Cyclic olefin copolymers and hydrogenates thereof, and optical elements

Abstract

This invention provides a resin that combines high refractive index, high heat resistance, and low birefringence. The cyclic olefin copolymer hydride of this invention is formed by hydrogenating a cyclic olefin copolymer, wherein the cyclic olefin copolymer comprises structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene, and the average internal bulk ratio of 1-naphthylnorbornene to 2-naphthylnorbornene is 50 mol% or more. The cyclic olefin copolymer hydride of this invention is preferably used as a material for optical components such as optical lenses.

Description

Technical Field

[0001] This invention relates to cyclic olefin copolymers, hydrides of cyclic olefin copolymers, and optical elements. Background Technology

[0002] In recent years, polymers obtained by polymerizing cyclic olefins have attracted attention as materials for optical components and medical containers.

[0003] Furthermore, for example, Patent Document 1 discloses a norbornene-based ring-opening polymer (copolymer) with excellent transparency and heat resistance, high solubility in organic solvents, and specific birefringence and wavelength dependence. Furthermore, Patent Document 2 discloses a cyclic olefin copolymer that effectively manifests birefringent reverse wavelength dispersion and a film formed from this copolymer. Moreover, Patent Document 3 discloses a cyclic olefin copolymer with a high refractive index and the ability to adjust the Abbe number to a low level, as well as a medical container exhibiting minimal discoloration and excellent transparency due to electron beam or gamma ray irradiation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-46615;

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-46614;

[0008] Patent document 3: International Publication No. 2019 / 107363. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] Regarding optical elements such as optical lenses, in order to increase design freedom for a wide range of applications, resins with high refractive index and high heat resistance, as well as low birefringence when made into optical elements, are required.

[0011] However, the aforementioned existing polymers cannot simultaneously achieve high refractive index, high heat resistance, and low birefringence (e.g., stress birefringence).

[0012] Therefore, the object of the present invention is to provide a resin that can take into account high refractive index, high heat resistance and low birefringence.

[0013] Solution for solving the problem

[0014] The inventors conducted in-depth research with the aim of solving the above-mentioned problems. Then, the inventors made a new discovery that if a cyclic olefin copolymer hydrogenated by polymerizing a monomer composition containing a mixture of 1-naphthylnorbornene and 2-naphthylnorbornene having a specified average endo-body ratio is obtained, it is possible to achieve a balance between high refractive index, high heat resistance and low birefringence, thus completing the present invention.

[0015] In other words, the object of the present invention is to advantageously solve the above-mentioned problems. The cyclic olefin copolymer of the present invention is characterized by comprising structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene, wherein the average endotype ratio of the 1-naphthylnorbornene and the 2-naphthylnorbornene is 50 mol% or more. Hydrogenation of such a cyclic olefin copolymer can provide a resin (cyclic olefin copolymer hydrogenation) that can achieve a balance of high refractive index, high heat resistance, and low birefringence. Therefore, the cyclic olefin copolymer of the present invention is useful as a raw material for a resin that can achieve a balance of high refractive index, high heat resistance, and low birefringence.

[0016] Furthermore, in this invention, the "average endotoluene ratio of 1-naphthylnorbornene and 2-naphthylnorbornene" can be determined using, for example, the method described in the examples.

[0017] Here, the cyclic olefin copolymer of the present invention preferably has a total ratio of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene of 30 mol% or more and 70 mol% or less. If the total ratio of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene is within the above range, a resin that balances high refractive index, high heat resistance and low birefringence at a higher level can be obtained.

[0018] Furthermore, in this invention, the "ratio of each structural unit" can be determined using nuclear magnetic resonance (NMR).

[0019] Furthermore, the cyclic olefin copolymer of the present invention preferably has a ratio of 1 mol% or more and 30 mol% or less of structural units from 1-naphthylnorbornene relative to the total ratio of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene. If the ratio of structural units from 1-naphthylnorbornene is within the above range, a resin that balances high refractive index, high heat resistance, and low birefringence at a higher level can be obtained.

[0020] Furthermore, the cyclic olefin copolymer of the present invention preferably further comprises structural units from norbornene monomers other than 1-naphthylnorbornene and 2-naphthylnorbornene.

[0021] Furthermore, the cyclic olefin copolymer of the present invention is preferably a ring-opening polymer.

[0022] Furthermore, the object of the present invention is to advantageously solve the above-mentioned problems. The cyclic olefin copolymer hydride of the present invention is characterized in that it is obtained by hydrogenating any of the above-mentioned cyclic olefin copolymers. The cyclic olefin copolymer hydride obtained by hydrogenating the above-mentioned cyclic olefin copolymers is useful as a material for optical elements such as optical lenses because it has high refractive index and heat resistance, and low birefringence.

[0023] Furthermore, the cyclic olefin copolymer hydride of the present invention preferably has a glass transition temperature of 135°C or higher. If the glass transition temperature is 135°C or higher, the heat resistance can be further improved.

[0024] Furthermore, in this invention, the "glass transition temperature" can be measured using differential scanning calorimetry according to JIS K6911.

[0025] Furthermore, the optical element of the present invention is characterized by comprising any one of the above-mentioned cyclic olefin copolymer hydrides. Using the above-mentioned cyclic olefin copolymer hydrides, an optical element with high refractive index and heat resistance, and low birefringence can be obtained.

[0026] Invention Effects

[0027] According to the present invention, it is possible to obtain a resin that can combine high refractive index, high heat resistance and low birefringence, as well as copolymers that are useful as raw materials thereon.

[0028] Furthermore, according to the present invention, an optical element with high refractive index and heat resistance and low birefringence can be obtained. Detailed Implementation

[0029] The embodiments of the present invention will now be described in detail.

[0030] Here, the cyclic olefin copolymer of the present invention can be used as a material for various molded articles such as optical elements, and is preferably used as a raw material for the cyclic olefin copolymer hydride of the present invention, without particular limitation. Furthermore, the cyclic olefin copolymer hydride of the present invention can preferably be used as a material for the optical elements (e.g., optical lenses) of the present invention, without particular limitation.

[0031] (Cyclic olefin copolymer)

[0032] The cyclic olefin copolymer of the present invention can be obtained by polymerizing a monomer composition comprising 1-naphthylnorbornene and 2-naphthylnorbornene, and optionally further comprising at least one of norbornene monomers other than 1-naphthylnorbornene and 2-naphthylnorbornene (hereinafter sometimes referred to as "other norbornene monomers") and non-norbornene monomers. That is, the cyclic olefin copolymer of the present invention comprises structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene, and optionally further comprises at least one of structural units from other norbornene monomers and structural units from non-norbornene monomers. Furthermore, the cyclic olefin copolymer of the present invention requires that the average endotype ratio of the 1-naphthylnorbornene and 2-naphthylnorbornene used for polymerization be 50 mol% or more.

[0033] <Structural unit from 1-naphthylnorbornene>

[0034] Here, in 1-naphthylnorbornene capable of forming structural units from 1-naphthylnorbornene, the bonding mode between the 1-naphthyl group and the norbornene ring exhibits stereoisomerism in terms of exo bonding (bonding along the same direction as the methylene group at the bridgehead) and endo bonding (bonding along the opposite direction to the methylene group at the bridgehead). Moreover, as long as the desired average endo ratio is met, exo-1-naphthylnorbornene, endo-1-naphthylnorbornene, or mixtures thereof can be used as 1-naphthylnorbornene.

