Method for manufacturing optical material

Abstract

The present invention relates to a method for producing an optical material with which it is possible to obtain an optical material having sufficient heat resistance at a high aromatic nucleus hydrogenation rate, wherein the optical material is produced by hydrogenating an aromatic ring (aromatic nucleus hydrogenation) of an aromatic vinyl compound-based polymer. More specifically, the present invention relates to a method for producing an optical material by hydrogenating an aromatic ring (aromatic nucleus hydrogenation) of an aromatic vinyl compound-based polymer, characterized by using a mixed solvent containing at least one first solvent and at least one second solvent.

Description

Technical Field

[0001] The present invention relates to a method for producing an optical material. More specifically, the present invention relates to a method for producing an optical material by hydrogenating the aromatic ring of an aromatic vinyl compound-based polymer (aromatic nucleus hydrogenation, Japanese: "nucleus hydrogenation"). Background Art

[0002] In recent years, polymers represented by acrylic resins, methacrylic resins, styrene resins, polycarbonate resins, and cyclic polyolefin resins are used for various purposes, and in particular, due to their optical properties, they are in great demand as optical materials such as optical lenses and optical disk substrates. Such optical materials require not only high transparency, but also high heat resistance, low water absorption, and excellent mechanical properties. In order to meet these demands, various improvements have been made to polymers, and as an example of such improvements, hydrogenation of aromatic polymers (aromatic nucleus hydrogenation) can be cited.

[0003] For example, Japanese Patent No. 5540703 (Patent Document 1) is an invention related to the hydrogenation of aromatic vinyl compound / (meth)acrylate copolymers, and Japanese Patent Publication No. 2014-77044 (Patent Document 2) is related to a method for producing aromatic core hydrogenated polymers using sulfur-free raw materials. In addition, Japanese Patent No. 2890748 (Patent Document 3) is related to a method for producing hydrogenated styrene resins, and Japanese Patent Publications No. 2001-527095 (Patent Document 4), No. 2002-511501 (Patent Document 5), and No. 2002-511508 (Patent Document 6) are related to methods for hydrogenating aromatic polymers. Japanese Patent No. 4224655 (Patent Document 7) and Japanese Patent No. 5007688 (Patent Document 8) are related to alicyclic hydrocarbon copolymers or polymers containing alicyclic structures, and record that these polymers can be obtained by hydrogenating aromatic polymers.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5540703

[0007] Patent Document 2: Japanese Patent Application Publication No. 2014-77044

[0008] Patent Document 3: Japanese Patent No. 2890748

[0009] Patent Document 4: Japanese Patent Application No. 2001-527095

[0010] Patent Document 5: Japanese Patent Publication No. 2002-511501

[0011] Patent Document 6: Japanese Patent Application No. 2002-511508

[0012] Patent Document 7: Japanese Patent No. 4224655

[0013] Patent Document 8: Japanese Patent No. 5007688 Summary of the invention

[0014] Problems to be solved by the invention

[0015] However, the heat resistance of the previously used styrene aromatic nucleus hydrogenated products and aromatic nucleus hydrogenated products of copolymers such as styrene / isoprene is not sufficient. In addition, in the aromatic ring hydrogenation (aromatic nucleus hydrogenation) method of aromatic vinyl compound-based polymers, a long reaction time is required to achieve a high aromatic nucleus hydrogenation rate.

[0016] Technical solutions to solve problems

[0017] After intensive research, the inventors found that in a method for manufacturing optical materials using aromatic ring hydrogenation (aromatic nucleus hydrogenation) of aromatic vinyl compound-based polymers, the reaction rate was increased by using a specific mixed solvent as the solvent used in the reaction, thereby completing the present invention.

[0018] That is, the present invention includes the following aspects.

[0019] <1> A method for producing an optical material, wherein the optical material is formed by hydrogenating the aromatic ring of an aromatic vinyl compound-based polymer, wherein:

[0020] The aromatic vinyl compound-based polymer comprises a first monomer unit and a second monomer unit.

[0021] The first monomer unit is a structural unit derived from an aromatic vinyl compound,

[0022] The second monomer unit is a structural unit derived from a conjugated diene compound,

[0023] The method comprises the steps of performing a hydrogenation reaction using the aromatic vinyl compound-based polymer, a solvent and a hydrogenation catalyst to obtain a hydrogenated polymer.

[0024] The above-mentioned solvent is a mixed solvent comprising at least one first solvent and at least one second solvent,

[0025] The first solvent is a solvent that dissolves the aromatic vinyl compound polymer before hydrogenation.

[0026] The second solvent is a solvent that dissolves the hydrogenated polymer.

[0027] <2> according to <1> In the method for producing an optical material, the hydrogenation catalyst is a hydrogenation catalyst that has been subjected to reduction treatment.

[0028] <3> according to <1> or <2> In the method for manufacturing an optical material, the at least one first solvent comprises one or more selected from methyl acetate, ethyl acetate, butyl acetate and methyl isobutyrate.

[0029] <4> according to <1> ~ <3> The method for producing an optical material as described in any one of the preceding claims, wherein the at least one second solvent comprises one or more selected from cyclohexane, C9-C10 alkylcyclohexane, C7-C15 monoalkylcyclohexane, C8-C15 dialkylcyclohexane, C9-C15 trialkylcyclohexane, C10-C15 tetraalkylcyclohexane, cyclooctane, C9-C15 monoalkylcyclooctane, C10-C15 dialkylcyclooctane, C11-C15 trialkylcyclooctane, C12-C15 tetraalkylcyclooctane, n-octane and n-decane.

[0030] <5> according to <1> ~ <4> In any one of the methods for producing an optical material, the first solvent has a boiling point of 50° C. or higher and an autoignition point of 400° C. or higher.

[0031] <6> according to <1> ~ <5> The method for producing an optical material according to any one of the above, wherein the second solvent has a boiling point of 80° C. or higher and an autoignition point of 230° C. or higher.

[0032] <7> according to <1> ~ <6> The method for producing an optical material according to any one of the preceding claims, wherein the first monomer is selected from the group consisting of styrene, α-methylstyrene, chlorostyrene, 4-methylstyrene, 4-tert-butylstyrene and 4-methoxystyrene.

[0033] <8> according to <1> ~ <7> The method for producing an optical material as described in any one of the above, wherein the second monomer is selected from butadiene, cyclopentadiene and isoprene.

[0034] <9> according to <1> ~ <6> The method for producing an optical material according to any one of the preceding claims, wherein the aromatic vinyl compound-based polymer is selected from the group consisting of a copolymer of styrene and butadiene, a copolymer of styrene and cyclopentadiene, and a copolymer of styrene and isoprene.

[0035] <10> according to <1> ~ <9> The method for producing an optical material as described in any one of the above, wherein in the aromatic vinyl compound-based polymer, a polymerization ratio (mol %) of the first monomer unit to the second monomer unit is 70:30 or more and less than 100:0.

[0036] <11> according to <1> ~ <10> The method for producing an optical material according to any one of the preceding claims, further comprising the step of forming a polymer resin by devolatilization extrusion after the hydrogenation reaction.

[0037] <12> according to <1> ~ <11> The method for producing an optical material according to any one of the above aspects further comprises a concentration step between the hydrogenation reaction and the devolatilization extrusion.

[0038] <13> according to <1> ~ <12> The method for producing an optical material as described in any one of the above, wherein the mass ratio (first:second) of the at least one first solvent to the at least one second solvent is 1:9 to 9:1.

[0039] <14> according to <1> ~ <13> The method for producing an optical material as described above, wherein the hydrogenation catalyst is a solid catalyst carrying palladium, platinum, ruthenium, rhodium or nickel.

[0040] <15> according to <1> ~ <14> The method for producing an optical material according to any one of the above, wherein the optical material is an optical lens.

[0041] Effects of the Invention

[0042] According to the method of the present invention, in the manufacturing method of the optical material realized by hydrogenating the aromatic ring of the aromatic vinyl compound-based polymer (aromatic nucleus hydrogenation), the speed of the hydrogenation reaction is increased, so that efficient manufacturing can be achieved. Moreover, by shortening the reaction time, the damage to the polymer such as molecular weight reduction can be reduced. By the method of the present invention, an optical material with sufficient heat resistance can be obtained. DETAILED DESCRIPTION

[0043] The present invention is described in detail below. The following embodiments are merely examples for illustrating the present invention and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various ways without departing from the gist of the present invention.

