Cyclic olefin copolymer, cyclic olefin copolymer hydride, resin composition, and resin molded article

Abstract

A cyclic olefin copolymer according to the present invention 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 norbornene monomer represented by formula (2). Further, a cyclic olefin copolymer hydride according to the present invention is characterized by being formed by hydrogenating this cyclic olefin copolymer. (In formula (1), R1-R5 are as defined in the description.) (In formula (2), L and R6-R8 are as defined in the description.)

Description

Cyclic olefin copolymers, cyclic olefin copolymer hydrides, resin compositions, and resin molded articles

[0001] The present invention relates to cyclic olefin copolymers, cyclic olefin copolymer hydrides, resin compositions, and resin molded articles.

[0002] Cyclic olefin polymer hydrides, obtained by hydrogenating cyclic olefin polymers resulting from the polymerization of cyclic olefin monomers, are widely used as molding materials for optical elements such as optical lenses due to their excellent transparency, low moisture absorption, heat resistance, insulation, and chemical resistance. Therefore, in recent years, various proposals have been made to improve the physical properties of cyclic olefin polymer hydrides.

[0003] For example, Patent Document 1 discloses alicyclic polymers and alicyclic polymer hydrides containing at least one polymerization unit represented by a predetermined formula. Patent Document 1 also states that these alicyclic polymers and alicyclic polymer hydrides have excellent low birefringence while retaining the good optical properties such as transparency, heat resistance, chemical resistance, electrical properties, and low water absorption of ordinary alicyclic polymers.

[0004] Japanese Patent Publication No. 2006-52326

[0005] In recent years, with the improvement of the performance of optical elements such as optical lenses, there has been an increasing demand to reduce the birefringence of cyclic olefin copolymer hydrides used as molding materials for manufacturing optical elements. Furthermore, in recent years, from the perspective of increasing the freedom of optical design, there has been a demand for the development of cyclic olefin copolymer hydrides with low Abbe numbers (e.g., 25 to 40) as molding materials for optical elements, in addition to cyclic olefin copolymer hydrides with medium to high Abbe numbers (e.g., above 40). However, the conventional alicyclic structural polymers and alicyclic structural polymer hydrides described above had room for improvement in achieving both a low Abbe number and low birefringence.

[0006] Therefore, the present invention aims to provide a cyclic olefin copolymer hydride having both a low Abbe number and low birefringence, and a raw material for the same. The present invention also aims 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.

[0007] The inventors diligently conducted research with the aim of solving the above problems. As a result, the inventors newly discovered that a cyclic olefin copolymer hydride obtained by hydrogenating a cyclic olefin copolymer containing a structural unit derived from a norbornene imide monomer having a predetermined structure and a structural unit derived from a norbornene monomer containing an aromatic hydrocarbon ring can achieve both a low Abbe number and reduced birefringence, and thus completed the present invention.

[0008] In other words, the present invention aims to advantageously solve the above problems, and the present invention is a cyclic olefin copolymer comprising [1] a structural unit (A) derived from a norborneneimide monomer represented by the following formula (1) and a structural unit (B) derived from a norbornene monomer represented by the following formula (2). (In formula (1), 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 these may be joined together to form a ring.) (In formula (2), R ６ R represents a group containing an aromatic hydrocarbon ring. ７ and R ８each independently represent a hydrogen atom, a halogen atom, or an optionally substituted hydrocarbon group (excluding those containing an aromatic hydrocarbon ring), and L represents a single bond or a linking group. As described above, a cyclic olefin copolymer comprising a structural unit derived from a norbornene imide monomer having the predetermined structure and a structural unit derived from a norbornene monomer having the predetermined structure containing an aromatic hydrocarbon ring can be advantageously used as a raw material for a hydrogenated ring-opened cyclic olefin polymer that can achieve both a low Abbe number (for example, 25 or more and 40 or less) and reduced birefringence.

[0009] [2] In the cyclic olefin copolymer according to [1] above, the content of the structural unit (A) is preferably 45% by mass or more and 85% by mass or less. When the content of the structural unit (A) is not less than the above lower limit, the birefringence of the hydrogenated cyclic olefin copolymer obtained by hydrogenating the cyclic olefin copolymer can be further reduced, and the solubility of the hydrogenated cyclic olefin copolymer can be improved. In the present invention, the "content of structural units" is １ 1H-NMR and １３ 13C-NMR can be measured using nuclear magnetic resonance (NMR) methods such as these.

[0010] [3] In the cyclic olefin copolymer according to [1] or [2] above, R in formula (1) １ and R ５ at least one of is preferably an optionally substituted alkyl group having 1 to 6 carbon atoms. R in formula (1) １ and R ５ when at least one is an optionally substituted alkyl group having 1 to 6 carbon atoms, the birefringence of the hydrogenated cyclic olefin copolymer obtained by hydrogenating the cyclic olefin copolymer can be further reduced.

[0011] [4] In the cyclic olefin copolymer according to any one of [1] to [3] above, L in formula (2) is preferably a single bond. When L in formula (2) is a single bond, a target polymer can be polymerized without inhibiting polymerization.

[0012] [5] In any of the above [1] to [4] cyclic olefin copolymers, R in formula (2) ６ It is preferable that R in formula (2) is a group containing an aromatic hydrocarbon ring that is either unsubstituted or has a nonpolar group as a substituent. ６ If the group contains an aromatic hydrocarbon ring group that is either unsubstituted or has a nonpolar group as a substituent, the water absorption of the cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer can be increased.

[0013] [6] In any of the above [1] to [5] cyclic olefin copolymers, R in formula (2) ６ R in formula (2) is preferably a phenyl group. ６ If the group is a phenyl group, the Abbe number and birefringence of the cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer can be further reduced.

[0014] [7] Preferably, any of the cyclic olefin copolymers described in [1] to [6] above is a ring-opened polymer. If the cyclic olefin copolymer is a ring-opened copolymer, the Abbe number and birefringence of the cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer can be further reduced.

[0015] Furthermore, this invention aims to advantageously solve the above problems, and the present invention is a cyclic olefin copolymer hydride obtained by hydrogenating any of the cyclic olefin copolymers of [1] to [7] above. The cyclic olefin copolymer hydride obtained by hydrogenating the above cyclic olefin copolymer has both a low Abbe number (for example, 25 or more and 40 or less) and low birefringence.

[0016] [9] The cyclic olefin copolymer hydride described in [8] above preferably has a weight-average molecular weight of 50,000 or more and 150,000 or less. If the weight-average molecular weight of the cyclic olefin ring-opening polymer hydride is above the lower limit, it is possible to suppress the decrease in strength of the resin molded article obtained using the cyclic olefin ring-opening polymer hydride. Furthermore, if the weight-average molecular weight of the cyclic olefin ring-opening polymer hydride is below the upper limit, it is possible to suppress the occurrence of molding defects caused by deterioration of fluidity during molding of the cyclic olefin ring-opening polymer hydride. In this invention, the "weight-average molecular weight" can be measured by the method described in the examples.

