METHOD FOR PRODUCING A CYCLOOLEFIN COPOLYMER

Abstract

A process for the preparation of a cycloolefin copolymer is provided, enabling the efficient production of a cycloolefin copolymer consisting of a cycloolefin monomer and an α-olefin with a carbon number of 3 to 20, exhibiting excellent toughness. It is produced in a process comprising a first polymerization, in which a cycloolefin monomer and an α-olefin are polymerized in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminum compound, and a borate compound; the second polymerization involves adding the monomer and the alkylaluminum compound to the polymerization vessel; and the second polymerization, in which the polymerization of the monomer is continued after the addition of the monomer and the alkylaluminum compound.

Description

Technical field

[0001] The present invention relates to a method for producing a cycloolefin copolymer. General state of the art

[0002] Cycloolefin polymers and cycloolefin copolymers (also referred to as "COP" and "COC," respectively) exhibit low hygroscopicity and high transparency. Therefore, COP and COC are used for various purposes, primarily in the field of optical materials such as optical plates, optical films, optical fibers, and the like. A representative COC is a copolymer of cycloolefin and ethylene. The glass transition temperature (Tg) of this copolymer can be modified by altering the specific cycloolefin and ethylene copolymer composition. Thus, the cycloolefin-ethylene copolymer can be produced with a higher Tg than COP, enabling the achievement of Tg values ​​exceeding 200 °C, which are difficult to attain with COP. However, this copolymer is hard and brittle.Therefore, the mechanical strength of this copolymer is low, which is why it is problematic in terms of its poor handling and processability.

[0003] One method for improving the mechanical strength of high Tg COC involves the copolymerization of cycloolefin with a non-ethylene α-olefin (hereinafter referred to as the "specific α-olefin"). Several studies on the copolymerization of cycloolefin and the specific α-olefin have been conducted.

[0004] The copolymerization of cycloolefin and the specified α-olefin differs significantly from the copolymerization of cycloolefin and ethylene. While high-molecular-weight compounds can be obtained in the copolymerization of cycloolefin and ethylene, the copolymerization of cycloolefin and the specified α-olefin involves a chain transfer reaction due to the specific α-olefin, making it difficult to obtain high-molecular-weight compounds to date. Therefore, copolymers of cycloolefin and the specified α-olefin are currently considered unsuitable for forming (see, for example, Non-Patent Document 1).

[0005] Therefore, various investigations were carried out on copolymers of cycloolefin and the specific α-olefin with regard to improving their forming properties. For example, a process is proposed as a method for producing a copolymer of cycloolefin and the specific α-olefin, which has a relatively high molecular weight and is formable into a film, in which cycloolefin and the specific α-olefin are copolymerized in the presence of a titanocene catalyst of a specific structure and triphenylmethyliumtetrakis(pentafluorophenyl)borate (see patent document 1). State-of-the-art documents, patent documents

[0006] Patent Document 1: JP 2016-56275 A Non-patent documents

[0007] Non-patent document 1: Jung, H. Y et al., Polyhedron, 2005, Vol. 24, pp. 1269-1273 Brief description of the invention; Problem of the present invention

[0008] However, even with the method from patent document 1, it is difficult to produce the copolymer of cycloolefin and the specific α-olefin with high efficiency as a cycloolefin copolymer with excellent toughness.

[0009] The present invention was made in view of these circumstances, and one of its objectives is to provide a process for producing a cycloolefin copolymer with which a cycloolefin copolymer can be produced with high efficiency, which is a copolymer of a cycloolefin monomer and an α-olefin with a carbon number of 3 to 20 and has excellent toughness. Means of solving the task

[0010] The inventors of the present invention have recognized that the above problem can be solved by producing a copolymer of a cycloolefin monomer and an α-olefin with a carbon number of 3 to 20 in a process comprising the first polymerization, in which a cycloolefin monomer and an α-olefin are polymerized in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminum compound, and a borate compound; the second polymerization, in which the polymerization of the monomer is continued after the first polymerization; and the second polymerization, in which the polymerization of the monomer is continued after the addition of the monomer and the alkylaluminum compound. More precisely, the present invention provides the following.

[0011] (I) A process for producing a cycloolefin copolymer comprising a unit derived from a cycloolefin monomer and a unit derived from an α-olefin having a carbon number of 3 to 20, wherein the production process comprises first polymerization, in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminium compound and a borate compound, polymerizing the cycloolefin monomer and a monomer containing the α-olefin, adding the monomer and the alkylaluminium compound to the polymerization vessel following the first polymerization, and second polymerization, wherein, after the addition of the monomer and the alkylaluminium compound, the polymerization of the monomer is continued, wherein, in the first polymerization, the polymerization of the monomer is carried out until the reaction rate of the cycloolefin monomer with respect to the mole number of the cycloolefin monomer,that which was added to the polymerization vessel at the beginning of the first polymerization is 80 mol% or more, wherein the amount of hindered phenol used in the first polymerization is an amount in which the amount of phenolic hydroxyl groups in the hindered phenol is at most 1.5 mol per mol of alkylaluminum compound.

[0012] (II) The process for producing a cycloolefin copolymer of (I) wherein the polymerization reaction terminates after carrying out the second polymerization.

[0013] (III) The process for producing a cycloolefin copolymer of (I), wherein, after a 1st second polymerization, the addition of the monomer and the alkylaluminium compound and the second polymerization are repeated until an addition frequency of the monomer and the alkylaluminium compound is reached n times, where n is an integer of 2 or more, wherein a p-th addition of a 2nd to nth addition of the monomer and the alkylaluminium compound is carried out after, at a (p-1)th second polymerization, the reaction rate of the cycloolefin monomer with respect to the number of moles of the cycloolefin monomer in the polymerization vessel at the beginning of the (p-1)th second polymerization has reached 80 mol% or more, where p is an integer of 2 to n, wherein the polymerization reaction terminates after carrying out the nth second polymerization.

[0014] (IV) The process for producing a cycloolefin copolymer from one of (I) to (III), wherein the alkylaluminium compound used in the first polymerization is a long-chain alkylaluminium compound having only alkyl groups with a carbon number of at least 6, and wherein the alkylaluminium compound added to the polymerization vessel after the first polymerization is a short-chain alkylaluminium compound having only alkyl groups with a carbon number of at most 5.

[0015] (V) The process for producing a cycloolefin copolymer of one of (I) to (IV), wherein from the beginning of the first polymerization to the end of the second polymerization both an alkylaluminium compound I and an alkylaluminium compound II different from the alkylaluminium compound I are used as the alkylaluminium compound, wherein the alkylaluminium compound I has at least one alkyl group having a carbon number of at least 6 and the alkylaluminium compound II has at least one alkyl group having a carbon number of at most 5.

[0016] (VI) The process for producing a cycloolefin copolymer of (IV) wherein the alkylaluminium compound is at least one compound selected from the group consisting of trimethylaluminium, triethylaluminium, triisobutylaluminium and trioctylaluminium.

[0017] (VII) The process for producing a cycloolefin copolymer of (V) wherein the alkylaluminium compound I is trioctylaluminium and the alkylaluminium compound II is trimethylaluminium, triethylaluminium or triisobutylaluminium.

[0018] (VIII) The process for producing a cycloolefin copolymer from one of (I) to (VII), wherein the number-average molecular weight of the cycloolefin copolymer obtained is 10,000-100,000.

[0019] (IX) The process for producing a cycloolefin copolymer from one of (I) to (VIII), wherein the titanocene catalyst is a compound expressed by the following formula (1): (where in formula (1) R 1 -R 3 Each is independently an alkyl group with a carbon number of 1 to 6 or an aryl group with a carbon number of 6 to 12, R 4 and R 5Each is independently an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12, or a halogen atom, and R 6 -R 13 each independently be a silyl group which may have a hydrogen atom, an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to at most 12 or a monovalent hydrocarbon group with a carbon number of 1 to 12 as a substituent group).

[0020] (X) The process for producing a cycloolefin copolymer from one of (I) to (IX), wherein the cycloolefin copolymer has at least two glass transition temperatures in a range of 0-300 °C. Effect of the invention

[0021] According to the present invention, a method for producing a cycloolefin copolymer can be provided which can be produced with high efficiency as a copolymer of a cycloolefin monomer and an α-olefin with a carbon number of 3 to 20 and which has excellent toughness. embodiment of the invention

[0022] One embodiment of the present invention is described in detail below. However, the present invention is not limited to the embodiment described below. < <cycloolefin-copolymer>>

[0023] The cycloolefin copolymer produced in the manufacturing process described below is an adduct-type copolymer of a cycloolefin monomer and an α-olefin with a carbon number of 3 to a maximum of 20.

