Cyclic olefin polymer, its production method, and optical element

Abstract

The purpose of the present invention is to provide: a cyclic olefin polymer which has high refractive index, low Abbe number and low birefringence at the same time; a method for producing this cyclic olefin polymer; and an optical element which uses this cyclic olefin polymer. A cyclic olefin polymer according to the present invention is a polymer or a hydride thereof, said polymer containing, at a predetermined ratio, a structural unit derived from a naphthyl group-containing alicyclic compound (A) that is represented by formula (1) (wherein one of R2a to R5a moieties represents a naphthyl group, and the other moieties and R1a moiety are as defined in the description).

Description

[Technical field]

[0001] The present invention relates to a cyclic olefin polymer, a method for producing a cyclic olefin polymer, and an optical element using the cyclic olefin polymer. [Background technology]

[0002] In recent years, polymers obtained by ring-opening or addition polymerization of cyclic olefins have been attracting attention as materials for optical elements and medical containers.

[0003] For example, Patent Document 1 discloses a norbornene-based ring-opening (co)polymer that is excellent in transparency and heat resistance, has high solubility in organic solvents, and has unique birefringence and wavelength dependency. Patent Document 2 discloses a cycloolefin copolymer that effectively exhibits reverse wavelength dispersion of birefringence and a film made of the copolymer. Patent Document 3 discloses a cyclic olefin copolymer that has a high refractive index and can adjust the Abbe number to a low level, and a medical container that is less discolored by electron beam or gamma ray irradiation and has excellent transparency. Patent Document 4 discloses a norbornene-based polymer film that can increase the degree of wavelength dispersion to improve the color appearance of a liquid crystal display device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-46615 A [Patent Document 2] JP 2009-46614 A [Patent Document 3] International Publication No. 2019 / 107363 [Patent Document 4] JP 2008-31319 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to increase the degree of freedom in designing optical elements such as optical lenses, there is a demand for resins that have a high refractive index, a lower Abbe number than conventional cyclic olefin resins, and small birefringence when made into optical elements.

[0006] However, the above-mentioned conventional ring-opening or addition polymers have been unable to simultaneously achieve a high refractive index, a low Abbe number, and low birefringence (eg, stress birefringence).

[0007] Therefore, an object of the present invention is to provide a cyclic olefin polymer (a polymer obtained by ring-opening polymerization or addition polymerization) that simultaneously exhibits a high refractive index, a low Abbe number, and low birefringence, a method for producing the same, and an optical element using the cyclic olefin polymer. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and have newly discovered that a cyclic olefin polymer, which is a polymer containing structural units derived from a naphthyl group-containing alicyclic compound (A) in a predetermined ratio as structural units, or a hydrogenated product thereof, can simultaneously achieve a high refractive index, a low Abbe number, and a low birefringence (low stress optical coefficient). Based on the above-mentioned new findings, the present inventors have completed the present invention.

[0009] That is, an object of the present invention is to advantageously solve the above problems, and the cyclic olefin polymer of the present invention comprises a structural unit derived from a naphthyl group-containing alicyclic compound (A) represented by the following formula (1): [ka] [In the formula, R 2a ~R 5a one of which is a naphthyl group, and the remaining groups and R 1a However, each independently, (i) a hydrogen atom; (ii) a halogen atom; or (iii) a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding those containing an aromatic ring) which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom; and Optionally, structural units derived from other monomers or a hydrogenated product thereof, The proportion of structural units derived from the compound (A) in all structural units is 20 mol % or more and 100 mol % or less.

[0010] The ratio of the structural units derived from the compound (A) to all the structural units is preferably 20 mol % or more and 90 mol % or less. 2a ~R 5a The remaining groups other than naphthyl groups, and R 1a is preferably a hydrogen atom.

[0011] The cyclic olefin polymer of the present invention is A structural unit derived from the compound (A); and one or more structural units derived from a norbornene-based monomer (B) different from the compound (A); and Optionally, structural units derived from other monomers or a hydrogenated product thereof.

[0012] Here, the norbornene monomer (B) is (i) norbornenes which are unsubstituted or have an alkyl group, an alkenyl group, an aromatic ring group, a polar group containing an oxygen atom, or a polar group containing a nitrogen atom as a substituent; (ii) A monomer represented by the following formula (3): [ka] [In formula (3), R 1b and R 2b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; or an organic group containing a silicon atom, an oxygen atom or a nitrogen atom; R 1b and R 2b may or may not be bonded to each other to form a ring, R 3b represents a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. or (iii) A monomer represented by the following formula (4): [ka] [In formula (4), R 4b ~R 7b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; or an organic group containing a silicon atom, an oxygen atom or a nitrogen atom; R 4b and R 6b may or may not be bonded to each other to form a ring, m is 1 or 2. It is preferable that:

[0013] The weight average molecular weight of the cyclic olefin polymer is preferably 20,000 or more and 40,000 or less.

[0014] Refractive index (n d ) is preferably 1.545 or more and preferably 1.640 or less. d ) is preferably 20 or more and preferably 50 or less. In addition, the cyclic olefin polymer of the present invention has a stress birefringence (C R ) is -500×10 -12 Pa -1 More preferably, 1400×10 -12 Pa -1 If the refractive index, Abbe number, and stress birefringence are within the above ranges, the degree of freedom in optical design can be increased when the material is used for an optical element. In the present invention, the refractive index, Abbe number, and stress birefringence can be measured according to the method described in the examples of this specification.

[0015] In addition, when the cyclic olefin polymer of the present invention is a polymer containing structural units derived from the naphthyl group-containing alicyclic compound (A) and optionally other monomers, or a hydrogenated product thereof, the cyclic olefin polymer of the present invention can be easily produced using a production method including a step of polymerizing (e.g., ring-opening polymerization, addition polymerization) a mixed monomer containing the naphthyl group-containing alicyclic compound (A) as a monomer or a polymer containing structural units derived from the compound (A) and optionally other monomers, and optionally other monomers in a predetermined ratio. In addition, when the cyclic olefin polymer of the present invention is a polymer or its hydrogenation product containing a naphthyl group-containing alicyclic compound (A), one or more structural units derived from a norbornene monomer (B) different from the compound (A), and optionally structural units derived from other monomers, the cyclic olefin polymer of the present invention can be easily produced using a production method including a step of polymerizing (e.g., ring-opening polymerization, addition polymerization) a mixed monomer containing a predetermined ratio of the naphthyl group-containing alicyclic compound (A) as a monomer or a polymer containing structural units derived from the compound (A) and optionally structural units derived from other monomers, one or more norbornene monomers (B) different from the naphthyl group-containing alicyclic compound (A) or a polymer containing structural units derived from the norbornene monomer (B) and optionally structural units derived from other monomers, and optionally other monomers or polymers. The ring-opening polymerization may be carried out, for example, in the presence of a metathesis polymerization catalyst. The addition polymerization may be carried out in the presence of, for example, a Ziegler-Natta catalyst, a metallocene catalyst, a nickel catalyst, or a palladium catalyst. The method for producing a cyclic olefin polymer may further include a step of hydrogenating the polymer.

[0016] The present invention also aims to advantageously solve the above problems, and the optical element of the present invention is characterized in that it contains the above-mentioned cyclic olefin polymer. If the optical element contains the above-mentioned cyclic olefin polymer, it can be advantageously used as a material for optical elements, etc. Effect of the Invention

[0017] According to the present invention, it is possible to provide a cyclic olefin polymer having a high refractive index, a low Abbe number, and low birefringence (e.g., stress birefringence) in combination, a production method thereof, and an optical element using the cyclic olefin polymer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described in detail.

[0019] (Cyclic Olefin Polymer) The cyclic olefin polymer of the present invention is a polymer of a mixed monomer containing a naphthyl group-containing alicyclic compound (A) and optionally containing other monomers (e.g., a polymer obtained by ring-opening polymerization or addition polymerization) or a hydrogenated product thereof. The ratio of the naphthyl group-containing alicyclic compound (A) in the mixed monomer is 20 mol% or more and 100 mol% or less. The cyclic olefin polymer of the present invention has excellent properties such as a high refractive index, a low Abbe number, a low birefringence (e.g., stress birefringence), or a high glass transition temperature. In this specification, the term "polymer" may be a polymer (e.g., a homopolymer) composed of a single structural unit, or a copolymer.

