Method for producing cycloolefin copolymer

Abstract

To provide a method for producing a cycloolefin copolymer that enables suppression of a pudding-like state during dissolution and has improved toughness.SOLUTION: This method comprises carrying out addition polymerization of a norbornene monomer and an α-olefin in the presence of a first catalyst, a second catalyst, and a chain transfer agent, the second catalyst being represented by formula (B), and the first catalyst having a similar specified structure.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a cyclic olefin copolymer. [Background technology]

[0002] Cyclic olefin copolymers are resins that have high transparency and are used in a wide range of fields, such as optical materials.

[0003] Known methods for producing cyclic olefin copolymers include addition polymerization of various monomers in the presence of a catalyst and a co-catalyst (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 204187 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, it is known that cyclic olefin copolymers tend to be inferior in toughness depending on the type of constituent monomer. Therefore, the present inventors have begun to develop a cyclic olefin copolymer with improved toughness.

[0006] In order to improve the toughness, the present inventors focused on the catalyst used and found that when a catalyst capable of increasing the toughness of a cyclic olefin copolymer is used in polymerization, when the resulting cyclic olefin copolymer is dissolved in a solvent, the viscosity of the copolymer increases over time, and the solution of the cyclic olefin copolymer may become "pudding-like."

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a cyclic olefin copolymer which has improved toughness while suppressing the formation of a pudding state during dissolution. [Means for solving the problem]

[0008] The present inventors have discovered that the above-mentioned problems can be solved by using a combination of two specific catalysts in addition polymerization, and have completed the present invention. Specifically, the present invention provides the following.

[0009] (1) A method for producing a cyclic olefin copolymer, comprising: the production method includes addition polymerization of a norbornene monomer and an α-olefin, the addition polymerization is carried out in the presence of a first catalyst, a second catalyst, and a chain transfer agent; The first catalyst is represented by the following formula (A): The second catalyst is represented by the following formula (B): Manufacturing method. [ka] In formula (A), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. 1 , R 2 , R 3 , and R 4 At least one of the groups has a hydrocarbon group. In formula (A), Y is a divalent group that connects two ligands. In formula (A), M is a Group 4 transition metal. In formula (A), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (A) may or may not be hydrogenated. [ka] In formula (B), R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. In formula (B), Y is a divalent group that connects two ligands. In formula (B), M is a Group 4 transition metal. In formula (B), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (B) may or may not be hydrogenated.

[0010] (2) The production method according to (1), wherein the molar ratio of the first catalyst to the second catalyst (first catalyst / second catalyst) is 5 / 5 to 9 / 1.

[0011] (3) The method according to (1) or (2), wherein the chain transfer agent is an alkyl zinc.

[0012] (4) R in the formula (A) 1 ~R 4 wherein at least one is an isopropyl group and the others are all hydrogen atoms. [Effects of the Invention]

[0013] According to the present invention, there is provided a method for producing a cyclic olefin copolymer which is improved in toughness while suppressing the formation of a purine state during dissolution. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a method for producing a cyclic olefin copolymer will be described. However, the method for producing a cyclic olefin copolymer is not limited to the specific embodiments described below, and may be appropriately modified as long as the desired effects are not impaired.

[0015] <Method of producing cyclic olefin copolymer> In one embodiment of the present invention, the method for producing a cyclic olefin copolymer satisfies the following requirements. The method includes addition polymerizing a norbornene monomer and an α-olefin, the addition polymerization being carried out in the presence of a first catalyst, a second catalyst, and a chain transfer agent. The first catalyst is represented by a predetermined formula (A), and the second catalyst is represented by a predetermined formula (B).

[0016] The present inventors have found that the selection of a catalyst used in addition polymerization is extremely important in the development of a cyclic olefin copolymer with improved toughness. As a result, it has been found that, for example, by using a predetermined catalyst (a catalyst referred to as a "first catalyst" in the specification of the present application), the toughness of the resulting cyclic olefin copolymer is good. On the other hand, it has been found that when the cyclic olefin copolymer is dissolved in a solvent, its viscosity increases over time, which may result in poor handling properties, etc. This state of increased viscosity is known as a "pudding state," etc.

