Copolymer and method for producing same, resin composition, and resin molded body

Abstract

The purpose of the present invention is to provide a copolymer which has excellent moldability and high refractive index properties. The present invention provides a copolymer which contains a structural unit (A) derived from a chain olefin and a structural unit (B) derived from a cyclic olefin, wherein the cyclic olefin is a compound represented by prescribed formula (I), and the weight average molecular weight of the copolymer is 20,000 to 250,000 inclusive.

Description

Copolymer, method for producing the same, resin composition, and resin molded article

[0001] The present invention relates to a copolymer, a method for producing the same, a resin composition, and a resin molded article.

[0002] Polymers containing structural units derived from cyclic olefins are excellent in transparency, low moisture absorption, heat resistance, insulation properties, chemical resistance and the like, and thus are widely used as various resin molded articles such as optical components and packaging materials.

[0003] As the polymer containing the structural unit derived from the cyclic olefin, for example, Patent Document 1 describes a cycloolefin-based copolymer containing repeating units derived from a predetermined cycloolefin monomer and repeating units derived from an α-olefin monomer each in a predetermined ratio. And, in the Examples of Patent Document 1, a cycloolefin-based copolymer obtained using norbornene (also known as bicyclo[2.2.1]hept-2-ene) and ethylene is described.

[0004] International Publication No. WO 2007 / 060723

[0005] Here, a resin molded article obtained by using a polymer containing a structural unit derived from norbornene has a relatively high refractive index. However, with the recent improvement in performance of optical components and the like, development of a polymer excellent in high refractive index property capable of imparting a higher refractive index to a resin molded article has been desired.

[0006] Further, from the viewpoint of performance, productivity and the like of the resin molded article, it is desirable that the polymer used for forming the resin molded article is excellent in moldability.

[0007] Accordingly, an object of the present invention is to provide a copolymer excellent in moldability and high refractive index property, and a method for producing the same. Another object of the present invention is to provide a resin composition containing the above copolymer. Still another object of the present invention is to provide a resin molded article obtained by molding the above resin composition.

[0008] The present inventors have conducted intensive studies to achieve the above object. The present inventors have newly found that a copolymer containing a structural unit derived from a chain olefin and a structural unit derived from a cyclic olefin having a predetermined structure, and having a weight average molecular weight within a predetermined numerical range can solve the above problems, and have completed the present invention.

[0009] That is, the present invention aims to advantageously solve the above problems, and provides [1] a copolymer comprising a structural unit (A) derived from a chain olefin and a structural unit (B) derived from a cyclic olefin, wherein the cyclic olefin is represented by the following formula (I): [In formula (I), X represents a divalent aliphatic hydrocarbon group having a carbon-carbon double bond copolymerizable with the chain olefin.] wherein the weight average molecular weight of the copolymer is 20,000 or more and 250,000 or less. The copolymer as described above is excellent in moldability and high refractive index property. In the present specification, "weight average molecular weight" can be determined as a value in terms of standard polyisoprene using gel permeation chromatography (GPC), and can be measured by the method described in the Examples of the present specification.

[0010] [2] In the copolymer of [1] above, the number of carbon atoms in the aliphatic hydrocarbon group is preferably 2 or more and 20 or less. When the number of carbon atoms in the aliphatic hydrocarbon group falls within the above range, the heat resistance and high refractive index property of the copolymer can be improved.

[0011] [3] In the copolymer of [1] or [2] above, the compound is represented by the following formula (Ia): [In formula (Ia), R １ and R ２ each independently represent a hydrogen atom or an aliphatic hydrocarbon group.] a compound represented by the following formula (Ib): [In formula (Ib), R ３ to R ６Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group. Preferably, it is at least one of the compounds represented by [ ]. If the compound represented by formula (I) is at least one of the compounds represented by (Ia) and (Ib), the heat resistance and high refractive index of the copolymer can be improved.

[0012] [4] In any copolymer of [1] to [3] above, the proportion of structural unit (B) is preferably 20 mol% or more and 60 mol% or less, when the total repeating units in the copolymer are set to 100 mol%. If the proportion of structural unit (B) is above the lower limit, the heat resistance and high refractive index of the copolymer can be effectively improved. On the other hand, if the proportion of structural unit (B) is below the upper limit, the birefringence of the resulting resin molded article can be effectively reduced. In other words, the low birefringence of the copolymer can be effectively improved. Furthermore, if the proportion of structural unit (B) is within the above range, the moldability of the copolymer can be effectively improved. In this specification, "the proportion of each repeating unit (monomer unit, structural unit) in the copolymer" is １３ It can be measured using nuclear magnetic resonance (NMR) methods such as 13C-NMR.

[0013] [5] In any copolymer of [1] to [4] above, the structural unit (A) consists of two or more structural units derived from chain-like olefins, and includes a structural unit (a1) derived from a chain-like olefin having 4 to 18 carbon atoms, and the proportion of the structural unit (a1) is preferably 0.1 mol% to 30 mol% when the total repeating units in the copolymer are 100 mol%. If the structural unit (A) has a predetermined configuration and the proportion of the structural unit (a1) is within the above range, the moldability of the copolymer can be effectively improved.

[0014] [6] In any copolymer of [1] to [5] above, the refractive index is preferably 1.540 or higher. If the refractive index of the copolymer is above the lower limit above, when the copolymer is used as a material for optical components, excellent performance can be effectively imparted to the optical components. In this specification, the "refractive index" of the copolymer is measured by forming the copolymer into a sheet by hot pressing and measuring the molded body. Specifically, it can be measured by the method described in the examples of this specification.

[0015] [7] In any copolymer of [1] to [6] above, the Abbe number is preferably 50.0 or higher. If the Abbe number of the copolymer is above the lower limit above, when the copolymer is used as a material for optical components, excellent performance can be effectively imparted to the optical components. In this specification, the "Abbe number" of the copolymer is measured by forming the copolymer into a sheet by hot pressing and measuring the molded body. Specifically, it can be measured by the method described in the examples of this specification.

[0016] [8] In any copolymer of [1] to [7] above, the glass transition temperature is preferably 130°C or higher and 160°C or lower. If the glass transition temperature of the copolymer is above the lower limit, the heat resistance of the copolymer can be effectively improved. Furthermore, if the glass transition temperature of the copolymer is within the above range, the moldability of the copolymer can be effectively improved. In this specification, the "glass transition temperature" of the copolymer can be measured by the method described in the examples of this specification.

