Cyclic olefin ring-opened polymer, cyclic olefin ring-opened polymer hydride, resin composition, and resin molded body

Abstract

The purpose of the present invention is to provide: a cyclic olefin ring-opened polymer hydride having both a low birefringence and an appropriate-level Abbe number; and a raw material thereof. This cyclic olefin ring-opened polymer is characterized by including a structural unit (A) derived from a norbornene imide monomer represented by formula (1) and a structural unit (B) derived from a cyclic olefin monomer not having a polar group. This cyclic olefin ring-opened polymer hydride is characterized by being obtained through hydrogenation of the cyclic olefin ring-opened polymer of the present invention.

Description

Cyclic olefin ring-opening polymer, hydrogenated cyclic olefin ring-opening polymer, resin composition, and resin molded product

[0001] The present invention relates to a cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, a resin composition, and a resin molded article.

[0002] Hydrogenated cyclic olefin ring-opening polymers obtained by hydrogenating cyclic olefin ring-opening polymers obtained by ring-opening polymerization of cyclic olefin monomers are widely used as molding materials for optical elements such as optical lenses because they have excellent transparency, low moisture absorption, heat resistance, insulating properties, chemical resistance, etc. Therefore, in recent years, various proposals have been made to improve the physical properties of hydrogenated cyclic olefin ring-opening polymers.

[0003] For example, Patent Document 1 discloses a method for producing a hydrogenated ring-opening metathesis polymer (hydrogenated ring-opening cyclic olefin polymer) by hydrogenating a ring-opening metathesis polymer obtained by ring-opening metathesis polymerization of a cyclic olefin in the presence of a polymerization catalyst, in which a specific ruthenium compound is used as the polymerization catalyst. Patent Document 1 also discloses that the production method enables the production of a hydrogenated ring-opening metathesis polymer having excellent light transmittance.

[0004] International Publication No. 2013 / 137398

[0005] Here, in recent years, with the improvement in the performance of optical elements such as optical lenses, there has been an increasing demand for reducing the birefringence of hydrogenated cyclic olefin ring-opening polymers used as molding materials for producing optical elements. Furthermore, in recent years, from the perspective of increasing the degree of freedom in optical design, there has been a demand for the development of not only hydrogenated cyclic olefin ring-opening polymers having a high Abbe number (e.g., 50 or more) as molding materials for optical elements, but also hydrogenated cyclic olefin ring-opening polymers having an appropriate Abbe number of low to medium magnitude (e.g., 35 or more and less than 50). However, the hydrogenated cyclic olefin ring-opening polymers obtained by the above-mentioned conventional techniques do not simultaneously have an appropriate Abbe number and low birefringence.

[0006] Therefore, an object of the present invention is to provide a hydrogenated cyclic olefin ring-opening polymer having both a moderate Abbe number and a low birefringence, a raw material thereof, a resin composition that can be advantageously used as a material for various molded articles such as optical elements, and a resin molded article formed using the resin composition.

[0007] The present inventors have conducted extensive research to solve the above problems, and have newly discovered that a hydrogenated cyclic olefin ring-opening polymer obtained by hydrogenating a cyclic olefin ring-opening polymer containing a structural unit derived from a specific norbornene imide monomer and a structural unit derived from a cyclic olefin monomer having no polar group can simultaneously achieve an appropriate Abbe number and reduced birefringence, thereby completing the present invention.

[0008] That is, an object of the present invention is to advantageously solve the above-mentioned problems, and the present invention provides [1] a cyclic olefin ring-opening polymer comprising a structural unit (A) derived from a norbornene imide monomer represented by the following formula (1) and a structural unit (B) derived from a cyclic olefin monomer having no polar group: (In formula (1), A represents an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group which may have a substituent (excluding a phenyl group which has no substituents at both of the two ortho-positions relative to the imide ring to which it is bonded).) A cyclic olefin monomer containing a structural unit (A) derived from a norbornene imide monomer represented by formula (1) and a structural unit (B) derived from a cyclic olefin monomer which does not have a polar group can be advantageously used as a raw material for a hydrogenated cyclic olefin ring-opening polymer which can achieve both an appropriate Abbe number (for example, 35 or more and less than 50) and a reduced birefringence.

[0009] [2] In the cyclic olefin ring-opening polymer of the above [1], the structural unit (A) is preferably a structural unit derived from a norbornene imide monomer represented by the following formula (2): (In formula (2), R １ ~R ５each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkoxy group, an optionally substituted aromatic hydrocarbon ring group, or an optionally substituted aromatic heterocyclic group; R １ ~R ５ Two or more of them may be bonded to form a ring. １ and R ５ When the structural unit (A) is a structural unit derived from the above-mentioned specified norbornene imide monomer, the birefringence of the obtained hydrogenated cyclic olefin ring-opening polymer can be further reduced while maintaining an appropriate Abbe number.

[0010] [3] In the cyclic olefin ring-opening polymer of the above [1] or [2], the content of the structural unit (A) is preferably 50% by mass or more and 90% by mass or less. If the content of the structural unit (A) is within the above-mentioned range, the birefringence of the obtained hydrogenated cyclic olefin ring-opening polymer can be further reduced while maintaining an appropriate Abbe number. In the present invention, the "content of the structural unit" means １ H-NMR and １３ It can be measured using a nuclear magnetic resonance (NMR) method such as C-NMR.

[0011] [4] In the cyclic olefin ring-opening polymer of any one of [1] to [3] above, the structural unit (B) preferably contains a structural unit derived from deltacyclene. When the structural unit (B) contains a structural unit derived from deltacyclene, the birefringence of the resulting hydrogenated cyclic olefin ring-opening polymer can be further reduced while maintaining an appropriate Abbe number.

[0012] Another object of the present invention is to advantageously solve the above-mentioned problems, and the present invention relates to [5] a hydrogenated cyclic olefin ring-opening polymer obtained by hydrogenating the cyclic olefin ring-opening polymer of any one of [1] to [4] above. The hydrogenated cyclic olefin ring-opening polymer obtained by hydrogenating the cyclic olefin ring-opening polymer has both a moderately large Abbe number and a low birefringence.

[0013] [6] The hydrogenated cyclic olefin ring-opening polymer of [5] above preferably has an Abbe number of less than 50. If the Abbe number is less than 50, the hydrogenated cyclic olefin ring-opening polymer can be suitably used for applications other than optical elements with high Abbe numbers. In the present invention, the "Abbe number" can be measured by the method described in the examples.

[0014] [7] The hydrogenated cyclic olefin ring-opening polymer of [5] or [6] above preferably has a glass transition temperature of 120°C or higher. If the glass transition temperature is 120°C or higher, deterioration of optical properties due to thermal deformation or the like of a resin molded article formed using the hydrogenated cyclic olefin ring-opening polymer can be suppressed. In the present invention, the "glass transition temperature" can be measured by the method described in the Examples.

[0015] Another object of the present invention is to advantageously solve the above-mentioned problems, and the present invention provides [8] a resin composition containing the hydrogenated cyclic olefin ring-opening polymer of any of the above [5] to [7]. The resin composition containing any of the above-mentioned hydrogenated cyclic olefin ring-opening polymers can be advantageously used as a material for various molded articles such as optical elements.