[0020] Also, preferably, the cyclic olefin polymer of the present invention may be a polymer of a mixed monomer (e.g., a polymer by ring-opening polymerization or addition polymerization) containing a naphthyl group-containing alicyclic compound (A) and one or more norbornene-based monomers (B) different from the naphthyl group-containing alicyclic compound (A) and optionally containing other monomers, or a hydrogenated product thereof. The ratio of the naphthyl group-containing alicyclic compound (A) in the mixed monomers is 20 mol% or more and 100 mol% or less. The cyclic olefin polymer of the present invention may be, for example, a random copolymer or a block copolymer. If the cyclic olefin polymer of the present invention is a copolymer containing a structural unit derived from the compound (A), a structural unit derived from the norbornene-based monomer (B), and optionally, a structural unit derived from another monomer, it is preferable because it has better properties such as a higher refractive index, a lower Abbe number, a lower birefringence (e.g., stress birefringence), or a higher glass transition temperature than a polymer obtained by polymerizing the naphthyl group-containing alicyclic compound (A) as a single monomer.

[0021] <Naphthyl group-containing alicyclic compound> The naphthyl group-containing alicyclic compound (A) is a compound represented by the following formula (1). [ka] [In the formula, R 2a ~R 5a one of which is a naphthyl group, and the remaining groups and R 1a However, each independently, (i) a hydrogen atom; (ii) a halogen atom; or (iii) A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding those containing an aromatic ring) which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom.

[0022] The naphthyl group-containing alicyclic compound (A) may be a compound in which a 1-naphthyl group or a 2-naphthyl group is bonded as the naphthyl group, or a mixture thereof. The bonding mode of the naphthyl group to the norbornene ring is stereoisomerically present as an exo bond (bonding in the same direction as the methylene at the bridgehead position) and an endo bond (bonding in the opposite direction to the methylene at the bridgehead position), and the naphthyl group-containing alicyclic compound (A) may be a compound in which the naphthyl group is bonded to the norbornene ring exo or endo (exo or endo isomer), or a mixture thereof. Thus, the naphthyl group-containing alicyclic compound (A) may be a 1-naphthyl group-exo bonded compound, a 2-naphthyl group-exo bonded compound, a 1-naphthyl group-endo bonded compound, a 2-naphthyl group-endo bonded compound, or any mixture thereof.

[0023] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0024] Examples of the hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as methyl, ethyl, and propyl groups, cycloalkyl groups such as cyclopentyl and cyclohexyl groups, alkenyl groups such as vinyl and allyl groups, and alkylidene groups such as ethylidene and propylidene groups. These hydrocarbon groups may be substituted, and examples of the substituent include halogen atoms such as fluorine, chlorine, and bromine, phenylsulfonyl groups, and cyano groups.

[0025] The substituted or unsubstituted hydrocarbon group may be directly bonded to the ring structure or may be bonded via a linking group. Examples of the linking group include divalent hydrocarbon groups having 1 to 10 carbon atoms (e.g., -(CH2) q- (where q is an integer of 1 to 10); a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom (for example, a carbonyl group (-CO-), a carbonyloxy group (-COO-), a sulfonyl group (-SO2-), a sulfonyl ester group (-SO2-O-), an ether bond (-O-), a thioether bond (-S-), an imino group (-NH-), an amide bond (-NHCO-), a siloxane bond (-Si(R2)O- (where R is an alkyl group such as methyl, ethyl, etc.)); or a combination of two or more of these linked together.

[0026] R 2a ~R 5a The remaining groups other than naphthyl groups, and R 1a are preferably all hydrogen atoms.

[0027] <Norbornene monomer> The norbornene monomer (B) is a compound having a norbornene structure represented by formula (2). [ka]

[0028] Examples of the norbornene monomer (B) include norbornene monomers that do not have a ring condensed with a norbornene ring in the molecule, and polycyclic norbornene monomers having three or more rings.

[0029] Examples of norbornene monomers not having a ring condensed with a norbornene ring in the molecule include norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-butylnorbornene, 5-hexylnorbornene, 5-decylnorbornene, 5-cyclohexylnorbornene, 5-cyclopentylnorbornene, and other unsubstituted or alkyl group-containing norbornenes; Norbornenes having an alkenyl group, such as 5-ethylidenenorbornene, 5-vinylnorbornene, 5-propenylnorbornene, 5-cyclohexenylnorbornene, and 5-cyclopentenylnorbornene; norbornenes having an aromatic ring such as 5-phenylnorbornene; norbornenes having a polar group containing an oxygen atom, such as 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene, 5-methyl-5-methoxycarbonylnorbornene, 5-methyl-5-ethoxycarbonylnorbornene, norbornenyl-2-methylpropionate, norbornenyl-2-methyloctanate, 5-hydroxymethylnorbornene, 5,6-di(hydroxymethyl)norbornene, 5,5-di(hydroxymethyl)norbornene, 5-hydroxy-i-propylnorbornene, 5,6-dicarboxynorbornene, and 5-methoxycarbonyl-6-carboxynorbornene; Norbornenes having a polar group containing a nitrogen atom, such as 5-cyanonorbornene; etc.

[0030] The polycyclic norbornene monomer having three or more rings is a norbornene monomer having a norbornene ring and one or more rings condensed with the norbornene ring in the molecule. Specific examples thereof include monomers represented by the following formula (3) or formula (4).

[0031] [ka]

[0032] (In formula (3), R 1b and R 2b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent (for example, an alkyl group); or a substituent containing a silicon atom, an oxygen atom or a nitrogen atom; and may be bonded to each other to form a ring, R 3b is a divalent hydrocarbon group having 1 to 20 carbon atoms (e.g., an alkylene group) which may have a substituent.

[0033] [ka]

[0034] (In formula (4), R 4b ~R 7b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent (e.g., an alkyl group); or a substituent containing a silicon atom, an oxygen atom, or a nitrogen atom; R 4b and R 6b may be bonded to each other to form a ring, m is 1 or 2.

[0035] The monomer represented by formula (3) is dicyclopentadiene, methyldicyclopentadiene, tricyclo[5.2.1.0 2,6 ]dec-8-ene and other norbornene monomers that do not contain an aromatic ring structure. 2,10 .0 3,8 ]tetradeca-3,5,7,12-tetraene (also called 1,4-methano-1,4,4a,9a-tetrahydro-9H-fluorene), tetracyclo[10.2.1.0 2,11 .0 4,9 Norbornene derivatives having an aromatic ring such as pentadeca-4,6,8,13-tetraene (also called 1,4-methano-1,4,4a,9,9a,10-hexahydroanthracene) can also be mentioned.

[0036] Examples of the monomer represented by the formula (4) include tetracyclododecenes in which m is 1 and hexacycloheptadecenes in which m is 2.

[0037] Examples of tetracyclododecenes include unsubstituted or alkyl group-containing tetracyclododecenes such as tetracyclododecene, 8-methyltetracyclododecene, 8-ethyltetracyclododecene, 8-cyclohexyltetracyclododecene, 8-cyclopentyltetracyclododecene, and 8-methoxycarbonyl-8-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene; tetracyclododecenes having an exocyclic double bond, such as 8-methylidenetetracyclododecene, 8-ethylidenetetracyclododecene, 8-vinyltetracyclododecene, 8-propenyltetracyclododecene, 8-cyclohexenyltetracyclododecene, and 8-cyclopentenyltetracyclododecene; Tetracyclododecenes having an aromatic ring, such as 8-phenyltetracyclododecene; tetracyclododecenes having a substituent containing an oxygen atom, such as 8-methoxycarbonyltetracyclododecene, 8-methyl-8-methoxycarbonyltetracyclododecene, 8-hydroxymethyltetracyclododecene, 8-carboxytetracyclododecene, tetracyclododecene-8,9-dicarboxylic acid, and tetracyclododecene-8,9-dicarboxylic anhydride; tetracyclododecenes having a nitrogen atom-containing substituent, such as 8-cyanotetracyclododecene and tetracyclododecene-8,9-dicarboxylic imide; Tetracyclododecenes having a substituent containing a halogen atom, such as 8-chlorotetracyclododecene; tetracyclododecenes having a substituent containing a silicon atom, such as 8-trimethoxysilyltetracyclododecene; etc.