[0017] Furthermore, this invention aims to advantageously solve the above problems, and [9] the present invention is a method for producing any of the copolymers described in [1] to [8] above, comprising the step of polymerizing the chain olefin and the cyclic olefin in a polymerization solution using a metallocene catalyst containing a metallocene compound, wherein the molar ratio of the amount of the metallocene compound used to the amount of the cyclic olefin used is 0.03 mmol / mol or more and 1.00 mmol / mol or less. With the above method for producing copolymers, copolymers with excellent moldability and high refractive index can be obtained.

[0018] Furthermore, this invention aims to advantageously solve the above problems, and

[10] the present invention is a resin composition comprising a copolymer of any of [1] to [8] above. Such a resin composition can impart excellent performance, productivity, and a high refractive index to a resin molded article.

[0019] Furthermore, this invention aims to advantageously solve the above problems, and

[11] the present invention is a resin molded article obtained by molding the resin composition of

[10] above. A resin molded article as described above has excellent performance and productivity and a high refractive index.

[0020]

[12] The resin molded body described in

[11] is preferably an optical component.

[0021] According to the present invention, a copolymer with excellent moldability and high refractive index, and a method for producing the same can be provided. Furthermore, according to the present invention, a resin composition containing the above copolymer can be provided. Moreover, according to the present invention, a resin molded article obtained by molding the above resin composition can be provided.

[0022] Embodiments of the present invention will be described in detail below.

[0023] (Copolymer) The copolymer of the present invention comprises a structural unit (A) derived from a chain-like olefin (hereinafter sometimes simply referred to as "structural unit (A)") and a structural unit (B) derived from a cyclic olefin (hereinafter sometimes simply referred to as "structural unit (B)"), wherein the cyclic olefin is of the following formula (I): The compound is represented by [Formula (I), where X represents a divalent aliphatic hydrocarbon group having a carbon-carbon double bond that can copolymerize with a chain-like olefin], and the weight-average molecular weight of the copolymer is 20,000 or more and 250,000 or less. Such copolymers have excellent moldability and high refractive index. These reasons are presumed to be due to the fact that copolymers having a weight-average molecular weight within a predetermined numerical range can have good fluidity when melted, and to the characteristic bulky structure of structural unit (B).

[0024] In addition, the copolymer of the present invention may optionally further contain monomer units other than the above-mentioned structural unit (A) and structural unit (B) (hereinafter sometimes referred to as "other monomer units").

[0025] <Structural Unit (B)> The structural unit (B) contained in the copolymer of the present invention is a structural unit derived from a cyclic olefin, and the cyclic olefin is represented by the following formula (I): which is a compound represented by. Here, in formula (I), X represents a divalent aliphatic hydrocarbon group having a carbon-carbon double bond copolymerizable with the chain olefin of the structural unit (A).

[0026] The number of carbon atoms in the aliphatic hydrocarbon group of X is preferably 2 or more, preferably 20 or less, more preferably 10 or less, and still more preferably 4 or less. When the number of carbon atoms of the aliphatic hydrocarbon group falls within the above range, the heat resistance and high refractive index of the copolymer can be improved.

[0027] Here, since the compound represented by formula (I) can improve the heat resistance and high refractive index of the copolymer, it is preferably at least one of the compound represented by (Ia) and the compound represented by (Ib) described later, and more preferably the compound represented by (Ia).

[0028] <<Compound Represented by (Ia)>> The compound represented by formula (I) is represented by the following formula (Ia): which may be a compound represented by. Here, in formula (Ia), R １ and R ２ each independently represent a hydrogen atom or an aliphatic hydrocarbon group.

[0029] R １ and R ２ are preferably hydrogen atoms. That is, the compound represented by (Ia) is preferably 1,2,3,3a,4,6a-hexahydro-1,2,4-methenopentalene (common name: dicyclopentene).

[0030] R １ and R ２Examples of aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups, but alkyl groups are preferred among these. Examples of alkyl groups include methyl groups, ethyl groups, propyl groups, and butyl groups. １ and R ２ The aliphatic hydrocarbon groups may be the same or different.

[0031] << Compounds represented by (Ib) >> Compounds represented by formula (I) are shown in formula (Ib): The compound may be represented by the formula (Ib), where R ３ ~R ６ Each of these independently represents either a hydrogen atom or an aliphatic hydrocarbon group.

[0032] R ３ ~R ６ It is preferable that (Ib) represents a hydrogen atom. That is, it is preferable that the compound represented by (Ib) is 1,2,3,3a,3b,4,7,7a,8,8a-decahydro-4,7-methano-2,3,8-methenocyclopent[a]indene (hereinafter sometimes abbreviated as "MMD"). MMD can be synthesized, for example, by carrying out reactions (α), (β), etc., described in International Publication No. 2016 / 163371.

[0033] R ３ ~R ６ Examples of aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups, but alkyl groups are preferred among these. Examples of alkyl groups include methyl groups, ethyl groups, propyl groups, and butyl groups. ３ ~R ６ The aliphatic hydrocarbon groups may be the same or different.

[0034] <<Proportion of Structural Units (B)>> The proportion of structural units (B) in the copolymer is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 35 mol% or more, preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less, when the total repeating units (monomer units, structural units) in the copolymer are taken as 100 mol%. If the proportion of structural units (B) is above the lower limit above, the heat resistance and high refractive index of the copolymer can be effectively improved. On the other hand, if the proportion of structural units (B) is below the upper limit above, the low birefringence of the copolymer can be effectively improved. Furthermore, if the proportion of structural units (B) is within the above range, the moldability of the copolymer can be effectively improved.

[0035] <Structural Unit (A)> The structural unit (A) contained in the copolymer of the present invention is a structural unit derived from a chain-like olefin. The chain-like olefin is a compound having a polymerizable carbon-carbon double bond in its molecule. Here, the chain-like olefin may be linear or branched. Furthermore, the chain-like olefin may be an α-olefin or an internal olefin. Note that an internal olefin is a compound that has the double bond inside the olefin chain rather than at the end of the olefin chain.