[0044] <Method for producing optical material>

[0045] In an embodiment of the present invention, a method for producing an optical material by hydrogenating an aromatic ring (hydrogenating an aromatic nucleus) of an aromatic vinyl compound-based polymer is provided.

[0046] In one embodiment of the present invention, a method for manufacturing an optical material is provided, wherein the aromatic ring of an aromatic vinyl compound-based polymer is hydrogenated to form the optical material, the aromatic vinyl compound-based polymer comprises a first monomer unit and a second monomer unit, the first monomer unit is a structural unit derived from an aromatic vinyl compound, and the second monomer unit is a structural unit derived from a conjugated diene compound, the method comprises the step of using the aromatic vinyl compound-based polymer, a solvent and a hydrogenation catalyst after reduction treatment to be put into a reaction apparatus for a hydrogenation reaction to obtain a hydrogenated polymer, the solvent is a mixed solvent comprising at least one first solvent and at least one second solvent, the first solvent is a solvent that dissolves the aromatic vinyl compound-based polymer before hydrogenation, and the second solvent is a solvent that dissolves the hydrogenated polymer.

[0047] <Aromatic vinyl compound polymer>

[0048] The manufacturing method of certain embodiments of the present invention relates to a method for manufacturing an optical material by hydrogenating the aromatic ring of an aromatic vinyl compound-based polymer. In this specification, "aromatic vinyl compound-based polymer" refers to a polymer containing units derived from aromatic vinyl compounds as structural units. Therefore, the aromatic vinyl compound-based polymer can be a polymer (homopolymer) formed by units derived from one aromatic vinyl compound, or a copolymer (copolymer) containing units derived from two or more aromatic vinyl compounds as structural units or containing units derived from one or more aromatic vinyl compounds and units derived from one or more compounds other than aromatic vinyl compounds as structural units. The unit derived from an aromatic vinyl compound refers to a unit having a structure in which the C=C double bond of the vinyl group in the aromatic vinyl compound is in an open state through polymerization.

[0049] In one embodiment of the present invention, the aromatic vinyl compound-based polymer includes a first monomer unit and a second monomer unit.

[0050] (monomer)

[0051] The aromatic vinyl compound polymer used in the manufacturing method of certain embodiments of the present invention is not particularly limited, and examples thereof include, but are not particularly limited to, styrene used as the aromatic vinyl compound monomer; alkyl styrenes such as α-methylstyrene, α-ethylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, and p-tert-butylstyrene (the number of carbon atoms in the alkyl portion is preferably 1 to 5); p-hydroxystyrene; alkoxystyrenes such as p-methoxystyrene, m-butoxystyrene, and p-butoxystyrene (the number of carbon atoms in the alkoxy portion is preferably 1 to 5); halogenated styrenes such as o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, 2,4-dichlorostyrene, and 2,6-dichlorostyrene; and polymers of vinylnaphthalene and vinylanthracene. These monomers may be used alone or in combination. In a preferred embodiment of the present invention, styrene is used as the aromatic vinyl compound monomer.

[0052] In one embodiment of the present invention, the first monomer is a monomer derived from an aromatic vinyl compound. In one embodiment of the present invention, the first monomer is selected from styrene, α-methylstyrene, chlorostyrene, 4-methylstyrene, 4-tert-butylstyrene and 4-methoxystyrene. In a preferred embodiment of the present invention, the first monomer is styrene.

[0053] The aromatic vinyl compound-based polymer used in the production method of certain embodiments of the present invention is a polymer using monomers of compounds other than aromatic vinyl compounds in addition to aromatic vinyl compound monomers. Examples of such monomers of compounds other than aromatic vinyl compounds include, but are not limited to, (meth)acrylates, dienes, and acid anhydrides. Examples of (meth)acrylates include, but are not limited to, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate (the number of carbon atoms in the alkyl portion is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5); cycloalkyl (meth)acrylates or cyclic saturated hydrocarbon esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate (the number of carbon atoms in the ring of both is preferably 5 to 20, and more preferably 5 to 10); hydroxyalkyl (meth)acrylates such as (2-hydroxyethyl) (meth)acrylate, (2-hydroxypropyl) (meth)acrylate, and (2-hydroxy-2-methylpropyl) (meth)acrylate (the alkyl portion is preferably 1 to 20, and the alkyl portion is preferably 1 to 5); The carbon number of the alkyl group is preferably 1 to 20, more preferably 1 to 10, and further preferably 1 to 5); (meth) acrylate alkoxyalkyl esters such as (meth) acrylate (2-methoxyethyl) ester and (meth) acrylate (2-ethoxyethyl) ester (the carbon number of the alkyl group is preferably 1 to 20, more preferably 1 to 10, and further preferably 1 to 5, and the carbon number of the alkoxy group is preferably 1 to 10, more preferably 1 to 5, and further preferably 1 or 2); (meth) acrylate phenyl esters such as (meth) acrylate; (meth) acrylate arylalkyl esters such as (meth) benzyl ester (the carbon number of the aryl group is preferably 6 to 10, and the carbon number of the alkyl group is preferably 1 to 5); (meth) acrylates having a phospholipid structure such as 2-(meth) acryloyloxyethyl phosphorylcholine, etc. The (meth) acrylates may be used alone or in combination of two or more. As the (meth) acrylate, methyl (meth) acrylate is preferred.

[0054] Examples of the diene include, but are not limited to, 1,2-butadiene, 1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,2-hexadiene, 1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene, 1,3-heptadiene, 1,3-octadiene, 1,3-nonadiene, 1,3-decadiene, isoprene, cyclopentadiene, 1,3-cyclohexadiene, and 1,4-cyclohexadiene. One diene may be used alone or two or more dienes may be used in combination. The diene is preferably a conjugated diene, such as 1,3-butadiene or isoprene.

[0055] Examples of the acid anhydride include, but are not limited to, anhydrides of maleic acid, itaconic acid, citraconic acid, and aconitic acid. Of these, maleic anhydride is preferred.

[0056] In one embodiment of the present invention, the second monomer is a monomer derived from a conjugated diene compound. In one embodiment of the present invention, the second monomer is selected from butadiene, cyclopentadiene and isoprene. In a preferred embodiment of the present invention, the second monomer is butadiene.

[0057] As long as the effect of the present invention is not impaired, the aromatic vinyl compound-based polymer used in the manufacturing method of certain embodiments of the present invention may also contain monomers other than the first monomer and the second monomer as structural components. For example, the monomer components other than the first monomer and the second monomer in the aromatic vinyl compound-based polymer may contain 0 to 10% or 0 to 5% in terms of molar ratio relative to all monomer components. Examples of monomers other than the first monomer and the second monomer include, but are not limited to, methyl methacrylate, maleic anhydride, vinyl acetate, acrylonitrile, ethylene, propylene, and the like.

[0058] In a preferred embodiment of the present invention, the aromatic vinyl compound-based polymer includes one or more selected from the copolymers of styrene and butadiene (1,2-butadiene, 1,3-butadiene or a combination thereof), copolymers of styrene and isoprene, copolymers of styrene and methyl methacrylate, copolymers of styrene and maleic anhydride, copolymers of styrene and vinyl acetate, and polystyrene. In another preferred embodiment of the present invention, the aromatic vinyl compound-based polymer is a polymer selected from the copolymers of styrene and butadiene (1,2-butadiene, 1,3-butadiene or a combination thereof), copolymers of styrene and isoprene, copolymers of styrene and methyl methacrylate, copolymers of styrene and maleic anhydride, copolymers of styrene and vinyl acetate, and polystyrene. These polymers, as described later, can be polymerized from each monomer, or commercial products can be used. For example, as polystyrene, "GPPS HF77" manufactured by PS Japan can be used.

[0059] In one embodiment of the present invention, the aromatic vinyl compound polymer is selected from the group consisting of copolymers of styrene and butadiene, copolymers of styrene and cyclopentadiene, and copolymers of styrene and isoprene. In a preferred embodiment of the present invention, the aromatic vinyl compound polymer is a copolymer of styrene and butadiene.