[0035] In addition, as 1-naphthylnorbornene, it is preferable to have a 1-naphthyl group bonded to the 5th position of bicyclo[2,2,1]hept-2-ene-5-(1-naphthyl).

[0036] <Structural unit from 2-naphthylnorbornene>

[0037] Furthermore, for 2-naphthylnorbornene capable of forming structural units derived from 2-naphthylnorbornene, both exo-bonding and endo-bonding exist as bonding modes between the 2-naphthyl group and the norbornene ring. Moreover, as long as the desired average endo-unit ratio is met, exo-2-naphthylnorbornene, endo-2-naphthylnorbornene, or mixtures thereof can be used as 2-naphthylnorbornene.

[0038] In addition, as 2-naphthylnorbornene, the preferred form is bicyclo[2,2,1]hept-2-ene-5-(2-naphthyl) bonded at position 5 of norbornene (bicyclo[2,2,1]hept-2-ene).

[0039] <Average endobody ratio>

[0040] Furthermore, the average endo fraction ratio of 1-naphthylnorbornene used to form the structural unit from 1-naphthylnorbornene and 2-naphthylnorbornene used to form the structural unit from 2-naphthylnorbornene needs to be 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. That is, in the cyclic olefin copolymer, the total ratio of the structural units from endo-1-naphthylnorbornene and the structural units from endo-2-naphthylnorbornene to the total ratio of the structural units from exo-1-naphthylnorbornene, the structural units from endo-1-naphthylnorbornene, the structural units from exo-2-naphthylnorbornene, and the structural units from endo-2-naphthylnorbornene needs to be 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. If the average endobody ratio is within the above range, the cyclic olefin copolymer hydrogenated by hydrogenating the cyclic olefin copolymer can achieve a high balance of high refractive index, high heat resistance and low birefringence.

[0041] In addition, there is no specific upper limit to the above average endo body ratio.

[0042] Furthermore, in the cyclic olefin copolymer, the total proportion of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene is preferably 30 mol% or more, more preferably 35 mol% or more, even more preferably 40 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less. If the total proportion of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene is within the above range, the cyclic olefin copolymer hydrogenated by hydrogenation can achieve a higher balance between high refractive index, high heat resistance, and low birefringence.

[0043] Furthermore, the proportion of structural units from 1-naphthylnorbornene relative to the total proportion of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less. If the proportion of structural units from 1-naphthylnorbornene is within the above range, the cyclic olefin copolymer hydrogenated by hydrogenation of the cyclic olefin copolymer can achieve a higher level of balance between high refractive index, high heat resistance, and low birefringence.

[0044] <Structural units from other norbornene monomers>

[0045] Other norbornene monomers that can form structural units from other norbornene monomers are not particularly limited, and examples include norbornene monomers without a naphthyl group, as well as norbornene monomers with a naphthyl group other than 1-naphthyl norbornene and 2-naphthyl norbornene.

[0046] Specifically, as a norbornene monomer without a naphthyl group, there are no particular limitations as long as the compound has a norbornene ring and does not have a naphthyl group. Examples include:

[0047] Norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-butylnorbornene, 5-hexylnorbornene, 5-decylnorbornene, 5-cyclohexylnorbornene, 5-cyclopentylnorbornene and other unsubstituted or alkyl-containing norbornene derivatives;

[0048] 5-Ethylene norbornene, 5-vinyl norbornene, 5-propenyl norbornene, 5-cyclohexenyl norbornene, 5-cyclopentenyl norbornene, and other norbornenes containing alkenyl groups;

[0049] 5-Phenylacene and other norbornene derivatives with aromatic rings;

[0050] Norbornene compounds containing polar groups with oxygen atoms include 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene, 5-methyl-5-methoxycarbonylnorbornene, 5-methyl-5-ethoxycarbonylnorbornene, norbornene-2-methylpropionate, norbornene-2-methyloctanoate, 5-hydroxymethylnorbornene, 5,6-di(hydroxymethyl)norbornene, 5,5-di(hydroxymethyl)norbornene, 5-hydroxy-isopropylnorbornene, 5,6-dicarboxylated norbornene, and 5-methoxycarbonyl-6-carboxylated norbornene.

[0051] 5-Cyanoboronene and other norbornenes containing polar groups with nitrogen atoms;

[0052] Dicyclopentadiene, methyldicyclopentadiene, tricyclo[5.2.1.0] 2,6 Dec-8-ene and other polycyclic norbornene compounds with three or more rings that do not contain aromatic ring structures;

[0053] Fourth Ring Road [9.2.1.0] 2,10 .0 3,8 [Tetradecane-3,5,7,12-tetraene (also known as 1,4-bridged methylene-1,4,4a,9a-tetrahydro-9H-fluorene), tetracyclic [10.2.1.0] 2,11 .0 4,9Pentadecyl-4,6,8,13-tetraene (also known as 1,4-bridged methylene-1,4,4a,9,9a,10-hexahydroanthracene) and other polycyclic norbornene compounds with 3 or more aromatic rings.

[0054] Tetracyclododecene, 8-methyltetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, 8-cyclopentyltetracyclododecene, 8-methoxycarbonyl-8-methyltetracyclo[4.4.0.1] 2,5 .1 7,10 Unsubstituted or alkyl-containing tetracyclic dodecenes, such as 3-dodecene;

[0055] Tetracyclic dodecenes, such as 8-methylenetetracyclic dodecene, 8-ethylidenetetracyclic dodecene, 8-vinyltetracyclic dodecene, 8-propenyltetracyclic dodecene, 8-cyclohexenyltetracyclic dodecene, and 8-cyclopentenyltetracyclic dodecene, are tetracyclic dodecenes with double bonds outside the ring.

[0056] Tetracyclic dodecenes, such as 8-phenyltetracyclic dodecene, which have aromatic rings;

[0057] Tetracyclic dodecenes with substituents containing oxygen atoms, such as 8-methoxycarbonyltetracyclic dodecene, 8-methyl-8-methoxycarbonyltetracyclic dodecene, 8-hydroxymethyltetracyclic dodecene, 8-carboxylated tetracyclic dodecene, tetracyclic dodecene-8,9-dicarboxylic acid, and tetracyclic dodecene-8,9-dicarboxylic anhydride.

[0058] Tetracyclic dodecenes, such as 8-cyanotetracyclododecene and tetracyclododecene-8,9-dicarboximide, are tetracyclic dodecenes with nitrogen-containing substituents.

[0059] Tetracyclic dodecenes, such as 8-chlorotetracyclododecene, are tetracyclic dodecenes with substituents containing halogen atoms.

[0060] Tetracyclic dodecenes, such as 8-trimethoxysilyltetracyclododecene, contain silicon-containing substituents;

[0061] The aforementioned tetracyclic dodecenes and Diels-Alder additions of cyclopentadiene, as well as hexacyclic heptadecenes, etc.

[0062] Furthermore, as a norbornene monomer containing a naphthyl group, there are no particular limitations as long as the compound has both a norbornene ring and a naphthyl group; examples include 9-naphthyltetracyclic [6.2.1.1]. 3,6 .0 2,7 Dodecyl-4-ene, 5-dinaphthylmethylsilylmethyl-2-norbornene, 5-trinaphthylsilylmethyl-2-norbornene, 5-(2-dinaphthylmethylsilylethyl)-2-norbornene, 5-(2-trinaphthylsilylethyl)-2-norbornene, etc.

