Cyclic olefin copolymer, resin composition, and molded body

Abstract

Provided is a cyclic olefin-based copolymer having both a high refractive index and a low Abbe number. The cyclic olefin-based copolymer of the present invention contains a structural unit (A) derived from an α-olefin having 2 or more and 10 or less carbon atoms, a structural unit (B) derived from a cyclic olefin, and a structural unit (C) derived from an aromatic vinyl compound. The value obtained by dividing the total number of aromatic rings contained in the above cyclic olefin-based copolymer by the number of all repeating units in the above cyclic olefin-based copolymer is 0.25 or more.

Description

Technical Field

[0001] This invention relates to cyclic olefin copolymers, resin compositions, and molded articles. Background Technology

[0002] Cyclic olefin copolymers have attracted attention as molding materials suitable for various applications, primarily optical applications, due to their excellent optical properties, such as transparency, heat resistance, and low birefringence, as well as their processability and chemical resistance. Therefore, in recent years, various solutions have been proposed to improve the physical properties of cyclic olefin copolymers.

[0003] Specifically, for example, Patent Document 1 discloses a cyclic olefin copolymer having structural units introduced by α-olefins having 2 to 20 carbon atoms, structural units introduced by cyclic olefins, and structural units introduced by aromatic vinyl compounds represented by specific chemical formulas. Furthermore, according to Patent Document 1, this cyclic olefin copolymer has a high refractive index and can achieve an Abbe number lower than that of existing resin materials.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent document 1: International Publication No. 2019 / 188447. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In recent years, from the perspective of increasing the freedom of optical design, there has been a demand for the development of cyclic olefin copolymers with low (e.g., below 40) Abbe numbers as optical materials for optical elements such as lenses. Furthermore, cyclic olefin copolymers used as materials for various molded bodies such as optical elements also require high refractive indices.

[0009] However, there is room for further improvement in the existing cyclic olefin copolymers in terms of balancing high refractive index and low Abbe number.

[0010] Therefore, the object of the present invention is to provide a cyclic olefin copolymer that has both high refractive index and low Abbe number.

[0011] Furthermore, the object of the present invention is to provide a resin composition that can be advantageously used as a material for various molded articles such as optical elements, and a molded article formed using the resin composition.

[0012] Solution for solving the problem

[0013] The inventors conducted in-depth research with the aim of solving the above-mentioned problems. Then, the inventors discovered that cyclic olefin copolymers containing specified structural units (A) to (C) and whose total number of aromatic rings divided by the total number of repeating units results in a value greater than or equal to a specified value can achieve both high refractive index and low Abbe number, thus completing the present invention.

[0014] That is, the object of the present invention is to advantageously solve the above-mentioned problems. According to the present invention, the following cyclic olefin copolymers [1] to [4], the following resin compositions [5], and the following molded articles [6] to [7] can be provided.

[0015] [1] A cyclic olefin copolymer comprising: structural units (A) from α-olefins having 2 or more and 10 or less carbon atoms, structural units (B) from cyclic olefins, and structural units (C) from aromatic vinyl compounds, wherein the total number of aromatic rings contained in the cyclic olefin copolymer is divided by the total number of repeating units in the cyclic olefin copolymer to obtain a value of 0.25 or more.

[0016] Furthermore, in this invention, "the value obtained by dividing the total number of aromatic rings contained in the cyclic olefin copolymer by the total number of repeating units in the cyclic olefin copolymer" (hereinafter, sometimes simply referred to as "the number of aromatic rings relative to the number of repeating units") can be determined using the method described in the embodiments of this specification.

[0017] Furthermore, in this invention, "aromatic ring" refers to aromatic hydrocarbon rings such as benzene rings, and does not include heteroaromatic rings.

[0018] Furthermore, in this invention, for example, regarding fused rings such as naphthalene rings and anthracene rings formed by the fusion of multiple benzene rings, the number of benzene rings used for the formation of such fusion is referred to as the "number of aromatic rings". Thus, for example, a naphthalene ring has two aromatic rings, and an anthracene ring has three aromatic rings.

[0019] [2] According to the cyclic olefin copolymer described in [1] above, the Abbe number is 20 or more and 40 or less.

[0020] Furthermore, in this invention, the "Abbe number" can be measured using the methods described in the embodiments of this specification.