[0060] (Method for producing aromatic vinyl compound-based polymer)

[0061] Aromatic vinyl compound-based polymers can be produced by polymerizing various monomers. For the method of polymerizing one or more aromatic vinyl compounds, the method of copolymerizing an aromatic vinyl compound with a monomer other than an aromatic vinyl compound monomer can be used, but is not particularly limited to, known methods such as free radical polymerization, ion polymerization, and coordination polymerization.

[0062] As a free radical polymerization method, it can be appropriately selected from known methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. For example, as an example of bulk polymerization or solution polymerization, there is a continuous polymerization method in which a monomer composition mixed with monomer components, a chain transfer agent and a polymerization initiator (and a solvent further added in the case of solution polymerization) is continuously supplied to a complete mixing tank and polymerization is carried out at a temperature of 100 to 180°C. As solvents used in the solution polymerization method, hydrocarbon solvents such as toluene, xylene, cyclohexane, methylcyclohexane, etc.; ester solvents such as ethyl acetate; ketone solvents such as acetone and butanone; ether solvents such as tetrahydrofuran and 1,4-dioxane; alcohol solvents such as methanol and isopropanol, etc. can be cited but are not limited to.

[0063] As ion polymerization methods, anion polymerization and cationic polymerization methods can be cited, but in particular, as a method for manufacturing a copolymer using an aromatic vinyl compound and butadiene as monomer components, anion polymerization is preferably used. As an anion polymerization method, there is a method of polymerizing an aromatic vinyl monomer in a solvent using an anion polymerization initiator to form an aromatic vinyl polymer segment with an active end, and then polymerizing the active end of the aromatic vinyl polymer segment with a butadiene segment to obtain an aromatic vinyl compound / butadiene diblock copolymer with an active end, and then using a coupling agent to react the aromatic vinyl compound / butadiene diblock copolymer with each other, and finally using an inhibitor to deactivate the remaining active end to obtain a copolymer. As the solvent used, hydrocarbon solvents such as toluene, xylene, cyclohexane, methylcyclohexane, etc. can be cited but are not limited to; ester solvents such as ethyl acetate; ketone solvents such as acetone and butanone; ether solvents such as tetrahydrofuran and 1,4-dioxane, etc. In addition, as a polymerization initiator, in the case of anionic polymerization, alkyl lithium compounds such as n-butyl lithium are generally used. As the polymerization inhibitor, for example, alcohol compounds such as methanol and isopropanol can be used.

[0064] It should be noted that after the reaction mixture after polymerization is extracted from the complete mixing tank, it is introduced into a devolatilization extruder or a vacuum devolatilization tank to distill off the volatile components (monomer components and solvents, etc.), thereby obtaining a polymer of an aromatic vinyl compound or a copolymer of an aromatic vinyl compound and a monomer other than an aromatic vinyl compound monomer (these polymers are also collectively referred to as "aromatic vinyl compound-based polymers").

[0065] In one embodiment of the present invention, the polymerization ratio (mol %) of the first monomer unit to the second monomer unit constituting the aromatic vinyl compound-based polymer may be 70:30 or more and less than 100:0.

[0066] In an embodiment of the present invention, the polymerization ratio (mol %) of the first monomer unit and the second monomer unit constituting the aromatic vinyl compound-based polymer may be, for example, 70:30 or more, 75:25 or more, 80:20 or more, 85:15 or more, 86:14 or more, 87:13 or more, 88:12 or more, 89:11 or more, 90:10 or more, 91:9 or more, 92:8 or more, 93:7 or more, 94:6 or more, 95:5 or more, 96:4 or more, 97:3 or more, 98:2 or more, or 99:1 or more.

[0067] In an embodiment of the present invention, the polymerization ratio (mol %) of the first monomer unit and the second monomer unit constituting the aromatic vinyl compound-based polymer may be, for example, less than 100:0, less than 99:1, less than 98:2, less than 97:3, less than 96:4, less than 95:5, less than 94:6, less than 93:7, less than 92:8, less than 91:9, less than 90:10, less than 89:11, less than 88:12, less than 87:13, less than 86:14, less than 85:15, less than 80:20, or less than 75:25.

[0068] In one embodiment of the present invention, the polymerization ratio (mol%) of the first monomer unit and the second monomer unit constituting the aromatic vinyl compound-based polymer is 70:30 or more and less than 100:0. In an embodiment of the present invention, the polymerization ratio (mol%) of the first monomer unit and the second monomer unit constituting the aromatic vinyl compound-based polymer may be, for example, 70:30 or more and less than 100:0, 75:25 or more and less than 100:0, 80:20 or more and less than 100:0, 85:15 or more and less than 100:0, 86:14 or more and less than 100:0, 87:13 or more and less than 100:0, 88:12 or more and less than 100:0. ∶0, 89∶11 or more and less than 100∶0, 90∶10 or more and less than 100∶0, 91∶9 or more and less than 100∶0, 92∶8 or more and less than 100∶0, 93∶7 or more and less than 100∶0, 94∶6 or more and less than 100∶0, 95∶5 or more and less than 100∶0, 96∶4 or more and less than 100∶0, 97∶3 or more and less than 100∶0, 98∶2 or more and less than 100∶0, 99∶1 or more and less than 100∶0;

[0069] 70:30 or more and 99:1 or less, 75:25 or more and 99:1 or less, 80:20 or more and 99:1 or less, 85:15 or more and 99:1 or less, 86:14 or more and 99:1 or less, 87:13 or more and 99:1 or less, 88:12 or more and 99:1 or less, 89:11 or more and 99:1 or less, 90:10 or more and 99:1 or less, 91:9 or more and 99:1 or less, 92:8 or more and 99:1 or less, 93:7 or more and 99:1 or less, 94:6 or more and 99:1 or less, 95:5 or more and 99:1 or less, 96:4 or more and 99:1 or less, 97:3 or more and 99:1 or less, 98:2 or more and 99:1 or less;

[0070] 70:30 or more and 98:2 or less, 75:25 or more and 98:2 or less, 80:20 or more and 98:2 or less, 85:15 or more and 98:2 or less, 86:14 or more and 98:2 or less, 87:13 or more and 98:2 or less, 88:12 or more and 98:2 or less, 89:11 or more and 98:2 or less, 90:10 or more and 98:2 or less, 91:9 or more and 98:2 or less, 92:8 or more and 98:2 or less, 93:7 or more and 98:2 or less, 94:6 or more and 98:2 or less, 95:5 or more and 98:2 or less, 96:4 or more and 98:2 or less, 97:3 or more and 98:2 or less;

[0071] 70:30 or more and 97:3 or less, 75:25 or more and 97:3 or less, 80:20 or more and 97:3 or less, 85:15 or more and 97:3 or less, 86:14 or more and 97:3 or less, 87:13 or more and 97:3 or less, 88:12 or more and 97:3 or less, 89:11 or more and 97:3 or less, 90:10 or more and 97:3 or less, 91:9 or more and 97:3 or less, 92:8 or more and 97:3 or less, 93:7 or more and 97:3 or less, 94:6 or more and 97:3 or less, 95:5 or more and 97:3 or less, 96:4 or more and 97:3 or less;

[0072] 70:30 or more and 96:4 or less, 75:25 or more and 96:4 or less, 80:20 or more and 96:4 or less, 85:15 or more and 96:4 or less, 86:14 or more and 96:4 or less, 87:13 or more and 96:4 or less, 88:12 or more and 96:4 or less, 89:11 or more and 96:4 or less, 90:10 or more and 96:4 or less, 91:9 or more and 96:4 or less, 92:8 or more and 96:4 or less, 93:7 or more and 96:4 or less, 94:6 or more and 96:4 or less, 95:5 or more and 96:4 or less;

[0073] 70:30 or more and 95:5 or less, 75:25 or more and 95:5 or less, 80:20 or more and 95:5 or less, 85:15 or more and 95:5 or less, 86:14 or more and 95:5 or less, 87:13 or more and 95:5 or less, 88:12 or more and 95:5 or less, 89:11 or more and 95:5 or less, 90:10 or more and 95:5 or less, 91:9 or more and 95:5 or less, 92:8 or more and 95:5 or less, 93:7 or more and 95:5 or less, 94:6 or more and 95:5 or less;

[0074] 70:30 or more and 94:6 or less, 75:25 or more and 94:6 or less, 80:20 or more and 94:6 or less, 85:15 or more and 94:6 or less, 86:14 or more and 94:6 or less, 87:13 or more and 94:6 or less, 88:12 or more and 94:6 or less, 89:11 or more and 94:6 or less, 90:10 or more and 94:6 or less, 91:9 or more and 94:6 or less, 92:8 or more and 94:6 or less, 93:7 or more and 94:6 or less;