[0017]

[10] The cyclic olefin copolymer hydride described in [8] or [9] above preferably has a glass transition temperature of 130°C or higher and 160°C or lower. If the glass transition temperature of the cyclic olefin ring-opening polymer hydride is above the lower limit, deterioration of heat resistance and deterioration of the optical properties of the resin molded article due to thermal deformation can be suppressed. Furthermore, if the glass transition temperature of the cyclic olefin ring-opening polymer hydride is below the upper limit, the occurrence of oxidative degradation of the cyclic olefin ring-opening polymer hydride caused by excessively high processing temperatures when molding the cyclic olefin ring-opening polymer hydride can be suppressed. In this invention, the "glass transition temperature" can be measured by the method described in the examples.

[0018]

[11] The cyclic olefin copolymer hydride of any of the above [8] to

[10] is preferably 25 or more and 40 or less in Abbe number. If the Abbe number is 40 or less, the cyclic olefin copolymer hydride can be suitably used for optical element applications other than those with medium to high Abbe numbers. In this invention, the "Abbe number" can be measured by the method described in the examples.

[0019]

[12] The cyclic olefin copolymer hydride of any of the above [8] to

[11] is preferably such that the melt index is 15 g / 10 min or more and 65 g / 10 min or less. If the melt index is above the lower limit, the increase in birefringence due to low fluidity during molding can be suppressed. If it is below the upper limit, the deterioration of moldability due to excessively high fluidity can be suppressed. In this invention, the "melt index" can be measured by the method described in the examples.

[0020] Furthermore, this invention aims to advantageously solve the above problems, and the present invention is a resin composition comprising any of the cyclic olefin copolymer hydrides described in [8] to

[12] above. A resin composition comprising any of the above-described cyclic olefin copolymer hydrides can be advantageously used as a material for various molded articles such as optical elements.

[0021] Furthermore, this invention aims to advantageously solve the above problems, and the present invention is a resin molded article formed by molding the resin composition of

[13] above. A resin molded article formed using the above-mentioned resin composition can exhibit excellent performance.

[0022]

[15] The resin molded body described in

[14] above is preferably an optical element. The resin molded body described above can exhibit excellent performance as an optical element.

[0023] According to the present invention, it is possible to provide a cyclic olefin copolymer hydride having both a low Abbe number and low birefringence, and a raw material for the same. 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.

[0024] Embodiments of the present invention will be described in detail below. Here, the cyclic olefin copolymer of the present invention can be suitably used, for example, as a raw material for the cyclic olefin copolymer hydride of the present invention. The cyclic olefin copolymer hydride of the present invention has a low 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 manufacturing the resin molded article of the present invention. Moreover, the resin molded article of the present invention can be suitably used as an optical element such as an optical film, a lens for a photographic device such as a camera, or a lens for a mobile phone or smartphone.

[0025] (Cyclic Olefin Copolymer) The cyclic olefin copolymer of the present invention can be obtained, for example, by polymerizing (addition polymerization or ring-opening polymerization) a monomer composition containing a predetermined cyclic olefin compound (monomer) in the presence of a polymerization catalyst. The cyclic olefin copolymer of the present invention comprises a structural unit (A) derived from a predetermined norbornene imide monomer and a structural unit (B) derived from a predetermined norbornene monomer, and may optionally further contain other structural units.

[0026] Here, the cyclic olefin copolymer of the present invention may be either an addition copolymer or a ring-opening copolymer, but from the viewpoint of further reducing the Abbe number and birefringence of the resulting cyclic olefin copolymer hydride, it is preferable to use a ring-opening copolymer.

[0027] Furthermore, the cyclic olefin copolymer of the present invention may be either a block copolymer or a random copolymer.

[0028] <Structural unit (A) derived from norborneneimide monomer> Structural unit (A) derived from norborneneimide monomer (hereinafter sometimes abbreviated as structural unit (A)) is a structural unit derived from norborneneimide monomer represented by the following formula (1). (In formula (1), 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 these may be joined together to form a ring.)

[0029] Here, R １ ~R ５ The halogen atoms that can constitute it are not particularly limited, and include chlorine atoms, fluorine atoms, bromine atoms, iodine atoms, and the like.

[0030] R １ ~R ５The alkyl group that may have substituents is not particularly limited, and examples include alkyl groups having 1 to 10 carbon atoms that may have substituents. The alkyl group having 1 to 10 carbon atoms that may have substituents can be linear or branched, and examples include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, neopentyl group, hexyl group, octyl group, nonyl group, and decyl group. Among these, alkyl groups having 1 to 6 carbon atoms are preferred, isopropyl group and methyl group are more preferred, and isopropyl group is even more preferred. Specific examples of substituents in "alkyl groups having 1 to 10 carbon atoms that may have substituents" include, for example, halogen atoms such as chlorine, fluorine, bromine, and iodine; cyano groups; nitro groups; unsubstituted alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, and propyl groups; unsubstituted alkenyl groups having 2 to 6 carbon atoms such as vinyl and allyl groups; alkyl groups having 1 to 10 carbon atoms in which one or more hydrogen atoms are substituted with halogen atoms such as fluorine, such as trifluoromethyl groups; alkoxy groups having 1 to 10 carbon atoms such as methoxy, ethoxy, and isopropoxy groups; and so on. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0031] R １ ~R ５The cycloalkyl group that may have substituents is not particularly limited and includes cycloalkyl groups having 3 to 12 carbon atoms that may have substituents. Examples of cycloalkyl groups having 3 to 12 carbon atoms that may have substituents include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. Specific examples of substituents for the cycloalkyl group that may have substituents are the same substituents that the above-mentioned cycloalkyl group that may have substituents can have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0032] R １ ~R ５ The alkenyl group which may have substituents is not particularly limited and includes alkenyl groups having 2 to 10 carbon atoms which may have substituents. The alkenyl group having 2 to 10 carbon atoms which may have substituents may be linear or branched and include, for example, vinyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, and decenyl group. Specific examples of substituents for the alkenyl group having 2 to 10 carbon atoms which may have substituents are the same as those for the alkyl group having 1 to 10 carbon atoms which may have substituents as described above. The number of substituents may be one or multiple. If there are multiple substituents, they may be the same or different from each other.