[0036] As the α-olefin, for example, an alkene having 2 to 20 carbon atoms and a double bond at the α-position can be used. Examples of such alkenes include 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, 1-eicosene, etc. Examples of internal olefins include 2-butene and 3-hexene. Among these, α-olefins are preferred, and ethylene and 1-hexene are more preferred. The chain-like olefins described above may be used individually or in combination of two or more types.

[0037] Here, in order to improve the moldability of the copolymer, it is preferable that structural unit (A) consists of two or more structural units derived from chain-like olefins, and includes a structural unit (a1) derived from a chain-like olefin having 4 to 18 carbon atoms. Furthermore, in order to further improve the moldability of the copolymer, it is even more preferable that structural unit (A) consists of two or more structural units derived from chain-like olefins, and includes a structural unit (a1) derived from a chain-like olefin having 4 to 18 carbon atoms and a structural unit (a2) derived from a chain-like olefin having 2 to 3 carbon atoms (hereinafter sometimes simply referred to as "structural unit (a2)").

[0038] Examples of chain olefins having 4 to 18 carbon atoms include the α-olefins and internal olefins listed above. Among these, α-olefins are preferred, and 1-hexene is more preferred. Examples of chain olefins having 2 to 3 carbon atoms include ethylene and propylene. Among these, ethylene is preferred.

[0039] When structural unit (A) consists of structural units derived from two or more chain-like olefins and includes structural unit (a1), the proportion of structural unit (a1) in the copolymer is preferably 0.1 mol% or more, more preferably 1 mol% or more, even more preferably 5 mol% or more, preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 15 mol% or less, based on the total repeating units (monomer units, structural units) in the copolymer being 100 mol%. If the proportion of structural unit (a1) is within the above range, the moldability of the copolymer can be effectively improved.

[0040] When structural unit (A) consists of two or more chain-like olefin-derived structural units and includes structural unit (a1), the molar ratio of structural unit (a1) to structural unit (B) in the copolymer (structural unit (a1) / structural unit (B)) is preferably 0.05 or more, more preferably 0.10 or more, even more preferably 0.15 or more, preferably 0.50 or less, more preferably 0.30 or less, and even more preferably 0.23 or less. If the molar ratio of structural unit (a1) to structural unit (B) in the copolymer is within the above range, the low birefringence of the copolymer can be effectively improved.

[0041] When structural unit (A) consists of two or more structural units derived from chain-like olefins and includes structural unit (a1) and structural unit (a2), the total proportion of structural unit (a1) and structural unit (a2) to the entire structural unit (A) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 99 mol% or more, and particularly preferably 100 mol%. That is, it is particularly preferable that structural unit (A) consists only of structural unit (a1) and structural unit (a2). If the total proportion of structural unit (a1) and structural unit (a2) to the entire structural unit (A) is above the above lower limit, the low birefringence of the copolymer can be effectively improved.

[0042] When structural unit (A) consists of two or more structural units derived from chain-like olefins and includes structural unit (a1) and structural unit (a2), the molar ratio of structural unit (a1) to structural unit (a2) in the copolymer (structural unit (a1) / structural unit (a2)) is preferably 0.05 or more, more preferably 0.10 or more, even more preferably 0.15 or more, preferably 0.70 or less, more preferably 0.50 or less, and even more preferably 0.25 or less. If the molar ratio of structural unit (a1) to structural unit (a2) in the copolymer is within the above range, the low birefringence of the copolymer can be effectively improved.

[0043] <<Proportion of structural units (A)>> The proportion of structural units (A) in the copolymer is preferably 40 mol% or more, more preferably 45 mol% or more, even more preferably 50 mol% or more, preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less, when the total repeating units (monomer units, structural units) in the copolymer are taken as 100 mol%.

[0044] <Other Monomer Units> Other monomers that can form other monomer units are not particularly limited as long as they are monomers that can copolymerize with the chain-like olefins and cyclic olefins described above.

[0045] The proportion of other monomer units in the copolymer is preferably 5 mol% or less, more preferably 1 mol% or less, even more preferably 0.1 mol% or less, and particularly preferably 0 mol%, when the total repeating units (monomer units, structural units) in the copolymer are taken as 100 mol%. In other words, it is particularly preferable that the copolymer does not contain other monomer units.

[0046] <Properties of Copolymer> The weight-average molecular weight (Mw) of the copolymer must be 20,000 or more, preferably 30,000 or more, more preferably 40,000 or more, and must be 250,000 or less, preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 95,000 or less. If the weight-average molecular weight of the copolymer is above the lower limit above, the heat resistance and strength of the copolymer can be effectively improved. On the other hand, if the weight-average molecular weight of the copolymer is below the upper limit above, the low birefringence of the copolymer can be effectively improved. Furthermore, if the weight-average molecular weight of the copolymer is within the above range, the moldability of the copolymer can be effectively improved.

[0047] The molecular weight distribution (Mw / Mn) of the copolymer is, for example, 1 to 5, but may also be 1 to 3, or 1 to 2.5. The molecular weight distribution of the copolymer refers to the ratio (Mw / Mn) of the weight-average molecular weight (Mw) of the copolymer to the number-average molecular weight (Mn) of the copolymer. In this specification, the "number-average molecular weight (Mn)" can be determined using gel permeation chromatography (GPC) as a standard polyisoprene equivalent, and can be measured by the method described in the examples of this specification.

[0048] The refractive index of the copolymer is preferably 1.540 or higher, more preferably 1.550 or higher, and even more preferably 1.555 or higher. If the refractive index of the copolymer is above the lower limit, when the copolymer is used as a material for optical components, excellent performance can be effectively imparted to the optical components. The refractive index of the copolymer may be, for example, 1.700 or lower, or 1.650 or lower.

[0049] The Abbe number of the copolymer is preferably 50.0 or higher, more preferably 52.0 or higher, and even more preferably 54.0 or higher. If the Abbe number of the copolymer is above the lower limit, when the copolymer is used as a material for optical components, excellent performance can be effectively imparted to the optical components. The Abbe number of the copolymer may be, for example, 70.0 or lower, or 60.0 or lower.

[0050] The glass transition temperature (Tg) of the copolymer is preferably 130°C or higher, more preferably 135°C or higher, preferably 160°C or lower, more preferably 150°C or lower, and even more preferably 145°C or lower. If the glass transition temperature of the copolymer is above the lower limit, the heat resistance of the copolymer can be effectively improved. Furthermore, if the glass transition temperature of the copolymer is within the above range, the moldability of the copolymer can be effectively improved.