[0075] 70:30 or more and 93:7 or less, 75:25 or more and 93:7 or less, 80:20 or more and 93:7 or less, 85:15 or more and 93:7 or less, 86:14 or more and 93:7 or less, 87:13 or more and 93:7 or less, 88:12 or more and 93:7 or less, 89:11 or more and 93:7 or less, 90:10 or more and 93:7 or less, 91:9 or more and 93:7 or less, 92:8 or more and 93:7 or less;

[0076] 70:30 or more and 92:8 or less, 75:25 or more and 92:8 or less, 80:20 or more and 92:8 or less, 85:15 or more and 92:8 or less, 86:14 or more and 92:8 or less, 87:13 or more and 92:8 or less, 88:12 or more and 92:8 or less, 89:11 or more and 92:8 or less, 90:10 or more and 92:8 or less, 91:9 or more and 92:8 or less;

[0077] 70:30 or more and 91:9 or less, 75:25 or more and 91:9 or less, 80:20 or more and 91:9 or less, 85:15 or more and 91:9 or less, 86:14 or more and 91:9 or less, 87:13 or more and 91:9 or less, 88:12 or more and 91:9 or less, 89:11 or more and 91:9 or less, 90:10 or more and 91:9 or less;

[0078] 70:30 or more and 90:10 or less, 75:25 or more and 90:10 or less, 80:20 or more and 90:10 or less, 85:15 or more and 90:10 or less, 86:14 or more and 90:10 or less, 87:13 or more and 90:10 or less, 88:12 or more and 90:10 or less, 89:11 or more and 90:10 or less;

[0079] 70:30 or more and 89:11 or less, 75:25 or more and 89:11 or less, 80:20 or more and 89:11 or less, 85:15 or more and 89:11 or less, 86:14 or more and 89:11 or less, 87:13 or more and 89:11 or less, 88:12 or more and 89:11 or less;

[0080] 70:30 or more and 88:12 or less, 75:25 or more and 88:12 or less, 80:20 or more and 88:12 or less, 85:15 or more and 88:12 or less, 86:14 or more and 88:12 or less, 87:13 or more and 88:12 or less;

[0081] 70:30 or more and 87:13 or less, 75:25 or more and 87:13 or less, 80:20 or more and 87:13 or less, 85:15 or more and 87:13 or less, 86:14 or more and 87:13 or less;

[0082] 70:30 or more and 86:14 or less, 75:25 or more and 86:14 or less, 80:20 or more and 86:14 or less, 85:15 or more and 86:14 or less;

[0083] 70:30 or more and 85:15 or less, 75:25 or more and 85:15 or less, 80:20 or more and 85:15 or less;

[0084] 70:30 or more and 80:20 or less, 75:25 or more and 80:20 or less;

[0085] Any one of 70:30 or more and 75:25 or less.

[0086] The weight average molecular weight of the aromatic vinyl compound-based polymer used in certain embodiments of the present invention is preferably 10,000 to 1,000,000, more preferably 50,000 to 700,000, further preferably 100,000 to 500,000, and particularly preferably 130,000 to 250,000. Although polymers less than 10,000 or more than 1,000,000 can also be hydrogenated with aromatic nuclei by the methods of certain embodiments of the present invention, copolymers with a weight average molecular weight within the above range have a sufficiently high mechanical strength to withstand practical use, and have a moderate viscosity and are easy to operate, so they are more preferred. It should be noted that in this specification, the weight average molecular weight is a value obtained by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and converted to polystyrene.

[0087] <Hydrogenation>

[0088] In this specification, "hydrogenation of an aromatic vinyl compound polymer" means hydrogenation reaction of the aromatic ring of an aromatic vinyl compound polymer, for example, reduction of a benzene ring to cyclohexane. This hydrogenation is also called aromatic nucleus hydrogenation or nucleus hydrogenation.

[0089] (Solvent)

[0090] The aromatic vinyl compound polymer used in some embodiments of the present invention is dissolved in a suitable solvent for hydrogenation, but as a factor to be considered when selecting a solvent, it is preferred that the polymer (i.e. both aromatic polymer and hydrogenated polymer) before and after hydrogenation has good solubility and no hydrogenated site. Moreover, it is more preferred to be a solvent that allows the reaction to proceed quickly. This is because the increase in the hydrogenation rate shortens the reaction time and can reduce damage to the polymer such as molecular weight reduction. In addition, in the case of assuming that there is devolatilization of the solvent component after hydrogenation, it is preferred that the autoignition point of the solvent is high. Because as long as the devolatilization extrusion process can be carried out, the hydrogenated polymer can be efficiently manufactured and is preferred.

[0091] The solvent used in the manufacturing method of certain embodiments of the present invention is a mixed solvent comprising at least one first solvent and at least one second solvent. Among them, the first solvent is preferably a solvent with high solubility of the polymer before hydrogenation, and the second solvent is preferably a solvent with high solubility of the polymer after hydrogenation. However, the solubility of the polymer in the solvent is not easy to predict, and mixing these two solvents does not necessarily mean that a solvent that can well dissolve both the polymer before and after the hydrogenation reaction can be obtained.

[0092] In one embodiment of the present invention, the solvent is a mixed solvent comprising at least one first solvent and at least one second solvent, wherein the first solvent is a solvent that dissolves the aromatic vinyl compound-based polymer before hydrogenation, and the second solvent is a solvent that dissolves the hydrogenated polymer.

[0093] In a certain embodiment of the present invention, the at least one first solvent may be an ester solvent, preferably a carboxylic acid ester. In a certain embodiment of the present invention, the at least one first solvent comprises one or more selected from methyl acetate, ethyl acetate, butyl acetate and methyl isobutyrate. In a certain embodiment of the present invention, the first solvent is methyl isobutyrate. In another embodiment of the present invention, the first solvent is methyl acetate. In another embodiment of the present invention, the first solvent is ethyl acetate.

[0094] In one embodiment of the present invention, the boiling point of the first solvent is above 50° C. and the autoignition point is above 400° C. By using a solvent having a high boiling point and autoignition point, the devolatilization extrusion process can be performed efficiently. Examples of such solvents include, but are not limited to, methyl isobutyrate, ethyl acetate, and butyl acetate.

[0095] In one embodiment of the present invention, the at least one second solvent may be a hydrocarbon solvent. In one embodiment of the present invention, the at least one second solvent is selected from cyclohexane, C9-C10 alkylcyclohexane, C7-C15 monoalkylcyclohexane, C8-C15 dialkylcyclohexane, C9-C15 trialkylcyclohexane, C10-C15 tetraalkylcyclohexane, cyclooctane, C9-C15 monoalkylcyclooctane, C10-C15 dialkylcyclooctane, C11-C15 trialkylcyclooctane, C12-C15 tetraalkylcyclooctane, n-octane and n-decane.

[0096] In one embodiment of the present invention, the second solvent has a boiling point of 80°C or more and an autoignition point of 230°C or more. By using a solvent having a high boiling point and an autoignition point, the devolatilization extrusion process can be performed efficiently. Examples of such solvents include, but are not limited to, cyclohexane, cyclopentane, methylcyclohexane, n-heptane, 2,2,4-trimethylpentane, cyclooctane, 1,3-dimethylcyclohexane, ethylcyclohexane, 1,2,4-trimethylcyclohexane, decalin (cis, trans-decalin), and Swa Clean 150.