[0033] R １ ~R ５The alkynyl group which may have substituents is not particularly limited and includes alkynyl groups having 2 to 10 carbon atoms which may have substituents. The alkynyl group having 2 to 10 carbon atoms which may have substituents may be linear or branched and include, for example, ethynyl group, propynyl group, 2-propynyl group (propargyl group), butynyl group, 2-butynyl group, 3-butynyl group, pentynyl group, 2-pentynyl group, hexynyl group, 5-hexynyl group, heptynyl group, octinyl group, 2-octinyl group, nonanyl group, decanyl group, 7-decanyl group, etc. Specific examples of substituents for the alkynyl group which may have substituents are the same as the substituents that the alkyl group which may have substituents which may have substituents. The number of substituents may be one or multiple. If there are multiple substituents, they may be identical or different from one another.

[0034] R １ ~R ５ The alkoxy group that may have substituents is not particularly limited and includes alkoxy groups having 1 to 10 carbon atoms that may have substituents. The alkoxy group having 1 to 10 carbon atoms in the "alkoxy group having 1 to 10 carbon atoms that may have substituents" may be linear or branched, and examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, and octoxy groups. Specific examples of substituents in the "alkoxy group having 1 to 10 carbon atoms that may have substituents" include the same substituents that the above-mentioned "alkyl group having 1 to 10 carbon atoms that may have substituents" may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0035] R １ ~R ５The aromatic hydrocarbon ring group that may have substituents is not particularly limited and includes aromatic hydrocarbon ring groups having 6 to 30 carbon atoms that may have substituents. Examples of aromatic hydrocarbon ring groups having 6 to 30 carbon atoms that may have substituents include phenyl groups, naphthyl groups, anthracenyl groups, etc. Specific examples of substituents in the aromatic hydrocarbon ring group having 6 to 30 carbon atoms that may have substituents are the same substituents that the alkyl group having 1 to 10 carbon atoms that may have substituents described above may have. The number of substituents may be one or more. If there are multiple substituents, they may be the same or different from each other.

[0036] R １ ~R ５ The aromatic heterocyclic groups that may have substituents are not particularly limited and include aromatic heterocyclic groups having 6 to 30 carbon atoms that may have substituents. Examples of aromatic hydrocarbon ring groups having 6 to 30 carbon atoms in the "aromatic heterocyclic groups having 6 to 30 carbon atoms that may have substituents" include furanyl group, 1-benzofuranyl group, 2-benzofuranyl group, pyrrolyl group, indolyl group, thienyl group, benzo[c]thienyl group, benzo[b]thienyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, triazolyl group, triazinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzothiazolyl group, oxazolyl group, and benzoxazolyl group. Specific examples of substituents in the "aromatic heterocyclic groups having 6 to 30 carbon atoms that may have substituents" include the same substituents that the above-mentioned "alkyl groups having 1 to 10 carbon atoms that may have substituents" may have. The number of substituents may be one or multiple. If there are multiple substituents, they may be identical or different from one another.

[0037] R １ ~R ５ The ring formed by the bonding of two or more of these elements may be monocyclic or polycyclic. １ ~R ５The ring formed by the bonding of two or more of these is not particularly limited and includes aromatic hydrocarbon rings, aromatic heterocycles, non-aromatic hydrocarbon rings, and polycyclic fused rings formed by the condensation of two or more of these rings. Specific examples of the aromatic hydrocarbon rings and aromatic heterocycles are the same as those described above for "aromatic hydrocarbon ring groups" and "aromatic heterocycles." Specific examples of non-aromatic hydrocarbon rings include cycloalkyl rings having 3 to 12 carbon atoms, such as cyclopropyl rings, cyclobutyl rings, cyclopentyl rings, cyclohexyl rings, and cyclooctyl rings.

[0038] In particular, from the viewpoint of further reducing the birefringence of the resulting cyclic olefin copolymer hydride, the norborneneimide monomer represented by formula (1) is R in formula (1). １ ~R ５ A compound in which one or more of the atoms are not hydrogen atoms is preferred, and R in formula (1) １ ~R ５ A compound in which one or more of the elements is an alkyl group having 1 to 6 carbon atoms which may have substituents is more preferred, and R in formula (1) １ and R ５ It is even more preferable that at least one of the compounds is an alkyl group having 1 to 6 carbon atoms which may have substituents, and R in formula (1) １ and R ５ It is particularly preferable that both are compounds in which "alkyl groups having 1 to 6 carbon atoms that may have substituents." Furthermore, the aforementioned "alkyl groups having 1 to 6 carbon atoms that may have substituents" are preferably methyl groups or isopropyl groups, and more preferably isopropyl groups.

[0039] Furthermore, from the viewpoint of further reducing the birefringence of the resulting cyclic olefin copolymer hydride, the norborneneimide monomer represented by formula (1) is R in formula (1). １ ~R ５ A compound in which one or more of the atoms are "alkyl groups having 1 to 6 carbon atoms which may have substituents" and the rest are hydrogen atoms is preferred, and R in formula (1) １ and R ５A compound in which at least one of is an alkyl group having 1 to 6 carbon atoms which may have substituents, and the rest are hydrogen atoms, is more preferable, and R in formula (1) １ and R ５ A compound in which at least one of the atoms is a methyl group or an isopropyl group and the rest are hydrogen atoms is even more preferred, and R in formula (1) １ and R ５ Compounds in which both are methyl or isopropyl groups and the remainder is a hydrogen atom are even more preferred, and R in formula (1) １ and R ５ Compounds in which both are isopropyl groups and the remainder is a hydrogen atom (i.e., N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide) are particularly preferred.

[0040] On the other hand, from the viewpoint of increasing the solubility of the resulting cyclic olefin copolymer hydride, the norborneneimide monomer represented by formula (1) is R in formula (1). ３ A compound in which R is "an alkyl group having 1 to 6 carbon atoms which may have substituents" is preferred, and R in formula (1) ３ Compounds in which the group is an ethyl group or an isopropyl group are more preferred.

[0041] Furthermore, from the viewpoint of improving the solubility of the resulting cyclic olefin copolymer hydride, the norborneneimide monomer represented by formula (1) is R in formula (1). ３ The compound is preferably one in which R is an alkyl group having 1 to 6 carbon atoms, which may have substituents, and the rest are hydrogen atoms. ３ A compound in which one of the groups is an ethyl group or an isopropyl group, with the remainder being hydrogen atoms, is more preferable.

[0042] The norborneneimide monomers mentioned above may be used individually or in combination of two or more.

[0043] [Content Ratio] The content ratio of structural unit (A) is preferably 10% by mass or more, more preferably 25% by mass or more, even more preferably 45% by mass or more, even more preferably 50% by mass or more, particularly preferably 65% ​​by mass or more, and also preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. If the content ratio of structural unit (A) is within the above predetermined range, the solubility can be increased while further reducing the birefringence of the resulting cyclic olefin copolymer hydride.

