjugated diene polymers can be prepared using free radical or anionic catalysts. This polymer can be prepared using bulk, solution or emulsion techniques. In general, when using solution anionic techniques, conjugated diene polymers are prepared by contacting one or more monomers to be polymerized simultaneously, or by sequentially contacting the monomers with an anionic polymerization initiator such as Group IA metals, their alkanes, amides, silanolates, naphthalenes, diphenyls and anthracene derivatives) are contacted together. It is best to use an organic alkali metal compound in a suitable solvent at a temperature of -150°C to 300°C, preferably at a temperature of 0°C to 100°C.

The catalysts of the invention can be used on all polymers having olefinically unsaturated double bonds. Preferably, the catalyst is applied to conjugated diene polymers. The number average molecular weight of the polymer is generally between 500 and 1,000,000. The conjugated diene polymers include homopolymers of conjugated dienes, copolymers of different conjugated dienes, and copolymers of at least one conjugated diene and at least one olefin monomer. The conjugated dienes used to make these conjugated diene polymers generally have 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 and 4,5-diethyl-1,3-butadiene, preferably homopolymers of 1,3-butadiene and/or isoprene Or copolymers, 1,3-butadiene and isoprene are particularly suitable for use because of their advantages in industrial application and the availability of elastomers with excellent properties.

The catalysts of the present invention are preferably applicable to the hydrogenation of copolymers obtained by the copolymerization of at least one conjugated diene and at least one olefinic monomer. Preferred conjugated dienes for use in preparing the copolymers are as described above. As the olefin monomer, all olefin monomers copolymerizable with the conjugated diene can be used, and vinyl-substituted aromatic hydrocarbons are particularly suitable. Specific examples of vinyl-substituted aromatics used to make such copolymers include: styrene, tert-butylstyrene, alpha-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenyl Ethylene, N,N-dimethyl-p-aminoethylstyrene and N,N-diethyl-p-aminoethylstyrene, etc. Of course, it is preferable to use styrene. Specific examples of copolymers of conjugated dienes and vinyl-substituted aromatics include butadiene/styrene copolymers and isoprene/styrene copolymers, since these two copolymers provide hydrogenated copolymers of high industrial value , so it is particularly suitable.

Copolymers of conjugated dienes and vinyl-substituted arenes, including random copolymers, tapered block copolymers, fully block copolymers, and graft copolymers in which the monomers are randomly distributed throughout the polymer chain things. Among these polymers, block copolymers are particularly suitable in order for the copolymers to exhibit properties as thermoplastic elastomers.

Such block copolymers comprise (a) at least one polymer block A which is predominantly vinyl-substituted arene, and (b) at least one predominantly conjugated diene, especially 1,3-butadiene and/or or polymer block B of isoprene. Block A may include minor amounts of conjugated dienes, while block B may also include minor amounts of vinyl substituted arenes. Block copolymers include not only linear types but also so-called branched, radial, and star types formed by coupling linear block polymers using a coupling agent. The block copolymer suitable for the present invention preferably contains 5% to 95% by weight of ethylene-substituted arene, and preferably, the main component is styrene-substituted polymer block A with a content of 0 to 90% by weight. The microstructure of the conjugated diene units of the block copolymer has a 1,2-ethylene content of 6% to 80% by weight, or the 1,2-ethylene content in the polymer block B is 6% to 80% by weight %, preferably 20%-70%. When a block copolymer satisfying these requirements is hydrogenated, its olefin portion has good elasticity, and therefore is not only industrially useful, but also has a low solution viscosity and is easily separated from a reaction solvent. Thus, hydrogenated block copolymers can be produced economically.

Generally, the hydrogenation reaction can be carried out in a suitable solvent at a temperature of 0°C to 120°C (preferably at 50°C to 90°C) and a hydrogen partial pressure of 1 psig to 1200 psig (preferably 100 to 200 psig). Catalyst concentrations of 0.001 mM (millimoles) per 100 grams of polymer to 20 mM per 100 grams of polymer are typically used, and contact times under hydrogenation conditions are from 10 to 360 minutes.

The catalyst components of the present invention may be added alone to the solution of the conjugated diene polymer, or pre-mixed with some of the catalyst components.

The reaction can be carried out in a stirred tank reactor or a loop reactor, wherein the hydrogenated solution mixture is withdrawn from the reactor, circulated by a pump through a heat exchanger, and then introduced into the reactor to be contacted with hydrogen gas . The reaction can be carried out continuously or batchwise. The catalyst of the present invention may be added to the reaction medium, or may be in the form of a solution in an inert organic solvent as described above.

