WO1999064479A1

WO1999064479A1 - Method of hydrogenating block copolymer

Info

Publication number: WO1999064479A1
Application number: PCT/JP1999/003080
Authority: WO
Inventors: Yoro Sasaki; Hiroshi Ishida; Masahiro Fujiwara; Tatsuo Yamaguchi
Original assignee: Asahi Kasei Kogyo Kabushiki Kaisha
Priority date: 1998-06-10
Filing date: 1999-06-09
Publication date: 1999-12-16
Also published as: AU4164899A

Abstract

A method of hydrogenating a block copolymer, which comprises passing a solution of an aromatic vinyl/conjugated diene block copolymer together with hydrogen gas through a fixed-bed reactor packed with a hydrogenation catalyst comprising a platinum group metal deposited on an inorganic support to convert the unsaturated bonds in the aromatic ring blocks and conjugated diene blocks of the block copolymer into saturated bonds through hydrogenation, wherein (1) the block copolymer has a number-average molecular weight of 40,000 to 450,000, (2) the conjugated diene blocks in the block copolymer have a number-average molecular weight of 30,000 or higher, (3) the concentration of the block copolymer in its solution is 5 to 30 wt.%, and (4) the fixed catalyst bed has a temperature of 150 to 250 °C.

Description

Description Hydrogenation method of block copolymer

The present invention relates to a method for hydrogenating a block copolymer of an aromatic vinyl and a conjugated diene. More specifically, using a fixed bed reactor packed with a hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier, a solution of a block copolymer of aromatic vinyl and a conjugated gen is passed along with hydrogen gas, The present invention relates to a hydrogenation method for hydrogenating an unsaturated bond in an aromatic ring portion and a conjugated gene block portion of the block copolymer into a saturated bond. Background art

By hydrogenating the unsaturated bond between the aromatic ring portion and the conjugated genlock portion of the block copolymer of aromatic butyl and conjugated diene, heat resistance, weather resistance, and mechanical properties can be improved.

Therefore, using a heterogeneous hydrogenation catalyst in which a platinum group metal or nickel metal is supported on an inorganic carrier, a block copolymer of an aromatic butyl and a conjugated gen in a saturated hydrocarbon solvent in a stirred tank in the presence of hydrogen gas. Various attempts have been made to hydrogenate the unsaturated bond between the aromatic ring block portion and the conjugated gen block portion (US Pat. No. 3,333,024, British Patent No. 2101191). No., W0963334896, and Japanese Patent Laid-Open No. 5-9716916).

However, when hydrogenation is carried out in a stirred tank, (1) it is difficult to separate the catalyst and the polymer solution after the hydrogenation reaction due to the high viscosity of the polymer solution, which complicates the purification process. (2) The polymer obtained by mixing the catalyst or catalyst components that have passed through the filter cloth or the like during the filtration process into the polymer tends to be colored, and (3) The activity is reduced when the catalyst is recycled. There was.

To avoid this inconvenience, it is conceivable to hydrogenate with a fixed bed filled with a catalyst.However, the viscosity of the polymer solution is low. Only examples of hydrogenation with polymers and low concentration polymer solutions have been reported.

Examples of fixed bed hydrogenation include, for example, US Pat. No. 3,809,687. In Saisho, pore volume 0. 3 mf / g or more, with a specific surface area 1 0 O m ² Z g carrier loaded with platinum group catalysts, the force 'molecular weight being attempted hydrogenation of the aromatic rings of polystyrene The hydrogenation of the polymer is about 1,000, and the hydrogenation of the high molecular weight product is not performed.

According to US Patent No. 5,378,767, hydrogenation of polyisoprene having a molecular weight of 10,000 or less was attempted in a fixed bed using a platinum or palladium catalyst supported on an α-alumina carrier. However, hydrogenation of a block copolymer having an aromatic ring has not been performed.

When performing hydrogenation in a fixed bed, platinum group catalysts are preferred because they have higher activity than nickel-based catalysts.However, in platinum group catalysts, the conjugated gen block moiety is generally more selective than the aromatic ring. Therefore, especially when a high-concentration solution of a polymer having a large molecular weight is used, (1) the expansion of the polymer single-molecule chain is increased, and the diffusion rate to the catalyst metal surface in the pores of the carrier is increased. (2) The viscosity of the solution increases significantly with the hydrogenation of the conjugated gen block. The disadvantage was that the rate of mass transfer from the gas phase to the liquid phase was reduced, and hydrogenation of the aromatic ring was difficult to proceed.

An example of a nickel-based catalyst is described in U.S. Pat. No. 4,629,767, in which a specific surface area is supported on a silica support having a specific surface area of 140 to 160 m ² / g. Using nickel-copper catalyst, at 160 ° C, LHSV (liquid hourly space velocity) 0.12, polymer concentration 12.6%, styrene content 61%, number average molecular weight about 50,000 Hydrogenation of a styrene-butadiene block copolymer was reported, and the aromatic ring and conjugated genblock were hydrogenated.

In this case, since the butadiene block, which is the conjugated gen block, has a molecular weight of about 20,000 and a short chain length, the expansion of the polymer molecular chain due to hydrogenation of the conjugated gen block is small, and the conjugated Even if hydrogenation is first performed, hydrogenation of the aromatic ring can also be achieved sequentially. However, it has this level of activity for diblock copolymers that are more susceptible to hydrogenation than triblock copolymers, and nickel-copper catalysts have low activity and are not suitable for hydrogenation of high molecular weight polymers. When the conjugated gen block is long and the aromatic ring portion of the other block chain is not easily hydrogenated, the disadvantage remains.

Disclosure of the invention

An object of the present invention is to hydrogenate unsaturated bonds between an aromatic ring portion and a conjugated gen block portion of a block copolymer of an aromatic biel and a conjugated gen, and (1) separation of a polymer solution and a catalyst is unnecessary; (2) High molecular weight, long conjugated gen block, and high concentration of polymer, high hydrogenation rate, good productivity,

(3) The present invention provides a hydrogenation method with a long catalyst life without the problem of polymer coloring due to no mixing of catalysts and catalyst components.

In order to solve the above problems, the present inventors have conducted intensive studies. As a result, when hydrogenating a polymer having a high concentration of a high molecular weight polymer and a long conjugated gen block in a fixed bed, (1) The fact that the temperature dependence of the hydrogenation rate of the aromatic ring portion is higher than expected in a stirred tank at higher temperatures than expected, and (2) the surprising fact that the catalyst life is longer at higher temperatures than at lower temperatures. The present inventors have discovered and completed the present invention based on the discovery.

That is, the present invention

1. A solution of a block copolymer of aromatic vinyl and a conjugated gen is passed along with hydrogen gas through a fixed bed reactor filled with a hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier. A hydrogenation method for hydrogenating an unsaturated bond between an aromatic ring portion and a conjugated gen-block portion to a saturated bond, wherein (1) the block copolymer has a number average molecular weight of 40,000 (4) the number average molecular weight of the conjugated gen block in the block copolymer is at least 30,000, and (3) the polymer in the block copolymer solution. The concentration is 5 to 30 weight. /. (4) the above-mentioned method, wherein the catalyst bed temperature of the fixed bed is 150 to 250 ° C.