[0024] There are no particular restrictions regarding the molar ratio of the structural units derived from the α-olefin to the total number of structural units of the cycloolefin copolymer, but it is preferably 10-50 mol%, more preferably 20-40 mol%, and particularly 20-30 mol%. When the cycloolefin copolymer has the structural units derived from the α-olefin in this ratio, the tensile strength and tensile modulus of the cycloolefin copolymer are high, and the cycloolefin copolymer exhibits a high glass transition temperature and excellent temperature resistance.

[0025] The molar ratio of the structural units derived from the α-olefin can be determined by measuring the 13 C-NMR spectrum can be calculated.

[0026] Provided that the fulfillment of the object of the present invention is not thereby impaired, the cycloolefin copolymer may include further structural units that are not derived from the cycloolefin monomer or from α-olefins with a carbon number of 3 to 20. Further structural units may be used that are polymerizable with the cycloolefin monomer and the α-olefin with a carbon number of 3 to 20 and are derived from compounds with an unsaturated carbon-carbon double bond. Generally, structural units derived from ethylene are preferred as further structural units.

[0027] In the cycloolefin copolymer, the ratio of the sum of the molar ratio of the structural units derived from the cycloolefin monomer and the molar ratio of the structural units derived from the α-olefin to the molar number of all structural units is preferably at least 80 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol% and most preferably 100 mol%.

[0028] Preferably, the cycloolefin copolymer has at least two glass transition temperatures in a range of 0-300 °C.

[0029] The glass transition temperature can be measured by observing the viscoelastic behavior at -100 to 300 °C using a solid-state rheometer and a 50 µm thick, foil-like specimen. Specifically, the temperature of the peak in a tanδ diagram obtained from the aforementioned measurement is considered the glass transition temperature.

[0030] For good mechanical properties, which are measured in a tensile test, the cycloolefin copolymer preferably has at least one glass transition temperature in a range of 0-100 °C and in a range of 160-300 °C.

[0031] In particular, for high elongation at break, measured in a tensile test, and excellent toughness, the cycloolefin copolymer preferably has at least one glass transition temperature in a range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0032] In the range of 0-100 °C, the range of 30-80 °C is preferred, and the range of 50-80 °C is even more preferred.

[0033] In the range of 160-300 °C, the range of 170-280 °C is preferred, and the range of 170-260 °C is even more preferred.

[0034] In the range below 0 °C, -50-0 °C is preferred and -40--10 °C is even more preferred.

[0035] Typically, the cycloolefin copolymer has a glass transition temperature in the range of 0-100 °C and in the range of 160-300 °C, but it is preferred if it has at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0036] There are no particular restrictions regarding the molecular weight of the cycloolefin copolymer. The weight-average molecular weight (Mw) of the cycloolefin copolymer, measured as a polystyrene equivalent by gel permeation chromatography (GPC), is preferably 5,000–200,000 and more preferably 10,000–100,000.

[0037] The number-average molecular weight (Mn) of the cycloolefin copolymer, measured as polystyrene equivalent value by gel permeation chromatography (GPC), is preferably 5,000-200,000 and more preferably 10,000-100,000.

[0038] For excellent toughness of the cycloolefin copolymer, it is preferred that the distribution ratio (Mw / Mn) is not excessively high. Specifically, the distribution ratio (Mw / Mn) is preferably at most 1.75, more preferably at most 1.70, and even more preferably at most 1.60. There is no particular restriction regarding the lower limit of the distribution ratio (Mw / Mn). The distribution ratio (Mw / Mn) can, for example, be at least 1.1. <cycloolefinmonomer>

[0039] Provided that the fulfillment of the objective of the present invention is not thereby impaired, there is no particular restriction with regard to the cycloolefin monomer. Norbornene and substituted norbornene are generally preferred as the cycloolefin monomer. From the perspective of balancing the cost, polymerizability, and physical properties of the resulting cycloolefin copolymer, norbornene is particularly preferred as the cycloolefin monomer. One type of cycloolefin monomer alone or two or more types in combination can be used.

[0040] There are no particular restrictions regarding substituted norbornene. The substituent group of substituted norbornene can be, for example, a halogen atom or a monovalent or divalent hydrocarbon group. A concrete example of substituted norbornene is the compound shown in formula (I) below.

[0041] In formula (I) R al -R a12 being the same or different and are an atom or group that is selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group.

[0042] R a9 and R a10 , R a11 and R 12 together they can form a divalent hydrocarbon group.

[0043] R a9 or R a10 and R a11 or R a12 can be tied together and form a ring.

[0044] n is 0 or a positive integer.

[0045] If n is 2 or more, R a5 -R a8 The repetition units may be the same or different.

[0046] However, if n is 0, then at least one of R a1 -R a4 and R a9 -R a12 no hydrogen atom.

[0047] As concrete examples of R a1 -R a8 Examples include a hydrogen atom; a halogen atom such as fluorine, chlorine, bromine, or the like; an alkyl group with a carbon number of 1 to 20, or the like. R a1 -R a8 They can all be different atoms or groups. From R a1 -R a8 Some or all of them may be the same atom or group.

[0048] As concrete examples of R a9 -R a12 Examples include a hydrogen atom; a halogen atom such as fluorine, chlorine, bromine, or the like; an alkyl group with a carbon number of 1 to 20; a cycloalkyl group such as a cyclohexyl group or the like; a substituted or unsubstituted aromatic hydrocarbon group such as a phenyl group, a tolyl group, an ethylphenyl group, an isopropylphenyl group, a naphthyl group, an anthryl group, or the like; and an aralkyl group such as a benzyl group, a phenethyl group, or the like. a9 -R a12 They can all be different atoms or groups. From R a9 -R a12 Some or all of them may be the same atom or group.

[0049] As a concrete example of the effects of R a9 and R a10 or R a11 and R a12 The resulting divalent hydrocarbon group can be called, for example, an alkylidene group or the like, such as an ethylidene group, a propylidene group, an isopropylidene group, or the like.

[0050] If R a9 or R a10 and R a11 or R a12 When the atoms are bonded together to form a ring, the resulting ring can be monocyclic or polycyclic. The resulting ring can be polycyclic with cross-linking. The resulting ring can contain a double bond. The resulting ring can contain a substituent group such as a methyl group or similar.