The hydrogenation process associated with the present invention can be carried out in bulk or in solution. In the solution process, the inert solvent used in the anionic polymerization process can be used directly without additional purification procedures. Thus, the present invention provides a simpler reaction process that can use the same reaction medium for simultaneous anionic polymerization and hydrogenation. In general, any known solvent for preparing conjugated diene polymers can be used. Suitable solvents include linear heptane, octane, etc., and their alkyl-substituted derivatives, and include cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane, cycloheptane, and their alkyl- and aryl-substituted Derivatives of aryl and alkyl substituted aromatics such as benzene, naphthalene, toluene, xylene and their derivatives, and hydrogenated aromatics such as tetralin, decalin and Derivatives thereof, and include linear and cyclic ethers such as dimethyl ether, methyl ethyl ether, diethyl ether, tetrahydrofuran and their derivatives.

After the hydrogenation reaction, alcohols such as methanol, ethanol or isopropanol can be used to quench the reaction solution to precipitate the desired hydrogenated polymer. The resulting polymer product can be collected by filtration and dried in vacuo to obtain the desired product in higher purity. It is worth noting that due to the high reactivity of the catalyst system of the present invention, only a small amount of catalyst components are needed in the hydrogenation reaction, and thus no additional deashing process is required to remove the catalyst components.

By correctly selecting hydrogenation conditions, the hydrogenation catalyst of the present invention can hydrogenate a considerable amount of unsaturated double bonds of olefins. The catalyst further allows hydrogenation of the double bond to the desired amount of hydrogenation. In the hydrogenation of the conjugated diene polymer, the amount of hydrogenation is such that at least 50% (preferably at least 90%) of the unsaturated double bonds of the conjugated diene units are hydrogenated. In the case of copolymers of conjugated dienes and vinyl-substituted arenes, the amount of hydrogenation is such that at least 50% (preferably 90%) of the unsaturated double bonds of the conjugated diene units of the original copolymer are hydrogenated , while 10% or less (preferably 5% or less) of the double bonds of the aromatic portion of the original copolymer are hydrogenated.

The percent hydrogenation of olefinic unsaturated double bonds can be measured by infrared absorption spectroscopy. When aromatic hydrocarbons are contained, it can be measured by combining ultraviolet absorption spectrum, NMR spectrum, and the like.

The present invention will be described in detail with reference to the following examples. However, the embodiments and preferred embodiments of the present invention are not intended to limit the scope of the present invention.

A, preparation reaction catalyst:

Example 1:

Dimethyl biscyclopentadienyl titanium (dimethyl titanocene) (a) and silane (b) of formula (i), (ii), (iii) or (iv) in an inert solvent (such as toluene or cyclohexane) Combine in medium to produce a pale tan to brown solution. The catalyst was isolated by removal of volatiles and drying in vacuo.

The reaction components for preparing the catalyst are listed in the table below:

Table 1: Catalyst Components for Preparation of Active Catalysts

1. Molecular weight of methylhydrogen cyclosiloxane = 240

2. The molecular weight of polymethyl hydrogen siloxane a = 420

3. Molecular weight of polymethylhydrogensiloxane b = 5000

Example 2:

Add metal compound (c) (alkyl lithium or alkyl magnesium) to silane (b) containing dicyclopentadienyl titanium chloride (a) and formula (i), (ii), (iii), or (iv) ) in an inert solution so that an active catalyst is generated in situ to obtain a hydrogenation catalyst. The reaction components are listed in the table below:

Table 2: Catalyst Components for Preparation of Active Catalysts 13 n-Butyllithium (10.0mmol) _Cp2TiCl2 ( _0.25g ; 1.0mmol) Methyldiacetoxysilane (0.97 g; 6.0 mmol) Toluene (20ml) 14 n-Butyllithium (10.0mmol) _Cp2TiCl2 ( _0.25g ; 1.0mmol) Methylhydrocyclosiloxane (0.36 g; 1.5 mmol ¹ ) Toluene (20ml) 15 n-Butyllithium (10.0mmol) _Cp2TiCl2 ( _0.25g ; 1.0mmol) Polymethylhydrogensiloxane a (0.48g; 1.1mmol ² ) Toluene (20ml) 16 n-Butyllithium (10.0mmol) _Cp2TiCl2 ( _0.25g ; 1.0mmol) Polymethylhydrogensiloxane ^b (0.48g; 0.096mmol ³ ) Toluene (20ml) 17 EtMgBr (12.0mmol) _Cp2TiCl2 ( _0.25g ; 1.0mmol) Polymethylhydrogensiloxane ^a (0.48g; 1.1mmol ² ) Toluene (20ml)