2. (1) A hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier, the carrier comprising at least one metal basic component selected from the group consisting of an alkali metal, an alkaline earth metal, and a rare earth metal in advance. Prepared by a process comprising insolubilizing and immobilizing the platinum group metal component by contacting with a platinum group metal compound solution. (2) the loading amount of the platinum group metal is 0.1 to 10% by weight with respect to the carrier,

(3) The platinum group metal has a surface area of 40 to 25 Om ² Zg—metal, and (4) the platinum group metal has a surface layer within 1/10 of the carrier diameter in the depth direction from the outer surface of the carrier. The method of the above 1 which is supported by 90% or more,

3. The pore diameter measured by the mercury intrusion method is 100 to 100, OOQ nm. The pore volume of the pores of the inorganic carrier is 5 to 100, 50 to the pore volume of the pores with OOO nm: I 00%. The method of 1 or 2 above,

4. The method of the above 1 or 2, wherein the platinum group metal is palladium and / or rhodium,

5. The method according to 1 or 2 above, wherein the inorganic carrier is selected from the group consisting of alumina, alumina silica, silica, titania, magnesium, zirconia, and zeolite;

6. Fixed bed conditions are hydrogen pressure 2 ~ 25MPa, hydrogen gas flow rate Z polymer solution flow rate specific force; 10 ~: I, 000NLZL, liquid hourly space velocity (LHSV) 0.01 ~~ 10 ( 1 / hr)

7. The block copolymer is a group consisting of A—B, A—B_A, A_B—A—B, and (AB) _m X (where A is a block of aromatic vinyl, and B is a block of conjugated gen) Wherein m represents 2, 3 or 4, and X represents a polyfunctional coupling agent.) The method according to 1 above, wherein at least one member selected from the group consisting of

8. The block copolymer is at least one selected from the group consisting of styrene-butadiene diblock copolymer, styrene-butadiene-styrene triblock copolymer, styrene-1 ^ soprene diblock copolymer, and styrene-isoprene-styrene triblock copolymer. Method 7 above, which is

It is.

9. A solution of a block copolymer of aromatic vinyl and a conjugated diene is passed along with hydrogen gas through a fixed-bed reactor filled with a hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier. A method for producing a hydrogenated block copolymer comprising hydrogenating unsaturated bonds of an aromatic ring portion and a conjugated genlock portion to form a saturated bond, wherein (1) the number average molecular weight of the block copolymer is 40,00 (2) the number average molecular weight of the conjugated gen block in the block copolymer is 30,000 or more; (3) the block copolymer solution (4) The above method, wherein the concentration of the polymer is 5 to 30% by weight, and (4) the catalyst bed temperature of the fixed bed is 150 to 250 ° C.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples of the aromatic butyl in the present invention include styrene, o-methylstyrene, o-, m-, p-methylstyrene, alkyl-substituted styrene such as p-t-butylstyrene, o-, m-, and ρ-medium. One or more kinds are selected from toxic styrene, vinyl / lenaphthalene and the like, and styrene is particularly preferred.

Further, as the conjugated diene in the present invention, for example, one or two or more selected from butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and the like are selected, and particularly preferred are butadiene, isoprene and these. It is a combination.

The block copolymer in the present invention is obtained by copolymerizing the aromatic vinyl and the conjugated gen by a known living anion polymerization method. The structure of the block copolymer may be, for example, linear, branched, radial, comb-shaped, or a mixture thereof. A preferred structure is as follows: A is a block composed of aromatic biels and B is a block composed of conjugated gens. A—B, A—B—A, A—B—A—B,

(A-B) _m — X (m represents 2, 3 or 4, and X is, for example, silicon tetrachloride, tetrashidani tin, epoxidized soybean oil, a compound having 2 to 6 functional epoxy groups, polyhalogen Represents the residue of a coupling agent such as a hydrocarbon compound, a carboxylate ester, or a polybutyl compound such as dibutylbenzene, or the residue of an initiator such as a polyfunctional organolithium compound. It also includes a tapered block in which the boundaries of each block are random and the composition of which gradually changes. Particularly preferred are styrene-butadiene diblock copolymer, styrene-isoprene diblock copolymer, styrene-butadiene-styrene triblock copolymer, and styrene-isoprene-styrene triblock copolymer.

The number average molecular weight of the block copolymer is 40,000 to 450,000, preferably 50,000 to 450,000. With a low molecular weight of less than 40,000, the strength of the polymer obtained by hydrogenation is insufficient. If the molecular weight is higher than 450,000, processing becomes difficult. The molecular weight here is gel permeation It is a value in terms of polystyrene measured by Yon chromatography (GPC). In the present specification, the number average molecular weight of the conjugated gen block in the block copolymer is a molecular weight obtained by multiplying the number average molecular weight of the block copolymer by the weight content of the conjugated gen. For example, a styrene-butadiene-styrene triblock copolymer having a number average molecular weight of 100,000 has a styrene content of 30% by weight. If / ₀ , the butadiene content is 70% by weight, and the number average molecular weight of the conjugated gen block in the block copolymer is 70,000. Even if the conjugated diene block in the block copolymer is two or more blocks, or even if the block boundaries are random and the composition of the tapered block gradually changes, the number average molecular weight of the conjugated diene block Is a value obtained by this calculation method.

The number average molecular weight of the conjugated gen block in the block copolymer is at least 30,000, preferably at least 30,000 and at most 400,000. If it is less than 30,000, the viscosity does not increase significantly due to the hydrogenation of the conjugated gem block, and the difference in the temperature dependence of the hydrogenation rate between the fixed bed and the stirred tank is not remarkable. There is no phenomena that the reaction rate sharply rises above ° C. If it exceeds 400, 000, processing of the obtained polymer becomes difficult.

The hydrogenation rate of the block copolymer in the present invention is preferably 70% or more, more preferably 85% or more of the whole aromatic ring in the aromatic ring portion, and 90% of the total unsaturated bond in the conjugated gen block portion. It is preferable that it is above. When the hydrogenation ratio of the aromatic ring portion is less than 70%, the improvement in the glass transition temperature is small, and the improvement in the mechanical properties of the hydrogenated polymer is small. If the hydrogenation ratio of the conjugated gen block is less than 90%, the thermal stability is poor, and deterioration is likely to occur. The hydrogenation rate here was measured by an ultraviolet absorption spectrum and a ¹ H—NMR spectrum. In the ultraviolet absorption spectrum, for example, when the aromatic vinyl monomer is styrene, the decrease in the absorbance at 262 nm of a cyclohexane solution of the polymer before and after hydrogenation is measured. The hydrogenation rate of the ring was determined.丄! In the NMR spectrum, for example, if the polymer is a styrene butane-styrene triblock copolymer, the polymer before and after hydrogenation is dissolved in a double-mouthed form, and tetramethylsilane is converted into a chemical shift δ0. , Δ 0.4 to 2.6, 4.6 to 5.8, and 6.2 to 7.6 Was determined.