[0044] <Structural Unit (B) Derived from Norborneneimide Monomer> The norborneneimide monomer that can form structural unit (B) derived from norborneneimide monomer (hereinafter sometimes abbreviated as structural unit (B)) is a monomer (compound) represented by the following formula (2), and is characterized by having a group containing an aromatic hydrocarbon ring. The presence of an aromatic hydrocarbon ring in structural unit (B) can sufficiently reduce the Abbe number of the resulting cyclic olefin copolymer hydride. (In formula (2), L represents a single bond or linking group, R ６ R represents a group containing an aromatic hydrocarbon ring. ７ and R ８ Each of these independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group which may have substituents (excluding those containing aromatic hydrocarbon rings; the same applies hereinafter).

[0045] Here, the linking group represented by L is not particularly limited as long as it is divalent, for example, alkylene groups (alkylene groups with 1 to 12 carbon atoms, etc.), -NH-, -SO-, -SO ２ Examples include -, -CO-, -O-, -COO-, OCO-, -S-, and groups formed by combining two or more of these. Note that, from the viewpoint of polymerizability, L must be a single bond (i.e., R ６ It is preferable that it is directly bonded to the norbornene skeleton.

[0046] Also, R ６The "groups containing aromatic hydrocarbon rings" that can constitute the compound are not particularly limited and include, for example, aromatic hydrocarbon ring groups which may have substituents, groups formed by the condensation of two or more such aromatic hydrocarbon ring groups, groups formed by the bonding of two or more such aromatic hydrocarbon ring groups via linking groups, and groups formed by combining two or more of these.

[0047] The above-mentioned "aromatic hydrocarbon ring group which may have substituents" is R １ ~R ５ Examples of possible constituents include those similar to the "optionally substituted aromatic hydrocarbon ring group". Furthermore, examples of substituents for the "optionally substituted aromatic hydrocarbon ring group" include those same as those that the above-mentioned "optionally substituted alkyl group having 1 to 10 carbon atoms" may have. In particular, from the viewpoint of increasing the water absorption of the resulting cyclic olefin copolymer hydride, it is preferable that the substituent be a nonpolar group such as an unsubstituted alkyl group having 1 to 10 carbon atoms or an unsubstituted alkenyl group having 2 to 6 carbon atoms. Here, the number of substituents that the aromatic hydrocarbon ring group may have may be one or more. If there are multiple substituents, they may be the same as or different from each other. Furthermore, examples of the above-mentioned linking group include those similar to the linking group that constitutes L.

[0048] Here, R ６ The number of aromatic hydrocarbon rings is not particularly limited, but from the viewpoint of further reducing the Abbe number of the resulting cyclic olefin copolymer hydride, ６ The number of aromatic hydrocarbon rings present is preferably one or more, and more preferably two or more. On the other hand, from the viewpoint of suppressing the increase in birefringence of the resulting cyclic olefin copolymer hydride, R ６ The number of aromatic hydrocarbon rings present is preferably four or less, and more preferably three or less.

[0049] Among them, R ６As for , from the viewpoint of further reducing the Abbe number and birefringence of the obtained cyclic olefin copolymer hydride, it is preferably an aromatic hydrocarbon cyclic group having 6 to 30 carbon atoms which may have a substituent, more preferably a phenyl group or a naphthyl group which may have a substituent, and still more preferably a phenyl group which may have a substituent. Further, from the viewpoint of further reducing the Abbe number and birefringence while increasing the water absorption of the obtained cyclic olefin copolymer hydride, R ６ is preferably an aromatic hydrocarbon cyclic group having 6 to 30 carbon atoms which has no substituent or has a non-polar group as a substituent, more preferably a phenyl group or a naphthyl group, and still more preferably a phenyl group.

[0050] Further, R ７ and R ８ examples of the halogen atom that can constitute include the same halogen atoms as those that can constitute R １ to R ５ described above.

[0051] Further, R ７ and R ８ The "hydrocarbon group which may have a substituent" that can constitute is not particularly limited, and includes the alkyl group having 1 to 10 carbon atoms in the "alkyl group which may have a substituent" that can constitute R １ to R ５ described above, the cycloalkyl group having 3 to 10 carbon atoms in the "cycloalkyl group which may have a substituent" that can constitute R １ to R ５ described above, the alkenyl group having 2 to 10 carbon atoms in the "alkenyl group which may have a substituent" that can constitute R １ to R ５ described above, the alkynyl group having 2 to 10 carbon atoms in the "alkynyl group which may have a substituent" that can constitute R １ to R ５ described above. Further, R ７ and R ８The substituents of the "optionally substituted hydrocarbon group" that can constitute are not particularly limited, and examples include the same substituents that may be possessed by the aforementioned "alkyl group having 1 to 10 carbon atoms which may have a substituent". Here, the number of substituents may be one or may be two or more. When having a plurality of substituents, they may be the same as or different from each other.

[0052] R ７ is preferably a group other than a hydrogen atom (that is, a halogen atom, or an optionally substituted hydrocarbon group) from the viewpoint of improving the heat resistance of the obtained hydrogenated cyclic olefin copolymer, and is more preferably an optionally substituted hydrocarbon group from the viewpoint of further reducing the birefringence of the obtained hydrogenated cyclic olefin copolymer while improving heat resistance, and a methyl group is even more preferred.

[0053] In addition, R ８ is preferably a hydrogen atom, a halogen atom, or an optionally substituted hydrocarbon group (excluding those containing an aromatic hydrocarbon ring) from the viewpoint of moldability, and a hydrogen atom is more preferred.

[0054] From the viewpoint of further reducing birefringence while imparting a lower Abbe number to the obtained hydrogenated cyclic olefin copolymer, as the norbornene monomer represented by formula (2), in formula (2), L is a single bond, and R ６ is an optionally substituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, and R ７ and R ８ are each a hydrogen atom or an optionally substituted hydrocarbon group; compounds satisfying the above are preferred. In formula (2), compounds where L is a single bond, R ６ is a phenyl group or a naphthyl group, and R ７ and R ８ are both hydrogen atoms (that is, phenylnorbornene or naphthylnorbornene) are more preferred, and phenylnorbornene is even more preferred.

[0055] The norbornene monomers described above may be used alone singly, or may be used in combination of two or more thereof.

[0056] [Content Ratio] The content ratio of structural unit (B) is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, particularly preferably 35% by mass or more, and also preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, when the content ratio of all repeating units contained in the cyclic olefin copolymer is taken as 100% by mass. If the content ratio of structural unit (B) is above the lower limit above, the Abbe number of the obtained cyclic olefin copolymer hydride can be further reduced. Also, if the content ratio of structural unit (B) is below the upper limit above, the deterioration of the heat resistance of the obtained cyclic olefin copolymer hydride can be suppressed.

[0057] <Other Structural Units> Other structural units that the cyclic olefin copolymer may optionally contain are not limited to structural units other than structural units (A) and structural unit (B) described above, as long as they do not impair the effects of the present invention. Other structural units are not limited to, but include structural units derived from cyclic olefin compounds that do not have an aromatic ring structure.