[0016] Another object of the present invention is to advantageously solve the above-mentioned problems, and the present invention provides [9] a resin molded article obtained by molding the resin composition according to the above-mentioned [8]. The resin molded article formed using the above-mentioned resin composition can exhibit excellent performance.

[0017] According to the present invention, it is possible to provide a hydrogenated cyclic olefin ring-opening polymer having both a moderate Abbe number and a low birefringence, and a raw material thereof. Furthermore, according to the present invention, it is possible to provide a resin composition that can be advantageously used as a material for various molded articles such as optical elements, and a resin molded article formed using the resin composition.

[0018] Hereinafter, embodiments of the present invention will be described in detail. Here, the cyclic olefin ring-opening polymer of the present invention can be suitably used, for example, as a raw material for the hydrogenated cyclic olefin ring-opening polymer of the present invention. The hydrogenated cyclic olefin ring-opening polymer of the present invention has an appropriate Abbe number and low birefringence, and can be suitably used as a material for various molded articles such as optical elements. Furthermore, the resin composition of the present invention can be suitably used, for example, as a material for producing the resin molded article of the present invention. Furthermore, the resin molded article of the present invention can be suitably used, for example, as an optical element such as an optical film, a lens for an imaging device such as a camera, or a lens for a mobile terminal such as a mobile phone or a smartphone.

[0019] (Cyclic Olefin Ring-Opening Polymer) The cyclic olefin ring-opening polymer of the present invention can be obtained, for example, by ring-opening polymerization of a monomer composition containing a predetermined cyclic olefin compound (monomer) in the presence of a polymerization catalyst. The cyclic olefin ring-opening polymer of the present invention contains a structural unit (A) derived from a predetermined norbornene imide monomer and a structural unit (B) derived from a cyclic olefin monomer having no polar group, and optionally further contains other structural units. Each structural unit will be described below.

[0020] <Structural Unit (A) Derived from Norbornene Imide Monomer> The structural unit (A) derived from a norbornene imide monomer is a structural unit derived from a norbornene imide monomer represented by the following formula (1) (hereinafter, may be abbreviated as structural unit (A)). In formula (1), A represents an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group which may have a substituent (excluding a phenyl group which has no substituents at either of the two ortho positions relative to the imide ring to which it is bonded).

[0021] Here, the "alkyl group" that can constitute A is not particularly limited, and examples thereof include alkyl groups having 1 to 10 carbon atoms. The "alkyl group having 1 to 10 carbon atoms" may be either linear or branched, and examples thereof include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a neopentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group.

[0022] The "cycloalkyl group" that can constitute A is not particularly limited, and examples thereof include cycloalkyl groups having from 3 to 12 carbon atoms. Examples of the "cycloalkyl group having from 3 to 12 carbon atoms" include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

[0023] The "alkoxy group" that can constitute A is not particularly limited, and examples thereof include alkoxy groups having from 1 to 10 carbon atoms. The "alkoxy group having from 1 to 10 carbon atoms" may be either linear or branched, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an octoxy group.

[0024] The "aryl group which may have a substituent (excluding a phenyl group which has no substituents at both ortho positions relative to the imide ring to which it is bonded; the same applies hereinafter)" which may constitute A is not particularly limited, and examples thereof include aryl groups having from 6 to 30 carbon atoms which may have a substituent. Examples of the aryl group having from 6 to 30 carbon atoms which is an "aryl group which may have a substituent" include a phenyl group, a naphthyl group, and an anthracenyl group.

[0025] Here, examples of the substituent in the "aryl group which may have a substituent" include a halogen atom; a hydroxyl group; a cyano group; a nitro group; an alkyl group which may have a substituent; a cycloalkyl group which may have a substituent; an alkenyl group which may have a substituent; an alkynyl group which may have a substituent; an alkoxy group which may have a substituent; an aromatic hydrocarbon ring group which may have a substituent; and an aromatic heterocyclic group which may have a substituent. The number of the substituent may be one or more. When there are multiple substituents, they may be the same as or different from each other.

[0026] The halogen atom that can constitute the substituent of the aryl group is not particularly limited, and examples thereof include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom.

[0027] The "optionally substituted alkyl group" that can constitute a substituent on the aryl group is not particularly limited, and examples thereof include alkyl groups having 1 to 10 carbon atoms, which may have a substituent. Examples of the alkyl group having 1 to 10 carbon atoms in the "optionally substituted alkyl group having 1 to 10 carbon atoms" include the same as those described above for A. Among these, a methyl group or an isopropyl group is preferred. Specific examples of the "substituent" in the "optionally substituted alkyl group" include, for example, a halogen atom such as a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom; a cyano group; a nitro group; an unsubstituted alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group; an unsubstituted alkenyl group having 2 to 6 carbon atoms, such as a vinyl group or an allyl group; an alkyl group having 1 to 10 carbon atoms, in which one or more hydrogen atoms, such as a trifluoromethyl group, are substituted with a halogen atom, such as a fluorine atom; and an unsubstituted alkoxy group having 1 to 10 carbon atoms, such as a methoxy group, an ethoxy group, or an isopropoxy group. The number of substituents may be one or more. When a group has a plurality of substituents, they may be the same or different.

[0028] Examples of the "cycloalkyl group which may have a substituent" that can constitute a substituent on the aryl group include a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent. The cycloalkyl group having 3 to 12 carbon atoms in the "cycloalkyl group which may have a substituent" is not particularly limited, and examples include the same as those of A described above. Specific examples of the substituent on the "cycloalkyl group which may have a substituent" include the same as the substituent that the "alkyl group which may have a substituent" described above may have. The number of substituents may be one or more. When multiple substituents are present, they may be the same as or different from each other.

[0029] The "optionally substituted alkenyl group" that can constitute a substituent of the aryl group is not particularly limited, and examples thereof include alkenyl groups having 2 to 10 carbon atoms, which may have a substituent. The alkenyl group having 2 to 10 carbon atoms in the "optionally substituted alkenyl group having 2 to 10 carbon atoms" may be either linear or branched, and examples thereof include vinyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, octenyl, and decenyl. Specific examples of the substituent of the "optionally substituted alkenyl group having 2 to 10 carbon atoms" include the same substituents as those that may be possessed by the above-mentioned "optionally substituted alkyl group." The number of substituents may be one or more. When multiple substituents are present, they may be the same or different.

[0030] The "optionally substituted alkynyl group" that can constitute a substituent on the aryl group is not particularly limited, and examples thereof include alkynyl groups having 2 to 10 carbon atoms, which may have a substituent. The alkynyl group having 2 to 10 carbon atoms in the "optionally substituted alkynyl group" may be either linear or branched, and examples thereof include ethynyl, propynyl, 2-propynyl (propargyl), butynyl, 2-butynyl, 3-butynyl, pentynyl, 2-pentynyl, hexynyl, 5-hexynyl, heptynyl, octynyl, 2-octynyl, nonanyl, decanyl, and 7-decanyl. Specific examples of the substituent on the "optionally substituted alkynyl group having 2 to 10 carbon atoms," which may have a substituent, include the same substituents as those that may be possessed by the above-mentioned "optionally substituted alkyl group." The number of substituents may be one or more. When a group has a plurality of substituents, they may be the same or different.