The block copolymer is dissolved in a solvent and subjected to a hydrogenation reaction. The solvent used is not particularly limited as long as it is a saturated hydrocarbon capable of dissolving the block copolymer, and specifically, cyclopentane, cyclohexane, cycloheptane, cyclooctane, methylcyclohexane, decalin and the like are used. n-Hexane, n-heptane, etc. may be mixed. In addition, ethers such as tetrahydrofuran, dioxane, and ethylene glycol dimethinoleatenole, and a small amount of alcohols such as methanol and ethanol may be added.

Further, in the polymer solution, a polymerization initiator component used at the time of living anion polymerization and ethers / diamines added as needed to control the polymer structure, and added to stop the deactivation of the living terminal. Alcohols, coupling agent components and the like may be contained.

The polymer concentration in the polymer solution is 5 to 30% by weight. /. And preferably 5 to 25% by weight. At a low concentration of less than 5%, the productivity is low due to the large amount of solvent used for the polymer, making recovery and reuse of the solvent difficult, and the hydrogen in the aromatic ring portion in the fixed bed and the stirring tank. The difference in the temperature dependence of the formation rate is not noticeable. At a high concentration exceeding 30%, the diffusion of hydrogen gas or the polymer into the catalyst becomes slow due to the high solution viscosity, so that hydrogenation of the aromatic ring and the conjugated gemlock portion does not easily proceed. The platinum group metal in the present invention contains at least one selected from the group consisting of palladium, rhodium and platinum. Particularly preferred are those containing at least palladium and Z or rhodium.

The inorganic carrier used in the present invention is preferably alumina, silica-alumina, silica, magnesia, titer, zirconia, zeolite, or the like. More preferred are alumina, silica or a molded article containing them as a main component, and particularly preferred is alumina. As described in Japanese Patent Application Laid-Open No. 58-171703 and Japanese Patent Application Laid-Open No. 2-2656447, generally, in order to hydrogenate a polymer, carrier fine particles are used. It is known that those having a large pore diameter are suitable, and alumina is because the pore shape is easily controlled.

A more preferred carrier used in the present invention has a pore diameter measured by a mercury intrusion method. The pore volume of the pores of 100 to: 100,000 nm is 50 to 100% of the pore volume of the pores of 5 to: 100,000 nm, and the BET specific surface area measured by the nitrogen gas adsorption method is A carrier that is 50-50 Om Zg. By using a carrier having macropores and a relatively large surface area, that is, a carrier having micropores and / or mesopores on the surface of the macropores, the carrier is preliminarily supported on the carrier by performing a support method described below. Dispersion of the metal-basic components such as alkali metals, alkaline earth metals, and rare earth elements is efficiently performed, and the activity of the obtained catalyst is further increased. In the present invention, macropores are defined as pores with a diameter of 50 nm or more, mesopores are defined as 10 nm or more and less than 50 nm, and micropores are defined as pores with a diameter of less than 10 nm.

Further preferred carriers used in the present invention are those having a peak at a pore diameter of 100 to 10,000 nm and a pore diameter of 100 nm or less in a pore distribution curve obtained by a pore distribution measurement by a mercury intrusion method. The carrier has a bimodal pore distribution with a peak. Particularly preferred is a bimodal carrier having a pore distribution curve with a peak at a pore diameter of 100 to 10,000 nm and a peak at a pore diameter of 10 nm or less. Even if the pore distribution measurement with a pore diameter of 2 nm or less cannot be performed by the mercury intrusion method, as in the case of the zeolite molded body, it is assumed that micropores with a pore diameter of 2 nm or less are practically known as information. If a peak exists at a pore diameter of 100 to 10 nm and OOO nm in the pore distribution curve obtained by the pore distribution measurement by the mercury intrusion method, it is included in the carrier with the bimodal pore distribution described above. It is.

The shape of the carrier is not particularly limited as long as it is granular such as a sphere or a cylinder.However, an extruded body or a ring-shaped body containing a side cut is preferably used because it can improve the outer surface area. is there. The size of the catalyst is 0.5 to 10 mm in diameter when the shape is a sphere, 132 to 3/8 inch (0.79 to 9.53 mm) in the case of a cylindrical shape, and the length is 0.2 to 2 cm is preferred. If the particle size is too small, the pressure loss when passing the polymer solution through the catalyst layer becomes too large.On the other hand, if the particle size is too large, the ratio of the surface layer portion to the catalyst core portion becomes small, so that the total amount of the catalyst becomes small. Too much.

As a method for supporting the platinum group metal on the inorganic carrier, a known supporting method may be used. For example, the carrier is impregnated with an aqueous solution of a platinum group metal salt or the like and then reduced. A supported catalyst is obtained. Alternatively, a platinum group metal compound soluble in an organic solvent may be used to adsorb the compound in the organic solvent.

The amount of the platinum group metal supported on the carrier is 0.1 to 10% by weight, more preferably 0.3 to 5% by weight. /. It is. If the amount is less than 0.1% by weight, the amount of the catalyst becomes too large, and if the amount exceeds 10% by weight, metal aggregation occurs on the surface of the carrier, and the activity decreases. In the present invention, a preferred method for supporting a platinum group metal on an inorganic carrier is a method of mixing a soluble platinum group metal compound with a metal basic component such as an alkali metal, an alkaline earth metal, or a rare earth element previously supported on the carrier. It utilizes the principle of insolubilizing and fixing platinum group metal components by chemical reaction. That is, a carrier obtained by impregnating at least one metal basic component selected from the group consisting of an alkali metal, an alkaline earth metal, and a rare earth metal, followed by drying and Z or firing, and a platinum group metal compound solution are used. It is prepared by a process including mixing.

The platinum group metal compound is not particularly limited as long as it is a salt soluble in water. Preferred examples of the compound include palladium halides such as palladium chloride, palladium tetrachloride and salts thereof, palladium salts such as potassium hexabutyl palladium, and salts of tetrabromopalladium such as sodium tetrabromopalladium. , Palladium acetate, palladium nitrate, palladium ammine complexes such as tetranitropalladium chloride, tetraamminepalladium chloride, palladium ethylenediamine complexes such as bisethylenediamine palladium chloride, and rhodium halides such as rhodium chloride for rhodium. Hexahalogenated rhodium acids and salts thereof, such as hexaclorophic rhodium acid, hexanitrorhodates such as sodium hexanitrorhodate, rhodium acetate, hexammine rhodium Rhodium ammine complexes such as chlorides; ruthenium; ruthenium chlorides and other ruthenium halides; hexacloporruthenic acid and salts thereof; pentachloroaquarthenium salts such as pentachloroaquarthene diamic acid rim; Ruthenium ammine complexes such as silruthenium salts, ruthenium acetate, and hexammineruthenium chloride; for platinum, hexacloplatinic acid and its salts; Tetraamine white such as salts, tetranitroplatinate, tetraammineplatinum chloride Gold complexes. More preferably, halogenated palladiums such as palladium chloride, palladium tetrachloride and salts thereof, palladium salts of palladium hexakis such as potassium palladium hexachloride, tetrabromopalladiums such as sodium tetrabromopalladium, etc. Salts, rhodium halides such as rhodium chloride, hexahalogenated rhodium acids such as hexachlororhodic acid and salts thereof, ruthenium halides such as ruthenium chloride, hexachlororuthenic acid and salts thereof, hexaclomouth Platinic acid and its salts, tetrachloroplatinic acid and its salts, hexabromoplatinic acid and its salts, tetrabromoplatinic acid and its salts, particularly preferably palladium halides such as palladium chloride, rhodium chloride and the like Rhodium halides, ruthenium chloride, etc. Ruthenium halide compound, a salt Ya tetrachloroethene opening salts of chloroplatinic acid in Kisakuro port chloroplatinic acid to.