[0058] The cyclic olefin compounds that lack an aromatic ring structure and can form structural units derived from such compounds are not particularly limited and include, for example, norbornene compounds that lack an aromatic ring structure and non-norbornene compounds that lack an aromatic ring structure.

[0059] Norbornene compounds that do not have an aromatic ring structure are not particularly limited, for example, tetracyclo[6.2.1.1 ３，６ . 0 ２，７ ] Dodeca-4-ene (common name: tetracyclododecene), 2-ethylidene-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (common name: ethylidenetetracyclododecene), tricyclo[5.2.1.0 2,6Deca-3,8-diene (common name: dicyclopentadiene), 5-ethylidenebicyclo[2.2.1]hept-2-ene (common name: ethylidenenorbornene), bicyclo[2.2.1]hept-2-ene (also called "norbornene"), 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-methylidene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, tetracyclo[10.2.1.0 2,11 . 0 4,9 ]Pentadeca-4,6,8,13-tetraene,9-methyltetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, 9-ethyl-tetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, 9-methylidene-tetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, 9-ethylidene-tetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, 9-vinyl-tetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, 9-propenyl-tetracyclo[6.2.1.1 3,6 . 0 2,7 ] Dodeca-4-ene, pentacyclo[9.2.1.1 3,9 . 0 2,10 . 0 4,8 ] Pentadeca-5,12-diene, tetracyclo[9.2.1.0 2,10 . 0 3,8 ] Tetradeca-3,5,7,12-tetraene, pentacyclo[9.2.1.1 3,9 . 0 2,10 . 0 4,8Examples include pentadeca-12-ene and derivatives thereof. A derivative refers to one that has substituents in its ring structure. The substituents that may be present in the ring structure are not particularly limited as long as they do not have an aromatic ring structure, and examples include alkyl groups, alkylene groups, vinyl groups, alkoxycarbonyl groups, and alkylidene groups. The ring structure of a derivative may have one of these substituents or two or more.

[0060] Furthermore, non-norbornene compounds that do not have an aromatic ring structure are not particularly limited and include, for example, cycloalkenes such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, 1,4-cyclooctadiene, and cyclodecene.

[0061] The cyclic olefin compounds that do not have the aromatic ring structure described above may be used individually or in combination of two or more.

[0062] [Content Ratio] The proportion of other structural units (total proportion of other structural units) within the total structural units (100% by mass) of the cyclic olefin ring-opening polymer is usually between 0% by mass and 60% by mass.

[0063] <Mass ratio of structural unit (A) to structural unit (B)> From the viewpoint of imparting an even lower Abbe number to the resulting cyclic olefin copolymer hydride and further reducing birefringence, the mass ratio of structural unit (A) to structural unit (B) in the cyclic olefin copolymer (structural unit (A) / structural unit (B)) is preferably 1 or more, more preferably 1.2 or more, preferably 2.4 or less, and more preferably 2 or less.

[0064] <Method for Producing Cyclic Olefin Copolymers> The cyclic olefin copolymer described above can be obtained by addition polymerization or ring-opening polymerization of a monomer composition (mixture) containing the various monomers described above in the section on "Cyclic Olefin Copolymers". Specifically, when obtaining a cyclic olefin copolymer as an addition copolymer, the cyclic olefin copolymer can be prepared by addition polymerization of the monomer composition using a known addition polymerization method, such as addition polymerization using an addition polymerization catalyst. When obtaining a cyclic olefin copolymer as a ring-opening copolymer, the cyclic olefin copolymer can be prepared by ring-opening polymerization of the monomer composition using a known ring-opening polymerization method, such as ring-opening polymerization using a metathesis polymerization catalyst.

[0065] Here, there are no particular limitations on the addition polymerization catalyst, and any known catalyst can be used. For example, a catalyst consisting of a titanium, zirconium, or vanadium compound and an organoaluminum compound can be used.

[0066] Furthermore, there are no particular limitations on the metathesis polymerization catalyst, and known catalysts can be used. Specifically, for example, catalyst systems consisting of a metal halide, nitrate, or acetylacetone compound selected from ruthenium, rhodium, palladium, osmium, iridium, and platinum, and a reducing agent; catalyst systems consisting of a metal halide or acetylacetone compound selected from titanium, vanadium, zirconium, tungsten, and molybdenum, and an organoaluminum compound as a co-catalyst; or, as described in Japanese Patent Publication No. 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 1996, 118, 100, can be used. These catalysts can be used individually or in combination of two or more. The amount of catalyst used should be appropriately selected depending on the polymerization conditions, etc.

[0067] Polymerization reactions may be carried out by bulk polymerization without a solvent, or in a solvent such as an organic solvent. There are no particular restrictions on the solvent as long as it is inert to the polymerization reaction, but examples 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-based solvents such as tetrahydrofuran and ethylene glycol dimethyl ether.

[0068] Polymerization conditions such as polymerization temperature, polymerization pressure, and polymerization time can be adjusted as appropriate.

[0069] (Hydrogenated Cyclic Olefin Copolymer) The hydrogenated cyclic olefin copolymer of the present invention is obtained by hydrogenating the above-mentioned hydrogenated cyclic olefin copolymer of the present invention as a raw material. The hydrogenated cyclic olefin copolymer of the present invention has both a low Abbe number and low birefringence. Here, hydrogenation of the hydrogenated cyclic olefin copolymer can be carried out using hydrogen and a hydrogenation catalyst. Hydrogenation of the hydrogenated cyclic olefin copolymer 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 hydrogenated cyclic olefin copolymer can be hydrogenated.

[0070] The hydrogenation of cyclic olefin copolymers is carried out such that the hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds, such as olefinic double bonds, present in the cyclic olefin copolymer (the proportion of hydrogenated non-aromatic carbon-carbon unsaturated bonds in the cyclic olefin copolymer) is usually 90% or higher, preferably 95% or higher, and more preferably 98% or higher. If the hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds, such as olefinic double bonds, contained in the cyclic olefin copolymer is above the above lower limit, the heat resistance of the cyclic olefin copolymer hydrogenate can be improved.

[0071] The carbon-carbon unsaturated bonds (aromatic carbon-carbon unsaturated bonds) of aromatic ring structures (aromatic rings and / or aromatic heterocycles) present in cyclic olefin copolymer hydrides may be hydrogenated, but from the viewpoint of further reducing the Abbe number and further reducing birefringence, it is preferable that they are not hydrogenated. Specifically, the hydrogenation rate of aromatic carbon-carbon unsaturated bonds in cyclic olefin copolymer hydrides (the proportion of hydrogenated aromatic carbon-carbon unsaturated bonds in the cyclic olefin copolymer) is preferably 20% or less, more preferably 10% or less, and particularly preferably 0% (i.e., not hydrogenated). In this 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. Furthermore, 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 hydrogenation catalyst and / or the conditions of the hydrogenation reaction (reaction temperature, etc.).