[0031] Examples of the "alkoxy group which may have a substituent" that can constitute a substituent of the above-mentioned aryl group include an alkoxy group having 1 to 10 carbon atoms which may have a substituent. Examples of the alkoxy group of the "alkoxy group which may have 1 to 10 carbon atoms which may have a substituent" include the same as those described above for A. Specific examples of the substituent of the "alkoxy group which may have a substituent" include the same as the substituent that the "alkyl group which may have a substituent" described above may have. The number of substituents may be one or more. When there are multiple substituents, they may be the same as or different from each other.

[0032] The "optionally substituted aromatic hydrocarbon ring group" that can constitute a substituent of the above-mentioned aryl group is not particularly limited, and examples thereof include aromatic hydrocarbon ring groups having 6 to 30 carbon atoms and which may have a substituent. Examples of the aromatic hydrocarbon ring group having 6 to 30 carbon atoms and which may have a substituent include a phenyl group, a naphthyl group, an anthracenyl group, etc. Specific examples of the substituent of the "optionally substituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms" include the same substituents as those that may be possessed by the above-mentioned "optionally substituted alkyl group." The number of substituents may be one or more. When multiple substituents are present, they may be the same as or different from each other.

[0033] The "optionally substituted aromatic heterocyclic group" that can constitute a substituent of the aryl group is not particularly limited, and examples thereof include aromatic heterocyclic groups having from 6 to 30 carbon atoms, which may have a substituent. Examples of the aromatic hydrocarbon ring group having from 6 to 30 carbon atoms in the "optionally substituted aromatic heterocyclic group" include a furanyl group, a 1-benzofuranyl group, a 2-benzofuranyl group, a pyrrolyl group, an indolyl group, a thienyl group, a benzo[c]thienyl group, a benzo[b]thienyl group, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a triazolyl group, a triazinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, a benzothiazolyl group, an oxazolyl group, and a benzoxazolyl group. Specific examples of the substituent of the "optionally substituted aromatic heterocyclic group having from 6 to 30 carbon atoms," which may have a substituent, include the same substituents as those that may be possessed by the above-mentioned "optionally substituted alkyl group." The number of substituents may be one or more. When a group has a plurality of substituents, they may be the same or different.

[0034] When multiple substituents are present on the aryl group, two or more of these may be bonded to form a ring. The ring formed by bonding multiple substituents may be monocyclic or polycyclic. The ring formed by bonding two or more substituents is not particularly limited, and examples thereof include aromatic hydrocarbon rings, aromatic heterocyclic rings, non-aromatic hydrocarbon rings, and polycyclic fused rings formed by condensing two or more of these rings. Specific examples of aromatic hydrocarbon rings include aromatic hydrocarbon rings having 6 to 30 carbon atoms, such as a benzene ring, a naphthalene ring, and an anthracene ring. Specific examples of aromatic heterocyclic rings include aromatic heterocyclic rings having 2 to 30 carbon atoms, such as a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, and a benzoxazole ring. Specific examples of the non-aromatic hydrocarbon ring include cycloalkyl rings having 3 to 12 carbon atoms, such as a cyclopropyl ring, a cyclobutyl ring, a cyclopentyl ring, a cyclohexyl ring, and a cyclooctyl ring.

[0035] Among these, from the viewpoint of further reducing the birefringence while imparting an appropriate Abbe number to the resulting hydrogenated cyclic olefin ring-opening polymer, A in formula (1) is preferably a phenyl group having the above-mentioned substituent. That is, the norbornene imide monomer represented by formula (1) is preferably a norbornene imide monomer represented by the following formula (2): (In formula (2), R １ ~R ５ each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkoxy group, an optionally substituted aromatic hydrocarbon ring group, or an optionally substituted aromatic heterocyclic group; R １ ~R ５ Two or more of them may be bonded to form a ring. １and R ５ At least one of these is not a hydrogen atom.)

[0036] Here, R in formula (2) １ ~R ５ and "halogen atom", "optionally substituted alkyl group", "optionally substituted cycloalkyl group", "optionally substituted alkenyl group", "optionally substituted alkynyl group", "optionally substituted alkoxy group", "optionally substituted aromatic hydrocarbon ring group", "optionally substituted aromatic heterocyclic group", "R １ ~R ５ The "ring formed by bonding two or more of these" are the same as the substituents and rings of the "optionally substituted aryl group" described above.

[0037] Among them, from the viewpoint of further reducing the birefringence while imparting an appropriate Abbe number to the resulting hydrogenated cyclic olefin ring-opening polymer, the norbornene imide monomer represented by formula (2) is preferably a norbornene imide monomer represented by formula (2) １ ~R ５ Compounds in which one or more of the groups are "an alkyl group having 1 to 10 carbon atoms which may have a substituent" and the remaining groups are hydrogen atoms (provided that R １ and R ５ At least one of R is not a hydrogen atom. The same applies hereinafter.) １ ~R ５ In order to further reduce the birefringence while imparting an appropriate Abbe number to the resulting hydrogenated cyclic olefin ring-opening polymer, the norbornene imide monomer represented by formula (2) is preferably a compound in which two of the R １ ~R ５ In the formula (2), one or more of R is a methyl group or an isopropyl group, and the remaining is a hydrogen atom. １ ~R ５ Among these, a compound in which two of R are methyl groups or isopropyl groups and the remaining is a hydrogen atom is more preferred. １and R ５ is a methyl group or an isopropyl group, and the remaining is a hydrogen atom (i.e., N-2-methylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide), and １ and R ５ is a methyl group or an isopropyl group, and the remaining is a hydrogen atom (i.e., N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide) is more preferred, and R １ and R ５ is an isopropyl group and the remainder are hydrogen atoms (ie, N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide).

[0038] The norbornene imide monomers described above may be used singly or in combination of two or more.

[0039] [Content ratio] When the content ratio of all repeating units contained in the cyclic olefin ring-opening polymer is taken as 100 mass%, the content ratio of the structural unit (A) is preferably 10 mass% or more, more preferably 25 mass% or more, even more preferably 40 mass% or more, particularly preferably 50 mass% or more, and is preferably 90 mass% or less, more preferably 85 mass% or less, even more preferably 80 mass% or less, particularly preferably 75 mass% or less. If the content ratio of the structural unit (A) is within the above-mentioned predetermined range, the birefringence of the obtained hydrogenated cyclic olefin ring-opening polymer can be further reduced while maintaining an appropriate Abbe number.

[0040] <Structural unit (B) derived from cyclic olefin monomer without polar group> The "cyclic olefin monomer without polar group" that can form the structural unit (B) (hereinafter sometimes referred to as structural unit (B)) derived from cyclic olefin monomer without polar group is not particularly limited, as long as it has one or more ethylenically unsaturated bonds that can undergo ring-opening polymerization and does not have polar group, for example, can be mentioned the norbornene compound that does not have polar group and the non-norbornene compound that does not have polar group.These can be used in combination, but from the viewpoint of giving the obtained cyclic olefin ring-opening polymer hydrogenation product an appropriate Abbe number and further reducing birefringence, it is preferred that the "cyclic olefin monomer without polar group" that can form structural unit (B) is the norbornene compound that does not have polar group.