The carrier containing the metal basic component in the present invention may be prepared in advance by using an alkali metal such as lithium, sodium, potassium, rubidium, and cesium; an alkaline earth metal such as beryllium, magnesium, calcium, strontium, and barium; lanthanum; It carries one or more metal basic components selected from rare earth elements such as praseodymium. As the metal basic component to be supported, for example, those which become an oxide by an operation such as baking of nitrate or acetate are preferable. Drying of a carrier supporting a metal basic component such as an alkali metal, an alkaline earth metal, and a rare earth element is performed at a temperature of 100 ° C. or higher, preferably 110 ° C. or higher, for 1 to 48 hours. Done in The calcination is at a temperature of 300 to 800 ° C, preferably at a temperature of 300 to 700 ° C :! It takes place in the range of ~ 48 hours.

In the present invention, the optimum amount of the alkali metal, alkaline earth metal, or basic element of the rare earth element to be dispersed and immobilized on the carrier varies depending on the amount of the platinum group metal to be supported. On the other hand, it is selected in the range of 1 to 100 times mol, preferably 2 to 50 times mol.

The reaction between the soluble platinum group metal compound and the metal basic component supported on the carrier is preferably performed at a temperature of 70 ° C. or higher. Depending on the amount of the platinum group metal supported and the amount of the metal basic component previously supported on the carrier, if the temperature is too low, the reaction slows down and the distribution of the supported layer of the platinum group metal is widened. In the present invention, the reaction temperature is more preferable. Is at least 80 ° C, more preferably at least 90 ° C. The reaction may be performed at a temperature equal to or higher than the boiling point under pressure, but the upper limit temperature is 150 ° C. or less in consideration of the complexity of the pressurizing equipment and the pressure of steam.

In the present invention, the carrier containing the metal basic component in advance and the platinum group metal compound solution are preferably brought into contact at the same time as much as possible in order to eliminate variations in the amount of supported platinum among the carrier particles. For this purpose, there is a method in which a carrier containing a metal basic component is instantaneously charged into a platinum group metal compound solution in advance.

The platinum group metal compound immobilized and supported on the carrier of the present invention is reduced to a platinum group metal by a reduction operation. Disperse the carrier in which the platinum group metal compound is dispersed and immobilized in an aqueous solution, etc., and perform a reduction process using formalin formic acid, hydrazine, methanol, sodium borohydride (sodium borohydride) or hydrogen gas while stirring. Thus, the platinum group metal can be reduced. In addition, a carrier in which a platinum group metal compound is dispersed and immobilized is charged into a reactor, and a solution containing formalin formic acid, hydrazine, methanol, sodium borohydride (sodium borohydride) or under high temperature Can be reduced to a platinum group metal by a reduction treatment by introducing hydrogen gas. When using formalin formic acid, hydrazine, methanol, or sodium borohydride (sodium borohydride), the reduction temperature is from room temperature to 200 ° C. If the boiling point is exceeded, apply the necessary pressure to maintain the liquid layer. The reduction conditions are preferably room temperature to 160 ° C. and normal pressure to several atmospheres. In order to make the metal particle size smaller, a condition of 60 to 160 ° C. is more preferable.

Platinum is obtained by a chemical reaction between a soluble platinum group metal compound and a metal basic component such as an alkali metal, an alkaline earth metal, or a rare earth element previously supported on a carrier, which is a preferred support method of the present invention. According to the supporting method of insoluble immobilized group metal component can be achieved a high surface area surface area of platinum group metal is 4 0~2 5 O m ² Bruno g- metal. The surface area is 4 0~2 5 O m ² and high productivity is Z g- metal, productivity is reduced it takes time to stabilize. The metal surface area was measured by a gas chemisorption method. In addition, it is also possible to achieve a loading of the platinum group metal on the surface layer portion within 110 of the carrier diameter in the depth direction from the outer surface of the carrier to 90% or more. The distance was measured by embedding the catalyst in a resin and polishing the sample to obtain it by electron beam microanalysis (EP MA). Then, it was determined by performing line analysis in the depth direction of the cross section of the catalyst particles. By supporting the platinum group metal carrying position in the depth direction from the outer surface of the carrier on the surface layer within iZi 0 of the carrier diameter, more preferably on the surface layer within 120, the platinum group metal and the polymer The contact is easy and the catalytic activity is improved. By using the catalyst, productivity is improved and elution of the platinum group metal component can be suppressed.

The term “hydrogenation in a fixed bed” in the present invention refers to a method in which a granular catalyst is filled in a vertical reaction tower, and a block polymer solution and hydrogen gas are circulated therein to perform hydrogenation. The flow direction of the polymer solution and the hydrogen gas may be either co-current or counter-current. However, co-current is preferable, and the direction may be an upward flow or a downward flow.

In the present invention, the catalyst layer filled with the block copolymer solution in the reaction tower has a catalyst layer temperature of 150 to 250 ° C, preferably 150 to 220 ° C, more preferably 180 to 220 ° C, and hydrogen pressure. 2 to 25 MPa, preferably 3 to 20 MPa, more preferably 4 to 15 MPa, hydrogen gas flow rate, polymer solution flow rate ratio of 10 to 1,000 NL / L, preferably 20 to: 1,000 NLZL, Preferably 20 to 800 NL / L, liquid hourly space velocity (LHSV) 0.01 to 10 (lZhr), preferably 0.03 to 10 (lZhr), more preferably 0.05 to 10 (lZhr) l Zh r) for hydrogenation.

The catalyst layer temperature in the present invention means the highest temperature in the catalyst layer because a temperature distribution occurs in the fixed bed catalyst layer. When the temperature is lower than 150 ° C, the hydrogenation rate of the aromatic ring is extremely reduced, and when the temperature is higher than 250 ° C, molecular chain cleavage is undesirably caused. If the hydrogen pressure is less than 2 MPa, the hydrogenation rate is not sufficient, and if it exceeds 25 MPa, the equipment becomes expensive. If the flow rate of hydrogen gas is less than 10 NLZL, the hydrogenation rate will decrease, and if it exceeds 1,000 NLZL, the equipment for collecting and recycling hydrogen gas will be expensive. If the liquid hourly space velocity (LHSV) is less than 0.01, the productivity will decrease, and if it exceeds 10, the hydrogenation rate will decrease.

The polymer solution may be replaced with an inert gas or hydrogen gas in advance, and then passed through.