[0063] From the viewpoint of obtaining cyclic olefin copolymer hydrides that achieve a higher level of balance between high refractive index, high heat resistance, and low birefringence, nonpolar norbornene monomers are preferred as other norbornene monomers. More preferably are unsubstituted or alkyl-containing norbornene monomers (e.g., norbornene, 8-ethyltetracyclododecene), alkenyl-containing norbornene monomers (e.g., ethylenetetracyclododecene (8-ethylenetetracyclododecene)), dicyclopentadiene, and norbornene derivatives with aromatic rings (e.g., tetracyclo[9.2.1.0]). 2,10 .0 3,8 Tetradecene-3,5,7,12-tetraene (also known as 1,4-bridged methylene-1,4,4a,9a-tetrahydro-9H-fluorene) and unsubstituted or alkyl-containing tetracyclic dodecenes (e.g., tetracyclic dodecene, 8-methoxycarbonyl-8-methyltetracyclo[4.4.0.1]). 2,5 .1 7,10 [-3-dodecene), further preferably tetracyclic dodecene, tetracyclic [9.2.1.0] 2,10 .0 3,8 Tetradecane-3,5,7,12-tetraene (also known as 1,4-bridged methylene-1,4,4a,9a-tetrahydro-9H-fluorene).

[0064] The other norbornene monomers mentioned above can be used alone or in combination of two or more. Furthermore, the other norbornene monomers can be mixtures of isomers.

[0065] Furthermore, in the cyclic olefin copolymer, the proportion of structural units from other norbornene monomers in all structural units is preferably 30 mol% or more, more preferably 35 mol% or more, even more preferably 40 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less.

[0066] <Structural units from nonnorbornene monomers>

[0067] Non-norbornene monomers, which can form structural units derived from non-norbornene monomers, are not particularly limited as long as they are compounds that do not possess a norbornene ring and can be copolymerized. Examples include cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, cyclooctene, 3a,5,6,7a-tetrahydro-4,7-bridged methylene-1H-indenene, and other cycloolefins; and non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene. These non-norbornene monomers can be used alone or in combination of two or more.

[0068] Furthermore, in the cyclic olefin copolymer, the proportion of structural units derived from non-norbornene monomers in all structural units is preferably 30 mol% or less, more preferably 10 mol% or less, and even more preferably 5 mol% or less. Alternatively, the proportion of structural units derived from non-norbornene monomers in all structural units can be 0 mol%.

[0069] <Structure of cyclic olefin copolymers>

[0070] The cyclic olefin copolymer of the present invention is a copolymer formed by polymerizing a monomer composition comprising 1-naphthylnorbornene and 2-naphthylnorbornene, and optionally further comprising at least one of other norbornene monomers and non-norbornene monomers.

[0071] Here, polymerization can be either ring-opening polymerization or addition polymerization, or a cyclic olefin copolymer can include both ring-opening polymerization and addition polymerization portions. Ring-opening polymerization is preferred. That is, the cyclic olefin copolymer of the present invention is preferably a ring-opening polymer, and more specifically, a ring-opening polymer polymerized by ring-opening of the norbornene ring.

[0072] <Methods for manufacturing cyclic olefin copolymers>

[0073] The method for manufacturing the cyclic olefin copolymer of the present invention is not particularly limited. For example, it can be obtained by polymerizing (ring-opening polymerization or addition polymerization) a monomer composition containing 1-naphthylnorbornene and 2-naphthylnorbornene, and optionally further containing at least one of other norbornene monomers and non-norbornene monomers, to obtain the copolymer (polymerization step), and then optionally recycling the copolymer (recycling step).

[0074] Here, the proportion of each monomer in the monomer composition is adjusted according to the proportion of structural units from that monomer in the target cyclic olefin copolymer. Furthermore, the 1-naphthylnorbornene and 2-naphthylnorbornene used for polymerization can be manufactured via, for example, palladium coupling reactions (e.g., the reaction of norbornadiene with bromonaphthalene) and Diels-Alder reactions (e.g., the reaction of cyclopentadiene with vinylnaphthalene). Additionally, there are no particular limitations on the 1-naphthylnorbornene and 2-naphthylnorbornene; 1-naphthylnorbornene and 2-naphthylnorbornene containing different proportions of endosomes can be mixed to achieve a desired average endosome ratio.

[0075] [Polymerization Process]

[0076] In the preparation of cyclic olefin copolymers via ring-opening polymerization, the monomer composition can be subjected to ring-opening metathesis polymerization in the presence of a metathesis polymerization catalyst. Ring-opening metathesis polymerization can be carried out in a reaction system in which the monomer composition and the metathesis polymerization catalyst are mixed in a solvent (e.g., an organic solvent). To improve polymerization efficiency, the reaction system may further include an activator, a chain transfer agent, and other auxiliaries (e.g., a Lewis base). The reagents such as catalysts used for ring-opening polymerization and the various reaction conditions are described below.

[0077] As a metathesis polymerization catalyst, the transition metal imide complex represented by formula (1) can be used.

[0078] M(NR a )X 4-p (OR b ) p ·L q (1)

[0079] (in the formula,

[0080] M is a metal atom selected from transition metal atoms in Group 6 of the periodic table.

[0081] R a A phenyl group or -CH2R that can have a substituent at at least one of the positions 3, 4, and 5. c The group represented here, R c It can be a hydrogen atom, an alkyl group capable of having substituents, or an aryl group capable of having substituents.

[0082] R b It can be an alkyl group that can have substituents or an aryl group that can have substituents.

[0083] X is a halogen atom, alkyl, aryl, aralkyl, or alkylsilyl.

[0084] L is an electron-donating neutral ligand.

[0085] p is 0 or 1,

[0086] q is an integer between 0 and 2.

[0087] When there are multiple X's, these X's can be the same or different.

[0088] When multiple L's exist, these L's can be the same or different.

[0089] In formula (1), M is a transition metal atom in group 6 of the periodic table, which can be selected from chromium, molybdenum, and tungsten. Among them, molybdenum and tungsten are preferred, and tungsten is more preferred.

[0090] The transition metal imide complex of formula (1) contains a metal imide bond (N=R).a R a These are substituents on the nitrogen atom that forms the metal imide bond.

[0091] R in equation (1) a A phenyl group or -CH2R that can have a substituent at at least one of the positions 3, 4, and 5. c The group represented.

[0092] As R a Examples of phenyl groups that can have substituents at at least one of the 3, 4, and 5 positions include:

[0093] Alkyl groups (e.g., alkyl groups with 1 to 4 carbon atoms, such as methyl and ethyl);

[0094] Halogen atoms (such as fluorine, chlorine, bromine, etc.);

[0095] Alkoxy groups (such as methoxy, ethoxy, isopropoxy, etc., with 1 to 4 carbon atoms) and substituents present at at least two positions at the 3, 4, and 5 positions can bond to each other.