[0041] [Norbornene Compounds Having No Polar Group] The norbornene compounds having no polar group are not particularly limited as long as they are non-polar and have one or more norbornene rings, and examples thereof include: bicyclic norbornene compounds such as bicyclo[2.2.1]hept-2-ene (common name: norbornene), 5-ethylidene-2-norbornene (common name: ethylidenenorbornene), and derivatives thereof; tricyclo[4.3.0.1]hept-2-ene (common name: norbornene), 5-ethylidene-2-norbornene (common name: ethylidenenorbornene), and derivatives thereof; ２，５ ]deca-3,7-diene (common name: dicyclopentadiene) and its derivatives, and other tricyclic norbornene compounds; 7,8-benzotricyclo[4.3.0.1 ２，５ ]dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]dodec-3-ene (trivial name: tetracyclododecene), 2-ethylidene-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (trivial name: ethylidenetetracyclododecene) and derivatives thereof, and other tetracyclic norbornene compounds; 7,8-benzotricyclo[4.3.0.1 ２，５ ]dec-3-ene (common name: methanotetrahydrofluorene, tetracyclo[7.4.0.0 ２，７ .1 １０，１３]trideca-2,4,6,11-tetraene), tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ] dodec-3-ene (common name: tetracyclododecene), 8-ethylidenetetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-3-dodecene and derivatives thereof; and norbornene compounds having five or more rings such as pentacyclo[6.5.1.13,6.02,7.09,13]pentadeca-4,10-diene, pentacyclo[9.2.1.14,7.02,10.03,8]pentadeca-5,12-diene, hexacyclo[6.6.1.13,6.110,13.02,7.09,14]heptadeca-4-ene, 1,2,3,3a,4,6a-hexahydro-1,2,4-methenopentalene (common name: deltacyclene) and derivatives thereof. Here, derivatives refer to those having a substituent in the ring structure. The substituent that can be contained in the ring structure is not particularly limited as long as it is not a polar group, and examples thereof include hydrocarbon groups such as alkyl groups, alkylene groups, alkylidene groups, aryl groups, vinyl groups, etc. The ring structure of the derivative may contain one type of these substituents or two or more types.

[0042] Among these, from the viewpoint of further reducing the birefringence while imparting an appropriate Abbe number to the resulting hydrogenated cyclic olefin ring-opening polymer, the norbornene compound having no polar group is preferably ethylidenetetracyclododecene or deltacyclene, and more preferably deltacyclene. In other words, the structural unit (B) preferably contains a structural unit derived from ethylidenetetracyclododecene or deltacyclene, more preferably contains a structural unit derived from deltacyclene, and even more preferably is a structural unit derived from deltacyclene. Deltacyclene is a compound represented by the following formula (3):

[0043] These norbornene compounds having no polar group may be used alone or in combination of two or more.

[0044] [Non-norbornene Compounds without Polar Groups] Non-norbornene compounds without polar groups are not particularly limited as long as they do not have a polar group or a norbornene ring. Examples include monocyclic cycloalkenes such as cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, cyclooctene, 3a,5,6,7a-tetrahydro-4,7-methano-1H-indene, and cycloheptene, and derivatives thereof. Here, "derivatives" refers to compounds having a substituent in the ring structure. The substituents that may be present in the ring structure are not particularly limited as long as they are not polar groups, and the same substituents as those described above in the section on "Norbornene Compounds without Polar Groups" can be used. The ring structure of the derivative may have one or more of these substituents.

[0045] The non-norbornene compounds having no polar group described above may be used singly or in combination of two or more.

[0046] [Content] The content of the structural unit (B), when the content of all repeating units contained in the cyclic olefin ring-opening polymer is taken as 100% by mass, is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. It is also preferably 90% by mass or less, more preferably 75% by mass or less, even more preferably 60% by mass or less, and particularly preferably 50% by mass or less. When the content of the structural unit (B) is equal to or greater than the above-mentioned lower limit, precipitation of the cyclic olefin ring-opening polymer after synthesis can be suppressed. Furthermore, when the content of the structural unit (B) is equal to or greater than the above-mentioned lower limit, the glass transition temperature of the resulting hydrogenated cyclic olefin ring-opening polymer can be suppressed from becoming too high. Furthermore, when the content of the structural unit (B) is equal to or less than the above-mentioned upper limit, precipitation of the cyclic olefin ring-opening polymer after synthesis and thermal deformation of the molded product due to a low glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer can be suppressed.

[0047] <Other Structural Units> The other structural units that the cyclic olefin ring-opening polymer may optionally contain are not particularly limited as long as they do not impair the effects of the present invention and are structural units other than the above-described structural unit (A) and structural unit (B).

[0048] [Content Ratio] The ratio of other structural units (total ratio of other structural units) to all structural units (100% by mass) contained in the cyclic olefin ring-opening polymer is usually 0% by mass or more and 60% by mass or less.

[0049] <Mass Ratio of Structural Unit (A) to Structural Unit (B)> From the viewpoint of further reducing the birefringence while imparting an appropriate Abbe number to the obtained hydrogenated cyclic olefin ring-opening polymer, the mass ratio of the structural unit (A) to the structural unit (B) in the cyclic olefin ring-opening polymer (structural unit (A) / structural unit (B)) is preferably 10 / 90 or more, more preferably 25 / 75 or more, and is preferably 90 / 10 or less, more preferably 75 / 25 or less.

[0050] <Method for producing cyclic olefin ring-opening polymer> The cyclic olefin ring-opening polymer can be obtained by ring-opening polymerization of a monomer composition (mixture) containing the various monomers described above in the section "Cyclic olefin ring-opening polymer." Specifically, for example, the cyclic olefin ring-opening polymer can be prepared by ring-opening polymerization of the above-mentioned monomer composition using a known ring-opening polymerization method such as ring-opening polymerization using a metathesis polymerization catalyst. Note that by performing ring-opening polymerization, the number of rings possessed by each of the above-mentioned monomers is reduced by at least one.

[0051] Here, the metathesis polymerization catalyst is not particularly limited, and known catalysts can be used. Specific examples include a catalyst system comprising a halide, nitrate, or acetylacetone compound of a metal selected from ruthenium, rhodium, palladium, osmium, iridium, platinum, etc., and a reducing agent; a catalyst system comprising a halide or acetylacetone compound of a metal selected from titanium, vanadium, zirconium, tungsten, and molybdenum, and an organoaluminum compound as a co-catalyst; or a catalyst system described in JP-A-7-179575, J. Am. Chem. Soc., 1986, 108, 733, J. Am. Chem. Soc., 1993, 115, 9858, and J. Am. Chem. Soc. Known Schrock-type or Grubbs-type living ring-opening metathesis catalysts, such as those disclosed in J. Chem. Soc., 1996, 118, 100, can be used. These catalysts can be used alone or in combination of two or more. The amount of catalyst used can be appropriately selected depending on the polymerization conditions, etc.