Known fixed-bed reactors can be used and are not particularly limited. Since the calorific value is large, a multitubular reactor may be used for efficient heat removal. When the block copolymer is hydrogenated in the fixed bed by recycling the effluent of the fixed bed to reach the target value of the hydrogenation rate in the fixed bed, in the low temperature region, the conjugated gem block in the block copolymer is used. Is more likely to be hydrogenated earlier than the aromatic ring portion. As the hydrogenation of the conjugated gem block progresses, the molecular chains expand and the solution viscosity increases significantly. As a result, the diffusion of the block copolymer into the pores of the carrier becomes slow, and the aromatic ring remains unhydrogenated. This phenomenon becomes more pronounced as the block copolymer becomes higher molecular weight, as the concentration increases, and as the conjugated gen block becomes longer. On the other hand, in the high temperature region, the aromatic ring portion and the conjugated gen block were efficiently hydrogenated even when the high molecular weight compound, the concentration was high, and the conjugated gen block was long. This is because the hydrogenation of the aromatic ring and the conjugated genblock proceeds competitively, (1) the increase in viscosity is suppressed by hydrogenation of the aromatic ring portion, and (2) the hydrogenation remains without hydrogenation. Block copolymers are considered to be relatively easy to diffuse into the pores because the chain spread is not expanded.

The temperature dependence of the hydrogenation rate of the aromatic ring portion in this fixed bed is significantly different from that in the stirred tank, and the hydrogenation rate of the aromatic ring portion rapidly rises in the fixed bed at a high temperature. In a stirred tank, even if the conjugated gem block portion is hydrogenated at a low temperature and the viscosity increases, the mass transfer rate of the system can be increased by stirring, so the temperature dependence is smaller than that of a fixed bed. It is thought that it is.

Also, regarding the catalyst life in the fixed bed, the diffusion of the polymer is better in the high temperature range, which is considered to have a good effect on the catalyst life.

As described above, in the hydrogenation with a high concentration, high molecular weight, and long conjugated gen block in the fixed bed, (1) the temperature dependence of the hydrogenation rate of the aromatic ring portion is higher than that in the stirred tank. The present inventors have discovered the surprising fact that the catalyst life becomes longer in a high temperature range than in a low temperature range, and based on such a finding, a method for efficiently hydrogenating the block copolymer based on such a finding is obtained. Invented.

The hydrogenation reaction effluent that has reached the target hydrogenation rate is hydrogenated by a known method. It is separated into gas, solvent and hydrogenated polymer. Hydrogen gas and solvent are recycled. The hydrogenation method of the present invention has a longer catalyst life, no catalyst / catalyst component is mixed into the obtained polymer, and the obtained block copolymer is colored, as compared with hydrogenation in a stirred tank. It has high transparency and can be used as optical materials, medical materials, electrical insulating materials, and electrical and electronic parts materials. Further, the obtained polymer is used as a thermoplastic block copolymer having excellent heat resistance, weather resistance, moldability, elasticity, and the like.

Next, the present invention will be described more specifically with reference to examples and comparative examples.

When comparing the fixed bed with the stirring tank, a catalyst with a catalyst particle size of 3 to 4 mm was used in the fixed bed. This is because if the particle size is small, the liquid cannot pass through due to a large pressure loss. In the stirring tank, a catalyst having a particle size of about 60 / m was used. This is because if the catalyst diameter is large, it will be crushed by stirring. Therefore, the catalyst particle size is different in the two types of reaction, and the catalytic activity is higher in the stirred tank, but the temperature dependence of the hydrogenation rate and the obtained polymer properties are fixed bed and stirred tank. Shows the differences in the hydrogenation methods.

The number average molecular weight and weight average molecular weight of the block copolymer were measured by gel permeation chromatography (GPC) (HLC-8120 GPC system, manufactured by Tosoh Corporation) using standard polystyrene.

The aromatic vinyl content was determined using an ultraviolet absorption spectrum (MPS-2000, manufactured by Shimadzu Corporation).

The hydrogenation rate of the block copolymer is determined by the UV absorption spectrum or

¹ H-NMR spectrum (JEOL-GX270 manufactured by JEOL Ltd.) was measured. The microstructure of the conjugated gen moiety, for example, the ratio of 1,2-bonds to 1,4-bonds in the case of butadiene, was determined by ¹ H-NMR spectrum. The hydrogenation rate of the olefin portion was also measured by ¹ H-NMR spectrum.

The melt flow rate was measured under the condition of 2.16 kg load and 230 ° C. according to JIS K7210.

The mechanical properties (rupture strength and elongation at break) were measured according to JIS K63◦1, using a compression molded sheet with a thickness of 2 mm for the sample, and measuring the sample piece as a No. 3 dumbbell. The amount of metal in the polymer was determined by subjecting the polymer to thermal decomposition in nitric acid by applying ultrasonic waves, and then performing measurement using a high-frequency induction plasma mass spectrometer (VG-ΡΟΩ manufactured by Fison).

In the polymer coloration test, the presence or absence of coloring after heat history at 180 ° C for 168 hours was visually compared.

The pore distribution of the used carrier was measured by a mercury intrusion method measuring apparatus (Pore Size 9220, manufactured by Shimadzu Corporation).

The specific surface area of the carrier was measured by a BET surface measurement by nitrogen gas adsorption (Carlo Elba's Soapmatic 1800).

The amount of platinum group metal in the catalyst was measured by using X-ray photoelectron spectroscopy (RIX3000 manufactured by Rigaku Corporation).

The surface area of the platinum group metal was measured using a fully automatic catalytic gas adsorption device (R-6015 manufactured by Okura Riken Co., Ltd.).

The distribution of the platinum group metal was measured using an electron beam microprobe (X650, manufactured by Tate Works Co., Ltd.) and an energy dispersive X-ray detector (EMAX 5,770 W, manufactured by Horiba, Ltd.).

Example 1

Preparation of block copolymer

O dried to an Tokurebu nitrogen substituted 40 L, hexanes 26 L to purified consequent opening, as tetrahydrofuran ⁷ 3 g, was charged styrene ³ 10 g, was heated to 60 ° C, n-heptyl lithium 3.3 g of cyclohexane solution was added with stirring to start polymerization, and after completion of styrene polymerization, 2,480 g of butadiene was added.After the polymerization was completed, 31 Og of styrene was further added, followed by polymerization. The reaction was completed. The growth terminal was stopped by adding 1.2 equivalents of methanol to the lithium used. In this way, the number average molecular weight is 98,000, styrene content is 20% by weight, butadiene block is 78,000, butadiene part has 1,2-// 1,4 single bond ratio = 0.40 / 0.60, concentration 13.5 weight ⁰ /. A styrene-butadiene-styrene (SBS) trib solution was obtained.