[0021] [3] According to the cyclic olefin copolymer described in [1] or [2] above, wherein the above structural unit (B) has at least one aromatic ring.

[0022] [4] The cyclic olefin copolymer according to any one of [1] to [3] above, wherein the value obtained by dividing the total number of aromatic rings contained in the cyclic olefin copolymer by the total number of repeating units in the cyclic olefin copolymer is 0.45 or more.

[0023] [5] A resin composition comprising any one of the cyclic olefin copolymers described in any one of [1] to [4] above.

[0024] [6] A molded body formed by molding the resin composition described in [5] above.

[0025] [7] The molded body according to [6] above, wherein the molded body is an optical lens.

[0026] Resin compositions comprising cyclic olefin copolymers having high refractive index and low Abbe number are preferably used for the formation of optical elements such as optical lenses.

[0027] Invention Effects

[0028] According to the present invention, a cyclic olefin copolymer with both high refractive index and low Abbe number can be provided.

[0029] 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 molded article formed using the resin composition. Detailed Implementation

[0030] The embodiments of the present invention will now be described in detail.

[0031] Here, the cyclic olefin copolymer of the present invention can be used in the preparation of the resin composition of the present invention. Furthermore, the resin composition of the present invention can be used in the formation of molded articles such as optical lenses. In addition, the molded articles of the present invention are formed using the resin composition of the present invention.

[0032] (Cyclic olefin copolymer)

[0033] The cyclic olefin polymer of the present invention comprises structural units (A) to (C), and may optionally further comprise structural units other than structural units (A) to (C).

[0034] Here, the cyclic olefin copolymer of the present invention is characterized in that the number of aromatic rings relative to the number of repeating units is 0.25 or more.

[0035] As long as the cyclic olefin polymer of the present invention contains structural units (A) to (C), it can be any of, for example, a random copolymer, a block copolymer, etc. From the viewpoint of further increasing the refractive index and further reducing the Abbe number, the cyclic olefin copolymer of the present invention is preferably a random copolymer.

[0036] <Structural Unit (A)>

[0037] The structural unit (A) is a repeating unit derived from an α-olefin with 2 or more but less than 10 carbon atoms. There are no particular limitations on α-olefins that can form structural unit (A) with 2 or more but less than 10 carbon atoms. Examples include: ethylene (2 carbon atoms), propylene (3 carbon atoms), 1-butene (4 carbon atoms), 1-pentene (5 carbon atoms), 1-hexene (6 carbon atoms), 3-methyl-1-butene (5 carbon atoms), 3-methyl-1-pentene (6 carbon atoms), 3-ethyl-1-pentene (7 carbon atoms), 4-methyl-1-pentene (6 carbon atoms), 4-methyl-1-hexene (7 carbon atoms), 4,4-dimethyl-1-hexene (8 carbon atoms), 4,4-dimethyl-1-pentene (7 carbon atoms), 4-ethyl-1-hexene (8 carbon atoms), 3-ethyl-1-hexene (8 carbon atoms), 1-octene (8 carbon atoms), 1-decene (10 carbon atoms), etc. Among these, from the viewpoint of ensuring good polymerization ease of cyclic olefin copolymers, α-olefins with 2 or more and 4 or less carbon atoms are preferred, α-olefins with 2 or more and 3 or less carbon atoms are more preferred, and ethylene is even more preferred.

[0038] In addition, α-olefins with 2 or more but less than 10 carbon atoms can be used alone or in combination of two or more.

[0039] Furthermore, the content of structural unit (A) in the cyclic olefin copolymer is preferably 30 mol% or more, more preferably 35 mol% or more, more preferably 85 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and particularly preferably less than 50 mol%. If the content of structural unit (A) is within the above range, the refractive index of the cyclic olefin copolymer can be further increased, and the Abbe number can be further reduced.

[0040] <Structural Unit (B)>

[0041] Structural unit (B) is a repeating unit derived from a cyclic olefin. There are no particular limitations on the cyclic olefin capable of forming structural unit (B), and examples include: norbornene compounds; cyclic olefins; and non-norbornene compounds with aromatic rings such as acenaphthene, cyclopentapyrene, 1H-cyclopenta[l]phenanthrene, and 2-methylcyclopenta[l]phenanthrene (compounds that have an aromatic ring within the molecule but not a norbornene ring). From the viewpoint of further increasing the refractive index of the cyclic olefin copolymer and further reducing the Abbe number, norbornene compounds are particularly preferred.