1. Molecular weight of methylhydrogen cyclosiloxane = 240

2. The molecular weight of polymethyl hydrogen siloxane ^a = 420

3. Molecular weight of polymethylhydrogensiloxane ^b = 5000

B. Hydrogenation of synthetic rubber

Example 3:

The catalyst components prepared in Example 1 were diluted in toluene or cyclohexane to form a 0.01M catalyst solution (based on Ti concentration). The resulting catalyst solution was used directly for the hydrogenation of styrene butadiene styrene (SBS) polymers. SBS polymer (linear block copolymer, number average molecular weight 100,000) was prepared by an anionic polymerization step followed by isopropanol termination of the living chain, followed by filtration and drying overnight under vacuum. The SBS polymer contains 30 wt% styrene units, 70 wt% butadiene units (containing 25 wt% 1,2-ethylene structure). Then, 15 grams of SBS polymer was dissolved in 125 ml of cyclohexane. The resulting SBS/cyclohexane solution was used directly for hydrogenation. Hydrogenation of the SBS polymer was carried out in a 500 ml autoclave under _H2 pressure of 200 psi at 60 °C using cyclohexane as the reaction solvent. After the reaction was maintained at 60° C. under H ₂ pressure of 200 psi for 60 minutes, the reaction solution was quenched with isopropanol. Filtration and drying overnight at 40°C gave the hydrogenated product. The overall conversion of olefinic double bonds was then analyzed by IR spectroscopy. The hydrogenation results are listed in the table below.

Table 3: Use the catalyst that embodiment 1 makes to carry out the hydrogenation of SBS polymer Catalyst number (volume used) Net weight of butadiene unit (g) Conversion rate of butadiene unit (%) Catalyst conversion (moles of butadiene converted/moles of catalyst used) Hydrogenation selectivity*(%) 1(1.2ml) 10.5 92 14900 99 2(1.2ml) 10.5 76 12300 99 3(1.2ml) 10.5 96 15500 99 4(1.2ml) 10.5 64 10300 99 5(1.2ml) 10.5 99 16000 99 6(1.2ml) 10.5 99 16000 99 7(1.2ml) 10.5 99 16000 99

*Hydrogenation selectivity is calculated as, (moles of butadiene converted)/(moles of butadiene converted) + (moles of benzyl double bonds converted)

Example 4:

The catalyst components prepared in Example 2 were diluted in toluene or cyclohexane to form a 0.01M catalyst solution (based on Ti concentration). The resulting catalyst solution was used directly for the hydrogenation of styrene butadiene styrene (SBS) polymers. The SBS polymer is the same as in Example 3. Using cyclohexane as the reaction solvent, the hydrogenation of the SBS polymer was carried out in a 500ml autoclave under _H2 pressure of 200psi and 60°C. After the reaction was maintained at 60° C. under H ₂ pressure of 200 psi for 60 minutes, the reaction solution was quenched with isopropanol. Filtration and drying overnight at 40°C gave the hydrogenated product. The overall conversion of olefinic double bonds was then analyzed by IR spectroscopy. The hydrogenation results are listed in the table below.

Table 4: Use the catalyst that embodiment 2 makes to carry out the hydrogenation of SBS polymer Catalyst number (volume used) Net weight of butadiene unit (g) Conversion rate of butadiene unit (%) Catalyst conversion (moles of butadiene converted/moles of catalyst used) Hydrogenation selectivity*(%) 8(1.2ml) 10.5 90 14600 99 9(1.2ml) 10.5 86 13900 99 10(1.2ml) 10.5 78 12700 99 11(1.2ml) 10.5 99 16000 99 12(1.2ml) 10.5 95 15400 99 13(1.2ml) 10.5 52 8400 99 14(1.2ml) 10.5 93 15100 99 15(1.2ml) 10.5 99 16000 99 15(0.8ml) 10.5 99 24100 99 16(1.2ml) 10.5 99 16000 99 17(1.2ml) 10.5 98 15900 99

*Hydrogenation selectivity is calculated as, (moles of butadiene converted)/(moles of butadiene converted) + (moles of benzyl double bonds converted)

Example 5:

The hydrogenation reaction of Example 4 was repeated, but the SBS polymer prepared by anionic polymerization was used directly without purification (the SBS polymer solution still contained active lithium chain ends). The hydrogenation results are listed in the table below.