[0096] Examples of phenyl groups that can have substituents at at least one of the 3, 4, and 5 positions include:

[0097] Phenyl;

[0098] Monosubstituted phenyl groups such as 4-methylphenyl, 4-chlorophenyl, 3-methoxyphenyl, 4-cyclohexylphenyl, and 4-methoxyphenyl;

[0099] Disubstituted phenyl groups such as 3,5-dimethylphenyl, 3,5-dichlorophenyl, 3,4-dimethylphenyl, and 3,5-dimethoxyphenyl;

[0100] Trisubstituted phenyl groups such as 3,4,5-trimethylphenyl and 3,4,5-trichlorophenyl;

[0101] 2-Naphthyl, 3-methyl-2-naphthyl, 4-methyl-2-naphthyl, and other 2-naphthyl groups that can have substituents.

[0102] R a -CH2R c The R in the represented group c The number of carbon atoms in the alkyl group capable of having substituents is not particularly limited, and is generally 1 to 20, preferably 1 to 10, and more preferably 1 to 4. The alkyl group can be straight-chain or branched. Substituents are not particularly limited, and examples include: phenyl, phenyl groups capable of having substituents (e.g., 4-methylphenyl); alkoxy groups (e.g., methoxy, ethoxy, etc., alkoxy groups with 1 to 4 carbon atoms), etc.

[0103] As R c Aryl groups that can have substituents include phenyl, 1-naphthyl, 2-naphthyl, etc. Substituents are not particularly limited, and examples include: phenyl, phenyl groups that can have substituents (e.g., 4-methylphenyl); alkoxy groups (e.g., methoxy, ethoxy, etc., alkoxy groups with 1 to 4 carbon atoms), etc.

[0104] As R c Preferably, alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, and decyl.

[0105] In formula (1), (4-p) is 4 or 3, and formula (1) has 4 or 3 X atoms. X is a halogen atom, alkyl, aryl, aralkyl, or alkylsilyl. X can be the same or different.

[0106] Regarding X, examples of halogen atoms include chlorine, bromine, and iodine. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and neopentyl.

[0107] Examples of aryl groups include phenyl, 4-methylphenyl, 2,6-dimethylphenyl, 1-naphthyl, and 2-naphthyl.

[0108] Examples of aralkyl groups include benzyl and 2-methyl-2-phenylpropyl (neophyl group).

[0109] Examples of alkylsilyl groups include trimethylsilyl, triethylsilyl, and tert-butyldimethylsilyl.

[0110] In equation (1), p is 0 or 1, and equation (1) can have one metal alkoxy bond or one metal aryloxy bond (OR). b R b Substituents are those on the oxygen atom that forms a metal alkoxy bond or a metal aryloxy bond.

[0111] R b For alkyl groups capable of having substituents or aryl groups capable of having substituents, it can be used as the above-mentioned R. c Examples of substituents include alkyl groups and aryl groups.

[0112] In equation (1), q is an integer from 0 to 2, and equation (1) can have one or two electron-donating neutral ligands (L).

[0113] As for L, examples of electron-donating compounds containing atoms from Group 14 or Group 15 of the periodic table can be given, such as:

[0114] Phosphine derivatives such as trimethylphosphine, triisopropylphosphine, tricyclohexylphosphine, and triphenylphosphine;

[0115] Ethers such as diethyl ether, dibutyl ether, 1,2-dimethoxyethane, tetrahydrofuran, and tetrahydropyran;

[0116] Amines such as trimethylamine, triethylamine, pyridine, and dimethylpyridine are preferred. Among them, ethers are preferred.

[0117] As a transition metal imide complex of formula (1), a tungstenimide complex having a phenylimide group is preferred (in formula (1), M is a tungsten atom, R...). a (a phenyl tungstenimide complex), more preferably tungsten tetrachloride phenylimide (tetrahydrofuran) or tungsten tetrachloride phenylimide (tetrahydropyran).

[0118] The transition metal imide complex of formula (1) can be used alone or in combination of two or more.

[0119] The transition metal imide complex of formula (1) can be synthesized by mixing a group 6 transition metal oxyhalide, a phenyl isocyanate or a monosubstituted methyl isocyanate having a substituent at at least one of the 3, 4, and 5 positions with an electron-donating neutral ligand (L), an alcohol, a metal alkoxide, or a metal aryl oxide as needed (e.g., the method described in Japanese Patent Application Publication No. 5-345817). The synthesized transition metal imide complex can be purified and separated by crystallization or the like before being used in a ring-opening polymerization reaction, or the resulting mixture can be used directly as a catalyst solution without purification.

[0120] The amount of the transition metal imide complex of formula (1) used relative to 100 mol% of monomer can be 0.00005 mol% or more and 1 mol% or less, preferably 0.0001 mol% or more and 0.7 mol% or less, more preferably 0.0002 mol% or more and 0.5 mol% or less. If the amount of the transition metal imide complex of formula (1) used is within the above range, the situation where the catalyst is difficult to remove can be sufficiently avoided, and sufficient polymerization activity can be obtained.

[0121] The transition metal imide complex of formula (1) also exhibits catalytic activity on its own, and can become a more active polymerization catalyst when combined with an activator.

[0122] Examples of activators include compounds from groups 1, 2, 12, 13, and 14 of the periodic table that have a hydrocarbon group (e.g., alkyl) with 1 to 20 carbon atoms. Among these, organolithium, organomagnesium, organozinc, organaluminum, or organotin are preferred, with organaluminum or organotin being particularly preferred.

[0123] Examples of organic lithium compounds include methyl lithium, n-butyl lithium, and phenyl lithium.

[0124] Examples of organic magnesium include butyl ethyl magnesium, butyl octyl magnesium, dihexyl magnesium, ethyl magnesium chloride, n-butyl magnesium chloride, and allyl magnesium bromide.

[0125] Examples of organic zinc compounds include dimethyl zinc, diethyl zinc, and diphenyl zinc.

[0126] Examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, sesquiethylaluminum chloride, ethylaluminum dichloride, diethylethoxyaluminum, diisobutylisobutoxyaluminum, ethyldiethoxyaluminum, and isobutyldiisobutoxyaluminum.

[0127] Examples of organotin compounds include tetramethyltin, tetra(n-butyl)tin, and tetraphenyltin.

[0128] Activators can be used alone or in combination of two or more.

[0129] When using an activator, the amount of activator used relative to the transition metal imide complex of formula (1) can be 0.1 mol times or more and 100 mol times or less, preferably 0.2 mol times or more and 50 mol times or less, and more preferably 0.5 mol times or more and 20 mol times or less. If the amount of activator used is within the above range, the improvement in polymerization activity brought about by the use of the activator can be fully obtained, and the occurrence of side reactions can be fully avoided.

[0130] Furthermore, Lewis bases can be added to control the polymerization rate and the molecular weight distribution of the resulting copolymer.

[0131] Examples of Lewis bases include: ethers such as diethyl ether and tetrahydrofuran; ketones such as acetone and cyclohexanone; nitriles such as acetonitrile and benzonitrile; amines such as triethylamine and N,N-diethylaniline; pyridines such as pyridine and dimethylpyridine; phosphines such as triphenylphosphine; amides such as dimethylformamide; sulfoxides such as dimethyl sulfoxide; phosphine oxides such as triphenylphosphine oxide; and esters such as ethyl acetate. Among these, ethers, pyridines, and nitriles are preferred. Lewis bases can be used alone or in combination of two or more.