[0042] In addition, cyclic olefins can be used alone or in combination of two or more.

[0043] Here, norbornene compounds are broadly classified into norbornene compounds with aromatic rings (compounds that have both norbornene and aromatic rings within the molecule) and norbornene compounds without aromatic rings (compounds that have neitherbornene norbornene rings within the molecule but without aromatic rings).

[0044] Furthermore, examples of norbornene compounds with aromatic rings include: phenyl norbornene such as 5-phenyl-2-norbornene; naphthyl norbornene such as 1-naphthyl norbornene and 2-naphthyl norbornene; 5-methyl-5-phenyl-bicyclo[2.2.1]hept-2-ene, 5-benzyl-bicyclo[2.2.1]hept-2-ene, 5-tolyl-bicyclo[2.2.1]hept-2-ene [i.e., 5-(4-methylphenyl)-2-norbornene], 5-(ethylphenyl)-bicyclo[2.2.1]hept-2-ene, 5-(isopropylphenyl)-bicyclo[2.2.1]hept-2-ene, 5-methyl-5-carboxybenzylbicyclo[2.2.1]hept-2-ene, and 8-phenyl-tetracyclo[4.4.0.1²]hept-2-ene. ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-Methyl-8-phenyl-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-Benzyl-Tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-Tolyl-Tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(ethylphenyl)-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(isopropylphenyl)-tetracyclo[4.4.0.1² ,5 .17, ¹ 0 ]-3-Dodecene, 8,9-Diphenyl-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(biphenyl)-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(β-naphthyl)-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(α-naphthyl)-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 8-(anthrayl)-tetracyclo[4.4.0.1² ,5 .1 7, ¹ 0 ]-3-Dodecene, 11-Phenyl-hexacyclo[6.6.1.1³ ,6 .1¹ 0, ¹³.0² ,7 .0 9, ¹ 4 ]-4-Heptadecanene, 6-(α-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5-(anthrayl)-bicyclo[2.2.1]-hept-2-ene, 5-(biphenyl)-bicyclo[2.2.1]-hept-2-ene, 5-(β-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5,6-diphenyl-bicyclo[2.2.1]-hept-2-ene, 9-(2-norbornene-5-yl)-carbazole, 1,4-methylbridged-1,4,4a,4b,5,8,8a,9a-octahydrofluorene, 1,4-methylbridged-1,4,4a,9a-tetrahydrofluorene, 1,4-methylbridged-8-methyl-1,4,4a,9a-tetrahydrofluorene, 1,4 - Methioninated-8-chloro-1,4,4a,9a-tetrahydrofluorene, 1,4-methioninated-8-bromo-1,4,4a,9a-tetrahydrofluorene, 1,4-methioninated-1,4,4a,9a-tetrahydrodibenzofuran, 1,4-methioninated-1,4,4a,9a-tetrahydrocarbazole, 1,4-methioninated-9-phenyl-1,4,4a,9a-tetrahydrocarbazole, 1,4-methioninated-1,4,4a,5,10,10a-hexahydroanthracene, 7,10-methioninated-6b,7,10,10a-tetrahydrofluoranthracene, cyclopentadiene-acenaphthene adduct, compounds obtained by further addition of cyclopentadiene to cyclopentadiene-acenaphthene adduct, 11,12-benzo-pentane [6.5.1.1³] ,6 0.0² ,7 .0 9,¹³]-4-pentadecanene, 11,12-benzo-pentacyclo[6.6.1.1³] ,6 0.0² ,7 .0 9, ¹ 4 ]-4-Hexadecene, 14,15-benzo-heptacyclo[8.7.0.1² ,9 .1 4,7 .1¹¹ , ¹ 7 0.0³ ,8 0¹² , ¹ 6 [5-Eicosene, 5,5a,6,9,9a,10,10a,11-octahydro-4bH-5,10;6,9-dimethylbridged-benzo[b]fluorene, and their derivatives, etc. Furthermore, a derivative refers to a derivative having substituents in its ring structure. Moreover, there are no particular limitations on the substituents that can be present in the ring structure; examples include alkyl, alkylene group, vinyl, alkoxycarbonyl, and alkylidene group. Furthermore, the ring structure of the derivative may have one or more of these substituents.