[0038] As the hexacycloheptadecenes, any of the Diels-Alder adducts of the above-mentioned tetracyclododecenes and cyclopentadiene can be used.

[0039] Of the above-mentioned norbornene-based monomers, the norbornene-based monomer (B) is preferably a non-polar norbornene-based monomer, from the viewpoint of improving the refractive index, Abbe number, birefringence (e.g., stress birefringence), or glass transition temperature. Examples of the norbornene-based monomer (B) include unsubstituted or alkyl group-containing norbornenes (e.g., norbornene (NB), 8-ethyltetracyclododecene), alkenyl group-containing norbornenes (e.g., ethylidenetetracyclododecene (ETD)), dicyclopentadiene (DCPD), and aromatic ring-containing norbornene derivatives (e.g., tetracyclo[9.2.1.0 2,10 .03,8 ]tetradeca-3,5,7,12-tetraene (also referred to as 1,4-methano-1,4,4a,9a-tetrahydro-9H-fluorene (MTF)), and unsubstituted or alkyl group-containing tetracyclododecenes (e.g., tetracyclododecene (TCD), 8-methoxycarbonyl-8-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene (MTCD)) are more preferred.

[0040] The norbornene monomer may be used alone or in combination of two or more. The polycyclic norbornene monomer having three or more rings includes endo and exo isomers, and either of these may be used, or a mixture of isomers may be used.

[0041] Other copolymerizable monomers can be used in combination as long as the effects of the present invention are not impaired. The amount of the other copolymerizable monomer is preferably 50 mol % or less when the total amount of the monomers is 100 mol %.

[0042] Examples of other copolymerizable monomers include cycloolefins such as cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, cyclooctene, and 3a,5,6,7a-tetrahydro-4,7-methano-1H-indene; non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene; etc. These copolymerizable monomers can be used alone or in combination of two or more kinds.

[0043] <Content of naphthyl group-containing alicyclic compound (A)> The ratio of the naphthalene ring-containing alicyclic compound (A) in the mixed monomer may be 20 mol% or more, preferably 25 mol% or more, more preferably 30 mol% or more, and may be, for example, 100 mol% or less, 95 mol% or less, or 90 mol% or less, preferably 87 mol% or less, more preferably 85 mol% or less. However, from the viewpoint of further improving the high refractive index, it is preferable that the mixed monomer contains the naphthyl group-containing alicyclic compound (A) and the norbornene-based monomer (B), and the total content ratio of the naphthyl group-containing alicyclic compound (A) and the norbornene-based monomer (B) contained in the mixed monomer is 100 mol%, that is, the monomers as the raw materials for the cyclic olefin polymer of the present invention are composed only of the compound (A) and the monomer (B), and the cyclic olefin polymer of the present invention is composed only of structural units derived from the compound (A) and the monomer (B).

[0044] <Hydrogenation rate> The cyclic olefin polymer of the present invention is preferably a hydrogenated product, and more preferably sufficiently hydrogenated, in order to improve stability and suppress coloration and deterioration due to heat. The hydrogenation rate of the cyclic olefin polymer of the present invention is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. If the hydrogenation rate is equal to or higher than the above lower limit, the heat resistance of the cyclic olefin polymer can be improved. The hydrogenation rate of the polymer is the hydrogenation rate of the carbon-carbon double bond in the main chain. Furthermore, naphthyl in the structure derived from the naphthyl group-containing alicyclic compound (A) is usually not hydrogenated.

[0045] <Structure of Cyclic Olefin Polymer> The cyclic olefin polymer of the present invention is a polymer formed by polymerizing the above-mentioned naphthyl group-containing alicyclic compound (A) and optionally other monomers. Preferably, the cyclic olefin polymer of the present invention may be a polymer formed by polymerizing the above-mentioned naphthyl group-containing alicyclic compound (A), one or more norbornene-based monomers (B), and optionally other monomers. The polymerization may be either ring-opening polymerization or addition polymerization, and both ring-opening polymerization and addition polymerization may be included in one cyclic olefin polymer. The polymerization is preferably ring-opening polymerization. The cyclic olefin polymer of the present invention can be represented as a polymer containing a structural unit derived from the compound (A) and a structural unit derived from any other monomer. Preferably, the cyclic olefin polymer of the present invention may be represented as a polymer containing a structural unit derived from the compound (A), a structural unit derived from the norbornene-based monomer (B), and a structural unit derived from any other monomer. The proportion of the structural units derived from the compound (A) in all structural units may be 20 mol% or more, preferably 25 mol% or more, more preferably 30 mol% or more, and may be, for example, 100 mol% or less, 95 mol% or less, or 90 mol% or less, preferably 87 mol% or less, more preferably 85 mol% or less. It is preferable that the total content of the structural units derived from the compound (A) and the structural units derived from the norbornene-based monomer (B) in all structural units is 100%, that is, the cyclic olefin polymer of the present invention is composed only of structural units derived from the compound (A) and the monomer (B).

[0046] When the polymerization is ring-opening polymerization, the cyclic olefin polymer of the present invention can be represented, for example, as a polymer containing a structural unit (a) derived from the compound (A) and optionally a structural unit derived from another monomer. Also, preferably, when the polymerization is ring-opening polymerization, the cyclic olefin polymer of the present invention can be represented, for example, as a polymer containing a structural unit (a) derived from the compound (A), a structural unit (b) derived from the norbornene monomer (B), and optionally a structural unit derived from another monomer.

[0047] <Structural unit (a) derived from compound (A)> In the case of ring-opening polymerization, a structural unit represented by formula (5) is generated by ring-opening reaction of compound (A) (a compound represented by formula (1)). Furthermore, a hydrogenation reaction is performed to hydrogenate the carbon-carbon double bond in the main chain of the structural unit represented by formula (5), generating a structural unit represented by formula (6). Therefore, the structural unit (a) derived from compound (A) in the case of ring-opening polymerization can be represented as a structural unit represented by formula (5) when no hydrogenation reaction is performed, and can be represented as a structural unit represented by formula (6) or a mixture of the structural unit represented by formula (5) and the structural unit represented by formula (6) (the mixing ratio can vary depending on the degree of hydrogenation) when a hydrogenation reaction is performed. [ka] [In the formula, R 1a ~R 5a is as described above.

[0048] <Structural unit (b) derived from norbornene monomer (B)> In the case of ring-opening polymerization, a structural unit having a main structure represented by formula (7) is generated by ring-opening reaction of norbornene-based monomer (B) (a compound having a main structure represented by formula (2)). Furthermore, a hydrogenation reaction is performed to hydrogenate the carbon-carbon double bond in the main chain of the structural unit having a main structure represented by formula (7), and a structural unit having a main structure represented by formula (8) is generated. Therefore, the structural unit (b) derived from norbornene-based monomer (B) in the case of ring-opening polymerization can be expressed as a structural unit having a main structure represented by formula (7) when no hydrogenation reaction is performed, and can be expressed as a structural unit having a main structure represented by formula (8) or a mixture of a structural unit having a main structure represented by formula (7) and a structural unit having a main structure represented by formula (8) (the mixing ratio can vary depending on the degree of hydrogenation). When norbornene-based monomer (B) contains a substituent and / or forms a condensed ring with another ring, structural unit (b) also contains a substituent at the corresponding position and / or forms a condensed ring. Examples of the substituent and the fused ring are as described above. [ka]

[0049] For example, when the norbornene monomer (B) is a monomer represented by the above formula (3), the structural unit (b) derived from the norbornene monomer (B) in the case of ring-opening polymerization can be represented as a structural unit represented by formula (9), a structural unit represented by formula (10), or a mixture thereof, depending on the presence or absence or the degree of hydrogenation. 1b ~R 3b is as described above. [ka]

[0050] Furthermore, for example, when the norbornene-based monomer (B) is a monomer represented by the above formula (3) or formula (4), the structural unit (b) derived from the norbornene-based monomer (B) in the case of ring-opening polymerization is represented by the following formula (9) or formula (10). 1b ~R 7b and m are as defined above. For example, when the norbornene monomer (B) is a monomer represented by the above formula (4), the structural unit (b) derived from the norbornene monomer (B) in the case of ring-opening polymerization can be represented by a structural unit represented by formula (11), a structural unit represented by formula (12), or a mixture thereof, depending on the presence or absence or the degree of hydrogenation. 4b ~R 7b and m are as defined above. [ka]

[0051] Specific examples of the structural unit (b) derived from the norbornene-based monomer (B) in the case of ring-opening polymerization correspond to structural units generated by ring-opening and optional hydrogenation of the compounds listed as specific examples of the norbornene-based monomer (B).