[0051] The melt volume rate (MVR) of the copolymer is 0.3 cm ３ Preferably, it should be 10 min or more, and 2 cm ３ It is more preferable that it be 10 min or more, and 3 cm ３ It is even more preferable that it be 10 min or more, and 130 cm ３ Preferably, it should be 10 min or less, and 100 cm ３ It is more preferable that it be 10 min or less, and 90 cm ３ It is even more preferable that the melt volume rate is 10 min or less. In this specification, the "melt volume rate" of the copolymer is measured by preparing a resin composition by mixing 0.5 parts of an antioxidant with 100 parts of the copolymer, and then using the resulting resin composition. Specifically, it can be measured by the method described in the examples of this specification.

[0052] The birefringence of the copolymer is preferably 500 nm or less, more preferably 200 nm or less, even more preferably 150 nm or less, even more preferably 100 nm or less, even more preferably 50 nm or less, preferably -500 nm or more, more preferably -200 nm or more, even more preferably -150 nm or more, even more preferably -100 nm or more, and even more preferably -50 nm or more. In this specification, the "birefringence" of a copolymer is defined as the average value of measurements taken when a resin composition containing 100 parts copolymer and 0.5 parts antioxidant is injection molded under the conditions that the resin temperature is 130°C higher than the glass transition temperature of the copolymer (= Tg + 130°C) and the mold temperature is 15°C lower than the glass transition temperature of the copolymer (= Tg - 15°C), producing a flat resin molded body of 70 mm × 30 mm × 3 mm, and the retardation values ​​of the resin flow direction (MD) and the direction perpendicular to the resin flow direction (TD) at a position 65 mm from the gate of the resin molded body using light with a wavelength of 543 nm, measured in a line using a birefringence meter (manufactured by Photonic Lattice, product name: WPA-200).

[0053] Here, the properties of the copolymer can be adjusted by the type, amount, and concentration of monomers used in the polymerization solution during the production of the copolymer, the type, amount, and concentration of catalyst in the polymerization solution, the polymerization temperature, and so on.

[0054] (Method for Producing Copolymers) The method for producing copolymers of the present invention (hereinafter sometimes simply referred to as the "production method") includes a step of polymerizing a chain-like olefin and a cyclic olefin in a polymerization solution using a metallocene catalyst containing a metallocene compound (hereinafter sometimes referred to as the "polymerization step"). In the polymerization step, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) is 0.03 mmol / mol or more and 1.00 mmol / mol or less. With the above production method, the copolymer of the present invention described above, that is, a copolymer with excellent moldability and high refractive index, can be obtained. The production method of the present invention may also include other steps such as a washing step in which the copolymer obtained in the polymerization step is optionally precipitated in the polymerization solution, separated from the polymerization solution and washed, and a drying step in which the washed copolymer is dried.

[0055] <Polymerization Process> In the polymerization process, linear olefins and cyclic olefins are polymerized in a polymerization solution using a metallocene catalyst containing a metallocene compound. Here, the polymerization solution usually contains an organic solvent. The polymerization process is not particularly limited, but it may be carried out in a reactor.

[0056] <<Cyclic Olefins>> The cyclic olefins used in the polymerization process can be the same as those described in the "Structural Units (B)" section above.

[0057] The concentration of the cyclic olefin in the polymerization solution is, for example, 1.0% by mass or more, may be 3.0% by mass or more, may be, for example, 30.0% by mass or less, or may be 15.0% by mass or less.

[0058] <<Chain Olefins>> The chain olefins used in the polymerization process can be the same as those described in the "Structural Unit (A)" section above.

[0059] The chain olefin can be used in either gaseous or liquid form under conditions of 25°C and 1 atm. Examples of gaseous chain olefins include ethylene, 1-propylene, and 1-butene. Examples of liquid chain olefins include 1-pentene and 1-hexene.

[0060] When using a gaseous chain olefin as the chain olefin, the polymerization step may be carried out in a state where the gas in the reactor is replaced with the gaseous chain olefin. The pressure at which the gaseous chain olefin is introduced into the reactor during the polymerization reaction is, for example, 0.05 MPa or higher, may be 0.10 MPa or higher, for example, 1.00 MPa or lower, or 0.30 MPa or lower, in gauge pressure.

[0061] Here, when using two or more chain olefins, it is preferable to use chain olefins having 4 to 18 carbon atoms, and more preferable to use a chain olefin having 4 to 18 carbon atoms and a chain olefin having 2 to 3 carbon atoms. The chain olefins having 4 to 18 carbon atoms and the chain olefins having 2 to 3 carbon atoms can be the same as those described in the "Structural Unit (A)" section above.

[0062] <<Organic solvents>> There are no particular restrictions on the organic solvent as long as it is inert to polymerization reactions. Examples of such organic solvents include aromatic hydrocarbon solvents such as benzene, toluene, and xylene; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, decalin, and bicyclononane; halogenated hydrocarbon solvents such as dichloroethane, chlorobenzene, dichlorobenzene, and trichlorobenzene; and so on. These organic solvents may be used individually or in combination of two or more.

[0063] <<Metallocene Catalyst>> The metallocene catalyst contains a metallocene compound and may optionally contain an activator and an organoaluminum compound.

[0064] In the polymerization step, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound / amount of cyclic olefin used) must be 0.03 mmol / mol or more, preferably 0.05 mmol / mol or more, more preferably 0.10 mmol / mol or more, and must be 1.00 mmol / mol or less, and preferably 0.50 mmol / mol or less. If the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used is within the above range, a copolymer having a predetermined weight-average molecular weight can be obtained.

[0065] Furthermore, in the polymerization process, the concentration of the metallocene compound in the polymerization solution at the start of polymerization is preferably 0.02 mmol / kg or more, more preferably 0.05 mmol / kg or more, even more preferably 0.10 mmol / kg or more, preferably 1.00 mmol / kg or less, and more preferably 0.50 mmol / kg or less. If the concentration of the metallocene compound in the polymerization solution at the start of polymerization is within the above range, the properties of the resulting copolymer, such as the weight-average molecular weight, can be effectively adjusted.