[0051] Specific examples of the substituted norbornene given in (I) include bicyclic cycloolefins such as 5-methyl-bicyclo[2.2.1]hepta-2-ene, 5,5-dimethyl-bicyclo[2.2.1]hepta-2-ene, 5-ethyl-bicyclo[2.2.1]hepta-2-ene, 5-butyl-bicyclo[2.2.1]hepta-2-ene, 5-ethylidene-bicyclo[2.2.1]hepta-2-ene, 5-hexyl-bicyclo[2.2.1]hepta-2-ene, 5-octyl-bicyclo[2.2.1]hepta-2-ene, 5-octadecyl-bicyclo[2.2.1]hepta-2-ene, 5-methylidene-bicyclo[2.2.1]hepta-2-ene, 5-Vinyl-bicyclo[2.2.1]hepta-2-ene, 5-propenyl-bicyclo[2.2.1]hepta-2-ene and the like; tricyclic cycloolefins such as tricyclo[4.3.0.1] 2,5 ]deka-3,7-diene (common name: dicyclopentadiene), Tricyclo[4.3.0.1 2,5 ]deka-3-ene; Tricyclo[4.4.0.1 2,5 ]undeka-3,7-diene or tricyclo[4.4.0.1 2,5 ]undeka-3,8-diene or Tricyclo[4.4.0.1 2,5 ]undeka-3-ene, which is its partially hydrogenated additive (or an adduct of cyclopentadiene and cyclohexene); 5-cyclopentyl-bicyclo[2.2.1]hepta-2-ene, 5-cyclohexyl-bicyclo[2.2.1]hepta-2-ene, 5-cyclohexenylbicyclo[2.2.1]hepta-2-ene or 5-phenyl-bicyclo[2.2.1]hepta-2-ene; tetracyclic cycloolefins such as tetracyclo[4.4.0.1 2,5 1 7,10 ]dodeka-3-ene (also known as tetracyclododecene), 8-methyltetracyclo[4.4.0.1 2,5 .1 7,10 ]dodeka-3-ene, 8-ethyltetracyclo[4. 4. 0.1 2,5 1 7,10 ]dodeka-3-ene, 8-methylidentetracyclo[4.4.0.1 2,5 1 7,10 ]dodeka-3-ene, 8-ethylidenetetracyclo[4.4.0.1 2,5 1 7,10 ]dodeka-3-ene, 8-vinyltetracyclo[4.4.0.1 2,5 1 7,10 ]dodeka-3-ene or 8-propenyl-tetracyclo[4.4.0.1 2,5 1 7,10 ]dodeka-3-ene; and polycyclic cycloolefins such as tetramers of cyclopentadiene; 8-cyclopentyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodeka-3-en, 8-Cyclohexyl-tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodeka-3-en, 8-Cyclohexenyl-tetracyclo[4.4.0.1 2,5 . 1 7,10 ]dodeka-3-en, 8-Phenyl-cyclopentyl-tetracyclo[4.4.0.1 2,5 . 1 7,10 ]dodeka-3-en; Tetracyclo[7.4.1 3,6 .0 1,9 .0 2,7 ]Tetradeka-4,9,11,13-Tetraen (auch als 1,4-Methano-1,4,4a,9a-Tetrahydrofluoren bezeichnet), Tetracyclo[8.4.1 4,7 .0 1,10 .0 3,8 ]pentadeka-5,10,12,14-tetraen (auch als 1,4-Methano-1,4,4a,5,10,10a-hexahydroanthracen bezeichnet); Pentacyclo[6.6.1.1 3,6 .0 2,7 .0 9,14 ]-4-hexadecen, Pentacyclo[6.5.1.1 3,6 .0 2,7 .0 9,13 ]-4-pentadecen, Pentacyclo[7.4.0.0 2,7 .1 3,6 .1 10,13 ]-4-pentadecen; Heptacyclo[8.7.0.1 2,9 .1 4,7 .1 11,17 .0 3,8 .0 12,16 ]-5-eicosen, Heptacyclo[8.7.0.1 2,9 .0 3,8 .1 4,7 .0 12,17 .1 13,16 ]-14-eicosen; or call it something similar.

[0052] Among these, alkyl-substituted norbornene, such as bicyclo[2.2.1]hepta-2-ene, in which one or more alkyl groups have been substituted, and alkylidene-substituted norbornene, such as bicyclo[2.2.1]hepta-2-ene, in which one or more alkylidene groups have been substituted, are preferred. 5-Ethylidene-bicyclo[2.2.1]hepta-2-ene (common name: 5-Ethylidene-2-norbornene or simply ethylidenenorbornene) is particularly preferred. <α-olefin>

[0053] The α-olefin is an α-olefin with a carbon number of 3 to 20.

[0054] The α-olefin can be not only unsubstituted α-olefin, but also substituted α-olefin, which has a substituted group such as a halogen atom or the like. The number of carbon atoms in the α-olefin is 3 to 20, preferably 4 to 12, and more preferably 6 to 10.

[0055] Specific examples of α-olefins with a carbon number of 3 to 12 include 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, and the like. Of these, 1-hexene, 1-octene, and 1-decene are preferred, and 1-hexene and 1-octene are more preferred.

[0056] The cycloolefin copolymer described above is versatile and can be used in various applications, such as in the packaging and optics industries, after being mixed with various additives as needed and formed into films, sheets, or similar products. Additives that can be added to the cycloolefin copolymer include antioxidants, weather stabilizers, UV absorbers, antibacterial agents, flame retardants, dyes, and the like. These additives are added to the cycloolefin copolymer according to the specific type and in the generally accepted quantities. <<Verfahren zum Herstellen von Cycloolefin-Copolymer> >

[0057] The following describes a process for producing the cycloolefin copolymer.

[0058] In the process for preparing the cycloolefin copolymer described below, a cycloolefin copolymer is produced comprising one unit derived from a cycloolefin monomer and one unit derived from an α-olefin with a carbon number of 3 to 20. The cycloolefin copolymer is discussed as above.

[0059] The above process includes first polymerization, wherein in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminium compound and a borate compound the cycloolefin monomer and a monomer containing the α-olefin are polymerized, adding the monomer and the alkylaluminium compound to the polymerization vessel following the first polymerization, and second polymerization, wherein after adding the monomer and the alkylaluminium compound the polymerization of the monomer is continued.

[0060] In the first polymerization, the polymerization of the monomer is carried out until the reaction rate of the cycloolefin monomer, in relation to the total mole number of cycloolefin monomer added to the polymerization vessel at the beginning of and during the first polymerization, is 80 mol% or more.

[0061] According to the above method, a cycloolefin copolymer can be produced with high efficiency, which is a copolymer of a cycloolefin monomer and an α-olefin with a carbon number of 3 to 20 and exhibits excellent toughness.

[0062] Specifically, at least 200 g of cycloolefin copolymer can be obtained per 1 g of titanocene catalyst.

[0063] The following describes the first polymerization, the addition of the monomer and the alkylaluminum compound, and the second polymerization. <Erstes Polymerisieren>

[0064] In the first polymerization, a cycloolefin monomer and a monomer containing α-olefin are polymerized in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminium compound and a borate compound.

[0065] In the first polymerization, the polymerization of the monomer is carried out until the reaction rate of the cycloolefin monomer, in relation to the total mole number of cycloolefin monomer added to the polymerization vessel at the beginning of and during the first polymerization, is 80 mol% or more.

[0066] In this case, a cycloolefin copolymer with excellent toughness can easily be obtained, exhibiting at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0067] The monomer, which contains cycloolefin monomer and α-olefin, is discussed as above.

[0068] As described below, the monomer is added to the polymerization vessel both at the beginning of the first polymerization and after the first polymerization when producing the cycloolefin copolymer.

[0069] The total amount of monomer added to the polymerization vessel during the first polymerization, in relation to the total mole number of the monomer used in the production of the cycloolefin copolymer, is preferably 20-80 mol%, more preferably 30-70 mol% and even more preferably 40-60 mol%. [Titanocene catalyst]

[0070] As long as the titanocene catalyst is one capable of polymerizing cycloolefin monomer and α-olefin with a carbon number of 3 to 20, there are no particular restrictions on its use. Generally, the titanocene catalyst can be selected appropriately from known titanocene catalysts capable of polymerizing cycloolefin monomer and α-olefin with a carbon number of 3 to 20.

[0071] One type of titanocene catalyst can be used alone, or two or more types can be used in combination.

[0072] The preferred titanocene catalyst is the titanocene catalyst shown in formula (1) below. (where in formula (1) R 1 -R 3 Each is independently an alkyl group with a carbon number of 1 to 6 or an aryl group with a carbon number of 6 to 12, R 4 and R 5 Each is independently an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12, or a halogen atom, and R 6 -R 13 each independently be a silyl group which may have a hydrogen atom, an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12 or a monovalent hydrocarbon group with a carbon number of 1 to 12 as a substituent group).

[0073] In formula (I) R 1 -R 3 Each independently consists of an alkyl group with a carbon number of 1 to 6 or an aryl group with a carbon number of 6 to 12. Specific examples include an alkyl group such as a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group, cyclohexyl group, or the like; and an aryl group such as a phenyl group, a biphenyl group, a phenyl group, or a biphenyl group containing the alkyl group as a substituent, a naphthyl group, a naphthyl group containing the alkyl group as a substituent, or the like.

[0074] R 4 and R 5 Each of these can be, independently of one another, an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12, or a halogen atom; and specifically, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like; a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, and one of these alkyl groups that has the halogen atom as a substituent group; a phenyl group, a biphenyl group, a naphthyl group, and one of these aryl groups that has the halogen atom or the alkyl group as a substituent group can be named.

[0075] R 6 -R 13 Each of these is independently defined as a silyl group, which can contain a hydrogen atom, an alkyl group with 1 to 12 carbon atoms, an aryl group with 6 to 12 carbon atoms, or a monohydric hydrocarbon group with 1 to 12 carbon atoms as a substituent. Specific examples of alkyl groups with 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopentyl, and cyclohexyl groups. Specific examples of aryl groups with 6 to 12 carbon atoms include phenyl, biphenyl, naphthyl, any of these aryl groups containing an alkyl group as a substituent, and similar compounds.Concrete examples of a silyl group that has a monovalent hydrocarbon group with a carbon number of 1 to 12 as a substituent group include a silyl group that has an alkyl group with a carbon number of 1 to 12, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, or the like, as a substituent group.