[0052] As long as the effect of the present invention is not impaired, the cyclic olefin polymer may contain other structural units. Examples of the other structural units include structural units derived from the above-mentioned other copolymerizable monomers. The other structural units may be of a single type or of two or more types. The number of other structural units is preferably 50% or less when the total number of structural units is taken as 100%.

[0053] <Average molecular weight of cyclic olefin polymer> The average molecular weight of the cyclic olefin polymer of the present invention can be expressed as a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. The weight average molecular weight (Mw) may be usually 18,000 or more, preferably 19,000 or more, and more preferably 20,000 or more. The weight average molecular weight (Mw) may be usually 100,000 or less, preferably 50,000 or less, and more preferably 40,000 or less. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) may be usually 4.0 or less, preferably 3.7 or less, and more preferably 3.5 or less. The ratio (Mw / Mn) is 1.0 or more, and may be 1.0.

[0054] (Production method of cyclic olefin polymer) <Method of manufacturing monomer> The monomers that are the raw materials of the cyclic olefin polymer of the present invention can be produced, for example, by known synthesis methods. The naphthyl group-containing alicyclic compound (A) may be produced, for example, by palladium coupling (e.g., reaction of norbornadiene with bromonaphthalene) or Diels-Alder reaction (e.g., reaction of cyclopentadiene with vinylnaphthalene). Specific examples of the method for producing the naphthyl group-containing alicyclic compound (A) include the methods described in the Examples. The naphthyl group-containing alicyclic compound (A) may be selectively obtained as the exo isomer or endo isomer, or may be obtained as a mixture of the exo isomer and the endo isomer.

[0055] <Method of Producing Polymer> When the cyclic olefin polymer of the present invention is a polymer containing structural units derived from the naphthyl group-containing alicyclic compound (A) and optionally other monomers, or a hydrogenated product thereof, the cyclic olefin polymer of the present invention is A polymerization raw material containing a naphthyl group-containing alicyclic compound (A) or a polymer containing a structural unit derived from the compound (A), and optionally, a polymer containing another monomer or a structural unit derived from the other monomer. A process of polymerizing (e.g., ring-opening polymerization, addition polymerization) the above to obtain a polymer (polymerization process). The composition can be produced by a method comprising the steps of:

[0056] In addition, when the cyclic olefin polymer of the present invention is a polymer or a hydrogenated product thereof containing a naphthyl group-containing alicyclic compound (A), one or more structural units derived from a norbornene monomer (B) different from the compound (A), and optionally a structural unit derived from another monomer, the cyclic olefin polymer of the present invention is A polymerization raw material containing a naphthyl group-containing alicyclic compound (A) or a polymer containing a structural unit derived from the compound (A), one or more norbornene-based monomers (B) different from the compound (A) or a polymer containing a structural unit derived from the norbornene-based monomers (B), and optionally a polymer containing another monomer or a structural unit derived from the monomer; or A polymerization raw material containing a polymer including a structural unit derived from a compound (A), a structural unit derived from a norbornene-based monomer (B), and optionally a structural unit derived from another monomer. A process of polymerizing (e.g., ring-opening polymerization, addition polymerization) the above to obtain a polymer (polymerization process). The composition can be produced by a method comprising the steps of:

[0057] The ratio of the total number of moles of the compound (A) and the structural units derived from the compound (A) to the total number of moles of all monomers and structural units in the polymerization raw material is adjusted according to the ratio of the structural units derived from the compound (A) in the total structural units of the target cyclic olefin polymer. For example, in order to produce a cyclic olefin polymer in which the ratio of the structural units derived from the compound (A) in the total structural units is 20 mol% or more and 100 mol% or less, preferably 20 mol% or more and 90 mol% or less, the ratio of the total number of moles of the compound (A) and the structural units derived from the compound (A) to the total number of moles of all monomers and structural units in the polymerization raw material can be 20 mol% or more, preferably 20 mol% or more and 90 mol% or less.

[0058] The method for producing a cyclic olefin polymer of the present invention may further include a step of hydrogenating the polymer to obtain a hydrogenated product of the polymer (hydrogenation step). Hydrogenation may improve the properties of the cyclic olefin polymer, such as heat resistance, weather resistance, light resistance, solvent resistance, chemical resistance, and water resistance.

[0059] The process for producing a cyclic olefin polymer of the present invention may further include a step of recovering the polymer (recovery step).

[0060] <Polymerization process> The polymerizable unit compound contained in the polymerization raw material may be either a monomer or a polymer (including a copolymer). The polymer as the polymerizable unit compound may be prepared by the same polymerization reaction as in the polymerization step.

[0061] Examples of the polymerization reaction used in the polymerization step and in the preparation of the polymer as the polymer unit compound include ring-opening polymerization and addition polymerization. The polymerization reaction in the polymerization step will be described below.

[0062] The ring-opening polymerization can be carried out by subjecting the polymerization raw materials to ring-opening metathesis polymerization in the presence of a metathesis polymerization catalyst. The ring-opening metathesis polymerization may be carried out in a reaction system in which the polymerization raw materials and the metathesis polymerization catalyst are mixed in a solvent (e.g., an organic solvent). In order to improve the polymerization efficiency, the reaction system may further contain an activator, a chain transfer agent, and other auxiliaries (e.g., Lewis bases). Reagents such as catalysts used in the ring-opening polymerization and various reaction conditions will be described below.

[0063] <Metathesis polymerization catalyst> As a metathesis polymerization catalyst, a transition metal imide complex represented by formula (1) is used. M(NR a )X 4-p (OR b ) p L q (1) (In the formula, M is a metal atom selected from the transition metal atoms of Group 6 of the periodic table; R a represents a phenyl group which may have a substituent at at least one of the 3-, 4- and 5-positions, or -CHR c where R c represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group, R b represents an optionally substituted alkyl group or an optionally substituted aryl group, X is a halogen atom, an alkyl group, an aryl group, an aralkyl group, or an alkylsilyl group; L is an electron donating neutral ligand; p is 0 or 1; q is an integer from 0 to 2, When multiple X's are present, the multiple X's may be the same or different. When multiple L's are present, the multiple L's may be the same or different.

[0064] <<Transition metal imido complexes>> In formula (1), M is a transition metal atom of Group 6 of the periodic table and can be selected from chromium, molybdenum, and tungsten. Among them, molybdenum and tungsten are preferred, and tungsten is more preferred.

[0065] The transition metal imido complex of formula (1) has a metal imido bond (N=R a ) is included. a is a substituent on the nitrogen atom that constitutes the metal imido bond.

[0066] R in formula (1) a represents a phenyl group which may have a substituent at at least one of the 3-, 4- and 5-positions, or -CHR c It is a group represented by the following formula:

[0067] R a The substituent of the phenyl group which may have a substituent at at least one of the 3-, 4- and 5-positions is Alkyl groups (for example, alkyl groups having 1 to 4 carbon atoms, such as a methyl group or an ethyl group); Halogen atoms (e.g., fluorine atoms, chlorine atoms, bromine atoms, etc.); Alkoxy groups (for example, alkoxy groups having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group, or an isopropoxy group); and the like, and the substituents present at at least two of the 3-, 4- and 5-positions may be bonded to each other.