[0072] Examples of hydrogenation catalysts that can be used include: hydrogenation catalysts consisting of dicyclopentadienyl titanium halide, nickel organic carboxylate, cobalt organic carboxylate, and organometallic compounds of groups 1 to 3 of the periodic table; metal catalysts such as nickel, platinum, palladium, ruthenium, rhenium, and rhodium metal catalysts supported on carbon, silica, diatomaceous earth, etc., and cobalt, nickel, rhodium, and ruthenium complexes; and hydrogenation compounds such as lithium aluminum hydride and p-toluenesulfonyl hydrazide. Among these, ruthenium compounds are preferred as hydrogenation catalysts from the viewpoint of obtaining the target product in good yield without isomerization.

[0073] 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 These are some examples.

[0074] Furthermore, the hydrogenation reaction of cyclic olefin copolymers can usually be carried out in an inert organic solvent. Examples of inert organic solvents include 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.

[0075] The reaction temperature for hydrogenating the cyclic olefin copolymer by adding hydrogen to a system containing the cyclic olefin copolymer and a hydrogenation catalyst 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 it 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 it is too high, it imposes limitations on the apparatus, requiring a high-pressure reactor. Furthermore, the reaction time depends on the scale of the reaction, but is typically 0.1 to 10 hours.

[0076] Furthermore, after the hydrogenation reaction, the resulting cyclic olefin copolymer hydride can be recovered according to conventional methods, and catalyst residue can be removed from the hydride by methods such as filtration.

[0077] <Structural Units> Structural units (A) in the cyclic olefin copolymer hydride may include structural units obtained when the norbornene imide monomer represented by formula (1) is polymerized, and structural units obtained by hydrogenating said structural units. Similarly, structural units (B) in the cyclic olefin copolymer hydride may include structural units obtained when the norbornene monomer represented by formula (2) is polymerized, and structural units obtained by hydrogenating said structural units. Furthermore, similarly, other structural units optionally included in the cyclic olefin copolymer hydride may include structural units obtained when a cyclic olefin compound that does not have a ring structure capable of forming other structural units is polymerized, and structural units obtained by hydrogenating said structural units. Furthermore, the "structural units obtained when the norborneneimide monomer represented by formula (1) is polymerized," the "structural units obtained when the norbornene monomer represented by formula (2) is polymerized," and the "structural units obtained when a cyclic olefin compound that can form other structural units is polymerized" in cyclic olefin copolymer hydrides are all unhydrogenated structural units (repeating units) that were not hydrogenated during the hydrogenation of the cyclic olefin copolymer.

[0078] Furthermore, the content ratio of structural unit (A) in the cyclic olefin copolymer hydride (the total ratio of structural units obtained when the norbornene imide monomer represented by formula (1) is polymerized and structural units obtained by hydrogenating said structural units) is the same as the preferred content ratio of structural unit (A) in the cyclic olefin copolymer described above in the "Cyclic Olefin Copolymer" section. Also, the content ratio of structural unit (B) in the cyclic olefin copolymer hydride (the total ratio of structural units obtained when the norbornene monomer represented by formula (2) is polymerized and structural units obtained by hydrogenating said structural units) is the same as the preferred content ratio of structural unit (B) in the cyclic olefin copolymer described above in the "Cyclic Olefin Copolymer" section. In addition, the content ratio of other structural units optionally included in the cyclic olefin copolymer hydride (the total ratio of structural units obtained when a cyclic olefin compound that does not have a ring structure capable of forming other structural units is polymerized and structural units obtained by hydrogenating said structural units) is the same as the preferred content ratio of other structural units in the cyclic olefin copolymer described above in the "Cyclic Olefin Copolymer" section. Furthermore, the preferred mass ratio of structural unit (A) to structural unit (B) in the cyclic olefin copolymer hydride is the same as the preferred content ratio described above in the "cyclic olefin copolymer" section.

[0079] <Weight-Average Molecular Weight> The weight-average molecular weight of the cyclic olefin copolymer hydride of the present invention is preferably 50,000 or more, more preferably 60,000 or more, even more preferably 70,000 or more, preferably 150,000 or less, more preferably 130,000 or less, and even more preferably 120,000 or less. If the weight-average molecular weight of the cyclic olefin copolymer hydride is above the lower limit, it is possible to suppress the decrease in strength of the resin molded article obtained using the cyclic olefin copolymer hydride. Furthermore, if the weight-average molecular weight of the cyclic olefin copolymer hydride is below the upper limit, it is possible to suppress the occurrence of molding defects caused by deterioration of fluidity during molding of the cyclic olefin copolymer hydride. In this invention, the "weight-average molecular weight" can be measured by the method described in the examples. Furthermore, the weight-average molecular weight of the cyclic olefin copolymer hydride can be adjusted, for example, by changing the type and / or amount of monomer used when preparing the cyclic olefin copolymer, and the type and / or amount of molecular weight adjusting agent (chain transfer agent).

[0080] <Glass Transition Temperature> The glass transition temperature of the cyclic olefin copolymer hydride of the present invention is preferably 100°C or higher, more preferably 120°C or higher, even more preferably 130°C or higher, preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower. If the glass transition temperature of the cyclic olefin copolymer hydride is above the lower limit above, deterioration of heat resistance and deterioration of optical properties due to thermal deformation can be suppressed. Furthermore, if the glass transition temperature of the cyclic olefin copolymer hydride is below the upper limit above, the occurrence of oxidative degradation of the cyclic olefin copolymer hydride caused by excessively high processing temperatures during molding can be suppressed. The glass transition temperature of the cyclic olefin copolymer hydride can be adjusted, for example, by changing the type and / or amount of monomer used when preparing the cyclic olefin copolymer.

[0081] <Melt Index> The melt index of the cyclic olefin copolymer hydride is preferably 15 g / 10 min or higher, more preferably 20 g / 10 min or higher, preferably 65 g / 10 min or lower, and more preferably 60 g / 10 min or lower. If the melt index is above the lower limit, the increase in birefringence due to low fluidity during molding can be suppressed. If it is below the upper limit, the deterioration of moldability due to excessively high fluidity can be suppressed. The melt index of the cyclic olefin copolymer hydride can be adjusted, for example, by changing the type and / or amount of monomer used when preparing the cyclic olefin copolymer, or by changing the weight-average molecular weight of the cyclic olefin copolymer hydride.

[0082] <Abbe Number> The cyclic olefin copolymer hydride of the present invention preferably has an Abbe number (vd) of 40 or less, more preferably 25 or more, more preferably 30 or more, and even more preferably 35 or more. If the Abbe number of the cyclic olefin copolymer hydride is below the above upper limit, the cyclic olefin copolymer hydride can be suitably used for optical element applications other than those with medium to high Abbe numbers. The lower limit of the Abbe number is not particularly limited, but is usually around 20.