[0017] Therefore, the present inventors conducted extensive research and unexpectedly found that by using a catalyst capable of improving toughness in combination with a catalyst not having such properties (a catalyst referred to as a "second catalyst" in the specification of the present application), it is possible to obtain a cyclic olefin copolymer in which the decrease in toughness is suppressed and the purine state is also suppressed.

[0018] In the specification of the present application, the "toughness (of a cyclic olefin copolymer)" refers to a property evaluated by the number of times a film can be bent until it breaks (number of folding times) as determined by a folding endurance test (MIT test). The greater the number of folding cycles, the higher the toughness of the cyclic olefin copolymer (including molded articles thereof). The folding endurance test is carried out by the method shown in the examples.

[0019] In the specification of the present application, the presence or absence and degree of the "purine state (of the cyclic olefin copolymer)" is evaluated by the rate of viscosity increase when the cyclic olefin copolymer is dissolved in a solvent (decalin, toluene, dichlorobenzene, etc.). The slower the rate of thickening, the more the pudding state is suppressed. The viscosity increase rate is measured by the method shown in the examples.

[0020] The method for producing the cyclic olefin copolymer will be described in detail below.

[0021] (1) Components used in addition polymerization The addition polymerization is carried out in the presence of a first catalyst, a second catalyst, and a chain transfer agent. The first catalyst, the second catalyst, and the chain transfer agent may each be used alone or in combination of two or more.

[0022] (1-1) First catalyst The first catalyst is represented by the following formula (A). The first catalyst alone can produce a cyclic olefin copolymer with good toughness, but the resulting cyclic olefin copolymer may become purine-like when dissolved.

[0023] [ka] In formula (A), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R7 , R 8 , R 9 and R 10 are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. 1 , R 2 , R 3 , and R 4 At least one of the groups has a hydrocarbon group. In formula (A), Y is a divalent group that connects two ligands. In formula (A), M is a Group 4 transition metal. In formula (A), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (A) may or may not be hydrogenated.

[0024] In a preferred embodiment of the present invention, in formula (A), R 1 , R 2 , R 3 , and R 4 wherein at least one is an isopropyl group and the rest are all hydrogen atoms.

[0025] In a preferred embodiment of the present invention, in formula (A), R 1 , R 2 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each independently a hydrogen atom.

[0026] In a preferred embodiment of the present invention, in formula (A), R 3 is an isopropyl group.

[0027] In a preferred embodiment of the present invention, in formula (A), each X is independently a halogen atom (more preferably a chlorine atom).

[0028] In a preferred embodiment of the present invention, in formula (A), M is zirconium.

[0029] In a preferred embodiment of the present invention, the first catalyst is "Catalyst-C1" used in the examples.

[0030] The concentration of the first catalyst in the addition polymerization is not particularly limited as long as the addition polymerization reaction proceeds well. The concentration of the first catalyst in the addition polymerization is preferably 0.05 to 56.5 mol / L, more preferably 0.25 to 11.5 mol / L, based on the entire reaction system.

[0031] (1-2) Second catalyst The second catalyst is represented by the following formula (B). Cyclic olefin copolymers obtained by using the second catalyst alone may have poor toughness.

[0032] [ka] In formula (B), R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. In formula (B), Y is a divalent group that connects two ligands. In formula (B), M is a Group 4 transition metal. In formula (B), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (B) may or may not be hydrogenated.

[0033] In a preferred embodiment of the present invention, in formula (B), R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently a hydrogen atom.

[0034] In a preferred embodiment of the present invention, in formula (B), each X is independently a halogen atom (more preferably a chlorine atom).

[0035] In a preferred embodiment of the present invention, in formula (B), M is zirconium.

[0036] In a preferred embodiment of the present invention, the second catalyst is "Catalyst-C2" used in the examples.