[0068] Examples of the phenyl group which may have a substituent at at least one of the 3-, 4- and 5-positions include a phenyl group; mono-substituted phenyl groups such as a 4-methylphenyl group, a 4-chlorophenyl group, a 3-methoxyphenyl group, a 4-cyclohexylphenyl group, and a 4-methoxyphenyl group; Disubstituted phenyl groups such as a 3,5-dimethylphenyl group, a 3,5-dichlorophenyl group, a 3,4-dimethylphenyl group, and a 3,5-dimethoxyphenyl group; Tri-substituted phenyl groups such as a 3,4,5-trimethylphenyl group and a 3,4,5-trichlorophenyl group; 2-naphthyl groups which may have a substituent, such as a 2-naphthyl group, a 3-methyl-2-naphthyl group, or a 4-methyl-2-naphthyl group; etc.

[0069] R a , -CH2R c R in the group represented by c The number of carbon atoms of the alkyl group which may have a substituent is not particularly limited, and is usually 1 to 20, preferably 1 to 10, and more preferably 1 to 4. This alkyl group may be linear or branched. The substituent is not particularly limited, and examples thereof include a phenyl group, a phenyl group which may have a substituent (e.g., a 4-methylphenyl group, etc.); an alkoxy group (e.g., an alkoxy group having 1 to 4 carbon atoms, such as a methoxy group or an ethoxy group); and the like.

[0070] R c Examples of the aryl group which may have a substituent include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, etc. The substituent is not particularly limited, and examples thereof include a phenyl group, a phenyl group which may have a substituent (e.g., a 4-methylphenyl group, etc.); an alkoxy group (e.g., an alkoxy group having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group, etc.); and the like.

[0071] R c As the alkyl group, an alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, or a decyl group, is preferred.

[0072] In formula (1), (4-p) is 4 or 3, and formula (1) has 4 or 3 X. X is a halogen atom, an alkyl group, an aryl group, an aralkyl group, or an alkylsilyl group. X may be the same or different. Regarding X, examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a neopentyl group. Examples of the aryl group include a phenyl group, a 4-methylphenyl group, a 2,6-dimethylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. Examples of the aralkyl group include a benzyl group and a neophyl group. Examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

[0073] In formula (1), p is 0 or 1, and formula (1) is a metal alkoxide bond or a metal aryloxide bond (OR b ) may be used. b is a substituent on an oxygen atom constituting a metal alkoxide bond or a metal aryloxide bond.

[0074] R b is an optionally substituted alkyl group or an optionally substituted aryl group, and c As the alkyl group which may have a substituent and the aryl group which may have a substituent, the exemplified and preferred examples are applied.

[0075] In the formula (1), q is an integer of 0 to 2, and the formula (1) may have one or two electron-donating neutral ligands (L). L includes an electron donor compound containing an atom of Group 14 or 15 of the periodic table; Phosphines such as trimethylphosphine, triisopropylphosphine, tricyclohexylphosphine, and triphenylphosphine; Ethers such as diethyl ether, dibutyl ether, 1,2-dimethoxyethane, tetrahydrofuran, and tetrahydropyran; Amines such as trimethylamine, triethylamine, pyridine, and lutidine; Among these, ethers are preferred.

[0076] The transition metal imido complex of formula (1) may be a tungsten imido complex having a phenylimido group (wherein M is a tungsten atom and R a is a phenyl group), and tetrachlorotungsten phenylimide (tetrahydrofuran) and tetrachlorotungsten phenylimide (tetrahydropyran) are more preferred.

[0077] The transition metal imido complexes of the formula (1) may be used alone or in combination of two or more kinds.

[0078] The transition metal imido complex of formula (1) can be synthesized by a method of mixing an oxyhalide of a Group 6 transition metal with phenyl isocyanates or monosubstituted methyl isocyanates which may have a substituent at at least one of the 3-, 4-, and 5-positions, together with an electron-donating neutral ligand (L), alcohols, metal alkoxides, and metal aryloxides, if necessary (for example, the method described in JP-A-5-345817). The synthesized transition metal imido complex may be purified and isolated by crystallization or the like and then used in a ring-opening polymerization reaction, or the resulting mixture may be used as it is as a catalyst liquid without purification.

[0079] The amount of the transition metal imide complex of formula (1) used can be 0.00005 mol% or more and 1 mol% or less, preferably 0.0001 mol% or more and 0.2 mol%, and more preferably 0.0002 mol% or more and 0.1 mol% or less, relative to 100 mol% of the norbornene monomer. If it is within the above range, it is possible to sufficiently avoid the difficulty in removing the catalyst, and to obtain sufficient polymerization activity.

[0080] <<Activator>> The transition metal imido complex of formula (1) exhibits catalytic activity even when used alone, but can become a more active polymerization catalyst when combined with an activator.

[0081] The activator may be a compound of Groups 1, 2, 12, 13, or 14 of the periodic table having a hydrocarbon group (e.g., an alkyl group) with 1 to 20 carbon atoms. Among these, organolithium, organomagnesium, organozinc, organoaluminum, or organotin is preferably used, and organoaluminum or organotin is particularly preferably used.

[0082] Examples of the organolithium include methyllithium, n-butyllithium, and phenyllithium. Examples of the organic magnesium include butylethylmagnesium, butyloctylmagnesium, dihexylmagnesium, ethylmagnesium chloride, n-butylmagnesium chloride, and allylmagnesium bromide. Examples of the organic zinc include dimethyl zinc, diethyl zinc, and diphenyl zinc. Examples of the organoaluminum include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum ethoxide, diisobutylaluminum isobutoxide, ethylaluminum diethoxide, and isobutylaluminum diisobutoxide. Examples of the organotin include tetramethyltin, tetra(n-butyl)tin, and tetraphenyltin.

[0083] The activators may be used alone or in combination of two or more kinds.

[0084] When an activator is used, the amount of the activator used can be 0.1 to 100 times by mole, preferably 0.2 to 50 times by mole, and more preferably 0.5 to 20 times by mole, relative to the transition metal imido complex of formula (1). Within the above range, the polymerization activity can be sufficiently improved by using the activator, and side reactions can be sufficiently avoided.

[0085] <<Other Auxiliaries>> In order to control the polymerization rate and the molecular weight distribution of the resulting polymer, a Lewis base can be further added. Examples of Lewis bases include ethers such as diethyl ether and tetrahydrofuran; ketones such as acetone and cyclohexanone; nitriles such as acetonitrile and benzonitrile; amines such as triethylamine and N,N-diethylaniline; pyridines such as pyridine and lutidine; phosphines such as triphenylphosphine; amides such as dimethylformamide; sulfoxides such as dimethyl sulfoxide; phosphine oxides such as triphenylphosphine oxide; esters such as ethyl acetate; and the like. Among these, ethers, pyridines, and nitriles are preferred. The Lewis base may be used alone or in combination of two or more.

[0086] When a Lewis base is used, the amount used may be 0.1 to 1,000 times by mole, preferably 0.2 to 500 times by mole, and more preferably 0.5 to 200 times by mole, relative to the amount of the transition metal imido complex of formula (1).

[0087] <Chain transfer agent> In the polymerization reaction, a chain transfer agent can be used. By using the chain transfer agent, the molecular weight of the resulting ring-opening polymer can be adjusted and the content of dimers and the like can be effectively reduced.

[0088] Chain transfer agents include α-olefins, internal olefins, aromatic vinyl compounds, etc. Internal olefins are compounds that have a double bond inside the olefin chain rather than at the end of the chain. Aromatic vinyl compounds include compounds that have a substituent (e.g., an alkyl group) on the vinyl group.

[0089] Examples of the α-olefin include alkenes having 2 to 20 carbon atoms and a double bond at the α-position, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. The internal olefins include 2-butene, 3-hexene, and the like. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, and 4-t-butylstyrene. Among these, from the viewpoints of reactivity and molecular weight controllability, 1-hexene, styrene and 1-decene are preferred, and 1-hexene and styrene are more preferred.

[0090] The chain transfer agents may be used alone or in combination of two or more kinds.