[0132] When using Lewis bases, the amount of Lewis base used relative to the transition metal imide complex of formula (1) can be 0.1 mol times or more and 1000 mol times or less, preferably 0.2 mol times or more and 500 mol times or less, and more preferably 0.5 mol times or more and 200 mol times or less.

[0133] Chain transfer agents can be used in polymerization reactions. By using chain transfer agents, the molecular weight of the resulting ring-opening polymer can be adjusted, and the content of dimers, etc., can be effectively reduced.

[0134] Examples of chain transfer agents include α-olefins, internal olefins, and aromatic vinyl compounds. Internal olefins are compounds that have double bonds internally, not at the end of the olefin chain. Aromatic vinyl compounds include compounds with substituents (e.g., alkyl groups) on the vinyl group.

[0135] Examples of α-olefins include olefins with 2 to 20 carbon atoms having a double bond at the α position, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

[0136] Examples of internal alkenes include 2-butene and 3-hexene.

[0137] Examples of aromatic vinyl compounds include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, and 4-tert-butylstyrene.

[0138] From the perspectives of reactivity and molecular weight control, 1-hexene, styrene, and 1-decene are preferred, and 1-hexene and styrene are more preferred.

[0139] Chain transfer agents can be used alone or in combination of two or more.

[0140] When using a chain transfer agent, the amount of the chain transfer agent used relative to 100 mol% of the monomer can be 0.1 mol% or more and less than 15 mol%. If the amount of the chain transfer agent used is within the above range, the effect brought about by using the chain transfer agent can be fully obtained. From the viewpoint of reducing the content of dimers, etc., the chain transfer agent is preferably 0.3 mol% or more and less than 10 mol%, more preferably 0.5 mol% or more and less than 9 mol%, and even more preferably 1 mol% or more and less than 6 mol%.

[0141] There are no particular limitations on organic solvents, as long as they can dissolve or disperse the monomer and the copolymer as the target substance and are inactive to the reaction. Examples include:

[0142] Aliphatic hydrocarbons such as pentane, hexane, and heptane;

[0143] Cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, tricyclodecane, hexahydroindene, cyclooctane, and other alicyclic hydrocarbons;

[0144] Aromatic hydrocarbons such as benzene, toluene, and xylene;

[0145] Halogenated aliphatic hydrocarbons such as dichloromethane, chloroform, and 1,2-dichloroethane;

[0146] Halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene;

[0147] Nitromethane, nitrobenzene, acetonitrile, and other nitrogen-containing hydrocarbon solvents;

[0148] Diethyl ether, tetrahydrofuran, or other ethers; or mixtures thereof. Among these solvents, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and ethers are preferred.

[0149] Organic solvents can be used alone or in combination of two or more.

[0150] The organic solvent can be used in an amount that results in a monomer concentration of 1% by mass or more and 50% by mass or less, preferably in an amount that results in a monomer concentration of 2% by mass or more and 45% by mass or less, and more preferably in an amount that results in a monomer concentration of 3% by mass or 40% by mass or less. If the organic solvent is within the above range, the productivity is sufficient and it is also convenient from a processability perspective.

[0151] Ring-opening polymerization can usually be carried out by stirring the monomer, the transition metal imide complex of formula (1), and any activator and chain transfer agent in an organic solvent, at which time at least a portion of norbornene monomers (1-naphthyl norbornene, 2-naphthyl norbornene and other norbornene monomers) can be added continuously.

[0152] Other than the continuously added norbornene monomers, the components can be pre-loaded into the reactor and stirred beforehand. Stirring of the reaction liquid within the reactor continues during the continuous addition of norbornene monomers, thus advancing the polymerization reaction.

[0153] The continuously added norbornene monomers can be either the entire amount or a portion. From the perspective of reaction selectivity and reaction stability, it is preferable that a portion of the continuously added norbornene monomers is added, with the remainder pre-charged into the reactor. When the total amount of the norbornene monomers is taken as 100% by mass, the amount of norbornene monomers pre-charged into the reactor can be 0.1% by mass or more and 70% by mass or less, preferably 0.5% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 35% by mass or less. If the amount of norbornene monomers pre-charged into the reactor is within the above range, the weight-average molecular weight of the obtained copolymer can be easily controlled.

[0154] The continuous addition of norbornene monomers can be carried out by continuously adding them dropwise from a liquid dissolved or dispersed in the aforementioned organic solvent. The concentration of the norbornene monomers in the liquid can be 1% by mass or more and 50% by mass or less, preferably 2% by mass or more and 45% by mass or less, more preferably 3% by mass or more and 40% by mass or less. If the concentration of the norbornene monomers in the liquid is within this range, the productivity is sufficient, and it is also convenient from a processability perspective.

[0155] The continuous addition time can be 20 minutes or more and 200 minutes or less. From the perspective of stereochemical control, the continuous addition time is preferably 40 minutes or more and 180 minutes or less, more preferably 60 minutes or more and 160 minutes or less.

[0156] The polymerization temperature can be above 20°C and below 60°C. From the perspective of stereochemical control, the polymerization temperature is preferably above 25°C and below 55°C, and more preferably above 30°C and below 50°C.

[0157] From the perspective of controlling molecular weight, the continuous addition of norbornene monomers is preferably carried out in such a manner that the polymerization conversion rate of the norbornene monomers in the polymerization reaction system at the end of the continuous addition is 40% or more. More preferably, the polymerization conversion rate is 60% or more. The polymerization conversion rate can be controlled by adjusting the addition conditions, such as the rate of addition of the norbornene monomers, and the polymerization reaction conditions, such as the polymerization temperature. Under the same conditions except for the addition rate, there is a tendency that the polymerization conversion rate increases when the rate is increased and decreases when the rate is decreased. There is also a tendency that the polymerization conversion rate increases when the temperature is high and decreases when the temperature is low. There is no particular upper limit, but it is typically below 99%.

[0158] After the continuous addition is completed, continue stirring the reaction solution to terminate the polymerization reaction. The mixing and stirring time after the addition is completed can be 15 minutes or more and 300 minutes or less. From the perspective of polymerization conversion and productivity, the mixing and stirring time is preferably 20 minutes or more and 270 minutes or less, more preferably 30 minutes or more and 240 minutes or less.

[0159] Regarding the transition metal imide complex, at least a portion can be added continuously. This allows for the expectation of reaction selectivity. The continuously added transition metal imide complex can be prepared by continuously adding it dropwise from a liquid dissolved or dispersed in the aforementioned organic solvent. The concentration of the transition metal imide complex in the liquid can be 0.01% by mass or more and 20% by mass or less. From the perspective of the solution stability of the complex, the concentration of the transition metal imide complex is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less. The timing of the continuous addition can be the same as or different from the timing of the continuous addition of the norbornene monomer.

[0160] When using a chain transfer agent, from the perspective of controlling stereochemistry and reducing the content of dimers, the amount of chain transfer agent continuously added can be 0.060 mol / min or more, preferably 0.080 mol / min or more, and can be 2.000 mol / min or less, preferably 1.000 mol / min or less.

[0161] In the preparation of cyclic olefin copolymers by addition polymerization, the addition polymerization can be carried out in the presence of, for example, a Ziegler-Natta catalyst, a metallocene catalyst, a nickel catalyst, or a palladium catalyst. Addition polymerization can also be carried out under reaction conditions that are appropriately modified from known reaction conditions.