Polymers with different molecular weights, etc. were prepared according to this method. Fixed bed hydrogenation

0.5 weight ⁰ /. Palladium (Pd) Ζα-alumina spheres (diameter 3 mm) (manufactured by N.C. Chemical Cat.) 30 Om of catalyst is charged into a reaction tube having an inner diameter of 27 mm, and the above 13.5% by weight styrene-butadiene is charged. The monostyrene styrene triblock copolymer Z cyclohexane solution was co-flowed with the hydrogen gas at an LHS V (1 / hr) of 0.1, a hydrogen gas flow rate of 400 NL / L, and an upflow. Thereafter, the hydrogen pressure was adjusted to 6 MPa and the temperature of the catalyst layer was adjusted to 180 ° C. After 15 hours from reaching the set temperature, the hydrogenation rate of the effluent polymer was 95.0% for the aromatic ring, 98.3% for the 1,4-butadiene portion, and 99.1% for the 1,2-butadiene portion. The Pd content in the polymer was less than 0.1 pm. No coloration occurred in the polymer coloration test.

The hydrogenation rate of the distillate polymer after 200 hours was 96.2% for aromatic ring, 99.3% for 1,4-butadiene part, and 98.6% for 1,2-butadiene part, and the catalyst activity decreased. There was no. Melt edge rate of the obtained polymer is 7.2 g / 1

At 0 minutes, the breaking strength was 220 kgf / cm "and the breaking elongation was 710%. The amount of Pd in the polymer was 0.1 ppm or less. No coloring occurred in the polymer coloring test. Table 1 Shows the results.

Example 2

In order to observe the temperature dependence of the fixed bed, in the fixed bed test of Example 1, the LH SV was increased to 0.3 and the temperature was changed to 180 ° C, 140 ° C, and 100 ° C. Then, the hydrogenation rate under each condition was measured to determine the hydrogenation rate. Table 1 shows the results. Below 140 ° C, the hydrogenation rate of the aromatic ring was extremely reduced. Table 1 shows the results.

Comparative Example 1

Stirred tank hydrogenation

Hydrogenation was carried out in a stirring tank using 5% Pd / alumina powder (average diameter 60 μm) (manufactured by N.C. Chemcat). Charge 1 g of the catalyst and 400 g of the polymer solution to a 1 L autoclave, and set the temperature to 180 ° C, 140 ° C, and 100 ° C under the conditions of a hydrogen pressure of 6 MPa, a stirring speed of 800 rpm, and a reaction time of 3 hours. And tested. After cooling, the content was taken out, the catalyst was separated by filtration, and the solvent was distilled off under reduced pressure. Poly obtained The hydrogenation rate of the mer was determined. Table 1 shows the results. Although the hydrogenation of the butadiene part is progressing first, the hydrogenation of the aromatic ring part is also progressing.The temperature dependence of the hydrogenation rate of the aromatic ring part is higher at higher temperatures than in the fixed bed. Did not stand up. The Pd content in the polymer at 180 ° C was 21 ppm. Table 1 shows the results.

Comparative Example 2

Stirred tank hydrogenation

According to the test at 180 ° C. in Comparative Example 1, the catalyst was filtered, separated and recycled, and the test was repeated. As shown in Table 1, the catalytic activity decreased.

Comparative Example 3

The test was performed in the same manner as in Comparative Example 1 except that the reaction time was changed to 10 hours according to the test at 180 ° C. Although the hydrogenation rate was high, the polymer contained 37 dpm of Pd. The polymer coloring test resulted in coloration. Table 1 shows the results.

Comparative Example 4

Using the polymer of Example 1, only the butadiene portion was hydrogenated with a known meta-mouthed hydrogenation catalyst. The melt flow of the resulting polymer rate 0. 3 GZL O content, the breaking strength 1 50 kgf Zc m ^2, was as low as elongation at break 440%. The results are shown in Table 1.

Example 3

The test was performed in the same manner as in Example 1 except that LHSV was 0.05 and the temperature was changed to 160 ° C. The resulting polymer has a melt flow rate of 7. O g / 10 min, breaking strength

220 kgf / cm ² and elongation at break were 700%. No coloration occurred in the polymer coloration test. Table 1 shows the results.

Examples 4 and 5

Using various block copolymers, hydrogenation was performed in a fixed bed with the catalyst of Example 1. Table 2 shows the results. The hydrogenation rate was good, and a colorless polymer was obtained. S and B in the structures in the table represent styrene and butadiene.

Example 6

In Example 5, the hydrogenation rate after 100 hours was measured. There was no decrease in catalytic activity. Table 2 shows the results. Examples 7 to 10

Using various block copolymers, hydrogenation was performed in a fixed bed with the catalyst of Example 1. Table 2 shows the results. The hydrogenation rate was good, and a colorless polymer was obtained. Note that S, B, and I in the structures in the table represent styrene, butadiene, and isoprene. (SB) ₄ Si in Example 10 is a polymer coupled with a silicon compound.

Comparative Example 5

In Example 5, when the temperature of the catalyst layer was set at 140 ° C., the hydrogenation rate was lowered even when the LHSV was lowered. Table 2 shows the results.

Comparative Example 6

In Comparative Example 5, the hydrogenation rate after 100 hours was measured. Table 2 shows the results. The catalytic activity was reduced.

ο

table 1

SBS polymer: number-average molecule 3: 98,000, styrene content 20 weight% t%, butabutadiene part 1,2-/, 4-bonding ratio = 0.40 / 0.60 13.5 weight% cycle Mouth hexane solution

(Note 2) Hydrogenation with meta-mouth catalyst

t> 5

o o

Table 2

Polymer LHSV Temperature Hydrogenation

Structure Number average molecular weight Atsushi styrene Conjugated styrene Styrene 1.4- 1,2-content Block Butadiene Butadiene

(Million) (%) (%) (million) (1 / hr) (¾) (%) () (%) 卖 ^ SBS 42.0 11.5 34 27.7 0.05 210 87.1 94.5 90.2 Example 5 SBS 4.6 16.2 29 3.3 0.2 180 98.0 99.3 99.5 Example 6 Same as above 0.2 180 98.2 99.1 98.8 Example 7 SIS 9.1 12.7 28 6.6 0.1 180 92.6 (Note) Isoprene part

1.4-conclusion • 98.8 Example 8 SB 7.5 21.8 40 4.5 0.5 160 93.3 99.8 99.7 Example 9 SBSB 23.1 12.2 20 18.5 0.1 210 90.5 91.9 94.1 Example 10 (SB) ₄ Si 32.0 11.7 31 22.1 0.05 210 92.6 90.7 93.1 Comparative Example 5 SBS 4.6 16.2 29 3.3 0.05 140 66.2 70.2 68.9 Comparative Example 6 Same as above 0.05 140 53.7 61.6 63.5

Example 1.1

Catalyst preparation

Water was added to a mixture of Zeolite Z SM-5 particles and alumina powder (containing 20% by weight) and extruded to a diameter of 11.6 inches (1.59 mm). Drying was performed at 120 ° C for 20 hours, and baking was performed at 600 ° C for 6 hours. The BET specific surface area of the carrier obtained by nitrogen gas adsorption was 355 m ₈ , the pore volume was 0.38 m Zg, the pore volume by the mercury intrusion method was 0.25 m / g, and the specific surface area was 15.4 m ² / g g, Peak top at 380 nm pore diameter in pore distribution curve. The pore volume of pores having a pore diameter of 100 to 100,000 nm was 0.21 m / g, which accounted for 84% of the pore volume of pores having a pore diameter of 5 to 100,000 nm. Since this carrier has pores with a pore diameter of about 0.6 nm, it is substantially a bimodal pore distribution carrier. Next, the obtained carrier was impregnated with a 15% by weight aqueous solution of magnesium nitrate, and calcined in an electric furnace at 600 ° C. for 5 hours to prepare a carrier having magnesium oxide adsorbed thereon. 3.34 g of palladium chloride, 2.22 g of sodium chloride and 1,000 ml of distilled water were placed in a 2-liter round bottom flask equipped with a cooling tube, and dissolved by heating to 95 ° C. 400 g of the carrier preheated at 50 ° C. was added to the solution, and the mixture was reacted for 20 minutes while gently shaking. After tilting to remove the solution, it was washed 10 times with distilled water. The thus obtained carrier carrying the palladium compound was air-dried in air.