[0066] [Metallocene Compounds] Examples of metallocene compounds include crosslinked metallocene compounds, half-metallocene compounds, and non-crosslinked half-metallocene compounds. Among these, non-crosslinked half-metallocene compounds are preferred from the viewpoint of polymerization efficiency and selectivity. In the following, non-crosslinked half-metallocene compounds will be used as an example to explain the details of metallocene compounds, but metallocene compounds are not limited to these.

[0067] Examples of non-crosslinked half-metallocene compounds include the compound represented by the following formula (i).

[0068] In formula (i), M is a metal atom selected from the group consisting of titanium, zirconium, and hafnium, with titanium being preferred.

[0069] X １ and X ２Each of these independently represents an alkyl group having 1 to 6 carbon atoms, or a halogen atom. １ and X ２ It is preferably a halogen atom, and more preferably a chlorine atom.

[0070] R ７ C1 represents a cyclopentadienyl group (hereinafter sometimes abbreviated as "Cp"), an indenyl group, or a fluorenyl group, with cyclopentadienyl group being preferred. These groups may have substituents at any position. Examples of such substituents include C1-C10 alkyl groups such as methyl, ethyl, isopropyl, and t-butyl groups (hereinafter sometimes abbreviated as "t-Bu"); C6-C12 aryl groups such as phenyl groups; and arylalkyl groups such as benzyl and phenethyl groups. Among these, C1-C10 alkyl groups are preferred, and t-butyl groups are more preferred.

[0071] R ８ and R ９ Each of these independently represents an alkyl group having 1 to 6 carbon atoms. ８ and R ９ It is preferable that it is a t-butyl group.

[0072] Here, a specific example of a compound represented by formula (i) is CpTi[N=C(t-Bu)] ２ ]Cl ２ , (t-BuCp)Ti[N=C(t-Bu) ２ ]Cl ２ , CpTi[N=C(t-Bu) ２ ] (CH ３ ) ２ , (t-BuCp)Ti[N=C(t-Bu) ２ ] (CH ３ ) ２ These are some examples. Among these, CpTi[N=C(t-Bu) ２ ]Cl ２ , (t-BuCp)Ti[N=C(t-Bu) ２ ]Cl ２ It is preferable.

[0073] [Activator] The activator that may be included in the metallocene catalyst is for activating the metallocene compound, and for example, an organoaluminum oxy compound can be used. The organoaluminum oxy compound may be a conventionally known aluminoxane. Alternatively, the organoaluminum oxy compound may be a benzene-insoluble organoaluminum oxy compound as disclosed in Japanese Patent Publication No. 2-78687.

[0074] [Organoaluminum Compounds] These are organoaluminum compounds that can be included in metallocene catalysts, other than the above-mentioned aluminum oxy compounds. Examples of such organoaluminum compounds include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, and trisec-butylaluminum; dialkylaluminum halides such as dimethylaluminum chloride and diisobutylaluminum chloride; dialkylaluminum hydrides such as diisobutylaluminum hydride; dialkylaluminum alkoxides such as dimethylaluminum methoxide; and dialkylaluminum allyloxides such as diethylaluminum phenoxide.

[0075] [Molar ratio of metal derived from metallocene compound to metal derived from activator] When the metallocene catalyst contains a metallocene compound and an activator, the molar ratio of metal derived from the metallocene compound to metal derived from the activator in the metallocene catalyst (metal derived from metallocene compound / metal derived from activator) is preferably 0.10 mol / mole or more, more preferably 0.30 mol / mole or more, even more preferably 0.50 mol / mole or more, preferably 10.0 mol / mole or less, more preferably 5.0 mol / mole or less, and even more preferably 1.5 mol / mole or less. If the molar ratio of metal derived from the metallocene compound to metal derived from the activator in the metallocene catalyst is within the above range, the properties of the resulting copolymer, such as its weight-average molecular weight, can be effectively adjusted.

[0076] <<Polymerization Conditions>> The polymerization temperature is preferably 0°C or higher, more preferably 20°C or higher, preferably 200°C or lower, and more preferably 100°C or lower. Furthermore, when two or more types of chain-like olefins are used as the chain-like olefin, the polymerization temperature is preferably 50°C or higher, more preferably 70°C or higher, preferably 200°C or lower, and more preferably 100°C or lower. If the polymerization temperature is within the above range, the properties of the resulting copolymer, such as the weight-average molecular weight, can be easily adjusted.

[0077] The polymerization time is preferably 1 minute or more, more preferably 3 minutes or more, preferably 5 hours or less, more preferably 1 hour or less, and even more preferably 20 minutes or less.

[0078] The stirring speed of the polymerization solution is preferably 200 rpm or more, more preferably 700 rpm or more, preferably 3000 rpm or less, and more preferably 1500 rpm or less.

[0079] (Resin Composition) The resin composition of the present invention contains the copolymer of the present invention described above. Because the resin composition of the present invention contains the copolymer of the present invention which has excellent moldability and high refractive index, it can impart excellent performance, productivity and high refractive index to resin molded articles. The resin composition of the present invention may also contain resin components other than the copolymer of the present invention (hereinafter sometimes referred to as "other resin components") and additives, to the extent that they do not hinder the effects of the present invention.

[0080] Other resin components include styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-isoprene-styrene block copolymers, and hydrogenated versions thereof, as well as styrene-butadiene random copolymers and other styrene-based polymers.

[0081] The content of other resin components is preferably 5 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.1 parts by mass or less, and particularly preferably 0 parts by mass, per 100 parts by mass of the copolymer of the present invention. In other words, it is particularly preferable that the resin composition does not contain other resin components.

[0082] Examples of additives include antioxidants, ultraviolet absorbers, light stabilizers, near-infrared absorbers, plasticizers, antistatic agents, and acid scavengers. These additives may be used individually or in combination of two or more.

[0083] Examples of antioxidants include phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of phenolic antioxidants include 3,5-di-t-butyl-4-hydroxytoluene, dibutylhydroxytoluene, 2,2'-methylenebis(6-t-butyl-4-methylphenol), 4,4'-butylidenebis(3-t-butyl-3-methylphenol), 4,4'-thiobis(6-t-butyl-3-methylphenol), α-tocopherol, 2,2,4-trimethyl-6-hydroxy-7-t-butylchroman, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, and [pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]]. Examples of phosphorus-based antioxidants include distearyl pentaerythritol diphosphite, bis(2,4-ditterbutylphenyl) pentaerythritol diphosphite, tris(2,4-ditterbutylphenyl) phosphite, tetrakis(2,4-ditterbutylphenyl) 4,4'-biphenyl diphosphite, and trinonylphenyl phosphite. Examples of sulfur-based antioxidants include distearyl thiodipropionate and dilauryl thiodipropionate.