[0097] In a certain embodiment of the present invention, the mass ratio of the at least one first solvent to the at least one second solvent (first: second) is 1:9 to 9:1. In certain embodiments of the present invention, the mass ratio of the at least one first solvent to the at least one second solvent (first solvent: second solvent) can be, for example, 1:9 to 9:1, 1:9 to 8:2, 1:9 to 7:3, 1:9 to 6:4, 1:9 to 5:5, 1:9 to 4:6, 1:9 to 3:7, 1:9 to 2:8; 2:8 to 9:1, 2:8 to 8:2, 2:8 to 7:3, 2:8 to 6:4, 2:8 to 5:5, 2:8 to 4:6, 2:8 to 3:7; 3:7-9:1, 3:7-8:2, 3:7-7:3, 3:7-6:4, 3:7-5:5, 3:7-4:6; 4:6-9:1, 4:6-8:2, 4:6-7:3, 4:6-6:4, 4:6-5:5; 5:5-9:1, 5:5-8:2, 5:5-7:3, 5:5-6:4; 6:4-9:1, 6:4-8:2, 6:4-7:3; 7:3-9:1, 7:3-8:2; 8:2-9:1. When the aromatic vinyl compound polymer is polystyrene, the first solvent: the second solvent is preferably 1:9-5:5. When the aromatic vinyl compound polymer is a copolymer of styrene and methyl methacrylate, the first solvent: the second solvent is preferably 3:7-7:3. When the aromatic vinyl compound polymer is a copolymer of styrene and maleic anhydride, the first solvent: second solvent ratio is preferably 3:7 to 9:1. When the aromatic vinyl compound polymer is a copolymer of styrene and butadiene or isoprene, the first solvent: second solvent ratio is preferably 1:9 to 7:3.

[0098] (Hydrogenation Catalyst)

[0099] As the effective component of the hydrogenation catalyst used in some embodiments of the present invention, metal elements with catalytic hydrogenation performance (hereinafter referred to as "specific metal components") can be cited. As specific metal components, for example, nickel, cobalt, iron, ruthenium, rhodium, palladium, platinum, iridium, copper, silver, molybdenum, tungsten, chromium and rhenium can be cited but not limited to. As long as the specific metal component exhibits hydrogenation performance, it can be either a metal (single substance) state or a cationic state. Among them, generally because the hydrogenation performance of the metallic state is stronger and stable under a reducing environment, it is preferably a metallic state. The specific metal component can be used in a state where a single one or two or more combinations are contained in a solid catalyst. In the case of using two or more specific metal components, their combination, mixing ratio and form are not particularly limited, and can be used in the form of a mixture of each metal (single substance), or an alloy or an intermetallic compound. In some embodiments of the present invention, the hydrogenation catalyst is preferably a solid catalyst supported by one or more selected from palladium, platinum, ruthenium, rhodium and nickel, and is particularly preferably a solid catalyst supported by palladium.

[0100] The raw materials of these specific metal components can be, but are not particularly limited to, materials used as raw materials when preparing catalysts by conventional known methods. Examples of such raw materials include hydroxides, oxides, fluorides, chlorides, bromides, iodides, sulfates, nitrates, acetates, ammine complexes, and carbonyl complexes of various metal elements. These raw materials can be used alone or in combination of two or more.

[0101] The hydrogenation catalyst used in certain embodiments of the present invention can also use a specific metal component as a metal component alone or in combination with a metal that does not have catalytic hydrogenation performance. As examples thereof, catalysts such as palladium black and platinum black formed from fine metal powders of the specific metal component, and sponge catalysts made by forming an alloy from the specific metal component, aluminum and a small amount of additives and then leaching all or part of the aluminum can be cited.

[0102] In addition, in order to further improve the activity, selectivity and physical properties of the catalyst, compounds of one or more elements selected from lithium, sodium, potassium, rubidium and cesium as alkali metal elements, magnesium, calcium, strontium and barium as alkaline earth metal elements, fluorine, chlorine, bromine and iodine as halogen elements, and mercury, lead, bismuth, tin, tellurium and antimony as auxiliary additive elements (hereinafter referred to as specific additive components) may be added to the catalyst together with the above-mentioned specific metal components.

[0103] The raw materials of these specific additive components are not particularly limited, and materials used as raw materials when preparing catalysts by conventional known methods can be used. Such raw materials include, for example, hydroxides, oxides, fluorides, chlorides, bromides, iodides, sulfates, nitrates, acetates and ammonia complexes of various metal elements. These raw materials can be used alone or in combination of two or more. In addition, there are no particular restrictions on the method of adding the specific additive components and the ratio of the specific additive components to the specific metal components.

[0104] In the hydrogenation catalyst used in some embodiments of the present invention, it is also possible to combine non-metallic substances in specific metal components for use. As non-metallic substances, it is mainly possible to cite such as elemental simple substance, carbide, nitride, oxide, hydroxide, sulfate, carbonate and phosphate (hereinafter referred to as "specific non-metallic component"). As its specific example, it is possible to cite such as graphite, diamond, activated carbon, silicon carbide, silicon nitride, aluminum nitride, boron nitride, boron oxide, aluminum oxide (alumina), silicon dioxide (silica), titanium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, cerium oxide, yttrium oxide, niobium oxide, magnesium silicate, calcium silicate, magnesium aluminate, calcium aluminate, zinc oxide, chromium oxide, aluminum silicate, aluminum silicophosphate, aluminum phosphate, boron phosphate, magnesium phosphate, calcium phosphate, strontium phosphate, hydroxyapatite (hydroxy calcium phosphate), apatite chloride, apatite fluoride, calcium sulfate, barium sulfate and barium carbonate. Specific non-metallic components can be used alone or in combination of two or more. When two or more compounds are used in combination, the combination, mixing ratio and form are not particularly limited, and the compounds may be used in the form of a mixture, a complex or a double salt.

[0105] From the perspective of industrial use, it is preferred that the specific non-metallic component can be obtained simply and cheaply. As such a specific non-metallic component, zirconium compounds, aluminum compounds and apatite compounds are preferred, and zirconium compounds and apatite compounds are more preferred. Among them, zirconium oxide and hydroxyapatite (hydroxy calcium phosphate) are particularly preferred. In addition, the above-mentioned specific additive components can also be used to modify or ion-exchange some or all of these specific non-metallic components.

[0106] In addition, as the specific non-metallic component, carbides, nitrides, oxides, etc. of specific metal components may also be used. However, since a part of these compounds will be reduced to metal once exposed to a hydrogen reduction environment, in this case, a part of them will be used as the specific metal component and the rest will be used as the non-metallic component. As such examples, oxides such as nickel oxide, iron oxide, cobalt oxide, molybdenum oxide, tungsten oxide, and chromium oxide can be cited.

[0107] As the hydrogenation catalyst used in certain embodiments of the present invention, a specific metal component can be used alone, or a specific metal component can be used in combination with a specific non-metal component. Depending on the circumstances, a specific additional component other than this can also be included. The method for manufacturing the hydrogenation catalyst used in certain embodiments of the present invention is not particularly limited, and a conventionally known method can be used. As examples thereof, there can be cited a method of impregnating a raw material compound of a specific metal component on a specific non-metal component (supporting method); a method of dissolving a raw material compound of a specific metal component and a raw material compound of a specific non-metal component together in an appropriate solvent, and then precipitating them simultaneously using an alkaline compound or the like (coprecipitation method); and a method of uniformly mixing a raw material compound of a specific metal component and a specific non-metal component in an appropriate proportion (mixing method), etc.

[0108] According to the composition of the hydrogenation catalyst or the situation of the catalyst preparation method, it is also possible to prepare a specific metal component in a cationic state and then perform a reduction treatment to reduce it to a metallic state. As the reduction method and reducing agent used for this purpose, the previously known methods and products can be used without particular limitation. As the reducing agent, reducing inorganic gases such as hydrogen, carbon monoxide gas, ammonia, hydrazine, phosphine and silane, low-level oxygen-containing compounds such as methanol, formaldehyde and formic acid, and hydrides such as sodium borohydride and lithium aluminum hydride can be cited. By reducing the specific metal component in a cationic state in the gas phase or liquid phase in the presence of these reducing agents, the specific metal component can be converted into a metallic state. The reduction treatment conditions at this time can be set to appropriate conditions according to the type and amount of the specific metal component and the reducing agent. The reduction treatment operation can be performed by using a catalytic reduction device separately before the hydrogenation reduction in the manufacturing method of certain embodiments of the present invention, or it can be performed before the reaction starts in the reaction device used in the manufacturing method of certain embodiments of the present invention or simultaneously with the reaction operation.

[0109] In addition, the metal content and shape of the hydrogenation catalyst used in certain embodiments of the present invention are not particularly limited. The shape can be powder or a molded product, and the shape and molding method in the case of molding are not particularly limited. For example, spherical products, tablet molded products and extrusion molded products, as well as the shapes of the above products crushed into appropriate sizes can be appropriately selected and used.