Table 5: Hydrogenation of SBS polymers with active anionic chain ends Catalyst number (volume used) Net weight of butadiene unit (g) Conversion rate of butadiene unit (%) Catalyst conversion (moles of butadiene converted/moles of catalyst used) Hydrogenation selectivity*(%) 8(1.2ml) 8.75 90 12200 99 10(1.2ml) 8.75 99 13300 99 11(1.2ml) 8.75 94 12700 99 13(1.2ml) 8.75 84 11300 99 14(1.2ml) 8.75 91 12300 99 15(1.2ml) 8.75 99 13300 99 15(0.8ml) 8.75 99 20100 99

*Hydrogenation selectivity is calculated as, (moles of butadiene converted)/(moles of butadiene converted) + (moles of benzyl double bonds converted)

Embodiment 6:

Catalyst No. 15 was used as catalyst to repeat the hydrogenation reaction of Example 5, but using different reaction temperature, _H2 pressure and reaction time. The hydrogenation results are listed in the table below.

Table 6: Hydrogenation of SBS using Catalyst No. 15 Catalyst serial number (all volumes) Net weight of butadiene unit (g) Reaction temperature (°C) Reaction pressure (psi) Response time (minutes) Conversion rate of butadiene unit (%) catalyst conversion Hydrogenation selectivity*(%) 15(1.2ml) 8.75 40 200 40 64 8600 99 15(1.2ml) 8.75 40 200 80 99 13300 99 15(1.2ml) 8.75 40 100 80 59 7780 99 15(1.2ml) 8.75 40 100 180 99 13300 99 15(1.2ml) 8.75 40 300 40 99 13300 99 15(1.2ml) 8.75 40 400 25 99 13300 99 15(1.2ml) 8.75 60 200 60 99 13300 99 15(1.2ml) 8.75 60 100 90 99 13300 99

*Hydrogenation selectivity is calculated as, (moles of butadiene converted)/(moles of butadiene converted) + (moles of benzyl double bonds converted)

Comparative Example 1

The hydrogenation reaction of Example 3 was repeated, but using Cp ₂ Ti(Me) ₂ as the reaction catalyst. After the reaction was maintained at 60° C. under H ₂ pressure of 200 psi for 60 minutes, the reaction solution was quenched with isopropanol. Filtration and drying overnight at 40°C gave the hydrogenated product. The total conversion of olefinic double bonds was then analyzed by IR spectroscopy to be 45%, corresponding to a catalyst conversion of 7250.

Comparative Example 2

The hydrogenation reaction of Example 4 was repeated, but using Cp ₂ TiCl ₂ as the reaction catalyst. After the reaction was maintained at 60° C. under H ₂ pressure of 200 psi for 60 minutes, the reaction solution was quenched with isopropanol. Filtration and drying overnight at 40°C gave the hydrogenated product. The overall conversion of olefinic double bonds was then analyzed by IR spectroscopy to be 28%, corresponding to a catalyst conversion of 4500.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any modification and modification made by those skilled in the art without departing from the spirit and scope of the present invention, All should belong to the protection scope of the present invention.

Claims (12)

1. method that is used for the hydrogenating conjugated diolefine polymkeric substance, it comprises: this polymkeric substance of hydrogenation in the presence of hydrogen and hydrogenation catalyst composition is characterized in that this hydrogenation catalyst composition comprises:

(a) at least a titanium compound, shown in (ai):

R in the formula ¹And R ²Can be identical or different, represent halogen atom, alkyl, aryl, aralkyl, alkoxyl group or carbonyl; (b) at least a silane, it is selected from following substances: (i) haplotype silane, shown in (i): X in the formula ¹, X ²And X ³Can be identical or different, represent hydrogen atom, halogen atom, alkyl, aryl, aralkyl, alkoxyl group, acyloxy or carboxyl, (iia) polymer-type silane, shown in (iia):

R in the formula ³Represent hydrogen atom, halogen atom, alkyl, aryl, aralkyl or alkoxyl group, and n＞0, (iib) siloxanes is shown in (iib): R ⁴ ₃Si-O-SiR ⁴ ₃(iib) R in the formula ⁴Represent hydrogen atom, halogen atom, alkyl, aryl, aralkyl or alkoxyl group,

(iii) cyclic silane, shown in (iii):

R in the formula ⁵Represent hydrogen atom, halogen atom, alkyl, aryl, aralkyl or alkoxyl group,

And n is the integer of 2-5,

And

(iv) silazane, shown in (iv):

R in the formula ^a, R ^b, R ^cCan be identical or different, represent hydrogen atom, halogen atom, alkyl, aryl, aralkyl or alkoxyl group;

And non-essential component

(c) at least a metallic compound, it is selected from organo-aluminium compound, organo-magnesium compound, lithium compound is arranged, organic zinc compound and lithium hydride.