[0084] Examples of UV absorbers include benzotriazole-based UV absorbers, benzoate-based UV absorbers, benzophenone-based UV absorbers, acrylate-based UV absorbers, and metal complex-based UV absorbers.

[0085] Examples of light stabilizers include hindered amine-based light stabilizers.

[0086] Examples of near-infrared absorbers include cyanine-based near-infrared absorbers; pyrylium-based infrared absorbers; squalylium-based near-infrared absorbers; crokonium-based infrared absorbers; azurenium-based near-infrared absorbers; phthalocyanine-based near-infrared absorbers; dithiol metal complex-based near-infrared absorbers; naphthoquinone-based near-infrared absorbers; anthraquinone-based near-infrared absorbers; indophenol-based near-infrared absorbers; az-based near-infrared absorbers; and the like.

[0087] Examples of plasticizers include phosphate triester plasticizers, fatty acid monobasic acid ester plasticizers, dihydric alcohol ester plasticizers, and oxyacid ester plasticizers.

[0088] Examples of antistatic agents include fatty acid esters of polyhydric alcohols.

[0089] Examples of acid scavengers include magnesium oxide and zinc stearate.

[0090] The amount of additives can be appropriately changed according to the purpose, but it is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.1 parts by mass or more, preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of the copolymer of the present invention.

[0091] The resin composition of the present invention can be obtained by mixing each component according to a conventional method.

[0092] (Resin Molded Article) The resin molded article of the present invention is obtained by molding the resin composition of the present invention described above. Because the resin molded article of the present invention uses the resin composition of the present invention which can impart excellent performance, productivity and a high refractive index to the resin molded article, it has excellent performance and productivity and a high refractive index.

[0093] The molding method for the resin composition is not particularly limited and includes injection molding, press molding, and extrusion molding. Among these, injection molding is preferred when the resin molded body is an optical component or the like, because it allows for the acquisition of the desired resin molded body with high precision.

[0094] The melting temperature of the resin composition during molding is preferably (Tg + 50°C) or higher, more preferably (Tg + 100°C) or higher, even more preferably (Tg + 120°C) or higher, preferably (Tg + 300°C) or lower, more preferably (Tg + 200°C) or lower, and even more preferably (Tg + 150°C) or lower, where Tg (unit: °C) is the glass transition temperature of the copolymer contained in the resin composition.

[0095] When using a mold, the mold temperature is preferably (Tg-30°C) or higher, more preferably (Tg-25°C) or higher, even more preferably (Tg-20°C) or higher, preferably (Tg+30°C) or lower, more preferably (Tg+10°C) or lower, and even more preferably (Tg-10°C) or lower, where Tg is the glass transition temperature of the copolymer contained in the resin composition.

[0096] The resin molded articles of the present invention are not particularly limited and can be used as, for example, capacitor dielectric films, electrical insulators, various packaging films, shrink films, optical lenses, prisms, light guides, diffraction gratings, substrates and cover films for optical recording media (CDs, DVDs, Blu-ray discs, etc.), solar cell covers and focusing substrates, high-power laser components, fibrous or film-like optical waveguides, liquid crystal display components, projection television screens, catheters, infusion bags, bags for dialysis fluid, tubes, containers, implantation components, medical device components, containers used for storing, exchanging, and administering drug solutions, vials, cartridges, syringes, etc. Here, since the resin molded articles of the present invention are excellent in performance and productivity and have a high refractive index, they are preferably used as optical components such as optical lenses, prisms, and light guides, and more preferably as optical lenses. That is, the resin molded articles of the present invention are preferably optical components, and more preferably optical lenses.

[0097] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, unless otherwise specified, "%" representing quantity is based on mass, and pressure is gauge pressure. In the examples and comparative examples, various measurements and evaluations were performed by the following methods.

[0098] <Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the copolymers obtained in the examples and comparative examples were measured by gel permeation chromatography (Tosoh Corporation, product name "HLC-8320"). Three Tosoh Corporation columns (TSKgel G2000HXL, TSKgel G4000HXL, and TSKgel G5000HXL) were connected in series, cyclohexane was used as the developing solvent, and the values ​​were determined as polyisoprene equivalents. The molecular weight distribution (Mw / Mn) was calculated using the obtained weight-average molecular weight (Mw) and number-average molecular weight (Mn).

[0099] <Percentage of each structural unit> Copolymers obtained in the examples and comparative examples １３¹³C-NMR (nuclear magnetic resonance) spectra were measured, and the proportion (mol%) of each structural unit was determined using the integrated signal values ​​originating from each structural unit in the copolymer.

[0100] <Refractive Index> The copolymers obtained in the examples and comparative examples were formed into sheets by hot pressing and used as samples for refractive index measurement. The refractive index of the obtained measurement samples was measured at a wavelength of 589.3 nm at 25°C using a refractometer (Anton Paar, product name "ABBEMAT-WR / MW").

[0101] <Abbe Number> The copolymers obtained in the examples and comparative examples were formed into sheets by hot pressing and used as samples for measuring the Abbe number. 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 were measured at 25°C using a refractometer (Anton Paar, product name "ABBEMAT-WR / MW"). The Abbe number (νd) was then calculated using the refractive index (nd, nC, nF) according to the following formula (1).

[0102] <Glass transition temperature (Tg)> The glass transition temperature (Tg) of the copolymers obtained in the examples and comparative examples was measured using a differential scanning calorimetry analyzer (manufactured by Nanotechnology Inc., product name: DSC6220SII) in accordance with JIS K6911, under conditions of a heating rate of 10°C / min.

[0103] <Melt Volume Flow Rate (MVR)> The melt volume flow rate (MVR) of the resin compositions obtained in the examples and comparative examples was determined using a melt flow rate tester (manufactured by Toyo Seiki Seisakusho, product name: Melt Indexer F-F01) based on Method B of JIS K7210, at 280°C and a load of 2.16 kg, by measuring the volume of resin discharged (unit: cm³). ３ The value ( / 10 min) was measured.