[0110] A particularly preferred specific metal component is palladium, and a catalyst using the specific metal component is described in detail below. When the specific metal component is palladium, considering that palladium is a precious metal, it is preferred that the amount used is small and palladium can be used effectively from the perspective of economic efficiency. Therefore, it is preferred that the palladium is dispersed and supported on a catalyst carrier for use.

[0111] The palladium compound as the raw material of palladium is preferably a palladium compound soluble in water or an organic solvent. As such a palladium compound, for example, palladium chloride, tetrachloropalladium salt, tetraamine palladium salt, palladium nitrate and palladium acetate can be cited. Among them, palladium chloride is preferably used for industrial purposes because of its high solubility relative to water or an organic solvent. Palladium chloride can be used after being dissolved in a sodium chloride aqueous solution, dilute hydrochloric acid, ammonia water, etc.

[0112] By adding a solution of a palladium compound to a catalyst support, or by impregnating the catalyst support into a solution of a palladium compound, etc., palladium or a palladium compound is fixed on a catalyst support. The fixing method is usually adsorbed on a support, crystallized by distilling off the solvent, and precipitation and precipitation of reducing substances and / or alkaline substances acting on the palladium compound are used, and a suitable method can be used as appropriate. The palladium content in the hydrogenation catalyst prepared by this method is converted to metallic palladium, preferably 0.01 to 20 mass %, more preferably 0.1 to 10 mass %, and further preferably 0.5 to 5 mass % relative to the total amount of the hydrogenation catalyst. Since the palladium content is above 0.01 mass %, a more sufficient hydrogenation rate can be achieved, further improving the conversion rate of the aromatic vinyl compound-based polymer. On the other hand, when the palladium content is below 20 mass %, the dispersion efficiency of palladium in the hydrogenation catalyst will become higher, so palladium can be used more effectively.

[0113] Depending on the conditions of the palladium compound and the catalyst preparation method, palladium is sometimes supported on the carrier in the state of cations rather than in the metallic state. In this case, the supported cationic palladium (for example, in the state of a palladium compound) can be used after being reduced to metallic palladium. The reduction method and reducing agent used for this purpose can use the previously known methods and products without particular limitation. As reducing agents, reducing inorganic gases such as hydrogen, carbon monoxide gas, ammonia and hydrazine, low-level oxygen-containing compounds such as methanol, formaldehyde and formic acid, hydrocarbon compounds such as ethylene, propylene, benzene and toluene, hydrides such as sodium borohydride and lithium aluminum hydride can be cited. In the gas phase or in the liquid phase, the cationic palladium is contacted with the reducing agent, and it will be able to be easily reduced to metallic palladium. The reduction treatment conditions at this time can be set to appropriate conditions according to the type and amount of the reducing agent. The operation of the reduction treatment can be carried out by using a catalytic reduction device separately before the hydrogenation reduction in the manufacturing method of the embodiment of the present invention, or it can be carried out before the reaction starts in the reaction device used in the manufacturing method of the embodiment of the present invention or simultaneously with the reaction operation.

[0114] As a specific non-metal component used together with the specific metal component, one preferred component is a zirconium compound, and the hydrogenation catalyst containing the compound will be described in detail below. The zirconium compound used in certain embodiments of the present invention is preferably selected from zirconium oxide, zirconium hydroxide, zirconium carbonate, alkaline earth metal zirconate, rare earth metal zirconate and zircon, alone or in combination of two or more thereof.

[0115] A particularly preferred zirconium compound is zirconium oxide, and there is no particular restriction on its preparation method. For example, a known conventional method is to decompose an aqueous solution of a soluble zirconium salt into zirconium hydroxide or zirconium carbonate with an alkaline substance, and then prepare it by heating and decomposing it. The raw materials of the zirconium compound in this case are not limited, and examples thereof include zirconium oxychloride, zirconium oxynitrate, zirconium chloride, zirconium sulfate, zirconium tetraol oxide, zirconium acetate, and zirconium acetylacetonate. These zirconium compounds can be used alone or in combination of two or more. In addition, as alkaline substances for decomposition, examples thereof include ammonia, alkylamines, ammonium carbonate, ammonium bicarbonate, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, magnesium hydroxide, calcium hydroxide, lanthanum hydroxide, yttrium hydroxide, and cerium hydroxide, and these alkaline substances can be used alone or in combination of two or more.

[0116] When zirconium oxide is used as the specific non-metal component, there are no particular restrictions on its physical properties, shape, etc. There are no particular restrictions on the purity of zirconium oxide, and zirconium oxide with a purity ranging from commercially available general-purpose products to high-purity products can be appropriately used.

[0117] When a specific non-metal component represented by a zirconium compound is used as a catalyst carrier, there are no particular restrictions on the physical properties of the carrier, such as the shape, particle size and porosity, and the method of supporting the metal component. The shape, carrier physical properties, supporting method, etc. suitable for the reaction mode and conditions can be appropriately selected and used.

[0118] The hydrogenation catalyst may also be a product that has been subjected to a reduction treatment before being used in the hydrogenation reaction. By performing a reduction treatment before being used in the hydrogenation reaction, the efficiency of the hydrogenation reaction can be improved. In one embodiment of the present invention, the hydrogenation catalyst is a hydrogenation catalyst that has been subjected to a reduction treatment.

[0119] (Other reaction conditions)

[0120] During the aromatic nucleus hydrogenation reaction, the concentration of the copolymer (aromatic polymer + aromatic nucleus hydrogenated polymer) in the solution is usually 1 to 50 mass %, preferably 3 to 30 mass %, and more preferably 5 to 25 mass %. By setting the upper limit of the concentration of the copolymer to below the predetermined value, the inconvenience of handling caused by the decrease in reaction rate and the increase in solution viscosity can be avoided. Moreover, from the perspective of production efficiency and / or economic benefit, it is preferred that the lower limit of the concentration be set to above the predetermined value.

[0121] Although the hydrogenation (hydrogenation) reaction in the manufacturing method of certain embodiments of the present invention is carried out using a raw material solution in which an aromatic vinyl compound-based polymer is dissolved in a solvent, it can be any of the reactions using a suspended bed or a fixed bed, and known methods such as intermittent reactions or continuous flow reactions can be used. In the case of a suspended bed reaction, the carrier particle size is generally in the range of 0.1 to 1,000 μm, preferably 1 to 500 μm, and more preferably 5 to 200 μm. By setting the particle size to a predetermined size or more, the catalyst separation after the hydrogenation reaction can be easily achieved, and by setting the upper limit of the particle size to a predetermined value or less, the reaction rate can be prevented from decreasing.

[0122] Preferred reaction conditions are a temperature of 60 to 250°C, a hydrogen partial pressure of 3 to 30 MPa, and a reaction time of 3 to 30 hours. By setting the reaction temperature to a predetermined temperature or higher, the reaction rate can be accelerated; by setting the upper limit of the reaction temperature to a predetermined temperature or lower, side reactions such as polymer decomposition and solvent hydrocracking can be suppressed. In addition, although the reaction rate can be accelerated by setting the hydrogen partial pressure to a predetermined value or higher, the upper limit is preferably 30 MPa from the perspective of economic benefits.

[0123] By separating the hydrogenation catalyst and volatile components (solvent, etc.) from the polymer solution after the hydrogenation reaction, an aromatic core hydrogenated polymer can be obtained. Catalyst separation can be performed by known techniques such as filtration or centrifugal separation. Considering coloration, the effect on mechanical properties, etc., it is preferred to reduce the residual concentration of the catalytic metal in the polymer as much as possible, preferably below 10 ppm, more preferably below 1 ppm.

[0124] As a method for separating volatile components such as solvent from the obtained aromatic core hydrogenated polymer solution after catalyst separation for polymer purification, known methods such as 1) a granulation method in which a concentrated solution is formed by continuously removing the solvent from the polymer solution and extruding it in a molten state under heating (also known as "devolatilization extrusion method"), 2) a method in which the solvent is evaporated from the polymer solution to obtain a block and then granulate it, 3) a method in which a polymer solution is added to a poor solvent or a poor solvent is added to the polymer solution for precipitation and then granulate it, 4) a method in which a block is obtained by contact with hot water and then granulate it. The manufacturing method of a preferred embodiment of the present invention includes a step of forming a polymer resin by devolatilization extrusion after the hydrogenation reaction. Devolatilization extrusion can be carried out by, for example, maintaining the polymerization solution obtained in the polymerization tank at 120°C to 180°C or introducing it into a devolatilization extruder equipped with an exhaust port in a heated state to remove volatile components. The manufacturing method according to another preferred embodiment of the present invention also includes a concentration step between the hydrogenation reaction and the devolatilization extrusion.