[0076] Als konkrete Beispiele für den in der allgemeinen Formel (1) angegebenen Titanocenkatalysator lassen sich (Isopropylamid)dimethyl-9-fluorenylsilantitandimethyl, (Isobutylamid)dimethyl-9-fluorenylsilantitandimethyl, (t-Butylamid)dimethyl-9-fluorenylsilantitandimethyl, (Isopropylamid)dimethyl-9-fluorenylsilantitandichlorid, (Isobutylamid)dimethyl-9-(3,6-dimethylfluorenyl)silantitandichlorid, (t-Butylamid)dimethyl-9-fluorenylsilantitandichlorid, (Isopropylamid)dimethyl-9-(3,6-dimethylfluorenyl)silantitandichlorid, (Isobutylamid)dimethyl-9-(3,6-dimethylfluorenyl)silantitandichlorid, (t-Butylamid)dimethyl-9-(3,6-dimethylfluorenyl)silantitandimethyl, (Isopropylamid)dimethyl-9-[3,6-di(i-propyl)fluorenyl]silantitandichlorid, (Isobutylamid)dimethyl-9-[3,6-di(i-propyl)fluorenyl]silantitandichlorid, (t-Butylamid)dimethyl-9-[3,6-di(i-propyl)fluorenyl]silantitandimethyl, (Isopropylamid)dimethyl-9-[3,6-di(t-butyl)fluorenyl]silantitandichlorid, (Isobutylamid)dimethyl-9-[3,6-di(t-butyl)fluorenyl]silantitanium dichloride, (t-butylamide)dimethyl-9-[3,6-di(t-butyl)fluorenyl]silantitanium dimethyl, (isopropylamide)dimethyl-9-[2,7-di(t-butyl)fluorenyl]silantitanium dichloride, (Isobutylamide)dimethyl-9-[2,7-di(t-butyl)fluorenyl]silantitanium dichloride, (t-butylamide)dimethyl-9-[2,7-di(t-butyl)fluorenyl]silantitanium dimethyl, (isopropylamide)dimethyl-9-(2,3,6,7-tetramethylfluorenyl)silantitanium dichloride, (Isobutylamide)dimethyl-9-(2,3,6,7-tetramethylfluorenyl)silane titanium dichloride, (t-Butylamide)dimethyl-9-(2,3,6,7-tetramethylfluorenyl)silantitaniumdimethyl and the like. Preferably, it is (t-Butylamide)dimethyl-9-fluorenylsilantitaniumdimethyl ((t-BuNSiMe2Flu)TiMe2). (t-BuNSiMe2Flu)TiMe2 is a titanium complex of formula (2) below and can be readily prepared, for example, based on the information in "Macromolecules, Vol. 31, p. 3184, 1998".

[0077] (In the formula, Me represents a methyl group and t-Bu a tert-butyl group.)

[0078] There are no particular restrictions regarding the amount of titanocene catalyst used, as long as the addition polymerization reaction proceeds smoothly. The following amounts of titanocene catalyst are preferred, relative to 100 parts by mass of the cycloolefin monomer and the α-olefin: 0.001–10 parts by mass, 0.01–5 parts by mass more preferred, and 0.1–1 parts by mass even more preferred.

[0079] The titanocene catalyst can be added to the polymerization vessel either at the beginning of the first polymerization or after it has begun. However, preferably the entire amount of titanocene catalyst used in the production of the cycloolefin copolymer is added to the polymerization vessel at the beginning of the first polymerization. [Alkylaluminum compound]

[0080] The first polymerization is carried out in the presence of the titanocene catalyst, the alkylaluminum compound, and the borate compound.

[0081] During the first polymerization, the alkylaluminium compound introduced into the polymerization vessel at the beginning of the polymerization process acts as an adsorber, capturing impurities such as water and oxygen.

[0082] Regarding the alkylaluminum compound introduced into the polymerization vessel at the start of the initial polymerization, any alkylaluminum compound commonly used in the single polymerization or copolymerization of cycloolefin monomers can be used without any particular restrictions. In the initial polymerization, one type of alkylaluminum compound can be used alone, or two or more types can be used in combination.

[0083] Preferred examples of alkylaluminium compounds introduced into the polymerization vessel at the start of the polymerization process include trialkylaluminium, dialkylaluminium halide, dialkylaluminium hydride, dialkylaluminium alkoxide, and the like. Trialkylaluminium is preferred among these.

[0084] Preferred examples of trialkylaluminium include trimethylaluminium, triethylaluminium, triisopropylaluminium, tri-n-butylaluminium, triisobutylaluminium, tri-sec-butylaluminium, tri-n-octylaluminium, and the like. Among these, triisobutylaluminium and trioctylaluminium are preferred.

[0085] Preferred concrete examples of dialkylaluminium halide include dimethylaluminium chloride, diisobutylaluminium chloride, and the like.

[0086] Preferred concrete examples of dialkylaluminium hydride include diisobutylaluminium hydride and the like.

[0087] Preferred concrete examples of dialkylaluminium alkoxide include dimethylaluminium methoxide and the like.

[0088] The alkylaluminium compound introduced into the polymerization vessel at the beginning of the polymerization process is preferably a long-chain alkylaluminium compound having only one alkyl group with a carbon number of at least 6.

[0089] The long-chain alkylaluminium compound acts advantageously as an adsorber.

[0090] The amount of alkylaluminium compound used in the first polymerization, relative to the total amount of 100 parts by mass of the titanocene catalyst used in the preparation of the cycloolefin copolymer, is preferably 0.1-200 parts by mass, more preferably 1-100 parts by mass and even more preferably 10-50 parts by mass. [Borate compound]

[0091] The first polymerization is carried out in the presence of the titanocene catalyst, the alkylaluminum compound, and the borate compound.

[0092] Any borate compound commonly used as an auxiliary catalyst in the single polymerization or copolymerization of cycloolefin monomers can be used without particular restrictions. In the initial polymerization, one type of borate compound can be used alone, or two or more types can be used in combination.

[0093] Preferred concrete examples of borate compounds include triphenylmethyliumtetrakis(pentafluorophenyl)borate, dimethylphenylammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N-methyldinomaldecylammoniumtetrakis(pentafluorophenyl)borate and the like.

[0094] There is no particular restriction regarding the amount of borate compound used in the first polymerization, as long as the addition polymerization reaction proceeds smoothly and cycloolefin copolymer with the desired properties is obtained. The amount of borate compound used is preferably 250-750 parts by mass, and 300-500 parts by mass, relative to the total amount of 100 parts by mass of the titanocene catalyst used in the production of the cycloolefin copolymer.

[0095] The borate compound can be added to the polymerization vessel either at the beginning of the first polymerization or after it has begun. However, it is preferable to add the entire amount of borate compound used in the production of the cycloolefin copolymer to the polymerization vessel at the beginning of the first polymerization. [Other components]

[0096] Provided that the fulfillment of the object of the present invention is not thereby impaired, the polymerization of the monomer can be carried out in the first polymerization in the presence of further components besides the alkylaluminium compound and the borate compound.

[0097] A preferred example of another component is hindered phenol. Without any particular restrictions, hindered phenol can be any type commonly used as an auxiliary catalyst in the single polymerization or copolymerization of cycloolefin monomers.

[0098] Hindered phenol is a type of phenol that has a bulky substituent group at at least one of two adjacent positions of the phenolic hydroxyl group. Examples of bulky substituent groups include alkyl groups other than methyl groups, such as isopropyl groups, isobutyl groups, sec-butyl groups, tert-butyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, alkoxy groups, aryloxy groups, substituted amino groups, alkylthio groups, arylthio groups, and the like.

[0099] Specific examples of hindered phenols include 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butylphenol, 2-tert-butylphenol, 2-tert-butylp-cresol, 3,3',5,5'-tetra-tert-butyl-4,4'-dihydroxybiphenyl, 3,3',5,5'-tetra-tert-butyl-2,2'-dihydroxybiphenyl, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 4,4',4''-(1-methylpropenyl-3-ilidene)tris(6-tert-butyl-m-cresol), and 1,3,5-tris(3,5-Di-tert-butyl-4-hydroxyphenylmethyl)2,4,6-trimethylbenzene and the like.

[0100] Of these, 2,6-di-tert-butyl-4-hydroxytoluene (BHT) and 2,6-di-tert-butylphenol are preferred because they have a low molecular weight and the desired effect from the use of the inhibited phenol can be achieved with a small amount of use.