A carrier supporting a palladium compound was added to 1,000 ml of a 10% aqueous hydrazine solution. The reduction reaction was performed for 20 minutes while gently shaking. After tilting to remove the solution, it was washed 10 times with distilled water. The palladium catalyst thus obtained was dried and stored under a heated and dried nitrogen stream. The loading amount of palladium metal is 0.

5 weight. /. The metal surface area was 146 m ² Zg—Pd metal (0.732 m g—catalyst). Palladium was supported within 80 // m from the outer surface of the carrier.

Polymer preparation

Dried and purified 26 liters of cyclohexane, 73 g of tetrahydrofuran, and 3 10 g of styrene were charged into a 40-liter autoclave purged with nitrogen, and 60 ° C Then, a cyclohexane solution containing 3.3 g of n_butyllithium was added with stirring to start polymerization, and after completion of styrene polymerization, 2,480 g of butadiene was added, and the polymerization was completed. Thereafter, 310 g of styrene was further added to complete the polymerization reaction. The end of growth was stopped by adding 1.2 equivalents of methanol to the lithium used. Thus, the weight average molecular weight is 101,000 (molecular weight distribution 1.03), and the styrene content is 20% by weight. /. A styrene-butadiene-styrene triploc copolymer / cyclohexane solution having a 1,2 -— / 1,4-bond ratio of butadiene portion of 0.40 / 0.60 and a concentration of 13.5% by weight was obtained. Polymers having different molecular weights were prepared by slightly modifying this method.

Fixed bed polymer hydrogenation

The above catalyst (213 g) was filled in a stainless steel reaction tube (catalyst layer volume: 312 mi) with an inner diameter of 22 mm, and cyclohexane solvent and hydrogen gas were first passed from the bottom to the top. Then, the temperature was raised so that the catalyst layer temperature (internal temperature) became 180 ° C. Preheating of the liquid flow was performed by heating the preheating layer provided below the catalyst layer. The flow was continued at LHSV 1.0 for 8 hours.

Thereafter, styrene one butadiene one styrene tri block Kukoporima (weight average molecular weight of 01,000 to liquid passing from the lower the temperature, molecular weight distribution 1.03, styrene content 20 wt ^_0/0, 1, 2/1 , 4 switched to a combined butadiene ratio 0.40 Bruno 0.60) cyclo hexane solution (polymer concentration 1 3.5 wt ^_0/0), at 80 g (1 03 milliliters) / hr, hydrogen 1 5NLZh r The flow was started with the gas. The LHSV at this time was 0.33 (1 / hr). While watching the temperature of the catalyst layer was heated preheating layer, and finally maintaining the catalyst layer temperature to 20 2 ^Q C. The hydrogen pressure was 6.5 MPa. A hydrogenation test was performed for 100 hours in a continuous manner, but no decrease in the hydrogenation rate was observed during this period. The hydrogenation rate in the olefin portion was 1,8-98% or more, and 1,4 part was 97. /. As described above, the hydrogenation rate of the aromatic ring was maintained at 92 to 95%. After 100 hours, the polymer obtained had a weight average molecular weight of 100,000 and a molecular weight distribution of 1.03. The amount of palladium in the polymer obtained by drying the effluent was 0.055 ppm.

Example 1 2 Catalyst preparation

Instead of zeolite alumina carrier, bimodal alumina spherical carrier (manufactured by Sumitomo Chemical Co., Ltd., particle size 8-14 mesh, BET specific surface area 8 lm ² / g, pore volume 0.53 ml / g, In the pore distribution measurement by the mercury intrusion method, the pore distribution curve has peak peaks at the pore diameters of 1800 nm and 6 nm, and the pore volume of pores having a pore diameter of 100 to 100,000 nm has a pore diameter of 5 to 100 nm. It occupied 63% of the pore volume of the pore having a diameter of 100,000 nm. The obtained catalyst had a supported amount of palladium metal of 0.5% by weight and a metal surface area of 152.6 m ² g—Pd metal (0.763 m ² / g—catalyst). Palladium was supported within 100 μm from the outer surface of the carrier.

Fixed bed polymer hydrogenation

The test was conducted in the same manner as in Example 11 except that 190 g of the above catalyst was charged into a fixed bed reactor. A hydrogenation test was conducted continuously for 300 hours. During this period, no decrease in the hydrogenation rate was observed. Ring hydrogenation remained above 98%. The polymer obtained after 300 hours had a weight average molecular weight of 1,000,000 and a molecular weight distribution of 1.03. The amount of palladium in the polymer obtained by drying the effluent was 0.071 ppm. Example 13

In Example 11, α-alumina spheres (diameter: about 3 mm, specific surface area: 6.4 m ² / g, and almost 100% of the pore volume were pores having a pore diameter of 50 nm or more) were used in Example 11 as a support. The same operation as in Example 11 was performed except that the support of the magnesium compound was not performed. The amount of palladium metal supported on the obtained catalyst was 0.5% by weight, and the metal surface area was 34.

- P d metal (0. 1 7m ² Zg- catalyst) and small, palladium was supported to the interior support.

300 g of this catalyst was charged into a reactor and hydrogenated in the same manner as in Example 1. Eight hours after passing through the polymer solution, the hydrogenation rate of the olefin portion was 1,3.5—63.5%, 1,4_portion 57.6%, and the hydrogenation ratio of the aromatic ring was 52.4%. It was low.

Example 14 A test was performed in the same manner as in Example 12 except that the carrier prepared by impregnating and calcining sodium nitrate was used instead of magnesium nitrate in Example 12. The resulting catalyst had a supported amount of palladium metal of 0.5% by weight and a metal surface area of 15.5.

— Pd metal (0.778 mZg—catalyst). Palladium was supported within 100 microns from the outer surface of the support. The hydrogenation rate of the olefin portion of the polymer obtained after 10 hours in fixed bed hydrogenation is over 99% for the 1,2_ and 1,4-portions, and the hydrogenation rate for the aromatic ring is 98.3%. High activity was shown. The weight average molecular weight of the polymer was 100,000, and the molecular weight distribution was 1.03. The amount of palladium in the polymer obtained by drying the effluent was 0.065 ppm. Example 15

The same test as in Example 15 was performed, except that in Example 14, sodium nitrate was used instead of sodium nitrate. Supported amount of palladium metal in the resulting catalyst 0.5 wt% Deari, metal surface area was 141. 2m ² Zg- P d metal (0. 706 m ² Zg- catalyst). Palladium was supported within 100 / im from the outer surface of the support. The hydrogenation rate of the olefin portion of the polymer obtained by fixed-bed hydrogenation is 99% or more for the 1,2- and 1,4-parts, and the hydrogenation rate of the aromatic ring is 95.9 ° /. And showed high activity. The weight average molecular weight of the polymer was 100,000, and the molecular weight distribution was 1.03. The amount of palladium in the polymer obtained by drying the effluent was 0.083 ppm.