[0125] When performing the separation of the catalyst and the separation of the volatile components, it is preferred to operate under an inert gas or non-oxidizing gas environment. As the inert gas and non-oxidizing gas, hydrogen, nitrogen, helium, argon, etc. can be used, but it is preferred to operate under an environment of industrially cheap nitrogen or hydrogen as a reaction gas.

[0126] The hydrogenation rate (aromatic nucleus hydrogenation rate) of the hydrogenated polymer obtained by the method of certain embodiments of the present invention is preferably, but not particularly limited to, 95% or more, more preferably 97% or more, and further preferably 98% or more. The hydrogenation rate can be obtained by UV spectrum measurement before and after the hydrogenation reaction as described in the examples.

[0127] <Optical Materials>

[0128] The hydrogenated polymer obtained by the method according to certain embodiments of the present invention can be appropriately mixed with additives such as antioxidants, colorants, release agents, surfactants, antibacterial agents, etc. to form an optical material composition. Since the obtained optical material composition has thermoplasticity, it can be used to manufacture precise and cost-effective optical products through various thermoforming methods such as extrusion molding, injection molding, and secondary processing molding of sheet molded bodies. Specific uses of optical products include but are not limited to various light guide plates and light guides, display front panels, plastic lens substrates, filters, optical films, lighting covers, lighting signs, etc. In a certain embodiment of the present invention, the above-mentioned optical material is an optical lens.

[0129] The polymer obtained by the method of the present invention after hydrogenation of the aromatic nucleus is transparent in appearance because it can transmit light in the visible light region well. Preferably, the total light transmittance of a 3 mm thick molded product is 90% or more. Since the loss caused by reflection on the surface of the molded product cannot be avoided, the upper limit of the total light transmittance depends on the refractive index, but in the case of use as an optical material, a higher transparency may be required, so it is more preferably 91% or more, and most preferably 92% or more. This high transparency is achieved by uniform hydrogenation of the aromatic rings in the polymer.

[0130] In addition, in a heat-molded article having a thickness of 160 μm, the haze of the heat-molded article using the resin of the present invention is preferably 0.0 to 1.0%, more preferably 0.0 to 0.8%, and particularly preferably 0.0 to 0.5%. By having such a haze value, the heat-molded article using the resin of the present invention can be well applied to applications requiring transparency, particularly to optical materials.

[0131] Example

[0132] The present invention will be described in more detail below by way of examples, but the present invention is not particularly limited by the following examples. The evaluation method of the resin is as follows.

[0133] (1) Aromatic nucleus hydrogenation rate

[0134] The aromatic nucleus hydrogenation rate was obtained by measuring the UV spectrum before and after the hydrogenation reaction. That is, the resin was dissolved in tetrahydrofuran (THF) as a solvent, and the absorption spectrum at 260nm was measured using a quartz cuvette. The copolymer resin before the aromatic nucleus hydrogenation reaction was used for calibration, and the proportion of unhydrogenated aromatic rings was calculated. The instrument used for the measurement was a UV-visible spectrophotometer "GENESYS10S" manufactured by Thermo, but it is not particularly limited to this, and any equivalent equipment will suffice.

[0135] (2) Weight average molecular weight

[0136] The weight average molecular weight (Mw) was obtained by gel permeation chromatography (GPC). The detection equipment used was a differential refractive index (RI) detector, THF was used as a solvent, and standard polystyrene was used for calibration. The instrument used for measurement was a high performance liquid chromatography system "Elite LaChrom" manufactured by Shimadzu Scientific Co., Ltd., but it is not particularly limited to this, as long as it is an equivalent device.

[0137] (3) Glass transition temperature (Tgm)

[0138] The glass transition temperature (Tgm) of the resin was determined by differential scanning calorimetry (DSC). The instrument used for measurement was "DSC7020" manufactured by SII (currently Hitachi High-Tech Sciences, Ltd.), but the instrument is not particularly limited thereto and any equivalent equipment may be used.

[0139] (4) Total light transmittance of heated molded products

[0140] Using an electric injection molding device (ROBOSHOTα-S30iA manufactured by FANUC), the aromatic core hydrogenated polymer was molded at a barrel temperature of 260°C while changing the metering conditions and holding pressure conditions. After achieving the ability to stably obtain dent-free molded products, a disc test piece with a diameter of 40mm and a thickness of 3mm was produced at a mold temperature of 130°C and a cooling time of 15 seconds. Using HM-150 manufactured by Murakami Color Technology Research Institute, the total light transmittance of the plate test piece was measured by the transmission method in accordance with JIS K7361-1:1997. Samples with a total light transmittance of 91% or more were considered qualified products.

[0141] (5) Haze value

[0142] The haze of the heat-molded product was measured using HM-150 manufactured by Murakami Color Research Laboratory in accordance with JIS K7136: 2000. Heat-molded products having a haze of 0.5% or less were considered acceptable.

[0143] <Example 1>

[0144] <Preparation of Hydrogenation Reaction Raw Polymer Solution>

[0145] After 0.5 parts by mass of a block copolymer (resin 1) composed of styrene and butadiene (CLEAREN 530L manufactured by Denka Co., Ltd., styrene / butadiene molar ratio = 72.7 / 27.3) having a weight average molecular weight of 127,000 was dissolved in 2.75 parts by mass of methyl isobutyrate (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as "IBM") (solvent 1), the water content in the polymer solution was reduced by distillation operation (0.5 parts by mass was removed by azeotropic distillation) to obtain a polymer solution after distillation and dehydration. To the polymer solution after distillation and dehydration, 2.25 parts by mass of cyclohexane (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as "CH") was added to prepare a 10% equivalent of hydrogenation reaction raw material polymer solution.

[0146] <Hydrogenation Reaction of Base Polymer>

[0147] The polymer solution of the hydrogenation reaction raw material obtained as described above was mixed with 0.08 parts by mass of 5.0% by mass Pd / ZrO 2 They were added together into a reaction vessel equipped with a stirring device, and a hydrogenation reaction was carried out for 24 hours under the conditions of a hydrogen partial pressure of 9 MPa and a temperature of 180°C. After the hydrogenation reaction, the catalyst was removed from the polymer solution by filtration, and then the reaction solution was added dropwise to an excess of isopropanol to precipitate the resin. The obtained resin powder was dried under reduced pressure to obtain a dry resin powder. The aromatic nucleus hydrogenation rate of the obtained resin was 99.1%, the weight-average molecular weight was 110,000, and the Tg was 143°C. In addition, the total light transmittance of the heated molded product was above 91%, and the haze value was below 0.5%, both of which were qualified levels.

[0148] <Examples 2 to 6>

[0149] The preparation of the hydrogenation reaction raw material polymer and the hydrogenation reaction were carried out in the same manner as in Example 1 except that the conditions were changed to those shown in Table 1 to obtain an optical material. Resin 1 and Resin 2 shown in Table 1, and Solvents 1 to 4 are shown below.

[0150] (Resin 1): Block copolymer composed of styrene and butadiene (Clearen 530L manufactured by Denka Co., Ltd., styrene / butadiene molar ratio = 72.7 / 27.3, weight average molecular weight 127,000)

[0151] (Resin 2): Block copolymer composed of styrene and butadiene (Clearen 730L manufactured by Denka Co., Ltd., styrene / butadiene molar ratio = 61.5 / 38.5, weight average molecular weight 116,000)

[0152] (Solvent 1): Methyl isobutyrate (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as "IBM")

[0153] (Solvent 2): Cyclohexane (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as "CH")

[0154] (Solvent 3): Butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as "BuOAc")

[0155] (Solvent 4): Swa Clean 150 (manufactured by Maruzen Petrochemical Co., Ltd., also referred to as "SWC")

[0156] <Example 7>

[0157] <Preparation of Hydrogenation Reaction Raw Material Polymer>

[0158] After 0.5 parts by mass of Resin 1 was dissolved in 2.75 parts by mass of methyl isobutyrate (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as "IBM") (Solvent 1), the water content in the polymer solution was reduced by distillation (0.5 parts by mass was removed by azeotropic distillation) to obtain a polymer solution after distillation and dehydration.