[0037] The concentration of the second catalyst in the addition polymerization is not particularly limited as long as the addition polymerization reaction proceeds well. The concentration of the second catalyst in the addition polymerization is preferably 0.025 to 50 mol / L, more preferably 0.125 to 10 mol / L, based on the entire reaction system.

[0038] (1-3) Ratio of the first catalyst and the second catalyst The ratio of the first catalyst to the second catalyst is not particularly limited as long as the addition polymerization reaction proceeds smoothly. From the viewpoint of more easily achieving the effects of the present invention, it is preferable that the ratio of the first catalyst is equal to or greater than that of the second catalyst. The molar ratio of the first catalyst to the second catalyst (first catalyst / second catalyst) is preferably 5 / 5 to 9 / 1, more preferably 5 / 5 to 8 / 2, and even more preferably 6 / 4 to 7 / 3.

[0039] (1-4) Chain transfer agent The chain transfer agent is not particularly limited as long as it is a compound having chain transfer ability, and any chain transfer agent that is used in the production of a cyclic olefin resin composition can be used.

[0040] In a preferred embodiment of the present invention, the chain transfer agent is an alkyl zinc, an alkyl aluminum, etc. Among these, an alkyl zinc is preferred.

[0041] Examples of the alkyl zinc include compounds represented by the following formula: (R c1 ) y ZnX 2-y In the formula, R c1 is an alkyl group having preferably 1 to 15 carbon atoms, more preferably 1 to 8 carbon atoms, X is a halogen atom or a hydrogen atom, y is an integer of 1 to 2.

[0042] Examples of zinc alkyls include: Dialkyl zinc (dimethyl zinc, diethyl zinc, diisopropyl zinc, di-n-butyl zinc, diisobutyl zinc, di-sec-butyl zinc, di-n-octyl zinc, etc.), Alkyl zinc halides (methyl zinc chloride, isobutyl zinc chloride, etc.), Alkyl zinc hydride (isobutyl zinc hydride, etc.), Alkyl zinc alkoxide (methyl zinc methoxide, etc.), etc. Examples include:

[0043] Examples of alkylaluminum include compounds represented by the following formula: (R c2 ) z AlX 3-z In the formula, R c2 is an alkyl group having preferably 1 to 15, more preferably 1 to 8 carbon atoms; X is a halogen atom or a hydrogen atom, z is an integer of 1 to 3.

[0044] Specific examples of alkylaluminum include: trialkylaluminum (trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-n-octylaluminum, etc.); Dialkylaluminum halides (dimethylaluminum chloride, diisobutylaluminum chloride, etc.), Dialkylaluminum hydrides (diisobutylaluminum hydride, etc.), Dialkylaluminum alkoxide (dimethylaluminum methoxide, etc.) Examples include:

[0045] The concentration of the chain transfer agent in the addition polymerization is not particularly limited as long as the addition polymerization reaction proceeds smoothly. The concentration of the chain transfer agent in the addition polymerization is preferably 12.5 to 125,000 μmol / L, more preferably 125 to 12,500 μmol / L, based on the entire reaction system.

[0046] (1-5) Norbornene monomer and α-olefin Norbornene monomer and α-olefin are polymerization targets (monomers) in addition polymerization.

[0047] (1-5-1) Norbornene Monomer Norbornene (CAS registration number: 498-66-8, chemical formula: CH 10 ) is a type of cyclic olefin monomer. Norbornene monomers also include substituted norbornenes, which are norbornenes having a substituent. The norbornene monomers may be used alone or in combination of two or more.

[0048] The substituted norbornene is not particularly limited. Examples of the substituents on the substituted norbornene include halogen atoms and monovalent or divalent hydrocarbon groups. Specific examples of the substituted norbornene include compounds represented by the following formula (I):

[0049] [ka]

[0050] In formula (I), R a1 ~R a12 may be the same or different and each represents an atom or group selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group. R a9 and R a10 , R a11 and R 12 may combine to form a divalent hydrocarbon group. R a9 or R a10 and R a11 or R a12 may be bonded to each other to form a ring. n is 0 or a positive integer. If n is 2 or more, R a5 ~R a8 may be the same or different in each repeating unit. However, if n is 0, R a1 ~R a4 and R a9 ~R a12 At least one of the is not a hydrogen atom.