[0045] Furthermore, examples of norbornene compounds that do not possess an aromatic ring include, for instance, tetracyclic [6.2.1.1³, 6 .0², 7 Dodecyl-4-ene (common name: tetracyclododecene), 2-ethylidene-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethylbridged naphthalene (common name: ethylidene tetracyclododecene), tricyclic [5.2.1.0², 6 ] Dec-3,8-diene (common name: dicyclopentadiene), 5-ethylidene bicyclo[2.2.1]hept-2-ene (common name: ethylidene norbornene), bicyclo[2.2.1]hept-2-ene (also known as "norbornene"), 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-methylene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, tetracyclo[10.2.1.0² , ¹¹.0 4,9 [Pentadecyl-4,6,8,13-tetraene, 9-methyl-tetracyclo[6.2.1.1³] ,6 0.0² ,7 [dodecyl-4-ene, 9-ethyl-tetracyclo[6.2.1.1³]] ,6 0.0² ,7 Dodecyl-4-ene, 9-methylene-tetracyclo[6.2.1.1³] ,6 0.0² ,7[dodec-4-ene, 9-ethylidene-tetracyclo[6.2.1.1³]] , 6 0.0² ,7 [dodec-4-ene, 9-vinyl-tetracyclo[6.2.1.1³]] ,6 0.0² ,7 [dodec-4-ene, 9-propenyl-tetracyclo[6.2.1.1³]] ,6 0.0² ,7 Dodecyl-4-ene, pentacyclic [9.2.1.1³] ,9 0.0² , ¹ 0 .0 4,8 [Pentadecyl-5,12-diene, tetracyclic [9.2.1.0²] , ¹ 0 0.0³ ,8 [Tetradecane-3,5,7,12-tetraene, pentacyclic [9.2.1.1³]] ,9 0.0² , ¹ 0 .0 4,8 Pentadecan-12-ene and their derivatives, etc.

[0046] In the above compounds, from the viewpoint of further increasing the refractive index of the cyclic olefin copolymer and further reducing the Abbe number, norbornene compounds having an aromatic ring are preferred, and 1,4-methylbridged-1,4,4a,9a-tetrahydrofluorene and 5,5a,6,9,9a,10,10a,11-octahydro-4bH-5,10;6,9-dimethylbridged-benzo[b]fluorene are more preferred.

[0047] From the viewpoint of further increasing the refractive index of the cyclic olefin copolymer and further reducing the Abbe number, the structural unit (B) preferably has at least one aromatic ring. Moreover, as a cyclic olefin capable of forming a structural unit (B) with an aromatic ring, examples include the aforementioned norbornene compound with an aromatic ring.

[0048] Furthermore, there is no particular limit to the number of aromatic rings in the structural unit (B), which can be, for example, 5 or less, or 3 or less.

[0049] The content of structural unit (B) in the cyclic olefin copolymer is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less. If the content of structural unit (B) is within the above range, the refractive index of the cyclic olefin copolymer can be further increased, and the Abbe number can be further reduced.

[0050] <Structural Unit (C)>

[0051] The structural unit (C) is a repeating unit derived from an aromatic vinyl compound. There are no particular limitations on the aromatic vinyl compounds capable of forming the structural unit (C), but examples include: styrene, styrene sulfonic acid and its salts, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, 5-tert-butyl-2-methylstyrene, butoxystyrene, 4-methoxystyrene, vinyltoluene, chlorostyrene, and other aromatic vinyl compounds having one aromatic ring; 1-vinylnaphthalene, 2-vinylnaphthalene, 4-vinylbiphenyl, 2-vinylfluorene, 9-vinylfluorene, and other aromatic vinyl compounds having two aromatic rings; 1-vinylanthracene, 2-vinylanthracene, 9-vinylanthracene, 1-vinylphenanthrene, 2-vinylphenanthrene, 3-vinylphenanthrene, 4-vinylphenanthrene, 9-vinylphenanthrene, and other compounds having three aromatic rings. Aromatic vinyl compounds having 1 to 3 aromatic rings are particularly preferred, aromatic vinyl compounds having 1 to 2 aromatic rings are more preferred, styrene, 2-vinylnaphthalene, and 4-vinylbiphenyl are even more preferred, and 2-vinylnaphthalene and 4-vinylbiphenyl are especially preferred.

[0052] In addition, aromatic vinyl compounds can be used alone or in combination of two or more.