[0083] <Birefringence> The cyclic olefin copolymer hydride of the present invention preferably has a birefringence of 1000 or less, more preferably 500 or less, even more preferably 300 or less, and also preferably -1000 or more, more preferably -500 or more, and even more preferably -300 or more. If the birefringence of the cyclic olefin copolymer hydride is within the above range, the optical properties of the resulting resin molded article as an optical element can be improved. For example, when the optical element is used as a lens, the resolution can be improved. In this invention, "birefringence" can be measured by the method described in the examples.

[0084] (Resin Composition) The resin composition of the present invention comprises the cyclic olefin copolymer hydride of the present invention described above, and optionally further comprises polymer materials other than the cyclic olefin copolymer hydride of the present invention and / or various additives.

[0085] The polymer materials and additives that the resin composition may contain are not particularly limited, but include, for example, the polymer materials and additives described in Japanese Patent Application Publication No. 10-139865.

[0086] In particular, the resin composition preferably contains antioxidants such as phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0087] The polymer materials and additives are not particularly limited as long as they can be sufficiently dispersed in the cyclic olefin copolymer hydride, and can be mixed with the cyclic olefin copolymer hydride by any method. Specifically, the polymer materials and additives may be added at any stage during the preparation of the cyclic olefin copolymer hydride, kneaded with the cyclic olefin copolymer hydride using a kneader, or mixed with the cyclic olefin copolymer hydride in a molding apparatus. The amount of polymer materials and additives blended is not particularly limited as long as the effects of the present invention are not impaired, but for example, it can be 0.01 parts by mass or more and 2.0 parts by mass or less per 100 parts by mass of the cyclic olefin copolymer hydride. The amount of antioxidant blended is not particularly limited as long as the effects of the present invention are not impaired, but for example, it can be 0.01 parts by mass or more and 2.0 parts by mass or less per 100 parts by mass of the cyclic olefin copolymer hydride.

[0088] (Resin Molded Article) The resin molded article of the present invention is obtained by molding the resin composition of the present invention described above into any shape. Furthermore, because the resin molded article of the present invention contains the cyclic olefin copolymer hydride of the present invention described above, it can exhibit excellent performance.

[0089] Here, the molding method is not particularly limited as long as it can mold the resin composition, and for example, 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, calendering, solution casting, hot press molding, and inflation molding can be used. Among these, extrusion molding is preferred.

[0090] The resin molded article of the present invention is preferably an optical element, and more preferably a lens. The lens is not particularly limited and can be obtained, for example, by uniformly heating and melting the resin composition of the present invention to form a pre-molded article, then pouring the pre-molded article into a mold, and then cooling it.

[0091] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing quantities refer to mass unless otherwise specified. In addition, 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 is usually equal to the ratio of that particular monomer to the total monomers used in the polymerization of the polymer (starting ratio), unless otherwise specified.

[0092] <Hydrogen conversion rate> １The hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds in cyclic olefin copolymer hydrides was determined by measuring the number of hydrogenated carbon-carbon double bonds using 1H-NMR spectroscopy and calculating the ratio to the number of hydrogenated carbon-carbon double bonds before hydrogenation. <Weight-average molecular weight> The weight-average molecular weight (Mw) of the cyclic olefin copolymer hydrides was calculated in polystyrene equivalent using gel permeation chromatography (Tosoh Corporation, "HLC-8020", using a combination of three columns: TSKgel SuperH2000, TSKgel SuperH4000, and TSKgel SuperH5000). Tetrahydrofuran (THF) was used as the developing solvent. <Glass Transition Temperature> The glass transition temperature (Tg) of the cyclic olefin copolymer hydride was measured using a differential scanning calorimetry analyzer (DSC6220, manufactured by SII Nanotechnology Co., Ltd.) at a heating rate of 10°C / min in accordance with JIS K7121. <Melt Index> The melt index (g / 10 min) of the cyclic olefin copolymer hydride was measured in accordance with JIS K7210, at 280°C and 2.16 kg. <Birefringence (Stress Birefringence CR)> The obtained resin composition was molded into a sheet measuring 35 mm in length, 10 mm in width, and 1 mm in thickness to obtain a sample sheet. After fixing both ends of this sample sheet with clips, a weight was attached to one of the clips. Next, the sample sheet was suspended for 1 hour in an oven set to the glass transition temperature Tg + 15°C of the resin, starting from the clip without the weight, and stretched. After that, the sample sheet was left to stand at room temperature for 30 minutes to obtain the measurement sample. For this sample, the in-plane retardation Re(b) [nm] at the center of the sample was measured at a measurement wavelength of 650 nm using a birefringent (Photonic Lattice "WPA-100"). The thickness T(b) [mm] at the center of the sample was also measured. Using these measured values ​​Re(b) and T(b), the δn value was calculated using the following formula (1): δn = Re(b) × (1 / T(b)) × 10 －６... (1) The δn value was calculated by taking measurements at three points while varying the stress F applied to the sample. When the stress F was plotted on the horizontal axis and the δn value on the vertical axis, the slope of the approximate straight line passing through the origin was defined as the stress birefringence CR value, and this was defined as birefringence. The closer the CR value is to 0, the smaller the birefringence. Weights of 26.062 g, 36.552 g, and 49.168 g were used to apply the stress F to the sample. <Abbe number> The obtained resin molded body was left for 20 hours in an atmosphere at a temperature 15°C lower than the glass transition temperature of the cyclic olefin ring-opening polymer hydride (= Tg - 15°C) to be used as the sample. The refractive index (n) at 25°C was measured on the obtained sample 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 The refractive index (n) at 25°C, obtained from the above refractive index measurement, was measured. ｄ , n Ｃ , n Ｆ Using ) the Abbe number (ν) according to the following formula (1). ｄ ) was calculated.

[0093] (Example 1) 50 parts of N-2,6-diisopropylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBDII") as a norborneneimide monomer represented by formula (1), 50 parts of phenylnorbornene (hereinafter sometimes abbreviated as "PhNB") as a norbornene monomer represented by formula (2), 0.25 parts of 1-hexene as a chain transfer agent, 0.025 parts of 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazole-2-ylidene[2-(isopropoxy)-5-(N,N-dimethylaminosulfonyl)phenyl]methyleneruthenium(II) dichloride as a polymerization catalyst, and 1000 parts of toluene as a solvent were charged into a nitrogen-purged glass pressure reactor, and the entire mixture was stirred at 55°C for 3 hours to carry out ring-opening polymerization.