[0051] R a1 ~R a8 Specific examples of R include a hydrogen atom; a halogen atom such as fluorine, chlorine, and bromine; and an alkyl group having 1 to 20 carbon atoms. a1 ~R a8 R may all consist of different atoms or groups. a1 ~R a8 Some or all of these may be the same atom or group.

[0052] R a9 ~R a12Specific examples of R include a hydrogen atom; halogen atoms such as fluorine, chlorine, and bromine; alkyl groups having 1 to 20 carbon atoms; cycloalkyl groups such as a cyclohexyl group; substituted or unsubstituted aromatic hydrocarbon groups such as a phenyl group, a tolyl group, an ethylphenyl group, an isopropylphenyl group, a naphthyl group, and an anthryl group; and aralkyl groups such as a benzyl group and a phenethyl group. a9 ~R a12 R may all consist of different atoms or groups. a9 ~R a12 Some or all of these may be the same atom or group.

[0053] R a9 and R a10 , or R a11 and R a12 Specific examples of divalent hydrocarbon groups that can be formed by combining the above groups include alkylidene groups such as an ethylidene group, a propylidene group, and an isopropylidene group.

[0054] R a9 or R a10 and R a11 or R a12 When these bond to each other to form a ring, the ring formed may be a monocyclic or polycyclic ring. The ring formed may be a polycyclic ring having a bridge. The ring formed may have a double bond. The ring formed may have a substituent such as a methyl group.

[0055] Specific examples of the substituted norbornene represented by formula (I) include 5-methyl-bicyclo[2.2.1]hept-2-ene, 5,5-dimethyl-bicyclo[2.2.1]hept-2-ene, 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-ethylidene-bicyclo[2.2.1]hept-2-ene, 5-hexyl-bicyclo[2.2.1]hept-2-ene, 5-methyl-bicyclo[2.2.1]hept-2-ene, 5,5-dimethyl-bicyclo[2.2.1]hept-2-ene, 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-hexyl-bicyclo[2.2.1]hept-2-ene, 5-methyl ... Bicyclic olefins such as cyclo[2.2.1]hept-2-ene, 5-octyl-bicyclo[2.2.1]hept-2-ene, 5-octadecyl-bicyclo[2.2.1]hept-2-ene, 5-methylidene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, and 5-propenyl-bicyclo[2.2.1]hept-2-ene; Tricyclo[4.3.0.1 2,5 ]Deca-3,7-diene (common name: dicyclopentadiene), tricyclo[4.3.0.1 2,5 ]dec-3-ene; tricyclo[4.4.0.1 2,5 ]undeca-3,7-diene or tricyclo[4.4.0.1 2,5 ]undeca-3,8-diene or partially hydrogenated products thereof (or adducts of cyclopentadiene and cyclohexene), tricyclo[4.4.0.1 2,5 ]undec-3-ene; three-ring cyclic olefins such as 5-cyclopentyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexenylbicyclo[2.2.1]hept-2-ene, and 5-phenyl-bicyclo[2.2.1]hept-2-ene; Tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene (also simply called tetracyclododecene), 8-methyltetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-methylidenetetracyclo[4.4.0.1 2,5 .1 7,10]dodec-3-ene, 8-ethylidenetetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-vinyltetracyclo[4,4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-propenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ] Four-ring cyclic olefins such as dodec-3-ene; 8-Cyclopentyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-cyclohexyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-cyclohexenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-phenyl-cyclopentyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene; tetracyclo[7.4.1 3,6 .0 1,9 .0 2,7 ]tetradeca-4,9,11,13-tetraene (also known as 1,4-methano-1,4,4a,9a-tetrahydrofluorene), tetracyclo[8.4.1 4,7 .0 1,10 .0 3,8 ]pentadeca-5,10,12,14-tetraene (also known as 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene); pentacyclo[6.6.1.1 3,6 .0 2,7 .0 9,14 ]-4-Hexadecene, Pentacyclo[6.5.1.1 3,6 .0 2,7 .0 9,13 ]-4-pentadecene, pentacyclo[7.4.0.0 2,7 .1 3,6 .1 10,13 ]-4-pentadecene;Heptacyclo[8.7.0.1 2,9 .1 4,7 .1 11,17 .0 3,8 .0 12,16]-5-eicosene, heptacyclo[8.7.0.1 2,9 .0 3,8 .1 4,7 .0 12,17 .1 13,l6 ]-14-eicosene; and polycyclic olefins such as a tetramer of cyclopentadiene.