[0091] When a chain transfer agent is used, the amount of the chain transfer agent can be 0.1 mol% or more and less than 15 mol% based on 100 mol% of the norbornene monomer. Within the above range, the effect of using the chain transfer agent can be sufficiently obtained. From the viewpoint of reducing the content of dimers, etc., the amount of the chain transfer agent is preferably 0.3 mol% or more and less than 10 mol%, more preferably 0.5 mol% or more and 9 mol% or less, and even more preferably 1 mol% or more and 6 mol% or less.

[0092] <Organic solvent> The polymerization reaction is usually carried out in an organic solvent.

[0093] The organic solvent is not particularly limited as long as it can dissolve or disperse the norbornene-based monomer and the target norbornene-based polymer and is inactive in the reaction. For example, Aliphatic hydrocarbons such as pentane, hexane, and heptane; Alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, tricyclodecane, hexahydroindene, and cyclooctane; Aromatic hydrocarbons such as benzene, toluene, and xylene; Halogenated aliphatic hydrocarbons such as dichloromethane, chloroform, and 1,2-dichloroethane; Halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene; Nitrogen-containing hydrocarbon solvents such as nitromethane, nitrobenzene, and acetonitrile; Ethers such as diethyl ether and tetrahydrofuran; or mixed solvents thereof. Among these solvents, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and ethers are preferably used.

[0094] The organic solvent may be used alone or in combination of two or more kinds.

[0095] The organic solvent can be used in an amount such that the concentration of the norbornene monomer is 1% by mass or more and 50% by mass or less, preferably 2% by mass or more and 45% by mass or less, and more preferably 3% by mass or less and 40% by mass or less. If the amount is within the above range, the productivity is sufficient and the handling is convenient.

[0096] <Polymerization reaction conditions> The polymerization reaction can be carried out by stirring a norbornene monomer, a transition metal imide complex of formula (1), and an optional activator and chain transfer agent in an organic solvent. The present invention is characterized in that at least a portion of the norbornene monomer is added continuously.

[0097] The components other than the norbornene-based monomer to be continuously added may be charged in advance into the reactor and stirred. The reaction solution in the reactor may be continuously stirred during the continuous addition of the norbornene-based monomer to allow the polymerization reaction to proceed.

[0098] The norbornene monomer may be added continuously in its entirety or in part. From the viewpoint of reaction selectivity and reaction stability, it is preferable that only a part of the norbornene monomer is added continuously, and the remainder is charged in the reactor in advance. The amount of the norbornene monomer charged in advance in the reactor can be 0.1% by mass or more and 70% by mass or less, preferably 0.5% by mass or more and 50% by mass or less, and more preferably 1% by mass or more and 35% by mass or less, when the total amount is taken as 100% by mass. If it is within the above range, it is easy to control the weight average molecular weight of the obtained polymer.

[0099] The continuous addition of the norbornene monomer can be carried out by continuously dropping the norbornene monomer dissolved or dispersed in the organic solvent as a liquid. The concentration of the norbornene monomer in the liquid can be 1% by mass or more and 50% by mass or less, preferably 2% by mass or more and 45% by mass or less, and more preferably 3% by mass or more and 40% by mass or less. Within this range, the productivity is sufficient and it is convenient in terms of handling.

[0100] The time for continuous addition can be from 20 minutes to 200 minutes, preferably from 40 minutes to 180 minutes, more preferably from 60 minutes to 160 minutes, from the viewpoint of stereochemical control.

[0101] The polymerization temperature can be from 20° C. to 60° C. From the viewpoint of stereochemical control, it is preferably from 25° C. to 55° C., more preferably from 30° C. to 50° C.

[0102] The temperature of the norbornene monomer to be continuously added can be from 20° C. to 60° C. From the viewpoint of stereochemical control, it is preferably from 22.5° C. to 50° C., more preferably from 25° C. to 45° C.

[0103] From the viewpoint of molecular weight control, the continuous addition of the norbornene monomer is preferably carried out so that the polymerization conversion rate of the norbornene monomer in the polymerization reaction system at the end of the continuous addition is 40% or more. The polymerization conversion rate is more preferably 60% or more. The polymerization conversion rate can be controlled by adjusting the addition conditions such as the rate of addition of the norbornene monomer and the polymerization reaction conditions such as the polymerization temperature. When the conditions other than the rate of addition are the same, the polymerization conversion rate tends to increase when the rate is increased and tends to decrease when the rate is decreased, and the polymerization conversion rate tends to increase when the temperature is high and decreases when the temperature is low. The upper limit is not particularly limited, but is usually 99% or less.

[0104] After the continuous addition is completed, the reaction solution is continuously stirred to complete the polymerization reaction. The time for mixing and stirring after the completion can be 15 minutes or more and 300 minutes or less. From the viewpoint of the polymerization conversion rate and productivity, it is preferably 20 minutes or more and 270 minutes or less, and more preferably 30 minutes or more and 240 minutes or less.

[0105] At least a part of the transition metal imido complex may be added continuously. This is expected to improve reaction selectivity. The transition metal imido complex to be added continuously can be dissolved or dispersed in the organic solvent as a liquid and then dropped continuously. The concentration of the transition metal imido complex in the liquid can be 0.01% by mass or more and 20% by mass or less. From the viewpoint of the solution stability of the complex, the concentration is preferably 0.1% by mass or more and 15% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less. The timing of the continuous addition may be the same as or different from the timing of the continuous addition of the norbornene monomer.

[0106] When a chain transfer agent is used, in terms of controlling stereochemistry and reducing the content of dimers and the like, the amount of the norbornene-based polymer continuously added per mole of the chain transfer agent can be set to 0.060 mol / min or more, preferably 0.080 mol / min or more, and can be set to 2.000 mol / min or less, preferably 1.000 mol / min or less.

[0107] The addition polymerization can be carried out in the presence of, for example, a Ziegler-Natta catalyst, a metallocene catalyst, a nickel catalyst, or a palladium catalyst. The addition polymerization may be carried out under reaction conditions obtained by appropriately modifying known reaction conditions.

[0108] <Hydrogenation process> The norbornene polymer obtained in the polymerization step has a carbon-carbon double bond in the main chain. Depending on the type of monomer used in the polymerization, the norbornene polymer may have a carbon-carbon double bond in the main chain, or in a substituent bonded to a five-membered ring or in a condensed ring with a five-membered ring (hereinafter referred to as a side chain). By hydrogenating the norbornene polymer, these carbon-carbon double bonds are hydrogenated to form saturated bonds, thereby obtaining a hydrogenated product. By making the norbornene polymer into a hydrogenated product, properties such as heat resistance, weather resistance, light resistance, solvent resistance, chemical resistance, and water resistance may be improved. As a method for hydrogenation, a known method can be used, and for example, hydrogen can be supplied to a solution of a norbornene polymer in the presence of a hydrogenation catalyst to cause an addition reaction. The hydrogenation catalyst is preferably a catalyst that hydrogenates the carbon-carbon double bond in the main chain and does not hydrogenate the naphthalene ring of the naphthyl group. Examples of such hydrogenation catalysts include ruthenium catalysts (chlorohydridocarbonyltris(triphenylphosphine)ruthenium) and palladium catalysts. Hydrogen may be supplied, for example, by adding hydrogen at high pressure (e.g., 1 MPa or higher) and stirring at high temperature (e.g., 120°C or higher).

[0109] <Recovery process> The norbornene polymer obtained in the polymerization step or the hydrogenated product obtained in the hydrogenation step can be recovered as a cyclic olefin polymer. For example, the reaction solution can be mixed with a precipitant (e.g., a poor solvent such as isopropanol or methanol) to precipitate the cyclic olefin polymer, and the cyclic olefin polymer can be recovered as a precipitate. The recovered cyclic olefin polymer may be dried (e.g., vacuum dried).

[0110] (Physical Properties of Cyclic Olefin Polymers) <Refractive index> The refractive index may vary depending on the wavelength and temperature, and may be measured under any wavelength and temperature conditions. In this specification, however, the refractive index is defined as the refractive index at 25° C. for light with a wavelength of 587.6 nm (n d The refractive index (n d In order to ensure that the optical element exhibits its optical function, the refractive index (n d ) is preferably 1.640 or less, and more preferably 1.635 or less, in order for the optical element to function properly.