[0162] [Recycling Process]

[0163] The copolymer obtained in the polymerization process can be recovered as a cyclic olefin copolymer. For example, the cyclic olefin copolymer can be precipitated by mixing the reaction solution with a precipitant (such as isopropanol, methanol, or other unsuitable solvents), and the cyclic olefin copolymer can be recovered as a precipitate. The recovered cyclic olefin copolymer can then be dried (e.g., vacuum dried).

[0164] (Hydrogenated cyclic olefin copolymer)

[0165] The cyclic olefin copolymer hydride of the present invention is obtained by hydrogenating the cyclic olefin copolymer of the present invention described above. Moreover, the cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer of the present invention can achieve a balance of high refractive index, high heat resistance and low birefringence.

[0166] <Hydrogenation>

[0167] The cyclic olefin copolymers of the present invention sometimes have carbon-carbon unsaturated bonds in the main chain. Furthermore, depending on the type of monomer used for polymerization, carbon-carbon unsaturated bonds may also be present in the main chain, or in substituents bonded to a 5-membered ring, or in fused rings to a 5-membered ring (hereinafter referred to as side chains). By hydrogenating the cyclic olefin copolymer, hydrogenated products can be obtained in which at least a portion of these carbon-carbon unsaturated bonds are hydrogenated to become saturated bonds.

[0168] As a method of hydrogenation, known methods can be used, such as supplying hydrogen to a solution of a cyclic olefin copolymer in the presence of a hydrogenation catalyst to induce an addition reaction, thereby carrying out hydrogenation. The hydrogenation catalyst is preferably a catalyst that hydrogenates the carbon-carbon double bonds in the main chain without hydrogenating the aromatic ring (e.g., the naphthyl ring of a naphthyl group). Examples of such hydrogenation catalysts include ruthenium catalysts (ruthenium carbonyl chloride tris(triphenylphosphine)) and palladium catalysts. The hydrogen addition can be carried out, for example, by supplying hydrogen under high pressure (e.g., above 1 MPa) and stirring at high temperature (e.g., above 120°C).

[0169] In addition, the resulting cyclic olefin copolymer hydrides can be recovered using, for example, the same methods described above for cyclic olefin copolymers.

[0170] <Hydrogenation rate>

[0171] The cyclic olefin copolymer hydride of the present invention is more preferably sufficiently hydrogenated. The hydrogenation rate of the cyclic olefin copolymer hydride of the present invention is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. If the hydrogenation rate is above the aforementioned lower limit, the heat resistance of the cyclic olefin copolymer hydride can be further improved. Furthermore, the hydrogenation rate refers to the hydrogenation rate of the carbon-carbon unsaturated bonds in the main chain; aromatic rings such as naphthalene rings are generally not hydrogenated.

[0172] <Physical Properties of Cyclic Olefin Copolymer Hydroxides>

[0173] Furthermore, the cyclic olefin copolymer hydrides of the present invention preferably have the following physical properties.

[0174] Glass transition temperature

[0175] From the viewpoint of heat resistance, the glass transition temperature of the cyclic olefin copolymer hydride is preferably 135°C or higher, more preferably 140°C or higher. However, the glass transition temperature of the cyclic olefin copolymer hydride can be, without particular limitation, 250°C or lower.

[0176] [Refractive Index]

[0177] Furthermore, in order to realize the optical function of optical components, the refractive index (n) of cyclic olefin copolymer hydrides is...d The refractive index (n) of the cyclic olefin copolymer hydride is preferably 1.550 or higher, more preferably 1.560 or higher. Furthermore, in order to maximize the function of the optical element, the refractive index (n) of the cyclic olefin copolymer hydride is... d Preferably, the value is 1.640 or less, and more preferably 1.635 or less.

[0178] Furthermore, the refractive index can vary with wavelength and temperature. In this specification, the refractive index refers to the refractive index (n) of light with a wavelength of 587.6 nm at 25°C. d ).

[0179] [Stress birefringence]

[0180] Regarding stress birefringence (C R The value of δn can be obtained by applying stress (F) to the test specimen and then measuring the in-plane delay (Re(b) [nm]) and thickness (T(b) [mm]) at the center of the test specimen at a specific wavelength (e.g., wavelength 543 nm), and then calculating it using the following formulas (X1) and (X2).

[0181] δn=Re(b)×(1 / T(b))×10 -6 …(X1)

[0182] C R =δn / F…(X2)

[0183] The closer the δn value is to 0, the smaller the birefringence. Furthermore, it shows a positive value when the slow axis is in the stretching direction, and a negative value when the slow axis is perpendicular to the stretching direction.

[0184] Furthermore, in order to suppress the quality deviation of optical components, stress birefringence (C0.05) of cyclic olefin copolymer hydrides is used. R The preferred size is 750×10. -12 Pa -1 The following is more preferably 400×10 -12 Pa -1 the following.

[0185] (Applications of cyclic olefin copolymer hydrides)

[0186] The cyclic olefin copolymer hydride of the present invention can be used as a composition. The composition comprises the cyclic olefin copolymer hydride of the present invention, and optionally further contains weather stabilizers, heat stabilizers, antistatic agents, flame retardants, slip agents, antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, fillers, and other additives and solvents.

[0187] Furthermore, the cyclic olefin copolymer hydride of the present invention can be mixed with additives and solvents using known mixing methods.

[0188] Specifically, as an additive, additives such as those exemplified in Japanese Patent Application Publication No. 2005-330465 can be used. Furthermore, as a solvent, known solvents such as the aforementioned organic solvents can be used.

[0189] Furthermore, the cyclic olefin copolymer hydrides of the present invention or compositions containing the cyclic olefin copolymer hydrides of the present invention can be advantageously used as materials for optical elements, etc.

[0190] Furthermore, the cyclic olefin copolymer hydride of the present invention can be used as a molded body. The molded body is formed by molding the cyclic olefin copolymer hydride of the present invention or a composition containing the cyclic olefin copolymer hydride of the present invention. Moreover, the molded body obtained from the cyclic olefin copolymer hydride of the present invention can be advantageously used as an optical element, etc.

[0191] In addition, as molding methods for molded bodies, methods such as injection molding, extrusion blow molding, injection blow molding, two-stage blow molding, multi-layer blow molding, joint blow molding, stretch blow molding, rotational molding, vacuum molding, extrusion molding, calendering, solution casting, thermoforming, and blow molding can be used.

[0192] Example

[0193] The present invention will now be described in detail based on embodiments and comparative examples, but the present invention is not limited to these embodiments.

[0194] In addition, in the following examples and comparative examples, the determination of various physical properties was carried out according to the following methods.

[0195] Furthermore, in the examples and comparative examples, the substances synthesized in the following synthesis examples 1 to 4 were used as naphthylnorbornene.

[0196] <endo / exo ratio of naphthylnorbornene>

[0197] Using deuterated chloroform as a solvent, the experiment was carried out at 23°C. 1 The endo / exo ratio of naphthylnorbornene was determined by ¹H-NMR analysis. Specifically, the endo / exo ratio (molar ratio) was determined based on the intensity ratio of the signal from the endo form (5.79 ppm) and the signal from the exo form (6.20 ppm).