[0052] A polar compound can be further added to the catalyst system to enhance polymerization activity and ring-opening polymerization selectivity. Examples of polar compounds include molecular oxygen, alcohols, ethers, peroxides, carboxylic acids, acid anhydrides, acid chlorides, esters, ketones, nitrogen-containing compounds, sulfur-containing compounds, halogen-containing compounds, molecular iodine, and other Lewis acids. Preferred nitrogen-containing compounds are aliphatic or aromatic tertiary amines, and specific examples include triethylamine, dimethylaniline, tri-n-butylamine, pyridine, and α-picoline. These polar compounds may be used alone or in combination of two or more. The amount of polar compound used can be selected appropriately, but the ratio to the metal in the catalyst, i.e., the polar compound / metal ratio (molar ratio), is typically in the range of 1 to 100,000, preferably 5 to 10,000.

[0053] The polymerization reaction may be carried out by bulk polymerization without using a solvent, or may be carried out in a solvent such as an organic solvent. There are no particular limitations on the solvent as long as it is inert to the polymerization reaction, and examples thereof include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as n-pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclohexane; halogenated hydrocarbons such as styrene dichloride, dichloroethane, dichloroethylene, tetrachloroethane, chlorobenzene, dichlorobenzene, and trichlorobenzene; nitrogen-containing hydrocarbons such as nitromethane, nitrobenzene, acetonitrile, and benzonitrile; and ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether.

[0054] The polymerization conditions such as polymerization temperature, polymerization pressure, and polymerization time can be adjusted appropriately.

[0055] (Hydrogenated Cyclic Olefin Ring-Opening Polymer) The hydrogenated cyclic olefin ring-opening polymer of the present invention is obtained by hydrogenating the above-mentioned cyclic olefin ring-opening polymer of the present invention as a raw material. The hydrogenated cyclic olefin ring-opening polymer of the present invention has both an appropriately large Abbe number and a low birefringence. Here, the hydrogenation of the cyclic olefin ring-opening polymer can be carried out using hydrogen and a hydrogenation catalyst. The hydrogenation of the cyclic olefin ring-opening polymer can be carried out using any hydrogenation catalyst and hydrogenation conditions as long as the non-aromatic carbon-carbon unsaturated bonds, such as olefinic double bonds, present in the cyclic olefin ring-opening polymer can be hydrogenated.

[0056] The hydrogenation of a cyclic olefin ring-opening polymer is carried out so that the hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds such as olefinic double bonds present in the cyclic olefin ring-opening polymer (the proportion of hydrogenated non-aromatic carbon-carbon unsaturated bonds in the cyclic olefin ring-opening polymer) is typically 90% or more, preferably 95% or more, and more preferably 99% or more. If the hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds such as olefinic double bonds contained in the cyclic olefin ring-opening polymer is equal to or higher than the above-mentioned lower limit, yellowing due to oxidative degradation of the resin during molding, etc. can be suppressed.

[0057] The carbon-carbon unsaturated bonds (aromatic carbon-carbon unsaturated bonds) of the aromatic ring structures (aromatic rings and / or aromatic heterocycles) present in the hydrogenated cyclic olefin ring-opening polymer may be hydrogenated, but are preferably not hydrogenated from the viewpoint of further reducing birefringence while maintaining an appropriate Abbe number. Specifically, the hydrogenation rate of aromatic carbon-carbon unsaturated bonds in the hydrogenated cyclic olefin ring-opening polymer (the proportion of hydrogenated aromatic carbon-carbon unsaturated bonds in the cyclic olefin ring-opening polymer) is preferably 20% or less, more preferably 10% or less, and particularly preferably 0% (i.e., not hydrogenated). In the present invention, the hydrogenation rates of non-aromatic carbon-carbon unsaturated bonds and aromatic carbon-carbon unsaturated bonds can be measured by the method described in the Examples. The hydrogenation rates of non-aromatic carbon-carbon unsaturated bonds and aromatic carbon-carbon unsaturated bonds can be adjusted, for example, by changing the type and amount of the hydrogenation catalyst and / or the hydrogenation reaction conditions (e.g., reaction temperature).

[0058] Examples of the hydrogenation catalyst that can be used include hydrogenation catalysts composed of dicyclopentadienyl titanium halide, organic nickel carboxylate, organic cobalt carboxylate, or the like, and an organometallic compound of Groups 1 to 3 of the periodic table; metal catalysts such as nickel, platinum, palladium, ruthenium, rhenium, or rhodium supported on carbon, silica, diatomaceous earth, or the like, and cobalt, nickel, rhodium, or ruthenium complexes; and hydrogenated compounds such as lithium aluminum hydride and p-toluenesulfonyl hydrazide. Among these, ruthenium compounds are preferred as the hydrogenation catalyst from the viewpoint of producing the target product in good yield without isomerization.

[0059] Examples of ruthenium compounds include RuHCl(CO)(PPh ３ ) ３ , RuHCl(CO)[P(p-Me-Ph) ３ ] ３ , RuHCl(CO)(PCy ３ ) ２ , RuHCl(CO)[P(n-Bu) ３ ] ３ , RuHCl(CO)[P(i-Pr) ３ ] ２ , RuH ２ (CO)(PPh ３ ) ３ , RuH ２ (CO)[P(p-Me-Ph) ３ ] ３ , RuH ２ (CO)(PCy ３ ) ３ , RuH ２ (CO)[P(n-Bu) ３ ] ３ , RuH(OCOCH ３ ) (CO) (PPh ３ ) ２ , RuH(OCOPh)(CO)(PPh ３ ) ２ , RuH(OCOPh-CH ３ ) (CO) (PPh ３ ) ２ , RuH(OCOPh-OCH ３ ) (CO) (PPh ３ ) ２, RuH(OCOPh)(CO)(PCy ３ ) ２ etc.

[0060] The hydrogenation reaction of the cyclic olefin ring-opening polymer can usually be carried out in an inert organic solvent, such as aromatic hydrocarbon solvents such as benzene, toluene, and xylene; aliphatic hydrocarbon solvents such as pentane and hexane; alicyclic hydrocarbon solvents such as cyclohexane and decahydronaphthalene; and ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether.

[0061] The reaction temperature when hydrogen is added to a system containing a cyclic olefin ring-opening polymer and a hydrogenation catalyst to hydrogenate the cyclic olefin ring-opening polymer varies depending on the hydrogenation catalyst used, but is typically −20°C to 250°C, preferably −10°C to 220°C, and more preferably 0°C to 200°C. If the reaction temperature is too low, the hydrogenation rate may be too slow, and if the reaction temperature is too high, side reactions may occur. The hydrogen pressure is typically 0.01 to 20 MPa, preferably 0.05 to 15 MPa, and more preferably 0.1 to 10 MPa. If the hydrogen pressure is too low, the hydrogenation rate may be too slow, and if the hydrogen pressure is too high, a high-pressure reactor is required, resulting in equipment limitations. Furthermore, the reaction time, although depending on the reaction scale, is typically 0.1 to 10 hours.