[0111] <Abbe number> The Abbe number is a value calculated based on the refractive index at three wavelengths. There are various definitions depending on the combination of wavelengths. In this specification, the Abbe number is defined as the Abbe number (ν d ) is used. ν d =(n d -1) / (n F -n C ) (1) In formula (1), n d , n C , and n F represent the refractive indices at wavelengths of 587.6 nm, 656.3 nm, and 486.1 nm at 25° C., respectively. The Abbe number (ν d ) is preferably 20 or more, more preferably 21 or more. In addition, the Abbe number (ν d ) is preferably 50 or less, and more preferably 49 or less, in order to reduce chromatic aberration of the optical element.

[0112] <Stress birefringence> Stress birefringence (C R) applies stress (F) to a measurement sample, and then measures the in-plane retardation (Re(b) [nm]) and thickness (T(b) [mm]) at the center of the measurement sample at a specific wavelength (e.g., 543 nm), and the Δn value can be calculated by the following formulas (X1) and (X2). δn=Re(b)×(1 / T(b))×10 -6 (X1) C R =δn / F(X2) The closer the δn value is to 0, the smaller the birefringence. Also, a film having a slow axis in the stretching direction has a positive value, whereas a film having a slow axis perpendicular to the stretching direction has a negative value. R ) is -500×10 -12 Pa -1 It is preferable that the value is equal to or greater than -400×10 -12 Pa -1 More preferably, the stress birefringence (C R ) is a 1400×10 -12 Pa -1 It is preferable that the value is less than 900×10 -12 Pa -1 It is more preferable that:

[0113] <Glass transition temperature> The glass transition temperature of the cyclic olefin polymer of the present invention may be, for example, from 40° C. to 200° C. The glass transition temperature can be controlled, for example, by adjusting the composition of the monomer composition used in synthesizing the cyclic olefin polymer of the present invention.

[0114] (Applications of cyclic olefin polymers) <Composition> The cyclic olefin polymer of the present invention can be used as a composition. The composition further contains the cyclic olefin polymer of the present invention, and optionally additives such as weather stabilizers, heat stabilizers, antistatic agents, flame retardants, slip agents, antiblocking agents, antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, and fillers, and solvents. The cyclic olefin polymer of the present invention and the additive or solvent can be mixed using a known mixing method.

[0115] Specifically, the additives may be those exemplified in JP-A-2005-330465, etc. The solvent may be any of the known solvents such as the organic solvents described above.

[0116] The cyclic olefin polymer of the present invention or a composition containing the cyclic olefin polymer of the present invention can be advantageously used as a material for optical elements and the like.

[0117] <Molded body> The cyclic olefin polymer of the present invention can be used as a molded article. The molded article is obtained by molding the cyclic olefin polymer of the present invention or a composition containing the cyclic olefin polymer of the present invention. The molded article obtained from the cyclic olefin polymer of the present invention can be advantageously used as an optical element or the like.

[0118] Examples of methods that can be used to form the molded body 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. EXAMPLES

[0119] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0120] <Physical property evaluation method> Various physical properties were measured according to the following methods.

[0121] (Method of measuring weight average molecular weight Mw) Weight average molecular weight Mw was measured by gel permeation chromatography (GPC) using cyclohexane as an eluent, and calculated as a value converted into standard polyisoprene. Standard polyisoprene manufactured by Tosoh Corporation was used as the standard polyisoprene. When the sample was not soluble in cyclohexane, it was measured by GPC using tetrahydrofuran (THF) as an eluent, and calculated as a value converted into standard polystyrene. Standard polystyrene manufactured by Tosoh Corporation was used as the standard polystyrene.

[0122] (Method of measuring glass transition temperature) The glass transition temperature (Tg) was measured using a differential scanning calorimeter (manufactured by Nano Technology Corporation, product name: DSC6220SII) in accordance with JIS K 6911 at a temperature rise rate of 10° C. / min.

[0123] (Stress birefringence of polymer C R (Method of measurement) The polymer was molded into a sheet of 35 mm length x 10 mm width x 1 mm thickness to obtain a sample sheet. Both ends of the sample sheet were fixed with clips, and then a weight of 55 g was fixed to one of the clips. Next, the sample sheet was hung for 1 hour in an oven set to the glass transition temperature (Tg) of the polymer + 15 ° C., starting from the clip on the side to which the weight was not fixed, and stretched. Thereafter, the sample sheet was slowly cooled to room temperature to obtain a measurement sample. The in-plane retardation (Re(b) [nm]) of the center of the measurement sample was measured at a wavelength of 543 nm using a birefringence meter (Photonic Lattice Co., Ltd., "WPA-100"). The thickness (T(b) [mm]) of the center of the measurement sample was also measured. Using these measured values ​​Re(b) and T(b), the Δn value was calculated according to the following formula (X1). δn=Re(b)×(1 / T(b))×10 -6 (X1) Using the δn value and the stress (F) applied to the sample, the stress birefringence (C R ) was calculated. C R=δn / F [Pa -1 ] (X2) The closer the δn value is to 0, the smaller the birefringence. Also, a film whose slow axis is in the stretching direction exhibits a positive value, while a film whose slow axis is perpendicular to the stretching direction exhibits a negative value.

[0124] (Refractive index measurement) The sample was formed into a sheet having a thickness of 5 mm and left in an atmosphere of [glass transition temperature (Tg) - 15]°C for 20 hours to prepare a measurement sample. The refractive index (n d , n C , and n F The refractive index for light with a wavelength of 587.6 nm is shown in the table.

[0125] (Abbe number measurement) The refractive index (n d , n C , and n F ) to calculate the Abbe number (ν d ) was calculated. ν d =(n d -1) / (n F -n C ) (1) In formula (1), n d , n C , and n F represent the refractive indices at wavelengths of 587.6 nm, 656.3 nm, and 486.1 nm, respectively.

[0126] <Synthesis Example 1: Method for Producing exo-1-naphthylnorbornene Monomer> 458g of 1-bromonaphthalene (manufactured by Wako Pure Chemical Industries, Ltd.), 500mL of dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.), 455mL of norbornadiene (manufactured by Tokyo Chemical Industry Co., Ltd.), 656mL of piperidine (manufactured by Wako Pure Chemical Industries, Ltd.), 220mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.), and 2.75g of a palladium catalyst (palladium dichlorobistriphenylphosphine, manufactured by Tokyo Chemical Industry Co., Ltd., product code: B1667) were charged and stirred at 90°C for 6.5 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. This was filtered and evaporated. The residue was subjected to column chromatography (developing solvent: hexane) to remove the palladium residue. The obtained solution was evaporated, and the remaining liquid was distilled under reduced pressure (1.2mmHg / 135-152°C). 269 ​​g of exo-1-naphthylnorbornene (exo-1-NaphNB) was obtained as a colorless, transparent liquid represented by the following formula. Its peak purity was measured by gas chromatography and found to be 95.0%.

[0127] [ka]

[0128] <Synthesis Example 2: Method for Producing exo-2-naphthylnorbornene Monomer> 458g of 2-bromonaphthalene (manufactured by Wako Pure Chemical Industries, Ltd.), 500mL of dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.), 455mL of norbornadiene (manufactured by Tokyo Chemical Industry Co., Ltd.), 656mL of piperidine (manufactured by Wako Pure Chemical Industries, Ltd.), 220mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.), and 2.75g of a palladium catalyst (palladium dichlorobistriphenylphosphine, manufactured by Tokyo Chemical Industry Co., Ltd., product code: B1667) were charged and stirred at 90°C for 6.5 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. This was filtered and evaporated. The residue was subjected to column chromatography (developing solvent: hexane) to remove the palladium residue. The obtained solution was evaporated, and the remaining liquid was distilled under reduced pressure (1.2mmHg / 135-152°C). 269 ​​g of exo-2-naphthylnorbornene (exo-2-NaphNB) was obtained as a colorless, transparent liquid represented by the following formula. Its peak purity was measured by gas chromatography and found to be 95.0%.