Example 15

Example 11 Instead of using palladium chloride at the time of preparing the catalyst of 1, using 8.13 g of rhodium chloride, 90 g of the catalyst was filled in a catalyst bed volume of 166 m during hydrogenation of the fixed bed polymer, and LHSV was added. The reaction was carried out under the same conditions as in Example 11 except that 0.5 was performed. The hydrogenation rate of the olefin moiety is 97% for the 1,2-part, 96% for the 1,4 part, and the hydrogenation rate of the aromatic ring is 93. /. Met.

Industrial applicability

According to the present invention, separation of a polymer solution and a catalyst is not required, a high molecular weight, a long conjugated gen block, and a high hydrogenation rate and high productivity can be obtained under a condition of a high concentration solution. No mixing of components, no problem of polymer coloring, catalyst It has become possible to provide a long-life hydrogenation method.

Claims

The scope of the claims

1. A solution of a block copolymer of aromatic vinyl and a conjugated gen is passed along with hydrogen gas through a fixed bed reactor filled with a hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier. A block copolymer hydrogenation method comprising hydrogenating unsaturated bonds of an aromatic ring portion and a conjugated genlock portion to form a saturated bond, wherein (1) the block copolymer has a number average molecular weight of 40,000 to 450, (2) the number average molecular weight of the conjugated gen block in the block copolymer is 30,000 or more, (3) the polymer concentration in the block copolymer solution is 5 to 30% by weight, (4) The above method, wherein the catalyst bed temperature of the fixed bed is 150 to 250 ° C.

2. (1) A hydrogenation catalyst in which a platinum group metal is supported on an inorganic carrier, the carrier comprising at least one metal basic component selected from the group consisting of alkali metals, alkaline earth metals, and rare earth metals in advance. It is prepared by a process including insolubilizing and fixing the platinum group metal component by contacting with a platinum group metal compound solution, and (2) the amount of the platinum group metal supported on the carrier 0.1 to 10 weight. / ₀ and

(3) The platinum group metal has a surface area of 40 to 25 Om ² Zg-metal, and (4) the platinum group metal has a surface layer within lZl 0 of the carrier diameter in the depth direction from the outer surface of the carrier. 2. The method according to claim 1, wherein 90% or more is supported.

3. The pore diameter measured by the mercury intrusion method is 100 ~: 100, OOO nm The pore volume of the pores of the inorganic carrier is 5 ~ 100, 50 ~ 100% of the pore volume of the pores with OOO nm 3. The method according to claim 1 or 2.

4. The method according to claim 1, wherein the platinum group metal is palladium and / or rhodium.

5. The method according to claim 1, wherein the inorganic carrier is selected from the group consisting of alumina, alumina silica, silica, titania, magnesium, zirconia, and zeolite.

6. Fixed bed conditions are hydrogen pressure 2 ~ 25MPa, hydrogen gas flow rate / polymer solution flow rate ratio is 10 ~ 1,000NLZL, liquid hourly space velocity (LHSV) is 0.01 ~ 10. 2. The method of claim 1, wherein (1 / hr).

7. The block copolymer is A—B, A—B_A, A—B—A—B, and

(A— B) _m — a group consisting of X (where A represents a block composed of aromatic vinyl, B represents a block composed of a conjugated diene, m represents 2, 3 or 4, and X represents polyfunctionality. The method according to claim 1, which is at least one member selected from the group consisting of:

8. The block copolymer is selected from the group consisting of styrene-butadiene diblock copolymer, styrene-butadiene-styrene triblock copolymer, styrene-isoprene diblock copolymer, and styrene-isoprene-styrene triplep copolymer. 8. The method according to claim 7, which is at least one selected from the group consisting of:

9. A solution of a block copolymer of aromatic vinyl and a conjugated diene was passed along with hydrogen gas through a fixed-bed reactor filled with a hydrogenation catalyst in which a platinum group metal was supported on an inorganic carrier. A method for producing a hydrogenated block copolymer comprising hydrogenating an unsaturated bond of an aromatic ring portion and a conjugated gen block portion to a saturated bond, wherein (1) the block copolymer has a number average molecular weight of 40,0 (2) the number average molecular weight of the conjugated gen block in the block copolymer is at least 30,000, and (3) the polymer concentration in the block copolymer solution. (5) The method as described above, wherein the catalyst bed temperature of the fixed bed is 150 to 250 ° C.

INTERNATIONAL SEARCH REPORT International application No.

PCT / JP99 / 03080

A. CLASSIFICATION OF SUBJECT MATTER

Int. CI ⁶ C08F8 / 04, C08F297 / 04

According to International Patent Classification (IPC) or to both national classification and IPC

B. FIELDS SEARCHED

Minimum documentation searched (classification system followed by classification symbols)

Int. CI ⁶ C08F8 / 04. C08F297 / 04

Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched

Electronic data base consulted during the international search (name of data base and, where practicable, search terms used)

C. DOCUMENTS CONSIDERED TO BE RELEVANT

Category * Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No.

JP, 59-136312, A (Arakawa Chemical Industries Ltd), L-94 August, 1984 (04.08.84) _f

Claims; page 2, lower left column, lines 13, 18, 19;

page 3, upper left column, lines 14 to 16, upper right

column, lines 14, 15

& DE, 3338393, -A & US, 4540480, A

JP, 7-118336, A (Japan Synthetic Rubber Co. _f Ltd.), L-9 9 May, 1995 (09.05.95)

Claims (Family: none)

〖I Further documents are listed in the continuation of Box C. ι ι See patent family annex.

* Special categories of cited documents: later document published after the international filing date or priority

"A" document defining the general state of the art which is not date and not in conflict with the application but cited to understand considered to be of particular relevance the principle or theory underlying the invention

"E" earlier document but published on or after the international filing date "X" document of particular relevance; the claimed invention cannot be "L" document which may throw doubts on priority claim (s) or which is considered novel or cannot be considered to involve an inventive step cited to establish the publication date of another citation or other when the document is taken alone

special reason (as specified) "Y" document of particular relevance; the claimed invention cannot be O "document referring to an oral disclosure, use, exhibition or other considered to involve an inventive step when the document is means combined with one or more other such documents, such combination

"P" document published prior to the international filing date but later than being obvious to a person skilled in the art

the priority date claimed document member of the same patent family

Date of the actual completion of the international search Date of mailing of the international search report

8 September, 1999 (08.09.99) 21 September, 1999 (08.09.99)

Name and mailing address of the ISA / Authorized officer

Japanese Patent Ofice

Facsimile No. Telephone No.

Form PCT / ISA / 210 (second sheet) (July 1992)