[0056] Among these, alkyl-substituted norbornenes such as bicyclo[2.2.1]hept-2-ene substituted with one or more alkyl groups, and alkylidene-substituted norbornenes such as bicyclo[2.2.1]hept-2-ene substituted with one or more alkylidene groups are preferred. 5-Ethylidene-bicyclo[2.2.1]hept-2-ene (common name: 5-ethylidene-2-norbornene, or simply ethylidenenorbornene) is particularly preferred.

[0057] (1-5-2) α-olefin The α-olefin is not particularly limited as long as it is an α-olefin copolymerizable with norbornene monomer, and the α-olefin may be substituted or unsubstituted.

[0058] In a preferred embodiment of the present invention, the α-olefin preferably has 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, and even more preferably 2 to 10 carbon atoms.

[0059] Specific examples of α-olefins 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, etc. Among them, 1-hexene, 1-octene, and 1-decene are particularly preferred.

[0060] In a preferred embodiment of the present invention, the α-olefin is ethylene.

[0061] (1-5-3) Amount of Monomer Used The amount of the monomer used is not particularly limited, but may satisfy any of the following requirements.

[0062] The amount of norbornene monomer charged relative to 1 part by mass of the total catalyst added to the reaction system at the start of polymerization is preferably 4,000 to 2,500,000 parts by mass, and more preferably 40,000 to 1,200,000 parts by mass.

[0063] The method for charging the α-olefin is not particularly limited as long as the desired amount of α-olefin can be charged into the polymerization vessel. Preferred conditions will be explained using the case where the α-olefin is ethylene as an example. The lower limit of the ethylene charging pressure (gauge pressure) in the polymerization vessel is preferably 0.5 MPa or more, more preferably 0.55 MPa or more, and even more preferably 0.6 MPa or more. Increasing the ethylene charging pressure allows the amount of catalyst used per polymer produced to be reduced. The upper limit of the charging pressure (gauge pressure) of ethylene in the polymerization vessel is preferably 10 MPa or less, more preferably 5 MPa or less, and further preferably 3 MPa or less. The charging pressure (gauge pressure) of ethylene in the polymerization vessel is preferably from 0.5 to 10 MPa, more preferably from 0.55 to 5 MPa, and even more preferably from 0.6 to 3 MPa.

[0064] (2) Addition polymerization conditions The conditions for addition polymerization of norbornene monomer and α-olefin are not particularly limited, and any conditions employed in the production of cyclic olefin copolymers can be employed. During polymerization, in addition to the above-mentioned components, an optional component (N-methyldialkylammonium tetrakis(pentafluorophenyl)borate (alkyl:C 14 ~C 18 ) (PF-42) or other promoters can be used.

[0065] In the addition polymerization, the components to be subjected to the reaction may be added to a reaction vessel simultaneously or separately.

[0066] The addition polymerization may be carried out in the presence of a solvent. The solvent is not particularly limited as long as it does not inhibit the polymerization reaction. Preferred solvents include, for example, hydrocarbon solvents and halogenated hydrocarbon solvents. When a solvent is used, the amount of the solvent to be used is not particularly limited and is appropriately determined depending on the amount of the monomer, etc.

[0067] The temperature conditions for the addition polymerization are not particularly limited. In a preferred embodiment of the present invention, the temperature condition for the addition polymerization is preferably 30 to 110°C, more preferably 50 to 90°C.