[0053] Furthermore, the content of structural unit (C) in the cyclic olefin copolymer is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, preferably 50 mol% or less, and more preferably 45 mol% or less. If the content of structural unit (C) is within the above range, the refractive index of the cyclic olefin copolymer can be further increased, and the Abbe number can be further reduced.

[0054] <Other structural units>

[0055] Other compounds that can form other structural units are not particularly limited, and examples include compounds that can copolymerize with the above-mentioned compounds.

[0056] In addition, other compounds can be used alone or in combination of two or more.

[0057] Furthermore, the other structural units in the cyclic olefin copolymer are typically less than 20 mol%, preferably less than 10 mol%, more preferably less than 5 mol%, further preferably less than 1 mol%, and particularly preferably 0 mol% (i.e., the cyclic olefin copolymer does not contain other structural units).

[0058] <Characteristics>

[0059] [Weight-average molecular weight]

[0060] The weight-average molecular weight of the cyclic olefin polymer of the present invention is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 17,500 or more, particularly preferably 20,000 or more, preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 70,000 or less. If the weight-average molecular weight of the cyclic olefin polymer is 10,000 or more, the reduction in strength of the molded article obtained using the cyclic olefin polymer can be suppressed. On the other hand, if the weight-average molecular weight of the cyclic olefin polymer is 200,000 or less, the occurrence of molding defects caused by deterioration of flowability during molding of the cyclic olefin polymer can be suppressed.

[0061] Furthermore, in this invention, the weight-average molecular weight can be determined using the methods described in the examples of this specification.

[0062] Glass transition temperature

[0063] The glass transition temperature of the cyclic olefin polymer of the present invention is preferably 50°C or higher, more preferably 80°C or higher, even more preferably 110°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 polymer is 50°C or higher, the deterioration of optical properties caused by heat deformation due to deterioration of heat resistance can be suppressed. On the other hand, if the glass transition temperature of the cyclic olefin polymer is 200°C or lower, the oxidative degradation of the cyclic olefin polymer caused by excessively high processing temperatures during molding can be suppressed.

[0064] In addition, the "glass transition temperature" can be measured, for example, according to JIS K7121.

[0065] Abbe numbers

[0066] The Abbe number of the cyclic olefin polymer of the present invention is preferably 15 or more, more preferably 20 or more, more preferably 40 or less, and more preferably 35 or less. If the Abbe number is within the above range, a high-performance lens module can be designed.

[0067] [Number of aromatic rings relative to the number of repeating units]

[0068] Here, the value obtained by dividing the total number of aromatic rings contained in the cyclic olefin copolymer by the total number of repeating units in the cyclic olefin copolymer (the number of aromatic rings relative to the number of repeating units) needs to be 0.25 or more. When the number of aromatic rings relative to the number of repeating units is less than 0.25, the refractive index decreases and the Abbe number increases. Moreover, the number of aromatic rings relative to the number of repeating units is preferably 0.45 or more, more preferably 0.55 or more, and even more preferably 0.65 or more. If the number of aromatic rings relative to the number of repeating units is 0.45 or more, the refractive index of the cyclic olefin copolymer can be further increased, and the Abbe number can be further reduced. In addition, there is no particular upper limit to the number of aromatic rings relative to the number of repeating units, and it can be, for example, 2.00 or less, or 1.50 or less.

[0069] <Preparation Methods of Cyclic Olefin Copolymers>

[0070] The preparation method of cyclic olefin copolymers is not particularly limited, and they can be manufactured by copolymerizing (addition polymerization) a monomer composition containing α-olefins, cyclic olefins, and aromatic vinyl compounds having 2 or more and 10 or fewer carbon atoms with any other compounds in a hydrocarbon solvent in the presence of a catalyst. Examples of such methods include those described in Japanese Patent Application Publication Nos. 2016-155327 and 2020-079357.

[0071] (Resin Composition)

[0072] The resin composition of the present invention comprises the above-described cyclic olefin copolymer of the present invention, and optionally further comprises polymeric materials other than the cyclic olefin copolymer of the present invention, and various additives.

[0073] Furthermore, since the resin composition of the present invention contains the cyclic olefin copolymer of the present invention, which has both high refractive index and low Abbe number, it can be used particularly advantageously as a material for various molded articles such as optical elements.