2. the method for claim 1, wherein said titanium compound is selected from: dicyclic pentylene titanium dichloride, bicyclic pentadiene dibrominated titanium, bicyclic pentadiene two carbonylation titaniums, bicyclic pentadiene dimethyl titanium, bicyclic pentadiene diethyl titanium, bicyclic pentadiene dipropyl titanium, bicyclic pentadiene dibutyl titanium, bicyclic pentadiene dimethoxy titanium, bicyclic pentadiene diethoxy titanium, bicyclic pentadiene dipropoxy titanium, bicyclic pentadiene dibutoxy titanium, bicyclic pentadiene methyl titanium chloride, bicyclic pentadiene methyl titanium bromide and composition thereof.

3. the method for claim 1, wherein said organolithium compound is selected from lithium methide, lithium ethide, n-propyl lithium, sec.-propyl lithium, n-Butyl Lithium, s-butyl lithium, tert-butyl lithium, n-pentyl lithium, and the active lithium that has on the key of conjugated diene polymer.

4. the method for claim 1, wherein said haplotype silane is selected from: dimethyl dichlorosilane (DMCS), ethyl dichlorosilane, the propyl group dichlorosilane, the butyl dichlorosilane, diphenyl dichlorosilane, dimethylchlorosilane, the diethyl chlorosilane, the dipropyl chlorosilane, the dibutyl chlorosilane, diphenyl chlorosilane, the dimethyl methyl TMOS, dimethylethoxysilane, the dimethyl propylene TMOS, the dimethyl butyrate TMOS, the diethyl Ethoxysilane, diethyl propoxy-silane, the diethyl butoxy silane, the dipropyl methoxy silane, the dipropyl Ethoxysilane, dipropyl propoxy-silane, the dipropyl butoxy silane, the dibutyl methoxy silane, the dibutyl Ethoxysilane, dibutyl propoxy-silane, the dibutyl butoxy silane, the diphenylmethyl TMOS, the phenylbenzene Ethoxysilane, the diphenylprop TMOS, the phenylbenzene butoxy silane, dimethylsilane, diethylsilane, dipropyl silane, dibutyl silane, diphenyl silane, diphenylmethylsilane, diphenyl-ethyl silane, the diphenylprop base silane, phenylbenzene butyl silane, trimethyl silane, triethyl silicane, tripropyl silane, tributyl silane, methyl-monosilane, ethylsilane, propyl silane, butyl silane, phenyl silane and methyl diacetoxy silane.

5. the method for claim 1, wherein said polymer-type silane is selected from: polymethyl hydrogen siloxane, poly-ethyl hydrogen siloxane, poly-propyl group hydrogen siloxane and poly-butyl hydrogen siloxane.

6. the method for claim 1, wherein said formula (iib) siloxanes is 1,1,3, the 3-tetramethyl disiloxane.

7. the method for claim 1, wherein said cyclic silane is selected from: methyl hydrogen cyclosiloxane, ethyl hydrogen cyclosiloxane, propyl group hydrogen cyclosiloxane and butyl hydrogen cyclosiloxane.

8. the method for claim 1, wherein said silazane is selected from: 1,1,3,3-tetramethyl-disilazane, 1,1,3,3-tetraethyl-disilazane, 1,1,3,3-tetrapropyl disilazane and 1,1,3,3-tetrabutyl disilazane.

9. the method for claim 1, the number-average molecular weight of wherein said polymkeric substance is 500 to 1,000, between 000.

10. the method for claim 1, wherein said polymkeric substance is the homopolymer or the multipolymer of 1,3-butadiene and/or isoprene.

11. the method for claim 1, wherein said polymkeric substance is a segmented copolymer, containing at least one principal constituent is that polymer blocks A and at least one principal constituent that vinylbenzene replaces is 1, the polymer blocks B of 3-divinyl and/or isoprene, the content of block A in this segmented copolymer is greater than 0 to 90 weight %, and 1 in the B block, 2-ethylene content are 6 weight % to 80 weight %.

12. the method for claim 1, wherein said metallic compound (c) is selected from organolithium compound or organo-magnesium compound.