[0101] There is no particular restriction regarding the amount of hindered phenol used in the first polymerization, as long as the addition polymerization reaction proceeds smoothly and cycloolefin copolymer with the desired properties is obtained. The following amounts of hindered phenol are preferred in relation to the total amount of 100 parts by mass of the titanocene catalyst used in the production of the cycloolefin copolymer: 1–1000 parts by mass, 10–500 parts by mass more preferred, and 100–200 parts by mass even more preferred.

[0102] However, the amount of hindered phenol used is such that the amount of phenolic hydroxyl groups in the hindered phenol is at most 1.5 mol per mol of alkylaluminum compound. The amount of phenolic hydroxyl groups in the hindered phenol per mol of alkylaluminum compound is preferably at most 1.4 mol, more preferably at most 1.3 mol, and even more preferably at most 1.2 mol. If the amount of hindered phenol used, relative to the alkylaluminum compound, is within the range mentioned above, the chain transfer reaction of the alkylaluminum compound is not necessarily hindered. <Lösungsmittel>

[0103] The first polymerization can be carried out in the presence of a solvent. Typically, the first polymerization is performed in the presence of a solvent. There are no particular restrictions regarding the solvent, as long as it is one that does not hinder the polymerization reaction. Hydrocarbon solvents and halogenated hydrocarbon solvents are examples of preferred solvents, with hydrocarbon solvents being preferred due to their better handling, thermal stability, and chemical stability.Specific examples of preferred solvents include hydrocarbon solvents such as pentane, hexane, heptane, octane, isooctane, isododecane, mineral oil, cyclohexane, methylcyclohexane, decahydronaphthalene (dekalin), benzene, toluene, xylene and the like, or halogenated hydrocarbon solvents such as chloroform, methylene chloride, dichloromethane, dichloroethane, chlorobenzene and the like.

[0104] The solvent can be introduced into the polymerization vessel alone or in the form of a monomer solvent, catalyst solvent or auxiliary catalyst solvent.

[0105] If solvent is used, there is no particular restriction regarding the amount used. The amount of solvent used, relative to the total amount of 100 parts by mass of the monomer used in the first polymerization, is preferably 100-100,000 parts by mass, more preferably 500-10,000 parts by mass, and even more preferably 1,000-5,000 parts by mass. <reaktionsbedingungen>

[0106] There are no particular restrictions regarding the polymerization temperature of the first polymerization. The polymerization temperature is preferably -20 to 200 °C, more preferably -10 to 10 °C, and even more preferably -5 to 5 °C.

[0107] There is no particular restriction regarding the duration of the first polymerization, as long as the polymerization continues until a certain amount of the monomer has been consumed.

[0108] In the first polymerization, the polymerization of the monomer is carried out until the reaction rate of the cycloolefin monomer, in relation to the mole number of cycloolefin monomer that was added to the polymerization vessel at the beginning of the first polymerization, is 80 mol% or more.

[0109] Typically, the duration of the first polymerization is preferably 5-30 minutes, more preferably 8-20 minutes and even more preferably 10-15 minutes.

[0110] There are no particular restrictions regarding the atmosphere under which the first polymerization reaction is carried out, but an inert gas atmosphere is preferred. Nitrogen gas or helium gas can be used as the inert gas. <Zusetzen des Monomers und der Alkylaluminiumverbindung>

[0111] After the first polymerization, the monomer and the alkylaluminum compound are added to the polymerization vessel. The alkylaluminum compound added to the polymerization vessel after the first polymerization acts as a chain transfer agent. By carrying out the second polymerization described below in the presence of the alkylaluminum compound acting as a chain transfer agent, the yield of cycloolefin copolymer per unit weight of titanocene catalyst can be increased without excessively increasing the dispersion ratio relative to the molecular weight of the resulting cycloolefin copolymer.

[0112] If, after the first polymerization, the monomer and the alkylaluminium compound are added as a mixture to the polymerization vessel, it is assumed that the alkylaluminium compound also acts as an adsorber for water, oxygen and other impurities in the monomer.

[0113] The alkylaluminium compound added to the polymerization vessel after the first polymerization can be an alkylaluminium compound of the same type as that used in the first polymerization.

[0114] The alkylaluminium compound added to the polymerization vessel after the first polymerization may be an alkylaluminium compound of the same compound as used in the first polymerization, or it may be different from it.

[0115] The alkylaluminium compound added to the polymerization vessel after the first polymerization can be used alone, or two or more types can be used in combination.

[0116] Preferred examples of trialkylaluminium added to the polymerization vessel after the initial polymerization include trimethylaluminium, triethylaluminium, triisopropylaluminium, tri-n-butylaluminium, triisobutylaluminium, tri-sec-butylaluminium, tri-n-octylaluminium, and the like. Among these, trimethylaluminium and triethylaluminium are preferred.

[0117] The alkylaluminium compound added to the polymerization vessel after the first polymerization is preferably a short-chain alkylaluminium compound having only one alkyl group with a carbon number of at most 5.

[0118] The short-chain alkylaluminium compound acts advantageously as a chain transfer agent. Therefore, if a short-chain alkylaluminium compound is used as the alkylaluminium compound added to the polymerization vessel after the initial polymerization, a cycloolefin copolymer with particularly good heat resistance and toughness can easily be obtained, and the yield of cycloolefin copolymer per unit weight of titanocene catalyst can also be easily increased.

[0119] As described above, the reason for using the alkylaluminium compound introduced into the polymerization vessel at the beginning of the first polymerization differs from the reason for using the alkylaluminium compound added to the polymerization vessel after the first polymerization.

[0120] In this respect, from the beginning of the first polymerization to the end of the second polymerization, preferably both an alkylaluminium compound I and an alkylaluminium compound II different from alkylaluminium compound I are used. Both alkylaluminium compound I and alkylaluminium compound II can be added to the polymerization vessel at any time from the beginning of the first polymerization to the end of the second polymerization.

[0121] Alkylaluminum compound I has at least one alkyl group with a carbon number of at least 6. Alkylaluminum compound II has at least one alkyl group with a carbon number of at most 5.

[0122] For example, at the beginning of the first polymerization, alkylaluminium compound I can be added to the polymerization vessel, and at any time after the first polymerization, alkylaluminium compound II can be added to the polymerization vessel.

[0123] Alternatively, at the beginning of the first polymerization, the alkylaluminium compound II can be added to the polymerization vessel, and at any time after the first polymerization, the alkylaluminium compound I can be added to the polymerization vessel.

[0124] Alternatively, at the beginning of the first polymerization, alkylaluminium compound I and alkylaluminium compound II can be added simultaneously to the polymerization vessel, or a mixture of alkylaluminium compound I and alkylaluminium compound II can be added to the polymerization vessel. In this case, any alkylaluminium compound can be added to the polymerization vessel at any time after the first polymerization, preferably alkylaluminium compound II being added at any time after the first polymerization.

[0125] Preferably, the alkylaluminium compound I has two or three alkyl groups with a carbon number of at least 6 and more preferably three alkyl groups with a carbon number of at least 6.

[0126] Preferably, the alkylaluminium compound II has two or three alkyl groups with a carbon number of at most 5, and more preferably three alkyl groups with a carbon number of at most 5.

[0127] The alkylaluminium compound I and the alkylaluminium compound II can each be dialkylaluminium halide, dialkylaluminium hydride or dialkylaluminium alkoxide.

[0128] If, in the first and second polymerizations, two types of alkylaluminium compounds are used as alkylaluminium compounds: one with an alkyl group(s) having a carbon number of at least 6 and the other with an alkyl group(s) having a carbon number of at most 5. Any one of the alkylaluminium compounds can be alkylaluminium compound I and any one of the alkylaluminium compounds can be alkylaluminium compound II.

[0129] If both alkylaluminium compound I and alkylaluminium compound II are used as alkylaluminium compounds in the first and second polymerization, the molar ratio of alkylaluminium compound I and alkylaluminium compound II is preferably 2:8-8:2, more preferably 3:7-7:3 and even more preferably 4:6-6:4.

[0130] Although details will be described later, after the first polymerization, the addition of the monomer and the alkylaluminum compound and the second polymerization can be repeated. The monomer and the alkylaluminum compound can therefore be added to the polymerization vessel several times after the first polymerization.

[0131] The total amount of alkylaluminium compound added to the polymerization vessel after the first polymerization is preferably 0.1-200 parts by mass, 1-100 parts by mass more preferred, and 10-50 parts by mass even more preferred, relative to the total amount of 100 parts by mass of the titanocene catalyst used in the preparation of the cycloolefin copolymer.