[0074] Here, there are no particular limitations on the polymer materials and additives that can be contained in the resin composition, and examples include the polymer materials and additives described in Japanese Patent Application Publication No. 10-139865.

[0075] Furthermore, there are no particular limitations on the polymeric materials and additives, as long as they can be sufficiently dispersed in the cyclic olefin copolymer, and they can be mixed with the cyclic olefin copolymer using any method. Specifically, the polymeric materials and additives can be added at any stage of the preparation of the cyclic olefin copolymer, can be mixed with the cyclic olefin copolymer using a mixer, or can be mixed with the cyclic olefin copolymer in a molding apparatus.

[0076] (Molded body)

[0077] The molded articles of the present invention are formed using the resin composition of the present invention, and because they contain the cyclic olefin copolymer of the present invention, they can exhibit excellent performance.

[0078] Here, as molding methods, methods such as injection molding, extrusion blow molding, injection blow molding, two-step blow molding, multi-layer blow molding, joint blow molding, stretch blow molding, rotational molding, vacuum molding, extrusion molding, calendering, solution casting, thermoforming, and inflation method can be used.

[0079] The molded body of the present invention is particularly preferably a lens, and more preferably an optical lens.

[0080] Moreover, the lens is not particularly limited and can be obtained by, for example, by uniformly heating and melting the resin composition of the present invention to form a preform, then heating and stretching the preform, and then heat-fixing as needed.

[0081] Example

[0082] The present invention will now be specifically described based on embodiments, but the present invention is not limited to these embodiments. Furthermore, in the following description, unless otherwise specified, "%" and "parts" refer to quantities based on mass. Moreover, in the embodiments and comparative examples, various measurements and evaluations were performed using the following methods.

[0083] (1) Weight-average molecular weight

[0084] The weight-average molecular weight (Mw) of the cyclic olefin copolymers was determined by gel permeation chromatography (product name "HLC-8320" manufactured by Tosoh Corporation).

[0085] In addition, the weight-average molecular weight (Mw) of the cyclic olefin copolymers obtained in the examples other than Comparative Example 2 and the Comparative Examples was obtained using a measuring apparatus consisting of three chromatographic columns manufactured by Tosoh Corporation (TSKgel SuperH2000, TSKgel SuperH4000 and TSKgel SuperH5000) connected in series, with tetrahydrofuran as the developing solvent, and as the polystyrene conversion value.

[0086] Furthermore, regarding the weight-average molecular weight (Mw) of the cyclic olefin copolymer obtained in Comparative Example 2, it was determined using a measuring apparatus consisting of three chromatographic columns manufactured by Tosoh Corporation (TSKgel G2000HXL, TSKgel G4000HXL, and TSKgel G5000HXL) connected in series, with cyclohexane as the developing solvent, and as the polyisoprene conversion value.

[0087] (2) Number of aromatic rings relative to the number of repeating units

[0088] Determination of cyclic olefin copolymers 1 H and 13 C-NMR (nuclear magnetic resonance) spectra were used to determine the proportion (mol%) of structural units (A) to (C) in the polymer using the integrated values ​​of the signals from structural units (A) to (C) respectively. Furthermore, the "number of aromatic rings relative to the number of repeating units" was calculated according to the following formula (1).

[0089] [Mathematical Expression 1]

[0090]

[0091] In equation (1),

[0092] a: The percentage (mol%) of structural unit (A)

[0093] b: The percentage (mol%) of structural unit (B)

[0094] c: The percentage (mol%) of structural unit (C)

[0095] x: The number of aromatic rings possessed by the monomers capable of forming structural unit (B).

[0096] y: The number of aromatic rings possessed by the monomers capable of forming structural units (C).

[0097] Where a+b+c=100.

[0098] (3) Refractive index

[0099] The cyclic olefin copolymers prepared in the examples and comparative examples were hot-pressed into sheets and used as test samples.

[0100] For the obtained test samples, the refractive index at a wavelength of 589.3 nm at 25 °C was measured using a refractometer (Anton Paar, product name "ABBEMAT-WR / MW").

[0101] (4) Abbe number

[0102] In the above "(3) Refractive Index", when measuring the refractive index at a wavelength of 589.3 nm, the refractive index (nd) at a wavelength of 587.6 nm, the refractive index (nC) at a wavelength of 656.3 nm, and the refractive index (nF) at a wavelength of 486.1 nm are also measured simultaneously. Moreover, using the refractive indices (nd, nC, nF) at a temperature of 25 °C, the Abbe number (νd) is calculated according to the following formula (2).