[0198] Glass transition temperature

[0199] The glass transition temperature (Tg) was determined using a differential scanning calorimeter (Nanotechnology, product name: DSC6220SII) based on JIS K6911, at a heating rate of 10 °C / min.

[0200] A higher glass transition temperature indicates better heat resistance.

[0201] Stress birefringence C R >

[0202] The copolymer hydride was molded into a sheet measuring 35 mm long × 10 mm wide × 1 mm thick to obtain a sample sheet. After fixing both ends of the sample sheet with clamps, a 55 g weight was fixed to one end of the clamp. Next, the sample sheet was subjected to a stretching treatment for 1 hour, starting from the clamp without the fixed weight, in an oven set at the glass transition temperature (Tg) of the copolymer hydride +15°C. Then, the sample sheet was slowly cooled to room temperature to obtain the test specimen.

[0203] For this test specimen, the in-plane retardation (Re(b) [nm]) of the center portion of the test specimen was measured using a birefringence meter (manufactured by Photonic Lattice, Inc., product name "WPA-100") at a measurement wavelength of 543 nm. Furthermore, the thickness (T(b) [mm]) of the aforementioned center portion of the test specimen was measured. Using these measured values ​​Re(b) and T(b), the value of δn was calculated using the following formula (X1).

[0204] δn=Re(b)×(1 / T(b))×10 -6 (X1)

[0205] Using the δn value and the stress (F) applied to the sample, the stress birefringence (C) is calculated using the following equation (X2). R ).

[0206] C R =δn / F[Pa -1 (X2)

[0207] The closer δn is to 0, the better C R The closer to 0, the smaller the birefringence. Additionally, a positive value is displayed when the slow axis is in the stretching direction, and a negative value is displayed when the slow axis is perpendicular to the stretching direction.

[0208] <Refractive index>

[0209] The copolymer hydrogenated material was molded into a sheet with a thickness of 5 mm and placed in an atmosphere with a glass transition temperature (Tg) of -15 °C for 20 hours to serve as the test sample.

[0210] For the obtained test samples, the refractive index (n) at 25°C was measured using a precision refractometer (manufactured by Shimadzu Corporation, product name: KPR-200, light source = He lamp (wavelength: 587.6nm), H2 lamp (wavelength: 656.3nm and 486.1nm)). d n C and n F The table shows the refractive index (n) of light with a wavelength of 587.6 nm. d ).

[0211] <Synthetic Example 1: Production of 1-naphthylnorbornene rich in exosomes>

[0212] 458 g of 1-bromonaphthalene (manufactured by Wako Pure Chemical Industries, Ltd.), 500 mL of dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.), 455 mL of norbornene (manufactured by Tokyo Chemical Industry Co., Ltd.), 656 mL of piperidine (manufactured by Wako Pure Chemical Industries, Ltd.), 220 mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.), and 2.75 g of palladium catalyst (bis(triphenylphosphine)dichloride palladium, manufactured by Tokyo Chemical Industry Co., Ltd., product code: B1667) were added to a reactor, and the mixture was stirred at 90 °C for 6.5 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. The mixture was filtered and evaporated. The residue was removed by column chromatography (developing solvent: hexane) to remove palladium residue. The evaporated solution was subjected to vacuum distillation (1.2 mmHg / 135–152 °C). The result yielded 269 g of 1-naphthylnorbornene (1-NPNB: bicyclo[2,2,1]hept-2-ene-5-(1-naphthyl)), which was a colorless and transparent liquid. The endo / exo ratio was determined to be 0 / 100.

[0213] <Synthetic Example 2: Production of 2-naphthylnorbornene rich in exosomes>

[0214] 458 g of 2-bromonaphthalene (manufactured by Wako Pure Chemical Industries, Ltd.), 500 mL of dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.), 455 mL of norbornene (manufactured by Tokyo Chemical Industry Co., Ltd.), 656 mL of piperidine (manufactured by Wako Pure Chemical Industries, Ltd.), 220 mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.), and 2.75 g of palladium catalyst (bis(triphenylphosphine)dichloride palladium, manufactured by Tokyo Chemical Industry Co., Ltd., product code: B1667) were added to a reactor, and the mixture was stirred at 90 °C for 6.5 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. The mixture was filtered and evaporated. The residue was removed by column chromatography (developing solvent: hexane) to remove palladium residue. The evaporated solution was subjected to vacuum distillation (1.2 mmHg / 135–152 °C). The result yielded 269 g of 2-naphthylnorbornene (2-NPNB: bicyclo[2,2,1]hept-2-ene-5-(2-naphthyl)), which was a colorless and transparent liquid. The endo / exo ratio was determined to be 0 / 100.

[0215] <Synthetic Example 3: Preparation of endo-rich 1-naphthylnorbornene>

[0216] 264 g of dicyclopentadiene (manufactured by Tokyo Chemical Co., Ltd.), 1234 g of 1-vinylnaphthalene (manufactured by Tokyo Chemical Co., Ltd.), and 15 g of N-nitrosophenylhydroxylamine aluminum salt (manufactured by Wako Pure Chemical Co., Ltd.) were added to a reactor, and the mixture was stirred at 180 °C for 1 hour. The crude product was then distilled under reduced pressure (1.2 mmHg / 135–152 °C). 42 g of 1-naphthylnorbornene (1-NPNB: bicyclo[2,2,1]hept-2-ene-5-(1-naphthyl)) was obtained as a colorless, transparent liquid. The endo / exo ratio was determined to be 85 / 15.

[0217] <Synthetic Example 4: Preparation of endo-rich 2-naphthylnorbornene>

[0218] 264 g of dicyclopentadiene (manufactured by Tokyo Chemical Co., Ltd.), 1234 g of 2-vinylnaphthalene (manufactured by Aldrich), and 15 g of N-nitrosophenylhydroxylamine aluminum salt (manufactured by Wako Pure Chemical Co., Ltd.) were added to a reactor, and the mixture was stirred at 180 °C for 1 hour. The crude product was then distilled under reduced pressure (1.2 mmHg / 135–152 °C). This yielded 58 g of 2-naphthylnorbornene (2-NPNB: bicyclo[2,2,1]hept-2-ene-5-(2-naphthyl)), a colorless and transparent liquid. The endo / exo ratio was determined to be 86 / 14.

[0219] (Example 1)

[0220] <Preparation of Cyclic Olefin Copolymers>

[0221] The exomeric 1-naphthylnorbornene (Synthesis Example 1), exomeric 2-naphthylnorbornene (Synthesis Example 2), endomeric 1-naphthylnorbornene (Synthesis Example 3), and endomeric 2-naphthylnorbornene (Synthesis Example 4) prepared in Synthesis Examples 1-4 were mixed in a molar ratio of 0.3 / 3.1 / 10.7 / 85.9 to obtain a naphthylnorbornene (NPNB) mixture. The endomeric / exomeric ratio of this mixture was measured and found to be 83 / 17.