[0062] After the hydrogenation reaction, the resulting hydrogenated cyclic olefin ring-opening polymer may be recovered by a conventional method, and in recovering the hydrogenated polymer, catalyst residues may be removed by a technique such as filtration.

[0063] <Structural Units> The structural unit (A) in the hydrogenated cyclic olefin ring-opening polymer may include a structural unit obtained by ring-opening polymerization of a norbornene imide monomer and a structural unit obtained by hydrogenating the structural unit. Similarly, the structural unit (B) in the hydrogenated cyclic olefin ring-opening polymer may include a structural unit obtained by ring-opening polymerization of a cyclic olefin monomer not having a polar group and a structural unit obtained by hydrogenating the structural unit. Furthermore, similarly, other structural units optionally contained in the hydrogenated cyclic olefin ring-opening polymer may include a structural unit obtained by ring-opening polymerization of a cyclic olefin compound capable of forming other structural units and a structural unit obtained by hydrogenating the structural unit. In the hydrogenated cyclic olefin ring-opening polymer, the "structural unit obtained by ring-opening polymerization of a norbornene imide monomer," the "structural unit obtained by ring-opening polymerization of a cyclic olefin monomer having no polar group," and the "structural unit obtained by ring-opening polymerization of a cyclic olefin compound capable of forming other structural units" are all unhydrogenated structural units (repeating units) that were not hydrogenated during the hydrogenation of the cyclic olefin ring-opening polymer.

[0064] The content of the structural unit (A) in the hydrogenated cyclic olefin ring-opening polymer (the total proportion of the structural unit obtained by ring-opening polymerization of a norbornene imide monomer and the structural unit obtained by hydrogenating the structural unit) is the same as the preferred content of the structural unit (A) in the cyclic olefin ring-opening polymer described above in the section "Cyclic Olefin Ring-Opening Polymer." Furthermore, the content of the structural unit (B) in the hydrogenated cyclic olefin ring-opening polymer (the total proportion of the structural unit obtained by ring-opening polymerization of a cyclic olefin monomer having no polar group and the structural unit obtained by hydrogenating the structural unit) is the same as the preferred content of the structural unit (B) in the cyclic olefin ring-opening polymer described above in the section "Cyclic Olefin Ring-Opening Polymer." Furthermore, the content of other structural units optionally contained in the hydrogenated cyclic olefin ring-opening polymer (the total content of structural units obtained by ring-opening polymerization of cyclic olefin compounds capable of forming such other structural units and structural units obtained by hydrogenating such structural units) is the same as the preferred content of other structural units in the cyclic olefin ring-opening polymer described above in the section "Cyclic olefin ring-opening polymer." Furthermore, the preferred mass ratio of structural unit (A) to structural unit (B) in the hydrogenated cyclic olefin ring-opening polymer is also the same as the preferred content ratio described above in the section "Cyclic olefin ring-opening polymer."

[0065] <Weight Average Molecular Weight> The weight average molecular weight of the hydrogenated cyclic olefin ring-opening polymer of the present invention is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, and particularly preferably 40,000 or more, and is preferably 160,000 or less, more preferably 80,000 or less, and even more preferably 70,000 or less. When the weight average molecular weight of the hydrogenated cyclic olefin ring-opening polymer is equal to or greater than the above-mentioned lower limit, a decrease in the strength of a resin molded article obtained using the hydrogenated cyclic olefin ring-opening polymer can be suppressed. Furthermore, when the weight average molecular weight of the hydrogenated cyclic olefin ring-opening polymer is equal to or less than the above-mentioned upper limit, molding defects due to poor flowability during molding of the hydrogenated cyclic olefin ring-opening polymer can be suppressed. In the present invention, the "weight average molecular weight" can be measured by the method described in the Examples. The weight average molecular weight of the hydrogenated cyclic olefin ring-opening polymer can be adjusted, for example, by changing the type and / or amount of the monomer used in preparing the cyclic olefin ring-opening polymer, or the type and / or amount of the molecular weight regulator (chain transfer agent).

[0066] <Glass Transition Temperature> The hydrogenated cyclic olefin ring-opening polymer of the present invention preferably has a glass transition temperature of 120°C or higher, more preferably 125°C or higher, and even more preferably 130°C or higher, and preferably 200°C or lower, more preferably 190°C or lower, and even more preferably 180°C or lower. When the glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer is equal to or higher than the above-mentioned lower limit, deterioration of heat resistance and deterioration of optical properties due to thermal deformation or the like can be suppressed. Furthermore, when the glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer is equal to or lower than the above-mentioned upper limit, oxidative degradation of the hydrogenated cyclic olefin ring-opening polymer caused by excessively high processing temperatures during molding of the hydrogenated cyclic olefin ring-opening polymer can be suppressed. The glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer can be adjusted, for example, by changing the type and / or amount of monomers used in preparing the cyclic olefin ring-opening polymer.

[0067] <Abbe number> The hydrogenated cyclic olefin ring-opening polymer of the present invention preferably has an Abbe number (vd) of less than 50, more preferably 46 or less, even more preferably 45 or less, even more preferably 43 or less, and particularly preferably 42 or less. If the Abbe number of the hydrogenated cyclic olefin ring-opening polymer is less than the above-mentioned upper limit, the hydrogenated cyclic olefin ring-opening polymer can be suitably used for applications other than optical elements with high Abbe numbers. The lower limit of the Abbe number is not particularly limited, but is usually about 20.

[0068] <Birefringence> The birefringence of the hydrogenated cyclic olefin ring-opening polymer of the present invention is preferably 300 or less, more preferably 200 or less, even more preferably 100 or less, even more preferably 90 or less, and particularly preferably 75 or less. If the birefringence of the hydrogenated cyclic olefin ring-opening polymer is not more than the above upper limit, the optical properties of the resulting resin molded article as an optical element can be improved. In the present invention, the "birefringence" can be measured by the method described in the examples.

[0069] <Refractive Index> The hydrogenated cyclic olefin ring-opening polymer of the present invention preferably has a refractive index of 1.5 or more, more preferably 1.52 or more, and even more preferably 1.54 or more. If the refractive index of the hydrogenated cyclic olefin ring-opening polymer is equal to or more than the above-mentioned lower limit, the degree of design freedom of the obtained resin molded article as an optical element can be increased. In the present invention, the "refractive index" can be measured by the method described in the Examples.

[0070] (Resin Composition) The resin composition of the present invention contains the above-mentioned hydrogenated cyclic olefin ring-opening polymer of the present invention, and optionally further contains polymer materials other than the hydrogenated cyclic olefin ring-opening polymer of the present invention and / or various additives.

[0071] The polymeric materials and additives that can be contained in the resin composition are not particularly limited, and examples thereof include the polymeric materials and additives described in JP-A-10-139865.

[0072] Among these, it is preferable that the resin composition contains an antioxidant such as a phenol-based antioxidant, a phosphorus-based antioxidant, or a sulfur-based antioxidant.