[0103] [Mathematical Expression 2]

[0104]

[0105] (Example 1)

[0106] <Preparation of Cyclic Olefin Copolymers>

[0107] In a 100 mL glass pressure reactor purged with nitrogen, 10 g of toluene, 2.5 g of 1,4-methyl-1,4,4a,9a-tetrahydrofluorene (MTF) as monomer (b), 7.5 g of styrene as monomer (c), and 3.0 g of a cyclohexane solution of solid methylaluminoxane (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 40 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas as monomer (a) was introduced into the polymerization reaction to achieve a pressure of 0.15 MPa, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 15 minutes, the reaction was terminated by reducing the pressure and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-containing 2-propanol to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70°C for 15 hours to obtain a cyclic olefin copolymer. Then, for this cyclic olefin copolymer, the weight-average molecular weight, the number of aromatic rings relative to the number of repeating units, the refractive index, and the Abbe number were determined. The results are shown in Table 1.

[0108] (Example 2)

[0109] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0110] <Preparation of Cyclic Olefin Copolymers>

[0111] In a 100 mL glass pressure reactor purged with nitrogen, 10.0 g of MTF, 10.0 g of styrene, and 1.5 g of a cyclohexane solution of solid methylaluminoxane (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 40 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 30 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactors were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0112] (Example 3)

[0113] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0114] <Preparation of Cyclic Olefin Copolymers>

[0115] In a 100 mL glass pressure reactor purged with nitrogen, a cyclohexane solution (Al concentration = 14.8%) containing 1.4 g toluene, 5.2 g MTF, 5.2 g 2-vinylnaphthalene, and 6.2 g solid methylaluminoxane was added and stirred. This mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 40 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 30 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactor were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0116] (Example 4)

[0117] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0118] <Preparation of Cyclic Olefin Copolymers>

[0119] In a 100 mL glass pressure reactor purged with nitrogen, a cyclohexane solution of 12.8 g MTF, 3.2 g 2-vinylnaphthalene, and 7.3 g solid methylaluminoxane (Al concentration = 14.8%) was added and stirred. This mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 49 mg rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 60 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactor were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0120] (Example 5)

[0121] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0122] <Preparation of Cyclic Olefin Copolymers>

[0123] In a 100 mL glass pressure reactor purged with nitrogen, 12.8 g of MTF, 3.2 g of 2-vinylnaphthalene, and 7.3 g of solid methylaluminoxane in cyclohexane (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor containing a stir bar and 45 mg of [2,6-bis(1-methylethyl)phenolate]dichloro[(1,2,3,4,5-η)-1,3-dimethyl-2,4-cyclopentadien-1-yl]titanium, thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 60 minutes, the reaction was terminated by reducing the pressure and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid and acidic 2-propanol to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70°C for 15 hours to obtain a cyclic olefin copolymer.

[0124] (Example 6)

[0125] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0126] <Preparation of Cyclic Olefin Copolymers>

[0127] In a 100 mL glass pressure reactor purged with nitrogen, 22.7 g of toluene, 5.9 g of 5,5a,6,9,9a,10,10a,11-octahydro-4bH-5,10;6,9-dimethylbridged-benzo[b]fluorene (HNT), 5.9 g of 2-vinylnaphthalene, and 17.0 g of solid methylaluminoxane in cyclohexane (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 120 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 70 minutes, the reaction was terminated by reducing the pressure and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid and acidic 2-propanol to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70°C for 15 hours to obtain a cyclic olefin copolymer.

[0128] (Example 7)

[0129] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0130] <Preparation of Cyclic Olefin Copolymers>

[0131] In a 100 mL glass pressure reactor purged with nitrogen, a cyclohexane solution of 10.2 g toluene, 3.0 g MTF, 3.0 g 4-vinylbiphenyl, and 3.1 g solid methylaluminoxane (Al concentration = 14.8%) was added and stirred. This mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 44 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 15 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactor were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0132] (Example 8)

[0133] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0134] <Preparation of Cyclic Olefin Copolymers>

[0135] In a 100 mL glass pressure reactor purged with nitrogen, 5.9 g of toluene, 11.5 g of MTF, 2.6 g of 4-vinylbiphenyl, and 10.9 g of solid methylaluminoxane in cyclohexane (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor containing a stir bar and 69 mg of [2,6-bis(1-methylethyl)phenolate]dichloro[(1,2,3,4,5-η)-1,3-dimethyl-2,4-cyclopentadien-1-yl]titanium, thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 60 minutes, the reaction was terminated by reducing the pressure and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid and acidic 2-propanol to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70°C for 15 hours to obtain a cyclic olefin copolymer.