[0132] If the alkylaluminium compound is added several times after the first polymerization, the amount of alkylaluminium compound added per addition is, if the total mole number of alkylaluminium compound added after the first polymerization is TA and the number of partitions is N, preferably TA / N×0.5-TA / N×1.5, more preferably TA / N×0.7-TA / N×1.3 and even more preferably TA / N×0.9-TA / N×1.1.

[0133] Together with the alkylaluminium compound, the monomer is added to the polymerization vessel after the first polymerization.

[0134] The composition of the monomer added after the first polymerization in the polymerization vessel can be different from or the same as the composition of the monomer used in the first polymerization, but it is preferably the same. After the first polymerization, only the cycloolefin monomer or only the α-olefin can be added as the monomer, but preferably a monomer containing both the cycloolefin monomer and the α-olefin is added.

[0135] As discussed above, the monomer can be added to the polymerization vessel several times after the first polymerization.

[0136] The total amount of monomer added to the polymerization vessel after the first polymerization, in relation to the total mole number of the monomer used in the production of the cycloolefin copolymer, is preferably 20-80 mol%, more preferably 30-70 mol% and even more preferably 40-60 mol%.

[0137] If the monomer is added several times after the first polymerization, the amount of monomer added per addition, where the total mole number of monomer added after the first polymerization is TA and the number of partitions is N, is preferably TA / N×0.5-TA / N×1.5, more preferably TA / N×0.7-TA / N×1.3 and even more preferably TA / N×0.9-TA / N×1.1. <Zweites Polymerisieren>

[0138] After the first polymerization, when the monomer and the alkylaluminium compound are placed in the polymerization vessel, a second polymerization is carried out, in which the polymerization of the monomer is continued.

[0139] The composition of the monomer added to the polymerization vessel during the second polymerization may be different from or the same as the monomer used in the first polymerization, but it is preferably the same. In the second polymerization, either only the cycloolefin monomer or only the α-olefin may be added as the monomer, but preferably a monomer containing both the cycloolefin monomer and the α-olefin is added.

[0140] Although details will be described later, the addition of the alkylaluminum compound and the second polymerization can be repeated after the first polymerization. Therefore, the second polymerization can be carried out several times after the first.

[0141] The reaction conditions for the second polymerization are the same as for the first polymerization, and there are no particular restrictions regarding the polymerization time. The second polymerization can be continued until the desired quantity of cycloolefin copolymer with the desired physical properties has been obtained. Typically, the duration of the second polymerization is preferably 5–300 minutes, more preferably 8–120 minutes, and even more preferably 10–60 minutes.

[0142] If the second polymerization is repeated several times, the polymerization time of the second polymerization is the sum of the polymerization times for the second polymerization.

[0143] If the second polymerization is repeated several times, there is no particular restriction regarding the polymerization time of each second polymerization.

[0144] If, after the first polymerization, the second polymerization is carried out several times, the duration of each second polymerization is, where the total duration of the second polymerization is TT and the number of iterations of the second polymerization is N, preferably TT / N×0.5-TT / N× 1.5, more preferably TT / N×0.7-TT / N×1.3 and even more preferably TT / N×0.9-TT / N×1.1.

[0145] After the first polymerization, the addition of the monomer and the alkylaluminum compound, and the second polymerization have been carried out in the process described above, the polymerization reaction can be completed. In this case, the production of cycloolefin copolymer is carried out simply in just a few steps.

[0146] If the second polymerization is carried out only once, there is no particular restriction regarding the reaction rate of the cycloolefin monomer during the second polymerization, but it is preferably at least 80 mol% in relation to the number of moles of cycloolefin monomer that was in the polymerization vessel at the beginning of the second polymerization.

[0147] In this case, a cycloolefin copolymer with excellent toughness can easily be obtained, exhibiting at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0148] The number of moles of cycloolefin monomer in the polymerization vessel at the beginning of the second polymerization is the sum of the number of moles of cycloolefin monomer that remained in the polymerization vessel after the first polymerization and the number of moles of cycloolefin monomer that is added to the polymerization vessel after the first polymerization.

[0149] After the first second polymerization, the addition of the monomer and the alkylaluminum compound and the second polymerization can be repeated until an addition frequency of n is reached. A p-th addition of the monomer and the alkylaluminum compound, from the second to the nth addition, is carried out after the (p-1)-th second polymerization, where n is an integer of 2 or more.

[0150] The p-th addition of the monomer and the alkylaluminum compound is carried out after the reaction rate of the cycloolefin monomer, in relation to the mole number of cycloolefin monomer in the polymerization vessel at the beginning of the (p-1)-th second polymerization, has reached 80 mol% or more.

[0151] In this case, a cycloolefin copolymer with excellent toughness can easily be obtained, exhibiting at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0152] The mole number of cycloolefin monomer in the polymerization vessel at the beginning of the (p-1)th second polymerization is the sum of the mole number of cycloolefin monomer remaining in the polymerization vessel at the end of the (p-2)th second polymerization and the mole number of cycloolefin monomer added to the polymerization vessel immediately before the beginning of the (p-1)th second polymerization.

[0153] With this method, the polymerization reaction is terminated after the nth second polymerization has been carried out.

[0154] In the above-described process for producing cycloolefin copolymer, the amount of cycloolefin copolymer obtained per 1 g of titanocene catalyst is preferably at least 200 g and the number-average molecular weight of the cycloolefin copolymer obtained is 10,000-100,000. Examples of implementation

[0155] The following are examples of embodiments that specifically describe the present invention, but the present invention is not limited to these examples.

[0156] In the following embodiments and comparative examples, a titanocene catalyst of the following structure was used. In the formula below, Me denotes a methyl group and t-Bu a tert-butyl group. Example 1 (First polymerization)

[0157] In embodiment 1, 2-norbornene (Nb) and 1-octene (Oct) were used in the proportions specified in Table 1 in such a quantity that the total quantity of 2-norbornene and 1-octene was 17.28 mmol.

[0158] In a 50 mL Schlenk flask, which had been replaced with a nitrogen atmosphere, 1 / 4 of the 2-norbornene and 1-octene and 0.016 mmol of trimethylaluminum were added. The contents of the flask were then brought to a volume of 21.9 mL using Dekalin. The contents of the flask were then cooled to 0 °C. After cooling, a toluene solution with a titanocene catalyst concentration of 0.16 mmol / mL was added to the reaction solution, resulting in a titanocene catalyst concentration of 0.016 mmol. A toluene solution with a borate compound concentration of 0.008 mmol / L was then added to the reaction solution, resulting in a borate compound concentration of 0.016 mmol. Triphenylmethyliumtetrakis(pentafluorophenyl)borate was used as the borate compound.

[0159] Following the start of the addition polymerization after the addition of the titanocene catalyst and the borate compound, the reaction was allowed to proceed for 10 minutes at 0 °C while stirring the reaction solution with a magnetic stirrer.

[0160] The reaction rate of 2-norbornene in relation to the mole number of 2-norbornene at the beginning of the polymerization was 87 mol%. (1st addition of the monomer and the alkylaluminum compound)

[0161] After 10 minutes of reaction, 1 / 4 of the 2-norbornene and the 1-octene and 0.016 mmol of trimethylaluminium were added to the Schlenk flask. (1st second polymerization)

[0162] The addition polymerization reaction was then continued for 10 minutes.

[0163] The reaction rate of 2-norbornene after a 10-minute reaction during the second polymerization, in relation to the mole number of 2-norbornene at the beginning of the first second polymerization, was 99 mol%. (2nd addition of the monomer and the alkylaluminum compound)

[0164] After 10 minutes of reaction, 1 / 4 of the 2-norbornene and the 1-octene and 0.016 mmol of trimethylaluminium were added to the Schlenk flask. (second polymerization)

[0165] The addition polymerization reaction was then continued for 10 minutes.

[0166] The reaction rate of 2-norbornene after a total of 20 minutes of reaction during the second polymerization, in relation to the mole number of 2-norbornene at the beginning of the second polymerization, was 96 mol%. (3rd addition of the monomer and the alkylaluminum compound)

[0167] After 10 minutes of reaction, 1 / 4 of the 2-norbornene and the 1-octene and 0.016 mmol of trimethylaluminium were added to the Schlenk flask. (3rd second polymerization)

[0168] The addition polymerization reaction was then continued for 10 minutes.