[0104] <High refractive index properties of copolymers> Using the refractive index measurements described above, the high refractive index properties of copolymers were evaluated according to the following criteria: A: Refractive index of 1.555 or higher B: Refractive index between 1.540 and 1.555 C: Refractive index less than 1.540

[0105] <Moldability of Copolymer> Using the melt volume flow rate (MVR) measurements described above, the moldability of the copolymer was evaluated according to the following criteria: AA: 3 cm ３ / 10 min or more, 90 cm ３ / 10min or less A: 2cm ３ / 10min or more 3cm ３ / Less than 10 min, or 90 cm ３ / 10min over 100cm ３ / 10min or less B: 0.3cm ３ / 10 min or more 2 cm ３ / Less than 10 min, or 100 cm ３ / 10min over 130cm ３ / 10min or less C:0.3cm ３ Less than 10 mins, or 130 cm ３ / 10min or more

[0106] (Example 1) <Preparation of Copolymer> A stirring bar, 44 g of toluene, 3.5 g (0.030 mol) of 1,2,3,3a,4,6a-hexahydro-1,2,4-metenopentalene (deltacycline; hereinafter sometimes abbreviated as "DCL") as a cyclic olefin, and 1.4 g of a hexane solution (Al concentration = 5.7 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added to a 100 mL glass pressure reactor whose interior was purged with nitrogen, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 25°C, the metallocene compound "CpTi[N=C(t-Bu) ２ ]Cl ２The polymerization reaction was initiated in the polymerization solution by adding a solution prepared by mixing 1.6 mg (0.0049 mmol) of (where "Cp" means cyclopentadienyl group and "t-Bu" means t-butyl group) with 0.65 g of toluene. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.10 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 7.1%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.17 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.60 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.15 MPa and the mixture was stirred at 1000 rpm. After reacting for 3 minutes, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of a glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the resulting precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer. Using the obtained copolymer, the weight-average molecular weight, molecular weight distribution, proportion of each structural unit, refractive index, Abbe number, and glass transition temperature were measured. The high refractive index of the obtained copolymer was also evaluated. The results are shown in Table 1.

[0107] <Preparation of Resin Composition> 100 parts of the obtained copolymer were dissolved in cyclohexane. A toluene solution containing 0.5 parts of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane (BASF Japan's "Irganox® 1010") as an antioxidant was mixed with the solution. The mixture was dried under reduced pressure at 180°C for 5 hours to remove the solvent, and a resin composition containing the copolymer (solids content concentration of 99.5% or more) was obtained. The melt volume flow rate was measured using the obtained resin composition. The moldability of the copolymer was also evaluated. The results are shown in Table 1.

[0108] <Preparation of Resin Molded Articles> The preparation of the copolymer and the resin composition described above were repeated multiple times. The resulting resin compositions were then injection molded into a mold using an ultra-compact compounding injection molding machine (Xplore Co., Ltd., product name MC 15HT) to obtain flat resin molded articles measuring 70 mm × 30 mm × 3 mm. In the injection molding process, the resin temperature was set to 130°C higher than the glass transition temperature of the copolymer (= Tg + 130°C), and the mold temperature was set to 15°C lower than the glass transition temperature of the copolymer (= Tg - 15°C).

[0109] (Example 2) Except for the preparation of the copolymer using the following procedure, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In Example 2, a resin molded article was obtained from the resin composition in the same manner as in Example 1.

[0110] <Preparation of Copolymer> In an 800 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 461 g of toluene, 22.5 g (0.190 mol) of DCL as a cyclic olefin, and 14.1 g of a hexane solution (Al concentration = 5.7 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 25°C, the copolymer was prepared as a metallocene compound, "CpTi[N=C(t-Bu) ２ ]Cl ２The polymerization reaction was initiated in the polymerization solution by adding a solution prepared by mixing 16.2 mg (0.0500 mmol) of the metallocene compound with 1.68 g of toluene. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.10 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 4.5%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.26 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.60 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.15 MPa and the mixture was stirred at 1000 rpm. After reacting for 3 minutes, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the resulting precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer.

[0111] (Example 3) Except for the preparation of the copolymer using the following procedure, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In Example 3, a resin molded article was obtained from the resin composition in the same manner as in Example 1.

[0112] <Preparation of Copolymer> In an 800 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 459 g of toluene, 22.5 g (0.190 mol) of DCL as a cyclic olefin, and 14.2 g of a hexane solution (Al concentration = 5.7 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 25°C, the copolymer was prepared as a metallocene compound, "CpTi[N=C(t-Bu) ２ ]Cl ２The polymerization reaction was initiated in the polymerization solution by adding a solution prepared by mixing 19.4 mg (0.0599 mmol) of the metallocene compound with 3.85 g of toluene. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.12 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 4.5%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.31 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.50 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.15 MPa and the mixture was stirred at 1000 rpm. After reacting for 3 minutes, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the resulting precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer.

[0113] (Example 4) Except for the preparation of the copolymer using the following procedure, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In Example 4, a resin molded article was obtained from the resin composition in the same manner as in Example 1.

[0114] <Preparation of Copolymer> In an 800 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 467 g of toluene, 17.5 g (0.148 mol) of DCL as a cyclic olefin, and 14.2 g of a hexane solution (Al concentration = 5.7 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 25°C, the copolymer was prepared as a metallocene compound, "CpTi[N=C(t-Bu) ２ ]Cl ２The polymerization reaction was initiated in the polymerization solution by adding a solution prepared by mixing 16.2 mg (0.0500 mmol) of the metallocene compound with 1.65 g of toluene. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.10 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 3.5%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.34 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.60 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.15 MPa and the mixture was stirred at 1000 rpm. After 3.5 minutes of reaction, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the resulting precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer.

[0115] (Example 5) Except for the preparation of the copolymer using the following procedure, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In Example 5, a resin molded article was obtained from the resin composition in the same manner as in Example 1.