[0068] The time for addition polymerization is not particularly limited. In a preferred embodiment of the present invention, the addition polymerization time is preferably 0.2 to 5 hours, more preferably 0.5 to 3 hours.

[0069] The atmosphere in which the addition polymerization reaction is carried out is not particularly limited as long as the reaction is not inhibited. In a preferred embodiment of the present invention, the atmosphere in which the addition polymerization reaction is carried out is an inert gas atmosphere (nitrogen gas, helium gas, etc.).

[0070] After the addition polymerization is completed, the cyclic olefin copolymer can be recovered from the reaction vessel in a conventional manner.

[0071] <Cyclic olefin copolymer> The cyclic olefin copolymer includes any cyclic olefin copolymer obtained by the above-mentioned production method. In a preferred embodiment, the cyclic olefin copolymer may satisfy, for example, the following requirements:

[0072] (1) Toughness According to the production method according to one aspect of the present invention, a cyclic olefin copolymer having excellent toughness can be obtained.

[0073] In a preferred embodiment of the present invention, the cyclic olefin copolymer has a folding endurance count measured by the following folding endurance test (MIT test) of preferably 100 or more, more preferably 200 or more, and even more preferably 300 or more. Although a higher folding endurance count is preferable, a practical upper limit of the folding endurance count is, for example, preferably 500 or less, more preferably 400 or less.

[0074] [Folding endurance test (MIT test)] A mold with a depth of 50 μm is made using Kapton (registered trademark) film (100 mm×100 mm×50 μm). Next, each cyclic olefin copolymer is filled into the mold, and then the cyclic olefin copolymer is vacuum-pressed using a hot vacuum press under conditions of a pressure of 15 MPa, a temperature of 290°C, and for 15 minutes. After the pressing is completed, each cyclic olefin copolymer is rapidly cooled by being sandwiched between metal plates at room temperature. After cooling, the metal plate is removed to obtain a cyclic olefin copolymer film with a thickness of about 50 μm. The obtained film is cut into a predetermined size (100 mm × 15 mm × 50 μmt) and subjected to an MIT test using an MIT folding fatigue tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) to measure the number of times the film can be folded until it breaks (folding endurance).

[0075] (2) Pudding state According to the production method of one aspect of the present invention, a cyclic olefin copolymer in which the purine state during dissolution is suppressed can be obtained.

[0076] In a preferred embodiment of the present invention, the cyclic olefin copolymer has a viscosity increase rate measured by the following method of preferably 0.5 Pa·s / min or less, more preferably 0.4 Pa·s / min or less, even more preferably 0.3 Pa·s / min or less, and still more preferably 0.2 Pa·s / min or less.

[0077] [Method for measuring viscosity increase rate] 0.6 g of the cyclic olefin copolymer was dissolved in 2.4 g of decalin at 145° C. for 1 hour with heating and stirring. After 1 hour, the 145°C solution is cooled by leaving it to stand in a 40°C water bath for 5 minutes. 1 ml of the solution is then sampled and the change in viscosity over time is measured using an E-type viscometer (TV25 viscometer, manufactured by Toki Sangyo Co., Ltd., measurement conditions: room temperature, rotation speed: 1 rpm, upper measurement limit: 250 Pa·s). The rate of viscosity increase is measured either until the viscosity reaches the upper limit of measurement or when the rate of change reaches a constant value within a maximum measurement time of 8 hours.

[0078] (3) Glass transition temperature The glass transition temperature (also referred to as "Tg") of the cyclic olefin copolymer is not particularly limited, but from the viewpoint that the heat resistance and processability of the cyclic olefin copolymer tend to be good, it is preferably 100 to 185°C, more preferably 115 to 170°C, and even more preferably 125 to 160°C.

[0079] In the specification of the present application, the "glass transition temperature (of the cyclic olefin copolymer)" is determined by the DSC method (the method described in JIS K7121).

[0080] (4) Uses of cyclic olefin copolymers The cyclic olefin copolymer can be used for any purpose. For example, it can be used in place of or in conjunction with conventional cyclic olefin copolymers. [Example]

[0081] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0082] <Preparation and Evaluation of Cyclic Olefin Copolymers> Cyclic olefin copolymers according to Examples or Comparative Examples were produced using the materials and conditions shown in Table 2 by the following methods.