[0169] The reaction rate of 2-norbornene after a total of 30 minutes of reaction during the second polymerization, in relation to the mole number of 2-norbornene at the beginning of the third second polymerization, was 82 mol%.

[0170] After a total reaction time of 40 minutes, a small amount of 2-propanol was added to the reaction solution, and the addition polymerization reaction was stopped. Hydrochloric acid was added to the reaction solution, the mixture was stirred for 10 minutes, and then the organic layer was washed with deionized water. Washing with deionized water was repeated until the water layer was neutral, at which point the washed organic layer was recovered. The recovered organic layer was trickled onto a large amount of acetone, causing the resulting cycloolefin copolymer to precipitate. The precipitated copolymer was obtained by filtration, after which it was washed at least twice with methanol and acetone. The washed copolymer was dried at 110 °C for at least 16 hours under reduced pressure, yielding dried cycloolefin copolymer. Example 2

[0171] Apart from changing the trimethylaluminium to a mixture with equal molar proportions of tri-n-octylaluminium and trimethylaluminium, the cycloolefin copolymer was obtained in the same manner as in embodiment 1. The incorporation ratio of norbornene and 1-octene was as specified in Table 1.

[0172] For the respective polymerization steps in embodiment 2, the reaction rate of 2-norbornene at the end of the respective polymerization steps in relation to the number of moles at the beginning of the respective polymerization steps is listed in Table 2.

[0173] After a total reaction time of 40 minutes, cycloolefin copolymer was obtained in the same way as in embodiment 1. Example 3

[0174] Apart from changing the trimethylaluminium to a mixture with equal molar proportions of triisobutylaluminium and trimethylaluminium, the cycloolefin copolymer was obtained in the same manner as in embodiment 1. The incorporation ratio of norbornene and 1-octene was as specified in Table 1.

[0175] For the respective polymerization steps in embodiment 3, the reaction rate of 2-norbornene at the end of the respective polymerization steps in relation to the number of moles at the beginning of the respective polymerization steps is listed in Table 2.

[0176] After a total reaction time of 40 minutes, cycloolefin copolymer was obtained in the same way as in embodiment 1. Examples 4-6

[0177] In embodiments 4-6, apart from the fact that the 1-octene was changed to 1-hexene (Hex), the cycloolefin copolymer was obtained in the same way as in embodiments 1-3.

[0178] The conditions for embodiment 1 and embodiment 4 are therefore the same, except for the type of monomer. Likewise, the conditions for embodiment 2 and embodiment 5, as well as the conditions for embodiment 3 and embodiment 6, are each the same, except for the type of monomer. Comparative example 1

[0179] 2-Norbornene (Nb) and 1-octene (Oct) were used in the proportions specified in Table 1 in such a way that the total amount of 2-norbornene and 1-octene was 118.8 mmol. (First polymerization)

[0180] Half of the 2-norbornene and 1-octene, 0.198 mmol of tri-n-octylaluminum, and 0.396 mmol of 2,6-di-tert-butyl-4-hydroxytoluene were placed in a 500 ml Erlenmeyer flask, which had been replaced by a nitrogen atmosphere. Thus, in the first polymerization of Comparative Example 1, twice the amount of tri-n-octylaluminum was used in terms of the amount of 2,6-di-tert-butyl-4-hydroxytoluene.

[0181] The contents of the flask were then brought to a volume of 258 ml using Dekalin. The flask was then cooled to 0 °C. After cooling, a toluene solution with a titanocene catalyst concentration of 0.04 mmol / ml was added to the reaction solution, resulting in a titanocene catalyst concentration of 0.22 mmol. A toluene solution with a borate compound concentration of 0.008 mmol / l was then added, resulting in a borate compound concentration of 0.22 mmol. Triphenylmethyliumtetrakis(pentafluorophenyl)borate was used as the borate compound. Following the initiation of the addition of the titanocene catalyst and the borate compound, the reaction was allowed to proceed at 0 °C for 10 minutes while stirring the reaction solution with a magnetic stirrer.

[0182] The reaction rate of 2-norbornene with respect to the mole number of 2-norbornene at the beginning of the polymerization was 99 mol%. (Second polymerization)

[0183] After a 10-minute reaction, half of the 2-norbornene and 1-octene, 0.022 mmol of tri-n-octylaluminum, and 0.044 mmol of 2,6-di-tert-butyl-4-hydroxytoluene were added to the Erlenmeyer flask. The addition polymerization reaction was then continued for 15 minutes.

[0184] The reaction rate of 2-norbornene during the second polymerization, relative to the mole amount of 2-norbornene at the beginning of the second polymerization, was 99 mol%.

[0185] After a total reaction time of 25 minutes, cycloolefin copolymer was obtained in the same way as in embodiment 1. Comparative example 2

[0186] 2-Norbornene (Nb) and 1-Octene (Oct) were used in the proportions specified in Table 1 in such a quantity that the total amount of 2-Norbornene and 1-Octene was 118.8 mmol.

[0187] In a 500 ml Erlenmeyer flask, which had been replaced with a nitrogen atmosphere, 2-norbornene and 1-octene, 0.97 mmol of CC1 and 0.68 mmol of CC2 were added. The volume of the flask was then increased to 258 ml using toluene. The contents of the flask were then heated to 40 °C. After heating, a toluene solution with a titanocene catalyst concentration of 0.04 mmol / ml was added to the reaction solution, resulting in a titanocene catalyst concentration of 0.22 mmol. Following the start of the addition polymerization after the addition of the titanocene catalyst, the reaction was allowed to proceed at 40 °C for 4 hours with continuous magnetic stirring of the reaction solution.

[0188] After a total reaction time of 4 hours, a small amount of 2-propanol was added to the reaction solution, halting the addition polymerization reaction. Hydrochloric acid was added to the reaction solution, the mixture was stirred for 10 minutes, and then the organic layer was washed with deionized water. This washing with deionized water was repeated until the water layer was neutral, at which point the washed organic layer was recovered. The recovered organic layer was trickled onto a large amount of acetone, causing the resulting cycloolefin copolymer to precipitate. The precipitated copolymer was obtained by filtration and then washed at least twice with methanol and acetone. The washed copolymer was dried at 110 °C for at least 16 hours under reduced pressure, yielding dried cycloolefin copolymer.

[0189] CC1: 6.5 wt% (as Al atom content) of an MMAO-3A toluene solution (solution of methyl isobutylaluminoxane, represented by [(CH3) 0,7 (iso-C4H9) 0,3 AlO] n , manufactured by Tosoh Finechem Corporation, contains 6 mol% trimethylaluminium based on the total Al content)

[0190] CC2: 9.0 wt% (as Al atom content) TMAO-211-toluene solution (solution of methylaluminoxane, manufactured by Tosoh Finechem Corporation, contains 26 mol% trimethylaluminium based on total Al content) Comparative example 3

[0191] Apart from changing the reaction time of the first polymerization and the reaction time of the second polymerization to the reaction time specified in Table 1, cycloolefin copolymer was obtained in the same way as in embodiment 1.

[0192] Table 3 lists the measurement of the molecular weight by gel permeation chromatography and the measurement of the glass transition temperature by the method discussed above, as well as the corresponding measurement results, performed on the cycloolefin copolymer of embodiments 1-6 and comparison examples 1-3.

[0193] It can be observed that the cycloolefin copolymer exhibits excellent toughness when it has at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C.

[0194] The fact that it exhibits excellent toughness when it has at least one glass transition temperature in the range below 0 °C, in the range of 0-100 °C and in the range of 160-300 °C is specified, among other things, in the embodiments of JP 2022-030194 A.

[0195] A film, which served as a test piece in the measurement of the glass transition temperature, was manufactured using the following procedure.