[0094] Next, the resulting polymerization reaction solution was placed in an autoclave and stirred at 150°C and a hydrogen pressure of 4.5 MPa for 6 hours to carry out the hydrogenation reaction. This solution was filtered through a funnel pre-coated with radiolite to obtain a cyclic olefin copolymer hydride. The hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds in the obtained cyclic olefin copolymer hydride was 98% or higher.

[0095] Next, 100 parts of the obtained cyclic olefin copolymer hydride were mixed with 1 part of an antioxidant (tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane; "Irganox® 1010" manufactured by BASF Japan) to obtain a resin composition containing the cyclic olefin copolymer hydride. The obtained resin composition was then fed into a miniature twin-screw injection molding machine (Xplore "MC15"). The resin composition was then melted by applying shear stress from the screw using the miniature twin-screw injection molding machine. Finally, a plate-shaped molded body was obtained by injecting the resin into a mold under a pressure of 8 MPa. • Barrel setting temperature: Tg + 130°C • Mold setting temperature: Tg - 120°C • Screw rotation speed: 100 rpm

[0096] (Example 2) In Example 2, cyclic olefin copolymers, cyclic olefin copolymer hydrides, resin compositions, and resin molded articles were produced in the same manner as in Example 1, except that the amount of NBDII was changed from 50 parts to 65 parts and the amount of PhNB was changed from 50 parts to 35 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0097] (Example 3) In the same manner as in Example 1, except that the amount of NBDII was changed from 50 parts to 80 parts and the amount of PhNB was changed from 50 parts to 20 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0098] (Example 4) A cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced in the same manner as in Example 1, except that N-2,6-dimethylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBXI") was used instead of NBDII. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0099] (Example 5) In Example 1, naphthylnorbornene (hereinafter sometimes abbreviated as "NpNB") was used as the norbornene monomer represented by formula (2) instead of PhNB, and the amount of 1-hexene used as a chain transfer agent was changed from 0.25 parts to 0.75 parts. Otherwise, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced in the same manner as in Example 1. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0100] (Example 6) In the same manner as in Example 1, except that the amount of NBDII was changed from 50 parts to 40 parts and the amount of PhNB was changed from 50 parts to 60 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0101] (Example 7) In the same manner as in Example 1, except that the amount of NBDII was changed from 50 parts to 90 parts, the amount of PhNB was changed from 50 parts to 10 parts, and the amount of 1-hexene as a chain transfer agent was changed from 0.25 parts to 0.75 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0102] (Example 8) In the same manner as in Example 1, except that N-phenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBPI") was used instead of NBDII, and the amount of 1-hexene used as a chain transfer agent was changed from 0.25 parts to 0.75 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0103] (Example 9) In the same manner as in Example 2, except that the amount of 1-hexene used as a chain transfer agent was changed from 0.25 parts to 0.75 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0104] (Example 10) In the same manner as in Example 9, cyclic olefin copolymer, cyclic olefin copolymer hydride, resin composition, and resin molded article were produced, except that the monomer mixture was divided into 30 parts and added dropwise to the reaction vessel over 150 minutes. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0105] (Comparative Example 1) A polymer, polymer hydride, resin composition, and resin molded article were produced in the same manner as in Example 1, except that NBDII was not used and the amount of PhNB was changed from 50 parts to 100 parts. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0106] (Comparative Example 2) A cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced in the same manner as in Example 1, except that 75 parts of N-2-methylphenyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide (hereinafter sometimes abbreviated as "NBTI") were used instead of 50 parts of NBDII in Example 1, and 25 parts of 2-ethylidene-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene (hereinafter sometimes abbreviated as "ETD"), a norbornene monomer without an aromatic hydrocarbon ring, were used instead of 50 parts of PhNB. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0107] (Comparative Example 3) In the same manner as in Example 1, except that the amount of NBDII was changed from 50 parts to 60 parts, 50 parts of PhNB were replaced with 40 parts of deltacyclene (hereinafter sometimes abbreviated as "DCL") as a norbornene monomer without an aromatic hydrocarbon ring, and the amount of 1-hexene as a chain transfer agent was changed from 0.25 parts to 0.32 parts, a cyclic olefin copolymer, a cyclic olefin copolymer hydride, a resin composition, and a resin molded article were produced. Various measurements and evaluations were then performed. The results are shown in Table 1.

[0108] Table 1 shows that the cyclic olefin copolymer hydrides of Examples 1 to 10, which include structural units (A) derived from the norborneneimide monomer represented by formula (1) and structural units (B) derived from the norbornene monomer represented by formula (2), have both a low Abbe number and low birefringence.

[0109] According to the present invention, it is possible to provide a cyclic olefin copolymer hydride having both a low Abbe number and low birefringence, and a raw material for the same. 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 copolymer comprising a structural unit (A) derived from a norborneneimide monomer represented by the following formula (1) and a structural unit (B) derived from a norbornene monomer represented by the following formula (2). (In formula (1), 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 these may be joined together to form a ring.) (In formula (2), R ６ R represents a group containing an aromatic hydrocarbon ring. ７ and R ８ Each of these independently represents a hydrogen atom, a halogen atom, or an optionally substituted hydrocarbon group (excluding those containing aromatic hydrocarbon rings), and L represents a single bond or linking group.

2. The cyclic olefin copolymer according to claim 1, wherein the content of the structural unit (A) is 45% by mass or more and 85% by mass or less.

3. In formula (1), R １ and R ５ is an alkyl group having 1 to 6 carbon atoms which optionally has a substituent, the cyclic olefin copolymer according to claim 1.

4. The cyclic olefin copolymer according to claim 1, wherein in formula (2), L is a single bond.

5. In equation (2), R ６ The cyclic olefin copolymer according to claim 1, wherein is a group comprising an aromatic hydrocarbon ring that is either without substituents or has a nonpolar group as a substituent.

6. In equation (2), R ６ The cyclic olefin copolymer according to claim 1, wherein is a phenyl group.

7. A cyclic olefin copolymer according to any one of claims 1 to 6, which is a ring-opened copolymer.

8. A cyclic olefin copolymer hydride obtained by hydrogenating the cyclic olefin copolymer described in claim 7.

9. The cyclic olefin copolymer hydride according to claim 8, wherein the weight-average molecular weight is 50,000 or more and 150,000 or less.

10. The cyclic olefin copolymer hydride according to claim 8, wherein the glass transition temperature is 130°C or higher and 160°C or lower.

11. The cyclic olefin copolymer hydride according to claim 8, wherein the Abbe number is 25 or more and 40 or less.

12. The cyclic olefin copolymer hydride according to claim 8, wherein the melt index is 15 g / 10 min or more and 65 g / 10 min or less.

13. A resin composition comprising the cyclic olefin copolymer hydride described in claim 8.

14. A resin molded article obtained by molding the resin composition described in claim 13.

15. The resin molded article according to claim 14, which is an optical element.

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