[0116] <Preparation of Copolymer> In a 100 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 46 g of toluene, 3.5 g (0.030 mol) of DCL as a cyclic olefin, 1.0 g of 1-hexene as a chain olefin, and 1.4 g of a hexane solution (Al concentration = 5.7 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 80°C, the metallocene compound "CpTi[N=C(t-Bu) ２ ]Cl ２The polymerization reaction was initiated in the polymerization solution by adding a solution prepared by mixing 1.6 mg (0.0049 mmol) of (where "Cp" means cyclopentadienyl group and "t-Bu" means t-butyl group) with 0.65 g of toluene. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.094 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 6.7%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.17 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.60 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.23 MPa and the mixture was stirred at 1000 rpm. After reacting for 3 minutes, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the resulting precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer.

[0117] (Comparative Example 1) A copolymer was obtained in the same manner as in Example 1 described in International Publication No. 2016 / 163371. In Comparative Example 1, the amount of metallocene compound ((t-BuCp)Ti[N=C(t-Bu)) relative to the amount of cyclic olefin (deltacycline) used was ２ ]Cl ２ The molar ratio of the amount of metallocene compound used (amount of metallocene compound used / amount of cyclic olefin used) is 0.01 mmol / mol. The molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) is 12.0 mol / mol. The resin composition was prepared, various measurements were taken, and various evaluations were performed in the same manner as in Example 1 of this specification. In Comparative Example 1, the melt volume flow rate (MVR) could not be measured because the fluidity of the obtained resin composition was too low. Also, because the fluidity of the obtained resin composition was too low, it was not possible to produce a resin molded article from the resin composition.

[0118] (Comparative Example 2) Except for the preparation of the copolymer using the following procedure, various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In Comparative Example 2, a resin molded article was obtained from the resin composition in the same manner as in Example 1.

[0119] <Preparation of Copolymer> In a 100 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 72.4 g of toluene, and 8.45 g of a hexane solution (Al concentration = 5.9 wt%) of modified methylaluminoxane (MMAO, manufactured by Tosoh Finechem Co., Ltd.) as an activator were added. Further, 31 mg (0.074 mmol) of "rac-ethylenebis(indenyl)zirconium(IV) dichloride" as a metallocene compound was added, and the mixture was stirred at 25°C to obtain a catalyst preparation solution. Separately, in an 800 mL glass pressure reactor with the interior purged with nitrogen, a stirring bar, 282.2 g of toluene, 92.3 g (0.980 mol) of norbornene as a cyclic olefin, and 0.6 g of 1-hexene as a chain olefin were added, and the interior was further purged with ethylene gas as a chain olefin. While stirring at 55°C, the catalyst preparation solution was added to initiate the polymerization reaction in the polymerization solution. At this time, the concentration of the metallocene compound in the polymerization solution at the start of polymerization was 0.16 mmol / kg, the concentration of the cyclic olefin in the polymerization solution at the start of polymerization was 20%, the molar ratio of the amount of metallocene compound used to the amount of cyclic olefin used (amount of metallocene compound used / amount of cyclic olefin used) was 0.08 mmol / mol, and the molar ratio of aluminum (derived from the activator) to titanium (derived from the metallocene compound) in the metallocene catalyst (Al / Ti) was 0.25 mol / mol. During the polymerization reaction, ethylene gas was introduced to maintain a pressure of 0.14 MPa and the mixture was stirred at 1000 rpm. After reacting for 70 minutes, the polymerization reaction was stopped by depressurizing and adding 2-propanol dropwise. Next, the contents of the glass pressure reactor were transferred to a large amount of hydrochloric acid-acidified 2-propanol to precipitate the polymer, and the obtained precipitate was filtered and washed. The washed precipitate was dried under reduced pressure at 70°C for 15 hours to obtain the desired copolymer. １３No peaks originating from 1-hexene units were detected in the 1C-NMR (nuclear magnetic resonance) spectrum.

[0120]

[0121] As is clear from Table 1, the copolymers of Examples 1 to 5 exhibit excellent moldability and high refractive index.

[0122] According to the present invention, a copolymer with excellent moldability and high refractive index, and a method for producing the same can be provided. Furthermore, according to the present invention, a resin composition containing the above copolymer can be provided. Moreover, according to the present invention, a resin molded article obtained by molding the above resin composition can be provided.

Claims

1. A copolymer comprising a structural unit (A) derived from a chain-like olefin and a structural unit (B) derived from a cyclic olefin, wherein the cyclic olefin is of the following formula (I): A copolymer represented by [Formula (I), where X represents a divalent aliphatic hydrocarbon group having a carbon-carbon double bond that can copolymerize with the chain-like olefin], wherein the weight-average molecular weight of the copolymer is 20,000 or more and 250,000 or less.

2. The copolymer according to claim 1, wherein the aliphatic hydrocarbon group has 2 or more carbon atoms and 20 or fewer carbon atoms.

3. The copolymer according to claim 1, wherein said compound is at least one selected from the group consisting of a compound represented by the following formula (Ia): [in formula (Ia), R １ and R ２ each independently represent a hydrogen atom or an aliphatic hydrocarbon group], and a compound represented by the following formula (Ib): [in formula (Ib), R ３ to R ６ each independently represent a hydrogen atom or an aliphatic hydrocarbon group].[] 4. The copolymer according to claim 1, wherein the proportion of the structural unit (B) is 20 mol% or more and 60 mol% or less, when the total repeating units in the copolymer are considered to be 100 mol%.

5. The copolymer according to claim 1, wherein the structural unit (A) consists of two or more structural units derived from chain-like olefins, and includes a structural unit (a1) derived from a chain-like olefin having 4 to 18 carbon atoms, and the proportion of the structural unit (a1) is 0.1 mol% to 30 mol% when the total repeating units in the copolymer are considered to be 100 mol%.

6. The copolymer according to claim 1, wherein the refractive index is 1.540 or higher.

7. The copolymer according to claim 1, wherein the Abbe number is 50.0 or higher.

8. The copolymer according to claim 1, wherein the glass transition temperature is 130°C or higher and 160°C or lower.

9. A method for producing a copolymer according to any one of claims 1 to 8, comprising the step of polymerizing the linear olefin and the cyclic olefin in a polymerization solution using a metallocene catalyst containing a metallocene compound, wherein the molar ratio of the amount of the metallocene compound used to the amount of the cyclic olefin used is 0.03 mmol / mol or more and 1.00 mmol / mol or less.

10. A resin composition comprising the copolymer according to any one of claims 1 to 8.

11. A resin molded article obtained by molding the resin composition described in claim 10.

12. The resin molded article according to claim 11, which is an optical component.

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