[0083] The terms used in this study have the following meanings: "Nb": 2-norbornene "Nb charge amount": the total molar amount of norbornene monomer (2-norbornene) charged at the start of polymerization "Tg": Glass transition temperature

[0084] (1) Production of cyclic olefin copolymer First, a polymerization solvent (toluene) and norbornene monomer (2-norbornene) were added to a thoroughly dried 150 mL stainless steel autoclave containing a stirrer. A toluene solution of triisobutylaluminum (1 mol / L, 250 μL) and a chain transfer agent were then added. Diethylzinc was used as the chain transfer agent in all examples except for Example 10, and triethylaluminum was used in Example 10. Next, the autoclave was heated until the polymerization temperature reached 60°C, after which the catalyst solution was added, and ethylene pressure (gauge pressure 0.9 MPa) was applied, with 30 seconds after the start being set as the polymerization initiation point for addition polymerization. The total amount of the monomer solution immediately before the application of ethylene pressure was 80 mL. After about 60 minutes had passed since the start of polymerization, the supply of ethylene was stopped, and the pressure was carefully returned to normal pressure, after which isopropyl alcohol was added to the reaction solution to terminate the reaction. Thereafter, the polymerization solution was poured into a mixed solvent (300 mL of acetone, 200 mL of methanol or isopropyl alcohol, and 5 mL of hydrochloric acid) to precipitate the copolymer. The copolymer was collected by suction filtration, washed with acetone and methanol, and then vacuum dried at 110° C. for 12 hours to obtain a cyclic olefin copolymer (copolymer of norbornene and ethylene).

[0085] In this example, the amount of norbornene monomer used is as shown in "Nb charge amount" in Table 2. The amount of chain transfer agent used is as shown in "Chain transfer agent" in Table 2. The amount of catalyst used is as shown in "Amount used" under "Catalyst used" in Table 2.

[0086] The catalysts used in this example are as shown in "Catalysts Used" in Table 2, and each name corresponds to the four types of catalysts shown in Table 1 below. The molar ratio of each catalyst (the molar ratio of the first catalyst to the second catalyst) is as shown in Table 2 under "First catalyst / Second catalyst".

[0087] [Table 1]

[0088] In this example, the following promoter was used: N-methyldialkylammonium tetrakis(pentafluorophenyl)borate (alkyl:C 14 ~C 18 )(PF-42)(AGC Co., Ltd.)

[0089] Each catalyst and co-catalyst was prepared as follows before use, and then prepared as a catalyst solution and added to the reaction system. To each of the catalysts (C1 to C4), toluene containing 10 molar equivalents of trimethylaluminum was added to dissolve the catalyst, thereby obtaining a toluene solution. Next, the co-catalyst (2 molar equivalents of the catalyst) was mixed with the toluene solution and stirred under a nitrogen atmosphere. However, in examples where two or more catalysts were used (e.g., Example 1), the dissolved catalyst solutions were mixed together before mixing with the co-catalyst. The mixture was autoclaved 20 minutes after the completion of stirring.

[0090] In addition, the copolymers corresponding to the examples maintained an appropriate viscosity during the polymerization process, and no pudding-like state was observed.

[0091] (2) Evaluation The toughness, viscosity increase rate, and glass transition temperature of each copolymer obtained were determined by the following methods, and the results are shown in Table 2.

[0092] (2-1) Toughness A folding endurance test (MIT test) was carried out according to a standard method to evaluate the toughness of each copolymer. Specifically, first, a mold having a depth of 50 μm was made using a Kapton (registered trademark) film (100 mm×100 mm×50 μm). Next, each cyclic olefin copolymer was filled into the mold, and then vacuum-pressed using a hot vacuum press under conditions of a pressure of 15 MPa, a temperature of 290°C, and for 15 minutes. After pressing, each cyclic olefin copolymer was rapidly cooled by being sandwiched between metal plates at room temperature. After cooling, the metal plate was removed to obtain a cyclic olefin copolymer film having a thickness of about 50 μm. The obtained film was cut into a predetermined size (100 mm × 15 mm × 50 μmt) and subjected to an MIT test using an MIT folding fatigue tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The number of times the film could be bent until it broke (folding endurance) was measured. The results are shown in the "Toughness" column in Table 2. The greater the number of folding times, the higher the toughness of the film.