[0136] (Comparative Example 1)

[0137] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0138] <Preparation of Cyclic Olefin Copolymers>

[0139] In a 100 mL glass pressure reactor purged with nitrogen, 15.1 g of toluene, 2.0 g of MTF, 2.0 g of styrene, and 0.8 g of solid methylaluminoxane in a cyclohexane solution (Al concentration = 14.8%) were added and stirred. The mixture was then added to another 100 mL glass pressure reactor equipped with a stir bar and 42 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 30 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactor were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0140] (Comparative Example 2)

[0141] The cyclic olefin copolymers prepared in the following manner were used, and all determinations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0142] <Preparation of Cyclic Olefin Copolymers>

[0143] In a 100 mL glass pressure-resistant reactor purged with nitrogen, 5.1 g of toluene and 10.2 g of tetracyclo[6.2.1.1³] were added. ,6 0.0² ,7 A cyclohexane solution of dodecane-4-ene (TCD), 5.2 g of styrene, and 6.5 g of solid methylaluminoxane (Al concentration = 14.8%) was stirred and then added to another 100 mL glass pressure reactor containing a stir bar and 40 mg of rac-ethylenebis(indenyl)zirconium dichloride (IV), thereby initiating the polymerization reaction. Ethylene gas was introduced to achieve a pressure of 0.15 MPa during the polymerization reaction, and the mixture was stirred at 1000 rpm. After reacting at 25 °C for 15 minutes, the polymerization reaction was terminated by reducing the pressure and adding 2-propanol dropwise. The contents of the glass pressure reactor were then transferred to a large amount of acidic 2-propanol hydrochloride to precipitate the polymer. After filtration and washing, the polymer was dried under reduced pressure at 70 °C for 15 hours to obtain a cyclic olefin copolymer.

[0144] Additionally, in Table 1 shown below,

[0145] “MTF” represents a structural unit derived from 1,4-methylbridge-1,4,4a,9a-tetrahydrofluorene;

[0146] “HNT” represents a structural unit derived from 5,5a,6,9,9a,10,10a,11-octahydro-4bH-5,10;6,9-dimethylbridged-benzo[b]fluorene;

[0147] “TCD” indicates that it comes from the Fourth Ring Road [6.2.1.1³] ,6 0.0² ,7 The structural unit of dodecane-4-ene;

[0148] “ST” indicates a structural unit derived from styrene;

[0149] “2-VN” represents a structural unit derived from 2-vinylnaphthalene;

[0150] “4-VB” represents a structural unit derived from 4-vinylbiphenyl;

[0151] “Mw” represents the weight-average molecular weight.

[0152] [Table 1]

[0153]

[0154] Industrial availability

[0155] According to the present invention, it is possible to provide cyclic olefin copolymers that have both high refractive index and low Abbe number.

[0156] 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 molded article formed using the resin composition.

Claims

1. A cyclic olefin copolymer comprising: Structural units (A) derived from α-olefins having 2 or more but less than 10 carbon atoms. Structural units (B) from cyclic olefins, and Structural unit (C) from aromatic vinyl compounds, The value obtained by dividing the total number of aromatic rings contained in the cyclic olefin copolymer by the total number of repeating units in the cyclic olefin copolymer is 0.25 or higher.

2. The cyclic olefin copolymer according to claim 1, wherein, An Abbe number of 20 or higher but less than 40.

3. The cyclic olefin copolymer according to claim 1, wherein, The structural unit (B) has at least one aromatic ring.

4. The cyclic olefin copolymer according to claim 1, wherein, The value obtained by dividing the total number of aromatic rings contained in the cyclic olefin copolymer by the total number of repeating units in the cyclic olefin copolymer is 0.45 or higher.

5. A resin composition comprising any one of the cyclic olefin copolymers according to claims 1 to 4.

6. A molded body formed by molding the resin composition of claim 5.

7. The molded article according to claim 6, wherein, The molded body is an optical lens.

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