[0196] A 50 µm deep mold box was prepared using a 10 cm × 10 cm × 50 µm Kapton (registered trademark) sheet. After filling the mold box with the resulting cycloolefin copolymer, the copolymer was vacuum-pressed using a thermo-vacuum press at a pressure of 15 MPa, a temperature of 320–340 °C, and a duration of 15 minutes. Following pressing, the pressed cycloolefin copolymer was clamped between metal plates at room temperature and thus rapidly cooled. After cooling, the metal plates were removed, resulting in a cycloolefin copolymer sheet approximately 50 µm thick. Table 1 Polymerization processes Monomer contribution ratio (mol-%) Reaction temperature (°C) Reaction time (min) Note Oct Hex Example 1 First polymerization once 75 25 - 0 10 Monomer, alkylaluminium compound- 3 times - - setting a bond Second polymerization 3 times 0 10×3 Example 2 First polymerization once 75 25 - 0 10 Add monomer, alkylaluminum compound 3 times - - Second polymerization 3 times 0 10×3 Example 3 First polymerization once 75 25 - 0 10 Add monomer, alkylaluminum compound 3 times - - Second polymerization 3 times 0 10×3 Example 4 First polymerization once 75 - 25 0 10 Add monomer, alkylaluminum compound 3 times - - Second polymerization 3 times 0 10×3 Example 5 First polymerization once 75 - 25 0 10 Monomer, Alkylalumini- 3 times - - set up reconnection Second polymerization 3 times 0 10×3 Example 6 First polymerization once 75 - 25 0 10 Add monomer, alkylaluminum compound 3 times - - Second polymerization 3 times 0 10×3 Comparative example 1 First polymerization once 70 30 - 0 10 Second polymerization once 0 15 Comparative example 2 Suddenly 80 20 - 40 240 Comparative example 3 First polymerization once 75 25 - 0 5 Add monomer, alkylaluminum compound 3 times - - Second polymerization 3 times 0 5×3 Table 2 Reaction rate of 2-norborne after end of polymerization (mol-%) Example 1 First polymerization 87 Second polymerization, first time 99 Second polymerization, 2nd time 96 Second polymerization, 3rd time 82 Example 2 First polymerization 97 Second polymerization, first time 95 Second polymerization, 2nd time 99 Second polymerization, 3rd time 86 Example 3 First polymerization 90 Second polymerization, first time 99 Second polymerization, 2nd time 98 Second polymerization, 3rd time 84 Example 4 First polymerization 89 Second polymerization, first time 95 Second polymerization, 2nd time 92 Second polymerization, 3rd time 88 Example 5 First polymerization 97 Second polymerization, first time 98 Second polymerization, 2nd time 95 Second polymerization, 3rd time 86 Example 6 First polymerization 95 Second polymerization, first time 98 Second polymerization, 2nd time 97 Second polymerization, 3rd time 89 Comparative example 1 First polymerization 99 Second polymerization 99 Comparative example 3 First polymerization 28 Second polymerization, first time 53 Second polymerization, 2nd time 58 Second polymerization, 3rd time 59 Table 3 Molecular weight Glass transition temperature (°C) Polymerization efficiency Weight-average molecular weight (Mw) Number-average molecular weight (Mn) Distribution ratio (Mw / Mn) Weight of copolymer / weight of catalyst (g / g) Example 1 60×10 3 42×10 3 1,43 -25 75 180 266 Example 2 65×10 3 40×10 3 1,63 -23 77 177 275 Example 3 66×10 3 45×10 3 1,47 -27 70 174 270 Example 4 58×10 3 39×10 3 1,49 -15 71 212 279 Example 5 62×10 3 37×10 3 1,68 -13 68 218 277 Example 6 61×10 3 40×10 3 1,53 -16 73 210 280 Comparative example 1 104×10 3 76×10 3 1,37 -27 65 186 145 Comparative example 2 127×10 3 73×10 3 1,76 -20 - 264 4800 Comparative example 3 30×10 3 17×10 3 1,76 - - 161 221

[0197] Tables 1 to 3 show that by producing a cycloolefin copolymer using the defined process discussed above, which includes a unit derived from a cycloolefin monomer and a unit derived from an α-olefin with a carbon number of 3 to 20, a cycloolefin copolymer with excellent toughness can be produced with high efficiency.

[0198] In contrast, in comparative example 1, where the first and second polymerizations were carried out, but a large amount of hindered phenol was used in the first polymerization with respect to the alkylaluminium compound, in comparative example 2, where the polymerization was carried out in a single step, and in comparative example 3, where the reaction rate of the cycloolefin monomer in the first polymerization was below 80 mol%, a balance between good toughness and good production efficiency of the cycloolefin copolymer could not be achieved in the resulting cycloolefin copolymer. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2016-56275 A

[0006] JP 2022-030194 A

[0194] Cited non-patent literature

[0000] Jung, H. Y et al., Polyhedron, 2005, Vol. 24, p. 1269-

[0007] Macromolecules, Vol. 31, p. 3184, 1998

[0076] < / reaktionsbedingungen> < / cycloolefinmonomer>

Claims

[1] A process for producing a cycloolefin copolymer comprising a unit derived from a cycloolefin monomer and a unit derived from an α-olefin having a carbon number of 3 to 20, the production process comprising: first polymerization, wherein a cycloolefin monomer and a monomer containing an α-olefin are polymerized in a polymerization vessel in the presence of a titanocene catalyst, an alkylaluminium compound and a borate compound, Adding the monomer and the alkylaluminum compound to the polymerization vessel following the first polymerization and second polymerization, wherein, after the addition of the monomer and the alkylaluminum compound, the polymerization of the monomer is continued, wherein in the first polymerization the polymerization of the monomer is carried out until the reaction rate of the cycloolefin monomer, in relation to the number of moles of cycloolefin monomer that was added to the polymerization vessel at the beginning of the first polymerization, is 80 mol% or more, wherein the amount of hindered phenol used in the first polymerization is an amount in which the amount of phenolic hydroxyl groups in the hindered phenol is at most 1.5 mol per mol of alkylaluminium compound. [2] Method for producing a cycloolefin copolymer according to claim 1, wherein the polymerization reaction terminates after carrying out the second polymerization. [3] A process for producing a cycloolefin copolymer according to claim 1, wherein, after a first second polymerization, the addition of the monomer and the alkylaluminium compound and the second polymerization are repeated until an addition frequency of the monomer and the alkylaluminium compound of n times is reached, where n is an integer of 2 or more, wherein a 2nd to nth addition of the monomer and the alkylaluminum compound is carried out after, at a (p-1)th second polymerization, the reaction rate of the cycloolefin monomer with respect to the mole number of cycloolefin monomer in the polymerization vessel at the beginning of the (p-1)th second polymerization has reached 80 mol% or more, where p is an integer from 2 to n, the polymerization reaction ends after the nth second polymerization has been carried out. [4] A process for producing a cycloolefin copolymer according to any one of claims 1 to 3, wherein the alkylaluminium compound used in the first polymerization is a long-chain alkylaluminium compound having only alkyl groups with a carbon number of at least 6, and wherein the alkylaluminium compound added to the polymerization vessel after the first polymerization is a short-chain alkylaluminium compound having only alkyl groups with a carbon number of at most 5. [5] A process for producing a cycloolefin copolymer according to any one of claims 1 to 3, wherein, from the beginning of the first polymerization to the end of the second polymerization, both an alkylaluminium compound I and an alkylaluminium compound II different from the alkylaluminium compound I are used as the alkylaluminium compound, wherein the alkylaluminium compound I has at least one alkyl group with a carbon number of at least 6 and The alkylaluminium compound II has at least one alkyl group with a carbon number of at most 5. [6] Method for producing a cycloolefin copolymer according to claim 4, wherein the alkylaluminium compound is at least one compound selected from the group consisting of trimethylaluminium, triethylaluminium, triisobutylaluminium and trioctylaluminium. [7] Method for producing a cycloolefin copolymer according to claim 5, wherein the alkylaluminium compound I is trioctylaluminium and the alkylaluminium compound II is trimethylaluminium, triethylaluminium or triisobutylaluminium. [8] A process for producing cycloolefin copolymer according to any one of claims 1 to 3, wherein the amount of cycloolefin copolymer obtained per 1 g of titanocene catalyst is at least 200 g and the number-average molecular weight of the cycloolefin copolymer obtained is 10,000-100,000. [9] A process for producing cycloolefin copolymer according to any one of claims 1 to 3, wherein the titanocene catalyst is a compound expressed by the following formula (1): (where in formula (1) R 1 -R 3 Each is independently an alkyl group with a carbon number of 1 to 6 or an aryl group with a carbon number of 6 to 12, R 4 and R 5 Each is independently an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12, or a halogen atom, and R 6 -R 13each independently be a silyl group which may have a hydrogen atom, an alkyl group with a carbon number of 1 to 12, an aryl group with a carbon number of 6 to 12 or a monovalent hydrocarbon group with a carbon number of 1 to 12 as a substituent group). [10] Method for producing a cycloolefin copolymer according to any one of claims 1 to 3, wherein the cycloolefin copolymer has at least two glass transition temperatures in a range of 0-300 °C.