[0129] [ka]

[0130] Example 1: Preparation and evaluation of norbornene-based polymer (1-1) Preparation of ring-opening polymer In a glass reaction vessel with the inside replaced with nitrogen, 96g of dehydrated toluene, 2mol% of 1-hexene, and 1.2mol% of diethylaluminum ethoxide (Et2Al(OEt)) were mixed at room temperature, and then 0.4mol% of a 2.0wt% toluene solution of tetrachlorotungsten phenylimide (tetrahydrofuran) (complex 1) was added in its entirety while maintaining the temperature at 50℃. Then, a mixed monomer of exo-2-naphthylnorbornene and tetracyclododecene (TCD) (molar ratio = 56:44, total 0.03mol) was added continuously over 2 hours to carry out ring-opening polymerization. Next, 48mol% of isopropyl alcohol was added to the polymerization solution to inactivate the polymerization catalyst and terminate the polymerization reaction. The total amount of the reaction solution was 121g. The weight average molecular weight Mw of the obtained ring-opening polymer was 2.5×10 4The conversion rate of the monomers to polymer was 100%. In the text, "mol%" indicates a percentage based on the number of moles of the mixed monomers.

[0131] (1-2) Production of norbornene-based polymers by hydrogenation Next, 155 g of cyclohexane was added to 95 g of the reaction solution containing the ring-opened polymer obtained in the above step (1-1), and 0.05 wt % of chlorohydridocarbonyltris(triphenylphosphine)ruthenium was further added as a hydrogenation catalyst. The mixture was pressurized to 4.5 MPa with hydrogen and heated to a temperature of 160° C. with stirring, and then reacted for 8 hours to obtain a reaction solution containing an exo-2-naphthylnorbornene / TCD ring-opened copolymer hydrogenation product. The obtained solution was poured into a large amount of isopropanol to precipitate a norbornene-based polymer as a hydrogenation product of the ring-opened polymer. The precipitated norbornene-based polymer was filtered and then dried in a vacuum dryer (200° C., 1 Torr) for 10 hours to obtain 5 g of a norbornene-based polymer. The weight average molecular weight of the norbornene-based polymer was 3.04×10 4 It was.

[0132] (1-3) Evaluation of norbornene-based polymers The glass transition temperature (Tg) and stress birefringence (C R ), refractive index (n d ), and Abbe number (ν d ) was measured by the method described above, and the results are shown in Table 1.

[0133] <Examples 2 to 7 and Comparative Example 1: Production and Evaluation of Norbornene-Based Polymers> The same as in Example 1, except that the types and composition ratios of the monomer compounds in the mixed monomer were those shown in Table 1, or that the monomer compounds shown in Table 1 were used instead of the mixed monomer. The evaluation results are shown in Table 1.

[0134] [Table 1]

[0135] The abbreviations for the compound names in Table 1 are as follows. exo-2-NaphNB: exo-2-naphthylnorbornene exo-1-NaphNB: exo-1-naphthylnorbornene TCD: Tetracyclododecene MTCD: 8-Methoxycarbonyl-8-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene MTF: 1,4-methano-1,4,4a,9a-tetrahydro-9H-fluorene [Industrial Applicability]

[0136] According to the present invention, it is possible to provide a cyclic olefin polymer having a high refractive index, a low Abbe number, and a low birefringence all at once. Furthermore, according to the present invention, it is possible to provide a composition that can be advantageously used as a material for optical elements and the like, and a molded article that can be advantageously used as an optical element and the like.

Claims

1. A structural unit derived from a naphthyl group-containing alicyclic compound (A) represented by the following formula (1): 【Chemistry 1】 [In the formula, R 2a ~R 5a Any one of them is a naphthyl group, and the remaining groups and R 1a However, each independently, (i) a hydrogen atom; (ii) a halogen atom; or (iii) A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding those containing an aromatic ring) which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. A cyclic olefin polymer which is a ring-opening polymer or a hydrogenated product thereof comprising: A cyclic olefin polymer having a ratio of structural units derived from the compound (A) to all structural units of 20 mol % or more and 100 mol % or less, and a weight average molecular weight of 18,000 or more and 100,000 or less.

2. 2. The cyclic olefin polymer according to claim 1, wherein the proportion of the structural units derived from the compound (A) in all structural units is from 20 mol % to 90 mol %.

3. R 2a ~R 5a The remaining groups other than naphthyl groups, and R 1a The cyclic olefin polymer according to claim 1 or 2, wherein: is a hydrogen atom.

4. A structural unit derived from the compound (A); and One or more structural units derived from a norbornene-based monomer (B) different from the compound (A). The cyclic olefin polymer according to any one of claims 1 to 3, which is a ring-opening polymer comprising the formula:

5. The norbornene monomer (B) is (i) norbornenes which are unsubstituted or have an alkyl group, an alkenyl group, an aromatic ring group, a polar group containing an oxygen atom, or a polar group containing a nitrogen atom as a substituent; (ii) A monomer represented by the following formula (3): 【Chemistry 2】 [In formula (3), R 1b and R 2b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; or an organic group containing a silicon atom, an oxygen atom or a nitrogen atom; R 1b and R 2b may or may not be bonded to each other to form a ring, R 3b represents a divalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; or (iii) A monomer represented by the following formula (4): 【Chemistry 3】 [In formula (4), R 4b ~R 7b each independently represents a hydrogen atom; a halogen atom; a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; or an organic group containing a silicon atom, an oxygen atom or a nitrogen atom; R 4b and R 6b may or may not be bonded to each other to form a ring, m is 1 or 2. The cyclic olefin polymer according to claim 4, wherein

6. The cyclic olefin polymer according to any one of claims 1 to 5, having a weight average molecular weight of 20,000 or more and 40,000 or less.

7. The cyclic olefin polymer according to any one of claims 1 to 6, which has a refractive index of 1.545 or more.

8. A naphthyl group-containing alicyclic compound (A) represented by the following formula (1) or a ring-opening polymer containing a structural unit derived from the compound (A): 【Chemistry 4】 [In the formula, R 2a ~R 5a is a naphthyl group; R 2a ~R 5a Other than those, and R 1 are each independently (i) a hydrogen atom; (ii) a halogen atom; or (iii) a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (excluding those containing an aromatic ring) which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. wherein a ratio of a total number of moles of the compound (A) and structural units derived from the compound (A) to a total number of moles of all monomers and structural units in a polymerization raw material is 20 mol % or more and 100 mol % or less, and the weight average molecular weight is 18,000 or more and 100,000 or less.

9. A ring-opening polymer containing the compound (A) or a structural unit derived from the compound (A); and one or more norbornene-based monomers (B) different from the naphthyl group-containing alicyclic compound (A) or a ring-opening polymer containing a structural unit derived from the norbornene-based monomer (B); A polymerization raw material comprising A polymerization raw material containing a ring-opening polymer containing a structural unit derived from the compound (A) and a structural unit derived from the norbornene-based monomer (B). The method of claim 8, comprising ring-opening polymerizing

10. The ring-opening polymerization is carried out in the presence of a metathesis polymerization catalyst, The metathesis polymerization catalyst has the formula (1): M(NR a )X 4-p (OR b ) p ・L q (1) (In the formula, M is a metal atom selected from the transition metal atoms of Group 6 of the periodic table; R a represents a phenyl group which may have a substituent at at least one of the 3-, 4- and 5-positions, or -CH 2 R c In this case, R c represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group, R b represents an optionally substituted alkyl group or an optionally substituted aryl group, X is a halogen atom, an alkyl group, an aryl group, an aralkyl group, or an alkylsilyl group; L is an electron donating neutral ligand; p is 0 or 1; q is an integer from 0 to 2, When multiple X's are present, the multiple X's may be the same or different. When multiple L's are present, the multiple L's may be the same or different. The method according to claim 8 or 9, wherein the transition metal imido complex is represented by the formula:

11. The method according to claim 8, further comprising hydrogenating the ring-opened polymer obtained by the ring-opening polymerization.

12. An optical element comprising the cyclic olefin polymer according to any one of claims 1 to 7.

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