[0093] The details of the MIT exam requirements are as follows: Loading method: Spring load Load: 0.25kgf Bending angle: 90° Bending speed: 90 cpm

[0094] (2-2) Thickening speed 0.6 g of each cyclic olefin copolymer was dissolved in 2.4 g of decalin at 145° C. for 1 hour with heating and stirring. After 1 hour, the 145°C solution was cooled by placing it in a 40°C water bath for 5 minutes. 1 ml of the solution was then sampled and the change in viscosity over time was measured using an E-type viscometer (TV25 viscometer, manufactured by Toki Sangyo Co., Ltd., measurement conditions: room temperature, rotation speed: 1 rpm, upper limit of measurement: 250 Pa·s). The viscosity increase rate was measured either until the viscosity reached the upper limit of measurement or until the rate of change reached a constant value within a maximum measurement time of 8 hours. The results are shown in "Thickening Rate" in Table 2. If the viscosity increase rate is 0.5 Pa·s / min or less, it can be determined that the pudding state is suppressed.

[0095] (2-3) Glass transition temperature The glass transition temperature was measured by a differential scanning calorimeter under conditions of a nitrogen atmosphere and a temperature rise rate of 20° C. / min according to the method described in JIS K7121. The results are shown in Table 2 under "Tg".

[0096] The details of the measurement conditions are as follows. DSC device: Differential scanning calorimeter ("DSC7000x", Hitachi High-Tech Science Corporation) Measurement atmosphere: Nitrogen Temperature rise condition: 20°C / min

[0097] [Table 2]

[0098] As shown in the above examples, a cyclic olefin copolymer having excellent toughness was obtained by the production method that satisfied the requirements of the present invention.

[0099] Furthermore, when the obtained cyclic olefin copolymer was dissolved in a solvent, no significant increase in the viscosity increase rate was observed, indicating that the pudding state was suppressed.

Claims

1. A method for producing a cyclic olefin copolymer, comprising: the production method includes addition polymerization of a norbornene monomer and an α-olefin, the addition polymerization is carried out in the presence of a first catalyst, a second catalyst, and a chain transfer agent; The first catalyst is represented by the following formula (A): The second catalyst is represented by the following formula (B): Manufacturing method. 【Chemical 1】 In formula (A), R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , R ８ , R ９ and R １０ are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. １ , R ２ , R ３ , and R ４ At least one of the groups has a hydrocarbon group. In formula (A), Y is a divalent group that bonds two ligands. In formula (A), M is a Group 4 transition metal. In formula (A), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (A) may or may not be hydrogenated. 【Chemistry 2】 In formula (B), R １ , R ２ , R ３ , R ４ , R ５ , and R ６ are each independently any one of a hydrogen atom, a hydrocarbon group, a halogen-containing group, an oxygen-containing group, a silicon-containing group, and a tin-containing group, and may be the same or different, and adjacent groups may be bonded to each other to form a ring. In formula (B), Y is a divalent group that bonds two ligands. In formula (B), M is a Group 4 transition metal. In formula (B), each X is independently any one of a halogen atom, a hydrogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, and an oxygen-containing group. The six-membered ring in the indene ring in formula (B) may or may not be hydrogenated.

2. 2. The method according to claim 1, wherein the molar ratio of the first catalyst to the second catalyst (first catalyst / second catalyst) is 5 / 5 to 9 / 1.

3. The process according to claim 1 or 2, wherein the chain transfer agent is an alkyl zinc.

4. R in the formula (A) １ ~R ４ 3. The method according to claim 1, wherein at least one of the groups is an isopropyl group and the others are all hydrogen atoms.

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