[0073] The polymeric material and additives can be mixed with the hydrogenated cyclic olefin ring-opening polymer using any method as long as they can be sufficiently dispersed in the hydrogenated cyclic olefin ring-opening polymer. Specifically, the polymeric material and additives can be added at any stage during the preparation of the hydrogenated cyclic olefin ring-opening polymer, kneaded with the hydrogenated cyclic olefin ring-opening polymer using a kneader, or mixed with the hydrogenated cyclic olefin ring-opening polymer in a molding machine. The amounts of the polymeric material and additives are not particularly limited as long as the effects of the present invention are not impaired, and can be, for example, 0.01 to 2.0 parts by mass per 100 parts by mass of the hydrogenated cyclic olefin ring-opening polymer. The amount of the antioxidant is also not particularly limited as long as the effects of the present invention are not impaired, and can be, for example, 0.01 to 2.0 parts by mass per 100 parts by mass of the hydrogenated cyclic olefin ring-opening polymer.

[0074] (Resin Molded Article) The resin molded article of the present invention is obtained by molding the above-described resin composition of the present invention into any shape. The resin molded article of the present invention contains the above-described hydrogenated cyclic olefin ring-opening polymer of the present invention, and therefore can exhibit excellent performance.

[0075] The molding method is not particularly limited as long as it can mold the resin composition, and examples that can be used include injection molding, extrusion blow molding, injection blow molding, two-stage blow molding, multi-layer blow molding, connection blow molding, stretch blow molding, rotational molding, vacuum molding, extrusion molding, calendar molding, solution casting, hot press molding, and inflation molding. Of these, extrusion molding is preferred.

[0076] The resin molded article of the present invention is preferably an optical element, more preferably a lens. The lens can be obtained, for example, by uniformly heating and melting the resin composition of the present invention to form a preform, pouring the preform into a mold, and then cooling it, without any particular limitation.

[0077] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. Furthermore, in a polymer produced by copolymerizing multiple types of monomers, the proportion of a structural unit formed by polymerizing a certain monomer in the polymer usually coincides with the ratio (feed ratio) of the certain monomer to all monomers used in the polymerization of the polymer, unless otherwise specified.

[0078] <Polymerization Conversion Rate> After the polymerization reaction was completed, the amount of the remaining monomer in the reaction solution was measured using gas chromatography, and the hydrogen conversion rate was calculated from the measured value. １The hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds and the hydrogenation rate of aromatic carbon-carbon unsaturated bonds in the hydrogenated cyclic olefin ring-opening polymer were determined by measuring the number of moles of hydrogenated carbon-carbon double bonds using H-NMR spectroscopy and calculating the ratio to the number of moles of carbon-carbon double bonds before hydrogenation. <Weight-average molecular weight> The weight-average molecular weight (Mw) of the cyclic olefin ring-opening polymer was calculated in polystyrene equivalent terms using gel permeation chromatography (using a combination of three types of columns: "HLC-8020," TSKgel Super H2000, TSKgel Super H4000, and TSKgel Super H5000, manufactured by Tosoh Corporation). Tetrahydrofuran (THF) was used as the developing solvent. <Glass Transition Temperature> The glass transition temperature (Tg) of the hydrogenated cyclic olefin ring-opening polymer was measured using a differential scanning calorimeter (DSC6220, manufactured by SII Nanotechnology Inc.) at a heating rate of 10°C / min in accordance with JIS K7121. <Birefringence> The dried pellets of the resin obtained were injection-molded using an injection molding machine (manufactured by Fanuc Corporation, product number α-100B) under the following conditions: resin temperature: a temperature 20°C lower than the glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer (= Tg - 20°C), mold temperature: a temperature 130°C lower than the glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer (= Tg - 130°C), and a cycle time of 1 minute, to obtain a flat plate-shaped resin molded product measuring 80 mm x 10 mm x 4 mm. The retardation values ​​of the resulting resin molded articles in the direction perpendicular to the resin flow direction at a location 10 mm from the gate of the resin molded articles were measured using a birefringence meter (Photonic Lattice, product name: WPA-200(-L)) using light with a wavelength of 543 nm. The maximum value among the measured values ​​was taken as the birefringence. <Refractive Index> A 5 ​​mm-thick sheet-shaped resin molded article was obtained in the same manner as the resin molded article obtained in the birefringence measurement, except that the resulting resin composition was changed from 80 mm x 10 mm x 4 mm to a 50 mm x 50 mm x 5 mm sheet-shaped resin molded article. The resulting 5 mm-thick sheet-shaped resin molded article was left for 20 hours in an atmosphere at a temperature 15°C lower than the glass transition temperature of the hydrogenated cyclic olefin ring-opening polymer (= Tg - 15°C). This was used as a measurement sample.The refractive index (n) of the obtained measurement sample at 25°C was measured using a precision refractometer (Shimadzu Corporation, product name: KPR-3000, light source = He lamp (587.6 nm), H2 lamp (656.3 nm, 486.1 nm) ｄ , n Ｃ , n Ｆ In Table 1, the refractive index (n ｄ <Abbe number> The refractive index (n ｄ , n Ｃ , n Ｆ ) to calculate the Abbe number (ν ｄ ) was calculated.

[0079] Example 1 60 parts of N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBDII") as the norbornene imide monomer represented by formula (1), 40 parts of deltacyclene (hereinafter sometimes abbreviated as "DCL") as a cyclic olefin monomer having no polar group, 2.5 parts of 1-hexene as a chain transfer agent, 0.025 parts of 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene[2-(isopropoxy)-5-(N,N-dimethylaminosulfonyl)phenyl]methyleneruthenium(II) dichloride as a polymerization catalyst, and 1,000 parts of tetrahydrofuran as a solvent were charged into a nitrogen-substituted glass pressure-resistant reactor, and the entire contents were stirred at 65°C for 3 hours to carry out ring-opening polymerization. The polymerization conversion rate of the resulting ring-opening polymer was 96%, and the weight-average molecular weight of the resulting cyclic olefin ring-opening polymer was 21,100. The resulting polymerization reaction solution was then placed in an autoclave and stirred at 150°C and a hydrogen pressure of 4.5 MPa for 6 hours to carry out a hydrogenation reaction. The solution was filtered through a radiolite-precoated funnel to obtain a hydrogenated cyclic olefin ring-opening polymer. The hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds in the resulting hydrogenated cyclic olefin ring-opening polymer was 90.0% or higher. Furthermore, the hydrogenation rate of aromatic carbon-carbon unsaturated bonds in the resulting hydrogenated cyclic olefin ring-opening polymer was 0%. Next, 100 parts of the obtained hydrogenated cyclic olefin ring-opening polymer was mixed with 1 part of an antioxidant (tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane; "Irganox (registered trademark) 1010" manufactured by BASF Japan Ltd.) to obtain a resin composition containing a hydrogenated cyclic olefin ring-opening polymer. The obtained resin composition was then charged into a twin-screw extruder ("TEM-37B" manufactured by Toshiba Machine Co., Ltd.) equipped with four die holes with an inner diameter of 3 mm. The resin composition was then hot-melt extruded using the twin-screw extruder to form a strand-shaped molded body. This molded body was shredded with a strand cutter to obtain dried resin pellets. The operating conditions of the twin-screw extruder are as follows.- Barrel set temperature: 270°C to 280°C - Die set temperature: 250°C - Screw rotation speed: 145 rpm - Feeder rotation speed: 50 rpm.