[0159] <Hydrogenation Reaction of Base Polymer>

[0160] 0.08 parts by mass of 5.0% by mass Pd / ZrO was added to a reaction vessel equipped with a stirrer. 2 and 2.25 parts by mass of CH, were replaced with a mixed gas of hydrogen / nitrogen = 5 / 95 (V / V), and stirred at 180°C for 1 hour to carry out catalyst pre-reduction. After the catalyst pre-reduction, the reaction vessel was cooled to room temperature, and then the raw polymer solution obtained by distillation and dehydration was added to the reaction vessel for reaction. Otherwise, the hydrogenation reaction was carried out under the same conditions as in <Hydrogenation of raw polymer> in Example 1.

[0161] <Example 8>

[0162] <Preparation of Hydrogenation Reaction Raw Material Polymer>

[0163] The same procedure as in <Preparation of Hydrogenation Reaction Raw Material Polymer> of Example 1 was carried out to obtain a polymer solution after distillation and dehydration.

[0164] <Hydrogenation Reaction of Base Polymer>

[0165] The hydrogenation reaction was carried out under the same conditions as in <Hydrogenation of base polymer> of Example 1, except that the method for taking out the resin after removing the catalyst of the hydrogenation reaction was changed to using a twin-screw kneading extruder equipped with a devolatilization device to carry out devolatilization extrusion at a temperature of 260°C by vacuum decompression to completely distill off the solvent from the polymer solution, instead of adding the reaction solution dropwise to isopropanol.

[0166] <Comparative Example 1>

[0167] <Preparation of Hydrogenation Reaction Raw Material Polymer>

[0168] After 0.5 parts by mass of Resin 1 was dissolved in 5.0 parts by mass of IBM (Solvent 1), the water content in the polymer solution was reduced by distillation (0.5 parts by mass was removed by azeotropic distillation) to obtain a distilled and dehydrated polymer solution.

[0169] <Hydrogenation Reaction of Base Polymer>

[0170] The obtained polymer solution after distillation and dehydration was subjected to hydrogenation reaction under the same conditions as in Example 1. After the interior of the reaction vessel was made safe after the reaction, it was opened for confirmation and it was found that the hydrogenated polymer precipitated in the IBM solvent and was difficult to separate from the catalyst, so a heat-molded product could not be formed, and the total light transmittance and haze value of the heat-molded product could not be measured.

[0171] <Reference Example 1>

[0172] <Preparation of Hydrogenation Reaction Raw Material Polymer>

[0173] After 0.5 parts by mass of Resin 1 was dissolved in 5.0 parts by mass of cyclohexane (Solvent 2), the water content in the polymer solution was reduced by distillation (0.5 parts by mass was removed by azeotropic distillation) to obtain a distilled and dehydrated polymer solution.

[0174] <Hydrogenation Reaction of Base Polymer>

[0175] The obtained polymer solution after distillation and dehydration was subjected to hydrogenation reaction under the same conditions as in Example 1. Since the autoignition point of cyclohexane is low, the resin could not be taken out by devolatilization and extrusion.

[0176] The results obtained in Examples 1 to 8, Comparative Example 1 and Reference Example 1 are shown in Tables 1 and 2, respectively.

[0177] [Table 1]

[0178]

[0179] [Table 2]

[0180] Comparative Example 1 Reference Example 1 Raw resin - Resin 1 Resin 1 Hydrogenation catalyst - <![CDATA[Pd / ZrO 2 ]]> <![CDATA[Pd / ZrO 2 ]]> Catalytic metal loading ％ 5 5 Pre-reduction with or without catalyst none none Solvents - Solvent 1 Solvent 2 Solvent mixing mass ratio Quality / Quality 10 / 0 0 / 10 Catalyst addition rate Mass 8 8 Raw material concentration quality% 10 10 Hydrogenation temperature ℃ 180 180 Hydrogenation pressure MPa 9 9 Hydrogenation reaction time h 24 24 Hydrogenation rate ％ 99.8 98.1 Weight average molecular weight Ten thousand 11.4 11.8 Glass transition temperature ℃ 143 143 Total light transmittance ％ - qualified Haze value ％ - qualified

[0181] According to the present invention, in the method for manufacturing an optical material by hydrogenating the aromatic ring (aromatic nucleus) of an aromatic vinyl compound-based polymer, efficient manufacturing can be achieved by increasing the hydrogenation reaction rate; and by shortening the reaction time, damage to the polymer such as molecular weight reduction can be reduced. Moreover, the optical material obtained by the method of the present invention has sufficient heat resistance.

Claims

1. A method for manufacturing an optical material, It is characterized in that The method for producing an optical material comprises hydrogenating an aromatic ring of an aromatic vinyl compound-based polymer to form the optical material. The aromatic vinyl compound-based polymer comprises a first monomer unit and a second monomer unit, The first monomer unit is a structural unit derived from an aromatic vinyl compound, The second monomer unit is a structural unit derived from a conjugated diene compound, The method comprises the steps of performing a hydrogenation reaction using the aromatic vinyl compound-based polymer, a solvent and a hydrogenation catalyst to obtain a hydrogenated polymer. The solvent is a mixed solvent comprising at least one first solvent and at least one second solvent, The first solvent is a solvent that dissolves the aromatic vinyl compound polymer before hydrogenation. The second solvent is a solvent that dissolves the hydrogenated polymer.

2. The method for producing an optical material according to claim 1, It is characterized in that The hydrogenation catalyst is a hydrogenation catalyst that has been subjected to reduction treatment.

3. The method for producing an optical material according to claim 1 or 2, It is characterized in that The at least one first solvent comprises one or more selected from methyl acetate, ethyl acetate, butyl acetate and methyl isobutyrate.

4. The method for producing an optical material according to any one of claims 1 to 3, It is characterized in that The at least one second solvent comprises one or more selected from cyclohexane, C9-C10 alkylcyclohexane, C7-C15 monoalkylcyclohexane, C8-C15 dialkylcyclohexane, C9-C15 trialkylcyclohexane, C10-C15 tetraalkylcyclohexane, cyclooctane, C9-C15 monoalkylcyclooctane, C10-C15 dialkylcyclooctane, C11-C15 trialkylcyclooctane, C12-C15 tetraalkylcyclooctane, n-octane and n-decane.

5. The method for producing an optical material according to any one of claims 1 to 4, It is characterized in that The first solvent has a boiling point of 50°C or higher and an autoignition point of 400°C or higher.

6. The method for producing an optical material according to any one of claims 1 to 5, It is characterized in that The second solvent has a boiling point of 80°C or higher and an autoignition point of 230°C or higher.

7. The method for producing an optical material according to any one of claims 1 to 6, It is characterized in that The first monomer is selected from styrene, α-methylstyrene, chlorostyrene, 4-methylstyrene, 4-tert-butylstyrene and 4-methoxystyrene.

8. The method for producing an optical material according to any one of claims 1 to 7, It is characterized in that The second monomer is selected from the group consisting of butadiene, cyclopentadiene and isoprene.

9. The method for producing an optical material according to any one of claims 1 to 6, It is characterized in that The aromatic vinyl compound-based polymer is selected from the group consisting of a copolymer of styrene and butadiene, a copolymer of styrene and cyclopentadiene, and a copolymer of styrene and isoprene.

10. The method for producing an optical material according to any one of claims 1 to 9, It is characterized in that In the aromatic vinyl compound-based polymer, a polymerization ratio (mol %) of the first monomer unit to the second monomer unit is 70:30 or more and less than 100:

0.

11. The method for producing an optical material according to any one of claims 1 to 10, It is characterized in that The process comprises the steps of forming a polymer resin by devolatilization extrusion after hydrogenation.

12. The method for producing an optical material according to any one of claims 1 to 11, It is characterized in that A concentration step is also included between the hydrogenation reaction and the devolatilization extrusion.

13. The method for producing an optical material according to any one of claims 1 to 12, It is characterized in that The mass ratio of the at least one first solvent to the at least one second solvent is first solvent:second solvent=1:9 to 9:

1.

14. The method for producing an optical material according to any one of claims 1 to 13, It is characterized in that The hydrogenation catalyst is a solid catalyst carrying palladium, platinum, ruthenium, rhodium or nickel.

15. The method for producing an optical material according to any one of claims 1 to 14, It is characterized in that The optical material is an optical lens.

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