[0222] Next, in a nitrogen-purified glass reaction vessel at room temperature, 96 g of dehydrated toluene, 2 mol% of 1-hexene, 1.2 mol% of aluminum diethylethoxide (Et2Al(OEt)), and 1 mol% of a mixture of naphthylnorbornene (NPNB) and tetracyclododecene (TCD) monomers (molar ratio = 70:30) were added and mixed. Then, while maintaining 50°C, a 2.0 wt% toluene solution of tungsten tetrachloride phenylimide (tetrahydrofuran) was added at a rate of 0.4 mol%. Ring-opening polymerization was then carried out by continuously adding the mixture of naphthylnorbornene (NPNB) and tetracyclododecene (TCD) monomers (molar ratio = 70:30, total 0.03 mol) over 2 hours. Finally, 48 mol% isopropanol was added to the polymerization solution to deactivate the polymerization catalyst and terminate the polymerization reaction. At this point, the monomer conversion to polymer was 100%.

[0223] In addition, "mol%" in the text refers to the percentage value based on the number of mol of the mixed monomers.

[0224] <Preparation of Cyclic Olefin Copolymer Hydroxides>

[0225] Next, relative to 95 g of the reaction solution containing the obtained ring-opening polymer (cyclic olefin copolymer), 155 g of cyclohexane was added, followed by 0.05% by mass of ruthenium carbonyl chloride tris(triphenylphosphine) as a hydrogenation catalyst. The mixture was pressurized to 4.5 MPa with hydrogen and stirred while being heated to 160 °C, and then allowed to react for 8 hours to obtain a reaction solution containing the cyclic olefin copolymer hydride. The obtained solution was injected into a large amount of isopropanol to precipitate the cyclic olefin copolymer hydride. After filtering the precipitated cyclic olefin copolymer hydride, it was dried using a vacuum dryer (200 °C, 1 Torr) for 10 hours to obtain 5 g of the cyclic olefin copolymer hydride.

[0226] Then, the glass transition temperature (Tg) and stress birefringence (C) of the obtained cyclic olefin copolymer hydride were determined by the above method. R and refractive index (n) d The results are shown in Table 1.

[0227] (Example 2)

[0228] In preparing the cyclic olefin copolymers, a mixture of naphthylnorbornene (NPNB) in the ratio of Synthesis Example 1 / Synthesis Example 2 / Synthesis Example 3 / Synthesis Example 4 = 1.0 / 3.3 / 28.0 / 67.7 (molar ratio) was used as the naphthylnorbornene mixture. A mixed monomer mixture in which the mixing ratio of naphthylnorbornene mixture and tetracyclododecene (TCD) was changed to 30:70 (molar ratio) was used. Otherwise, the cyclic olefin copolymers and cyclic olefin copolymer hydrides were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0229] (Example 3)

[0230] In preparing the cyclic olefin copolymers, a mixture of naphthylnorbornene (NPNB) in the ratio of Synthesis Example 1 / Synthesis Example 2 / Synthesis Example 3 / Synthesis Example 4 = 0 / 1.0 / 11.0 / 88.0 (molar ratio) was used as the naphthylnorbornene mixture. A mixture of naphthylnorbornene and 1,4-bridged methylene-1,4,4a,9a-tetrahydro-9H-fluorene (MTF) in a 50:50 (molar ratio) ratio was used as the mixed monomer. Otherwise, the cyclic olefin copolymers and cyclic olefin copolymer hydrides were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0231] (Example 4)

[0232] In preparing the cyclic olefin copolymers, a mixture of naphthylnorbornene (NPNB) in the ratio of Synthesis Example 1 / Synthesis Example 2 / Synthesis Example 3 / Synthesis Example 4 = 4.7 / 34.8 / 7.3 / 53.2 (molar ratio) was used as the naphthylnorbornene mixture. A mixed monomer mixture in which the mixing ratio of naphthylnorbornene mixture and tetracyclododecene (TCD) was changed to 30:70 (molar ratio) was used. Otherwise, the cyclic olefin copolymers and cyclic olefin copolymer hydrides were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0233] (Comparative Example 1)

[0234] In preparing the cyclic olefin copolymer, exomeric 2-naphthylnorbornene (Synthesis Example 2) was used instead of the naphthylnorbornene mixture, and a mixed monomer mixture in which the mixing ratio of exomeric 2-naphthylnorbornene (Synthesis Example 2) and tetracyclododecene (TCD) was changed to 56:44 (molar ratio) was used. Otherwise, the cyclic olefin copolymer and the cyclic olefin copolymer hydride were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0235] (Comparative Example 2)

[0236] In preparing the cyclic olefin copolymers, a mixture of naphthylnorbornene (NPNB) in the ratio of Synthesis Example 1 / Synthesis Example 2 / Synthesis Example 3 / Synthesis Example 4 = 4.7 / 0 / 95.3 / 0 (molar ratio) was used as the naphthylnorbornene mixture. A mixed monomer mixture in which the mixing ratio of naphthylnorbornene mixture and tetracyclododecene (TCD) was changed to 30:70 (molar ratio) was used. Otherwise, the cyclic olefin copolymers and cyclic olefin copolymer hydrides were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0237] (Comparative Example 3)

[0238] In preparing the cyclic olefin copolymers, a mixture of Naphthylnorbornene (NPNB) in the ratio of Synthesis Example 1 / Synthesis Example 2 / Synthesis Example 3 / Synthesis Example 4 = 3.9 / 40.2 / 5.1 / 50.8 (molar ratio) was used. Otherwise, the cyclic olefin copolymers and cyclic olefin copolymer hydrides were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0239] [Table 1]

[0240]

[0241] As shown in Table 1, the cyclic olefin copolymer hydrides of Examples 1-4 can achieve a balance of high refractive index, high heat resistance, and low birefringence. Furthermore, as shown in Table 1, the cyclic olefin copolymer hydrides of Comparative Examples 1 and 3 exhibit low heat resistance, while the cyclic olefin copolymer hydride of Comparative Example 2 shows poor birefringence.

[0242] Industrial availability

[0243] According to the present invention, it is possible to obtain a resin that can combine high refractive index, high heat resistance and low birefringence, as well as copolymers that are useful as raw materials thereon.

[0244] Furthermore, according to the present invention, an optical element with high refractive index and heat resistance and low birefringence can be obtained.

Claims

1. A cyclic olefin copolymer comprising structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene, wherein the average internal bulk ratio of the 1-naphthylnorbornene and the 2-naphthylnorbornene is 50 mol% or more. The average endotype ratio is the ratio of the total number of structural units from endo-1-naphthylnorbornene and endo-2-naphthylnorbornene to the total number of structural units from exo-1-naphthylnorbornene, endo-1-naphthylnorbornene, exo-2-naphthylnorbornene, and endo-2-naphthylnorbornene. The total proportion of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene in all structural units of the cyclic olefin copolymer is more than 30 mol% and less than 70 mol%. The proportion of structural units from 1-naphthylnorbornene relative to the total proportion of structural units from 1-naphthylnorbornene and structural units from 2-naphthylnorbornene is greater than 1 mol% and less than 30 mol%. The cyclic olefin copolymer is a ring-opening polymer.

2. The cyclic olefin copolymer according to claim 1, further comprising structural units from norbornene monomers other than 1-naphthylnorbornene and 2-naphthylnorbornene.

3. A cyclic olefin copolymer hydrogenation product, which is obtained by hydrogenating the cyclic olefin copolymer according to claim 1 or 2.

4. The cyclic olefin copolymer hydride according to claim 3, wherein, The glass transition temperature of the cyclic olefin copolymer hydride is above 135°C.

5. An optical element comprising the cyclic olefin copolymer hydride of claim 3 or 4.

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