[0080] Example 2 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, a resin composition, and resin pellets were produced in the same manner as in Example 1, except that 70 parts of N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBXI") was used instead of 60 parts of NBDII as the norbornene imide monomer represented by formula (1), and the amount of DCL was changed from 40 parts to 30 parts. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0081] Example 3 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 1, except that the amount of NBDII was changed from 60 parts to 90 parts and the amount of DCL was changed from 40 parts to 10 parts. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0082] Example 4 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 2, except that the amount of NBXI was changed from 70 parts to 50 parts and the amount of DCL was changed from 30 parts to 50 parts. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0083] Example 5 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 1, except that 60 parts of N-2-methylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBTI") was used instead of 60 parts of NBDII as the norbornene imide monomer represented by formula (1), the amount of DCL was changed from 40 parts to 20 parts, and 20 parts of 2-ethylidene-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (hereinafter sometimes abbreviated as "ETD") was used in addition to DCL as the cyclic olefin monomer not having a polar group. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0084] Example 6 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 1, except that in Example 5, the amount of NBTI was changed from 60 parts to 75 parts, the amount of ETD was changed from 20 parts to 25 parts, and the amount of 1-hexene was changed from 2.5 parts to 1.0 part, and no DCL was used. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0085] Example 7 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 4, except that the amount of NBXI was changed from 50 parts to 49 parts, the amount of DCL was changed from 50 parts to 51 parts, and the amount of 1-hexene was changed from 2.5 parts to 2.0 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0086] Example 8 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 7, except that the amount of NBXI was changed from 49 parts to 60 parts, the amount of DCL was changed from 51 parts to 40 parts, and the amount of 1-hexene was changed from 2.0 parts to 0.5 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0087] Example 9 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 7, except that the amount of NBXI was changed from 49 parts to 60 parts, the amount of DCL was changed from 51 parts to 40 parts, and the amount of 1-hexene was changed from 2.0 parts to 0.25 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0088] Example 10 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 7, except that the amount of NBXI was changed from 49 parts to 56 parts, the amount of DCL was changed from 51 parts to 44 parts, and the amount of 1-hexene was changed from 2.0 parts to 0.24 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0089] Example 11 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 7, except that the amount of NBXI was changed from 49 parts to 56 parts, the amount of DCL was changed from 51 parts to 44 parts, and the amount of 1-hexene was changed from 2.0 parts to 0.18 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0090] Example 12 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 7, except that the amount of NBXI was changed from 49 parts to 56 parts, the amount of DCL was changed from 51 parts to 44 parts, and the amount of 1-hexene was changed from 2.0 parts to 0.1 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0091] Comparative Example 1 A cyclic olefin ring-opening polymer was produced in the same manner as in Example 1, except that the amount of NBDII was changed from 60 parts to 100 parts and DCL was not used. Since the polymerization reaction solution containing the cyclic olefin ring-opening polymer contained precipitates, it was not possible to measure the weight average molecular weight or to hydrogenate the cyclic olefin ring-opening polymer. Therefore, various measurements and evaluations could not be performed.

[0092] Comparative Example 2 A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 1, except that 60 parts of NBDII and 40 parts of DCL in Example 1 were replaced with 100 parts of ETD as a cyclic olefin monomer not having a polar group. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0093] Comparative Example 3 In Example 6, 75 parts of NBTI as the norbornene imide monomer represented by formula (1) was replaced with a norbornene imide monomer having a phenyl group bonded to the imide ring (i.e., R １ and R ５ A cyclic olefin ring-opening polymer, a hydrogenated cyclic olefin ring-opening polymer, and resin pellets were produced in the same manner as in Example 6, except that 75 parts of N-phenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBPI"), which is a norbornene imide monomer in which both are hydrogen atoms, were used and the amount of 1-hexene blended was changed from 1.0 part to 0.75 part. Various measurements and evaluations were then carried out. The results are shown in Table 1.

[0094] Table 1 shows that the hydrogenated cyclic olefin ring-opening polymers of Examples 1 to 12, which contain the structural unit (A) derived from the norbornene imide monomer represented by formula (1) and the structural unit (B) derived from a cyclic olefin monomer having no polar group, have both a moderately large Abbe number and a low birefringence. On the other hand, Table 1 shows that the hydrogenated cyclic olefin ring-opening polymer of Comparative Example 2, which does not contain the structural unit (A) derived from the norbornene imide monomer represented by formula (1), has an excessively large Abbe number and a high birefringence. Table 1 also shows that the hydrogenated cyclic olefin ring-opening polymer of Comparative Example 3, which contains a structural unit derived from a norbornene imide monomer in which a phenyl group having no substituents at both ortho positions is bonded to the imide ring instead of the structural unit (A) derived from the norbornene imide monomer represented by formula (1), has a moderate Abbe number but a high birefringence.

[0095] According to the present invention, it is possible to provide a hydrogenated cyclic olefin ring-opening polymer having both a moderate Abbe number and a low birefringence, and a raw material thereof. Furthermore, according to the present invention, it is possible to provide a resin composition that can be advantageously used as a material for various molded articles such as optical elements, and a resin molded article formed using the resin composition.

Claims

1. A cyclic olefin ring-opening polymer comprising a structural unit (A) derived from a norbornene imide monomer represented by the following formula (1) and a structural unit (B) derived from a cyclic olefin monomer having no polar group: In formula (1), A represents an alkyl group, a cycloalkyl group, an alkoxy group, or an aryl group which may have a substituent (excluding a phenyl group which has no substituents at either of the two ortho positions relative to the imide ring to which it is bonded).

2. The cyclic olefin ring-opening polymer according to claim 1, wherein the structural unit (A) is a structural unit derived from a norbornene imide monomer represented by the following formula (2): (In formula (2), R １ ~R ５ each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted alkoxy group, an optionally substituted aromatic hydrocarbon ring group, or an optionally substituted aromatic heterocyclic group; R １ ~R ５ may be bonded to form a ring. １ and R ５ At least one of the is not a hydrogen atom.) 3. The cyclic olefin ring-opening polymer according to claim 1, wherein the content of the structural unit (A) is 50% by mass or more and 90% by mass or less.

4. The cyclic olefin ring-opening polymer according to claim 1, wherein the structural unit (B) comprises a structural unit derived from deltacyclene.

5. A hydrogenated cyclic olefin ring-opening polymer obtained by hydrogenating the cyclic olefin ring-opening polymer according to claim 1.

6. The hydrogenated cyclic olefin ring-opening polymer according to claim 5, having an Abbe number of less than 50.

7. The hydrogenated cyclic olefin ring-opening polymer according to claim 5, having a glass transition temperature of 120° C. or higher.

8. A resin composition comprising the hydrogenated cyclic olefin ring-opening polymer according to any one of claims 5 to 7.

9. A resin molded product obtained by molding the resin composition according to claim 8.